1 pub use self::code_stats::{DataTypeKind, SizeKind, FieldInfo, VariantInfo};
2 use self::code_stats::CodeStats;
4 use rustc_session::cgu_reuse_tracker::CguReuseTracker;
5 use rustc_data_structures::fingerprint::Fingerprint;
6 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
9 use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
10 use crate::session::search_paths::{PathKind, SearchPath};
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 errors::json::JsonEmitter;
25 use syntax::source_map;
26 use syntax::sess::ParseSess;
27 use syntax_pos::{MultiSpan, Span};
29 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
30 use rustc_data_structures::flock;
31 use rustc_data_structures::jobserver;
32 use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
33 use ::jobserver::Client;
36 use std::cell::{self, RefCell};
40 use std::num::NonZeroU32;
41 use std::path::PathBuf;
42 use std::time::Duration;
50 pub struct OptimizationFuel {
51 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
53 /// We're rejecting all further optimizations.
57 /// Represents the data associated with a compilation
58 /// session for a single crate.
60 pub target: config::Config,
62 pub opts: config::Options,
63 pub host_tlib_path: SearchPath,
64 /// `None` if the host and target are the same.
65 pub target_tlib_path: Option<SearchPath>,
66 pub parse_sess: ParseSess,
68 /// The name of the root source file of the crate, in the local file system.
69 /// `None` means that there is no source file.
70 pub local_crate_source_file: Option<PathBuf>,
71 /// The directory the compiler has been executed in plus a flag indicating
72 /// if the value stored here has been affected by path remapping.
73 pub working_dir: (PathBuf, bool),
75 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
76 /// (sub)diagnostics that have been set once, but should not be set again,
77 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
78 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
79 pub crate_types: Once<Vec<config::CrateType>>,
80 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
81 /// arguments passed to the compiler. Its value together with the crate-name
82 /// forms a unique global identifier for the crate. It is used to allow
83 /// multiple crates with the same name to coexist. See the
84 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
85 pub crate_disambiguator: Once<CrateDisambiguator>,
87 features: Once<rustc_feature::Features>,
89 /// The maximum recursion limit for potentially infinitely recursive
90 /// operations such as auto-dereference and monomorphization.
91 pub recursion_limit: Once<usize>,
93 /// The maximum length of types during monomorphization.
94 pub type_length_limit: Once<usize>,
96 /// Map from imported macro spans (which consist of
97 /// the localized span for the macro body) to the
98 /// macro name and definition span in the source crate.
99 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
101 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
102 /// Used for incremental compilation tests. Will only be populated if
103 /// `-Zquery-dep-graph` is specified.
104 pub cgu_reuse_tracker: CguReuseTracker,
106 /// Used by `-Z self-profile`.
107 pub prof: SelfProfilerRef,
109 /// Some measurements that are being gathered during compilation.
110 pub perf_stats: PerfStats,
112 /// Data about code being compiled, gathered during compilation.
113 pub code_stats: CodeStats,
115 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
116 optimization_fuel_crate: Option<String>,
118 /// Tracks fuel info if `-zfuel=crate=n` is specified.
119 optimization_fuel: Lock<OptimizationFuel>,
121 // The next two are public because the driver needs to read them.
122 /// If `-zprint-fuel=crate`, `Some(crate)`.
123 pub print_fuel_crate: Option<String>,
124 /// Always set to zero and incremented so that we can print fuel expended by a crate.
125 pub print_fuel: AtomicU64,
127 /// Loaded up early on in the initialization of this `Session` to avoid
128 /// false positives about a job server in our environment.
129 pub jobserver: Client,
131 /// Cap lint level specified by a driver specifically.
132 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
134 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
135 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
137 /// Mapping from ident span to path span for paths that don't exist as written, but that
138 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
139 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
142 pub struct PerfStats {
143 /// The accumulated time spent on computing symbol hashes.
144 pub symbol_hash_time: Lock<Duration>,
145 /// The accumulated time spent decoding def path tables from metadata.
146 pub decode_def_path_tables_time: Lock<Duration>,
147 /// Total number of values canonicalized queries constructed.
