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::{self, AttributeType};
25 use syntax::json::JsonEmitter;
26 use syntax::source_map;
27 use syntax::sess::{ParseSess, ProcessCfgMod};
28 use syntax::symbol::Symbol;
29 use syntax_pos::{MultiSpan, Span};
31 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
32 use rustc_data_structures::flock;
33 use rustc_data_structures::jobserver;
34 use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
35 use ::jobserver::Client;
38 use std::cell::{self, RefCell};
42 use std::num::NonZeroU32;
43 use std::path::PathBuf;
44 use std::time::Duration;
52 pub struct OptimizationFuel {
53 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
55 /// We're rejecting all further optimizations.
59 /// Represents the data associated with a compilation
60 /// session for a single crate.
62 pub target: config::Config,
64 pub opts: config::Options,
65 pub host_tlib_path: SearchPath,
66 /// `None` if the host and target are the same.
67 pub target_tlib_path: Option<SearchPath>,
68 pub parse_sess: ParseSess,
70 /// The name of the root source file of the crate, in the local file system.
71 /// `None` means that there is no source file.
72 pub local_crate_source_file: Option<PathBuf>,
73 /// The directory the compiler has been executed in plus a flag indicating
74 /// if the value stored here has been affected by path remapping.
75 pub working_dir: (PathBuf, bool),
77 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
78 /// (sub)diagnostics that have been set once, but should not be set again,
79 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
80 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
81 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
82 pub plugin_attributes: Lock<Vec<(Symbol, AttributeType)>>,
83 pub crate_types: Once<Vec<config::CrateType>>,
84 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
85 /// arguments passed to the compiler. Its value together with the crate-name
86 /// forms a unique global identifier for the crate. It is used to allow
87 /// multiple crates with the same name to coexist. See the
88 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
89 pub crate_disambiguator: Once<CrateDisambiguator>,
91 features: Once<feature_gate::Features>,
93 /// The maximum recursion limit for potentially infinitely recursive
94 /// operations such as auto-dereference and monomorphization.
95 pub recursion_limit: Once<usize>,
97 /// The maximum length of types during monomorphization.
98 pub type_length_limit: Once<usize>,
100 /// The maximum number of stackframes allowed in const eval.
101 pub const_eval_stack_frame_limit: usize,
103 /// Map from imported macro spans (which consist of
104 /// the localized span for the macro body) to the
105 /// macro name and definition span in the source crate.
106 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
108 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
109 /// Used for incremental compilation tests. Will only be populated if
110 /// `-Zquery-dep-graph` is specified.
111 pub cgu_reuse_tracker: CguReuseTracker,
113 /// Used by `-Z self-profile`.
114 pub prof: SelfProfilerRef,
116 /// Some measurements that are being gathered during compilation.
117 pub perf_stats: PerfStats,
119 /// Data about code being compiled, gathered during compilation.
120 pub code_stats: CodeStats,
122 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
123 optimization_fuel_crate: Option<String>,
125 /// Tracks fuel info if `-zfuel=crate=n` is specified.
126 optimization_fuel: Lock<OptimizationFuel>,
128 // The next two are public because the driver needs to read them.
129 /// If `-zprint-fuel=crate`, `Some(crate)`.
130 pub print_fuel_crate: Option<String>,
131 /// Always set to zero and incremented so that we can print fuel expended by a crate.
132 pub print_fuel: AtomicU64,
134 /// Loaded up early on in the initialization of this `Session` to avoid
135 /// false positives about a job server in our environment.
136 pub jobserver: Client,
138 /// Metadata about the allocators for the current crate being compiled.
139 pub has_global_allocator: Once<bool>,
141 /// Cap lint level specified by a driver specifically.
142 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
144 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
145 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
147 /// Mapping from ident span to path span for paths that don't exist as written, but that
148 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
149 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
152 pub struct PerfStats {
153 /// The accumulated time spent on computing symbol hashes.
154 pub symbol_hash_time: Lock<Duration>,
155 /// The accumulated time spent decoding def path tables from metadata.
