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_codegen_ssa::back::linker::LinkerInfo;
7 use rustc_codegen_ssa::{CodegenResults, CompiledModule, CrateInfo, ModuleKind};
8 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
9 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
10 use rustc_middle::middle::cstore::EncodedMetadata;
11 use rustc_middle::mir::mono::{CodegenUnit, MonoItem};
12 use rustc_session::cgu_reuse_tracker::CguReuse;
13 use rustc_session::config::{DebugInfo, OutputType};
15 use cranelift_object::ObjectModule;
17 use crate::{prelude::*, BackendConfig};
19 struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
21 impl<HCX> HashStable<HCX> for ModuleCodegenResult {
22 fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
29 backend_config: &BackendConfig,
33 debug: Option<DebugContext<'_>>,
34 unwind_context: UnwindContext,
35 ) -> ModuleCodegenResult {
36 let mut product = module.finish();
38 if let Some(mut debug) = debug {
39 debug.emit(&mut product);
42 unwind_context.emit(&mut product);
44 let tmp_file = tcx.output_filenames(LOCAL_CRATE).temp_path(OutputType::Object, Some(&name));
45 let obj = product.object.write().unwrap();
46 if let Err(err) = std::fs::write(&tmp_file, obj) {
47 tcx.sess.fatal(&format!("error writing object file: {}", err));
50 let work_product = if backend_config.disable_incr_cache {
53 rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
56 &Some(tmp_file.clone()),
61 CompiledModule { name, kind, object: Some(tmp_file), dwarf_object: None, bytecode: None },
66 fn reuse_workproduct_for_cgu(
68 cgu: &CodegenUnit<'_>,
69 work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
71 let incr_comp_session_dir = tcx.sess.incr_comp_session_dir();
72 let mut object = None;
73 let work_product = cgu.work_product(tcx);
74 if let Some(saved_file) = &work_product.saved_file {
76 .output_filenames(LOCAL_CRATE)
77 .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(rustc_hir::GlobalAsm { asm }) = item.kind {
129 cx.global_asm.push_str(&*asm.as_str());
130 cx.global_asm.push_str("\n\n");
132 bug!("Expected GlobalAsm found {:?}", item);
137 crate::main_shim::maybe_create_entry_wrapper(tcx, &mut module, &mut cx.unwind_context, false);
139 let debug_context = cx.debug_context;
140 let unwind_context = cx.unwind_context;
141 let codegen_result = tcx.sess.time("write object file", || {
145 cgu.name().as_str().to_string(),
153 codegen_global_asm(tcx, &cgu.name().as_str(), &cx.global_asm);
158 pub(crate) fn run_aot(
160 backend_config: BackendConfig,
161 metadata: EncodedMetadata,
162 need_metadata_module: bool,
163 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
164 use rustc_span::symbol::sym;
166 let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
167 let subsystem = tcx.sess.first_attr_value_str_by_name(crate_attrs, sym::windows_subsystem);
168 let windows_subsystem = subsystem.map(|subsystem| {
169 if subsystem != sym::windows && subsystem != sym::console {
170 tcx.sess.fatal(&format!(
171 "invalid windows subsystem `{}`, only \
172 `windows` and `console` are allowed",
176 subsystem.to_string()
179 let mut work_products = FxHashMap::default();
181 let cgus = if tcx.sess.opts.output_types.should_codegen() {
182 tcx.collect_and_partition_mono_items(LOCAL_CRATE).1
184 // If only `--emit metadata` is used, we shouldn't perform any codegen.
