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* data/glr.c (yyreportSyntaxError): Fix off-by-one error in

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checking against YYLAST that caused the parser to miss a potential
alternative in its diagnostic.
Problem reported by Maria Jose Moron Fernandez in
<http://lists.gnu.org/archive/html/bug-bison/2006-05/msg00024.html>.
* data/lalr1.cc (yysyntax_error_): Likewise.
* data/yacc.c (yysyntax_error): Likewise.
* tests/regression.at (_AT_DATA_DANCER_Y): Use static array for
tokens, in case we run into an older C compiler.
(_AT_DATA_EXPECT2_Y, AT_CHECK_EXPECT2): New macros.
Use them to check for the off-by-one error fixed above.
This commit is contained in:
Paul Eggert
2006-05-15 06:13:53 +00:00
parent 276f48df88
commit d664514801
5 changed files with 116 additions and 7 deletions
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12
ChangeLog
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@@ -1,5 +1,17 @@
2006-05-14 Paul Eggert <eggert@cs.ucla.edu>
* data/glr.c (yyreportSyntaxError): Fix off-by-one error in
checking against YYLAST that caused the parser to miss a potential
alternative in its diagnostic.
Problem reported by Maria Jose Moron Fernandez in
<http://lists.gnu.org/archive/html/bug-bison/2006-05/msg00024.html>.
* data/lalr1.cc (yysyntax_error_): Likewise.
* data/yacc.c (yysyntax_error): Likewise.
* tests/regression.at (_AT_DATA_DANCER_Y): Use static array for
tokens, in case we run into an older C compiler.
(_AT_DATA_EXPECT2_Y, AT_CHECK_EXPECT2): New macros.
Use them to check for the off-by-one error fixed above.
* data/yacc.c (yytnamerr): Fix typo: local var should be of type
YYSIZE_T, not size_t.
* tests/regression.at (Trivial grammars): New test, to catch

4
data/glr.c
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@@ -2077,7 +2077,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
#if YYERROR_VERBOSE
int yyn;
yyn = yypact[yystackp->yytops.yystates[0]->yylrState];
if (YYPACT_NINF < yyn && yyn < YYLAST)
if (YYPACT_NINF < yyn && yyn <= YYLAST)
{
yySymbol yytoken = YYTRANSLATE (yychar);
size_t yysize0 = yytnamerr (NULL, yytokenName (yytoken));
@@ -2104,7 +2104,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */
int yychecklim = YYLAST - yyn;
int yychecklim = YYLAST - yyn + 1;
int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
int yycount = 1;

4
data/lalr1.cc
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@@ -838,14 +838,14 @@ b4_error_verbose_if([, int tok])[)
YYUSE (yystate);
#if YYERROR_VERBOSE
int yyn = yypact_[yystate];
if (yypact_ninf_ < yyn && yyn < yylast_)
if (yypact_ninf_ < yyn && yyn <= yylast_)
{
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */
int yychecklim = yylast_ - yyn;
int yychecklim = yylast_ - yyn + 1;
int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
int count = 0;
for (int x = yyxbegin; x < yyxend; ++x)

4
data/yacc.c
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@@ -847,7 +847,7 @@ yysyntax_error (char *yyresult, int yystate, int yychar)
{
int yyn = yypact[yystate];
if (! (YYPACT_NINF < yyn && yyn < YYLAST))
if (! (YYPACT_NINF < yyn && yyn <= YYLAST))
return 0;
else
{
@@ -885,7 +885,7 @@ yysyntax_error (char *yyresult, int yystate, int yychar)
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */
int yychecklim = YYLAST - yyn;
int yychecklim = YYLAST - yyn + 1;
int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
int yycount = 1;

99
tests/regression.at
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@@ -824,7 +824,7 @@ static int
yylex (AT_LALR1_CC_IF([int *lval], [void]))
[{
static int toknum = 0;
int tokens[] =
static int tokens[] =
{
':', -1
};
@@ -864,3 +864,100 @@ AT_CLEANUP
AT_CHECK_DANCER()
AT_CHECK_DANCER([%glr-parser])
AT_CHECK_DANCER([%skeleton "lalr1.cc"])
## ------------------------------------------ ##
## Diagnostic that expects two alternatives. ##
## ------------------------------------------ ##
# _AT_DATA_EXPECT2_Y(BISON-OPTIONS)
# --------------------------------
m4_define([_AT_DATA_EXPECT2_Y],
[AT_DATA_GRAMMAR([expect2.y],
[%{
static int yylex (AT_LALR1_CC_IF([int *], [void]));
AT_LALR1_CC_IF([],
[#include <stdio.h>
static void yyerror (const char *);])
%}
$1
%defines
%error-verbose
%token A 1000
%token B
%%
program: /* empty */
| program e ';'
| program error ';';
e: e '+' t | t;
t: A | B;
%%
AT_LALR1_CC_IF(
[/* A C++ error reporting function. */
void
yy::parser::error (const location&, const std::string& m)
{
std::cerr << m << std::endl;
}
int
yyparse ()
{
yy::parser parser;
return parser.parse ();
}
],
[static void
yyerror (const char *s)
{
fprintf (stderr, "%s\n", s);
}])
static int
yylex (AT_LALR1_CC_IF([int *lval], [void]))
[{
static int toknum = 0;
static int tokens[] =
{
1000, '+', '+', -1
};
]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC. */])[
return tokens[toknum++];
}]
int
main (void)
{
return yyparse ();
}
])
])# _AT_DATA_EXPECT2_Y
# AT_CHECK_EXPECT2(BISON-OPTIONS)
# ------------------------------
# Generate the grammar, compile it, run it.
m4_define([AT_CHECK_EXPECT2],
[AT_SETUP([Expecting two tokens $1])
AT_BISON_OPTION_PUSHDEFS([$1])
_AT_DATA_EXPECT2_Y([$1])
AT_CHECK([bison -o expect2.c expect2.y])
AT_LALR1_CC_IF(
[AT_CHECK([bison -o expect2.cc expect2.y])
AT_COMPILE_CXX([expect2])],
[AT_CHECK([bison -o expect2.c expect2.y])
AT_COMPILE([expect2])])
AT_PARSER_CHECK([./expect2], 1, [],
[syntax error, unexpected '+', expecting A or B
])
AT_BISON_OPTION_POPDEFS
AT_CLEANUP
])
AT_CHECK_EXPECT2()
AT_CHECK_EXPECT2([%glr-parser])
AT_CHECK_EXPECT2([%skeleton "lalr1.cc"])