1 pub use self::code_stats::{DataTypeKind, SizeKind, FieldInfo, VariantInfo};
2 use self::code_stats::CodeStats;
4 use crate::dep_graph::cgu_reuse_tracker::CguReuseTracker;
5 use rustc_data_structures::fingerprint::Fingerprint;
8 use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
9 use crate::session::search_paths::{PathKind, SearchPath};
10 use crate::util::nodemap::{FxHashMap, FxHashSet};
11 use crate::util::common::{duration_to_secs_str, ErrorReported};
13 use rustc_data_structures::base_n;
14 use rustc_data_structures::sync::{
15 self, Lrc, Lock, OneThread, Once, AtomicU64, AtomicUsize, Ordering,
19 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
20 use errors::emitter::{Emitter, EmitterWriter};
21 use errors::emitter::HumanReadableErrorType;
22 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
23 use syntax::edition::Edition;
24 use syntax::feature_gate;
25 use errors::json::JsonEmitter;
26 use syntax::source_map;
27 use syntax::sess::ParseSess;
28 use syntax_pos::{MultiSpan, Span};
30 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
31 use rustc_data_structures::flock;
32 use rustc_data_structures::jobserver;
33 use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
34 use ::jobserver::Client;
37 use std::cell::{self, RefCell};
41 use std::num::NonZeroU32;
42 use std::path::PathBuf;
43 use std::time::Duration;
51 pub struct OptimizationFuel {
52 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
54 /// We're rejecting all further optimizations.
58 /// Represents the data associated with a compilation
59 /// session for a single crate.
61 pub target: config::Config,
63 pub opts: config::Options,
64 pub host_tlib_path: SearchPath,
65 /// `None` if the host and target are the same.
66 pub target_tlib_path: Option<SearchPath>,
67 pub parse_sess: ParseSess,
69 /// The name of the root source file of the crate, in the local file system.
70 /// `None` means that there is no source file.
71 pub local_crate_source_file: Option<PathBuf>,
72 /// The directory the compiler has been executed in plus a flag indicating
73 /// if the value stored here has been affected by path remapping.
74 pub working_dir: (PathBuf, bool),
76 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
77 /// (sub)diagnostics that have been set once, but should not be set again,
78 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
79 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
80 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
81 pub crate_types: Once<Vec<config::CrateType>>,
82 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
83 /// arguments passed to the compiler. Its value together with the crate-name
84 /// forms a unique global identifier for the crate. It is used to allow
85 /// multiple crates with the same name to coexist. See the
86 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
87 pub crate_disambiguator: Once<CrateDisambiguator>,
89 features: Once<feature_gate::Features>,
91 /// The maximum recursion limit for potentially infinitely recursive
92 /// operations such as auto-dereference and monomorphization.
93 pub recursion_limit: Once<usize>,
95 /// The maximum length of types during monomorphization.
96 pub type_length_limit: Once<usize>,
98 /// The maximum number of stackframes allowed in const eval.
99 pub const_eval_stack_frame_limit: usize,
101 /// Map from imported macro spans (which consist of
102 /// the localized span for the macro body) to the
103 /// macro name and definition span in the source crate.
104 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
106 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
107 /// Used for incremental compilation tests. Will only be populated if
108 /// `-Zquery-dep-graph` is specified.
109 pub cgu_reuse_tracker: CguReuseTracker,
111 /// Used by `-Z self-profile`.
112 pub prof: SelfProfilerRef,
114 /// Some measurements that are being gathered during compilation.
115 pub perf_stats: PerfStats,
117 /// Data about code being compiled, gathered during compilation.
118 pub code_stats: CodeStats,
120 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
121 optimization_fuel_crate: Option<String>,
123 /// Tracks fuel info if `-zfuel=crate=n` is specified.
124 optimization_fuel: Lock<OptimizationFuel>,
126 // The next two are public because the driver needs to read them.
127 /// If `-zprint-fuel=crate`, `Some(crate)`.
128 pub print_fuel_crate: Option<String>,
129 /// Always set to zero and incremented so that we can print fuel expended by a crate.
130 pub print_fuel: AtomicU64,
132 /// Loaded up early on in the initialization of this `Session` to avoid
133 /// false positives about a job server in our environment.
