SQLite

#!/usr/make
#
# Makefile for SQLITE

# The toplevel directory of the source tree
#
TOP = @srcdir@

# C Compiler and options for use in building executables that
# will run on the platform that is doing the build.
#
BCC = @BUILD_CC@ @BUILD_CFLAGS@

# C Compile and options for use in building executables that 
# will run on the target platform.
#
TCC = @TARGET_CC@ @TARGET_CFLAGS@ -I. -I${TOP}/src

# Tools used to build a static library.
#
AR = @TARGET_AR@
RANLIB = @TARGET_RANLIB@

# Compiler options needed for programs that use the GDBM library.
#
GDBM_FLAGS = @TARGET_GDBM_INC@

# The library that programs using GDBM must link against.
#
LIBGDBM = @TARGET_GDBM_LIBS@

# Compiler options needed for programs that use the readline() library.
#
READLINE_FLAGS = -DHAVE_READLINE=@TARGET_HAVE_READLINE@ @TARGET_READLINE_INC@

# The library that programs using readline() must link against.
#
LIBREADLINE = @TARGET_READLINE_LIBS@

# Object files for the SQLite library.
#
LIBOBJ = build.o dbbe.o main.o parse.o tokenize.o util.o vdbe.o where.o

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	libsqlite.a sqlite
# libtclsqlite.a tclsqlite

libsqlite.a:	$(LIBOBJ)
	$(AR) libsqlite.a $(LIBOBJ)
	$(RANLIB) libsqlite.a

sqlite:	$(TOP)/src/shell.c libsqlite.a $(TOP)/src/sqlite.h
	$(TCC) $(READLINE_FLAGS) -o sqlite $(TOP)/src/shell.c \
		libsqlite.a $(LIBGDBM) $(LIBREADLINE)

# Rules to build the LEMON compiler generator
#
lemon:	$(TOP)/tool/lemon.c $(TOP)/tool/lempar.c
	$(BCC) -o lemon $(TOP)/tool/lemon.c
	cp $(TOP)/tool/lempar.c .

# Header files used by all library source files.
#
HDR = \
   $(TOP)/src/sqlite.h  \
   $(TOP)/src/sqliteInt.h  \
   $(TOP)/src/dbbe.h  \
   $(TOP)/src/vdbe.h  \
   parse.h

build.o:	$(TOP)/src/build.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/build.c

dbbe.o:	$(TOP)/src/dbbe.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/dbbe.c

main.o:	$(TOP)/src/main.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/main.c

parse.o:	parse.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c parse.c

parse.h:	parse.c

parse.c:	$(TOP)/src/parse.y lemon
	cp $(TOP)/src/parse.y .
	./lemon parse.y

tokenize.o:	$(TOP)/src/tokenize.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/tokenize.c

util.o:	$(TOP)/src/util.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/util.c

vdbe.o:	$(TOP)/src/vdbe.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/vdbe.c

where.o:	$(TOP)/src/where.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/where.c

clean:	
	rm -f *.o sqlite libsqlite.a
	rm -f lemon lempar.c parse.*

#! /bin/sh

# Guess values for system-dependent variables and create Makefiles.
# Generated automatically using autoconf version 2.13 
# Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.

# Defaults:
ac_help=
ac_default_prefix=/usr/local
# Any additions from configure.in:
ac_help="$ac_help
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host=NONE
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nonopt=NONE
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prefix=NONE
program_prefix=NONE
program_suffix=NONE
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silent=
site=
srcdir=
target=NONE
verbose=
x_includes=NONE
x_libraries=NONE
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sbindir='${exec_prefix}/sbin'
libexecdir='${exec_prefix}/libexec'
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sharedstatedir='${prefix}/com'
localstatedir='${prefix}/var'
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Host type:
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trap 'rm -fr conftest* confdefs* core core.* *.core $ac_clean_files; exit 1' 1 2 15

# File descriptor usage:
# 0 standard input
# 1 file creation
# 2 errors and warnings
# 3 some systems may open it to /dev/tty
# 4 used on the Kubota Titan
# 6 checking for... messages and results
# 5 compiler messages saved in config.log
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else
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fi
exec 5>./config.log

echo "\
This file contains any messages produced by compilers while
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" 1>&5

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do
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# NLS nuisances.
# Only set these to C if already set.  These must not be set unconditionally
# because not all systems understand e.g. LANG=C (notably SCO).
# Fixing LC_MESSAGES prevents Solaris sh from translating var values in `set'!
# Non-C LC_CTYPE values break the ctype check.
if test "${LANG+set}"   = set; then LANG=C;   export LANG;   fi
if test "${LC_ALL+set}" = set; then LC_ALL=C; export LC_ALL; fi
if test "${LC_MESSAGES+set}" = set; then LC_MESSAGES=C; export LC_MESSAGES; fi
if test "${LC_CTYPE+set}"    = set; then LC_CTYPE=C;    export LC_CTYPE;    fi

# confdefs.h avoids OS command line length limits that DEFS can exceed.
rm -rf conftest* confdefs.h
# AIX cpp loses on an empty file, so make sure it contains at least a newline.
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# A filename unique to this package, relative to the directory that
# configure is in, which we can look for to find out if srcdir is correct.
ac_unique_file=src/sqlite.h

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fi
srcdir=`echo "${srcdir}" | sed 's%\([^/]\)/*$%\1%'`

# Prefer explicitly selected file to automatically selected ones.
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    CONFIG_SITE="$prefix/share/config.site $prefix/etc/config.site"
  else
    CONFIG_SITE="$ac_default_prefix/share/config.site $ac_default_prefix/etc/config.site"
  fi
fi
for ac_site_file in $CONFIG_SITE; do
  if test -r "$ac_site_file"; then
    echo "loading site script $ac_site_file"
    . "$ac_site_file"
  fi
done

if test -r "$cache_file"; then
  echo "loading cache $cache_file"
  . $cache_file
else
  echo "creating cache $cache_file"
  > $cache_file
fi

ac_ext=c
# CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
ac_cpp='$CPP $CPPFLAGS'
ac_compile='${CC-cc} -c $CFLAGS $CPPFLAGS conftest.$ac_ext 1>&5'
ac_link='${CC-cc} -o conftest${ac_exeext} $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS 1>&5'
cross_compiling=$ac_cv_prog_cc_cross

ac_exeext=
ac_objext=o
if (echo "testing\c"; echo 1,2,3) | grep c >/dev/null; then
  # Stardent Vistra SVR4 grep lacks -e, says ghazi@caip.rutgers.edu.
  if (echo -n testing; echo 1,2,3) | sed s/-n/xn/ | grep xn >/dev/null; then
    ac_n= ac_c='
' ac_t='	'
  else
    ac_n=-n ac_c= ac_t=
  fi
else
  ac_n= ac_c='\c' ac_t=
fi



# The following RCS revision string applies to configure.in
# $Revision: 1.1 $

#########
# Make sure we are not building in a subdirectory of the source tree.
#

temp=`echo $srcdir | grep '[^./]'`

if test "$temp" = ""; then
  { echo "configure: error: 
**************************************************************************
** This program may not be compiled in the same directory that contains **
** the configure script or any subdirectory of that directory.   Rerun  **
** the configure script from a directory that is separate from the      **
** source tree.                                                         **
**************************************************************************" 1>&2; exit 1; }
fi

#########
# Set up an appropriate program prefix
#
if test "$program_prefix" = "NONE"; then
  program_prefix=""
fi


#########
# Check to see if the --with-hints=FILE option is used.  If there is none,
# then check for a files named "$host.hints" and ../$hosts.hints where
# $host is the hostname of the build system.  If still no hints are
# found, try looking in $system.hints and ../$system.hints where
# $system is the result of uname -s.
#
# Check whether --with-hints or --without-hints was given.
if test "${with_hints+set}" = set; then
  withval="$with_hints"
  hints=$withval
fi

if test "$hints" = ""; then
  host=`hostname | sed 's/\..*//'`
  if test -r $host.hints; then
    hints=$host.hints
  else
     if test -r ../$host.hints; then
       hints=../$host.hints
     fi
  fi
fi
if test "$hints" = ""; then
  sys=`uname -s`
  if test -r $sys.hints; then
    hints=$sys.hints
  else
     if test -r ../$sys.hints; then
       hints=../$sys.hints
     fi
  fi
fi
if test "$hints" != ""; then
  echo "$ac_t""reading hints from $hints" 1>&6
  . $hints
fi

#########
# Locate a compiler for the build machine.  This compiler should
# generate command-line programs that run on the build machine.
#
default_build_cflags="-g"
if test "$config_BUILD_CC" = ""; then
  # Extract the first word of "gcc", so it can be a program name with args.
set dummy gcc; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
echo "configure:602: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test -n "$CC"; then
  ac_cv_prog_CC="$CC" # Let the user override the test.
else
  IFS="${IFS= 	}"; ac_save_ifs="$IFS"; IFS=":"
  ac_dummy="$PATH"
  for ac_dir in $ac_dummy; do
    test -z "$ac_dir" && ac_dir=.
    if test -f $ac_dir/$ac_word; then
      ac_cv_prog_CC="gcc"
      break
    fi
  done
  IFS="$ac_save_ifs"
fi
fi
CC="$ac_cv_prog_CC"
if test -n "$CC"; then
  echo "$ac_t""$CC" 1>&6
else
  echo "$ac_t""no" 1>&6
fi

if test -z "$CC"; then
  # Extract the first word of "cc", so it can be a program name with args.
set dummy cc; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
echo "configure:632: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test -n "$CC"; then
  ac_cv_prog_CC="$CC" # Let the user override the test.
else
  IFS="${IFS= 	}"; ac_save_ifs="$IFS"; IFS=":"
  ac_prog_rejected=no
  ac_dummy="$PATH"
  for ac_dir in $ac_dummy; do
    test -z "$ac_dir" && ac_dir=.
    if test -f $ac_dir/$ac_word; then
      if test "$ac_dir/$ac_word" = "/usr/ucb/cc"; then
        ac_prog_rejected=yes
	continue
      fi
      ac_cv_prog_CC="cc"
      break
    fi
  done
  IFS="$ac_save_ifs"
if test $ac_prog_rejected = yes; then
  # We found a bogon in the path, so make sure we never use it.
  set dummy $ac_cv_prog_CC
  shift
  if test $# -gt 0; then
    # We chose a different compiler from the bogus one.
    # However, it has the same basename, so the bogon will be chosen
    # first if we set CC to just the basename; use the full file name.
    shift
    set dummy "$ac_dir/$ac_word" "$@"
    shift
    ac_cv_prog_CC="$@"
  fi
fi
fi
fi
CC="$ac_cv_prog_CC"
if test -n "$CC"; then
  echo "$ac_t""$CC" 1>&6
else
  echo "$ac_t""no" 1>&6
fi

  if test -z "$CC"; then
    case "`uname -s`" in
    *win32* | *WIN32*)
      # Extract the first word of "cl", so it can be a program name with args.
set dummy cl; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
echo "configure:683: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test -n "$CC"; then
  ac_cv_prog_CC="$CC" # Let the user override the test.
else
  IFS="${IFS= 	}"; ac_save_ifs="$IFS"; IFS=":"
  ac_dummy="$PATH"
  for ac_dir in $ac_dummy; do
    test -z "$ac_dir" && ac_dir=.
    if test -f $ac_dir/$ac_word; then
      ac_cv_prog_CC="cl"
      break
    fi
  done
  IFS="$ac_save_ifs"
fi
fi
CC="$ac_cv_prog_CC"
if test -n "$CC"; then
  echo "$ac_t""$CC" 1>&6
else
  echo "$ac_t""no" 1>&6
fi
 ;;
    esac
  fi
  test -z "$CC" && { echo "configure: error: no acceptable cc found in \$PATH" 1>&2; exit 1; }
fi

echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works""... $ac_c" 1>&6
echo "configure:715: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5

ac_ext=c
# CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
ac_cpp='$CPP $CPPFLAGS'
ac_compile='${CC-cc} -c $CFLAGS $CPPFLAGS conftest.$ac_ext 1>&5'
ac_link='${CC-cc} -o conftest${ac_exeext} $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS 1>&5'
cross_compiling=$ac_cv_prog_cc_cross

cat > conftest.$ac_ext << EOF

#line 726 "configure"
#include "confdefs.h"

main(){return(0);}
EOF
if { (eval echo configure:731: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  ac_cv_prog_cc_works=yes
  # If we can't run a trivial program, we are probably using a cross compiler.
  if (./conftest; exit) 2>/dev/null; then
    ac_cv_prog_cc_cross=no
  else
    ac_cv_prog_cc_cross=yes
  fi
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  ac_cv_prog_cc_works=no
fi
rm -fr conftest*
ac_ext=c
# CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
ac_cpp='$CPP $CPPFLAGS'
ac_compile='${CC-cc} -c $CFLAGS $CPPFLAGS conftest.$ac_ext 1>&5'
ac_link='${CC-cc} -o conftest${ac_exeext} $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS 1>&5'
cross_compiling=$ac_cv_prog_cc_cross

echo "$ac_t""$ac_cv_prog_cc_works" 1>&6
if test $ac_cv_prog_cc_works = no; then
  { echo "configure: error: installation or configuration problem: C compiler cannot create executables." 1>&2; exit 1; }
fi
echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
echo "configure:757: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
echo "$ac_t""$ac_cv_prog_cc_cross" 1>&6
cross_compiling=$ac_cv_prog_cc_cross

echo $ac_n "checking whether we are using GNU C""... $ac_c" 1>&6
echo "configure:762: checking whether we are using GNU C" >&5
if eval "test \"`echo '$''{'ac_cv_prog_gcc'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.c <<EOF
#ifdef __GNUC__
  yes;
#endif
EOF
if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:771: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
  ac_cv_prog_gcc=yes
else
  ac_cv_prog_gcc=no
fi
fi

echo "$ac_t""$ac_cv_prog_gcc" 1>&6

if test $ac_cv_prog_gcc = yes; then
  GCC=yes
else
  GCC=
fi

ac_test_CFLAGS="${CFLAGS+set}"
ac_save_CFLAGS="$CFLAGS"
CFLAGS=
echo $ac_n "checking whether ${CC-cc} accepts -g""... $ac_c" 1>&6
echo "configure:790: checking whether ${CC-cc} accepts -g" >&5
if eval "test \"`echo '$''{'ac_cv_prog_cc_g'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  echo 'void f(){}' > conftest.c
if test -z "`${CC-cc} -g -c conftest.c 2>&1`"; then
  ac_cv_prog_cc_g=yes
else
  ac_cv_prog_cc_g=no
fi
rm -f conftest*

fi

echo "$ac_t""$ac_cv_prog_cc_g" 1>&6
if test "$ac_test_CFLAGS" = set; then
  CFLAGS="$ac_save_CFLAGS"
elif test $ac_cv_prog_cc_g = yes; then
  if test "$GCC" = yes; then
    CFLAGS="-g -O2"
  else
    CFLAGS="-g"
  fi
else
  if test "$GCC" = yes; then
    CFLAGS="-O2"
  else
    CFLAGS=
  fi
fi

  if test "$cross_compiling" = "yes"; then
    { echo "configure: error: unable to find a compiler for building build tools" 1>&2; exit 1; }
  fi
  BUILD_CC=$CC
  default_build_cflags=$CFLAGS
else
  BUILD_CC=$config_BUILD_CC
  echo $ac_n "checking host compiler""... $ac_c" 1>&6
echo "configure:829: checking host compiler" >&5
  CC=$BUILD_CC
  echo "$ac_t""$BUILD_CC" 1>&6
fi
echo $ac_n "checking switches for the host compiler""... $ac_c" 1>&6
echo "configure:834: checking switches for the host compiler" >&5
if test "$config_BUILD_CFLAGS" != ""; then
  CFLAGS=$config_BUILD_CFLAGS
  BUILD_CFLAGS=$config_BUILD_CFLAGS
else
  BUILD_CFLAGS=$default_build_cflags
fi
echo "$ac_t""$BUILD_CFLAGS" 1>&6
if test "$config_BUILD_LIBS" != ""; then
  BUILD_LIBS=$config_BUILD_LIBS
fi




##########
# Locate a compiler that converts C code into *.o files that run on
# the target machine.
#
echo $ac_n "checking target compiler""... $ac_c" 1>&6
echo "configure:854: checking target compiler" >&5
if test "$config_TARGET_CC" != ""; then
  TARGET_CC=$config_TARGET_CC
else
  TARGET_CC=$BUILD_CC
fi
echo "$ac_t""$TARGET_CC" 1>&6
echo $ac_n "checking switches on the target compiler""... $ac_c" 1>&6
echo "configure:862: checking switches on the target compiler" >&5
if test "$config_TARGET_CFLAGS" != ""; then
  TARGET_CFLAGS=$config_TARGET_CFLAGS
else
  TARGET_CFLAGS=$BUILD_CFLAGS
fi
echo "$ac_t""$TARGET_CFLAGS" 1>&6
echo $ac_n "checking target linker""... $ac_c" 1>&6
echo "configure:870: checking target linker" >&5
if test "$config_TARGET_LINK" = ""; then
  TARGET_LINK=$TARGET_CC
else
  TARGET_LINK=$config_TARGET_LINK
fi
echo "$ac_t""$TARGET_LINK" 1>&6
echo $ac_n "checking switches on the target compiler""... $ac_c" 1>&6
echo "configure:878: checking switches on the target compiler" >&5
if test "$config_TARGET_TFLAGS" != ""; then
  TARGET_TFLAGS=$config_TARGET_TFLAGS
else
  TARGET_TFLAGS=$BUILD_CFLAGS
fi
if test "$config_TARGET_RANLIB" != ""; then
  TARGET_RANLIB=$config_TARGET_RANLIB
else
  # Extract the first word of "ranlib", so it can be a program name with args.
set dummy ranlib; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
echo "configure:890: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test -n "$RANLIB"; then
  ac_cv_prog_RANLIB="$RANLIB" # Let the user override the test.
else
  IFS="${IFS= 	}"; ac_save_ifs="$IFS"; IFS=":"
  ac_dummy="$PATH"
  for ac_dir in $ac_dummy; do
    test -z "$ac_dir" && ac_dir=.
    if test -f $ac_dir/$ac_word; then
      ac_cv_prog_RANLIB="ranlib"
      break
    fi
  done
  IFS="$ac_save_ifs"
  test -z "$ac_cv_prog_RANLIB" && ac_cv_prog_RANLIB=":"
fi
fi
RANLIB="$ac_cv_prog_RANLIB"
if test -n "$RANLIB"; then
  echo "$ac_t""$RANLIB" 1>&6
else
  echo "$ac_t""no" 1>&6
fi

  TARGET_RANLIB=$RANLIB
fi
if test "$config_TARGET_AR" != ""; then
  TARGET_RANLIB=$config_TARGET_AR
else
  TARGET_AR='ar cr'
fi
echo "$ac_t""$TARGET_TFLAGS" 1>&6







# Set the $cross variable if we are cross-compiling.  Make
# it 0 if we are not.
#
echo $ac_n "checking if host and target compilers are the same""... $ac_c" 1>&6
echo "configure:936: checking if host and target compilers are the same" >&5
if test "$BUILD_CC" = "$TARGET_CC"; then
  cross=0
  echo "$ac_t""yes" 1>&6
else
  cross=1
  echo "$ac_t""no" 1>&6
fi

###########
# Lots of things are different if we are compiling for Windows using
# the CYGWIN environment.  So check for that special case and handle
# things accordingly.
#
echo $ac_n "checking if executables have the .exe suffix""... $ac_c" 1>&6
echo "configure:951: checking if executables have the .exe suffix" >&5
if test "$config_BUILD_EXEEXT" = ".exe"; then
  CYGWIN=yes
  echo "$ac_t""yes" 1>&6
else
  echo "$ac_t""unknown" 1>&6
fi
if test "$CYGWIN" != "yes"; then
  echo $ac_n "checking for Cygwin environment""... $ac_c" 1>&6
echo "configure:960: checking for Cygwin environment" >&5
if eval "test \"`echo '$''{'ac_cv_cygwin'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.$ac_ext <<EOF
#line 965 "configure"
#include "confdefs.h"

int main() {

#ifndef __CYGWIN__
#define __CYGWIN__ __CYGWIN32__
#endif
return __CYGWIN__;
; return 0; }
EOF
if { (eval echo configure:976: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
  rm -rf conftest*
  ac_cv_cygwin=yes
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  ac_cv_cygwin=no
fi
rm -f conftest*
rm -f conftest*
fi

echo "$ac_t""$ac_cv_cygwin" 1>&6
CYGWIN=
test "$ac_cv_cygwin" = yes && CYGWIN=yes
fi
if test "$CYGWIN" = "yes"; then
  BUILD_EXEEXT=.exe
else
  BUILD_EXEEXT=""
fi
if test "$cross" = "0"; then
  TARGET_EXEEXT=$BUILD_EXEEXT
else
  TARGET_EXEEXT=$config_TARGET_EXEEXT
fi
if test "$TARGET_EXEEXT" = ".exe"; then
  OS_UNIX=0
  OS_WIN=1
  tclsubdir=win
else
  OS_UNIX=1
  OS_WIN=0
  tclsubdir=unix
fi
TARGET_CFLAGS="$TARGET_CFLAGS -DOS_UNIX=$OS_UNIX -DOS_WIN=$OS_WIN"






##########
# Extract generic linker options from the environment.
#
if test "$config_TARGET_LIBS" != ""; then
  TARGET_LIBS=$config_TARGET_LIBS
else
  TARGET_LIBS=""
fi


##########
# Figure out what C libraries are required to compile Tcl programs.
#
if test "$config_TARGET_TCL_LIBS" != ""; then
  TARGET_TCL_LIBS="$config_TARGET_TCL_LIBS"
else
  if test "$with_tcl" != ""; then
    extra=`echo $with_tcl/$tclsubdir/libtcl8*.a`
  fi
  CC=$TARGET_CC
  echo $ac_n "checking for sin""... $ac_c" 1>&6
echo "configure:1040: checking for sin" >&5
if eval "test \"`echo '$''{'ac_cv_func_sin'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.$ac_ext <<EOF
#line 1045 "configure"
#include "confdefs.h"
/* System header to define __stub macros and hopefully few prototypes,
    which can conflict with char sin(); below.  */
#include <assert.h>
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char sin();

int main() {

/* The GNU C library defines this for functions which it implements
    to always fail with ENOSYS.  Some functions are actually named
    something starting with __ and the normal name is an alias.  */
#if defined (__stub_sin) || defined (__stub___sin)
choke me
#else
sin();
#endif

; return 0; }
EOF
if { (eval echo configure:1068: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  eval "ac_cv_func_sin=yes"
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  eval "ac_cv_func_sin=no"
fi
rm -f conftest*
fi

if eval "test \"`echo '$ac_cv_func_'sin`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  LIBS=""
else
  echo "$ac_t""no" 1>&6
LIBS="-lm"
fi

  echo $ac_n "checking for dlopen in -ldl""... $ac_c" 1>&6
echo "configure:1089: checking for dlopen in -ldl" >&5
ac_lib_var=`echo dl'_'dlopen | sed 'y%./+-%__p_%'`
if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  ac_save_LIBS="$LIBS"
LIBS="-ldl  $LIBS"
cat > conftest.$ac_ext <<EOF
#line 1097 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char dlopen();

int main() {
dlopen()
; return 0; }
EOF
if { (eval echo configure:1108: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  eval "ac_cv_lib_$ac_lib_var=yes"
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  eval "ac_cv_lib_$ac_lib_var=no"
fi
rm -f conftest*
LIBS="$ac_save_LIBS"

fi
if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
  echo "$ac_t""yes" 1>&6
    ac_tr_lib=HAVE_LIB`echo dl | sed -e 's/[^a-zA-Z0-9_]/_/g' \
    -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'`
  cat >> confdefs.h <<EOF
#define $ac_tr_lib 1
EOF

  LIBS="-ldl $LIBS"

else
  echo "$ac_t""no" 1>&6
fi

  otherlibs=$LIBS
  if test "$extra" != ""; then
    LIBS=$extra
  else 
    LIBS=""
    
echo $ac_n "checking for library containing Tcl_Init""... $ac_c" 1>&6
echo "configure:1142: checking for library containing Tcl_Init" >&5
if eval "test \"`echo '$''{'ac_cv_search_Tcl_Init'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  ac_func_search_save_LIBS="$LIBS"
ac_cv_search_Tcl_Init="no"
cat > conftest.$ac_ext <<EOF
#line 1149 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char Tcl_Init();

int main() {
Tcl_Init()
; return 0; }
EOF
if { (eval echo configure:1160: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_Tcl_Init="none required"
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
test "$ac_cv_search_Tcl_Init" = "no" && for i in         tcl8.4 tcl8.3 tcl8.2 tcl8.1 tcl8.0 tcl80 tcl; do
LIBS="-l$i $otherlibs $ac_func_search_save_LIBS"
cat > conftest.$ac_ext <<EOF
#line 1171 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char Tcl_Init();

int main() {
Tcl_Init()
; return 0; }
EOF
if { (eval echo configure:1182: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_Tcl_Init="-l$i"
break
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
done
LIBS="$ac_func_search_save_LIBS"
fi

echo "$ac_t""$ac_cv_search_Tcl_Init" 1>&6
if test "$ac_cv_search_Tcl_Init" != "no"; then
  test "$ac_cv_search_Tcl_Init" = "none required" || LIBS="$ac_cv_search_Tcl_Init $LIBS"
  
else :
  
fi
  fi
  TARGET_TCL_LIBS="$LIBS $otherlibs"
fi


##########
# Figure out where to get the TCL header files.
#
echo $ac_n "checking TCL header files""... $ac_c" 1>&6
echo "configure:1211: checking TCL header files" >&5
found=no
if test "$config_TARGET_TCL_INC" != ""; then
  TARGET_TCL_INC=$config_TARGET_TCL_INC
  found=yes
else
  if test "$with_tcl" != ""; then
    TARGET_TCL_INC="-I$with_tcl/generic -I$with_tcl/$tclsubdir"
    found=yes
  else
    TARGET_TCL_INC=""
    found=no
  fi
fi
if test "$found" = "yes"; then
  echo "$ac_t""$TARGET_TCL_INC" 1>&6
else
  echo "$ac_t""not specified: still searching..." 1>&6
  echo $ac_n "checking how to run the C preprocessor""... $ac_c" 1>&6
echo "configure:1230: checking how to run the C preprocessor" >&5
# On Suns, sometimes $CPP names a directory.
if test -n "$CPP" && test -d "$CPP"; then
  CPP=
fi
if test -z "$CPP"; then
if eval "test \"`echo '$''{'ac_cv_prog_CPP'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
    # This must be in double quotes, not single quotes, because CPP may get
  # substituted into the Makefile and "${CC-cc}" will confuse make.
  CPP="${CC-cc} -E"
  # On the NeXT, cc -E runs the code through the compiler's parser,
  # not just through cpp.
  cat > conftest.$ac_ext <<EOF
#line 1245 "configure"
#include "confdefs.h"
#include <assert.h>
Syntax Error
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1251: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  :
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  CPP="${CC-cc} -E -traditional-cpp"
  cat > conftest.$ac_ext <<EOF
#line 1262 "configure"
#include "confdefs.h"
#include <assert.h>
Syntax Error
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1268: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  :
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  CPP="${CC-cc} -nologo -E"
  cat > conftest.$ac_ext <<EOF
#line 1279 "configure"
#include "confdefs.h"
#include <assert.h>
Syntax Error
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1285: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  :
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  CPP=/lib/cpp
fi
rm -f conftest*
fi
rm -f conftest*
fi
rm -f conftest*
  ac_cv_prog_CPP="$CPP"
fi
  CPP="$ac_cv_prog_CPP"
else
  ac_cv_prog_CPP="$CPP"
fi
echo "$ac_t""$CPP" 1>&6

ac_safe=`echo "tcl.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for tcl.h""... $ac_c" 1>&6
echo "configure:1311: checking for tcl.h" >&5
if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.$ac_ext <<EOF
#line 1316 "configure"
#include "confdefs.h"
#include <tcl.h>
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1321: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=yes"
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=no"
fi
rm -f conftest*
fi
if eval "test \"`echo '$ac_cv_header_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6
fi

fi
if test "$found" = "no"; then
  for dir in /usr/local /usr/X11* /usr/pkg /usr/contrib /usr; do
    
ac_safe=`echo "$dir/include/tcl.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for $dir/include/tcl.h""... $ac_c" 1>&6
echo "configure:1348: checking for $dir/include/tcl.h" >&5
if eval "test \"`echo '$''{'ac_cv_file_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test "$cross_compiling" = yes; then
    { echo "configure: error: Cannot check for file existence when cross compiling" 1>&2; exit 1; }
else
  if test -r $dir/include/tcl.h; then
    eval "ac_cv_file_$ac_safe=yes"
  else
    eval "ac_cv_file_$ac_safe=no"
  fi
fi
fi
if eval "test \"`echo '$ac_cv_file_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6

fi

    if test "$found" = "yes"; then
      TARGET_TCL_INC="-I$dir/include"
      break
    fi
  done
fi


##########
# Figure out what C libraries are required to compile programs
# that use GDBM.
#
if test "$config_TARGET_GDBM_LIBS" != ""; then
  TARGET_GDBM_LIBS="$config_TARGET_GDBM_LIBS"
else
  CC=$TARGET_CC
  LIBS=""
  
echo $ac_n "checking for library containing gdbm_open""... $ac_c" 1>&6
echo "configure:1389: checking for library containing gdbm_open" >&5
if eval "test \"`echo '$''{'ac_cv_search_gdbm_open'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  ac_func_search_save_LIBS="$LIBS"
ac_cv_search_gdbm_open="no"
cat > conftest.$ac_ext <<EOF
#line 1396 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char gdbm_open();

int main() {
gdbm_open()
; return 0; }
EOF
if { (eval echo configure:1407: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_gdbm_open="none required"
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
test "$ac_cv_search_gdbm_open" = "no" && for i in gdbm; do
LIBS="-l$i  $ac_func_search_save_LIBS"
cat > conftest.$ac_ext <<EOF
#line 1418 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char gdbm_open();

int main() {
gdbm_open()
; return 0; }
EOF
if { (eval echo configure:1429: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_gdbm_open="-l$i"
break
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
done
LIBS="$ac_func_search_save_LIBS"
fi

echo "$ac_t""$ac_cv_search_gdbm_open" 1>&6
if test "$ac_cv_search_gdbm_open" != "no"; then
  test "$ac_cv_search_gdbm_open" = "none required" || LIBS="$ac_cv_search_gdbm_open $LIBS"
  
else :
  
fi
  TARGET_GDBM_LIBS="$LIBS"
fi


##########
# Figure out where to get the GDBM header files.
#
echo $ac_n "checking GDBM header files""... $ac_c" 1>&6
echo "configure:1457: checking GDBM header files" >&5
found=no
if test "$config_TARGET_GDBM_INC" != ""; then
  TARGET_GDBM_INC=$config_TARGET_GDBM_INC
  found=yes
fi
if test "$found" = "yes"; then
  echo "$ac_t""$TARGET_TCL_INC" 1>&6
else
  echo "$ac_t""not specified: still searching..." 1>&6
  ac_safe=`echo "gdbm.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for gdbm.h""... $ac_c" 1>&6
echo "configure:1469: checking for gdbm.h" >&5
if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.$ac_ext <<EOF
#line 1474 "configure"
#include "confdefs.h"
#include <gdbm.h>
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1479: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=yes"
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=no"
fi
rm -f conftest*
fi
if eval "test \"`echo '$ac_cv_header_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6
fi

fi
if test "$found" = "no"; then
  for dir in /usr/local /usr/pkg /usr/contrib; do
    
ac_safe=`echo "$dir/include/gdbm.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for $dir/include/gdbm.h""... $ac_c" 1>&6
echo "configure:1506: checking for $dir/include/gdbm.h" >&5
if eval "test \"`echo '$''{'ac_cv_file_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test "$cross_compiling" = yes; then
    { echo "configure: error: Cannot check for file existence when cross compiling" 1>&2; exit 1; }
else
  if test -r $dir/include/gdbm.h; then
    eval "ac_cv_file_$ac_safe=yes"
  else
    eval "ac_cv_file_$ac_safe=no"
  fi
fi
fi
if eval "test \"`echo '$ac_cv_file_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6

fi

    if test "$found" = "yes"; then
      TARGET_GDBM_INC="-I$dir/include"
      break
    fi
  done
fi


