Replace obsolete AC_LANG_FUNC_LINK_TRY autoconf macro.

The version of this macro used in autoconf 2.59 is capable of incorrectly
succeeding (ie, reporting that a library function is available when it
isn't), if the compiler performs link-time optimization and decides that
it can optimize the function reference away entirely.  Replace it with the
coding used in autoconf 2.61 and later, which forces the program result to
depend on the function's result so that it cannot be optimized away.  This
should fix build failures currently being seen on buildfarm member anchovy.

This patch affects the 8.2 and 8.3 branches only, since later branches are
using autoconf versions that don't have this problem.

2 files changed, 298 insertions, 325 deletions

diff --git a/config/c-library.m4 b/config/c-library.m4
index 31dba1cbfdd..d8d5dcd5b64 100644
--- a/config/c-library.m4
+++ b/config/c-library.m4
@@ -297,3 +297,72 @@ int main()
 ])dnl AC_CACHE_VAL
 AC_MSG_RESULT([$pgac_cv_printf_arg_control])
 ])# PGAC_FUNC_PRINTF_ARG_CONTROL
+
+
+# backport improved FUNC_LINK_TRY test from Autoconf 2.61, cf
+# http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=f50d0bd4c7d92fbabcd9169920a23889524790e7
+# This is needed to avoid incorrect results when compiler does link-time
+# optimization.
+
+# AC_LANG_CALL(C)(PROLOGUE, FUNCTION)
+# -----------------------------------
+# Avoid conflicting decl of main.
+m4_define([AC_LANG_CALL(C)],
+[AC_LANG_PROGRAM([$1
+m4_if([$2], [main], ,
+[/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char $2 ();])], [return $2 ();])])
+
+
+# AC_LANG_FUNC_LINK_TRY(C)(FUNCTION)
+# ----------------------------------
+# Don't include <ctype.h> because on OSF/1 3.0 it includes
+# <sys/types.h> which includes <sys/select.h> which contains a
+# prototype for select.  Similarly for bzero.
+#
+# This test used to merely assign f=$1 in main(), but that was
+# optimized away by HP unbundled cc A.05.36 for ia64 under +O3,
+# presumably on the basis that there's no need to do that store if the
+# program is about to exit.  Conversely, the AIX linker optimizes an
+# unused external declaration that initializes f=$1.  So this test
+# program has both an external initialization of f, and a use of f in
+# main that affects the exit status.
+#
+m4_define([AC_LANG_FUNC_LINK_TRY(C)],
+[AC_LANG_PROGRAM(
+[/* Define $1 to an innocuous variant, in case <limits.h> declares $1.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $1 innocuous_$1
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $1 (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $1
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char $1 ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined __stub_$1 || defined __stub___$1
+choke me
+#endif
+], [return $1 ();])])
diff --git a/configure b/configure
index e89d2bdc1e3..1e602914aca 100755
--- a/configure
+++ b/configure
@@ -5130,7 +5130,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 int
 main ()
 {
-main ();
+return main ();
   ;
   return 0;
 }
@@ -5193,17 +5193,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char setproctitle ();
 int
 main ()
 {
-setproctitle ();
+return setproctitle ();
   ;
   return 0;
 }
@@ -5248,17 +5248,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char setproctitle ();
 int
 main ()
 {
-setproctitle ();
+return setproctitle ();
   ;
   return 0;
 }
@@ -5319,17 +5319,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char dlopen ();
 int
 main ()
 {
-dlopen ();
+return dlopen ();
   ;
   return 0;
 }
@@ -5374,17 +5374,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char dlopen ();
 int
 main ()
 {
-dlopen ();
+return dlopen ();
   ;
   return 0;
 }
@@ -5445,17 +5445,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char socket ();
 int
 main ()
 {
-socket ();
+return socket ();
   ;
   return 0;
 }
@@ -5500,17 +5500,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char socket ();
 int
 main ()
 {
-socket ();
+return socket ();
   ;
   return 0;
 }
@@ -5571,17 +5571,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char shl_load ();
 int
 main ()
 {
-shl_load ();
+return shl_load ();
   ;
   return 0;
 }
@@ -5626,17 +5626,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char shl_load ();
 int
 main ()
 {
-shl_load ();
+return shl_load ();
   ;
   return 0;
 }
@@ -5700,17 +5700,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char ldopen ();
 int
 main ()
 {
-ldopen ();
+return ldopen ();
   ;
   return 0;
 }
@@ -5755,17 +5755,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char ldopen ();
 int
 main ()
 {
-ldopen ();
+return ldopen ();
   ;
   return 0;
 }
@@ -5828,17 +5828,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char getopt_long ();
 int
 main ()
 {
-getopt_long ();
+return getopt_long ();
   ;
   return 0;
 }
@@ -5883,17 +5883,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char getopt_long ();
 int
 main ()
 {
-getopt_long ();
+return getopt_long ();
   ;
   return 0;
 }
@@ -5954,17 +5954,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char crypt ();
 int
 main ()
 {
-crypt ();
+return crypt ();
   ;
   return 0;
 }
@@ -6009,17 +6009,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char crypt ();
 int
 main ()
 {
-crypt ();
+return crypt ();
   ;
   return 0;
 }
@@ -6081,17 +6081,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char fdatasync ();
 int
 main ()
 {
-fdatasync ();
+return fdatasync ();
   ;
   return 0;
 }
@@ -6136,17 +6136,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char fdatasync ();
 int
 main ()
 {
-fdatasync ();
+return fdatasync ();
   ;
   return 0;
 }
@@ -6208,17 +6208,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char shmget ();
 int
 main ()
 {
-shmget ();
+return shmget ();
   ;
   return 0;