148 pub queries_canonicalized: AtomicUsize,
149 /// Number of times this query is invoked.
150 pub normalize_ty_after_erasing_regions: AtomicUsize,
151 /// Number of times this query is invoked.
152 pub normalize_projection_ty: AtomicUsize,
155 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
156 enum DiagnosticBuilderMethod {
159 SpanSuggestion(String), // suggestion
160 // Add more variants as needed to support one-time diagnostics.
163 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
164 /// emitting the same message more than once.
165 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
166 pub enum DiagnosticMessageId {
167 ErrorId(u16), // EXXXX error code as integer
168 LintId(lint::LintId),
169 StabilityId(Option<NonZeroU32>), // issue number
172 impl From<&'static lint::Lint> for DiagnosticMessageId {
173 fn from(lint: &'static lint::Lint) -> Self {
174 DiagnosticMessageId::LintId(lint::LintId::of(lint))
179 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
180 *self.crate_disambiguator.get()
183 pub fn struct_span_warn<S: Into<MultiSpan>>(
187 ) -> DiagnosticBuilder<'_> {
188 self.diagnostic().struct_span_warn(sp, msg)
190 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
195 ) -> DiagnosticBuilder<'_> {
196 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
198 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
199 self.diagnostic().struct_warn(msg)
201 pub fn struct_span_err<S: Into<MultiSpan>>(
205 ) -> DiagnosticBuilder<'_> {
206 self.diagnostic().struct_span_err(sp, msg)
208 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
213 ) -> DiagnosticBuilder<'_> {
214 self.diagnostic().struct_span_err_with_code(sp, msg, code)
216 // FIXME: This method should be removed (every error should have an associated error code).
217 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
218 self.diagnostic().struct_err(msg)
220 pub fn struct_err_with_code(
224 ) -> DiagnosticBuilder<'_> {
225 self.diagnostic().struct_err_with_code(msg, code)
227 pub fn struct_span_fatal<S: Into<MultiSpan>>(
231 ) -> DiagnosticBuilder<'_> {
232 self.diagnostic().struct_span_fatal(sp, msg)
234 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
239 ) -> DiagnosticBuilder<'_> {
240 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
242 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
243 self.diagnostic().struct_fatal(msg)
246 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
247 self.diagnostic().span_fatal(sp, msg).raise()
249 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
256 .span_fatal_with_code(sp, msg, code)
259 pub fn fatal(&self, msg: &str) -> ! {
260 self.diagnostic().fatal(msg).raise()
262 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
264 self.span_warn(sp, msg);
266 self.span_err(sp, msg);
269 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
270 self.diagnostic().span_err(sp, msg)
272 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
273 self.diagnostic().span_err_with_code(sp, &msg, code)
275 pub fn err(&self, msg: &str) {
276 self.diagnostic().err(msg)
278 pub fn err_count(&self) -> usize {
279 self.diagnostic().err_count()
281 pub fn has_errors(&self) -> bool {
282 self.diagnostic().has_errors()
284 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
285 self.diagnostic().has_errors_or_delayed_span_bugs()
287 pub fn abort_if_errors(&self) {
288 self.diagnostic().abort_if_errors();
290 pub fn compile_status(&self) -> Result<(), ErrorReported> {
291 if self.has_errors() {
292 self.diagnostic().emit_stashed_diagnostics();
298 // FIXME(matthewjasper) Remove this method, it should never be needed.
