llvm-project

4ea39c43 - [LIT] Use forward slashes in substitutions when LLVM_WINDOWS_PREFER_FORWARD_SLASH is set (#179865)

[LIT] Use forward slashes in substitutions when LLVM_WINDOWS_PREFER_FORWARD_SLASH is set (#179865) When building with `-DLLVM_WINDOWS_PREFER_FORWARD_SLASH=ON`, tools like lld output paths with forward slashes on Windows. However, lit's default substitutions (`%t`, `%p`) typically use backslashes on Windows, causing FileCheck failures in tests that strictly match path separators. This patch propagates the `LLVM_WINDOWS_PREFER_FORWARD_SLASH` build flag to llvm-lit via `builtin_parameters`. It also updates lit's TestRunner to respect the 'use_normalized_slashes' parameter. When enabled, lit normalizes paths in substitutions to use forward slashes, ensuring that test expectations align with the tool output. With this fix, the number of failed tests with `-DLLVM_WINDOWS_PREFER_FORWARD_SLASH=ON` changes as follow: - The total number of failed tests: 303 -> 168 - Break down: - `Builtins-i386-windows` tests: 99 -> 0 - `Clang` tests: 28 -> 5 - `Clang Tools` tests: 7 -> 1 - `LLVM` tests: 6 -> 4 - `lld` tests: 2 -> 0 - Other failed tests: - `glang`: 1 - `Clang-Unit`: 5 - `Clangd`: 3 - `Clangd Unit Tests`: 150 - `LLVM-Unit`: 1