From: Zachary Turner <zturner@google.com>
Date: Thu, 30 Aug 2018 20:53:29 +0000 (+0000)
Subject: [MS Demangler] Add support for $$Z parameter pack separator.
X-Git-Tag: llvmorg-8.0.0-rc1~9742
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=78ab3cb238d7803c54a654eb8e49857b0a134810;p=platform%2Fupstream%2Fllvm.git

[MS Demangler] Add support for $$Z parameter pack separator.

$$Z appears between adjacent expanded parameter packs in the
same template instantiation.  We don't need to print it, it's
only there to disambiguate between manglings that would otherwise
be ambiguous.  So we just need to parse it and throw it away.

llvm-svn: 341119
---

diff --git a/llvm/lib/Demangle/MicrosoftDemangle.cpp b/llvm/lib/Demangle/MicrosoftDemangle.cpp
index ad6990c..bd7faa3 100644
--- a/llvm/lib/Demangle/MicrosoftDemangle.cpp
+++ b/llvm/lib/Demangle/MicrosoftDemangle.cpp
@@ -520,14 +520,27 @@ Demangler::demangleRttiBaseClassDescriptorNode(ArenaAllocator &Arena,
   return VSN;
 }
 
+void dump(Node *N) {
+  OutputStream OS = OutputStream::create(nullptr, nullptr, 1024);
+  N->output(OS, OF_Default);
+  OS << '\0';
+  char *Name = OS.getBuffer();
+
+  printf(Name);
+  printf("\n");
+  std::free(Name);
+}
+
 FunctionSymbolNode *Demangler::demangleInitFiniStub(StringView &MangledName,
                                                     bool IsDestructor) {
   DynamicStructorIdentifierNode *DSIN =
       Arena.alloc<DynamicStructorIdentifierNode>();
   DSIN->IsDestructor = IsDestructor;
 
-  // What follows is a main symbol name. This may include namespaces or class
-  // back references.
+  bool IsKnownStaticDataMember = false;
+  if (MangledName.consumeFront('?'))
+    IsKnownStaticDataMember = true;
+
   QualifiedNameNode *QN = demangleFullyQualifiedSymbolName(MangledName);
 
   SymbolNode *Symbol = demangleEncodedSymbol(MangledName, QN);
@@ -536,7 +549,15 @@ FunctionSymbolNode *Demangler::demangleInitFiniStub(StringView &MangledName,
 
   if (Symbol->kind() == NodeKind::VariableSymbol) {
     DSIN->Variable = static_cast<VariableSymbolNode *>(Symbol);
-    if (!MangledName.consumeFront('@')) {
+
+    // Older versions of clang mangled this type of symbol incorrectly.  They
+    // would omit the leading ? and they would only emit a single @ at the end.
+    // The correct mangling is a leading ? and 2 trailing @ signs.  Handle
+    // both cases.
+    int AtCount = IsKnownStaticDataMember ? 2 : 1;
+    for (int I = 0; I < AtCount; ++I) {
+      if (MangledName.consumeFront('@'))
+        continue;
       Error = true;
       return nullptr;
     }
@@ -544,6 +565,12 @@ FunctionSymbolNode *Demangler::demangleInitFiniStub(StringView &MangledName,
     FSN = demangleFunctionEncoding(MangledName);
     FSN->Name = synthesizeQualifiedName(Arena, DSIN);
   } else {
+    if (IsKnownStaticDataMember) {
+      // This was supposed to be a static data member, but we got a function.
+      Error = true;
+      return nullptr;
+    }
+
     FSN = static_cast<FunctionSymbolNode *>(Symbol);
     DSIN->Name = Symbol->Name;
     FSN->Name = synthesizeQualifiedName(Arena, DSIN);
@@ -2148,8 +2175,8 @@ Demangler::demangleTemplateParameterList(StringView &MangledName) {
 
   while (!Error && !MangledName.startsWith('@')) {
     if (MangledName.consumeFront("$S") || MangledName.consumeFront("$$V") ||
-        MangledName.consumeFront("$$$V")) {
-      // Empty parameter pack.
+        MangledName.consumeFront("$$$V") || MangledName.consumeFront("$$Z")) {
+      // parameter pack separator
       continue;
     }
 
diff --git a/llvm/test/Demangle/ms-cxx11.test b/llvm/test/Demangle/ms-cxx11.test
index 54299da..fa756a5 100644
--- a/llvm/test/Demangle/ms-cxx11.test
+++ b/llvm/test/Demangle/ms-cxx11.test
@@ -86,6 +86,10 @@
 ??$templ_fun_with_pack@$S@@YAXXZ
 ; CHECK: void __cdecl templ_fun_with_pack<>(void)
 
+; $$Z is a parameter pack separator.
+??$func@H$$ZH@@YAHAEBU?$Foo@H@@0@Z
+; CHECK: int __cdecl func<int, int>(struct Foo<int> const &, struct Foo<int> const &)
+
 ??$templ_fun_with_ty_pack@$$$V@@YAXXZ
 ; CHECK: void __cdecl templ_fun_with_ty_pack<>(void)
 ??$templ_fun_with_ty_pack@$$V@@YAXXZ