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 crate::hir::def_id::CrateNum;
6 use rustc_data_structures::fingerprint::Fingerprint;
9 use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
10 use crate::session::search_paths::{PathKind, SearchPath};
11 use crate::util::nodemap::{FxHashMap, FxHashSet};
12 use crate::util::common::{duration_to_secs_str, ErrorReported};
14 use rustc_data_structures::base_n;
15 use rustc_data_structures::sync::{
16 self, Lrc, Lock, OneThread, Once, AtomicU64, AtomicUsize, Ordering,
20 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
21 use errors::emitter::{Emitter, EmitterWriter};
22 use errors::emitter::HumanReadableErrorType;
23 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
24 use syntax::ast::{self, NodeId};
25 use syntax::edition::Edition;
26 use syntax::expand::allocator::AllocatorKind;
27 use syntax::feature_gate::{self, AttributeType};
28 use syntax::json::JsonEmitter;
29 use syntax::source_map;
30 use syntax::sess::ParseSess;
31 use syntax::symbol::Symbol;
32 use syntax_pos::{MultiSpan, Span};
33 use crate::util::profiling::{SelfProfiler, SelfProfilerRef};
35 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
36 use rustc_data_structures::flock;
37 use rustc_data_structures::jobserver;
38 use ::jobserver::Client;
41 use std::cell::{self, Cell, RefCell};
45 use std::path::PathBuf;
46 use std::time::Duration;
54 pub struct OptimizationFuel {
55 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
57 /// We're rejecting all further optimizations.
61 /// Represents the data associated with a compilation
62 /// session for a single crate.
64 pub target: config::Config,
66 pub opts: config::Options,
67 pub host_tlib_path: SearchPath,
68 /// `None` if the host and target are the same.
69 pub target_tlib_path: Option<SearchPath>,
70 pub parse_sess: ParseSess,
72 /// The name of the root source file of the crate, in the local file system.
73 /// `None` means that there is no source file.
74 pub local_crate_source_file: Option<PathBuf>,
75 /// The directory the compiler has been executed in plus a flag indicating
76 /// if the value stored here has been affected by path remapping.
77 pub working_dir: (PathBuf, bool),
79 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
80 /// (sub)diagnostics that have been set once, but should not be set again,
81 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
82 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
83 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
84 pub plugin_attributes: Lock<Vec<(Symbol, AttributeType)>>,
85 pub crate_types: Once<Vec<config::CrateType>>,
86 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
87 /// arguments passed to the compiler. Its value together with the crate-name
88 /// forms a unique global identifier for the crate. It is used to allow
89 /// multiple crates with the same name to coexist. See the
90 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
91 pub crate_disambiguator: Once<CrateDisambiguator>,
93 features: Once<feature_gate::Features>,
95 /// The maximum recursion limit for potentially infinitely recursive
96 /// operations such as auto-dereference and monomorphization.
97 pub recursion_limit: Once<usize>,
99 /// The maximum length of types during monomorphization.
100 pub type_length_limit: Once<usize>,
102 /// The maximum number of stackframes allowed in const eval.
103 pub const_eval_stack_frame_limit: usize,
105 /// The `metadata::creader` module may inject an allocator/`panic_runtime`
106 /// dependency if it didn't already find one, and this tracks what was
108 pub allocator_kind: Once<Option<AllocatorKind>>,
109 pub injected_panic_runtime: Once<Option<CrateNum>>,
111 /// Map from imported macro spans (which consist of
112 /// the localized span for the macro body) to the
113 /// macro name and definition span in the source crate.
114 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
116 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
117 /// Used for incremental compilation tests. Will only be populated if
118 /// `-Zquery-dep-graph` is specified.
119 pub cgu_reuse_tracker: CguReuseTracker,
121 /// Used by `-Z self-profile`.
122 pub prof: SelfProfilerRef,
124 /// Some measurements that are being gathered during compilation.
125 pub perf_stats: PerfStats,
127 /// Data about code being compiled, gathered during compilation.
128 pub code_stats: Lock<CodeStats>,
130 next_node_id: OneThread<Cell<ast::NodeId>>,
132 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
133 optimization_fuel_crate: Option<String>,
135 /// Tracks fuel info if `-zfuel=crate=n` is specified.
136 optimization_fuel: Lock<OptimizationFuel>,
138 // The next two are public because the driver needs to read them.
139 /// If `-zprint-fuel=crate`, `Some(crate)`.
140 pub print_fuel_crate: Option<String>,
141 /// Always set to zero and incremented so that we can print fuel expended by a crate.
142 pub print_fuel: AtomicU64,
144 /// Loaded up early on in the initialization of this `Session` to avoid
145 /// false positives about a job server in our environment.
146 pub jobserver: Client,
148 /// Metadata about the allocators for the current crate being compiled.
149 pub has_global_allocator: Once<bool>,
151 /// Metadata about the panic handlers for the current crate being compiled.
152 pub has_panic_handler: Once<bool>,
154 /// Cap lint level specified by a driver specifically.
155 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
157 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
158 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
160 /// Mapping from ident span to path span for paths that don't exist as written, but that
161 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
162 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
165 pub struct PerfStats {
166 /// The accumulated time spent on computing symbol hashes.
167 pub symbol_hash_time: Lock<Duration>,
168 /// The accumulated time spent decoding def path tables from metadata.
169 pub decode_def_path_tables_time: Lock<Duration>,
170 /// Total number of values canonicalized queries constructed.
171 pub queries_canonicalized: AtomicUsize,
172 /// Number of times this query is invoked.
173 pub normalize_ty_after_erasing_regions: AtomicUsize,
174 /// Number of times this query is invoked.
175 pub normalize_projection_ty: AtomicUsize,
178 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
179 enum DiagnosticBuilderMethod {
182 SpanSuggestion(String), // suggestion
183 // Add more variants as needed to support one-time diagnostics.
186 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
187 /// emitting the same message more than once.
188 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
189 pub enum DiagnosticMessageId {
190 ErrorId(u16), // EXXXX error code as integer
191 LintId(lint::LintId),
192 StabilityId(u32), // issue number
195 impl From<&'static lint::Lint> for DiagnosticMessageId {
196 fn from(lint: &'static lint::Lint) -> Self {
197 DiagnosticMessageId::LintId(lint::LintId::of(lint))
202 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
203 *self.crate_disambiguator.get()
206 pub fn struct_span_warn<S: Into<MultiSpan>>(
210 ) -> DiagnosticBuilder<'_> {
211 self.diagnostic().struct_span_warn(sp, msg)
213 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
218 ) -> DiagnosticBuilder<'_> {
219 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
221 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
222 self.diagnostic().struct_warn(msg)
224 pub fn struct_span_err<S: Into<MultiSpan>>(
228 ) -> DiagnosticBuilder<'_> {
229 self.diagnostic().struct_span_err(sp, msg)
231 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
236 ) -> DiagnosticBuilder<'_> {
237 self.diagnostic().struct_span_err_with_code(sp, msg, code)
239 // FIXME: This method should be removed (every error should have an associated error code).
240 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
241 self.diagnostic().struct_err(msg)
243 pub fn struct_err_with_code(
247 ) -> DiagnosticBuilder<'_> {
248 self.diagnostic().struct_err_with_code(msg, code)
250 pub fn struct_span_fatal<S: Into<MultiSpan>>(
254 ) -> DiagnosticBuilder<'_> {
255 self.diagnostic().struct_span_fatal(sp, msg)
257 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
262 ) -> DiagnosticBuilder<'_> {
263 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
265 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
266 self.diagnostic().struct_fatal(msg)
269 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
270 self.diagnostic().span_fatal(sp, msg).raise()
272 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
279 .span_fatal_with_code(sp, msg, code)
282 pub fn fatal(&self, msg: &str) -> ! {
283 self.diagnostic().fatal(msg).raise()
285 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
287 self.span_warn(sp, msg);
289 self.span_err(sp, msg);
292 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
293 self.diagnostic().span_err(sp, msg)
295 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
296 self.diagnostic().span_err_with_code(sp, &msg, code)
298 pub fn err(&self, msg: &str) {
299 self.diagnostic().err(msg)
301 pub fn err_count(&self) -> usize {
302 self.diagnostic().err_count()
304 pub fn has_errors(&self) -> bool {
305 self.diagnostic().has_errors()
307 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
308 self.diagnostic().has_errors_or_delayed_span_bugs()
310 pub fn abort_if_errors(&self) {
311 self.diagnostic().abort_if_errors();
313 pub fn compile_status(&self) -> Result<(), ErrorReported> {
314 if self.has_errors() {
315 self.diagnostic().emit_stashed_diagnostics();
321 // FIXME(matthewjasper) Remove this method, it should never be needed.
