1 pub use self::code_stats::{DataTypeKind, SizeKind, FieldInfo, VariantInfo};
2 use self::code_stats::CodeStats;
4 use crate::dep_graph::cgu_reuse_tracker::CguReuseTracker;
5 use rustc_data_structures::fingerprint::Fingerprint;
8 use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
9 use crate::session::search_paths::{PathKind, SearchPath};
10 use crate::util::nodemap::{FxHashMap, FxHashSet};
11 use crate::util::common::{duration_to_secs_str, ErrorReported};
13 use rustc_data_structures::base_n;
14 use rustc_data_structures::sync::{
15 self, Lrc, Lock, OneThread, Once, AtomicU64, AtomicUsize, Ordering,
19 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
20 use errors::emitter::{Emitter, EmitterWriter};
21 use errors::emitter::HumanReadableErrorType;
22 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
23 use syntax::edition::Edition;
24 use syntax::feature_gate;
25 use errors::json::JsonEmitter;
26 use syntax::source_map;
27 use syntax::sess::ParseSess;
28 use syntax_pos::{MultiSpan, Span};
30 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
31 use rustc_data_structures::flock;
32 use rustc_data_structures::jobserver;
33 use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
34 use ::jobserver::Client;
37 use std::cell::{self, RefCell};
41 use std::num::NonZeroU32;
42 use std::path::PathBuf;
43 use std::time::Duration;
51 pub struct OptimizationFuel {
52 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
54 /// We're rejecting all further optimizations.
58 /// Represents the data associated with a compilation
59 /// session for a single crate.
61 pub target: config::Config,
63 pub opts: config::Options,
64 pub host_tlib_path: SearchPath,
65 /// `None` if the host and target are the same.
66 pub target_tlib_path: Option<SearchPath>,
67 pub parse_sess: ParseSess,
69 /// The name of the root source file of the crate, in the local file system.
70 /// `None` means that there is no source file.
71 pub local_crate_source_file: Option<PathBuf>,
72 /// The directory the compiler has been executed in plus a flag indicating
73 /// if the value stored here has been affected by path remapping.
74 pub working_dir: (PathBuf, bool),
76 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
77 /// (sub)diagnostics that have been set once, but should not be set again,
78 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
79 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
80 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
81 pub crate_types: Once<Vec<config::CrateType>>,
82 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
83 /// arguments passed to the compiler. Its value together with the crate-name
84 /// forms a unique global identifier for the crate. It is used to allow
85 /// multiple crates with the same name to coexist. See the
86 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
87 pub crate_disambiguator: Once<CrateDisambiguator>,
89 features: Once<feature_gate::Features>,
91 /// The maximum recursion limit for potentially infinitely recursive
92 /// operations such as auto-dereference and monomorphization.
93 pub recursion_limit: Once<usize>,
95 /// The maximum length of types during monomorphization.
96 pub type_length_limit: Once<usize>,
98 /// The maximum number of stackframes allowed in const eval.
99 pub const_eval_stack_frame_limit: usize,
101 /// Map from imported macro spans (which consist of
102 /// the localized span for the macro body) to the
103 /// macro name and definition span in the source crate.
104 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
106 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
107 /// Used for incremental compilation tests. Will only be populated if
108 /// `-Zquery-dep-graph` is specified.
109 pub cgu_reuse_tracker: CguReuseTracker,
111 /// Used by `-Z self-profile`.
112 pub prof: SelfProfilerRef,
114 /// Some measurements that are being gathered during compilation.
115 pub perf_stats: PerfStats,
117 /// Data about code being compiled, gathered during compilation.
118 pub code_stats: CodeStats,
120 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
121 optimization_fuel_crate: Option<String>,
123 /// Tracks fuel info if `-zfuel=crate=n` is specified.
124 optimization_fuel: Lock<OptimizationFuel>,
126 // The next two are public because the driver needs to read them.
127 /// If `-zprint-fuel=crate`, `Some(crate)`.
128 pub print_fuel_crate: Option<String>,
129 /// Always set to zero and incremented so that we can print fuel expended by a crate.
130 pub print_fuel: AtomicU64,
132 /// Loaded up early on in the initialization of this `Session` to avoid
133 /// false positives about a job server in our environment.
