diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -896,12 +896,7 @@
 bool MachO::HasNativeLLVMSupport() const { return true; }
 
 ToolChain::CXXStdlibType Darwin::GetDefaultCXXStdlibType() const {
-  // Use libstdc++ on old targets (OSX < 10.9 and iOS < 7)
-  if ((isTargetMacOSBased() && isMacosxVersionLT(10, 9)) ||
-      (isTargetIOSBased() && isIPhoneOSVersionLT(7, 0)))
-    return ToolChain::CST_Libstdcxx;
-
-  // On all other targets, use libc++
+  // Always use libc++ by default
   return ToolChain::CST_Libcxx;
 }
 
diff --git a/clang/test/Driver/Xarch.c b/clang/test/Driver/Xarch.c
--- a/clang/test/Driver/Xarch.c
+++ b/clang/test/Driver/Xarch.c
@@ -1,12 +1,12 @@
-// RUN: %clang -target i386-apple-darwin9 -m32 -Xarch_i386 -O3 %s -S -### 2>&1 | FileCheck -check-prefix=O3ONCE %s
+// RUN: %clang -target i386-apple-darwin11 -m32 -Xarch_i386 -O3 %s -S -### 2>&1 | FileCheck -check-prefix=O3ONCE %s
 // O3ONCE: "-O3"
 // O3ONCE-NOT: "-O3"
 
-// RUN: %clang -target i386-apple-darwin9 -m64 -Xarch_i386 -O3 %s -S -### 2>&1 | FileCheck -check-prefix=O3NONE %s
+// RUN: %clang -target i386-apple-darwin11 -m64 -Xarch_i386 -O3 %s -S -### 2>&1 | FileCheck -check-prefix=O3NONE %s
 // O3NONE-NOT: "-O3"
 // O3NONE: argument unused during compilation: '-Xarch_i386 -O3'
 
-// RUN: not %clang -target i386-apple-darwin9 -m32 -Xarch_i386 -o -Xarch_i386 -S %s -S -Xarch_i386 -o 2>&1 | FileCheck -check-prefix=INVALID %s
+// RUN: not %clang -target i386-apple-darwin11 -m32 -Xarch_i386 -o -Xarch_i386 -S %s -S -Xarch_i386 -o 2>&1 | FileCheck -check-prefix=INVALID %s
 // INVALID: error: invalid Xarch argument: '-Xarch_i386 -o'
 // INVALID: error: invalid Xarch argument: '-Xarch_i386 -S'
 // INVALID: error: invalid Xarch argument: '-Xarch_i386 -o'
diff --git a/clang/test/Driver/apple-kext-mkernel.c b/clang/test/Driver/apple-kext-mkernel.c
--- a/clang/test/Driver/apple-kext-mkernel.c
+++ b/clang/test/Driver/apple-kext-mkernel.c
@@ -1,20 +1,20 @@
-// RUN: %clang -target x86_64-apple-darwin10 -mkernel -### -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-X86 %s
-// RUN: %clang -target x86_64-apple-darwin10 -mkernel -### -fsyntax-only -fbuiltin -fno-builtin -fcommon -fno-common %s 2>&1 | FileCheck --check-prefix=CHECK-X86 %s
+// RUN: %clang -target x86_64-apple-darwin11 -mkernel -### -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-X86 %s
+// RUN: %clang -target x86_64-apple-darwin11 -mkernel -### -fsyntax-only -fbuiltin -fno-builtin -fcommon -fno-common %s 2>&1 | FileCheck --check-prefix=CHECK-X86 %s
 
 // CHECK-X86: "-disable-red-zone"
 // CHECK-X86: "-fno-builtin"
 // CHECK-X86: "-fno-rtti"
 // CHECK-X86-NOT: "-fcommon"
 
-// RUN: %clang -target x86_64-apple-darwin10 -mkernel -### -fsyntax-only -fbuiltin -fcommon %s 2>&1 | FileCheck --check-prefix=CHECK-X86-2 %s
+// RUN: %clang -target x86_64-apple-darwin11 -mkernel -### -fsyntax-only -fbuiltin -fcommon %s 2>&1 | FileCheck --check-prefix=CHECK-X86-2 %s
 