156 pub decode_def_path_tables_time: Lock<Duration>,
157 /// Total number of values canonicalized queries constructed.
158 pub queries_canonicalized: AtomicUsize,
159 /// Number of times this query is invoked.
160 pub normalize_ty_after_erasing_regions: AtomicUsize,
161 /// Number of times this query is invoked.
162 pub normalize_projection_ty: AtomicUsize,
165 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
166 enum DiagnosticBuilderMethod {
169 SpanSuggestion(String), // suggestion
170 // Add more variants as needed to support one-time diagnostics.
173 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
174 /// emitting the same message more than once.
175 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
176 pub enum DiagnosticMessageId {
177 ErrorId(u16), // EXXXX error code as integer
178 LintId(lint::LintId),
179 StabilityId(Option<NonZeroU32>), // issue number
182 impl From<&'static lint::Lint> for DiagnosticMessageId {
183 fn from(lint: &'static lint::Lint) -> Self {
184 DiagnosticMessageId::LintId(lint::LintId::of(lint))
189 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
190 *self.crate_disambiguator.get()
193 pub fn struct_span_warn<S: Into<MultiSpan>>(
197 ) -> DiagnosticBuilder<'_> {
198 self.diagnostic().struct_span_warn(sp, msg)
200 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
205 ) -> DiagnosticBuilder<'_> {
206 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
208 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
209 self.diagnostic().struct_warn(msg)
211 pub fn struct_span_err<S: Into<MultiSpan>>(
215 ) -> DiagnosticBuilder<'_> {
216 self.diagnostic().struct_span_err(sp, msg)
218 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
223 ) -> DiagnosticBuilder<'_> {
224 self.diagnostic().struct_span_err_with_code(sp, msg, code)
226 // FIXME: This method should be removed (every error should have an associated error code).
227 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
228 self.diagnostic().struct_err(msg)
230 pub fn struct_err_with_code(
234 ) -> DiagnosticBuilder<'_> {
235 self.diagnostic().struct_err_with_code(msg, code)
237 pub fn struct_span_fatal<S: Into<MultiSpan>>(
241 ) -> DiagnosticBuilder<'_> {
242 self.diagnostic().struct_span_fatal(sp, msg)
244 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
249 ) -> DiagnosticBuilder<'_> {
250 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
252 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
253 self.diagnostic().struct_fatal(msg)
256 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
257 self.diagnostic().span_fatal(sp, msg).raise()
259 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
266 .span_fatal_with_code(sp, msg, code)
269 pub fn fatal(&self, msg: &str) -> ! {
270 self.diagnostic().fatal(msg).raise()
272 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
274 self.span_warn(sp, msg);
276 self.span_err(sp, msg);
279 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
280 self.diagnostic().span_err(sp, msg)
282 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
283 self.diagnostic().span_err_with_code(sp, &msg, code)
285 pub fn err(&self, msg: &str) {
286 self.diagnostic().err(msg)
288 pub fn err_count(&self) -> usize {
289 self.diagnostic().err_count()
291 pub fn has_errors(&self) -> bool {
292 self.diagnostic().has_errors()
294 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
295 self.diagnostic().has_errors_or_delayed_span_bugs()
297 pub fn abort_if_errors(&self) {
298 self.diagnostic().abort_if_errors();
300 pub fn compile_status(&self) -> Result<(), ErrorReported> {
301 if self.has_errors() {
302 self.diagnostic().emit_stashed_diagnostics();
308 // FIXME(matthewjasper) Remove this method, it should never be needed.
