[IRGen] Stop forcing Objective-C class references to be file-local.

Now that we're never relatively addressing an Objective-C class reference,
stop emitting them as file-local (by eliminating the \01l_ prefix). This
is both a minor optimization and also a way to ensure that things will
break more consistently if a problem remains.

Author: DougGregor

lib/IRGen/Linking.cpp

@@ -265,7 +265,7 @@ std::string LinkEntity::mangleAsString() const {
   case Kind::ObjCClassRef: {
     llvm::SmallString<64> tempBuffer;
     StringRef name = cast<ClassDecl>(getDecl())->getObjCRuntimeName(tempBuffer);
-    std::string Result("\01l_OBJC_CLASS_REF_$_");
+    std::string Result("OBJC_CLASS_REF_$_");
     Result.append(name.data(), name.size());
     return Result;
   }

test/ClangImporter/attr-swift_private.swift

@@ -92,7 +92,7 @@ public func testTopLevel() {
 }
 
 // CHECK-LABEL: define linkonce_odr hidden swiftcc %swift.metadata_response @"$sSo10PrivFooSubCMa{{.*}} {
-// CHECK: %objc_class** @"\01l_OBJC_CLASS_REF_$_PrivFooSub"
+// CHECK: %objc_class** @"OBJC_CLASS_REF_$_PrivFooSub"
 // CHECK: }
 
 // CHECK-LABEL: define linkonce_odr hidden {{.+}} @"$sSo3BarC8__noArgsABSgyt_tcfcTO"

test/ClangImporter/objc_ir.swift

@@ -74,15 +74,15 @@ func propertyAccess(b b: B) {
    // CHECK: load i8*, i8** @"\01L_selector(setCounter:)"
    b.counter = b.counter + 1
 
-   // CHECK: load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_B"
+   // CHECK: load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_B"
    // CHECK: load i8*, i8** @"\01L_selector(sharedCounter)"
    // CHECK: load i8*, i8** @"\01L_selector(setSharedCounter:)"
    B.sharedCounter = B.sharedCounter + 1
 }
 
 // CHECK-LABEL: define hidden swiftcc %TSo1BC* @"$s7objc_ir8downcast1aSo1BCSo1AC_tF"(
 func downcast(a a: A) -> B {
-  // CHECK: [[CLASS:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_B"
+  // CHECK: [[CLASS:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_B"
   // CHECK: [[T0:%.*]] = call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[CLASS]])
   // CHECK: [[T1:%.*]] = bitcast %objc_class* [[T0]] to i8*
   // CHECK: call i8* @swift_dynamicCastObjCClassUnconditional(i8* [[A:%.*]], i8* [[T1]]) [[NOUNWIND:#[0-9]+]]

test/IRGen/objc_casts.sil

@@ -33,7 +33,7 @@ bb0(%unused : $@thick T.Type, %obj : $NSObject):
 // CHECK:       [[T0:%.*]] = call %objc_object* @swift_dynamicCastMetatypeToObjectUnconditional(%swift.type* %0)
 //   TODO: is this really necessary? also, this really shouldn't use a direct reference
 // CHECK-NEXT:  [[T1:%.*]] = bitcast %objc_object* [[T0]] to i8*
-// CHECK-NEXT:  [[T2a:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_Foo"
+// CHECK-NEXT:  [[T2a:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_Foo"
 // CHECK-NEXT:  [[T2:%.*]] = call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[T2a]])
 // CHECK-NEXT:  [[T3:%.*]] = bitcast %objc_class* [[T2]] to i8*
 // CHECK-NEXT:  call i8* @swift_dynamicCastObjCClassUnconditional(i8* [[T1]], i8* [[T3]])
@@ -49,7 +49,7 @@ bb0(%metatype : $@thick T.Type):
 // CHECK:       [[T0:%.*]] = call %objc_object* @swift_dynamicCastMetatypeToObjectUnconditional(%swift.type* [[ARG]])
 //   TODO: is this really necessary? also, this really shouldn't use a direct reference
 // CHECK-NEXT:  [[T1:%.*]] = bitcast %objc_object* [[T0]] to i8*
-// CHECK-NEXT:  [[T2a:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_Foo"
+// CHECK-NEXT:  [[T2a:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_Foo"
 // CHECK-NEXT:  [[T2:%.*]] = call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[T2a]])
 // CHECK-NEXT:  [[T3:%.*]] = bitcast %objc_class* [[T2]] to i8*
 // CHECK-NEXT:  call i8* @swift_dynamicCastObjCClassUnconditional(i8* [[T1]], i8* [[T3]])

test/IRGen/objc_generic_class_metadata.sil

@@ -39,7 +39,7 @@ entry:
   %b = metatype $@thick GenericClass<NSObject>.Type
   apply %z<GenericClass<NSObject>>(%b) : $@convention(thin) <T> (@thick T.Type) -> ()
 
-  // CHECK: [[T0:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_GenericClass",
+  // CHECK: [[T0:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_GenericClass",
   // CHECK: [[OBJC_CLASS:%.*]] = call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[T0]])
   // CHECK: call swiftcc void @objc_class_sink(%objc_class* [[OBJC_CLASS]], %swift.type* [[METADATA]])
   %c = metatype $@objc_metatype GenericClass<NSString>.Type
@@ -79,7 +79,7 @@ entry(%0: @owned $Subclass, %1: @owned $NSDictionary):
 }
 
 // CHECK-LABEL: define linkonce_odr hidden swiftcc %swift.metadata_response @"$sSo12GenericClassCMa"(
-// CHECK:         [[T0:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_GenericClass",
+// CHECK:         [[T0:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_GenericClass",
 // CHECK:         call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[T0]])
 
 // CHECK-LABEL: define linkonce_odr hidden swiftcc %swift.metadata_response @"$sSaySo12GenericClassC_SitGMa"

test/IRGen/objc_properties_jit.swift

@@ -14,7 +14,7 @@ extension NSString {
 }
 
 // CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} private void @runtime_registration
-// CHECK:         [[NSOBJECT_UNINIT:%.*]] = load %objc_class*, %objc_class** @"\01l_OBJC_CLASS_REF_$_NSString"
+// CHECK:         [[NSOBJECT_UNINIT:%.*]] = load %objc_class*, %objc_class** @"OBJC_CLASS_REF_$_NSString"
 // CHECK:         [[NSOBJECT:%.*]] = call %objc_class* @swift_getInitializedObjCClass(%objc_class* [[NSOBJECT_UNINIT]])
 // CHECK:         [[GET_CLASS_PROP:%.*]] = call i8* @sel_registerName({{.*}}(classProp)
 // CHECK:         call i8* @class_replaceMethod(%objc_class* @"OBJC_METACLASS_$_NSString", i8* [[GET_CLASS_PROP]]