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 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 plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
80 pub crate_types: Once<Vec<config::CrateType>>,
81 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
82 /// arguments passed to the compiler. Its value together with the crate-name
83 /// forms a unique global identifier for the crate. It is used to allow
84 /// multiple crates with the same name to coexist. See the
85 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
86 pub crate_disambiguator: Once<CrateDisambiguator>,
88 features: Once<rustc_feature::Features>,
90 /// The maximum recursion limit for potentially infinitely recursive
91 /// operations such as auto-dereference and monomorphization.
92 pub recursion_limit: Once<usize>,
94 /// The maximum length of types during monomorphization.
95 pub type_length_limit: Once<usize>,
97 /// The maximum number of stackframes allowed in const eval.
98 pub const_eval_stack_frame_limit: usize,
100 /// Map from imported macro spans (which consist of
101 /// the localized span for the macro body) to the
102 /// macro name and definition span in the source crate.
103 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
105 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
106 /// Used for incremental compilation tests. Will only be populated if
107 /// `-Zquery-dep-graph` is specified.
108 pub cgu_reuse_tracker: CguReuseTracker,
110 /// Used by `-Z self-profile`.
111 pub prof: SelfProfilerRef,
113 /// Some measurements that are being gathered during compilation.
114 pub perf_stats: PerfStats,
116 /// Data about code being compiled, gathered during compilation.
117 pub code_stats: CodeStats,
119 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
120 optimization_fuel_crate: Option<String>,
122 /// Tracks fuel info if `-zfuel=crate=n` is specified.
123 optimization_fuel: Lock<OptimizationFuel>,
125 // The next two are public because the driver needs to read them.
126 /// If `-zprint-fuel=crate`, `Some(crate)`.
127 pub print_fuel_crate: Option<String>,
128 /// Always set to zero and incremented so that we can print fuel expended by a crate.
129 pub print_fuel: AtomicU64,
131 /// Loaded up early on in the initialization of this `Session` to avoid
132 /// false positives about a job server in our environment.
133 pub jobserver: Client,
135 /// Metadata about the allocators for the current crate being compiled.
136 pub has_global_allocator: Once<bool>,
138 /// Cap lint level specified by a driver specifically.
139 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
141 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
142 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
144 /// Mapping from ident span to path span for paths that don't exist as written, but that
145 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
146 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
149 pub struct PerfStats {
150 /// The accumulated time spent on computing symbol hashes.
151 pub symbol_hash_time: Lock<Duration>,
152 /// The accumulated time spent decoding def path tables from metadata.
153 pub decode_def_path_tables_time: Lock<Duration>,
154 /// Total number of values canonicalized queries constructed.
155 pub queries_canonicalized: AtomicUsize,
156 /// Number of times this query is invoked.
157 pub normalize_ty_after_erasing_regions: AtomicUsize,
158 /// Number of times this query is invoked.
159 pub normalize_projection_ty: AtomicUsize,
162 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
163 enum DiagnosticBuilderMethod {
166 SpanSuggestion(String), // suggestion
167 // Add more variants as needed to support one-time diagnostics.
170 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
171 /// emitting the same message more than once.
172 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
173 pub enum DiagnosticMessageId {
174 ErrorId(u16), // EXXXX error code as integer
175 LintId(lint::LintId),
176 StabilityId(Option<NonZeroU32>), // issue number
179 impl From<&'static lint::Lint> for DiagnosticMessageId {
180 fn from(lint: &'static lint::Lint) -> Self {
181 DiagnosticMessageId::LintId(lint::LintId::of(lint))
186 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
187 *self.crate_disambiguator.get()
190 pub fn struct_span_warn<S: Into<MultiSpan>>(
194 ) -> DiagnosticBuilder<'_> {
195 self.diagnostic().struct_span_warn(sp, msg)
197 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
202 ) -> DiagnosticBuilder<'_> {
203 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
205 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
206 self.diagnostic().struct_warn(msg)
208 pub fn struct_span_err<S: Into<MultiSpan>>(
212 ) -> DiagnosticBuilder<'_> {
213 self.diagnostic().struct_span_err(sp, msg)
215 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
220 ) -> DiagnosticBuilder<'_> {
221 self.diagnostic().struct_span_err_with_code(sp, msg, code)
223 // FIXME: This method should be removed (every error should have an associated error code).
