| use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen, CompiledModule, CrateInfo, |
| CodegenResults, RLIB_BYTECODE_EXTENSION}; |
| use super::linker::LinkerInfo; |
| use super::lto::{self, SerializedModule}; |
| use super::link::{self, remove, get_linker}; |
| use super::command::Command; |
| use super::symbol_export::ExportedSymbols; |
| |
| use crate::traits::*; |
| use rustc_incremental::{copy_cgu_workproducts_to_incr_comp_cache_dir, |
| in_incr_comp_dir, in_incr_comp_dir_sess}; |
| use rustc::dep_graph::{WorkProduct, WorkProductId, WorkProductFileKind}; |
| use rustc_session::cgu_reuse_tracker::CguReuseTracker; |
| use rustc::middle::cstore::EncodedMetadata; |
| use rustc::session::config::{self, OutputFilenames, OutputType, Passes, Lto, |
| Sanitizer, SwitchWithOptPath}; |
| use rustc::session::Session; |
| use rustc::util::nodemap::FxHashMap; |
| use rustc::hir::def_id::{CrateNum, LOCAL_CRATE}; |
| use rustc::ty::TyCtxt; |
| use rustc::util::common::{time_depth, set_time_depth, print_time_passes_entry}; |
| use rustc_data_structures::profiling::SelfProfilerRef; |
| use rustc_fs_util::link_or_copy; |
| use rustc_data_structures::svh::Svh; |
| use rustc_data_structures::sync::Lrc; |
| use rustc_errors::{Handler, Level, FatalError, DiagnosticId}; |
| use syntax_pos::source_map::SourceMap; |
| use rustc_errors::emitter::{Emitter}; |
| use rustc_target::spec::MergeFunctions; |
| use syntax::attr; |
| use syntax_pos::hygiene::ExpnId; |
| use syntax_pos::symbol::{Symbol, sym}; |
| use jobserver::{Client, Acquired}; |
| |
| use std::any::Any; |
| use std::fs; |
| use std::io; |
| use std::mem; |
| use std::path::{Path, PathBuf}; |
| use std::str; |
| use std::sync::Arc; |
| use std::sync::mpsc::{channel, Sender, Receiver}; |
| use std::time::Instant; |
| use std::thread; |
| |
| const PRE_LTO_BC_EXT: &str = "pre-lto.bc"; |
| |
| /// Module-specific configuration for `optimize_and_codegen`. |
| pub struct ModuleConfig { |
| /// Names of additional optimization passes to run. |
| pub passes: Vec<String>, |
| /// Some(level) to optimize at a certain level, or None to run |
| /// absolutely no optimizations (used for the metadata module). |
| pub opt_level: Option<config::OptLevel>, |
| |
| /// Some(level) to optimize binary size, or None to not affect program size. |
| pub opt_size: Option<config::OptLevel>, |
| |
| pub pgo_gen: SwitchWithOptPath, |
| pub pgo_use: Option<PathBuf>, |
| |
| pub sanitizer: Option<Sanitizer>, |
| pub sanitizer_recover: Vec<Sanitizer>, |
| pub sanitizer_memory_track_origins: usize, |
| |
| // Flags indicating which outputs to produce. |
| pub emit_pre_lto_bc: bool, |
| pub emit_no_opt_bc: bool, |
| pub emit_bc: bool, |
| pub emit_bc_compressed: bool, |
| pub emit_lto_bc: bool, |
| pub emit_ir: bool, |
| pub emit_asm: bool, |
| pub emit_obj: bool, |
| // Miscellaneous flags. These are mostly copied from command-line |
| // options. |
| pub verify_llvm_ir: bool, |
| pub no_prepopulate_passes: bool, |
| pub no_builtins: bool, |
| pub time_passes: bool, |
| pub vectorize_loop: bool, |
| pub vectorize_slp: bool, |
| pub merge_functions: bool, |
| pub inline_threshold: Option<usize>, |
| // Instead of creating an object file by doing LLVM codegen, just |
| // make the object file bitcode. Provides easy compatibility with |
| // emscripten's ecc compiler, when used as the linker. |
| pub obj_is_bitcode: bool, |
| pub no_integrated_as: bool, |
| pub embed_bitcode: bool, |
| pub embed_bitcode_marker: bool, |
| } |
| |
| impl ModuleConfig { |
| fn new(passes: Vec<String>) -> ModuleConfig { |
| ModuleConfig { |
| passes, |
| opt_level: None, |
| opt_size: None, |
| |
| pgo_gen: SwitchWithOptPath::Disabled, |
| pgo_use: None, |
| |
| sanitizer: None, |
| sanitizer_recover: Default::default(), |
| sanitizer_memory_track_origins: 0, |
| |
| emit_no_opt_bc: false, |
| emit_pre_lto_bc: false, |
| emit_bc: false, |
| emit_bc_compressed: false, |
| emit_lto_bc: false, |
| emit_ir: false, |
| emit_asm: false, |
| emit_obj: false, |
| obj_is_bitcode: false, |
| embed_bitcode: false, |
| embed_bitcode_marker: false, |
| no_integrated_as: false, |
| |
| verify_llvm_ir: false, |
| no_prepopulate_passes: false, |
| no_builtins: false, |
| time_passes: false, |
| vectorize_loop: false, |
| vectorize_slp: false, |
| merge_functions: false, |
| inline_threshold: None |
| } |
| } |
| |
| fn set_flags(&mut self, sess: &Session, no_builtins: bool) { |
| self.verify_llvm_ir = sess.verify_llvm_ir(); |
| self.no_prepopulate_passes = sess.opts.cg.no_prepopulate_passes; |
| self.no_builtins = no_builtins || sess.target.target.options.no_builtins; |
| self.time_passes = sess.time_extended(); |
| self.inline_threshold = sess.opts.cg.inline_threshold; |
| self.obj_is_bitcode = sess.target.target.options.obj_is_bitcode || |
| sess.opts.cg.linker_plugin_lto.enabled(); |
| let embed_bitcode = sess.target.target.options.embed_bitcode || |
| sess.opts.debugging_opts.embed_bitcode; |
| if embed_bitcode { |
| match sess.opts.optimize { |
| config::OptLevel::No | |
| config::OptLevel::Less => { |
| self.embed_bitcode_marker = embed_bitcode; |
| } |
| _ => self.embed_bitcode = embed_bitcode, |
| } |
| } |
| |
| // Copy what clang does by turning on loop vectorization at O2 and |
| // slp vectorization at O3. Otherwise configure other optimization aspects |
| // of this pass manager builder. |
| self.vectorize_loop = !sess.opts.cg.no_vectorize_loops && |
| (sess.opts.optimize == config::OptLevel::Default || |
| sess.opts.optimize == config::OptLevel::Aggressive); |
| |
| self.vectorize_slp = !sess.opts.cg.no_vectorize_slp && |
| sess.opts.optimize == config::OptLevel::Aggressive; |
| |
| // Some targets (namely, NVPTX) interact badly with the MergeFunctions |
| // pass. This is because MergeFunctions can generate new function calls |
| // which may interfere with the target calling convention; e.g. for the |
| // NVPTX target, PTX kernels should not call other PTX kernels. |
| // MergeFunctions can also be configured to generate aliases instead, |
| // but aliases are not supported by some backends (again, NVPTX). |
| // Therefore, allow targets to opt out of the MergeFunctions pass, |
| // but otherwise keep the pass enabled (at O2 and O3) since it can be |
| // useful for reducing code size. |
| self.merge_functions = match sess.opts.debugging_opts.merge_functions |
| .unwrap_or(sess.target.target.options.merge_functions) { |
| MergeFunctions::Disabled => false, |
| MergeFunctions::Trampolines | |
| MergeFunctions::Aliases => { |
| sess.opts.optimize == config::OptLevel::Default || |
| sess.opts.optimize == config::OptLevel::Aggressive |
| } |
| }; |
| } |
| |
| pub fn bitcode_needed(&self) -> bool { |
| self.emit_bc || self.obj_is_bitcode |
| || self.emit_bc_compressed || self.embed_bitcode |
| } |
| } |
| |
| /// Assembler name and command used by codegen when no_integrated_as is enabled |
| pub struct AssemblerCommand { |
| name: PathBuf, |
| cmd: Command, |
| } |
| |
| // HACK(eddyb) work around `#[derive]` producing wrong bounds for `Clone`. |
| pub struct TargetMachineFactory<B: WriteBackendMethods>( |
| pub Arc<dyn Fn() -> Result<B::TargetMachine, String> + Send + Sync>, |
| ); |
| |
| impl<B: WriteBackendMethods> Clone for TargetMachineFactory<B> { |
| fn clone(&self) -> Self { |
| TargetMachineFactory(self.0.clone()) |
| } |
| } |
| |
| /// Additional resources used by optimize_and_codegen (not module specific) |
| #[derive(Clone)] |
| pub struct CodegenContext<B: WriteBackendMethods> { |
| // Resources needed when running LTO |
| pub backend: B, |
| pub time_passes: bool, |
| pub prof: SelfProfilerRef, |
| pub lto: Lto, |
| pub no_landing_pads: bool, |
| pub save_temps: bool, |
| pub fewer_names: bool, |
| pub exported_symbols: Option<Arc<ExportedSymbols>>, |
| pub opts: Arc<config::Options>, |
| pub crate_types: Vec<config::CrateType>, |
| pub each_linked_rlib_for_lto: Vec<(CrateNum, PathBuf)>, |
| pub output_filenames: Arc<OutputFilenames>, |
| pub regular_module_config: Arc<ModuleConfig>, |
| pub metadata_module_config: Arc<ModuleConfig>, |
| pub allocator_module_config: Arc<ModuleConfig>, |
| pub tm_factory: TargetMachineFactory<B>, |
| pub msvc_imps_needed: bool, |
| pub target_pointer_width: String, |
| pub target_arch: String, |
| pub debuginfo: config::DebugInfo, |
| |
| // Number of cgus excluding the allocator/metadata modules |
| pub total_cgus: usize, |