##########
# Figure out what C libraries are required to compile programs
# that use "readline()" library.
#
if test "$config_TARGET_READLINE_LIBS" != ""; then
  TARGET_READLINE_LIBS="$config_TARGET_READLINE_LIBS"
else
  CC=$TARGET_CC
  LIBS=""
  
echo $ac_n "checking for library containing readline""... $ac_c" 1>&6
echo "configure:1547: checking for library containing readline" >&5
if eval "test \"`echo '$''{'ac_cv_search_readline'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  ac_func_search_save_LIBS="$LIBS"
ac_cv_search_readline="no"
cat > conftest.$ac_ext <<EOF
#line 1554 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char readline();

int main() {
readline()
; return 0; }
EOF
if { (eval echo configure:1565: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_readline="none required"
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
test "$ac_cv_search_readline" = "no" && for i in readline; do
LIBS="-l$i  $ac_func_search_save_LIBS"
cat > conftest.$ac_ext <<EOF
#line 1576 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char readline();

int main() {
readline()
; return 0; }
EOF
if { (eval echo configure:1587: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
  rm -rf conftest*
  ac_cv_search_readline="-l$i"
break
else
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
fi
rm -f conftest*
done
LIBS="$ac_func_search_save_LIBS"
fi

echo "$ac_t""$ac_cv_search_readline" 1>&6
if test "$ac_cv_search_readline" != "no"; then
  test "$ac_cv_search_readline" = "none required" || LIBS="$ac_cv_search_readline $LIBS"
  
else :
  
fi
  TARGET_READLINE_LIBS="$LIBS"
fi


##########
# Figure out where to get the READLINE header files.
#
echo $ac_n "checking readline header files""... $ac_c" 1>&6
echo "configure:1615: checking readline header files" >&5
found=no
if test "$config_TARGET_READLINE_INC" != ""; then
  TARGET_READLINE_INC=$config_TARGET_READLINE_INC
  found=yes
fi
if test "$found" = "yes"; then
  echo "$ac_t""$TARGET_READLINE_INC" 1>&6
else
  echo "$ac_t""not specified: still searching..." 1>&6
  ac_safe=`echo "readline.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for readline.h""... $ac_c" 1>&6
echo "configure:1627: checking for readline.h" >&5
if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  cat > conftest.$ac_ext <<EOF
#line 1632 "configure"
#include "confdefs.h"
#include <readline.h>
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
{ (eval echo configure:1637: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
if test -z "$ac_err"; then
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=yes"
else
  echo "$ac_err" >&5
  echo "configure: failed program was:" >&5
  cat conftest.$ac_ext >&5
  rm -rf conftest*
  eval "ac_cv_header_$ac_safe=no"
fi
rm -f conftest*
fi
if eval "test \"`echo '$ac_cv_header_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6
fi

fi
if test "$found" = "no"; then
  for dir in /usr /usr/local /usr/local/readline /usr/contrib; do
    
ac_safe=`echo "$dir/include/readline.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for $dir/include/readline.h""... $ac_c" 1>&6
echo "configure:1664: checking for $dir/include/readline.h" >&5
if eval "test \"`echo '$''{'ac_cv_file_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test "$cross_compiling" = yes; then
    { echo "configure: error: Cannot check for file existence when cross compiling" 1>&2; exit 1; }
else
  if test -r $dir/include/readline.h; then
    eval "ac_cv_file_$ac_safe=yes"
  else
    eval "ac_cv_file_$ac_safe=no"
  fi
fi
fi
if eval "test \"`echo '$ac_cv_file_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6

fi

    if test "$found" = "yes"; then
      TARGET_READLINE_INC="-I$dir/include"
      break
    fi
    
ac_safe=`echo "$dir/include/readline/readline.h" | sed 'y%./+-%__p_%'`
echo $ac_n "checking for $dir/include/readline/readline.h""... $ac_c" 1>&6
echo "configure:1693: checking for $dir/include/readline/readline.h" >&5
if eval "test \"`echo '$''{'ac_cv_file_$ac_safe'+set}'`\" = set"; then
  echo $ac_n "(cached) $ac_c" 1>&6
else
  if test "$cross_compiling" = yes; then
    { echo "configure: error: Cannot check for file existence when cross compiling" 1>&2; exit 1; }
else
  if test -r $dir/include/readline/readline.h; then
    eval "ac_cv_file_$ac_safe=yes"
  else
    eval "ac_cv_file_$ac_safe=no"
  fi
fi
fi
if eval "test \"`echo '$ac_cv_file_'$ac_safe`\" = yes"; then
  echo "$ac_t""yes" 1>&6
  found=yes
else
  echo "$ac_t""no" 1>&6

fi

    if test "$found" = "yes"; then
      TARGET_READLINE_INC="-I$dir/include/readline"
      break
    fi
  done
fi
if test "$found" = "yes"; then
  TARGET_HAVE_READLINE=1
else
  TARGET_HAVE_READLINE=0
fi



#########
# Generate the output files.
#
trap '' 1 2 15
cat > confcache <<\EOF
# This file is a shell script that caches the results of configure
# tests run on this system so they can be shared between configure
# scripts and configure runs.  It is not useful on other systems.
# If it contains results you don't want to keep, you may remove or edit it.
#
# By default, configure uses ./config.cache as the cache file,
# creating it if it does not exist already.  You can give configure
# the --cache-file=FILE option to use a different cache file; that is
# what configure does when it calls configure scripts in
# subdirectories, so they share the cache.
# Giving --cache-file=/dev/null disables caching, for debugging configure.
# config.status only pays attention to the cache file if you give it the
# --recheck option to rerun configure.
#
EOF
# The following way of writing the cache mishandles newlines in values,
# but we know of no workaround that is simple, portable, and efficient.
# So, don't put newlines in cache variables' values.
# Ultrix sh set writes to stderr and can't be redirected directly,
# and sets the high bit in the cache file unless we assign to the vars.
(set) 2>&1 |
  case `(ac_space=' '; set | grep ac_space) 2>&1` in
  *ac_space=\ *)
    # `set' does not quote correctly, so add quotes (double-quote substitution
    # turns \\\\ into \\, and sed turns \\ into \).
    sed -n \
      -e "s/'/'\\\\''/g" \
      -e "s/^\\([a-zA-Z0-9_]*_cv_[a-zA-Z0-9_]*\\)=\\(.*\\)/\\1=\${\\1='\\2'}/p"
    ;;
  *)
    # `set' quotes correctly as required by POSIX, so do not add quotes.
    sed -n -e 's/^\([a-zA-Z0-9_]*_cv_[a-zA-Z0-9_]*\)=\(.*\)/\1=${\1=\2}/p'
    ;;
  esac >> confcache
if cmp -s $cache_file confcache; then
  :
else
  if test -w $cache_file; then
    echo "updating cache $cache_file"
    cat confcache > $cache_file
  else
    echo "not updating unwritable cache $cache_file"
  fi
fi
rm -f confcache

trap 'rm -fr conftest* confdefs* core core.* *.core $ac_clean_files; exit 1' 1 2 15

test "x$prefix" = xNONE && prefix=$ac_default_prefix
# Let make expand exec_prefix.
test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'

# Any assignment to VPATH causes Sun make to only execute
# the first set of double-colon rules, so remove it if not needed.
# If there is a colon in the path, we need to keep it.
if test "x$srcdir" = x.; then
  ac_vpsub='/^[ 	]*VPATH[ 	]*=[^:]*$/d'
fi

trap 'rm -f $CONFIG_STATUS conftest*; exit 1' 1 2 15

# Transform confdefs.h into DEFS.
# Protect against shell expansion while executing Makefile rules.
# Protect against Makefile macro expansion.
cat > conftest.defs <<\EOF
s%#define \([A-Za-z_][A-Za-z0-9_]*\) *\(.*\)%-D\1=\2%g
s%[ 	`~#$^&*(){}\\|;'"<>?]%\\&%g
s%\[%\\&%g
s%\]%\\&%g
s%\$%$$%g
EOF
DEFS=`sed -f conftest.defs confdefs.h | tr '\012' ' '`
rm -f conftest.defs


# Without the "./", some shells look in PATH for config.status.
: ${CONFIG_STATUS=./config.status}

echo creating $CONFIG_STATUS
rm -f $CONFIG_STATUS
cat > $CONFIG_STATUS <<EOF
#! /bin/sh
# Generated automatically by configure.
# Run this file to recreate the current configuration.
# This directory was configured as follows,
# on host `(hostname || uname -n) 2>/dev/null | sed 1q`:
#
# $0 $ac_configure_args
#
# Compiler output produced by configure, useful for debugging
# configure, is in ./config.log if it exists.

ac_cs_usage="Usage: $CONFIG_STATUS [--recheck] [--version] [--help]"
for ac_option
do
  case "\$ac_option" in
  -recheck | --recheck | --rechec | --reche | --rech | --rec | --re | --r)
    echo "running \${CONFIG_SHELL-/bin/sh} $0 $ac_configure_args --no-create --no-recursion"
    exec \${CONFIG_SHELL-/bin/sh} $0 $ac_configure_args --no-create --no-recursion ;;
  -version | --version | --versio | --versi | --vers | --ver | --ve | --v)
    echo "$CONFIG_STATUS generated by autoconf version 2.13"
    exit 0 ;;
  -help | --help | --hel | --he | --h)
    echo "\$ac_cs_usage"; exit 0 ;;
  *) echo "\$ac_cs_usage"; exit 1 ;;
  esac
done

ac_given_srcdir=$srcdir

trap 'rm -fr `echo "Makefile" | sed "s/:[^ ]*//g"` conftest*; exit 1' 1 2 15
EOF
cat >> $CONFIG_STATUS <<EOF

# Protect against being on the right side of a sed subst in config.status.
sed 's/%@/@@/; s/@%/@@/; s/%g\$/@g/; /@g\$/s/[\\\\&%]/\\\\&/g;
 s/@@/%@/; s/@@/@%/; s/@g\$/%g/' > conftest.subs <<\\CEOF
$ac_vpsub
$extrasub
s%@SHELL@%$SHELL%g
s%@CFLAGS@%$CFLAGS%g
s%@CPPFLAGS@%$CPPFLAGS%g
s%@CXXFLAGS@%$CXXFLAGS%g
s%@FFLAGS@%$FFLAGS%g
s%@DEFS@%$DEFS%g
s%@LDFLAGS@%$LDFLAGS%g
s%@LIBS@%$LIBS%g
s%@exec_prefix@%$exec_prefix%g
s%@prefix@%$prefix%g
s%@program_transform_name@%$program_transform_name%g
s%@bindir@%$bindir%g
s%@sbindir@%$sbindir%g
s%@libexecdir@%$libexecdir%g
s%@datadir@%$datadir%g
s%@sysconfdir@%$sysconfdir%g
s%@sharedstatedir@%$sharedstatedir%g
s%@localstatedir@%$localstatedir%g
s%@libdir@%$libdir%g
s%@includedir@%$includedir%g
s%@oldincludedir@%$oldincludedir%g
s%@infodir@%$infodir%g
s%@mandir@%$mandir%g
s%@program_prefix@%$program_prefix%g
s%@CC@%$CC%g
s%@BUILD_CC@%$BUILD_CC%g
s%@BUILD_CFLAGS@%$BUILD_CFLAGS%g
s%@BUILD_LIBS@%$BUILD_LIBS%g
s%@RANLIB@%$RANLIB%g
s%@TARGET_CC@%$TARGET_CC%g
s%@TARGET_CFLAGS@%$TARGET_CFLAGS%g
s%@TARGET_LINK@%$TARGET_LINK%g
s%@TARGET_LFLAGS@%$TARGET_LFLAGS%g
s%@TARGET_RANLIB@%$TARGET_RANLIB%g
s%@TARGET_AR@%$TARGET_AR%g
s%@BUILD_EXEEXT@%$BUILD_EXEEXT%g
s%@OS_UNIX@%$OS_UNIX%g
s%@OS_WIN@%$OS_WIN%g
s%@TARGET_EXEEXT@%$TARGET_EXEEXT%g
s%@TARGET_LIBS@%$TARGET_LIBS%g
s%@TARGET_TCL_LIBS@%$TARGET_TCL_LIBS%g
s%@CPP@%$CPP%g
s%@TARGET_TCL_INC@%$TARGET_TCL_INC%g
s%@TARGET_GDBM_LIBS@%$TARGET_GDBM_LIBS%g
s%@TARGET_GDBM_INC@%$TARGET_GDBM_INC%g
s%@TARGET_READLINE_LIBS@%$TARGET_READLINE_LIBS%g
s%@TARGET_READLINE_INC@%$TARGET_READLINE_INC%g
s%@TARGET_HAVE_READLINE@%$TARGET_HAVE_READLINE%g

CEOF
EOF

cat >> $CONFIG_STATUS <<\EOF

# Split the substitutions into bite-sized pieces for seds with
# small command number limits, like on Digital OSF/1 and HP-UX.
ac_max_sed_cmds=90 # Maximum number of lines to put in a sed script.
ac_file=1 # Number of current file.
ac_beg=1 # First line for current file.
ac_end=$ac_max_sed_cmds # Line after last line for current file.
ac_more_lines=:
ac_sed_cmds=""
while $ac_more_lines; do
  if test $ac_beg -gt 1; then
    sed "1,${ac_beg}d; ${ac_end}q" conftest.subs > conftest.s$ac_file
  else
    sed "${ac_end}q" conftest.subs > conftest.s$ac_file
  fi
  if test ! -s conftest.s$ac_file; then
    ac_more_lines=false
    rm -f conftest.s$ac_file
  else
    if test -z "$ac_sed_cmds"; then
      ac_sed_cmds="sed -f conftest.s$ac_file"
    else
      ac_sed_cmds="$ac_sed_cmds | sed -f conftest.s$ac_file"
    fi
    ac_file=`expr $ac_file + 1`
    ac_beg=$ac_end
    ac_end=`expr $ac_end + $ac_max_sed_cmds`
  fi
done
if test -z "$ac_sed_cmds"; then
  ac_sed_cmds=cat
fi
EOF

cat >> $CONFIG_STATUS <<EOF

CONFIG_FILES=\${CONFIG_FILES-"Makefile"}
EOF
cat >> $CONFIG_STATUS <<\EOF
for ac_file in .. $CONFIG_FILES; do if test "x$ac_file" != x..; then
  # Support "outfile[:infile[:infile...]]", defaulting infile="outfile.in".
  case "$ac_file" in
  *:*) ac_file_in=`echo "$ac_file"|sed 's%[^:]*:%%'`
       ac_file=`echo "$ac_file"|sed 's%:.*%%'` ;;
  *) ac_file_in="${ac_file}.in" ;;
  esac

  # Adjust a relative srcdir, top_srcdir, and INSTALL for subdirectories.

  # Remove last slash and all that follows it.  Not all systems have dirname.
  ac_dir=`echo $ac_file|sed 's%/[^/][^/]*$%%'`
  if test "$ac_dir" != "$ac_file" && test "$ac_dir" != .; then
    # The file is in a subdirectory.
    test ! -d "$ac_dir" && mkdir "$ac_dir"
    ac_dir_suffix="/`echo $ac_dir|sed 's%^\./%%'`"
    # A "../" for each directory in $ac_dir_suffix.
    ac_dots=`echo $ac_dir_suffix|sed 's%/[^/]*%../%g'`
  else
    ac_dir_suffix= ac_dots=
  fi

  case "$ac_given_srcdir" in
  .)  srcdir=.
      if test -z "$ac_dots"; then top_srcdir=.
      else top_srcdir=`echo $ac_dots|sed 's%/$%%'`; fi ;;
  /*) srcdir="$ac_given_srcdir$ac_dir_suffix"; top_srcdir="$ac_given_srcdir" ;;
  *) # Relative path.
    srcdir="$ac_dots$ac_given_srcdir$ac_dir_suffix"
    top_srcdir="$ac_dots$ac_given_srcdir" ;;
  esac


  echo creating "$ac_file"
  rm -f "$ac_file"
  configure_input="Generated automatically from `echo $ac_file_in|sed 's%.*/%%'` by configure."
  case "$ac_file" in
  *Makefile*) ac_comsub="1i\\
# $configure_input" ;;
  *) ac_comsub= ;;
  esac

  ac_file_inputs=`echo $ac_file_in|sed -e "s%^%$ac_given_srcdir/%" -e "s%:% $ac_given_srcdir/%g"`
  sed -e "$ac_comsub
s%@configure_input@%$configure_input%g
s%@srcdir@%$srcdir%g
s%@top_srcdir@%$top_srcdir%g
" $ac_file_inputs | (eval "$ac_sed_cmds") > $ac_file
fi; done
rm -f conftest.s*

EOF
cat >> $CONFIG_STATUS <<EOF

EOF
cat >> $CONFIG_STATUS <<\EOF

exit 0
EOF
chmod +x $CONFIG_STATUS
rm -fr confdefs* $ac_clean_files
test "$no_create" = yes || ${CONFIG_SHELL-/bin/sh} $CONFIG_STATUS || exit 1

#
# This file describes a "configure" script that is used to build
# makefiles for a particular platform.  Process this file using 
# Autoconf version 1.13 in order to generate that script.  All 
# lines of this file up to the AC_INIT macro are ignored.
#
# The build process allows for using a cross-compiler.  But the default
# action is to target the same platform that we are running on.  The
# configure script needs to discover the following properties of the 
# build and target systems:
#
#    srcdir
#
#        The is the name of the directory that contains the
#        "configure" shell script.  All source files are
#        located relative to this directory.
#
#    bindir
#
#        The name of the directory where executables should be
#        written by the "install" target of the makefile.
#
#    program_prefix
#
#        Add this prefix to the names of all executables that run
#        on the target machine.  Default: ""
#
#    ENABLE_SHARED
#
#        True if shared libraries should be generated.
#
#    BUILD_CC
#
#        The name of a command that is used to convert C
#        source files into executables that run on the build
#        platform.
#
#    BUILD_CFLAGS
#
#        Switches that the build compiler needs in order to construct
#        command-line programs.
#
#    BUILD_LIBS
#
#        Libraries that the build compiler needs in order to construct
#        command-line programs.
#
#    BUILD_EXEEXT
#
#        The filename extension for executables on the build
#        platform.  "" for Unix and ".exe" for Windows.
#
#    TARGET_CC
#
#        The name of a command that runs on the build platform
#        and converts C source files into *.o files for the
#        target platform.  In other words, the cross-compiler.
#
#    TARGET_CFLAGS
#
#        Switches that the target compiler needs to turn C source files
#        into *.o files.  Do not include TARGET_TCL_INC in this list.
#        Makefiles might add additional switches such as "-I.".
#
#    TARGET_TCL_LIBS
#
#        This is the library directives passed to the target linker
#        that cause the executable to link against Tcl.  This might
#        be a switch like "-ltcl8.0" or pathnames of library file
#        like "../../src/libtcl8.0.a".
#
#    TARGET_TCL_INC
#
#        This variables define the directory that contain header
#        files for Tcl.  If the compiler is able to find <tcl.h>
#        on its own, then this can be blank.
#
#    TARGET_GDBM_LIBS
#
#        This is the library directives passed to the target linker
#        that cause the executable to link against GDBM.  This might
#        be a switch like "-lgdbm" or pathnames of library file
#        like "../../src/libgdbm.a".
#
#    TARGET_GDBM_INC
#
#        This variables define the directory that contain header
#        files for GDBM.  If the compiler is able to find <gdbm.h>
#        on its own, then this can be blank.
#
#    TARGET_READLINE_LIBS
#
#        This is the library directives passed to the target linker
#        that cause the executable to link against GDBM.  This might
#        be a switch like "-lreadline" or pathnames of library file
#        like "../../src/libreadline.a".
#
#    TARGET_READLINE_INC
#
#        This variables define the directory that contain header
#        files for the readline library.  If the compiler is able 
#        to find <readline.h> on its own, then this can be blank.
#
#    TARGET_LINK
#
#        The name of the linker that combines *.o files generated
#        by TARGET_CC into executables for the target platform.
#
#    TARGET_LIBS
#
#        Additional libraries or other switch that the target linker needs
#        to build an executable on the target.  Do not include
#        on this list any libraries in TARGET_TCL_LIBS, TARGET_GDBM_LIBS,
#        TARGET_READLINE_LIBS, etc.
#
#    TARGET_EXEEXT
#
#        The filename extension for executables on the
#        target platform.  "" for Unix and ".exe" for windows.
#
# The generated configure script will make an attempt to guess
# at all of the above parameters.  You can override any of
# the guesses by setting the environment variable named
# "config_AAAA" where "AAAA" is the name of the parameter
# described above.  (Exception: srcdir cannot be set this way.)
# If you have a file that sets one or more of these environment
# variables, you can invoke configure as follows:
#
#           configure --with-hints=FILE
#
# where FILE is the name of the file that sets the environment
# variables.  FILE should be an absolute pathname.
#
# If you have a Tcl/Tk/BLT source distribution available, then the
# files in that distribution will be used instead of any other
# Tcl/Tk/BLT files the script might discover if you tell the configure
# script about the source tree.  Use commandline options:
#
#         --with-tcl=PATH  --with-tk=PATH  --with-blt=PATH
#
# Or set environment variables config_WITH_TCL, config_WITH_TK, or
# config_WITH_BLT.
#
# This configure.in file is easy to reuse on other projects.  Just
# change the argument to AC_INIT().  And disable any features that
# you don't need (for example BLT) by erasing or commenting out
# the corresponding code.
#
AC_INIT(src/sqlite.h)

dnl Put the RCS revision string after AC_INIT so that it will also
dnl show in in configure.
# The following RCS revision string applies to configure.in
# $Revision: 1.1 $

#########
# Make sure we are not building in a subdirectory of the source tree.
#
changequote(<<<,>>>)
temp=`echo $srcdir | grep '[^./]'`
changequote([,])
if test "$temp" = ""; then
  AC_MSG_ERROR([
**************************************************************************
** This program may not be compiled in the same directory that contains **
** the configure script or any subdirectory of that directory.   Rerun  **
** the configure script from a directory that is separate from the      **
** source tree.                                                         **
**************************************************************************])
fi

#########
# Set up an appropriate program prefix
#
if test "$program_prefix" = "NONE"; then
  program_prefix=""
fi
AC_SUBST(program_prefix)

#########
# Check to see if the --with-hints=FILE option is used.  If there is none,
# then check for a files named "$host.hints" and ../$hosts.hints where
# $host is the hostname of the build system.  If still no hints are
# found, try looking in $system.hints and ../$system.hints where
# $system is the result of uname -s.
#
AC_ARG_WITH(hints,
  [  --with-hints=FILE       Read configuration options from FILE],
  hints=$withval)
if test "$hints" = ""; then
  host=`hostname | sed 's/\..*//'`
  if test -r $host.hints; then
    hints=$host.hints
  else
     if test -r ../$host.hints; then
       hints=../$host.hints
     fi
  fi
fi
if test "$hints" = ""; then
  sys=`uname -s`
  if test -r $sys.hints; then
    hints=$sys.hints
  else
     if test -r ../$sys.hints; then
       hints=../$sys.hints
     fi
  fi
fi
if test "$hints" != ""; then
  AC_MSG_RESULT(reading hints from $hints)
  . $hints
fi

#########
# Locate a compiler for the build machine.  This compiler should
# generate command-line programs that run on the build machine.
#
default_build_cflags="-g"
if test "$config_BUILD_CC" = ""; then
  AC_PROG_CC
  if test "$cross_compiling" = "yes"; then
    AC_MSG_ERROR([unable to find a compiler for building build tools])
  fi
  BUILD_CC=$CC
  default_build_cflags=$CFLAGS
else
  BUILD_CC=$config_BUILD_CC
  AC_MSG_CHECKING([host compiler])
  CC=$BUILD_CC
  AC_MSG_RESULT($BUILD_CC)
fi
AC_MSG_CHECKING([switches for the host compiler])
if test "$config_BUILD_CFLAGS" != ""; then
  CFLAGS=$config_BUILD_CFLAGS
  BUILD_CFLAGS=$config_BUILD_CFLAGS
else
  BUILD_CFLAGS=$default_build_cflags
fi
AC_MSG_RESULT($BUILD_CFLAGS)
if test "$config_BUILD_LIBS" != ""; then
  BUILD_LIBS=$config_BUILD_LIBS
fi
AC_SUBST(BUILD_CC)
AC_SUBST(BUILD_CFLAGS)
AC_SUBST(BUILD_LIBS)

##########
# Locate a compiler that converts C code into *.o files that run on
# the target machine.
#
AC_MSG_CHECKING([target compiler])
if test "$config_TARGET_CC" != ""; then
  TARGET_CC=$config_TARGET_CC
else
  TARGET_CC=$BUILD_CC
fi
AC_MSG_RESULT($TARGET_CC)
AC_MSG_CHECKING([switches on the target compiler])
if test "$config_TARGET_CFLAGS" != ""; then
  TARGET_CFLAGS=$config_TARGET_CFLAGS
else
  TARGET_CFLAGS=$BUILD_CFLAGS
fi
AC_MSG_RESULT($TARGET_CFLAGS)
AC_MSG_CHECKING([target linker])
if test "$config_TARGET_LINK" = ""; then
  TARGET_LINK=$TARGET_CC
else
  TARGET_LINK=$config_TARGET_LINK
fi
AC_MSG_RESULT($TARGET_LINK)
AC_MSG_CHECKING([switches on the target compiler])
if test "$config_TARGET_TFLAGS" != ""; then
  TARGET_TFLAGS=$config_TARGET_TFLAGS
else
  TARGET_TFLAGS=$BUILD_CFLAGS
fi
if test "$config_TARGET_RANLIB" != ""; then
  TARGET_RANLIB=$config_TARGET_RANLIB
else
  AC_PROG_RANLIB
  TARGET_RANLIB=$RANLIB
fi
if test "$config_TARGET_AR" != ""; then
  TARGET_RANLIB=$config_TARGET_AR
else
  TARGET_AR='ar cr'
fi
AC_MSG_RESULT($TARGET_TFLAGS)
AC_SUBST(TARGET_CC)
AC_SUBST(TARGET_CFLAGS)
AC_SUBST(TARGET_LINK)
AC_SUBST(TARGET_LFLAGS)
AC_SUBST(TARGET_RANLIB)
AC_SUBST(TARGET_AR)

# Set the $cross variable if we are cross-compiling.  Make
# it 0 if we are not.
#
AC_MSG_CHECKING([if host and target compilers are the same])
if test "$BUILD_CC" = "$TARGET_CC"; then
  cross=0
  AC_MSG_RESULT(yes)
else
  cross=1
  AC_MSG_RESULT(no)
fi

###########
# Lots of things are different if we are compiling for Windows using
# the CYGWIN environment.  So check for that special case and handle
# things accordingly.
#
AC_MSG_CHECKING([if executables have the .exe suffix])
if test "$config_BUILD_EXEEXT" = ".exe"; then
  CYGWIN=yes
  AC_MSG_RESULT(yes)
else
  AC_MSG_RESULT(unknown)
fi
if test "$CYGWIN" != "yes"; then
  AC_CYGWIN
fi
if test "$CYGWIN" = "yes"; then
  BUILD_EXEEXT=.exe
else
  BUILD_EXEEXT=""
fi
if test "$cross" = "0"; then
  TARGET_EXEEXT=$BUILD_EXEEXT
else
  TARGET_EXEEXT=$config_TARGET_EXEEXT
fi
if test "$TARGET_EXEEXT" = ".exe"; then
  OS_UNIX=0
  OS_WIN=1
  tclsubdir=win
else
  OS_UNIX=1
  OS_WIN=0
  tclsubdir=unix
fi
TARGET_CFLAGS="$TARGET_CFLAGS -DOS_UNIX=$OS_UNIX -DOS_WIN=$OS_WIN"

AC_SUBST(BUILD_EXEEXT)
AC_SUBST(OS_UNIX)
AC_SUBST(OS_WIN)
AC_SUBST(TARGET_EXEEXT)

##########
# Extract generic linker options from the environment.
#
if test "$config_TARGET_LIBS" != ""; then
  TARGET_LIBS=$config_TARGET_LIBS
else
  TARGET_LIBS=""
fi
AC_SUBST(TARGET_LIBS)

##########
# Figure out what C libraries are required to compile Tcl programs.
#
if test "$config_TARGET_TCL_LIBS" != ""; then
  TARGET_TCL_LIBS="$config_TARGET_TCL_LIBS"
else
  if test "$with_tcl" != ""; then
    extra=`echo $with_tcl/$tclsubdir/libtcl8*.a`
  fi
  CC=$TARGET_CC
  AC_CHECK_FUNC(sin, LIBS="", LIBS="-lm")
  AC_CHECK_LIB(dl, dlopen)
  otherlibs=$LIBS
  if test "$extra" != ""; then
    LIBS=$extra
  else 
    LIBS=""
    AC_SEARCH_LIBS(Tcl_Init, dnl
        tcl8.4 tcl8.3 tcl8.2 tcl8.1 tcl8.0 tcl80 tcl,,,$otherlibs)
  fi
  TARGET_TCL_LIBS="$LIBS $otherlibs"
fi
AC_SUBST(TARGET_TCL_LIBS)

##########
# Figure out where to get the TCL header files.
#
AC_MSG_CHECKING([TCL header files])
found=no
if test "$config_TARGET_TCL_INC" != ""; then
  TARGET_TCL_INC=$config_TARGET_TCL_INC
  found=yes
else
  if test "$with_tcl" != ""; then
    TARGET_TCL_INC="-I$with_tcl/generic -I$with_tcl/$tclsubdir"
    found=yes
  else
    TARGET_TCL_INC=""
    found=no
  fi
fi
if test "$found" = "yes"; then
  AC_MSG_RESULT($TARGET_TCL_INC)
else
  AC_MSG_RESULT(not specified: still searching...)
  AC_CHECK_HEADER(tcl.h, [found=yes])
fi
if test "$found" = "no"; then
  for dir in /usr/local /usr/X11* /usr/pkg /usr/contrib /usr; do
    AC_CHECK_FILE($dir/include/tcl.h, found=yes)
    if test "$found" = "yes"; then
      TARGET_TCL_INC="-I$dir/include"
      break
    fi
  done
fi
AC_SUBST(TARGET_TCL_INC)

##########
# Figure out what C libraries are required to compile programs
# that use GDBM.
#
if test "$config_TARGET_GDBM_LIBS" != ""; then
  TARGET_GDBM_LIBS="$config_TARGET_GDBM_LIBS"
else
  CC=$TARGET_CC
  LIBS=""
  AC_SEARCH_LIBS(gdbm_open, gdbm,,,)
  TARGET_GDBM_LIBS="$LIBS"
fi
AC_SUBST(TARGET_GDBM_LIBS)

##########
# Figure out where to get the GDBM header files.
#
AC_MSG_CHECKING([GDBM header files])
found=no
if test "$config_TARGET_GDBM_INC" != ""; then
  TARGET_GDBM_INC=$config_TARGET_GDBM_INC
  found=yes
fi
if test "$found" = "yes"; then
  AC_MSG_RESULT($TARGET_TCL_INC)
else
  AC_MSG_RESULT(not specified: still searching...)
  AC_CHECK_HEADER(gdbm.h, [found=yes])
fi
if test "$found" = "no"; then
  for dir in /usr/local /usr/pkg /usr/contrib; do
    AC_CHECK_FILE($dir/include/gdbm.h, found=yes)
    if test "$found" = "yes"; then
      TARGET_GDBM_INC="-I$dir/include"
      break
    fi
  done
fi
AC_SUBST(TARGET_GDBM_INC)

##########
# Figure out what C libraries are required to compile programs
# that use "readline()" library.
#
if test "$config_TARGET_READLINE_LIBS" != ""; then
  TARGET_READLINE_LIBS="$config_TARGET_READLINE_LIBS"
else
  CC=$TARGET_CC
  LIBS=""
  AC_SEARCH_LIBS(readline, readline,,,)
  TARGET_READLINE_LIBS="$LIBS"
fi
AC_SUBST(TARGET_READLINE_LIBS)

##########
# Figure out where to get the READLINE header files.
#
AC_MSG_CHECKING([readline header files])
found=no
if test "$config_TARGET_READLINE_INC" != ""; then
  TARGET_READLINE_INC=$config_TARGET_READLINE_INC
  found=yes
fi
if test "$found" = "yes"; then
  AC_MSG_RESULT($TARGET_READLINE_INC)
else
  AC_MSG_RESULT(not specified: still searching...)
  AC_CHECK_HEADER(readline.h, [found=yes])
fi
if test "$found" = "no"; then
  for dir in /usr /usr/local /usr/local/readline /usr/contrib; do
    AC_CHECK_FILE($dir/include/readline.h, found=yes)
    if test "$found" = "yes"; then
      TARGET_READLINE_INC="-I$dir/include"
      break
    fi
    AC_CHECK_FILE($dir/include/readline/readline.h, found=yes)
    if test "$found" = "yes"; then
      TARGET_READLINE_INC="-I$dir/include/readline"
      break
    fi
  done
fi
if test "$found" = "yes"; then
  TARGET_HAVE_READLINE=1
else
  TARGET_HAVE_READLINE=0
fi
AC_SUBST(TARGET_READLINE_INC)
AC_SUBST(TARGET_HAVE_READLINE)

#########
# Generate the output files.
#
AC_OUTPUT(Makefile)

<html>
<head>
<title>The Lemon Parser Generator</title>
</head>
<body bgcolor=white>
<h1 align=center>The Lemon Parser Generator</h1>

<p>Lemon is an LALR(1) parser generator for C or C++.  
It does the same job as ``bison'' and ``yacc''.
But lemon is not another bison or yacc clone.  It
uses a different grammar syntax which is designed to
reduce the number of coding errors.  Lemon also uses a more
sophisticated parsing engine that is faster than yacc and
bison and which is both reentrant and thread-safe.
Furthermore, Lemon implements features that can be used
to eliminate resource leaks, making is suitable for use
in long-running programs such as graphical user interfaces
or embedded controllers.</p>

<p>This document is an introduction to the Lemon
parser generator.</p>

<h2>Theory of Operation</h2>

<p>The main goal of Lemon is to translate a context free grammar (CFG)
for a particular language into C code that implements a parser for
that language.
The program has two inputs:
<ul>
<li>The grammar specification.
<li>A parser template file.
</ul>
Typically, only the grammar specification is supplied by the programmer.
Lemon comes with a default parser template which works fine for most
applications.  But the user is free to substitute a different parser
template if desired.</p>

<p>Depending on command-line options, Lemon will generate between
one and three files of outputs.
<ul>
<li>C code to implement the parser.
<li>A header file defining an integer ID for each terminal symbol.
<li>An information file that describes the states of the generated parser
    automaton.
</ul>
By default, all three of these output files are generated.
The header file is suppressed if the ``-m'' command-line option is
used and the report file is omitted when ``-q'' is selected.</p>

<p>The grammar specification file uses a ``.y'' suffix, by convention.
In the examples used in this document, we'll assume the name of the
grammar file is ``gram.y''.  A typical use of Lemon would be the
following command:
<pre>
   lemon gram.y
</pre>
This command will generate three output files named ``gram.c'',
``gram.h'' and ``gram.out''.
The first is C code to implement the parser.  The second
is the header file that defines numerical values for all
terminal symbols, and the last is the report that explains
the states used by the parser automaton.</p>

