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 {
78 .temp_path(OutputType::Object, Some(&cgu.name().as_str()));
79 object = Some(obj_out.clone());
80 let source_file = rustc_incremental::in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
81 if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
82 tcx.sess.err(&format!(
83 "unable to copy {} to {}: {}",
84 source_file.display(),
91 work_products.insert(cgu.work_product_id(), work_product);
94 name: cgu.name().to_string(),
95 kind: ModuleKind::Regular,
104 (backend_config, cgu_name): (BackendConfig, rustc_span::Symbol),
105 ) -> ModuleCodegenResult {
106 let cgu = tcx.codegen_unit(cgu_name);
107 let mono_items = cgu.items_in_deterministic_order(tcx);
109 let isa = crate::build_isa(tcx.sess, &backend_config);
110 let mut module = crate::backend::make_module(tcx.sess, isa, cgu_name.as_str().to_string());
112 let mut cx = crate::CodegenCx::new(
114 backend_config.clone(),
116 tcx.sess.opts.debuginfo != DebugInfo::None,
118 super::predefine_mono_items(tcx, &mut module, &mono_items);
119 for (mono_item, _) in mono_items {
121 MonoItem::Fn(inst) => {
124 .time("codegen fn", || crate::base::codegen_fn(&mut cx, &mut module, inst));
126 MonoItem::Static(def_id) => crate::constant::codegen_static(tcx, &mut module, def_id),
127 MonoItem::GlobalAsm(item_id) => {
128 let item = cx.tcx.hir().item(item_id);
129 if let rustc_hir::ItemKind::GlobalAsm(asm) = item.kind {
130 if !asm.options.contains(InlineAsmOptions::ATT_SYNTAX) {
131 cx.global_asm.push_str("\n.intel_syntax noprefix\n");
133 cx.global_asm.push_str("\n.att_syntax\n");
135 for piece in asm.template {
137 InlineAsmTemplatePiece::String(ref s) => cx.global_asm.push_str(s),
138 InlineAsmTemplatePiece::Placeholder { .. } => todo!(),
141 cx.global_asm.push_str("\n.att_syntax\n\n");
143 bug!("Expected GlobalAsm found {:?}", item);
148 crate::main_shim::maybe_create_entry_wrapper(tcx, &mut module, &mut cx.unwind_context, false);
150 let debug_context = cx.debug_context;
151 let unwind_context = cx.unwind_context;
152 let codegen_result = tcx.sess.time("write object file", || {
156 cgu.name().as_str().to_string(),
164 codegen_global_asm(tcx, &cgu.name().as_str(), &cx.global_asm);
169 pub(crate) fn run_aot(
171 backend_config: BackendConfig,
172 metadata: EncodedMetadata,
173 need_metadata_module: bool,
174 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
175 use rustc_span::symbol::sym;
177 let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
178 let subsystem = tcx.sess.first_attr_value_str_by_name(crate_attrs, sym::windows_subsystem);
179 let windows_subsystem = subsystem.map(|subsystem| {
180 if subsystem != sym::windows && subsystem != sym::console {
181 tcx.sess.fatal(&format!(
182 "invalid windows subsystem `{}`, only \
183 `windows` and `console` are allowed",
187 subsystem.to_string()
190 let mut work_products = FxHashMap::default();
192 let cgus = if tcx.sess.opts.output_types.should_codegen() {
193 tcx.collect_and_partition_mono_items(()).1
195 // If only `--emit metadata` is used, we shouldn't perform any codegen.