134 pub jobserver: Client,
136 /// Cap lint level specified by a driver specifically.
137 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
139 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
140 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
142 /// Mapping from ident span to path span for paths that don't exist as written, but that
143 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
144 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
147 pub struct PerfStats {
148 /// The accumulated time spent on computing symbol hashes.
149 pub symbol_hash_time: Lock<Duration>,
150 /// The accumulated time spent decoding def path tables from metadata.
151 pub decode_def_path_tables_time: Lock<Duration>,
152 /// Total number of values canonicalized queries constructed.
153 pub queries_canonicalized: AtomicUsize,
154 /// Number of times this query is invoked.
155 pub normalize_ty_after_erasing_regions: AtomicUsize,
156 /// Number of times this query is invoked.
157 pub normalize_projection_ty: AtomicUsize,
160 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
161 enum DiagnosticBuilderMethod {
164 SpanSuggestion(String), // suggestion
165 // Add more variants as needed to support one-time diagnostics.
168 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
169 /// emitting the same message more than once.
170 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
171 pub enum DiagnosticMessageId {
172 ErrorId(u16), // EXXXX error code as integer
173 LintId(lint::LintId),
174 StabilityId(Option<NonZeroU32>), // issue number
177 impl From<&'static lint::Lint> for DiagnosticMessageId {
178 fn from(lint: &'static lint::Lint) -> Self {
179 DiagnosticMessageId::LintId(lint::LintId::of(lint))
184 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
185 *self.crate_disambiguator.get()
188 pub fn struct_span_warn<S: Into<MultiSpan>>(
192 ) -> DiagnosticBuilder<'_> {
193 self.diagnostic().struct_span_warn(sp, msg)
195 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
200 ) -> DiagnosticBuilder<'_> {
201 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
203 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
204 self.diagnostic().struct_warn(msg)
206 pub fn struct_span_err<S: Into<MultiSpan>>(
210 ) -> DiagnosticBuilder<'_> {
211 self.diagnostic().struct_span_err(sp, msg)
213 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
218 ) -> DiagnosticBuilder<'_> {
219 self.diagnostic().struct_span_err_with_code(sp, msg, code)
221 // FIXME: This method should be removed (every error should have an associated error code).
222 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
223 self.diagnostic().struct_err(msg)
225 pub fn struct_err_with_code(
229 ) -> DiagnosticBuilder<'_> {
230 self.diagnostic().struct_err_with_code(msg, code)
232 pub fn struct_span_fatal<S: Into<MultiSpan>>(
236 ) -> DiagnosticBuilder<'_> {
237 self.diagnostic().struct_span_fatal(sp, msg)
239 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
244 ) -> DiagnosticBuilder<'_> {
245 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
247 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
248 self.diagnostic().struct_fatal(msg)
251 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
252 self.diagnostic().span_fatal(sp, msg).raise()
254 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
261 .span_fatal_with_code(sp, msg, code)
264 pub fn fatal(&self, msg: &str) -> ! {
265 self.diagnostic().fatal(msg).raise()
267 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
269 self.span_warn(sp, msg);
271 self.span_err(sp, msg);
274 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
275 self.diagnostic().span_err(sp, msg)
277 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
278 self.diagnostic().span_err_with_code(sp, &msg, code)
280 pub fn err(&self, msg: &str) {
281 self.diagnostic().err(msg)
283 pub fn err_count(&self) -> usize {
284 self.diagnostic().err_count()
286 pub fn has_errors(&self) -> bool {
287 self.diagnostic().has_errors()
289 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
290 self.diagnostic().has_errors_or_delayed_span_bugs()
292 pub fn abort_if_errors(&self) {
293 self.diagnostic().abort_if_errors();
295 pub fn compile_status(&self) -> Result<(), ErrorReported> {
296 if self.has_errors() {
297 self.diagnostic().emit_stashed_diagnostics();
303 // FIXME(matthewjasper) Remove this method, it should never be needed.
