|  | use std::any::Any; | 
|  | use std::env::consts::{DLL_PREFIX, DLL_SUFFIX}; | 
|  | use std::path::{Path, PathBuf}; | 
|  | use std::sync::atomic::{AtomicBool, Ordering}; | 
|  | use std::sync::{Arc, OnceLock}; | 
|  | use std::{env, thread}; | 
|  |  | 
|  | use rustc_ast as ast; | 
|  | use rustc_attr_parsing::{ShouldEmit, validate_attr}; | 
|  | use rustc_codegen_ssa::back::archive::ArArchiveBuilderBuilder; | 
|  | use rustc_codegen_ssa::back::link::link_binary; | 
|  | use rustc_codegen_ssa::target_features::{self, cfg_target_feature}; | 
|  | use rustc_codegen_ssa::traits::CodegenBackend; | 
|  | use rustc_codegen_ssa::{CodegenResults, CrateInfo, TargetConfig}; | 
|  | use rustc_data_structures::fx::FxIndexMap; | 
|  | use rustc_data_structures::jobserver::Proxy; | 
|  | use rustc_data_structures::sync; | 
|  | use rustc_errors::LintBuffer; | 
|  | use rustc_metadata::{DylibError, EncodedMetadata, load_symbol_from_dylib}; | 
|  | use rustc_middle::dep_graph::{WorkProduct, WorkProductId}; | 
|  | use rustc_middle::ty::{CurrentGcx, TyCtxt}; | 
|  | use rustc_session::config::{ | 
|  | Cfg, CrateType, OutFileName, OutputFilenames, OutputTypes, Sysroot, host_tuple, | 
|  | }; | 
|  | use rustc_session::output::{CRATE_TYPES, categorize_crate_type}; | 
|  | use rustc_session::{EarlyDiagCtxt, Session, filesearch, lint}; | 
|  | use rustc_span::edit_distance::find_best_match_for_name; | 
|  | use rustc_span::edition::Edition; | 
|  | use rustc_span::source_map::SourceMapInputs; | 
|  | use rustc_span::{SessionGlobals, Symbol, sym}; | 
|  | use rustc_target::spec::Target; | 
|  | use tracing::info; | 
|  |  | 
|  | use crate::errors; | 
|  | use crate::passes::parse_crate_name; | 
|  |  | 
|  | /// Function pointer type that constructs a new CodegenBackend. | 
|  | type MakeBackendFn = fn() -> Box<dyn CodegenBackend>; | 
|  |  | 
|  | /// Adds `target_feature = "..."` cfgs for a variety of platform | 
|  | /// specific features (SSE, NEON etc.). | 
|  | /// | 
|  | /// This is performed by checking whether a set of permitted features | 
|  | /// is available on the target machine, by querying the codegen backend. | 
|  | pub(crate) fn add_configuration( | 
|  | cfg: &mut Cfg, | 
|  | sess: &mut Session, | 
|  | codegen_backend: &dyn CodegenBackend, | 
|  | ) { | 
|  | let tf = sym::target_feature; | 
|  | let tf_cfg = codegen_backend.target_config(sess); | 
|  |  | 
|  | sess.unstable_target_features.extend(tf_cfg.unstable_target_features.iter().copied()); | 
|  | sess.target_features.extend(tf_cfg.target_features.iter().copied()); | 
|  |  | 
|  | cfg.extend(tf_cfg.target_features.into_iter().map(|feat| (tf, Some(feat)))); | 
|  |  | 
|  | if tf_cfg.has_reliable_f16 { | 
|  | cfg.insert((sym::target_has_reliable_f16, None)); | 
|  | } | 
|  | if tf_cfg.has_reliable_f16_math { | 
|  | cfg.insert((sym::target_has_reliable_f16_math, None)); | 
|  | } | 
|  | if tf_cfg.has_reliable_f128 { | 
|  | cfg.insert((sym::target_has_reliable_f128, None)); | 
|  | } | 
|  | if tf_cfg.has_reliable_f128_math { | 
|  | cfg.insert((sym::target_has_reliable_f128_math, None)); | 
|  | } | 
|  |  | 
|  | if sess.crt_static(None) { | 
|  | cfg.insert((tf, Some(sym::crt_dash_static))); | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Ensures that all target features required by the ABI are present. | 
|  | /// Must be called after `unstable_target_features` has been populated! | 
|  | pub(crate) fn check_abi_required_features(sess: &Session) { | 
