stpncpy: Allow stpncpy to be defined as a macro.

[gnulib.git] / m4 / stpncpy.m4

diff --git a/m4/stpncpy.m4 b/m4/stpncpy.m4
index 8852579..158cc08 100644 (file)
--- a/m4/stpncpy.m4
+++ b/m4/stpncpy.m4
@@ -1,5 +1,6 @@
-# stpncpy.m4 serial 5
-dnl Copyright (C) 2002-2003, 2005-2007 Free Software Foundation, Inc.
+# stpncpy.m4 serial 12
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2010 Free Software Foundation,
+dnl 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.
@@ -7,7 +8,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_STPNCPY],
 [
   dnl Persuade glibc <string.h> to declare stpncpy().
-  AC_REQUIRE([AC_GNU_SOURCE])
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  dnl The stpncpy() declaration in lib/string.in.h uses 'restrict'.
+  AC_REQUIRE([AC_C_RESTRICT])
+
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
 
   dnl Both glibc and AIX (4.3.3, 5.1) have an stpncpy() function
   dnl declared in <string.h>. Its side effects are the same as those
@@ -19,12 +25,17 @@ AC_DEFUN([gl_FUNC_STPNCPY],
   dnl   in AIX:     dest + max(0,n-1)
   dnl Only the glibc return value is useful in practice.
 
-  AC_CACHE_CHECK([for working stpncpy], gl_cv_func_stpncpy, [
-    AC_TRY_RUN([
+  AC_CHECK_DECLS_ONCE([stpncpy])
+  AC_CHECK_FUNCS_ONCE([stpncpy])
+  if test $ac_cv_func_stpncpy = yes; then
+    AC_CACHE_CHECK([for working stpncpy], [gl_cv_func_stpncpy], [
+      AC_TRY_RUN([
 #include <stdlib.h>
 #include <string.h> /* for strcpy */
 /* The stpncpy prototype is missing in <string.h> on AIX 4.  */
+#if !HAVE_DECL_STPNCPY
 extern char *stpncpy (char *dest, const char *src, size_t n);
+#endif
 int main () {
   const char *src = "Hello";
   char dest[10];
@@ -39,17 +50,23 @@ int main () {
   if (stpncpy (dest, src, 7) != dest + 5) exit(1);
   exit(0);
 }
-], gl_cv_func_stpncpy=yes, gl_cv_func_stpncpy=no,
-  [AC_EGREP_CPP([Thanks for using GNU], [
+], [gl_cv_func_stpncpy=yes], [gl_cv_func_stpncpy=no],
+        [AC_EGREP_CPP([Thanks for using GNU], [
 #include <features.h>
 #ifdef __GNU_LIBRARY__
   Thanks for using GNU
 #endif
-], gl_cv_func_stpncpy=yes, gl_cv_func_stpncpy=no)])])
-
-  if test $gl_cv_func_stpncpy = yes; then
-    AC_DEFINE(HAVE_STPNCPY, 1,
-      [Define if you have the stpncpy() function and it works.])
+], [gl_cv_func_stpncpy=yes], [gl_cv_func_stpncpy=no])
+        ])
+    ])
+    if test $gl_cv_func_stpncpy = yes; then
+      AC_DEFINE([HAVE_STPNCPY], [1],
+        [Define if you have the stpncpy() function and it works.])
+    else
+      REPLACE_STPNCPY=1
+      AC_LIBOBJ([stpncpy])
+      gl_PREREQ_STPNCPY
+    fi
   else
     HAVE_STPNCPY=0
     AC_LIBOBJ([stpncpy])