Fix demangling of optional template-args for vendor extended type qualifier.

[aorlov]

Summary

This fixes https://bugs.llvm.org/show_bug.cgi?id=48009 bug.

[jhenderson]

I don't know how demangler changes are usually tested, as I don't maintain the lower-level library, but I don't think testing it inside llvm/test/tools/llvm-cxxfilt/ is the right place, as those are tests for the top-level tool features (i.e. changes in the llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp). A quick look at past commits to the demangler library and existing tests suggests that you should probably test this in llvm/unittests/Demangle somewhere.

[aorlov]

Thanks, James!
The test is moved to llvm/unittests/Demangle/DemangleTest.cpp.

[jhenderson]

Thanks for the test update - that bit looks good to me. I'm not familiar enough with the demangling code to review the rest, so am resigning as reviewer, in the hope that will clear my "request changes" mark.

llvm/unittests/Demangle/DemangleTest.cpp

26

[krisb]

It seems it makes sense to apply the same changes to libcxxabi (see, libcxxabi/src/demangle/ItaniumDemangle.h) to keep them in sync.

[aorlov]

Thanks for the comment, Kristina.
I have added the same changes to libcxxabi.

[erik.pilkington]

LGTM, thanks!

[krisb]

LGTM, thank you!

libcxxabi/src/demangle/ItaniumDemangle.h

void printLeft(OutputStream &s) const override {
     s += Suffix;
     s += ")";
   }
 };
 
 class VendorExtQualType final : public Node {
   const Node *Ty;
   StringView Ext;
+  const Node *TA;
 
 public:
-  VendorExtQualType(const Node *Ty_, StringView Ext_)
-      : Node(KVendorExtQualType), Ty(Ty_), Ext(Ext_) {}
+  VendorExtQualType(const Node *Ty_, StringView Ext_, const Node *TA_)
+      : Node(KVendorExtQualType), Ty(Ty_), Ext(Ext_), TA(TA_) {}
 
-  template<typename Fn> void match(Fn F) const { F(Ty, Ext); }
+  template <typename Fn> void match(Fn F) const { F(Ty, Ext, TA); }
 
   void printLeft(OutputStream &S) const override {
     Ty->print(S);
     S += " ";
     S += Ext;
+    if (TA != nullptr)
+      TA->print(S);
   }
 };
 
 enum FunctionRefQual : unsigned char {
   FrefQualNone,
   FrefQualLValue,
   FrefQualRValue,
 };

 // <extended-qualifier> ::= U <source-name> [<template-args>] # vendor extended type qualifier
 template <typename Derived, typename Alloc>
 Node *AbstractManglingParser<Derived, Alloc>::parseQualifiedType() {
   if (consumeIf('U')) {
     StringView Qual = parseBareSourceName();
     if (Qual.empty())
       return nullptr;
 
-    // FIXME parse the optional <template-args> here!
-
     // extension            ::= U <objc-name> <objc-type>  # objc-type<identifier>
     if (Qual.startsWith("objcproto")) {
       StringView ProtoSourceName = Qual.dropFront(std::strlen("objcproto"));
       StringView Proto;
       {
         SwapAndRestore<const char *> SaveFirst(First, ProtoSourceName.begin()),
                                      SaveLast(Last, ProtoSourceName.end());
         Proto = parseBareSourceName();
       }
       if (Proto.empty())
         return nullptr;
       Node *Child = getDerived().parseQualifiedType();
       if (Child == nullptr)
         return nullptr;
       return make<ObjCProtoName>(Child, Proto);
     }
 
+    Node *TA = nullptr;
+    if (look() == 'I') {
+      TA = getDerived().parseTemplateArgs();
+      if (TA == nullptr)
+        return nullptr;
+    }
+
     Node *Child = getDerived().parseQualifiedType();
     if (Child == nullptr)
       return nullptr;
-    return make<VendorExtQualType>(Child, Qual);
+    return make<VendorExtQualType>(Child, Qual, TA);
   }
 
   Qualifiers Quals = parseCVQualifiers();
   Node *Ty = getDerived().parseType();
   if (Ty == nullptr)
     return nullptr;
   if (Quals != QualNone)
     Ty = make<QualType>(Ty, Quals);

libcxxabi/test/test_demangle.pass.cpp

//    {"_Z1fM1XRFivEMS_OFivEMS_KOFivE", "f(int (X::*)() &, int (X::*)() &&, int (X::*)() const &&)"},
     // "double&&". But we can't cope with a substitution that represents a
     // different type the node it is a substitute for.
     // See https://github.com/itanium-cxx-abi/cxx-abi/issues/106.
     {"_Z1h1XIJZ1fIiEDaOT_E1AZ1gIdEDaS2_E1BEE", "h(X<auto f<int>(int&&)::A, auto g<double>(int&&)::B>)"},
 
     {"_Z1fIL4Enumn1EEvv", "void f<(Enum)-1>()"},
 
     {"_ZN1A1gIiEEDTcldtptfpT1b1fIT_EEEv", "decltype(this->b.f<int>()) A::g<int>()"},
+
+    // Optional template-args for vendor extended type qualifier.
+    // See https://bugs.llvm.org/show_bug.cgi?id=48009.
+    {"_Z3fooILi79EEbU7_ExtIntIXT_EEi", "bool foo<79>(int _ExtInt<79>)"},
 };
 
 const unsigned N = sizeof(cases) / sizeof(cases[0]);
 
 struct FPLiteralCase {
     const char *mangled;
     // There are four possible demanglings of a given float.
     std::string expecting[4];

llvm/include/llvm/Demangle/ItaniumDemangle.h

void printLeft(OutputStream &s) const override {
     s += Suffix;
     s += ")";
   }
 };
 
 class VendorExtQualType final : public Node {
   const Node *Ty;
   StringView Ext;
+  const Node *TA;
 
 public:
-  VendorExtQualType(const Node *Ty_, StringView Ext_)
-      : Node(KVendorExtQualType), Ty(Ty_), Ext(Ext_) {}
+  VendorExtQualType(const Node *Ty_, StringView Ext_, const Node *TA_)
+      : Node(KVendorExtQualType), Ty(Ty_), Ext(Ext_), TA(TA_) {}
 
-  template<typename Fn> void match(Fn F) const { F(Ty, Ext); }
+  template <typename Fn> void match(Fn F) const { F(Ty, Ext, TA); }
 
   void printLeft(OutputStream &S) const override {
     Ty->print(S);
     S += " ";
     S += Ext;
+    if (TA != nullptr)
+      TA->print(S);
   }
 };
 
 enum FunctionRefQual : unsigned char {
   FrefQualNone,
   FrefQualLValue,
   FrefQualRValue,
 };

 // <extended-qualifier> ::= U <source-name> [<template-args>] # vendor extended type qualifier
 template <typename Derived, typename Alloc>
 Node *AbstractManglingParser<Derived, Alloc>::parseQualifiedType() {
   if (consumeIf('U')) {
     StringView Qual = parseBareSourceName();
     if (Qual.empty())
       return nullptr;
 
-    // FIXME parse the optional <template-args> here!
-
     // extension            ::= U <objc-name> <objc-type>  # objc-type<identifier>
     if (Qual.startsWith("objcproto")) {
       StringView ProtoSourceName = Qual.dropFront(std::strlen("objcproto"));
       StringView Proto;
       {
         SwapAndRestore<const char *> SaveFirst(First, ProtoSourceName.begin()),
                                      SaveLast(Last, ProtoSourceName.end());
         Proto = parseBareSourceName();
       }
       if (Proto.empty())
         return nullptr;
       Node *Child = getDerived().parseQualifiedType();
       if (Child == nullptr)
         return nullptr;
       return make<ObjCProtoName>(Child, Proto);
     }
 
+    Node *TA = nullptr;
+    if (look() == 'I') {
+      TA = getDerived().parseTemplateArgs();
+      if (TA == nullptr)
+        return nullptr;
+    }
+
     Node *Child = getDerived().parseQualifiedType();
     if (Child == nullptr)
       return nullptr;
-    return make<VendorExtQualType>(Child, Qual);
+    return make<VendorExtQualType>(Child, Qual, TA);
   }
 
   Qualifiers Quals = parseCVQualifiers();
   Node *Ty = getDerived().parseType();
   if (Ty == nullptr)
     return nullptr;
   if (Quals != QualNone)
     Ty = make<QualType>(Ty, Quals);

llvm/unittests/Demangle/DemangleTest.cpp

TEST(Demangle, demangleTest) {
   EXPECT_EQ(demangle("_Z3fooi"), "foo(int)");
   EXPECT_EQ(demangle("__Z3fooi"), "foo(int)");
   EXPECT_EQ(demangle("___Z3fooi_block_invoke"),
             "invocation function for block in foo(int)");
   EXPECT_EQ(demangle("____Z3fooi_block_invoke"),
             "invocation function for block in foo(int)");
   EXPECT_EQ(demangle("?foo@@YAXH@Z"), "void __cdecl foo(int)");
   EXPECT_EQ(demangle("foo"), "foo");
+
+  // Regression test for demangling of optional template-args for vendor
+  // extended type qualifier (https://bugs.llvm.org/show_bug.cgi?id=48009)
+  EXPECT_EQ(demangle("_Z3fooILi79EEbU7_ExtIntIXT_EEi"),
+            "bool foo<79>(int _ExtInt<79>)");
 }