[PATCH v2] configure: Check for __builtin_ms_va_list on all x86_64 platforms.

[Charles Davis]

If we're running configure, we're probably not going to be using Visual
C++, even on Windows. Everywhere else, we need this for variadic
argument lists to work.

Signed-off-by: Charles Davis <cdavis5x at gmail.com>
---
Try 2: Fold most of the Mac OS-specific goop into the generic x86-64 checks.

As part of this, I've refactored that case block. Now there are two case
blocks: one that checks operating systems and one that check architectures.

 configure.ac | 31 +++++++++++--------------------
 1 file changed, 11 insertions(+), 20 deletions(-)

diff --git a/configure.ac b/configure.ac
index 6582b82..98d371e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -127,23 +127,15 @@ AC_CHECK_TOOL(LD,ld)
 
 case $host in
   *-darwin*)
-    if test "x$enable_win64" = "xyes"
-    then
-      CC="$CC -m64"
-      CXX="$CXX -m64"
-      host_cpu="x86_64"
-      notice_platform="64-bit "
-      AC_SUBST(TARGETFLAGS,"-m64")
-    else
-      CC="$CC -m32"
-      CXX="$CXX -m32"
-      host_cpu="i386"
-      notice_platform="32-bit "
-      AC_SUBST(TARGETFLAGS,"-m32")
-      enable_win16=${enable_win16:-yes}
-    fi
     with_fontconfig=${with_fontconfig:-no}
     ;;
+  *-mingw32*|*-cygwin*)
+    enable_win16=${enable_win16:-no}
+    CFLAGS="$CFLAGS -D_WIN32"
+    ;;
+esac
+
+case $host in
   x86_64*|amd64*)
     if test "x$enable_win64" != "xyes" -a "$cross_compiling" != "yes"
     then
@@ -164,9 +156,12 @@ case $host in
         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdarg.h>]], [[void func(__builtin_ms_va_list *args);]])],
                           [AC_MSG_RESULT([yes])],
                           [AC_MSG_RESULT([no])
-                           AC_MSG_ERROR([You need gcc >= 4.4 to build Wine as 64-bit.])])
+                           AC_MSG_ERROR([You need gcc >= 4.4 or clang >= 3.8 to build Wine as 64-bit.])])
       fi
+      CC="$CC -m64"
+      CXX="$CXX -m64"
       host_cpu="x86_64"
+      notice_platform="64-bit "
       AC_SUBST(TARGETFLAGS,"-m64")
     fi
     ;;
@@ -179,10 +174,6 @@ case $host in
     CFLAGS="$CFLAGS -marm"
     AC_SUBST(TARGETFLAGS,"-marm")
     ;;
-  *-mingw32*|*-cygwin*)
-    enable_win16=${enable_win16:-no}
-    CFLAGS="$CFLAGS -D_WIN32"
-    ;;
   i[[3456789]]86*)
     enable_win16=${enable_win16:-yes}
     ;;
-- 
2.7.2