<h3>Command Line Options</h3>

<p>The behavior of Lemon can be modified using command-line options.
You can obtain a list of the available command-line options together
with a brief explanation of what each does by typing
<pre>
   lemon -?
</pre>
As of this writing, the following command-line options are supported:
<ul>
<li><tt>-b</tt>
<li><tt>-c</tt>
<li><tt>-g</tt>
<li><tt>-m</tt>
<li><tt>-q</tt>
<li><tt>-s</tt>
<li><tt>-x</tt>
</ul>
The ``-b'' option reduces the amount of text in the report file by
printing only the basis of each parser state, rather than the full
configuration.
The ``-c'' option suppresses action table compression.  Using -c
will make the parser a little larger and slower but it will detect
syntax errors sooner.
The ``-g'' option causes no output files to be generated at all.
Instead, the input grammar file is printed on standard output but
with all comments, actions and other extraneous text deleted.  This
is a useful way to get a quick summary of a grammar.
The ``-m'' option causes the output C source file to be compatible
with the ``makeheaders'' program.
Makeheaders is a program that automatically generates header files
from C source code.  When the ``-m'' option is used, the header
file is not output since the makeheaders program will take care
of generated all header files automatically.
The ``-q'' option suppresses the report file.
Using ``-s'' causes a brief summary of parser statistics to be
printed.  Like this:
<pre>
   Parser statistics: 74 terminals, 70 nonterminals, 179 rules
                      340 states, 2026 parser table entries, 0 conflicts
</pre>
Finally, the ``-x'' option causes Lemon to print its version number
and copyright information
and then stop without attempting to read the grammar or generate a parser.</p>

<h3>The Parser Interface</h3>

<p>Lemon doesn't generate a complete, working program.  It only generates
a few subroutines that implement a parser.  This section describes
the interface to those subroutines.  It is up to the programmer to
call these subroutines in an appropriate way in order to produce a
complete system.</p>

<p>Before a program begins using a Lemon-generated parser, the program
must first create the parser.
A new parser is created as follows:
<pre>
   void *pParser = ParseAlloc( malloc );
</pre>
The ParseAlloc() routine allocates and initializes a new parser and
returns a pointer to it.
The actual data structure used to represent a parser is opaque --
its internal structure is not visible or usable by the calling routine.
For this reason, the ParseAlloc() routine returns a pointer to void
rather than a pointer to some particular structure.
The sole argument to the ParseAlloc() routine is a pointer to the
subroutine used to allocate memory.  Typically this means ``malloc()''.</p>

<p>After a program is finished using a parser, it can reclaim all
memory allocated by that parser by calling
<pre>
   ParseFree(pParser, free);
</pre>
The first argument is the same pointer returned by ParseAlloc().  The
second argument is a pointer to the function used to release bulk
memory back to the system.</p>

<p>After a parser has been allocated using ParseAlloc(), the programmer
must supply the parser with a sequence of tokens (terminal symbols) to
be parsed.  This is accomplished by calling the following function
once for each token:
<pre>
   Parse(pParser, hTokenID, sTokenData, pArg);
</pre>
The first argument to the Parse() routine is the pointer returned by
ParseAlloc().
The second argument is a small positive integer that tells the parse the
type of the next token in the data stream.
There is one token type for each terminal symbol in the grammar.
The gram.h file generated by Lemon contains #define statements that
map symbolic terminal symbol names into appropriate integer values.
(A value of 0 for the second argument is a special flag to the
parser to indicate that the end of input has been reached.)
The third argument is the value of the given token.  By default,
the type of the third argument is integer, but the grammar will
usually redefine this type to be some kind of structure.
Typically the second argument will be a broad category of tokens
such as ``identifier'' or ``number'' and the third argument will
be the name of the identifier or the value of the number.</p>

<p>The Parse() function may have either three or four arguments,
depending on the grammar.  If the grammar specification file request
it, the Parse() function will have a fourth parameter that can be
of any type chosen by the programmer.  The parser doesn't do anything
with this argument except to pass it through to action routines.
This is a convenient mechanism for passing state information down
to the action routines without having to use global variables.</p>

<p>A typical use of a Lemon parser might look something like the
following:
<pre>
   01 ParseTree *ParseFile(const char *zFilename){
   02    Tokenizer *pTokenizer;
   03    void *pParser;
   04    Token sToken;
   05    int hTokenId;
   06    ParserState sState;
   07
   08    pTokenizer = TokenizerCreate(zFilename);
   09    pParser = ParseAlloc( malloc );
   10    InitParserState(&sState);
   11    while( GetNextToken(pTokenizer, &hTokenId, &sToken) ){
   12       Parse(pParser, hTokenId, sToken, &sState);
   13    }
   14    Parse(pParser, 0, sToken, &sState);
   15    ParseFree(pParser, free );
   16    TokenizerFree(pTokenizer);
   17    return sState.treeRoot;
   18 }
</pre>
This example shows a user-written routine that parses a file of
text and returns a pointer to the parse tree.
(We've omitted all error-handling from this example to keep it
simple.)
We assume the existence of some kind of tokenizer which is created
using TokenizerCreate() on line 8 and deleted by TokenizerFree()
on line 16.  The GetNextToken() function on line 11 retrieves the
next token from the input file and puts its type in the 
integer variable hTokenId.  The sToken variable is assumed to be
some kind of structure that contains details about each token,
such as its complete text, what line it occurs on, etc. </p>

<p>This example also assumes the existence of structure of type
ParserState that holds state information about a particular parse.
An instance of such a structure is created on line 6 and initialized
on line 10.  A pointer to this structure is passed into the Parse()
routine as the optional 4th argument.
The action routine specified by the grammar for the parser can use
the ParserState structure to hold whatever information is useful and
appropriate.  In the example, we note that the treeRoot field of
the ParserState structure is left pointing to the root of the parse
tree.</p>

<p>The core of this example as it relates to Lemon is as follows:
<pre>
   ParseFile(){
      pParser = ParseAlloc( malloc );
      while( GetNextToken(pTokenizer,&hTokenId, &sToken) ){
         Parse(pParser, hTokenId, sToken);
      }
      Parse(pParser, 0, sToken);
      ParseFree(pParser, free );
   }
</pre>
Basically, what a program has to do to use a Lemon-generated parser
is first create the parser, then send it lots of tokens obtained by
tokenizing an input source.  When the end of input is reached, the
Parse() routine should be called one last time with a token type
of 0.  This step is necessary to inform the parser that the end of
input has been reached.  Finally, we reclaim memory used by the
parser by calling ParseFree().</p>

<p>There is one other interface routine that should be mentioned
before we move on.
The ParseTrace() function can be used to generate debugging output
from the parser.  A prototype for this routine is as follows:
<pre>
   ParseTrace(FILE *stream, char *zPrefix);
</pre>
After this routine is called, a short (one-line) message is written
to the designated output stream every time the parser changes states
or calls an action routine.  Each such message is prefaced using
the text given by zPrefix.  This debugging output can be turned off
by calling ParseTrace() again with a first argument of NULL (0).</p>

<h3>Differences With YACC and BISON</h3>

<p>Programmers who have previously used the yacc or bison parser
generator will notice several important differences between yacc and/or
bison and Lemon.
<ul>
<li>In yacc and bison, the parser calls the tokenizer.  In Lemon,
    the tokenizer calls the parser.
<li>Lemon uses no global variables.  Yacc and bison use global variables
    to pass information between the tokenizer and parser.
<li>Lemon allows multiple parsers to be running simultaneously.  Yacc
    and bison do not.
</ul>
These differences may cause some initial confusion for programmers
with prior yacc and bison experience.
But after years of experience using Lemon, I firmly
believe that the Lemon way of doing things is better.</p>

<h2>Input File Syntax</h2>

<p>The main purpose of the grammar specification file for Lemon is
to define the grammar for the parser.  But the input file also
specifies additional information Lemon requires to do its job.
Most of the work in using Lemon is in writing an appropriate
grammar file.</p>

<p>The grammar file for lemon is, for the most part, free format.
It does not have sections or divisions like yacc or bison.  Any
declaration can occur at any point in the file.
Lemon ignores whitespace (except where it is needed to separate
tokens) and it honors the same commenting conventions as C and C++.</p>

<h3>Terminals and Nonterminals</h3>

<p>A terminal symbol (token) is any string of alphanumeric
and underscore characters
that begins with an upper case letter.
A terminal can contain lower class letters after the first character,
but the usual convention is to make terminals all upper case.
A nonterminal, on the other hand, is any string of alphanumeric
and underscore characters than begins with a lower case letter.
Again, the usual convention is to make nonterminals use all lower
case letters.</p>

<p>In Lemon, terminal and nonterminal symbols do not need to 
be declared or identified in a separate section of the grammar file.
Lemon is able to generate a list of all terminals and nonterminals
by examining the grammar rules, and it can always distinguish a
terminal from a nonterminal by checking the case of the first
character of the name.</p>

<p>Yacc and bison allow terminal symbols to have either alphanumeric
names or to be individual characters included in single quotes, like
this: ')' or '$'.  Lemon does not allow this alternative form for
terminal symbols.  With Lemon, all symbols, terminals and nonterminals,
must have alphanumeric names.</p>

<h3>Grammar Rules</h3>

<p>The main component of a Lemon grammar file is a sequence of grammar
rules.
Each grammar rule consists of a nonterminal symbol followed by
the special symbol ``::='' and then a list of terminals and/or nonterminals.
The rule is terminated by a period.
The list of terminals and nonterminals on the right-hand side of the
rule can be empty.
Rules can occur in any order, except that the left-hand side of the
first rule is assumed to be the start symbol for the grammar (unless
specified otherwise using the <tt>%start</tt> directive described below.)
A typical sequence of grammar rules might look something like this:
<pre>
  expr ::= expr PLUS expr.
  expr ::= expr TIMES expr.
  expr ::= LPAREN expr RPAREN.
  expr ::= VALUE.
</pre>
</p>

<p>There is one non-terminal in this example, ``expr'', and five
terminal symbols or tokens: ``PLUS'', ``TIMES'', ``LPAREN'',
``RPAREN'' and ``VALUE''.</p>

<p>Like yacc and bison, Lemon allows the grammar to specify a block
of C code that will be executed whenever a grammar rule is reduced
by the parser.
In Lemon, this action is specified by putting the C code (contained
within curly braces <tt>{...}</tt>) immediately after the
period that closes the rule.
For example:
<pre>
  expr ::= expr PLUS expr.   { printf("Doing an addition...\n"); }
</pre>
</p>

<p>In order to be useful, grammar actions must normally be linked to
their associated grammar rules.
In yacc and bison, this is accomplished by embedding a ``$$'' in the
action to stand for the value of the left-hand side of the rule and
symbols ``$1'', ``$2'', and so forth to stand for the value of
the terminal or nonterminal at position 1, 2 and so forth on the
right-hand side of the rule.
This idea is very powerful, but it is also very error-prone.  The
single most common source of errors in a yacc or bison grammar is
to miscount the number of symbols on the right-hand side of a grammar
rule and say ``$7'' when you really mean ``$8''.</p>

<p>Lemon avoids the need to count grammar symbols by assigning symbolic
names to each symbol in a grammar rule and then using those symbolic
names in the action.
In yacc or bison, one would write this:
<pre>
  expr -> expr PLUS expr  { $$ = $1 + $3; };
</pre>
But in Lemon, the same rule becomes the following:
<pre>
  expr(A) ::= expr(B) PLUS expr(C).  { A = B+C; }
</pre>
In the Lemon rule, any symbol in parentheses after a grammar rule
symbol becomes a place holder for that symbol in the grammar rule.
This place holder can then be used in the associated C action to
stand for the value of that symbol.<p>

<p>The Lemon notation for linking a grammar rule with its reduce
action is superior to yacc/bison on several counts.
First, as mentioned above, the Lemon method avoids the need to
count grammar symbols.
Secondly, if a terminal or nonterminal in a Lemon grammar rule
includes a linking symbol in parentheses but that linking symbol
is not actually used in the reduce action, then an error message
is generated.
For example, the rule
<pre>
  expr(A) ::= expr(B) PLUS expr(C).  { A = B; }
</pre>
will generate an error because the linking symbol ``C'' is used
in the grammar rule but not in the reduce action.</p>

<p>The Lemon notation for linking grammar rules to reduce actions
also facilitates the use of destructors for reclaiming memory
allocated by the values of terminals and nonterminals on the
right-hand side of a rule.</p>

<h3>Precedence Rules</h3>

<p>Lemon resolves parsing ambiguities in exactly the same way as
yacc and bison.  A shift-reduce conflict is resolved in favor
of the shift, and a reduce-reduce conflict is resolved by reducing
whichever rule comes first in the grammar file.</p>

<p>Just like in
yacc and bison, Lemon allows a measure of control 
over the resolution of paring conflicts using precedence rules.
A precedence value can be assigned to any terminal symbol
using the %left, %right or %nonassoc directives.  Terminal symbols
mentioned in earlier directives have a lower precedence that
terminal symbols mentioned in later directives.  For example:</p>

<p><pre>
   %left AND.
   %left OR.
   %nonassoc EQ NE GT GE LT LE.
   %left PLUS MINUS.
   %left TIMES DIVIDE MOD.
   %right EXP NOT.
</pre></p>

<p>In the preceding sequence of directives, the AND operator is
defined to have the lowest precedence.  The OR operator is one
precedence level higher.  And so forth.  Hence, the grammar would
attempt to group the ambiguous expression
<pre>
     a AND b OR c
</pre>
like this
<pre>
     a AND (b OR c).
</pre>
The associativity (left, right or nonassoc) is used to determine
the grouping when the precedence is the same.  AND is left-associative
in our example, so
<pre>
     a AND b AND c
</pre>
is parsed like this
<pre>
     (a AND b) AND c.
</pre>
The EXP operator is right-associative, though, so
<pre>
     a EXP b EXP c
</pre>
is parsed like this
<pre>
     a EXP (b EXP c).
</pre>
The nonassoc precedence is used for non-associative operators.
So
<pre>
     a EQ b EQ c
</pre>
is an error.</p>

<p>The precedence of non-terminals is transferred to rules as follows:
The precedence of a grammar rule is equal to the precedence of the
left-most terminal symbol in the rule for which a precedence is
defined.  This is normally what you want, but in those cases where
you want to precedence of a grammar rule to be something different,
you can specify an alternative precedence symbol by putting the
symbol in square braces after the period at the end of the rule and
before any C-code.  For example:</p>

<p><pre>
   expr = MINUS expr.  [NOT]
</pre></p>

<p>This rule has a precedence equal to that of the NOT symbol, not the
MINUS symbol as would have been the case by default.</p>

<p>With the knowledge of how precedence is assigned to terminal
symbols and individual
grammar rules, we can now explain precisely how parsing conflicts
are resolved in Lemon.  Shift-reduce conflicts are resolved
as follows:
<ul>
<li> If either the token to be shifted or the rule to be reduced
     lacks precedence information, then resolve in favor of the
     shift, but report a parsing conflict.
<li> If the precedence of the token to be shifted is greater than
     the precedence of the rule to reduce, then resolve in favor
     of the shift.  No parsing conflict is reported.
<li> If the precedence of the token it be shifted is less than the
     precedence of the rule to reduce, then resolve in favor of the
     reduce action.  No parsing conflict is reported.
<li> If the precedences are the same and the shift token is
     right-associative, then resolve in favor of the shift.
     No parsing conflict is reported.
<li> If the precedences are the same the the shift token is
     left-associative, then resolve in favor of the reduce.
     No parsing conflict is reported.
<li> Otherwise, resolve the conflict by doing the shift and
     report the parsing conflict.
</ul>
Reduce-reduce conflicts are resolved this way:
<ul>
<li> If either reduce rule 
     lacks precedence information, then resolve in favor of the
     rule that appears first in the grammar and report a parsing
     conflict.
<li> If both rules have precedence and the precedence is different
     then resolve the dispute in favor of the rule with the highest
     precedence and do not report a conflict.
<li> Otherwise, resolve the conflict by reducing by the rule that
     appears first in the grammar and report a parsing conflict.
</ul>

<h3>Special Directives</h3>

<p>The input grammar to Lemon consists of grammar rules and special
directives.  We've described all the grammar rules, so now we'll
talk about the special directives.</p>

<p>Directives in lemon can occur in any order.  You can put them before
the grammar rules, or after the grammar rules, or in the mist of the
grammar rules.  It doesn't matter.  The relative order of
directives used to assign precedence to terminals is important, but
other than that, the order of directives in Lemon is arbitrary.</p>

<p>Lemon supports the following special directives:
<ul>
<li><tt>%destructor</tt>
<li><tt>%extra_argument</tt>
<li><tt>%include</tt>
<li><tt>%left</tt>
<li><tt>%name</tt>
<li><tt>%nonassoc</tt>
<li><tt>%parse_accept</tt>
<li><tt>%parse_failure </tt>
<li><tt>%right</tt>
<li><tt>%stack_overflow</tt>
<li><tt>%stack_size</tt>
<li><tt>%start_symbol</tt>
<li><tt>%syntax_error</tt>
<li><tt>%token_destructor</tt>
<li><tt>%token_prefix</tt>
<li><tt>%token_type</tt>
<li><tt>%type</tt>
</ul>
Each of these directives will be described separately in the
following sections:</p>

<h4>The <tt>%destructor</tt> directive</h4>

<p>The %destructor directive is used to specify a destructor for
a non-terminal symbol.
(See also the %token_destructor directive which is used to
specify a destructor for terminal symbols.)</p>

<p>A non-terminal's destructor is called to dispose of the
non-terminal's value whenever the non-terminal is popped from
the stack.  This includes all of the following circumstances:
<ul>
<li> When a rule reduces and the value of a non-terminal on
     the right-hand side is not linked to C code.
<li> When the stack is popped during error processing.
<li> When the ParseFree() function runs.
</ul>
The destructor can do whatever it wants with the value of
the non-terminal, but its design is to deallocate memory
or other resources held by that non-terminal.</p>

<p>Consider an example:
<pre>
   %type nt {void*}
   %destructor nt { free($$); }
   nt(A) ::= ID NUM.   { A = malloc( 100 ); }
</pre>
This example is a bit contrived but it serves to illustrate how
destructors work.  The example shows a non-terminal named
``nt'' that holds values of type ``void*''.  When the rule for
an ``nt'' reduces, it sets the value of the non-terminal to
space obtained from malloc().  Later, when the nt non-terminal
is popped from the stack, the destructor will fire and call
free() on this malloced space, thus avoiding a memory leak.
(Note that the symbol ``$$'' in the destructor code is replaced
by the value of the non-terminal.)</p>

<p>It is important to note that the value of a non-terminal is passed
to the destructor whenever the non-terminal is removed from the
stack, unless the non-terminal is used in a C-code action.  If
the non-terminal is used by C-code, then it is assumed that the
C-code will take care of destroying it if it should really
be destroyed.  More commonly, the value is used to build some
larger structure and we don't want to destroy it, which is why
the destructor is not called in this circumstance.</p>

<p>By appropriate use of destructors, it is possible to
build a parser using Lemon that can be used within a long-running
program, such as a GUI, that will not leak memory or other resources.
To do the same using yacc or bison is much more difficult.</p>

<h4>The <tt>%extra_argument</tt> directive</h4>

The %extra_argument directive instructs Lemon to add a 4th parameter
to the parameter list of the Parse() function it generates.  Lemon
doesn't do anything itself with this extra argument, but it does
make the argument available to C-code action routines, destructors,
and so forth.  For example, if the grammar file contains:</p>

<p><pre>
    %extra_argument { MyStruct *pAbc }
</pre></p>

<p>Then the Parse() function generated will have an 4th parameter
of type ``MyStruct*'' and all action routines will have access to
a variable named ``pAbc'' that is the value of the 4th parameter
in the most recent call to Parse().</p>

<h4>The <tt>%include</tt> directive</h4>

<p>The %include directive specifies C code that is included at the
top of the generated parser.  You can include any text you want --
the Lemon parser generator copies to blindly.  If you have multiple
%include directives in your grammar file, their values are concatenated
before being put at the beginning of the generated parser.</p>

<p>The %include directive is very handy for getting some extra #include
preprocessor statements at the beginning of the generated parser.
For example:</p>

<p><pre>
   %include {#include &lt;unistd.h&gt;}
</pre></p>

<p>This might be needed, for example, if some of the C actions in the
grammar call functions that are prototyed in unistd.h.</p>

<h4>The <tt>%left</tt> directive</h4>

The %left directive is used (along with the %right and
%nonassoc directives) to declare precedences of terminal
symbols.  Every terminal symbol whose name appears after
a %left directive but before the next period (``.'') is
given the same left-associative precedence value.  Subsequent
%left directives have higher precedence.  For example:</p>

<p><pre>
   %left AND.
   %left OR.
   %nonassoc EQ NE GT GE LT LE.
   %left PLUS MINUS.
   %left TIMES DIVIDE MOD.
   %right EXP NOT.
</pre></p>

<p>Note the period that terminates each %left, %right or %nonassoc
directive.</p>

<p>LALR(1) grammars can get into a situation where they require
a large amount of stack space if you make heavy use or right-associative
operators.  For this reason, it is recommended that you use %left
rather than %right whenever possible.</p>

<h4>The <tt>%name</tt> directive</h4>

<p>By default, the functions generated by Lemon all begin with the
five-character string ``Parse''.  You can change this string to something
different using the %name directive.  For instance:</p>

<p><pre>
   %name Abcde
</pre></p>

<p>Putting this directive in the grammar file will cause Lemon to generate
functions named
<ul>
<li> AbcdeAlloc(),
<li> AbcdeFree(),
<li> AbcdeTrace(), and
<li> Abcde().
</ul>
The %name directive allows you to generator two or more different
parsers and link them all into the same executable.
</p>

<h4>The <tt>%nonassoc</tt> directive</h4>

<p>This directive is used to assign non-associative precedence to
one or more terminal symbols.  See the section on precedence rules
or on the %left directive for additional information.</p>

<h4>The <tt>%parse_accept</tt> directive</h4>

<p>The %parse_accept directive specifies a block of C code that is
executed whenever the parser accepts its input string.  To ``accept''
an input string means that the parser was able to process all tokens
without error.</p>

<p>For example:</p>

<p><pre>
   %parse_accept {
      printf("parsing complete!\n");
   }
</pre></p>


<h4>The <tt>%parse_failure</tt> directive</h4>

<p>The %parse_failure directive specifies a block of C code that
is executed whenever the parser fails complete.  This code is not
executed until the parser has tried and failed to resolve an input
error using is usual error recovery strategy.  The routine is
only invoked when parsing is unable to continue.</p>

<p><pre>
   %parse_failure {
     fprintf(stderr,"Giving up.  Parser is hopelessly lost...\n");
   }
</pre></p>

<h4>The <tt>%right</tt> directive</h4>

<p>This directive is used to assign right-associative precedence to
one or more terminal symbols.  See the section on precedence rules
or on the %left directive for additional information.</p>

<h4>The <tt>%stack_overflow</tt> directive</h4>

<p>The %stack_overflow directive specifies a block of C code that
is executed if the parser's internal stack ever overflows.  Typically
this just prints an error message.  After a stack overflow, the parser
will be unable to continue and must be reset.</p>

<p><pre>
   %stack_overflow {
     fprintf(stderr,"Giving up.  Parser stack overflow\n");
   }
</pre></p>

<p>You can help prevent parser stack overflows by avoiding the use
of right recursion and right-precedence operators in your grammar.
Use left recursion and and left-precedence operators instead, to
encourage rules to reduce sooner and keep the stack size down.
For example, do rules like this:
<pre>
   list ::= list element.      // left-recursion.  Good!
   list ::= .
</pre>
Not like this:
<pre>
   list ::= element list.      // right-recursion.  Bad!
   list ::= .
</pre>

<h4>The <tt>%stack_size</tt> directive</h4>

<p>If stack overflow is a problem and you can't resolve the trouble
by using left-recursion, then you might want to increase the size
of the parser's stack using this directive.  Put an positive integer
after the %stack_size directive and Lemon will generate a parse
with a stack of the requested size.  The default value is 100.</p>

<p><pre>
   %stack_size 2000
</pre></p>

<h4>The <tt>%start_symbol</tt> directive</h4>

<p>By default, the start-symbol for the grammar that Lemon generates
is the first non-terminal that appears in the grammar file.  But you
can choose a different start-symbol using the %start_symbol directive.</p>

<p><pre>
   %start_symbol  prog
</pre></p>

<h4>The <tt>%token_destructor</tt> directive</h4>

<p>The %destructor directive assigns a destructor to a non-terminal
symbol.  (See the description of the %destructor directive above.)
This directive does the same thing for all terminal symbols.</p>

<p>Unlike non-terminal symbols which may each have a different data type
for their values, terminals all use the same data type (defined by
the %token_type directive) and so they use a common destructor.  Other
than that, the token destructor works just like the non-terminal
destructors.</p>

<h4>The <tt>%token_prefix</tt> directive</h4>

<p>Lemon generates #defines that assign small integer constants
to each terminal symbol in the grammar.  If desired, Lemon will
add a prefix specified by this directive
to each of the #defines it generates.
So if the default output of Lemon looked like this:
<pre>
    #define AND              1
    #define MINUS            2
    #define OR               3
    #define PLUS             4
</pre>
You can insert a statement into the grammar like this:
<pre>
    %token_prefix    TOKEN_
</pre>
to cause Lemon to produce these symbols instead:
<pre>
    #define TOKEN_AND        1
    #define TOKEN_MINUS      2
    #define TOKEN_OR         3
    #define TOKEN_PLUS       4
</pre>

<h4>The <tt>%token_type</tt> and <tt>%type</tt> directives</h4>

<p>These directives are used to specify the data types for values
on the parser's stack associated with terminal and non-terminal
symbols.  The values of all terminal symbols must be of the same
type.  This turns out to be the same data type as the 3rd parameter
to the Parse() function generated by Lemon.  Typically, you will
make the value of a terminal symbol by a pointer to some kind of
token structure.  Like this:</p>

<p><pre>
   %token_type    {Token*}
</pre></p>

<p>If the data type of terminals is not specified, the default value
is ``int''.</p>

<p>Non-terminal symbols can each have their own data types.  Typically
the data type  of a non-terminal is a pointer to the root of a parse-tree
structure that contains all information about that non-terminal.
For example:</p>

<p><pre>
   %type   expr  {Expr*}
</pre></p>

<p>Each entry on the parser's stack is actually a union containing
instances of all data types for every non-terminal and terminal symbol.
Lemon will automatically use the correct element of this union depending
on what the corresponding non-terminal or terminal symbol is.  But
the grammar designer should keep in mind that the size of the union
will be the size of its largest element.  So if you have a single
non-terminal whose data type requires 1K of storage, then your 100
entry parser stack will require 100K of heap space.  If you are willing
and able to pay that price, fine.  You just need to know.</p>

<h3>Error Processing</h3>

<p>After extensive experimentation over several years, it has been
discovered that the error recovery strategy used by yacc is about
as good as it gets.  And so that is what Lemon uses.</p>

<p>When a Lemon-generated parser encounters a syntax error, it
first invokes the code specified by the %syntax_error directive, if
any.  It then enters its error recovery strategy.  The error recovery
strategy is to begin popping the parsers stack until it enters a
state where it is permitted to shift a special non-terminal symbol
named ``error''.  It then shifts this non-terminal and continues
parsing.  But the %syntax_error routine will not be called again
until at least three new tokens have been successfully shifted.</p>

<p>If the parser pops its stack until the stack is empty, and it still
is unable to shift the error symbol, then the %parse_failed routine
is invoked and the parser resets itself to its start state, ready
to begin parsing a new file.  This is what will happen at the very
first syntax error, of course, if there are no instances of the 
``error'' non-terminal in your grammar.</p>

</body>
</html>

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** when syntax rules are reduced.
**
** $Id: build.c,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called after a single SQL statement has been
** parsed and we want to execute the code to implement 
** the statement.  Prior action routines should have already
** constructed VDBE code to do the work of the SQL statement.
** This routine just has to execute the VDBE code.
**
** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
void sqliteExec(Parse *pParse){
  if( pParse->pVdbe ){
    if( pParse->explain ){
      sqliteVdbeList(pParse->pVdbe, pParse->xCallback, pParse->pArg, 
                     &pParse->zErrMsg);
    }else{
      FILE *trace = (pParse->db->flags & SQLITE_VdbeTrace)!=0 ? stderr : 0;
      sqliteVdbeTrace(pParse->pVdbe, trace);
      sqliteVdbeExec(pParse->pVdbe, pParse->xCallback, pParse->pArg, 
                     &pParse->zErrMsg);
    }
    sqliteVdbeDelete(pParse->pVdbe);
    pParse->pVdbe = 0;
  }
}

/*
** Construct a new expression node and return a pointer to it.
*/
Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ) return 0;
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = "";
    pNew->token.n = 0;
  }
  return pNew;
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ) return 0;
  pNew->op = TK_FUNCTION;
  pNew->pList = pList;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = "";
    pNew->token.n = 0;
  }
  return pNew;
}

/*
** Recursively delete an expression tree.
*/
void sqliteExprDelete(Expr *p){
  if( p==0 ) return;
  if( p->pLeft ) sqliteExprDelete(p->pLeft);
  if( p->pRight ) sqliteExprDelete(p->pRight);
  sqliteFree(p);
}

/*
** Locate the in-memory structure that describes the
** format of a particular database table given the name
** of that table.  Return NULL if not found.
*/
Table *sqliteFindTable(sqlite *db, char *zName){
  Table *pTable;
  int h;

  h = sqliteHashNoCase(zName, 0) % N_HASH;
  for(pTable=db->apTblHash[h]; pTable; pTable=pTable->pHash){
    if( sqliteStrICmp(pTable->zName, zName)==0 ) return pTable;
  }
  return 0;
}

/*
** Locate the in-memory structure that describes the
** format of a particular index table given the name
** of that table.  Return NULL if not found.
*/
Index *sqliteFindIndex(sqlite *db, char *zName){
  Index *p;
  int h;

  h = sqliteHashNoCase(zName, 0) % N_HASH;
  for(p=db->apIdxHash[h]; p; p=p->pHash){
    if( sqliteStrICmp(p->zName, zName)==0 ) return p;
  }
  return 0;
}

/*
** Remove the given index from the index hash table, and free
** its memory structures.
**
** The index is removed from the database hash table, but it is
** not unlinked from the table that is being indexed.  Unlinking
** from the table must be done by the calling function.
*/
static void sqliteDeleteIndex(sqlite *db, Index *pIndex){
  int h;
  if( pIndex->zName ){
    h = sqliteHashNoCase(pIndex->zName, 0) % N_HASH;
    if( db->apIdxHash[h]==pIndex ){
      db->apIdxHash[h] = pIndex->pHash;
    }else{
      Index *p;
      for(p=db->apIdxHash[h]; p && p->pHash!=pIndex; p=p->pHash){}
      if( p && p->pHash==pIndex ){
        p->pHash = pIndex->pHash;
      }
    }
  }
  sqliteFree(pIndex);
}

/*
** Remove the memory data structures associated with the given
** table.  No changes are made to disk by this routine.
**
** This routine just deletes the data structure.  It does not unlink
** the table data structure from the hash table.  But does it destroy
** memory structures of the indices associated with the table.
*/
void sqliteDeleteTable(sqlite *db, Table *pTable){
  int i;
  Index *pIndex, *pNext;
  if( pTable==0 ) return;
  for(i=0; i<pTable->nCol; i++){
    if( pTable->azCol[i] ) sqliteFree(pTable->azCol[i]);
  }
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    sqliteDeleteIndex(db, pIndex);
  }
  sqliteFree(pTable->azCol);
  sqliteFree(pTable);
}

/*
** Construct the name of a user table from a token.
**
** Space to hold the name is obtained from sqliteMalloc() and must
** be freed by the calling function.
*/
static char *sqliteTableNameFromToken(Token *pName){
  char *zName = 0;
  sqliteSetNString(&zName, pName->z, pName->n, 0);
  return zName;
}

/*
** Begin constructing a new table representation in memory.  This is
** the first of several action routines that get called in response
** to a CREATE TABLE statement.
*/
void sqliteStartTable(Parse *pParse, Token *pStart, Token *pName){
  Table *pTable;
  char *zName;

  pParse->sFirstToken = *pStart;
  zName = sqliteTableNameFromToken(pName);
  pTable = sqliteFindTable(pParse->db, zName);
  if( pTable!=0 ){
    sqliteSetNString(&pParse->zErrMsg, "table \"", 0, pName->z, pName->n,
        "\" already exists", 0, 0);
    sqliteFree(zName);
    pParse->nErr++;
    return;
  }
  if( sqliteFindIndex(pParse->db, zName) ){
    sqliteSetString(&pParse->zErrMsg, "there is already an index named \"", 
       zName, "\"", 0);
    sqliteFree(zName);
    pParse->nErr++;
    return;
  }
  pTable = sqliteMalloc( sizeof(Table) );
  if( pTable==0 ){
    sqliteSetString(&pParse->zErrMsg, "out of memory", 0);
    pParse->nErr++;
    return;
  }
  pTable->zName = zName;
  pTable->pHash = 0;
  pTable->nCol = 0;
  pTable->azCol = 0;
  pTable->pIndex = 0;
  if( pParse->pNewTable ) sqliteDeleteTable(pParse->db, pParse->pNewTable);
  pParse->pNewTable = pTable;
}

/*
** Add a new column to the table currently being constructed.
*/
void sqliteAddColumn(Parse *pParse, Token *pName){
  Table *p;
  char **pz;
  if( (p = pParse->pNewTable)==0 ) return;
  if( (p->nCol & 0x7)==0 ){
    p->azCol = sqliteRealloc( p->azCol, p->nCol+8);
  }
  if( p->azCol==0 ){
    p->nCol = 0;
    return;
  }
  pz = &p->azCol[p->nCol++];
  *pz = 0;
  sqliteSetNString(pz, pName->z, pName->n, 0);
}

/*
** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure is added to the internal hash tables.  
**
** An entry for the table is made in the master table, unless 
** initFlag==1.  When initFlag==1, it means we are reading the
** master table because we just connected to the database, so 
** the entry for this table already exists in the master table.
** We do not want to create it again.
*/
void sqliteEndTable(Parse *pParse, Token *pEnd){
  Table *p;
  int h;

  if( pParse->nErr ) return;

  /* Add the table to the in-memory representation of the database
  */
  if( (p = pParse->pNewTable)!=0 && pParse->explain==0 ){
    h = sqliteHashNoCase(p->zName, 0) % N_HASH;
    p->pHash = pParse->db->apTblHash[h];
    pParse->db->apTblHash[h] = p;
    pParse->pNewTable = 0;
  }

