OS X: detect clang and build for x86 target only.

Newer versions of Xcode / OS X don't support PPC code anymore and replace gcc
with clang. When clang is detected assume we want to build for the default
architecture only and change the minimum OS X version to 10.5.

Change-Id: I5843fa9bb3d957ec6f0a537e857608ad99c31517

1 files changed, 7 insertions, 1 deletions

diff --git a/rbutil/libtools.make b/rbutil/libtools.make
index 4623808f94..7a125f98ea 100644
--- a/rbutil/libtools.make
+++ b/rbutil/libtools.make
@@ -63,7 +63,12 @@ $(info Compiler creates $(COMPILETARGET) binaries)
 
 # OS X specifics. Needs to consider cross compiling for Windows.
 ifeq ($(findstring APPLE,$(CPPDEFINES)),APPLE)
-# when building libs for OS X build for both i386 and ppc at the same time.
+# When building for 10.4+ we need to use gcc. Otherwise clang is used, so use
+# that to determine if we need to set arch and isysroot.
+ifeq ($(findstring __clang__,$(CPPDEFINES)),__clang__)
+CFLAGS += -mmacosx-version-min=10.5
+else
+# when building libs for OS X 10.4+ build for both i386 and ppc at the same time.
 # This creates fat objects, and ar can only create the archive but not operate
 # on it. As a result the ar call must NOT use the u (update) flag.
 ARCHFLAGS += -arch ppc -arch i386
@@ -73,6 +78,7 @@ CC = gcc-4.0
 CFLAGS += -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4
 NATIVECC = gcc-4.0
 endif
+endif
 WINDRES = windres
 
 BUILD_DIR ?= $(TARGET_DIR)build$(COMPILETARGET)