304 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
308 let old_count = self.err_count();
310 let errors = self.err_count() - old_count;
317 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
318 self.diagnostic().span_warn(sp, msg)
320 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
321 self.diagnostic().span_warn_with_code(sp, msg, code)
323 pub fn warn(&self, msg: &str) {
324 self.diagnostic().warn(msg)
326 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
328 Some(sp) => self.span_warn(sp, msg),
329 None => self.warn(msg),
332 /// Delay a span_bug() call until abort_if_errors()
333 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
334 self.diagnostic().delay_span_bug(sp, msg)
336 pub fn note_without_error(&self, msg: &str) {
337 self.diagnostic().note_without_error(msg)
339 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
340 self.diagnostic().span_note_without_error(sp, msg)
343 pub fn diagnostic(&self) -> &errors::Handler {
344 &self.parse_sess.span_diagnostic
347 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
348 /// deduplicates on lint ID, span (if any), and message for this `Session`
349 fn diag_once<'a, 'b>(
351 diag_builder: &'b mut DiagnosticBuilder<'a>,
352 method: DiagnosticBuilderMethod,
353 msg_id: DiagnosticMessageId,
355 span_maybe: Option<Span>,
357 let id_span_message = (msg_id, span_maybe, message.to_owned());
358 let fresh = self.one_time_diagnostics
360 .insert(id_span_message);
363 DiagnosticBuilderMethod::Note => {
364 diag_builder.note(message);
366 DiagnosticBuilderMethod::SpanNote => {
367 let span = span_maybe.expect("`span_note` needs a span");
368 diag_builder.span_note(span, message);
370 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
371 let span = span_maybe.expect("`span_suggestion_*` needs a span");
372 diag_builder.span_suggestion(
376 Applicability::Unspecified,
383 pub fn diag_span_note_once<'a, 'b>(
385 diag_builder: &'b mut DiagnosticBuilder<'a>,
386 msg_id: DiagnosticMessageId,
392 DiagnosticBuilderMethod::SpanNote,
399 pub fn diag_note_once<'a, 'b>(
401 diag_builder: &'b mut DiagnosticBuilder<'a>,
402 msg_id: DiagnosticMessageId,
407 DiagnosticBuilderMethod::Note,
414 pub fn diag_span_suggestion_once<'a, 'b>(
416 diag_builder: &'b mut DiagnosticBuilder<'a>,
417 msg_id: DiagnosticMessageId,
424 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
431 pub fn source_map(&self) -> &source_map::SourceMap {
432 self.parse_sess.source_map()
434 pub fn verbose(&self) -> bool {
435 self.opts.debugging_opts.verbose
437 pub fn time_passes(&self) -> bool {
438 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
440 pub fn time_extended(&self) -> bool {
441 self.opts.debugging_opts.time_passes
443 pub fn instrument_mcount(&self) -> bool {
444 self.opts.debugging_opts.instrument_mcount
446 pub fn time_llvm_passes(&self) -> bool {
447 self.opts.debugging_opts.time_llvm_passes
449 pub fn meta_stats(&self) -> bool {
450 self.opts.debugging_opts.meta_stats
452 pub fn asm_comments(&self) -> bool {
453 self.opts.debugging_opts.asm_comments
455 pub fn verify_llvm_ir(&self) -> bool {
456 self.opts.debugging_opts.verify_llvm_ir
457 || cfg!(always_verify_llvm_ir)
459 pub fn borrowck_stats(&self) -> bool {
460 self.opts.debugging_opts.borrowck_stats
462 pub fn print_llvm_passes(&self) -> bool {
463 self.opts.debugging_opts.print_llvm_passes
465 pub fn binary_dep_depinfo(&self) -> bool {
466 self.opts.debugging_opts.binary_dep_depinfo
469 /// Gets the features enabled for the current compilation session.
470 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
471 /// dependency tracking. Use tcx.features() instead.
473 pub fn features_untracked(&self) -> &feature_gate::Features {
477 pub fn init_features(&self, features: feature_gate::Features) {
478 self.features.set(features);
481 /// Calculates the flavor of LTO to use for this compilation.
482 pub fn lto(&self) -> config::Lto {
483 // If our target has codegen requirements ignore the command line
484 if self.target.target.options.requires_lto {
485 return config::Lto::Fat;
488 // If the user specified something, return that. If they only said `-C
489 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
490 // then ensure we can't use a ThinLTO.
