From 748dba2bafab14117f626348b716a824d301cffd Mon Sep 17 00:00:00 2001 From: Ben Kimock Date: Mon, 1 Apr 2024 20:17:12 -0400 Subject: [PATCH] Only allow upstream calls to LLVM intrinsics, not any link_name function --- compiler/rustc_monomorphize/src/lib.rs | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/compiler/rustc_monomorphize/src/lib.rs b/compiler/rustc_monomorphize/src/lib.rs index 9c4a6e69a3c..2a91d69529a 100644 --- a/compiler/rustc_monomorphize/src/lib.rs +++ b/compiler/rustc_monomorphize/src/lib.rs @@ -14,6 +14,7 @@ use rustc_middle::ty::Instance; use rustc_middle::ty::TyCtxt; use rustc_middle::ty::{self, Ty}; +use rustc_span::def_id::DefId; use rustc_span::def_id::LOCAL_CRATE; use rustc_span::ErrorGuaranteed; @@ -57,13 +58,24 @@ fn custom_coerce_unsize_info<'tcx>( /// linkers will optimize such that dead calls to unresolved symbols are not an error, but this is /// not guaranteed. So we used this function in codegen backends to ensure we do not generate any /// unlinkable calls. +/// +/// Note that calls to LLVM intrinsics are uniquely okay because they won't make it to the linker. pub fn is_call_from_compiler_builtins_to_upstream_monomorphization<'tcx>( tcx: TyCtxt<'tcx>, instance: Instance<'tcx>, ) -> bool { - !instance.def_id().is_local() + fn is_llvm_intrinsic(tcx: TyCtxt<'_>, def_id: DefId) -> bool { + if let Some(name) = tcx.codegen_fn_attrs(def_id).link_name { + name.as_str().starts_with("llvm.") + } else { + false + } + } + + let def_id = instance.def_id(); + !def_id.is_local() && tcx.is_compiler_builtins(LOCAL_CRATE) - && tcx.codegen_fn_attrs(instance.def_id()).link_name.is_none() + && !is_llvm_intrinsic(tcx, def_id) && !should_codegen_locally(tcx, instance) }