Extend type nullability qualifiers for Objective-C.

Introduce context-sensitive, non-underscored nullability specifiers
(nonnull, nullable, null_unspecified) for Objective-C method return
types, method parameter types, and properties.

Introduce Objective-C-specific semantics, including computation of the
nullability of the result of a message send, merging of nullability
information from the @interface of a class into its @implementation,
etc .

This is the Objective-C part of rdar://problem/18868820.

llvm-svn: 240154

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/SemaObjC/override-nullability.m b/clang/test/SemaObjC/override-nullability.m
new file mode 100644
index 00000000000..8e29f915275
--- /dev/null
+++ b/clang/test/SemaObjC/override-nullability.m
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fobjc-arc -fobjc-runtime-has-weak -Wnonnull %s -verify
+//rdar://19211059
+
+@interface NSObject @end
+
+@interface Base : NSObject
+- (nonnull id)bad:(nullable id)obj; // expected-note 2 {{previous declaration is here}}
+- (nullable id)notAsBad:(nonnull id)obj;
+@end
+
+@interface Sub : Base
+- (nullable id)bad:(nonnull id)obj; // expected-warning {{conflicting nullability specifier on return types, 'nullable' conflicts with existing specifier 'nonnull'}} \
+                                    // expected-warning {{conflicting nullability specifier on parameter types, 'nonnull' conflicts with existing specifier 'nullable'}}
+- (nonnull id)notAsBad:(nullable id)obj;
+@end