alloca

[Hans Aberg]

I assume that the work on Bison 1.29a already has begun.

I suggest that one change the skeleton file so that one can choose whether
to use alloca or not. -- The function alloca() is considered as a low level
hack, and it does not work under some circumstances (like in function
wrapping, often used in C++, or if the parameter stack has limits on it).

One point of this is that the "#ifdef YYSTACK_USE_ALLOCA" mess in the
bison.simple file" might be simplified.

I added to my bison.simple:
#ifdef YYSTACK_USE_ALLOCA
# include <alloca.h>
#endif

Then as the "#ifdef YYSTACK_USE_ALLOCA" mess in the bison.simple file does
is used on my platform, I can choose whether to use alloca by inserting in
my .y file
  #define YYSTACK_USE_ALLOCA 1

I have to define this to 1, because the bison.simple file forgets to use
#ifdef instead of #if at one place. If think this should be change too, so
that one can merely write
  #define YYSTACK_USE_ALLOCA
just as one can write
  #define YYERROR_VERBOSE

  Hans Aberg