134 pub jobserver: Client,
136 /// Metadata about the allocators for the current crate being compiled.
137 pub has_global_allocator: Once<bool>,
139 /// Cap lint level specified by a driver specifically.
140 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
142 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
143 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
145 /// Mapping from ident span to path span for paths that don't exist as written, but that
146 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
147 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
150 pub struct PerfStats {
151 /// The accumulated time spent on computing symbol hashes.
152 pub symbol_hash_time: Lock<Duration>,
153 /// The accumulated time spent decoding def path tables from metadata.
154 pub decode_def_path_tables_time: Lock<Duration>,
155 /// Total number of values canonicalized queries constructed.
156 pub queries_canonicalized: AtomicUsize,
157 /// Number of times this query is invoked.
158 pub normalize_ty_after_erasing_regions: AtomicUsize,
159 /// Number of times this query is invoked.
160 pub normalize_projection_ty: AtomicUsize,
163 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
164 enum DiagnosticBuilderMethod {
167 SpanSuggestion(String), // suggestion
168 // Add more variants as needed to support one-time diagnostics.
171 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
172 /// emitting the same message more than once.
173 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
174 pub enum DiagnosticMessageId {
175 ErrorId(u16), // EXXXX error code as integer
176 LintId(lint::LintId),
177 StabilityId(Option<NonZeroU32>), // issue number
180 impl From<&'static lint::Lint> for DiagnosticMessageId {
181 fn from(lint: &'static lint::Lint) -> Self {
182 DiagnosticMessageId::LintId(lint::LintId::of(lint))
187 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
188 *self.crate_disambiguator.get()
191 pub fn struct_span_warn<S: Into<MultiSpan>>(
195 ) -> DiagnosticBuilder<'_> {
196 self.diagnostic().struct_span_warn(sp, msg)
198 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
203 ) -> DiagnosticBuilder<'_> {
204 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
206 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
207 self.diagnostic().struct_warn(msg)
209 pub fn struct_span_err<S: Into<MultiSpan>>(
213 ) -> DiagnosticBuilder<'_> {
214 self.diagnostic().struct_span_err(sp, msg)
216 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
221 ) -> DiagnosticBuilder<'_> {
222 self.diagnostic().struct_span_err_with_code(sp, msg, code)
224 // FIXME: This method should be removed (every error should have an associated error code).
225 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
226 self.diagnostic().struct_err(msg)
228 pub fn struct_err_with_code(
232 ) -> DiagnosticBuilder<'_> {
233 self.diagnostic().struct_err_with_code(msg, code)
235 pub fn struct_span_fatal<S: Into<MultiSpan>>(
239 ) -> DiagnosticBuilder<'_> {
240 self.diagnostic().struct_span_fatal(sp, msg)
242 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
247 ) -> DiagnosticBuilder<'_> {
248 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
250 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
251 self.diagnostic().struct_fatal(msg)
254 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
255 self.diagnostic().span_fatal(sp, msg).raise()
257 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
264 .span_fatal_with_code(sp, msg, code)
267 pub fn fatal(&self, msg: &str) -> ! {
268 self.diagnostic().fatal(msg).raise()
270 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
272 self.span_warn(sp, msg);
274 self.span_err(sp, msg);
277 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
278 self.diagnostic().span_err(sp, msg)
280 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
281 self.diagnostic().span_err_with_code(sp, &msg, code)
283 pub fn err(&self, msg: &str) {
284 self.diagnostic().err(msg)
286 pub fn err_count(&self) -> usize {
287 self.diagnostic().err_count()
289 pub fn has_errors(&self) -> bool {
290 self.diagnostic().has_errors()
292 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
293 self.diagnostic().has_errors_or_delayed_span_bugs()
295 pub fn abort_if_errors(&self) {
296 self.diagnostic().abort_if_errors();
298 pub fn compile_status(&self) -> Result<(), ErrorReported> {
299 if self.has_errors() {
300 self.diagnostic().emit_stashed_diagnostics();
306 // FIXME(matthewjasper) Remove this method, it should never be needed.
307 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
311 let old_count = self.err_count();
313 let errors = self.err_count() - old_count;
320 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
321 self.diagnostic().span_warn(sp, msg)
323 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
324 self.diagnostic().span_warn_with_code(sp, msg, code)
326 pub fn warn(&self, msg: &str) {
327 self.diagnostic().warn(msg)
329 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
331 Some(sp) => self.span_warn(sp, msg),
332 None => self.warn(msg),
335 /// Delay a span_bug() call until abort_if_errors()
336 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
337 self.diagnostic().delay_span_bug(sp, msg)
339 pub fn note_without_error(&self, msg: &str) {
340 self.diagnostic().note_without_error(msg)
342 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
343 self.diagnostic().span_note_without_error(sp, msg)
346 pub fn diagnostic(&self) -> &errors::Handler {
347 &self.parse_sess.span_diagnostic
350 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
351 /// deduplicates on lint ID, span (if any), and message for this `Session`
352 fn diag_once<'a, 'b>(
354 diag_builder: &'b mut DiagnosticBuilder<'a>,
355 method: DiagnosticBuilderMethod,
356 msg_id: DiagnosticMessageId,
358 span_maybe: Option<Span>,
360 let id_span_message = (msg_id, span_maybe, message.to_owned());
361 let fresh = self.one_time_diagnostics
363 .insert(id_span_message);
366 DiagnosticBuilderMethod::Note => {
367 diag_builder.note(message);
369 DiagnosticBuilderMethod::SpanNote => {
370 let span = span_maybe.expect("`span_note` needs a span");
371 diag_builder.span_note(span, message);
373 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
374 let span = span_maybe.expect("`span_suggestion_*` needs a span");
375 diag_builder.span_suggestion(
379 Applicability::Unspecified,
386 pub fn diag_span_note_once<'a, 'b>(
388 diag_builder: &'b mut DiagnosticBuilder<'a>,
389 msg_id: DiagnosticMessageId,
395 DiagnosticBuilderMethod::SpanNote,
402 pub fn diag_note_once<'a, 'b>(
404 diag_builder: &'b mut DiagnosticBuilder<'a>,
405 msg_id: DiagnosticMessageId,
410 DiagnosticBuilderMethod::Note,
417 pub fn diag_span_suggestion_once<'a, 'b>(
419 diag_builder: &'b mut DiagnosticBuilder<'a>,
420 msg_id: DiagnosticMessageId,
427 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
434 pub fn source_map(&self) -> &source_map::SourceMap {
435 self.parse_sess.source_map()
437 pub fn verbose(&self) -> bool {
438 self.opts.debugging_opts.verbose
440 pub fn time_passes(&self) -> bool {
441 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
443 pub fn time_extended(&self) -> bool {
444 self.opts.debugging_opts.time_passes
446 pub fn instrument_mcount(&self) -> bool {
447 self.opts.debugging_opts.instrument_mcount
449 pub fn time_llvm_passes(&self) -> bool {
450 self.opts.debugging_opts.time_llvm_passes
452 pub fn meta_stats(&self) -> bool {
453 self.opts.debugging_opts.meta_stats
455 pub fn asm_comments(&self) -> bool {
456 self.opts.debugging_opts.asm_comments
458 pub fn verify_llvm_ir(&self) -> bool {
459 self.opts.debugging_opts.verify_llvm_ir
460 || cfg!(always_verify_llvm_ir)
462 pub fn borrowck_stats(&self) -> bool {
463 self.opts.debugging_opts.borrowck_stats
465 pub fn print_llvm_passes(&self) -> bool {
466 self.opts.debugging_opts.print_llvm_passes
468 pub fn binary_dep_depinfo(&self) -> bool {
469 self.opts.debugging_opts.binary_dep_depinfo
472 /// Gets the features enabled for the current compilation session.
473 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
474 /// dependency tracking. Use tcx.features() instead.
476 pub fn features_untracked(&self) -> &feature_gate::Features {
480 pub fn init_features(&self, features: feature_gate::Features) {
481 self.features.set(features);
484 /// Calculates the flavor of LTO to use for this compilation.
