Re: Bug in compatibility mode

[Akim Demaille]

| Hello,
|       there is a bug in yacc emulation mode, the original bug report is 
available 
| on debian bug tracking system : 
| http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=134068&repeatmerged=yes
| 
| I made a patch for this bug, but I am not sure that it does not create 
| another problem.
| 
| here is the patch :
| diff -bBdNrw -U5 bison-1.33-orig/src/reader.c bison-1.33/src/reader.c
| --- bison-1.33-orig/src/reader.c        Thu Feb  7 18:12:44 2002
| +++ bison-1.33/src/reader.c     Tue Feb 19 15:38:37 2002
| @@ -1142,13 +1142,13 @@
|      }
| 
|    /* As a Bison extension, add the ending semicolon.  Since some Yacc
|       don't do that, help people using bison as a Yacc finding their
|       missing semicolons.  */
| -  if (yacc_flag)
| +  /*if (yacc_flag)
|      obstack_sgrow (&action_obstack, "}\n    break;");
| -  else
| +    else*/
|      obstack_sgrow (&action_obstack, ";\n    break;}");
|  }
| 
| 
|  /*-------------------------------------------------------------------.
|  | After `%guard' is seen in the input file, copy the actual guard    |
| 
| 
| here is the problem description :
| $ cat test.yy
| %{
| #include "stdio.h"
| %}
| 
| %token PARAMS
| 
| %%
| 
| 
| ocr: PARAMS {printf("params\n")}  '{' /*...*/ '}'
| ;
| 
| %%
| 
| 
| extern char *yytext;
| int yyerror(char *err)
| {
|   fprintf(stderr, "%s at %s\n", err, yytext);
|   exit(1);
| }
| $bison -y test.yy
| $gcc -c y.tab.c
| test.yy: In function `yyparse':
| test.yy:10: parse error before `}'
|       
| please Cc me replies, thanks.

Your Bison file appears to be wrong: add the ending `;' in the { block
}.  This is no bug, or rather, this bug (Bison adding the `;' itself)
is finely removed.