  /* If not initializing, then create the table on disk.
  */
  if( !pParse->initFlag ){
    static VdbeOp addTable[] = {
      { OP_Open,        0, 0, MASTER_NAME },
      { OP_New,         0, 0, 0},
      { OP_String,      0, 0, "table"     },
      { OP_String,      0, 0, 0},            /* 2 */
      { OP_String,      0, 0, 0},            /* 3 */
      { OP_String,      0, 0, 0},            /* 4 */
      { OP_MakeRecord,  4, 0, 0},
      { OP_Put,         0, 0, 0},
      { OP_Close,       0, 0, 0},
    };
    int n, base;
    Vdbe *v = pParse->pVdbe;

    if( v==0 ){
      v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
    }
    if( v==0 ) return;
    n = (int)pEnd->z - (int)pParse->sFirstToken.z + 1;
    base = sqliteVdbeAddOpList(v, ArraySize(addTable), addTable);
    sqliteVdbeChangeP3(v, base+2, p->zName, 0);
    sqliteVdbeChangeP3(v, base+3, p->zName, 0);
    sqliteVdbeChangeP3(v, base+4, pParse->sFirstToken.z, n);
  }
}

/*
** Given a token, look up a table with that name.  If not found, leave
** an error for the parser to find and return NULL.
*/
static Table *sqliteTableFromToken(Parse *pParse, Token *pTok){
  char *zName = sqliteTableNameFromToken(pTok);
  Table *pTab = sqliteFindTable(pParse->db, zName);
  sqliteFree(zName);
  if( pTab==0 ){
    sqliteSetNString(&pParse->zErrMsg, "no such table: \"", 0, 
        pTok->z, pTok->n, "\"", 1, 0);
    pParse->nErr++;
  }
  return pTab;
}

/*
** This routine is called to do the work of a DROP TABLE statement.
*/
void sqliteDropTable(Parse *pParse, Token *pName){
  Table *pTable;
  int h;
  Vdbe *v;
  int base;

  pTable = sqliteTableFromToken(pParse, pName);
  if( pTable==0 ) return;
  if( pTable->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table \"", pTable->zName, 
       "\" may not be dropped", 0);
    pParse->nErr++;
    return;
  }

  /* Generate code to remove the table and its reference in sys_master */
  v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  }
  if( v ){
    static VdbeOp dropTable[] = {
      { OP_Open,       0, 0,        MASTER_NAME },
      { OP_ListOpen,   0, 0,        0},
      { OP_String,     0, 0,        0}, /* 2 */
      { OP_Next,       0, ADDR(10), 0}, /* 3 */
      { OP_Dup,        0, 0,        0},
      { OP_Field,      0, 2,        0},
      { OP_Ne,         0, ADDR(3),  0},
      { OP_Key,        0, 0,        0},
      { OP_ListWrite,  0, 0,        0},
      { OP_Goto,       0, ADDR(3),  0},
      { OP_ListRewind, 0, 0,        0}, /* 10 */
      { OP_ListRead,   0, ADDR(14), 0}, /* 11 */
      { OP_Delete,     0, 0,        0},
      { OP_Goto,       0, ADDR(11), 0},
      { OP_Destroy,    0, 0,        0}, /* 14 */
      { OP_Close,      0, 0,        0},
    };
    Index *pIdx;
    base = sqliteVdbeAddOpList(v, ArraySize(dropTable), dropTable);
    sqliteVdbeChangeP3(v, base+2, pTable->zName, 0);
    sqliteVdbeChangeP3(v, base+14, pTable->zName, 0);
    for(pIdx=pTable->pIndex; pIdx; pIdx=pIdx->pNext){
      sqliteVdbeAddOp(v, OP_Destroy, 0, 0, pIdx->zName, 0);
    }
  }

  /* Remove the table structure and free its memory.
  **
  ** Exception: if the SQL statement began with the EXPLAIN keyword,
  ** then no changes are made.
  */
  if( !pParse->explain ){
    h = sqliteHashNoCase(pTable->zName, 0) % N_HASH;
    if( pParse->db->apTblHash[h]==pTable ){
      pParse->db->apTblHash[h] = pTable->pHash;
    }else{
      Table *p;
      for(p=pParse->db->apTblHash[h]; p && p->pHash!=pTable; p=p->pHash){}
      if( p && p->pHash==pTable ){
        p->pHash = pTable->pHash;
      }
    }
    sqliteDeleteTable(pParse->db, pTable);
  }
}

/*
** Create a new index for an SQL table.  pIndex is the name of the index 
** and pTable is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key.  In that case, use pParse->pNewTable as the 
** table to be indexed.
**
** pList is a list of fields to be indexed.  pList will be NULL if the
** most recently added field of the table is labeled as the primary key.
*/
void sqliteCreateIndex(
  Parse *pParse,   /* All information about this parse */
  Token *pName,    /* Name of the index.  May be NULL */
  Token *pTable,   /* Name of the table to index.  Use pParse->pNewTable if 0 */
  IdList *pList,   /* A list of fields to be indexed */
  Token *pStart,   /* The CREATE token that begins a CREATE TABLE statement */
  Token *pEnd      /* The ")" that closes the CREATE INDEX statement */
){
  Table *pTab;     /* Table to be indexed */
  Index *pIndex;   /* The index to be created */
  char *zName = 0;
  int i, j, h;
  Token nullId;    /* Fake token for an empty ID list */

  /*
  ** Find the table that is to be indexed.  Return early if not found.
  */
  if( pTable!=0 ){
    pTab =  sqliteTableFromToken(pParse, pTable);
  }else{
    pTab =  pParse->pNewTable;
  }
  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( pTab->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table \"", pTab->zName, 
      "\" may not have new indices added", 0);
    pParse->nErr++;
    goto exit_create_index;
  }

  /*
  ** Find the name of the index.  Make sure there is not already another
  ** index or table with the same name.
  */
  if( pName ){
    zName = sqliteTableNameFromToken(pName);
  }else{
    zName = 0;
    sqliteSetString(&zName, pTab->zName, "__primary_key", 0);
  }
  if( sqliteFindIndex(pParse->db, zName) ){
    sqliteSetString(&pParse->zErrMsg, "index \"", zName, 
       "\" already exists", 0);
    pParse->nErr++;
    goto exit_create_index;
  }
  if( sqliteFindTable(pParse->db, zName) ){
    sqliteSetString(&pParse->zErrMsg, "there is already a table named \"",
       zName, "\"", 0);
    pParse->nErr++;
    goto exit_create_index;
  }

  /* If pList==0, it means this routine was called to make a primary
  ** key out of the last field added to the table under construction.
  ** So create a fake list to simulate this.
  */
  if( pList==0 ){
    nullId.z = pTab->azCol[pTab->nCol-1];
    nullId.n = strlen(nullId.z);
    pList = sqliteIdListAppend(0, &nullId);
    if( pList==0 ) goto exit_create_index;
  }

  /* 
  ** Allocate the index structure. 
  */
  pIndex = sqliteMalloc( sizeof(Index) + strlen(zName) + 
                        sizeof(int)*pList->nId );
  if( pIndex==0 ){
    sqliteSetString(&pParse->zErrMsg, "out of memory", 0);
    pParse->nErr++;
    goto exit_create_index;
  }
  pIndex->aiField = (int*)&pIndex[1];
  pIndex->zName = (char*)&pIndex->aiField[pList->nId];
  strcpy(pIndex->zName, zName);
  pIndex->pTable = pTab;
  pIndex->nField = pList->nId;

  /* Scan the names of the fields of the table to be indexed and
  ** load the field indices into the Index structure.  Report an error
  ** if any field is not found.
  */
  for(i=0; i<pList->nId; i++){
    for(j=0; j<pTab->nCol; j++){
      if( sqliteStrICmp(pList->a[i].zName, pTab->azCol[j])==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqliteSetString(&pParse->zErrMsg, "table being indexed has no field "
        "named \"", pList->a[i].zName, "\"", 0);
      pParse->nErr++;
      sqliteFree(pIndex);
      goto exit_create_index;
    }
    pIndex->aiField[i] = j;
  }

  /* Link the new Index structure to its table and to the other
  ** in-memory database structures.
  */
  if( pParse->explain==0 ){
    h = sqliteHashNoCase(pIndex->zName, 0) % N_HASH;
    pIndex->pHash = pParse->db->apIdxHash[h];
    pParse->db->apIdxHash[h] = pIndex;
    pIndex->pNext = pTab->pIndex;
    pTab->pIndex = pIndex;
  }

  /* If the initFlag is 0 then create the index on disk.  This
  ** involves writing the index into the master table and filling in the
  ** index with the current table contents.
  **
  ** The initFlag is 0 when the user first enters a CREATE INDEX 
  ** command.  The initFlag is 1 when a database is opened and 
  ** CREATE INDEX statements are read out of the master table.  In
  ** the latter case the index already exists on disk, which is why
  ** we don't want to recreate it.
  */
  if( pParse->initFlag==0 ){
    static VdbeOp addTable[] = {
      { OP_Open,        0, 0, MASTER_NAME},
      { OP_New,         0, 0, 0},
      { OP_String,      0, 0, "index"},
      { OP_String,      0, 0, 0},  /* 2 */
      { OP_String,      0, 0, 0},  /* 3 */
      { OP_String,      0, 0, 0},  /* 4 */
      { OP_MakeRecord,  4, 0, 0},
      { OP_Put,         0, 0, 0},
      { OP_Close,       0, 0, 0},
    };
    int n;
    Vdbe *v = pParse->pVdbe;
    int lbl1, lbl2;
    int i;

    if( v==0 ){
      v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
    }
    if( v==0 ) goto exit_create_index;
    if( pStart && pEnd ){
      int base;
      n = (int)pEnd->z - (int)pStart->z + 1;
      base = sqliteVdbeAddOpList(v, ArraySize(addTable), addTable);
      sqliteVdbeChangeP3(v, base+2, pIndex->zName, 0);
      sqliteVdbeChangeP3(v, base+3, pTab->zName, 0);
      sqliteVdbeChangeP3(v, base+4, pStart->z, n);
    }
    sqliteVdbeAddOp(v, OP_Open, 0, 0, pTab->zName, 0);
    sqliteVdbeAddOp(v, OP_Open, 1, 0, pIndex->zName, 0);
    lbl1 = sqliteVdbeMakeLabel(v);
    lbl2 = sqliteVdbeMakeLabel(v);
    sqliteVdbeAddOp(v, OP_Next, 0, lbl2, 0, lbl1);
    sqliteVdbeAddOp(v, OP_Key, 0, 0, 0, 0);
    for(i=0; i<pIndex->nField; i++){
      sqliteVdbeAddOp(v, OP_Field, 0, pIndex->aiField[i], 0, 0);
    }
    sqliteVdbeAddOp(v, OP_MakeKey, pIndex->nField, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_PutIdx, 1, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Goto, 0, lbl1, 0, 0);
    sqliteVdbeAddOp(v, OP_Noop, 0, 0, 0, lbl2);
    sqliteVdbeAddOp(v, OP_Close, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Close, 1, 0, 0, 0);
  }

  /* Reclaim memory on an EXPLAIN call.
  */
  if( pParse->explain ){
    sqliteFree(pIndex);
  }

  /* Clean up before exiting */
exit_create_index:
  sqliteIdListDelete(pList);
  sqliteFree(zName);
  return;
}

/*
** This routine will drop an existing named index.
*/
void sqliteDropIndex(Parse *pParse, Token *pName){
  Index *pIndex;
  char *zName;
  Vdbe *v;

  zName = sqliteTableNameFromToken(pName);
  pIndex = sqliteFindIndex(pParse->db, zName);
  sqliteFree(zName);
  if( pIndex==0 ){
    sqliteSetNString(&pParse->zErrMsg, "no such index: \"", 0, 
        pName->z, pName->n, "\"", 1, 0);
    pParse->nErr++;
    return;
  }

  /* Generate code to remove the index and from the master table */
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    static VdbeOp dropIndex[] = {
      { OP_Open,       0, 0,       MASTER_NAME},
      { OP_ListOpen,   0, 0,       0},
      { OP_String,     0, 0,       0}, /* 2 */
      { OP_Next,       0, ADDR(9), 0}, /* 3 */
      { OP_Dup,        0, 0,       0},
      { OP_Field,      0, 1,       0},
      { OP_Ne,         0, ADDR(3), 0},
      { OP_Key,        0, 0,       0},
      { OP_Delete,     0, 0,       0},
      { OP_Destroy,    0, 0,       0}, /* 9 */
      { OP_Close,      0, 0,       0},
    };
    int base;

    base = sqliteVdbeAddOpList(v, ArraySize(dropIndex), dropIndex);
    sqliteVdbeChangeP3(v, base+2, pIndex->zName, 0);
    sqliteVdbeChangeP3(v, base+9, pIndex->zName, 0);
  }

  /* Remove the index structure and free its memory.  Except if the
  ** EXPLAIN keyword is present, no changes are made.
  */
  if( !pParse->explain ){
    if( pIndex->pTable->pIndex==pIndex ){
      pIndex->pTable->pIndex = pIndex->pNext;
    }else{
      Index *p;
      for(p=pIndex->pTable->pIndex; p && p->pNext!=pIndex; p=p->pNext){}
      if( p && p->pNext==pIndex ){
        p->pNext = pIndex->pNext;
      }
    }
    sqliteDeleteIndex(pParse->db, pIndex);
  }
}

/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqliteExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  int i;
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
  }
  if( pList==0 ) return 0;
  if( (pList->nExpr & 7)==0 ){
    int n = pList->nExpr + 8;
    pList->a = sqliteRealloc(pList->a, n*sizeof(pList->a[0]));
    if( pList->a==0 ){
      pList->nExpr = 0;
      return pList;
    }
  }
  i = pList->nExpr++;
  pList->a[i].pExpr = pExpr;
  pList->a[i].zName = 0;
  if( pName ){
    sqliteSetNString(&pList->a[i].zName, pName->z, pName->n, 0);
  }
  return pList;
}

/*
** Delete an entire expression list.
*/
void sqliteExprListDelete(ExprList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nExpr; i++){
    sqliteExprDelete(pList->a[i].pExpr);
    sqliteFree(pList->a[i].zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
*/
IdList *sqliteIdListAppend(IdList *pList, Token *pToken){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(IdList) );
    if( pList==0 ) return 0;
  }
  if( (pList->nId & 7)==0 ){
    pList->a = sqliteRealloc(pList->a, (pList->nId+8)*sizeof(pList->a[0]) );
    if( pList->a==0 ){
      pList->nId = 0;
      return pList;
    }
  }
  memset(&pList->a[pList->nId], 0, sizeof(pList->a[0]));
  if( pToken ){
    sqliteSetNString(&pList->a[pList->nId].zName, pToken->z, pToken->n, 0);
  }
  pList->nId++;
  return pList;
}

/*
** Add an alias to the last identifier on the given identifier list.
*/
void sqliteIdListAddAlias(IdList *pList, Token *pToken){
  if( pList && pList->nId>0 ){
    int i = pList->nId - 1;
    sqliteSetNString(&pList->a[i].zAlias, pToken->z, pToken->n, 0);
  }
}

/*
** Delete an entire IdList
*/
void sqliteIdListDelete(IdList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nId; i++){
    sqliteFree(pList->a[i].zName);
    sqliteFree(pList->a[i].zAlias);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** This routine is call to handle SQL of the following form:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)
**
** The parameters are the table name and the expression list.
*/
void sqliteInsert(
  Parse *pParse,        /* Parser context */
  Token *pTableName,    /* Name of table into which we are inserting */
  ExprList *pList,      /* List of values to be inserted */
  IdList *pField        /* Field name corresponding to pList.  Might be NULL */
){
  Table *pTab;
  char *zTab;
  int i, j;
  Vdbe *v;

  zTab = sqliteTableNameFromToken(pTableName);
  pTab = sqliteFindTable(pParse->db, zTab);
  sqliteFree(zTab);
  if( pTab==0 ){
    sqliteSetNString(&pParse->zErrMsg, "no such table: \"", 0, 
        pTableName->z, pTableName->n, "\"", 1, 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  if( pTab->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table \"", pTab->zName,
        "\" may not be modified", 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  if( pField==0 && pList->nExpr!=pTab->nCol ){
    char zNum1[30];
    char zNum2[30];
    sprintf(zNum1,"%d", pList->nExpr);
    sprintf(zNum2,"%d", pTab->nCol);
    sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
       " has ", zNum2, " columns but only ",
       zNum1, " values were supplied", 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  if( pField!=0 && pList->nExpr!=pField->nId ){
    char zNum1[30];
    char zNum2[30];
    sprintf(zNum1,"%d", pList->nExpr);
    sprintf(zNum2,"%d", pTab->nCol);
    sqliteSetString(&pParse->zErrMsg, zNum1, " values for ",
       zNum2, " columns", 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  if( pField ){
    for(i=0; i<pField->nId; i++){
      pField->a[i].idx = -1;
    }
    for(i=0; i<pField->nId; i++){
      for(j=0; j<pTab->nCol; j++){
        if( sqliteStrICmp(pField->a[i].zName, pTab->azCol[j])==0 ){
          pField->a[i].idx = j;
          break;
        }
      }
      if( j>=pTab->nCol ){
        sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
           " has no column named ", pField->a[i].zName, 0);
        pParse->nErr++;
        goto insert_cleanup;
      }
    }
  }
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    Index *pIdx;
    sqliteVdbeAddOp(v, OP_Open, 0, 0, pTab->zName, 0);
    sqliteVdbeAddOp(v, OP_New, 0, 0, 0, 0);
    if( pTab->pIndex ){
      sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( pField==0 ){
        j = i;
      }else{
        for(j=0; j<pField->nId; j++){
          if( pField->a[j].idx==i ) break;
        }
      }
      if( pField && j>=pField->nId ){
        sqliteVdbeAddOp(v, OP_String, 0, 0, "", 0);
      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Put, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Close, 0, 0, 0, 0);
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( pIdx->pNext ){
        sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
      }
      sqliteVdbeAddOp(v, OP_Open, 0, 0, pIdx->zName, 0);
      for(i=0; i<pIdx->nField; i++){
        int idx = pIdx->aiField[i];
        if( pField==0 ){
          j = idx;
        }else{
          for(j=0; j<pField->nId; j++){
            if( pField->a[j].idx==idx ) break;
          }
        }
        if( pField && j>=pField->nId ){
          sqliteVdbeAddOp(v, OP_String, 0, 0, "", 0);
        }else{
          sqliteExprCode(pParse, pList->a[j].pExpr);
        }
      }
      sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nField, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_PutIdx, 0, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_Close, 0, 0, 0, 0);
    }
  }

insert_cleanup:
  sqliteExprListDelete(pList);
  sqliteIdListDelete(pField);
}

/*
** This routine walks an expression tree and resolves references to
** table fields.  Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a field offset.  The opcode
** for such nodes is changed to TK_FIELD.  The iTable value is changed
** to the index of the referenced table in pTabList, and the iField value
** is changed to the index of the field of the referenced table.
**
** Unknown fields or tables provoke an error.  The function returns
** the number of errors seen and leaves an error message on pParse->zErrMsg.
*/
int sqliteExprResolveIds(Parse *pParse, IdList *pTabList, Expr *pExpr){
  if( pExpr==0 ) return 0;
  switch( pExpr->op ){
    /* A lone identifier */
    case TK_ID: {
      int cnt = 0;   /* Number of matches */
      int i;         /* Loop counter */
      char *z = pExpr->token.z;
      int n = pExpr->token.n;
      for(i=0; i<pTabList->nId; i++){
        int j;
        Table *pTab = pTabList->a[i].pTab;
        if( pTab==0 ) continue;
        for(j=0; j<pTab->nCol; j++){
          if( sqliteStrNICmp(pTab->azCol[j], z, n)==0 ){
            cnt++;
            pExpr->iTable = i;
            pExpr->iField = j;
          }
        }
      }
      if( cnt==0 ){
        sqliteSetNString(&pParse->zErrMsg, "unknown field name: \"", -1,  
          pExpr->token.z, pExpr->token.n, "\"", -1, 0);
        pParse->nErr++;
        return 1;
      }else if( cnt>1 ){
        sqliteSetNString(&pParse->zErrMsg, "ambiguous field name: \"", -1,  
          pExpr->token.z, pExpr->token.n, "\"", -1, 0);
        pParse->nErr++;
        return 1;
      }
      pExpr->op = TK_FIELD;
      break; 
    }
  
    /* A table name and field name:  ID.ID */
    case TK_DOT: {
      int cnt = 0;   /* Number of matches */
      int i;         /* Loop counter */
      Expr *pLeft, *pRight;    /* Left and right subbranches of the expr */
      int n;                   /* Length of an identifier */
      char *z;                 /* Text of an identifier */

      pLeft = pExpr->pLeft;
      pRight = pExpr->pRight;
      assert( pLeft && pLeft->op==TK_ID );
      assert( pRight && pRight->op==TK_ID );
      n = pRight->token.n;
      z = pRight->token.z;      
      for(i=0; i<pTabList->nId; i++){
        int j;
        char *zTab;
        Table *pTab = pTabList->a[i].pTab;
        if( pTab==0 ) continue;
        if( pTabList->a[i].zAlias ){
          zTab = pTabList->a[i].zAlias;
        }else{
          zTab = pTab->zName;
        }
        if( sqliteStrNICmp(zTab, pLeft->token.z, pLeft->token.n)!=0 ) continue;
        for(j=0; j<pTab->nCol; j++){
          if( sqliteStrNICmp(pTab->azCol[j], z, n)==0 ){
            cnt++;
            pExpr->iTable = i;
            pExpr->iField = j;
          }
        }
      }
      if( cnt==0 ){
        sqliteSetNString(&pParse->zErrMsg, "unknown field name: \"", -1,  
          pLeft->token.z, pLeft->token.n, ".", 1, z, n, "\"", 1, 0);
        pParse->nErr++;
        return 1;
      }else if( cnt>1 ){
        sqliteSetNString(&pParse->zErrMsg, "ambiguous field name: \"", -1,  
          pExpr->token.z, pExpr->token.n, ".", 1, z, n, "\"", 1, 0);
        pParse->nErr++;
        return 1;
      }
      sqliteExprDelete(pLeft);
      pExpr->pLeft = 0;
      sqliteExprDelete(pRight);
      pExpr->pRight = 0;
      pExpr->op = TK_FIELD;
      break;
    }

    /* For all else, just recursively walk the tree */
    default: {
      if( pExpr->pLeft 
            && sqliteExprResolveIds(pParse, pTabList, pExpr->pLeft) ){
        return 1;
      }
      if( pExpr->pRight 
            && sqliteExprResolveIds(pParse, pTabList, pExpr->pRight) ){
        return 1;
      }
      if( pExpr->pList ){
        int i;
        ExprList *pList = pExpr->pList;
        for(i=0; i<pList->nExpr; i++){
          if( sqliteExprResolveIds(pParse, pTabList, pList->a[i].pExpr) ){
            return 1;
          }
        }
      }
    }
  }
  return 0;
}

/*
** Process a SELECT statement.
*/
void sqliteSelect(
  Parse *pParse,         /* The parser context */
  ExprList *pEList,      /* List of fields to extract.  NULL means "*" */
  IdList *pTabList,      /* List of tables to select from */
  Expr *pWhere,          /* The WHERE clause.  May be NULL */
  ExprList *pOrderBy     /* The ORDER BY clause.  May be NULL */
){
  int i, j;
  WhereInfo *pWInfo;
  Vdbe *v;

  if( pParse->nErr>0 ) goto select_cleanup;

  /* Look up every table in the table list.
  */
  for(i=0; i<pTabList->nId; i++){
    pTabList->a[i].pTab = sqliteFindTable(pParse->db, pTabList->a[i].zName);
    if( pTabList->a[i].pTab==0 ){
      sqliteSetString(&pParse->zErrMsg, "unknown table \"", 
         pTabList->a[i].zName, "\"", 0);
      pParse->nErr++;
      goto select_cleanup;
    }
  }

  /* If the list of fields to retrieve is "*" then replace it with
  ** a list of all fields from all tables.
  */
  if( pEList==0 ){
    for(i=0; i<pTabList->nId; i++){
      Table *pTab = pTabList->a[i].pTab;
      for(j=0; j<pTab->nCol; j++){
        Expr *pExpr = sqliteExpr(TK_FIELD, 0, 0, 0);
        pExpr->iTable = i;
        pExpr->iField = j;
        pEList = sqliteExprListAppend(pEList, pExpr, 0);
      }
    }
  }

  /* Resolve the field names in all the expressions.
  */
  for(i=0; i<pEList->nExpr; i++){
    if( sqliteExprResolveIds(pParse, pTabList, pEList->a[i].pExpr) ){
      goto select_cleanup;
    }
  }
  if( pWhere && sqliteExprResolveIds(pParse, pTabList, pWhere) ){
    goto select_cleanup;
  }
  if( pOrderBy ){
    for(i=0; i<pOrderBy->nExpr; i++){
      if( sqliteExprResolveIds(pParse, pTabList, pOrderBy->a[i].pExpr) ){
        goto select_cleanup;
      }
    }
  }

  /* Begin generating code.
  */
  v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  }
  if( v==0 ) goto select_cleanup;
  if( pOrderBy ){
    sqliteVdbeAddOp(v, OP_SortOpen, 0, 0, 0, 0);
  }


  /* Identify column names
  */
  sqliteVdbeAddOp(v, OP_ColumnCount, pEList->nExpr, 0, 0, 0);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p;
    if( pEList->a[i].zName ){
      char *zName = pEList->a[i].zName;
      int addr = sqliteVdbeAddOp(v, OP_ColumnName, i, 0, zName, 0);
      if( zName[0]=='\'' || zName[0]=='"' ){
        sqliteVdbeDequoteP3(v, addr);
      }
      continue;
    }
    p = pEList->a[i].pExpr;
    if( p->op!=TK_FIELD ){
      char zName[30];
      sprintf(zName, "field%d", i+1);
      sqliteVdbeAddOp(v, OP_ColumnName, i, 0, zName, 0);
    }else{
      if( pTabList->nId>1 ){
        char *zName = 0;
        Table *pTab = pTabList->a[p->iTable].pTab;
        sqliteSetString(&zName, pTab->zName, ".", 
               pTab->azCol[p->iField], 0);
        sqliteVdbeAddOp(v, OP_ColumnName, i, 0, zName, 0);
        sqliteFree(zName);
      }else{
        Table *pTab = pTabList->a[0].pTab;
        sqliteVdbeAddOp(v, OP_ColumnName, i, 0, pTab->azCol[p->iField], 0);
      }
    }
  }

  /* Begin the database scan
  */  
  pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 0);
  if( pWInfo==0 ) goto select_cleanup;

  /* Pull the requested fields.
  */
  for(i=0; i<pEList->nExpr; i++){
    sqliteExprCode(pParse, pEList->a[i].pExpr);
  }
  
  /* If there is no ORDER BY clause, then we can invoke the callback
  ** right away.  If there is an ORDER BY, then we need to put the
  ** data into an appropriate sorter record.
  */
  if( pOrderBy==0 ){
    sqliteVdbeAddOp(v, OP_Callback, pEList->nExpr, 0, 0, 0);
  }else{
    char *zSortOrder;
    sqliteVdbeAddOp(v, OP_SortMakeRec, pEList->nExpr, 0, 0, 0);
    zSortOrder = sqliteMalloc( pOrderBy->nExpr + 1 );
    if( zSortOrder==0 ) goto select_cleanup;
    for(i=0; i<pOrderBy->nExpr; i++){
      zSortOrder[i] = pOrderBy->a[i].idx ? '-' : '+';
      sqliteExprCode(pParse, pOrderBy->a[i].pExpr);
    }
    zSortOrder[pOrderBy->nExpr] = 0;
    sqliteVdbeAddOp(v, OP_SortMakeKey, pOrderBy->nExpr, 0, zSortOrder, 0);
    sqliteVdbeAddOp(v, OP_SortPut, 0, 0, 0, 0);
  }

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* If there is an ORDER BY clause, then we need to sort the results
  ** and send them to the callback one by one.
  */
  if( pOrderBy ){
    int end = sqliteVdbeMakeLabel(v);
    int addr;
    sqliteVdbeAddOp(v, OP_Sort, 0, 0, 0, 0);
    addr = sqliteVdbeAddOp(v, OP_SortNext, 0, end, 0, 0);
    sqliteVdbeAddOp(v, OP_SortCallback, pEList->nExpr, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Goto, 0, addr, 0, 0);
    sqliteVdbeAddOp(v, OP_Noop, 0, 0, 0, end);
  }

  /* Always execute the following code before exiting, in order to
  ** release resources.
  */
select_cleanup:
  sqliteExprListDelete(pEList);
  sqliteIdListDelete(pTabList);
  sqliteExprDelete(pWhere);
  sqliteExprListDelete(pOrderBy);
  return;
}

/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(
  Parse *pParse,         /* The parser context */
  Token *pTableName,     /* The table from which we should delete things */
  Expr *pWhere           /* The WHERE clause.  May be null */
){
  Vdbe *v;               /* The virtual database engine */
  Table *pTab;           /* The table from which records will be deleted */
  IdList *pTabList;      /* An ID list holding pTab and nothing else */
  int end, addr;         /* A couple addresses of generated code */
  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */

  /* Locate the table which we want to update.  This table has to be
  ** put in an IdList structure because some of the subroutines will
  ** will be calling are designed to work with multiple tables and expect
  ** an IdList* parameter instead of just a Table* parameger.
  */
  pTabList = sqliteIdListAppend(0, pTableName);
  for(i=0; i<pTabList->nId; i++){
    pTabList->a[i].pTab = sqliteFindTable(pParse->db, pTabList->a[i].zName);
    if( pTabList->a[i].pTab==0 ){
      sqliteSetString(&pParse->zErrMsg, "unknown table \"", 
         pTabList->a[i].zName, "\"", 0);
      pParse->nErr++;
      goto delete_from_cleanup;
    }
    if( pTabList->a[i].pTab->readOnly ){
      sqliteSetString(&pParse->zErrMsg, "table \"", pTabList->a[i].zName,
        "\" may not be modified", 0);
      pParse->nErr++;
      goto delete_from_cleanup;
    }
  }
  pTab = pTabList->a[0].pTab;

  /* Resolve the field names in all the expressions.
  */
  if( pWhere && sqliteExprResolveIds(pParse, pTabList, pWhere) ){
    goto delete_from_cleanup;
  }

  /* Begin generating code.
  */
  v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  }
  if( v==0 ) goto delete_from_cleanup;

  /* Begin the database scan
  */
  sqliteVdbeAddOp(v, OP_ListOpen, 0, 0, 0, 0);
  pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 1);
  if( pWInfo==0 ) goto delete_from_cleanup;

  /* Remember the index of every item to be deleted.
  */
  sqliteVdbeAddOp(v, OP_ListWrite, 0, 0, 0, 0);

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* Delete every item identified in the list.
  */
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0, 0, 0);
  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    sqliteVdbeAddOp(v, OP_Open, i, 0, pIdx->zName, 0);
  }
  end = sqliteVdbeMakeLabel(v);
  addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end, 0, 0);
  if( pTab->pIndex ){
    sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Fetch, 0, 0, 0, 0);
    for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
      int j;
      sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
      for(j=0; j<pIdx->nField; j++){
        sqliteVdbeAddOp(v, OP_Field, 0, pIdx->aiField[j], 0, 0);
      }
      sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nField, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_DeleteIdx, i, 0, 0, 0);
    }
  }
  sqliteVdbeAddOp(v, OP_Delete, 0, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Goto, 0, addr, 0, 0);
  sqliteVdbeAddOp(v, OP_ListClose, 0, 0, 0, end);

delete_from_cleanup:
  sqliteIdListDelete(pTabList);
  sqliteExprDelete(pWhere);
  return;
}

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(
  Parse *pParse,         /* The parser context */
  Token *pTableName,     /* The table in which we should change things */
  ExprList *pChanges,    /* Things to be changed */
  Expr *pWhere           /* The WHERE clause.  May be null */
){
  int i, j;              /* Loop counters */
  Table *pTab;           /* The table to be updated */
  IdList *pTabList = 0;  /* List containing only pTab */
  int end, addr;         /* A couple of addresses in the generated code */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Vdbe *v;               /* The virtual database engine */
  Index *pIdx;           /* For looping over indices */
  int nIdx;              /* Number of indices that need updating */
  Index **apIdx = 0;     /* An array of indices that need updating too */
  int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
                         ** an expression for the i-th field of the table.
                         ** aXRef[i]==-1 if the i-th field is not changed. */

  /* Locate the table which we want to update.  This table has to be
  ** put in an IdList structure because some of the subroutines will
  ** will be calling are designed to work with multiple tables and expect
  ** an IdList* parameter instead of just a Table* parameger.
  */
  pTabList = sqliteIdListAppend(0, pTableName);
  for(i=0; i<pTabList->nId; i++){
    pTabList->a[i].pTab = sqliteFindTable(pParse->db, pTabList->a[i].zName);
    if( pTabList->a[i].pTab==0 ){
      sqliteSetString(&pParse->zErrMsg, "unknown table \"", 
         pTabList->a[i].zName, "\"", 0);
      pParse->nErr++;
      goto update_cleanup;
    }
    if( pTabList->a[i].pTab->readOnly ){
      sqliteSetString(&pParse->zErrMsg, "table \"", pTabList->a[i].zName,
        "\" may not be modified", 0);
      pParse->nErr++;
      goto update_cleanup;
    }
  }
  pTab = pTabList->a[0].pTab;
  aXRef = sqliteMalloc( sizeof(int) * pTab->nCol );
  if( aXRef==0 ) goto update_cleanup;
  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

  /* Resolve the field names in all the expressions in both the
  ** WHERE clause and in the new values.  Also find the field index
  ** for each field to be updated in the pChanges array.
  */
  if( pWhere && sqliteExprResolveIds(pParse, pTabList, pWhere) ){
    goto update_cleanup;
  }
  for(i=0; i<pChanges->nExpr; i++){
    if( sqliteExprResolveIds(pParse, pTabList, pChanges->a[i].pExpr) ){
      goto update_cleanup;
    }
    for(j=0; j<pTab->nCol; j++){
      if( strcmp(pTab->azCol[j], pChanges->a[i].zName)==0 ){
        pChanges->a[i].idx = j;
        aXRef[j] = i;
        break;
      }
    }
    if( j>=pTab->nCol ){
      sqliteSetString(&pParse->zErrMsg, "no such field: \"", 
         pChanges->a[i].zName, "\"", 0);
      pParse->nErr++;
      goto update_cleanup;
    }
  }

