/* Driver template for the LEMON parser generator. ** The author disclaims copyright to this source code. */ /* First off, code is include which follows the "include" declaration ** in the input file. */ #include %% /* Next is all token values, in a form suitable for use by makeheaders. ** This section will be null unless lemon is run with the -m switch. */ /* ** These constants (all generated automatically by the parser generator) ** specify the various kinds of tokens (terminals) that the parser ** understands. ** ** Each symbol here is a terminal symbol in the grammar. */ %% /* Make sure the INTERFACE macro is defined. */ #ifndef INTERFACE # define INTERFACE 1 #endif /* The next thing included is series of defines which control ** various aspects of the generated parser. ** YYCODETYPE is the data type used for storing terminal ** and nonterminal numbers. "unsigned char" is ** used if there are fewer than 250 terminals ** and nonterminals. "int" is used otherwise. ** YYNOCODE is a number of type YYCODETYPE which corresponds ** to no legal terminal or nonterminal number. This ** number is used to fill in empty slots of the hash ** table. ** YYFALLBACK If defined, this indicates that one or more tokens ** have fall-back values which should be used if the ** original value of the token will not parse. ** YYACTIONTYPE is the data type used for storing terminal ** and nonterminal numbers. "unsigned char" is ** used if there are fewer than 250 rules and ** states combined. "int" is used otherwise. ** ParseTOKENTYPE is the data type used for minor tokens given ** directly to the parser from the tokenizer. ** YYMINORTYPE is the data type used for all minor tokens. ** This is typically a union of many types, one of ** which is ParseTOKENTYPE. The entry in the union ** for base tokens is called "yy0". ** YYSTACKDEPTH is the maximum depth of the parser's stack. ** ParseARG_SDECL A static variable declaration for the %extra_argument ** ParseARG_PDECL A parameter declaration for the %extra_argument ** ParseARG_STORE Code to store %extra_argument into yypParser ** ParseARG_FETCH Code to extract %extra_argument from yypParser ** YYNSTATE the combined number of states. ** YYNRULE the number of rules in the grammar ** YYERRORSYMBOL is the code number of the error symbol. If not ** defined, then do no error processing. */ %% #define YY_NO_ACTION (YYNSTATE+YYNRULE+2) #define YY_ACCEPT_ACTION (YYNSTATE+YYNRULE+1) #define YY_ERROR_ACTION (YYNSTATE+YYNRULE) /* Next is the action table. Each entry in this table contains ** ** + An integer which is the number representing the look-ahead ** token ** ** + An integer indicating what action to take. Number (N) between ** 0 and YYNSTATE-1 mean shift the look-ahead and go to state N. ** Numbers between YYNSTATE and YYNSTATE+YYNRULE-1 mean reduce by ** rule N-YYNSTATE. Number YYNSTATE+YYNRULE means that a syntax ** error has occurred. Number YYNSTATE+YYNRULE+1 means the parser ** accepts its input. ** ** + A pointer to the next entry with the same hash value. ** ** The action table is really a series of hash tables. Each hash ** table contains a number of entries which is a power of two. The ** "state" table (which follows) contains information about the starting ** point and size of each hash table. */ struct yyActionEntry { YYCODETYPE lookahead; /* The value of the look-ahead token */ YYCODETYPE next; /* Next entry + 1. Zero at end of collision chain */ YYACTIONTYPE action; /* Action to take for this look-ahead */ }; typedef struct yyActionEntry yyActionEntry; static const yyActionEntry yyActionTable[] = { %% }; /* The state table contains information needed to look up the correct ** action in the action table, given the current state of the parser. ** Information needed includes: ** ** + A pointer to the start of the action hash table in yyActionTable. ** ** + The number of entries in the action hash table. ** ** + The default action. This is the action to take if no entry for ** the given look-ahead is found in the action hash table. */ struct yyStateEntry { const yyActionEntry *hashtbl; /* Start of the hash table in yyActionTable */ YYCODETYPE nEntry; /* Number of entries in action hash table */ YYACTIONTYPE actionDefault; /* Default action if look-ahead not found */ }; typedef struct yyStateEntry yyStateEntry; static const yyStateEntry yyStateTable[] = { %% }; /* The next table maps tokens into fallback tokens. If a construct ** like the following: ** ** %fallback ID X Y Z. ** ** appears in the grammer, then ID becomes a fallback token for X, Y, ** and Z. Whenever one of