491 match self.opts.cg.lto {
492 config::LtoCli::Unspecified => {
493 // The compiler was invoked without the `-Clto` flag. Fall
494 // through to the default handling
496 config::LtoCli::No => {
497 // The user explicitly opted out of any kind of LTO
498 return config::Lto::No;
500 config::LtoCli::Yes |
501 config::LtoCli::Fat |
502 config::LtoCli::NoParam => {
503 // All of these mean fat LTO
504 return config::Lto::Fat;
506 config::LtoCli::Thin => {
507 return if self.opts.cli_forced_thinlto_off {
515 // Ok at this point the target doesn't require anything and the user
516 // hasn't asked for anything. Our next decision is whether or not
517 // we enable "auto" ThinLTO where we use multiple codegen units and
518 // then do ThinLTO over those codegen units. The logic below will
519 // either return `No` or `ThinLocal`.
521 // If processing command line options determined that we're incompatible
522 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
523 if self.opts.cli_forced_thinlto_off {
524 return config::Lto::No;
527 // If `-Z thinlto` specified process that, but note that this is mostly
528 // a deprecated option now that `-C lto=thin` exists.
529 if let Some(enabled) = self.opts.debugging_opts.thinlto {
531 return config::Lto::ThinLocal;
533 return config::Lto::No;
537 // If there's only one codegen unit and LTO isn't enabled then there's
538 // no need for ThinLTO so just return false.
539 if self.codegen_units() == 1 {
540 return config::Lto::No;
543 // Now we're in "defaults" territory. By default we enable ThinLTO for
544 // optimized compiles (anything greater than O0).
545 match self.opts.optimize {
546 config::OptLevel::No => config::Lto::No,
547 _ => config::Lto::ThinLocal,
551 /// Returns the panic strategy for this compile session. If the user explicitly selected one
552 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
553 pub fn panic_strategy(&self) -> PanicStrategy {
557 .unwrap_or(self.target.target.options.panic_strategy)
559 pub fn fewer_names(&self) -> bool {
560 let more_names = self.opts
562 .contains_key(&OutputType::LlvmAssembly)
563 || self.opts.output_types.contains_key(&OutputType::Bitcode);
565 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
566 let more_names = match self.opts.debugging_opts.sanitizer {
567 Some(Sanitizer::Address) => true,
568 Some(Sanitizer::Memory) => true,
572 self.opts.debugging_opts.fewer_names || !more_names
575 pub fn no_landing_pads(&self) -> bool {
576 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
578 pub fn unstable_options(&self) -> bool {
579 self.opts.debugging_opts.unstable_options
581 pub fn overflow_checks(&self) -> bool {
585 .or(self.opts.debugging_opts.force_overflow_checks)
586 .unwrap_or(self.opts.debug_assertions)
589 pub fn crt_static(&self) -> bool {
590 // If the target does not opt in to crt-static support, use its default.
591 if self.target.target.options.crt_static_respected {
592 self.crt_static_feature()
594 self.target.target.options.crt_static_default
598 pub fn crt_static_feature(&self) -> bool {
599 let requested_features = self.opts.cg.target_feature.split(',');
600 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
601 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
603 // If the target we're compiling for requests a static crt by default,
604 // then see if the `-crt-static` feature was passed to disable that.
605 // Otherwise if we don't have a static crt by default then see if the
606 // `+crt-static` feature was passed.
607 if self.target.target.options.crt_static_default {
614 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
615 // "mcount" function relies on stack pointer.
616 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
617 if self.instrument_mcount() {
619 } else if let Some(x) = self.opts.cg.force_frame_pointers {
622 !self.target.target.options.eliminate_frame_pointer
626 /// Returns the symbol name for the registrar function,
627 /// given the crate `Svh` and the function `DefIndex`.
628 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
630 "__rustc_plugin_registrar_{}__",
631 disambiguator.to_fingerprint().to_hex()
635 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
637 "__rustc_proc_macro_decls_{}__",
638 disambiguator.to_fingerprint().to_hex()
642 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
643 filesearch::FileSearch::new(
645 self.opts.target_triple.triple(),
646 &self.opts.search_paths,
647 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
648 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
652 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
653 filesearch::FileSearch::new(
655 config::host_triple(),
656 &self.opts.search_paths,
657 &self.host_tlib_path,
662 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
663 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
665 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
666 *load_dep_graph = load;
670 pub fn incr_session_load_dep_graph(&self) -> bool {
671 let incr_comp_session = self.incr_comp_session.borrow();
672 match *incr_comp_session {
673 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
678 pub fn init_incr_comp_session(
680 session_dir: PathBuf,
681 lock_file: flock::Lock,
682 load_dep_graph: bool,
684 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
686 if let IncrCompSession::NotInitialized = *incr_comp_session {
689 "Trying to initialize IncrCompSession `{:?}`",
694 *incr_comp_session = IncrCompSession::Active {
695 session_directory: session_dir,
701 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
702 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
704 if let IncrCompSession::Active { .. } = *incr_comp_session {
707 "trying to finalize `IncrCompSession` `{:?}`",
712 // Note: this will also drop the lock file, thus unlocking the directory.
713 *incr_comp_session = IncrCompSession::Finalized {
714 session_directory: new_directory_path,
718 pub fn mark_incr_comp_session_as_invalid(&self) {
719 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
721 let session_directory = match *incr_comp_session {
722 IncrCompSession::Active {
723 ref session_directory,
725 } => session_directory.clone(),
726 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
728 "trying to invalidate `IncrCompSession` `{:?}`",
733 // Note: this will also drop the lock file, thus unlocking the directory.
734 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
739 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
740 let incr_comp_session = self.incr_comp_session.borrow();
743 |incr_comp_session| match *incr_comp_session {
744 IncrCompSession::NotInitialized => bug!(
745 "trying to get session directory from `IncrCompSession`: {:?}",
748 IncrCompSession::Active {
749 ref session_directory,
752 | IncrCompSession::Finalized {
753 ref session_directory,
755 | IncrCompSession::InvalidBecauseOfErrors {
756 ref session_directory,
757 } => session_directory,
762 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
763 if self.opts.incremental.is_some() {
764 Some(self.incr_comp_session_dir())
770 pub fn print_perf_stats(&self) {
772 "Total time spent computing symbol hashes: {}",
773 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
776 "Total time spent decoding DefPath tables: {}",
777 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
779 println!("Total queries canonicalized: {}",
780 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
781 println!("normalize_ty_after_erasing_regions: {}",
782 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
783 println!("normalize_projection_ty: {}",
784 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
787 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
788 /// This expends fuel if applicable, and records fuel if applicable.
789 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
791 if let Some(ref c) = self.optimization_fuel_crate {
793 assert_eq!(self.threads(), 1);
794 let mut fuel = self.optimization_fuel.lock();
795 ret = fuel.remaining != 0;
796 if fuel.remaining == 0 && !fuel.out_of_fuel {
797 eprintln!("optimization-fuel-exhausted: {}", msg());
798 fuel.out_of_fuel = true;
799 } else if fuel.remaining > 0 {
804 if let Some(ref c) = self.print_fuel_crate {
806 assert_eq!(self.threads(), 1);
807 self.print_fuel.fetch_add(1, SeqCst);
813 /// Returns the number of query threads that should be used for this
815 pub fn threads(&self) -> usize {
816 self.opts.debugging_opts.threads
819 /// Returns the number of codegen units that should be used for this
821 pub fn codegen_units(&self) -> usize {
822 if let Some(n) = self.opts.cli_forced_codegen_units {
825 if let Some(n) = self.target.target.options.default_codegen_units {
829 // Why is 16 codegen units the default all the time?
831 // The main reason for enabling multiple codegen units by default is to
832 // leverage the ability for the codegen backend to do codegen and
833 // optimization in parallel. This allows us, especially for large crates, to
834 // make good use of all available resources on the machine once we've
835 // hit that stage of compilation. Large crates especially then often
836 // take a long time in codegen/optimization and this helps us amortize that
839 // Note that a high number here doesn't mean that we'll be spawning a
840 // large number of threads in parallel. The backend of rustc contains
841 // global rate limiting through the `jobserver` crate so we'll never
842 // overload the system with too much work, but rather we'll only be
843 // optimizing when we're otherwise cooperating with other instances of
846 // Rather a high number here means that we should be able to keep a lot
847 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
848 // to build we'll be guaranteed that all cpus will finish pretty closely
849 // to one another and we should make relatively optimal use of system
852 // Note that the main cost of codegen units is that it prevents LLVM
853 // from inlining across codegen units. Users in general don't have a lot
854 // of control over how codegen units are split up so it's our job in the
855 // compiler to ensure that undue performance isn't lost when using
856 // codegen units (aka we can't require everyone to slap `#[inline]` on
859 // If we're compiling at `-O0` then the number doesn't really matter too
860 // much because performance doesn't matter and inlining is ok to lose.
861 // In debug mode we just want to try to guarantee that no cpu is stuck
862 // doing work that could otherwise be farmed to others.
864 // In release mode, however (O1 and above) performance does indeed
865 // matter! To recover the loss in performance due to inlining we'll be
866 // enabling ThinLTO by default (the function for which is just below).
867 // This will ensure that we recover any inlining wins we otherwise lost
868 // through codegen unit partitioning.
872 // Ok that's a lot of words but the basic tl;dr; is that we want a high
873 // number here -- but not too high. Additionally we're "safe" to have it
874 // always at the same number at all optimization levels.
876 // As a result 16 was chosen here! Mostly because it was a power of 2
877 // and most benchmarks agreed it was roughly a local optimum. Not very
882 pub fn teach(&self, code: &DiagnosticId) -> bool {
883 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
886 pub fn rust_2015(&self) -> bool {
887 self.opts.edition == Edition::Edition2015
890 /// Are we allowed to use features from the Rust 2018 edition?
891 pub fn rust_2018(&self) -> bool {
892 self.opts.edition >= Edition::Edition2018
895 pub fn edition(&self) -> Edition {
899 /// Returns `true` if we cannot skip the PLT for shared library calls.
900 pub fn needs_plt(&self) -> bool {
901 // Check if the current target usually needs PLT to be enabled.
902 // The user can use the command line flag to override it.
903 let needs_plt = self.target.target.options.needs_plt;
905 let dbg_opts = &self.opts.debugging_opts;
907 let relro_level = dbg_opts.relro_level
908 .unwrap_or(self.target.target.options.relro_level);
910 // Only enable this optimization by default if full relro is also enabled.
911 // In this case, lazy binding was already unavailable, so nothing is lost.
912 // This also ensures `-Wl,-z,now` is supported by the linker.
913 let full_relro = RelroLevel::Full == relro_level;
915 // If user didn't explicitly forced us to use / skip the PLT,
916 // then try to skip it where possible.
917 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
921 pub fn build_session(
922 sopts: config::Options,
923 local_crate_source_file: Option<PathBuf>,
924 registry: errors::registry::Registry,
926 let file_path_mapping = sopts.file_path_mapping();
928 build_session_with_source_map(
930 local_crate_source_file,
932 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
933 DiagnosticOutput::Default,
939 sopts: &config::Options,
940 registry: errors::registry::Registry,
941 source_map: &Lrc<source_map::SourceMap>,
942 emitter_dest: Option<Box<dyn Write + Send>>,
943 ) -> Box<dyn Emitter + sync::Send> {
944 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
945 match (sopts.error_format, emitter_dest) {
946 (config::ErrorOutputType::HumanReadable(kind), dst) => {
947 let (short, color_config) = kind.unzip();
949 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
950 let emitter = AnnotateSnippetEmitterWriter::new(
951 Some(source_map.clone()),
953 external_macro_backtrace,
955 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
957 let emitter = match dst {
958 None => EmitterWriter::stderr(
960 Some(source_map.clone()),
962 sopts.debugging_opts.teach,
963 sopts.debugging_opts.terminal_width,
964 external_macro_backtrace,
966 Some(dst) => EmitterWriter::new(
968 Some(source_map.clone()),
970 false, // no teach messages when writing to a buffer
971 false, // no colors when writing to a buffer
972 None, // no terminal width
973 external_macro_backtrace,
976 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
979 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
985 external_macro_backtrace,
986 ).ui_testing(sopts.debugging_opts.ui_testing),
988 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
995 external_macro_backtrace,
996 ).ui_testing(sopts.debugging_opts.ui_testing),
1001 pub enum DiagnosticOutput {
1003 Raw(Box<dyn Write + Send>)
1006 pub fn build_session_with_source_map(
1007 sopts: config::Options,
1008 local_crate_source_file: Option<PathBuf>,
1009 registry: errors::registry::Registry,
1010 source_map: Lrc<source_map::SourceMap>,
1011 diagnostics_output: DiagnosticOutput,
1012 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1014 // FIXME: This is not general enough to make the warning lint completely override
1015 // normal diagnostic warnings, since the warning lint can also be denied and changed
1016 // later via the source code.
