[PATCH 1/1] autoconf: add support for caching in the macro gl_LD_VERSION_SCRIPT

[Christophe CURIS]

Autoconf propose a mechanism to cache the result of checks, so that a user
who needs to re-run configure can get a very fast result. Unfortunately,
the code in the macro gl_LD_VERSION_SCRIPT did not implement this feature,
so it would always spend time re-testing.

This patch inserts the AC_CACHE_CHECK macro at the appropriate place, so
now the check will not be re-run if the user enabled autoconf's cache.

Signed-off-by: Christophe CURIS <christophe.cu...@free.fr>
---
 m4/ld-version-script.m4 | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/m4/ld-version-script.m4 b/m4/ld-version-script.m4
index f8b4a5c..bb3cd88 100644
--- a/m4/ld-version-script.m4
+++ b/m4/ld-version-script.m4
@@ -1,4 +1,4 @@
-# ld-version-script.m4 serial 3
+# ld-version-script.m4 serial 4
 dnl Copyright (C) 2008-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -22,16 +22,17 @@ AC_DEFUN([gl_LD_VERSION_SCRIPT],
       [enable linker version script (default is enabled when possible)]),
       [have_ld_version_script=$enableval], [])
   if test -z "$have_ld_version_script"; then
-    AC_MSG_CHECKING([if LD -Wl,--version-script works])
-    save_LDFLAGS="$LDFLAGS"
-    LDFLAGS="$LDFLAGS -Wl,--version-script=conftest.map"
-    cat > conftest.map <<EOF
+    AC_CACHE_CHECK([if LD -Wl,--version-script works], 
[gl_cv_sys_ld_version_script],
+    [
+      save_LDFLAGS="$LDFLAGS"
+      LDFLAGS="$LDFLAGS -Wl,--version-script=conftest.map"
+      cat > conftest.map <<EOF
 foo
 EOF
-    AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
-                   [accepts_syntax_errors=yes], [accepts_syntax_errors=no])
-    if test "$accepts_syntax_errors" = no; then
-      cat > conftest.map <<EOF
+      AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
+                     [], [gl_cv_sys_ld_version_script=no])
+      if test "x$gl_cv_sys_ld_version_script" != "xno"; then
+        cat > conftest.map <<EOF
 VERS_1 {
         global: sym;
 };
@@ -40,14 +41,13 @@ VERS_2 {
         global: sym;
 } VERS_1;
 EOF
-      AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
-                     [have_ld_version_script=yes], [have_ld_version_script=no])
-    else
-      have_ld_version_script=no
-    fi
-    rm -f conftest.map
-    LDFLAGS="$save_LDFLAGS"
-    AC_MSG_RESULT($have_ld_version_script)
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
+                       [gl_cv_sys_ld_version_script=yes], 
[gl_cv_sys_ld_version_script=no])
+      fi
+      rm -f conftest.map
+      LDFLAGS="$save_LDFLAGS"
+    ])
+    have_ld_version_script=$gl_cv_sys_ld_version_script
   fi
   AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = 
"yes")
 ])
-- 
2.1.3