 // CHECK-X86-2: "-disable-red-zone"
 // CHECK-X86-2-NOT: "-fno-builtin"
 // CHECK-X86-2: "-fno-rtti"
 // CHECK-X86-2-NOT: "-fno-common"
 
-// RUN: %clang -target x86_64-apple-darwin10 -arch armv7 -mkernel -mstrict-align -### -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-ARM %s
-// RUN: %clang -target x86_64-apple-darwin10 -arch armv7 -mkernel -mstrict-align -### -fsyntax-only -fbuiltin -fno-builtin -fcommon -fno-common %s 2>&1 | FileCheck --check-prefix=CHECK-ARM %s
+// RUN: %clang -target x86_64-apple-darwin11 -arch armv7 -mkernel -mstrict-align -### -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-ARM %s
+// RUN: %clang -target x86_64-apple-darwin11 -arch armv7 -mkernel -mstrict-align -### -fsyntax-only -fbuiltin -fno-builtin -fcommon -fno-common %s 2>&1 | FileCheck --check-prefix=CHECK-ARM %s
 
 // CHECK-ARM: "-target-feature" "+long-calls"
 // CHECK-ARM: "-target-feature" "+strict-align"
@@ -23,6 +23,6 @@
 // CHECK-ARM: "-fno-rtti"
 // CHECK-ARM-NOT: "-fcommon"
 
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -Werror -fno-builtin -fno-exceptions -fno-common -fno-rtti \
 // RUN:   -mkernel -fsyntax-only %s
diff --git a/clang/test/Driver/arc.c b/clang/test/Driver/arc.c
--- a/clang/test/Driver/arc.c
+++ b/clang/test/Driver/arc.c
@@ -1,8 +1,8 @@
-// RUN: not %clang -ObjC -target i386-apple-darwin10 -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
-// RUN: not %clang -x objective-c -target i386-apple-darwin10 -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
-// RUN: not %clang -x objective-c++ -target i386-apple-darwin10 -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
-// RUN: not %clang -x c -target i386-apple-darwin10 -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck -check-prefix NOTOBJC %s
-// RUN: not %clang -x c++ -target i386-apple-darwin10 -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck -check-prefix NOTOBJC %s
+// RUN: not %clang -ObjC -target i386-apple-darwin10 -stdlib=libstdc++ -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
+// RUN: not %clang -x objective-c -target i386-apple-darwin10 -stdlib=libstdc++ -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
+// RUN: not %clang -x objective-c++ -target i386-apple-darwin10 -stdlib=libstdc++ -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck %s
+// RUN: not %clang -x c -target i386-apple-darwin10 -stdlib=libstdc++ -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck -check-prefix NOTOBJC %s
+// RUN: not %clang -x c++ -target i386-apple-darwin10 -stdlib=libstdc++ -m32 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck -check-prefix NOTOBJC %s
 // RUN: not %clang -x objective-c -target x86_64-apple-darwin11 -mmacosx-version-min=10.5 -fobjc-arc %s -fsyntax-only 2>&1 | FileCheck -check-prefix NOTSUPPORTED %s
 
 // Just to test clang is working.
diff --git a/clang/test/Driver/bindings.c b/clang/test/Driver/bindings.c
--- a/clang/test/Driver/bindings.c
+++ b/clang/test/Driver/bindings.c
@@ -12,14 +12,14 @@
 // RUN: %clang -target i386-unknown-unknown -ccc-print-bindings -fsyntax-only -x c++ %s 2>&1 | FileCheck %s --check-prefix=CHECK08
 // CHECK08: "clang", inputs: ["{{.*}}bindings.c"], output: (nothing)
 
-// RUN: %clang -target i386-apple-darwin9 -ccc-print-bindings %s -S -arch ppc 2>&1 | FileCheck %s --check-prefix=CHECK11
+// RUN: %clang -target i386-apple-darwin11 -ccc-print-bindings %s -S -arch ppc 2>&1 | FileCheck %s --check-prefix=CHECK11
 // CHECK11: "clang", inputs: ["{{.*}}bindings.c"], output: "bindings.s"
 
