From 6c4e958fad41710337b9827a0a8cb351e78a838f Mon Sep 17 00:00:00 2001 From: Romain Perier Date: Sat, 6 Sep 2025 16:35:11 +0200 Subject: [PATCH] Update comment for werror on rust-lang/rust CI explaining why we keep MSVC definitively excluded --- compiler/rustc_llvm/build.rs | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs index d01f79dcade0b..225ab8c846d82 100644 --- a/compiler/rustc_llvm/build.rs +++ b/compiler/rustc_llvm/build.rs @@ -174,10 +174,10 @@ fn main() { // Prevent critical warnings when we're compiling from rust-lang/rust CI, // except on MSVC, as the compiler throws warnings that are only reported - // for this platform. See https://github.com/rust-lang/rust/pull/145031#issuecomment-3162677202 - // FIXME(llvm22): It looks like the specific problem code has been removed - // in https://github.com/llvm/llvm-project/commit/e8fc808bf8e78a3c80d1f8e293a92677b92366dd, - // retry msvc once we bump our LLVM version. + // for this platform. See https://github.com/rust-lang/rust/pull/145031#issuecomment-3162677202. + // Moreover, LLVM generally guarantees warning-freedom only when building with Clang, as other + // compilers have too many false positives. This is typically the case for MSVC, which throws + // many false-positive warnings. We keep it excluded, for these reasons. if std::env::var_os("CI").is_some() && !target.contains("msvc") { cfg.warnings_into_errors(true); }