224 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
225 self.diagnostic().struct_err(msg)
227 pub fn struct_err_with_code(
231 ) -> DiagnosticBuilder<'_> {
232 self.diagnostic().struct_err_with_code(msg, code)
234 pub fn struct_span_fatal<S: Into<MultiSpan>>(
238 ) -> DiagnosticBuilder<'_> {
239 self.diagnostic().struct_span_fatal(sp, msg)
241 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
246 ) -> DiagnosticBuilder<'_> {
247 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
249 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
250 self.diagnostic().struct_fatal(msg)
253 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
254 self.diagnostic().span_fatal(sp, msg).raise()
256 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
263 .span_fatal_with_code(sp, msg, code)
266 pub fn fatal(&self, msg: &str) -> ! {
267 self.diagnostic().fatal(msg).raise()
269 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
271 self.span_warn(sp, msg);
273 self.span_err(sp, msg);
276 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
277 self.diagnostic().span_err(sp, msg)
279 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
280 self.diagnostic().span_err_with_code(sp, &msg, code)
282 pub fn err(&self, msg: &str) {
283 self.diagnostic().err(msg)
285 pub fn err_count(&self) -> usize {
286 self.diagnostic().err_count()
288 pub fn has_errors(&self) -> bool {
289 self.diagnostic().has_errors()
291 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
292 self.diagnostic().has_errors_or_delayed_span_bugs()
294 pub fn abort_if_errors(&self) {
295 self.diagnostic().abort_if_errors();
297 pub fn compile_status(&self) -> Result<(), ErrorReported> {
298 if self.has_errors() {
299 self.diagnostic().emit_stashed_diagnostics();
305 // FIXME(matthewjasper) Remove this method, it should never be needed.
306 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
310 let old_count = self.err_count();
312 let errors = self.err_count() - old_count;
319 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
320 self.diagnostic().span_warn(sp, msg)
322 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
323 self.diagnostic().span_warn_with_code(sp, msg, code)
325 pub fn warn(&self, msg: &str) {
326 self.diagnostic().warn(msg)
328 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
330 Some(sp) => self.span_warn(sp, msg),
331 None => self.warn(msg),
334 /// Delay a span_bug() call until abort_if_errors()
335 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
336 self.diagnostic().delay_span_bug(sp, msg)
338 pub fn note_without_error(&self, msg: &str) {
339 self.diagnostic().note_without_error(msg)
341 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
342 self.diagnostic().span_note_without_error(sp, msg)
345 pub fn diagnostic(&self) -> &errors::Handler {
346 &self.parse_sess.span_diagnostic
349 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
350 /// deduplicates on lint ID, span (if any), and message for this `Session`
351 fn diag_once<'a, 'b>(
353 diag_builder: &'b mut DiagnosticBuilder<'a>,
354 method: DiagnosticBuilderMethod,
355 msg_id: DiagnosticMessageId,
357 span_maybe: Option<Span>,
359 let id_span_message = (msg_id, span_maybe, message.to_owned());
360 let fresh = self.one_time_diagnostics
362 .insert(id_span_message);
365 DiagnosticBuilderMethod::Note => {
366 diag_builder.note(message);
368 DiagnosticBuilderMethod::SpanNote => {
369 let span = span_maybe.expect("`span_note` needs a span");
370 diag_builder.span_note(span, message);
372 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
373 let span = span_maybe.expect("`span_suggestion_*` needs a span");
