[clang][StaticAnalyzer] Crash when analyzing code importing C++20 modules built with coverage flags

[mrwsl]

The Clang static analyzer crashes when analyzing code that imports C++20 modules built with coverage instrumentation flags (-fprofile-instr-generate -fcoverage-mapping).

Environment:

• Clang version: 21.1.6 (could also reproduce with Ubuntu clang version 21.1.8)
• OS: Linux
• Standard: C++26 (also reproducible with C++23)

There is a minimal reproducer attached.

minimal-standalone.zip

[llvmbot]

@llvm/issue-subscribers-clang-modules

Author: None (mrwsl)

Details

The Clang static analyzer crashes when analyzing code that imports C++20 modules **built with coverage instrumentation flags** (`-fprofile-instr-generate -fcoverage-mapping`).

No external dependencies required - crashes with just standard library templates.

Environment:

• Clang version: 21.1.6 (could also reproduce with Ubuntu clang version 21.1.8)
• OS: Linux
• Standard: C++26 (also reproducible with C++23)

There is a minimal reproducer attached.

minimal-standalone.zip

[llvmbot]

@llvm/issue-subscribers-clang-static-analyzer

Author: None (mrwsl)

Details

The Clang static analyzer crashes when analyzing code that imports C++20 modules **built with coverage instrumentation flags** (`-fprofile-instr-generate -fcoverage-mapping`).

No external dependencies required - crashes with just standard library templates.

Environment:

• Clang version: 21.1.6 (could also reproduce with Ubuntu clang version 21.1.8)
• OS: Linux
• Standard: C++26 (also reproducible with C++23)

There is a minimal reproducer attached.

minimal-standalone.zip

[steakhal]

Could you try clang main if that reproduces the crash?
I build it just now, and it doesn't seem to crash.

[mrwsl]

You are correct. I could not reproduce the crash on main. Thanks! Do you know by any chance what commit fixed it? This one: 6c2caa6?

[steakhal]

You are correct. I could not reproduce the crash on main. Thanks! Do you know by any chance what commit fixed it? This one: 6c2caa6?

I don't know, and unfortunately I don't have the time to bisect this.
If it wasn't fixed on main, but would have worked in some earlier clang version; then I would have bisected this to find the cause. But I guess, this way it's less interesting for me.