+2006-03-02 Joel E. Denny <jdenny@ces.clemson.edu>
+
+ Don't leak semantic values for parent RHS when a user action cuts the
+ parser, and clean up related code a bit.
+ * tests/glr-regression.at (Leaked merged semantic value if user action
+ cuts parse) Rename to...
+ (Leaked semantic values if user action cuts parse) ... this. Add check
+ for leaked parent RHS values.
+ * data/glr.c (yydestroyGLRState): In debugging output, distinguish
+ between an unresolved state (non-empty chain of semantic options) and
+ an incomplete one (signaled by an empty chain).
+ (yyresolveStates): Document the interface. Move all manipulation of an
+ successfully or unsuccessfully resolved yyGLRState to...
+ (yyresolveValue): ... here so that yyresolveValue always leaves a
+ yyGLRState with consistent data and thus is easier to understand.
+ Remove the yyvalp and yylocp parameters since they are always just
+ taken from the yys parameter. When reporting a discarded merged value
+ in debugging output, note that it is incompletely merged. Document the
+ interface.
+ (yyresolveAction): If resolving any of the RHS states fails, destroy
+ them all rather than leaking them. Thus, as long as user actions are
+ written to clean up the RHS correctly, yyresolveAction always cleans up
+ the RHS of a semantic option. Document the interface.
+
2006-02-27 Paul Eggert <eggert@cs.ucla.edu>
* data/glr.c (yyexpandGLRStack): Catch an off-by-one error that
#if YYDEBUG
if (yydebug)
{
- YYFPRINTF (stderr, "%s unresolved ", yymsg);
+ if (yys->yysemantics.yyfirstVal)
+ YYFPRINTF (stderr, "%s unresolved ", yymsg);
+ else
+ YYFPRINTF (stderr, "%s incomplete ", yymsg);
yy_symbol_print (stderr, yystos[yys->yylrState],
NULL]b4_location_if([, &yys->yyloc])[]b4_user_args[);
YYFPRINTF (stderr, "\n");
}
static YYRESULTTAG yyresolveValue (yyGLRState* yys,
- yyGLRStack* yystackp, YYSTYPE* yyvalp,
- YYLTYPE* yylocp]b4_user_formals[);
+ yyGLRStack* yystackp]b4_user_formals[);
+
+/** Resolve the previous N states starting at and including state S. If result
+ * != yyok, some states may have been left unresolved possibly with empty
+ * semantic option chains. Regardless of whether result = yyok, each state
+ * has been left with consistent data so that yydestroyGLRState can be invoked
+ * if necessary. */
static YYRESULTTAG
yyresolveStates (yyGLRState* yys, int yyn,
yyGLRStack* yystackp]b4_user_formals[)
YYASSERT (yys->yypred);
YYCHK (yyresolveStates (yys->yypred, yyn-1, yystackp]b4_user_args[));
if (! yys->yyresolved)
- {
- YYSTYPE yysval;
- YYRESULTTAG yyflag = yyresolveValue (yys, yystackp, &yysval,
- &yys->yyloc]b4_user_args[);
- if (yyflag != yyok)
- {
- yys->yysemantics.yyfirstVal = NULL;
- return yyflag;
- }
- yys->yysemantics.yysval = yysval;
- yys->yyresolved = yytrue;
- }
+ YYCHK (yyresolveValue (yys, yystackp]b4_user_args[));
}
return yyok;
}
+/** Resolve the states for the RHS of OPT, perform its user action, and return
+ * the semantic value and location. Regardless of whether result = yyok, all
+ * RHS states have been destroyed (assuming the user action destroys all RHS
+ * semantic values if invoked). */
