MSVC mangler in Clang fails with "cannot mangle this template type parameter type yet"

[etkramer]

Brief Description

When used on QtCore's "qhashfunctions.h", CppSharp 1.0.1 fails with the message:

(0,0): error: cannot mangle this template type parameter type yet
(0,0): error: cannot mangle this dependent name type yet

OS: Windows 11 22621 (64-bit)

Used headers

qhashfunctions.h from Qt 6.2.4 (msvc2019) or minimal sample:

#include <numeric>

template <typename T, typename = void>
constexpr inline bool HasQHashSingleArgOverload = false;

template <typename T>
constexpr inline bool HasQHashSingleArgOverload<T, std::enable_if_t<
	std::is_convertible_v<decltype(qHash(std::declval<const T &>())), size_t>
>> = true;

Used settings

Target: x86_64-pc-win32-msvc

Other settings

var options = driver.Options;
options.GeneratorKind = GeneratorKind.CSharp;

var parserOptions = driver.ParserOptions;
parserOptions.TargetTriple = "x86_64-pc-win32-msvc";
parserOptions.LanguageVersion = CppSharp.Parser.LanguageVersion.CPP17;

var module = options.AddModule("Qt");
module.IncludeDirs.Add(@"E:\Qt\6.2.4\msvc2019_64\include");
module.IncludeDirs.Add(@"E:\Qt\6.2.4\msvc2019_64\include\QtCore");
module.LibraryDirs.Add(@"E:\Qt\6.2.4\msvc2019_64\lib");

module.Libraries.Add("Qt6Core.lib");
module.Headers.Add("qhashfunctions.h");

Stack trace or incompilable generated code

Parsing libraries...
Parsed 'Qt6Core.lib'
Parsing code...
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 322)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 322)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 322)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 322)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 337)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 337)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 337)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 337)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 283)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 399)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 399)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 402)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 402)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 402)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 405)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 405)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 405)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 405)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 408)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 408)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 408)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 411)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 411)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 411)
Unhandled declaration kind: CXXDeductionGuide
  E:\Qt\6.2.4\msvc2019_64\include\QtCore/qstringtokenizer.h (line 411)
Error parsing 'qhashfunctions.h'
(0,0): error: cannot mangle this template type parameter type yet
(0,0): error: cannot mangle this dependent name type yet
CppSharp has encountered an error while parsing code.

[tritao]

#include

template <typename T, typename = void>
constexpr inline bool HasQHashSingleArgOverload = false;

template
constexpr inline bool HasQHashSingleArgOverload<T, std::enable_if_t<
std::is_convertible_v<decltype(qHash(std::declval<const T &>())), size_t>

= true;

Cool, this is a big help.

I've tried to reproduce here but not really being able to.

Yeah, meanwhile I've checked and we already a fix in place for this: fd3f82a

[etkramer]

Thanks for looking into it! It looks like the NuGet package is a ways behind that commit, so I'll just go ahead and build from source for now.

[etkramer]

Just gave the latest master a shot and... yeah, no luck. Still getting the same results with the same code sample.

[tritao]

Can you try to reproduce with the CLI like this: dotnet CppSharp.CLI.dll --gen=csharp --platform=linux --arch=x64 -I/home/joao/dev/CppSharp/tests/workbench/.. -I/home/joao/dev/CppSharp/tests/workbench/../../include -o /home/joao/dev/CppSharp/tests/workbench/gen -m tests /home/joao/dev/CppSharp/tests/workbench/../tests.h

You need to modify the command to work on your system.

This is my tests.h:

#include <numeric>
#include <type_traits>
#include <cstddef>

template <typename T, typename = void>
constexpr inline bool HasQHashSingleArgOverload = false;

template <typename T>
constexpr inline bool HasQHashSingleArgOverload<T, std::enable_if_t<
	std::is_convertible_v<decltype(qHash(std::declval<const T &>())), size_t>
>> = true;

And my output:

Generating C# bindings for Linux x64...
Parsing libraries...
Parsing code...
Parsed '/home/joao/dev/CppSharp/tests/workbench/../tests.h'
Processing code...
Generating code...
Generated 'Std.cs'
Generated 'tests.cs'

[etkramer]

Hmm...

A:\Projects\Code\CS\QtCore>dotnet "A:\Projects\Code\CS\QtCore\Libs\CppSharp\bin\Release_x64\CppSharp.CLI.dll" --gen=csharp --platform=win --arch=x64 -IA:\Projects\Code\CS\QtCore -o A:\Projects\Code\CS\QtCore\out\ -m tests A:\Projects\Code\CS\QtCore\sample.h
Generating C# bindings for Windows x64...
Parsing libraries...
Parsing code...
Error parsing 'A:\Projects\Code\CS\QtCore\sample.h'
(0,0): error: cannot mangle this template type parameter type yet
(0,0): error: cannot mangle this dependent name type yet
CppSharp has encountered an error while parsing code.

[tritao]

Hmm, that's making me think it might be an issue with the Windows mangler specifically.

It's possible an update to the latest version of Clang might fix it.

[tritao]

Probably not: https://github.com/llvm/llvm-project/blob/main/clang/lib/AST/MicrosoftMangle.cpp#L2978

We need to check this on Parser.cpp and not try to mangle these. Unfortunately I don't even use Windows that much so most likely I won't be working on this any time soon.

[etkramer]

Understood. Thanks for looking into it regardless!