485 pub fn lto(&self) -> config::Lto {
486 // If our target has codegen requirements ignore the command line
487 if self.target.target.options.requires_lto {
488 return config::Lto::Fat;
491 // If the user specified something, return that. If they only said `-C
492 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
493 // then ensure we can't use a ThinLTO.
494 match self.opts.cg.lto {
495 config::LtoCli::Unspecified => {
496 // The compiler was invoked without the `-Clto` flag. Fall
497 // through to the default handling
499 config::LtoCli::No => {
500 // The user explicitly opted out of any kind of LTO
501 return config::Lto::No;
503 config::LtoCli::Yes |
504 config::LtoCli::Fat |
505 config::LtoCli::NoParam => {
506 // All of these mean fat LTO
507 return config::Lto::Fat;
509 config::LtoCli::Thin => {
510 return if self.opts.cli_forced_thinlto_off {
518 // Ok at this point the target doesn't require anything and the user
519 // hasn't asked for anything. Our next decision is whether or not
520 // we enable "auto" ThinLTO where we use multiple codegen units and
521 // then do ThinLTO over those codegen units. The logic below will
522 // either return `No` or `ThinLocal`.
524 // If processing command line options determined that we're incompatible
525 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
526 if self.opts.cli_forced_thinlto_off {
527 return config::Lto::No;
530 // If `-Z thinlto` specified process that, but note that this is mostly
531 // a deprecated option now that `-C lto=thin` exists.
532 if let Some(enabled) = self.opts.debugging_opts.thinlto {
534 return config::Lto::ThinLocal;
536 return config::Lto::No;
540 // If there's only one codegen unit and LTO isn't enabled then there's
541 // no need for ThinLTO so just return false.
542 if self.codegen_units() == 1 {
543 return config::Lto::No;
546 // Now we're in "defaults" territory. By default we enable ThinLTO for
547 // optimized compiles (anything greater than O0).
548 match self.opts.optimize {
549 config::OptLevel::No => config::Lto::No,
550 _ => config::Lto::ThinLocal,
554 /// Returns the panic strategy for this compile session. If the user explicitly selected one
555 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
556 pub fn panic_strategy(&self) -> PanicStrategy {
560 .unwrap_or(self.target.target.options.panic_strategy)
562 pub fn fewer_names(&self) -> bool {
563 let more_names = self.opts
565 .contains_key(&OutputType::LlvmAssembly)
566 || self.opts.output_types.contains_key(&OutputType::Bitcode);
568 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
569 let more_names = match self.opts.debugging_opts.sanitizer {
570 Some(Sanitizer::Address) => true,
571 Some(Sanitizer::Memory) => true,
575 self.opts.debugging_opts.fewer_names || !more_names
578 pub fn no_landing_pads(&self) -> bool {
579 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
581 pub fn unstable_options(&self) -> bool {
582 self.opts.debugging_opts.unstable_options
584 pub fn overflow_checks(&self) -> bool {
588 .or(self.opts.debugging_opts.force_overflow_checks)
589 .unwrap_or(self.opts.debug_assertions)
592 pub fn crt_static(&self) -> bool {
593 // If the target does not opt in to crt-static support, use its default.
594 if self.target.target.options.crt_static_respected {
595 self.crt_static_feature()
597 self.target.target.options.crt_static_default
601 pub fn crt_static_feature(&self) -> bool {
602 let requested_features = self.opts.cg.target_feature.split(',');
603 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
604 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
606 // If the target we're compiling for requests a static crt by default,
607 // then see if the `-crt-static` feature was passed to disable that.
608 // Otherwise if we don't have a static crt by default then see if the
609 // `+crt-static` feature was passed.
610 if self.target.target.options.crt_static_default {
617 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
618 // "mcount" function relies on stack pointer.
619 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
620 if self.instrument_mcount() {
622 } else if let Some(x) = self.opts.cg.force_frame_pointers {
625 !self.target.target.options.eliminate_frame_pointer
629 /// Returns the symbol name for the registrar function,
630 /// given the crate `Svh` and the function `DefIndex`.