309 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
313 let old_count = self.err_count();
315 let errors = self.err_count() - old_count;
322 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
323 self.diagnostic().span_warn(sp, msg)
325 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
326 self.diagnostic().span_warn_with_code(sp, msg, code)
328 pub fn warn(&self, msg: &str) {
329 self.diagnostic().warn(msg)
331 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
333 Some(sp) => self.span_warn(sp, msg),
334 None => self.warn(msg),
337 /// Delay a span_bug() call until abort_if_errors()
338 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
339 self.diagnostic().delay_span_bug(sp, msg)
341 pub fn note_without_error(&self, msg: &str) {
342 self.diagnostic().note_without_error(msg)
344 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
345 self.diagnostic().span_note_without_error(sp, msg)
348 pub fn diagnostic(&self) -> &errors::Handler {
349 &self.parse_sess.span_diagnostic
352 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
353 /// deduplicates on lint ID, span (if any), and message for this `Session`
354 fn diag_once<'a, 'b>(
356 diag_builder: &'b mut DiagnosticBuilder<'a>,
357 method: DiagnosticBuilderMethod,
358 msg_id: DiagnosticMessageId,
360 span_maybe: Option<Span>,
362 let id_span_message = (msg_id, span_maybe, message.to_owned());
363 let fresh = self.one_time_diagnostics
365 .insert(id_span_message);
368 DiagnosticBuilderMethod::Note => {
369 diag_builder.note(message);
371 DiagnosticBuilderMethod::SpanNote => {
372 let span = span_maybe.expect("`span_note` needs a span");
373 diag_builder.span_note(span, message);
375 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
376 let span = span_maybe.expect("`span_suggestion_*` needs a span");
377 diag_builder.span_suggestion(
381 Applicability::Unspecified,
388 pub fn diag_span_note_once<'a, 'b>(
390 diag_builder: &'b mut DiagnosticBuilder<'a>,
391 msg_id: DiagnosticMessageId,
397 DiagnosticBuilderMethod::SpanNote,
404 pub fn diag_note_once<'a, 'b>(
406 diag_builder: &'b mut DiagnosticBuilder<'a>,
407 msg_id: DiagnosticMessageId,
412 DiagnosticBuilderMethod::Note,
419 pub fn diag_span_suggestion_once<'a, 'b>(
421 diag_builder: &'b mut DiagnosticBuilder<'a>,
422 msg_id: DiagnosticMessageId,
429 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
436 pub fn source_map(&self) -> &source_map::SourceMap {
437 self.parse_sess.source_map()
439 pub fn verbose(&self) -> bool {
440 self.opts.debugging_opts.verbose
442 pub fn time_passes(&self) -> bool {
443 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
445 pub fn time_extended(&self) -> bool {
446 self.opts.debugging_opts.time_passes
448 pub fn instrument_mcount(&self) -> bool {
449 self.opts.debugging_opts.instrument_mcount
451 pub fn time_llvm_passes(&self) -> bool {
452 self.opts.debugging_opts.time_llvm_passes
454 pub fn meta_stats(&self) -> bool {
455 self.opts.debugging_opts.meta_stats
457 pub fn asm_comments(&self) -> bool {
458 self.opts.debugging_opts.asm_comments
460 pub fn verify_llvm_ir(&self) -> bool {
461 self.opts.debugging_opts.verify_llvm_ir
462 || cfg!(always_verify_llvm_ir)
464 pub fn borrowck_stats(&self) -> bool {
465 self.opts.debugging_opts.borrowck_stats
467 pub fn print_llvm_passes(&self) -> bool {
468 self.opts.debugging_opts.print_llvm_passes
470 pub fn binary_dep_depinfo(&self) -> bool {
471 self.opts.debugging_opts.binary_dep_depinfo
474 /// Gets the features enabled for the current compilation session.
475 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
476 /// dependency tracking. Use tcx.features() instead.
478 pub fn features_untracked(&self) -> &feature_gate::Features {
482 pub fn init_features(&self, features: feature_gate::Features) {
483 self.features.set(features);
486 /// Calculates the flavor of LTO to use for this compilation.
487 pub fn lto(&self) -> config::Lto {
488 // If our target has codegen requirements ignore the command line
489 if self.target.target.options.requires_lto {
490 return config::Lto::Fat;
493 // If the user specified something, return that. If they only said `-C
494 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
495 // then ensure we can't use a ThinLTO.
