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* data/glr.c (yyresolveValue): When merging semantic options, if at

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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.
This commit is contained in:
Joel E. Denny
2006-01-05 21:07:54 +00:00
parent 6ec2c0f295
commit d659304d0a
3 changed files with 242 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
ChangeLog
View File

@@ -1,3 +1,22 @@
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/.

37
data/glr.c
View File

@@ -1612,7 +1612,7 @@ yypreference (yySemanticOption* y0, yySemanticOption* y1)
return 0;
}
static YYRESULTTAG yyresolveValue (yySemanticOption* yyoptionList,
static YYRESULTTAG yyresolveValue (yyGLRState* yys,
yyGLRStack* yystackp, YYSTYPE* yyvalp,
YYLTYPE* yylocp]b4_user_formals[);
@@ -1620,20 +1620,21 @@ static YYRESULTTAG
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;
}
}
@@ -1728,12 +1729,13 @@ yyreportAmbiguity (yySemanticOption* yyx0, yySemanticOption* yyx1,
}
/** 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;
@@ -1786,8 +1788,15 @@ yyresolveValue (yySemanticOption* yyoptionList, yyGLRStack* yystackp,
{
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);
}
}

200
tests/glr-regression.at
View File

@@ -815,3 +815,203 @@ AT_CHECK([[./glr-regr9]], 0, [],
])
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