Use the more standard files xalloc.h' and xmalloc.c' instead of

Bison's `allocate.c' and `alloc.h'.  This patch was surprisingly
difficult and introduced a lot of core dump.  It turns out that
Bison used an implementation of `xmalloc' based on `calloc', and
at various places it does depend upon the initialization to 0.  I
have not tried to isolate the pertinent places, and all the former
calls to Bison's `xmalloc' are now using `XCALLOC'.  Someday,
someone should address this issue.
* src/allocate.c, src/alloc.h, m4/bison-decl.m4: Remove.
* lib/xmalloc.c, lib/xalloc.h, m4/malloc.m4, m4/realloc.m4: New
files.
Adjust dependencies.
* src/warshall.h: New file.
Propagate.

m4/Makefile.am

@@ -1,10 +1,11 @@
 ## Process this file with automake to produce Makefile.in -*-Makefile-*-
 EXTRA_DIST = \
 atconfig.m4 \
-bison-decl.m4 \
 error.m4 \
 gettext.m4 \
 lcmessage.m4 \
 m4.m4 \
+malloc.m4 \
 progtest.m4 \
+realloc.m4 \
 warning.m4

m4/bison-decl.m4

@@ -1,48 +0,0 @@
-dnl FIXME: This should be soon obsoleted by AC_CHECK_DECL.
-
-dnl See whether we need a declaration for a function.
-dnl BISON_NEED_DECLARATION(FUNCTION [, EXTRA-HEADER-FILES])
-AC_DEFUN(BISON_NEED_DECLARATION,
-[AC_MSG_CHECKING([whether $1 must be declared])
-AC_CACHE_VAL(bison_cv_decl_needed_$1,
-[AC_TRY_COMPILE([
-#include <stdio.h>
-#ifdef HAVE_STRING_H
-#include <string.h>
-#else
-#ifdef HAVE_STRINGS_H
-#include <strings.h>
-#endif
-#endif
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
-#endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-#ifndef HAVE_RINDEX
-#define rindex strrchr
-#endif
-#ifndef HAVE_INDEX
-#define index strchr
-#endif
-$2],
-[char *(*pfn) = (char *(*)) $1],
-eval "bison_cv_decl_needed_$1=no", eval "bison_cv_decl_needed_$1=yes")])
-if eval "test \"`echo '$bison_cv_decl_needed_'$1`\" = yes"; then
-  AC_MSG_RESULT(yes)
-  bison_tr_decl=NEED_DECLARATION_`echo $1 | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
-  AC_DEFINE_UNQUOTED($bison_tr_decl)
-else
-  AC_MSG_RESULT(no)
-fi
-])dnl
-
-dnl Check multiple functions to see whether each needs a declaration.
-dnl BISON_NEED_DECLARATIONS(FUNCTION... [, EXTRA-HEADER-FILES])
-AC_DEFUN(BISON_NEED_DECLARATIONS,
-[for ac_func in $1
-do
-BISON_NEED_DECLARATION($ac_func, $2)
-done
-])

m4/malloc.m4

@@ -0,0 +1,35 @@
+#serial 3
+
+dnl From Jim Meyering.
+dnl Determine whether malloc accepts 0 as its argument.
+dnl If it doesn't, arrange to use the replacement function.
+dnl
+
+AC_DEFUN(jm_FUNC_MALLOC,
+[
+ dnl xmalloc.c requires that this symbol be defined so it doesn't
+ dnl mistakenly use a broken malloc -- as it might if this test were omitted.
+ AC_DEFINE_UNQUOTED(HAVE_DONE_WORKING_MALLOC_CHECK, 1,
+                    [Define if the malloc check has been performed. ])
+
+ AC_CACHE_CHECK([for working malloc], jm_cv_func_working_malloc,
+  [AC_TRY_RUN([
+    char *malloc ();
+    int
+    main ()
+    {
+      exit (malloc (0) ? 0 : 1);
+    }
+	  ],
+	 jm_cv_func_working_malloc=yes,
+	 jm_cv_func_working_malloc=no,
+	 dnl When crosscompiling, assume malloc is broken.
+	 jm_cv_func_working_malloc=no)
+  ])
+  if test $jm_cv_func_working_malloc = no; then
+    AC_SUBST(LIBOBJS)
+    LIBOBJS="$LIBOBJS malloc.$ac_objext"
+    AC_DEFINE_UNQUOTED(malloc, rpl_malloc,
+      [Define to rpl_malloc if the replacement function should be used.])
+  fi
+])

m4/realloc.m4

@@ -0,0 +1,35 @@
+#serial 3
+
+dnl From Jim Meyering.
+dnl Determine whether realloc works when both arguments are 0.
+dnl If it doesn't, arrange to use the replacement function.
+dnl
+
+AC_DEFUN(jm_FUNC_REALLOC,
+[
+ dnl xmalloc.c requires that this symbol be defined so it doesn't
+ dnl mistakenly use a broken realloc -- as it might if this test were omitted.
+ AC_DEFINE_UNQUOTED(HAVE_DONE_WORKING_REALLOC_CHECK, 1,
+                    [Define if the realloc check has been performed. ])
+
+ AC_CACHE_CHECK([for working realloc], jm_cv_func_working_realloc,
+  [AC_TRY_RUN([
+    char *realloc ();
+    int
+    main ()
+    {
+      exit (realloc (0, 0) ? 0 : 1);
+    }
+	  ],
+	 jm_cv_func_working_realloc=yes,
+	 jm_cv_func_working_realloc=no,
+	 dnl When crosscompiling, assume realloc is broken.
+	 jm_cv_func_working_realloc=no)
+  ])
+  if test $jm_cv_func_working_realloc = no; then
+    AC_SUBST(LIBOBJS)
+    LIBOBJS="$LIBOBJS realloc.$ac_objext"
+    AC_DEFINE_UNQUOTED(realloc, rpl_realloc,
+      [Define to rpl_realloc if the replacement function should be used.])
+  fi
+])