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* data/glr.c (YYERROR): Update definition.

Browse Source 
(yyrecoverSyntaxError): Correct yyerrState logic. Correct comment.
Allow states with only a default reduction.

Fixes to avoid problem that $-N rules in GLR parsers can cause
buffer overruns, corrupting state.

* src/output.c (prepare_rules): Output max_left_semantic_context.
* src/reader.h (max_left_semantic_context): New
* src/scan-gram.l (max_left_semantic_context): Define.
(handle_action_dollar): Update max_left_semantic_context.
* data/glr.c (YYMAXLEFT): New.
(yydoAction): Increase yyrhsVals size.
(yyresolveAction): Ditto.

Fixes to problems with location handling in GLR parsers reported by
Frank Heckenbach (2003/06/05).

* data/glr.c (YYLTYPE): Make trivial if locations not used.
(YYRHSLOC): Add parentheses, make depend on whether locations used.
(YYLLOC_DEFAULT): Ditto.
(yyuserAction): Use YYLLOC_DEFAULT.
(yydoAction): Remove redundant code.

* tests/cxx-type.at: Exercise location information.
(yylex): Track locations.
(stmtMerge): Return value rather than printing.
This commit is contained in:
Paul Hilfinger
2003-06-10 02:44:58 +00:00
parent 144c1e767a
commit 25005f6ab0
6 changed files with 240 additions and 144 deletions
Download Patch File Download Diff File Expand all files Collapse all files

