[ObjCARC] Add an new attribute, objc_externally_retained
This attribute, called "objc_externally_retained", exposes clang's
notion of pseudo-__strong variables in ARC. Pseudo-strong variables
"borrow" their initializer, meaning that they don't retain/release
it, instead assuming that someone else is keeping their value alive.
If a function is annotated with this attribute, implicitly strong
parameters of that function aren't implicitly retained/released in
the function body, and are implicitly const. This is useful to expose
for performance reasons, most functions don't need the extra safety
of the retain/release, so programmers can opt out as needed.
This attribute can also apply to declarations of local variables,
with similar effect.
Differential revision: https://reviews.llvm.org/D55865
llvm-svn: 350422
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 6ef1091..34a921e 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -419,8 +419,12 @@
EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
const Expr *E = M->GetTemporaryExpr();
- // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
- // as that will cause the lifetime adjustment to be lost for ARC
+ assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
+ !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
+ "Reference should never be pseudo-strong!");
+
+ // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
+ // as that will cause the lifetime adjustment to be lost for ARC
auto ownership = M->getType().getObjCLifetime();
if (ownership != Qualifiers::OCL_None &&
ownership != Qualifiers::OCL_ExplicitNone) {