diff --git a/build/unix/build-clang/build-clang.py b/build/unix/build-clang/build-clang.py
index 2de0aab8e0c0..a51dba19cc4a 100755
--- a/build/unix/build-clang/build-clang.py
+++ b/build/unix/build-clang/build-clang.py
@@ -13,6 +13,7 @@ import os.path
 import shutil
 import tarfile
 import subprocess
+import platform
 
 def check_run(args):
     r = subprocess.call(args)
@@ -46,7 +47,7 @@ def with_env(env, f):
 
 def build_tar_package(tar, name, base, directory):
     name = os.path.realpath(name)
-    run_in(base, [tar, "-cjf", name, "--owner=root", directory])
+    run_in(base, [tar, "-cjf", name, directory])
 
 def svn_co(url, directory, revision):
     check_run(["svn", "co", "-r", revision, url, directory])
@@ -83,6 +84,8 @@ def build_one_stage_aux(stage_dir, is_stage_one):
 
     build_package(llvm_source_dir, build_dir, configure_opts)
 
+isDarwin = platform.system() == "Darwin"
+
 if not os.path.exists(source_dir):
     os.makedirs(source_dir)
     svn_co("http://llvm.org/svn/llvm-project/llvm/trunk",
@@ -93,8 +96,12 @@ if not os.path.exists(source_dir):
            compiler_rt_source_dir, llvm_revision)
     os.symlink("../../clang", llvm_source_dir + "/tools/clang")
     os.symlink("../../compiler-rt", llvm_source_dir + "/projects/compiler-rt")
-    patch("old-ld-hack.patch", 1, llvm_source_dir)
-    patch("compiler-rt-gnu89-inline.patch", 0, compiler_rt_source_dir)
+    if isDarwin:
+        patch("clang-no-ios.patch", 0, clang_source_dir)
+        patch("compiler-rt-no-ios.patch", 0, compiler_rt_source_dir)
+    else:
+        patch("old-ld-hack.patch", 1, llvm_source_dir)
+        patch("compiler-rt-gnu89-inline.patch", 0, compiler_rt_source_dir)
 
 if os.path.exists(build_dir):
     shutil.rmtree(build_dir)
@@ -102,13 +109,28 @@ os.makedirs(build_dir)
 
 stage1_dir = build_dir + '/stage1'
 stage1_inst_dir = stage1_dir + '/clang'
-build_one_stage({"CC"  : "/tools/gcc-4.5-0moz3/bin/gcc -static-libgcc",
-                 "CXX" : "/tools/gcc-4.5-0moz3/bin/g++ -static-libgcc -static-libstdc++"},
+
+if isDarwin:
+    extra_cflags = ""
+    extra_cxxflags = ""
+    cc = "/usr/bin/clang"
+    cxx = "/usr/bin/clang++"
+else:
+    extra_cflags = "-static-libgcc"
+    extra_cxxflags = "-static-libgcc -static-libstdc++"
+    cc = "/tools/gcc-4.5-0moz3/bin/gcc %s" % extra_cflags
+    cxx = "/tools/gcc-4.5-0moz3/bin/g++ %s" % extra_cxxflags
+
+build_one_stage({"CC"  : cc,
+                 "CXX" : cxx },
                 stage1_dir, True)
 
+if not isDarwin:
+    extra_cflags += " -fgnu89-inline"
+
 stage2_dir = build_dir + '/stage2'
-build_one_stage({"CC"  : stage1_inst_dir + "/bin/clang -static-libgcc -fgnu89-inline",
-                 "CXX" : stage1_inst_dir + "/bin/clang++ -static-libgcc -static-libstdc++"},
+build_one_stage({"CC"  : stage1_inst_dir + "/bin/clang %s" % extra_cflags,
+                 "CXX" : stage1_inst_dir + "/bin/clang++ %s" % extra_cxxflags},
                 stage2_dir, False)
 
-build_tar_package("/bin/tar", "clang.tar.bz2", stage2_dir, "clang")
+build_tar_package("tar", "clang.tar.bz2", stage2_dir, "clang")
diff --git a/build/unix/build-clang/clang-no-ios.patch b/build/unix/build-clang/clang-no-ios.patch
new file mode 100644
index 000000000000..6266c2a99dfa
--- /dev/null
+++ b/build/unix/build-clang/clang-no-ios.patch
@@ -0,0 +1,15 @@
+Index: runtime/compiler-rt/Makefile
+===================================================================
+--- runtime/compiler-rt/Makefile	(revision 157958)
++++ runtime/compiler-rt/Makefile	(working copy)
+@@ -74,8 +74,8 @@
+ ifeq ($(OS),Darwin)
+ RuntimeDirs += darwin
+ RuntimeLibrary.darwin.Configs := \
+-	eprintf 10.4 osx ios cc_kext \
+-	asan_osx profile_osx profile_ios
++	eprintf 10.4 osx  \
++	asan_osx profile_osx
+ endif
+ 
+ # On Linux, include a library which has all the runtime functions.
diff --git a/build/unix/build-clang/compiler-rt-no-ios.patch b/build/unix/build-clang/compiler-rt-no-ios.patch
new file mode 100644
index 000000000000..dd5cdcd1ce2e
--- /dev/null
+++ b/build/unix/build-clang/compiler-rt-no-ios.patch
@@ -0,0 +1,29 @@
+Index: make/platform/clang_darwin.mk
+===================================================================
+--- make/platform/clang_darwin.mk	(revision 157958)
++++ make/platform/clang_darwin.mk	(working copy)
+@@ -47,7 +47,7 @@
+ # Configuration for targetting iOS, for some ARMv6 functions, which must be
+ # in the same linkage unit, and for a couple of other functions that didn't
+ # make it into libSystem.
+-Configs += ios
++#Configs += ios
+ UniversalArchs.ios := $(call CheckArches,i386 x86_64 armv6 armv7,ios)
+ 
+ # Configuration for targetting OSX. These functions may not be in libSystem
+@@ -56,13 +56,13 @@
+ UniversalArchs.osx := $(call CheckArches,i386 x86_64,osx)
+ 
+ # Configuration for use with kernel/kexts.
+-Configs += cc_kext
++#Configs += cc_kext
+ UniversalArchs.cc_kext := $(call CheckArches,armv6 armv7 i386 x86_64,cc_kext)
+ 
+ # Configurations which define the profiling support functions.
+ Configs += profile_osx
+ UniversalArchs.profile_osx := $(call CheckArches,i386 x86_64,profile_osx)
+-Configs += profile_ios
++#Configs += profile_ios
+ UniversalArchs.profile_ios := $(call CheckArches,i386 x86_64 armv6 armv7,profile_ios)
+ 
+ # Configurations which define the ASAN support functions.