299 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
303 let old_count = self.err_count();
305 let errors = self.err_count() - old_count;
312 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
313 self.diagnostic().span_warn(sp, msg)
315 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
316 self.diagnostic().span_warn_with_code(sp, msg, code)
318 pub fn warn(&self, msg: &str) {
319 self.diagnostic().warn(msg)
321 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
323 Some(sp) => self.span_warn(sp, msg),
324 None => self.warn(msg),
327 /// Delay a span_bug() call until abort_if_errors()
328 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
329 self.diagnostic().delay_span_bug(sp, msg)
331 pub fn note_without_error(&self, msg: &str) {
332 self.diagnostic().note_without_error(msg)
334 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
335 self.diagnostic().span_note_without_error(sp, msg)
338 pub fn diagnostic(&self) -> &errors::Handler {
339 &self.parse_sess.span_diagnostic
342 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
343 /// deduplicates on lint ID, span (if any), and message for this `Session`
344 fn diag_once<'a, 'b>(
346 diag_builder: &'b mut DiagnosticBuilder<'a>,
347 method: DiagnosticBuilderMethod,
348 msg_id: DiagnosticMessageId,
350 span_maybe: Option<Span>,
352 let id_span_message = (msg_id, span_maybe, message.to_owned());
353 let fresh = self.one_time_diagnostics
355 .insert(id_span_message);
358 DiagnosticBuilderMethod::Note => {
359 diag_builder.note(message);
361 DiagnosticBuilderMethod::SpanNote => {
362 let span = span_maybe.expect("`span_note` needs a span");
363 diag_builder.span_note(span, message);
365 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
366 let span = span_maybe.expect("`span_suggestion_*` needs a span");
367 diag_builder.span_suggestion(
371 Applicability::Unspecified,
378 pub fn diag_span_note_once<'a, 'b>(
380 diag_builder: &'b mut DiagnosticBuilder<'a>,
381 msg_id: DiagnosticMessageId,
387 DiagnosticBuilderMethod::SpanNote,
394 pub fn diag_note_once<'a, 'b>(
396 diag_builder: &'b mut DiagnosticBuilder<'a>,
397 msg_id: DiagnosticMessageId,
402 DiagnosticBuilderMethod::Note,
409 pub fn diag_span_suggestion_once<'a, 'b>(
411 diag_builder: &'b mut DiagnosticBuilder<'a>,
412 msg_id: DiagnosticMessageId,
419 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
426 pub fn source_map(&self) -> &source_map::SourceMap {
427 self.parse_sess.source_map()
429 pub fn verbose(&self) -> bool {
430 self.opts.debugging_opts.verbose
432 pub fn time_passes(&self) -> bool {
433 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
435 pub fn time_extended(&self) -> bool {
436 self.opts.debugging_opts.time_passes
438 pub fn instrument_mcount(&self) -> bool {
439 self.opts.debugging_opts.instrument_mcount
441 pub fn time_llvm_passes(&self) -> bool {
442 self.opts.debugging_opts.time_llvm_passes
444 pub fn meta_stats(&self) -> bool {
445 self.opts.debugging_opts.meta_stats
447 pub fn asm_comments(&self) -> bool {
448 self.opts.debugging_opts.asm_comments
450 pub fn verify_llvm_ir(&self) -> bool {
451 self.opts.debugging_opts.verify_llvm_ir
452 || cfg!(always_verify_llvm_ir)
454 pub fn borrowck_stats(&self) -> bool {
455 self.opts.debugging_opts.borrowck_stats
457 pub fn print_llvm_passes(&self) -> bool {
458 self.opts.debugging_opts.print_llvm_passes
460 pub fn binary_dep_depinfo(&self) -> bool {
461 self.opts.debugging_opts.binary_dep_depinfo
464 /// Gets the features enabled for the current compilation session.
465 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
466 /// dependency tracking. Use tcx.features() instead.
468 pub fn features_untracked(&self) -> &rustc_feature::Features {
472 pub fn init_features(&self, features: rustc_feature::Features) {
473 self.features.set(features);
476 /// Calculates the flavor of LTO to use for this compilation.
477 pub fn lto(&self) -> config::Lto {
478 // If our target has codegen requirements ignore the command line
479 if self.target.target.options.requires_lto {
480 return config::Lto::Fat;
483 // If the user specified something, return that. If they only said `-C
484 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
485 // then ensure we can't use a ThinLTO.