| // Handler to use for diagnostics produced during codegen. |
| pub diag_emitter: SharedEmitter, |
| // LLVM optimizations for which we want to print remarks. |
| pub remark: Passes, |
| // Worker thread number |
| pub worker: usize, |
| // The incremental compilation session directory, or None if we are not |
| // compiling incrementally |
| pub incr_comp_session_dir: Option<PathBuf>, |
| // Used to update CGU re-use information during the thinlto phase. |
| pub cgu_reuse_tracker: CguReuseTracker, |
| // Channel back to the main control thread to send messages to |
| pub coordinator_send: Sender<Box<dyn Any + Send>>, |
| // The assembler command if no_integrated_as option is enabled, None otherwise |
| pub assembler_cmd: Option<Arc<AssemblerCommand>> |
| } |
| |
| impl<B: WriteBackendMethods> CodegenContext<B> { |
| pub fn create_diag_handler(&self) -> Handler { |
| Handler::with_emitter(true, None, Box::new(self.diag_emitter.clone())) |
| } |
| |
| pub fn config(&self, kind: ModuleKind) -> &ModuleConfig { |
| match kind { |
| ModuleKind::Regular => &self.regular_module_config, |
| ModuleKind::Metadata => &self.metadata_module_config, |
| ModuleKind::Allocator => &self.allocator_module_config, |
| } |
| } |
| } |
| |
| fn generate_lto_work<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| needs_fat_lto: Vec<FatLTOInput<B>>, |
| needs_thin_lto: Vec<(String, B::ThinBuffer)>, |
| import_only_modules: Vec<(SerializedModule<B::ModuleBuffer>, WorkProduct)> |
| ) -> Vec<(WorkItem<B>, u64)> { |
| let _prof_timer = cgcx.prof.generic_activity("codegen_generate_lto_work"); |
| |
| let (lto_modules, copy_jobs) = if !needs_fat_lto.is_empty() { |
| assert!(needs_thin_lto.is_empty()); |
| let lto_module = B::run_fat_lto( |
| cgcx, |
| needs_fat_lto, |
| import_only_modules, |
| ) |
| .unwrap_or_else(|e| e.raise()); |
| (vec![lto_module], vec![]) |
| } else { |
| assert!(needs_fat_lto.is_empty()); |
| B::run_thin_lto(cgcx, needs_thin_lto, import_only_modules) |
| .unwrap_or_else(|e| e.raise()) |
| }; |
| |
| let result = lto_modules.into_iter().map(|module| { |
| let cost = module.cost(); |
| (WorkItem::LTO(module), cost) |
| }).chain(copy_jobs.into_iter().map(|wp| { |
| (WorkItem::CopyPostLtoArtifacts(CachedModuleCodegen { |
| name: wp.cgu_name.clone(), |
| source: wp, |
| }), 0) |
| })).collect(); |
| |
| result |
| } |
| |
| pub struct CompiledModules { |
| pub modules: Vec<CompiledModule>, |
| pub metadata_module: Option<CompiledModule>, |
| pub allocator_module: Option<CompiledModule>, |
| } |
| |
| fn need_crate_bitcode_for_rlib(sess: &Session) -> bool { |
| sess.crate_types.borrow().contains(&config::CrateType::Rlib) && |
| sess.opts.output_types.contains_key(&OutputType::Exe) |
| } |
| |
| fn need_pre_lto_bitcode_for_incr_comp(sess: &Session) -> bool { |
| if sess.opts.incremental.is_none() { |
| return false |
| } |
| |
| match sess.lto() { |
| Lto::No => false, |
| Lto::Fat | |
| Lto::Thin | |
| Lto::ThinLocal => true, |
| } |
| } |
| |
| pub fn start_async_codegen<B: ExtraBackendMethods>( |
| backend: B, |
| tcx: TyCtxt<'_>, |
| metadata: EncodedMetadata, |
| total_cgus: usize, |
| ) -> OngoingCodegen<B> { |
| let (coordinator_send, coordinator_receive) = channel(); |
| let sess = tcx.sess; |
| |
| let crate_name = tcx.crate_name(LOCAL_CRATE); |
| let crate_hash = tcx.crate_hash(LOCAL_CRATE); |
| let no_builtins = attr::contains_name(&tcx.hir().krate().attrs, sym::no_builtins); |
| let subsystem = attr::first_attr_value_str_by_name(&tcx.hir().krate().attrs, |
| sym::windows_subsystem); |
| let windows_subsystem = subsystem.map(|subsystem| { |
| if subsystem != sym::windows && subsystem != sym::console { |
| tcx.sess.fatal(&format!("invalid windows subsystem `{}`, only \ |
| `windows` and `console` are allowed", |
| subsystem)); |
| } |
| subsystem.to_string() |
| }); |
| |
| let linker_info = LinkerInfo::new(tcx); |
| let crate_info = CrateInfo::new(tcx); |
| |
| // Figure out what we actually need to build. |
| let mut modules_config = ModuleConfig::new(sess.opts.cg.passes.clone()); |
| let mut metadata_config = ModuleConfig::new(vec![]); |
| let mut allocator_config = ModuleConfig::new(vec![]); |
| |
| if sess.opts.debugging_opts.profile { |
| modules_config.passes.push("insert-gcov-profiling".to_owned()) |
| } |
| |
| modules_config.pgo_gen = sess.opts.cg.profile_generate.clone(); |
| modules_config.pgo_use = sess.opts.cg.profile_use.clone(); |
| modules_config.sanitizer = sess.opts.debugging_opts.sanitizer.clone(); |
| modules_config.sanitizer_recover = sess.opts.debugging_opts.sanitizer_recover.clone(); |
| modules_config.sanitizer_memory_track_origins = |
| sess.opts.debugging_opts.sanitizer_memory_track_origins; |
| modules_config.opt_level = Some(sess.opts.optimize); |
| modules_config.opt_size = Some(sess.opts.optimize); |
| |
| // Save all versions of the bytecode if we're saving our temporaries. |
| if sess.opts.cg.save_temps { |
| modules_config.emit_no_opt_bc = true; |
| modules_config.emit_pre_lto_bc = true; |
| modules_config.emit_bc = true; |
| modules_config.emit_lto_bc = true; |
| metadata_config.emit_bc = true; |
| allocator_config.emit_bc = true; |
| } |
| |
| // Emit compressed bitcode files for the crate if we're emitting an rlib. |
| // Whenever an rlib is created, the bitcode is inserted into the archive in |
| // order to allow LTO against it. |
| if need_crate_bitcode_for_rlib(sess) { |
| modules_config.emit_bc_compressed = true; |
| allocator_config.emit_bc_compressed = true; |
| } |
| |
| modules_config.emit_pre_lto_bc = |
| need_pre_lto_bitcode_for_incr_comp(sess); |
| |
| modules_config.no_integrated_as = tcx.sess.opts.cg.no_integrated_as || |
| tcx.sess.target.target.options.no_integrated_as; |
| |
| for output_type in sess.opts.output_types.keys() { |
| match *output_type { |
| OutputType::Bitcode => { modules_config.emit_bc = true; } |
| OutputType::LlvmAssembly => { modules_config.emit_ir = true; } |
| OutputType::Assembly => { |
| modules_config.emit_asm = true; |
| // If we're not using the LLVM assembler, this function |
| // could be invoked specially with output_type_assembly, so |
| // in this case we still want the metadata object file. |
| if !sess.opts.output_types.contains_key(&OutputType::Assembly) { |
| metadata_config.emit_obj = true; |
| allocator_config.emit_obj = true; |
| } |
| } |
| OutputType::Object => { modules_config.emit_obj = true; } |
| OutputType::Metadata => { metadata_config.emit_obj = true; } |
| OutputType::Exe => { |
| modules_config.emit_obj = true; |
| metadata_config.emit_obj = true; |
| allocator_config.emit_obj = true; |
| }, |
| OutputType::Mir => {} |
| OutputType::DepInfo => {} |
| } |
| } |
| |
| modules_config.set_flags(sess, no_builtins); |
| metadata_config.set_flags(sess, no_builtins); |
| allocator_config.set_flags(sess, no_builtins); |
| |
| // Exclude metadata and allocator modules from time_passes output, since |
| // they throw off the "LLVM passes" measurement. |
| metadata_config.time_passes = false; |
| allocator_config.time_passes = false; |
| |
| let (shared_emitter, shared_emitter_main) = SharedEmitter::new(); |
| let (codegen_worker_send, codegen_worker_receive) = channel(); |
| |
| let coordinator_thread = start_executing_work(backend.clone(), |
| tcx, |
| &crate_info, |
| shared_emitter, |
| codegen_worker_send, |
| coordinator_receive, |
| total_cgus, |
| sess.jobserver.clone(), |
| Arc::new(modules_config), |
| Arc::new(metadata_config), |
| Arc::new(allocator_config), |
| coordinator_send.clone()); |
| |
| OngoingCodegen { |
| backend, |
| crate_name, |
| crate_hash, |
| metadata, |
| windows_subsystem, |
| linker_info, |
| crate_info, |
| |
| coordinator_send, |
| codegen_worker_receive, |
| shared_emitter_main, |
| future: coordinator_thread, |
| output_filenames: tcx.output_filenames(LOCAL_CRATE), |
| } |
| } |
| |
| fn copy_all_cgu_workproducts_to_incr_comp_cache_dir( |
| sess: &Session, |
| compiled_modules: &CompiledModules, |
| ) -> FxHashMap<WorkProductId, WorkProduct> { |
| let mut work_products = FxHashMap::default(); |
| |
| if sess.opts.incremental.is_none() { |
| return work_products; |
| } |
| |
| for module in compiled_modules.modules.iter().filter(|m| m.kind == ModuleKind::Regular) { |
| let mut files = vec![]; |
| |
| if let Some(ref path) = module.object { |
| files.push((WorkProductFileKind::Object, path.clone())); |
| } |
| if let Some(ref path) = module.bytecode { |
