1 //! The AOT driver uses [`cranelift_object`] to write object files suitable for linking into a
2 //! standalone executable.
4 use std::path::PathBuf;
6 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
7 use rustc_codegen_ssa::back::metadata::create_compressed_metadata_file;
8 use rustc_codegen_ssa::{CodegenResults, CompiledModule, CrateInfo, ModuleKind};
9 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
10 use rustc_metadata::EncodedMetadata;
11 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
12 use rustc_middle::mir::mono::{CodegenUnit, MonoItem};
13 use rustc_session::cgu_reuse_tracker::CguReuse;
14 use rustc_session::config::{DebugInfo, OutputType};
15 use rustc_session::Session;
17 use cranelift_codegen::isa::TargetIsa;
18 use cranelift_object::{ObjectBuilder, ObjectModule};
20 use crate::{prelude::*, BackendConfig};
22 struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
24 impl<HCX> HashStable<HCX> for ModuleCodegenResult {
25 fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
30 fn make_module(sess: &Session, isa: Box<dyn TargetIsa>, name: String) -> ObjectModule {
32 ObjectBuilder::new(isa, name + ".o", cranelift_module::default_libcall_names()).unwrap();
33 // Unlike cg_llvm, cg_clif defaults to disabling -Zfunction-sections. For cg_llvm binary size
34 // is important, while cg_clif cares more about compilation times. Enabling -Zfunction-sections
35 // can easily double the amount of time necessary to perform linking.
36 builder.per_function_section(sess.opts.unstable_opts.function_sections.unwrap_or(false));
37 ObjectModule::new(builder)
42 backend_config: &BackendConfig,
46 debug: Option<DebugContext<'_>>,
47 unwind_context: UnwindContext,
48 ) -> ModuleCodegenResult {
49 let mut product = module.finish();
51 if let Some(mut debug) = debug {
52 debug.emit(&mut product);
55 unwind_context.emit(&mut product);
57 let tmp_file = tcx.output_filenames(()).temp_path(OutputType::Object, Some(&name));
58 let obj = product.object.write().unwrap();
60 tcx.sess.prof.artifact_size("object_file", name.clone(), obj.len().try_into().unwrap());
62 if let Err(err) = std::fs::write(&tmp_file, obj) {
63 tcx.sess.fatal(&format!("error writing object file: {}", err));
66 let work_product = if backend_config.disable_incr_cache {
69 rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
77 CompiledModule { name, kind, object: Some(tmp_file), dwarf_object: None, bytecode: None },
82 fn reuse_workproduct_for_cgu(
84 cgu: &CodegenUnit<'_>,
85 work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
87 let work_product = cgu.previous_work_product(tcx);
88 let obj_out = tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));
89 let source_file = rustc_incremental::in_incr_comp_dir_sess(
91 &work_product.saved_files.get("o").expect("no saved object file in work product"),
93 if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
94 tcx.sess.err(&format!(
95 "unable to copy {} to {}: {}",
96 source_file.display(),
102 work_products.insert(cgu.work_product_id(), work_product);
105 name: cgu.name().to_string(),
106 kind: ModuleKind::Regular,
107 object: Some(obj_out),
115 (backend_config, cgu_name): (BackendConfig, rustc_span::Symbol),
116 ) -> ModuleCodegenResult {
117 let cgu = tcx.codegen_unit(cgu_name);
118 let mono_items = cgu.items_in_deterministic_order(tcx);
120 let isa = crate::build_isa(tcx.sess, &backend_config);
121 let mut module = make_module(tcx.sess, isa, cgu_name.as_str().to_string());
123 let mut cx = crate::CodegenCx::new(
125 backend_config.clone(),
127 tcx.sess.opts.debuginfo != DebugInfo::None,
130 super::predefine_mono_items(tcx, &mut module, &mono_items);
131 for (mono_item, _) in mono_items {
133 MonoItem::Fn(inst) => {
136 .time("codegen fn", || crate::base::codegen_fn(&mut cx, &mut module, inst));
138 MonoItem::Static(def_id) => crate::constant::codegen_static(tcx, &mut module, def_id),
139 MonoItem::GlobalAsm(item_id) => {
140 let item = cx.tcx.hir().item(item_id);
141 if let rustc_hir::ItemKind::GlobalAsm(asm) = item.kind {
142 if !asm.options.contains(InlineAsmOptions::ATT_SYNTAX) {
143 cx.global_asm.push_str("\n.intel_syntax noprefix\n");
145 cx.global_asm.push_str("\n.att_syntax\n");
147 for piece in asm.template {
149 InlineAsmTemplatePiece::String(ref s) => cx.global_asm.push_str(s),
150 InlineAsmTemplatePiece::Placeholder { .. } => todo!(),
153 cx.global_asm.push_str("\n.att_syntax\n\n");
155 bug!("Expected GlobalAsm found {:?}", item);
160 crate::main_shim::maybe_create_entry_wrapper(
163 &mut cx.unwind_context,
168 let debug_context = cx.debug_context;
169 let unwind_context = cx.unwind_context;
170 let codegen_result = tcx.sess.time("write object file", || {
174 cgu.name().as_str().to_string(),
182 codegen_global_asm(tcx, cgu.name().as_str(), &cx.global_asm);
187 pub(crate) fn run_aot(
189 backend_config: BackendConfig,
190 metadata: EncodedMetadata,
191 need_metadata_module: bool,
192 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
193 let mut work_products = FxHashMap::default();
195 let cgus = if tcx.sess.opts.output_types.should_codegen() {
196 tcx.collect_and_partition_mono_items(()).1
198 // If only `--emit metadata` is used, we shouldn't perform any codegen.