|  | let abi_feature_constraints = sess.target.abi_required_features(); | 
|  | // We check this against `unstable_target_features` as that is conveniently already | 
|  | // back-translated to rustc feature names, taking into account `-Ctarget-cpu` and `-Ctarget-feature`. | 
|  | // Just double-check that the features we care about are actually on our list. | 
|  | for feature in | 
|  | abi_feature_constraints.required.iter().chain(abi_feature_constraints.incompatible.iter()) | 
|  | { | 
|  | assert!( | 
|  | sess.target.rust_target_features().iter().any(|(name, ..)| feature == name), | 
|  | "target feature {feature} is required/incompatible for the current ABI but not a recognized feature for this target" | 
|  | ); | 
|  | } | 
|  |  | 
|  | for feature in abi_feature_constraints.required { | 
|  | if !sess.unstable_target_features.contains(&Symbol::intern(feature)) { | 
|  | sess.dcx().emit_warn(errors::AbiRequiredTargetFeature { feature, enabled: "enabled" }); | 
|  | } | 
|  | } | 
|  | for feature in abi_feature_constraints.incompatible { | 
|  | if sess.unstable_target_features.contains(&Symbol::intern(feature)) { | 
|  | sess.dcx().emit_warn(errors::AbiRequiredTargetFeature { feature, enabled: "disabled" }); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub static STACK_SIZE: OnceLock<usize> = OnceLock::new(); | 
|  | pub const DEFAULT_STACK_SIZE: usize = 8 * 1024 * 1024; | 
|  |  | 
|  | fn init_stack_size(early_dcx: &EarlyDiagCtxt) -> usize { | 
|  | // Obey the environment setting or default | 
|  | *STACK_SIZE.get_or_init(|| { | 
|  | env::var_os("RUST_MIN_STACK") | 
|  | .as_ref() | 
|  | .map(|os_str| os_str.to_string_lossy()) | 
|  | // if someone finds out `export RUST_MIN_STACK=640000` isn't enough stack | 
|  | // they might try to "unset" it by running `RUST_MIN_STACK=  rustc code.rs` | 
|  | // this is wrong, but std would nonetheless "do what they mean", so let's do likewise | 
|  | .filter(|s| !s.trim().is_empty()) | 
|  | // rustc is a batch program, so error early on inputs which are unlikely to be intended | 
|  | // so no one thinks we parsed them setting `RUST_MIN_STACK="64 megabytes"` | 
|  | // FIXME: we could accept `RUST_MIN_STACK=64MB`, perhaps? | 
|  | .map(|s| { | 
|  | let s = s.trim(); | 
|  | // FIXME(workingjubilee): add proper diagnostics when we factor out "pre-run" setup | 
|  | #[allow(rustc::untranslatable_diagnostic, rustc::diagnostic_outside_of_impl)] | 
|  | s.parse::<usize>().unwrap_or_else(|_| { | 
|  | let mut err = early_dcx.early_struct_fatal(format!( | 
|  | r#"`RUST_MIN_STACK` should be a number of bytes, but was "{s}""#, | 
|  | )); | 
|  | err.note("you can also unset `RUST_MIN_STACK` to use the default stack size"); | 
|  | err.emit() | 
|  | }) | 
|  | }) | 
|  | // otherwise pick a consistent default | 
|  | .unwrap_or(DEFAULT_STACK_SIZE) | 
|  | }) | 
|  | } | 
|  |  | 
|  | fn run_in_thread_with_globals<F: FnOnce(CurrentGcx, Arc<Proxy>) -> R + Send, R: Send>( | 
|  | thread_stack_size: usize, | 
|  | edition: Edition, | 
|  | sm_inputs: SourceMapInputs, | 
|  | extra_symbols: &[&'static str], | 
|  | f: F, | 
|  | ) -> R { | 
|  | // The "thread pool" is a single spawned thread in the non-parallel | 
|  | // compiler. We run on a spawned thread instead of the main thread (a) to | 
|  | // provide control over the stack size, and (b) to increase similarity with | 
|  | // the parallel compiler, in particular to ensure there is no accidental | 
|  | // sharing of data between the main thread and the compilation thread | 
|  | // (which might cause problems for the parallel compiler). | 
|  | let builder = thread::Builder::new().name("rustc".to_string()).stack_size(thread_stack_size); | 
|  |  | 
|  | // We build the session globals and run `f` on the spawned thread, because | 
|  | // `SessionGlobals` does not impl `Send` in the non-parallel compiler. | 
|  | thread::scope(|s| { | 
|  | // `unwrap` is ok here because `spawn_scoped` only panics if the thread | 
|  | // name contains null bytes. | 
|  | let r = builder | 
|  | .spawn_scoped(s, move || { | 
|  | rustc_span::create_session_globals_then( | 
|  | edition, | 
|  | extra_symbols, | 
|  | Some(sm_inputs), | 
|  | || f(CurrentGcx::new(), Proxy::new()), | 
|  | ) | 
|  | }) | 
|  | .unwrap() | 
|  | .join(); | 
|  |  | 
|  | match r { | 
|  | Ok(v) => v, | 
|  | Err(e) => std::panic::resume_unwind(e), | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | pub(crate) fn run_in_thread_pool_with_globals< | 
|  | F: FnOnce(CurrentGcx, Arc<Proxy>) -> R + Send, | 
|  | R: Send, | 
|  | >( | 
|  | thread_builder_diag: &EarlyDiagCtxt, | 
|  | edition: Edition, | 
|  | threads: usize, | 
|  | extra_symbols: &[&'static str], | 
|  | sm_inputs: SourceMapInputs, | 
|  | f: F, | 
|  | ) -> R { | 
|  | use std::process; | 
|  |  | 
|  | use rustc_data_structures::defer; | 
|  | use rustc_data_structures::sync::FromDyn; | 
|  | use rustc_middle::ty::tls; | 
|  | use rustc_query_impl::QueryCtxt; | 
|  | use rustc_query_system::query::{QueryContext, break_query_cycles}; | 
|  |  | 
|  | let thread_stack_size = init_stack_size(thread_builder_diag); | 
|  |  | 
|  | let registry = sync::Registry::new(std::num::NonZero::new(threads).unwrap()); | 
|  |  | 
|  | if !sync::is_dyn_thread_safe() { | 
|  | return run_in_thread_with_globals( | 
|  | thread_stack_size, | 
|  | edition, | 
|  | sm_inputs, | 
|  | extra_symbols, | 
|  | |current_gcx, jobserver_proxy| { | 
|  | // Register the thread for use with the `WorkerLocal` type. | 
|  | registry.register(); | 
|  |  | 
|  | f(current_gcx, jobserver_proxy) | 
|  | }, | 
|  | ); | 
|  | } | 
|  |  | 
|  | let current_gcx = FromDyn::from(CurrentGcx::new()); | 
|  | let current_gcx2 = current_gcx.clone(); | 
|  |  | 
|  | let proxy = Proxy::new(); | 
|  |  | 
|  | let proxy_ = Arc::clone(&proxy); | 
|  | let proxy__ = Arc::clone(&proxy); | 
|  | let builder = rustc_thread_pool::ThreadPoolBuilder::new() | 
|  | .thread_name(|_| "rustc".to_string()) | 
|  | .acquire_thread_handler(move || proxy_.acquire_thread()) | 
|  | .release_thread_handler(move || proxy__.release_thread()) | 
|  | .num_threads(threads) | 
|  | .deadlock_handler(move || { | 
|  | // On deadlock, creates a new thread and forwards information in thread | 
|  | // locals to it. The new thread runs the deadlock handler. | 
|  |  | 
|  | let current_gcx2 = current_gcx2.clone(); | 
|  | let registry = rustc_thread_pool::Registry::current(); | 
|  | let session_globals = rustc_span::with_session_globals(|session_globals| { | 
|  | session_globals as *const SessionGlobals as usize | 
|  | }); | 
|  | thread::Builder::new() | 
|  | .name("rustc query cycle handler".to_string()) | 
|  | .spawn(move || { | 
|  | let on_panic = defer(|| { | 
|  | eprintln!("internal compiler error: query cycle handler thread panicked, aborting process"); | 
|  | // We need to abort here as we failed to resolve the deadlock, | 
|  | // otherwise the compiler could just hang, | 
|  | process::abort(); | 
|  | }); | 
|  |  | 
|  | // Get a `GlobalCtxt` reference from `CurrentGcx` as we cannot rely on having a | 
|  | // `TyCtxt` TLS reference here. | 
|  | current_gcx2.access(|gcx| { | 
|  | tls::enter_context(&tls::ImplicitCtxt::new(gcx), || { | 
|  | tls::with(|tcx| { | 
|  | // Accessing session globals is sound as they outlive `GlobalCtxt`. | 
|  | // They are needed to hash query keys containing spans or symbols. | 
|  | let query_map = rustc_span::set_session_globals_then(unsafe { &*(session_globals as *const SessionGlobals) }, || { | 
|  | // Ensure there was no errors collecting all active jobs. | 
|  | // We need the complete map to ensure we find a cycle to break. | 
|  | QueryCtxt::new(tcx).collect_active_jobs().expect("failed to collect active queries in deadlock handler") | 
|  | }); | 
|  | break_query_cycles(query_map, ®istry); | 
|  | }) | 
|  | }) | 
|  | }); | 
|  |  | 
|  | on_panic.disable(); | 
|  | }) | 
|  | .unwrap(); | 
|  | }) | 
|  | .stack_size(thread_stack_size); | 
|  |  | 
|  | // We create the session globals on the main thread, then create the thread | 
|  | // pool. Upon creation, each worker thread created gets a copy of the | 
|  | // session globals in TLS. This is possible because `SessionGlobals` impls | 
|  | // `Send` in the parallel compiler. | 
|  | rustc_span::create_session_globals_then(edition, extra_symbols, Some(sm_inputs), || { | 
|  | rustc_span::with_session_globals(|session_globals| { | 
|  | let session_globals = FromDyn::from(session_globals); | 
|  | builder | 
|  | .build_scoped( | 
|  | // Initialize each new worker thread when created. | 
|  | move |thread: rustc_thread_pool::ThreadBuilder| { | 
|  | // Register the thread for use with the `WorkerLocal` type. | 
|  | registry.register(); | 
|  |  | 
|  | rustc_span::set_session_globals_then(session_globals.into_inner(), || { | 
|  | thread.run() | 
|  | }) | 
|  | }, | 
|  | // Run `f` on the first thread in the thread pool. | 
|  | move |pool: &rustc_thread_pool::ThreadPool| { | 
|  | pool.install(|| f(current_gcx.into_inner(), proxy)) | 
|  | }, | 
|  | ) | 
|  | .unwrap_or_else(|err| { | 
|  | let mut diag = thread_builder_diag.early_struct_fatal(format!( | 
|  | "failed to spawn compiler thread pool: could not create {threads} threads ({err})", | 
|  | )); | 
|  | diag.help( | 
|  | "try lowering `-Z threads` or checking the operating system's resource limits", | 
|  | ); | 
|  | diag.emit(); | 
|  | }) | 
|  | }) | 
|  | }) | 
|  | } | 
|  |  | 
|  | #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable | 
|  | fn load_backend_from_dylib(early_dcx: &EarlyDiagCtxt, path: &Path) -> MakeBackendFn { | 
|  | match unsafe { load_symbol_from_dylib::<MakeBackendFn>(path, "__rustc_codegen_backend") } { | 
|  | Ok(backend_sym) => backend_sym, | 
|  | Err(DylibError::DlOpen(path, err)) => { | 
|  | let err = format!("couldn't load codegen backend {path}{err}"); | 
|  | early_dcx.early_fatal(err); | 
|  | } | 
|  | Err(DylibError::DlSym(_path, err)) => { | 
|  | let e = format!( | 
|  | "`__rustc_codegen_backend` symbol lookup in the codegen backend failed{err}", | 
|  | ); | 
|  | early_dcx.early_fatal(e); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Get the codegen backend based on the name and specified sysroot. | 
|  | /// | 
|  | /// A name of `None` indicates that the default backend should be used. | 
|  | pub fn get_codegen_backend( | 
|  | early_dcx: &EarlyDiagCtxt, | 
|  | sysroot: &Sysroot, | 
|  | backend_name: Option<&str>, | 
|  | target: &Target, | 
|  | ) -> Box<dyn CodegenBackend> { | 
|  | static LOAD: OnceLock<unsafe fn() -> Box<dyn CodegenBackend>> = OnceLock::new(); | 
|  |  | 
|  | let load = LOAD.get_or_init(|| { | 
|  | let backend = backend_name | 
|  | .or(target.default_codegen_backend.as_deref()) | 
|  | .or(option_env!("CFG_DEFAULT_CODEGEN_BACKEND")) | 
|  | .unwrap_or("dummy"); | 
|  |  | 
|  | match backend { | 
|  | filename if filename.contains('.') => { | 
|  | load_backend_from_dylib(early_dcx, filename.as_ref()) | 
|  | } | 
|  | "dummy" => || Box::new(DummyCodegenBackend), | 
|  | #[cfg(feature = "llvm")] | 
|  | "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new, | 
|  | backend_name => get_codegen_sysroot(early_dcx, sysroot, backend_name), | 
|  | } | 
|  | }); | 
|  |  | 
|  | // SAFETY: In case of a builtin codegen backend this is safe. In case of an external codegen | 
|  | // backend we hope that the backend links against the same rustc_driver version. If this is not | 
|  | // the case, we get UB. | 
|  | unsafe { load() } | 
|  | } | 
|  |  | 
|  | struct DummyCodegenBackend; | 
|  |  | 
|  | impl CodegenBackend for DummyCodegenBackend { | 
|  | fn locale_resource(&self) -> &'static str { | 
|  | "" | 
|  | } | 
|  |  | 
|  | fn name(&self) -> &'static str { | 
|  | "dummy" | 
|  | } | 
|  |  | 
|  | fn target_config(&self, sess: &Session) -> TargetConfig { | 
|  | let (target_features, unstable_target_features) = cfg_target_feature(sess, |feature| { | 
|  | // This is a standin for the list of features a backend is expected to enable. | 
|  | // It would be better to parse target.features instead and handle implied features, | 
|  | // but target.features is a list of LLVM target features, not Rust target features. | 
|  | // The dummy backend doesn't know the mapping between LLVM and Rust target features. | 
|  | sess.target.abi_required_features().required.contains(&feature) | 
|  | }); | 
|  |  | 
|  | // To report warnings about unknown features | 
|  | target_features::flag_to_backend_features::<0>( | 
|  | sess, | 
|  | true, | 
|  | |_| Default::default(), | 
|  | |_, _| {}, | 
|  | ); | 
|  |  | 
|  | TargetConfig { | 
|  | target_features, | 
|  | unstable_target_features, | 
|  | has_reliable_f16: true, | 
|  | has_reliable_f16_math: true, | 
|  | has_reliable_f128: true, | 
|  | has_reliable_f128_math: true, | 
|  | } | 
|  | } | 
|  |  | 
|  | fn supported_crate_types(&self, _sess: &Session) -> Vec<CrateType> { | 
|  | // This includes bin despite failing on the link step to ensure that you | 
|  | // can still get the frontend handling for binaries. For all library | 
|  | // like crate types cargo will fallback to rlib unless you specifically | 
|  | // say that only a different crate type must be used. | 
|  | vec![CrateType::Rlib, CrateType::Executable] | 
|  | } | 
|  |  | 
|  | fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Box<dyn Any> { | 
|  | Box::new(CodegenResults { | 
|  | modules: vec![], | 
|  | allocator_module: None, | 
|  | crate_info: CrateInfo::new(tcx, String::new()), | 
|  | }) | 
|  | } | 
|  |  | 
|  | fn join_codegen( | 
|  | &self, | 
|  | ongoing_codegen: Box<dyn Any>, | 
|  | _sess: &Session, | 
|  | _outputs: &OutputFilenames, | 
|  | ) -> (CodegenResults, FxIndexMap<WorkProductId, WorkProduct>) { | 
|  | (*ongoing_codegen.downcast().unwrap(), FxIndexMap::default()) | 
|  | } | 
|  |  | 
|  | fn link( | 
|  | &self, | 
|  | sess: &Session, | 
|  | codegen_results: CodegenResults, | 
|  | metadata: EncodedMetadata, | 
|  | outputs: &OutputFilenames, | 
|  | ) { | 
|  | // JUSTIFICATION: TyCtxt no longer available here | 
|  | #[allow(rustc::bad_opt_access)] | 
|  | if let Some(&crate_type) = codegen_results | 
|  | .crate_info | 
|  | .crate_types | 
|  | .iter() | 
|  | .find(|&&crate_type| crate_type != CrateType::Rlib) | 
|  | && outputs.outputs.should_link() | 
|  | { | 
|  | #[allow(rustc::untranslatable_diagnostic)] | 
|  | #[allow(rustc::diagnostic_outside_of_impl)] | 
|  | sess.dcx().fatal(format!( | 
|  | "crate type {crate_type} not supported by the dummy codegen backend" | 
|  | )); | 
|  | } | 
|  |  | 
|  | link_binary( | 
|  | sess, | 
|  | &ArArchiveBuilderBuilder, | 
|  | codegen_results, | 
|  | metadata, | 
|  | outputs, | 
|  | self.name(), | 
|  | ); | 
|  | } | 
|  | } | 
|  |  | 
|  | // This is used for rustdoc, but it uses similar machinery to codegen backend | 
|  | // loading, so we leave the code here. It is potentially useful for other tools | 
|  | // that want to invoke the rustc binary while linking to rustc as well. | 
|  | pub fn rustc_path<'a>(sysroot: &Sysroot) -> Option<&'a Path> { | 
|  | static RUSTC_PATH: OnceLock<Option<PathBuf>> = OnceLock::new(); | 
|  |  | 
|  | RUSTC_PATH | 
|  | .get_or_init(|| { | 
|  | let candidate = sysroot | 
|  | .default | 
|  | .join(env!("RUSTC_INSTALL_BINDIR")) | 
|  | .join(if cfg!(target_os = "windows") { "rustc.exe" } else { "rustc" }); | 
|  | candidate.exists().then_some(candidate) | 
|  | }) | 
|  | .as_deref() | 
|  | } | 
|  |  | 
|  | #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable | 
|  | fn get_codegen_sysroot( | 
|  | early_dcx: &EarlyDiagCtxt, | 
|  | sysroot: &Sysroot, | 
|  | backend_name: &str, | 
|  | ) -> MakeBackendFn { | 
|  | // For now we only allow this function to be called once as it'll dlopen a | 
|  | // few things, which seems to work best if we only do that once. In | 
|  | // general this assertion never trips due to the once guard in `get_codegen_backend`, | 
|  | // but there's a few manual calls to this function in this file we protect | 
|  | // against. | 
|  | static LOADED: AtomicBool = AtomicBool::new(false); | 
|  | assert!( | 
|  | !LOADED.fetch_or(true, Ordering::SeqCst), | 
|  | "cannot load the default codegen backend twice" | 
|  | ); | 
|  |  | 
|  | let target = host_tuple(); | 
|  |  | 
|  | let sysroot = sysroot | 
|  | .all_paths() | 
|  | .map(|sysroot| { | 
|  | filesearch::make_target_lib_path(sysroot, target).with_file_name("codegen-backends") | 
|  | }) | 
|  | .find(|f| { | 
|  | info!("codegen backend candidate: {}", f.display()); | 
|  | f.exists() | 
|  | }) | 
|  | .unwrap_or_else(|| { | 
|  | let candidates = sysroot | 
|  | .all_paths() | 
|  | .map(|p| p.display().to_string()) | 
|  | .collect::<Vec<_>>() | 
|  | .join("\n* "); | 
|  | let err = format!( | 
|  | "failed to find a `codegen-backends` folder in the sysroot candidates:\n\ | 
|  | * {candidates}" | 
|  | ); | 
|  | early_dcx.early_fatal(err); | 
|  | }); | 
|  |  | 
|  | info!("probing {} for a codegen backend", sysroot.display()); | 
|  |  | 
|  | let d = sysroot.read_dir().unwrap_or_else(|e| { | 
|  | let err = format!( | 
|  | "failed to load default codegen backend, couldn't read `{}`: {e}", | 
|  | sysroot.display(), | 
|  | ); | 
|  | early_dcx.early_fatal(err); | 
|  | }); | 
|  |  | 
|  | let mut file: Option<PathBuf> = None; | 
|  |  | 
|  | let expected_names = &[ | 
|  | format!("rustc_codegen_{}-{}", backend_name, env!("CFG_RELEASE")), | 
|  | format!("rustc_codegen_{backend_name}"), | 
|  | ]; | 
|  | for entry in d.filter_map(|e| e.ok()) { | 
|  | let path = entry.path(); | 
|  | let Some(filename) = path.file_name().and_then(|s| s.to_str()) else { continue }; | 
|  | if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) { | 
|  | continue; | 
|  | } | 
|  | let name = &filename[DLL_PREFIX.len()..filename.len() - DLL_SUFFIX.len()]; | 
|  | if !expected_names.iter().any(|expected| expected == name) { | 
|  | continue; | 
|  | } | 
|  | if let Some(ref prev) = file { | 
|  | let err = format!( | 
|  | "duplicate codegen backends found\n\ | 
|  | first:  {}\n\ | 
|  | second: {}\n\ | 
|  | ", | 
|  | prev.display(), | 
|  | path.display() | 
|  | ); | 
|  | early_dcx.early_fatal(err); | 
|  | } | 
|  | file = Some(path.clone()); | 
|  | } | 
|  |  | 
|  | match file { | 
|  | Some(ref s) => load_backend_from_dylib(early_dcx, s), | 
|  | None => { | 
|  | let err = format!("unsupported builtin codegen backend `{backend_name}`"); | 
|  | early_dcx.early_fatal(err); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub(crate) fn check_attr_crate_type( | 
|  | sess: &Session, | 
|  | attrs: &[ast::Attribute], | 
|  | lint_buffer: &mut LintBuffer, | 
|  | ) { | 
|  | // Unconditionally collect crate types from attributes to make them used | 
|  | for a in attrs.iter() { | 
|  | if a.has_name(sym::crate_type) { | 
|  | if let Some(n) = a.value_str() { | 
|  | if categorize_crate_type(n).is_some() { | 
|  | return; | 
|  | } | 
|  |  | 
|  | if let ast::MetaItemKind::NameValue(spanned) = a.meta_kind().unwrap() { | 
|  | let span = spanned.span; | 
|  | let candidate = find_best_match_for_name( | 
|  | &CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(), | 
|  | n, | 
|  | None, | 
|  | ); | 
|  | lint_buffer.buffer_lint( | 
|  | lint::builtin::UNKNOWN_CRATE_TYPES, | 
|  | ast::CRATE_NODE_ID, | 
|  | span, | 
|  | errors::UnknownCrateTypes { | 
|  | sugg: candidate | 
|  | .map(|cand| errors::UnknownCrateTypesSub { span, snippet: cand }), | 
|  | }, | 
|  | ); | 
|  | } | 
|  | } else { | 
|  | // This is here mainly to check for using a macro, such as | 
|  | // `#![crate_type = foo!()]`. That is not supported since the | 
|  | // crate type needs to be known very early in compilation long | 
|  | // before expansion. Otherwise, validation would normally be | 
|  | // caught during semantic analysis via `TyCtxt::check_mod_attrs`, | 
|  | // but by the time that runs the macro is expanded, and it doesn't | 
|  | // give an error. | 
|  | validate_attr::emit_fatal_malformed_builtin_attribute( | 
|  | &sess.psess, | 
|  | a, | 
|  | sym::crate_type, | 
|  | ); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | fn multiple_output_types_to_stdout( | 
|  | output_types: &OutputTypes, | 
|  | single_output_file_is_stdout: bool, | 
|  | ) -> bool { | 
|  | use std::io::IsTerminal; | 
|  | if std::io::stdout().is_terminal() { | 
|  | // If stdout is a tty, check if multiple text output types are | 
|  | // specified by `--emit foo=- --emit bar=-` or `-o - --emit foo,bar` | 
|  | let named_text_types = output_types | 
|  | .iter() | 
|  | .filter(|(f, o)| f.is_text_output() && *o == &Some(OutFileName::Stdout)) | 
|  | .count(); | 
|  | let unnamed_text_types = | 
|  | output_types.iter().filter(|(f, o)| f.is_text_output() && o.is_none()).count(); | 
|  | named_text_types > 1 || unnamed_text_types > 1 && single_output_file_is_stdout | 
|  | } else { | 
|  | // Otherwise, all the output types should be checked | 
|  | let named_types = | 
|  | output_types.values().filter(|o| *o == &Some(OutFileName::Stdout)).count(); | 
|  | let unnamed_types = output_types.values().filter(|o| o.is_none()).count(); | 
|  | named_types > 1 || unnamed_types > 1 && single_output_file_is_stdout | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> OutputFilenames { | 
|  | if multiple_output_types_to_stdout( | 
|  | &sess.opts.output_types, | 
|  | sess.io.output_file == Some(OutFileName::Stdout), | 
|  | ) { | 
|  | sess.dcx().emit_fatal(errors::MultipleOutputTypesToStdout); | 
|  | } | 
|  |  | 
|  | let crate_name = | 
|  | sess.opts.crate_name.clone().or_else(|| { | 
|  | parse_crate_name(sess, attrs, ShouldEmit::Nothing).map(|i| i.0.to_string()) | 
|  | }); | 
|  |  | 
|  | match sess.io.output_file { | 
|  | None => { | 
|  | // "-" as input file will cause the parser to read from stdin so we | 
|  | // have to make up a name | 
|  | // We want to toss everything after the final '.' | 
|  | let dirpath = sess.io.output_dir.clone().unwrap_or_default(); | 
|  |  | 
|  | // If a crate name is present, we use it as the link name | 
|  | let stem = crate_name.clone().unwrap_or_else(|| sess.io.input.filestem().to_owned()); | 
|  |  | 
|  | OutputFilenames::new( | 
|  | dirpath, | 
|  | crate_name.unwrap_or_else(|| stem.replace('-', "_")), | 
|  | stem, | 
|  | None, | 
|  | sess.io.temps_dir.clone(), | 
|  | sess.opts.unstable_opts.split_dwarf_out_dir.clone(), | 
|  | sess.opts.cg.extra_filename.clone(), | 
|  | sess.opts.output_types.clone(), | 
|  | ) | 
|  | } | 
|  |  | 
|  | Some(ref out_file) => { | 
|  | let unnamed_output_types = | 
|  | sess.opts.output_types.values().filter(|a| a.is_none()).count(); | 
|  | let ofile = if unnamed_output_types > 1 { | 
|  | sess.dcx().emit_warn(errors::MultipleOutputTypesAdaption); | 
|  | None | 
|  | } else { | 
|  | if !sess.opts.cg.extra_filename.is_empty() { | 
|  | sess.dcx().emit_warn(errors::IgnoringExtraFilename); | 
|  | } | 
|  | Some(out_file.clone()) | 
|  | }; | 
|  | if sess.io.output_dir.is_some() { | 
|  | sess.dcx().emit_warn(errors::IgnoringOutDir); | 
|  | } | 
|  |  | 
|  | let out_filestem = | 
|  | out_file.filestem().unwrap_or_default().to_str().unwrap().to_string(); | 
|  | OutputFilenames::new( | 
|  | out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(), | 
|  | crate_name.unwrap_or_else(|| out_filestem.replace('-', "_")), | 
|  | out_filestem, | 
|  | ofile, | 
|  | sess.io.temps_dir.clone(), | 
|  | sess.opts.unstable_opts.split_dwarf_out_dir.clone(), | 
|  | sess.opts.cg.extra_filename.clone(), | 
|  | sess.opts.output_types.clone(), | 
|  | ) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Returns a version string such as "1.46.0 (04488afe3 2020-08-24)" when invoked by an in-tree tool. | 
|  | pub macro version_str() { | 
|  | option_env!("CFG_VERSION") | 
|  | } | 
|  |  | 
|  | /// Returns the version string for `rustc` itself (which may be different from a tool version). | 
|  | pub fn rustc_version_str() -> Option<&'static str> { | 
|  | version_str!() | 
|  | } |