Convert nx-X11/lib/ build flow from imake to autotools.

1 files changed, 47 insertions, 0 deletions

diff --git a/m4/nx-macros.m4 b/m4/nx-macros.m4
index 61acfb58a..b40f628b0 100644
--- a/m4/nx-macros.m4
+++ b/m4/nx-macros.m4
@@ -304,6 +304,53 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])],
     [AC_SUBST([AM_DEFAULT_VERBOSITY], [1])])
 ]) # NX_DEFAULT_OPTIONS
 
+# NX_CHECK_MALLOC_ZERO
+# ----------------------
+# Minimum version: 1.0.0
+#
+# Defines {MALLOC,XMALLOC,XTMALLOC}_ZERO_CFLAGS appropriately if
+# malloc(0) returns NULL.  Packages should add one of these cflags to
+# their AM_CFLAGS (or other appropriate *_CFLAGS) to use them.
+AC_DEFUN([NX_CHECK_MALLOC_ZERO],[
+AC_ARG_ENABLE(malloc0returnsnull,
+        AS_HELP_STRING([--enable-malloc0returnsnull],
+                       [malloc(0) returns NULL (default: auto)]),
+        [MALLOC_ZERO_RETURNS_NULL=$enableval],
+        [MALLOC_ZERO_RETURNS_NULL=auto])
+
+AC_MSG_CHECKING([whether malloc(0) returns NULL])
+if test "x$MALLOC_ZERO_RETURNS_NULL" = xauto; then
+        AC_RUN_IFELSE([AC_LANG_PROGRAM([
+#include <stdlib.h>
+],[
+    char *m0, *r0, *c0, *p;
+    m0 = malloc(0);
+    p = malloc(10);
+    r0 = realloc(p,0);
+    c0 = calloc(0,10);
+    exit((m0 == 0 || r0 == 0 || c0 == 0) ? 0 : 1);
+])],
+                [MALLOC_ZERO_RETURNS_NULL=yes],
+                [MALLOC_ZERO_RETURNS_NULL=no],
+                [MALLOC_ZERO_RETURNS_NULL=yes])
+fi
+AC_MSG_RESULT([$MALLOC_ZERO_RETURNS_NULL])
+
+if test "x$MALLOC_ZERO_RETURNS_NULL" = xyes; then
+        MALLOC_ZERO_CFLAGS="-DMALLOC_0_RETURNS_NULL"
+        XMALLOC_ZERO_CFLAGS=$MALLOC_ZERO_CFLAGS
+        XTMALLOC_ZERO_CFLAGS="$MALLOC_ZERO_CFLAGS -DXTMALLOC_BC"
+else
+        MALLOC_ZERO_CFLAGS=""
+        XMALLOC_ZERO_CFLAGS=""
+        XTMALLOC_ZERO_CFLAGS=""
+fi
+
+AC_SUBST([MALLOC_ZERO_CFLAGS])
+AC_SUBST([XMALLOC_ZERO_CFLAGS])
+AC_SUBST([XTMALLOC_ZERO_CFLAGS])
+]) # NX_CHECK_MALLOC_ZERO
+
 
 dnl Check to see if we're running under Cygwin32.