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 /// Map from imported macro spans (which consist of
99 /// the localized span for the macro body) to the
100 /// macro name and definition span in the source crate.
101 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
103 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
104 /// Used for incremental compilation tests. Will only be populated if
105 /// `-Zquery-dep-graph` is specified.
106 pub cgu_reuse_tracker: CguReuseTracker,
108 /// Used by `-Z self-profile`.
109 pub prof: SelfProfilerRef,
111 /// Some measurements that are being gathered during compilation.
112 pub perf_stats: PerfStats,
114 /// Data about code being compiled, gathered during compilation.
115 pub code_stats: CodeStats,
117 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
118 optimization_fuel_crate: Option<String>,
120 /// Tracks fuel info if `-zfuel=crate=n` is specified.
121 optimization_fuel: Lock<OptimizationFuel>,
123 // The next two are public because the driver needs to read them.
124 /// If `-zprint-fuel=crate`, `Some(crate)`.
125 pub print_fuel_crate: Option<String>,
126 /// Always set to zero and incremented so that we can print fuel expended by a crate.
127 pub print_fuel: AtomicU64,
129 /// Loaded up early on in the initialization of this `Session` to avoid
130 /// false positives about a job server in our environment.
131 pub jobserver: Client,
133 /// Cap lint level specified by a driver specifically.
134 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
136 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
137 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
139 /// Mapping from ident span to path span for paths that don't exist as written, but that
140 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
141 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
144 pub struct PerfStats {
145 /// The accumulated time spent on computing symbol hashes.
146 pub symbol_hash_time: Lock<Duration>,
147 /// The accumulated time spent decoding def path tables from metadata.
148 pub decode_def_path_tables_time: Lock<Duration>,
149 /// Total number of values canonicalized queries constructed.
150 pub queries_canonicalized: AtomicUsize,
151 /// Number of times this query is invoked.
152 pub normalize_ty_after_erasing_regions: AtomicUsize,
153 /// Number of times this query is invoked.
154 pub normalize_projection_ty: AtomicUsize,
157 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
158 enum DiagnosticBuilderMethod {
161 SpanSuggestion(String), // suggestion
162 // Add more variants as needed to support one-time diagnostics.
165 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
166 /// emitting the same message more than once.
167 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
168 pub enum DiagnosticMessageId {
169 ErrorId(u16), // EXXXX error code as integer
170 LintId(lint::LintId),
171 StabilityId(Option<NonZeroU32>), // issue number
174 impl From<&'static lint::Lint> for DiagnosticMessageId {
175 fn from(lint: &'static lint::Lint) -> Self {
176 DiagnosticMessageId::LintId(lint::LintId::of(lint))
181 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
182 *self.crate_disambiguator.get()
185 pub fn struct_span_warn<S: Into<MultiSpan>>(
189 ) -> DiagnosticBuilder<'_> {
190 self.diagnostic().struct_span_warn(sp, msg)
192 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
197 ) -> DiagnosticBuilder<'_> {
198 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
200 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
201 self.diagnostic().struct_warn(msg)
203 pub fn struct_span_err<S: Into<MultiSpan>>(
207 ) -> DiagnosticBuilder<'_> {
208 self.diagnostic().struct_span_err(sp, msg)
210 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
215 ) -> DiagnosticBuilder<'_> {
216 self.diagnostic().struct_span_err_with_code(sp, msg, code)
218 // FIXME: This method should be removed (every error should have an associated error code).
219 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
220 self.diagnostic().struct_err(msg)
222 pub fn struct_err_with_code(
226 ) -> DiagnosticBuilder<'_> {
227 self.diagnostic().struct_err_with_code(msg, code)
229 pub fn struct_span_fatal<S: Into<MultiSpan>>(
233 ) -> DiagnosticBuilder<'_> {
234 self.diagnostic().struct_span_fatal(sp, msg)
236 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
241 ) -> DiagnosticBuilder<'_> {
242 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
244 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
245 self.diagnostic().struct_fatal(msg)
248 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
249 self.diagnostic().span_fatal(sp, msg).raise()
251 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
258 .span_fatal_with_code(sp, msg, code)
261 pub fn fatal(&self, msg: &str) -> ! {
262 self.diagnostic().fatal(msg).raise()
264 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
266 self.span_warn(sp, msg);
268 self.span_err(sp, msg);
271 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
272 self.diagnostic().span_err(sp, msg)
274 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
275 self.diagnostic().span_err_with_code(sp, &msg, code)
277 pub fn err(&self, msg: &str) {
278 self.diagnostic().err(msg)
280 pub fn err_count(&self) -> usize {
281 self.diagnostic().err_count()
283 pub fn has_errors(&self) -> bool {
284 self.diagnostic().has_errors()
286 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
287 self.diagnostic().has_errors_or_delayed_span_bugs()
289 pub fn abort_if_errors(&self) {
290 self.diagnostic().abort_if_errors();
292 pub fn compile_status(&self) -> Result<(), ErrorReported> {
293 if self.has_errors() {
294 self.diagnostic().emit_stashed_diagnostics();
300 // FIXME(matthewjasper) Remove this method, it should never be needed.
301 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
305 let old_count = self.err_count();
307 let errors = self.err_count() - old_count;
314 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
315 self.diagnostic().span_warn(sp, msg)
317 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
318 self.diagnostic().span_warn_with_code(sp, msg, code)
320 pub fn warn(&self, msg: &str) {
321 self.diagnostic().warn(msg)
323 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
325 Some(sp) => self.span_warn(sp, msg),
326 None => self.warn(msg),
329 /// Delay a span_bug() call until abort_if_errors()
330 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
331 self.diagnostic().delay_span_bug(sp, msg)
333 pub fn note_without_error(&self, msg: &str) {
334 self.diagnostic().note_without_error(msg)
336 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
337 self.diagnostic().span_note_without_error(sp, msg)
340 pub fn diagnostic(&self) -> &errors::Handler {
341 &self.parse_sess.span_diagnostic
344 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
345 /// deduplicates on lint ID, span (if any), and message for this `Session`
346 fn diag_once<'a, 'b>(
348 diag_builder: &'b mut DiagnosticBuilder<'a>,
349 method: DiagnosticBuilderMethod,
350 msg_id: DiagnosticMessageId,
352 span_maybe: Option<Span>,
354 let id_span_message = (msg_id, span_maybe, message.to_owned());
355 let fresh = self.one_time_diagnostics
357 .insert(id_span_message);
360 DiagnosticBuilderMethod::Note => {
361 diag_builder.note(message);
363 DiagnosticBuilderMethod::SpanNote => {
364 let span = span_maybe.expect("`span_note` needs a span");
365 diag_builder.span_note(span, message);
367 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
368 let span = span_maybe.expect("`span_suggestion_*` needs a span");
369 diag_builder.span_suggestion(
373 Applicability::Unspecified,
380 pub fn diag_span_note_once<'a, 'b>(
382 diag_builder: &'b mut DiagnosticBuilder<'a>,
383 msg_id: DiagnosticMessageId,
389 DiagnosticBuilderMethod::SpanNote,
396 pub fn diag_note_once<'a, 'b>(
398 diag_builder: &'b mut DiagnosticBuilder<'a>,
399 msg_id: DiagnosticMessageId,
404 DiagnosticBuilderMethod::Note,
411 pub fn diag_span_suggestion_once<'a, 'b>(
413 diag_builder: &'b mut DiagnosticBuilder<'a>,
414 msg_id: DiagnosticMessageId,
421 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
428 pub fn source_map(&self) -> &source_map::SourceMap {
429 self.parse_sess.source_map()
431 pub fn verbose(&self) -> bool {
432 self.opts.debugging_opts.verbose
434 pub fn time_passes(&self) -> bool {
435 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
437 pub fn time_extended(&self) -> bool {
438 self.opts.debugging_opts.time_passes
440 pub fn instrument_mcount(&self) -> bool {
441 self.opts.debugging_opts.instrument_mcount
443 pub fn time_llvm_passes(&self) -> bool {
444 self.opts.debugging_opts.time_llvm_passes
446 pub fn meta_stats(&self) -> bool {
447 self.opts.debugging_opts.meta_stats
449 pub fn asm_comments(&self) -> bool {
450 self.opts.debugging_opts.asm_comments
452 pub fn verify_llvm_ir(&self) -> bool {
453 self.opts.debugging_opts.verify_llvm_ir
454 || cfg!(always_verify_llvm_ir)
456 pub fn borrowck_stats(&self) -> bool {
457 self.opts.debugging_opts.borrowck_stats
459 pub fn print_llvm_passes(&self) -> bool {
460 self.opts.debugging_opts.print_llvm_passes
462 pub fn binary_dep_depinfo(&self) -> bool {
463 self.opts.debugging_opts.binary_dep_depinfo
466 /// Gets the features enabled for the current compilation session.
467 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
468 /// dependency tracking. Use tcx.features() instead.
470 pub fn features_untracked(&self) -> &feature_gate::Features {
474 pub fn init_features(&self, features: feature_gate::Features) {
475 self.features.set(features);
478 /// Calculates the flavor of LTO to use for this compilation.
479 pub fn lto(&self) -> config::Lto {
480 // If our target has codegen requirements ignore the command line
481 if self.target.target.options.requires_lto {
482 return config::Lto::Fat;
485 // If the user specified something, return that. If they only said `-C
486 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
487 // then ensure we can't use a ThinLTO.
488 match self.opts.cg.lto {
489 config::LtoCli::Unspecified => {
490 // The compiler was invoked without the `-Clto` flag. Fall
491 // through to the default handling
493 config::LtoCli::No => {
494 // The user explicitly opted out of any kind of LTO
495 return config::Lto::No;
497 config::LtoCli::Yes |
498 config::LtoCli::Fat |
499 config::LtoCli::NoParam => {
500 // All of these mean fat LTO
501 return config::Lto::Fat;
503 config::LtoCli::Thin => {
504 return if self.opts.cli_forced_thinlto_off {
512 // Ok at this point the target doesn't require anything and the user
513 // hasn't asked for anything. Our next decision is whether or not
514 // we enable "auto" ThinLTO where we use multiple codegen units and
515 // then do ThinLTO over those codegen units. The logic below will
516 // either return `No` or `ThinLocal`.
518 // If processing command line options determined that we're incompatible
519 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
520 if self.opts.cli_forced_thinlto_off {
521 return config::Lto::No;
524 // If `-Z thinlto` specified process that, but note that this is mostly
525 // a deprecated option now that `-C lto=thin` exists.
526 if let Some(enabled) = self.opts.debugging_opts.thinlto {
528 return config::Lto::ThinLocal;
530 return config::Lto::No;
534 // If there's only one codegen unit and LTO isn't enabled then there's
535 // no need for ThinLTO so just return false.
536 if self.codegen_units() == 1 {
537 return config::Lto::No;
540 // Now we're in "defaults" territory. By default we enable ThinLTO for
541 // optimized compiles (anything greater than O0).
542 match self.opts.optimize {
543 config::OptLevel::No => config::Lto::No,
544 _ => config::Lto::ThinLocal,
548 /// Returns the panic strategy for this compile session. If the user explicitly selected one
549 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
550 pub fn panic_strategy(&self) -> PanicStrategy {
554 .unwrap_or(self.target.target.options.panic_strategy)
556 pub fn fewer_names(&self) -> bool {
557 let more_names = self.opts
559 .contains_key(&OutputType::LlvmAssembly)
560 || self.opts.output_types.contains_key(&OutputType::Bitcode);
562 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
563 let more_names = match self.opts.debugging_opts.sanitizer {
564 Some(Sanitizer::Address) => true,
565 Some(Sanitizer::Memory) => true,
569 self.opts.debugging_opts.fewer_names || !more_names
572 pub fn no_landing_pads(&self) -> bool {
573 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
575 pub fn unstable_options(&self) -> bool {
576 self.opts.debugging_opts.unstable_options
578 pub fn overflow_checks(&self) -> bool {
582 .or(self.opts.debugging_opts.force_overflow_checks)
583 .unwrap_or(self.opts.debug_assertions)
586 pub fn crt_static(&self) -> bool {
587 // If the target does not opt in to crt-static support, use its default.
588 if self.target.target.options.crt_static_respected {
589 self.crt_static_feature()
591 self.target.target.options.crt_static_default
595 pub fn crt_static_feature(&self) -> bool {
596 let requested_features = self.opts.cg.target_feature.split(',');
597 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
598 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
600 // If the target we're compiling for requests a static crt by default,
601 // then see if the `-crt-static` feature was passed to disable that.
602 // Otherwise if we don't have a static crt by default then see if the
603 // `+crt-static` feature was passed.
