removing alloca from Bison itself

[Paul Eggert]

The recent alloca changes prompted me to look again at the use of
alloca within Bison.  I found a couple of places where the alloca gorp
can be removed, so I did that.  I also found one place where the
yacc.c skeleton is including <stdlib.h> when it's not needed, and one
place where alloca's tests should match its uses better.  I installed
the following change.

This change effectively removes three files from the Bison tarball:
lib/alloca.c, lib/alloca_.h, and m4/alloca.m4.

2005-09-21  Paul Eggert  <address@hidden>

        * bootstrap (gnulib_modules): Remove alloca.  Bison doesn't need
        it itself.
        * src/main.c (main) [C_ALLOCA]: Don't flush alloca'ed memory; we
        don't use alloca any more.

        * data/yacc.c [YYSTACK_USE_ALLOCA && !defined __GNUC__ && ! defined
        __BUILTIN_VA_ARG_INCR && ! defined _AIX && ! defined _MSC_VER &&
        defined _ALLOCA_H]: Don't include <stdlib.h>; not needed in this case.
        * tests/torture.at (Exploding the Stack Size with Alloca): Adjust
        to match yacc.c, to test more hosts.

Index: bootstrap
===================================================================
RCS file: /cvsroot/bison/bison/bootstrap,v
retrieving revision 1.26
retrieving revision 1.27
diff -p -u -r1.26 -r1.27
--- bootstrap   8 Sep 2005 18:26:43 -0000       1.26
+++ bootstrap   21 Sep 2005 19:54:48 -0000      1.27
@@ -92,7 +92,6 @@ esac
 <$GNULIB_SRCDIR/gnulib-tool || exit
 
 gnulib_modules='
-alloca
 argmatch
 dirname
 error
Index: src/main.c
===================================================================
RCS file: /cvsroot/bison/bison/src/main.c,v
retrieving revision 1.83
retrieving revision 1.84
diff -p -u -r1.83 -r1.84
--- src/main.c  25 Jul 2005 03:12:53 -0000      1.83
+++ src/main.c  21 Sep 2005 19:54:48 -0000      1.84
@@ -172,14 +172,6 @@ main (int argc, char *argv[])
   scanner_free ();
   muscle_free ();
   uniqstrs_free ();
-  /* If using alloca.c, flush the alloca'ed memory for the benefit of
-     people running Bison as a library in IDEs.  */
-#if C_ALLOCA
-  {
-    extern void *alloca (size_t);
-    alloca (0);
-  }
-#endif
   timevar_pop (TV_FREE);
 
   if (trace_flag & trace_bitsets)
Index: data/yacc.c
===================================================================
RCS file: /cvsroot/bison/bison/data/yacc.c,v
retrieving revision 1.107
retrieving revision 1.109
diff -p -u -r1.107 -r1.109
--- data/yacc.c 20 Sep 2005 23:08:03 -0000      1.107
+++ data/yacc.c 21 Sep 2005 20:08:38 -0000      1.109
@@ -263,7 +263,8 @@ b4_syncline(address@hidden@], address@hidden@])[
 #    define alloca _alloca
 #   else
 #    define YYSTACK_ALLOC alloca
-#    if ! defined (_STDLIB_H) && (defined (__STDC__) || defined (__cplusplus))
+#    if (! defined (_ALLOCA_H) && ! defined (_STDLIB_H) \
+        && (defined (__STDC__) || defined (__cplusplus)))
 #     include <stdlib.h> /* INFRINGES ON USER NAME SPACE */
 #     ifndef _STDLIB_H
 #      define _STDLIB_H 1
Index: tests/torture.at
===================================================================
RCS file: /cvsroot/bison/bison/tests/torture.at,v
retrieving revision 1.28
retrieving revision 1.30
diff -p -u -r1.28 -r1.30
--- tests/torture.at    24 Jul 2005 07:24:22 -0000      1.28
+++ tests/torture.at    21 Sep 2005 20:08:38 -0000      1.30
@@ -444,7 +444,8 @@ AT_COMPILE([input])
 AT_SETUP([Exploding the Stack Size with Alloca])
 
 AT_DATA_STACK_TORTURE([[
-#if defined __GNUC__ || defined alloca
+#if (defined __GNUC__ || defined __BUILTIN_VA_ARG_INCR \
+     || defined _AIX || defined _MSC_VER || defined _ALLOCA_H)
 # define YYSTACK_USE_ALLOCA 1
 #endif
 ]])