631 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
633 "__rustc_plugin_registrar_{}__",
634 disambiguator.to_fingerprint().to_hex()
638 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
640 "__rustc_proc_macro_decls_{}__",
641 disambiguator.to_fingerprint().to_hex()
645 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
646 filesearch::FileSearch::new(
648 self.opts.target_triple.triple(),
649 &self.opts.search_paths,
650 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
651 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
655 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
656 filesearch::FileSearch::new(
658 config::host_triple(),
659 &self.opts.search_paths,
660 &self.host_tlib_path,
665 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
666 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
668 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
669 *load_dep_graph = load;
673 pub fn incr_session_load_dep_graph(&self) -> bool {
674 let incr_comp_session = self.incr_comp_session.borrow();
675 match *incr_comp_session {
676 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
681 pub fn init_incr_comp_session(
683 session_dir: PathBuf,
684 lock_file: flock::Lock,
685 load_dep_graph: bool,
687 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
689 if let IncrCompSession::NotInitialized = *incr_comp_session {
692 "Trying to initialize IncrCompSession `{:?}`",
697 *incr_comp_session = IncrCompSession::Active {
698 session_directory: session_dir,
704 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
705 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
707 if let IncrCompSession::Active { .. } = *incr_comp_session {
710 "trying to finalize `IncrCompSession` `{:?}`",
715 // Note: this will also drop the lock file, thus unlocking the directory.
716 *incr_comp_session = IncrCompSession::Finalized {
717 session_directory: new_directory_path,
721 pub fn mark_incr_comp_session_as_invalid(&self) {
722 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
724 let session_directory = match *incr_comp_session {
725 IncrCompSession::Active {
726 ref session_directory,
728 } => session_directory.clone(),
729 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
731 "trying to invalidate `IncrCompSession` `{:?}`",
736 // Note: this will also drop the lock file, thus unlocking the directory.
737 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
742 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
743 let incr_comp_session = self.incr_comp_session.borrow();
746 |incr_comp_session| match *incr_comp_session {
747 IncrCompSession::NotInitialized => bug!(
748 "trying to get session directory from `IncrCompSession`: {:?}",
751 IncrCompSession::Active {
752 ref session_directory,
755 | IncrCompSession::Finalized {
756 ref session_directory,
758 | IncrCompSession::InvalidBecauseOfErrors {
759 ref session_directory,
760 } => session_directory,
765 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
766 if self.opts.incremental.is_some() {
767 Some(self.incr_comp_session_dir())
773 pub fn print_perf_stats(&self) {
775 "Total time spent computing symbol hashes: {}",
776 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
779 "Total time spent decoding DefPath tables: {}",
780 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
782 println!("Total queries canonicalized: {}",
783 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
784 println!("normalize_ty_after_erasing_regions: {}",
785 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
786 println!("normalize_projection_ty: {}",
787 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
790 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
791 /// This expends fuel if applicable, and records fuel if applicable.
792 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
794 if let Some(ref c) = self.optimization_fuel_crate {
796 assert_eq!(self.threads(), 1);
797 let mut fuel = self.optimization_fuel.lock();
798 ret = fuel.remaining != 0;
799 if fuel.remaining == 0 && !fuel.out_of_fuel {
800 eprintln!("optimization-fuel-exhausted: {}", msg());
801 fuel.out_of_fuel = true;
802 } else if fuel.remaining > 0 {
807 if let Some(ref c) = self.print_fuel_crate {
809 assert_eq!(self.threads(), 1);
810 self.print_fuel.fetch_add(1, SeqCst);
816 /// Returns the number of query threads that should be used for this
818 pub fn threads(&self) -> usize {
819 self.opts.debugging_opts.threads
822 /// Returns the number of codegen units that should be used for this
824 pub fn codegen_units(&self) -> usize {
825 if let Some(n) = self.opts.cli_forced_codegen_units {
828 if let Some(n) = self.target.target.options.default_codegen_units {
832 // Why is 16 codegen units the default all the time?