| files.push((WorkProductFileKind::Bytecode, path.clone())); |
| } |
| if let Some(ref path) = module.bytecode_compressed { |
| files.push((WorkProductFileKind::BytecodeCompressed, path.clone())); |
| } |
| |
| if let Some((id, product)) = |
| copy_cgu_workproducts_to_incr_comp_cache_dir(sess, &module.name, &files) { |
| work_products.insert(id, product); |
| } |
| } |
| |
| work_products |
| } |
| |
| fn produce_final_output_artifacts(sess: &Session, |
| compiled_modules: &CompiledModules, |
| crate_output: &OutputFilenames) { |
| let mut user_wants_bitcode = false; |
| let mut user_wants_objects = false; |
| |
| // Produce final compile outputs. |
| let copy_gracefully = |from: &Path, to: &Path| { |
| if let Err(e) = fs::copy(from, to) { |
| sess.err(&format!("could not copy {:?} to {:?}: {}", from, to, e)); |
| } |
| }; |
| |
| let copy_if_one_unit = |output_type: OutputType, |
| keep_numbered: bool| { |
| if compiled_modules.modules.len() == 1 { |
| // 1) Only one codegen unit. In this case it's no difficulty |
| // to copy `foo.0.x` to `foo.x`. |
| let module_name = Some(&compiled_modules.modules[0].name[..]); |
| let path = crate_output.temp_path(output_type, module_name); |
| copy_gracefully(&path, |
| &crate_output.path(output_type)); |
| if !sess.opts.cg.save_temps && !keep_numbered { |
| // The user just wants `foo.x`, not `foo.#module-name#.x`. |
| remove(sess, &path); |
| } |
| } else { |
| let ext = crate_output.temp_path(output_type, None) |
| .extension() |
| .unwrap() |
| .to_str() |
| .unwrap() |
| .to_owned(); |
| |
| if crate_output.outputs.contains_key(&output_type) { |
| // 2) Multiple codegen units, with `--emit foo=some_name`. We have |
| // no good solution for this case, so warn the user. |
| sess.warn(&format!("ignoring emit path because multiple .{} files \ |
| were produced", ext)); |
| } else if crate_output.single_output_file.is_some() { |
| // 3) Multiple codegen units, with `-o some_name`. We have |
| // no good solution for this case, so warn the user. |
| sess.warn(&format!("ignoring -o because multiple .{} files \ |
| were produced", ext)); |
| } else { |
| // 4) Multiple codegen units, but no explicit name. We |
| // just leave the `foo.0.x` files in place. |
| // (We don't have to do any work in this case.) |
| } |
| } |
| }; |
| |
| // Flag to indicate whether the user explicitly requested bitcode. |
| // Otherwise, we produced it only as a temporary output, and will need |
| // to get rid of it. |
| for output_type in crate_output.outputs.keys() { |
| match *output_type { |
| OutputType::Bitcode => { |
| user_wants_bitcode = true; |
| // Copy to .bc, but always keep the .0.bc. There is a later |
| // check to figure out if we should delete .0.bc files, or keep |
| // them for making an rlib. |
| copy_if_one_unit(OutputType::Bitcode, true); |
| } |
| OutputType::LlvmAssembly => { |
| copy_if_one_unit(OutputType::LlvmAssembly, false); |
| } |
| OutputType::Assembly => { |
| copy_if_one_unit(OutputType::Assembly, false); |
| } |
| OutputType::Object => { |
| user_wants_objects = true; |
| copy_if_one_unit(OutputType::Object, true); |
| } |
| OutputType::Mir | |
| OutputType::Metadata | |
| OutputType::Exe | |
| OutputType::DepInfo => {} |
| } |
| } |
| |
| // Clean up unwanted temporary files. |
| |
| // We create the following files by default: |
| // - #crate#.#module-name#.bc |
| // - #crate#.#module-name#.o |
| // - #crate#.crate.metadata.bc |
| // - #crate#.crate.metadata.o |
| // - #crate#.o (linked from crate.##.o) |
| // - #crate#.bc (copied from crate.##.bc) |
| // We may create additional files if requested by the user (through |
| // `-C save-temps` or `--emit=` flags). |
| |
| if !sess.opts.cg.save_temps { |
| // Remove the temporary .#module-name#.o objects. If the user didn't |
| // explicitly request bitcode (with --emit=bc), and the bitcode is not |
| // needed for building an rlib, then we must remove .#module-name#.bc as |
| // well. |
| |
| // Specific rules for keeping .#module-name#.bc: |
| // - If the user requested bitcode (`user_wants_bitcode`), and |
| // codegen_units > 1, then keep it. |
| // - If the user requested bitcode but codegen_units == 1, then we |
| // can toss .#module-name#.bc because we copied it to .bc earlier. |
| // - If we're not building an rlib and the user didn't request |
| // bitcode, then delete .#module-name#.bc. |
| // If you change how this works, also update back::link::link_rlib, |
| // where .#module-name#.bc files are (maybe) deleted after making an |
| // rlib. |
| let needs_crate_object = crate_output.outputs.contains_key(&OutputType::Exe); |
| |
| let keep_numbered_bitcode = user_wants_bitcode && sess.codegen_units() > 1; |
| |
| let keep_numbered_objects = needs_crate_object || |
| (user_wants_objects && sess.codegen_units() > 1); |
| |
| for module in compiled_modules.modules.iter() { |
| if let Some(ref path) = module.object { |
| if !keep_numbered_objects { |
| remove(sess, path); |
| } |
| } |
| |
| if let Some(ref path) = module.bytecode { |
| if !keep_numbered_bitcode { |
| remove(sess, path); |
| } |
| } |
| } |
| |
| if !user_wants_bitcode { |
| if let Some(ref metadata_module) = compiled_modules.metadata_module { |
| if let Some(ref path) = metadata_module.bytecode { |
| remove(sess, &path); |
| } |
| } |
| |
| if let Some(ref allocator_module) = compiled_modules.allocator_module { |
| if let Some(ref path) = allocator_module.bytecode { |
| remove(sess, path); |
| } |
| } |
| } |
| } |
| |
| // We leave the following files around by default: |
| // - #crate#.o |
| // - #crate#.crate.metadata.o |
| // - #crate#.bc |
| // These are used in linking steps and will be cleaned up afterward. |
| } |
| |
| pub fn dump_incremental_data(_codegen_results: &CodegenResults) { |
| // FIXME(mw): This does not work at the moment because the situation has |
| // become more complicated due to incremental LTO. Now a CGU |
| // can have more than two caching states. |
| // println!("[incremental] Re-using {} out of {} modules", |
| // codegen_results.modules.iter().filter(|m| m.pre_existing).count(), |
| // codegen_results.modules.len()); |
| } |
| |
| pub enum WorkItem<B: WriteBackendMethods> { |
| /// Optimize a newly codegened, totally unoptimized module. |
| Optimize(ModuleCodegen<B::Module>), |
| /// Copy the post-LTO artifacts from the incremental cache to the output |
| /// directory. |
| CopyPostLtoArtifacts(CachedModuleCodegen), |
| /// Performs (Thin)LTO on the given module. |
| LTO(lto::LtoModuleCodegen<B>), |
| } |
| |
| impl<B: WriteBackendMethods> WorkItem<B> { |
| pub fn module_kind(&self) -> ModuleKind { |
| match *self { |
| WorkItem::Optimize(ref m) => m.kind, |
| WorkItem::CopyPostLtoArtifacts(_) | |
| WorkItem::LTO(_) => ModuleKind::Regular, |
| } |
| } |
| |
| fn profiling_event_id(&self) -> &'static str { |
| match *self { |
| WorkItem::Optimize(_) => "codegen_module_optimize", |
| WorkItem::CopyPostLtoArtifacts(_) => "codegen_copy_artifacts_from_incr_cache", |
| WorkItem::LTO(_) => "codegen_module_perform_lto", |
| } |
| } |
| } |
| |
| enum WorkItemResult<B: WriteBackendMethods> { |
| Compiled(CompiledModule), |
| NeedsFatLTO(FatLTOInput<B>), |
| NeedsThinLTO(String, B::ThinBuffer), |
| } |
| |
| pub enum FatLTOInput<B: WriteBackendMethods> { |
| Serialized { |
| name: String, |
| buffer: B::ModuleBuffer, |
| }, |
| InMemory(ModuleCodegen<B::Module>), |
| } |
| |
| fn execute_work_item<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| work_item: WorkItem<B>, |
| ) -> Result<WorkItemResult<B>, FatalError> { |
| let module_config = cgcx.config(work_item.module_kind()); |
| |
| match work_item { |
| WorkItem::Optimize(module) => { |
| execute_optimize_work_item(cgcx, module, module_config) |
| } |
| WorkItem::CopyPostLtoArtifacts(module) => { |
| execute_copy_from_cache_work_item(cgcx, module, module_config) |
| } |
| WorkItem::LTO(module) => { |
| execute_lto_work_item(cgcx, module, module_config) |
| } |
| } |
| } |
| |
| // Actual LTO type we end up chosing based on multiple factors. |
| enum ComputedLtoType { |
| No, |
| Thin, |
| Fat, |
| } |
| |
| fn execute_optimize_work_item<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| module: ModuleCodegen<B::Module>, |
| module_config: &ModuleConfig, |
| ) -> Result<WorkItemResult<B>, FatalError> { |
| let diag_handler = cgcx.create_diag_handler(); |
| |
| unsafe { |