496 match self.opts.cg.lto {
497 config::LtoCli::Unspecified => {
498 // The compiler was invoked without the `-Clto` flag. Fall
499 // through to the default handling
501 config::LtoCli::No => {
502 // The user explicitly opted out of any kind of LTO
503 return config::Lto::No;
505 config::LtoCli::Yes |
506 config::LtoCli::Fat |
507 config::LtoCli::NoParam => {
508 // All of these mean fat LTO
509 return config::Lto::Fat;
511 config::LtoCli::Thin => {
512 return if self.opts.cli_forced_thinlto_off {
520 // Ok at this point the target doesn't require anything and the user
521 // hasn't asked for anything. Our next decision is whether or not
522 // we enable "auto" ThinLTO where we use multiple codegen units and
523 // then do ThinLTO over those codegen units. The logic below will
524 // either return `No` or `ThinLocal`.
526 // If processing command line options determined that we're incompatible
527 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
528 if self.opts.cli_forced_thinlto_off {
529 return config::Lto::No;
532 // If `-Z thinlto` specified process that, but note that this is mostly
533 // a deprecated option now that `-C lto=thin` exists.
534 if let Some(enabled) = self.opts.debugging_opts.thinlto {
536 return config::Lto::ThinLocal;
538 return config::Lto::No;
542 // If there's only one codegen unit and LTO isn't enabled then there's
543 // no need for ThinLTO so just return false.
544 if self.codegen_units() == 1 {
545 return config::Lto::No;
548 // Now we're in "defaults" territory. By default we enable ThinLTO for
549 // optimized compiles (anything greater than O0).
550 match self.opts.optimize {
551 config::OptLevel::No => config::Lto::No,
552 _ => config::Lto::ThinLocal,
556 /// Returns the panic strategy for this compile session. If the user explicitly selected one
557 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
558 pub fn panic_strategy(&self) -> PanicStrategy {
562 .unwrap_or(self.target.target.options.panic_strategy)
564 pub fn fewer_names(&self) -> bool {
565 let more_names = self.opts
567 .contains_key(&OutputType::LlvmAssembly)
568 || self.opts.output_types.contains_key(&OutputType::Bitcode);
570 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
571 let more_names = match self.opts.debugging_opts.sanitizer {
572 Some(Sanitizer::Address) => true,
573 Some(Sanitizer::Memory) => true,
577 self.opts.debugging_opts.fewer_names || !more_names
580 pub fn no_landing_pads(&self) -> bool {
581 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
583 pub fn unstable_options(&self) -> bool {
584 self.opts.debugging_opts.unstable_options
586 pub fn overflow_checks(&self) -> bool {
590 .or(self.opts.debugging_opts.force_overflow_checks)
591 .unwrap_or(self.opts.debug_assertions)
594 pub fn crt_static(&self) -> bool {
595 // If the target does not opt in to crt-static support, use its default.
596 if self.target.target.options.crt_static_respected {
597 self.crt_static_feature()
599 self.target.target.options.crt_static_default
603 pub fn crt_static_feature(&self) -> bool {
604 let requested_features = self.opts.cg.target_feature.split(',');
605 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
606 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
608 // If the target we're compiling for requests a static crt by default,
609 // then see if the `-crt-static` feature was passed to disable that.
610 // Otherwise if we don't have a static crt by default then see if the
611 // `+crt-static` feature was passed.
612 if self.target.target.options.crt_static_default {
619 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
620 // "mcount" function relies on stack pointer.
621 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
622 if self.instrument_mcount() {
624 } else if let Some(x) = self.opts.cg.force_frame_pointers {
627 !self.target.target.options.eliminate_frame_pointer
631 /// Returns the symbol name for the registrar function,
632 /// given the crate `Svh` and the function `DefIndex`.
633 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
635 "__rustc_plugin_registrar_{}__",
636 disambiguator.to_fingerprint().to_hex()
640 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
642 "__rustc_proc_macro_decls_{}__",
643 disambiguator.to_fingerprint().to_hex()
647 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
648 filesearch::FileSearch::new(
650 self.opts.target_triple.triple(),
651 &self.opts.search_paths,
652 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
653 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
657 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
658 filesearch::FileSearch::new(
660 config::host_triple(),
661 &self.opts.search_paths,
662 &self.host_tlib_path,
667 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
668 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
670 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
671 *load_dep_graph = load;
675 pub fn incr_session_load_dep_graph(&self) -> bool {
676 let incr_comp_session = self.incr_comp_session.borrow();
677 match *incr_comp_session {
678 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
683 pub fn init_incr_comp_session(
685 session_dir: PathBuf,
686 lock_file: flock::Lock,
687 load_dep_graph: bool,
689 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
691 if let IncrCompSession::NotInitialized = *incr_comp_session {
694 "Trying to initialize IncrCompSession `{:?}`",
699 *incr_comp_session = IncrCompSession::Active {
700 session_directory: session_dir,
706 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
707 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
709 if let IncrCompSession::Active { .. } = *incr_comp_session {
712 "trying to finalize `IncrCompSession` `{:?}`",
717 // Note: this will also drop the lock file, thus unlocking the directory.
718 *incr_comp_session = IncrCompSession::Finalized {
719 session_directory: new_directory_path,
723 pub fn mark_incr_comp_session_as_invalid(&self) {
724 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
726 let session_directory = match *incr_comp_session {
727 IncrCompSession::Active {
728 ref session_directory,
730 } => session_directory.clone(),
731 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
733 "trying to invalidate `IncrCompSession` `{:?}`",
738 // Note: this will also drop the lock file, thus unlocking the directory.
739 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
744 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
745 let incr_comp_session = self.incr_comp_session.borrow();
748 |incr_comp_session| match *incr_comp_session {
749 IncrCompSession::NotInitialized => bug!(
750 "trying to get session directory from `IncrCompSession`: {:?}",
753 IncrCompSession::Active {
754 ref session_directory,
757 | IncrCompSession::Finalized {
758 ref session_directory,
760 | IncrCompSession::InvalidBecauseOfErrors {
761 ref session_directory,
762 } => session_directory,
767 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
768 if self.opts.incremental.is_some() {
769 Some(self.incr_comp_session_dir())
775 pub fn print_perf_stats(&self) {
777 "Total time spent computing symbol hashes: {}",
778 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
781 "Total time spent decoding DefPath tables: {}",
782 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
784 println!("Total queries canonicalized: {}",
785 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
786 println!("normalize_ty_after_erasing_regions: {}",
787 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
788 println!("normalize_projection_ty: {}",
789 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
792 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
793 /// This expends fuel if applicable, and records fuel if applicable.
794 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
796 if let Some(ref c) = self.optimization_fuel_crate {
798 assert_eq!(self.threads(), 1);
799 let mut fuel = self.optimization_fuel.lock();
800 ret = fuel.remaining != 0;
801 if fuel.remaining == 0 && !fuel.out_of_fuel {
802 eprintln!("optimization-fuel-exhausted: {}", msg());
803 fuel.out_of_fuel = true;
804 } else if fuel.remaining > 0 {
809 if let Some(ref c) = self.print_fuel_crate {
811 assert_eq!(self.threads(), 1);
812 self.print_fuel.fetch_add(1, SeqCst);
818 /// Returns the number of query threads that should be used for this
820 pub fn threads(&self) -> usize {
821 self.opts.debugging_opts.threads
824 /// Returns the number of codegen units that should be used for this
826 pub fn codegen_units(&self) -> usize {
827 if let Some(n) = self.opts.cli_forced_codegen_units {
830 if let Some(n) = self.target.target.options.default_codegen_units {
834 // Why is 16 codegen units the default all the time?
836 // The main reason for enabling multiple codegen units by default is to
837 // leverage the ability for the codegen backend to do codegen and
838 // optimization in parallel. This allows us, especially for large crates, to
839 // make good use of all available resources on the machine once we've
840 // hit that stage of compilation. Large crates especially then often
841 // take a long time in codegen/optimization and this helps us amortize that
844 // Note that a high number here doesn't mean that we'll be spawning a
845 // large number of threads in parallel. The backend of rustc contains
846 // global rate limiting through the `jobserver` crate so we'll never
847 // overload the system with too much work, but rather we'll only be
848 // optimizing when we're otherwise cooperating with other instances of
851 // Rather a high number here means that we should be able to keep a lot
852 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
853 // to build we'll be guaranteed that all cpus will finish pretty closely
854 // to one another and we should make relatively optimal use of system
857 // Note that the main cost of codegen units is that it prevents LLVM
858 // from inlining across codegen units. Users in general don't have a lot
859 // of control over how codegen units are split up so it's our job in the
860 // compiler to ensure that undue performance isn't lost when using
861 // codegen units (aka we can't require everyone to slap `#[inline]` on
864 // If we're compiling at `-O0` then the number doesn't really matter too
865 // much because performance doesn't matter and inlining is ok to lose.