static YYRESULTTAG
yyresolveAction (yySemanticOption* yyopt, yyGLRStack* yystackp,
YYSTYPE* yyvalp, YYLTYPE* yylocp]b4_user_formals[)
int yychar_current;
YYSTYPE yylval_current;
YYLTYPE yylloc_current;
- YYRESULTTAG yyresult;
+ YYRESULTTAG yyflag;
yynrhs = yyrhsLength (yyopt->yyrule);
- YYCHK (yyresolveStates (yyopt->yystate, yynrhs, yystackp]b4_user_args[));
+ yyflag = yyresolveStates (yyopt->yystate, yynrhs, yystackp]b4_user_args[);
+ if (yyflag != yyok)
+ {
+ yyGLRState *yys;
+ for (yys = yyopt->yystate; yynrhs > 0; yys = yys->yypred, yynrhs -= 1)
+ yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
+ return yyflag;
+ }
+
yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred = yyopt->yystate;]b4_location_if([[
if (yynrhs == 0)
/* Set default location. */
yychar = yyopt->yyrawchar;
yylval = yyopt->yyval;
yylloc = yyopt->yyloc;
- yyresult = yyuserAction (yyopt->yyrule, yynrhs,
+ yyflag = yyuserAction (yyopt->yyrule, yynrhs,
yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
yyvalp, yylocp, yystackp]b4_user_args[);
yychar = yychar_current;
yylval = yylval_current;
yylloc = yylloc_current;
- return yyresult;
+ return yyflag;
}
#if YYDEBUG
/** Resolve the ambiguity represented in state S, perform the indicated
- * actions, and return the result. */
+ * actions, and set the semantic value of S. If result != yyok, the chain of
+ * semantic options in S has been cleared instead or it has been left
+ * unmodified except that redundant options may have been removed. Regardless
+ * of whether result = yyok, S has been left with consistent data so that
+ * yydestroyGLRState can be invoked if necessary. */
static YYRESULTTAG
-yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp, YYSTYPE* yyvalp,
- YYLTYPE* yylocp]b4_user_formals[)
+yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
{
yySemanticOption* yyoptionList = yys->yysemantics.yyfirstVal;
yySemanticOption* yybest;
yySemanticOption** yypp;
yybool yymerge;
+ YYSTYPE yysval;
+ YYRESULTTAG yyflag;
+ YYLTYPE *yylocp = &yys->yyloc;
yybest = yyoptionList;
yymerge = yyfalse;
{
yySemanticOption* yyp;
int yyprec = yydprec[yybest->yyrule];
- YYCHK (yyresolveAction (yybest, yystackp, yyvalp, yylocp]b4_user_args[));
- for (yyp = yybest->yynext; yyp != NULL; yyp = yyp->yynext)
- {
- if (yyprec == yydprec[yyp->yyrule])
- {
- YYSTYPE yyval1;
- YYLTYPE yydummy;
- YYRESULTTAG yyflag = yyresolveAction (yyp, yystackp, &yyval1,
- &yydummy]b4_user_args[);
- if (yyflag != yyok)
- {
- yydestruct ("Cleanup: discarding merged value",
- yystos[yys->yylrState],
- yyvalp]b4_location_if([, yylocp])[]b4_user_args[);
- return yyflag;
- }
- yyuserMerge (yymerger[yyp->yyrule], yyvalp, &yyval1);
- }
- }
- return yyok;
+ yyflag = yyresolveAction (yybest, yystackp, &yysval,
+ yylocp]b4_user_args[);
+ if (yyflag == yyok)
+ for (yyp = yybest->yynext; yyp != NULL; yyp = yyp->yynext)
+ {
+ if (yyprec == yydprec[yyp->yyrule])
+ {
+ YYSTYPE yysval_other;
+ YYLTYPE yydummy;
+ yyflag = yyresolveAction (yyp, yystackp, &yysval_other,
+ &yydummy]b4_user_args[);
+ if (yyflag != yyok)
+ {
+ yydestruct ("Cleanup: discarding incompletely merged value for",
