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 fn new_module(tcx: TyCtxt<'_>, name: String) -> ObjectModule {
20 let module = crate::backend::make_module(tcx.sess, name);
21 assert_eq!(pointer_ty(tcx), module.target_config().pointer_type());
25 struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
27 impl<HCX> HashStable<HCX> for ModuleCodegenResult {
28 fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
38 debug: Option<DebugContext<'_>>,
39 unwind_context: UnwindContext<'_>,
40 ) -> ModuleCodegenResult {
41 let mut product = module.finish();
43 if let Some(mut debug) = debug {
44 debug.emit(&mut product);
47 unwind_context.emit(&mut product);
49 let tmp_file = tcx.output_filenames(LOCAL_CRATE).temp_path(OutputType::Object, Some(&name));
50 let obj = product.object.write().unwrap();
51 if let Err(err) = std::fs::write(&tmp_file, obj) {
52 tcx.sess.fatal(&format!("error writing object file: {}", err));
55 let work_product = if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() {
58 rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
61 &Some(tmp_file.clone()),
66 CompiledModule { name, kind, object: Some(tmp_file), dwarf_object: None, bytecode: None },
71 fn reuse_workproduct_for_cgu(
73 cgu: &CodegenUnit<'_>,
74 work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
76 let incr_comp_session_dir = tcx.sess.incr_comp_session_dir();
77 let mut object = None;
78 let work_product = cgu.work_product(tcx);
79 if let Some(saved_file) = &work_product.saved_file {
81 .output_filenames(LOCAL_CRATE)
82 .temp_path(OutputType::Object, Some(&cgu.name().as_str()));
83 object = Some(obj_out.clone());
84 let source_file = rustc_incremental::in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
85 if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
86 tcx.sess.err(&format!(
87 "unable to copy {} to {}: {}",
88 source_file.display(),
95 work_products.insert(cgu.work_product_id(), work_product);
98 name: cgu.name().to_string(),
99 kind: ModuleKind::Regular,
108 (backend_config, cgu_name): (BackendConfig, rustc_span::Symbol),
109 ) -> ModuleCodegenResult {
110 let cgu = tcx.codegen_unit(cgu_name);
111 let mono_items = cgu.items_in_deterministic_order(tcx);
113 let mut module = new_module(tcx, cgu_name.as_str().to_string());
115 let mut cx = crate::CodegenCx::new(
119 tcx.sess.opts.debuginfo != DebugInfo::None,
121 super::predefine_mono_items(&mut cx, &mono_items);
122 for (mono_item, (linkage, visibility)) in mono_items {
123 let linkage = crate::linkage::get_clif_linkage(mono_item, linkage, visibility);
125 MonoItem::Fn(inst) => {
126 cx.tcx.sess.time("codegen fn", || crate::base::codegen_fn(&mut cx, inst, linkage));
128 MonoItem::Static(def_id) => {
129 crate::constant::codegen_static(&mut cx.constants_cx, def_id)
131 MonoItem::GlobalAsm(item_id) => {
132 let item = cx.tcx.hir().item(item_id);
133 if let rustc_hir::ItemKind::GlobalAsm(rustc_hir::GlobalAsm { asm }) = item.kind {
134 cx.global_asm.push_str(&*asm.as_str());
135 cx.global_asm.push_str("\n\n");
137 bug!("Expected GlobalAsm found {:?}", item);
142 let (global_asm, debug, mut unwind_context) =
143 tcx.sess.time("finalize CodegenCx", || cx.finalize());
144 crate::main_shim::maybe_create_entry_wrapper(tcx, &mut module, &mut unwind_context);
146 let codegen_result = emit_module(
148 cgu.name().as_str().to_string(),
155 codegen_global_asm(tcx, &cgu.name().as_str(), &global_asm);
160 pub(super) fn run_aot(
162 backend_config: BackendConfig,
163 metadata: EncodedMetadata,
164 need_metadata_module: bool,
165 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
166 use rustc_span::symbol::sym;
168 let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
169 let subsystem = tcx.sess.first_attr_value_str_by_name(crate_attrs, sym::windows_subsystem);
170 let windows_subsystem = subsystem.map(|subsystem| {
171 if subsystem != sym::windows && subsystem != sym::console {
172 tcx.sess.fatal(&format!(
173 "invalid windows subsystem `{}`, only \
174 `windows` and `console` are allowed",
178 subsystem.to_string()
181 let mut work_products = FxHashMap::default();
183 let cgus = if tcx.sess.opts.output_types.should_codegen() {
184 tcx.collect_and_partition_mono_items(LOCAL_CRATE).1
186 // If only `--emit metadata` is used, we shouldn't perform any codegen.