486 match self.opts.cg.lto {
487 config::LtoCli::Unspecified => {
488 // The compiler was invoked without the `-Clto` flag. Fall
489 // through to the default handling
491 config::LtoCli::No => {
492 // The user explicitly opted out of any kind of LTO
493 return config::Lto::No;
495 config::LtoCli::Yes |
496 config::LtoCli::Fat |
497 config::LtoCli::NoParam => {
498 // All of these mean fat LTO
499 return config::Lto::Fat;
501 config::LtoCli::Thin => {
502 return if self.opts.cli_forced_thinlto_off {
510 // Ok at this point the target doesn't require anything and the user
511 // hasn't asked for anything. Our next decision is whether or not
512 // we enable "auto" ThinLTO where we use multiple codegen units and
513 // then do ThinLTO over those codegen units. The logic below will
514 // either return `No` or `ThinLocal`.
516 // If processing command line options determined that we're incompatible
517 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
518 if self.opts.cli_forced_thinlto_off {
519 return config::Lto::No;
522 // If `-Z thinlto` specified process that, but note that this is mostly
523 // a deprecated option now that `-C lto=thin` exists.
524 if let Some(enabled) = self.opts.debugging_opts.thinlto {
526 return config::Lto::ThinLocal;
528 return config::Lto::No;
532 // If there's only one codegen unit and LTO isn't enabled then there's
533 // no need for ThinLTO so just return false.
534 if self.codegen_units() == 1 {
535 return config::Lto::No;
538 // Now we're in "defaults" territory. By default we enable ThinLTO for
539 // optimized compiles (anything greater than O0).
540 match self.opts.optimize {
541 config::OptLevel::No => config::Lto::No,
542 _ => config::Lto::ThinLocal,
546 /// Returns the panic strategy for this compile session. If the user explicitly selected one
547 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
548 pub fn panic_strategy(&self) -> PanicStrategy {
552 .unwrap_or(self.target.target.options.panic_strategy)
554 pub fn fewer_names(&self) -> bool {
555 let more_names = self.opts
557 .contains_key(&OutputType::LlvmAssembly)
558 || self.opts.output_types.contains_key(&OutputType::Bitcode);
560 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
561 let more_names = match self.opts.debugging_opts.sanitizer {
562 Some(Sanitizer::Address) => true,
563 Some(Sanitizer::Memory) => true,
567 self.opts.debugging_opts.fewer_names || !more_names
570 pub fn no_landing_pads(&self) -> bool {
571 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
573 pub fn unstable_options(&self) -> bool {
574 self.opts.debugging_opts.unstable_options
576 pub fn overflow_checks(&self) -> bool {
580 .or(self.opts.debugging_opts.force_overflow_checks)
581 .unwrap_or(self.opts.debug_assertions)
584 pub fn crt_static(&self) -> bool {
585 // If the target does not opt in to crt-static support, use its default.
586 if self.target.target.options.crt_static_respected {
587 self.crt_static_feature()
589 self.target.target.options.crt_static_default
593 pub fn crt_static_feature(&self) -> bool {
594 let requested_features = self.opts.cg.target_feature.split(',');
595 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
596 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
598 // If the target we're compiling for requests a static crt by default,
599 // then see if the `-crt-static` feature was passed to disable that.
600 // Otherwise if we don't have a static crt by default then see if the
601 // `+crt-static` feature was passed.
602 if self.target.target.options.crt_static_default {
609 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
610 // "mcount" function relies on stack pointer.
611 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
612 if self.instrument_mcount() {
614 } else if let Some(x) = self.opts.cg.force_frame_pointers {
617 !self.target.target.options.eliminate_frame_pointer
621 /// Returns the symbol name for the registrar function,
622 /// given the crate `Svh` and the function `DefIndex`.
