ccan: fix configure tests for __builtin_clz etc.

It's not enough to compile-test them: Michael Adam points out that nonexistant
functions merely cause a warning.  We have to try to link them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-User: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-Date: Tue Jul  5 07:08:55 CEST 2011 on sn-devel-104

diff --git a/lib/ccan/libccan.m4 b/lib/ccan/libccan.m4
index 92676c3184287725a2b03ee51899f377ee5d566e..df38d3b962dc21074ebe78065e1a62f42db46eac 100644 (file)
--- a/lib/ccan/libccan.m4
+++ b/lib/ccan/libccan.m4
@@ -135,7 +135,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_clz],
               samba_cv_builtin_clz,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_clz(1) == (sizeof(int)*8 - 1) ? 0 : 1;
                        }],
@@ -150,7 +150,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_clzl],
               samba_cv_builtin_clzl,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_clzl(1) == (sizeof(int)*8 - 1) ? 0 : 1;
                        }],
@@ -164,7 +164,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_clzll],
               samba_cv_builtin_clzll,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_clzll(1) == (sizeof(int)*8 - 1) ? 0 : 1;
                        }],
@@ -179,7 +179,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_constant_p],
               samba_cv_builtin_constant_p,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_constant_p(1) ? 0 : 1;
                        }],
@@ -194,7 +194,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_expect],
               samba_cv_builtin_expect,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_expect(main != 0) ? 0 : 1;
                        }],
@@ -209,7 +209,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_popcountl],
               samba_cv_builtin_popcountl,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_popcountl(255L) == 8 ? 0 : 1;
                        }],
@@ -224,7 +224,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_types_compatible_p],
               samba_cv_builtin_types_compatible_p,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [int main(void) {
                                return __builtin_types_compatible_p(char *, int) ? 1 : 0;
                        }],
@@ -255,7 +255,7 @@ fi
 AC_CACHE_CHECK([whether we have __builtin_have_isblank],
               samba_cv_builtin_have_isblank,
               [
-                AC_COMPILE_IFELSE(
+                AC_LINK_IFELSE(
                        [#include <ctype.h>
                         int main(void) { return isblank(' ') ? 0 : 1; }
                        ],