604 if self.target.target.options.crt_static_default {
611 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
612 // "mcount" function relies on stack pointer.
613 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
614 if self.instrument_mcount() {
616 } else if let Some(x) = self.opts.cg.force_frame_pointers {
619 !self.target.target.options.eliminate_frame_pointer
623 /// Returns the symbol name for the registrar function,
624 /// given the crate `Svh` and the function `DefIndex`.
625 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
627 "__rustc_plugin_registrar_{}__",
628 disambiguator.to_fingerprint().to_hex()
632 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
634 "__rustc_proc_macro_decls_{}__",
635 disambiguator.to_fingerprint().to_hex()
639 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
640 filesearch::FileSearch::new(
642 self.opts.target_triple.triple(),
643 &self.opts.search_paths,
644 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
645 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
649 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
650 filesearch::FileSearch::new(
652 config::host_triple(),
653 &self.opts.search_paths,
654 &self.host_tlib_path,
659 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
660 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
662 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
663 *load_dep_graph = load;
667 pub fn incr_session_load_dep_graph(&self) -> bool {
668 let incr_comp_session = self.incr_comp_session.borrow();
669 match *incr_comp_session {
670 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
675 pub fn init_incr_comp_session(
677 session_dir: PathBuf,
678 lock_file: flock::Lock,
679 load_dep_graph: bool,
681 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
683 if let IncrCompSession::NotInitialized = *incr_comp_session {
686 "Trying to initialize IncrCompSession `{:?}`",
691 *incr_comp_session = IncrCompSession::Active {
692 session_directory: session_dir,
698 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
699 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
701 if let IncrCompSession::Active { .. } = *incr_comp_session {
704 "trying to finalize `IncrCompSession` `{:?}`",
709 // Note: this will also drop the lock file, thus unlocking the directory.
710 *incr_comp_session = IncrCompSession::Finalized {
711 session_directory: new_directory_path,
715 pub fn mark_incr_comp_session_as_invalid(&self) {
716 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
718 let session_directory = match *incr_comp_session {
719 IncrCompSession::Active {
720 ref session_directory,
722 } => session_directory.clone(),
723 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
725 "trying to invalidate `IncrCompSession` `{:?}`",
730 // Note: this will also drop the lock file, thus unlocking the directory.
731 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
736 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
737 let incr_comp_session = self.incr_comp_session.borrow();
740 |incr_comp_session| match *incr_comp_session {
741 IncrCompSession::NotInitialized => bug!(
742 "trying to get session directory from `IncrCompSession`: {:?}",
745 IncrCompSession::Active {
746 ref session_directory,
749 | IncrCompSession::Finalized {
750 ref session_directory,
752 | IncrCompSession::InvalidBecauseOfErrors {
753 ref session_directory,
754 } => session_directory,
759 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
760 if self.opts.incremental.is_some() {
761 Some(self.incr_comp_session_dir())
767 pub fn print_perf_stats(&self) {
769 "Total time spent computing symbol hashes: {}",
770 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
773 "Total time spent decoding DefPath tables: {}",
774 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
776 println!("Total queries canonicalized: {}",
777 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
778 println!("normalize_ty_after_erasing_regions: {}",
779 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
780 println!("normalize_projection_ty: {}",
781 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
784 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
785 /// This expends fuel if applicable, and records fuel if applicable.
786 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
788 if let Some(ref c) = self.optimization_fuel_crate {
790 assert_eq!(self.threads(), 1);
791 let mut fuel = self.optimization_fuel.lock();
792 ret = fuel.remaining != 0;
793 if fuel.remaining == 0 && !fuel.out_of_fuel {
794 eprintln!("optimization-fuel-exhausted: {}", msg());
795 fuel.out_of_fuel = true;
796 } else if fuel.remaining > 0 {
801 if let Some(ref c) = self.print_fuel_crate {
803 assert_eq!(self.threads(), 1);
804 self.print_fuel.fetch_add(1, SeqCst);
810 /// Returns the number of query threads that should be used for this
812 pub fn threads(&self) -> usize {
813 self.opts.debugging_opts.threads
816 /// Returns the number of codegen units that should be used for this
818 pub fn codegen_units(&self) -> usize {
819 if let Some(n) = self.opts.cli_forced_codegen_units {
822 if let Some(n) = self.target.target.options.default_codegen_units {
826 // Why is 16 codegen units the default all the time?