| B::optimize(cgcx, &diag_handler, &module, module_config)?; |
| } |
| |
| // After we've done the initial round of optimizations we need to |
| // decide whether to synchronously codegen this module or ship it |
| // back to the coordinator thread for further LTO processing (which |
| // has to wait for all the initial modules to be optimized). |
| |
| // If the linker does LTO, we don't have to do it. Note that we |
| // keep doing full LTO, if it is requested, as not to break the |
| // assumption that the output will be a single module. |
| let linker_does_lto = cgcx.opts.cg.linker_plugin_lto.enabled(); |
| |
| // When we're automatically doing ThinLTO for multi-codegen-unit |
| // builds we don't actually want to LTO the allocator modules if |
| // it shows up. This is due to various linker shenanigans that |
| // we'll encounter later. |
| let is_allocator = module.kind == ModuleKind::Allocator; |
| |
| // We ignore a request for full crate grath LTO if the cate type |
| // is only an rlib, as there is no full crate graph to process, |
| // that'll happen later. |
| // |
| // This use case currently comes up primarily for targets that |
| // require LTO so the request for LTO is always unconditionally |
| // passed down to the backend, but we don't actually want to do |
| // anything about it yet until we've got a final product. |
| let is_rlib = cgcx.crate_types.len() == 1 |
| && cgcx.crate_types[0] == config::CrateType::Rlib; |
| |
| // Metadata modules never participate in LTO regardless of the lto |
| // settings. |
| let lto_type = if module.kind == ModuleKind::Metadata { |
| ComputedLtoType::No |
| } else { |
| match cgcx.lto { |
| Lto::ThinLocal if !linker_does_lto && !is_allocator |
| => ComputedLtoType::Thin, |
| Lto::Thin if !linker_does_lto && !is_rlib |
| => ComputedLtoType::Thin, |
| Lto::Fat if !is_rlib => ComputedLtoType::Fat, |
| _ => ComputedLtoType::No, |
| } |
| }; |
| |
| // If we're doing some form of incremental LTO then we need to be sure to |
| // save our module to disk first. |
| let bitcode = if cgcx.config(module.kind).emit_pre_lto_bc { |
| let filename = pre_lto_bitcode_filename(&module.name); |
| cgcx.incr_comp_session_dir.as_ref().map(|path| path.join(&filename)) |
| } else { |
| None |
| }; |
| |
| Ok(match lto_type { |
| ComputedLtoType::No => { |
| let module = unsafe { |
| B::codegen(cgcx, &diag_handler, module, module_config)? |
| }; |
| WorkItemResult::Compiled(module) |
| } |
| ComputedLtoType::Thin => { |
| let (name, thin_buffer) = B::prepare_thin(module); |
| if let Some(path) = bitcode { |
| fs::write(&path, thin_buffer.data()).unwrap_or_else(|e| { |
| panic!("Error writing pre-lto-bitcode file `{}`: {}", |
| path.display(), |
| e); |
| }); |
| } |
| WorkItemResult::NeedsThinLTO(name, thin_buffer) |
| } |
| ComputedLtoType::Fat => { |
| match bitcode { |
| Some(path) => { |
| let (name, buffer) = B::serialize_module(module); |
| fs::write(&path, buffer.data()).unwrap_or_else(|e| { |
| panic!("Error writing pre-lto-bitcode file `{}`: {}", |
| path.display(), |
| e); |
| }); |
| WorkItemResult::NeedsFatLTO(FatLTOInput::Serialized { name, buffer }) |
| } |
| None => WorkItemResult::NeedsFatLTO(FatLTOInput::InMemory(module)), |
| } |
| } |
| }) |
| } |
| |
| fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| module: CachedModuleCodegen, |
| module_config: &ModuleConfig, |
| ) -> Result<WorkItemResult<B>, FatalError> { |
| let incr_comp_session_dir = cgcx.incr_comp_session_dir |
| .as_ref() |
| .unwrap(); |
| let mut object = None; |
| let mut bytecode = None; |
| let mut bytecode_compressed = None; |
| for (kind, saved_file) in &module.source.saved_files { |
| let obj_out = match kind { |
| WorkProductFileKind::Object => { |
| let path = cgcx.output_filenames.temp_path(OutputType::Object, |
| Some(&module.name)); |
| object = Some(path.clone()); |
| path |
| } |
| WorkProductFileKind::Bytecode => { |
| let path = cgcx.output_filenames.temp_path(OutputType::Bitcode, |
| Some(&module.name)); |
| bytecode = Some(path.clone()); |
| path |
| } |
| WorkProductFileKind::BytecodeCompressed => { |
| let path = cgcx.output_filenames.temp_path(OutputType::Bitcode, |
| Some(&module.name)) |
| .with_extension(RLIB_BYTECODE_EXTENSION); |
| bytecode_compressed = Some(path.clone()); |
| path |
| } |
| }; |
| let source_file = in_incr_comp_dir(&incr_comp_session_dir, |
| &saved_file); |
| debug!("copying pre-existing module `{}` from {:?} to {}", |
| module.name, |
| source_file, |
| obj_out.display()); |
| if let Err(err) = link_or_copy(&source_file, &obj_out) { |
| let diag_handler = cgcx.create_diag_handler(); |
| diag_handler.err(&format!("unable to copy {} to {}: {}", |
| source_file.display(), |
| obj_out.display(), |
| err)); |
| } |
| } |
| |
| assert_eq!(object.is_some(), module_config.emit_obj); |
| assert_eq!(bytecode.is_some(), module_config.emit_bc); |
| assert_eq!(bytecode_compressed.is_some(), module_config.emit_bc_compressed); |
| |
| Ok(WorkItemResult::Compiled(CompiledModule { |
| name: module.name, |
| kind: ModuleKind::Regular, |
| object, |
| bytecode, |
| bytecode_compressed, |
| })) |
| } |
| |
| fn execute_lto_work_item<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| mut module: lto::LtoModuleCodegen<B>, |
| module_config: &ModuleConfig, |
| ) -> Result<WorkItemResult<B>, FatalError> { |
| let diag_handler = cgcx.create_diag_handler(); |
| |
| unsafe { |
| let module = module.optimize(cgcx)?; |
| let module = B::codegen(cgcx, &diag_handler, module, module_config)?; |
| Ok(WorkItemResult::Compiled(module)) |
| } |
| } |
| |
| pub enum Message<B: WriteBackendMethods> { |
| Token(io::Result<Acquired>), |
| NeedsFatLTO { |
| result: FatLTOInput<B>, |
| worker_id: usize, |
| }, |
| NeedsThinLTO { |
| name: String, |
| thin_buffer: B::ThinBuffer, |
| worker_id: usize, |
| }, |
| Done { |
| result: Result<CompiledModule, ()>, |
| worker_id: usize, |
| }, |
| CodegenDone { |
| llvm_work_item: WorkItem<B>, |
| cost: u64, |
| }, |
| AddImportOnlyModule { |
| module_data: SerializedModule<B::ModuleBuffer>, |
| work_product: WorkProduct, |
| }, |
| CodegenComplete, |
| CodegenItem, |
| CodegenAborted, |
| } |
| |
| struct Diagnostic { |
| msg: String, |
| code: Option<DiagnosticId>, |
| lvl: Level, |
| } |
| |
| #[derive(PartialEq, Clone, Copy, Debug)] |
| enum MainThreadWorkerState { |
| Idle, |
| Codegenning, |
| LLVMing, |
| } |
| |
| fn start_executing_work<B: ExtraBackendMethods>( |
| backend: B, |
| tcx: TyCtxt<'_>, |
| crate_info: &CrateInfo, |
| shared_emitter: SharedEmitter, |
| codegen_worker_send: Sender<Message<B>>, |
| coordinator_receive: Receiver<Box<dyn Any + Send>>, |
| total_cgus: usize, |
| jobserver: Client, |
| modules_config: Arc<ModuleConfig>, |
| metadata_config: Arc<ModuleConfig>, |
| allocator_config: Arc<ModuleConfig>, |
| tx_to_llvm_workers: Sender<Box<dyn Any + Send>>, |
| ) -> thread::JoinHandle<Result<CompiledModules, ()>> { |
| let coordinator_send = tx_to_llvm_workers; |
| let sess = tcx.sess; |
| |
| // Compute the set of symbols we need to retain when doing LTO (if we need to) |
| let exported_symbols = { |
| let mut exported_symbols = FxHashMap::default(); |
| |
| let copy_symbols = |cnum| { |
| let symbols = tcx.exported_symbols(cnum) |
| .iter() |
| .map(|&(s, lvl)| (s.symbol_name(tcx).to_string(), lvl)) |
| .collect(); |
| Arc::new(symbols) |
| }; |
| |
| match sess.lto() { |
| Lto::No => None, |
| Lto::ThinLocal => { |
| exported_symbols.insert(LOCAL_CRATE, copy_symbols(LOCAL_CRATE)); |
| Some(Arc::new(exported_symbols)) |
| } |
| Lto::Fat | Lto::Thin => { |
| exported_symbols.insert(LOCAL_CRATE, copy_symbols(LOCAL_CRATE)); |
| for &cnum in tcx.crates().iter() { |
| exported_symbols.insert(cnum, copy_symbols(cnum)); |
| } |
| Some(Arc::new(exported_symbols)) |
| } |
| } |
| }; |
| |
| // First up, convert our jobserver into a helper thread so we can use normal |
| // mpsc channels to manage our messages and such. |
| // After we've requested tokens then we'll, when we can, |
| // get tokens on `coordinator_receive` which will |
| // get managed in the main loop below. |
| let coordinator_send2 = coordinator_send.clone(); |
| let helper = jobserver.into_helper_thread(move |token| { |
| drop(coordinator_send2.send(Box::new(Message::Token::<B>(token)))); |
| }).expect("failed to spawn helper thread"); |
| |
| let mut each_linked_rlib_for_lto = Vec::new(); |
| drop(link::each_linked_rlib(crate_info, &mut |cnum, path| { |
