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;
12 use rustc_session::cgu_reuse_tracker::CguReuse;
13 use rustc_session::config::{DebugInfo, OutputType};
15 use cranelift_object::{ObjectModule, ObjectProduct};
17 use crate::prelude::*;
19 use crate::backend::AddConstructor;
21 fn new_module(tcx: TyCtxt<'_>, name: String) -> ObjectModule {
22 let module = crate::backend::make_module(tcx.sess, name);
23 assert_eq!(pointer_ty(tcx), module.target_config().pointer_type());
27 struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
29 impl<HCX> HashStable<HCX> for ModuleCodegenResult {
30 fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
40 debug: Option<DebugContext<'_>>,
41 unwind_context: UnwindContext<'_>,
42 map_product: impl FnOnce(ObjectProduct) -> ObjectProduct,
43 ) -> ModuleCodegenResult {
44 let mut product = module.finish();
46 if let Some(mut debug) = debug {
47 debug.emit(&mut product);
50 unwind_context.emit(&mut product);
52 let product = map_product(product);
55 .output_filenames(LOCAL_CRATE)
56 .temp_path(OutputType::Object, Some(&name));
57 let obj = product.object.write().unwrap();
58 if let Err(err) = std::fs::write(&tmp_file, obj) {
60 .fatal(&format!("error writing object file: {}", err));
63 let work_product = if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() {
66 rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir(
69 &Some(tmp_file.clone()),
77 object: Some(tmp_file),
84 fn reuse_workproduct_for_cgu(
86 cgu: &CodegenUnit<'_>,
87 work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
89 let incr_comp_session_dir = tcx.sess.incr_comp_session_dir();
90 let mut object = None;
91 let work_product = cgu.work_product(tcx);
92 if let Some(saved_file) = &work_product.saved_file {
94 .output_filenames(LOCAL_CRATE)
95 .temp_path(OutputType::Object, Some(&cgu.name().as_str()));
96 object = Some(obj_out.clone());
97 let source_file = rustc_incremental::in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
98 if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
99 tcx.sess.err(&format!(
100 "unable to copy {} to {}: {}",
101 source_file.display(),
108 work_products.insert(cgu.work_product_id(), work_product);
111 name: cgu.name().to_string(),
112 kind: ModuleKind::Regular,
118 fn module_codegen(tcx: TyCtxt<'_>, cgu_name: rustc_span::Symbol) -> ModuleCodegenResult {
119 let cgu = tcx.codegen_unit(cgu_name);
120 let mono_items = cgu.items_in_deterministic_order(tcx);
122 let mut module = new_module(tcx, cgu_name.as_str().to_string());
124 // Initialize the global atomic mutex using a constructor for proc-macros.
125 // FIXME implement atomic instructions in Cranelift.
126 let mut init_atomics_mutex_from_constructor = None;
130 .contains(&rustc_session::config::CrateType::ProcMacro)
132 if mono_items.iter().any(|(mono_item, _)| match mono_item {
133 rustc_middle::mir::mono::MonoItem::Static(def_id) => tcx
134 .symbol_name(Instance::mono(tcx, *def_id))
136 .contains("__rustc_proc_macro_decls_"),
139 init_atomics_mutex_from_constructor =
140 Some(crate::atomic_shim::init_global_lock_constructor(
142 &format!("{}_init_atomics_mutex", cgu_name.as_str()),
147 let mut cx = crate::CodegenCx::new(tcx, module, tcx.sess.opts.debuginfo != DebugInfo::None);
148 super::predefine_mono_items(&mut cx, &mono_items);
149 for (mono_item, (linkage, visibility)) in mono_items {
150 let linkage = crate::linkage::get_clif_linkage(mono_item, linkage, visibility);
151 super::codegen_mono_item(&mut cx, mono_item, linkage);
153 let (mut module, global_asm, debug, mut unwind_context) =
154 tcx.sess.time("finalize CodegenCx", || cx.finalize());
155 crate::main_shim::maybe_create_entry_wrapper(tcx, &mut module, &mut unwind_context, false);
157 let codegen_result = emit_module(
159 cgu.name().as_str().to_string(),
165 if let Some(func_id) = init_atomics_mutex_from_constructor {
166 product.add_constructor(func_id);
173 codegen_global_asm(tcx, &cgu.name().as_str(), &global_asm);
178 pub(super) fn run_aot(
180 metadata: EncodedMetadata,
181 need_metadata_module: bool,
182 ) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
183 let mut work_products = FxHashMap::default();
185 let cgus = if tcx.sess.opts.output_types.should_codegen() {
186 tcx.collect_and_partition_mono_items(LOCAL_CRATE).1
188 // If only `--emit metadata` is used, we shouldn't perform any codegen.
189 // Also `tcx.collect_and_partition_mono_items` may panic in that case.