 // RUN: %clang -target powerpc-unknown-unknown -ccc-print-bindings %s -S 2>&1 | FileCheck %s --check-prefix=CHECK12
 // CHECK12: "clang", inputs: ["{{.*}}bindings.c"], output: "bindings.s"
 
 // Darwin bindings
-// RUN: %clang -target i386-apple-darwin9 -no-integrated-as -ccc-print-bindings %s 2>&1 | FileCheck %s --check-prefix=CHECK14
+// RUN: %clang -target i386-apple-darwin11 -no-integrated-as -ccc-print-bindings %s 2>&1 | FileCheck %s --check-prefix=CHECK14
 // CHECK14: "clang", inputs: ["{{.*}}bindings.c"], output: "{{.*}}.s"
 // CHECK14: "darwin::Assembler", inputs: ["{{.*}}.s"], output: "{{.*}}.o"
 // CHECK14: "darwin::Linker", inputs: ["{{.*}}.o"], output: "a.out"
@@ -29,5 +29,5 @@
 // CHECK15: "x86_64-unknown-linux-gnu" - "GNU::StaticLibTool", inputs: ["{{.*}}.o"], output: "a.out"
 
 // Darwin StaticLibTool binding
-// RUN: %clang -target i386-apple-darwin9 -ccc-print-bindings --emit-static-lib %s 2>&1 | FileCheck %s --check-prefix=CHECK16
-// CHECK16: "i386-apple-darwin9" - "darwin::StaticLibTool", inputs: ["{{.*}}.o"], output: "a.out"
+// RUN: %clang -target i386-apple-darwin11 -ccc-print-bindings --emit-static-lib %s 2>&1 | FileCheck %s --check-prefix=CHECK16
+// CHECK16: "i386-apple-darwin11" - "darwin::StaticLibTool", inputs: ["{{.*}}.o"], output: "a.out"
diff --git a/clang/test/Driver/cc-log-diagnostics.c b/clang/test/Driver/cc-log-diagnostics.c
--- a/clang/test/Driver/cc-log-diagnostics.c
+++ b/clang/test/Driver/cc-log-diagnostics.c
@@ -1,7 +1,7 @@
 // RUN: rm -f %t.log
 // RUN: env RC_DEBUG_OPTIONS=1 \
 // RUN:     CC_LOG_DIAGNOSTICS=1 CC_LOG_DIAGNOSTICS_FILE=%t.log \
-// RUN: %clang -Wfoobar --target=x86_64-apple-darwin10 -fsyntax-only %s
+// RUN: %clang -Wfoobar --target=x86_64-apple-darwin11 -fsyntax-only %s
 // RUN: FileCheck %s < %t.log
 
 int f0(void) {}
diff --git a/clang/test/Driver/cpp-precomp.c b/clang/test/Driver/cpp-precomp.c
--- a/clang/test/Driver/cpp-precomp.c
+++ b/clang/test/Driver/cpp-precomp.c
@@ -1,5 +1,5 @@
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -Werror -cpp-precomp -fsyntax-only %s
 
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -Werror -no-cpp-precomp -fsyntax-only %s
diff --git a/clang/test/Driver/darwin-debug-flags.c b/clang/test/Driver/darwin-debug-flags.c
--- a/clang/test/Driver/darwin-debug-flags.c
+++ b/clang/test/Driver/darwin-debug-flags.c
@@ -1,15 +1,15 @@
-// RUN: env RC_DEBUG_OPTIONS=1 %clang -target i386-apple-darwin9 -I "path with \spaces" -g -Os %s  -emit-llvm -S -o - | FileCheck %s
+// RUN: env RC_DEBUG_OPTIONS=1 %clang -target i386-apple-darwin11 -I "path with \spaces" -g -Os %s  -emit-llvm -S -o - | FileCheck %s
 // <rdar://problem/7256886>
 // RUN: touch %t.s
-// RUN: env RC_DEBUG_OPTIONS=1 %clang -### -target i386-apple-darwin9 -c -g %t.s 2>&1 | FileCheck -check-prefix=S %s
+// RUN: env RC_DEBUG_OPTIONS=1 %clang -### -target i386-apple-darwin11 -c -g %t.s 2>&1 | FileCheck -check-prefix=S %s
 // <rdar://problem/12955296>
-// RUN: %clang -### -target i386-apple-darwin9 -c -g %t.s 2>&1 | FileCheck -check-prefix=P %s
+// RUN: %clang -### -target i386-apple-darwin11 -c -g %t.s 2>&1 | FileCheck -check-prefix=P %s
 
