Add support for C++ modules IFC version 0.43

[smilediver]

Environment

• OS and Version: Windows 22621.1555
• VS Code Version: 1.77.3
• C/C++ Extension Version: v1.14.5

Bug Summary and Steps to Reproduce

Same issue as in #9884, just for new IFC version 0.43

Configuration and Logs

-

Other Extensions

No response

Additional context

No response

[sean-mcmanus]

VS hasn't added this support yet, so we'll get this soon after they add it.

[MathiasMagnus]

@sean-mcmanus Having followed the evolution of modules via talks and blog posts I did anticipate some extra friction regarding binary module interfaces, but mostly from a cross-compiler compatibility perspective. Until modules we only needed to care about binary/link compatibility, but now also about BMI compatibility.

I would've never imagined to hit this limit on the stable branch of a vendor wrt. their own tooling. On the VS Insider/Preview channel maybe, but not on stable. A user upgrading their toolchain and losing IntelliSense is terrible UX. I would suggest the VS team considering to delay releases until the IntelliSense engine catches up to the IFC format of the bundled compiler. If modules had more widespread adoption, such a fallout would anger quite some folks.

Minimally if there exists a flag to tell the compiler to emit an older version of the IFC, document that please as an escape hatch.

[bobbrow]

Are you reporting a problem with VS or VS Code? Please note that modules are not officially supported in VS Code (#6302).

VS should be able to deal with the difference between 0.42 in IntelliSense and 0.43 in the compiler because it manages the modules in a special way. But still, the modules support in IntelliSense for VS has a ways to go. We should be getting the 0.43 update from EDG this month and hopefully other fixes.

[MathiasMagnus]

@bobbrow I am working in VS Code.

• Latest VS Code
• Latest cpptools
• Latest cmake-tools
• Latest CMake
• Latest MSVC Build Tools
• Project uses CMake presets and Ninja Multi-Config

If it's not officially supported, than please disregard my comment on release schedules. I am developing a C API wrapper in C++23 and I was looking to maybe not just develop as an ordinary header then wrap it with a module interface, but perhaps also develop it as a module with IntelliSense. I guess the tooling isn't there yet and it wasn't just CMake 3.28 that needed landing but we also need to wait a few cpptools releases.

[sean-mcmanus]

@smilediver Fixed with https://github.com/microsoft/vscode-cpptools/releases/tag/v1.20.0

[GGsrvg]

I created a project for testing modules https://github.com/GGsrvg/tModule.

It works, but IntelliSense shows me an error like "could not find module file for module "ttt.Anchor"C/C++""
These errors are confusing
Clean and rebuild didn't help

VSCode: 1.87.2
Extensions
C/C++: 1.20.0 (pre-release)
CMakeTools: 1.18.15 (pre-release)

Clang: 17.0.6

[bobbrow]

@GGsrvg, we don't have full modules support in the C++ extension yet. It is being tracked with issue #6302. It is possible to get it working with some caveats, but it requires the Visual Studio compiler right now. A guide to configuring can be found here: #6302 (comment)

[GGsrvg]

@bobbrow thanks for your comment. Oh I use mac