828 // The main reason for enabling multiple codegen units by default is to
829 // leverage the ability for the codegen backend to do codegen and
830 // optimization in parallel. This allows us, especially for large crates, to
831 // make good use of all available resources on the machine once we've
832 // hit that stage of compilation. Large crates especially then often
833 // take a long time in codegen/optimization and this helps us amortize that
836 // Note that a high number here doesn't mean that we'll be spawning a
837 // large number of threads in parallel. The backend of rustc contains
838 // global rate limiting through the `jobserver` crate so we'll never
839 // overload the system with too much work, but rather we'll only be
840 // optimizing when we're otherwise cooperating with other instances of
843 // Rather a high number here means that we should be able to keep a lot
844 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
845 // to build we'll be guaranteed that all cpus will finish pretty closely
846 // to one another and we should make relatively optimal use of system
849 // Note that the main cost of codegen units is that it prevents LLVM
850 // from inlining across codegen units. Users in general don't have a lot
851 // of control over how codegen units are split up so it's our job in the
852 // compiler to ensure that undue performance isn't lost when using
853 // codegen units (aka we can't require everyone to slap `#[inline]` on
856 // If we're compiling at `-O0` then the number doesn't really matter too
857 // much because performance doesn't matter and inlining is ok to lose.
858 // In debug mode we just want to try to guarantee that no cpu is stuck
859 // doing work that could otherwise be farmed to others.
861 // In release mode, however (O1 and above) performance does indeed
862 // matter! To recover the loss in performance due to inlining we'll be
863 // enabling ThinLTO by default (the function for which is just below).
864 // This will ensure that we recover any inlining wins we otherwise lost
865 // through codegen unit partitioning.
869 // Ok that's a lot of words but the basic tl;dr; is that we want a high
870 // number here -- but not too high. Additionally we're "safe" to have it
871 // always at the same number at all optimization levels.
873 // As a result 16 was chosen here! Mostly because it was a power of 2
874 // and most benchmarks agreed it was roughly a local optimum. Not very
879 pub fn teach(&self, code: &DiagnosticId) -> bool {
880 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
883 pub fn rust_2015(&self) -> bool {
884 self.opts.edition == Edition::Edition2015
887 /// Are we allowed to use features from the Rust 2018 edition?
888 pub fn rust_2018(&self) -> bool {
889 self.opts.edition >= Edition::Edition2018
892 pub fn edition(&self) -> Edition {
896 /// Returns `true` if we cannot skip the PLT for shared library calls.
897 pub fn needs_plt(&self) -> bool {
898 // Check if the current target usually needs PLT to be enabled.
899 // The user can use the command line flag to override it.
900 let needs_plt = self.target.target.options.needs_plt;
902 let dbg_opts = &self.opts.debugging_opts;
904 let relro_level = dbg_opts.relro_level
905 .unwrap_or(self.target.target.options.relro_level);
907 // Only enable this optimization by default if full relro is also enabled.
908 // In this case, lazy binding was already unavailable, so nothing is lost.
909 // This also ensures `-Wl,-z,now` is supported by the linker.
910 let full_relro = RelroLevel::Full == relro_level;
912 // If user didn't explicitly forced us to use / skip the PLT,
913 // then try to skip it where possible.
