1 /* Driver template for the LEMON parser generator.
2 ** The author disclaims copyright to this source code.
4 ** This version of "lempar.c" is modified, slightly, for use by SQLite.
5 ** The only modifications are the addition of a couple of NEVER()
6 ** macros to disable tests that are needed in the case of a general
7 ** LALR(1) grammar but which are always false in the
8 ** specific grammar used by SQLite.
10 /* First off, code is included that follows the "include" declaration
11 ** in the input grammar file. */
14 /* Next is all token values, in a form suitable for use by makeheaders.
15 ** This section will be null unless lemon is run with the -m switch.
18 ** These constants (all generated automatically by the parser generator)
19 ** specify the various kinds of tokens (terminals) that the parser
22 ** Each symbol here is a terminal symbol in the grammar.
25 /* Make sure the INTERFACE macro is defined.
30 /* The next thing included is series of defines which control
31 ** various aspects of the generated parser.
32 ** YYCODETYPE is the data type used for storing terminal
33 ** and nonterminal numbers. "unsigned char" is
34 ** used if there are fewer than 250 terminals
35 ** and nonterminals. "int" is used otherwise.
36 ** YYNOCODE is a number of type YYCODETYPE which corresponds
37 ** to no legal terminal or nonterminal number. This
38 ** number is used to fill in empty slots of the hash
40 ** YYFALLBACK If defined, this indicates that one or more tokens
41 ** have fall-back values which should be used if the
42 ** original value of the token will not parse.
43 ** YYACTIONTYPE is the data type used for storing terminal
44 ** and nonterminal numbers. "unsigned char" is
45 ** used if there are fewer than 250 rules and
46 ** states combined. "int" is used otherwise.
47 ** ParseTOKENTYPE is the data type used for minor tokens given
48 ** directly to the parser from the tokenizer.
49 ** YYMINORTYPE is the data type used for all minor tokens.
50 ** This is typically a union of many types, one of
51 ** which is ParseTOKENTYPE. The entry in the union
52 ** for base tokens is called "yy0".
53 ** YYSTACKDEPTH is the maximum depth of the parser's stack. If
54 ** zero the stack is dynamically sized using realloc()
55 ** ParseARG_SDECL A static variable declaration for the %extra_argument
56 ** ParseARG_PDECL A parameter declaration for the %extra_argument
57 ** ParseARG_STORE Code to store %extra_argument into yypParser
58 ** ParseARG_FETCH Code to extract %extra_argument from yypParser
59 ** YYNSTATE the combined number of states.
60 ** YYNRULE the number of rules in the grammar
61 ** YYERRORSYMBOL is the code number of the error symbol. If not
62 ** defined, then do no error processing.
65 #define YY_NO_ACTION (YYNSTATE+YYNRULE+2)
66 #define YY_ACCEPT_ACTION (YYNSTATE+YYNRULE+1)
67 #define YY_ERROR_ACTION (YYNSTATE+YYNRULE)
69 /* The yyzerominor constant is used to initialize instances of
70 ** YYMINORTYPE objects to zero. */
71 static const YYMINORTYPE yyzerominor
= { 0 };
73 /* Define the yytestcase() macro to be a no-op if is not already defined
76 ** Applications can choose to define yytestcase() in the %include section
77 ** to a macro that can assist in verifying code coverage. For production
78 ** code the yytestcase() macro should be turned off. But it is useful
82 # define yytestcase(X)
86 /* Next are the tables used to determine what action to take based on the
87 ** current state and lookahead token. These tables are used to implement
88 ** functions that take a state number and lookahead value and return an
91 ** Suppose the action integer is N. Then the action is determined as
94 ** 0 <= N < YYNSTATE Shift N. That is, push the lookahead
95 ** token onto the stack and goto state N.
97 ** YYNSTATE <= N < YYNSTATE+YYNRULE Reduce by rule N-YYNSTATE.
99 ** N == YYNSTATE+YYNRULE A syntax error has occurred.
101 ** N == YYNSTATE+YYNRULE+1 The parser accepts its input.
