diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/back/write.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/back/write.rs | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs index 8e835039970..af1c6594446 100644 --- a/compiler/rustc_codegen_ssa/src/back/write.rs +++ b/compiler/rustc_codegen_ssa/src/back/write.rs @@ -148,12 +148,23 @@ impl ModuleConfig { let emit_obj = if !should_emit_obj { EmitObj::None - } else if sess.target.obj_is_bitcode || sess.opts.cg.linker_plugin_lto.enabled() { + } else if sess.target.obj_is_bitcode + || (sess.opts.cg.linker_plugin_lto.enabled() && !no_builtins) + { // This case is selected if the target uses objects as bitcode, or // if linker plugin LTO is enabled. In the linker plugin LTO case // the assumption is that the final link-step will read the bitcode // and convert it to object code. This may be done by either the // native linker or rustc itself. + // + // Note, however, that the linker-plugin-lto requested here is + // explicitly ignored for `#![no_builtins]` crates. These crates are + // specifically ignored by rustc's LTO passes and wouldn't work if + // loaded into the linker. These crates define symbols that LLVM + // lowers intrinsics to, and these symbol dependencies aren't known + // until after codegen. As a result any crate marked + // `#![no_builtins]` is assumed to not participate in LTO and + // instead goes on to generate object code. EmitObj::Bitcode } else if need_bitcode_in_object(tcx) { EmitObj::ObjectCode(BitcodeSection::Full) @@ -1023,6 +1034,9 @@ fn start_executing_work<B: ExtraBackendMethods>( let mut each_linked_rlib_for_lto = Vec::new(); drop(link::each_linked_rlib(crate_info, None, &mut |cnum, path| { + if link::ignored_for_lto(sess, crate_info, cnum) { + return; + } each_linked_rlib_for_lto.push((cnum, path.to_path_buf())); })); |