866 // In debug mode we just want to try to guarantee that no cpu is stuck
867 // doing work that could otherwise be farmed to others.
869 // In release mode, however (O1 and above) performance does indeed
870 // matter! To recover the loss in performance due to inlining we'll be
871 // enabling ThinLTO by default (the function for which is just below).
872 // This will ensure that we recover any inlining wins we otherwise lost
873 // through codegen unit partitioning.
877 // Ok that's a lot of words but the basic tl;dr; is that we want a high
878 // number here -- but not too high. Additionally we're "safe" to have it
879 // always at the same number at all optimization levels.
881 // As a result 16 was chosen here! Mostly because it was a power of 2
882 // and most benchmarks agreed it was roughly a local optimum. Not very
887 pub fn teach(&self, code: &DiagnosticId) -> bool {
888 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
891 pub fn rust_2015(&self) -> bool {
892 self.opts.edition == Edition::Edition2015
895 /// Are we allowed to use features from the Rust 2018 edition?
896 pub fn rust_2018(&self) -> bool {
897 self.opts.edition >= Edition::Edition2018
900 pub fn edition(&self) -> Edition {
904 /// Returns `true` if we cannot skip the PLT for shared library calls.
905 pub fn needs_plt(&self) -> bool {
906 // Check if the current target usually needs PLT to be enabled.
907 // The user can use the command line flag to override it.
908 let needs_plt = self.target.target.options.needs_plt;
910 let dbg_opts = &self.opts.debugging_opts;
912 let relro_level = dbg_opts.relro_level
913 .unwrap_or(self.target.target.options.relro_level);
915 // Only enable this optimization by default if full relro is also enabled.
916 // In this case, lazy binding was already unavailable, so nothing is lost.
917 // This also ensures `-Wl,-z,now` is supported by the linker.
918 let full_relro = RelroLevel::Full == relro_level;
920 // If user didn't explicitly forced us to use / skip the PLT,
921 // then try to skip it where possible.
922 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
926 pub fn build_session(
927 sopts: config::Options,
928 local_crate_source_file: Option<PathBuf>,
929 registry: errors::registry::Registry,
930 process_cfg_mod: ProcessCfgMod,
932 let file_path_mapping = sopts.file_path_mapping();
934 build_session_with_source_map(
936 local_crate_source_file,
938 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
939 DiagnosticOutput::Default,
946 sopts: &config::Options,
947 registry: errors::registry::Registry,
948 source_map: &Lrc<source_map::SourceMap>,
949 emitter_dest: Option<Box<dyn Write + Send>>,
950 ) -> Box<dyn Emitter + sync::Send> {
951 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
952 match (sopts.error_format, emitter_dest) {
953 (config::ErrorOutputType::HumanReadable(kind), dst) => {
954 let (short, color_config) = kind.unzip();
956 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
957 let emitter = AnnotateSnippetEmitterWriter::new(
958 Some(source_map.clone()),
960 external_macro_backtrace,
962 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
964 let emitter = match dst {
965 None => EmitterWriter::stderr(
967 Some(source_map.clone()),
969 sopts.debugging_opts.teach,
970 sopts.debugging_opts.terminal_width,
971 external_macro_backtrace,
973 Some(dst) => EmitterWriter::new(
975 Some(source_map.clone()),
977 false, // no teach messages when writing to a buffer
978 false, // no colors when writing to a buffer
979 None, // no terminal width
980 external_macro_backtrace,
983 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
986 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
992 external_macro_backtrace,
993 ).ui_testing(sopts.debugging_opts.ui_testing),
995 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1002 external_macro_backtrace,
1003 ).ui_testing(sopts.debugging_opts.ui_testing),
1008 pub enum DiagnosticOutput {
1010 Raw(Box<dyn Write + Send>)
1013 pub fn build_session_with_source_map(
1014 sopts: config::Options,
1015 local_crate_source_file: Option<PathBuf>,
1016 registry: errors::registry::Registry,
1017 source_map: Lrc<source_map::SourceMap>,
1018 diagnostics_output: DiagnosticOutput,
1019 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1020 process_cfg_mod: ProcessCfgMod,
1022 // FIXME: This is not general enough to make the warning lint completely override
1023 // normal diagnostic warnings, since the warning lint can also be denied and changed
1024 // later via the source code.