111
data/glr.c
View File

@@ -192,10 +192,12 @@ b4_syncline([@oline@], [@ofile@])],
#if ! defined (YYLTYPE) && ! defined (YYLTYPE_IS_DECLARED)
typedef struct YYLTYPE
{
]b4_location_if([
int first_line;
int first_column;
int last_line;
int last_column;
])[
} YYLTYPE;
# define YYLTYPE_IS_DECLARED 1
# define YYLTYPE_IS_TRIVIAL 1
@@ -254,6 +256,9 @@ b4_syncline([@oline@], [@ofile@])
#define YYNSTATES ]b4_states_number[
/* YYMAXRHS -- Maximum number of symbols on right-hand side of rule. */
#define YYMAXRHS ]b4_r2_max[
/* YYMAXLEFT -- Maximum number of symbols to the left of a handle
accessed by $0, $-1, etc., in any rule. */
#define YYMAXLEFT ]b4_max_left_semantic_context[
/* YYTRANSLATE(X) -- Bison symbol number corresponding to X. */
#define YYUNDEFTOK ]b4_undef_token_number[
@@ -402,15 +407,22 @@ static const ]b4_int_type_for([b4_stos])[ yystos[] =
/* YYLLOC_DEFAULT -- Compute the default location (before the actions
are run). */
#define YYRHSLOC(yyRhs,YYK) (yyRhs[YYK].yystate.yyloc)
]b4_location_if([[
#define YYRHSLOC(yyRhs,YYK) ((yyRhs)[YYK].yystate.yyloc)
#ifndef YYLLOC_DEFAULT
# define YYLLOC_DEFAULT(yyCurrent, yyRhs, YYN) \
yyCurrent.first_line = YYRHSLOC(yyRhs,1).first_line; \
yyCurrent.first_column = YYRHSLOC(yyRhs,1).first_column; \
yyCurrent.last_line = YYRHSLOC(yyRhs,YYN).last_line; \
yyCurrent.last_column = YYRHSLOC(yyRhs,YYN).last_column;
(yyCurrent).first_line = YYRHSLOC(yyRhs,1).first_line; \
(yyCurrent).first_column = YYRHSLOC(yyRhs,1).first_column; \
(yyCurrent).last_line = YYRHSLOC(yyRhs,YYN).last_line; \
(yyCurrent).last_column = YYRHSLOC(yyRhs,YYN).last_column;
#endif
]],[
#ifndef YYLLOC_DEFAULT
# define YYLLOC_DEFAULT(yyCurrent, yyRhs, YYN)
#endif
])[
/* YYLEX -- calling `yylex' with the right arguments. */
#define YYLEX ]b4_c_function_call([yylex], [int], b4_lex_param)[
@@ -663,16 +675,6 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
yybool yynormal ATTRIBUTE_UNUSED = (yystack->yysplitPoint == NULL);
int yylow;
if (yyrhslen == 0)
{
*yyvalp = yyval_default;
*yylocp = yyloc_default;
}
else
{
*yyvalp = yyvsp[1-yyrhslen].yystate.yysemantics.yysval;
*yylocp = yyvsp[1-yyrhslen].yystate.yyloc;
}
# undef yyerrok
# define yyerrok (yystack->yyerrState = 0)
# undef YYACCEPT
@@ -680,7 +682,7 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
# undef YYABORT
# define YYABORT return yyabort
# undef YYERROR
# define YYERROR return yyerr
# define YYERROR do { yystack->yyerrState = 0; return yyerr; } while (0)
# undef YYRECOVERING
# define YYRECOVERING (yystack->yyerrState != 0)
# undef yyclearin
@@ -694,14 +696,25 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
YYERROR; \
} while (0)
]
yylow = 1;
switch (yyn)
{
b4_actions
}
yylow = 1;
if (yyrhslen == 0)
{
*yyvalp = yyval_default;
*yylocp = yyloc_default;
}
else
{
*yyvalp = yyvsp[YYFILL (1-yyrhslen)].yystate.yysemantics.yysval;
YYLLOC_DEFAULT (*yylocp, yyvsp - yyrhslen, yyrhslen);
}
return yyok;
]
switch (yyn)
{
b4_actions
}
return yyok;
# undef yyerrok
# undef YYABORT
# undef YYACCEPT
@@ -1080,16 +1093,6 @@ yydoAction (yyGLRStack* yystack, int yyk, yyRuleNum yyrule,
yystack->yynextFree -= yynrhs;
yystack->yyspaceLeft += yynrhs;
yystack->yytops.yystates[0] = & yystack->yynextFree[-1].yystate;
if (yynrhs == 0)
{
*yyvalp = yyval_default;
*yylocp = yyloc_default;
}
else
{
*yyvalp = rhs[1-yynrhs].yystate.yysemantics.yysval;
*yylocp = rhs[1-yynrhs].yystate.yyloc;
}
return yyuserAction (yyrule, yynrhs, rhs,
yyvalp, yylocp, yystack]b4_user_args[);
}
@@ -1097,8 +1100,9 @@ yydoAction (yyGLRStack* yystack, int yyk, yyRuleNum yyrule,
{
int yyi;
yyGLRState* yys;
yyGLRStackItem yyrhsVals[YYMAXRHS+1];
yys = yyrhsVals[YYMAXRHS].yystate.yypred = yystack->yytops.yystates[yyk];
yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
yys = yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred
= yystack->yytops.yystates[yyk];
for (yyi = 0; yyi < yynrhs; yyi += 1)
{
yys = yys->yypred;
@@ -1107,17 +1111,7 @@ yydoAction (yyGLRStack* yystack, int yyk, yyRuleNum yyrule,
}
yyupdateSplit (yystack, yys);
yystack->yytops.yystates[yyk] = yys;
if (yynrhs == 0)
{
*yyvalp = yyval_default;
*yylocp = yyloc_default;
}
else
{
*yyvalp = yyrhsVals[1].yystate.yysemantics.yysval;
*yylocp = yyrhsVals[1].yystate.yyloc;
}
return yyuserAction (yyrule, yynrhs, yyrhsVals + YYMAXRHS - 1,
return yyuserAction (yyrule, yynrhs, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
yyvalp, yylocp, yystack]b4_user_args[);
}
}
@@ -1348,13 +1342,14 @@ static YYRESULTTAG
yyresolveAction (yySemanticOption* yyopt, yyGLRStack* yystack,
YYSTYPE* yyvalp, YYLTYPE* yylocp]b4_user_formals[)
{
yyGLRStackItem yyrhsVals[YYMAXRHS+1];
yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
int yynrhs;
yynrhs = yyrhsLength (yyopt->yyrule);
YYCHK (yyresolveStates (yyopt->yystate, yynrhs, yystack]b4_user_args[));
yyrhsVals[YYMAXRHS].yystate.yypred = yyopt->yystate;
return yyuserAction (yyopt->yyrule, yynrhs, yyrhsVals + YYMAXRHS - 1,
yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred = yyopt->yystate;
return yyuserAction (yyopt->yyrule, yynrhs,
yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
yyvalp, yylocp, yystack]b4_user_args[);
}
@@ -1687,17 +1682,14 @@ yyrecoverSyntaxError (yyGLRStack* yystack,
size_t yyk;
int yyj;
if (yystack->yyerrState == 0)
yystack->yyerrState = 3;
else if (yystack->yyerrState == 3)
if (yystack->yyerrState == 3)
/* We just shifted the error token and (perhaps) took some
reductions. Skip tokens until we can proceed. */
while (yytrue)
{
if (*yytokenp == YYEOF)
{
/* Now pop stack until we find a state that shifts the
error token. */
/* Now pop stack until empty and fail. */
while (yystack->yytops.yystates[0] != NULL)
{
yyGLRState *yys = yystack->yytops.yystates[0];
@@ -1723,8 +1715,7 @@ yyrecoverSyntaxError (yyGLRStack* yystack,
YYDSYMPRINTF ("Next token is", *yytokenp, yylvalp, yyllocp);
yyj = yypact[yystack->yytops.yystates[0]->yylrState];
if (yyis_pact_ninf (yyj))
/* Something's not right; we shouldn't be here. */
yyFail (yystack][]b4_lpure_args[, NULL);
return;
yyj += *yytokenp;
if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != *yytokenp)
{
@@ -1747,6 +1738,7 @@ yyrecoverSyntaxError (yyGLRStack* yystack,
yycompressStack (yystack);
/* Now pop stack until we find a state that shifts the error token. */
yystack->yyerrState = 3;
while (yystack->yytops.yystates[0] != NULL)
{
yyGLRState *yys = yystack->yytops.yystates[0];
@@ -2016,20 +2008,21 @@ b4_syncline([@oline@], [@ofile@])],
b4_pure_if([],
[extern YYSTYPE b4_prefix[]lval;])
b4_location_if(
[#if ! defined (YYLTYPE) && ! defined (YYLTYPE_IS_DECLARED)
#if ! defined (YYLTYPE) && ! defined (YYLTYPE_IS_DECLARED)
typedef struct YYLTYPE
{
b4_location_if([
int first_line;
int first_column;
int last_line;
int last_column;
])
} YYLTYPE;
# define YYLTYPE_IS_DECLARED 1
# define YYLTYPE_IS_TRIVIAL 1
#endif
m4_if(b4_pure, [0],
b4_location_if([m4_if(b4_pure, [0],
[extern YYLTYPE b4_prefix[]lloc;])
])
])