| if link::ignored_for_lto(sess, crate_info, cnum) { |
| return |
| } |
| each_linked_rlib_for_lto.push((cnum, path.to_path_buf())); |
| })); |
| |
| let assembler_cmd = if modules_config.no_integrated_as { |
| // HACK: currently we use linker (gcc) as our assembler |
| let (linker, flavor) = link::linker_and_flavor(sess); |
| |
| let (name, mut cmd) = get_linker(sess, &linker, flavor); |
| cmd.args(&sess.target.target.options.asm_args); |
| Some(Arc::new(AssemblerCommand { |
| name, |
| cmd, |
| })) |
| } else { |
| None |
| }; |
| |
| let ol = if tcx.sess.opts.debugging_opts.no_codegen |
| || !tcx.sess.opts.output_types.should_codegen() { |
| // If we know that we won’t be doing codegen, create target machines without optimisation. |
| config::OptLevel::No |
| } else { |
| tcx.backend_optimization_level(LOCAL_CRATE) |
| }; |
| let cgcx = CodegenContext::<B> { |
| backend: backend.clone(), |
| crate_types: sess.crate_types.borrow().clone(), |
| each_linked_rlib_for_lto, |
| lto: sess.lto(), |
| no_landing_pads: sess.no_landing_pads(), |
| fewer_names: sess.fewer_names(), |
| save_temps: sess.opts.cg.save_temps, |
| opts: Arc::new(sess.opts.clone()), |
| time_passes: sess.time_extended(), |
| prof: sess.prof.clone(), |
| exported_symbols, |
| remark: sess.opts.cg.remark.clone(), |
| worker: 0, |
| incr_comp_session_dir: sess.incr_comp_session_dir_opt().map(|r| r.clone()), |
| cgu_reuse_tracker: sess.cgu_reuse_tracker.clone(), |
| coordinator_send, |
| diag_emitter: shared_emitter.clone(), |
| output_filenames: tcx.output_filenames(LOCAL_CRATE), |
| regular_module_config: modules_config, |
| metadata_module_config: metadata_config, |
| allocator_module_config: allocator_config, |
| tm_factory: TargetMachineFactory(backend.target_machine_factory(tcx.sess, ol, false)), |
| total_cgus, |
| msvc_imps_needed: msvc_imps_needed(tcx), |
| target_pointer_width: tcx.sess.target.target.target_pointer_width.clone(), |
| target_arch: tcx.sess.target.target.arch.clone(), |
| debuginfo: tcx.sess.opts.debuginfo, |
| assembler_cmd, |
| }; |
| |
| // This is the "main loop" of parallel work happening for parallel codegen. |
| // It's here that we manage parallelism, schedule work, and work with |
| // messages coming from clients. |
| // |
| // There are a few environmental pre-conditions that shape how the system |
| // is set up: |
| // |
| // - Error reporting only can happen on the main thread because that's the |
| // only place where we have access to the compiler `Session`. |
| // - LLVM work can be done on any thread. |
| // - Codegen can only happen on the main thread. |
| // - Each thread doing substantial work most be in possession of a `Token` |
| // from the `Jobserver`. |
| // - The compiler process always holds one `Token`. Any additional `Tokens` |
| // have to be requested from the `Jobserver`. |
| // |
| // Error Reporting |
| // =============== |
| // The error reporting restriction is handled separately from the rest: We |
| // set up a `SharedEmitter` the holds an open channel to the main thread. |
| // When an error occurs on any thread, the shared emitter will send the |
| // error message to the receiver main thread (`SharedEmitterMain`). The |
| // main thread will periodically query this error message queue and emit |
| // any error messages it has received. It might even abort compilation if |
| // has received a fatal error. In this case we rely on all other threads |
| // being torn down automatically with the main thread. |
| // Since the main thread will often be busy doing codegen work, error |
| // reporting will be somewhat delayed, since the message queue can only be |
| // checked in between to work packages. |
| // |
| // Work Processing Infrastructure |
| // ============================== |
| // The work processing infrastructure knows three major actors: |
| // |
| // - the coordinator thread, |
| // - the main thread, and |
| // - LLVM worker threads |
| // |
| // The coordinator thread is running a message loop. It instructs the main |
| // thread about what work to do when, and it will spawn off LLVM worker |
| // threads as open LLVM WorkItems become available. |
| // |
| // The job of the main thread is to codegen CGUs into LLVM work package |
| // (since the main thread is the only thread that can do this). The main |
| // thread will block until it receives a message from the coordinator, upon |
| // which it will codegen one CGU, send it to the coordinator and block |
| // again. This way the coordinator can control what the main thread is |
| // doing. |
| // |
| // The coordinator keeps a queue of LLVM WorkItems, and when a `Token` is |
| // available, it will spawn off a new LLVM worker thread and let it process |
| // that a WorkItem. When a LLVM worker thread is done with its WorkItem, |
| // it will just shut down, which also frees all resources associated with |
| // the given LLVM module, and sends a message to the coordinator that the |
| // has been completed. |
| // |
| // Work Scheduling |
| // =============== |
| // The scheduler's goal is to minimize the time it takes to complete all |
| // work there is, however, we also want to keep memory consumption low |
| // if possible. These two goals are at odds with each other: If memory |
| // consumption were not an issue, we could just let the main thread produce |
| // LLVM WorkItems at full speed, assuring maximal utilization of |
| // Tokens/LLVM worker threads. However, since codegen usual is faster |
| // than LLVM processing, the queue of LLVM WorkItems would fill up and each |
| // WorkItem potentially holds on to a substantial amount of memory. |
| // |
| // So the actual goal is to always produce just enough LLVM WorkItems as |
| // not to starve our LLVM worker threads. That means, once we have enough |
| // WorkItems in our queue, we can block the main thread, so it does not |
| // produce more until we need them. |
| // |
| // Doing LLVM Work on the Main Thread |
| // ---------------------------------- |
| // Since the main thread owns the compiler processes implicit `Token`, it is |
| // wasteful to keep it blocked without doing any work. Therefore, what we do |
| // in this case is: We spawn off an additional LLVM worker thread that helps |
| // reduce the queue. The work it is doing corresponds to the implicit |
| // `Token`. The coordinator will mark the main thread as being busy with |
| // LLVM work. (The actual work happens on another OS thread but we just care |
| // about `Tokens`, not actual threads). |
| // |
| // When any LLVM worker thread finishes while the main thread is marked as |
| // "busy with LLVM work", we can do a little switcheroo: We give the Token |
| // of the just finished thread to the LLVM worker thread that is working on |
| // behalf of the main thread's implicit Token, thus freeing up the main |
| // thread again. The coordinator can then again decide what the main thread |
| // should do. This allows the coordinator to make decisions at more points |
| // in time. |
| // |
| // Striking a Balance between Throughput and Memory Consumption |
| // ------------------------------------------------------------ |
| // Since our two goals, (1) use as many Tokens as possible and (2) keep |
| // memory consumption as low as possible, are in conflict with each other, |
| // we have to find a trade off between them. Right now, the goal is to keep |
| // all workers busy, which means that no worker should find the queue empty |
| // when it is ready to start. |
| // How do we do achieve this? Good question :) We actually never know how |
| // many `Tokens` are potentially available so it's hard to say how much to |
| // fill up the queue before switching the main thread to LLVM work. Also we |
| // currently don't have a means to estimate how long a running LLVM worker |
| // will still be busy with it's current WorkItem. However, we know the |
| // maximal count of available Tokens that makes sense (=the number of CPU |
| // cores), so we can take a conservative guess. The heuristic we use here |
| // is implemented in the `queue_full_enough()` function. |
| // |
| // Some Background on Jobservers |
| // ----------------------------- |
| // It's worth also touching on the management of parallelism here. We don't |
| // want to just spawn a thread per work item because while that's optimal |