1025 let warnings_allow = sopts
1028 .filter(|&&(ref key, _)| *key == "warnings")
1029 .map(|&(_, ref level)| *level == lint::Allow)
1032 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1034 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1036 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1037 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1038 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1040 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1042 let emitter = match diagnostics_output {
1043 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1044 DiagnosticOutput::Raw(write) => {
1045 default_emitter(&sopts, registry, &source_map, Some(write))
1049 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1051 errors::HandlerFlags {
1054 report_delayed_bugs,
1055 dont_buffer_diagnostics,
1056 external_macro_backtrace,
1057 ..Default::default()
1063 local_crate_source_file,
1072 sopts: config::Options,
1073 local_crate_source_file: Option<PathBuf>,
1074 span_diagnostic: errors::Handler,
1075 source_map: Lrc<source_map::SourceMap>,
1076 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1077 process_cfg_mod: ProcessCfgMod,
1080 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1081 let directory = if let Some(ref directory) = d {
1084 std::path::Path::new(".")
1087 let profiler = SelfProfiler::new(
1089 sopts.crate_name.as_ref().map(|s| &s[..]),
1090 &sopts.debugging_opts.self_profile_events
1094 Some(Arc::new(profiler))
1097 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1104 let host_triple = TargetTriple::from_triple(config::host_triple());
1105 let host = Target::search(&host_triple).unwrap_or_else(|e|
1107 .fatal(&format!("Error loading host specification: {}", e))
1110 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1112 let parse_sess = ParseSess::with_span_handler(
1117 let sysroot = match &sopts.maybe_sysroot {
1118 Some(sysroot) => sysroot.clone(),
1119 None => filesearch::get_or_default_sysroot(),
1122 let host_triple = config::host_triple();
1123 let target_triple = sopts.target_triple.triple();
1124 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1125 let target_tlib_path = if host_triple == target_triple {
1128 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1131 let file_path_mapping = sopts.file_path_mapping();
1133 let local_crate_source_file =
1134 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1136 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1137 let optimization_fuel = Lock::new(OptimizationFuel {
1138 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1141 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1142 let print_fuel = AtomicU64::new(0);
1144 let working_dir = env::current_dir().unwrap_or_else(|e|
1145 parse_sess.span_diagnostic
1146 .fatal(&format!("Current directory is invalid: {}", e))
1149 let working_dir = file_path_mapping.map_prefix(working_dir);
1151 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1152 CguReuseTracker::new()
1154 CguReuseTracker::new_disabled()
1157 let sess = Session {
1165 local_crate_source_file,
1167 one_time_diagnostics: Default::default(),
1168 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1169 plugin_attributes: Lock::new(Vec::new()),
1170 crate_types: Once::new(),
1171 crate_disambiguator: Once::new(),
1172 features: Once::new(),
1173 recursion_limit: Once::new(),
1174 type_length_limit: Once::new(),
1175 const_eval_stack_frame_limit: 100,
1176 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1177 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1179 prof: SelfProfilerRef::new(self_profiler),
1180 perf_stats: PerfStats {
1181 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1182 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1183 queries_canonicalized: AtomicUsize::new(0),
1184 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1185 normalize_projection_ty: AtomicUsize::new(0),
1187 code_stats: Default::default(),
1188 optimization_fuel_crate,
1192 jobserver: jobserver::client(),
1193 has_global_allocator: Once::new(),
1195 trait_methods_not_found: Lock::new(Default::default()),
1196 confused_type_with_std_module: Lock::new(Default::default()),
1199 validate_commandline_args_with_session_available(&sess);
1204 // If it is useful to have a Session available already for validating a
1205 // commandline argument, you can do so here.
