From cc4bfd7f59d5a0024ada2a5c2a6f46d53290882b Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Wed, 25 Aug 2021 09:55:50 -0700 Subject: [PATCH] [Sema][ObjC] Allow conversions between pointers to ObjC pointers and pointers to structs clang was just being conservative and trying to prevent users from messing up the qualifier on the inner pointer type. Lifting this restriction enables using some of the libc++ templates with ObjC pointer arguments, which clang currently rejects. rdar://79018677 Differential Revision: https://reviews.llvm.org/D107021 --- clang/lib/Sema/SemaExprObjC.cpp | 9 +++++++-- clang/test/SemaObjC/arc-type-conversion.m | 13 ++++++++++++- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp index 9e46801ea508..102edb0136e5 100644 --- a/clang/lib/Sema/SemaExprObjC.cpp +++ b/clang/lib/Sema/SemaExprObjC.cpp @@ -4450,9 +4450,14 @@ Sema::CheckObjCConversion(SourceRange castRange, QualType castType, // Allow casts between pointers to lifetime types (e.g., __strong id*) // and pointers to void (e.g., cv void *). Casting from void* to lifetime* // must be explicit. - if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr) + // Allow conversions between pointers to lifetime types and coreFoundation + // pointers too, but only when the conversions are explicit. + if (exprACTC == ACTC_indirectRetainable && + (castACTC == ACTC_voidPtr || + (castACTC == ACTC_coreFoundation && isCast(CCK)))) return ACR_okay; - if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr && + if (castACTC == ACTC_indirectRetainable && + (exprACTC == ACTC_voidPtr || exprACTC == ACTC_coreFoundation) && isCast(CCK)) return ACR_okay; diff --git a/clang/test/SemaObjC/arc-type-conversion.m b/clang/test/SemaObjC/arc-type-conversion.m index 5cf2cf4b745e..a349d00ec851 100644 --- a/clang/test/SemaObjC/arc-type-conversion.m +++ b/clang/test/SemaObjC/arc-type-conversion.m @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -fsyntax-only -fobjc-arc -fobjc-runtime-has-weak -verify -fblocks %s +// RUN: %clang_cc1 -fsyntax-only -fobjc-arc -fobjc-runtime-has-weak -verify -fblocks -Wno-incompatible-pointer-types %s typedef const void * CFTypeRef; CFTypeRef CFBridgingRetain(id X); @@ -96,3 +96,14 @@ void conversion_in_conditional(id a, void* b) { id c = 1 ? a : b; // expected-error {{operands to conditional of types 'id' and 'void *' are incompatible in ARC mode}} id d = 1 ? b : a; // expected-error {{operands to conditional of types 'void *' and 'id' are incompatible in ARC mode}} } + +void conversion_pointer_to_id(__strong id *x) { + struct S { + int a[2]; + } s, *p; + + x = (__strong id *)&s; + x = &s; // expected-error {{implicit conversion of a non-Objective-C pointer type 'struct S *' to '__strong id *' is disallowed with ARC}} + p = (struct S *)x; + p = x; // expected-error {{implicit conversion of an indirect pointer to an Objective-C pointer to 'struct S *' is disallowed with ARC}} +}