| // parallelism it may overload a system with too many threads or violate our |
| // configuration for the maximum amount of cpu to use for this process. To |
| // manage this we use the `jobserver` crate. |
| // |
| // Job servers are an artifact of GNU make and are used to manage |
| // parallelism between processes. A jobserver is a glorified IPC semaphore |
| // basically. Whenever we want to run some work we acquire the semaphore, |
| // and whenever we're done with that work we release the semaphore. In this |
| // manner we can ensure that the maximum number of parallel workers is |
| // capped at any one point in time. |
| // |
| // LTO and the coordinator thread |
| // ------------------------------ |
| // |
| // The final job the coordinator thread is responsible for is managing LTO |
| // and how that works. When LTO is requested what we'll to is collect all |
| // optimized LLVM modules into a local vector on the coordinator. Once all |
| // modules have been codegened and optimized we hand this to the `lto` |
| // module for further optimization. The `lto` module will return back a list |
| // of more modules to work on, which the coordinator will continue to spawn |
| // work for. |
| // |
| // Each LLVM module is automatically sent back to the coordinator for LTO if |
| // necessary. There's already optimizations in place to avoid sending work |
| // back to the coordinator if LTO isn't requested. |
| return thread::spawn(move || { |
| // We pretend to be within the top-level LLVM time-passes task here: |
| set_time_depth(1); |
| |
| let max_workers = ::num_cpus::get(); |
| let mut worker_id_counter = 0; |
| let mut free_worker_ids = Vec::new(); |
| let mut get_worker_id = |free_worker_ids: &mut Vec<usize>| { |
| if let Some(id) = free_worker_ids.pop() { |
| id |
| } else { |
| let id = worker_id_counter; |
| worker_id_counter += 1; |
| id |
| } |
| }; |
| |
| // This is where we collect codegen units that have gone all the way |
| // through codegen and LLVM. |
| let mut compiled_modules = vec![]; |
| let mut compiled_metadata_module = None; |
| let mut compiled_allocator_module = None; |
| let mut needs_fat_lto = Vec::new(); |
| let mut needs_thin_lto = Vec::new(); |
| let mut lto_import_only_modules = Vec::new(); |
| let mut started_lto = false; |
| let mut codegen_aborted = false; |
| |
| // This flag tracks whether all items have gone through codegens |
| let mut codegen_done = false; |
| |
| // This is the queue of LLVM work items that still need processing. |
| let mut work_items = Vec::<(WorkItem<B>, u64)>::new(); |
| |
| // This are the Jobserver Tokens we currently hold. Does not include |
| // the implicit Token the compiler process owns no matter what. |
| let mut tokens = Vec::new(); |
| |
| let mut main_thread_worker_state = MainThreadWorkerState::Idle; |
| let mut running = 0; |
| |
| let mut llvm_start_time = None; |
| |
| // Run the message loop while there's still anything that needs message |
| // processing. Note that as soon as codegen is aborted we simply want to |
| // wait for all existing work to finish, so many of the conditions here |
| // only apply if codegen hasn't been aborted as they represent pending |
| // work to be done. |
| while !codegen_done || |
| running > 0 || |
| (!codegen_aborted && ( |
| work_items.len() > 0 || |
| needs_fat_lto.len() > 0 || |
| needs_thin_lto.len() > 0 || |
| lto_import_only_modules.len() > 0 || |
| main_thread_worker_state != MainThreadWorkerState::Idle |
| )) |
| { |
| |
| // While there are still CGUs to be codegened, the coordinator has |
| // to decide how to utilize the compiler processes implicit Token: |
| // For codegenning more CGU or for running them through LLVM. |
| if !codegen_done { |
| if main_thread_worker_state == MainThreadWorkerState::Idle { |
| if !queue_full_enough(work_items.len(), running, max_workers) { |
| // The queue is not full enough, codegen more items: |
| if let Err(_) = codegen_worker_send.send(Message::CodegenItem) { |
| panic!("Could not send Message::CodegenItem to main thread") |
| } |
| main_thread_worker_state = MainThreadWorkerState::Codegenning; |
| } else { |
| // The queue is full enough to not let the worker |
| // threads starve. Use the implicit Token to do some |
| // LLVM work too. |
| let (item, _) = work_items.pop() |
| .expect("queue empty - queue_full_enough() broken?"); |
| let cgcx = CodegenContext { |
| worker: get_worker_id(&mut free_worker_ids), |
| .. cgcx.clone() |
| }; |
| maybe_start_llvm_timer(cgcx.config(item.module_kind()), |
| &mut llvm_start_time); |
| main_thread_worker_state = MainThreadWorkerState::LLVMing; |
| spawn_work(cgcx, item); |
| } |
| } |
| } else if codegen_aborted { |
| // don't queue up any more work if codegen was aborted, we're |
| // just waiting for our existing children to finish |
| } else { |
| // If we've finished everything related to normal codegen |
| // then it must be the case that we've got some LTO work to do. |
| // Perform the serial work here of figuring out what we're |
| // going to LTO and then push a bunch of work items onto our |
| // queue to do LTO |
| if work_items.len() == 0 && |
| running == 0 && |
| main_thread_worker_state == MainThreadWorkerState::Idle { |
| assert!(!started_lto); |
| started_lto = true; |
| |
| let needs_fat_lto = mem::take(&mut needs_fat_lto); |
| let needs_thin_lto = mem::take(&mut needs_thin_lto); |
| let import_only_modules = mem::take(&mut lto_import_only_modules); |
| |
| for (work, cost) in generate_lto_work(&cgcx, needs_fat_lto, |
| needs_thin_lto, import_only_modules) { |
| let insertion_index = work_items |
| .binary_search_by_key(&cost, |&(_, cost)| cost) |
| .unwrap_or_else(|e| e); |
| work_items.insert(insertion_index, (work, cost)); |
| if !cgcx.opts.debugging_opts.no_parallel_llvm { |
| helper.request_token(); |
| } |
| } |
| } |
| |
| // In this branch, we know that everything has been codegened, |
| // so it's just a matter of determining whether the implicit |
| // Token is free to use for LLVM work. |
| match main_thread_worker_state { |
| MainThreadWorkerState::Idle => { |
| if let Some((item, _)) = work_items.pop() { |
| let cgcx = CodegenContext { |
| worker: get_worker_id(&mut free_worker_ids), |
| .. cgcx.clone() |
| }; |
| maybe_start_llvm_timer(cgcx.config(item.module_kind()), |
| &mut llvm_start_time); |
| main_thread_worker_state = MainThreadWorkerState::LLVMing; |
| spawn_work(cgcx, item); |
| } else { |
| // There is no unstarted work, so let the main thread |
| // take over for a running worker. Otherwise the |
| // implicit token would just go to waste. |
| // We reduce the `running` counter by one. The |
| // `tokens.truncate()` below will take care of |
| // giving the Token back. |
| debug_assert!(running > 0); |
| running -= 1; |
| main_thread_worker_state = MainThreadWorkerState::LLVMing; |
| } |
| } |
| MainThreadWorkerState::Codegenning => { |
| bug!("codegen worker should not be codegenning after \ |
| codegen was already completed") |
| } |
| MainThreadWorkerState::LLVMing => { |
| // Already making good use of that token |
| } |
| } |
| } |
| |
| // Spin up what work we can, only doing this while we've got available |
| // parallelism slots and work left to spawn. |
| while !codegen_aborted && work_items.len() > 0 && running < tokens.len() { |
| let (item, _) = work_items.pop().unwrap(); |
| |
| maybe_start_llvm_timer(cgcx.config(item.module_kind()), |
| &mut llvm_start_time); |
| |
| let cgcx = CodegenContext { |
| worker: get_worker_id(&mut free_worker_ids), |
| .. cgcx.clone() |
| }; |
| |
| spawn_work(cgcx, item); |
| running += 1; |
| } |
| |
| // Relinquish accidentally acquired extra tokens |
| tokens.truncate(running); |
| |
| // If a thread exits successfully then we drop a token associated |
| // with that worker and update our `running` count. We may later |
| // re-acquire a token to continue running more work. We may also not |
| // actually drop a token here if the worker was running with an |
| // "ephemeral token" |
| let mut free_worker = |worker_id| { |
| if main_thread_worker_state == MainThreadWorkerState::LLVMing { |
| main_thread_worker_state = MainThreadWorkerState::Idle; |
| } else { |
| running -= 1; |
| } |
| |
| free_worker_ids.push(worker_id); |
| }; |
| |
| let msg = coordinator_receive.recv().unwrap(); |
| match *msg.downcast::<Message<B>>().ok().unwrap() { |
| // Save the token locally and the next turn of the loop will use |