374 diag_builder.span_suggestion(
378 Applicability::Unspecified,
385 pub fn diag_span_note_once<'a, 'b>(
387 diag_builder: &'b mut DiagnosticBuilder<'a>,
388 msg_id: DiagnosticMessageId,
394 DiagnosticBuilderMethod::SpanNote,
401 pub fn diag_note_once<'a, 'b>(
403 diag_builder: &'b mut DiagnosticBuilder<'a>,
404 msg_id: DiagnosticMessageId,
409 DiagnosticBuilderMethod::Note,
416 pub fn diag_span_suggestion_once<'a, 'b>(
418 diag_builder: &'b mut DiagnosticBuilder<'a>,
419 msg_id: DiagnosticMessageId,
426 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
433 pub fn source_map(&self) -> &source_map::SourceMap {
434 self.parse_sess.source_map()
436 pub fn verbose(&self) -> bool {
437 self.opts.debugging_opts.verbose
439 pub fn time_passes(&self) -> bool {
440 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
442 pub fn time_extended(&self) -> bool {
443 self.opts.debugging_opts.time_passes
445 pub fn instrument_mcount(&self) -> bool {
446 self.opts.debugging_opts.instrument_mcount
448 pub fn time_llvm_passes(&self) -> bool {
449 self.opts.debugging_opts.time_llvm_passes
451 pub fn meta_stats(&self) -> bool {
452 self.opts.debugging_opts.meta_stats
454 pub fn asm_comments(&self) -> bool {
455 self.opts.debugging_opts.asm_comments
457 pub fn verify_llvm_ir(&self) -> bool {
458 self.opts.debugging_opts.verify_llvm_ir
459 || cfg!(always_verify_llvm_ir)
461 pub fn borrowck_stats(&self) -> bool {
462 self.opts.debugging_opts.borrowck_stats
464 pub fn print_llvm_passes(&self) -> bool {
465 self.opts.debugging_opts.print_llvm_passes
467 pub fn binary_dep_depinfo(&self) -> bool {
468 self.opts.debugging_opts.binary_dep_depinfo
471 /// Gets the features enabled for the current compilation session.
472 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
473 /// dependency tracking. Use tcx.features() instead.
475 pub fn features_untracked(&self) -> &rustc_feature::Features {
479 pub fn init_features(&self, features: rustc_feature::Features) {
480 self.features.set(features);
483 /// Calculates the flavor of LTO to use for this compilation.
484 pub fn lto(&self) -> config::Lto {
485 // If our target has codegen requirements ignore the command line
486 if self.target.target.options.requires_lto {
487 return config::Lto::Fat;
490 // If the user specified something, return that. If they only said `-C
491 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
492 // then ensure we can't use a ThinLTO.
493 match self.opts.cg.lto {
494 config::LtoCli::Unspecified => {
495 // The compiler was invoked without the `-Clto` flag. Fall
496 // through to the default handling
498 config::LtoCli::No => {
499 // The user explicitly opted out of any kind of LTO
500 return config::Lto::No;
502 config::LtoCli::Yes |
503 config::LtoCli::Fat |
504 config::LtoCli::NoParam => {
505 // All of these mean fat LTO
506 return config::Lto::Fat;
508 config::LtoCli::Thin => {
509 return if self.opts.cli_forced_thinlto_off {
517 // Ok at this point the target doesn't require anything and the user
518 // hasn't asked for anything. Our next decision is whether or not
519 // we enable "auto" ThinLTO where we use multiple codegen units and
520 // then do ThinLTO over those codegen units. The logic below will
521 // either return `No` or `ThinLocal`.
523 // If processing command line options determined that we're incompatible
524 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
525 if self.opts.cli_forced_thinlto_off {
526 return config::Lto::No;
529 // If `-Z thinlto` specified process that, but note that this is mostly
530 // a deprecated option now that `-C lto=thin` exists.
