AST: Mangle reference temporaries reliably

Summary:
Previously, we would generate a single name for all reference
temporaries and allow LLVM to rename them for us.  Instead, number the
reference temporaries as we build them in Sema.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D3554

llvm-svn: 207776

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index ee4992590a2..0181235bff5 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -1446,6 +1446,25 @@ FunctionParmPackExpr::CreateEmpty(const ASTContext &Context,
     FunctionParmPackExpr(QualType(), 0, SourceLocation(), 0, 0);
 }
 
+void MaterializeTemporaryExpr::setExtendingDecl(const ValueDecl *ExtendedBy,
+                                                unsigned ManglingNumber) {
+  // We only need extra state if we have to remember more than just the Stmt.
+  if (!ExtendedBy)
+    return;
+
+  // We may need to allocate extra storage for the mangling number and the
+  // extended-by ValueDecl.
+  if (!State.is<ExtraState *>()) {
+    auto ES = new (ExtendedBy->getASTContext()) ExtraState;
+    ES->Temporary = State.get<Stmt *>();
+    State = ES;
+  }
+
+  auto ES = State.get<ExtraState *>();
+  ES->ExtendingDecl = ExtendedBy;
+  ES->ManglingNumber = ManglingNumber;
+}
+
 TypeTraitExpr::TypeTraitExpr(QualType T, SourceLocation Loc, TypeTrait Kind,
                              ArrayRef<TypeSourceInfo *> Args,
                              SourceLocation RParenLoc,