[danielepoterti]

The import was a throwing stub in Export.cpp, kept as a dead import of Cyberpunk 2077 (no call sites) that the Windows loader resolves strictly. It now sits with the other Atomic helpers in RuntimeSupport.cpp and throws std::runtime_error carrying both string arguments, with "(null)" for a null pointer.

The mangled name gives two const char* parameters. Naming them expression and file follows the usual assert handler order (__assert_fail, _wassert); no source confirms the order for this library.

What

Implement std::_Atomic_assert (_ZSt14_Atomic_assertPKcS0_) in libc.

The export was a throwing stub in Export.cpp, kept for a dead import of Cyberpunk 2077 that the Windows loader resolves strictly. It now sits with the other _Atomic_ helpers in RuntimeSupport.cpp and throws std::runtime_error carrying both string arguments ("(null)" for a null pointer).

The mangled name gives two const char* parameters. The names expression and file follow the usual assert handler order (__assert_fail, _wassert); no source confirms the order for this library.

guest_atomic_assert checks the message for both strings and for null pointers, on every platform.

Tested

Windows 11, MinGW-w64 GCC 15.2.0 (WinLibs r7): built libc, guest_atomic_assert passes; checked that it fails with the wrong expected message. Linux not tested locally.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed in TechnicalDebt
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• AI-assisted: yes

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
#1498		_ZSt14_Atomic_assertPKcS0__nid_postfix

[danielepoterti]

Closing in favour of #1498, which already implements std::_Atomic_assert; I missed it before opening this.