Import upstream version 1.27

[debian/tar] / m4 / memchr.m4

diff --git a/m4/memchr.m4 b/m4/memchr.m4
index 3c2b313916841cd2a2e9efa8f60ab1b6d6dcf21c..2d8abe75d7a8a1603cd3a65d1ae06eac50612454 100644 (file)
--- a/m4/memchr.m4
+++ b/m4/memchr.m4
@@ -1,5 +1,5 @@
-# memchr.m4 serial 10
-dnl Copyright (C) 2002-2004, 2009-2011 Free Software Foundation, Inc.
+# memchr.m4 serial 12
+dnl Copyright (C) 2002-2004, 2009-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -11,10 +11,16 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR],
   AC_CHECK_HEADERS_ONCE([sys/mman.h])
   AC_CHECK_FUNCS_ONCE([mprotect])
 
-  dnl These days, we assume memchr is present.  But just in case...
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
-  AC_CHECK_FUNCS_ONCE([memchr])
-  if test $ac_cv_func_memchr = yes; then
+  m4_ifdef([gl_FUNC_MEMCHR_OBSOLETE], [
+    dnl These days, we assume memchr is present.  But if support for old
+    dnl platforms is desired:
+    AC_CHECK_FUNCS_ONCE([memchr])
+    if test $ac_cv_func_memchr = no; then
+      HAVE_MEMCHR=0
+    fi
+  ])
+  if test $HAVE_MEMCHR = 1; then
     # Detect platform-specific bugs in some versions of glibc:
     # memchr should not dereference anything with length 0
     #   http://bugzilla.redhat.com/499689
@@ -73,12 +79,6 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR],
     if test "$gl_cv_func_memchr_works" != yes; then
       REPLACE_MEMCHR=1
     fi
-  else
-    HAVE_MEMCHR=0
-  fi
-  if test $HAVE_MEMCHR = 0 || test $REPLACE_MEMCHR = 1; then
-    AC_LIBOBJ([memchr])
-    gl_PREREQ_MEMCHR
   fi
 ])