623 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
625 "__rustc_plugin_registrar_{}__",
626 disambiguator.to_fingerprint().to_hex()
630 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
632 "__rustc_proc_macro_decls_{}__",
633 disambiguator.to_fingerprint().to_hex()
637 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
638 filesearch::FileSearch::new(
640 self.opts.target_triple.triple(),
641 &self.opts.search_paths,
642 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
643 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
647 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
648 filesearch::FileSearch::new(
650 config::host_triple(),
651 &self.opts.search_paths,
652 &self.host_tlib_path,
657 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
658 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
660 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
661 *load_dep_graph = load;
665 pub fn incr_session_load_dep_graph(&self) -> bool {
666 let incr_comp_session = self.incr_comp_session.borrow();
667 match *incr_comp_session {
668 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
673 pub fn init_incr_comp_session(
675 session_dir: PathBuf,
676 lock_file: flock::Lock,
677 load_dep_graph: bool,
679 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
681 if let IncrCompSession::NotInitialized = *incr_comp_session {
684 "Trying to initialize IncrCompSession `{:?}`",
689 *incr_comp_session = IncrCompSession::Active {
690 session_directory: session_dir,
696 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
697 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
699 if let IncrCompSession::Active { .. } = *incr_comp_session {
702 "trying to finalize `IncrCompSession` `{:?}`",
707 // Note: this will also drop the lock file, thus unlocking the directory.
708 *incr_comp_session = IncrCompSession::Finalized {
709 session_directory: new_directory_path,
713 pub fn mark_incr_comp_session_as_invalid(&self) {
714 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
716 let session_directory = match *incr_comp_session {
717 IncrCompSession::Active {
718 ref session_directory,
720 } => session_directory.clone(),
721 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
723 "trying to invalidate `IncrCompSession` `{:?}`",
728 // Note: this will also drop the lock file, thus unlocking the directory.
729 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
734 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
735 let incr_comp_session = self.incr_comp_session.borrow();
738 |incr_comp_session| match *incr_comp_session {
739 IncrCompSession::NotInitialized => bug!(
740 "trying to get session directory from `IncrCompSession`: {:?}",
743 IncrCompSession::Active {
744 ref session_directory,
747 | IncrCompSession::Finalized {
748 ref session_directory,
750 | IncrCompSession::InvalidBecauseOfErrors {
751 ref session_directory,
752 } => session_directory,
757 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
758 if self.opts.incremental.is_some() {
759 Some(self.incr_comp_session_dir())
765 pub fn print_perf_stats(&self) {
767 "Total time spent computing symbol hashes: {}",
768 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
771 "Total time spent decoding DefPath tables: {}",
772 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
774 println!("Total queries canonicalized: {}",
775 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
776 println!("normalize_ty_after_erasing_regions: {}",
777 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
778 println!("normalize_projection_ty: {}",
779 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
782 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
783 /// This expends fuel if applicable, and records fuel if applicable.
784 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
786 if let Some(ref c) = self.optimization_fuel_crate {
788 assert_eq!(self.threads(), 1);
789 let mut fuel = self.optimization_fuel.lock();
790 ret = fuel.remaining != 0;
791 if fuel.remaining == 0 && !fuel.out_of_fuel {
792 eprintln!("optimization-fuel-exhausted: {}", msg());
793 fuel.out_of_fuel = true;
794 } else if fuel.remaining > 0 {
799 if let Some(ref c) = self.print_fuel_crate {
801 assert_eq!(self.threads(), 1);
802 self.print_fuel.fetch_add(1, SeqCst);
808 /// Returns the number of query threads that should be used for this
810 pub fn threads(&self) -> usize {
811 self.opts.debugging_opts.threads
814 /// Returns the number of codegen units that should be used for this
816 pub fn codegen_units(&self) -> usize {
817 if let Some(n) = self.opts.cli_forced_codegen_units {
820 if let Some(n) = self.target.target.options.default_codegen_units {
824 // Why is 16 codegen units the default all the time?
826 // The main reason for enabling multiple codegen units by default is to
827 // leverage the ability for the codegen backend to do codegen and
828 // optimization in parallel. This allows us, especially for large crates, to
829 // make good use of all available resources on the machine once we've
830 // hit that stage of compilation. Large crates especially then often
831 // take a long time in codegen/optimization and this helps us amortize that
834 // Note that a high number here doesn't mean that we'll be spawning a
835 // large number of threads in parallel. The backend of rustc contains
836 // global rate limiting through the `jobserver` crate so we'll never
837 // overload the system with too much work, but rather we'll only be
838 // optimizing when we're otherwise cooperating with other instances of
841 // Rather a high number here means that we should be able to keep a lot
842 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
843 // to build we'll be guaranteed that all cpus will finish pretty closely
844 // to one another and we should make relatively optimal use of system
847 // Note that the main cost of codegen units is that it prevents LLVM
848 // from inlining across codegen units. Users in general don't have a lot
849 // of control over how codegen units are split up so it's our job in the
850 // compiler to ensure that undue performance isn't lost when using
851 // codegen units (aka we can't require everyone to slap `#[inline]` on
854 // If we're compiling at `-O0` then the number doesn't really matter too
855 // much because performance doesn't matter and inlining is ok to lose.
