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::linker::LinkerInfo;
8 use rustc_codegen_ssa::{CodegenResults, CompiledModule, CrateInfo, ModuleKind};
9 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
10 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
11 use rustc_middle::middle::cstore::EncodedMetadata;
12 use rustc_middle::mir::mono::{CodegenUnit, MonoItem};
13 use rustc_session::cgu_reuse_tracker::CguReuse;
14 use rustc_session::config::{DebugInfo, OutputType};
16 use cranelift_object::ObjectModule;
18 use crate::{prelude::*, BackendConfig};
20 struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
22 impl<HCX> HashStable<HCX> for ModuleCodegenResult {
23 fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
30 backend_config: &BackendConfig,
34 debug: Option<DebugContext<'_>>,
35 unwind_context: UnwindContext,
36 ) -> ModuleCodegenResult {
37 let mut product = module.finish();
39 if let Some(mut debug) = debug {
40 debug.emit(&mut product);
43 unwind_context.emit(&mut product);
45 let tmp_file = tcx.output_filenames(()).temp_path(OutputType::Object, Some(&name));
46 let obj = product.object.write().unwrap();
47 if let Err(err) = std::fs::write(&tmp_file, obj) {
48 tcx.sess.fatal(&format!("error writing object file: {}", err));
51 let work_product = if backend_config.disable_incr_cache {
54 rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
57 &Some(tmp_file.clone()),
62 CompiledModule { name, kind, object: Some(tmp_file), dwarf_object: None, bytecode: None },
67 fn reuse_workproduct_for_cgu(
69 cgu: &CodegenUnit<'_>,
70 work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
72 let incr_comp_session_dir = tcx.sess.incr_comp_session_dir();
73 let mut object = None;
74 let work_product = cgu.work_product(tcx);
75 if let Some(saved_file) = &work_product.saved_file {
77 tcx.output_filenames(()).temp_path(OutputType::Object, Some(&cgu.name().as_str()));
78 object = Some(obj_out.clone());
79 let source_file = rustc_incremental::in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
80 if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
81 tcx.sess.err(&format!(
82 "unable to copy {} to {}: {}",
83 source_file.display(),
90 work_products.insert(cgu.work_product_id(), work_product);
93 name: cgu.name().to_string(),
94 kind: ModuleKind::Regular,
103 (backend_config, cgu_name): (BackendConfig, rustc_span::Symbol),
104 ) -> ModuleCodegenResult {
105 let cgu = tcx.codegen_unit(cgu_name);
106 let mono_items = cgu.items_in_deterministic_order(tcx);
108 let isa = crate::build_isa(tcx.sess, &backend_config);
109 let mut module = crate::backend::make_module(tcx.sess, isa, cgu_name.as_str().to_string());
111 let mut cx = crate::CodegenCx::new(
113 backend_config.clone(),
115 tcx.sess.opts.debuginfo != DebugInfo::None,
117 super::predefine_mono_items(tcx, &mut module, &mono_items);
118 for (mono_item, _) in mono_items {
120 MonoItem::Fn(inst) => {
123 .time("codegen fn", || crate::base::codegen_fn(&mut cx, &mut module, inst));
125 MonoItem::Static(def_id) => crate::constant::codegen_static(tcx, &mut module, def_id),
126 MonoItem::GlobalAsm(item_id) => {
127 let item = cx.tcx.hir().item(item_id);
128 if let rustc_hir::ItemKind::GlobalAsm(asm) = item.kind {
129 if !asm.options.contains(InlineAsmOptions::ATT_SYNTAX) {
130 cx.global_asm.push_str("\n.intel_syntax noprefix\n");
132 cx.global_asm.push_str("\n.att_syntax\n");
134 for piece in asm.template {
136 InlineAsmTemplatePiece::String(ref s) => cx.global_asm.push_str(s),
137 InlineAsmTemplatePiece::Placeholder { .. } => todo!(),
140 cx.global_asm.push_str("\n.att_syntax\n\n");
142 bug!("Expected GlobalAsm found {:?}", item);
147 crate::main_shim::maybe_create_entry_wrapper(
150 &mut cx.unwind_context,
155 let debug_context = cx.debug_context;
156 let unwind_context = cx.unwind_context;
157 let codegen_result = tcx.sess.time("write object file", || {
161 cgu.name().as_str().to_string(),
169 codegen_global_asm(tcx, &cgu.name().as_str(), &cx.global_asm);
174 pub(crate) fn run_aot(
176 backend_config: BackendConfig,
177 metadata: EncodedMetadata,
178 need_metadata_module: bool,
179 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
180 use rustc_span::symbol::sym;
182 let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
183 let subsystem = tcx.sess.first_attr_value_str_by_name(crate_attrs, sym::windows_subsystem);
184 let windows_subsystem = subsystem.map(|subsystem| {
185 if subsystem != sym::windows && subsystem != sym::console {
186 tcx.sess.fatal(&format!(
187 "invalid windows subsystem `{}`, only \
188 `windows` and `console` are allowed",
192 subsystem.to_string()
195 let mut work_products = FxHashMap::default();
197 let cgus = if tcx.sess.opts.output_types.should_codegen() {
198 tcx.collect_and_partition_mono_items(()).1
200 // If only `--emit metadata` is used, we shouldn't perform any codegen.
201 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
205 if tcx.dep_graph.is_fully_enabled() {
207 tcx.ensure().codegen_unit(cgu.name());
211 let modules = super::time(tcx, backend_config.display_cg_time, "codegen mono items", || {
214 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
215 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
218 _ if backend_config.disable_incr_cache => {}
220 CguReuse::PreLto => {
221 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
223 CguReuse::PostLto => unreachable!(),
226 let dep_node = cgu.codegen_dep_node(tcx);
227 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
230 (backend_config.clone(), cgu.name()),
232 rustc_middle::dep_graph::hash_result,
235 if let Some((id, product)) = work_product {
236 work_products.insert(id, product);
244 tcx.sess.abort_if_errors();
246 let isa = crate::build_isa(tcx.sess, &backend_config);
247 let mut allocator_module =
248 crate::backend::make_module(tcx.sess, isa, "allocator_shim".to_string());
249 assert_eq!(pointer_ty(tcx), allocator_module.target_config().pointer_type());
250 let mut allocator_unwind_context = UnwindContext::new(tcx, allocator_module.isa(), true);
251 let created_alloc_shim =
252 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
254 let allocator_module = if created_alloc_shim {
255 let ModuleCodegenResult(module, work_product) = emit_module(
258 "allocator_shim".to_string(),
259 ModuleKind::Allocator,
262 allocator_unwind_context,
264 if let Some((id, product)) = work_product {
265 work_products.insert(id, product);
272 let metadata_module = if need_metadata_module {
273 let _timer = tcx.prof.generic_activity("codegen crate metadata");
274 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
275 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
277 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
278 let metadata_cgu_name = cgu_name_builder
279 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
284 tcx.output_filenames(()).temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
286 let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
287 crate::metadata::write_metadata(tcx, object);
290 if let Err(err) = std::fs::write(&tmp_file, obj) {
291 tcx.sess.fatal(&format!("error writing metadata object file: {}", err));
294 (metadata_cgu_name, tmp_file)
297 Some(CompiledModule {
298 name: metadata_cgu_name,
299 kind: ModuleKind::Metadata,
300 object: Some(tmp_file),
310 crate_name: tcx.crate_name(LOCAL_CRATE),
316 linker_info: LinkerInfo::new(tcx, crate::target_triple(tcx.sess).to_string()),
317 crate_info: CrateInfo::new(tcx),
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 }