531 if let Some(enabled) = self.opts.debugging_opts.thinlto {
533 return config::Lto::ThinLocal;
535 return config::Lto::No;
539 // If there's only one codegen unit and LTO isn't enabled then there's
540 // no need for ThinLTO so just return false.
541 if self.codegen_units() == 1 {
542 return config::Lto::No;
545 // Now we're in "defaults" territory. By default we enable ThinLTO for
546 // optimized compiles (anything greater than O0).
547 match self.opts.optimize {
548 config::OptLevel::No => config::Lto::No,
549 _ => config::Lto::ThinLocal,
553 /// Returns the panic strategy for this compile session. If the user explicitly selected one
554 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
555 pub fn panic_strategy(&self) -> PanicStrategy {
559 .unwrap_or(self.target.target.options.panic_strategy)
561 pub fn fewer_names(&self) -> bool {
562 let more_names = self.opts
564 .contains_key(&OutputType::LlvmAssembly)
565 || self.opts.output_types.contains_key(&OutputType::Bitcode);
567 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
568 let more_names = match self.opts.debugging_opts.sanitizer {
569 Some(Sanitizer::Address) => true,
570 Some(Sanitizer::Memory) => true,
574 self.opts.debugging_opts.fewer_names || !more_names
577 pub fn no_landing_pads(&self) -> bool {
578 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
580 pub fn unstable_options(&self) -> bool {
581 self.opts.debugging_opts.unstable_options
583 pub fn overflow_checks(&self) -> bool {
587 .or(self.opts.debugging_opts.force_overflow_checks)
588 .unwrap_or(self.opts.debug_assertions)
591 pub fn crt_static(&self) -> bool {
592 // If the target does not opt in to crt-static support, use its default.
593 if self.target.target.options.crt_static_respected {
594 self.crt_static_feature()
596 self.target.target.options.crt_static_default
600 pub fn crt_static_feature(&self) -> bool {
601 let requested_features = self.opts.cg.target_feature.split(',');
602 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
603 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
605 // If the target we're compiling for requests a static crt by default,
606 // then see if the `-crt-static` feature was passed to disable that.
607 // Otherwise if we don't have a static crt by default then see if the
608 // `+crt-static` feature was passed.
609 if self.target.target.options.crt_static_default {
616 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
617 // "mcount" function relies on stack pointer.
618 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
619 if self.instrument_mcount() {
621 } else if let Some(x) = self.opts.cg.force_frame_pointers {
624 !self.target.target.options.eliminate_frame_pointer
628 /// Returns the symbol name for the registrar function,
629 /// given the crate `Svh` and the function `DefIndex`.
630 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
632 "__rustc_plugin_registrar_{}__",
633 disambiguator.to_fingerprint().to_hex()
637 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
639 "__rustc_proc_macro_decls_{}__",
640 disambiguator.to_fingerprint().to_hex()
644 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
645 filesearch::FileSearch::new(
647 self.opts.target_triple.triple(),
648 &self.opts.search_paths,
649 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
650 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
654 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
655 filesearch::FileSearch::new(
657 config::host_triple(),
658 &self.opts.search_paths,
659 &self.host_tlib_path,
664 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
665 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
667 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
668 *load_dep_graph = load;
672 pub fn incr_session_load_dep_graph(&self) -> bool {
673 let incr_comp_session = self.incr_comp_session.borrow();
674 match *incr_comp_session {
675 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
680 pub fn init_incr_comp_session(
682 session_dir: PathBuf,
683 lock_file: flock::Lock,
684 load_dep_graph: bool,
686 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
688 if let IncrCompSession::NotInitialized = *incr_comp_session {
691 "Trying to initialize IncrCompSession `{:?}`",
696 *incr_comp_session = IncrCompSession::Active {
697 session_directory: session_dir,
703 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
704 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
706 if let IncrCompSession::Active { .. } = *incr_comp_session {
709 "trying to finalize `IncrCompSession` `{:?}`",
714 // Note: this will also drop the lock file, thus unlocking the directory.