914 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
918 pub fn build_session(
919 sopts: config::Options,
920 local_crate_source_file: Option<PathBuf>,
921 registry: errors::registry::Registry,
923 let file_path_mapping = sopts.file_path_mapping();
925 build_session_with_source_map(
927 local_crate_source_file,
929 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
930 DiagnosticOutput::Default,
936 sopts: &config::Options,
937 registry: errors::registry::Registry,
938 source_map: &Lrc<source_map::SourceMap>,
939 emitter_dest: Option<Box<dyn Write + Send>>,
940 ) -> Box<dyn Emitter + sync::Send> {
941 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
942 match (sopts.error_format, emitter_dest) {
943 (config::ErrorOutputType::HumanReadable(kind), dst) => {
944 let (short, color_config) = kind.unzip();
946 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
947 let emitter = AnnotateSnippetEmitterWriter::new(
948 Some(source_map.clone()),
950 external_macro_backtrace,
952 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
954 let emitter = match dst {
955 None => EmitterWriter::stderr(
957 Some(source_map.clone()),
959 sopts.debugging_opts.teach,
960 sopts.debugging_opts.terminal_width,
961 external_macro_backtrace,
963 Some(dst) => EmitterWriter::new(
965 Some(source_map.clone()),
967 false, // no teach messages when writing to a buffer
968 false, // no colors when writing to a buffer
969 None, // no terminal width
970 external_macro_backtrace,
973 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
976 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
982 external_macro_backtrace,
983 ).ui_testing(sopts.debugging_opts.ui_testing),
985 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
992 external_macro_backtrace,
993 ).ui_testing(sopts.debugging_opts.ui_testing),
998 pub enum DiagnosticOutput {
1000 Raw(Box<dyn Write + Send>)
1003 pub fn build_session_with_source_map(
1004 sopts: config::Options,
1005 local_crate_source_file: Option<PathBuf>,
1006 registry: errors::registry::Registry,
1007 source_map: Lrc<source_map::SourceMap>,
1008 diagnostics_output: DiagnosticOutput,
1009 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1011 // FIXME: This is not general enough to make the warning lint completely override
1012 // normal diagnostic warnings, since the warning lint can also be denied and changed
1013 // later via the source code.
1014 let warnings_allow = sopts
1017 .filter(|&&(ref key, _)| *key == "warnings")
1018 .map(|&(_, ref level)| *level == lint::Allow)
1021 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1023 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1025 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1026 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1027 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1029 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1031 let write_dest = match diagnostics_output {
1032 DiagnosticOutput::Default => None,
1033 DiagnosticOutput::Raw(write) => Some(write),
1035 let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
1037 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1039 errors::HandlerFlags {
1042 report_delayed_bugs,
1043 dont_buffer_diagnostics,
1044 external_macro_backtrace,
1045 ..Default::default()
1051 local_crate_source_file,
1059 sopts: config::Options,
1060 local_crate_source_file: Option<PathBuf>,
1061 span_diagnostic: errors::Handler,
1062 source_map: Lrc<source_map::SourceMap>,
1063 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1066 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1067 let directory = if let Some(ref directory) = d {
1070 std::path::Path::new(".")
1073 let profiler = SelfProfiler::new(
1075 sopts.crate_name.as_ref().map(|s| &s[..]),
1076 &sopts.debugging_opts.self_profile_events
1080 Some(Arc::new(profiler))
1083 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1090 let host_triple = TargetTriple::from_triple(config::host_triple());
1091 let host = Target::search(&host_triple).unwrap_or_else(|e|
1093 .fatal(&format!("Error loading host specification: {}", e))
1096 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1098 let parse_sess = ParseSess::with_span_handler(
1102 let sysroot = match &sopts.maybe_sysroot {
1103 Some(sysroot) => sysroot.clone(),
1104 None => filesearch::get_or_default_sysroot(),
1107 let host_triple = config::host_triple();
1108 let target_triple = sopts.target_triple.triple();
1109 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1110 let target_tlib_path = if host_triple == target_triple {
1113 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1116 let file_path_mapping = sopts.file_path_mapping();
1118 let local_crate_source_file =
1119 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1121 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1122 let optimization_fuel = Lock::new(OptimizationFuel {
1123 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1126 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1127 let print_fuel = AtomicU64::new(0);
1129 let working_dir = env::current_dir().unwrap_or_else(|e|
1130 parse_sess.span_diagnostic
1131 .fatal(&format!("Current directory is invalid: {}", e))
1134 let working_dir = file_path_mapping.map_prefix(working_dir);
1136 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1137 CguReuseTracker::new()
1139 CguReuseTracker::new_disabled()
1142 let sess = Session {
1150 local_crate_source_file,
1152 one_time_diagnostics: Default::default(),
1153 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1154 crate_types: Once::new(),
1155 crate_disambiguator: Once::new(),
1156 features: Once::new(),
1157 recursion_limit: Once::new(),
1158 type_length_limit: Once::new(),
1159 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1160 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1162 prof: SelfProfilerRef::new(self_profiler),
1163 perf_stats: PerfStats {
1164 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1165 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1166 queries_canonicalized: AtomicUsize::new(0),
1167 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1168 normalize_projection_ty: AtomicUsize::new(0),
1170 code_stats: Default::default(),
1171 optimization_fuel_crate,
1175 jobserver: jobserver::client(),
1177 trait_methods_not_found: Lock::new(Default::default()),
1178 confused_type_with_std_module: Lock::new(Default::default()),
1181 validate_commandline_args_with_session_available(&sess);
1186 // If it is useful to have a Session available already for validating a
1187 // commandline argument, you can do so here.