322 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
326 let old_count = self.err_count();
328 let errors = self.err_count() - old_count;
335 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
336 self.diagnostic().span_warn(sp, msg)
338 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
339 self.diagnostic().span_warn_with_code(sp, msg, code)
341 pub fn warn(&self, msg: &str) {
342 self.diagnostic().warn(msg)
344 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
346 Some(sp) => self.span_warn(sp, msg),
347 None => self.warn(msg),
350 /// Delay a span_bug() call until abort_if_errors()
351 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
352 self.diagnostic().delay_span_bug(sp, msg)
354 pub fn note_without_error(&self, msg: &str) {
355 self.diagnostic().note_without_error(msg)
357 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
358 self.diagnostic().span_note_without_error(sp, msg)
361 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
362 let id = self.next_node_id.get();
364 match id.as_usize().checked_add(count) {
366 self.next_node_id.set(ast::NodeId::from_usize(next));
368 None => bug!("input too large; ran out of node-IDs!"),
373 pub fn next_node_id(&self) -> NodeId {
374 self.reserve_node_ids(1)
376 pub fn diagnostic(&self) -> &errors::Handler {
377 &self.parse_sess.span_diagnostic
380 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
381 /// deduplicates on lint ID, span (if any), and message for this `Session`
382 fn diag_once<'a, 'b>(
384 diag_builder: &'b mut DiagnosticBuilder<'a>,
385 method: DiagnosticBuilderMethod,
386 msg_id: DiagnosticMessageId,
388 span_maybe: Option<Span>,
390 let id_span_message = (msg_id, span_maybe, message.to_owned());
391 let fresh = self.one_time_diagnostics
393 .insert(id_span_message);
396 DiagnosticBuilderMethod::Note => {
397 diag_builder.note(message);
399 DiagnosticBuilderMethod::SpanNote => {
400 let span = span_maybe.expect("`span_note` needs a span");
401 diag_builder.span_note(span, message);
403 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
404 let span = span_maybe.expect("`span_suggestion_*` needs a span");
405 diag_builder.span_suggestion(
409 Applicability::Unspecified,
416 pub fn diag_span_note_once<'a, 'b>(
418 diag_builder: &'b mut DiagnosticBuilder<'a>,
419 msg_id: DiagnosticMessageId,
425 DiagnosticBuilderMethod::SpanNote,
432 pub fn diag_note_once<'a, 'b>(
434 diag_builder: &'b mut DiagnosticBuilder<'a>,
435 msg_id: DiagnosticMessageId,
440 DiagnosticBuilderMethod::Note,
447 pub fn diag_span_suggestion_once<'a, 'b>(
449 diag_builder: &'b mut DiagnosticBuilder<'a>,
450 msg_id: DiagnosticMessageId,
457 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
464 pub fn source_map(&self) -> &source_map::SourceMap {
465 self.parse_sess.source_map()
467 pub fn verbose(&self) -> bool {
468 self.opts.debugging_opts.verbose
470 pub fn time_passes(&self) -> bool {
471 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
473 pub fn time_extended(&self) -> bool {
474 self.opts.debugging_opts.time_passes
476 pub fn instrument_mcount(&self) -> bool {
477 self.opts.debugging_opts.instrument_mcount
479 pub fn time_llvm_passes(&self) -> bool {
480 self.opts.debugging_opts.time_llvm_passes
482 pub fn meta_stats(&self) -> bool {
483 self.opts.debugging_opts.meta_stats
485 pub fn asm_comments(&self) -> bool {
486 self.opts.debugging_opts.asm_comments
488 pub fn verify_llvm_ir(&self) -> bool {
489 self.opts.debugging_opts.verify_llvm_ir
490 || cfg!(always_verify_llvm_ir)
492 pub fn borrowck_stats(&self) -> bool {
493 self.opts.debugging_opts.borrowck_stats
495 pub fn print_llvm_passes(&self) -> bool {
496 self.opts.debugging_opts.print_llvm_passes
498 pub fn binary_dep_depinfo(&self) -> bool {
499 self.opts.debugging_opts.binary_dep_depinfo
502 /// Gets the features enabled for the current compilation session.