856 // In debug mode we just want to try to guarantee that no cpu is stuck
857 // doing work that could otherwise be farmed to others.
859 // In release mode, however (O1 and above) performance does indeed
860 // matter! To recover the loss in performance due to inlining we'll be
861 // enabling ThinLTO by default (the function for which is just below).
862 // This will ensure that we recover any inlining wins we otherwise lost
863 // through codegen unit partitioning.
867 // Ok that's a lot of words but the basic tl;dr; is that we want a high
868 // number here -- but not too high. Additionally we're "safe" to have it
869 // always at the same number at all optimization levels.
871 // As a result 16 was chosen here! Mostly because it was a power of 2
872 // and most benchmarks agreed it was roughly a local optimum. Not very
877 pub fn teach(&self, code: &DiagnosticId) -> bool {
878 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
881 pub fn rust_2015(&self) -> bool {
882 self.opts.edition == Edition::Edition2015
885 /// Are we allowed to use features from the Rust 2018 edition?
886 pub fn rust_2018(&self) -> bool {
887 self.opts.edition >= Edition::Edition2018
890 pub fn edition(&self) -> Edition {
894 /// Returns `true` if we cannot skip the PLT for shared library calls.
895 pub fn needs_plt(&self) -> bool {
896 // Check if the current target usually needs PLT to be enabled.
897 // The user can use the command line flag to override it.
898 let needs_plt = self.target.target.options.needs_plt;
900 let dbg_opts = &self.opts.debugging_opts;
902 let relro_level = dbg_opts.relro_level
903 .unwrap_or(self.target.target.options.relro_level);
905 // Only enable this optimization by default if full relro is also enabled.
906 // In this case, lazy binding was already unavailable, so nothing is lost.
907 // This also ensures `-Wl,-z,now` is supported by the linker.
908 let full_relro = RelroLevel::Full == relro_level;
910 // If user didn't explicitly forced us to use / skip the PLT,
911 // then try to skip it where possible.
912 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
916 pub fn build_session(
917 sopts: config::Options,
918 local_crate_source_file: Option<PathBuf>,
919 registry: errors::registry::Registry,
921 let file_path_mapping = sopts.file_path_mapping();
923 build_session_with_source_map(
925 local_crate_source_file,
927 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
928 DiagnosticOutput::Default,
934 sopts: &config::Options,
935 registry: errors::registry::Registry,
936 source_map: &Lrc<source_map::SourceMap>,
937 emitter_dest: Option<Box<dyn Write + Send>>,
938 ) -> Box<dyn Emitter + sync::Send> {
939 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
940 match (sopts.error_format, emitter_dest) {
941 (config::ErrorOutputType::HumanReadable(kind), dst) => {
942 let (short, color_config) = kind.unzip();
944 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
945 let emitter = AnnotateSnippetEmitterWriter::new(
946 Some(source_map.clone()),
948 external_macro_backtrace,
950 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
952 let emitter = match dst {
953 None => EmitterWriter::stderr(
955 Some(source_map.clone()),
957 sopts.debugging_opts.teach,
958 sopts.debugging_opts.terminal_width,
959 external_macro_backtrace,
961 Some(dst) => EmitterWriter::new(
963 Some(source_map.clone()),
965 false, // no teach messages when writing to a buffer
966 false, // no colors when writing to a buffer
967 None, // no terminal width
968 external_macro_backtrace,
971 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
974 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
980 external_macro_backtrace,
981 ).ui_testing(sopts.debugging_opts.ui_testing),
983 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
990 external_macro_backtrace,
991 ).ui_testing(sopts.debugging_opts.ui_testing),
996 pub enum DiagnosticOutput {
998 Raw(Box<dyn Write + Send>)
1001 pub fn build_session_with_source_map(
1002 sopts: config::Options,
1003 local_crate_source_file: Option<PathBuf>,
1004 registry: errors::registry::Registry,
1005 source_map: Lrc<source_map::SourceMap>,
1006 diagnostics_output: DiagnosticOutput,
1007 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1009 // FIXME: This is not general enough to make the warning lint completely override
1010 // normal diagnostic warnings, since the warning lint can also be denied and changed
1011 // later via the source code.
1012 let warnings_allow = sopts
1015 .filter(|&&(ref key, _)| *key == "warnings")
1016 .map(|&(_, ref level)| *level == lint::Allow)
1019 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1021 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1023 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1024 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1025 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1027 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1029 let write_dest = match diagnostics_output {
1030 DiagnosticOutput::Default => None,
1031 DiagnosticOutput::Raw(write) => Some(write),
1033 let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
1035 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1037 errors::HandlerFlags {
1040 report_delayed_bugs,
1041 dont_buffer_diagnostics,
1042 external_macro_backtrace,
1043 ..Default::default()
1049 local_crate_source_file,
1057 sopts: config::Options,
1058 local_crate_source_file: Option<PathBuf>,
1059 span_diagnostic: errors::Handler,
1060 source_map: Lrc<source_map::SourceMap>,
1061 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1064 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1065 let directory = if let Some(ref directory) = d {
1068 std::path::Path::new(".")
1071 let profiler = SelfProfiler::new(
1073 sopts.crate_name.as_ref().map(|s| &s[..]),
1074 &sopts.debugging_opts.self_profile_events
1078 Some(Arc::new(profiler))
1081 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1088 let host_triple = TargetTriple::from_triple(config::host_triple());
1089 let host = Target::search(&host_triple).unwrap_or_else(|e|
1091 .fatal(&format!("Error loading host specification: {}", e))
1094 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1096 let parse_sess = ParseSess::with_span_handler(
1100 let sysroot = match &sopts.maybe_sysroot {
1101 Some(sysroot) => sysroot.clone(),
1102 None => filesearch::get_or_default_sysroot(),
1105 let host_triple = config::host_triple();
1106 let target_triple = sopts.target_triple.triple();
1107 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1108 let target_tlib_path = if host_triple == target_triple {
1111 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1114 let file_path_mapping = sopts.file_path_mapping();
1116 let local_crate_source_file =
1117 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1119 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1120 let optimization_fuel = Lock::new(OptimizationFuel {
1121 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1124 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1125 let print_fuel = AtomicU64::new(0);
1127 let working_dir = env::current_dir().unwrap_or_else(|e|
1128 parse_sess.span_diagnostic
1129 .fatal(&format!("Current directory is invalid: {}", e))
1132 let working_dir = file_path_mapping.map_prefix(working_dir);
1134 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1135 CguReuseTracker::new()
1137 CguReuseTracker::new_disabled()
1140 let sess = Session {
1148 local_crate_source_file,
1150 one_time_diagnostics: Default::default(),
1151 crate_types: Once::new(),
1152 crate_disambiguator: Once::new(),
1153 features: Once::new(),
1154 recursion_limit: Once::new(),
1155 type_length_limit: Once::new(),
1156 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1157 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1159 prof: SelfProfilerRef::new(self_profiler),
1160 perf_stats: PerfStats {
1161 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1162 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1163 queries_canonicalized: AtomicUsize::new(0),
1164 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1165 normalize_projection_ty: AtomicUsize::new(0),
1167 code_stats: Default::default(),
1168 optimization_fuel_crate,
1172 jobserver: jobserver::client(),
1174 trait_methods_not_found: Lock::new(Default::default()),
1175 confused_type_with_std_module: Lock::new(Default::default()),
1178 validate_commandline_args_with_session_available(&sess);
1183 // If it is useful to have a Session available already for validating a
1184 // commandline argument, you can do so here.