715 *incr_comp_session = IncrCompSession::Finalized {
716 session_directory: new_directory_path,
720 pub fn mark_incr_comp_session_as_invalid(&self) {
721 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
723 let session_directory = match *incr_comp_session {
724 IncrCompSession::Active {
725 ref session_directory,
727 } => session_directory.clone(),
728 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
730 "trying to invalidate `IncrCompSession` `{:?}`",
735 // Note: this will also drop the lock file, thus unlocking the directory.
736 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
741 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
742 let incr_comp_session = self.incr_comp_session.borrow();
745 |incr_comp_session| match *incr_comp_session {
746 IncrCompSession::NotInitialized => bug!(
747 "trying to get session directory from `IncrCompSession`: {:?}",
750 IncrCompSession::Active {
751 ref session_directory,
754 | IncrCompSession::Finalized {
755 ref session_directory,
757 | IncrCompSession::InvalidBecauseOfErrors {
758 ref session_directory,
759 } => session_directory,
764 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
765 if self.opts.incremental.is_some() {
766 Some(self.incr_comp_session_dir())
772 pub fn print_perf_stats(&self) {
774 "Total time spent computing symbol hashes: {}",
775 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
778 "Total time spent decoding DefPath tables: {}",
779 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
781 println!("Total queries canonicalized: {}",
782 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
783 println!("normalize_ty_after_erasing_regions: {}",
784 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
785 println!("normalize_projection_ty: {}",
786 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
789 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
790 /// This expends fuel if applicable, and records fuel if applicable.
791 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
793 if let Some(ref c) = self.optimization_fuel_crate {
795 assert_eq!(self.threads(), 1);
796 let mut fuel = self.optimization_fuel.lock();
797 ret = fuel.remaining != 0;
798 if fuel.remaining == 0 && !fuel.out_of_fuel {
799 eprintln!("optimization-fuel-exhausted: {}", msg());
800 fuel.out_of_fuel = true;
801 } else if fuel.remaining > 0 {
806 if let Some(ref c) = self.print_fuel_crate {
808 assert_eq!(self.threads(), 1);
809 self.print_fuel.fetch_add(1, SeqCst);
815 /// Returns the number of query threads that should be used for this
817 pub fn threads(&self) -> usize {
818 self.opts.debugging_opts.threads
821 /// Returns the number of codegen units that should be used for this
823 pub fn codegen_units(&self) -> usize {
824 if let Some(n) = self.opts.cli_forced_codegen_units {
827 if let Some(n) = self.target.target.options.default_codegen_units {
831 // Why is 16 codegen units the default all the time?
833 // The main reason for enabling multiple codegen units by default is to
834 // leverage the ability for the codegen backend to do codegen and
835 // optimization in parallel. This allows us, especially for large crates, to
836 // make good use of all available resources on the machine once we've
837 // hit that stage of compilation. Large crates especially then often
838 // take a long time in codegen/optimization and this helps us amortize that
841 // Note that a high number here doesn't mean that we'll be spawning a
842 // large number of threads in parallel. The backend of rustc contains
843 // global rate limiting through the `jobserver` crate so we'll never
844 // overload the system with too much work, but rather we'll only be
845 // optimizing when we're otherwise cooperating with other instances of
848 // Rather a high number here means that we should be able to keep a lot
849 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
850 // to build we'll be guaranteed that all cpus will finish pretty closely
851 // to one another and we should make relatively optimal use of system
854 // Note that the main cost of codegen units is that it prevents LLVM
855 // from inlining across codegen units. Users in general don't have a lot
856 // of control over how codegen units are split up so it's our job in the
857 // compiler to ensure that undue performance isn't lost when using
858 // codegen units (aka we can't require everyone to slap `#[inline]` on
861 // If we're compiling at `-O0` then the number doesn't really matter too
862 // much because performance doesn't matter and inlining is ok to lose.