103 ** N == YYNSTATE+YYNRULE+2 No such action. Denotes unused
104 ** slots in the yy_action[] table.
106 ** The action table is constructed as a single large table named yy_action[].
107 ** Given state S and lookahead X, the action is computed as
109 ** yy_action[ yy_shift_ofst[S] + X ]
111 ** If the index value yy_shift_ofst[S]+X is out of range or if the value
112 ** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X or if yy_shift_ofst[S]
113 ** is equal to YY_SHIFT_USE_DFLT, it means that the action is not in the table
114 ** and that yy_default[S] should be used instead.
116 ** The formula above is for computing the action when the lookahead is
117 ** a terminal symbol. If the lookahead is a non-terminal (as occurs after
118 ** a reduce action) then the yy_reduce_ofst[] array is used in place of
119 ** the yy_shift_ofst[] array and YY_REDUCE_USE_DFLT is used in place of
120 ** YY_SHIFT_USE_DFLT.
122 ** The following are the tables generated in this section:
124 ** yy_action[] A single table containing all actions.
125 ** yy_lookahead[] A table containing the lookahead for each entry in
126 ** yy_action. Used to detect hash collisions.
127 ** yy_shift_ofst[] For each state, the offset into yy_action for
128 ** shifting terminals.
129 ** yy_reduce_ofst[] For each state, the offset into yy_action for
130 ** shifting non-terminals after a reduce.
131 ** yy_default[] Default action for each state.
135 /* The next table maps tokens into fallback tokens. If a construct
136 ** like the following:
138 ** %fallback ID X Y Z.
140 ** appears in the grammar, then ID becomes a fallback token for X, Y,
141 ** and Z. Whenever one of the tokens X, Y, or Z is input to the parser
142 ** but it does not parse, the type of the token is changed to ID and
143 ** the parse is retried before an error is thrown.
146 static const YYCODETYPE yyFallback
[] = {
149 #endif /* YYFALLBACK */
151 /* The following structure represents a single element of the
152 ** parser's stack. Information stored includes:
154 ** + The state number for the parser at this level of the stack.
156 ** + The value of the token stored at this level of the stack.
157 ** (In other words, the "major" token.)
159 ** + The semantic value stored at this level of the stack. This is
160 ** the information used by the action routines in the grammar.
161 ** It is sometimes called the "minor" token.
163 struct yyStackEntry
{
164 YYACTIONTYPE stateno
; /* The state-number */
165 YYCODETYPE major
; /* The major token value. This is the code
166 ** number for the token at this stack level */
167 YYMINORTYPE minor
; /* The user-supplied minor token value. This
168 ** is the value of the token */
170 typedef struct yyStackEntry yyStackEntry
;
172 /* The state of the parser is completely contained in an instance of
173 ** the following structure */
175 int yyidx
; /* Index of top element in stack */
176 #ifdef YYTRACKMAXSTACKDEPTH
177 int yyidxMax
; /* Maximum value of yyidx */
179 int yyerrcnt
; /* Shifts left before out of the error */
180 ParseARG_SDECL
/* A place to hold %extra_argument */
182 int yystksz
; /* Current side of the stack */
183 yyStackEntry
*yystack
; /* The parser's stack */
185 yyStackEntry yystack
[YYSTACKDEPTH
]; /* The parser's stack */
188 typedef struct yyParser yyParser
;
192 static FILE *yyTraceFILE
= 0;
193 static char *yyTracePrompt
= 0;
198 ** Turn parser tracing on by giving a stream to which to write the trace
199 ** and a prompt to preface each trace message. Tracing is turned off
200 ** by making either argument NULL
204 ** <li> A FILE* to which trace output should be written.
205 ** If NULL, then tracing is turned off.
206 ** <li> A prefix string written at the beginning of every
207 ** line of trace output. If NULL, then tracing is
214 void ParseTrace(FILE *TraceFILE
, char *zTracePrompt
){
215 yyTraceFILE
= TraceFILE
;
216 yyTracePrompt
= zTracePrompt
;
217 if( yyTraceFILE
==0 ) yyTracePrompt
= 0;
218 else if( yyTracePrompt
==0 ) yyTraceFILE
= 0;
223 /* For tracing shifts, the names of all terminals and nonterminals
224 ** are required. The following table supplies these names */
225 static const char *const yyTokenName
[] = {
231 /* For tracing reduce actions, the names of all rules are required.
