Index: clang/lib/AST/Mangle.cpp
===================================================================
--- clang/lib/AST/Mangle.cpp
+++ clang/lib/AST/Mangle.cpp
@@ -36,11 +36,14 @@
                                 StringRef Outer,
                                 const BlockDecl *BD,
                                 raw_ostream &Out) {
-  unsigned discriminator = Context.getBlockId(BD, true);
-  if (discriminator == 0)
-    Out << "__" << Outer << "_block_invoke";
-  else
-    Out << "__" << Outer << "_block_invoke_" << discriminator+1;
+  Out << "__" << Outer << "_block_invoke";
+
+  ArrayRef<ParmVarDecl *> params = BD->parameters();
+  for(unsigned i = 0; i < params.size(); i++) {
+    ParmVarDecl *param = params[i];
+    Context.mangleTypeName(param->getType(), Out);
+  }
+  llvm::raw_svector_ostream *Out2 = (llvm::raw_svector_ostream*)&Out;
 }
 
 void MangleContext::anchor() { }
Index: llvm/include/llvm/Demangle/ItaniumDemangle.h
===================================================================
--- llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -5524,14 +5524,35 @@
     Node *Encoding = getDerived().parseEncoding();
     if (Encoding == nullptr || !consumeIf("_block_invoke"))
       return nullptr;
-    bool RequireNumber = consumeIf('_');
-    if (parseNumber().empty() && RequireNumber)
-      return nullptr;
+
+    OutputStream ParamOS;
+    if (!initializeOutputStream(nullptr, nullptr, ParamOS, 1024)) {
+      std::terminate();
+    }
+
+    while (consumeIf("_ZTS")) {
+      Node *paramType = getDerived().parseType();
+      ParamOS += ParamOS.empty() ? "(" : ", ";
+
+      paramType->print(ParamOS);
+    }
+    if (!ParamOS.empty()) {
+      ParamOS += ")";
+    }
+
     if (look() == '.')
       First = Last;
     if (numLeft() != 0)
       return nullptr;
-    return make<SpecialName>("invocation function for block in ", Encoding);
+
+    OutputStream DescOS;
+    if (!initializeOutputStream(nullptr, nullptr, DescOS, 1024)) {
+      std::terminate();
+    }
+    DescOS += "invocation function for block with params '";
+    DescOS += ParamOS.getBuffer();
+    DescOS += "' in ";
+    return make<SpecialName>(DescOS.getBuffer(), Encoding);
   }
 
   Node *Ty = getDerived().parseType();