503 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
504 /// dependency tracking. Use tcx.features() instead.
506 pub fn features_untracked(&self) -> &feature_gate::Features {
510 pub fn init_features(&self, features: feature_gate::Features) {
511 self.features.set(features);
514 /// Calculates the flavor of LTO to use for this compilation.
515 pub fn lto(&self) -> config::Lto {
516 // If our target has codegen requirements ignore the command line
517 if self.target.target.options.requires_lto {
518 return config::Lto::Fat;
521 // If the user specified something, return that. If they only said `-C
522 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
523 // then ensure we can't use a ThinLTO.
524 match self.opts.cg.lto {
525 config::LtoCli::Unspecified => {
526 // The compiler was invoked without the `-Clto` flag. Fall
527 // through to the default handling
529 config::LtoCli::No => {
530 // The user explicitly opted out of any kind of LTO
531 return config::Lto::No;
533 config::LtoCli::Yes |
534 config::LtoCli::Fat |
535 config::LtoCli::NoParam => {
536 // All of these mean fat LTO
537 return config::Lto::Fat;
539 config::LtoCli::Thin => {
540 return if self.opts.cli_forced_thinlto_off {
548 // Ok at this point the target doesn't require anything and the user
549 // hasn't asked for anything. Our next decision is whether or not
550 // we enable "auto" ThinLTO where we use multiple codegen units and
551 // then do ThinLTO over those codegen units. The logic below will
552 // either return `No` or `ThinLocal`.
554 // If processing command line options determined that we're incompatible
555 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
556 if self.opts.cli_forced_thinlto_off {
557 return config::Lto::No;
560 // If `-Z thinlto` specified process that, but note that this is mostly
561 // a deprecated option now that `-C lto=thin` exists.
562 if let Some(enabled) = self.opts.debugging_opts.thinlto {
564 return config::Lto::ThinLocal;
566 return config::Lto::No;
570 // If there's only one codegen unit and LTO isn't enabled then there's
571 // no need for ThinLTO so just return false.
572 if self.codegen_units() == 1 {
573 return config::Lto::No;
576 // Now we're in "defaults" territory. By default we enable ThinLTO for
577 // optimized compiles (anything greater than O0).
578 match self.opts.optimize {
579 config::OptLevel::No => config::Lto::No,
580 _ => config::Lto::ThinLocal,
584 /// Returns the panic strategy for this compile session. If the user explicitly selected one
585 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
586 pub fn panic_strategy(&self) -> PanicStrategy {
590 .unwrap_or(self.target.target.options.panic_strategy)
592 pub fn fewer_names(&self) -> bool {
593 let more_names = self.opts
595 .contains_key(&OutputType::LlvmAssembly)
596 || self.opts.output_types.contains_key(&OutputType::Bitcode);
598 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
599 let more_names = match self.opts.debugging_opts.sanitizer {
600 Some(Sanitizer::Address) => true,
601 Some(Sanitizer::Memory) => true,
605 self.opts.debugging_opts.fewer_names || !more_names
608 pub fn no_landing_pads(&self) -> bool {
609 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
611 pub fn unstable_options(&self) -> bool {
612 self.opts.debugging_opts.unstable_options
614 pub fn overflow_checks(&self) -> bool {
618 .or(self.opts.debugging_opts.force_overflow_checks)
619 .unwrap_or(self.opts.debug_assertions)
622 pub fn crt_static(&self) -> bool {
623 // If the target does not opt in to crt-static support, use its default.
624 if self.target.target.options.crt_static_respected {
625 self.crt_static_feature()
627 self.target.target.options.crt_static_default
631 pub fn crt_static_feature(&self) -> bool {
632 let requested_features = self.opts.cg.target_feature.split(',');
633 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
634 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
636 // If the target we're compiling for requests a static crt by default,
637 // then see if the `-crt-static` feature was passed to disable that.
638 // Otherwise if we don't have a static crt by default then see if the
639 // `+crt-static` feature was passed.
640 if self.target.target.options.crt_static_default {
647 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
648 // "mcount" function relies on stack pointer.
649 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
650 if self.instrument_mcount() {
652 } else if let Some(x) = self.opts.cg.force_frame_pointers {
655 !self.target.target.options.eliminate_frame_pointer
659 /// Returns the symbol name for the registrar function,
660 /// given the crate `Svh` and the function `DefIndex`.
