[Sema][ObjC] Infer availability of +new from availability of -init.

When defined in NSObject, +new will call -init. If -init has been marked
unavailable, diagnose uses of +new.

rdar://18335828

Differential revision: https://reviews.llvm.org/D51189

llvm-svn: 341874

1 files changed, 58 insertions, 0 deletions

diff --git a/clang/test/SemaObjC/infer-availability-from-init.m b/clang/test/SemaObjC/infer-availability-from-init.m
new file mode 100644
index 00000000000..f9996ec7087
--- /dev/null
+++ b/clang/test/SemaObjC/infer-availability-from-init.m
@@ -0,0 +1,58 @@
+// RUN: %clang_cc1 -triple x86_64-apple-macosx-10.9 -Wunguarded-availability -fblocks -fsyntax-only -verify %s
+
+__attribute__((objc_root_class))
+@interface NSObject
++(instancetype)new;
+-(instancetype)init;
+@end
+
+@interface MyObject : NSObject
+-(instancetype)init __attribute__((unavailable)); // expected-note{{'init' has been explicitly marked unavailable here}}
+@end
+
+void usemyobject() {
+  [MyObject new]; // expected-error{{'new' is unavailable}}
+}
+
+@interface MyOtherObject : NSObject
++(instancetype)init __attribute__((unavailable));
++(instancetype)new;
+@end
+
+void usemyotherobject() {
+  [MyOtherObject new]; // no error; new is overrideen.
+}
+
+@interface NotGoodOverride : NSObject
++(instancetype)init __attribute__((unavailable));
+-(instancetype)new;
++(instancetype)new: (int)x;
+@end
+
+void usenotgoodoverride() {
+  [NotGoodOverride new]; // no error
+}
+
+@interface NotNSObject
++(instancetype)new;
+-(instancetype)init;
+@end
+
+@interface NotMyObject : NotNSObject
+-(instancetype)init __attribute__((unavailable));
+@end
+
+void usenotmyobject() {
+  [NotMyObject new]; // no error; this isn't NSObject
+}
+
+@interface FromSelf : NSObject
+-(instancetype)init __attribute__((unavailable)); // expected-note {{'init' has been explicitly marked unavailable here}}
++(FromSelf*)another_one;
+@end
+
+@implementation FromSelf
++(FromSelf*)another_one {
+  [self new]; // expected-error{{'new' is unavailable}}
+}
+@end