1185 fn validate_commandline_args_with_session_available(sess: &Session) {
1186 // Since we don't know if code in an rlib will be linked to statically or
1187 // dynamically downstream, rustc generates `__imp_` symbols that help the
1188 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1189 // these manually generated symbols confuse LLD when it tries to merge
1190 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1191 // when compiling for LLD ThinLTO. This way we can validly just not generate
1192 // the `dllimport` attributes and `__imp_` symbols in that case.
1193 if sess.opts.cg.linker_plugin_lto.enabled() &&
1194 sess.opts.cg.prefer_dynamic &&
1195 sess.target.target.options.is_like_msvc {
1196 sess.err("Linker plugin based LTO is not supported together with \
1197 `-C prefer-dynamic` when targeting MSVC");
1200 // Make sure that any given profiling data actually exists so LLVM can't
1201 // decide to silently skip PGO.
1202 if let Some(ref path) = sess.opts.cg.profile_use {
1204 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1209 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1210 // an error to combine the two for now. It always runs into an assertions
1211 // if LLVM is built with assertions, but without assertions it sometimes
1212 // does not crash and will probably generate a corrupted binary.
1213 // We should only display this error if we're actually going to run PGO.
1214 // If we're just supposed to print out some data, don't show the error (#61002).
1215 if sess.opts.cg.profile_generate.enabled() &&
1216 sess.target.target.options.is_like_msvc &&
1217 sess.panic_strategy() == PanicStrategy::Unwind &&
1218 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1219 sess.err("Profile-guided optimization does not yet work in conjunction \
1220 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1221 See https://github.com/rust-lang/rust/issues/61002 for details.");
1225 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1226 /// compiler. Together with the crate-name forms a unique global identifier for
1228 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1229 pub struct CrateDisambiguator(Fingerprint);
1231 impl CrateDisambiguator {
1232 pub fn to_fingerprint(self) -> Fingerprint {
1237 impl fmt::Display for CrateDisambiguator {
1238 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1239 let (a, b) = self.0.as_value();
1240 let as_u128 = a as u128 | ((b as u128) << 64);
1241 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1245 impl From<Fingerprint> for CrateDisambiguator {
1246 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1247 CrateDisambiguator(fingerprint)
1251 impl_stable_hash_via_hash!(CrateDisambiguator);
1253 /// Holds data on the current incremental compilation session, if there is one.
1255 pub enum IncrCompSession {
1256 /// This is the state the session will be in until the incr. comp. dir is
1259 /// This is the state during which the session directory is private and can
1262 session_directory: PathBuf,
1263 lock_file: flock::Lock,
1264 load_dep_graph: bool,
1266 /// This is the state after the session directory has been finalized. In this
1267 /// state, the contents of the directory must not be modified any more.
1268 Finalized { session_directory: PathBuf },
1269 /// This is an error state that is reached when some compilation error has
1270 /// occurred. It indicates that the contents of the session directory must
1271 /// not be used, since they might be invalid.
1272 InvalidBecauseOfErrors { session_directory: PathBuf },
1275 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1276 let emitter: Box<dyn Emitter + sync::Send> = match output {
1277 config::ErrorOutputType::HumanReadable(kind) => {
1278 let (short, color_config) = kind.unzip();
1279 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1281 config::ErrorOutputType::Json { pretty, json_rendered } =>
1282 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1284 let handler = errors::Handler::with_emitter(true, None, emitter);
1285 handler.struct_fatal(msg).emit();
1286 errors::FatalError.raise();
1289 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1290 let emitter: Box<dyn Emitter + sync::Send> = match output {
1291 config::ErrorOutputType::HumanReadable(kind) => {
1292 let (short, color_config) = kind.unzip();
1293 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1295 config::ErrorOutputType::Json { pretty, json_rendered } =>
1296 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1298 let handler = errors::Handler::with_emitter(true, None, emitter);
1299 handler.struct_warn(msg).emit();
1302 pub type CompileResult = Result<(), ErrorReported>;