661 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
663 "__rustc_plugin_registrar_{}__",
664 disambiguator.to_fingerprint().to_hex()
668 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
670 "__rustc_proc_macro_decls_{}__",
671 disambiguator.to_fingerprint().to_hex()
675 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
676 filesearch::FileSearch::new(
678 self.opts.target_triple.triple(),
679 &self.opts.search_paths,
680 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
681 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
685 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
686 filesearch::FileSearch::new(
688 config::host_triple(),
689 &self.opts.search_paths,
690 &self.host_tlib_path,
695 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
696 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
698 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
699 *load_dep_graph = load;
703 pub fn incr_session_load_dep_graph(&self) -> bool {
704 let incr_comp_session = self.incr_comp_session.borrow();
705 match *incr_comp_session {
706 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
711 pub fn init_incr_comp_session(
713 session_dir: PathBuf,
714 lock_file: flock::Lock,
715 load_dep_graph: bool,
717 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
719 if let IncrCompSession::NotInitialized = *incr_comp_session {
722 "Trying to initialize IncrCompSession `{:?}`",
727 *incr_comp_session = IncrCompSession::Active {
728 session_directory: session_dir,
734 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
735 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
737 if let IncrCompSession::Active { .. } = *incr_comp_session {
740 "trying to finalize `IncrCompSession` `{:?}`",
745 // Note: this will also drop the lock file, thus unlocking the directory.
746 *incr_comp_session = IncrCompSession::Finalized {
747 session_directory: new_directory_path,
751 pub fn mark_incr_comp_session_as_invalid(&self) {
752 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
754 let session_directory = match *incr_comp_session {
755 IncrCompSession::Active {
756 ref session_directory,
758 } => session_directory.clone(),
759 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
761 "trying to invalidate `IncrCompSession` `{:?}`",
766 // Note: this will also drop the lock file, thus unlocking the directory.
767 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
772 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
773 let incr_comp_session = self.incr_comp_session.borrow();
776 |incr_comp_session| match *incr_comp_session {
777 IncrCompSession::NotInitialized => bug!(
778 "trying to get session directory from `IncrCompSession`: {:?}",
781 IncrCompSession::Active {
782 ref session_directory,
785 | IncrCompSession::Finalized {
786 ref session_directory,
788 | IncrCompSession::InvalidBecauseOfErrors {
789 ref session_directory,
790 } => session_directory,
795 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
796 if self.opts.incremental.is_some() {
797 Some(self.incr_comp_session_dir())
803 pub fn print_perf_stats(&self) {
805 "Total time spent computing symbol hashes: {}",
806 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
809 "Total time spent decoding DefPath tables: {}",
810 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
812 println!("Total queries canonicalized: {}",
813 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
814 println!("normalize_ty_after_erasing_regions: {}",
815 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
816 println!("normalize_projection_ty: {}",
817 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
820 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
821 /// This expends fuel if applicable, and records fuel if applicable.
822 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
824 if let Some(ref c) = self.optimization_fuel_crate {
826 assert_eq!(self.threads(), 1);
827 let mut fuel = self.optimization_fuel.lock();
828 ret = fuel.remaining != 0;
829 if fuel.remaining == 0 && !fuel.out_of_fuel {
830 eprintln!("optimization-fuel-exhausted: {}", msg());
831 fuel.out_of_fuel = true;
832 } else if fuel.remaining > 0 {
837 if let Some(ref c) = self.print_fuel_crate {
839 assert_eq!(self.threads(), 1);
840 self.print_fuel.fetch_add(1, SeqCst);
846 /// Returns the number of query threads that should be used for this
848 pub fn threads(&self) -> usize {
849 self.opts.debugging_opts.threads
852 /// Returns the number of codegen units that should be used for this
854 pub fn codegen_units(&self) -> usize {
855 if let Some(n) = self.opts.cli_forced_codegen_units {
858 if let Some(n) = self.target.target.options.default_codegen_units {
862 // Why is 16 codegen units the default all the time?