  /* Allocate memory for the array apIdx[] and fill it pointers to every
  ** index that needs to be updated.  Indices only need updating if their
  ** key includes one of the fields named in pChanges.
  */
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    for(i=0; i<pIdx->nField; i++){
      if( aXRef[pIdx->aiField[i]]>=0 ) break;
    }
    if( i<pIdx->nField ) nIdx++;
  }
  apIdx = sqliteMalloc( sizeof(Index*) * nIdx );
  if( apIdx==0 ) goto update_cleanup;
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    for(i=0; i<pIdx->nField; i++){
      if( aXRef[pIdx->aiField[i]]>=0 ) break;
    }
    if( i<pIdx->nField ) apIdx[nIdx++] = pIdx;
  }

  /* Begin generating code.
  */
  v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  }
  if( v==0 ) goto update_cleanup;

  /* Begin the database scan
  */
  sqliteVdbeAddOp(v, OP_ListOpen, 0, 0, 0, 0);
  pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 1);
  if( pWInfo==0 ) goto update_cleanup;

  /* Remember the index of every item to be updated.
  */
  sqliteVdbeAddOp(v, OP_ListWrite, 0, 0, 0, 0);

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* Rewind the list of records that need to be updated and
  ** open every index that needs updating.
  */
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0, 0, 0);
  for(i=0; i<nIdx; i++){
    sqliteVdbeAddOp(v, OP_Open, i+1, 0, apIdx[i]->zName, 0);
  }

  /* Loop over every record that needs updating.  We have to load
  ** the old data for each record to be updated because some fields
  ** might not change and we will need to copy the old value, therefore.
  ** Also, the old data is needed to delete the old index entires.
  */
  end = sqliteVdbeMakeLabel(v);
  addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end, 0, 0);
  sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Fetch, 0, 0, 0, 0);

  /* Delete the old indices for the current record.
  */
  for(i=0; i<nIdx; i++){
    sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    pIdx = apIdx[i];
    for(j=0; j<pIdx->nField; j++){
      sqliteVdbeAddOp(v, OP_Field, 0, pIdx->aiField[j], 0, 0);
    }
    sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nField, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_DeleteIdx, i+1, 0, 0, 0);
  }

  /* Compute a completely new data for this record.  
  */
  for(i=0; i<pTab->nCol; i++){
    j = aXRef[i];
    if( j<0 ){
      sqliteVdbeAddOp(v, OP_Field, 0, i, 0, 0);
    }else{
      sqliteExprCode(pParse, pChanges->a[j].pExpr);
    }
  }

  /* Insert new index entries that correspond to the new data
  */
  for(i=0; i<nIdx; i++){
    sqliteVdbeAddOp(v, OP_Dup, pTab->nCol, 0, 0, 0); /* The KEY */
    pIdx = apIdx[i];
    for(j=0; j<pIdx->nField; j++){
      sqliteVdbeAddOp(v, OP_Dup, j+pTab->nCol-pIdx->aiField[j], 0, 0, 0);
    }
    sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nField, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_PutIdx, i+1, 0, 0, 0);
  }

  /* Write the new data back into the database.
  */
  sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Put, 0, 0, 0, 0);

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqliteVdbeAddOp(v, OP_Goto, 0, addr, 0, 0);
  sqliteVdbeAddOp(v, OP_ListClose, 0, 0, 0, end);

update_cleanup:
  sqliteFree(apIdx);
  sqliteFree(aXRef);
  sqliteIdListDelete(pTabList);
  sqliteExprListDelete(pChanges);
  sqliteExprDelete(pWhere);
  return;
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains code to implement the database baseend (DBBE)
** for sqlite.  The database backend is the interface between
** sqlite and the code that does the actually reading and writing
** of information to the disk.
**
** This file uses GDBM as the database backend.  It should be
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
** $Id: dbbe.c,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

/*
** Each open database file is an instance of this structure.
*/
typedef struct BeFile BeFile;
struct BeFile {
  char *zName;            /* Name of the file */
  GDBM_FILE dbf;          /* The file itself */
  int nRef;               /* Number of references */
  BeFile *pNext, *pPrev;  /* Next and previous on list of open files */
};

/*
** The complete database is an instance of the following structure.
*/
struct Dbbe {
  char *zDir;        /* The directory containing the database */
  int write;         /* True for write permission */
  BeFile *pOpen;     /* List of open files */
  int nTemp;         /* Number of temporary files created */
  FILE **apTemp;     /* Space to hold temporary file pointers */
};

/*
** Each file within the database is an instance of this
** structure.
*/
struct DbbeTable {
  Dbbe *pBe;         /* The database of which this record is a part */
  BeFile *pFile;     /* The database file for this table */
  datum key;         /* Most recently used key */
  datum data;        /* Most recent data */
  int needRewind;    /* Next key should be the first */
  int readPending;   /* The fetch hasn't actually been done yet */
};

/*
** This routine opens a new database.  For the current driver scheme,
** the database name is the name of the directory
** containing all the files of the database.
*/
Dbbe *sqliteDbbeOpen(
  const char *zName,     /* The name of the database */
  int write,             /* True if we will be writing to the database */
  int create,            /* True to create database if it doesn't exist */
  char **pzErrMsg        /* Write error messages (if any) here */
){
  Dbbe *pNew;
  struct stat statbuf;

  if( stat(zName, &statbuf)!=0 ){
    sqliteSetString(pzErrMsg, "can't find file \"", zName, "\"", 0);
    return 0;
  }
  if( !S_ISDIR(statbuf.st_mode) ){
    sqliteSetString(pzErrMsg, "not a directory: \"", zName, "\"", 0);
    return 0;
  }
  pNew = sqliteMalloc(sizeof(Dbbe) + strlen(zName) + 1);
  if( pNew==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 0;
  }
  pNew->zDir = (char*)&pNew[1];
  strcpy(pNew->zDir, zName);
  pNew->write = write;
  pNew->pOpen = 0;
  return pNew;
}

/*
** Completely shutdown the given database.  Close all files.  Free all memory.
*/
void sqliteDbbeClose(Dbbe *pBe){
  BeFile *pFile, *pNext;
  for(pFile=pBe->pOpen; pFile; pFile=pNext){
    pNext = pFile->pNext;
    gdbm_close(pFile->dbf);
    memset(pFile, 0, sizeof(*pFile));   
    sqliteFree(pFile);
  }
  memset(pBe, 0, sizeof(*pBe));
  sqliteFree(pBe);
}

/*
** Translate the name of a table into the name of a file that holds
** that table.  Space to hold the filename is obtained from
** sqliteMalloc() and must be freed by the calling function.
*/
static char *sqliteFileOfTable(Dbbe *pBe, const char *zTable){
  char *zFile = 0;
  int i;
  sqliteSetString(&zFile, pBe->zDir, "/", zTable, ".tbl", 0);
  if( zFile==0 ) return 0;
  for(i=strlen(pBe->zDir)+1; zFile[i]; i++){
    int c = zFile[i];
    if( isupper(c) ){
      zFile[i] = tolower(c);
    }else if( !isalnum(c) && c!='-' && c!='_' && c!='.' ){
      zFile[i] = '+';
    }
  }
  return zFile;
}

/*
** Open a new table cursor
*/
DbbeTable *sqliteDbbeOpenTable(
  Dbbe *pBe,              /* The database the table belongs to */
  const char *zTable,     /* The name of the table */
  int writeable           /* True to open for writing */
){
  char *zFile;            /* Name of the table file */
  DbbeTable *pTable;      /* The new table cursor */
  BeFile *pFile;          /* The underlying data file for this table */

  pTable = sqliteMalloc( sizeof(*pTable) );
  if( pTable==0 ) return 0;
  zFile = sqliteFileOfTable(pBe, zTable);
  for(pFile=pBe->pOpen; pFile; pFile=pFile->pNext){
    if( strcmp(pFile->zName,zFile)==0 ) break;
  }
  if( pFile==0 ){
    pFile = sqliteMalloc( sizeof(*pFile) );
    if( pFile==0 ){
      sqliteFree(zFile);
      return 0;
    }
    pFile->zName = zFile;
    pFile->nRef = 1;
    pFile->pPrev = 0;
    if( pBe->pOpen ){
      pBe->pOpen->pPrev = pFile;
    }
    pFile->pNext = pBe->pOpen;
    pBe->pOpen = pFile;
    pFile->dbf = gdbm_open(pFile->zName, 0, GDBM_WRCREAT, 0640, 0);
  }else{
    sqliteFree(zFile);
    pFile->nRef++;
  }
  pTable->pBe = pBe;
  pTable->pFile = pFile;
  pTable->readPending = 0;
  pTable->needRewind = 1;
  return pTable;
}

/*
** Drop a table from the database.
*/
void sqliteDbbeDropTable(Dbbe *pBe, const char *zTable){
  char *zFile;            /* Name of the table file */

  zFile = sqliteFileOfTable(pBe, zTable);
  unlink(zFile);
  sqliteFree(zFile);
}

/*
** Close a table previously opened by sqliteDbbeOpenTable().
*/
void sqliteDbbeCloseTable(DbbeTable *pTable){
  BeFile *pFile;
  Dbbe *pBe;
  if( pTable==0 ) return;
  pFile = pTable->pFile;
  pBe = pTable->pBe;
  pFile->nRef--;
  if( pFile->nRef<=0 ){
    if( pFile->dbf!=NULL ){
      gdbm_close(pFile->dbf);
    }
    if( pFile->pPrev ){
      pFile->pPrev->pNext = pFile->pNext;
    }else{
      pBe->pOpen = pFile->pNext;
    }
    if( pFile->pNext ){
      pFile->pNext->pPrev = pFile->pPrev;
    }
    sqliteFree(pFile->zName);
    memset(pFile, 0, sizeof(*pFile));
    sqliteFree(pFile);
  }
  if( pTable->key.dptr ) free(pTable->key.dptr);
  if( pTable->data.dptr ) free(pTable->data.dptr);
  memset(pTable, 0, sizeof(*pTable));
  sqliteFree(pTable);
}

/*
** Clear the given datum
*/
static void datumClear(datum *p){
  if( p->dptr ) free(p->dptr);
  p->dptr = 0;
  p->dsize = 0;
}

/*
** Fetch a single record from an open table.  Return 1 on success
** and 0 on failure.
*/
int sqliteDbbeFetch(DbbeTable *pTable, int nKey, char *pKey){
  datum key;
  key.dsize = nKey;
  key.dptr = pKey;
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  if( pTable->pFile && pTable->pFile->dbf ){
    pTable->data = gdbm_fetch(pTable->pFile->dbf, key);
  }
  return pTable->data.dptr!=0;
}

/*
** Copy bytes from the current key or data into a buffer supplied by
** the calling function.  Return the number of bytes copied.
*/
int sqliteDbbeCopyKey(DbbeTable *pTable, int offset, int size, char *zBuf){
  int n;
  if( offset>=pTable->key.dsize ) return 0;
  if( offset+size>pTable->key.dsize ){
    n = pTable->key.dsize - offset;
  }else{
    n = size;
  }
  memcpy(zBuf, &pTable->key.dptr[offset], n);
  return n;
}
int sqliteDbbeCopyData(DbbeTable *pTable, int offset, int size, char *zBuf){
  int n;
  if( pTable->readPending && pTable->pFile && pTable->pFile->dbf ){
    pTable->data = gdbm_fetch(pTable->pFile->dbf, pTable->key);
    pTable->readPending = 0;
  }
  if( offset>=pTable->data.dsize ) return 0;
  if( offset+size>pTable->data.dsize ){
    n = pTable->data.dsize - offset;
  }else{
    n = size;
  }
  memcpy(zBuf, &pTable->data.dptr[offset], n);
  return n;
}

/*
** Return a pointer to bytes from the key or data.  The data returned
** is ephemeral.
*/
char *sqliteDbbeReadKey(DbbeTable *pTable, int offset){
  if( offset<0 || offset>=pTable->key.dsize ) return "";
  return &pTable->key.dptr[offset];
}
char *sqliteDbbeReadData(DbbeTable *pTable, int offset){
  if( pTable->readPending && pTable->pFile && pTable->pFile->dbf ){
    pTable->data = gdbm_fetch(pTable->pFile->dbf, pTable->key);
    pTable->readPending = 0;
  }
  if( offset<0 || offset>=pTable->data.dsize ) return "";
  return &pTable->data.dptr[offset];
}

/*
** Return the total number of bytes in either data or key.
*/
int sqliteDbbeKeyLength(DbbeTable *pTable){
  return pTable->key.dsize;
}
int sqliteDbbeDataLength(DbbeTable *pTable){
  if( pTable->readPending && pTable->pFile && pTable->pFile->dbf ){
    pTable->data = gdbm_fetch(pTable->pFile->dbf, pTable->key);
    pTable->readPending = 0;
  }
  return pTable->data.dsize;
}

/*
** Make is so that the next call to sqliteNextKey() finds the first
** key of the table.
*/
int sqliteDbbeRewind(DbbeTable *pTable){
  pTable->needRewind = 1;
  return 0;
}

/*
** Read the next key from the table.  Return 1 on success.  Return
** 0 if there are no more keys.
*/
int sqliteDbbeNextKey(DbbeTable *pTable){
  datum nextkey;
  int rc;
  if( pTable==0 || pTable->pFile==0 || pTable->pFile->dbf==0 ){
    pTable->readPending = 0;
    return 0;
  }
  if( pTable->needRewind ){
    nextkey = gdbm_firstkey(pTable->pFile->dbf);
    pTable->needRewind = 0;
  }else{
    nextkey = gdbm_nextkey(pTable->pFile->dbf, pTable->key);
  }
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  pTable->key = nextkey;
  if( pTable->key.dptr ){
    pTable->readPending = 1;
    rc = 1;
  }else{
    pTable->needRewind = 1;
    pTable->readPending = 0;
    rc = 0;
  }
  return rc;
}

/*
** The following are state variables for the RC4 algorithm.  We
** use RC4 as a random number generator.  Each call to RC4 gives
** a random 8-bit number.
*/
static struct {
  int i, j;
  int s[256];
} rc4;

/*
** Initialize the RC4 algorithm.
*/
static void rc4init(char *key, int keylen){
  int i;
  char k[256];
  rc4.j = 0;
  rc4.i = 0;
  for(i=0; i<256; i++){
    rc4.s[i] = i;
    k[i] = key[i%keylen];
  }
  for(i=0; i<256; i++){
    int t;
    rc4.j = (rc4.j + rc4.s[i] + k[i]) & 0xff;
    t = rc4.s[rc4.j];
    rc4.s[rc4.j] = rc4.s[i];
    rc4.s[i] = t;
  }
}

/*
** Get a single 8-bit random value from the RC4 algorithm.
*/
static int rc4byte(void){
  int t;
  rc4.i = (rc4.i + 1) & 0xff;
  rc4.j = (rc4.j + rc4.s[rc4.i]) & 0xff;
  t = rc4.s[rc4.i];
  rc4.s[rc4.i] = rc4.s[rc4.j];
  rc4.s[rc4.j] = t;
  t = rc4.s[rc4.i] + rc4.s[rc4.j];
  return t & 0xff;
}

/*
** Get a new integer key.
*/
int sqliteDbbeNew(DbbeTable *pTable){
  static int isInit = 0;
  int iKey;
  datum key;
  int go = 1;
  int i;

  if( !isInit ){
    struct stat statbuf;
    stat(pTable->pFile->zName, &statbuf);
    time(&statbuf.st_ctime);
    rc4init((char*)&statbuf, sizeof(statbuf));
    isInit = 1;
  }
  if( pTable->pFile==0 || pTable->pFile->dbf==0 ) return 1;
  while( go ){
    iKey = 0;
    for(i=0; i<4; i++){
      iKey = (iKey<<8) + rc4byte();
    }
    key.dptr = (char*)&iKey;
    key.dsize = 4;
    go = gdbm_exists(pTable->pFile->dbf, key);
  }
  return iKey;
}   

/*
** Write an entry into the table.  Overwrite any prior entry with the
** same key.
*/
int sqliteDbbePut(DbbeTable *pTable, int nKey,char *pKey,int nData,char *pData){
  datum data, key;
  if( pTable->pFile==0 || pTable->pFile->dbf==0 ) return 0;
  data.dsize = nData;
  data.dptr = pData;
  key.dsize = nKey;
  key.dptr = pKey;
  gdbm_store(pTable->pFile->dbf, key, data, GDBM_REPLACE);
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  return 1;
}

/*
** Remove an entry from a table, if the entry exists.
*/
int sqliteDbbeDelete(DbbeTable *pTable, int nKey, char *pKey){
  datum key;
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  if( pTable->pFile==0 || pTable->pFile->dbf==0 ) return 0;
  key.dsize = nKey;
  key.dptr = pKey;
  gdbm_delete(pTable->pFile->dbf, key);
  return 1;
}

/*
** Open a temporary file.
*/
FILE *sqliteDbbeOpenTempFile(Dbbe *pBe){
  char *zFile;
  char zBuf[30];
  int i;

  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]==0 ) break;
  }
  if( i>=pBe->nTemp ){
    pBe->nTemp++;
    pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
  }
  if( pBe->apTemp==0 ) return 0;
  sprintf(zBuf, "/_temp_%d~", i);
  zFile = 0;
  sqliteSetString(&zFile, pBe->zDir, zBuf, 0);
  pBe->apTemp[i] = fopen(zFile, "w+");
  sqliteFree(zFile);
  return pBe->apTemp[i];
}

/*
** Close a temporary file opened using sqliteDbbeOpenTempFile()
*/
void sqliteDbbeCloseTempFile(Dbbe *pBe, FILE *f){
  int i;
  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]==f ){
      char *zFile;
      char zBuf[30];
      sprintf(zBuf, "/_temp_%d~", i);
      zFile = 0;
      sqliteSetString(&zFile, pBe->zDir, zBuf, 0);
      unlink(zFile);
      sqliteFree(zFile);
      pBe->apTemp[i] = 0;
      break;
    }
  }
  fclose(f);
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file defines the interface to the database backend (Dbbe).
**
** The database backend is designed to be as general as possible
** so that it can easily be replaced by a different backend.
** This library was originally designed to support the following
** backends: GDBM, NDBM, SDBM, Berkeley DB.
**
** $Id: dbbe.h,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#ifndef _SQLITE_DBBE_H_
#define _SQLITE_DBBE_H_
#include <stdio.h>

/*
** The database backend supports two opaque structures.  A Dbbe is
** a context for the entire set of tables forming a complete
** database.  A DbbeTable is a single table.  
**
** The DbbeTable structure holds some state information, such as
** the key and data from the last retrieval.  For this reason, 
** the backend must allow the creation of multiple independent
** DbbeTable structures for each table in the database.
*/
typedef struct Dbbe Dbbe;
typedef struct DbbeTable DbbeTable;

/*
** The 18 interface routines.
*/

/* Open a complete database */
Dbbe *sqliteDbbeOpen(const char *zName, int write, int create, char **pzErr);

/* Close the whole database. */
void sqliteDbbeClose(Dbbe*);

/* Open a particular table of a previously opened database.
** Create the table if it doesn't already exist and writeable!=0.
*/
DbbeTable *sqliteDbbeOpenTable(Dbbe*, const char *zTableName, int writeable);

/* Delete a table from the database */
void sqliteDbbeDropTable(Dbbe*, const char *zTableName);

/* Close a table */
void sqliteDbbeCloseTable(DbbeTable*);

/* Fetch an entry from a table with the given key.  Return 1 if
** successful and 0 if no such entry exists.
*/
int sqliteDbbeFetch(DbbeTable*, int nKey, char *pKey);

/* Retrieve the key or data used for the last fetch.  Only size
** bytes are read beginning with the offset-th byte.  The return
** value is the actual number of bytes read.
*/
int sqliteDbbeCopyKey(DbbeTable*, int offset, int size, char *zBuf);
int sqliteDbbeCopyData(DbbeTable*, int offset, int size, char *zBuf);

/* Retrieve the key or data.  The result is ephemeral.
*/
char *sqliteDbbeReadKey(DbbeTable*, int offset);
char *sqliteDbbeReadData(DbbeTable*, int offset);

/* Return the length of the most recently fetched key or data. */
int sqliteDbbeKeyLength(DbbeTable*);
int sqliteDbbeDataLength(DbbeTable*);

/* Retrieve the next entry in the table.  The first key is retrieved
** the first time this routine is called, or after a call to
** sqliteDbbeRewind().  The return value is 1 if there is another
** entry, or 0 if there are no more entries. */
int sqliteDbbeNextKey(DbbeTable*);

/* Make it so that the next call to sqliteDbbeNextKey() returns
** the first entry of the table. */
int sqliteDbbeRewind(DbbeTable*);

/* Get a new integer key for this table. */
int sqliteDbbeNew(DbbeTable*);

/* Write an entry into a table.  If another entry already exists with
** the same key, the old entry is discarded first.
*/
int sqliteDbbePut(DbbeTable*, int nKey, char *pKey, int nData, char *pData);

/* Remove an entry from the table */
int sqliteDbbeDelete(DbbeTable*, int nKey, char *pKey);

/* Open a file suitable for temporary storage */
FILE *sqliteDbbeOpenTempFile(Dbbe*);

/* Close a temporary file */
void sqliteDbbeCloseTempFile(Dbbe *, FILE *);

#endif /* defined(_SQLITE_DBBE_H_) */

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include "sqliteInt.h"

/*
** This is the callback routine for the code that initializes the
** database.  Each callback contains text of a CREATE TABLE or
** CREATE INDEX statement that must be parsed to yield the internal
** structures that describe the tables.
*/
static int sqliteOpenCb(void *pDb, int argc, char **argv, char **azColName){
  sqlite *db = (sqlite*)pDb;
  Parse sParse;
  int nErr;
  char *zErrMsg = 0;

  if( argc!=1 ) return 0;
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sParse.initFlag = 1;
  nErr = sqliteRunParser(&sParse, argv[0], &zErrMsg);
  return nErr;
}

/*
** Open a new SQLite database.  Construct an "sqlite" structure to define
** the state of this database and return a pointer to that structure.
*/
sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
  sqlite *db;
  Vdbe *vdbe;
  Table *pTab;
  char *azArg[2];
  static char master_schema[] = 
     "CREATE TABLE " MASTER_NAME " (\n"
     "  type text,\n"
     "  name text,\n"
     "  tbl_name text,\n"
     "  sql text\n"
     ")"
  ;

  /* The following program is used to initialize the internal
  ** structure holding the tables and indexes of the database.
  ** The database contains a special table named "sqlite_master"
  ** defined as follows:
  **
  **    CREATE TABLE sqlite_master (
  **        type       text,    --  Either "table" or "index"
  **        name       text,    --  Name of table or index
  **        tbl_name   text,    --  Associated table 
  **        sql        text     --  The CREATE statement for this object
  **    );
  **
  ** The sqlite_master table contains a single entry for each table
  ** and each index.  The "type" field tells whether the entry is
  ** a table or index.  The "name" field is the name of the object.
  ** The "tbl_name" is the name of the associated table.  For tables,
  ** the tbl_name field is always the same as name.  For indices, the
  ** tbl_name field contains the name of the table that the index
  ** indexes.  Finally, the sql field contains the complete text of
  ** the CREATE TABLE or CREATE INDEX statement that originally created
  ** the table or index.
  **
  ** The following program invokes its callback on the SQL for each
  ** table then goes back and invokes the callback on the
  ** SQL for each index.  The callback will invoke the
  ** parser to build the internal representation of the
  ** database scheme.
  */
  static VdbeOp initProg[] = {
    { OP_Open,     0, 0,  MASTER_NAME},
    { OP_Next,     0, 8,  0},           /* 1 */
    { OP_Field,    0, 0,  0},
    { OP_String,   0, 0,  "table"},
    { OP_Ne,       0, 1,  0},
    { OP_Field,    0, 3,  0},
    { OP_Callback, 1, 0,  0},
    { OP_Goto,     0, 1,  0},
    { OP_Rewind,   0, 0,  0},           /* 8 */
    { OP_Next,     0, 16, 0},           /* 9 */
    { OP_Field,    0, 0,  0},
    { OP_String,   0, 0,  "index"},
    { OP_Ne,       0, 9,  0},
    { OP_Field,    0, 3,  0},
    { OP_Callback, 1, 0,  0},
    { OP_Goto,     0, 9,  0},
    { OP_Halt,     0, 0,  0},           /* 16 */
  };

  /* Allocate space to hold the main database structure */
  db = sqliteMalloc( sizeof(sqlite) );
  if( pzErrMsg ) *pzErrMsg = 0;
  if( db==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 0;
  }
  
  /* Open the backend database driver */
  db->pBe = sqliteDbbeOpen(zFilename, (mode&0222)!=0, mode!=0, pzErrMsg);
  if( db->pBe==0 ){
    sqliteFree(db);
    return 0;
  }

  /* Create a virtual machine to run the initialization program.  Run
  ** the program.  The delete the virtual machine.
  */
  azArg[0] = master_schema;
  azArg[1] = 0;
  sqliteOpenCb(db, 1, azArg, 0);
  pTab = sqliteFindTable(db, MASTER_NAME);
  if( pTab ){
    pTab->readOnly = 1;
  }
  vdbe = sqliteVdbeCreate(db->pBe);
  sqliteVdbeAddOpList(vdbe, sizeof(initProg)/sizeof(initProg[0]), initProg);
  sqliteVdbeExec(vdbe, sqliteOpenCb, db, pzErrMsg);
  sqliteVdbeDelete(vdbe);
  return db;
}

/*
** Close an existing SQLite database
*/
void sqlite_close(sqlite *db){
  int i;
  sqliteDbbeClose(db->pBe);
  for(i=0; i<N_HASH; i++){
    Table *pNext, *pList = db->apTblHash[i];
    db->apTblHash[i] = 0;
    while( pList ){
      pNext = pList->pHash;
      pList->pHash = 0;
      sqliteDeleteTable(db, pList);
      pList = pNext;
    }
  }
  sqliteFree(db);
}

/*
** Return TRUE if the given SQL string ends in a semicolon.
*/
int sqlite_complete(const char *zSql){
  int i;
  int lastWasSemi = 0;

  i = 0;
  while( i>=0 && zSql[i]!=0 ){
    int tokenType;
    int n;

    n = sqliteGetToken(&zSql[i], &tokenType);
    switch( tokenType ){
      case TK_SPACE:
      case TK_COMMENT:
        break;
      case TK_SEMI:
        lastWasSemi = 1;
        break;
      default:
        lastWasSemi = 0;
        break;
    }
    i += n;
  }
  return lastWasSemi;
}

/*
** Execute SQL code 
*/
int sqlite_exec(
  sqlite *db,                 /* The database on which the SQL executes */
  char *zSql,                 /* The SQL to be executed */
  sqlite_callback xCallback,  /* Invoke this callback routine */
  void *pArg,                 /* First argument to xCallback() */
  char **pzErrMsg             /* Write error messages here */
){
  Parse sParse;
  int nErr;

  if( pzErrMsg ) *pzErrMsg = 0;
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sParse.xCallback = xCallback;
  sParse.pArg = pArg;
  nErr = sqliteRunParser(&sParse, zSql, pzErrMsg);
  return nErr;
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains code to implement the "sqlite" command line
** utility for accessing SQLite databases.
**
** $Id: shell.c,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "sqlite.h"
#include <unistd.h>
#include <ctype.h>

#if !defined(NO_READLINE)
#include <readline/readline.h>
#include <readline/history.h>
#endif

/*
** An pointer to an instance of this structure is passed from
** the main program to the callback.  This is used to communicate
** state and mode information.
*/
struct callback_data {
  int cnt;           /* Number of records displayed so far */
  FILE *out;         /* Write results here */
  int mode;          /* An output mode setting */
  int showHeader;    /* True to show column names in List or Column mode */
  char separator[20];/* Separator character for MODE_List */
  int colWidth[30];  /* Width of each column when in column mode */
};

/*
** These are the allowed modes.
*/
#define MODE_Line     0  /* One field per line.  Blank line between records */
#define MODE_Column   1  /* One record per line in neat columns */
#define MODE_List     2  /* One record per line with a separator */

/*
** Number of elements in an array
*/
#define ArraySize(X)  (sizeof(X)/sizeof(X[0]))

/*
** This is the callback routine that the SQLite library
** invokes for each row of a query result.
*/
static int callback(void *pArg, int nArg, char **azArg, char **azCol){
  int i;
  struct callback_data *p = (struct callback_data*)pArg;
  switch( p->mode ){
    case MODE_Line: {
      if( p->cnt++>0 ) fprintf(p->out,"\n");
      for(i=0; i<nArg; i++){
        fprintf(p->out,"%s = %s\n", azCol[i], azArg[i]);
      }
      break;
    }
    case MODE_Column: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          int w;
          if( i<ArraySize(p->colWidth) && p->colWidth[i]>0 ){
             w = p->colWidth[i]; 
          }else{
             w = 10;
          }
          fprintf(p->out,"%-*.*s%s",w,w,azCol[i], i==nArg-1 ? "\n": "  ");
        }
        for(i=0; i<nArg; i++){
          int w;
          if( i<ArraySize(p->colWidth) && p->colWidth[i]>0 ){
             w = p->colWidth[i];
          }else{
             w = 10;
          }
          fprintf(p->out,"%-*.*s%s",w,w,"-------------------------------------",
                  i==nArg-1 ? "\n": "  ");
        }
      }
      for(i=0; i<nArg; i++){
        int w;
        if( i<ArraySize(p->colWidth) && p->colWidth[i]>0 ){
           w = p->colWidth[i];
        }else{
           w = 10;
        }
        fprintf(p->out,"%-*.*s%s",w,w,azArg[i], i==nArg-1 ? "\n": "  ");
      }
      break;
    }
    case MODE_List: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          fprintf(p->out,"%s%s",azCol[i], i==nArg-1 ? "\n" : p->separator);
        }
      }
      for(i=0; i<nArg; i++){
        fprintf(p->out,"%s%s",azArg[i], i==nArg-1 ? "\n" : p->separator);
      }
      break;
    }
  }      
  return 0;
}

/*
** Text of a help message
*/
static char zHelp[] = 
  ".exit                  Exit this program\n"
  ".explain               Set output mode suitable for EXPLAIN\n"
  ".header ON|OFF         Turn display of headers on or off\n"
  ".help                  Show this message\n"
  ".indices TABLE         Show names of all indices on TABLE\n"
  ".mode MODE             Set mode to one of \"line\", \"column\", or"
                                      " \"list\"\n"
  ".output FILENAME       Send output to FILENAME\n"
  ".output stdout         Send output to the screen\n"
  ".schema ?TABLE?        Show the CREATE statements\n"
  ".separator STRING      Change separator string for \"list\" mode\n"
  ".tables                List names all tables in the database\n"
  ".width NUM NUM ...     Set column widths for \"column\" mode\n"
;

/*
** If an input line begins with "." then invoke this routine to
** process that line.
*/
static void do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
  int i = 1;
  int nArg = 0;
  int n, c;
  char *azArg[50];

  /* Parse the input line into tokens.
  */
  while( zLine[i] && nArg<ArraySize(azArg) ){
    while( isspace(zLine[i]) ){ i++; }
    if( zLine[i]=='\'' || zLine[i]=='"' ){
      int delim = zLine[i++];
      azArg[nArg++] = &zLine[i];
      while( zLine[i] && zLine[i]!=delim ){ i++; }
      if( zLine[i]==delim ){
        zLine[i++] = 0;
      }
    }else{
      azArg[nArg++] = &zLine[i];
      while( zLine[i] && !isspace(zLine[i]) ){ i++; }
      if( zLine[i] ) zLine[i++] = 0;
    }
  }

  /* Process the input line.
  */
  if( nArg==0 ) return;
  n = strlen(azArg[0]);
  c = azArg[0][0];

  if( c=='e' && strncmp(azArg[0], "exit", n)==0 ){
    exit(0);
  }else

  if( c=='e' && strncmp(azArg[0], "explain", n)==0 ){
    p->mode = MODE_Column;
    p->showHeader = 1;
    p->colWidth[0] = 4;
    p->colWidth[1] = 12;
    p->colWidth[2] = 5;
    p->colWidth[3] = 5;
    p->colWidth[4] = 40;
  }else

  if( c=='h' && strncmp(azArg[0], "header", n)==0 && nArg>1 ){
    int j;
    char *z = azArg[1];
    int val = atoi(azArg[1]);
    for(j=0; z[j]; j++){
      if( isupper(z[j]) ) z[j] = tolower(z[j]);
    }
    if( strcmp(z,"on")==0 ){
      val = 1;
    }else if( strcmp(z,"yes")==0 ){
      val = 1;
    } 
    p->showHeader = val;
  }else

  if( c=='h' && strncmp(azArg[0], "help", n)==0 ){
    fprintf(stderr,zHelp);
  }else

  if( c=='i' && strncmp(azArg[0], "indices", n)==0 && nArg>1 ){
    struct callback_data data;
    char *zErrMsg = 0;
    char zSql[1000];
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.mode = MODE_List;
    sprintf(zSql, "SELECT name FROM sqlite_master "
                  "WHERE type='index' AND tbl_name='%.900s'", azArg[1]);
    sqlite_exec(db, zSql, callback, &data, &zErrMsg);
    if( zErrMsg ){
      fprintf(stderr,"Error: %s\n", zErrMsg);
      free(zErrMsg);
    }
  }else

  if( c=='m' && strncmp(azArg[0], "mode", n)==0 && nArg==2 ){
    int n2 = strlen(azArg[1]);
    if( strncmp(azArg[1],"line",n2)==0 ){
      p->mode = MODE_Line;
    }else if( strncmp(azArg[1],"column",n2)==0 ){
      p->mode = MODE_Column;
    }else if( strncmp(azArg[1],"list",n2)==0 ){
      p->mode = MODE_List;
    }
  }else

  if( c=='o' && strncmp(azArg[0], "output", n)==0 && nArg==2 ){
    if( p->out!=stdout ){
      fclose(p->out);
    }
    if( strcmp(azArg[1],"stdout")==0 ){
      p->out = stdout;
    }else{
      p->out = fopen(azArg[1], "w");
      if( p->out==0 ){
        fprintf(stderr,"can't write to \"%s\"\n", azArg[1]);
        p->out = stdout;
      }
    }
  }else

  if( c=='s' && strncmp(azArg[0], "schema", n)==0 ){
    struct callback_data data;
    char *zErrMsg = 0;
    char zSql[1000];
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.mode = MODE_List;
    if( nArg>1 ){
      sprintf(zSql, "SELECT sql FROM sqlite_master WHERE name='%.900s'",
         azArg[1]);
    }else{
      sprintf(zSql, "SELECT sql FROM sqlite_master "
         "ORDER BY tbl_name, type DESC, name");
    }
    sqlite_exec(db, zSql, callback, &data, &zErrMsg);
    if( zErrMsg ){
      fprintf(stderr,"Error: %s\n", zErrMsg);
      free(zErrMsg);
    }
  }else

  if( c=='s' && strncmp(azArg[0], "separator", n)==0 && nArg==2 ){
    sprintf(p->separator, "%.*s", (int)ArraySize(p->separator)-1, azArg[1]);
  }else

  if( c=='t' && strncmp(azArg[0], "tables", n)==0 ){
    struct callback_data data;
    char *zErrMsg = 0;
    static char zSql[] = "SELECT name FROM sqlite_master WHERE type='table'";
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.mode = MODE_List;
    sqlite_exec(db, zSql, callback, &data, &zErrMsg);
    if( zErrMsg ){
      fprintf(stderr,"Error: %s\n", zErrMsg);
      free(zErrMsg);
    }
  }else

  if( c=='w' && strncmp(azArg[0], "width", n)==0 ){
    int j;
    for(j=1; j<nArg && j<ArraySize(p->colWidth); j++){
      p->colWidth[j-1] = atoi(azArg[j]);
    }
  }else

