[PATCH, fixincludes] Fix NULL on AIX

[David Edelsohn]

AIX headers do not have a complete definition of NULL and the GCC
build complains about "missing sentinel".

The appended patch substitutes a more complete definition of NULL that
satisfies GCC/G++.

I also updated the void_null fix, which was discussed in 2011 to
substitute a more complete definition of NULL.  void_null no longer
triggers on AIX because of the "__cplusplus" bypass, which appears in
AIX header files.  I can omit void_null from the patch or remove the
fix completely if it no longer is applicable to any target.

(Yes, I will update fixinclude tests, but I first want agreement on
the fix itself.)

Bootstrapped on powerpc-ibm-aix7.1.0.0.

Thanks, David

        * inclhack.def (aix_null): New.
        (void_null): Substitute newer definition of NULL.
        * fixincl.x: Regenerate.

Index: inclhack.def
===================================================================
--- inclhack.def        (revision 198437)
+++ inclhack.def        (working copy)
@@ -617,6 +617,31 @@
 };

 /*
+ *  Fix AIX definition of NULL for G++.
+ */
+fix = {
+    hackname  = aix_null;
+    mach      = "*-*-aix*";
+    files     = curses.h, dbm.h, locale.h, stdio.h, stdlib.h, string.h,
+    time.h, unistd.h, wchar.h, sys/dir.h, sys/param.h, sys/types.h;
+    bypass    = __null;
+    select    = "#define[ \t]+NULL[ \t]+\\(*0L*\\)*";
+    c_fix     = format;
+    c_fix_arg = "#ifndef NULL\n"
+               "#ifdef __cplusplus\n"
+               "#ifdef __GNUG__\n"
+               "#define NULL\t__null\n"
+               "#else\t /* ! __GNUG__  */\n"
+               "#define NULL\t0L\n"
+               "#endif\t /* __GNUG__  */\n"
+               "#else\t /* ! __cplusplus  */\n"
+               "#define NULL\t((void *)0)\n"
+               "#endif\t /* __cplusplus  */\n"
+               "#endif\t /* !NULL  */";
+    test_text = "# define\tNULL \t(0L)  /* typed NULL */";
+};
+
+/*
  *  pthread.h on AIX defines PTHREAD_ONCE_INIT, PTHREAD_MUTEX_INITIALIZER,
  *  PTHREAD_COND_INITIALIZER and PTHREAD_RWLOCK_INITIALIZER without enough
  *  braces.
@@ -4552,23 +4577,24 @@
  */
 fix = {
     hackname  = void_null;
-    files     = curses.h;
-    files     = dbm.h;
-    files     = locale.h;
-    files     = stdio.h;
-    files     = stdlib.h;
-    files     = string.h;
-    files     = time.h;
-    files     = unistd.h;
-    files     = sys/dir.h;
-    files     = sys/param.h;
-    files     = sys/types.h;
+    files     = curses.h, dbm.h, locale.h, stdio.h, stdlib.h, string.h,
+    time.h, unistd.h, sys/dir.h, sys/param.h, sys/types.h;
     /* avoid changing C++ friendly NULL */
     bypass    = __cplusplus;
     bypass    = __null;
     select    = "^#[ \t]*define[ \t]+NULL[ \t]+\\(\\(void[ \t]*\\*\\)0\\)";
     c_fix     = format;
-    c_fix_arg = "#define NULL 0";
+    c_fix_arg = "#ifndef NULL\n"
+               "#ifdef __cplusplus\n"
+               "#ifdef __GNUG__\n"
+               "#define NULL\t__null\n"
+               "#else\t /* ! __GNUG__  */\n"
+               "#define NULL\t0L\n"
+               "#endif\t /* __GNUG__  */\n"
+               "#else\t /* ! __cplusplus  */\n"
+               "#define NULL\t((void *)0)\n"
+               "#endif\t /* __cplusplus  */\n"
+               "#endif\t /* !NULL  */";
     test_text = "# define\tNULL \t((void *)0)  /* typed NULL */";
 };