864 // The main reason for enabling multiple codegen units by default is to
865 // leverage the ability for the codegen backend to do codegen and
866 // optimization in parallel. This allows us, especially for large crates, to
867 // make good use of all available resources on the machine once we've
868 // hit that stage of compilation. Large crates especially then often
869 // take a long time in codegen/optimization and this helps us amortize that
872 // Note that a high number here doesn't mean that we'll be spawning a
873 // large number of threads in parallel. The backend of rustc contains
874 // global rate limiting through the `jobserver` crate so we'll never
875 // overload the system with too much work, but rather we'll only be
876 // optimizing when we're otherwise cooperating with other instances of
879 // Rather a high number here means that we should be able to keep a lot
880 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
881 // to build we'll be guaranteed that all cpus will finish pretty closely
882 // to one another and we should make relatively optimal use of system
885 // Note that the main cost of codegen units is that it prevents LLVM
886 // from inlining across codegen units. Users in general don't have a lot
887 // of control over how codegen units are split up so it's our job in the
888 // compiler to ensure that undue performance isn't lost when using
889 // codegen units (aka we can't require everyone to slap `#[inline]` on
892 // If we're compiling at `-O0` then the number doesn't really matter too
893 // much because performance doesn't matter and inlining is ok to lose.
894 // In debug mode we just want to try to guarantee that no cpu is stuck
895 // doing work that could otherwise be farmed to others.
897 // In release mode, however (O1 and above) performance does indeed
898 // matter! To recover the loss in performance due to inlining we'll be
899 // enabling ThinLTO by default (the function for which is just below).
900 // This will ensure that we recover any inlining wins we otherwise lost
901 // through codegen unit partitioning.
905 // Ok that's a lot of words but the basic tl;dr; is that we want a high
906 // number here -- but not too high. Additionally we're "safe" to have it
907 // always at the same number at all optimization levels.
909 // As a result 16 was chosen here! Mostly because it was a power of 2
910 // and most benchmarks agreed it was roughly a local optimum. Not very
915 pub fn teach(&self, code: &DiagnosticId) -> bool {
916 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
919 pub fn rust_2015(&self) -> bool {
920 self.opts.edition == Edition::Edition2015
923 /// Are we allowed to use features from the Rust 2018 edition?
924 pub fn rust_2018(&self) -> bool {
925 self.opts.edition >= Edition::Edition2018
928 pub fn edition(&self) -> Edition {
932 /// Returns `true` if we cannot skip the PLT for shared library calls.
933 pub fn needs_plt(&self) -> bool {
934 // Check if the current target usually needs PLT to be enabled.
935 // The user can use the command line flag to override it.
936 let needs_plt = self.target.target.options.needs_plt;
938 let dbg_opts = &self.opts.debugging_opts;
940 let relro_level = dbg_opts.relro_level
941 .unwrap_or(self.target.target.options.relro_level);
943 // Only enable this optimization by default if full relro is also enabled.
944 // In this case, lazy binding was already unavailable, so nothing is lost.
945 // This also ensures `-Wl,-z,now` is supported by the linker.
946 let full_relro = RelroLevel::Full == relro_level;
948 // If user didn't explicitly forced us to use / skip the PLT,
949 // then try to skip it where possible.
950 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
954 pub fn build_session(
955 sopts: config::Options,
956 local_crate_source_file: Option<PathBuf>,
957 registry: errors::registry::Registry,
959 let file_path_mapping = sopts.file_path_mapping();
961 build_session_with_source_map(
963 local_crate_source_file,
965 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
966 DiagnosticOutput::Default,
972 sopts: &config::Options,
973 registry: errors::registry::Registry,
974 source_map: &Lrc<source_map::SourceMap>,
975 emitter_dest: Option<Box<dyn Write + Send>>,
976 ) -> Box<dyn Emitter + sync::Send> {
977 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
978 match (sopts.error_format, emitter_dest) {
979 (config::ErrorOutputType::HumanReadable(kind), dst) => {
980 let (short, color_config) = kind.unzip();
982 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
983 let emitter = AnnotateSnippetEmitterWriter::new(
984 Some(source_map.clone()),
986 external_macro_backtrace,
988 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
990 let emitter = match dst {
991 None => EmitterWriter::stderr(
993 Some(source_map.clone()),
995 sopts.debugging_opts.teach,
996 sopts.debugging_opts.terminal_width,
997 external_macro_backtrace,
999 Some(dst) => EmitterWriter::new(
1001 Some(source_map.clone()),
1003 false, // no teach messages when writing to a buffer
1004 false, // no colors when writing to a buffer
1005 None, // no terminal width
1006 external_macro_backtrace,
1009 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1012 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1013 JsonEmitter::stderr(
1018 external_macro_backtrace,
1019 ).ui_testing(sopts.debugging_opts.ui_testing),
1021 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1028 external_macro_backtrace,
1029 ).ui_testing(sopts.debugging_opts.ui_testing),
1034 pub enum DiagnosticOutput {
1036 Raw(Box<dyn Write + Send>)
1039 pub fn build_session_with_source_map(
1040 sopts: config::Options,
1041 local_crate_source_file: Option<PathBuf>,
1042 registry: errors::registry::Registry,
1043 source_map: Lrc<source_map::SourceMap>,
1044 diagnostics_output: DiagnosticOutput,
1045 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1047 // FIXME: This is not general enough to make the warning lint completely override
1048 // normal diagnostic warnings, since the warning lint can also be denied and changed
1049 // later via the source code.