+ yystos[yys->yylrState],
+ &yysval]b4_location_if([, yylocp])[]b4_user_args[);
+ break;
+ }
+ yyuserMerge (yymerger[yyp->yyrule], &yysval, &yysval_other);
+ }
+ }
+ }
+ else
+ yyflag = yyresolveAction (yybest, yystackp, &yysval, yylocp]b4_user_args[);
+
+ if (yyflag == yyok)
+ {
+ yys->yyresolved = yytrue;
+ yys->yysemantics.yysval = yysval;
}
else
- return yyresolveAction (yybest, yystackp, yyvalp, yylocp]b4_user_args[);
+ yys->yysemantics.yyfirstVal = NULL;
+ return yyflag;
}
static YYRESULTTAG
## ------------------------------------------------------------------------- ##
-## Leaked merged semantic value if user action cuts parse. ##
+## Leaked semantic values if user action cuts parse. ##
## ------------------------------------------------------------------------- ##
-AT_SETUP([Leaked merged semantic value if user action cuts parse])
+AT_SETUP([Leaked semantic values if user action cuts parse])
AT_DATA_GRAMMAR([glr-regr12.y],
[[
%glr-parser
%union { int dummy; }
-%type <dummy> start
-%destructor { has_value = 0; } start
+%token PARENT_RHS_AFTER
+%type <dummy> parent_rhs_before merged PARENT_RHS_AFTER
+%destructor { parent_rhs_before_value = 0; } parent_rhs_before
+%destructor { merged_value = 0; } merged
+%destructor { parent_rhs_after_value = 0; } PARENT_RHS_AFTER
%{
# include <stdlib.h>
static int merge (YYSTYPE, YYSTYPE);
static void yyerror (char const *);
static int yylex (void);
- static int has_value = 0;
+ static int parent_rhs_before_value = 0;
+ static int merged_value = 0;
+ static int parent_rhs_after_value = 0;
# define USE(val)
%}
%%
start:
- %merge<merge> { has_value = 1; USE ($$); }
- | %merge<merge> { USE ($$); YYACCEPT; }
+ alt1 %dprec 1
+ | alt2 %dprec 2
+ ;
+
+alt1:
+ PARENT_RHS_AFTER {
+ USE ($1);
+ parent_rhs_after_value = 0;
+ }
+ ;
+
+alt2:
+ parent_rhs_before merged PARENT_RHS_AFTER {
+ USE (($1, $2, $3));
+ parent_rhs_before_value = 0;
+ merged_value = 0;
+ parent_rhs_after_value = 0;
+ }
+ ;
+
+parent_rhs_before:
+ {
+ USE ($$);
+ parent_rhs_before_value = 1;
+ }
;
+merged:
+ %merge<merge> {
+ USE ($$);
+ merged_value = 1;
+ }
+ | cut %merge<merge> {
+ USE ($$);
+ merged_value = 1;
+ }
+ ;
+
+cut: { YYACCEPT; } ;
+
%%
static int
static int
yylex (void)
{
- return 0;
+ static int const input[] = { PARENT_RHS_AFTER, 0 };
+ static const int *inputp = input;
+ if (*inputp == PARENT_RHS_AFTER)
+ parent_rhs_after_value = 1;
+ return *inputp++;
}
int
main (void)
{
int exit_status = yyparse ();
- if (has_value)
+ if (parent_rhs_before_value)
{
- fprintf (stderr, "Destructor not called.\n");
- return 1;
+ fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ exit_status = 1;
+ }
+ if (merged_value)
+ {
+ fprintf (stderr, "`merged' destructor not called.\n");
+ exit_status = 1;
+ }
+ if (parent_rhs_after_value)
+ {
+ fprintf (stderr, "`PARENT_RHS_AFTER' destructor not called.\n");
+ exit_status = 1;
}
return exit_status;
}
]])
AT_CHECK([[bison -t -o glr-regr12.c glr-regr12.y]], 0, [],
-[glr-regr12.y: conflicts: 1 reduce/reduce
+[glr-regr12.y: conflicts: 1 shift/reduce, 1 reduce/reduce
])
AT_COMPILE([glr-regr12])
projects / bison.git / commitdiff