1017 let warnings_allow = sopts
1020 .filter(|&&(ref key, _)| *key == "warnings")
1021 .map(|&(_, ref level)| *level == lint::Allow)
1024 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1026 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1028 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1029 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1030 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1032 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1034 let write_dest = match diagnostics_output {
1035 DiagnosticOutput::Default => None,
1036 DiagnosticOutput::Raw(write) => Some(write),
1038 let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
1040 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1042 errors::HandlerFlags {
1045 report_delayed_bugs,
1046 dont_buffer_diagnostics,
1047 external_macro_backtrace,
1048 ..Default::default()
1054 local_crate_source_file,
1062 sopts: config::Options,
1063 local_crate_source_file: Option<PathBuf>,
1064 span_diagnostic: errors::Handler,
1065 source_map: Lrc<source_map::SourceMap>,
1066 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1069 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1070 let directory = if let Some(ref directory) = d {
1073 std::path::Path::new(".")
1076 let profiler = SelfProfiler::new(
1078 sopts.crate_name.as_ref().map(|s| &s[..]),
1079 &sopts.debugging_opts.self_profile_events
1083 Some(Arc::new(profiler))
1086 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1093 let host_triple = TargetTriple::from_triple(config::host_triple());
1094 let host = Target::search(&host_triple).unwrap_or_else(|e|
1096 .fatal(&format!("Error loading host specification: {}", e))
1099 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1101 let parse_sess = ParseSess::with_span_handler(
1105 let sysroot = match &sopts.maybe_sysroot {
1106 Some(sysroot) => sysroot.clone(),
1107 None => filesearch::get_or_default_sysroot(),
1110 let host_triple = config::host_triple();
1111 let target_triple = sopts.target_triple.triple();
1112 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1113 let target_tlib_path = if host_triple == target_triple {
1116 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1119 let file_path_mapping = sopts.file_path_mapping();
1121 let local_crate_source_file =
1122 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1124 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1125 let optimization_fuel = Lock::new(OptimizationFuel {
1126 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1129 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1130 let print_fuel = AtomicU64::new(0);
1132 let working_dir = env::current_dir().unwrap_or_else(|e|
1133 parse_sess.span_diagnostic
1134 .fatal(&format!("Current directory is invalid: {}", e))
1137 let working_dir = file_path_mapping.map_prefix(working_dir);
1139 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1140 CguReuseTracker::new()
1142 CguReuseTracker::new_disabled()
1145 let sess = Session {
1153 local_crate_source_file,
1155 one_time_diagnostics: Default::default(),
1156 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1157 crate_types: Once::new(),
1158 crate_disambiguator: Once::new(),
1159 features: Once::new(),
1160 recursion_limit: Once::new(),
1161 type_length_limit: Once::new(),
1162 const_eval_stack_frame_limit: 100,
1163 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1164 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1166 prof: SelfProfilerRef::new(self_profiler),
1167 perf_stats: PerfStats {
1168 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1169 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1170 queries_canonicalized: AtomicUsize::new(0),
1171 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1172 normalize_projection_ty: AtomicUsize::new(0),
1174 code_stats: Default::default(),
1175 optimization_fuel_crate,
1179 jobserver: jobserver::client(),
1181 trait_methods_not_found: Lock::new(Default::default()),
1182 confused_type_with_std_module: Lock::new(Default::default()),
1185 validate_commandline_args_with_session_available(&sess);
1190 // If it is useful to have a Session available already for validating a
1191 // commandline argument, you can do so here.