185 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
189 if tcx.dep_graph.is_fully_enabled() {
191 tcx.ensure().codegen_unit(cgu.name());
195 let modules = super::time(tcx, backend_config.display_cg_time, "codegen mono items", || {
198 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
199 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
202 _ if backend_config.disable_incr_cache => {}
204 CguReuse::PreLto => {
205 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
207 CguReuse::PostLto => unreachable!(),
210 let dep_node = cgu.codegen_dep_node(tcx);
211 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
214 (backend_config.clone(), cgu.name()),
216 rustc_middle::dep_graph::hash_result,
219 if let Some((id, product)) = work_product {
220 work_products.insert(id, product);
228 tcx.sess.abort_if_errors();
230 let isa = crate::build_isa(tcx.sess, &backend_config);
231 let mut allocator_module =
232 crate::backend::make_module(tcx.sess, isa, "allocator_shim".to_string());
233 assert_eq!(pointer_ty(tcx), allocator_module.target_config().pointer_type());
234 let mut allocator_unwind_context = UnwindContext::new(tcx, allocator_module.isa(), true);
235 let created_alloc_shim =
236 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
238 let allocator_module = if created_alloc_shim {
239 let ModuleCodegenResult(module, work_product) = emit_module(
242 "allocator_shim".to_string(),
243 ModuleKind::Allocator,
246 allocator_unwind_context,
248 if let Some((id, product)) = work_product {
249 work_products.insert(id, product);
256 let metadata_module = if need_metadata_module {
257 let _timer = tcx.prof.generic_activity("codegen crate metadata");
258 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
259 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
261 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
262 let metadata_cgu_name = cgu_name_builder
263 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
268 .output_filenames(LOCAL_CRATE)
269 .temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
271 let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
272 crate::metadata::write_metadata(tcx, object);
275 if let Err(err) = std::fs::write(&tmp_file, obj) {
276 tcx.sess.fatal(&format!("error writing metadata object file: {}", err));
279 (metadata_cgu_name, tmp_file)
282 Some(CompiledModule {
283 name: metadata_cgu_name,
284 kind: ModuleKind::Metadata,
285 object: Some(tmp_file),
295 crate_name: tcx.crate_name(LOCAL_CRATE),
301 linker_info: LinkerInfo::new(tcx),
302 crate_info: CrateInfo::new(tcx),
308 fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
310 use std::process::{Command, Stdio};
312 if global_asm.is_empty() {
316 if cfg!(not(feature = "inline_asm"))
317 || tcx.sess.target.is_like_osx
318 || tcx.sess.target.is_like_windows
320 if global_asm.contains("__rust_probestack") {
324 // FIXME fix linker error on macOS
325 if cfg!(not(feature = "inline_asm")) {
327 "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift",
330 tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
334 let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as");
335 let linker = crate::toolchain::get_toolchain_binary(tcx.sess, "ld");
337 // Remove all LLVM style comments
338 let global_asm = global_asm
340 .map(|line| if let Some(index) = line.find("//") { &line[0..index] } else { line })
344 let output_object_file =
345 tcx.output_filenames(LOCAL_CRATE).temp_path(OutputType::Object, Some(cgu_name));
347 // Assemble `global_asm`
348 let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
349 let mut child = Command::new(assembler)
351 .arg(&global_asm_object_file)
352 .stdin(Stdio::piped())
354 .expect("Failed to spawn `as`.");
355 child.stdin.take().unwrap().write_all(global_asm.as_bytes()).unwrap();
356 let status = child.wait().expect("Failed to wait for `as`.");
357 if !status.success() {
358 tcx.sess.fatal(&format!("Failed to assemble `{}`", global_asm));
361 // Link the global asm and main object file together
362 let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main");
363 std::fs::rename(&output_object_file, &main_object_file).unwrap();
364 let status = Command::new(linker)
365 .arg("-r") // Create a new object file
367 .arg(output_object_file)
368 .arg(&main_object_file)
369 .arg(&global_asm_object_file)
372 if !status.success() {
373 tcx.sess.fatal(&format!(
374 "Failed to link `{}` and `{}` together",
375 main_object_file.display(),
376 global_asm_object_file.display(),
380 std::fs::remove_file(global_asm_object_file).unwrap();
381 std::fs::remove_file(main_object_file).unwrap();
384 fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf {
385 let mut new_filename = path.file_stem().unwrap().to_owned();
386 new_filename.push(postfix);
387 if let Some(extension) = path.extension() {
388 new_filename.push(".");
389 new_filename.push(extension);
391 path.set_file_name(new_filename);
395 // Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
396 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
397 if !tcx.dep_graph.is_fully_enabled() {
401 let work_product_id = &cgu.work_product_id();
402 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
403 // We don't have anything cached for this CGU. This can happen
404 // if the CGU did not exist in the previous session.
408 // Try to mark the CGU as green. If it we can do so, it means that nothing
409 // affecting the LLVM module has changed and we can re-use a cached version.
410 // If we compile with any kind of LTO, this means we can re-use the bitcode
411 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
412 // know that later). If we are not doing LTO, there is only one optimized
413 // version of each module, so we re-use that.
414 let dep_node = cgu.codegen_dep_node(tcx);
416 !tcx.dep_graph.dep_node_exists(&dep_node),
417 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
421 if tcx.try_mark_green(&dep_node) { CguReuse::PreLto } else { CguReuse::No }