diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index a4fbf064f03..c1569c0984b 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -1112,7 +1112,7 @@ static llvm::Constant *constStructWithPadding(CodeGenModule &CGM,
   }
   if (NestedIntact && Values.size() == STy->getNumElements())
     return constant;
-  return llvm::ConstantStruct::getAnon(Values);
+  return llvm::ConstantStruct::getAnon(Values, STy->isPacked());
 }
 
 /// Replace all padding bytes in a given constant with either a pattern byte or
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 143bd3a2eb6..86bb73562d4 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -6812,7 +6812,7 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocolRef(
     // reference or not. At module finalization we add the empty
     // contents for protocols which were referenced but never defined.
     llvm::SmallString<64> Protocol;
-    llvm::raw_svector_ostream(Protocol) << "\01l_OBJC_PROTOCOL_$_"
+    llvm::raw_svector_ostream(Protocol) << "_OBJC_PROTOCOL_$_"
                                         << PD->getObjCRuntimeNameAsString();
 
     Entry = new llvm::GlobalVariable(CGM.getModule(), ObjCTypes.ProtocolnfABITy,
@@ -6903,7 +6903,7 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocol(
   } else {
     llvm::SmallString<64> symbolName;
     llvm::raw_svector_ostream(symbolName)
-      << "\01l_OBJC_PROTOCOL_$_" << PD->getObjCRuntimeNameAsString();
+      << "_OBJC_PROTOCOL_$_" << PD->getObjCRuntimeNameAsString();
 
     Entry = values.finishAndCreateGlobal(symbolName, CGM.getPointerAlign(),
                                          /*constant*/ false,
@@ -6919,7 +6919,7 @@ llvm::Constant *CGObjCNonFragileABIMac::GetOrEmitProtocol(
   // Use this protocol meta-data to build protocol list table in section
   // __DATA, __objc_protolist
   llvm::SmallString<64> ProtocolRef;
-  llvm::raw_svector_ostream(ProtocolRef) << "\01l_OBJC_LABEL_PROTOCOL_$_"
+  llvm::raw_svector_ostream(ProtocolRef) << "_OBJC_LABEL_PROTOCOL_$_"
                                          << PD->getObjCRuntimeNameAsString();
 
   llvm::GlobalVariable *PTGV =
diff --git a/test/CodeGenCXX/auto-var-init.cpp b/test/CodeGenCXX/auto-var-init.cpp
index 04f147cf8c8..b670d9196f4 100644
--- a/test/CodeGenCXX/auto-var-init.cpp
+++ b/test/CodeGenCXX/auto-var-init.cpp
@@ -85,6 +85,8 @@ struct paddedpacked { char c; int i; } __attribute__((packed));
 // PATTERN: @__const.test_paddedpackedarray_custom.custom = private unnamed_addr constant %struct.paddedpackedarray { [2 x %struct.paddedpacked] [%struct.paddedpacked <{ i8 42, i32 13371337 }>, %struct.paddedpacked <{ i8 43, i32 13371338 }>] }, align 1
 // ZERO: @__const.test_paddedpackedarray_custom.custom = private unnamed_addr constant %struct.paddedpackedarray { [2 x %struct.paddedpacked] [%struct.paddedpacked <{ i8 42, i32 13371337 }>, %struct.paddedpacked <{ i8 43, i32 13371338 }>] }, align 1
 struct paddedpackedarray { struct paddedpacked p[2]; };
+// PATTERN-O0: @__const.test_unpackedinpacked_uninit.uninit = private unnamed_addr constant <{ { i8, [3 x i8], i32 }, i8 }> <{ { i8, [3 x i8], i32 } { i8 -86, [3 x i8] c"\AA\AA\AA", i32 -1431655766 }, i8 -86 }>, align 1
+struct unpackedinpacked { padded a; char b; } __attribute__((packed));
 // PATTERN-O0: @__const.test_paddednested_uninit.uninit = private unnamed_addr constant { { i8, [3 x i8], i32 }, { i8, [3 x i8], i32 } } { { i8, [3 x i8], i32 } { i8 -86, [3 x i8] c"\AA\AA\AA", i32 -1431655766 }, { i8, [3 x i8], i32 } { i8 -86, [3 x i8] c"\AA\AA\AA", i32 -1431655766 } }, align 4
 // PATTERN: @__const.test_paddednested_custom.custom = private unnamed_addr constant { { i8, [3 x i8], i32 }, { i8, [3 x i8], i32 } } { { i8, [3 x i8], i32 } { i8 42, [3 x i8] c"\AA\AA\AA", i32 13371337 }, { i8, [3 x i8], i32 } { i8 43, [3 x i8] c"\AA\AA\AA", i32 13371338 } }, align 4
 // ZERO: @__const.test_paddednested_custom.custom = private unnamed_addr constant { { i8, [3 x i8], i32 }, { i8, [3 x i8], i32 } } { { i8, [3 x i8], i32 } { i8 42, [3 x i8] zeroinitializer, i32 13371337 }, { i8, [3 x i8], i32 } { i8 43, [3 x i8] zeroinitializer, i32 13371338 } }, align 4
@@ -779,6 +781,10 @@ TEST_CUSTOM(paddedpackedarray, paddedpackedarray, { {{ 42, 13371337 }, { 43, 133
 // CHECK-NEXT:  call void @llvm.memcpy{{.*}}({{.*}}@__const.test_paddedpackedarray_custom.custom
 // CHECK-NEXT:  call void @{{.*}}used{{.*}}%custom)
 