| // this to spawn a new unit of work, or it may get dropped |
| // immediately if we have no more work to spawn. |
| Message::Token(token) => { |
| match token { |
| Ok(token) => { |
| tokens.push(token); |
| |
| if main_thread_worker_state == MainThreadWorkerState::LLVMing { |
| // If the main thread token is used for LLVM work |
| // at the moment, we turn that thread into a regular |
| // LLVM worker thread, so the main thread is free |
| // to react to codegen demand. |
| main_thread_worker_state = MainThreadWorkerState::Idle; |
| running += 1; |
| } |
| } |
| Err(e) => { |
| let msg = &format!("failed to acquire jobserver token: {}", e); |
| shared_emitter.fatal(msg); |
| // Exit the coordinator thread |
| panic!("{}", msg) |
| } |
| } |
| } |
| |
| Message::CodegenDone { llvm_work_item, cost } => { |
| // We keep the queue sorted by estimated processing cost, |
| // so that more expensive items are processed earlier. This |
| // is good for throughput as it gives the main thread more |
| // time to fill up the queue and it avoids scheduling |
| // expensive items to the end. |
| // Note, however, that this is not ideal for memory |
| // consumption, as LLVM module sizes are not evenly |
| // distributed. |
| let insertion_index = |
| work_items.binary_search_by_key(&cost, |&(_, cost)| cost); |
| let insertion_index = match insertion_index { |
| Ok(idx) | Err(idx) => idx |
| }; |
| work_items.insert(insertion_index, (llvm_work_item, cost)); |
| |
| if !cgcx.opts.debugging_opts.no_parallel_llvm { |
| helper.request_token(); |
| } |
| assert!(!codegen_aborted); |
| assert_eq!(main_thread_worker_state, |
| MainThreadWorkerState::Codegenning); |
| main_thread_worker_state = MainThreadWorkerState::Idle; |
| } |
| |
| Message::CodegenComplete => { |
| codegen_done = true; |
| assert!(!codegen_aborted); |
| assert_eq!(main_thread_worker_state, |
| MainThreadWorkerState::Codegenning); |
| main_thread_worker_state = MainThreadWorkerState::Idle; |
| } |
| |
| // If codegen is aborted that means translation was aborted due |
| // to some normal-ish compiler error. In this situation we want |
| // to exit as soon as possible, but we want to make sure all |
| // existing work has finished. Flag codegen as being done, and |
| // then conditions above will ensure no more work is spawned but |
| // we'll keep executing this loop until `running` hits 0. |
| Message::CodegenAborted => { |
| assert!(!codegen_aborted); |
| codegen_done = true; |
| codegen_aborted = true; |
| assert_eq!(main_thread_worker_state, |
| MainThreadWorkerState::Codegenning); |
| } |
| Message::Done { result: Ok(compiled_module), worker_id } => { |
| free_worker(worker_id); |
| match compiled_module.kind { |
| ModuleKind::Regular => { |
| compiled_modules.push(compiled_module); |
| } |
| ModuleKind::Metadata => { |
| assert!(compiled_metadata_module.is_none()); |
| compiled_metadata_module = Some(compiled_module); |
| } |
| ModuleKind::Allocator => { |
| assert!(compiled_allocator_module.is_none()); |
| compiled_allocator_module = Some(compiled_module); |
| } |
| } |
| } |
| Message::NeedsFatLTO { result, worker_id } => { |
| assert!(!started_lto); |
| free_worker(worker_id); |
| needs_fat_lto.push(result); |
| } |
| Message::NeedsThinLTO { name, thin_buffer, worker_id } => { |
| assert!(!started_lto); |
| free_worker(worker_id); |
| needs_thin_lto.push((name, thin_buffer)); |
| } |
| Message::AddImportOnlyModule { module_data, work_product } => { |
| assert!(!started_lto); |
| assert!(!codegen_done); |
| assert_eq!(main_thread_worker_state, |
| MainThreadWorkerState::Codegenning); |
| lto_import_only_modules.push((module_data, work_product)); |
| main_thread_worker_state = MainThreadWorkerState::Idle; |
| } |
| // If the thread failed that means it panicked, so we abort immediately. |
| Message::Done { result: Err(()), worker_id: _ } => { |
| bug!("worker thread panicked"); |
| } |
| Message::CodegenItem => { |
| bug!("the coordinator should not receive codegen requests") |
| } |
| } |
| } |
| |
| if let Some(llvm_start_time) = llvm_start_time { |
| let total_llvm_time = Instant::now().duration_since(llvm_start_time); |
| // This is the top-level timing for all of LLVM, set the time-depth |
| // to zero. |
| set_time_depth(1); |
| print_time_passes_entry(cgcx.time_passes, |
| "LLVM passes", |
| total_llvm_time); |
| } |
| |
| // Regardless of what order these modules completed in, report them to |
| // the backend in the same order every time to ensure that we're handing |
| // out deterministic results. |
| compiled_modules.sort_by(|a, b| a.name.cmp(&b.name)); |
| |
| Ok(CompiledModules { |
| modules: compiled_modules, |
| metadata_module: compiled_metadata_module, |
| allocator_module: compiled_allocator_module, |
| }) |
| }); |
| |
| // A heuristic that determines if we have enough LLVM WorkItems in the |
| // queue so that the main thread can do LLVM work instead of codegen |
| fn queue_full_enough(items_in_queue: usize, |
| workers_running: usize, |
| max_workers: usize) -> bool { |
| // Tune me, plz. |
| items_in_queue > 0 && |
| items_in_queue >= max_workers.saturating_sub(workers_running / 2) |
| } |
| |
| fn maybe_start_llvm_timer(config: &ModuleConfig, |
| llvm_start_time: &mut Option<Instant>) { |
| // We keep track of the -Ztime-passes output manually, |
| // since the closure-based interface does not fit well here. |
| if config.time_passes { |
| if llvm_start_time.is_none() { |
| *llvm_start_time = Some(Instant::now()); |
| } |
| } |
| } |
| } |
| |
| pub const CODEGEN_WORKER_ID: usize = ::std::usize::MAX; |
| |
| fn spawn_work<B: ExtraBackendMethods>( |
| cgcx: CodegenContext<B>, |
| work: WorkItem<B> |
| ) { |
| let depth = time_depth(); |
| |
| thread::spawn(move || { |
| set_time_depth(depth); |
| |
| // Set up a destructor which will fire off a message that we're done as |
| // we exit. |
| struct Bomb<B: ExtraBackendMethods> { |
| coordinator_send: Sender<Box<dyn Any + Send>>, |
| result: Option<WorkItemResult<B>>, |
| worker_id: usize, |
| } |
| impl<B: ExtraBackendMethods> Drop for Bomb<B> { |
| fn drop(&mut self) { |
| let worker_id = self.worker_id; |
| let msg = match self.result.take() { |
| Some(WorkItemResult::Compiled(m)) => { |
| Message::Done::<B> { result: Ok(m), worker_id } |
| } |
| Some(WorkItemResult::NeedsFatLTO(m)) => { |
| Message::NeedsFatLTO::<B> { result: m, worker_id } |
| } |
| Some(WorkItemResult::NeedsThinLTO(name, thin_buffer)) => { |
| Message::NeedsThinLTO::<B> { name, thin_buffer, worker_id } |
| } |
| None => Message::Done::<B> { result: Err(()), worker_id } |
| }; |
| drop(self.coordinator_send.send(Box::new(msg))); |
| } |
| } |
| |
| let mut bomb = Bomb::<B> { |
| coordinator_send: cgcx.coordinator_send.clone(), |
| result: None, |
| worker_id: cgcx.worker, |
| }; |
| |
| // Execute the work itself, and if it finishes successfully then flag |
| // ourselves as a success as well. |
| // |
| // Note that we ignore any `FatalError` coming out of `execute_work_item`, |
| // as a diagnostic was already sent off to the main thread - just |
| // surface that there was an error in this worker. |
| bomb.result = { |
| let _prof_timer = cgcx.prof.generic_activity(work.profiling_event_id()); |
| execute_work_item(&cgcx, work).ok() |
| }; |
| }); |
| } |
| |
| pub fn run_assembler<B: ExtraBackendMethods>( |
| cgcx: &CodegenContext<B>, |
| handler: &Handler, |
| assembly: &Path, |
| object: &Path |
| ) { |
| let assembler = cgcx.assembler_cmd |
| .as_ref() |
| .expect("cgcx.assembler_cmd is missing?"); |
| |
| let pname = &assembler.name; |
| let mut cmd = assembler.cmd.clone(); |
| cmd.arg("-c").arg("-o").arg(object).arg(assembly); |
| debug!("{:?}", cmd); |
| |
| match cmd.output() { |
| Ok(prog) => { |
| if !prog.status.success() { |
| let mut note = prog.stderr.clone(); |
| note.extend_from_slice(&prog.stdout); |
| |
| handler.struct_err(&format!("linking with `{}` failed: {}", |
| pname.display(), |
| prog.status)) |
| .note(&format!("{:?}", &cmd)) |
| .note(str::from_utf8(¬e[..]).unwrap()) |
| .emit(); |
| handler.abort_if_errors(); |
| } |
| }, |
| Err(e) => { |
| handler.err(&format!("could not exec the linker `{}`: {}", pname.display(), e)); |
| handler.abort_if_errors(); |
| } |
| } |
| } |
| |
| |
| enum SharedEmitterMessage { |
| Diagnostic(Diagnostic), |
| InlineAsmError(u32, String), |
| AbortIfErrors, |
| Fatal(String), |
