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Overview
| Comment: | Change the parser engine so that it (once again) waits for a lookahead token before reducing, even in a SHIFTREDUCE action. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | lemon-update |
| Files: | files | file ages | folders |
| SHA1: |
2c17a1358353a0845b039283be79353f |
| User & Date: | drh 2015-09-07 19:52:55 |
Context
|
2015-09-07
| ||
| 20:02 | Fix an unreachable branch in the new parse automaton. (Closed-Leaf check-in: e9d604b4 user: drh tags: lemon-update) | |
| 19:52 | Change the parser engine so that it (once again) waits for a lookahead token before reducing, even in a SHIFTREDUCE action. (check-in: 2c17a135 user: drh tags: lemon-update) | |
| 18:23 | For the Lemon-generated parser, add a new action type SHIFTREDUCE and use it to further compress the parser tables and improve parser performance. (check-in: 531c3974 user: drh tags: lemon-update) | |
Changes
Changes to src/lempar.c.
163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 ... 399 400 401 402 403 404 405 406 407 408 409 410 411 412 ... 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 ... 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 ... 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 ... 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 ... 879 880 881 882 883 884 885 886 887 888 889 890 891 892 |
**
** + 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 {
YYACTIONTYPE stateno; /* The state-number */
YYCODETYPE 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;
................................................................................
static int yy_find_shift_action(
yyParser *pParser, /* The parser */
YYCODETYPE iLookAhead /* The look-ahead token */
){
int i;
int stateno = pParser->yystack[pParser->yyidx].stateno;
if( stateno>YY_SHIFT_COUNT
|| (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){
return yy_default[stateno];
}
assert( iLookAhead!=YYNOCODE );
i += iLookAhead;
if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
................................................................................
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 */
}
/*
** Perform a shift action. Return the number of errors.
*/
static int 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 to the minor token to shift in */
){
yyStackEntry *yytos;
yypParser->yyidx++;
................................................................................
if( yypParser->yyidx>yypParser->yyidxMax ){
yypParser->yyidxMax = yypParser->yyidx;
}
#endif
#if YYSTACKDEPTH>0
if( yypParser->yyidx>=YYSTACKDEPTH ){
yyStackOverflow(yypParser, yypMinor);
return 1;
}
#else
if( yypParser->yyidx>=yypParser->yystksz ){
yyGrowStack(yypParser);
if( yypParser->yyidx>=yypParser->yystksz ){
yyStackOverflow(yypParser, yypMinor);
return 1;
}
}
#endif
yytos = &yypParser->yystack[yypParser->yyidx];
yytos->stateno = (YYACTIONTYPE)yyNewState;
yytos->major = (YYCODETYPE)yyMajor;
yytos->minor = *yypMinor;
#ifndef NDEBUG
if( yyTraceFILE && yypParser->yyidx>0 ){
int i;
if( yyNewState<YYNSTATE ){
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");
}else{
fprintf(yyTraceFILE,"%sShift *\n",yyTracePrompt);
}
}
#endif
return 0;
}
/* The following table contains information about every rule that
** is used during the reduce.
*/
static const struct {
YYCODETYPE lhs; /* Symbol on the left-hand side of the rule */
................................................................................
};
assert( yyruleno>=0 && yyruleno<sizeof(yyRuleInfo)/sizeof(yyRuleInfo[0]) );
yygoto = yyRuleInfo[yyruleno].lhs;
yysize = yyRuleInfo[yyruleno].nrhs;
yypParser->yyidx -= yysize;
yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto);
if( yyact <= YY_MAX_SHIFTREDUCE ){
/* If the reduce action popped at least
** one element off the stack, then we can push the new element back
** onto the stack here, and skip the stack overflow test in yy_shift().
** That gives a significant speed improvement. */
if( yysize ){
yypParser->yyidx++;
yymsp -= yysize-1;
yymsp->stateno = (YYACTIONTYPE)yyact;
yymsp->major = (YYCODETYPE)yygoto;
yymsp->minor = yygotominor;
#ifndef NDEBUG
if( yyTraceFILE ){
fprintf(yyTraceFILE,"%sShift %d\n",yyTracePrompt,yyact);
}
#endif
}else{
if( yy_shift(yypParser,yyact,yygoto,&yygotominor) ) yyact = 0;
}
if( yyact>=YY_MIN_SHIFTREDUCE ){
yy_reduce(yypParser, yyact - YY_MIN_SHIFTREDUCE);
}
}else{
assert( yyact == YY_ACCEPT_ACTION );
yy_accept(yypParser);
}
}
................................................................................
fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]);
}
#endif
do{
yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
if( yyact <= YY_MAX_SHIFTREDUCE ){
if( yy_shift(yypParser,yyact,yymajor,&yyminorunion)==0 ){
yypParser->yyerrcnt--;
yymajor = YYNOCODE;
if( yyact > YY_MAX_SHIFT ){
yy_reduce(yypParser, yyact-YY_MIN_SHIFTREDUCE);
}
}
}else if( yyact <= YY_MAX_REDUCE ){
yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
}else{
assert( yyact == YY_ERROR_ACTION );
#ifdef YYERRORSYMBOL
int yymx;
#endif
................................................................................
if( yyendofinput ){
yy_parse_failed(yypParser);
}
yymajor = YYNOCODE;
#endif
}
}while( yymajor!=YYNOCODE && yypParser->yyidx>=0 );
#ifdef SQLITE_DEBUG
if( yyTraceFILE ){
fprintf(yyTraceFILE,"%sReturn\n",yyTracePrompt);
}
#endif
return;
}
|
> > > > | > > > > > > > > > > > > > > > > > > > > > > > | | | | < < < < < < < < < < < < < < > | < < < < | < < < > | | | < < < < | |
163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 ... 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 ... 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 ... 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 ... 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 ... 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 ... 883 884 885 886 887 888 889 890 891 892 893 894 895 896 |
** ** + 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. ** ** After the "shift" half of a SHIFTREDUCE action, the stateno field ** actually contains the reduce action for the second half of the ** SHIFTREDUCE. */ struct yyStackEntry { YYACTIONTYPE stateno; /* The state-number, or reduce action in SHIFTREDUCE */ YYCODETYPE 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; ................................................................................ static int yy_find_shift_action( yyParser *pParser, /* The parser */ YYCODETYPE iLookAhead /* The look-ahead token */ ){ int i; int stateno = pParser->yystack[pParser->yyidx].stateno; if( stateno>=YY_MIN_REDUCE ) return stateno; if( stateno>YY_SHIFT_COUNT || (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){ return yy_default[stateno]; } assert( iLookAhead!=YYNOCODE ); i += iLookAhead; if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){ ................................................................................ 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 */ } /* ** Print tracing information for a SHIFT action */ #ifndef NDEBUG static void yyTraceShift(yyParser *yypParser, int yyNewState){ if( yyTraceFILE ){ int i; if( yyNewState<YYNSTATE ){ 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"); }else{ fprintf(yyTraceFILE,"%sShift *\n",yyTracePrompt); } } } #else # define yyTraceShift(X,Y) #endif /* ** Perform a shift action. Return the number of errors. */ 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 to the minor token to shift in */ ){ yyStackEntry *yytos; yypParser->yyidx++; ................................................................................ if( yypParser->yyidx>yypParser->yyidxMax ){ yypParser->yyidxMax = yypParser->yyidx; } #endif #if YYSTACKDEPTH>0 if( yypParser->yyidx>=YYSTACKDEPTH ){ yyStackOverflow(yypParser, yypMinor); return; } #else if( yypParser->yyidx>=yypParser->yystksz ){ yyGrowStack(yypParser); if( yypParser->yyidx>=yypParser->yystksz ){ yyStackOverflow(yypParser, yypMinor); return; } } #endif yytos = &yypParser->yystack[yypParser->yyidx]; yytos->stateno = (YYACTIONTYPE)yyNewState; yytos->major = (YYCODETYPE)yyMajor; yytos->minor = *yypMinor; yyTraceShift(yypParser, yyNewState); } /* The following table contains information about every rule that ** is used during the reduce. */ static const struct { YYCODETYPE lhs; /* Symbol on the left-hand side of the rule */ ................................................................................ }; assert( yyruleno>=0 && yyruleno<sizeof(yyRuleInfo)/sizeof(yyRuleInfo[0]) ); yygoto = yyRuleInfo[yyruleno].lhs; yysize = yyRuleInfo[yyruleno].nrhs; yypParser->yyidx -= yysize; yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto); if( yyact <= YY_MAX_SHIFTREDUCE ){ if( yyact>YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE; /* If the reduce action popped at least ** one element off the stack, then we can push the new element back ** onto the stack here, and skip the stack overflow test in yy_shift(). ** That gives a significant speed improvement. */ if( yysize ){ yypParser->yyidx++; yymsp -= yysize-1; yymsp->stateno = (YYACTIONTYPE)yyact; yymsp->major = (YYCODETYPE)yygoto; yymsp->minor = yygotominor; yyTraceShift(yypParser, yyact); }else{ yy_shift(yypParser,yyact,yygoto,&yygotominor); } }else{ assert( yyact == YY_ACCEPT_ACTION ); yy_accept(yypParser); } } ................................................................................ fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]); } #endif do{ yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor); if( yyact <= YY_MAX_SHIFTREDUCE ){ if( yyact > YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE; yy_shift(yypParser,yyact,yymajor,&yyminorunion); yypParser->yyerrcnt--; yymajor = YYNOCODE; }else if( yyact <= YY_MAX_REDUCE ){ yy_reduce(yypParser,yyact-YY_MIN_REDUCE); }else{ assert( yyact == YY_ERROR_ACTION ); #ifdef YYERRORSYMBOL int yymx; #endif ................................................................................ if( yyendofinput ){ yy_parse_failed(yypParser); } yymajor = YYNOCODE; #endif } }while( yymajor!=YYNOCODE && yypParser->yyidx>=0 ); #ifndef NDEBUG if( yyTraceFILE ){ fprintf(yyTraceFILE,"%sReturn\n",yyTracePrompt); } #endif return; } |
Changes to src/parse.y.
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 |
}
// "seltablist" is a "Select Table List" - the content of the FROM clause
// in a SELECT statement. "stl_prefix" is a prefix of this list.
//
stl_prefix(A) ::= seltablist(X) joinop(Y). {
A = X;
if( A && A->nSrc>0 ) A->a[A->nSrc-1].fg.jointype = (u8)Y;
}
stl_prefix(A) ::= . {A = 0;}
seltablist(A) ::= stl_prefix(X) nm(Y) dbnm(D) as(Z) indexed_opt(I)
on_opt(N) using_opt(U). {
A = sqlite3SrcListAppendFromTerm(pParse,X,&Y,&D,&Z,0,N,U);
sqlite3SrcListIndexedBy(pParse, A, &I);
}
|
| |
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 |
}
// "seltablist" is a "Select Table List" - the content of the FROM clause
// in a SELECT statement. "stl_prefix" is a prefix of this list.
//
stl_prefix(A) ::= seltablist(X) joinop(Y). {
A = X;
if( ALWAYS(A && A->nSrc>0) ) A->a[A->nSrc-1].fg.jointype = (u8)Y;
}
stl_prefix(A) ::= . {A = 0;}
seltablist(A) ::= stl_prefix(X) nm(Y) dbnm(D) as(Z) indexed_opt(I)
on_opt(N) using_opt(U). {
A = sqlite3SrcListAppendFromTerm(pParse,X,&Y,&D,&Z,0,N,U);
sqlite3SrcListIndexedBy(pParse, A, &I);
}
|
Changes to src/tokenize.c.
455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 |
}
abort_parse:
assert( nErr==0 );
if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
assert( zSql[i]==0 );
if( lastTokenParsed!=TK_SEMI ){
sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
}
if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
}
}
pParse->zTail = &zSql[i];
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3_mutex_enter(sqlite3MallocMutex());
sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
sqlite3_mutex_leave(sqlite3MallocMutex());
#endif /* YYDEBUG */
|
> < |
455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 |
}
abort_parse:
assert( nErr==0 );
if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
assert( zSql[i]==0 );
if( lastTokenParsed!=TK_SEMI ){
sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
pParse->zTail = &zSql[i];
}
if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
}
}
#ifdef YYTRACKMAXSTACKDEPTH
sqlite3_mutex_enter(sqlite3MallocMutex());
sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
sqlite3ParserStackPeak(pEngine)
);
sqlite3_mutex_leave(sqlite3MallocMutex());
#endif /* YYDEBUG */
|
Changes to test/misc1.test.