863 // In debug mode we just want to try to guarantee that no cpu is stuck
864 // doing work that could otherwise be farmed to others.
866 // In release mode, however (O1 and above) performance does indeed
867 // matter! To recover the loss in performance due to inlining we'll be
868 // enabling ThinLTO by default (the function for which is just below).
869 // This will ensure that we recover any inlining wins we otherwise lost
870 // through codegen unit partitioning.
874 // Ok that's a lot of words but the basic tl;dr; is that we want a high
875 // number here -- but not too high. Additionally we're "safe" to have it
876 // always at the same number at all optimization levels.
878 // As a result 16 was chosen here! Mostly because it was a power of 2
879 // and most benchmarks agreed it was roughly a local optimum. Not very
884 pub fn teach(&self, code: &DiagnosticId) -> bool {
885 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
888 pub fn rust_2015(&self) -> bool {
889 self.opts.edition == Edition::Edition2015
892 /// Are we allowed to use features from the Rust 2018 edition?
893 pub fn rust_2018(&self) -> bool {
894 self.opts.edition >= Edition::Edition2018
897 pub fn edition(&self) -> Edition {
901 /// Returns `true` if we cannot skip the PLT for shared library calls.
902 pub fn needs_plt(&self) -> bool {
903 // Check if the current target usually needs PLT to be enabled.
904 // The user can use the command line flag to override it.
905 let needs_plt = self.target.target.options.needs_plt;
907 let dbg_opts = &self.opts.debugging_opts;
909 let relro_level = dbg_opts.relro_level
910 .unwrap_or(self.target.target.options.relro_level);
912 // Only enable this optimization by default if full relro is also enabled.
913 // In this case, lazy binding was already unavailable, so nothing is lost.
914 // This also ensures `-Wl,-z,now` is supported by the linker.
915 let full_relro = RelroLevel::Full == relro_level;
917 // If user didn't explicitly forced us to use / skip the PLT,
918 // then try to skip it where possible.
919 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
923 pub fn build_session(
924 sopts: config::Options,
925 local_crate_source_file: Option<PathBuf>,
926 registry: errors::registry::Registry,
928 let file_path_mapping = sopts.file_path_mapping();
930 build_session_with_source_map(
932 local_crate_source_file,
934 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
935 DiagnosticOutput::Default,
941 sopts: &config::Options,
942 registry: errors::registry::Registry,
943 source_map: &Lrc<source_map::SourceMap>,
944 emitter_dest: Option<Box<dyn Write + Send>>,
945 ) -> Box<dyn Emitter + sync::Send> {
946 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
947 match (sopts.error_format, emitter_dest) {
948 (config::ErrorOutputType::HumanReadable(kind), dst) => {
949 let (short, color_config) = kind.unzip();
951 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
952 let emitter = AnnotateSnippetEmitterWriter::new(
953 Some(source_map.clone()),
955 external_macro_backtrace,
957 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
959 let emitter = match dst {
960 None => EmitterWriter::stderr(
962 Some(source_map.clone()),
964 sopts.debugging_opts.teach,
965 sopts.debugging_opts.terminal_width,
966 external_macro_backtrace,
968 Some(dst) => EmitterWriter::new(
970 Some(source_map.clone()),
972 false, // no teach messages when writing to a buffer
973 false, // no colors when writing to a buffer
974 None, // no terminal width
975 external_macro_backtrace,
978 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
981 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
987 external_macro_backtrace,
988 ).ui_testing(sopts.debugging_opts.ui_testing),
990 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
997 external_macro_backtrace,
998 ).ui_testing(sopts.debugging_opts.ui_testing),
1003 pub enum DiagnosticOutput {
1005 Raw(Box<dyn Write + Send>)
1008 pub fn build_session_with_source_map(
1009 sopts: config::Options,
1010 local_crate_source_file: Option<PathBuf>,
1011 registry: errors::registry::Registry,
1012 source_map: Lrc<source_map::SourceMap>,
1013 diagnostics_output: DiagnosticOutput,
1014 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1016 // FIXME: This is not general enough to make the warning lint completely override
1017 // normal diagnostic warnings, since the warning lint can also be denied and changed
1018 // later via the source code.
