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| author | Matthias Krüger <476013+matthiaskrgr@users.noreply.github.com> | 2025-10-04 12:31:27 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-10-04 12:31:27 +0200 |
| commit | 82ccda32f48d52d1cadd0eb7826e72bf5f83bf9b (patch) | |
| tree | 65a41d4ada7e6361ba2c3717435e5edf0aa30808 /compiler/rustc_codegen_ssa/src | |
| parent | 65577da49cb7b7db1cc9b3aa8a4790d8d46349d2 (diff) | |
| parent | c721fa243825255c0f195d4282021e7c263c3e7f (diff) | |
| download | rust-82ccda32f48d52d1cadd0eb7826e72bf5f83bf9b.tar.gz rust-82ccda32f48d52d1cadd0eb7826e72bf5f83bf9b.zip | |
Rollup merge of #147117 - iximeow:ixi/illumos-used-attr, r=Noratrieb
interpret `#[used]` as `#[used(compiler)]` on illumos helps rust-lang/rust#146169 not be as painful: fixes the illumos regression in rust-lang/rust#140872, but `#[used(linker)]` is still erroneous on illumos generally. illumos' `ld` does not support a flag like either SHF_GNU_RETAIN or SHF_SUNW_NODISCARD, so there is no way to communicate `#[used(linker)]` for that target. Setting `USED_LINKER` to try results in LLVM setting SHF_SUNW_NODISCARD for Solaris-like targets, which is an unknown section header flag for illumos `ld` and prevents sections from being merged that otherwise would. As a motivating example, the `inventory` crate produces `#[used]` items to merge into `.init_array`. Because those items have an unknown section header flag they are not merged with the default `.init_array` with `frame_dummy`, and end up never executed. Downgrading `#[used]` to `#[used(compiler)]` on illumos keeps so-attributed items as preserved as they had been before https://github.com/rust-lang/rust/pull/140872. As was the case before that change, because rustc passes `-z ignore` to illumos `ld`, it's possible that `used` sections are GC'd at link time. https://github.com/rust-lang/rust/issues/146169 describes this unfortunate circumstance. ---- as it turns out, `tests/ui/attributes/used_with_archive.rs` had broken on `x86_64-unknown-illumos`, and this patch fixes it. the trials and tribulations of tier 2 :( r? ``@Noratrieb`` probably?
Diffstat (limited to 'compiler/rustc_codegen_ssa/src')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/codegen_attrs.rs | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs index 32ae810ecc8..2c7643e46ce 100644 --- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -263,6 +263,19 @@ fn process_builtin_attrs( AttributeKind::Used { used_by, .. } => match used_by { UsedBy::Compiler => codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_COMPILER, UsedBy::Linker => codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_LINKER, + UsedBy::Default => { + let used_form = if tcx.sess.target.os == "illumos" { + // illumos' `ld` doesn't support a section header that would represent + // `#[used(linker)]`, see + // https://github.com/rust-lang/rust/issues/146169. For that target, + // downgrade as if `#[used(compiler)]` was requested and hope for the + // best. + CodegenFnAttrFlags::USED_COMPILER + } else { + CodegenFnAttrFlags::USED_LINKER + }; + codegen_fn_attrs.flags |= used_form; + } }, AttributeKind::FfiConst(_) => { codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST |