Improve handling of __FUNCTION__ and other predefined expression for Objective-C Blocks

Instead of always displaying the mangled name, try to do better
and get something closer to regular functions.

Recommit r287039 (that was reverted in r287039) with a tweak to
be more generic, and test fixes!

Differential Revision: https://reviews.llvm.org/D26522

llvm-svn: 287085

1 files changed, 13 insertions, 12 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index a269c9945e4..6f0b5fe6d51 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -518,20 +518,21 @@ std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
     }
     return "";
   }
-  if (auto *BD = dyn_cast<BlockDecl>(CurrentDecl)) {
-    std::unique_ptr<MangleContext> MC;
-    MC.reset(Context.createMangleContext());
-    SmallString<256> Buffer;
-    llvm::raw_svector_ostream Out(Buffer);
+  if (isa<BlockDecl>(CurrentDecl)) {
+    // For blocks we only emit something if it is enclosed in a function
+    // For top-level block we'd like to include the name of variable, but we
+    // don't have it at this point.
     auto DC = CurrentDecl->getDeclContext();
     if (DC->isFileContext())
-      MC->mangleGlobalBlock(BD, /*ID*/ nullptr, Out);
-    else if (const auto *CD = dyn_cast<CXXConstructorDecl>(DC))
-      MC->mangleCtorBlock(CD, /*CT*/ Ctor_Complete, BD, Out);
-    else if (const auto *DD = dyn_cast<CXXDestructorDecl>(DC))
-      MC->mangleDtorBlock(DD, /*DT*/ Dtor_Complete, BD, Out);
-    else
-      MC->mangleBlock(DC, BD, Out);
+      return "";
+
+    SmallString<256> Buffer;
+    llvm::raw_svector_ostream Out(Buffer);
+    if (auto *DCBlock = dyn_cast<BlockDecl>(DC))
+      // For nested blocks, propagate up to the parent.
+      Out << ComputeName(IT, DCBlock);
+    else if (auto *DCDecl = dyn_cast<Decl>(DC))
+      Out << ComputeName(IT, DCDecl) << "_block_invoke";
     return Out.str();
   }
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {