arphaman created this revision.
Objective-C NSString has a class method `stringWithUTF8String` that creates a
new NSString from a C string. Objective-C box expression `@(...)` can be used
to create an NSString instead of invoking the `stringWithUTF8String` method
directly (The compiler lowers it down to the invocation though). This patch
ensures that the type of `@(string-value)` gets the same nullability attributes
as the return type of `stringWithUTF8String` to ensure that the diagnostics are
consistent between the two.
rdar://33847186
Repository:
rL LLVM
https://reviews.llvm.org/D39762
Files:
lib/Sema/SemaExprObjC.cpp
test/SemaObjC/transfer-boxed-string-nullability.m
Index: test/SemaObjC/transfer-boxed-string-nullability.m
===================================================================
--- /dev/null
+++ test/SemaObjC/transfer-boxed-string-nullability.m
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -fblocks -fobjc-arc -Wnullable-to-nonnull-conversion
-fsyntax-only -verify -Wno-objc-root-class %s
+// RUN: %clang_cc1 -fblocks -fobjc-arc -Wnullable-to-nonnull-conversion
-fsyntax-only -verify -Wno-objc-root-class -DNOWARN %s
+
+@interface NSString
+
++ (NSString*
+#ifndef NOWARN
+ _Nullable
+#else
+ _Nonnull
+#endif
+) stringWithUTF8String:(const char*)x;
+
+@end
+
+void takesNonNull(NSString * _Nonnull ptr);
+
+void testBoxedString() {
+ const char *str = "hey";
+ takesNonNull([NSString stringWithUTF8String:str]);
+ takesNonNull(@(str));
+#ifndef NOWARN
+ // expected-warning@-3 {{implicit conversion from nullable pointer 'NSString
* _Nullable' to non-nullable pointer type 'NSString * _Nonnull'}}
+ // expected-warning@-3 {{implicit conversion from nullable pointer 'NSString
* _Nullable' to non-nullable pointer type 'NSString * _Nonnull'}}
+#else
+ // expected-no-diagnostics
+#endif
+}
Index: lib/Sema/SemaExprObjC.cpp
===================================================================
--- lib/Sema/SemaExprObjC.cpp
+++ lib/Sema/SemaExprObjC.cpp
@@ -564,6 +564,13 @@
BoxingMethod = StringWithUTF8StringMethod;
BoxedType = NSStringPointer;
+ // Transfer the nullability from method's return type.
+ Optional<NullabilityKind> Nullability =
+ BoxingMethod->getReturnType()->getNullability(Context);
+ if (Nullability)
+ BoxedType = Context.getAttributedType(
+ AttributedType::getNullabilityAttrKind(*Nullability), BoxedType,
+ BoxedType);
}
} else if (ValueType->isBuiltinType()) {
// The other types we support are numeric, char and BOOL/bool. We could
also
Index: test/SemaObjC/transfer-boxed-string-nullability.m
===================================================================
--- /dev/null
+++ test/SemaObjC/transfer-boxed-string-nullability.m
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -fblocks -fobjc-arc -Wnullable-to-nonnull-conversion -fsyntax-only -verify -Wno-objc-root-class %s
+// RUN: %clang_cc1 -fblocks -fobjc-arc -Wnullable-to-nonnull-conversion -fsyntax-only -verify -Wno-objc-root-class -DNOWARN %s
+
+@interface NSString
+
++ (NSString*
+#ifndef NOWARN
+ _Nullable
+#else
+ _Nonnull
+#endif
+) stringWithUTF8String:(const char*)x;
+
+@end
+
+void takesNonNull(NSString * _Nonnull ptr);
+
+void testBoxedString() {
+ const char *str = "hey";
+ takesNonNull([NSString stringWithUTF8String:str]);
+ takesNonNull(@(str));
+#ifndef NOWARN
+ // expected-warning@-3 {{implicit conversion from nullable pointer 'NSString * _Nullable' to non-nullable pointer type 'NSString * _Nonnull'}}
+ // expected-warning@-3 {{implicit conversion from nullable pointer 'NSString * _Nullable' to non-nullable pointer type 'NSString * _Nonnull'}}
+#else
+ // expected-no-diagnostics
+#endif
+}
Index: lib/Sema/SemaExprObjC.cpp
===================================================================
--- lib/Sema/SemaExprObjC.cpp
+++ lib/Sema/SemaExprObjC.cpp
@@ -564,6 +564,13 @@
BoxingMethod = StringWithUTF8StringMethod;
BoxedType = NSStringPointer;
+ // Transfer the nullability from method's return type.
+ Optional<NullabilityKind> Nullability =
+ BoxingMethod->getReturnType()->getNullability(Context);
+ if (Nullability)
+ BoxedType = Context.getAttributedType(
+ AttributedType::getNullabilityAttrKind(*Nullability), BoxedType,
+ BoxedType);
}
} else if (ValueType->isBuiltinType()) {
// The other types we support are numeric, char and BOOL/bool. We could also
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