193 if tcx.dep_graph.is_fully_enabled() {
195 tcx.ensure().codegen_unit(cgu.name());
199 let modules = super::time(tcx, "codegen mono items", || {
202 let cgu_reuse = determine_cgu_reuse(tcx, cgu);
205 .set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
208 _ if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() => {}
210 CguReuse::PreLto => {
211 return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
213 CguReuse::PostLto => unreachable!(),
216 let dep_node = cgu.codegen_dep_node(tcx);
217 let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task(
222 rustc_middle::dep_graph::hash_result,
225 if let Some((id, product)) = work_product {
226 work_products.insert(id, product);
234 tcx.sess.abort_if_errors();
236 let mut allocator_module = new_module(tcx, "allocator_shim".to_string());
237 let mut allocator_unwind_context = UnwindContext::new(tcx, allocator_module.isa());
238 let created_alloc_shim =
239 crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context);
241 let allocator_module = if created_alloc_shim {
242 let ModuleCodegenResult(module, work_product) = emit_module(
244 "allocator_shim".to_string(),
245 ModuleKind::Allocator,
248 allocator_unwind_context,
251 if let Some((id, product)) = work_product {
252 work_products.insert(id, product);
259 rustc_incremental::assert_dep_graph(tcx);
260 rustc_incremental::save_dep_graph(tcx);
262 let metadata_module = if need_metadata_module {
263 let _timer = tcx.prof.generic_activity("codegen crate metadata");
264 let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
265 use rustc_middle::mir::mono::CodegenUnitNameBuilder;
267 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
268 let metadata_cgu_name = cgu_name_builder
269 .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
274 .output_filenames(LOCAL_CRATE)
275 .temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
277 let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
278 crate::metadata::write_metadata(tcx, object);
281 if let Err(err) = std::fs::write(&tmp_file, obj) {
283 .fatal(&format!("error writing metadata object file: {}", err));
286 (metadata_cgu_name, tmp_file)
289 Some(CompiledModule {
290 name: metadata_cgu_name,
291 kind: ModuleKind::Metadata,
292 object: Some(tmp_file),
299 if tcx.sess.opts.output_types.should_codegen() {
300 rustc_incremental::assert_module_sources::assert_module_sources(tcx);
305 crate_name: tcx.crate_name(LOCAL_CRATE),
310 windows_subsystem: None, // Windows is not yet supported
311 linker_info: LinkerInfo::new(tcx),
312 crate_info: CrateInfo::new(tcx),
318 fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) {
320 use std::process::{Command, Stdio};
322 if global_asm.is_empty() {
326 if cfg!(not(feature = "inline_asm"))
327 || tcx.sess.target.is_like_osx
328 || tcx.sess.target.is_like_windows
330 if global_asm.contains("__rust_probestack") {
334 // FIXME fix linker error on macOS
335 if cfg!(not(feature = "inline_asm")) {
337 "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift",
341 .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
352 if let Some(index) = line.find("//") {
361 let output_object_file = tcx
362 .output_filenames(LOCAL_CRATE)
363 .temp_path(OutputType::Object, Some(cgu_name));
365 // Assemble `global_asm`
366 let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm");
367 let mut child = Command::new(assembler)
369 .arg(&global_asm_object_file)
370 .stdin(Stdio::piped())
372 .expect("Failed to spawn `as`.");
377 .write_all(global_asm.as_bytes())
379 let status = child.wait().expect("Failed to wait for `as`.");
380 if !status.success() {
382 .fatal(&format!("Failed to assemble `{}`", global_asm));
385 // Link the global asm and main object file together
386 let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main");
387 std::fs::rename(&output_object_file, &main_object_file).unwrap();
388 let status = Command::new(linker)
389 .arg("-r") // Create a new object file
391 .arg(output_object_file)
392 .arg(&main_object_file)
393 .arg(&global_asm_object_file)
396 if !status.success() {
397 tcx.sess.fatal(&format!(
398 "Failed to link `{}` and `{}` together",
399 main_object_file.display(),
400 global_asm_object_file.display(),
404 std::fs::remove_file(global_asm_object_file).unwrap();
405 std::fs::remove_file(main_object_file).unwrap();
408 fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf {
409 let mut new_filename = path.file_stem().unwrap().to_owned();
410 new_filename.push(postfix);
411 if let Some(extension) = path.extension() {
412 new_filename.push(".");
413 new_filename.push(extension);
415 path.set_file_name(new_filename);
419 // Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
420 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
421 if !tcx.dep_graph.is_fully_enabled() {
425 let work_product_id = &cgu.work_product_id();
428 .previous_work_product(work_product_id)
431 // We don't have anything cached for this CGU. This can happen
432 // if the CGU did not exist in the previous session.
436 // Try to mark the CGU as green. If it we can do so, it means that nothing
437 // affecting the LLVM module has changed and we can re-use a cached version.
438 // If we compile with any kind of LTO, this means we can re-use the bitcode
439 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
440 // know that later). If we are not doing LTO, there is only one optimized
441 // version of each module, so we re-use that.
442 let dep_node = cgu.codegen_dep_node(tcx);
444 !tcx.dep_graph.dep_node_exists(&dep_node),
445 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
449 if tcx.dep_graph.try_mark_green(tcx, &dep_node).is_some() {