1206 fn validate_commandline_args_with_session_available(sess: &Session) {
1207 // Since we don't know if code in an rlib will be linked to statically or
1208 // dynamically downstream, rustc generates `__imp_` symbols that help the
1209 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1210 // these manually generated symbols confuse LLD when it tries to merge
1211 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1212 // when compiling for LLD ThinLTO. This way we can validly just not generate
1213 // the `dllimport` attributes and `__imp_` symbols in that case.
1214 if sess.opts.cg.linker_plugin_lto.enabled() &&
1215 sess.opts.cg.prefer_dynamic &&
1216 sess.target.target.options.is_like_msvc {
1217 sess.err("Linker plugin based LTO is not supported together with \
1218 `-C prefer-dynamic` when targeting MSVC");
1221 // Make sure that any given profiling data actually exists so LLVM can't
1222 // decide to silently skip PGO.
1223 if let Some(ref path) = sess.opts.cg.profile_use {
1225 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1230 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1231 // an error to combine the two for now. It always runs into an assertions
1232 // if LLVM is built with assertions, but without assertions it sometimes
1233 // does not crash and will probably generate a corrupted binary.
1234 // We should only display this error if we're actually going to run PGO.
1235 // If we're just supposed to print out some data, don't show the error (#61002).
1236 if sess.opts.cg.profile_generate.enabled() &&
1237 sess.target.target.options.is_like_msvc &&
1238 sess.panic_strategy() == PanicStrategy::Unwind &&
1239 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1240 sess.err("Profile-guided optimization does not yet work in conjunction \
1241 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1242 See https://github.com/rust-lang/rust/issues/61002 for details.");
1246 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1247 /// compiler. Together with the crate-name forms a unique global identifier for
1249 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1250 pub struct CrateDisambiguator(Fingerprint);
1252 impl CrateDisambiguator {
1253 pub fn to_fingerprint(self) -> Fingerprint {
1258 impl fmt::Display for CrateDisambiguator {
1259 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1260 let (a, b) = self.0.as_value();
1261 let as_u128 = a as u128 | ((b as u128) << 64);
1262 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1266 impl From<Fingerprint> for CrateDisambiguator {
1267 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1268 CrateDisambiguator(fingerprint)
1272 impl_stable_hash_via_hash!(CrateDisambiguator);
1274 /// Holds data on the current incremental compilation session, if there is one.
1276 pub enum IncrCompSession {
1277 /// This is the state the session will be in until the incr. comp. dir is
1280 /// This is the state during which the session directory is private and can
1283 session_directory: PathBuf,
1284 lock_file: flock::Lock,
1285 load_dep_graph: bool,
1287 /// This is the state after the session directory has been finalized. In this
1288 /// state, the contents of the directory must not be modified any more.
1289 Finalized { session_directory: PathBuf },
1290 /// This is an error state that is reached when some compilation error has
1291 /// occurred. It indicates that the contents of the session directory must
1292 /// not be used, since they might be invalid.
1293 InvalidBecauseOfErrors { session_directory: PathBuf },
1296 pub fn early_error(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_fatal(msg).emit();
1307 errors::FatalError.raise();
1310 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1311 let emitter: Box<dyn Emitter + sync::Send> = match output {
1312 config::ErrorOutputType::HumanReadable(kind) => {
1313 let (short, color_config) = kind.unzip();
1314 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1316 config::ErrorOutputType::Json { pretty, json_rendered } =>
1317 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1319 let handler = errors::Handler::with_emitter(true, None, emitter);
1320 handler.struct_warn(msg).emit();
1323 pub type CompileResult = Result<(), ErrorReported>;