  {
    fprintf(stderr, "unknown command: \"%s\". Enter \".help\" for help\n",
      azArg[0]);
  }
}

int main(int argc, char **argv){
  sqlite *db;
  char *zErrMsg = 0;
  struct callback_data data;

  if( argc!=2 && argc!=3 ){
    fprintf(stderr,"Usage: %s FILENAME ?SQL?\n", *argv);
    exit(1);
  }
  db = sqlite_open(argv[1], 0666, &zErrMsg);
  if( db==0 ){
    fprintf(stderr,"Unable to open database \"%s\": %s\n", argv[1], zErrMsg);
    exit(1);
  }
  memset(&data, 0, sizeof(data));
  data.out = stdout;
  if( argc==3 ){
    data.mode = MODE_List;
    strcpy(data.separator,"|");
    if( sqlite_exec(db, argv[2], callback, &data, &zErrMsg)!=0 && zErrMsg!=0 ){
      fprintf(stderr,"SQL error: %s\n", zErrMsg);
      exit(1);
    }
  }else{
    char *zLine;
    char *zSql = 0;
    int nSql = 0;
    int istty = isatty(0);
    data.mode = MODE_Line;
    strcpy(data.separator,"|");
    data.showHeader = 0;
    if( istty ){
      printf(
        "Enter \".help\" for instructions\n"
      );
    }
    while( (zLine = readline(istty ? (zSql==0 ? "sql> " : ".... ") : 0))!=0 ){
      if( zLine && zLine[0]=='.' ){
        do_meta_command(zLine, db, &data);
        free(zLine);
        continue;
      }
      if( zSql==0 ){
        nSql = strlen(zLine);
        zSql = malloc( nSql+1 );
        strcpy(zSql, zLine);
      }else{
        int len = strlen(zLine);
        zSql = realloc( zSql, nSql + len + 2 );
        if( zSql==0 ){
          fprintf(stderr,"%s: out of memory!\n", *argv);
          exit(1);
        }
        strcpy(&zSql[nSql++], "\n");
        strcpy(&zSql[nSql], zLine);
        nSql += len;
      }
      free(zLine);
      if( sqlite_complete(zSql) ){
        data.cnt = 0;
        if( sqlite_exec(db, zSql, callback, &data, &zErrMsg)!=0 
             && zErrMsg!=0 ){
          printf("SQL error: %s\n", zErrMsg);
          free(zErrMsg);
          zErrMsg = 0;
        }
        free(zSql);
        zSql = 0;
        nSql = 0;
      }
    }
  }
  sqlite_close(db);
  return 0;
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This header file defines the interface that the sqlite library
** presents to client programs.
**
** @(#) $Id: sqlite.h,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_

/*
** Each open sqlite database is represented by an instance of the
** following opaque structure.
*/
typedef struct sqlite sqlite;

/*
** A function to open a new sqlite database.  
**
** If the database does not exist and mode indicates write
** permission, then a new database is created.  If the database
** does not exist and mode does not indicate write permission,
** then the open fails, an error message generated (if errmsg!=0)
** and the function returns 0.
** 
** If mode does not indicates user write permission, then the 
** database is opened read-only.
**
** The Truth:  As currently implemented, all databases are opened
** for writing all the time.  Maybe someday we will provide the
** ability to open a database readonly.  The mode parameters is
** provide in anticipation of that enhancement.
*/
sqlite *sqlite_open(const char *filename, int mode, char **errmsg);

/*
** A function to close the database.
**
** Call this function with a pointer to a structure that was previously
** returned from sqlite_open() and the corresponding database will by closed.
*/
void sqlite_close(sqlite *);

/*
** The type for a callback function.
*/
typedef int (*sqlite_callback)(void*,int,char**, char**);

/*
** A function to executes one or more statements of SQL.
**
** If one or more of the SQL statements are queries, then
** the callback function specified by the 3rd parameter is
** invoked once for each row of the query result.  This callback
** should normally return 0.  If the callback returns a non-zero
** value then the query is aborted, all subsequent SQL statements
** are skipped and the sqlite_exec() function returns the same
** value that the callback returned.
**
** The 4th parameter is an arbitrary pointer that is passed
** to the callback function as its first parameter.
**
** The 2nd parameter to the callback function is the number of
** columns in the query result.  The 3rd parameter is an array
** of string holding the values for each column.  The 4th parameter
** is an array of strings holding the names of each column.
**
** The callback function may be NULL, even for queries.  A NULL
** callback is not an error.  It just means that no callback
** will be invoked.
**
** If an error occurs while parsing or evaluating the SQL (but
** not while executing the callback) then an appropriate error
** message is written into memory obtained from malloc() and
** *errmsg is made to point to that message.  If errmsg==NULL,
** then no error message is ever written.  The return value is
** non-zero if an error occurs.
*/
int sqlite_exec(
  sqlite*,                      /* An open database */
  char *sql,                    /* SQL to be executed */
  sqlite_callback,              /* Callback function */
  void *,                       /* 1st argument to callback function */
  char **errmsg                 /* Error msg written here */
);


/* This function returns true if the given input string comprises
** one or more complete SQL statements.
**
** The algorithm is simple.  If the last token other than spaces
** and comments is a semicolon, then return true.  otherwise return
** false.
*/
int sqlite_complete(const char *sql);

#endif /* _SQLITE_H_ */

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
#include "vdbe.h"
#include "parse.h"
#include <gdbm.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

/*
** The number of entries in the in-memory hash table holding the
** schema.
*/
#define N_HASH        51

/*
** Name of the master database table.  The master database table
** is a special table that holds the names and attributes of all
** user tables and indices.
*/
#define MASTER_NAME   "sqlite_master"

/*
** A convenience macro that returns the number of elements in
** an array.
*/
#define ArraySize(X)    (sizeof(X)/sizeof(X[0]))

/*
** Forward references to structures
*/
typedef struct Table Table;
typedef struct Index Index;
typedef struct Instruction Instruction;
typedef struct Expr Expr;
typedef struct ExprList ExprList;
typedef struct Parse Parse;
typedef struct Token Token;
typedef struct IdList IdList;
typedef struct WhereInfo WhereInfo;

/*
** Each database is an instance of the following structure
*/
struct sqlite {
  Dbbe *pBe;                 /* The backend driver */
  int flags;                 /* Miscellanous flags */
  Table *apTblHash[N_HASH];  /* All tables of the database */
  Index *apIdxHash[N_HASH];  /* All indices of the database */
};

/*
** Possible values for the flags field of sqlite
*/
#define SQLITE_VdbeTrace    0x00000001

/*
** Each table is represented in memory by
** an instance of the following structure
*/
struct Table {
  char *zName;        /* Name of the table */
  Table *pHash;       /* Next table with same hash on zName */
  int nCol;           /* Number of columns in this table */
  int readOnly;       /* True if this table should not be written by the user */
  char **azCol;       /* Name of each column */
  Index *pIndex;      /* List of indices on this table. */
};

/*
** Each index is represented in memory by and
** instance of the following structure.
*/
struct Index {
  char *zName;        /* Name of this index */
  Index *pHash;       /* Next index with the same hash on zName */
  int nField;         /* Number of fields in the table indexed by this index */
  int *aiField;       /* Indices of fields used by this index.  1st is 0 */
  Table *pTable;      /* The table being indexed */
  Index *pNext;       /* The next index associated with the same table */
};

/*
** Each token coming out of the lexer is an instance of
** this structure.
*/
struct Token {
  char *z;      /* Text of the token */
  int n;        /* Number of characters in this token */
};

/*
** Each node of an expression in the parse tree is an instance
** of this structure
*/
struct Expr {
  int op;                /* Operation performed by this node */
  Expr *pLeft, *pRight;  /* Left and right subnodes */
  ExprList *pList;       /* A list of expressions used as a function argument */
  Token token;           /* An operand token */
  int iTable, iField;    /* When op==TK_FIELD, then this node means the
                         ** iField-th field of the iTable-th table */
};

/*
** A list of expressions.  Each expression may optionally have a
** name.  An expr/name combination can be used in several ways, such
** as the list of "expr AS ID" fields following a "SELECT" or in the
** list of "ID = expr" items in an UPDATE.  A list of expressions can
** also be used as the argument to a function, in which case the azName
** field is not used.
*/
struct ExprList {
  int nExpr;             /* Number of expressions on the list */
  struct {
    Expr *pExpr;           /* The list of expressions */
    char *zName;           /* Token associated with this expression */
    int idx;               /* ... */
  } *a;                  /* One entry for each expression */
};

/*
** A list of identifiers.
*/
struct IdList {
  int nId;         /* Number of identifiers on the list */
  struct {
    char *zName;      /* Text of the identifier. */
    char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
    Table *pTab;      /* Table corresponding to zName */
    int idx;          /* Index of a field name in the table */
  } *a;            /* One entry for each identifier on the list */
};

/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
struct WhereInfo {
  Parse *pParse;
  IdList *pTabList;
  int iContinue;
  int iBreak;
};

/*
** An SQL parser context
*/
struct Parse {
  sqlite *db;          /* The main database structure */
  sqlite_callback xCallback;  /* The callback function */
  void *pArg;          /* First argument to the callback function */
  char *zErrMsg;       /* An error message */
  Token sErrToken;     /* The token at which the error occurred */
  Token sFirstToken;   /* The first token parsed */
  Token sLastToken;    /* The last token parsed */
  Table *pNewTable;    /* A table being constructed by CREATE TABLE */
  Vdbe *pVdbe;         /* An engine for executing database bytecode */
  int explain;         /* True if the EXPLAIN flag is found on the query */
  int initFlag;        /* True if reparsing CREATE TABLEs */
  int nErr;            /* Number of errors seen */
};

/*
** Internal function prototypes
*/
int sqliteStrICmp(const char *, const char *);
int sqliteStrNICmp(const char *, const char *, int);
int sqliteHashNoCase(const char *, int);
int sqliteCompare(const char *, const char *);
int sqliteSortCompare(const char *, const char *);
void *sqliteMalloc(int);
void sqliteFree(void*);
void *sqliteRealloc(void*,int);
int sqliteGetToken(const char*, int *);
void sqliteSetString(char **, const char *, ...);
void sqliteSetNString(char **, ...);
int sqliteRunParser(Parse*, char*, char **);
void sqliteExec(Parse*);
Expr *sqliteExpr(int, Expr*, Expr*, Token*);
Expr *sqliteExprFunction(ExprList*, Token*);
void sqliteExprDelete(Expr*);
ExprList *sqliteExprListAppend(ExprList*,Expr*,Token*);
void sqliteExprListDelete(ExprList*);
void sqliteStartTable(Parse*,Token*,Token*);
void sqliteAddColumn(Parse*,Token*);
void sqliteEndTable(Parse*,Token*);
void sqliteDropTable(Parse*, Token*);
void sqliteDeleteTable(sqlite*, Table*);
void sqliteInsert(Parse*, Token*, ExprList*, IdList*);
IdList *sqliteIdListAppend(IdList*, Token*);
void sqliteIdListAddAlias(IdList*, Token*);
void sqliteIdListDelete(IdList*);
void sqliteCreateIndex(Parse*, Token*, Token*, IdList*, Token*, Token*);
void sqliteDropIndex(Parse*, Token*);
void sqliteSelect(Parse*, ExprList*, IdList*, Expr*, ExprList*);
void sqliteDeleteFrom(Parse*, Token*, Expr*);
void sqliteUpdate(Parse*, Token*, ExprList*, Expr*);
WhereInfo *sqliteWhereBegin(Parse*, IdList*, Expr*, int);
void sqliteWhereEnd(WhereInfo*);
void sqliteExprCode(Parse*, Expr*);
void sqliteExprIfTrue(Parse*, Expr*, int);
void sqliteExprIfFalse(Parse*, Expr*, int);
Table *sqliteFindTable(sqlite*,char*);

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.1 2000/05/29 14:26:01 drh Exp $
*/
#include "sqlite.h"
#include <tcl.h>
#include <stdlib.h>
#include <string.h>

/*
** An instance of this structure passes information thru the sqlite
** logic from the original TCL command into the callback routine.
*/
typedef struct CallbackData CallbackData;
struct CallbackData {
  Tcl_Interp *interp;       /* The TCL interpreter */
  char *zArray;             /* The array into which data is written */
  char *zCode;              /* The code to execute for each row */
  int once;                 /* Set only for the first invocation of callback */
};

/*
** Called for each row of the result.
*/
static int DbEvalCallback(
  void *clientData,      /* An instance of CallbackData */
  int nCol,              /* Number of columns in the result */
  char ** azCol,         /* Data for each column */
  char ** azN            /* Name for each column */
){
  CallbackData *cbData = (CallbackData*)clientData;
  int i, rc;
  if( cbData->zArray[0] ){
    if( cbData->once ){
      for(i=0; i<nCol; i++){
        Tcl_SetVar2(cbData->interp, cbData->zArray, "*", azN[i],
           TCL_LIST_ELEMENT|TCL_APPEND_VALUE);
      }
    }
    for(i=0; i<nCol; i++){
      Tcl_SetVar2(cbData->interp, cbData->zArray, azN[i], azCol[i], 0);
    }
  }else{
    for(i=0; i<nCol; i++){
      Tcl_SetVar(cbData->interp, azN[i], azCol[i], 0);
    }
  }
  cbData->once = 0;
  rc = Tcl_Eval(cbData->interp, cbData->zCode);
  return rc;
}

/*
** Called when the command is deleted.
*/
static void DbDeleteCmd(void *db){
  sqlite_close((sqlite*)db);
}

/*
** The "sqlite" command below creates a new Tcl command for each
** connection it opens to an SQLite database.  This routine is invoked
** whenever one of those connection-specific commands is executed
** in Tcl.  For example, if you run Tcl code like this:
**
**       sqlite db1  "my_database"
**       db1 close
**
** The first command opens a connection to the "my_database" database
** and calls that connection "db1".  The second command causes this
** subroutine to be invoked.
*/
static int DbCmd(void *cd, Tcl_Interp *interp, int argc, char **argv){
  char *z;
  int n, c;
  sqlite *db = cd;
  if( argc<2 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
        " SUBCOMMAND ...\"", 0);
    return TCL_ERROR;
  }
  z = argv[1];
  n = strlen(z);
  c = z[0];

  /*    $db close
  **
  ** Shutdown the database
  */
  if( c=='c' && n>=2 && strncmp(z,"close",n)==0 ){
    Tcl_DeleteCommand(interp, argv[0]);
  }else

  /*    $db complete SQL
  **
  ** Return TRUE if SQL is a complete SQL statement.  Return FALSE if
  ** additional lines of input are needed.  This is similar to the
  ** built-in "info complete" command of Tcl.
  */
  if( c=='c' && n>=2 && strncmp(z,"complete",n)==0 ){
    char *zRes;
    if( argc!=3 ){
      Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
          " complete SQL\"", 0);
      return TCL_ERROR;
    }
    zRes = sqlite_complete(argv[2]) ? "1" : "0";
    Tcl_SetResult(interp, zRes, TCL_VOLATILE);
  }else
   
  /*
  **    $db eval $sql ?array {  ...code... }?
  **
  ** The SQL statement in $sql is evaluated.  For each row, the values are
  ** placed in elements of the array named "array" and ...code.. is executed.
  ** If "array" and "code" are omitted, then no callback is every invoked.
  ** If "array" is an empty string, then the values are placed in variables
  ** that have the same name as the fields extracted by the query.
  */
  if( c=='e' && strncmp(z,"eval",n)==0 ){
    CallbackData cbData;
    char *zErrMsg;
    int rc;

    if( argc!=5 && argc!=3 ){
      Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
         " eval SQL ?ARRAY-NAME CODE?", 0);
      return TCL_ERROR;
    }
    if( argc==5 ){
      cbData.interp = interp;
      cbData.zArray = argv[3];
      cbData.zCode = argv[4];
      zErrMsg = 0;
      rc = sqlite_exec(db, argv[2], DbEvalCallback, &cbData, &zErrMsg);
    }else{
      rc = sqlite_exec(db, argv[2], 0, 0, &zErrMsg);
    }
    if( zErrMsg ){
      Tcl_SetResult(interp, zErrMsg, TCL_VOLATILE);
      free(zErrMsg);
    }
    return rc;
  }

  /* The default
  */
  else{
    Tcl_AppendResult(interp,"unknown subcommand \"", z, 
        "\" - should be one of: close complete eval", 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

/*
**   sqlite DBNAME FILENAME ?MODE?
**
** This is the main Tcl command.  When the "sqlite" Tcl command is
** invoked, this routine runs to process that command.
**
** The first argument, DBNAME, is an arbitrary name for a new
** database connection.  This command creates a new command named
** DBNAME that is used to control that connection.  The database
** connection is deleted when the DBNAME command is deleted.
**
** The second argument is the name of the directory that contains
** the sqlite database that is to be accessed.
*/
static int DbMain(void *cd, Tcl_Interp *interp, int argc, char **argv){
  int mode;
  sqlite *p;
  char *zErrMsg;
  if( argc!=3 && argc!=4 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
       " HANDLE FILENAME ?MODE?\"", 0);
    return TCL_ERROR;
  }
  if( argc==3 ){
    mode = 0;
  }else if( Tcl_GetInt(interp, argv[3], &mode)!=TCL_OK ){
    return TCL_ERROR;
  }
  zErrMsg = 0;
  p = sqlite_open(argv[2], mode, &zErrMsg);
  if( p==0 ){
    Tcl_SetResult(interp, zErrMsg, TCL_VOLATILE);
    free(zErrMsg);
    return TCL_ERROR;
  }
  Tcl_CreateCommand(interp, argv[1], DbCmd, p, DbDeleteCmd);
  return TCL_OK;
}

/*
** Initialize this module.
**
** This Tcl module contains only a single new Tcl command named "sqlite".
** (Hence there is no namespace.  There is no point in using a namespace
** if the extension only supplies one new name!)  The "sqlite" command is
** used to open a new SQLite database.  See the DbMain() routine above
** for additional information.
*/
int Sqlite_Init(Tcl_Interp *interp){
  Tcl_CreateCommand(interp, "sqlite", DbMain, 0, 0);
  return TCL_OK;
}
int Sqlite_SafeInit(Tcl_Interp *interp){
  return TCL_OK;
}

/*
** If compiled using mktclapp, this routine runs to initialize
** everything.
*/
int Et_AppInit(Tcl_Interp *interp){
  return Sqlite_Init(interp);
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.1 2000/05/29 14:26:02 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** All the keywords of the SQL language are stored as in a hash
** table composed of instances of the following structure.
*/
typedef struct Keyword Keyword;
struct Keyword {
  char *zName;             /* The keyword name */
  int len;                 /* Number of characters in the keyword */
  int tokenType;           /* The token value for this keyword */
  Keyword *pNext;          /* Next keyword with the same hash */
};

/*
** These are the keywords
*/
static Keyword aKeywordTable[] = {
  { "AND",               0, TK_AND,              0 },
  { "AS",                0, TK_AS,               0 },
  { "ASC",               0, TK_ASC,              0 },
  { "BY",                0, TK_BY,               0 },
  { "CHECK",             0, TK_CHECK,            0 },
  { "CONSTRAINT",        0, TK_CONSTRAINT,       0 },
  { "CREATE",            0, TK_CREATE,           0 },
  { "DEFAULT",           0, TK_DEFAULT,          0 },
  { "DELETE",            0, TK_DELETE,           0 },
  { "DESC",              0, TK_DESC,             0 },
  { "DROP",              0, TK_DROP,             0 },
  { "EXPLAIN",           0, TK_EXPLAIN,          0 },
  { "FROM",              0, TK_FROM,             0 },
  { "INDEX",             0, TK_INDEX,            0 },
  { "INSERT",            0, TK_INSERT,           0 },
  { "INTO",              0, TK_INTO,             0 },
  { "IS",                0, TK_IS,               0 },
  { "ISNULL",            0, TK_ISNULL,           0 },
  { "KEY",               0, TK_KEY,              0 },
  { "NOT",               0, TK_NOT,              0 },
  { "NOTNULL",           0, TK_NOTNULL,          0 },
  { "NULL",              0, TK_NULL,             0 },
  { "ON",                0, TK_ON,               0 },
  { "OR",                0, TK_OR,               0 },
  { "ORDER",             0, TK_ORDER,            0 },
  { "PRIMARY",           0, TK_PRIMARY,          0 },
  { "SELECT",            0, TK_SELECT,           0 },
  { "SET",               0, TK_SET,              0 },
  { "TABLE",             0, TK_TABLE,            0 },
  { "UNIQUE",            0, TK_UNIQUE,           0 },
  { "UPDATE",            0, TK_UPDATE,           0 },
  { "VALUES",            0, TK_VALUES,           0 },
  { "WHERE",             0, TK_WHERE,            0 },
};

/*
** This is the hash table
*/
#define KEY_HASH_SIZE 37
static Keyword *apHashTable[KEY_HASH_SIZE];


/*
** This function looks up an identifier to determine if it is a
** keyword.  If it is a keyword, the token code of that keyword is 
** returned.  If the input is not a keyword, TK_ID is returned.
*/
static int sqliteKeywordCode(const char *z, int n){
  int h;
  Keyword *p;
  if( aKeywordTable[0].len==0 ){
    /* Initialize the keyword hash table */
    int i;
    int n;
    n = sizeof(aKeywordTable)/sizeof(aKeywordTable[0]);
    for(i=0; i<n; i++){
      aKeywordTable[i].len = strlen(aKeywordTable[i].zName);
      h = sqliteHashNoCase(aKeywordTable[i].zName, aKeywordTable[i].len);
      h %= KEY_HASH_SIZE;
      aKeywordTable[i].pNext = apHashTable[h];
      apHashTable[h] = &aKeywordTable[i];
    }
  }
  h = sqliteHashNoCase(z, n) % KEY_HASH_SIZE;
  for(p=apHashTable[h]; p; p=p->pNext){
    if( p->len==n && sqliteStrNICmp(p->zName, z, n)==0 ){
      return p->tokenType;
    }
  }
  return TK_ID;
}

/*
** Return the length of the token that begins at z[0].  Return
** -1 if the token is (or might be) incomplete.  Store the token
** type in *tokenType before returning.
*/
int sqliteGetToken(const char *z, int *tokenType){
  int i;
  switch( *z ){
    case ' ': case '\t': case '\n': case '\f': {
      for(i=1; z[i] && isspace(z[i]); i++){}
      *tokenType = TK_SPACE;
      return i;
    }
    case '-': {
      if( z[1]==0 ) return -1;
      if( z[1]=='-' ){
        for(i=2; z[i] && z[i]!='\n'; i++){}
        *tokenType = TK_COMMENT;
        return i;
      }
      *tokenType = TK_MINUS;
      return 1;
    }
    case '(': {
      *tokenType = TK_LP;
      return 1;
    }
    case ')': {
      *tokenType = TK_RP;
      return 1;
    }
    case ';': {
      *tokenType = TK_SEMI;
      return 1;
    }
    case '+': {
      *tokenType = TK_PLUS;
      return 1;
    }
    case '*': {
      *tokenType = TK_STAR;
      return 1;
    }
    case '/': {
      *tokenType = TK_SLASH;
      return 1;
    }
    case '=': {
      *tokenType = TK_EQ;
      return 1 + (z[1]=='=');
    }
    case '<': {
      if( z[1]=='=' ){
        *tokenType = TK_LE;
        return 2;
      }else if( z[1]=='>' ){
        *tokenType = TK_NE;
        return 2;
      }else{
        *tokenType = TK_LT;
        return 1;
      }
    }
    case '>': {
      if( z[1]=='=' ){
        *tokenType = TK_GE;
        return 2;
      }else{
        *tokenType = TK_GT;
        return 1;
      }
    }
    case '!': {
      if( z[1]!='=' ){
        *tokenType = TK_ILLEGAL;
        return 1;
      }else{
        *tokenType = TK_NE;
        return 2;
      }
    }
    case ',': {
      *tokenType = TK_COMMA;
      return 1;
    }
    case '\'': case '"': {
      int delim = z[0];
      for(i=1; z[i]; i++){
        if( z[i]==delim ){
          if( z[i+1]==delim ){
            i++;
          }else{
            break;
          }
        }
      }
      if( z[i] ) i++;
      *tokenType = TK_STRING;
      return i;
    }
    case '.': {
      if( !isdigit(z[1]) ){
        *tokenType = TK_DOT;
        return 1;
      }
      /* Fall thru into the next case */
    }
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': {
      for(i=1; z[i] && isdigit(z[i]); i++){}
      if( z[i]=='.' ){
        i++;
        while( z[i] && isdigit(z[i]) ){ i++; }
        if( (z[i]=='e' || z[i]=='E') &&
           ( isdigit(z[i+1]) 
            || ((z[i+1]=='+' || z[i+1]=='-') && isdigit(z[i+2]))
           )
        ){
          i += 2;
          while( z[i] && isdigit(z[i]) ){ i++; }
        }
        *tokenType = TK_FLOAT;
      }else if( z[0]=='.' ){
        *tokenType = TK_FLOAT;
      }else{
        *tokenType = TK_INTEGER;
      }
      return i;
    }
    case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
    case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
    case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
    case 's': case 't': case 'u': case 'v': case 'w': case 'x':
    case 'y': case 'z': case '_':
    case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
    case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
    case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
    case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
    case 'Y': case 'Z': {
      for(i=1; z[i] && (isalnum(z[i]) || z[i]=='_'); i++){}
      *tokenType = sqliteKeywordCode(z, i);
      return i;
    }
    default: {
      break;
    }
  }
  *tokenType = TK_ILLEGAL;
  return 1;
}

/*
** Run the parser on the given SQL string.  The parser structure is
** passed in.  Return the number of errors.
*/
int sqliteRunParser(Parse *pParse, char *zSql, char **pzErrMsg){
  int nErr = 0;
  int i;
  void *pEngine;
  int once = 1;
  static FILE *trace = 0;
  extern void *sqliteParserAlloc(void*(*)(int));
  extern void sqliteParserFree(void*, void(*)(void*));
  extern int sqliteParser(void*, int, ...);
  extern void sqliteParserTrace(FILE*, char *);

  i = 0;
  pEngine = sqliteParserAlloc(sqliteMalloc);
  if( pEngine==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 1;
  }
  sqliteParserTrace(trace, "parser: ");
  while( nErr==0 && i>=0 && zSql[i]!=0 ){
    int tokenType;
    
    pParse->sLastToken.z = &zSql[i];
    pParse->sLastToken.n = sqliteGetToken(&zSql[i], &tokenType);
    i += pParse->sLastToken.n;
    if( once ){
      pParse->sFirstToken = pParse->sLastToken;
      once = 0;
    }
    switch( tokenType ){
      case TK_SPACE:
        break;
      case TK_COMMENT: {
        /* Various debugging modes can be turned on and off using
        ** special SQL comments.  Check for the special comments
        ** here and take approriate action if found.
        */
        char *z = pParse->sLastToken.z;
        if( sqliteStrNICmp(z,"--parser-trace-on--",19)==0 ){
          trace = stderr;
          sqliteParserTrace(trace, "parser: ");
        }else if( sqliteStrNICmp(z,"--parser-trace-off--", 20)==0 ){
          trace = 0;
          sqliteParserTrace(trace, "parser: ");
        }else if( sqliteStrNICmp(z,"--vdbe-trace-on--",17)==0 ){
          pParse->db->flags |= SQLITE_VdbeTrace;
        }else if( sqliteStrNICmp(z,"--vdbe-trace-off--", 19)==0 ){
          pParse->db->flags &= ~SQLITE_VdbeTrace;
        }
        break;
      }
      case TK_ILLEGAL:
        sqliteSetNString(pzErrMsg, "illegal token: \"", -1, 
           pParse->sLastToken.z, pParse->sLastToken.n, 0);
        nErr++;
        break;
      default:
        sqliteParser(pEngine, tokenType, pParse->sLastToken, pParse);
        if( pParse->zErrMsg ){
          sqliteSetNString(pzErrMsg, "near \"", -1, 
             pParse->sErrToken.z, pParse->sErrToken.n,
             "\": ", -1,
             pParse->zErrMsg, -1,
             0);
          nErr++;
        }
        break;
    }
  }
  if( nErr==0 ){
    sqliteParser(pEngine, 0, pParse->sLastToken, pParse);
    if( pParse->zErrMsg ){
       sqliteSetNString(pzErrMsg, "near \"", -1, 
          pParse->sErrToken.z, pParse->sErrToken.n,
          "\": ", -1,
          pParse->zErrMsg, -1,
          0);
       nErr++;
    }
  }
  sqliteParserFree(pEngine, sqliteFree);
  if( pParse->zErrMsg ){
    if( pzErrMsg ){
      *pzErrMsg = pParse->zErrMsg;
    }else{
      sqliteFree(pParse->zErrMsg);
    }
    if( !nErr ) nErr++;
  }
  if( pParse->pVdbe ){
    sqliteVdbeDelete(pParse->pVdbe);
    pParse->pVdbe = 0;
  }
  if( pParse->pNewTable ){
    sqliteDeleteTable(pParse->db, pParse->pNewTable);
    pParse->pNewTable = 0;
  }
  return nErr;
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.1 2000/05/29 14:26:02 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

/*
** Allocate new memory and set it to zero.  Return NULL if
** no memory is available.
*/
void *sqliteMalloc(int n){
  void *p = malloc(n);
  if( p==0 ) return 0;
  memset(p, 0, n);
  return p;
}

/*
** Free memory previously obtained from sqliteMalloc()
*/
void sqliteFree(void *p){
  if( p ) free(p);
}

/*
** Resize a prior allocation.  If p==0, then this routine
** works just like sqliteMalloc().  If n==0, then this routine
** works just like sqliteFree().
*/
void *sqliteRealloc(void *p, int n){
  if( p==0 ){
    return sqliteMalloc(n);
  }
  if( n==0 ){
    sqliteFree(p);
    return 0;
  }
  return realloc(p, n);
}

/*
** Create a string from the 2nd and subsequent arguments (up to the
** first NULL argument), store the string in memory obtained from
** sqliteMalloc() and make the pointer indicated by the 1st argument
** point to that string.
*/
void sqliteSetString(char **pz, const char *zFirst, ...){
  va_list ap;
  int nByte;
  const char *z;
  char *zResult;

  if( pz==0 ) return;
  nByte = strlen(zFirst) + 1;
  va_start(ap, zFirst);
  while( (z = va_arg(ap, const char*))!=0 ){
    nByte += strlen(z);
  }
  va_end(ap);
  sqliteFree(*pz);
  *pz = zResult = sqliteMalloc( nByte );
  if( zResult==0 ) return;
  strcpy(zResult, zFirst);
  zResult += strlen(zResult);
  va_start(ap, zFirst);
  while( (z = va_arg(ap, const char*))!=0 ){
    strcpy(zResult, z);
    zResult += strlen(zResult);
  }
  va_end(ap);
}

/*
** Works like sqliteSetString, but each string is now followed by
** a length integer.  -1 means use the whole string.
*/
void sqliteSetNString(char **pz, ...){
  va_list ap;
  int nByte;
  const char *z;
  char *zResult;
  int n;

  if( pz==0 ) return;
  nByte = 0;
  va_start(ap, pz);
  while( (z = va_arg(ap, const char*))!=0 ){
    n = va_arg(ap, int);
    if( n<=0 ) n = strlen(z);
    nByte += n;
  }
  va_end(ap);
  sqliteFree(*pz);
  *pz = zResult = sqliteMalloc( nByte + 1 );
  if( zResult==0 ) return;
  va_start(ap, pz);
  while( (z = va_arg(ap, const char*))!=0 ){
    n = va_arg(ap, int);
    if( n<=0 ) n = strlen(z);
    strncpy(zResult, z, n);
    zResult += n;
  }
  *zResult = 0;
  va_end(ap);
}

/* An array to map all upper-case characters into their corresponding
** lower-case character. 
*/
static unsigned char UpperToLower[] = {
      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
     18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
     36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
     54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
    104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
    122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
    108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
    126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
    162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
    180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
    198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
    216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
    234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
    252,253,254,255
};

/*
** This function computes a hash on the name of a keyword.
** Case is not significant.
*/
int sqliteHashNoCase(const char *z, int n){
  int h = 0;
  int c;
  if( n<=0 ) n = strlen(z);
  while( n-- > 0 && (c = *z++)!=0 ){
    h = h<<3 ^ h ^ UpperToLower[c];
  }
  if( h<0 ) h = -h;
  return h;
}