834 // The main reason for enabling multiple codegen units by default is to
835 // leverage the ability for the codegen backend to do codegen and
836 // optimization in parallel. This allows us, especially for large crates, to
837 // make good use of all available resources on the machine once we've
838 // hit that stage of compilation. Large crates especially then often
839 // take a long time in codegen/optimization and this helps us amortize that
842 // Note that a high number here doesn't mean that we'll be spawning a
843 // large number of threads in parallel. The backend of rustc contains
844 // global rate limiting through the `jobserver` crate so we'll never
845 // overload the system with too much work, but rather we'll only be
846 // optimizing when we're otherwise cooperating with other instances of
849 // Rather a high number here means that we should be able to keep a lot
850 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
851 // to build we'll be guaranteed that all cpus will finish pretty closely
852 // to one another and we should make relatively optimal use of system
855 // Note that the main cost of codegen units is that it prevents LLVM
856 // from inlining across codegen units. Users in general don't have a lot
857 // of control over how codegen units are split up so it's our job in the
858 // compiler to ensure that undue performance isn't lost when using
859 // codegen units (aka we can't require everyone to slap `#[inline]` on
862 // If we're compiling at `-O0` then the number doesn't really matter too
863 // much because performance doesn't matter and inlining is ok to lose.
864 // In debug mode we just want to try to guarantee that no cpu is stuck
865 // doing work that could otherwise be farmed to others.
867 // In release mode, however (O1 and above) performance does indeed
868 // matter! To recover the loss in performance due to inlining we'll be
869 // enabling ThinLTO by default (the function for which is just below).
870 // This will ensure that we recover any inlining wins we otherwise lost
871 // through codegen unit partitioning.
875 // Ok that's a lot of words but the basic tl;dr; is that we want a high
876 // number here -- but not too high. Additionally we're "safe" to have it
877 // always at the same number at all optimization levels.
879 // As a result 16 was chosen here! Mostly because it was a power of 2
880 // and most benchmarks agreed it was roughly a local optimum. Not very
885 pub fn teach(&self, code: &DiagnosticId) -> bool {
886 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
889 pub fn rust_2015(&self) -> bool {
890 self.opts.edition == Edition::Edition2015
893 /// Are we allowed to use features from the Rust 2018 edition?
894 pub fn rust_2018(&self) -> bool {
895 self.opts.edition >= Edition::Edition2018
898 pub fn edition(&self) -> Edition {
902 /// Returns `true` if we cannot skip the PLT for shared library calls.
903 pub fn needs_plt(&self) -> bool {
904 // Check if the current target usually needs PLT to be enabled.
905 // The user can use the command line flag to override it.
906 let needs_plt = self.target.target.options.needs_plt;
908 let dbg_opts = &self.opts.debugging_opts;
910 let relro_level = dbg_opts.relro_level
911 .unwrap_or(self.target.target.options.relro_level);
913 // Only enable this optimization by default if full relro is also enabled.
914 // In this case, lazy binding was already unavailable, so nothing is lost.
915 // This also ensures `-Wl,-z,now` is supported by the linker.
916 let full_relro = RelroLevel::Full == relro_level;
918 // If user didn't explicitly forced us to use / skip the PLT,
919 // then try to skip it where possible.
920 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
924 pub fn build_session(
925 sopts: config::Options,
926 local_crate_source_file: Option<PathBuf>,
927 registry: errors::registry::Registry,
929 let file_path_mapping = sopts.file_path_mapping();
931 build_session_with_source_map(
933 local_crate_source_file,
935 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
936 DiagnosticOutput::Default,
942 sopts: &config::Options,
943 registry: errors::registry::Registry,
944 source_map: &Lrc<source_map::SourceMap>,
945 emitter_dest: Option<Box<dyn Write + Send>>,
946 ) -> Box<dyn Emitter + sync::Send> {
947 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
948 match (sopts.error_format, emitter_dest) {
949 (config::ErrorOutputType::HumanReadable(kind), dst) => {
950 let (short, color_config) = kind.unzip();
952 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
953 let emitter = AnnotateSnippetEmitterWriter::new(
954 Some(source_map.clone()),
956 external_macro_backtrace,
958 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
960 let emitter = match dst {
961 None => EmitterWriter::stderr(
963 Some(source_map.clone()),
965 sopts.debugging_opts.teach,
966 sopts.debugging_opts.terminal_width,
967 external_macro_backtrace,
969 Some(dst) => EmitterWriter::new(
971 Some(source_map.clone()),
973 false, // no teach messages when writing to a buffer
974 false, // no colors when writing to a buffer
975 None, // no terminal width
976 external_macro_backtrace,
979 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
982 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
988 external_macro_backtrace,
989 ).ui_testing(sopts.debugging_opts.ui_testing),
991 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
998 external_macro_backtrace,
999 ).ui_testing(sopts.debugging_opts.ui_testing),
1004 pub enum DiagnosticOutput {
1006 Raw(Box<dyn Write + Send>)
1009 pub fn build_session_with_source_map(
1010 sopts: config::Options,
1011 local_crate_source_file: Option<PathBuf>,
1012 registry: errors::registry::Registry,
1013 source_map: Lrc<source_map::SourceMap>,
1014 diagnostics_output: DiagnosticOutput,
1015 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1017 // FIXME: This is not general enough to make the warning lint completely override
1018 // normal diagnostic warnings, since the warning lint can also be denied and changed
1019 // later via the source code.
