CodeGen: correct mangling for blocks

This addresses a regression introduced with SVN r219393.  A block may be
contained within another block.  In such a scenario, we would end up within a
BlockDecl, which is not a NamedDecl (as the names are synthesised).  The cast to
a NamedDecl of the DeclContext would then assert as the types are unrelated.

Restore the mangling behaviour to that prior to SVN r219393.  If the current
block is contained within a BlockDecl, walk up to the parent DeclContext,
recursively, until we have a non-BlockDecl.  This is expected to be a NamedDecl.
Add in a couple of asserts to ensure that the assumption that we only encounter
a block within a NamedDecl or a BlockDecl.

llvm-svn: 219696

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/AST/Mangle.cpp b/clang/lib/AST/Mangle.cpp
index fdc00e389350..fba835451e29 100644
--- a/clang/lib/AST/Mangle.cpp
+++ b/clang/lib/AST/Mangle.cpp
@@ -215,6 +215,12 @@ void MangleContext::mangleBlock(const DeclContext *DC, const BlockDecl *BD,
   if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
     mangleObjCMethodName(Method, Stream);
   } else {
+    assert((isa<NamedDecl>(DC) || isa<BlockDecl>(DC)) &&
+           "expected a NamedDecl or BlockDecl");
+    if (isa<BlockDecl>(DC))
+      for (; DC && isa<BlockDecl>(DC); DC = DC->getParent())
+        (void) getBlockId(cast<BlockDecl>(DC), true);
+    assert(isa<NamedDecl>(DC) && "expected a NamedDecl");
     const NamedDecl *ND = cast<NamedDecl>(DC);
     if (!shouldMangleDeclName(ND) && ND->getIdentifier())
       Stream << ND->getIdentifier()->getName();