1188 fn validate_commandline_args_with_session_available(sess: &Session) {
1189 // Since we don't know if code in an rlib will be linked to statically or
1190 // dynamically downstream, rustc generates `__imp_` symbols that help the
1191 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1192 // these manually generated symbols confuse LLD when it tries to merge
1193 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1194 // when compiling for LLD ThinLTO. This way we can validly just not generate
1195 // the `dllimport` attributes and `__imp_` symbols in that case.
1196 if sess.opts.cg.linker_plugin_lto.enabled() &&
1197 sess.opts.cg.prefer_dynamic &&
1198 sess.target.target.options.is_like_msvc {
1199 sess.err("Linker plugin based LTO is not supported together with \
1200 `-C prefer-dynamic` when targeting MSVC");
1203 // Make sure that any given profiling data actually exists so LLVM can't
1204 // decide to silently skip PGO.
1205 if let Some(ref path) = sess.opts.cg.profile_use {
1207 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1212 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1213 // an error to combine the two for now. It always runs into an assertions
1214 // if LLVM is built with assertions, but without assertions it sometimes
1215 // does not crash and will probably generate a corrupted binary.
1216 // We should only display this error if we're actually going to run PGO.
1217 // If we're just supposed to print out some data, don't show the error (#61002).
1218 if sess.opts.cg.profile_generate.enabled() &&
1219 sess.target.target.options.is_like_msvc &&
1220 sess.panic_strategy() == PanicStrategy::Unwind &&
1221 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1222 sess.err("Profile-guided optimization does not yet work in conjunction \
1223 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1224 See https://github.com/rust-lang/rust/issues/61002 for details.");
1228 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1229 /// compiler. Together with the crate-name forms a unique global identifier for
1231 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1232 pub struct CrateDisambiguator(Fingerprint);
1234 impl CrateDisambiguator {
1235 pub fn to_fingerprint(self) -> Fingerprint {
1240 impl fmt::Display for CrateDisambiguator {
1241 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1242 let (a, b) = self.0.as_value();
1243 let as_u128 = a as u128 | ((b as u128) << 64);
1244 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1248 impl From<Fingerprint> for CrateDisambiguator {
1249 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1250 CrateDisambiguator(fingerprint)
1254 impl_stable_hash_via_hash!(CrateDisambiguator);
1256 /// Holds data on the current incremental compilation session, if there is one.
1258 pub enum IncrCompSession {
1259 /// This is the state the session will be in until the incr. comp. dir is
1262 /// This is the state during which the session directory is private and can
1265 session_directory: PathBuf,
1266 lock_file: flock::Lock,
1267 load_dep_graph: bool,
1269 /// This is the state after the session directory has been finalized. In this
1270 /// state, the contents of the directory must not be modified any more.
1271 Finalized { session_directory: PathBuf },
1272 /// This is an error state that is reached when some compilation error has
1273 /// occurred. It indicates that the contents of the session directory must
1274 /// not be used, since they might be invalid.
1275 InvalidBecauseOfErrors { session_directory: PathBuf },
1278 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1279 let emitter: Box<dyn Emitter + sync::Send> = match output {
1280 config::ErrorOutputType::HumanReadable(kind) => {
1281 let (short, color_config) = kind.unzip();
1282 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1284 config::ErrorOutputType::Json { pretty, json_rendered } =>
1285 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1287 let handler = errors::Handler::with_emitter(true, None, emitter);
1288 handler.struct_fatal(msg).emit();
1289 errors::FatalError.raise();
1292 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1293 let emitter: Box<dyn Emitter + sync::Send> = match output {
1294 config::ErrorOutputType::HumanReadable(kind) => {
1295 let (short, color_config) = kind.unzip();
1296 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1298 config::ErrorOutputType::Json { pretty, json_rendered } =>
1299 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1301 let handler = errors::Handler::with_emitter(true, None, emitter);
1302 handler.struct_warn(msg).emit();
1305 pub type CompileResult = Result<(), ErrorReported>;