 // CHECK: distinct !DICompileUnit(
 // CHECK-SAME:                flags:
 // CHECK-SAME:                -I path\\ with\\ \\\\spaces
 // CHECK-SAME:                -g -Os
-// CHECK-SAME:                -mmacos-version-min=10.5.0
+// CHECK-SAME:                -mmacos-version-min=10.7.0
 
 int x;
 
diff --git a/clang/test/Driver/darwin-dsymutil.c b/clang/test/Driver/darwin-dsymutil.c
--- a/clang/test/Driver/darwin-dsymutil.c
+++ b/clang/test/Driver/darwin-dsymutil.c
@@ -1,6 +1,6 @@
 // Check that we run dsymutil properly with multiple -arch options.
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-phases \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-phases \
 // RUN:   -arch i386 -arch x86_64 %s -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-MULTIARCH-ACTIONS < %t %s
 //
@@ -15,57 +15,57 @@
 // CHECK-MULTIARCH-ACTIONS: 8: lipo, {6, 7}, image
 // CHECK-MULTIARCH-ACTIONS: 9: dsymutil, {8}, dSYM
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   -arch i386 -arch x86_64 %s -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-MULTIARCH-BINDINGS < %t %s
 //
-// CHECK-MULTIARCH-BINDINGS: "x86_64-apple-darwin10" - "darwin::Lipo", inputs: [{{.*}}, {{.*}}], output: "a.out"
-// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin10" - "darwin::Dsymutil", inputs: ["a.out"], output: "a.out.dSYM"
+// CHECK-MULTIARCH-BINDINGS: "x86_64-apple-darwin11" - "darwin::Lipo", inputs: [{{.*}}, {{.*}}], output: "a.out"
+// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin11" - "darwin::Dsymutil", inputs: ["a.out"], output: "a.out.dSYM"
 
 // Check output name derivation.
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   -o foo %s -g 2> %t
 // RUN: FileCheck -Doutfile=foo -Ddsymfile=foo.dSYM \
 // RUN:          -check-prefix=CHECK-OUTPUT-NAME < %t %s
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   -o bar/foo %s -g 2> %t
 // RUN: FileCheck -Doutfile=bar/foo -Ddsymfile=bar/foo.dSYM \
 // RUN:           -check-prefix=CHECK-OUTPUT-NAME < %t %s
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   -o bar/foo -dsym-dir external %s -g 2> %t
 // RUN: FileCheck -Doutfile=bar/foo -Ddsymfile=external/foo.dSYM \
 // RUN:           -check-prefix=CHECK-OUTPUT-NAME < %t %s
 //
-// CHECK-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::Linker", inputs: [{{.*}}], output: "[[outfile]]"
-// CHECK-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::Dsymutil", inputs: ["[[outfile]]"], output: "[[dsymfile]]"
+// CHECK-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::Linker", inputs: [{{.*}}], output: "[[outfile]]"
+// CHECK-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::Dsymutil", inputs: ["[[outfile]]"], output: "[[dsymfile]]"
 
 // Check output name derivation for multiple -arch options.
 //
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -arch x86_64 -arch arm64 -ccc-print-bindings %s 2> %t
 // RUN: FileCheck --check-prefix=CHECK-MULTIARCH-OUTPUT-NAME < %t %s
 //
-// CHECK-MULTIARCH-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::Linker", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out"
-// CHECK-MULTIARCH-OUTPUT-NAME: "arm64-apple-darwin10" - "darwin::Linker", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-arm64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"
-// CHECK-MULTIARCH-OUTPUT-NAME: "arm64-apple-darwin10" - "darwin::Lipo", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out", "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"], output: "a.out"
+// CHECK-MULTIARCH-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::Linker", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out"
+// CHECK-MULTIARCH-OUTPUT-NAME: "arm64-apple-darwin11" - "darwin::Linker", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-arm64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"
+// CHECK-MULTIARCH-OUTPUT-NAME: "arm64-apple-darwin11" - "darwin::Lipo", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out", "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"], output: "a.out"
 //
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -Wl,-foo -arch x86_64 -arch arm64 -ccc-print-bindings %s 2> %t
 // RUN: FileCheck --check-prefix=CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG < %t %s
 //
-// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "x86_64-apple-darwin10" - "darwin::Linker", inputs: [(input arg), "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out"
-// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "arm64-apple-darwin10" - "darwin::Linker", inputs: [(input arg), "{{.*}}{{/|\\}}darwin-dsymutil-arm64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"
-// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "arm64-apple-darwin10" - "darwin::Lipo", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out", "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"], output: "a.out"
+// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "x86_64-apple-darwin11" - "darwin::Linker", inputs: [(input arg), "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out"
+// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "arm64-apple-darwin11" - "darwin::Linker", inputs: [(input arg), "{{.*}}{{/|\\}}darwin-dsymutil-arm64.o"], output: "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"
+// CHECK-MULTIARCH-OUTPUT-NAME-WITH-ARG: "arm64-apple-darwin11" - "darwin::Lipo", inputs: ["{{.*}}{{/|\\}}darwin-dsymutil-x86_64.out", "{{.*}}{{/|\\}}darwin-dsymutil-arm64.out"], output: "a.out"
 
 // Check that we only use dsymutil when needed.
 //
 // RUN: touch %t.o
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   -o foo %t.o -g 2> %t
 // RUN: not grep "Dsymutil" %t
 
 // Check that we don't crash when translating arguments for dsymutil.
-// RUN: %clang -m32 -target x86_64-apple-darwin10 -arch x86_64 -g %s -###
+// RUN: %clang -m32 -target x86_64-apple-darwin11 -arch x86_64 -g %s -###
diff --git a/clang/test/Driver/darwin-iphone-defaults.m b/clang/test/Driver/darwin-iphone-defaults.m
--- a/clang/test/Driver/darwin-iphone-defaults.m
+++ b/clang/test/Driver/darwin-iphone-defaults.m
@@ -1,4 +1,4 @@
-// RUN: %clang -target i386-apple-darwin9 -miphoneos-version-min=3.0 -arch armv7 -stdlib=platform -flto -S -o - %s | FileCheck %s
+// RUN: %clang -target i386-apple-darwin -miphoneos-version-min=5.0 -arch armv7 -stdlib=platform -flto -S -o - %s | FileCheck %s
 
 // CHECK: @f0() [[F0:#[0-9]+]]
 // CHECK: @__f0_block_invoke
diff --git a/clang/test/Driver/darwin-stdlib.cpp b/clang/test/Driver/darwin-stdlib.cpp
--- a/clang/test/Driver/darwin-stdlib.cpp
+++ b/clang/test/Driver/darwin-stdlib.cpp
@@ -1,14 +1,10 @@
-// This test will fail if CLANG_DEFAULT_CXX_STDLIB is set to anything different
-// than the platform default. (see https://llvm.org/bugs/show_bug.cgi?id=30548)
-// XFAIL: default-cxx-stdlib-set
+// This test will fail if CLANG_DEFAULT_CXX_STDLIB is set to libstdc++.
+// XFAIL: default-cxx-stdlib=libstdc++
 
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBCXX
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.8 -Wno-stdlibcxx-not-found %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBSTDCXX
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBCXX
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=6.1 -Wno-stdlibcxx-not-found %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBSTDCXX
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBCXX
-// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LIBCXX
+// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
+// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 %s -### 2>&1 | FileCheck %s
+// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
+// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k %s -### 2>&1 | FileCheck %s
 
