diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/consts.rs | 34 |
1 files changed, 7 insertions, 27 deletions
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index a1ab590335a..ea5df912438 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -543,33 +543,13 @@ impl<'ll> StaticMethods for CodegenCx<'ll, '_> { // 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). // - // However, unconditional use of `llvm.compiler.used` caused a nontrivial amount of - // ecosystem breakage, especially on Mach-O targets. To resolve this, we compile it - // as llvm.compiler.used on ELF targets and llvm.used elsewhere, which should be - // equivalent to how we compiled `#[used]` before LLVM 13, as `llvm.used` and - // `llvm.compiler.used` were treated the same on ELF targets prior in earlier LLVM - // versions (additionally, it seems to be how Clang handles `__attribute__((used))`, - // perhaps for similar compatibility-motivated reasons). - // - // See https://github.com/rust-lang/rust/issues/47384#issuecomment-1019080146 and - // following comments for some discussion of this. - // - // The final wrinkle is it's not really clear how to tell if we're going to output - // ELF, so it's been approximated as "not like wasm, osx, or windows", which is - // not exactly correct, but is pretty close and hopefully handles all the platforms - // platforms where old versions of `ld.gold` are likely to show up. - // - // All this is subject to change in the future. Which is a good thing, because this - // probably should be firmed up somehow! - let seems_like_elf = !(self.tcx.sess.target.is_like_osx - || self.tcx.sess.target.is_like_windows - || self.tcx.sess.target.is_like_wasm); - - if seems_like_elf { - self.add_compiler_used_global(g); - } else { - self.add_used_global(g); - } + // 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) { // `USED` and `USED_LINKER` can't be used together. |