1019 let warnings_allow = sopts
1022 .filter(|&&(ref key, _)| *key == "warnings")
1023 .map(|&(_, ref level)| *level == lint::Allow)
1026 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1028 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1030 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1031 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1032 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1034 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1036 let write_dest = match diagnostics_output {
1037 DiagnosticOutput::Default => None,
1038 DiagnosticOutput::Raw(write) => Some(write),
1040 let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
1042 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1044 errors::HandlerFlags {
1047 report_delayed_bugs,
1048 dont_buffer_diagnostics,
1049 external_macro_backtrace,
1050 ..Default::default()
1056 local_crate_source_file,
1064 sopts: config::Options,
1065 local_crate_source_file: Option<PathBuf>,
1066 span_diagnostic: errors::Handler,
1067 source_map: Lrc<source_map::SourceMap>,
1068 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1071 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1072 let directory = if let Some(ref directory) = d {
1075 std::path::Path::new(".")
1078 let profiler = SelfProfiler::new(
1080 sopts.crate_name.as_ref().map(|s| &s[..]),
1081 &sopts.debugging_opts.self_profile_events
1085 Some(Arc::new(profiler))
1088 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1095 let host_triple = TargetTriple::from_triple(config::host_triple());
1096 let host = Target::search(&host_triple).unwrap_or_else(|e|
1098 .fatal(&format!("Error loading host specification: {}", e))
1101 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1103 let parse_sess = ParseSess::with_span_handler(
1107 let sysroot = match &sopts.maybe_sysroot {
1108 Some(sysroot) => sysroot.clone(),
1109 None => filesearch::get_or_default_sysroot(),
1112 let host_triple = config::host_triple();
1113 let target_triple = sopts.target_triple.triple();
1114 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1115 let target_tlib_path = if host_triple == target_triple {
1118 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1121 let file_path_mapping = sopts.file_path_mapping();
1123 let local_crate_source_file =
1124 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1126 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1127 let optimization_fuel = Lock::new(OptimizationFuel {
1128 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1131 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1132 let print_fuel = AtomicU64::new(0);
1134 let working_dir = env::current_dir().unwrap_or_else(|e|
1135 parse_sess.span_diagnostic
1136 .fatal(&format!("Current directory is invalid: {}", e))
1139 let working_dir = file_path_mapping.map_prefix(working_dir);
1141 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1142 CguReuseTracker::new()
1144 CguReuseTracker::new_disabled()
1147 let sess = Session {
1155 local_crate_source_file,
1157 one_time_diagnostics: Default::default(),
1158 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1159 crate_types: Once::new(),
1160 crate_disambiguator: Once::new(),
1161 features: Once::new(),
1162 recursion_limit: Once::new(),
1163 type_length_limit: Once::new(),
1164 const_eval_stack_frame_limit: 100,
1165 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1166 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1168 prof: SelfProfilerRef::new(self_profiler),
1169 perf_stats: PerfStats {
1170 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1171 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1172 queries_canonicalized: AtomicUsize::new(0),
1173 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1174 normalize_projection_ty: AtomicUsize::new(0),
1176 code_stats: Default::default(),
1177 optimization_fuel_crate,
1181 jobserver: jobserver::client(),
1182 has_global_allocator: Once::new(),
1184 trait_methods_not_found: Lock::new(Default::default()),
1185 confused_type_with_std_module: Lock::new(Default::default()),
1188 validate_commandline_args_with_session_available(&sess);
1193 // If it is useful to have a Session available already for validating a
1194 // commandline argument, you can do so here.
