diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/back/link.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/codegen_attrs.rs | 33 |
2 files changed, 7 insertions, 31 deletions
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs index c5792da2678..30128c4bea2 100644 --- a/compiler/rustc_codegen_ssa/src/back/link.rs +++ b/compiler/rustc_codegen_ssa/src/back/link.rs @@ -1986,7 +1986,7 @@ fn add_post_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor /// This method creates a synthetic object file, which contains undefined references to all symbols /// that are necessary for the linking. They are only present in symbol table but not actually /// used in any sections, so the linker will therefore pick relevant rlibs for linking, but -/// unused `#[no_mangle]` or `#[used]` can still be discard by GC sections. +/// unused `#[no_mangle]` or `#[used(compiler)]` can still be discard by GC sections. /// /// There's a few internal crates in the standard library (aka libcore and /// libstd) which actually have a circular dependence upon one another. This @@ -2020,7 +2020,8 @@ fn add_linked_symbol_object( if file.format() == object::BinaryFormat::MachO { // Divide up the sections into sub-sections via symbols for dead code stripping. - // Without this flag, unused `#[no_mangle]` or `#[used]` cannot be discard on MachO targets. + // Without this flag, unused `#[no_mangle]` or `#[used(compiler)]` cannot be + // discard on MachO targets. file.set_subsections_via_symbols(); } diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs index 4bcafa3be36..0b31fa8fa88 100644 --- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -195,35 +195,10 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs { tcx.dcx().emit_err(errors::ExpectedUsedSymbol { span: attr.span() }); } None => { - // Unfortunately, unconditionally using `llvm.used` causes - // issues in handling `.init_array` with the gold linker, - // but using `llvm.compiler.used` caused a nontrivial amount - // of unintentional ecosystem breakage -- particularly on - // Mach-O targets. - // - // As a result, we emit `llvm.compiler.used` only on ELF - // targets. This is somewhat ad-hoc, but actually follows - // our pre-LLVM 13 behavior (prior to the ecosystem - // breakage), and seems to match `clang`'s behavior as well - // (both before and after LLVM 13), possibly because they - // have similar compatibility concerns to us. See - // https://github.com/rust-lang/rust/issues/47384#issuecomment-1019080146 - // and following comments for some discussion of this, as - // well as the comments in `rustc_codegen_llvm` where these - // flags are handled. - // - // Anyway, to be clear: this is still up in the air - // somewhat, and is subject to change in the future (which - // is a good thing, because this would ideally be a bit - // more firmed up). - let is_like_elf = !(tcx.sess.target.is_like_darwin - || tcx.sess.target.is_like_windows - || tcx.sess.target.is_like_wasm); - codegen_fn_attrs.flags |= if is_like_elf { - CodegenFnAttrFlags::USED_COMPILER - } else { - CodegenFnAttrFlags::USED_LINKER - }; + // Unconditionally using `llvm.used` causes issues in handling + // `.init_array` with the gold linker. Luckily gold has been + // deprecated with GCC 15 and rustc now warns about using gold. + codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_LINKER } } } |