+2006-01-05 Joel E. Denny <jdenny@ces.clemson.edu>
+
+ * data/glr.c (yyresolveValue): When merging semantic options, if at
+ least one user action succeeds but a later one cuts the parse, then
+ destroy the semantic value before returning rather than leaking it.
+ (yyresolveStates): If a user action cuts the parse and thus
+ yyresolveValue fails, ignore the (unset) semantic value rather than
+ corrupting the yyGLRState, and empty the semantic options list since
+ the user actions should have called all necessary destructors.
+ Simplify code with YYCHK.
+ * tests/glr-regression.at (Corrupted semantic options if user action
+ cuts parse): New test case.
+ (Undesirable destructors if user action cuts parse): New test case.
+ Before applying any of this patch, this test case never actually failed
+ for me... but only because the corrupted semantic options usually
+ masked this bug.
+ (Leaked merged semantic value if user action cuts parse): New test
+ case.
+
2006-01-05 Akim Demaille <akim@epita.fr>
* src/reader.c, src/symlist.h, src/symlist.c: s/mid_rule/midrule/.
return 0;
}
-static YYRESULTTAG yyresolveValue (yySemanticOption* yyoptionList,
+static YYRESULTTAG yyresolveValue (yyGLRState* yys,
yyGLRStack* yystackp, YYSTYPE* yyvalp,
YYLTYPE* yylocp]b4_user_formals[);
yyresolveStates (yyGLRState* yys, int yyn,
yyGLRStack* yystackp]b4_user_formals[)
{
- YYRESULTTAG yyflag;
if (0 < yyn)
{
YYASSERT (yys->yypred);
- yyflag = yyresolveStates (yys->yypred, yyn-1, yystackp]b4_user_args[);
- if (yyflag != yyok)
- return yyflag;
+ YYCHK (yyresolveStates (yys->yypred, yyn-1, yystackp]b4_user_args[));
if (! yys->yyresolved)
{
- yyflag = yyresolveValue (yys->yysemantics.yyfirstVal, yystackp,
- &yys->yysemantics.yysval, &yys->yyloc
- ]b4_user_args[);
+ YYSTYPE yysval;
+ YYRESULTTAG yyflag = yyresolveValue (yys, yystackp, &yysval,
+ &yys->yyloc]b4_user_args[);
if (yyflag != yyok)
- return yyflag;
+ {
+ yys->yysemantics.yyfirstVal = NULL;
+ return yyflag;
+ }
+ yys->yysemantics.yysval = yysval;
yys->yyresolved = yytrue;
}
}
}
-/** Resolve the ambiguity represented by OPTIONLIST, perform the indicated
+/** Resolve the ambiguity represented in state S, perform the indicated
* actions, and return the result. */
static YYRESULTTAG
-yyresolveValue (yySemanticOption* yyoptionList, yyGLRStack* yystackp,
- YYSTYPE* yyvalp, YYLTYPE* yylocp]b4_user_formals[)
+yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp, YYSTYPE* yyvalp,
+ YYLTYPE* yylocp]b4_user_formals[)
{
+ yySemanticOption* yyoptionList = yys->yysemantics.yyfirstVal;
yySemanticOption* yybest;
yySemanticOption** yypp;
yybool yymerge;
{
YYSTYPE yyval1;
YYLTYPE yydummy;
- YYCHK (yyresolveAction (yyp, yystackp, &yyval1,
- &yydummy]b4_user_args[));
+ 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);
}
}
])
AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Corrupted semantic options if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Corrupted semantic options if user action cuts parse.])
+
+AT_DATA_GRAMMAR([glr-regr10.y],
+[[
+%{
+# include <stdio.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ #define GARBAGE_SIZE 50
+ static char garbage[GARBAGE_SIZE];
+%}
+
+%glr-parser
+%union { char *ptr; }
+%type <ptr> start
+
+%%
+
+start:
+ %dprec 2 { $$ = garbage; YYACCEPT; }
+ | %dprec 1 { $$ = garbage; YYACCEPT; }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ return 0;
+}
+
+int
+main (void)
+{
+ int index;
+ for (index = 0; index < GARBAGE_SIZE; index+=1)
+ garbage[index] = 132;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr10.c glr-regr10.y]], 0, [],
+[glr-regr10.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr10])
+
+AT_CHECK([[./glr-regr10]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Undesirable destructors if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Undesirable destructors if user action cuts parse.])
+
+AT_DATA_GRAMMAR([glr-regr11.y],
+[[
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int destructors = 0;
+# define USE(val)
+%}
+
+%glr-parser
+%union { int dummy; }
+%type <int> 'a'
+%destructor { destructors += 1; } 'a'
+
+%%
+
+start:
+ 'a' %dprec 2 { USE ($1); destructors += 1; YYACCEPT; }
+ | 'a' %dprec 1 { USE ($1); destructors += 1; YYACCEPT; }
+ ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const *input = "a";
+ return *input++;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (destructors != 1)
+ {
+ fprintf (stderr, "Destructor calls: %d\n", destructors);
+ return 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr11.c glr-regr11.y]], 0, [],
+[glr-regr11.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr11])
+
+AT_CHECK([[./glr-regr11]], 0, [], [])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked merged semantic value if user action cuts parse. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked merged semantic value if user action cuts parse.])
+
+AT_DATA_GRAMMAR([glr-regr12.y],
+[[
+%glr-parser
+%union { int dummy; }
+%type <dummy> start
+%destructor { has_value = 0; } start
+
+%{
+# include <stdlib.h>
+ static int merge (YYSTYPE, YYSTYPE);
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int has_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start:
+ %merge<merge> { has_value = 1; USE ($$); }
+ | %merge<merge> { USE ($$); YYACCEPT; }
+ ;
+
+%%
+
+static int
+merge (YYSTYPE s1, YYSTYPE s2)
+{
+ /* Not invoked. */
+ return 0;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ return 0;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse ();
+ if (has_value)
+ {
+ fprintf (stderr, "Destructor not called.\n");
+ return 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_CHECK([[bison -t -o glr-regr12.c glr-regr12.y]], 0, [],
+[glr-regr12.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr12])
+
+AT_CHECK([[./glr-regr12]], 0, [], [])
+
+AT_CLEANUP
projects / bison.git / commitdiff