-// CHECK-LIBCXX: "-stdlib=libc++"
-// CHECK-LIBSTDCXX-NOT: -stdlib=libc++
-// CHECK-LIBSTDCXX-NOT: -stdlib=libstdc++
+// CHECK: "-stdlib=libc++"
+// CHECK-NOT: "-stdlib=libstdc++"
diff --git a/clang/test/Driver/darwin-verify-debug.c b/clang/test/Driver/darwin-verify-debug.c
--- a/clang/test/Driver/darwin-verify-debug.c
+++ b/clang/test/Driver/darwin-verify-debug.c
@@ -1,6 +1,6 @@
 // Check that we verify debug output properly with multiple -arch options.
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-phases \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-phases \
 // RUN:   --verify-debug-info -arch i386 -arch x86_64 %s -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-MULTIARCH-ACTIONS < %t %s
 //
@@ -8,26 +8,26 @@
 // CHECK-MULTIARCH-ACTIONS: 9: dsymutil, {8}, dSYM
 // CHECK-MULTIARCH-ACTIONS: 10: verify-debug-info, {9}, none
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   --verify-debug-info -arch i386 -arch x86_64 %s -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-MULTIARCH-BINDINGS < %t %s
 //
-// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin10" - "darwin::Dsymutil", inputs: ["a.out"], output: "a.out.dSYM"
-// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin10" - "darwin::VerifyDebug", inputs: ["a.out.dSYM"], output: (nothing)
+// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin11" - "darwin::Dsymutil", inputs: ["a.out"], output: "a.out.dSYM"
+// CHECK-MULTIARCH-BINDINGS: # "x86_64-apple-darwin11" - "darwin::VerifyDebug", inputs: ["a.out.dSYM"], output: (nothing)
 
 // Check output name derivation.
 //
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   --verify-debug-info -o foo %s -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-OUTPUT-NAME < %t %s
 //
-// CHECK-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::Linker", inputs: [{{.*}}], output: "foo"
-// CHECK-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::Dsymutil", inputs: ["foo"], output: "foo.dSYM"
-// CHECK-OUTPUT-NAME: "x86_64-apple-darwin10" - "darwin::VerifyDebug", inputs: ["foo.dSYM"], output: (nothing)
+// CHECK-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::Linker", inputs: [{{.*}}], output: "foo"
+// CHECK-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::Dsymutil", inputs: ["foo"], output: "foo.dSYM"
+// CHECK-OUTPUT-NAME: "x86_64-apple-darwin11" - "darwin::VerifyDebug", inputs: ["foo.dSYM"], output: (nothing)
 
 // Check that we only verify when needed.
 //
 // RUN: touch %t.o
-// RUN: %clang -target x86_64-apple-darwin10 -ccc-print-bindings \
+// RUN: %clang -target x86_64-apple-darwin11 -ccc-print-bindings \
 // RUN:   --verify-debug-info -o foo %t.o -g 2> %t
 // RUN: not grep "Verify" %t
diff --git a/clang/test/Driver/diagnostics.c b/clang/test/Driver/diagnostics.c
--- a/clang/test/Driver/diagnostics.c
+++ b/clang/test/Driver/diagnostics.c
@@ -6,37 +6,37 @@
 // diagnostics when only compiling for all targets.
 
 // This is normally a non-fatal warning:
-// RUN: %clang --target=x86_64-apple-darwin10 \
+// RUN: %clang --target=x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -lfoo %s 2>&1 | FileCheck %s
 
 // Either with a specific -Werror=unused.. or a blanket -Werror, this
 // causes the command to fail.
-// RUN: not %clang --target=x86_64-apple-darwin10 \
+// RUN: not %clang --target=x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -lfoo \
 // RUN:   -Werror=unused-command-line-argument %s 2>&1 | FileCheck %s
 
-// RUN: not %clang --target=x86_64-apple-darwin10 \
+// RUN: not %clang --target=x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -lfoo -Werror %s 2>&1 | FileCheck %s
 
 // With a specific -Wno-..., no diagnostic should be printed.
-// RUN: %clang --target=x86_64-apple-darwin10 \
+// RUN: %clang --target=x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -lfoo -Werror \
 // RUN:   -Wno-unused-command-line-argument %s 2>&1 | count 0
 
 // With -Qunused-arguments, no diagnostic should be printed.
-// RUN: %clang --target=x86_64-apple-darwin10 \
+// RUN: %clang --target=x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -lfoo -Werror \
 // RUN:   -Qunused-arguments %s 2>&1 | count 0
 
 // With the argument enclosed in --{start,end}-no-unused-arguments,
 // there's no diagnostic.
-// RUN: %clang --target=x86_64-apple-darwin10 -fsyntax-only \
+// RUN: %clang --target=x86_64-apple-darwin11 -fsyntax-only \
 // RUN:   --start-no-unused-arguments -lfoo --end-no-unused-arguments \
 // RUN:   -Werror %s 2>&1 | count 0
 
