[gtkhtml] Bug 626090 - Only set -fno-strict-aliasing for GCC

[Matthew Barnes <mbarnes src gnome org>]

commit 9aef7ef27bda52bc8bb9fbc35deab5c047fc2429
Author: Matthew Barnes <mbarnes redhat com>
Date:   Thu Aug 5 08:40:49 2010 -0400

    Bug 626090 - Only set -fno-strict-aliasing for GCC

 configure.ac |   20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8976af5..99a9f8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -96,13 +96,8 @@ dnl	-Wmissing-format-attribute
 dnl	-Wshadow
 dnl	-Wstrict-aliasing=2
 
-dnl GCC 4.4 got more aggressive in its aliasing optimizations, changing
-dnl behavior that -- according to the C99 standard -- is supposed to be
-dnl undefined.  We may still have aliasing abuses lying around that rely
-dnl on GCC's previous "undefined" behavior, so disable strict-aliasing
-dnl optimization until we can find and fix all the abuses.
-dnl XXX This really belongs in AM_CFLAGS.
-CFLAGS="$CFLAGS $WARNING_FLAGS -fno-strict-aliasing"
+dnl XXX This really belongs in AM_CPPFLAGS.
+CFLAGS="$CFLAGS $WARNING_FLAGS"
 
 dnl *********************
 dnl Necessary programs
@@ -117,6 +112,17 @@ AC_TYPE_SIZE_T
 AC_CHECK_FUNCS([memchr memmove memset regcomp setlocale strchr strcspn strrchr strstr strtol strtoull])
 AC_CHECK_HEADERS([fcntl.h libintl.h])
 
+dnl GCC 4.4 got more aggressive in its aliasing optimizations, changing
+dnl behavior that -- according to the C99 standard -- is supposed to be
+dnl undefined.  We may still have aliasing abuses lying around that rely
+dnl on GCC's previous "undefined" behavior, so disable strict-aliasing
+dnl optimization until we can find and fix all the abuses.
+dnl (AC_PROG_CC must run first to set the GCC variable.)
+dnl XXX This really belongs in AM_CFLAGS.
+if test "x${GCC}" = "xyes"; then
+	CFLAGS="$CFLAGS -fno-strict-aliasing"
+fi
+
 dnl *****************
 dnl libtool
 dnl *****************