/*
** Some system shave stricmp().  Others have strcasecmp().  Because
** there is no consistency, we will define our own.
*/
int sqliteStrICmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return *a - *b;
}
int sqliteStrNICmp(const char *zLeft, const char *zRight, int N){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return N<=0 ? 0 : *a - *b;
}

/* Notes on string comparisions.
**
** We want the main string comparision function used for sorting to
** sort both numbers and alphanumeric words into the correct sequence.
** The same routine should do both without prior knowledge of which
** type of text the input represents.  It should even work for strings
** which are a mixture of text and numbers.
**
** To accomplish this, we keep track of a state number while scanning
** the two strings.  The states are as follows:
**
**    1      Beginning of word
**    2      Arbitrary text
**    3      Integer
**    4      Negative integer
**    5      Real number
**    6      Negative real
**
** The scan begins in state 1, beginning of word.  Transitions to other
** states are determined by characters seen, as shown in the following
** chart:
**
**      Current State         Character Seen  New State
**      --------------------  --------------  -------------------
**      0 Beginning of word   "-"             3 Negative integer
**                            digit           2 Integer
**                            space           0 Beginning of word
**                            otherwise       1 Arbitrary text
**
**      1 Arbitrary text      space           0 Beginning of word
**                            digit           2 Integer
**                            otherwise       1 Arbitrary text
**
**      2 Integer             space           0 Beginning of word
**                            "."             4 Real number
**                            digit           2 Integer
**                            otherwise       1 Arbitrary text
**
**      3 Negative integer    space           0 Beginning of word
**                            "."             5 Negative Real num
**                            digit           3 Negative integer
**                            otherwise       1 Arbitrary text
**
**      4 Real number         space           0 Beginning of word
**                            digit           4 Real number
**                            otherwise       1 Arbitrary text
**
**      5 Negative real num   space           0 Beginning of word
**                            digit           5 Negative real num
**                            otherwise       1 Arbitrary text
**
** To implement this state machine, we first classify each character
** into on of the following categories:
**
**      0  Text
**      1  Space
**      2  Digit
**      3  "-"
**      4  "."
**
** Given an arbitrary character, the array charClass[] maps that character
** into one of the atove categories.
*/
static const unsigned char charClass[] = {
        /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
/* 0x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0,
/* 1x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 2x */   1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 4, 0,
/* 3x */   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0,
/* 4x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 5x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 6x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 7x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 8x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 9x */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Ax */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Bx */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Cx */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Dx */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Ex */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* Fx */   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};
#define N_CHAR_CLASS 5

/*
** Given the current state number (0 thru 5), this array figures
** the new state number given the character class.
*/
static const unsigned char stateMachine[] = {
 /* Text,  Space, Digit, "-", "." */
      1,      0,    2,    3,   1,      /* State 0: Beginning of word */
      1,      0,    2,    1,   1,      /* State 1: Arbitrary text */
      1,      0,    2,    1,   4,      /* State 2: Integer */
      1,      0,    3,    1,   5,      /* State 3: Negative integer */
      1,      0,    4,    1,   1,      /* State 4: Real number */
      1,      0,    5,    1,   1,      /* State 5: Negative real num */
};

/* This routine does a comparison of two strings.  Case is used only
** if useCase!=0.  Numbers compare in numerical order.
*/
static int privateStrCmp(const char *atext, const char *btext, int useCase){
  register unsigned char *a, *b, *map, ca, cb;
  int result;
  register int cclass = 0;

  a = (unsigned char *)atext;
  b = (unsigned char *)btext;
  if( useCase ){
    do{
      if( (ca= *a++)!=(cb= *b++) ) break;
      cclass = stateMachine[cclass*N_CHAR_CLASS + charClass[ca]];
    }while( ca!=0 );
  }else{
    map = UpperToLower;
    do{
      if( (ca=map[*a++])!=(cb=map[*b++]) ) break;
      cclass = stateMachine[cclass*N_CHAR_CLASS + charClass[ca]];
    }while( ca!=0 );
  }
  switch( cclass ){
    case 0:
    case 1: {
      if( isdigit(ca) && isdigit(cb) ){
        cclass = 2;
      }
      break;
    }
    default: {
      break;
    }
  }
  switch( cclass ){
    case 2:
    case 3: {
      if( isdigit(ca) ){
        if( isdigit(cb) ){
          int acnt, bcnt;
          acnt = bcnt = 0;
          while( isdigit(*a++) ) acnt++;
          while( isdigit(*b++) ) bcnt++;
          result = acnt - bcnt;
          if( result==0 ) result = ca-cb;
        }else{
          result = 1;
        }
      }else if( isdigit(cb) ){
        result = -1;
      }else if( ca=='.' ){
        result = 1;
      }else if( cb=='.' ){
        result = -1;
      }else{
        result = ca - cb;
        cclass = 2;
      }
      if( cclass==3 ) result = -result;
      break;
    }
    case 0:
    case 1:
    case 4: {
      result = ca - cb;
      break;
    }
    case 5: {
      result = cb - ca;
    };
  }
  return result;
}

/* This comparison routine is what we use for comparison operations
** in an SQL expression.  (Ex:  name<'Hello' or value<5).  Compare two
** strings.  Use case only as a tie-breaker.  Numbers compare in
** numerical order.
*/
int sqliteCompare(const char *atext, const char *btext){
  int result;
  result = privateStrCmp(atext, btext, 0);
  if( result==0 ) result = privateStrCmp(atext, btext, 1);
  return result;
}

/*
** If you compile just this one file with the -DTEST_COMPARE=1 option,
** it generates a program to test the comparisons routines.  
*/
#ifdef TEST_COMPARE
#include <stdlib.h>
#include <stdio.h>
int sortCmp(const char **a, const char **b){
  return sqliteCompare(*a, *b);
}
int main(int argc, char **argv){
  int i, j, k, n;
  static char *azStr[] = {
     "abc", "aBc", "abcd", "aBcd", 
     "123", "124", "1234", "-123", "-124", "-1234", 
     "123.45", "123.456", "123.46", "-123.45", "-123.46", "-123.456", 
     "x9", "x10", "x-9", "x-10", "X9", "X10",
  };
  n = sizeof(azStr)/sizeof(azStr[0]);
  qsort(azStr, n, sizeof(azStr[0]), sortCmp);
  for(i=0; i<n; i++){
    printf("%s\n", azStr[i]);
  }
  printf("Sanity1...");
  fflush(stdout);
  for(i=0; i<n-1; i++){
    char *a = azStr[i];
    for(j=i+1; j<n; j++){
      char *b = azStr[j];
      if( sqliteCompare(a,b) != -sqliteCompare(b,a) ){
        printf("Failed!  \"%s\" vs \"%s\"\n", a, b);
        i = j = n;
      }
    }
  }
  if( i<n ){
    printf(" OK\n");
  }
  return 0;
}
#endif

/*
** This routine is used for sorting.  Each key is a list one or more
** null-terminated strings.  The list is terminated by two null in
** a row.  For example, the following text is strings:
**
**            +one\000-two\000+three\000\000
**
** Both arguments will have the same number of strings.  This routine
** returns negative, zero, or positive if the first argument is less
** than, equal to, or greater than the first.  (Result is a-b).
**
** Every string begins with either a "+" or "-" character.  If the
** character is "-" then the return value is negated.  This is done
** to implement a sort in descending order.
*/
int sqliteSortCompare(const char *a, const char *b){
  int len;
  int res = 0;

  while( res==0 && *a && *b ){
    res = sqliteCompare(&a[1], &b[1]);
    if( res==0 ){
      len = strlen(a) + 1;
      a += len;
      b += len;
    }
  }
  if( *a=='-' ) res = -res;
  return res;
}

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** The code in this file implements the Virtual Database Engine (VDBE)
**
** The SQL parser generates a program which is then executed by
** the VDBE to do the work of the SQL statement.  VDBE programs are 
** similar in form to assembly language.  The program consists of
** a linear sequence of operations.  Each operation has an opcode 
** and 3 operands.  Operands P1 and P2 are integers.  Operand P3 
** is a null-terminated string.   The P2 operand must be non-negative.
** Opcodes will typically ignore one or more operands.  Many opcodes
** ignore all three operands.
**
** Computation results are stored on a stack.  Each entry on the
** stack is either an integer or a null-terminated string.  An
** inplicit conversion from one type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.1 2000/05/29 14:26:02 drh Exp $
*/
#include "sqliteInt.h"

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.
*/
typedef struct VdbeOp Op;

/*
** Every table that the virtual machine has open is represented by an
** instance of the following structure.
*/
struct VdbeTable {
  DbbeTable *pTable;    /* The table structure of the backend */
  int index;            /* The next index to extract */
};
typedef struct VdbeTable VdbeTable;

/*
** A sorter builds a list of elements to be sorted.  Each element of
** the list is an instance of the following structure.
*/
typedef struct Sorter Sorter;
struct Sorter {
  int nKey;           /* Number of bytes in the key */
  char *zKey;         /* The key by which we will sort */
  int nData;          /* Number of bytes in the data */
  char *pData;        /* The data associated with this key */
  Sorter *pNext;      /* Next in the list */
};

/* 
** Number of buckets used for merge-sort.  
*/
#define NSORT 30

/*
** An instance of the virtual machine
*/
struct Vdbe {
  Dbbe *pBe;          /* Opaque context structure used by DB backend */
  FILE *trace;        /* Write an execution trace here, if not NULL */
  int nOp;            /* Number of instructions in the program */
  int nOpAlloc;       /* Number of slots allocated for aOp[] */
  Op *aOp;            /* Space to hold the virtual machine's program */
  int nLabel;         /* Number of labels used */
  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
  int *aLabel;        /* Space to hold the labels */
  int tos;            /* Index of top of stack */
  int nStackAlloc;    /* Size of the stack */
  int *iStack;        /* Integer values of the stack */
  char **zStack;      /* Text or binary values of the stack */
  char **azColName;   /* Becomes the 4th parameter to callbacks */
  int nTable;         /* Number of slots in aTab[] */
  VdbeTable *aTab;    /* On element of this array for each open table */
  int nList;          /* Number of slots in apList[] */
  FILE **apList;      /* An open file for each list */
  int nSort;          /* Number of slots in apSort[] */
  Sorter **apSort;    /* An open sorter list */
};

/*
** Create a new virtual database engine.
*/
Vdbe *sqliteVdbeCreate(Dbbe *pBe){
  Vdbe *p;

  p = sqliteMalloc( sizeof(Vdbe) );
  p->pBe = pBe;
  return p;
}

/*
** Turn tracing on or off
*/
void sqliteVdbeTrace(Vdbe *p, FILE *trace){
  p->trace = trace;
}

/*
** Add a new instruction to the list of instructions current in the
** VDBE.  Return the address of the new instruction.
**
** Parameters:
**
**    p               Pointer to the VDBE
**
**    op              The opcode for this instruction
**
**    p1, p2, p3      Three operands.
**
**    lbl             A symbolic label for this instruction.
**
** Symbolic labels are negative numbers that stand for the address
** of instructions that have yet to be coded.  When the instruction
** is coded, its real address is substituted in the p2 field of
** prior and subsequent instructions that have the lbl value in
** their p2 fields.
*/
int sqliteVdbeAddOp(Vdbe *p, int op, int p1, int p2, const char *p3, int lbl){
  int i, j;

  i = p->nOp;
  p->nOp++;
  if( i>=p->nOpAlloc ){
    int oldSize = p->nOpAlloc;
    p->nOpAlloc = p->nOpAlloc*2 + 10;
    p->aOp = sqliteRealloc(p->aOp, p->nOpAlloc*sizeof(Op));
    if( p->aOp==0 ){
      p->nOp = 0;
      p->nOpAlloc = 0;
      return 0;
    }
    memset(&p->aOp[oldSize], 0, (p->nOpAlloc-oldSize)*sizeof(Op));
  }
  p->aOp[i].opcode = op;
  p->aOp[i].p1 = p1;
  if( p2<0 && (-1-p2)<p->nLabel && p->aLabel[-1-p2]>=0 ){
    p2 = p->aLabel[-1-p2];
  }
  p->aOp[i].p2 = p2;
  if( p3 && p3[0] ){
    sqliteSetString(&p->aOp[i].p3, p3, 0);
  }else{
    p->aOp[i].p3 = 0;
  }
  if( lbl<0 && (-lbl)<=p->nLabel ){
    p->aLabel[-1-lbl] = i;
    for(j=0; j<i; j++){
      if( p->aOp[j].p2==lbl ) p->aOp[j].p2 = i;
    }
  }
  return i;
}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.
*/
void sqliteVdbeResolveLabel(Vdbe *p, int x){
  int j;
  if( x<0 && (-x)<=p->nLabel ){
    p->aLabel[-1-x] = p->nOp;
    for(j=0; j<p->nOp; j++){
      if( p->aOp[j].p2==x ) p->aOp[j].p2 = p->nOp;
    }
  }
}

/*
** Return the address of the next instruction to be inserted.
*/
int sqliteVdbeCurrentAddr(Vdbe *p){
  return p->nOp;
}

/*
** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.
*/
int sqliteVdbeAddOpList(Vdbe *p, int nOp, VdbeOp const *aOp){
  int addr;
  if( p->nOp + nOp >= p->nOpAlloc ){
    int oldSize = p->nOpAlloc;
    p->nOpAlloc = p->nOpAlloc*2 + nOp + 10;
    p->aOp = sqliteRealloc(p->aOp, p->nOpAlloc*sizeof(Op));
    if( p->aOp==0 ){
      p->nOp = 0;
      p->nOpAlloc = 0;
      return 0;
    }
    memset(&p->aOp[oldSize], 0, (p->nOpAlloc-oldSize)*sizeof(Op));
  }
  addr = p->nOp;
  if( nOp>0 ){
    int i;
    for(i=0; i<nOp; i++){
      int p2 = aOp[i].p2;
      if( p2<0 ) p2 = addr + ADDR(p2);
      sqliteVdbeAddOp(p, aOp[i].opcode, aOp[i].p1, p2, aOp[i].p3, 0);
    }
  }
  return addr;
}

/*
** Change the value of the P3 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqliteVdbeAddOpList but we want to make a
** few minor changes to the program.
*/
void sqliteVdbeChangeP3(Vdbe *p, int addr, const char *zP3, int n){
  if( p && addr>=0 && p->nOp>addr && zP3 ){
    sqliteSetNString(&p->aOp[addr].p3, zP3, n, 0);
  }
}

/*
** If the P3 operand to the specified instruction appears
** to be a quoted string token, then this procedure removes 
** the quotes.
**
** The quoting operator can be either a grave ascent (ASCII 0x27)
** or a double quote character (ASCII 0x22).  Two quotes in a row
** resolve to be a single actual quote character within the string.
*/
void sqliteVdbeDequoteP3(Vdbe *p, int addr){
  int quote;
  int i, j;
  char *z;
  if( addr<0 || addr>=p->nOp ) return;
  z = p->aOp[addr].p3;
  quote = z[0];
  if( quote!='\'' && quote!='"' ) return;
  for(i=1, j=0; z[i]; i++){
    if( z[i]==quote ){
      if( z[i+1]==quote ){
        z[j++] = quote;
        i++;
      }else{
        z[j++] = 0;
        break;
      }
    }else{
      z[j++] = z[i];
    }
  }
}

/*
** Create a new symbolic label for an instruction that has yet to be
** coded.  The symbolic label is really just a negative number.  The
** label can be used as the P2 value of an operation.  Later, when
** the label is resolved to a specific address, the VDBE will scan
** through its operation list and change all values of P2 which match
** the label into the resolved address.
**
** The VDBE knows that a P2 value is a label because labels are
** always negative and P2 values are suppose to be non-negative.
** Hence, a negative P2 value is a label that has yet to be resolved.
*/
int sqliteVdbeMakeLabel(Vdbe *p){
  int i;
  i = p->nLabel++;
  if( i>=p->nLabelAlloc ){
    p->nLabelAlloc = p->nLabelAlloc*2 + 10;
    p->aLabel = sqliteRealloc( p->aLabel, p->nLabelAlloc*sizeof(int));
  }
  if( p->aLabel==0 ){
    p->nLabel = 0;
    p->nLabelAlloc = 0;
    return 0;
  }
  p->aLabel[i] = -1;
  return -1-i;
}

/*
** Pop the stack N times.  Free any memory associated with the
** popped stack elements.
*/
static void PopStack(Vdbe *p, int N){
  if( p->zStack==0 ) return;
  while( p->tos>=0 && N-->0 ){
    int i = p->tos--;
    sqliteFree(p->zStack[i]);
    p->zStack[i] = 0;
  }    
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any tables, list, and/or
** sorters that were left open.
*/
static void Cleanup(Vdbe *p){
  int i;
  PopStack(p, p->tos+1);
  sqliteFree(p->azColName);
  p->azColName = 0;
  for(i=0; i<p->nTable; i++){
    if( p->aTab[i].pTable ){
      sqliteDbbeCloseTable(p->aTab[i].pTable);
      p->aTab[i].pTable = 0;
    }
  }
  sqliteFree(p->aTab);
  p->aTab = 0;
  p->nTable = 0;
  for(i=0; i<p->nList; i++){
    if( p->apList[i] ){
      sqliteDbbeCloseTempFile(p->pBe, p->apList[i]);
      p->apList[i] = 0;
    }
  }
  sqliteFree(p->apList);
  p->apList = 0;
  p->nList = 0;
  for(i=0; i<p->nSort; i++){
    Sorter *pSorter;
    while( (pSorter = p->apSort[i])!=0 ){
      p->apSort[i] = pSorter->pNext;
      sqliteFree(pSorter->zKey);
      sqliteFree(pSorter->pData);
      sqliteFree(pSorter);
    }
  }
  sqliteFree(p->apSort);
  p->apSort = 0;
  p->nSort = 0;
}

/*
** Delete an entire VDBE.
*/
void sqliteVdbeDelete(Vdbe *p){
  int i;
  if( p==0 ) return;
  Cleanup(p);
  if( p->nOpAlloc==0 ){
    p->aOp = 0;
    p->nOp = 0;
  }
  for(i=0; i<p->nOp; i++){
    sqliteFree(p->aOp[i].p3);
  }
  sqliteFree(p->aOp);
  sqliteFree(p->aLabel);
  sqliteFree(p->iStack);
  sqliteFree(p->zStack);
  sqliteFree(p);
}

/*
** A translation from opcode numbers to opcode names.  Used for testing
** and debugging only.
**
** If any of the numeric OP_ values for opcodes defined in sqliteVdbe.h
** change, be sure to change this array to match.  You can use the
** "opNames.awk" awk script which is part of the source tree to regenerate
** this array, then copy and paste it into this file, if you want.
*/
static char *zOpName[] = { 0,
  "Open",           "Close",          "Destroy",        "Fetch",
  "New",            "Put",            "Delete",         "Field",
  "Key",            "Rewind",         "Next",           "ResetIdx",
  "NextIdx",        "PutIdx",         "DeleteIdx",      "ListOpen",
  "ListWrite",      "ListRewind",     "ListRead",       "ListClose",
  "SortOpen",       "SortPut",        "SortMakeRec",    "SortMakeKey",
  "Sort",           "SortNext",       "SortKey",        "SortCallback",
  "SortClose",      "MakeRecord",     "MakeKey",        "Goto",
  "If",             "Halt",           "ColumnCount",    "ColumnName",
  "Callback",       "Integer",        "String",         "Pop",
  "Dup",            "Pull",           "Add",            "AddImm",
  "Subtract",       "Multiply",       "Divide",         "Min",
  "Max",            "Eq",             "Ne",             "Lt",
  "Le",             "Gt",             "Ge",             "IsNull",
  "NotNull",        "Negative",       "And",            "Or",
  "Not",            "Concat",         "Noop",         
};

/*
** Given the name of an opcode, return its number.  Return 0 if
** there is no match.
**
** This routine is used for testing and debugging.
*/
int sqliteVdbeOpcode(const char *zName){
  int i;
  for(i=1; i<=OP_MAX; i++){
    if( sqliteStrICmp(zName, zOpName[i])==0 ) return i;
  }
  return 0;
}

/*
** Give a listing of the program in the virtual machine.
**
** The interface is the same as sqliteVdbeExec().  But instead of
** running the code, it invokes the callback once for each instruction.
** This feature is used to implement "EXPLAIN".
*/
int sqliteVdbeList(
  Vdbe *p,                   /* The VDBE */
  sqlite_callback xCallback, /* The callback */
  void *pArg,                /* 1st argument to callback */
  char **pzErrMsg            /* Error msg written here */
){
  int i, rc;
  char *azField[6];
  char zAddr[20];
  char zP1[20];
  char zP2[20];
  static char *azColumnNames[] = {
     "addr", "opcode", "p1", "p2", "p3", 0
  };

  if( xCallback==0 ) return 0;
  azField[0] = zAddr;
  azField[2] = zP1;
  azField[3] = zP2;
  azField[5] = 0;
  rc = 0;
  if( pzErrMsg ){ *pzErrMsg = 0; }
  for(i=0; rc==0 && i<p->nOp; i++){
    sprintf(zAddr,"%d",i);
    sprintf(zP1,"%d", p->aOp[i].p1);
    sprintf(zP2,"%d", p->aOp[i].p2);
    azField[4] = p->aOp[i].p3;
    if( azField[4]==0 ) azField[4] = "";
    azField[1] = zOpName[p->aOp[i].opcode];
    rc = xCallback(pArg, 5, azField, azColumnNames);
  }
  return rc;
}

/*
** Make sure space has been allocated to hold at least N
** stack elements.  Allocate additional stack space if
** necessary.
**
** Return 0 on success and non-zero if there are memory
** allocation errors.
*/
static int NeedStack(Vdbe *p, int N){
  int oldAlloc;
  int i;
  if( N>=p->nStackAlloc ){
    oldAlloc = p->nStackAlloc;
    p->nStackAlloc = N + 20;
    p->iStack = sqliteRealloc(p->iStack, p->nStackAlloc*sizeof(int));
    p->zStack = sqliteRealloc(p->zStack, p->nStackAlloc*sizeof(char*));
    if( p->iStack==0 || p->zStack==0 ){
      sqliteFree(p->iStack);
      sqliteFree(p->zStack);
      p->iStack = 0;
      p->zStack = 0;
      p->nStackAlloc = 0;
      return 1;
    }
    for(i=oldAlloc; i<p->nStackAlloc; i++){
      p->zStack[i] = 0;
    }
  }
  return 0;
}

/*
** Convert the given stack entity into a string if it isn't one
** already.  Return non-zero if we run out of memory.
*/
static int Stringify(Vdbe *p, int i){
  if( p->zStack[i]==0 ){
    char zBuf[30];
    sprintf(zBuf,"%d",p->iStack[i]);
    sqliteSetString(&p->zStack[i], zBuf, 0);
    if( p->zStack[i]==0 ) return 1;
    p->iStack[i] = strlen(p->zStack[i])+1;
  }
  return 0;
}

/*
** Convert the given stack entity into a integer if it isn't one
** already.
*/
static int Integerify(Vdbe *p, int i){
  if( p->zStack[i]!=0 ){
    p->iStack[i] = atoi(p->zStack[i]);
    sqliteFree(p->zStack[i]);
    p->zStack[i] = 0;
  }
  return p->iStack[i];
}

/*
** The parameters are pointers to the head of two sorted lists
** of Sorter structures.  Merge these two lists together and return
** a single sorted list.  This routine forms the core of the merge-sort
** algorithm.
**
** In the case of a tie, left sorts in front of right.
*/
static Sorter *Merge(Sorter *pLeft, Sorter *pRight){
  Sorter sHead;
  Sorter *pTail;
  pTail = &sHead;
  pTail->pNext = 0;
  while( pLeft && pRight ){
    int c = sqliteSortCompare(pLeft->zKey, pRight->zKey);
    if( c<=0 ){
      pTail->pNext = pLeft;
      pLeft = pLeft->pNext;
    }else{
      pTail->pNext = pRight;
      pRight = pRight->pNext;
    }
    pTail = pTail->pNext;
  }
  if( pLeft ){
    pTail->pNext = pLeft;
  }else if( pRight ){
    pTail->pNext = pRight;
  }
  return sHead.pNext;
}


/*
** Execute the program in the VDBE.
**
** If an error occurs, an error message is written to memory obtained
** from sqliteMalloc() and *pzErrMsg is made to point to that memory.
** The return parameter is the number of errors.
**
** If the callback every returns non-zero, then the program exits
** immediately.  No error message is written but the return value
** from the callback because the return value of this routine.
*/
int sqliteVdbeExec(
  Vdbe *p,                   /* The VDBE */
  sqlite_callback xCallback, /* The callback */
  void *pArg,                /* 1st argument to callback */
  char **pzErrMsg            /* Error msg written here */
){
  int pc;                    /* The program counter */
  Op *pOp;                   /* Current operation */
  int rc;                    /* Value to return */
  char zBuf[100];            /* Space to sprintf() and integer */

  p->tos = -1;
  rc = 0;
  if( pzErrMsg ){ *pzErrMsg = 0; }
  for(pc=0; rc==0 && pc<p->nOp && pc>=0; pc++){
    pOp = &p->aOp[pc];
    if( p->trace ){
      fprintf(p->trace,"%4d %-12s %4d %4d %s\n",
        pc, zOpName[pOp->opcode], pOp->p1, pOp->p2,
           pOp->p3 ? pOp->p3 : "");
    }
    switch( pOp->opcode ){
      /* Opcode:  Goto P2 * *
      **
      ** An unconditional jump to address P2.
      ** The next instruction executed will be 
      ** the one at index P2 from the beginning of
      ** the program.
      */
      case OP_Goto: {
        pc = pOp->p2;
        if( pc<0 || pc>p->nOp ){
          sqliteSetString(pzErrMsg, "jump destination out of range", 0);
          rc = 1;
        }
        pc--;
        break;
      }

      /* Opcode:  Halt * * *
      **
      ** Exit immediately.  All open DBs, Lists, Sorts, etc are closed
      ** automatically.
      */
      case OP_Halt: {
        pc = p->nOp-1;
        break;
      }

      /* Opcode: Integer P1 * *
      **
      ** The integer value P1 is pushed onto the stack.
      */
      case OP_Integer: {
        int i = ++p->tos;
        if( NeedStack(p, p->tos) ) goto no_mem;
        p->iStack[i] = pOp->p1;
        p->zStack[i] = 0;
        break;
      }

      /* Opcode: String * * P3
      **
      ** The string value P3 is pushed onto the stack.
      */
      case OP_String: {
        int i = ++p->tos;
        char *z;
        if( NeedStack(p, p->tos) ) goto no_mem;
        z = pOp->p3;
        if( z==0 ) z = "";
        p->iStack[i] = strlen(z) + 1;
        sqliteSetString(&p->zStack[i], z, 0);
        break;
      }

      /* Opcode: Pop P1 * *
      **
      ** P1 elements are popped off of the top of stack and discarded.
      */
      case OP_Pop: {
        PopStack(p, pOp->p1);
        break;
      }

      /* Opcode: Dup P1 * *
      **
      ** A copy of the P1-th element of the stack 
      ** is made and pushed onto the top of the stack.
      ** The top of the stack is element 0.  So the
      ** instruction "Dup 0 0 0" will make a copy of the
      ** top of the stack.
      */
      case OP_Dup: {
        int i = p->tos - pOp->p1;
        int j = ++p->tos;
        if( i<0 ) goto not_enough_stack;
        if( NeedStack(p, p->tos) ) goto no_mem;
        p->iStack[j] = p->iStack[i];
        if( p->zStack[i] ){
          p->zStack[j] = sqliteMalloc( p->iStack[j] );
          if( p->zStack[j] ) memcpy(p->zStack[j], p->zStack[i], p->iStack[j]);
        }else{
          p->zStack[j] = 0;
        }
        break;
      }

      /* Opcode: Pull P1 * *
      **
      ** The P1-th element is removed its current location on 
      ** the stack and pushed back on top of the stack.  The
      ** top of the stack is element 0, so "Pull 0 0 0" is
      ** a no-op.
      */
      case OP_Pull: {
        int from = p->tos - pOp->p1;
        int to = p->tos;
        int i;
        int ti;
        char *tz;
        if( from<0 ) goto not_enough_stack;
        ti = p->iStack[from];
        tz = p->zStack[from];
        for(i=from; i<to; i++){
          p->iStack[i] = p->iStack[i+1];
          p->zStack[i] = p->zStack[i+1];
        }
        p->iStack[to] = ti;
        p->zStack[to] = tz;
        break;
      }

      /* Opcode: ColumnCount P1 * *
      **
      ** Specify the number of column values that will appear in the
      ** array passed as the 4th parameter to the callback.  No checking
      ** is done.  If this value is wrong, a coredump can result.
      */
      case OP_ColumnCount: {
        p->azColName = sqliteRealloc(p->azColName, (pOp->p1+1)*sizeof(char*));
        if( p->azColName==0 ) goto no_mem;
        p->azColName[pOp->p1] = 0;
        break;
      }

      /* Opcode: ColumnName P1 * P3
      **
      ** P3 becomes the P1-th column name (first is 0).  An array of pointers
      ** to all column names is passed as the 4th parameter to the callback.
      ** The ColumnCount opcode must be executed first to allocate space to
      ** hold the column names.  Failure to do this will likely result in
      ** a coredump.
      */
      case OP_ColumnName: {
        p->azColName[pOp->p1] = pOp->p3 ? pOp->p3 : "";
        break;
      }

      /* Opcode: Callback P1 * *
      **
      ** Pop P1 values off the stack and form them into an array.  Then
      ** invoke the callback function using the newly formed array as the
      ** 3rd parameter.
      */
      case OP_Callback: {
        int i = p->tos - pOp->p1 + 1;
        int j;
        if( i<0 ) goto not_enough_stack;
        if( NeedStack(p, p->tos+2) ) goto no_mem;
        for(j=i; j<=p->tos; j++){
          if( Stringify(p, j) ) goto no_mem;
        }
        p->zStack[p->tos+1] = 0;
        rc = xCallback(pArg, pOp->p1, &p->zStack[i], p->azColName);
        PopStack(p, pOp->p1);
        break;
      }

      /* Opcode: Concat * * *
      **
      ** Pop two elements from the stack.  Append the first (what used
      ** to be the top of stack) to the second (the next on stack) to 
      ** form a new string.  Push the new string back onto the stack.
      */
      case OP_Concat: {
        int tos = p->tos;
        int nos = tos - 1;
        char *z;
        if( nos<0 ) goto not_enough_stack;
        Stringify(p, tos);
        Stringify(p, nos);
        z = 0;
        sqliteSetString(&z, p->zStack[nos], p->zStack[tos], 0);
        PopStack(p, 1);
        sqliteFree(p->zStack[nos]);
        p->zStack[nos] = z;
        p->iStack[nos] = strlen(p->zStack[nos])+1;
        break;
      }

      /* Opcode: Add * * *
      **
      ** Pop the top two elements from the stack, add them together,
      ** and push the result back onto the stack.  If either element
      ** is a string then it is converted to a double using the atof()
      ** function before the addition.
      */
      /* Opcode: Multiply * * *
      **
      ** Pop the top two elements from the stack, multiply them together,
      ** and push the result back onto the stack.  If either element
      ** is a string then it is converted to a double using the atof()
      ** function before the multiplication.
      */
      /* Opcode: Subtract * * *
      **
      ** Pop the top two elements from the stack, subtract the
      ** first (what was on top of the stack) from the second (the
      ** next on stack)
      ** and push the result back onto the stack.  If either element
      ** is a string then it is converted to a double using the atof()
      ** function before the subtraction.
      */
      /* Opcode: Divide * * *
      **
      ** Pop the top two elements from the stack, divide the
      ** first (what was on top of the stack) from the second (the
      ** next on stack)
      ** and push the result back onto the stack.  If either element
      ** is a string then it is converted to a double using the atof()
      ** function before the division.  Division by zero causes the
      ** program to abort with an error.
      */
      case OP_Add:
      case OP_Subtract:
      case OP_Multiply:
      case OP_Divide: {
        int tos = p->tos;
        int nos = tos - 1;
        if( nos<0 ) goto not_enough_stack;
        if( p->zStack[tos]==0 && p->zStack[nos]==0 ){
          int a, b;
          a = p->iStack[tos];
          b = p->iStack[nos];
          switch( pOp->opcode ){
            case OP_Add:         b += a;       break;
            case OP_Subtract:    b -= a;       break;
            case OP_Multiply:    b *= a;       break;
            default: {
              if( a==0 ){ 
                sqliteSetString(pzErrMsg, "division by zero", 0);
                rc = 1;
                goto cleanup;
              }
              b /= a;
              break;
            }
          }
          PopStack(p, 1);
          p->iStack[nos] = b;
        }else{
          double a, b;
          Stringify(p, tos);
          Stringify(p, nos);
          a = atof(p->zStack[tos]);
          b = atof(p->zStack[nos]);
          switch( pOp->opcode ){
            case OP_Add:         b += a;       break;
            case OP_Subtract:    b -= a;       break;
            case OP_Multiply:    b *= a;       break;
            default: {
              if( a==0.0 ){ 
                sqliteSetString(pzErrMsg, "division by zero", 0);
                rc = 1;
                goto cleanup;
              }
              b /= a;
              break;
            }
          }
          sprintf(zBuf,"%g",b);
          PopStack(p, 1);
          sqliteSetString(&p->zStack[nos], zBuf, 0);
          if( p->zStack[nos]==0 ) goto no_mem;
          p->iStack[nos] = strlen(p->zStack[nos]) + 1;
        }
        break;
      }

      /* Opcode: Max * * *
      **
      ** Pop the top two elements from the stack then push back the
      ** largest of the two.
      */
      case OP_Max: {
        int tos = p->tos;
        int nos = tos - 1;
        if( nos<0 ) goto not_enough_stack;
        if( p->zStack[tos]==0 && p->zStack[nos]==0 ){
          if( p->iStack[nos]<p->iStack[tos] ){
            p->iStack[nos] = p->iStack[tos];
          }
        }else{
          Stringify(p, tos);
          Stringify(p, nos);
          if( sqliteCompare(p->zStack[nos], p->zStack[tos])<0 ){
            sqliteFree(p->zStack[nos]);
            p->zStack[nos] = p->zStack[tos];
            p->iStack[nos] = p->iStack[tos];
          }
        }
        p->tos--;
        break;
      }