1020 let warnings_allow = sopts
1023 .filter(|&&(ref key, _)| *key == "warnings")
1024 .map(|&(_, ref level)| *level == lint::Allow)
1027 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1029 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1031 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1032 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1033 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1035 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1037 let write_dest = match diagnostics_output {
1038 DiagnosticOutput::Default => None,
1039 DiagnosticOutput::Raw(write) => Some(write),
1041 let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
1043 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1045 errors::HandlerFlags {
1048 report_delayed_bugs,
1049 dont_buffer_diagnostics,
1050 external_macro_backtrace,
1051 ..Default::default()
1057 local_crate_source_file,
1065 sopts: config::Options,
1066 local_crate_source_file: Option<PathBuf>,
1067 span_diagnostic: errors::Handler,
1068 source_map: Lrc<source_map::SourceMap>,
1069 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1072 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1073 let directory = if let Some(ref directory) = d {
1076 std::path::Path::new(".")
1079 let profiler = SelfProfiler::new(
1081 sopts.crate_name.as_ref().map(|s| &s[..]),
1082 &sopts.debugging_opts.self_profile_events
1086 Some(Arc::new(profiler))
1089 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1096 let host_triple = TargetTriple::from_triple(config::host_triple());
1097 let host = Target::search(&host_triple).unwrap_or_else(|e|
1099 .fatal(&format!("Error loading host specification: {}", e))
1102 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1104 let parse_sess = ParseSess::with_span_handler(
1108 let sysroot = match &sopts.maybe_sysroot {
1109 Some(sysroot) => sysroot.clone(),
1110 None => filesearch::get_or_default_sysroot(),
1113 let host_triple = config::host_triple();
1114 let target_triple = sopts.target_triple.triple();
1115 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1116 let target_tlib_path = if host_triple == target_triple {
1119 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1122 let file_path_mapping = sopts.file_path_mapping();
1124 let local_crate_source_file =
1125 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1127 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1128 let optimization_fuel = Lock::new(OptimizationFuel {
1129 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1132 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1133 let print_fuel = AtomicU64::new(0);
1135 let working_dir = env::current_dir().unwrap_or_else(|e|
1136 parse_sess.span_diagnostic
1137 .fatal(&format!("Current directory is invalid: {}", e))
1140 let working_dir = file_path_mapping.map_prefix(working_dir);
1142 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1143 CguReuseTracker::new()
1145 CguReuseTracker::new_disabled()
1148 let sess = Session {
1156 local_crate_source_file,
1158 one_time_diagnostics: Default::default(),
1159 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1160 crate_types: Once::new(),
1161 crate_disambiguator: Once::new(),
1162 features: Once::new(),
1163 recursion_limit: Once::new(),
1164 type_length_limit: Once::new(),
1165 const_eval_stack_frame_limit: 100,
1166 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1167 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1169 prof: SelfProfilerRef::new(self_profiler),
1170 perf_stats: PerfStats {
1171 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1172 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1173 queries_canonicalized: AtomicUsize::new(0),
1174 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1175 normalize_projection_ty: AtomicUsize::new(0),
1177 code_stats: Default::default(),
1178 optimization_fuel_crate,
1182 jobserver: jobserver::client(),
1183 has_global_allocator: Once::new(),
1185 trait_methods_not_found: Lock::new(Default::default()),
1186 confused_type_with_std_module: Lock::new(Default::default()),
1189 validate_commandline_args_with_session_available(&sess);
1194 // If it is useful to have a Session available already for validating a
1195 // commandline argument, you can do so here.
