diff options
| author | Kevin E Martin <kem@kem.org> | 2005-12-03 04:41:21 +0000 |
|---|---|---|
| committer | Kevin E Martin <kem@kem.org> | 2005-12-03 04:41:21 +0000 |
| commit | 222df94cf4d433b893c092ccd7c38d86d59ce034 (patch) | |
| tree | 07bb03c42956dc687897c87606e61d71ccb7275f /xorg-macros.m4 | |
| parent | 07aaba7edc3028b6066a552ef0636986adddb6ef (diff) | |
Add macro to detect when malloc(0) returns NULL for use in libraries.
Diffstat (limited to 'xorg-macros.m4')
| -rw-r--r-- | xorg-macros.m4 | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/xorg-macros.m4 b/xorg-macros.m4 index 784401f..387810e 100644 --- a/xorg-macros.m4 +++ b/xorg-macros.m4 @@ -205,3 +205,42 @@ MAKE_TEXT="SGML_SEARCH_PATH=$DEFS_ENT_PATH $LINUXDOC -B txt" AC_SUBST(MAKE_TEXT) ]) # XORG_CHECK_LINUXDOC + +# XORG_CHECK_MALLOC_ZERO +# ---------------------- +# Defines {MALLOC,XMALLOC,XTMALLOC}_ZERO_CFLAGS appropriately if +# malloc(0) returns NULL. Packages should add one of these cflags to +# their AM_CFLAGS (or other appropriate *_CFLAGS) to use them. +AC_DEFUN([XORG_CHECK_MALLOC_ZERO],[ +AC_ARG_ENABLE(malloc0returnsnull, + AC_HELP_STRING([--enable-malloc0returnsnull], + [malloc(0) returns NULL (default: auto)]), + [MALLOC_ZERO_RETURNS_NULL=$enableval], + [MALLOC_ZERO_RETURNS_NULL=auto]) + +AC_MSG_CHECKING([whether malloc(0) returns NULL]) +if test "x$MALLOC_ZERO_RETURNS_NULL" = xauto; then + AC_RUN_IFELSE([ +char *malloc(); +main() { + exit(malloc(0) == NULL ? 0 : 1); +}], + [MALLOC_ZERO_RETURNS_NULL=yes], + [MALLOC_ZERO_RETURNS_NULL=no]) +fi +AC_MSG_RESULT([$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]) +]) # XORG_CHECK_MALLOC_ZERO |