1050 let warnings_allow = sopts
1053 .filter(|&&(ref key, _)| *key == "warnings")
1054 .map(|&(_, ref level)| *level == lint::Allow)
1057 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1059 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1061 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1062 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1063 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1065 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1067 let emitter = match diagnostics_output {
1068 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1069 DiagnosticOutput::Raw(write) => {
1070 default_emitter(&sopts, registry, &source_map, Some(write))
1074 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1076 errors::HandlerFlags {
1079 report_delayed_bugs,
1080 dont_buffer_diagnostics,
1081 external_macro_backtrace,
1082 ..Default::default()
1086 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1090 sopts: config::Options,
1091 local_crate_source_file: Option<PathBuf>,
1092 span_diagnostic: errors::Handler,
1093 source_map: Lrc<source_map::SourceMap>,
1094 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1097 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1098 let directory = if let Some(ref directory) = d {
1101 std::path::Path::new(".")
1104 let profiler = SelfProfiler::new(
1106 sopts.crate_name.as_ref().map(|s| &s[..]),
1107 &sopts.debugging_opts.self_profile_events
1111 crate::ty::query::QueryName::register_with_profiler(&profiler);
1112 Some(Arc::new(profiler))
1115 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1122 let host_triple = TargetTriple::from_triple(config::host_triple());
1123 let host = Target::search(&host_triple).unwrap_or_else(|e|
1125 .fatal(&format!("Error loading host specification: {}", e))
1128 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1130 let parse_sess = ParseSess::with_span_handler(
1134 let sysroot = match &sopts.maybe_sysroot {
1135 Some(sysroot) => sysroot.clone(),
1136 None => filesearch::get_or_default_sysroot(),
1139 let host_triple = config::host_triple();
1140 let target_triple = sopts.target_triple.triple();
1141 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1142 let target_tlib_path = if host_triple == target_triple {
1145 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1148 let file_path_mapping = sopts.file_path_mapping();
1150 let local_crate_source_file =
1151 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1153 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1154 let optimization_fuel = Lock::new(OptimizationFuel {
1155 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1158 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1159 let print_fuel = AtomicU64::new(0);
1161 let working_dir = env::current_dir().unwrap_or_else(|e|
1162 parse_sess.span_diagnostic
1163 .fatal(&format!("Current directory is invalid: {}", e))
1166 let working_dir = file_path_mapping.map_prefix(working_dir);
1168 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1169 CguReuseTracker::new()
1171 CguReuseTracker::new_disabled()
1174 let sess = Session {
1182 local_crate_source_file,
1184 one_time_diagnostics: Default::default(),
1185 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1186 plugin_attributes: Lock::new(Vec::new()),
1187 crate_types: Once::new(),
1188 crate_disambiguator: Once::new(),
1189 features: Once::new(),
1190 recursion_limit: Once::new(),
1191 type_length_limit: Once::new(),
1192 const_eval_stack_frame_limit: 100,
1193 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1194 allocator_kind: Once::new(),
1195 injected_panic_runtime: Once::new(),
1196 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1197 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1199 prof: SelfProfilerRef::new(self_profiler),
1200 perf_stats: PerfStats {
1201 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1202 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1203 queries_canonicalized: AtomicUsize::new(0),
1204 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1205 normalize_projection_ty: AtomicUsize::new(0),
1207 code_stats: Default::default(),
1208 optimization_fuel_crate,
1212 jobserver: jobserver::client(),
1213 has_global_allocator: Once::new(),
1214 has_panic_handler: Once::new(),
1216 trait_methods_not_found: Lock::new(Default::default()),
1217 confused_type_with_std_module: Lock::new(Default::default()),
1220 validate_commandline_args_with_session_available(&sess);
1225 // If it is useful to have a Session available already for validating a
1226 // commandline argument, you can do so here.