233 static const char *const yyRuleName
[] = {
241 ** Try to increase the size of the parser stack.
243 static void yyGrowStack(yyParser
*p
){
247 newSize
= p
->yystksz
*2 + 100;
248 pNew
= realloc(p
->yystack
, newSize
*sizeof(pNew
[0]));
251 p
->yystksz
= newSize
;
254 fprintf(yyTraceFILE
,"%sStack grows to %d entries!\n",
255 yyTracePrompt
, p
->yystksz
);
263 ** This function allocates a new parser.
264 ** The only argument is a pointer to a function which works like
268 ** A pointer to the function used to allocate memory.
271 ** A pointer to a parser. This pointer is used in subsequent calls
272 ** to Parse and ParseFree.
274 void *ParseAlloc(void *(*mallocProc
)(u64
)){
276 pParser
= (yyParser
*)(*mallocProc
)( (u64
)sizeof(yyParser
) );
279 #ifdef YYTRACKMAXSTACKDEPTH
280 pParser
->yyidxMax
= 0;
283 pParser
->yystack
= NULL
;
284 pParser
->yystksz
= 0;
285 yyGrowStack(pParser
);
291 /* The following function deletes the value associated with a
292 ** symbol. The symbol can be either a terminal or nonterminal.
293 ** "yymajor" is the symbol code, and "yypminor" is a pointer to
296 static void yy_destructor(
297 yyParser
*yypParser
, /* The parser */
298 YYCODETYPE yymajor
, /* Type code for object to destroy */
299 YYMINORTYPE
*yypminor
/* The object to be destroyed */
303 /* Here is inserted the actions which take place when a
304 ** terminal or non-terminal is destroyed. This can happen
305 ** when the symbol is popped from the stack during a
306 ** reduce or during error processing or when a parser is
307 ** being destroyed before it is finished parsing.
309 ** Note: during a reduce, the only symbols destroyed are those
310 ** which appear on the RHS of the rule, but which are not used
311 ** inside the C code.
314 default: break; /* If no destructor action specified: do nothing */
319 ** Pop the parser's stack once.
321 ** If there is a destructor routine associated with the token which
322 ** is popped from the stack, then call it.
324 ** Return the major token number for the symbol popped.
326 static int yy_pop_parser_stack(yyParser
*pParser
){
328 yyStackEntry
*yytos
= &pParser
->yystack
[pParser
->yyidx
];
330 /* There is no mechanism by which the parser stack can be popped below
331 ** empty in SQLite. */
332 if( NEVER(pParser
->yyidx
<0) ) return 0;
334 if( yyTraceFILE
&& pParser
->yyidx
>=0 ){
335 fprintf(yyTraceFILE
,"%sPopping %s\n",
337 yyTokenName
[yytos
->major
]);
340 yymajor
= yytos
->major
;
341 yy_destructor(pParser
, yymajor
, &yytos
->minor
);
347 ** Deallocate and destroy a parser. Destructors are all called for
348 ** all stack elements before shutting the parser down.
352 ** <li> A pointer to the parser. This should be a pointer
353 ** obtained from ParseAlloc.
354 ** <li> A pointer to a function used to reclaim memory obtained
359 void *p
, /* The parser to be deleted */
360 void (*freeProc
)(void*) /* Function used to reclaim memory */
362 yyParser
*pParser
= (yyParser
*)p
;
363 /* In SQLite, we never try to destroy a parser that was not successfully
364 ** created in the first place. */
365 if( NEVER(pParser
==0) ) return;
366 while( pParser
->yyidx
>=0 ) yy_pop_parser_stack(pParser
);
368 free(pParser
->yystack
);
370 (*freeProc
)((void*)pParser
);
374 ** Return the peak depth of the stack for a parser.