1195 fn validate_commandline_args_with_session_available(sess: &Session) {
1196 // Since we don't know if code in an rlib will be linked to statically or
1197 // dynamically downstream, rustc generates `__imp_` symbols that help the
1198 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1199 // these manually generated symbols confuse LLD when it tries to merge
1200 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1201 // when compiling for LLD ThinLTO. This way we can validly just not generate
1202 // the `dllimport` attributes and `__imp_` symbols in that case.
1203 if sess.opts.cg.linker_plugin_lto.enabled() &&
1204 sess.opts.cg.prefer_dynamic &&
1205 sess.target.target.options.is_like_msvc {
1206 sess.err("Linker plugin based LTO is not supported together with \
1207 `-C prefer-dynamic` when targeting MSVC");
1210 // Make sure that any given profiling data actually exists so LLVM can't
1211 // decide to silently skip PGO.
1212 if let Some(ref path) = sess.opts.cg.profile_use {
1214 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1219 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1220 // an error to combine the two for now. It always runs into an assertions
1221 // if LLVM is built with assertions, but without assertions it sometimes
1222 // does not crash and will probably generate a corrupted binary.
1223 // We should only display this error if we're actually going to run PGO.
1224 // If we're just supposed to print out some data, don't show the error (#61002).
1225 if sess.opts.cg.profile_generate.enabled() &&
1226 sess.target.target.options.is_like_msvc &&
1227 sess.panic_strategy() == PanicStrategy::Unwind &&
1228 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1229 sess.err("Profile-guided optimization does not yet work in conjunction \
1230 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1231 See https://github.com/rust-lang/rust/issues/61002 for details.");
1235 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1236 /// compiler. Together with the crate-name forms a unique global identifier for
1238 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1239 pub struct CrateDisambiguator(Fingerprint);
1241 impl CrateDisambiguator {
1242 pub fn to_fingerprint(self) -> Fingerprint {
1247 impl fmt::Display for CrateDisambiguator {
1248 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1249 let (a, b) = self.0.as_value();
1250 let as_u128 = a as u128 | ((b as u128) << 64);
1251 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1255 impl From<Fingerprint> for CrateDisambiguator {
1256 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1257 CrateDisambiguator(fingerprint)
1261 impl_stable_hash_via_hash!(CrateDisambiguator);
1263 /// Holds data on the current incremental compilation session, if there is one.
1265 pub enum IncrCompSession {
1266 /// This is the state the session will be in until the incr. comp. dir is
1269 /// This is the state during which the session directory is private and can
1272 session_directory: PathBuf,
1273 lock_file: flock::Lock,
1274 load_dep_graph: bool,
1276 /// This is the state after the session directory has been finalized. In this
1277 /// state, the contents of the directory must not be modified any more.
1278 Finalized { session_directory: PathBuf },
1279 /// This is an error state that is reached when some compilation error has
1280 /// occurred. It indicates that the contents of the session directory must
1281 /// not be used, since they might be invalid.
1282 InvalidBecauseOfErrors { session_directory: PathBuf },
1285 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1286 let emitter: Box<dyn Emitter + sync::Send> = match output {
1287 config::ErrorOutputType::HumanReadable(kind) => {
1288 let (short, color_config) = kind.unzip();
1289 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1291 config::ErrorOutputType::Json { pretty, json_rendered } =>
1292 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1294 let handler = errors::Handler::with_emitter(true, None, emitter);
1295 handler.struct_fatal(msg).emit();
1296 errors::FatalError.raise();
1299 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1300 let emitter: Box<dyn Emitter + sync::Send> = match output {
1301 config::ErrorOutputType::HumanReadable(kind) => {
1302 let (short, color_config) = kind.unzip();
1303 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1305 config::ErrorOutputType::Json { pretty, json_rendered } =>
1306 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1308 let handler = errors::Handler::with_emitter(true, None, emitter);
1309 handler.struct_warn(msg).emit();
1312 pub type CompileResult = Result<(), ErrorReported>;