199 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
203 if tcx.dep_graph.is_fully_enabled() {
205 tcx.ensure().codegen_unit(cgu.name());
209 let modules = super::time(tcx, backend_config.display_cg_time, "codegen mono items", || {
212 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
213 tcx.sess.cgu_reuse_tracker.set_actual_reuse(cgu.name().as_str(), cgu_reuse);
216 _ if backend_config.disable_incr_cache => {}
218 CguReuse::PreLto => {
219 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
221 CguReuse::PostLto => unreachable!(),
224 let dep_node = cgu.codegen_dep_node(tcx);
225 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
228 (backend_config.clone(), cgu.name()),
230 Some(rustc_middle::dep_graph::hash_result),
233 if let Some((id, product)) = work_product {
234 work_products.insert(id, product);
242 tcx.sess.abort_if_errors();
244 let isa = crate::build_isa(tcx.sess, &backend_config);
245 let mut allocator_module = make_module(tcx.sess, isa, "allocator_shim".to_string());
246 assert_eq!(pointer_ty(tcx), allocator_module.target_config().pointer_type());
247 let mut allocator_unwind_context = UnwindContext::new(allocator_module.isa(), true);
248 let created_alloc_shim =
249 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
251 let allocator_module = if created_alloc_shim {
252 let ModuleCodegenResult(module, work_product) = emit_module(
255 "allocator_shim".to_string(),
256 ModuleKind::Allocator,
259 allocator_unwind_context,
261 if let Some((id, product)) = work_product {
262 work_products.insert(id, product);
269 let metadata_module = if need_metadata_module {
270 let _timer = tcx.prof.generic_activity("codegen crate metadata");
271 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
272 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
274 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
275 let metadata_cgu_name = cgu_name_builder
276 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
281 tcx.output_filenames(()).temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
283 let symbol_name = rustc_middle::middle::exported_symbols::metadata_symbol_name(tcx);
284 let obj = create_compressed_metadata_file(tcx.sess, &metadata, &symbol_name);
286 if let Err(err) = std::fs::write(&tmp_file, obj) {
287 tcx.sess.fatal(&format!("error writing metadata object file: {}", err));
290 (metadata_cgu_name, tmp_file)
293 Some(CompiledModule {
294 name: metadata_cgu_name,
295 kind: ModuleKind::Metadata,
296 object: Some(tmp_file),
304 // FIXME handle `-Ctarget-cpu=native`
305 let target_cpu = match tcx.sess.opts.cg.target_cpu {
306 Some(ref name) => name,
307 None => tcx.sess.target.cpu.as_ref(),
317 crate_info: CrateInfo::new(tcx, target_cpu),
323 fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
325 use std::process::{Command, Stdio};
327 if global_asm.is_empty() {
331 if cfg!(not(feature = "inline_asm"))
332 || tcx.sess.target.is_like_osx
333 || tcx.sess.target.is_like_windows
335 if global_asm.contains("__rust_probestack") {
339 // FIXME fix linker error on macOS
340 if cfg!(not(feature = "inline_asm")) {
342 "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift",
345 tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
349 let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as");
350 let linker = crate::toolchain::get_toolchain_binary(tcx.sess, "ld");
352 // Remove all LLVM style comments
353 let global_asm = global_asm
355 .map(|line| if let Some(index) = line.find("//") { &line[0..index] } else { line })
359 let output_object_file = tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu_name));
361 // Assemble `global_asm`
362 let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
363 let mut child = Command::new(assembler)
365 .arg(&global_asm_object_file)
366 .stdin(Stdio::piped())
368 .expect("Failed to spawn `as`.");
369 child.stdin.take().unwrap().write_all(global_asm.as_bytes()).unwrap();
370 let status = child.wait().expect("Failed to wait for `as`.");
371 if !status.success() {
372 tcx.sess.fatal(&format!("Failed to assemble `{}`", global_asm));
375 // Link the global asm and main object file together
376 let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main");
377 std::fs::rename(&output_object_file, &main_object_file).unwrap();
378 let status = Command::new(linker)
379 .arg("-r") // Create a new object file
381 .arg(output_object_file)
382 .arg(&main_object_file)
383 .arg(&global_asm_object_file)
386 if !status.success() {
387 tcx.sess.fatal(&format!(
388 "Failed to link `{}` and `{}` together",
389 main_object_file.display(),
390 global_asm_object_file.display(),
394 std::fs::remove_file(global_asm_object_file).unwrap();
395 std::fs::remove_file(main_object_file).unwrap();
398 fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf {
399 let mut new_filename = path.file_stem().unwrap().to_owned();
400 new_filename.push(postfix);
401 if let Some(extension) = path.extension() {
402 new_filename.push(".");
403 new_filename.push(extension);
405 path.set_file_name(new_filename);
409 // Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
410 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
411 if !tcx.dep_graph.is_fully_enabled() {
415 let work_product_id = &cgu.work_product_id();
416 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
417 // We don't have anything cached for this CGU. This can happen
418 // if the CGU did not exist in the previous session.
422 // Try to mark the CGU as green. If it we can do so, it means that nothing
423 // affecting the LLVM module has changed and we can re-use a cached version.
424 // If we compile with any kind of LTO, this means we can re-use the bitcode
425 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
426 // know that later). If we are not doing LTO, there is only one optimized
427 // version of each module, so we re-use that.
428 let dep_node = cgu.codegen_dep_node(tcx);
430 !tcx.dep_graph.dep_node_exists(&dep_node),
431 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
435 if tcx.try_mark_green(&dep_node) { CguReuse::PreLto } else { CguReuse::No }