1196 fn validate_commandline_args_with_session_available(sess: &Session) {
1197 // Since we don't know if code in an rlib will be linked to statically or
1198 // dynamically downstream, rustc generates `__imp_` symbols that help the
1199 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1200 // these manually generated symbols confuse LLD when it tries to merge
1201 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1202 // when compiling for LLD ThinLTO. This way we can validly just not generate
1203 // the `dllimport` attributes and `__imp_` symbols in that case.
1204 if sess.opts.cg.linker_plugin_lto.enabled() &&
1205 sess.opts.cg.prefer_dynamic &&
1206 sess.target.target.options.is_like_msvc {
1207 sess.err("Linker plugin based LTO is not supported together with \
1208 `-C prefer-dynamic` when targeting MSVC");
1211 // Make sure that any given profiling data actually exists so LLVM can't
1212 // decide to silently skip PGO.
1213 if let Some(ref path) = sess.opts.cg.profile_use {
1215 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1220 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1221 // an error to combine the two for now. It always runs into an assertions
1222 // if LLVM is built with assertions, but without assertions it sometimes
1223 // does not crash and will probably generate a corrupted binary.
1224 // We should only display this error if we're actually going to run PGO.
1225 // If we're just supposed to print out some data, don't show the error (#61002).
1226 if sess.opts.cg.profile_generate.enabled() &&
1227 sess.target.target.options.is_like_msvc &&
1228 sess.panic_strategy() == PanicStrategy::Unwind &&
1229 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1230 sess.err("Profile-guided optimization does not yet work in conjunction \
1231 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1232 See https://github.com/rust-lang/rust/issues/61002 for details.");
1236 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1237 /// compiler. Together with the crate-name forms a unique global identifier for
1239 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1240 pub struct CrateDisambiguator(Fingerprint);
1242 impl CrateDisambiguator {
1243 pub fn to_fingerprint(self) -> Fingerprint {
1248 impl fmt::Display for CrateDisambiguator {
1249 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1250 let (a, b) = self.0.as_value();
1251 let as_u128 = a as u128 | ((b as u128) << 64);
1252 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1256 impl From<Fingerprint> for CrateDisambiguator {
1257 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1258 CrateDisambiguator(fingerprint)
1262 impl_stable_hash_via_hash!(CrateDisambiguator);
1264 /// Holds data on the current incremental compilation session, if there is one.
1266 pub enum IncrCompSession {
1267 /// This is the state the session will be in until the incr. comp. dir is
1270 /// This is the state during which the session directory is private and can
1273 session_directory: PathBuf,
1274 lock_file: flock::Lock,
1275 load_dep_graph: bool,
1277 /// This is the state after the session directory has been finalized. In this
1278 /// state, the contents of the directory must not be modified any more.
1279 Finalized { session_directory: PathBuf },
1280 /// This is an error state that is reached when some compilation error has
1281 /// occurred. It indicates that the contents of the session directory must
1282 /// not be used, since they might be invalid.
1283 InvalidBecauseOfErrors { session_directory: PathBuf },
1286 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1287 let emitter: Box<dyn Emitter + sync::Send> = match output {
1288 config::ErrorOutputType::HumanReadable(kind) => {
1289 let (short, color_config) = kind.unzip();
1290 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1292 config::ErrorOutputType::Json { pretty, json_rendered } =>
1293 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1295 let handler = errors::Handler::with_emitter(true, None, emitter);
1296 handler.struct_fatal(msg).emit();
1297 errors::FatalError.raise();
1300 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1301 let emitter: Box<dyn Emitter + sync::Send> = match output {
1302 config::ErrorOutputType::HumanReadable(kind) => {
1303 let (short, color_config) = kind.unzip();
1304 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1306 config::ErrorOutputType::Json { pretty, json_rendered } =>
1307 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1309 let handler = errors::Handler::with_emitter(true, None, emitter);
1310 handler.struct_warn(msg).emit();
1313 pub type CompileResult = Result<(), ErrorReported>;