 }
@@ -6263,17 +6263,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char shmget ();
 int
 main ()
 {
-shmget ();
+return shmget ();
   ;
   return 0;
 }
@@ -6345,17 +6345,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char readline ();
 int
 main ()
 {
-readline ();
+return readline ();
   ;
   return 0;
 }
@@ -6456,17 +6456,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char inflate ();
 int
 main ()
 {
-inflate ();
+return inflate ();
   ;
   return 0;
 }
@@ -6556,17 +6556,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char com_err ();
 int
 main ()
 {
-com_err ();
+return com_err ();
   ;
   return 0;
 }
@@ -6611,17 +6611,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char com_err ();
 int
 main ()
 {
-com_err ();
+return com_err ();
   ;
   return 0;
 }
@@ -6686,17 +6686,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char krb5_sendauth ();
 int
 main ()
 {
-krb5_sendauth ();
+return krb5_sendauth ();
   ;
   return 0;
 }
@@ -6741,17 +6741,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char krb5_sendauth ();
 int
 main ()
 {
-krb5_sendauth ();
+return krb5_sendauth ();
   ;
   return 0;
 }
@@ -6817,17 +6817,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char com_err ();
 int
 main ()
 {
-com_err ();
+return com_err ();
   ;
   return 0;
 }
@@ -6872,17 +6872,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char com_err ();
 int
 main ()
 {
-com_err ();
+return com_err ();
   ;
   return 0;
 }
@@ -6953,17 +6953,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char CRYPTO_new_ex_data ();
 int
 main ()
 {
-CRYPTO_new_ex_data ();
+return CRYPTO_new_ex_data ();
   ;
   return 0;
 }
@@ -7031,17 +7031,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char SSL_library_init ();
 int
 main ()
 {
-SSL_library_init ();
+return SSL_library_init ();
   ;
   return 0;
 }
@@ -7110,17 +7110,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char CRYPTO_new_ex_data ();
 int
 main ()
 {
-CRYPTO_new_ex_data ();
+return CRYPTO_new_ex_data ();
   ;
   return 0;
 }
@@ -7188,17 +7188,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char SSL_library_init ();
 int
 main ()
 {
-SSL_library_init ();
+return SSL_library_init ();
   ;
   return 0;
 }
@@ -7270,17 +7270,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char pam_start ();
 int
 main ()
 {
-pam_start ();
+return pam_start ();
   ;
   return 0;
 }
@@ -13559,30 +13559,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14125,30 +14119,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14229,30 +14217,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14562,30 +14544,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14684,30 +14660,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14805,30 +14775,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -14949,30 +14913,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -15102,30 +15060,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -15316,30 +15268,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -15418,30 +15364,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -15634,30 +15574,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef syslog
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char syslog ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_syslog) || defined (__stub___syslog)
+#if defined __stub_syslog || defined __stub___syslog
 choke me
-#else
-char (*f) () = syslog;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != syslog;
+return syslog ();
   ;
   return 0;
 }
@@ -15941,30 +15875,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -16044,30 +15972,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -16148,30 +16070,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -16248,30 +16164,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -16543,17 +16453,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char pthread_join ();
 int
 main ()
 {
-pthread_join ();
+return pthread_join ();
   ;
   return 0;
 }
@@ -17224,30 +17134,24 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 #undef $ac_func
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
-{
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char $ac_func ();
 /* The GNU C library defines this for functions which it implements
     to always fail with ENOSYS.  Some functions are actually named
     something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+#if defined __stub_$ac_func || defined __stub___$ac_func
 choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
 #endif
 
 int
 main ()
 {
-return f != $ac_func;
+return $ac_func ();
   ;
   return 0;
 }
@@ -17462,17 +17366,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char ldap_bind ();
 int
 main ()
 {
-ldap_bind ();
+return ldap_bind ();
   ;
   return 0;
 }
@@ -17543,17 +17447,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char ldap_simple_bind ();
 int
 main ()
 {
-ldap_simple_bind ();
+return ldap_simple_bind ();
   ;
   return 0;
 }
@@ -17626,17 +17530,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char ldap_bind ();
 int
 main ()
 {
-ldap_bind ();
+return ldap_bind ();
   ;
   return 0;
 }
@@ -22120,17 +22024,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char bind_textdomain_codeset ();
 int
 main ()
 {
-bind_textdomain_codeset ();
+return bind_textdomain_codeset ();
   ;
   return 0;
 }
@@ -22175,17 +22079,17 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-/* Override any gcc2 internal prototype to avoid an error.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
 #ifdef __cplusplus
 extern "C"
 #endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
 char bind_textdomain_codeset ();
 int
 main ()
 {
-bind_textdomain_codeset ();
+return bind_textdomain_codeset ();
   ;
   return 0;
 }