196 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
200 if tcx.dep_graph.is_fully_enabled() {
202 tcx.ensure().codegen_unit(cgu.name());
206 let modules = super::time(tcx, backend_config.display_cg_time, "codegen mono items", || {
209 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
210 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
213 _ if backend_config.disable_incr_cache => {}
215 CguReuse::PreLto => {
216 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
218 CguReuse::PostLto => unreachable!(),
221 let dep_node = cgu.codegen_dep_node(tcx);
222 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
225 (backend_config.clone(), cgu.name()),
227 rustc_middle::dep_graph::hash_result,
230 if let Some((id, product)) = work_product {
231 work_products.insert(id, product);
239 tcx.sess.abort_if_errors();
241 let isa = crate::build_isa(tcx.sess, &backend_config);
242 let mut allocator_module =
243 crate::backend::make_module(tcx.sess, isa, "allocator_shim".to_string());
244 assert_eq!(pointer_ty(tcx), allocator_module.target_config().pointer_type());
245 let mut allocator_unwind_context = UnwindContext::new(tcx, allocator_module.isa(), true);
246 let created_alloc_shim =
247 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
249 let allocator_module = if created_alloc_shim {
250 let ModuleCodegenResult(module, work_product) = emit_module(
253 "allocator_shim".to_string(),
254 ModuleKind::Allocator,
257 allocator_unwind_context,
259 if let Some((id, product)) = work_product {
260 work_products.insert(id, product);
267 let metadata_module = if need_metadata_module {
268 let _timer = tcx.prof.generic_activity("codegen crate metadata");
269 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
270 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
272 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
273 let metadata_cgu_name = cgu_name_builder
274 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
279 .output_filenames(())
280 .temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
282 let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
283 crate::metadata::write_metadata(tcx, object);
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),
306 crate_name: tcx.crate_name(LOCAL_CRATE),
312 linker_info: LinkerInfo::new(tcx, crate::target_triple(tcx.sess).to_string()),
313 crate_info: CrateInfo::new(tcx),
319 fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
321 use std::process::{Command, Stdio};
323 if global_asm.is_empty() {
327 if cfg!(not(feature = "inline_asm"))
328 || tcx.sess.target.is_like_osx
329 || tcx.sess.target.is_like_windows
331 if global_asm.contains("__rust_probestack") {
335 // FIXME fix linker error on macOS
336 if cfg!(not(feature = "inline_asm")) {
338 "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift",
341 tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
345 let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as");
346 let linker = crate::toolchain::get_toolchain_binary(tcx.sess, "ld");
348 // Remove all LLVM style comments
349 let global_asm = global_asm
351 .map(|line| if let Some(index) = line.find("//") { &line[0..index] } else { line })
355 let output_object_file =
356 tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu_name));
358 // Assemble `global_asm`
359 let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
360 let mut child = Command::new(assembler)
362 .arg(&global_asm_object_file)
363 .stdin(Stdio::piped())
365 .expect("Failed to spawn `as`.");
366 child.stdin.take().unwrap().write_all(global_asm.as_bytes()).unwrap();
367 let status = child.wait().expect("Failed to wait for `as`.");
368 if !status.success() {
369 tcx.sess.fatal(&format!("Failed to assemble `{}`", global_asm));
372 // Link the global asm and main object file together
373 let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main");
374 std::fs::rename(&output_object_file, &main_object_file).unwrap();
375 let status = Command::new(linker)
376 .arg("-r") // Create a new object file
378 .arg(output_object_file)
379 .arg(&main_object_file)
380 .arg(&global_asm_object_file)
383 if !status.success() {
384 tcx.sess.fatal(&format!(
385 "Failed to link `{}` and `{}` together",
386 main_object_file.display(),
387 global_asm_object_file.display(),
391 std::fs::remove_file(global_asm_object_file).unwrap();
392 std::fs::remove_file(main_object_file).unwrap();
395 fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf {
396 let mut new_filename = path.file_stem().unwrap().to_owned();
397 new_filename.push(postfix);
398 if let Some(extension) = path.extension() {
399 new_filename.push(".");
400 new_filename.push(extension);
402 path.set_file_name(new_filename);
406 // Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
407 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
408 if !tcx.dep_graph.is_fully_enabled() {
412 let work_product_id = &cgu.work_product_id();
413 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
414 // We don't have anything cached for this CGU. This can happen
415 // if the CGU did not exist in the previous session.
419 // Try to mark the CGU as green. If it we can do so, it means that nothing
420 // affecting the LLVM module has changed and we can re-use a cached version.
421 // If we compile with any kind of LTO, this means we can re-use the bitcode
422 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
423 // know that later). If we are not doing LTO, there is only one optimized
424 // version of each module, so we re-use that.
425 let dep_node = cgu.codegen_dep_node(tcx);
427 !tcx.dep_graph.dep_node_exists(&dep_node),
428 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
432 if tcx.try_mark_green(&dep_node) { CguReuse::PreLto } else { CguReuse::No }