the tokens X, Y, or Z is input to the parser ** but it does not parse, the type of the token is changed to ID and ** the parse is retried before an error is thrown. */ #ifdef YYFALLBACK static const YYCODETYPE yyFallback[] = { %% }; #endif /* YYFALLBACK */ /* The following structure represents a single element of the ** parser's stack. Information stored includes: ** ** + The state number for the parser at this level of the stack. ** ** + The value of the token stored at this level of the stack. ** (In other words, the "major" token.) ** ** + The semantic value stored at this level of the stack. This is ** the information used by the action routines in the grammar. ** It is sometimes called the "minor" token. */ struct yyStackEntry { int stateno; /* The state-number */ int major; /* The major token value. This is the code ** number for the token at this stack level */ YYMINORTYPE minor; /* The user-supplied minor token value. This ** is the value of the token */ }; typedef struct yyStackEntry yyStackEntry; /* The state of the parser is completely contained in an instance of ** the following structure */ struct yyParser { int yyidx; /* Index of top element in stack */ int yyerrcnt; /* Shifts left before out of the error */ yyStackEntry *yytop; /* Pointer to the top stack element */ ParseARG_SDECL /* A place to hold %extra_argument */ yyStackEntry yystack[YYSTACKDEPTH]; /* The parser's stack */ }; typedef struct yyParser yyParser; #ifndef NDEBUG #include static FILE *yyTraceFILE = 0; static char *yyTracePrompt = 0; #endif /* NDEBUG */ #ifndef NDEBUG /* ** Turn parser tracing on by giving a stream to which to write the trace ** and a prompt to preface each trace message. Tracing is turned off ** by making either argument NULL ** ** Inputs: ** ** ** Outputs: ** None. */ void ParseTrace(FILE *TraceFILE, char *zTracePrompt){ yyTraceFILE = TraceFILE; yyTracePrompt = zTracePrompt; if( yyTraceFILE==0 ) yyTracePrompt = 0; else if( yyTracePrompt==0 ) yyTraceFILE = 0; } #endif /* NDEBUG */ #ifndef NDEBUG /* For tracing shifts, the names of all terminals and nonterminals ** are required. The following table supplies these names */ static const char *yyTokenName[] = { %% }; #endif /* NDEBUG */ #ifndef NDEBUG /* For tracing reduce actions, the names of all rules are required. */ static const char *yyRuleName[] = { %% }; #endif /* NDEBUG */ /* ** This function returns the symbolic name associated with a token ** value. */ const char *ParseTokenName(int tokenType){ #ifndef NDEBUG if( tokenType>0 && tokenType<(sizeof(yyTokenName)/sizeof(yyTokenName[0])) ){ return yyTokenName[tokenType]; }else{ return "Unknown"; } #else return ""; #endif } /* ** This function allocates a new parser. ** The only argument is a pointer to a function which works like ** malloc. ** ** Inputs: ** A pointer to the function used to allocate memory. ** ** Outputs: ** A pointer to a parser. This pointer is used in subsequent calls ** to Parse and ParseFree. */ void *ParseAlloc(void *(*mallocProc)(size_t)){ yyParser *pParser; pParser = (yyParser*)(*mallocProc)( (size_t)sizeof(yyParser) ); if( pParser ){ pParser->yyidx = -1; } return pParser; } /* The following function deletes the value associated with a ** symbol. The symbol can be either a terminal or nonterminal. ** "yymajor" is the symbol code, and "yypminor" is a pointer to ** the value. */ static void yy_destructor(YYCODETYPE yymajor, YYMINORTYPE *yypminor){ switch( yymajor ){ /* Here is inserted the actions which take place when a ** terminal or non-terminal is destroyed. This can happen ** when the symbol is popped from the stack during a ** reduce or during error processing or when a parser is ** being destroyed before it is finished parsing. ** ** Note: during a reduce, the only symbols destroyed are those ** which appear on the RHS of the rule, but which are not used ** inside the C code. */ %% default: break; /* If no destructor action specified: do nothing */ } } /* ** Pop the parser's stack once. ** ** If there is a destructor routine associated with the token which ** is popped from the stack, then call it. ** ** Return the major token number for the symbol popped. */ static int yy_pop_parser_stack(yyParser *pParser){ YYCODETYPE yymajor; if( pParser->yyidx<0 ) return 0; #ifndef NDEBUG if( yyTraceFILE && pParser->yyidx>=0 ){ fprintf(yyTraceFILE,"%sPopping %s\n", yyTracePrompt, yyTokenName[pParser->yytop->major]); } #endif yymajor = pParser->yytop->major; yy_destructor( yymajor, &pParser->yytop->minor); pParser->yyidx--; pParser->yytop--; return yymajor; } /* ** Deallocate and destroy a parser. Destructors are all called for ** all stack elements before shutting the parser down. ** ** Inputs: ** */ void ParseFree( void *p, /* The parser to be deleted */ void (*freeProc)(void*) /* Function used to reclaim memory */ ){ yyParser *pParser = (yyParser*)p; if( pParser==0 ) return; while( pParser->yyidx>=0 ) yy_pop_parser_stack(pParser); (*freeProc)((void*)pParser); } /* ** Find the appropriate action for a parser given the look-ahead token. ** ** If the look-ahead token is YYNOCODE, then check to see if the action is ** independent of the look-ahead. If it is, return the action, otherwise ** return YY_NO_ACTION. */ static int yy_find_parser_action( yyParser *pParser, /* The parser */ int iLookAhead /* The look-ahead token */ ){ const yyStateEntry *pState; /* Appropriate entry in the state table */ const yyActionEntry *pAction; /* Action appropriate for the look-ahead */ int iFallback; /* Fallback token */ /* if( pParser->yyidx<0 ) return YY_NO_ACTION; */ pState = &yyStateTable[pParser->yytop->stateno]; if( pState->nEntry==0 ){ return pState->actionDefault; }else if( iLookAhead!=YYNOCODE ){ pAction = &pState->hashtbl[iLookAhead % pState->nEntry]; while( 1 ){ if( pAction->lookahead==iLookAhead ) return pAction->action; if( pAction->next==0 ) break; pAction = &pState->hashtbl[pAction->next-1]; } #ifdef YYFALLBACK if( iLookAhead %s\n", yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]); } #endif return yy_find_parser_action(pParser, iFallback); } #endif }else if( pState->hashtbl->lookahead!=YYNOCODE ){ return YY_NO_ACTION; } return pState->actionDefault; } /* ** Perform a shift action. */ static void yy_shift( yyParser *yypParser, /* The parser to be shifted */ int yyNewState, /* The new state to shift in */ int yyMajor, /* The major token to shift in */ YYMINORTYPE *yypMinor /* Pointer ot the minor token to shift in */ ){ yypParser->yyidx++; yypParser->yytop++; if( yypParser->yyidx>=YYSTACKDEPTH ){ ParseARG_FETCH; yypParser->yyidx--; yypParser->yytop--; #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sStack Overflow!\n",yyTracePrompt); } #endif while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser); /* Here code is inserted which will execute if the parser ** stack every overflows */ %% ParseARG_STORE; /* Suppress warning about unused %extra_argument var */ return; } yypParser->yytop->stateno = yyNewState; yypParser->yytop->major = yyMajor; yypParser->yytop->minor = *yypMinor; #ifndef NDEBUG if( yyTraceFILE && yypParser->yyidx>0 ){ int i; fprintf(yyTraceFILE,"%sShift %d\n",yyTracePrompt,yyNewState); fprintf(yyTraceFILE,"%sStack:",yyTracePrompt); for(i=1; i<=yypParser->yyidx; i++) fprintf(yyTraceFILE," %s",yyTokenName[yypParser->yystack[i].major]); fprintf(yyTraceFILE,"\n"); } #endif } /* The following table contains information about every rule that ** is used during the reduce. */ static struct { YYCODETYPE lhs; /* Symbol on the left-hand side of the rule */ unsigned char nrhs; /* Number of right-hand side symbols in the rule */ } yyRuleInfo[] = { %% }; static void yy_accept(yyParser*); /* Forward Declaration */ /* ** Perform a reduce action and the shift that must immediately ** follow the reduce. */ static void yy_reduce( yyParser *yypParser, /* The parser */ int yyruleno /* Number of the rule by which to reduce */ ){ int yygoto; /* The next state */ int yyact; /* The next action */ YYMINORTYPE yygotominor; /* The LHS of the rule reduced */ yyStackEntry *yymsp; /* The top of the parser's stack */ int yysize; /* Amount to pop the stack */ ParseARG_FETCH; yymsp = yypParser->yytop; #ifndef NDEBUG if( yyTraceFILE && yyruleno>=0 && yyruleno ** { ... } // User supplied code ** #line ** break; */ %% }; yygoto = yyRuleInfo[yyruleno].lhs; yysize = yyRuleInfo[yyruleno].nrhs; yypParser->yyidx -= yysize; yypParser->yytop -= yysize; yyact = yy_find_parser_action(yypParser,yygoto); if( yyact < YYNSTATE ){ yy_shift(yypParser,yyact,yygoto,&yygotominor); }else if( yyact == YYNSTATE + YYNRULE + 1 ){ yy_accept(yypParser); } } /* ** The following code executes when the parse fails */ static void yy_parse_failed( yyParser *yypParser /* The parser */ ){ ParseARG_FETCH; #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt); } #endif while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser); /* Here code is inserted which will be executed whenever the ** parser fails */ %% ParseARG_STORE; /* Suppress warning about unused %extra_argument variable */ } /* ** The following code executes when a syntax error first occurs. */ static void yy_syntax_error( yyParser *yypParser, /* The parser */ int yymajor, /* The major type of the error token */ YYMINORTYPE yyminor /* The minor type of the error token */ ){ ParseARG_FETCH; #define TOKEN (yyminor.yy0) %% ParseARG_STORE; /* Suppress warning about unused %extra_argument variable */ } /* ** The following is executed when the parser accepts */ static void yy_accept( yyParser *yypParser /* The parser */ ){ ParseARG_FETCH; #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sAccept!\n",yyTracePrompt); } #endif while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser); /* Here code is inserted which will be executed whenever the ** parser accepts */ %% ParseARG_STORE; /* Suppress warning about unused %extra_argument variable */ } /* The main parser program. ** The first argument is a pointer to a structure obtained from ** "ParseAlloc" which describes the current state of the parser. ** The second argument is the major token number. The third is ** the minor token. The fourth optional argument is whatever the ** user wants (and specified in the grammar) and is available for ** use by the action routines. ** ** Inputs: **
    **
  • A pointer to the parser (an opaque structure.) **
  • The major token number. **
  • The minor token number. **
  • An option argument of a grammar-specified type. **
** ** Outputs: ** None. */ void Parse( void *yyp, /* The parser */ int yymajor, /* The major token code number */ ParseTOKENTYPE yyminor /* The value for the token */ ParseARG_PDECL /* Optional %extra_argument parameter */ ){ YYMINORTYPE yyminorunion; int yyact; /* The parser action. */ int yyendofinput; /* True if we are at the end of input */ int yyerrorhit = 0; /* True if yymajor has invoked an error */ yyParser *yypParser; /* The parser */ /* (re)initialize the parser, if necessary */ yypParser = (yyParser*)yyp; if( yypParser->yyidx<0 ){ if( yymajor==0 ) return; yypParser->yyidx = 0; yypParser->yyerrcnt = -1; yypParser->yytop = &yypParser->yystack[0]; yypParser->yytop->stateno = 0; yypParser->yytop->major = 0; } yyminorunion.yy0 = yyminor; yyendofinput = (yymajor==0); ParseARG_STORE; #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]); } #endif do{ yyact = yy_find_parser_action(yypParser,yymajor); if( yyactyyerrcnt--; if( yyendofinput && yypParser->yyidx>=0 ){ yymajor = 0; }else{ yymajor = YYNOCODE; } }else if( yyact < YYNSTATE + YYNRULE ){ yy_reduce(yypParser,yyact-YYNSTATE); }else if( yyact == YY_ERROR_ACTION ){ #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sSyntax Error!\n",yyTracePrompt); } #endif #ifdef YYERRORSYMBOL /* A syntax error has occurred. ** The response to an error depends upon whether or not the ** grammar defines an error token "ERROR". ** ** This is what we do if the grammar does define ERROR: ** ** * Call the %syntax_error function. ** ** * Begin popping the stack until we enter a state where ** it is legal to shift the error symbol, then shift ** the error symbol. ** ** * Set the error count to three. ** ** * Begin accepting and shifting new tokens. No new error ** processing will occur until three tokens have been ** shifted successfully. ** */ if( yypParser->yyerrcnt<0 ){ yy_syntax_error(yypParser,yymajor,yyminorunion); } if( yypParser->yytop->major==YYERRORSYMBOL || yyerrorhit ){ #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sDiscard input token %s\n", yyTracePrompt,yyTokenName[yymajor]); } #endif yy_destructor(yymajor,&yyminorunion); yymajor = YYNOCODE; }else{ while( yypParser->yyidx >= 0 && yypParser->yytop->major != YYERRORSYMBOL && (yyact = yy_find_parser_action(yypParser,YYERRORSYMBOL)) >= YYNSTATE ){ yy_pop_parser_stack(yypParser); } if( yypParser->yyidx < 0 || yymajor==0 ){ yy_destructor(yymajor,&yyminorunion); yy_parse_failed(yypParser); yymajor = YYNOCODE; }else if( yypParser->yytop->major!=YYERRORSYMBOL ){ YYMINORTYPE u2; u2.YYERRSYMDT = 0; yy_shift(yypParser,yyact,YYERRORSYMBOL,&u2); } } yypParser->yyerrcnt = 3; yyerrorhit = 1; #else /* YYERRORSYMBOL is not defined */ /* This is what we do if the grammar does not define ERROR: ** ** * Report an error message, and throw away the input token. ** ** * If the input token is $, then fail the parse. ** ** As before, subsequent error messages are suppressed until ** three input tokens have been successfully shifted. */ if( yypParser->yyerrcnt<=0 ){ yy_syntax_error(yypParser,yymajor,yyminorunion); } yypParser->yyerrcnt = 3; yy_destructor(yymajor,&yyminorunion); if( yyendofinput ){ yy_parse_failed(yypParser); } yymajor = YYNOCODE; #endif }else{ yy_accept(yypParser); yymajor = YYNOCODE; } }while( yymajor!=YYNOCODE && yypParser->yyidx>=0 ); return; }