1192 fn validate_commandline_args_with_session_available(sess: &Session) {
1193 // Since we don't know if code in an rlib will be linked to statically or
1194 // dynamically downstream, rustc generates `__imp_` symbols that help the
1195 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1196 // these manually generated symbols confuse LLD when it tries to merge
1197 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1198 // when compiling for LLD ThinLTO. This way we can validly just not generate
1199 // the `dllimport` attributes and `__imp_` symbols in that case.
1200 if sess.opts.cg.linker_plugin_lto.enabled() &&
1201 sess.opts.cg.prefer_dynamic &&
1202 sess.target.target.options.is_like_msvc {
1203 sess.err("Linker plugin based LTO is not supported together with \
1204 `-C prefer-dynamic` when targeting MSVC");
1207 // Make sure that any given profiling data actually exists so LLVM can't
1208 // decide to silently skip PGO.
1209 if let Some(ref path) = sess.opts.cg.profile_use {
1211 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1216 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1217 // an error to combine the two for now. It always runs into an assertions
1218 // if LLVM is built with assertions, but without assertions it sometimes
1219 // does not crash and will probably generate a corrupted binary.
1220 // We should only display this error if we're actually going to run PGO.
1221 // If we're just supposed to print out some data, don't show the error (#61002).
1222 if sess.opts.cg.profile_generate.enabled() &&
1223 sess.target.target.options.is_like_msvc &&
1224 sess.panic_strategy() == PanicStrategy::Unwind &&
1225 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1226 sess.err("Profile-guided optimization does not yet work in conjunction \
1227 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1228 See https://github.com/rust-lang/rust/issues/61002 for details.");
1232 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1233 /// compiler. Together with the crate-name forms a unique global identifier for
1235 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1236 pub struct CrateDisambiguator(Fingerprint);
1238 impl CrateDisambiguator {
1239 pub fn to_fingerprint(self) -> Fingerprint {
1244 impl fmt::Display for CrateDisambiguator {
1245 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1246 let (a, b) = self.0.as_value();
1247 let as_u128 = a as u128 | ((b as u128) << 64);
1248 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1252 impl From<Fingerprint> for CrateDisambiguator {
1253 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1254 CrateDisambiguator(fingerprint)
1258 impl_stable_hash_via_hash!(CrateDisambiguator);
1260 /// Holds data on the current incremental compilation session, if there is one.
1262 pub enum IncrCompSession {
1263 /// This is the state the session will be in until the incr. comp. dir is
1266 /// This is the state during which the session directory is private and can
1269 session_directory: PathBuf,
1270 lock_file: flock::Lock,
1271 load_dep_graph: bool,
1273 /// This is the state after the session directory has been finalized. In this
1274 /// state, the contents of the directory must not be modified any more.
1275 Finalized { session_directory: PathBuf },
1276 /// This is an error state that is reached when some compilation error has
1277 /// occurred. It indicates that the contents of the session directory must
1278 /// not be used, since they might be invalid.
1279 InvalidBecauseOfErrors { session_directory: PathBuf },
1282 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1283 let emitter: Box<dyn Emitter + sync::Send> = match output {
1284 config::ErrorOutputType::HumanReadable(kind) => {
1285 let (short, color_config) = kind.unzip();
1286 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1288 config::ErrorOutputType::Json { pretty, json_rendered } =>
1289 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1291 let handler = errors::Handler::with_emitter(true, None, emitter);
1292 handler.struct_fatal(msg).emit();
1293 errors::FatalError.raise();
1296 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1297 let emitter: Box<dyn Emitter + sync::Send> = match output {
1298 config::ErrorOutputType::HumanReadable(kind) => {
1299 let (short, color_config) = kind.unzip();
1300 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1302 config::ErrorOutputType::Json { pretty, json_rendered } =>
1303 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1305 let handler = errors::Handler::with_emitter(true, None, emitter);
1306 handler.struct_warn(msg).emit();
1309 pub type CompileResult = Result<(), ErrorReported>;