Improve name mangling for blocks and support mangling of static local
variables within blocks. We loosely follow GCC's mangling, but since
these are always internal symbols the names don't really matter. I
intend to revisit block mangling later, because GCC's mangling is
rather verbose. <rdar://problem/8015719>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104610 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 46a9f6c..88e4c64 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -102,6 +102,7 @@
   llvm::raw_svector_ostream &getStream() { return Out; }
 
   void mangle(const NamedDecl *D, llvm::StringRef Prefix = "_Z");
+  void mangleBlock(const BlockDecl *BD);
   void mangleCallOffset(int64_t NonVirtual, int64_t Virtual);
   void mangleNumber(int64_t Number);
   void mangleFunctionEncoding(const FunctionDecl *FD);
@@ -469,6 +470,31 @@
   Out << Number;
 }
 
+void CXXNameMangler::mangleBlock(const BlockDecl *BD) {
+  // Mangle the context of the block.
+  // FIXME: We currently mimic GCC's mangling scheme, which leaves much to be
+  // desired. Come up with a better mangling scheme.
+  const DeclContext *DC = BD->getDeclContext();
+  while (isa<BlockDecl>(DC) || isa<EnumDecl>(DC))
+    DC = DC->getParent();
+  if (DC->isFunctionOrMethod()) {
+    Out << "__";
+    if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC))
+      mangleObjCMethodName(Method);
+    else {
+      const NamedDecl *ND = cast<NamedDecl>(DC);
+      if (IdentifierInfo *II = ND->getIdentifier())
+        Out << II->getName();
+      else {
+        mangleUnqualifiedName(ND);
+      }
+    }
+    Out << "_block_invoke_" << Context.getBlockId(BD, true);
+  } else {
+    Out << "__block_global_" << Context.getBlockId(BD, false);
+  }
+}
+
 void CXXNameMangler::mangleCallOffset(int64_t NonVirtual, int64_t Virtual) {
   //  <call-offset>  ::= h <nv-offset> _
   //                 ::= v <v-offset> _
@@ -752,6 +778,14 @@
   if (DC->isTranslationUnit())
     return;
 
+  if (const BlockDecl *Block = dyn_cast<BlockDecl>(DC)) {
+    manglePrefix(DC->getParent(), NoFunction);    
+    llvm::SmallString<64> Name;
+    Context.mangleBlock(Block, Name);
+    Out << Name.size() << Name;
+    return;
+  }
+  
   if (mangleSubstitution(cast<NamedDecl>(DC)))
     return;
 
@@ -762,8 +796,10 @@
     TemplateParameterList *TemplateParameters = TD->getTemplateParameters();
     mangleTemplateArgs(*TemplateParameters, *TemplateArgs);
   }
-  else if(NoFunction && isa<FunctionDecl>(DC))
+  else if(NoFunction && (isa<FunctionDecl>(DC) || isa<ObjCMethodDecl>(DC)))
     return;
+  else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC))
+    mangleObjCMethodName(Method);
   else {
     manglePrefix(DC->getParent(), NoFunction);
     mangleUnqualifiedName(cast<NamedDecl>(DC));
@@ -2033,6 +2069,12 @@
   Mangler.mangle(D);
 }
 
+void MangleContext::mangleBlock(const BlockDecl *BD,
+                                llvm::SmallVectorImpl<char> &Res) {
+  CXXNameMangler Mangler(*this, Res);
+  Mangler.mangleBlock(BD);
+}
+
 void MangleContext::mangleThunk(const CXXMethodDecl *MD,
                                 const ThunkInfo &Thunk,
                                 llvm::SmallVectorImpl<char> &Res) {