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glr: fix ambiguity reports.

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Fix a regression introduced in commit
783aa653f4.

	* tests/glr-regression.at (Ambiguity reports): New.
	* data/glr.c (yyreportTree): Fix an offset error.
This commit is contained in:
Akim Demaille
2012-02-21 11:51:37 +01:00
parent d4fca42763
commit a6b2f4fc02
2 changed files with 119 additions and 2 deletions
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4
data/glr.c
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@@ -1727,10 +1727,10 @@ yyreportTree (yySemanticOption* yyx, int yyindent)
{
if (yystates[yyi-1]->yyposn+1 > yystates[yyi]->yyposn)
YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",
yytokenName (yystos[yystates[yyi-1]->yylrState]));
yytokenName (yystos[yystates[yyi]->yylrState]));
else
YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",
yytokenName (yystos[yystates[yyi-1]->yylrState]),
yytokenName (yystos[yystates[yyi]->yylrState]),
(unsigned long int) (yystates[yyi-1]->yyposn + 1),
(unsigned long int) yystates[yyi]->yyposn);
}

117
tests/glr-regression.at
View File

@@ -1788,3 +1788,120 @@ glr-regr18.y:26.18-24: previous declaration
])
AT_CLEANUP
## ------------------- ##
## Ambiguity reports. ##
## ------------------- ##
AT_SETUP([Ambiguity reports])
AT_DATA_GRAMMAR([input.y],
[[
%{
#include <stdio.h>
#include <stdlib.h>
static void yyerror (char const *);
static int yylex (void);
%}
%debug
%glr-parser
%%
start:
'a' b 'c' d
| 'a' b 'c' d
;
b: 'b';
d: /* nada. */;
%%
static int
yylex (void)
{
static char const input[] = "abc";
static size_t toknum;
if (! (toknum < sizeof input))
abort ();
return input[toknum++];
}
static void
yyerror (char const *msg)
{
fprintf (stderr, "%s\n", msg);
}
int
main (void)
{
yydebug = 1;
return !!yyparse ();
}
]])
AT_BISON_CHECK([[-o input.c input.y]], 0, [],
[input.y: conflicts: 1 reduce/reduce
])
AT_COMPILE([input])
AT_PARSER_CHECK([[./input]], 1, [],
[Starting parse
Entering state 0
Reading a token: Next token is token 'a' ()
Shifting token 'a' ()
Entering state 1
Reading a token: Next token is token 'b' ()
Shifting token 'b' ()
Entering state 3
Reducing stack 0 by rule 3 (line 25):
$1 = token 'b' ()
-> $$ = nterm b ()
Entering state 4
Reading a token: Next token is token 'c' ()
Shifting token 'c' ()
Entering state 6
Reducing stack 0 by rule 4 (line 26):
-> $$ = nterm d ()
Entering state 7
Reading a token: Now at end of input.
Stack 0 Entering state 7
Now at end of input.
Splitting off stack 1 from 0.
Reduced stack 1 by rule #2; action deferred. Now in state 2.
Stack 1 Entering state 2
Now at end of input.
Reduced stack 0 by rule #1; action deferred. Now in state 2.
Merging stack 0 into stack 1.
Stack 1 Entering state 2
Now at end of input.
Removing dead stacks.
Rename stack 1 -> 0.
On stack 0, shifting token $end ()
Stack 0 now in state #5
Ambiguity detected.
Option 1,
start -> <Rule 1, tokens 1 .. 3>
'a' <tokens 1 .. 1>
b <tokens 2 .. 2>
'c' <tokens 3 .. 3>
d <empty>
Option 2,
start -> <Rule 2, tokens 1 .. 3>
'a' <tokens 1 .. 1>
b <tokens 2 .. 2>
'c' <tokens 3 .. 3>
d <empty>
syntax is ambiguous
Cleanup: popping token $end ()
Cleanup: popping unresolved nterm start ()
Cleanup: popping nterm d ()
Cleanup: popping token 'c' ()
Cleanup: popping nterm b ()
Cleanup: popping token 'a' ()
])
AT_CLEANUP