642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 |
# 2015-03-22: NULL pointer dereference after a syntax error
#
do_catchsql_test misc1-21.1 {
select''like''like''like#0;
} {1 {near "#0": syntax error}}
do_catchsql_test misc1-21.2 {
VALUES(0,0x0MATCH#0;
} {1 {near "#0": syntax error}}
# 2015-04-15
do_execsql_test misc1-22.1 {
SELECT ""+3 FROM (SELECT ""+5);
} {3}
# 2015-04-19: NULL pointer dereference on a corrupt schema
|
| |
642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 |
# 2015-03-22: NULL pointer dereference after a syntax error
#
do_catchsql_test misc1-21.1 {
select''like''like''like#0;
} {1 {near "#0": syntax error}}
do_catchsql_test misc1-21.2 {
VALUES(0,0x0MATCH#0;
} {1 {near ";": syntax error}}
# 2015-04-15
do_execsql_test misc1-22.1 {
SELECT ""+3 FROM (SELECT ""+5);
} {3}
# 2015-04-19: NULL pointer dereference on a corrupt schema
|
Changes to tool/lempar.c.
157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 ... 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 ... 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 ... 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 ... 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 ... 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 |
**
** + 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 {
YYACTIONTYPE stateno; /* The state-number */
YYCODETYPE 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;
................................................................................
*/
static int yy_find_shift_action(
yyParser *pParser, /* The parser */
YYCODETYPE iLookAhead /* The look-ahead token */
){
int i;
int stateno = pParser->yystack[pParser->yyidx].stateno;
if( stateno>YY_SHIFT_COUNT
|| (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){
return yy_default[stateno];
}
assert( iLookAhead!=YYNOCODE );
i += iLookAhead;
if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
................................................................................
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 */
}
/*
** Perform a shift action. Return the number of errors.
*/
static int 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 to the minor token to shift in */
){
yyStackEntry *yytos;
yypParser->yyidx++;
................................................................................
if( yypParser->yyidx>yypParser->yyidxMax ){
yypParser->yyidxMax = yypParser->yyidx;
}
#endif
#if YYSTACKDEPTH>0
if( yypParser->yyidx>=YYSTACKDEPTH ){
yyStackOverflow(yypParser, yypMinor);
return 1;
}
#else
if( yypParser->yyidx>=yypParser->yystksz ){
yyGrowStack(yypParser);
if( yypParser->yyidx>=yypParser->yystksz ){
yyStackOverflow(yypParser, yypMinor);
return 1;
}
}
#endif
yytos = &yypParser->yystack[yypParser->yyidx];
yytos->stateno = (YYACTIONTYPE)yyNewState;
yytos->major = (YYCODETYPE)yyMajor;
yytos->minor = *yypMinor;
#ifndef NDEBUG
if( yyTraceFILE && yypParser->yyidx>0 ){
int i;
if( yyNewState<YYNSTATE ){
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");
}else{
fprintf(yyTraceFILE,"%sShift *\n",yyTracePrompt);
}
}
#endif
return 0;
}
/* The following table contains information about every rule that
** is used during the reduce.
*/
static const struct {
YYCODETYPE lhs; /* Symbol on the left-hand side of the rule */
................................................................................
*/
%%
};
yygoto = yyRuleInfo[yyruleno].lhs;
yysize = yyRuleInfo[yyruleno].nrhs;
yypParser->yyidx -= yysize;
yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto);
if( yyact < YY_MAX_SHIFTREDUCE ){
/* If the reduce action popped at least
** one element off the stack, then we can push the new element back
** onto the stack here, and skip the stack overflow test in yy_shift().
** That gives a significant speed improvement. */
if( yysize ){
yypParser->yyidx++;
yymsp -= yysize-1;
yymsp->stateno = (YYACTIONTYPE)yyact;
yymsp->major = (YYCODETYPE)yygoto;
yymsp->minor = yygotominor;
#ifndef NDEBUG
if( yyTraceFILE ){
fprintf(yyTraceFILE,"%sShift %d\n",yyTracePrompt,yyact);
}
#endif
}else{
if( yy_shift(yypParser,yyact,yygoto,&yygotominor) ) yyact = 0;
}
if( yyact>=YY_MIN_SHIFTREDUCE ){
yy_reduce(yypParser, yyact - YY_MIN_SHIFTREDUCE);
}
}else{
assert( yyact == YY_ACCEPT_ACTION );
yy_accept(yypParser);
}
}
................................................................................
fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]);
}
#endif
do{
yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
if( yyact <= YY_MAX_SHIFTREDUCE ){
if( yy_shift(yypParser,yyact,yymajor,&yyminorunion)==0 ){
yypParser->yyerrcnt--;
yymajor = YYNOCODE;
if( yyact > YY_MAX_SHIFT ){
yy_reduce(yypParser, yyact-YY_MIN_SHIFTREDUCE);
}
}
}else if( yyact <= YY_MAX_REDUCE ){
yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
}else{
assert( yyact == YY_ERROR_ACTION );
#ifdef YYERRORSYMBOL
int yymx;
#endif
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** ** + 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. ** ** After the "shift" half of a SHIFTREDUCE action, the stateno field ** actually contains the reduce action for the second half of the ** SHIFTREDUCE. */ struct yyStackEntry { YYACTIONTYPE stateno; /* The state-number, or reduce action in SHIFTREDUCE */ YYCODETYPE 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; ................................................................................ */ static int yy_find_shift_action( yyParser *pParser, /* The parser */ YYCODETYPE iLookAhead /* The look-ahead token */ ){ int i; int stateno = pParser->yystack[pParser->yyidx].stateno; if( stateno>=YY_MIN_REDUCE ) return stateno; if( stateno>YY_SHIFT_COUNT || (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){ return yy_default[stateno]; } assert( iLookAhead!=YYNOCODE ); i += iLookAhead; if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){ ................................................................................ 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 */ } /* ** Print tracing information for a SHIFT action */ #ifndef NDEBUG static void yyTraceShift(yyParser *yypParser, int yyNewState){ if( yyTraceFILE ){ int i; if( yyNewState<YYNSTATE ){ 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"); }else{ fprintf(yyTraceFILE,"%sShift *\n",yyTracePrompt); } } } #else # define yyTraceShift(X,Y) #endif /* ** Perform a shift action. Return the number of errors. */ 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 to the minor token to shift in */ ){ yyStackEntry *yytos; yypParser->yyidx++; ................................................................................ if( yypParser->yyidx>yypParser->yyidxMax ){ yypParser->yyidxMax = yypParser->yyidx; } #endif #if YYSTACKDEPTH>0 if( yypParser->yyidx>=YYSTACKDEPTH ){ yyStackOverflow(yypParser, yypMinor); return; } #else if( yypParser->yyidx>=yypParser->yystksz ){ yyGrowStack(yypParser); if( yypParser->yyidx>=yypParser->yystksz ){ yyStackOverflow(yypParser, yypMinor); return; } } #endif yytos = &yypParser->yystack[yypParser->yyidx]; yytos->stateno = (YYACTIONTYPE)yyNewState; yytos->major = (YYCODETYPE)yyMajor; yytos->minor = *yypMinor; yyTraceShift(yypParser, yyNewState); } /* The following table contains information about every rule that ** is used during the reduce. */ static const struct { YYCODETYPE lhs; /* Symbol on the left-hand side of the rule */ ................................................................................ */ %% }; yygoto = yyRuleInfo[yyruleno].lhs; yysize = yyRuleInfo[yyruleno].nrhs; yypParser->yyidx -= yysize; yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto); if( yyact <= YY_MAX_SHIFTREDUCE ){ if( yyact>YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE; /* If the reduce action popped at least ** one element off the stack, then we can push the new element back ** onto the stack here, and skip the stack overflow test in yy_shift(). ** That gives a significant speed improvement. */ if( yysize ){ yypParser->yyidx++; yymsp -= yysize-1; yymsp->stateno = (YYACTIONTYPE)yyact; yymsp->major = (YYCODETYPE)yygoto; yymsp->minor = yygotominor; yyTraceShift(yypParser, yyact); }else{ yy_shift(yypParser,yyact,yygoto,&yygotominor); } }else{ assert( yyact == YY_ACCEPT_ACTION ); yy_accept(yypParser); } } ................................................................................ fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]); } #endif do{ yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor); if( yyact <= YY_MAX_SHIFTREDUCE ){ if( yyact > YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE; yy_shift(yypParser,yyact,yymajor,&yyminorunion); yypParser->yyerrcnt--; yymajor = YYNOCODE; }else if( yyact <= YY_MAX_REDUCE ){ yy_reduce(yypParser,yyact-YY_MIN_REDUCE); }else{ assert( yyact == YY_ERROR_ACTION ); #ifdef YYERRORSYMBOL int yymx; #endif |