diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/consts.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/consts.rs | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index 2b16ae1a88d..9d40f9c5d86 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -535,10 +535,20 @@ impl<'ll> StaticMethods for CodegenCx<'ll, '_> { // The semantics of #[used] in Rust only require the symbol to make it into the // object file. It is explicitly allowed for the linker to strip the symbol if it - // is dead. As such, use llvm.compiler.used instead of llvm.used. + // is dead, which means we are allowed use `llvm.compiler.used` instead of + // `llvm.used` here. + // // Additionally, https://reviews.llvm.org/D97448 in LLVM 13 started emitting unique // sections with SHF_GNU_RETAIN flag for llvm.used symbols, which may trigger bugs - // in some versions of the gold linker. + // in the handling of `.init_array` (the static constructor list) in versions of + // the gold linker (prior to the one released with binutils 2.36). + // + // That said, we only ever emit these when compiling for ELF targets, unless + // `#[used(compiler)]` is explicitly requested. This is to avoid similar breakage + // on other targets, in particular MachO targets have *their* static constructor + // lists broken if `llvm.compiler.used` is emitted rather than llvm.used. However, + // that check happens when assigning the `CodegenFnAttrFlags` in `rustc_typeck`, + // so we don't need to take care of it here. self.add_compiler_used_global(g); } if attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) { |