[Clang] cherry-pick "Fix __{add,remove}_pointer in Objective-C++"

[philnik777]

This aligns the builtins with how implementations work which don't use
the buitins.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Nikolas Klauser (philnik777)

Changes

This aligns the builtins with how implementations work which don't use
the buitins.

---

Full diff: https://github.com/llvm/llvm-project/pull/125185.diff

4 Files Affected:

• (modified) clang/docs/ReleaseNotes.rst (+2)
• (modified) clang/lib/Sema/SemaType.cpp (+3-3)
• (removed) clang/test/SemaCXX/remove_pointer.mm (-8)
• (added) clang/test/SemaObjCXX/type-traits.mm (+17)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d8a94703bd9c57..25329e9e8a04ae 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -906,6 +906,8 @@ Bug Fixes to Compiler Builtins
 
 - Fix ``__builtin_source_location`` incorrectly returning wrong column for method chains. (#GH119129)
 
+- The behvaiour of ``__add_pointer`` and ``__remove_pointer`` for Objective-C++'s ``id`` and interfaces has been fixed.
+
 Bug Fixes to Attribute Support
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 33d5378944ddbf..2781651b5d8f7d 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1826,7 +1826,8 @@ QualType Sema::BuildPointerType(QualType T,
   if (checkQualifiedFunction(*this, T, Loc, QFK_Pointer))
     return QualType();
 
-  assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
+  if (T->isObjCObjectType())
+    return Context.getObjCObjectPointerType(T);
 
   // In ARC, it is forbidden to build pointers to unqualified pointers.
   if (getLangOpts().ObjCAutoRefCount)
@@ -9807,8 +9808,7 @@ QualType Sema::BuiltinAddPointer(QualType BaseType, SourceLocation Loc) {
 }
 
 QualType Sema::BuiltinRemovePointer(QualType BaseType, SourceLocation Loc) {
-  // We don't want block pointers or ObjectiveC's id type.
-  if (!BaseType->isAnyPointerType() || BaseType->isObjCIdType())
+  if (!BaseType->isAnyPointerType())
     return BaseType;
 
   return BaseType->getPointeeType();
diff --git a/clang/test/SemaCXX/remove_pointer.mm b/clang/test/SemaCXX/remove_pointer.mm
deleted file mode 100644
index d1cf1fa9f4efca..00000000000000
--- a/clang/test/SemaCXX/remove_pointer.mm
+++ /dev/null
@@ -1,8 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
-
-// expected-no-diagnostics
-
-@class X;
-
-static_assert(__is_same(__remove_pointer(X *), X), "");
-static_assert(__is_same(__remove_pointer(id), id), "");
diff --git a/clang/test/SemaObjCXX/type-traits.mm b/clang/test/SemaObjCXX/type-traits.mm
new file mode 100644
index 00000000000000..81b9573b521929
--- /dev/null
+++ b/clang/test/SemaObjCXX/type-traits.mm
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fsyntax-only -verify -std=c++17  %s
+
+// expected-no-diagnostics
+
+@interface I;
+@end
+
+@class C;
+
+static_assert(__is_same(__add_pointer(id), id*));
+static_assert(__is_same(__add_pointer(I), I*));
+
+static_assert(__is_same(__remove_pointer(C*), C));
+static_assert(!__is_same(__remove_pointer(id), id));
+static_assert(__is_same(__remove_pointer(id*), id));
+static_assert(__is_same(__remove_pointer(__add_pointer(id)), id));
+static_assert(__is_same(__add_pointer(__remove_pointer(id)), id));

[AaronBallman]

LGTM

[github-actions]

@philnik777 (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR.