llvm-project

b7cc3c56 - [C++20][Modules] Do not apply `getAdjustedOffset` to file-internal byte offset. (#184956)

[C++20][Modules] Do not apply `getAdjustedOffset` to file-internal byte offset. (#184956) In https://reviews.llvm.org/D137214 and https://reviews.llvm.org/D136624, offset adjustment logic was added to account for the non-affecting module map files that are removed. While the adjustment logic applies to global source location offsets, they do not apply to file-internal offsets (relative within the file). In `ASTWriter::WritePragmaDiagnosticMappings`, the adjustment is applied to `StatePoint.Offset`s in `StateTransitions`. However, these offsets are file-internal offsets, not global source location offsets. As such, applying adjustment to these offsets result in incorrect diagnostic behavior from the module. Specifically, wrapping a piece of code in `pragma clang diagnostic push/pop`, inside of a module is not applied correctly. A new test case `diag-pragma-nonaffecting.cpp` was added to verify the broken behavior as well as the corrected behavior with this commit. Assisted-by: Claude Opus 4.6