+TEST_UNINIT(unpackedinpacked, unpackedinpacked);
+// CHECK-LABEL: @test_unpackedinpacked_uninit()
+// PATTERN-O0:  call void @llvm.memcpy{{.*}}, i64 9, i1 false)
+
 TEST_UNINIT(paddednested, paddednested);
 // CHECK-LABEL: @test_paddednested_uninit()
 // CHECK:       %uninit = alloca %struct.paddednested, align
diff --git a/test/CodeGenObjC/forward-protocol-metadata-symbols.m b/test/CodeGenObjC/forward-protocol-metadata-symbols.m
index 16d33ec15d8..42b4537a01b 100644
--- a/test/CodeGenObjC/forward-protocol-metadata-symbols.m
+++ b/test/CodeGenObjC/forward-protocol-metadata-symbols.m
@@ -18,14 +18,15 @@ int main() {
   return 0;
 }
 
-// CHECK: @"\01l_OBJC_PROTOCOL_$_P0" = weak hidden global
+// CHECK: @"_OBJC_PROTOCOL_$_P0" = weak hidden global
+// CHECK: @"_OBJC_LABEL_PROTOCOL_$_P0" = weak hidden global
 // CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global
 // CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P0" = weak hidden global
 // CHECK: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P0" = weak hidden global
 
 // CHECK: llvm.used = appending global [3 x i8*]
-// CHECK-SAME: "\01l_OBJC_PROTOCOL_$_P0"
-// CHECK-SAME: "\01l_OBJC_LABEL_PROTOCOL_$_P0"
+// CHECK-SAME: "_OBJC_PROTOCOL_$_P0"
+// CHECK-SAME: "_OBJC_LABEL_PROTOCOL_$_P0"
 // CHECK-SAME: "\01l_OBJC_PROTOCOL_REFERENCE_$_P0"
 
 // CHECK: llvm.compiler.used = appending global [7 x i8*]
diff --git a/test/CodeGenObjC/hidden-visibility.m b/test/CodeGenObjC/hidden-visibility.m
index cb23ca18f81..7e56e7ae11d 100644
--- a/test/CodeGenObjC/hidden-visibility.m
+++ b/test/CodeGenObjC/hidden-visibility.m
@@ -2,7 +2,7 @@
 // CHECK: @"OBJC_IVAR_$_I.P" = hidden
 // CHECK: @"OBJC_CLASS_$_I" = hidden
 // CHECK: @"OBJC_METACLASS_$_I" = hidden
-// CHECK: @"\01l_OBJC_PROTOCOL_$_Prot0" = weak hidden
+// CHECK: @"_OBJC_PROTOCOL_$_Prot0" = weak hidden
 
 @interface I {
   int P;
diff --git a/test/CodeGenObjC/metadata-class-properties.m b/test/CodeGenObjC/metadata-class-properties.m
index 58841bc1230..09609bb8fd6 100644
--- a/test/CodeGenObjC/metadata-class-properties.m
+++ b/test/CodeGenObjC/metadata-class-properties.m
@@ -3,7 +3,7 @@
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.11  -emit-llvm -o - -fobjc-runtime=macosx-fragile-10.5 %s | FileCheck -check-prefix=CHECK-FRAGILE %s
 