187 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
191 if tcx.dep_graph.is_fully_enabled() {
193 tcx.ensure().codegen_unit(cgu.name());
197 let modules = super::time(tcx, "codegen mono items", || {
200 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
201 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
204 _ if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() => {}
206 CguReuse::PreLto => {
207 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
209 CguReuse::PostLto => unreachable!(),
212 let dep_node = cgu.codegen_dep_node(tcx);
213 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
216 (backend_config, cgu.name()),
218 rustc_middle::dep_graph::hash_result,
221 if let Some((id, product)) = work_product {
222 work_products.insert(id, product);
230 tcx.sess.abort_if_errors();
232 let mut allocator_module = new_module(tcx, "allocator_shim".to_string());
233 let mut allocator_unwind_context = UnwindContext::new(tcx, allocator_module.isa(), true);
234 let created_alloc_shim =
235 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
237 let allocator_module = if created_alloc_shim {
238 let ModuleCodegenResult(module, work_product) = emit_module(
240 "allocator_shim".to_string(),
241 ModuleKind::Allocator,
244 allocator_unwind_context,
246 if let Some((id, product)) = work_product {
247 work_products.insert(id, product);
254 let metadata_module = if need_metadata_module {
255 let _timer = tcx.prof.generic_activity("codegen crate metadata");
256 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
257 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
259 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
260 let metadata_cgu_name = cgu_name_builder
261 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
266 .output_filenames(LOCAL_CRATE)
267 .temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
269 let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
270 crate::metadata::write_metadata(tcx, object);
273 if let Err(err) = std::fs::write(&tmp_file, obj) {
274 tcx.sess.fatal(&format!("error writing metadata object file: {}", err));
277 (metadata_cgu_name, tmp_file)
280 Some(CompiledModule {
281 name: metadata_cgu_name,
282 kind: ModuleKind::Metadata,
283 object: Some(tmp_file),
293 crate_name: tcx.crate_name(LOCAL_CRATE),
299 linker_info: LinkerInfo::new(tcx),
300 crate_info: CrateInfo::new(tcx),
306 fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
308 use std::process::{Command, Stdio};
310 if global_asm.is_empty() {
314 if cfg!(not(feature = "inline_asm"))
315 || tcx.sess.target.is_like_osx
316 || tcx.sess.target.is_like_windows
318 if global_asm.contains("__rust_probestack") {
322 // FIXME fix linker error on macOS
323 if cfg!(not(feature = "inline_asm")) {
325 "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift",
328 tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows");
332 let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as");
333 let linker = crate::toolchain::get_toolchain_binary(tcx.sess, "ld");
335 // Remove all LLVM style comments
336 let global_asm = global_asm
338 .map(|line| if let Some(index) = line.find("//") { &line[0..index] } else { line })
342 let output_object_file =
343 tcx.output_filenames(LOCAL_CRATE).temp_path(OutputType::Object, Some(cgu_name));
345 // Assemble `global_asm`
346 let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
347 let mut child = Command::new(assembler)
349 .arg(&global_asm_object_file)
350 .stdin(Stdio::piped())
352 .expect("Failed to spawn `as`.");
353 child.stdin.take().unwrap().write_all(global_asm.as_bytes()).unwrap();
354 let status = child.wait().expect("Failed to wait for `as`.");
355 if !status.success() {
356 tcx.sess.fatal(&format!("Failed to assemble `{}`", global_asm));
359 // Link the global asm and main object file together
360 let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main");
361 std::fs::rename(&output_object_file, &main_object_file).unwrap();
362 let status = Command::new(linker)
363 .arg("-r") // Create a new object file
365 .arg(output_object_file)
366 .arg(&main_object_file)
367 .arg(&global_asm_object_file)
370 if !status.success() {
371 tcx.sess.fatal(&format!(
372 "Failed to link `{}` and `{}` together",
373 main_object_file.display(),
374 global_asm_object_file.display(),
378 std::fs::remove_file(global_asm_object_file).unwrap();
379 std::fs::remove_file(main_object_file).unwrap();
382 fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf {
383 let mut new_filename = path.file_stem().unwrap().to_owned();
384 new_filename.push(postfix);
385 if let Some(extension) = path.extension() {
386 new_filename.push(".");
387 new_filename.push(extension);
389 path.set_file_name(new_filename);
393 // Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
394 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
395 if !tcx.dep_graph.is_fully_enabled() {
399 let work_product_id = &cgu.work_product_id();
400 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
401 // We don't have anything cached for this CGU. This can happen
402 // if the CGU did not exist in the previous session.
406 // Try to mark the CGU as green. If it we can do so, it means that nothing
407 // affecting the LLVM module has changed and we can re-use a cached version.
408 // If we compile with any kind of LTO, this means we can re-use the bitcode
409 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
410 // know that later). If we are not doing LTO, there is only one optimized
411 // version of each module, so we re-use that.
412 let dep_node = cgu.codegen_dep_node(tcx);
414 !tcx.dep_graph.dep_node_exists(&dep_node),
415 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
419 if tcx.try_mark_green(&dep_node) { CguReuse::PreLto } else { CguReuse::No }