Objective-C++ ARC: do not mangle __unsafe_unretained lifetime
qualifiers, so that an __unsafe_unretained-qualified type T in ARC code
will have the same mangling as T in non-ARC code, improving ABI
interoperability. This works now because we infer or require a
lifetime qualifier everywhere one can appear in an external
interface. Another part of <rdar://problem/9595486>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index a77fe5f..5f0b2a6 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -1472,7 +1472,6 @@
// <type> ::= U "__strong"
// <type> ::= U "__weak"
// <type> ::= U "__autoreleasing"
- // <type> ::= U "__unsafe_unretained"
case Qualifiers::OCL_None:
break;
@@ -1489,7 +1488,13 @@
break;
case Qualifiers::OCL_ExplicitNone:
- LifetimeName = "__unsafe_unretained";
+ // The __unsafe_unretained qualifier is *not* mangled, so that
+ // __unsafe_unretained types in ARC produce the same manglings as the
+ // equivalent (but, naturally, unqualified) types in non-ARC, providing
+ // better ABI compatibility.
+ //
+ // It's safe to do this because unqualified 'id' won't show up
+ // in any type signatures that need to be mangled.
break;
}
if (!LifetimeName.empty())