[empathy] add m4/as-compiler-flag.m4

[Guillaume Desmottes <gdesmott src gnome org>]

commit be027f7002d11677cf32601acd1370c45f2d2c57
Author: Guillaume Desmottes <guillaume desmottes collabora co uk>
Date:   Mon May 25 12:14:34 2009 +0100

    add m4/as-compiler-flag.m4

 m4/as-compiler-flag.m4 |   33 +++++++++++++++++++++++++++++++++
 1 files changed, 33 insertions(+), 0 deletions(-)
---
diff --git a/m4/as-compiler-flag.m4 b/m4/as-compiler-flag.m4
new file mode 100644
index 0000000..605708a
--- /dev/null
+++ b/m4/as-compiler-flag.m4
@@ -0,0 +1,33 @@
+dnl as-compiler-flag.m4 0.1.0
+
+dnl autostars m4 macro for detection of compiler flags
+
+dnl David Schleef <ds schleef org>
+
+dnl $Id: as-compiler-flag.m4,v 1.1 2005/06/18 18:02:46 burgerman Exp $
+
+dnl AS_COMPILER_FLAG(CFLAGS, ACTION-IF-ACCEPTED, [ACTION-IF-NOT-ACCEPTED])
+dnl Tries to compile with the given CFLAGS.
+dnl Runs ACTION-IF-ACCEPTED if the compiler can compile with the flags,
+dnl and ACTION-IF-NOT-ACCEPTED otherwise.
+
+AC_DEFUN([AS_COMPILER_FLAG],
+[
+  AC_MSG_CHECKING([to see if compiler understands $1])
+
+  save_CFLAGS="$CFLAGS"
+  CFLAGS="$CFLAGS $1"
+
+  AC_TRY_COMPILE([ ], [], [flag_ok=yes], [flag_ok=no])
+  CFLAGS="$save_CFLAGS"
+
+  if test "X$flag_ok" = Xyes ; then
+    $2
+    true
+  else
+    $3
+    true
+  fi
+  AC_MSG_RESULT([$flag_ok])
+])
+