 // With --{start,end}-no-unused-argument around a different argument, it
 // still warns about the unused argument.
-// RUN: not %clang --target=x86_64-apple-darwin10 \
+// RUN: not %clang --target=x86_64-apple-darwin11 \
 // RUN:   --start-no-unused-arguments -fsyntax-only --end-no-unused-arguments \
 // RUN:   -lfoo -Werror %s 2>&1 | FileCheck %s
 
diff --git a/clang/test/Driver/exceptions.m b/clang/test/Driver/exceptions.m
--- a/clang/test/Driver/exceptions.m
+++ b/clang/test/Driver/exceptions.m
@@ -1,4 +1,4 @@
-// RUN: %clang -target x86_64-apple-darwin9 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -fsyntax-only -fno-exceptions %s
 
 void f1(void) {
diff --git a/clang/test/Driver/redundant-args.c b/clang/test/Driver/redundant-args.c
--- a/clang/test/Driver/redundant-args.c
+++ b/clang/test/Driver/redundant-args.c
@@ -1,2 +1,2 @@
-// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN: %clang -target x86_64-apple-darwin11 \
 // RUN:   -Werror -x c -x c -fsyntax-only %s
diff --git a/clang/test/Headers/float-darwin.c b/clang/test/Headers/float-darwin.c
--- a/clang/test/Headers/float-darwin.c
+++ b/clang/test/Headers/float-darwin.c
@@ -1,5 +1,5 @@
 // REQUIRES: system-darwin
-// RUN: %clang -target x86_64-apple-darwin10 -fsyntax-only -std=c11 -isysroot %S/Inputs %s
+// RUN: %clang -target x86_64-apple-darwin11 -fsyntax-only -std=c11 -isysroot %S/Inputs %s
 #include <float.h>
 
 // Test the #include_next on float.h works on Darwin.
diff --git a/clang/test/Headers/tgmath-darwin.c b/clang/test/Headers/tgmath-darwin.c
--- a/clang/test/Headers/tgmath-darwin.c
+++ b/clang/test/Headers/tgmath-darwin.c
@@ -1,5 +1,5 @@
 // REQUIRES: system-darwin
-// RUN: %clang -target x86_64-apple-darwin10 -fsyntax-only -std=c11 -isysroot %S/Inputs %s
+// RUN: %clang -target x86_64-apple-darwin11 -fsyntax-only -std=c11 -isysroot %S/Inputs %s
 #include <tgmath.h>
 
 // Test the #include_next of tgmath.h works on Darwin.
diff --git a/clang/test/PCH/reloc.c b/clang/test/PCH/reloc.c
--- a/clang/test/PCH/reloc.c
+++ b/clang/test/PCH/reloc.c
@@ -1,8 +1,8 @@
-// RUN: %clang -target x86_64-apple-darwin10 --relocatable-pch -o %t \
+// RUN: %clang -target x86_64-apple-darwin11 --relocatable-pch -o %t \
 // RUN:   -isysroot %S/Inputs/libroot %S/Inputs/libroot/usr/include/reloc.h
-// RUN: %clang -target x86_64-apple-darwin10 -fsyntax-only \
+// RUN: %clang -target x86_64-apple-darwin11 -fsyntax-only \
 // RUN:   -include-pch %t -isysroot %S/Inputs/libroot %s -Xclang -verify
-// RUN: not %clang -target x86_64-apple-darwin10 -include-pch %t %s
+// RUN: not %clang -target x86_64-apple-darwin11 -include-pch %t %s
 // REQUIRES: x86-registered-target
 
 #include <reloc.h>
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -134,7 +134,7 @@
 # Set available features we allow tests to conditionalize on.
 #
 if config.clang_default_cxx_stdlib != '':
-    config.available_features.add('default-cxx-stdlib-set')
+    config.available_features.add('default-cxx-stdlib={}'.format(config.clang_default_cxx_stdlib))
 
 # As of 2011.08, crash-recovery tests still do not pass on FreeBSD.
 if platform.system() not in ['FreeBSD']: