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		af46699f81
		
			
		
	
	
	
	
		
			
			Instead of updating global state to mark attributes as used, we now explicitly emit a warning when an attribute is used in an unsupported position. As a side effect, we are to emit more detailed warning messages (instead of just a generic "unused" message). `Session.check_name` is removed, since its only purpose was to mark the attribute as used. All of the callers are modified to use `Attribute.has_name` Additionally, `AttributeType::AssumedUsed` is removed - an 'assumed used' attribute is implemented by simply not performing any checks in `CheckAttrVisitor` for a particular attribute. We no longer emit unused attribute warnings for the `#[rustc_dummy]` attribute - it's an internal attribute used for tests, so it doesn't mark sense to treat it as 'unused'. With this commit, a large source of global untracked state is removed.
		
			
				
	
	
		
			902 lines
		
	
	
		
			33 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			902 lines
		
	
	
		
			33 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| use rustc_ast::mut_visit::{visit_clobber, MutVisitor, *};
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| use rustc_ast::ptr::P;
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| use rustc_ast::{self as ast, AttrVec, BlockCheckMode};
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| use rustc_codegen_ssa::traits::CodegenBackend;
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| use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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| #[cfg(parallel_compiler)]
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| use rustc_data_structures::jobserver;
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| use rustc_data_structures::sync::Lrc;
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| use rustc_errors::registry::Registry;
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| use rustc_metadata::dynamic_lib::DynamicLibrary;
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| #[cfg(parallel_compiler)]
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| use rustc_middle::ty::tls;
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| #[cfg(parallel_compiler)]
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| use rustc_query_impl::QueryCtxt;
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| use rustc_resolve::{self, Resolver};
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| use rustc_session as session;
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| use rustc_session::config::{self, CrateType};
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| use rustc_session::config::{ErrorOutputType, Input, OutputFilenames};
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| use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
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| use rustc_session::parse::CrateConfig;
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| use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session};
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| use rustc_span::edition::Edition;
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| use rustc_span::lev_distance::find_best_match_for_name;
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| use rustc_span::source_map::FileLoader;
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| use rustc_span::symbol::{sym, Symbol};
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| use smallvec::SmallVec;
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| use std::env;
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| use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
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| use std::io;
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| use std::lazy::SyncOnceCell;
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| use std::mem;
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| use std::ops::DerefMut;
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| #[cfg(not(parallel_compiler))]
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| use std::panic;
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| use std::path::{Path, PathBuf};
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| use std::sync::atomic::{AtomicBool, Ordering};
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| use std::sync::{Arc, Mutex};
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| use std::thread;
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| use tracing::info;
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| 
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| /// Adds `target_feature = "..."` cfgs for a variety of platform
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| /// specific features (SSE, NEON etc.).
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| ///
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| /// This is performed by checking whether a set of permitted features
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| /// is available on the target machine, by querying LLVM.
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| pub fn add_configuration(
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|     cfg: &mut CrateConfig,
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|     sess: &mut Session,
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|     codegen_backend: &dyn CodegenBackend,
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| ) {
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|     let tf = sym::target_feature;
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| 
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|     let target_features = codegen_backend.target_features(sess);
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|     sess.target_features.extend(target_features.iter().cloned());
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| 
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|     cfg.extend(target_features.into_iter().map(|feat| (tf, Some(feat))));
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| 
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|     if sess.crt_static(None) {
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|         cfg.insert((tf, Some(sym::crt_dash_static)));
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|     }
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| }
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| 
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| pub fn create_session(
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|     sopts: config::Options,
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|     cfg: FxHashSet<(String, Option<String>)>,
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|     diagnostic_output: DiagnosticOutput,
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|     file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
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|     input_path: Option<PathBuf>,
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|     lint_caps: FxHashMap<lint::LintId, lint::Level>,
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|     make_codegen_backend: Option<
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|         Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
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|     >,
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|     descriptions: Registry,
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| ) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>) {
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|     let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
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|         make_codegen_backend(&sopts)
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|     } else {
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|         get_codegen_backend(
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|             &sopts.maybe_sysroot,
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|             sopts.debugging_opts.codegen_backend.as_ref().map(|name| &name[..]),
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|         )
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|     };
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| 
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|     // target_override is documented to be called before init(), so this is okay
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|     let target_override = codegen_backend.target_override(&sopts);
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| 
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|     let mut sess = session::build_session(
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|         sopts,
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|         input_path,
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|         descriptions,
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|         diagnostic_output,
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|         lint_caps,
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|         file_loader,
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|         target_override,
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|     );
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| 
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|     codegen_backend.init(&sess);
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| 
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|     let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
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|     add_configuration(&mut cfg, &mut sess, &*codegen_backend);
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|     sess.parse_sess.config = cfg;
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| 
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|     (Lrc::new(sess), Lrc::new(codegen_backend))
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| }
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| 
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| const STACK_SIZE: usize = 8 * 1024 * 1024;
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| 
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| fn get_stack_size() -> Option<usize> {
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|     // FIXME: Hacks on hacks. If the env is trying to override the stack size
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|     // then *don't* set it explicitly.
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|     env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE)
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| }
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| 
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| /// Like a `thread::Builder::spawn` followed by a `join()`, but avoids the need
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| /// for `'static` bounds.
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| #[cfg(not(parallel_compiler))]
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| pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
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|     struct Ptr(*mut ());
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|     unsafe impl Send for Ptr {}
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|     unsafe impl Sync for Ptr {}
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| 
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|     let mut f = Some(f);
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|     let run = Ptr(&mut f as *mut _ as *mut ());
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|     let mut result = None;
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|     let result_ptr = Ptr(&mut result as *mut _ as *mut ());
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| 
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|     let thread = cfg.spawn(move || {
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|         let run = unsafe { (*(run.0 as *mut Option<F>)).take().unwrap() };
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|         let result = unsafe { &mut *(result_ptr.0 as *mut Option<R>) };
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|         *result = Some(run());
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|     });
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| 
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|     match thread.unwrap().join() {
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|         Ok(()) => result.unwrap(),
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|         Err(p) => panic::resume_unwind(p),
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|     }
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| }
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| 
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| #[cfg(not(parallel_compiler))]
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| pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
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|     edition: Edition,
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|     _threads: usize,
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|     stderr: &Option<Arc<Mutex<Vec<u8>>>>,
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|     f: F,
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| ) -> R {
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|     let mut cfg = thread::Builder::new().name("rustc".to_string());
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| 
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|     if let Some(size) = get_stack_size() {
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|         cfg = cfg.stack_size(size);
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|     }
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| 
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|     crate::callbacks::setup_callbacks();
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| 
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|     let main_handler = move || {
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|         rustc_span::create_session_globals_then(edition, || {
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|             io::set_output_capture(stderr.clone());
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|             f()
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|         })
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|     };
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| 
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|     scoped_thread(cfg, main_handler)
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| }
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| 
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| /// Creates a new thread and forwards information in thread locals to it.
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| /// The new thread runs the deadlock handler.
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| /// Must only be called when a deadlock is about to happen.
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| #[cfg(parallel_compiler)]
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| unsafe fn handle_deadlock() {
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|     let registry = rustc_rayon_core::Registry::current();
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| 
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|     let context = tls::get_tlv();
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|     assert!(context != 0);
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|     rustc_data_structures::sync::assert_sync::<tls::ImplicitCtxt<'_, '_>>();
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|     let icx: &tls::ImplicitCtxt<'_, '_> = &*(context as *const tls::ImplicitCtxt<'_, '_>);
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| 
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|     let session_globals = rustc_span::with_session_globals(|sg| sg as *const _);
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|     let session_globals = &*session_globals;
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|     thread::spawn(move || {
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|         tls::enter_context(icx, |_| {
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|             rustc_span::set_session_globals_then(session_globals, || {
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|                 tls::with(|tcx| QueryCtxt::from_tcx(tcx).deadlock(®istry))
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|             })
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|         });
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|     });
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| }
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| 
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| #[cfg(parallel_compiler)]
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| pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
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|     edition: Edition,
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|     threads: usize,
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|     stderr: &Option<Arc<Mutex<Vec<u8>>>>,
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|     f: F,
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| ) -> R {
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|     crate::callbacks::setup_callbacks();
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| 
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|     let mut config = rayon::ThreadPoolBuilder::new()
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|         .thread_name(|_| "rustc".to_string())
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|         .acquire_thread_handler(jobserver::acquire_thread)
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|         .release_thread_handler(jobserver::release_thread)
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|         .num_threads(threads)
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|         .deadlock_handler(|| unsafe { handle_deadlock() });
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| 
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|     if let Some(size) = get_stack_size() {
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|         config = config.stack_size(size);
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|     }
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| 
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|     let with_pool = move |pool: &rayon::ThreadPool| pool.install(f);
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| 
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|     rustc_span::create_session_globals_then(edition, || {
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|         rustc_span::with_session_globals(|session_globals| {
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|             // The main handler runs for each Rayon worker thread and sets up
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|             // the thread local rustc uses. `session_globals` is captured and set
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|             // on the new threads.
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|             let main_handler = move |thread: rayon::ThreadBuilder| {
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|                 rustc_span::set_session_globals_then(session_globals, || {
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|                     io::set_output_capture(stderr.clone());
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|                     thread.run()
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|                 })
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|             };
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| 
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|             config.build_scoped(main_handler, with_pool).unwrap()
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|         })
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|     })
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| }
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| 
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| fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
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|     let lib = DynamicLibrary::open(path).unwrap_or_else(|err| {
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|         let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
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|         early_error(ErrorOutputType::default(), &err);
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|     });
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|     unsafe {
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|         match lib.symbol("__rustc_codegen_backend") {
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|             Ok(f) => {
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|                 mem::forget(lib);
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|                 mem::transmute::<*mut u8, _>(f)
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|             }
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|             Err(e) => {
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|                 let err = format!(
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|                     "couldn't load codegen backend as it \
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|                                    doesn't export the `__rustc_codegen_backend` \
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|                                    symbol: {:?}",
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|                     e
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|                 );
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|                 early_error(ErrorOutputType::default(), &err);
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|             }
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|         }
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|     }
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| }
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| 
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| /// Get the codegen backend based on the name and specified sysroot.
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| ///
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| /// A name of `None` indicates that the default backend should be used.
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| pub fn get_codegen_backend(
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|     maybe_sysroot: &Option<PathBuf>,
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|     backend_name: Option<&str>,
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| ) -> Box<dyn CodegenBackend> {
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|     static LOAD: SyncOnceCell<unsafe fn() -> Box<dyn CodegenBackend>> = SyncOnceCell::new();
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| 
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|     let load = LOAD.get_or_init(|| {
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|         #[cfg(feature = "llvm")]
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|         const DEFAULT_CODEGEN_BACKEND: &str = "llvm";
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| 
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|         #[cfg(not(feature = "llvm"))]
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|         const DEFAULT_CODEGEN_BACKEND: &str = "cranelift";
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| 
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|         match backend_name.unwrap_or(DEFAULT_CODEGEN_BACKEND) {
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|             filename if filename.contains('.') => load_backend_from_dylib(filename.as_ref()),
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|             #[cfg(feature = "llvm")]
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|             "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
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|             backend_name => get_codegen_sysroot(maybe_sysroot, backend_name),
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|         }
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|     });
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| 
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|     // SAFETY: In case of a builtin codegen backend this is safe. In case of an external codegen
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|     // backend we hope that the backend links against the same rustc_driver version. If this is not
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|     // the case, we get UB.
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|     unsafe { load() }
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| }
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| 
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| // This is used for rustdoc, but it uses similar machinery to codegen backend
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| // loading, so we leave the code here. It is potentially useful for other tools
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| // that want to invoke the rustc binary while linking to rustc as well.
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| pub fn rustc_path<'a>() -> Option<&'a Path> {
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|     static RUSTC_PATH: SyncOnceCell<Option<PathBuf>> = SyncOnceCell::new();
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| 
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|     const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
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| 
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|     RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_ref().map(|v| &**v)
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| }
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| 
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| fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
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|     sysroot_candidates().iter().find_map(|sysroot| {
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|         let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
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|             "rustc.exe"
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|         } else {
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|             "rustc"
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|         });
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|         candidate.exists().then_some(candidate)
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|     })
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| }
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| 
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| fn sysroot_candidates() -> Vec<PathBuf> {
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|     let target = session::config::host_triple();
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|     let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
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|     let path = current_dll_path().and_then(|s| s.canonicalize().ok());
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|     if let Some(dll) = path {
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|         // use `parent` twice to chop off the file name and then also the
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|         // directory containing the dll which should be either `lib` or `bin`.
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|         if let Some(path) = dll.parent().and_then(|p| p.parent()) {
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|             // The original `path` pointed at the `rustc_driver` crate's dll.
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|             // Now that dll should only be in one of two locations. The first is
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|             // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
 | |
|             // other is the target's libdir, for example
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|             // `$sysroot/lib/rustlib/$target/lib/*.dll`.
 | |
|             //
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|             // We don't know which, so let's assume that if our `path` above
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|             // ends in `$target` we *could* be in the target libdir, and always
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|             // assume that we may be in the main libdir.
 | |
|             sysroot_candidates.push(path.to_owned());
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| 
 | |
|             if path.ends_with(target) {
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|                 sysroot_candidates.extend(
 | |
|                     path.parent() // chop off `$target`
 | |
|                         .and_then(|p| p.parent()) // chop off `rustlib`
 | |
|                         .and_then(|p| p.parent()) // chop off `lib`
 | |
|                         .map(|s| s.to_owned()),
 | |
|                 );
 | |
|             }
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|         }
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|     }
 | |
| 
 | |
|     return sysroot_candidates;
 | |
| 
 | |
|     #[cfg(unix)]
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|     fn current_dll_path() -> Option<PathBuf> {
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|         use std::ffi::{CStr, OsStr};
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|         use std::os::unix::prelude::*;
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| 
 | |
|         unsafe {
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|             let addr = current_dll_path as usize as *mut _;
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|             let mut info = mem::zeroed();
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|             if libc::dladdr(addr, &mut info) == 0 {
 | |
|                 info!("dladdr failed");
 | |
|                 return None;
 | |
|             }
 | |
|             if info.dli_fname.is_null() {
 | |
|                 info!("dladdr returned null pointer");
 | |
|                 return None;
 | |
|             }
 | |
|             let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
 | |
|             let os = OsStr::from_bytes(bytes);
 | |
|             Some(PathBuf::from(os))
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     #[cfg(windows)]
 | |
|     fn current_dll_path() -> Option<PathBuf> {
 | |
|         use std::ffi::OsString;
 | |
|         use std::os::windows::prelude::*;
 | |
|         use std::ptr;
 | |
| 
 | |
|         use winapi::um::libloaderapi::{
 | |
|             GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
 | |
|         };
 | |
| 
 | |
|         unsafe {
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|             let mut module = ptr::null_mut();
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|             let r = GetModuleHandleExW(
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|                 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
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|                 current_dll_path as usize as *mut _,
 | |
|                 &mut module,
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|             );
 | |
|             if r == 0 {
 | |
|                 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
 | |
|                 return None;
 | |
|             }
 | |
|             let mut space = Vec::with_capacity(1024);
 | |
|             let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
 | |
|             if r == 0 {
 | |
|                 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
 | |
|                 return None;
 | |
|             }
 | |
|             let r = r as usize;
 | |
|             if r >= space.capacity() {
 | |
|                 info!("our buffer was too small? {}", io::Error::last_os_error());
 | |
|                 return None;
 | |
|             }
 | |
|             space.set_len(r);
 | |
|             let os = OsString::from_wide(&space);
 | |
|             Some(PathBuf::from(os))
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| pub fn get_codegen_sysroot(
 | |
|     maybe_sysroot: &Option<PathBuf>,
 | |
|     backend_name: &str,
 | |
| ) -> fn() -> Box<dyn CodegenBackend> {
 | |
|     // 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 = session::config::host_triple();
 | |
|     let sysroot_candidates = sysroot_candidates();
 | |
| 
 | |
|     let sysroot = maybe_sysroot
 | |
|         .iter()
 | |
|         .chain(sysroot_candidates.iter())
 | |
|         .map(|sysroot| {
 | |
|             filesearch::make_target_lib_path(&sysroot, &target).with_file_name("codegen-backends")
 | |
|         })
 | |
|         .find(|f| {
 | |
|             info!("codegen backend candidate: {}", f.display());
 | |
|             f.exists()
 | |
|         });
 | |
|     let sysroot = sysroot.unwrap_or_else(|| {
 | |
|         let candidates = sysroot_candidates
 | |
|             .iter()
 | |
|             .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_error(ErrorOutputType::default(), &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 `{}`: {}",
 | |
|             sysroot.display(),
 | |
|             e
 | |
|         );
 | |
|         early_error(ErrorOutputType::default(), &err);
 | |
|     });
 | |
| 
 | |
|     let mut file: Option<PathBuf> = None;
 | |
| 
 | |
|     let expected_names = &[
 | |
|         format!("rustc_codegen_{}-{}", backend_name, release_str().expect("CFG_RELEASE")),
 | |
|         format!("rustc_codegen_{}", backend_name),
 | |
|     ];
 | |
|     for entry in d.filter_map(|e| e.ok()) {
 | |
|         let path = entry.path();
 | |
|         let filename = match path.file_name().and_then(|s| s.to_str()) {
 | |
|             Some(s) => s,
 | |
|             None => 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_error(ErrorOutputType::default(), &err);
 | |
|         }
 | |
|         file = Some(path.clone());
 | |
|     }
 | |
| 
 | |
|     match file {
 | |
|         Some(ref s) => load_backend_from_dylib(s),
 | |
|         None => {
 | |
|             let err = format!("unsupported builtin codegen backend `{}`", backend_name);
 | |
|             early_error(ErrorOutputType::default(), &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().unwrap().kind {
 | |
|                     let span = spanned.span;
 | |
|                     let lev_candidate = find_best_match_for_name(
 | |
|                         &CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(),
 | |
|                         n,
 | |
|                         None,
 | |
|                     );
 | |
|                     if let Some(candidate) = lev_candidate {
 | |
|                         lint_buffer.buffer_lint_with_diagnostic(
 | |
|                             lint::builtin::UNKNOWN_CRATE_TYPES,
 | |
|                             ast::CRATE_NODE_ID,
 | |
|                             span,
 | |
|                             "invalid `crate_type` value",
 | |
|                             BuiltinLintDiagnostics::UnknownCrateTypes(
 | |
|                                 span,
 | |
|                                 "did you mean".to_string(),
 | |
|                                 format!("\"{}\"", candidate),
 | |
|                             ),
 | |
|                         );
 | |
|                     } else {
 | |
|                         lint_buffer.buffer_lint(
 | |
|                             lint::builtin::UNKNOWN_CRATE_TYPES,
 | |
|                             ast::CRATE_NODE_ID,
 | |
|                             span,
 | |
|                             "invalid `crate_type` value",
 | |
|                         );
 | |
|                     }
 | |
|                 }
 | |
|             }
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| const CRATE_TYPES: &[(Symbol, CrateType)] = &[
 | |
|     (sym::rlib, CrateType::Rlib),
 | |
|     (sym::dylib, CrateType::Dylib),
 | |
|     (sym::cdylib, CrateType::Cdylib),
 | |
|     (sym::lib, config::default_lib_output()),
 | |
|     (sym::staticlib, CrateType::Staticlib),
 | |
|     (sym::proc_dash_macro, CrateType::ProcMacro),
 | |
|     (sym::bin, CrateType::Executable),
 | |
| ];
 | |
| 
 | |
| fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
 | |
|     Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
 | |
| }
 | |
| 
 | |
| pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
 | |
|     // Unconditionally collect crate types from attributes to make them used
 | |
|     let attr_types: Vec<CrateType> = attrs
 | |
|         .iter()
 | |
|         .filter_map(|a| {
 | |
|             if a.has_name(sym::crate_type) {
 | |
|                 match a.value_str() {
 | |
|                     Some(s) => categorize_crate_type(s),
 | |
|                     _ => None,
 | |
|                 }
 | |
|             } else {
 | |
|                 None
 | |
|             }
 | |
|         })
 | |
|         .collect();
 | |
| 
 | |
|     // If we're generating a test executable, then ignore all other output
 | |
|     // styles at all other locations
 | |
|     if session.opts.test {
 | |
|         return vec![CrateType::Executable];
 | |
|     }
 | |
| 
 | |
|     // Only check command line flags if present. If no types are specified by
 | |
|     // command line, then reuse the empty `base` Vec to hold the types that
 | |
|     // will be found in crate attributes.
 | |
|     let mut base = session.opts.crate_types.clone();
 | |
|     if base.is_empty() {
 | |
|         base.extend(attr_types);
 | |
|         if base.is_empty() {
 | |
|             base.push(output::default_output_for_target(session));
 | |
|         } else {
 | |
|             base.sort();
 | |
|             base.dedup();
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     base.retain(|crate_type| {
 | |
|         let res = !output::invalid_output_for_target(session, *crate_type);
 | |
| 
 | |
|         if !res {
 | |
|             session.warn(&format!(
 | |
|                 "dropping unsupported crate type `{}` for target `{}`",
 | |
|                 *crate_type, session.opts.target_triple
 | |
|             ));
 | |
|         }
 | |
| 
 | |
|         res
 | |
|     });
 | |
| 
 | |
|     base
 | |
| }
 | |
| 
 | |
| pub fn build_output_filenames(
 | |
|     input: &Input,
 | |
|     odir: &Option<PathBuf>,
 | |
|     ofile: &Option<PathBuf>,
 | |
|     attrs: &[ast::Attribute],
 | |
|     sess: &Session,
 | |
| ) -> OutputFilenames {
 | |
|     match *ofile {
 | |
|         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 = (*odir).as_ref().cloned().unwrap_or_default();
 | |
| 
 | |
|             // If a crate name is present, we use it as the link name
 | |
|             let stem = sess
 | |
|                 .opts
 | |
|                 .crate_name
 | |
|                 .clone()
 | |
|                 .or_else(|| rustc_attr::find_crate_name(&sess, attrs).map(|n| n.to_string()))
 | |
|                 .unwrap_or_else(|| input.filestem().to_owned());
 | |
| 
 | |
|             OutputFilenames::new(
 | |
|                 dirpath,
 | |
|                 stem,
 | |
|                 None,
 | |
|                 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.warn(
 | |
|                     "due to multiple output types requested, the explicitly specified \
 | |
|                      output file name will be adapted for each output type",
 | |
|                 );
 | |
|                 None
 | |
|             } else {
 | |
|                 if !sess.opts.cg.extra_filename.is_empty() {
 | |
|                     sess.warn("ignoring -C extra-filename flag due to -o flag");
 | |
|                 }
 | |
|                 Some(out_file.clone())
 | |
|             };
 | |
|             if *odir != None {
 | |
|                 sess.warn("ignoring --out-dir flag due to -o flag");
 | |
|             }
 | |
| 
 | |
|             OutputFilenames::new(
 | |
|                 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
 | |
|                 out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(),
 | |
|                 ofile,
 | |
|                 sess.opts.cg.extra_filename.clone(),
 | |
|                 sess.opts.output_types.clone(),
 | |
|             )
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| #[cfg(not(target_os = "linux"))]
 | |
| pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> {
 | |
|     std::fs::rename(src, dst)
 | |
| }
 | |
| 
 | |
| /// This function attempts to bypass the auto_da_alloc heuristic implemented by some filesystems
 | |
| /// such as btrfs and ext4. When renaming over a file that already exists then they will "helpfully"
 | |
| /// write back the source file before committing the rename in case a developer forgot some of
 | |
| /// the fsyncs in the open/write/fsync(file)/rename/fsync(dir) dance for atomic file updates.
 | |
| ///
 | |
| /// To avoid triggering this heuristic we delete the destination first, if it exists.
 | |
| /// The cost of an extra syscall is much lower than getting descheduled for the sync IO.
 | |
| #[cfg(target_os = "linux")]
 | |
| pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> {
 | |
|     let _ = std::fs::remove_file(dst);
 | |
|     std::fs::rename(src, dst)
 | |
| }
 | |
| 
 | |
| /// Replaces function bodies with `loop {}` (an infinite loop). This gets rid of
 | |
| /// all semantic errors in the body while still satisfying the return type,
 | |
| /// except in certain cases, see below for more.
 | |
| ///
 | |
| /// This pass is known as `everybody_loops`. Very punny.
 | |
| ///
 | |
| /// As of March 2021, `everybody_loops` is only used for the
 | |
| /// `-Z unpretty=everybody_loops` debugging option.
 | |
| ///
 | |
| /// FIXME: Currently the `everybody_loops` transformation is not applied to:
 | |
| ///  * `const fn`; support could be added, but hasn't. Originally `const fn`
 | |
| ///    was skipped due to issue #43636 that `loop` was not supported for
 | |
| ///    const evaluation.
 | |
| ///  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
 | |
| ///    Solving this may require `!` to implement every trait, which relies on the an even more
 | |
| ///    ambitious form of the closed RFC #1637. See also [#34511].
 | |
| ///
 | |
| /// [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
 | |
| pub struct ReplaceBodyWithLoop<'a, 'b> {
 | |
|     within_static_or_const: bool,
 | |
|     nested_blocks: Option<Vec<ast::Block>>,
 | |
|     resolver: &'a mut Resolver<'b>,
 | |
| }
 | |
| 
 | |
| impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
 | |
|     pub fn new(resolver: &'a mut Resolver<'b>) -> ReplaceBodyWithLoop<'a, 'b> {
 | |
|         ReplaceBodyWithLoop { within_static_or_const: false, nested_blocks: None, resolver }
 | |
|     }
 | |
| 
 | |
|     fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
 | |
|         let old_const = mem::replace(&mut self.within_static_or_const, is_const);
 | |
|         let old_blocks = self.nested_blocks.take();
 | |
|         let ret = action(self);
 | |
|         self.within_static_or_const = old_const;
 | |
|         self.nested_blocks = old_blocks;
 | |
|         ret
 | |
|     }
 | |
| 
 | |
|     fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
 | |
|         if let ast::FnRetTy::Ty(ref ty) = ret_ty {
 | |
|             fn involves_impl_trait(ty: &ast::Ty) -> bool {
 | |
|                 match ty.kind {
 | |
|                     ast::TyKind::ImplTrait(..) => true,
 | |
|                     ast::TyKind::Slice(ref subty)
 | |
|                     | ast::TyKind::Array(ref subty, _)
 | |
|                     | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
 | |
|                     | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
 | |
|                     | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
 | |
|                     ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
 | |
|                     ast::TyKind::Path(_, ref path) => {
 | |
|                         path.segments.iter().any(|seg| match seg.args.as_deref() {
 | |
|                             None => false,
 | |
|                             Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
 | |
|                                 data.args.iter().any(|arg| match arg {
 | |
|                                     ast::AngleBracketedArg::Arg(arg) => match arg {
 | |
|                                         ast::GenericArg::Type(ty) => involves_impl_trait(ty),
 | |
|                                         ast::GenericArg::Lifetime(_)
 | |
|                                         | ast::GenericArg::Const(_) => false,
 | |
|                                     },
 | |
|                                     ast::AngleBracketedArg::Constraint(c) => match c.kind {
 | |
|                                         ast::AssocTyConstraintKind::Bound { .. } => true,
 | |
|                                         ast::AssocTyConstraintKind::Equality { ref ty } => {
 | |
|                                             involves_impl_trait(ty)
 | |
|                                         }
 | |
|                                     },
 | |
|                                 })
 | |
|                             }
 | |
|                             Some(&ast::GenericArgs::Parenthesized(ref data)) => {
 | |
|                                 any_involves_impl_trait(data.inputs.iter())
 | |
|                                     || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
 | |
|                             }
 | |
|                         })
 | |
|                     }
 | |
|                     _ => false,
 | |
|                 }
 | |
|             }
 | |
| 
 | |
|             fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
 | |
|                 it.any(|subty| involves_impl_trait(subty))
 | |
|             }
 | |
| 
 | |
|             involves_impl_trait(ty)
 | |
|         } else {
 | |
|             false
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     fn is_sig_const(sig: &ast::FnSig) -> bool {
 | |
|         matches!(sig.header.constness, ast::Const::Yes(_))
 | |
|             || ReplaceBodyWithLoop::should_ignore_fn(&sig.decl.output)
 | |
|     }
 | |
| }
 | |
| 
 | |
| impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
 | |
|     fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
 | |
|         let is_const = match i {
 | |
|             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
 | |
|             ast::ItemKind::Fn(box ast::FnKind(_, ref sig, _, _)) => Self::is_sig_const(sig),
 | |
|             _ => false,
 | |
|         };
 | |
|         self.run(is_const, |s| noop_visit_item_kind(i, s))
 | |
|     }
 | |
| 
 | |
|     fn flat_map_trait_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
 | |
|         let is_const = match i.kind {
 | |
|             ast::AssocItemKind::Const(..) => true,
 | |
|             ast::AssocItemKind::Fn(box ast::FnKind(_, ref sig, _, _)) => Self::is_sig_const(sig),
 | |
|             _ => false,
 | |
|         };
 | |
|         self.run(is_const, |s| noop_flat_map_assoc_item(i, s))
 | |
|     }
 | |
| 
 | |
|     fn flat_map_impl_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
 | |
|         self.flat_map_trait_item(i)
 | |
|     }
 | |
| 
 | |
|     fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
 | |
|         self.run(true, |s| noop_visit_anon_const(c, s))
 | |
|     }
 | |
| 
 | |
|     fn visit_block(&mut self, b: &mut P<ast::Block>) {
 | |
|         fn stmt_to_block(
 | |
|             rules: ast::BlockCheckMode,
 | |
|             s: Option<ast::Stmt>,
 | |
|             resolver: &mut Resolver<'_>,
 | |
|         ) -> ast::Block {
 | |
|             ast::Block {
 | |
|                 stmts: s.into_iter().collect(),
 | |
|                 rules,
 | |
|                 id: resolver.next_node_id(),
 | |
|                 span: rustc_span::DUMMY_SP,
 | |
|                 tokens: None,
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         fn block_to_stmt(b: ast::Block, resolver: &mut Resolver<'_>) -> ast::Stmt {
 | |
|             let expr = P(ast::Expr {
 | |
|                 id: resolver.next_node_id(),
 | |
|                 kind: ast::ExprKind::Block(P(b), None),
 | |
|                 span: rustc_span::DUMMY_SP,
 | |
|                 attrs: AttrVec::new(),
 | |
|                 tokens: None,
 | |
|             });
 | |
| 
 | |
|             ast::Stmt {
 | |
|                 id: resolver.next_node_id(),
 | |
|                 kind: ast::StmtKind::Expr(expr),
 | |
|                 span: rustc_span::DUMMY_SP,
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.resolver);
 | |
|         let loop_expr = P(ast::Expr {
 | |
|             kind: ast::ExprKind::Loop(P(empty_block), None),
 | |
|             id: self.resolver.next_node_id(),
 | |
|             span: rustc_span::DUMMY_SP,
 | |
|             attrs: AttrVec::new(),
 | |
|             tokens: None,
 | |
|         });
 | |
| 
 | |
|         let loop_stmt = ast::Stmt {
 | |
|             id: self.resolver.next_node_id(),
 | |
|             span: rustc_span::DUMMY_SP,
 | |
|             kind: ast::StmtKind::Expr(loop_expr),
 | |
|         };
 | |
| 
 | |
|         if self.within_static_or_const {
 | |
|             noop_visit_block(b, self)
 | |
|         } else {
 | |
|             visit_clobber(b.deref_mut(), |b| {
 | |
|                 let mut stmts = vec![];
 | |
|                 for s in b.stmts {
 | |
|                     let old_blocks = self.nested_blocks.replace(vec![]);
 | |
| 
 | |
|                     stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
 | |
| 
 | |
|                     // we put a Some in there earlier with that replace(), so this is valid
 | |
|                     let new_blocks = self.nested_blocks.take().unwrap();
 | |
|                     self.nested_blocks = old_blocks;
 | |
|                     stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, self.resolver)));
 | |
|                 }
 | |
| 
 | |
|                 let mut new_block = ast::Block { stmts, ..b };
 | |
| 
 | |
|                 if let Some(old_blocks) = self.nested_blocks.as_mut() {
 | |
|                     //push our fresh block onto the cache and yield an empty block with `loop {}`
 | |
|                     if !new_block.stmts.is_empty() {
 | |
|                         old_blocks.push(new_block);
 | |
|                     }
 | |
| 
 | |
|                     stmt_to_block(b.rules, Some(loop_stmt), &mut self.resolver)
 | |
|                 } else {
 | |
|                     //push `loop {}` onto the end of our fresh block and yield that
 | |
|                     new_block.stmts.push(loop_stmt);
 | |
| 
 | |
|                     new_block
 | |
|                 }
 | |
|             })
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| /// Returns a version string such as "1.46.0 (04488afe3 2020-08-24)"
 | |
| pub fn version_str() -> Option<&'static str> {
 | |
|     option_env!("CFG_VERSION")
 | |
| }
 | |
| 
 | |
| /// Returns a version string such as "0.12.0-dev".
 | |
| pub fn release_str() -> Option<&'static str> {
 | |
|     option_env!("CFG_RELEASE")
 | |
| }
 | |
| 
 | |
| /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
 | |
| pub fn commit_hash_str() -> Option<&'static str> {
 | |
|     option_env!("CFG_VER_HASH")
 | |
| }
 | |
| 
 | |
| /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
 | |
| pub fn commit_date_str() -> Option<&'static str> {
 | |
|     option_env!("CFG_VER_DATE")
 | |
| }
 |