 // CHECK: @"\01l_OBJC_$_CLASS_PROP_LIST_Proto" = private global {{.*}} section "__DATA, __objc_const", align 8
-// CHECK: @"\01l_OBJC_PROTOCOL_$_Proto" = {{.*}} global %struct._protocol_t { {{.*}} i32 96, i32 {{.*}} @"\01l_OBJC_$_CLASS_PROP_LIST_Proto" {{.*}} }
+// CHECK: @"_OBJC_PROTOCOL_$_Proto" = {{.*}} global %struct._protocol_t { {{.*}} i32 96, i32 {{.*}} @"\01l_OBJC_$_CLASS_PROP_LIST_Proto" {{.*}} }
 // CHECK: @"\01l_OBJC_$_CLASS_PROP_LIST_Foo_$_Category" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_CATEGORY_Foo_$_Category" = private global %struct._category_t { {{.*}} @"\01l_OBJC_$_CLASS_PROP_LIST_Foo_$_Category" {{.*}}, i32 64 }, section "__DATA, __objc_const", align 8
 
@@ -13,7 +13,7 @@
 // CHECK: !{i32 1, !"Objective-C Class Properties", i32 64}
 
 // CHECK-NULL-NOT: @"\01l_OBJC_$_CLASS_PROP_LIST_Proto"
-// CHECK-NULL: @"\01l_OBJC_PROTOCOL_$_Proto" = {{.*}} global %struct._protocol_t { {{.*}} %struct._prop_list_t* null, i32 96, i32 {{.*}} %struct._prop_list_t* null }
+// CHECK-NULL: @"_OBJC_PROTOCOL_$_Proto" = {{.*}} global %struct._protocol_t { {{.*}} %struct._prop_list_t* null, i32 96, i32 {{.*}} %struct._prop_list_t* null }
 // CHECK-NULL-NOT: @"\01l_OBJC_$_CLASS_PROP_LIST_Foo_$_Category" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK-NULL: @"\01l_OBJC_$_CATEGORY_Foo_$_Category" = private global %struct._category_t { {{.*}} %struct._prop_list_t* null, %struct._prop_list_t* null, {{.*}} }, section "__DATA, __objc_const", align 8
 
diff --git a/test/CodeGenObjC/metadata-symbols-64.m b/test/CodeGenObjC/metadata-symbols-64.m
index b94f1b63843..b634cd980b9 100644
--- a/test/CodeGenObjC/metadata-symbols-64.m
+++ b/test/CodeGenObjC/metadata-symbols-64.m
@@ -11,8 +11,8 @@
 // CHECK: @"\01l_OBJC_$_CLASS_METHODS_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_PROTOCOL_INSTANCE_METHODS_P" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_PROTOCOL_CLASS_METHODS_P" = private global {{.*}} section "__DATA, __objc_const", align 8
-// CHECK: @"\01l_OBJC_PROTOCOL_$_P" = weak hidden global {{.*}}, align 8
-// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = weak hidden global {{.*}} section "__DATA,__objc_protolist,coalesced,no_dead_strip", align 8
+// CHECK: @"_OBJC_PROTOCOL_$_P" = weak hidden global {{.*}}, align 8
+// CHECK: @"_OBJC_LABEL_PROTOCOL_$_P" = weak hidden global {{.*}} section "__DATA,__objc_protolist,coalesced,no_dead_strip", align 8
 // CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_METACLASS_RO_$_A" = private global {{.*}} section "__DATA, __objc_const", align 8
 // CHECK: @"\01l_OBJC_$_INSTANCE_METHODS_A" = private global {{.*}} section "__DATA, __objc_const", align 8
diff --git a/test/CodeGenObjC/protocol-comdat.m b/test/CodeGenObjC/protocol-comdat.m
index a19ba8cf35d..f035fa3f3ae 100644
--- a/test/CodeGenObjC/protocol-comdat.m
+++ b/test/CodeGenObjC/protocol-comdat.m
@@ -18,11 +18,11 @@ _Bool f(void) {
   return @protocol(Q) == @protocol(R);
 }
 
-// CHECK: $"\01l_OBJC_PROTOCOL_$_P" = comdat any
-// CHECK: $"\01l_OBJC_LABEL_PROTOCOL_$_P" = comdat any
+// CHECK: $"_OBJC_PROTOCOL_$_P" = comdat any
+// CHECK: $"_OBJC_LABEL_PROTOCOL_$_P" = comdat any
 // CHECK: $"\01l_OBJC_PROTOCOL_REFERENCE_$_Q" = comdat any
 // CHECK: $"\01l_OBJC_PROTOCOL_REFERENCE_$_R" = comdat any
 
-// CHECK: @"\01l_OBJC_PROTOCOL_$_P" = {{.*}}, comdat
-// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, comdat
+// CHECK: @"_OBJC_PROTOCOL_$_P" = {{.*}}, comdat
+// CHECK: @"_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, comdat
 
diff --git a/test/CodeGenObjC/protocol-in-extended-class.m b/test/CodeGenObjC/protocol-in-extended-class.m
index 49b290133af..26c858e53e8 100644
--- a/test/CodeGenObjC/protocol-in-extended-class.m
+++ b/test/CodeGenObjC/protocol-in-extended-class.m
@@ -24,6 +24,6 @@ -(void) Meth {
  }
 @end
 
-// CHECK-LP64: l_OBJC_PROTOCOL_$_ExtendedProtocol:
+// CHECK-LP64: __OBJC_PROTOCOL_$_ExtendedProtocol:
 
 // CHECK-LP32: L_OBJC_PROTOCOL_ExtendedProtocol:
diff --git a/test/CodeGenObjC/protocols.m b/test/CodeGenObjC/protocols.m
index 6dadb11273d..82244ad7d2a 100644
--- a/test/CodeGenObjC/protocols.m
+++ b/test/CodeGenObjC/protocols.m
@@ -1,4 +1,19 @@
-// RUN: %clang_cc1 -emit-llvm-only %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s | FileCheck %s
+
+// HECK: @[[PROTO_P1:"_OBJC_PROTOCOL_$_P1"]] = weak hidden
+// CHECK: @[[PROTO_P1:"_OBJC_PROTOCOL_\$_P1"]] = weak hidden
+// CHECK: @[[LABEL_PROTO_P1:"_OBJC_LABEL_PROTOCOL_\$_P1"]] = weak hidden global %{{.*}}* @[[PROTO_P1]]
+// CHECK: @[[PROTO_P2:"_OBJC_PROTOCOL_\$_P2"]] = weak hidden
+// CHECK: @[[LABEL_PROTO_P2:"_OBJC_LABEL_PROTOCOL_\$_P2"]] = weak hidden global %{{.*}}* @[[PROTO_P2]]
+// CHECK: @"\01l_OBJC_$_PROTOCOL_REFS_P3" = private global { i64, [3 x %{{.*}}] } { i64 2, [3 x %{{.*}}*] [%{{.*}}* @[[PROTO_P1]], %{{.*}}* @[[PROTO_P2]], %{{.*}}* null] }
+// CHECK: @[[PROTO_P3:"_OBJC_PROTOCOL_\$_P3"]] = weak hidden
+// CHECK: @[[LABEL_PROTO_P3:"_OBJC_LABEL_PROTOCOL_\$_P3"]] = weak hidden global %{{.*}}* @[[PROTO_P3]]
+// CHECK: "\01l_OBJC_PROTOCOL_REFERENCE_$_P3" = weak hidden global %{{.*}}* bitcast (%{{.*}}* @[[PROTO_P3]] to %{{.*}}*)
+// CHECK: @[[PROTO_P0:"_OBJC_PROTOCOL_\$_P0"]] = weak hidden
+// CHECK: @[[LABEL_PROTO_P0:"_OBJC_LABEL_PROTOCOL_\$_P0"]] = weak hidden global %{{.*}}* @[[PROTO_P0]]
+// CHECK: "\01l_OBJC_PROTOCOL_REFERENCE_$_P0" = weak hidden global %0* bitcast (%{{.*}}* @[[PROTO_P0]] to %{{.*}}*)
+// CHECK: "\01l_OBJC_PROTOCOL_REFERENCE_$_P1" = weak hidden global %0* bitcast (%{{.*}}* @[[PROTO_P1]] to %{{.*}}*)
+// CHECK: "\01l_OBJC_PROTOCOL_REFERENCE_$_P2" = weak hidden global %0* bitcast (%{{.*}}* @[[PROTO_P2]] to %{{.*}}*)
 
 void p(const char*, ...);
 
diff --git a/test/CodeGenObjC/sections.m b/test/CodeGenObjC/sections.m
index f98b7db073c..b6f7b8eb438 100644
--- a/test/CodeGenObjC/sections.m
+++ b/test/CodeGenObjC/sections.m
@@ -38,7 +38,7 @@ _Bool f(J *j) {
 // CHECK-COFF: @OBJC_SELECTOR_REFERENCES_ = {{.*}}, section ".objc_selrefs$B"
 // CHECK-COFF: @"OBJC_CLASSLIST_REFERENCES_$_" = {{.*}}, section ".objc_classrefs$B"
 // CHECK-COFF: @"\01l_objc_msgSend_fixup_class" = {{.*}}, section ".objc_msgrefs$B"
-// CHECK-COFF: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section ".objc_protolist$B"
+// CHECK-COFF: @"_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section ".objc_protolist$B"
 // CHECK-COFF: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P" = {{.*}}, section ".objc_protorefs$B"
 // CHECK-COFF: @"OBJC_LABEL_CLASS_$" = {{.*}}, section ".objc_classlist$B"
 // CHECK-COFF: @"OBJC_LABEL_NONLAZY_CLASS_$" = {{.*}}, section ".objc_nlclslist$B"
@@ -50,7 +50,7 @@ _Bool f(J *j) {
 // CHECK-ELF: @OBJC_SELECTOR_REFERENCES_ = {{.*}}, section "objc_selrefs"
 // CHECK-ELF: @"OBJC_CLASSLIST_REFERENCES_$_" = {{.*}}, section "objc_classrefs"
 // CHECK-ELF: @"\01l_objc_msgSend_fixup_class" = {{.*}}, section "objc_msgrefs"
-// CHECK-ELF: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section "objc_protolist"
+// CHECK-ELF: @"_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section "objc_protolist"
 // CHECK-ELF: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P" = {{.*}}, section "objc_protorefs"
 // CHECK-ELF: @"OBJC_LABEL_CLASS_$" = {{.*}}, section "objc_classlist"
 // CHECK-ELF: @"OBJC_LABEL_NONLAZY_CLASS_$" = {{.*}}, section "objc_nlclslist"
@@ -62,7 +62,7 @@ _Bool f(J *j) {
 // CHECK-MACHO: @OBJC_SELECTOR_REFERENCES_ = {{.*}}, section "__DATA,__objc_selrefs,literal_pointers,no_dead_strip"
 // CHECK-MACHO: @"OBJC_CLASSLIST_REFERENCES_$_" = {{.*}}, section "__DATA,__objc_classrefs,regular,no_dead_strip"
 // CHECK-MACHO: @"\01l_objc_msgSend_fixup_class" = {{.*}}, section "__DATA,__objc_msgrefs,coalesced"
-// CHECK-MACHO: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section "__DATA,__objc_protolist,coalesced,no_dead_strip"
+// CHECK-MACHO: @"_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, section "__DATA,__objc_protolist,coalesced,no_dead_strip"
 // CHECK-MACHO: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P" = {{.*}}, section "__DATA,__objc_protorefs,coalesced,no_dead_strip"
 // CHECK-MACHO: @"OBJC_LABEL_CLASS_$" = {{.*}}, section "__DATA,__objc_classlist,regular,no_dead_strip"
 // CHECK-MACHO: @"OBJC_LABEL_NONLAZY_CLASS_$" = {{.*}}, section "__DATA,__objc_nlclslist,regular,no_dead_strip"
diff --git a/test/CodeGenObjC/undefined-protocol2.m b/test/CodeGenObjC/undefined-protocol2.m
index f171523b042..3115e406cfe 100644
--- a/test/CodeGenObjC/undefined-protocol2.m
+++ b/test/CodeGenObjC/undefined-protocol2.m
@@ -3,7 +3,7 @@
 // Test that we produce a declaration for the protocol. It must be matched
 // by a definition in another TU, so external is the correct linkage
 // (not extern_weak).
-// CHECK: @"\01l_OBJC_PROTOCOL_$_p1" = external global
+// CHECK: @"_OBJC_PROTOCOL_$_p1" = external global
 
 @interface NSObject
 @end
diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 020d7030aa2..df7de9b9063 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -39,3 +39,5 @@ add_clang_subdirectory(libclang)
 
 add_clang_subdirectory(clang-refactor-test)
 
+# Support building the TAPI project as Clang tool.
+add_llvm_external_project(tapi)