      /* Opcode: Min * * *
      **
      ** Pop the top two elements from the stack then push back the
      ** smaller of the two.
      */
      case OP_Min: {
        int tos = p->tos;
        int nos = tos - 1;
        if( nos<0 ) goto not_enough_stack;
        if( p->zStack[tos]==0 && p->zStack[nos]==0 ){
          if( p->iStack[nos]>p->iStack[tos] ){
            p->iStack[nos] = p->iStack[tos];
          }
        }else{
          Stringify(p, tos);
          Stringify(p, nos);
          if( sqliteCompare(p->zStack[nos], p->zStack[tos])>0 ){
            sqliteFree(p->zStack[nos]);
            p->zStack[nos] = p->zStack[tos];
            p->iStack[nos] = p->iStack[tos];
          }
        }
        p->tos--;
        break;
      }

      /* Opcode: AddImm  P1 * *
      ** 
      ** Add the value P1 to whatever is on top of the stack.
      */
      case OP_AddImm: {
        int tos = p->tos;
        if( tos<0 ) goto not_enough_stack;
        Integerify(p, tos);
        p->iStack[tos] += pOp->p1;
        break;
      }

      /* Opcode: Eq * P2 *
      **
      ** Pop the top two elements from the stack.  If they are equal, then
      ** jump to instruction P2.  Otherwise, continue to the next instruction.
      */
      /* Opcode: Ne * P2 *
      **
      ** Pop the top two elements from the stack.  If they are not equal, then
      ** jump to instruction P2.  Otherwise, continue to the next instruction.
      */
      /* Opcode: Lt * P2 *
      **
      ** Pop the top two elements from the stack.  If second element (the
      ** next on stack) is less than the first (the top of stack), then
      ** jump to instruction P2.  Otherwise, continue to the next instruction.
      ** In other words, jump if NOS<TOS.
      */
      /* Opcode: Le * P2 *
      **
      ** Pop the top two elements from the stack.  If second element (the
      ** next on stack) is less than or equal to the first (the top of stack),
      ** then jump to instruction P2. In other words, jump if NOS<=TOS.
      */
      /* Opcode: Gt * P2 *
      **
      ** Pop the top two elements from the stack.  If second element (the
      ** next on stack) is greater than the first (the top of stack),
      ** then jump to instruction P2. In other words, jump if NOS>TOS.
      */
      /* Opcode: Ge * P2 *
      **
      ** Pop the top two elements from the stack.  If second element (the next
      ** on stack) is greater than or equal to the first (the top of stack),
      ** then jump to instruction P2. In other words, jump if NOS>=TOS.
      */
      case OP_Eq:
      case OP_Ne:
      case OP_Lt:
      case OP_Le:
      case OP_Gt:
      case OP_Ge: {
        int tos = p->tos;
        int nos = tos - 1;
        int c;
        if( nos<0 ) goto not_enough_stack;
        if( p->zStack[tos]==0 && p->zStack[nos]==0 ){
          int a, b;
          a = p->iStack[tos];
          b = p->iStack[nos];
          switch( pOp->opcode ){
            case OP_Eq:    c = b==a;     break;
            case OP_Ne:    c = b!=a;     break;
            case OP_Lt:    c = b<a;      break;
            case OP_Le:    c = b<=a;     break;
            case OP_Gt:    c = b>a;      break;
            default:       c = b>=a;     break;
          }
        }else{
          Stringify(p, tos);
          Stringify(p, nos);
          c = sqliteCompare(p->zStack[nos], p->zStack[tos]);
          switch( pOp->opcode ){
            case OP_Eq:    c = c==0;     break;
            case OP_Ne:    c = c!=0;     break;
            case OP_Lt:    c = c<0;      break;
            case OP_Le:    c = c<=0;     break;
            case OP_Gt:    c = c>0;      break;
            default:       c = c>=0;     break;
          }
        }
        PopStack(p, 2);
        if( c ) pc = pOp->p2-1;
        break;
      }

      /* Opcode: And * * *
      **
      ** Pop two values off the stack.  Take the logical AND of the
      ** two values and push the resulting boolean value back onto the
      ** stack.  Integers are considered false if zero and true otherwise.
      ** Strings are considered false if their length is zero and true
      ** otherwise.
      */
      /* Opcode: Or * * *
      **
      ** Pop two values off the stack.  Take the logical OR of the
      ** two values and push the resulting boolean value back onto the
      ** stack.  Integers are considered false if zero and true otherwise.
      ** Strings are considered false if their length is zero and true
      ** otherwise.
      */
      case OP_And:
      case OP_Or: {
        int tos = p->tos;
        int nos = tos - 1;
        int x, y, c;
        if( nos<0 ) goto not_enough_stack;
        x = p->zStack[nos] ? p->zStack[nos][0] : p->iStack[nos];
        y = p->zStack[tos] ? p->zStack[tos][0] : p->iStack[tos];
        if( pOp->opcode==OP_And ){
          c = x && y;
        }else{
          c = x || y;
        }
        PopStack(p, 2);
        p->tos++;
        p->iStack[nos] = c;
        break;
      }

      /* Opcode: Negative * * *
      **
      ** Treat the top of the stack as a numeric quantity.  Replace it
      ** with its additive inverse.  If the top of stack is a string,
      ** then it is converted into a number using atof().
      */
      case OP_Negative: {
        int tos;
        if( (tos = p->tos)<0 ) goto not_enough_stack;
        if( p->zStack[tos] ){
          double r = atof(p->zStack[tos]);
          sprintf(zBuf, "%g", -r);
          sqliteSetString(&p->zStack[tos], zBuf, 0);
          p->iStack[tos] = strlen(zBuf) + 1;
        }else{
          p->iStack[tos] = -p->iStack[tos];
        }
        break;
      }

      /* Opcode: Not * * *
      **
      ** Treat the top of the stack as a boolean value.  Replace it
      ** with its complement.  Integers are false if zero and true
      ** otherwise.  Strings are false if zero-length and true otherwise.
      */
      case OP_Not: {
        int c;
        if( p->tos<0 ) goto not_enough_stack;
        c = p->zStack[p->tos] ? p->zStack[p->tos][0] : p->iStack[p->tos];
        PopStack(p, 1);
        p->tos++;
        p->iStack[p->tos] = !c;
        break;
      }

      /* Opcode: Noop * * *
      **
      ** Do nothing.  This instruction is often useful as a jump
      ** destination.
      */
      case OP_Noop: {
        break;
      }

      /* Opcode: If * P2 *
      **
      ** Pop a single boolean from the stack.  If the boolean popped is
      ** true, then jump to p2.  Otherwise continue to the next instruction.
      ** An integer is false if zero and true otherwise.  A string is
      ** false if it has zero length and true otherwise.
      */
      case OP_If: {
        int c;
        if( p->tos<0 ) goto not_enough_stack;
        c = p->zStack[p->tos] ? p->zStack[p->tos][0] : p->iStack[p->tos];
        PopStack(p, 1);
        if( c ) pc = pOp->p2-1;
        break;
      }

      /* Opcode: IsNull * P2 *
      **
      ** Pop a single value from the stack.  If the value popped is the
      ** empty string, then jump to p2.  Otherwise continue to the next 
      ** instruction.
      */
      case OP_IsNull: {
        int c;
        if( p->tos<0 ) goto not_enough_stack;
        c = p->zStack[p->tos]!=0 && p->zStack[p->tos][0]==0;
        PopStack(p, 1);
        if( c ) pc = pOp->p2-1;
        break;
      }

      /* Opcode: NotNull * P2 *
      **
      ** Pop a single value from the stack.  If the value popped is not an
      ** empty string, then jump to p2.  Otherwise continue to the next 
      ** instruction.
      */
      case OP_NotNull: {
        int c;
        if( p->tos<0 ) goto not_enough_stack;
        c = p->zStack[p->tos]==0 || p->zStack[p->tos][0]!=0;
        PopStack(p, 1);
        if( c ) pc = pOp->p2-1;
        break;
      }

      /* Opcode: MakeRecord P1 * *
      **
      ** Convert the top P1 entries of the stack into a single entry
      ** suitable for use as a data record in the database.  To do this
      ** each entry is converted to a string and all the strings are
      ** concatenated.  The null-terminators are preserved by the concatation
      ** and serve as a boundry marker between fields.  The lowest entry
      ** on the stack is the first in the concatenation and the top of
      ** the stack is the last.  After all fields are concatenated, an
      ** index header is added.  The index header consists of P1 integers
      ** which hold the offset of the beginning of each field from the
      ** beginning of the completed record including the header.
      */
      case OP_MakeRecord: {
        char *zNewRecord;
        int nByte;
        int nField;
        int i, j;
        int addr;

        nField = pOp->p1;
        if( p->tos+1<nField ) goto not_enough_stack;
        nByte = 0;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          if( Stringify(p, i) ) goto no_mem;
          nByte += p->iStack[i];
        }
        nByte += sizeof(int)*nField;
        zNewRecord = sqliteMalloc( nByte );
        if( zNewRecord==0 ) goto no_mem;
        j = 0;
        addr = sizeof(int)*nField;
        for(i=p->tos-nField+1; i<p->tos; i++){
          memcpy(&zNewRecord[j], (char*)&addr, sizeof(int));
          addr += p->iStack[i];
          j += sizeof(int);
        }
        memcpy(&zNewRecord[j], (char*)&addr, sizeof(int));
        j += sizeof(int);
        for(i=p->tos-nField+1; i<=p->tos; i++){
          memcpy(&zNewRecord[j], p->zStack[i], p->iStack[i]);
          j += p->iStack[i];
        }
        PopStack(p, nField);
        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = nByte;
        p->zStack[p->tos] = zNewRecord;
        break;
      }

      /* Opcode: MakeKey P1 * *
      **
      ** Convert the top P1 entries of the stack into a single entry suitable
      ** for use as the key in an index or a sort.  The top P1 records are
      ** concatenated with a tab character (ASCII 0x09) used as a record
      ** separator.  The entire concatenation is null-terminated.  The
      ** lowest entry in the stack is the first field and the top of the
      ** stack becomes the last.
      **
      ** See also the SortMakeKey opcode.
      */
      case OP_MakeKey: {
        char *zNewKey;
        int nByte;
        int nField;
        int i, j;

        nField = pOp->p1;
        if( p->tos+1<nField ) goto not_enough_stack;
        nByte = 0;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          if( Stringify(p, i) ) goto no_mem;
          nByte += p->iStack[i]+1;
        }
        zNewKey = sqliteMalloc( nByte );
        if( zNewKey==0 ) goto no_mem;
        j = 0;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          memcpy(&zNewKey[j], p->zStack[i], p->iStack[i]-1);
          j += p->iStack[i]-1;
          if( i<p->tos ) zNewKey[j++] = '\t';
        }
        zNewKey[j] = 0;
        PopStack(p, nField);
        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = nByte;
        p->zStack[p->tos] = zNewKey;
        break;
      }

      /*  Open P1 P3 P2
      **
      ** Open a new database table named P3.  Give it an identifier P1.
      ** Open readonly if P2==0 and for reading and writing if P2!=0.
      ** The table is created if it does not already exist and P2!=0.
      ** If there is already another table opened on P1, then the old
      ** table is closed first.  All tables are automatically closed when
      ** the VDBE finishes execution.  The P1 values need not be
      ** contiguous but all P1 values should be small integers.  It is
      ** an error for P1 to be negative.
      */
      case OP_Open: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i>=p->nTable ){
          int j;
          p->aTab = sqliteRealloc( p->aTab, (i+1)*sizeof(VdbeTable) );
          if( p->aTab==0 ){ p->nTable = 0; goto no_mem; }
          for(j=p->nTable; j<=i; j++) p->aTab[j].pTable = 0;
          p->nTable = i+1;
        }else if( p->aTab[i].pTable ){
          sqliteDbbeCloseTable(p->aTab[i].pTable);
        }
        p->aTab[i].pTable = sqliteDbbeOpenTable(p->pBe, pOp->p3, pOp->p2);
        p->aTab[i].index = 0;
        break;
      }

      /* Opcode: Close P1 * *
      **
      ** Close a database table previously opened as P1.  If P1 is not
      ** currently open, this instruction is a no-op.
      */
      case OP_Close: {
        int i = pOp->p1;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable ){
          sqliteDbbeCloseTable(p->aTab[i].pTable);
          p->aTab[i].pTable = 0;
        }
        break;
      }

      /* Opcode: Fetch P1 * *
      **
      ** Pop the top of the stack and use its value as a key to fetch
      ** a record from database table or index P1.  The data is held
      ** in the P1 cursor until needed.  The data is not pushed onto the
      ** stack or anything like that.
      */
      case OP_Fetch: {
        int i = pOp->p1;
        int tos = p->tos;
        if( tos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable ){
          if( p->zStack[tos]==0 ){
            sqliteDbbeFetch(p->aTab[i].pTable, sizeof(int), 
                           (char*)&p->iStack[tos]);
          }else{
            sqliteDbbeFetch(p->aTab[i].pTable, p->iStack[tos], p->zStack[tos]);
          }
        }
        PopStack(p, 1);
        break;
      }

      /* Opcode: New P1 * *
      **
      ** Get a new integer key not previous used by table P1 and
      ** push it onto the stack.
      */
      case OP_New: {
        int i = pOp->p1;
        int v;
        if( i<0 || i>=p->nTable || p->aTab[i].pTable==0 ){
          v = 0;
        }else{
          v = sqliteDbbeNew(p->aTab[i].pTable);
        }
        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = v;
        break;
      }

      /* Opcode: Put P1 * *
      **
      ** Write an entry into the database table P1.  A new entry is
      ** created if it doesn't already exist, or the data for an existing
      ** entry is overwritten.  The data is the value on the top of the
      ** stack.  The key is the next value down on the stack.  The stack
      ** is popped twice by this instruction.
      */
      case OP_Put: {
        int tos = p->tos;
        int nos = p->tos-1;
        int i = pOp->p1;
        if( nos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable!=0 ){
          char *zKey;
          int nKey;
          Stringify(p, tos);
          if( p->zStack[nos]!=0 ){
            nKey = p->iStack[nos];
            zKey = p->zStack[nos];
          }else{
            nKey = sizeof(int);
            zKey = (char*)&p->iStack[nos];
          }
          sqliteDbbePut(p->aTab[i].pTable, nKey, zKey,
                        p->iStack[tos], p->zStack[tos]);
        }
        PopStack(p, 2);
        break;
      }

      /* Opcode: Delete P1 * *
      **
      ** The top of the stack is a key.  Remove this key and its data
      ** from database table P1.  Then pop the stack to discard the key.
      */
      case OP_Delete: {
        int tos = p->tos;
        int i = pOp->p1;
        if( tos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable!=0 ){
          char *zKey;
          int nKey;
          if( p->zStack[tos]!=0 ){
            nKey = p->iStack[tos];
            zKey = p->zStack[tos];
          }else{
            nKey = sizeof(int);
            zKey = (char*)&p->iStack[tos];
          }
          sqliteDbbeDelete(p->aTab[i].pTable, nKey, zKey);
        }
        PopStack(p, 1);
        break;
      }

      /* Opcode: Field P1 P2 *
      **
      ** Push onto the stack the value of the P2-th field from the
      ** most recent Fetch from table P1.
      */
      case OP_Field: {
        int *pAddr;
        int amt;
        int i = pOp->p1;
        int p2 = pOp->p2;
        int tos = ++p->tos;
        DbbeTable *pTab;
        char *z;

        if( NeedStack(p, p->tos) ) goto no_mem;
        if( i>=0 && i<p->nTable && (pTab = p->aTab[i].pTable)!=0 ){
          amt = sqliteDbbeDataLength(pTab);
          if( amt<=sizeof(int)*(p2+1) ){
            sqliteSetString(&p->zStack[tos], "", 0);
            break;
          }
          pAddr = (int*)sqliteDbbeReadData(pTab, sizeof(int)*p2);
          z = sqliteDbbeReadData(pTab, *pAddr);
          sqliteSetString(&p->zStack[tos], z, 0);
          p->iStack[tos] = strlen(z)+1;
        }
        break;
      }

      /* Opcode: Key P1 * *
      **
      ** Push onto the stack an integer which is the first 4 bytes of the
      ** the key to the current entry in a sequential scan of the table P1.
      ** A sequential scan is started using the Next opcode.
      */
      case OP_Key: {
        int i = pOp->p1;
        int tos = ++p->tos;
        DbbeTable *pTab;

        if( NeedStack(p, p->tos) ) goto no_mem;
        if( i>=0 && i<p->nTable && (pTab = p->aTab[i].pTable)!=0 ){
          char *z = sqliteDbbeReadKey(pTab, 0);
          memcpy(&p->iStack[tos], z, sizeof(int));
          p->zStack[tos] = 0;
        }
        break;
      }

      /* Opcode: Rewind P1 * *
      **
      ** The next use of the Key or Field or Next instruction for P1 
      ** will refer to the first entry in the table.
      */
      case OP_Rewind: {
        int i = pOp->p1;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable!=0 ){
          sqliteDbbeRewind(p->aTab[i].pTable);
        }
        break;
      }

      /* Opcode: Next P1 P2 *
      **
      ** Advance P1 to the next entry in the table.  Or, if there are no
      ** more entries, rewind P1 and jump to location P2.
      */
      case OP_Next: {
        int i = pOp->p1;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable!=0 ){
          if( sqliteDbbeNextKey(p->aTab[i].pTable)==0 ){
            pc = pOp->p2;
            if( pc<0 || pc>p->nOp ){
              sqliteSetString(pzErrMsg, "jump destination out of range", 0);
              rc = 1;
            }
            pc--;
          }
        }
        break;
      }

      /* Opcode: ResetIdx P1 * *
      **
      ** Begin treating the current row of table P1 as an index.  The next
      ** NextIdx instruction will refer to the first index in the table.
      */
      case OP_ResetIdx: {
        int i = pOp->p1;
        if( i>=0 && i<p->nTable ){
          p->aTab[i].index = 0;
        }
        break;
      }

      /* Opcode: NextIdx P1 P2 *
      **
      ** Push the next index from the current entry of table P1 onto the
      ** stack and advance the pointer.  If there are no more indices, then
      ** reset the table entry and jump to P2
      */
      case OP_NextIdx: {
        int i = pOp->p1;
        int tos = ++p->tos;
        DbbeTable *pTab;

        if( NeedStack(p, p->tos) ) goto no_mem;
        p->zStack[tos] = 0;
        if( i>=0 && i<p->nTable && (pTab = p->aTab[i].pTable)!=0 ){
          int *aIdx;
          int nIdx;
          int j;
          nIdx = sqliteDbbeDataLength(pTab)/sizeof(int);
          aIdx = (int*)sqliteDbbeReadData(pTab, 0);
          for(j=p->aTab[i].index; j<nIdx; j++){
            if( aIdx[j]!=0 ){
              p->iStack[tos] = aIdx[j];
              break;
            }
          }
          if( j>=nIdx ){
            j = -1;
            pc = pOp->p2;
            if( pc<0 || pc>p->nOp ){
              sqliteSetString(pzErrMsg, "jump destination out of range", 0);
              rc = 1;
            }
            pc--;
          }
          p->aTab[i].index = j+1;
        }
        break;
      }

      /* Opcode: PutIdx P1 * *
      **
      ** The top of the stack hold an index key (proably made using the
      ** MakeKey instruction) and next on stack holds an index value for
      ** a table.  Locate the record in the index P1 that has the key 
      ** and insert the index value into its
      ** data.  Write the results back to the index.
      ** If the key doesn't exist it is created.
      */
      case OP_PutIdx: {
        int i = pOp->p1;
        int tos = p->tos;
        int nos = tos - 1;
        DbbeTable *pTab;
        if( nos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && (pTab = p->aTab[i].pTable)!=0 ){
          int r;
          int newVal = Integerify(p, nos);
          Stringify(p, tos);
          r = sqliteDbbeFetch(pTab, p->iStack[tos], p->zStack[tos]);
          if( r==0 ){
            /* Create a new record for this index */
            sqliteDbbePut(pTab, p->iStack[tos], p->zStack[tos],
                          sizeof(int), (char*)&newVal);
          }else{
            /* Extend the existing record */
            int nIdx;
            int *aIdx;
            nIdx = sqliteDbbeDataLength(pTab)/sizeof(int);
            aIdx = sqliteMalloc( sizeof(int)*(nIdx+1) );
            if( aIdx==0 ) goto no_mem;
            sqliteDbbeCopyData(pTab, 0, nIdx*sizeof(int), (char*)aIdx);
            aIdx[nIdx] = newVal;
            sqliteDbbePut(pTab, p->iStack[tos], p->zStack[tos],
                          sizeof(int)*(nIdx+1), (char*)aIdx);
            sqliteFree(aIdx);
          }
        }
        PopStack(p, 2);
        break;
      }

      /* Opcode: DeleteIdx P1 * *
      **
      ** The top of the stack is a key and next on stack is an index value.
      ** Locate the record
      ** in index P1 that has the key and remove the index value from its
      ** data.  Write the results back to the table.  If after removing
      ** the index value no more indices remain in the record, then the
      ** record is removed from the table.
      */
      case OP_DeleteIdx: {
        int i = pOp->p1;
        int tos = p->tos;
        int nos = tos - 1;
        DbbeTable *pTab;
        if( nos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && (pTab = p->aTab[i].pTable)!=0 ){
          int *aIdx;
          int nIdx;
          int j;
          int r;
          int oldVal = Integerify(p, nos);
          Stringify(p, tos);
          r = sqliteDbbeFetch(pTab, p->iStack[tos], p->zStack[tos]);
          if( r==0 ) break;
          nIdx = sqliteDbbeDataLength(pTab)/sizeof(int);
          aIdx = (int*)sqliteDbbeReadData(pTab, 0);
          for(j=0; j<nIdx && aIdx[j]!=oldVal; j++){}
          if( j>=nIdx ) break;
          aIdx[j] = aIdx[nIdx-1];
          if( nIdx==1 ){
            sqliteDbbeDelete(pTab, p->iStack[tos], p->zStack[tos]);
          }else{
            sqliteDbbePut(pTab, p->iStack[tos], p->zStack[tos], 
                          sizeof(int)*(nIdx-1), (char*)aIdx);
          }
        }
        PopStack(p, 2);
        break;
      }

      /* Opcode: Destroy * * P3
      **
      ** Drop the table whose name is P3.  The file that holds this table
      ** is removed from the disk drive.
      */
      case OP_Destroy: {
        sqliteDbbeDropTable(p->pBe, pOp->p3);
        break;
      }

      /* Opcode: ListOpen P1 * *
      **
      ** Open a file used for temporary storage of index numbers.  P1
      ** will server as a handle to this temporary file for future
      ** interactions.  If another temporary file with the P1 handle is
      ** already opened, the prior file is closed and a new one opened
      ** in its place.
      */
      case OP_ListOpen: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i>=p->nList ){
          int j;
          p->apList = sqliteRealloc( p->apList, (i+1)*sizeof(FILE*) );
          if( p->apList==0 ){ p->nList = 0; goto no_mem; }
          for(j=p->nList; j<=i; j++) p->apList[j] = 0;
          p->nList = i+1;
        }else if( p->apList[i] ){
          sqliteDbbeCloseTempFile(p->pBe, p->apList[i]);
        }
        p->apList[i] = sqliteDbbeOpenTempFile(p->pBe);
        break;
      }

      /* Opcode: ListWrite P1 * *
      **
      ** Write the integer on the top of the stack
      ** into the temporary storage file P1.
      */
      case OP_ListWrite: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( p->tos<0 ) goto not_enough_stack;
        if( i<p->nList && p->apList[i]!=0 ){
          int val = Integerify(p, p->tos);
          PopStack(p, 1);
          fwrite(&val, sizeof(int), 1, p->apList[i]);
        }
        break;
      }

      /* Opcode: ListRewind P1 * *
      **
      ** Rewind the temporary buffer P1 back to the beginning.
      */
      case OP_ListRewind: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i<p->nList && p->apList[i]!=0 ){
          rewind(p->apList[i]);
        }
        break;
      }

      /* Opcode: ListRead P1 P2 *
      **
      ** Attempt to read an integer from temporary storage buffer P1
      ** and push it onto the stack.  If the storage buffer is empty
      ** push nothing but instead jump to P2.
      */
      case OP_ListRead: {
        int i = pOp->p1;
        int val, amt;
        if( i<0 || i>=p->nList || p->apList[i]==0 ) goto bad_instruction;
        amt = fread(&val, sizeof(int), 1, p->apList[i]);
        if( amt==1 ){
          p->tos++;
          if( NeedStack(p, p->tos) ) goto no_mem;
          p->iStack[p->tos] = val;
          p->zStack[p->tos] = 0;
        }else{
          pc = pOp->p2;
          if( pc<0 || pc>p->nOp ){
            sqliteSetString(pzErrMsg, "jump destination out of range", 0);
            rc = 1;
          }
          pc--;
        }
        break;
      }

      /* Opcode: ListClose P1 * *
      **
      ** Close the temporary storage buffer and discard its contents.
      */
      case OP_ListClose: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i<p->nList && p->apList[i]!=0 ){
          sqliteDbbeCloseTempFile(p->pBe, p->apList[i]);
          p->apList[i] = 0;
        }
        break;
      }

      /* Opcode: SortOpen P1 * *
      **
      ** Create a new sorter with index P1
      */
      case OP_SortOpen: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i>=p->nSort ){
          int j;
          p->apSort = sqliteRealloc( p->apSort, (i+1)*sizeof(Sorter*) );
          if( p->apSort==0 ){ p->nSort = 0; goto no_mem; }
          for(j=p->nSort; j<=i; j++) p->apSort[j] = 0;
          p->nSort = i+1;
        }
        break;
      }

      /* Opcode: SortPut P1 * *
      **
      ** The TOS is the key and the NOS is the data.  Pop both from the stack
      ** and put them on the sorter.
      */
      case OP_SortPut: {
        int i = pOp->p1;
        Sorter *pSorter;
        if( i<0 || i>=p->nSort ) goto bad_instruction;
        if( p->tos<1 ) goto not_enough_stack;
        Stringify(p, p->tos);
        Stringify(p, p->tos-1);
        pSorter = sqliteMalloc( sizeof(Sorter) );
        if( pSorter==0 ) goto no_mem;
        pSorter->pNext = p->apSort[i];
        p->apSort[i] = pSorter;
        pSorter->nKey = p->iStack[p->tos];
        pSorter->zKey = p->zStack[p->tos];
        pSorter->nData = p->iStack[p->tos-1];
        pSorter->pData = p->zStack[p->tos-1];
        p->zStack[p->tos] = p->zStack[p->tos-1] = 0;
        PopStack(p, 2);
        break;
      }

      /* Opcode: SortMakeRec P1 * *
      **
      ** The top P1 elements are the arguments to a callback.  Form these
      ** elements into a single data entry that can be stored on a sorter
      ** using SortPut and later fed to a callback using SortCallback.
      */
      case OP_SortMakeRec: {
        char *z;
        char **azArg;
        int nByte;
        int nField;
        int i, j;

        nField = pOp->p1;
        if( p->tos+1<nField ) goto not_enough_stack;
        nByte = 0;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          if( Stringify(p, i) ) goto no_mem;
          nByte += p->iStack[i];
        }
        nByte += sizeof(char*)*(nField+1);
        azArg = sqliteMalloc( nByte );
        if( azArg==0 ) goto no_mem;
        z = (char*)&azArg[nField+1];
        for(j=0, i=p->tos-nField+1; i<=p->tos; i++, j++){
          azArg[j] = z;
          strcpy(z, p->zStack[i]);
          z += p->iStack[i];
        }
        PopStack(p, nField);
        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = nByte;
        p->zStack[p->tos] = (char*)azArg;
        break;
      }

      /* Opcode: SortMakeKey P1 * P3
      **
      ** Convert the top few entries of the stack into a sort key.  The
      ** number of stack entries consumed is the number of characters in 
      ** the string P3.  One character from P3 is prepended to each entry.
      ** The first character of P3 is prepended to the element lowest in
      ** the stack and the last character of P3 is appended to the top of
      ** the stack.  All stack entries are separated by a \000 character
      ** in the result.  The whole key is terminated by two \000 characters
      ** in a row.
      **
      ** See also the MakeKey opcode.
      */
      case OP_SortMakeKey: {
        char *zNewKey;
        int nByte;
        int nField;
        int i, j, k;

        nField = strlen(pOp->p3);
        if( p->tos+1<nField ) goto not_enough_stack;
        nByte = 1;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          if( Stringify(p, i) ) goto no_mem;
          nByte += p->iStack[i]+2;
        }
        zNewKey = sqliteMalloc( nByte );
        if( zNewKey==0 ) goto no_mem;
        j = 0;
        k = nField-1;
        for(i=p->tos-nField+1; i<=p->tos; i++){
          zNewKey[j++] = pOp->p3[k--];
          memcpy(&zNewKey[j], p->zStack[i], p->iStack[i]-1);
          j += p->iStack[i]-1;
          zNewKey[j++] = 0;
        }
        zNewKey[j] = 0;
        PopStack(p, nField);
        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = nByte;
        p->zStack[p->tos] = zNewKey;
        break;
      }

      /* Opcode: Sort P1 * *
      **
      ** Sort all elements on the given sorter.  The algorithm is a
      ** mergesort.
      */
      case OP_Sort: {
        int j;
        j = pOp->p1;
        if( j<0 ) goto bad_instruction;
        if( j<p->nSort ){
          int i;
          Sorter *pElem;
          Sorter *apSorter[NSORT];
          for(i=0; i<NSORT; i++){
            apSorter[i] = 0;
          }
          while( p->apSort[j] ){
            pElem = p->apSort[j];
            p->apSort[j] = pElem->pNext;
            pElem->pNext = 0;
            for(i=0; i<NSORT-1; i++){
              if( apSorter[i]==0 ){
                apSorter[i] = pElem;
                break;
              }else{
                pElem = Merge(apSorter[i], pElem);
                apSorter[i] = 0;
              }
            }
            if( i>=NSORT-1 ){
              apSorter[NSORT-1] = Merge(apSorter[NSORT-1],pElem);
            }
          }
          pElem = 0;
          for(i=0; i<NSORT; i++){
            pElem = Merge(apSorter[i], pElem);
          }
          p->apSort[j] = pElem;
        }
        break;
      }

      /* Opcode: SortNext P1 P2 *
      **
      ** Push the data for the topmost element in the given sorter onto the
      ** stack, then remove the element from the sorter.
      */
      case OP_SortNext: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i<p->nSort && p->apSort[i]!=0 ){
          Sorter *pSorter = p->apSort[i];
          p->apSort[i] = pSorter->pNext;
          p->tos++;
          NeedStack(p, p->tos);
          p->zStack[p->tos] = pSorter->pData;
          p->iStack[p->tos] = pSorter->nData;
          sqliteFree(pSorter->zKey);
          sqliteFree(pSorter);
        }else{
          pc = pOp->p2;
          if( pc<0 || pc>p->nOp ){
            sqliteSetString(pzErrMsg, "jump destination out of range", 0);
            rc = 1;
          }
          pc--;
        }
        break;
      }

      /* Opcode: SortKey P1 * *
      **
      ** Push the key for the topmost element of the sorter onto the stack.
      ** But don't change the sorter an any other way.
      */
      case OP_SortKey: {
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i<p->nSort && p->apSort[i]!=0 ){
          Sorter *pSorter = p->apSort[i];
          p->tos++;
          NeedStack(p, p->tos);
          sqliteSetString(&p->zStack[p->tos], pSorter->zKey, 0);
          p->iStack[p->tos] = pSorter->nKey;
        }
        break;
      }

      /* Opcode: SortCallback P1 P2 *
      **
      ** The top of the stack contains a callback record built using
      ** the SortMakeRec operation with the same P1 value as this
      ** instruction.  Pop this record from the stack and invoke the
      ** callback on it.
      */
      case OP_SortCallback: {
        int i = p->tos;
        if( i<0 ) goto not_enough_stack;
        rc = xCallback(pArg, pOp->p1, (char**)p->zStack[i], p->azColName);
        PopStack(p, 1);
        break;
      }

      /* Opcode: SortClose P1 * *
      **
      ** Close the given sorter and remove all its elements.
      */
      case OP_SortClose: {
        Sorter *pSorter;
        int i = pOp->p1;
        if( i<0 ) goto bad_instruction;
        if( i<p->nSort ){
           while( (pSorter = p->apSort[i])!=0 ){
             p->apSort[i] = pSorter->pNext;
             sqliteFree(pSorter->zKey);
             sqliteFree(pSorter->pData);
             sqliteFree(pSorter);
           }
        }
        break;
      }

      /* An other opcode is illegal...
      */
      default: {
        sprintf(zBuf,"%d",pOp->opcode);
        sqliteSetString(pzErrMsg, "unknown opcode ", zBuf, 0);
        rc = 1;
        break;
      }
    }
    if( p->trace && p->tos>=0 ){
      int i;
      fprintf(p->trace, "Stack:");
      for(i=p->tos; i>=0 && i>p->tos-5; i--){
        if( p->zStack[i] ){
          fprintf(p->trace, " [%.11s]", p->zStack[i]);
        }else{
          fprintf(p->trace, " [%d]", p->iStack[i]);
        }
      }
      fprintf(p->trace,"\n");
    }
  }

cleanup:
  Cleanup(p);
  return rc;

  /* Jump to here if a malloc() fails.  It's hard to get a malloc()
  ** to fail on a modern VM computer, so this code is untested.
  */
no_mem:
  Cleanup(p);
  sqliteSetString(pzErrMsg, "out or memory", 0);
  return 1;

  /* Jump to here if a operator is encountered that requires more stack
  ** operands than are currently available on the stack.
  */
not_enough_stack:
  sprintf(zBuf,"%d",pc);
  sqliteSetString(pzErrMsg, "too few operands on stack at ", zBuf, 0);
  rc = 1;
  goto cleanup;

  /* Jump here if an illegal or illformed instruction is executed.
  */
bad_instruction:
  sprintf(zBuf,"%d",pc);
  sqliteSetString(pzErrMsg, "illegal operation at ", zBuf, 0);
  rc = 1;
  goto cleanup;

}