376 #ifdef YYTRACKMAXSTACKDEPTH
377 int ParseStackPeak(void *p
){
378 yyParser
*pParser
= (yyParser
*)p
;
379 return pParser
->yyidxMax
;
384 ** Find the appropriate action for a parser given the terminal
385 ** look-ahead token iLookAhead.
387 ** If the look-ahead token is YYNOCODE, then check to see if the action is
388 ** independent of the look-ahead. If it is, return the action, otherwise
389 ** return YY_NO_ACTION.
391 static int yy_find_shift_action(
392 yyParser
*pParser
, /* The parser */
393 YYCODETYPE iLookAhead
/* The look-ahead token */
396 int stateno
= pParser
->yystack
[pParser
->yyidx
].stateno
;
398 if( stateno
>YY_SHIFT_COUNT
399 || (i
= yy_shift_ofst
[stateno
])==YY_SHIFT_USE_DFLT
){
400 return yy_default
[stateno
];
402 assert( iLookAhead
!=YYNOCODE
);
404 if( i
<0 || i
>=YY_ACTTAB_COUNT
|| yy_lookahead
[i
]!=iLookAhead
){
407 YYCODETYPE iFallback
; /* Fallback token */
408 if( iLookAhead
<sizeof(yyFallback
)/sizeof(yyFallback
[0])
409 && (iFallback
= yyFallback
[iLookAhead
])!=0 ){
412 fprintf(yyTraceFILE
, "%sFALLBACK %s => %s\n",
413 yyTracePrompt
, yyTokenName
[iLookAhead
], yyTokenName
[iFallback
]);
416 return yy_find_shift_action(pParser
, iFallback
);
421 int j
= i
- iLookAhead
+ YYWILDCARD
;
423 #if YY_SHIFT_MIN+YYWILDCARD<0
426 #if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT
429 yy_lookahead
[j
]==YYWILDCARD
433 fprintf(yyTraceFILE
, "%sWILDCARD %s => %s\n",
434 yyTracePrompt
, yyTokenName
[iLookAhead
], yyTokenName
[YYWILDCARD
]);
440 #endif /* YYWILDCARD */
442 return yy_default
[stateno
];
449 ** Find the appropriate action for a parser given the non-terminal
450 ** look-ahead token iLookAhead.
452 ** If the look-ahead token is YYNOCODE, then check to see if the action is
453 ** independent of the look-ahead. If it is, return the action, otherwise
454 ** return YY_NO_ACTION.
456 static int yy_find_reduce_action(
457 int stateno
, /* Current state number */
458 YYCODETYPE iLookAhead
/* The look-ahead token */
462 if( stateno
>YY_REDUCE_COUNT
){
463 return yy_default
[stateno
];
466 assert( stateno
<=YY_REDUCE_COUNT
);
468 i
= yy_reduce_ofst
[stateno
];
469 assert( i
!=YY_REDUCE_USE_DFLT
);
470 assert( iLookAhead
!=YYNOCODE
);
473 if( i
<0 || i
>=YY_ACTTAB_COUNT
|| yy_lookahead
[i
]!=iLookAhead
){
474 return yy_default
[stateno
];
477 assert( i
>=0 && i
<YY_ACTTAB_COUNT
);
478 assert( yy_lookahead
[i
]==iLookAhead
);
484 ** The following routine is called if the stack overflows.
486 static void yyStackOverflow(yyParser
*yypParser
, YYMINORTYPE
*yypMinor
){
491 fprintf(yyTraceFILE
,"%sStack Overflow!\n",yyTracePrompt
);
494 while( yypParser
->yyidx
>=0 ) yy_pop_parser_stack(yypParser
);
495 /* Here code is inserted which will execute if the parser
496 ** stack every overflows */
498 ParseARG_STORE
; /* Suppress warning about unused %extra_argument var */
502 ** Perform a shift action.
504 static void yy_shift(
505 yyParser
*yypParser
, /* The parser to be shifted */
506 int yyNewState
, /* The new state to shift in */
507 int yyMajor
, /* The major token to shift in */
508 YYMINORTYPE
*yypMinor
/* Pointer to the minor token to shift in */
512 #ifdef YYTRACKMAXSTACKDEPTH
513 if( yypParser
->yyidx
>yypParser
->yyidxMax
){
514 yypParser
->yyidxMax
= yypParser
->yyidx
;
518 if( yypParser
->yyidx
>=YYSTACKDEPTH
){
519 yyStackOverflow(yypParser
, yypMinor
);
523 if( yypParser
->yyidx
>=yypParser
->yystksz
){
524 yyGrowStack(yypParser
);
525 if( yypParser
->yyidx
>=yypParser
->yystksz
){
526 yyStackOverflow(yypParser
, yypMinor
);
531 yytos
= &yypParser
->yystack
[yypParser
->yyidx
];
532 yytos
->stateno
= (YYACTIONTYPE
)yyNewState
;
533 yytos
->major
= (YYCODETYPE
)yyMajor
;
534 yytos
->minor
= *yypMinor
;
536 if( yyTraceFILE
&& yypParser
->yyidx
>0 ){
538 fprintf(yyTraceFILE
,"%sShift %d\n",yyTracePrompt
,yyNewState
);
539 fprintf(yyTraceFILE
,"%sStack:",yyTracePrompt
);
540 for(i
=1; i
<=yypParser
->yyidx
; i
++)
541 fprintf(yyTraceFILE
," %s",yyTokenName
[yypParser
->yystack
[i
].major
]);
542 fprintf(yyTraceFILE
,"\n");
547 /* The following table contains information about every rule that
548 ** is used during the reduce.
550 static const struct {
551 YYCODETYPE lhs
; /* Symbol on the left-hand side of the rule */
552 unsigned char nrhs
; /* Number of right-hand side symbols in the rule */
557 static void yy_accept(yyParser
*); /* Forward Declaration */
560 ** Perform a reduce action and the shift that must immediately
561 ** follow the reduce.
563 static void yy_reduce(
564 yyParser
*yypParser
, /* The parser */
565 int yyruleno
/* Number of the rule by which to reduce */
567 int yygoto
; /* The next state */
568 int yyact
; /* The next action */
569 YYMINORTYPE yygotominor
; /* The LHS of the rule reduced */
570 yyStackEntry
*yymsp
; /* The top of the parser's stack */
571 int yysize
; /* Amount to pop the stack */
573 yymsp
= &yypParser
->yystack
[yypParser
->yyidx
];
575 if( yyTraceFILE
&& yyruleno
>=0
576 && yyruleno
<(int)(sizeof(yyRuleName
)/sizeof(yyRuleName
[0])) ){
577 fprintf(yyTraceFILE
, "%sReduce [%s].\n", yyTracePrompt
,
578 yyRuleName
[yyruleno
]);
582 /* Silence complaints from purify about yygotominor being uninitialized
583 ** in some cases when it is copied into the stack after the following
584 ** switch. yygotominor is uninitialized when a rule reduces that does
585 ** not set the value of its left-hand side nonterminal. Leaving the
586 ** value of the nonterminal uninitialized is utterly harmless as long
587 ** as the value is never used. So really the only thing this code
588 ** accomplishes is to quieten purify.
590 ** 2007-01-16: The wireshark project (www.wireshark.org) reports that
591 ** without this code, their parser segfaults. I'm not sure what there
592 ** parser is doing to make this happen. This is the second bug report
593 ** from wireshark this week. Clearly they are stressing Lemon in ways
594 ** that it has not been previously stressed... (SQLite ticket #2172)
596 /*memset(&yygotominor, 0, sizeof(yygotominor));*/
597 yygotominor
= yyzerominor
;
601 /* Beginning here are the reduction cases. A typical example
604 ** #line <lineno> <grammarfile>
605 ** { ... } // User supplied code
606 ** #line <lineno> <thisfile>
611 assert( yyruleno
>=0 && yyruleno
<sizeof(yyRuleInfo
)/sizeof(yyRuleInfo
[0]) );
612 yygoto
= yyRuleInfo
[yyruleno
].lhs
;
613 yysize
= yyRuleInfo
[yyruleno
].nrhs
;
614 yypParser
->yyidx
-= yysize
;
615 yyact
= yy_find_reduce_action(yymsp
[-yysize
].stateno
,(YYCODETYPE
)yygoto
);
616 if( yyact
< YYNSTATE
){
618 /* If we are not debugging and the reduce action popped at least
619 ** one element off the stack, then we can push the new element back
620 ** onto the stack here, and skip the stack overflow test in yy_shift().
621 ** That gives a significant speed improvement. */
625 yymsp
->stateno
= (YYACTIONTYPE
)yyact
;
626 yymsp
->major
= (YYCODETYPE
)yygoto
;
627 yymsp
->minor
= yygotominor
;
631 yy_shift(yypParser
,yyact
,yygoto
,&yygotominor
);
634 assert( yyact
== YYNSTATE
+ YYNRULE
+ 1 );
635 yy_accept(yypParser
);
640 ** The following code executes when the parse fails
642 #ifndef YYNOERRORRECOVERY
643 static void yy_parse_failed(
644 yyParser
*yypParser
/* The parser */
649 fprintf(yyTraceFILE
,"%sFail!\n",yyTracePrompt
);
652 while( yypParser
->yyidx
>=0 ) yy_pop_parser_stack(yypParser
);
653 /* Here code is inserted which will be executed whenever the
656 ParseARG_STORE
; /* Suppress warning about unused %extra_argument variable */
658 #endif /* YYNOERRORRECOVERY */
661 ** The following code executes when a syntax error first occurs.
663 static void yy_syntax_error(
664 yyParser
*yypParser
, /* The parser */
665 int yymajor
, /* The major type of the error token */
666 YYMINORTYPE yyminor
/* The minor type of the error token */
669 #define TOKEN (yyminor.yy0)
671 ParseARG_STORE
; /* Suppress warning about unused %extra_argument variable */
675 ** The following is executed when the parser accepts
677 static void yy_accept(
678 yyParser
*yypParser
/* The parser */
683 fprintf(yyTraceFILE
,"%sAccept!\n",yyTracePrompt
);
686 while( yypParser
->yyidx
>=0 ) yy_pop_parser_stack(yypParser
);
687 /* Here code is inserted which will be executed whenever the
690 ParseARG_STORE
; /* Suppress warning about unused %extra_argument variable */
693 /* The main parser program.
694 ** The first argument is a pointer to a structure obtained from
695 ** "ParseAlloc" which describes the current state of the parser.
696 ** The second argument is the major token number. The third is
697 ** the minor token. The fourth optional argument is whatever the
698 ** user wants (and specified in the grammar) and is available for
699 ** use by the action routines.
703 ** <li> A pointer to the parser (an opaque structure.)
704 ** <li> The major token number.
705 ** <li> The minor token number.
706 ** <li> An option argument of a grammar-specified type.
713 void *yyp
, /* The parser */
714 int yymajor
, /* The major token code number */
715 ParseTOKENTYPE yyminor
/* The value for the token */
716 ParseARG_PDECL
/* Optional %extra_argument parameter */
718 YYMINORTYPE yyminorunion
;
719 int yyact
; /* The parser action. */
720 #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
721 int yyendofinput
; /* True if we are at the end of input */
724 int yyerrorhit
= 0; /* True if yymajor has invoked an error */
726 yyParser
*yypParser
; /* The parser */
728 /* (re)initialize the parser, if necessary */
729 yypParser
= (yyParser
*)yyp
;
730 if( yypParser
->yyidx
<0 ){
732 if( yypParser
->yystksz
<=0 ){
733 /*memset(&yyminorunion, 0, sizeof(yyminorunion));*/
734 yyminorunion
= yyzerominor
;
735 yyStackOverflow(yypParser
, &yyminorunion
);
739 yypParser
->yyidx
= 0;
740 yypParser
->yyerrcnt
= -1;
741 yypParser
->yystack
[0].stateno
= 0;
742 yypParser
->yystack
[0].major
= 0;
744 yyminorunion
.yy0
= yyminor
;
745 #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
746 yyendofinput
= (yymajor
==0);
752 fprintf(yyTraceFILE
,"%sInput %s\n",yyTracePrompt
,yyTokenName
[yymajor
]);
757 yyact
= yy_find_shift_action(yypParser
,(YYCODETYPE
)yymajor
);
758 if( yyact
<YYNSTATE
){
759 yy_shift(yypParser
,yyact
,yymajor
,&yyminorunion
);
760 yypParser
->yyerrcnt
--;
762 }else if( yyact
< YYNSTATE
+ YYNRULE
){
763 yy_reduce(yypParser
,yyact
-YYNSTATE
);
765 assert( yyact
== YY_ERROR_ACTION
);
771 fprintf(yyTraceFILE
,"%sSyntax Error!\n",yyTracePrompt
);
775 /* A syntax error has occurred.