| } |
| |
| #[derive(Clone)] |
| pub struct SharedEmitter { |
| sender: Sender<SharedEmitterMessage>, |
| } |
| |
| pub struct SharedEmitterMain { |
| receiver: Receiver<SharedEmitterMessage>, |
| } |
| |
| impl SharedEmitter { |
| pub fn new() -> (SharedEmitter, SharedEmitterMain) { |
| let (sender, receiver) = channel(); |
| |
| (SharedEmitter { sender }, SharedEmitterMain { receiver }) |
| } |
| |
| pub fn inline_asm_error(&self, cookie: u32, msg: String) { |
| drop(self.sender.send(SharedEmitterMessage::InlineAsmError(cookie, msg))); |
| } |
| |
| pub fn fatal(&self, msg: &str) { |
| drop(self.sender.send(SharedEmitterMessage::Fatal(msg.to_string()))); |
| } |
| } |
| |
| impl Emitter for SharedEmitter { |
| fn emit_diagnostic(&mut self, diag: &rustc_errors::Diagnostic) { |
| drop(self.sender.send(SharedEmitterMessage::Diagnostic(Diagnostic { |
| msg: diag.message(), |
| code: diag.code.clone(), |
| lvl: diag.level, |
| }))); |
| for child in &diag.children { |
| drop(self.sender.send(SharedEmitterMessage::Diagnostic(Diagnostic { |
| msg: child.message(), |
| code: None, |
| lvl: child.level, |
| }))); |
| } |
| drop(self.sender.send(SharedEmitterMessage::AbortIfErrors)); |
| } |
| fn source_map(&self) -> Option<&Lrc<SourceMap>> { |
| None |
| } |
| } |
| |
| impl SharedEmitterMain { |
| pub fn check(&self, sess: &Session, blocking: bool) { |
| loop { |
| let message = if blocking { |
| match self.receiver.recv() { |
| Ok(message) => Ok(message), |
| Err(_) => Err(()), |
| } |
| } else { |
| match self.receiver.try_recv() { |
| Ok(message) => Ok(message), |
| Err(_) => Err(()), |
| } |
| }; |
| |
| match message { |
| Ok(SharedEmitterMessage::Diagnostic(diag)) => { |
| let handler = sess.diagnostic(); |
| let mut d = rustc_errors::Diagnostic::new(diag.lvl, &diag.msg); |
| if let Some(code) = diag.code { |
| d.code(code); |
| } |
| handler.emit_diagnostic(&d); |
| handler.abort_if_errors_and_should_abort(); |
| } |
| Ok(SharedEmitterMessage::InlineAsmError(cookie, msg)) => { |
| sess.span_err(ExpnId::from_u32(cookie).expn_data().call_site, &msg) |
| } |
| Ok(SharedEmitterMessage::AbortIfErrors) => { |
| sess.abort_if_errors(); |
| } |
| Ok(SharedEmitterMessage::Fatal(msg)) => { |
| sess.fatal(&msg); |
| } |
| Err(_) => { |
| break; |
| } |
| } |
| |
| } |
| } |
| } |
| |
| pub struct OngoingCodegen<B: ExtraBackendMethods> { |
| pub backend: B, |
| pub crate_name: Symbol, |
| pub crate_hash: Svh, |
| pub metadata: EncodedMetadata, |
| pub windows_subsystem: Option<String>, |
| pub linker_info: LinkerInfo, |
| pub crate_info: CrateInfo, |
| pub coordinator_send: Sender<Box<dyn Any + Send>>, |
| pub codegen_worker_receive: Receiver<Message<B>>, |
| pub shared_emitter_main: SharedEmitterMain, |
| pub future: thread::JoinHandle<Result<CompiledModules, ()>>, |
| pub output_filenames: Arc<OutputFilenames>, |
| } |
| |
| impl<B: ExtraBackendMethods> OngoingCodegen<B> { |
| pub fn join( |
| self, |
| sess: &Session |
| ) -> (CodegenResults, FxHashMap<WorkProductId, WorkProduct>) { |
| self.shared_emitter_main.check(sess, true); |
| let compiled_modules = match self.future.join() { |
| Ok(Ok(compiled_modules)) => compiled_modules, |
| Ok(Err(())) => { |
| sess.abort_if_errors(); |
| panic!("expected abort due to worker thread errors") |
| }, |
| Err(_) => { |
| bug!("panic during codegen/LLVM phase"); |
| } |
| }; |
| |
| sess.cgu_reuse_tracker.check_expected_reuse(sess.diagnostic()); |
| |
| sess.abort_if_errors(); |
| |
| let work_products = |
| copy_all_cgu_workproducts_to_incr_comp_cache_dir(sess, |
| &compiled_modules); |
| produce_final_output_artifacts(sess, |
| &compiled_modules, |
| &self.output_filenames); |
| |
| // FIXME: time_llvm_passes support - does this use a global context or |
| // something? |
| if sess.codegen_units() == 1 && sess.time_llvm_passes() { |
| self.backend.print_pass_timings() |
| } |
| |
| (CodegenResults { |
| crate_name: self.crate_name, |
| crate_hash: self.crate_hash, |
| metadata: self.metadata, |
| windows_subsystem: self.windows_subsystem, |
| linker_info: self.linker_info, |
| crate_info: self.crate_info, |
| |
| modules: compiled_modules.modules, |
| allocator_module: compiled_modules.allocator_module, |
| metadata_module: compiled_modules.metadata_module, |
| }, work_products) |
| } |
| |
| pub fn submit_pre_codegened_module_to_llvm( |
| &self, |
| tcx: TyCtxt<'_>, |
| module: ModuleCodegen<B::Module>, |
| ) { |
| self.wait_for_signal_to_codegen_item(); |
| self.check_for_errors(tcx.sess); |
| |
| // These are generally cheap and won't throw off scheduling. |
| let cost = 0; |
| submit_codegened_module_to_llvm(&self.backend, &self.coordinator_send, module, cost); |
| } |
| |
| pub fn codegen_finished(&self, tcx: TyCtxt<'_>) { |
| self.wait_for_signal_to_codegen_item(); |
| self.check_for_errors(tcx.sess); |
| drop(self.coordinator_send.send(Box::new(Message::CodegenComplete::<B>))); |
| } |
| |
| /// Consumes this context indicating that codegen was entirely aborted, and |
| /// we need to exit as quickly as possible. |
| /// |
| /// This method blocks the current thread until all worker threads have |
| /// finished, and all worker threads should have exited or be real close to |
| /// exiting at this point. |
| pub fn codegen_aborted(self) { |
| // Signal to the coordinator it should spawn no more work and start |
| // shutdown. |
| drop(self.coordinator_send.send(Box::new(Message::CodegenAborted::<B>))); |
| drop(self.future.join()); |
| } |
| |
| pub fn check_for_errors(&self, sess: &Session) { |
| self.shared_emitter_main.check(sess, false); |
| } |
| |
| pub fn wait_for_signal_to_codegen_item(&self) { |
| match self.codegen_worker_receive.recv() { |
| Ok(Message::CodegenItem) => { |
| // Nothing to do |
| } |
| Ok(_) => panic!("unexpected message"), |
| Err(_) => { |
| // One of the LLVM threads must have panicked, fall through so |
| // error handling can be reached. |
| } |
| } |
| } |
| } |
| |
| pub fn submit_codegened_module_to_llvm<B: ExtraBackendMethods>( |
| _backend: &B, |
| tx_to_llvm_workers: &Sender<Box<dyn Any + Send>>, |
| module: ModuleCodegen<B::Module>, |
| cost: u64, |
| ) { |
| let llvm_work_item = WorkItem::Optimize(module); |
| drop(tx_to_llvm_workers.send(Box::new(Message::CodegenDone::<B> { |
| llvm_work_item, |
| cost, |
| }))); |
| } |
| |
| pub fn submit_post_lto_module_to_llvm<B: ExtraBackendMethods>( |
| _backend: &B, |
| tx_to_llvm_workers: &Sender<Box<dyn Any + Send>>, |
| module: CachedModuleCodegen, |
| ) { |
| let llvm_work_item = WorkItem::CopyPostLtoArtifacts(module); |
| drop(tx_to_llvm_workers.send(Box::new(Message::CodegenDone::<B> { |
| llvm_work_item, |
| cost: 0, |
| }))); |
| } |
| |
| pub fn submit_pre_lto_module_to_llvm<B: ExtraBackendMethods>( |
| _backend: &B, |
| tcx: TyCtxt<'_>, |
| tx_to_llvm_workers: &Sender<Box<dyn Any + Send>>, |
| module: CachedModuleCodegen, |
| ) { |
| let filename = pre_lto_bitcode_filename(&module.name); |
| let bc_path = in_incr_comp_dir_sess(tcx.sess, &filename); |
| let file = fs::File::open(&bc_path).unwrap_or_else(|e| { |
| panic!("failed to open bitcode file `{}`: {}", bc_path.display(), e) |
| }); |
| |
| let mmap = unsafe { |
| memmap::Mmap::map(&file).unwrap_or_else(|e| { |
| panic!("failed to mmap bitcode file `{}`: {}", bc_path.display(), e) |
| }) |
| }; |
| // Schedule the module to be loaded |
| drop(tx_to_llvm_workers.send(Box::new(Message::AddImportOnlyModule::<B> { |
| module_data: SerializedModule::FromUncompressedFile(mmap), |
| work_product: module.source, |
| }))); |
| } |
| |
| pub fn pre_lto_bitcode_filename(module_name: &str) -> String { |
| format!("{}.{}", module_name, PRE_LTO_BC_EXT) |
| } |
| |
| fn msvc_imps_needed(tcx: TyCtxt<'_>) -> bool { |
| // This should never be true (because it's not supported). If it is true, |
| // something is wrong with commandline arg validation. |
| assert!(!(tcx.sess.opts.cg.linker_plugin_lto.enabled() && |
| tcx.sess.target.target.options.is_like_msvc && |
| tcx.sess.opts.cg.prefer_dynamic)); |
| |
| tcx.sess.target.target.options.is_like_msvc && |
| tcx.sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateType::Rlib) && |
| // ThinLTO can't handle this workaround in all cases, so we don't |
| // emit the `__imp_` symbols. Instead we make them unnecessary by disallowing |
| // dynamic linking when linker plugin LTO is enabled. |
| !tcx.sess.opts.cg.linker_plugin_lto.enabled() |
| } |
