1.875: can't compile output with g++-2.95.3

[Scott McPeak]

With bison-1.875 on linux, I can't compile bison's output using
g++-2.95.3.  In the past I've been able to simply compile bison's output
with a C++ compiler by adding necessary prototypes to the top, but with
1.875 a parse error prevents such a simple solution.

With the enclosed Makefile and foo.y input, 'make' produces:

  $ make
  bison foo.y
  mv -f foo.tab.c foo.tab.cc
  g++ foo.tab.cc
  foo.tab.c: In function `int yyparse()':
  foo.tab.c:1149: parse error before `goto'
  make: *** [foo] Error 1

The problem is this sequence from the skeleton parser:

  /* Suppress GCC warning that yyerrlab1 is unused when no action
     invokes YYERROR.  */
#if defined (__GNUC_MINOR__) && 2093 <= (__GNUC__ * 1000 + __GNUC_MINOR__)
  __attribute__ ((__unused__))
#endif

gcc may accept this, but g++ does not.  An alternative solution that seems
to achieve the goal of this passage and be acceptable to g++ is to insert
"goto yyerrlab1;" just above "yyerrlab1:".

-Scott

foo.y
Description: Text document

Makefile
Description: Text document