776 ** The response to an error depends upon whether or not the
777 ** grammar defines an error token "ERROR".
779 ** This is what we do if the grammar does define ERROR:
781 ** * Call the %syntax_error function.
783 ** * Begin popping the stack until we enter a state where
784 ** it is legal to shift the error symbol, then shift
787 ** * Set the error count to three.
789 ** * Begin accepting and shifting new tokens. No new error
790 ** processing will occur until three tokens have been
791 ** shifted successfully.
794 if( yypParser
->yyerrcnt
<0 ){
795 yy_syntax_error(yypParser
,yymajor
,yyminorunion
);
797 yymx
= yypParser
->yystack
[yypParser
->yyidx
].major
;
798 if( yymx
==YYERRORSYMBOL
|| yyerrorhit
){
801 fprintf(yyTraceFILE
,"%sDiscard input token %s\n",
802 yyTracePrompt
,yyTokenName
[yymajor
]);
805 yy_destructor(yypParser
, (YYCODETYPE
)yymajor
,&yyminorunion
);
809 yypParser
->yyidx
>= 0 &&
810 yymx
!= YYERRORSYMBOL
&&
811 (yyact
= yy_find_reduce_action(
812 yypParser
->yystack
[yypParser
->yyidx
].stateno
,
813 YYERRORSYMBOL
)) >= YYNSTATE
815 yy_pop_parser_stack(yypParser
);
817 if( yypParser
->yyidx
< 0 || yymajor
==0 ){
818 yy_destructor(yypParser
,(YYCODETYPE
)yymajor
,&yyminorunion
);
819 yy_parse_failed(yypParser
);
821 }else if( yymx
!=YYERRORSYMBOL
){
824 yy_shift(yypParser
,yyact
,YYERRORSYMBOL
,&u2
);
827 yypParser
->yyerrcnt
= 3;
829 #elif defined(YYNOERRORRECOVERY)
830 /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to
831 ** do any kind of error recovery. Instead, simply invoke the syntax
832 ** error routine and continue going as if nothing had happened.
834 ** Applications can set this macro (for example inside %include) if
835 ** they intend to abandon the parse upon the first syntax error seen.
837 yy_syntax_error(yypParser
,yymajor
,yyminorunion
);
838 yy_destructor(yypParser
,(YYCODETYPE
)yymajor
,&yyminorunion
);
841 #else /* YYERRORSYMBOL is not defined */
842 /* This is what we do if the grammar does not define ERROR:
844 ** * Report an error message, and throw away the input token.
846 ** * If the input token is $, then fail the parse.
848 ** As before, subsequent error messages are suppressed until
849 ** three input tokens have been successfully shifted.
851 if( yypParser
->yyerrcnt
<=0 ){
852 yy_syntax_error(yypParser
,yymajor
,yyminorunion
);
854 yypParser
->yyerrcnt
= 3;
855 yy_destructor(yypParser
,(YYCODETYPE
)yymajor
,&yyminorunion
);
857 yy_parse_failed(yypParser
);
862 }while( yymajor
!=YYNOCODE
&& yypParser
->yyidx
>=0 );