1227 fn validate_commandline_args_with_session_available(sess: &Session) {
1228 // Since we don't know if code in an rlib will be linked to statically or
1229 // dynamically downstream, rustc generates `__imp_` symbols that help the
1230 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1231 // these manually generated symbols confuse LLD when it tries to merge
1232 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1233 // when compiling for LLD ThinLTO. This way we can validly just not generate
1234 // the `dllimport` attributes and `__imp_` symbols in that case.
1235 if sess.opts.cg.linker_plugin_lto.enabled() &&
1236 sess.opts.cg.prefer_dynamic &&
1237 sess.target.target.options.is_like_msvc {
1238 sess.err("Linker plugin based LTO is not supported together with \
1239 `-C prefer-dynamic` when targeting MSVC");
1242 // Make sure that any given profiling data actually exists so LLVM can't
1243 // decide to silently skip PGO.
1244 if let Some(ref path) = sess.opts.cg.profile_use {
1246 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1251 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1252 // an error to combine the two for now. It always runs into an assertions
1253 // if LLVM is built with assertions, but without assertions it sometimes
1254 // does not crash and will probably generate a corrupted binary.
1255 // We should only display this error if we're actually going to run PGO.
1256 // If we're just supposed to print out some data, don't show the error (#61002).
1257 if sess.opts.cg.profile_generate.enabled() &&
1258 sess.target.target.options.is_like_msvc &&
1259 sess.panic_strategy() == PanicStrategy::Unwind &&
1260 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1261 sess.err("Profile-guided optimization does not yet work in conjunction \
1262 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1263 See https://github.com/rust-lang/rust/issues/61002 for details.");
1267 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1268 /// compiler. Together with the crate-name forms a unique global identifier for
1270 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1271 pub struct CrateDisambiguator(Fingerprint);
1273 impl CrateDisambiguator {
1274 pub fn to_fingerprint(self) -> Fingerprint {
1279 impl fmt::Display for CrateDisambiguator {
1280 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1281 let (a, b) = self.0.as_value();
1282 let as_u128 = a as u128 | ((b as u128) << 64);
1283 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1287 impl From<Fingerprint> for CrateDisambiguator {
1288 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1289 CrateDisambiguator(fingerprint)
1293 impl_stable_hash_via_hash!(CrateDisambiguator);
1295 /// Holds data on the current incremental compilation session, if there is one.
1297 pub enum IncrCompSession {
1298 /// This is the state the session will be in until the incr. comp. dir is
1301 /// This is the state during which the session directory is private and can
1304 session_directory: PathBuf,
1305 lock_file: flock::Lock,
1306 load_dep_graph: bool,
1308 /// This is the state after the session directory has been finalized. In this
1309 /// state, the contents of the directory must not be modified any more.
1310 Finalized { session_directory: PathBuf },
1311 /// This is an error state that is reached when some compilation error has
1312 /// occurred. It indicates that the contents of the session directory must
1313 /// not be used, since they might be invalid.
1314 InvalidBecauseOfErrors { session_directory: PathBuf },
1317 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1318 let emitter: Box<dyn Emitter + sync::Send> = match output {
1319 config::ErrorOutputType::HumanReadable(kind) => {
1320 let (short, color_config) = kind.unzip();
1321 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1323 config::ErrorOutputType::Json { pretty, json_rendered } =>
1324 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1326 let handler = errors::Handler::with_emitter(true, None, emitter);
1327 handler.struct_fatal(msg).emit();
1328 errors::FatalError.raise();
1331 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1332 let emitter: Box<dyn Emitter + sync::Send> = match output {
1333 config::ErrorOutputType::HumanReadable(kind) => {
1334 let (short, color_config) = kind.unzip();
1335 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1337 config::ErrorOutputType::Json { pretty, json_rendered } =>
1338 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1340 let handler = errors::Handler::with_emitter(true, None, emitter);
1341 handler.struct_warn(msg).emit();
1344 pub type CompileResult = Result<(), ErrorReported>;