ObjC Class Property: don't emit class properties on old deployment targets.

For old deployment targets, emit nil for all class property lists.

rdar://25616128


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@266800 91177308-0d34-0410-b5e6-96231b3b80d8

Author: manman-ren

lib/CodeGen/CGObjCMac.cpp

@@ -2953,6 +2953,15 @@ llvm::Constant *CGObjCCommonMac::EmitPropertyList(Twine Name,
                                        const ObjCContainerDecl *OCD,
                                        const ObjCCommonTypesHelper &ObjCTypes,
                                        bool IsClassProperty) {
+  if (IsClassProperty) {
+    // Make this entry NULL for OS X with deployment target < 10.11, for iOS
+    // with deployment target < 9.0.
+    const llvm::Triple &Triple = CGM.getTarget().getTriple();
+    if ((Triple.isMacOSX() && Triple.isMacOSXVersionLT(10, 11)) ||
+        (Triple.isiOS() && Triple.isOSVersionLT(9)))
+      return llvm::Constant::getNullValue(ObjCTypes.PropertyListPtrTy);
+  }
+
   SmallVector<llvm::Constant *, 16> Properties;
   llvm::SmallPtrSet<const IdentifierInfo*, 16> PropertySet;
 

test/CodeGenObjC/metadata-class-properties.m

@@ -1,5 +1,6 @@
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10  -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10  -emit-llvm -o - -fobjc-runtime=macosx-fragile-10.5 %s | FileCheck -check-prefix=CHECK-FRAGILE %s
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.11  -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.10  -emit-llvm -o - %s | FileCheck -check-prefix=CHECK-NULL %s
+// 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" {{.*}} }
@@ -11,6 +12,16 @@
 
 // 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-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
+
+// CHECK-NULL-NOT: @"\01l_OBJC_$_CLASS_PROP_LIST_C" = private global {{.*}} section "__DATA, __objc_const", align 8
+// CHECK-NULL: @"\01l_OBJC_METACLASS_RO_$_C" = private global %struct._class_ro_t { {{.*}} %struct._prop_list_t* null }, section "__DATA, __objc_const", align 8
+
+// CHECK-NULL: !{i32 1, !"Objective-C Class Properties", i32 64}
+
 // CHECK-FRAGILE: @"OBJC_$_CLASS_PROP_PROTO_LIST_Proto" = private global {{.*}} section "__OBJC,__property,regular,no_dead_strip", align 8
 // CHECK-FRAGILE: @"\01l_OBJC_PROTOCOLEXT_Proto" = private global %struct._objc_protocol_extension { i32 48, {{.*}} @"OBJC_$_CLASS_PROP_PROTO_LIST_Proto" {{.*}} }, align 8
 // CHECK-FRAGILE: @"\01l_OBJC_$_CLASS_PROP_LIST_Foo_Category" = private global {{.*}} section "__OBJC,__property,regular,no_dead_strip", align 8