[ObjC] Add a -Wobjc-messaging-id warning
-Wobjc-messaging-id is a new, non-default warning that warns about
message sends to unqualified id in Objective-C. This warning is useful
for projects that would like to avoid any potential future compiler
errors/warnings, as the system frameworks might add a method with the same
selector which could make the message send to id ambiguous.
rdar://33303354
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@311779 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 6f135344102bde8d81237cef04ea3d4e1a1b8b46)
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index c78b407..3d3dbae 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -69,6 +69,15 @@
``\returns`` documentation directives in the documentation comments for
declarations with a function or a block pointer type.
+- ``-Wobjc-messaging-id`` is a new, non-default warning that warns about
+ message sends to unqualified ``id`` in Objective-C. This warning is useful
+ for projects that would like to avoid any potential future compiler
+ errors/warnings, as the system frameworks might add a method with the same
+ selector which could make the message send to ``id`` ambiguous.
+
+Non-comprehensive list of changes in this release
+-------------------------------------------------
+
- The compiler no longer warns about unreachable ``__builtin_unreachable``
statements.
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index fd992e7..14b6e61 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1201,6 +1201,10 @@
"%0 %select{parameter|return}1 type is unsupported; "
"support for vector types for this target is introduced in %2">;
+def warn_messaging_unqualified_id : Warning<
+ "messaging unqualified id">, DefaultIgnore,
+ InGroup<DiagGroup<"objc-messaging-id">>;
+
// C++ declarations
def err_static_assert_expression_is_not_constant : Error<
"static_assert expression is not an integral constant expression">;
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 28581ba..83ef799 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -2705,6 +2705,9 @@
}
}
+ if (ReceiverType->isObjCIdType() && !isImplicit)
+ Diag(Receiver->getExprLoc(), diag::warn_messaging_unqualified_id);
+
// There's a somewhat weird interaction here where we assume that we
// won't actually have a method unless we also don't need to do some
// of the more detailed type-checking on the receiver.
diff --git a/test/SemaObjC/warn-messaging-id.mm b/test/SemaObjC/warn-messaging-id.mm
new file mode 100644
index 0000000..8112cfa
--- /dev/null
+++ b/test/SemaObjC/warn-messaging-id.mm
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wno-objc-root-class -Wobjc-messaging-id %s
+
+@interface CallMeMaybe
+
+- (void)doThing:(int)intThing;
+
+@property int thing;
+
+@end
+
+template<typename T>
+void instantiate(const T &x) {
+ [x setThing: 22]; // expected-warning {{messaging unqualified id}}
+}
+
+void fn() {
+ id myObject;
+ [myObject doThing: 10]; // expected-warning {{messaging unqualified id}}
+ [myObject setThing: 11]; // expected-warning {{messaging unqualified id}}
+ instantiate(myObject); // expected-note {{in instantiation}}
+}
