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::lint::builtin::BuiltinLintDiagnostics;
10 use crate::middle::allocator::AllocatorKind;
11 use crate::middle::dependency_format;
12 use crate::session::config::OutputType;
13 use crate::session::search_paths::{PathKind, SearchPath};
14 use crate::util::nodemap::{FxHashMap, FxHashSet};
15 use crate::util::common::{duration_to_secs_str, ErrorReported};
16 use crate::util::common::ProfileQueriesMsg;
18 use rustc_data_structures::base_n;
19 use rustc_data_structures::sync::{
20 self, Lrc, Lock, OneThread, Once, RwLock, AtomicU64, AtomicUsize, Ordering,
24 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
25 use errors::emitter::{Emitter, EmitterWriter};
26 use syntax::ast::{self, NodeId};
27 use syntax::edition::Edition;
28 use syntax::feature_gate::{self, AttributeType};
29 use syntax::json::JsonEmitter;
30 use syntax::source_map;
31 use syntax::parse::{self, ParseSess};
32 use syntax::symbol::Symbol;
33 use syntax_pos::{MultiSpan, Span};
34 use crate::util::profiling::SelfProfiler;
36 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
37 use rustc_data_structures::flock;
38 use rustc_data_structures::jobserver;
39 use ::jobserver::Client;
42 use std::cell::{self, Cell, RefCell};
46 use std::path::PathBuf;
47 use std::time::Duration;
48 use std::sync::{Arc, mpsc};
55 pub struct OptimizationFuel {
56 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
58 /// We're rejecting all further optimizations.
62 /// Represents the data associated with a compilation
63 /// session for a single crate.
65 pub target: config::Config,
67 pub opts: config::Options,
68 pub host_tlib_path: SearchPath,
69 /// `None` if the host and target are the same.
70 pub target_tlib_path: Option<SearchPath>,
71 pub parse_sess: ParseSess,
73 /// The name of the root source file of the crate, in the local file system.
74 /// `None` means that there is no source file.
75 pub local_crate_source_file: Option<PathBuf>,
76 /// The directory the compiler has been executed in plus a flag indicating
77 /// if the value stored here has been affected by path remapping.
78 pub working_dir: (PathBuf, bool),
80 // FIXME: lint_store and buffered_lints are not thread-safe,
81 // but are only used in a single thread
82 pub lint_store: RwLock<lint::LintStore>,
83 pub buffered_lints: Lock<Option<lint::LintBuffer>>,
85 /// Set of (DiagnosticId, Option<Span>, message) tuples tracking
86 /// (sub)diagnostics that have been set once, but should not be set again,
87 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
88 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
89 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
90 pub plugin_attributes: Lock<Vec<(Symbol, AttributeType)>>,
91 pub crate_types: Once<Vec<config::CrateType>>,
92 pub dependency_formats: Once<dependency_format::Dependencies>,
93 /// The crate_disambiguator is constructed out of all the `-C metadata`
94 /// arguments passed to the compiler. Its value together with the crate-name
95 /// forms a unique global identifier for the crate. It is used to allow
96 /// multiple crates with the same name to coexist. See the
97 /// rustc_codegen_llvm::back::symbol_names module for more information.
98 pub crate_disambiguator: Once<CrateDisambiguator>,
100 features: Once<feature_gate::Features>,
102 /// The maximum recursion limit for potentially infinitely recursive
103 /// operations such as auto-dereference and monomorphization.
104 pub recursion_limit: Once<usize>,
106 /// The maximum length of types during monomorphization.
107 pub type_length_limit: Once<usize>,
109 /// The maximum number of stackframes allowed in const eval.
110 pub const_eval_stack_frame_limit: usize,
112 /// The metadata::creader module may inject an allocator/panic_runtime
113 /// dependency if it didn't already find one, and this tracks what was
115 pub allocator_kind: Once<Option<AllocatorKind>>,
116 pub injected_panic_runtime: Once<Option<CrateNum>>,
118 /// Map from imported macro spans (which consist of
119 /// the localized span for the macro body) to the
120 /// macro name and definition span in the source crate.
121 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
123 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
124 /// Used for incremental compilation tests. Will only be populated if
125 /// `-Zquery-dep-graph` is specified.
126 pub cgu_reuse_tracker: CguReuseTracker,
128 /// Used by `-Z profile-queries` in `util::common`.
129 pub profile_channel: Lock<Option<mpsc::Sender<ProfileQueriesMsg>>>,
131 /// Used by -Z self-profile
132 pub self_profiling: Option<Arc<SelfProfiler>>,
134 /// Some measurements that are being gathered during compilation.
135 pub perf_stats: PerfStats,
137 /// Data about code being compiled, gathered during compilation.
138 pub code_stats: Lock<CodeStats>,
140 next_node_id: OneThread<Cell<ast::NodeId>>,
142 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
143 optimization_fuel_crate: Option<String>,
145 /// Tracks fuel info if `-zfuel=crate=n` is specified.
146 optimization_fuel: Lock<OptimizationFuel>,
148 // The next two are public because the driver needs to read them.
149 /// If `-zprint-fuel=crate`, `Some(crate)`.
150 pub print_fuel_crate: Option<String>,
151 /// Always set to zero and incremented so that we can print fuel expended by a crate.
152 pub print_fuel: AtomicU64,
154 /// Loaded up early on in the initialization of this `Session` to avoid
155 /// false positives about a job server in our environment.
156 pub jobserver: Client,
158 /// Metadata about the allocators for the current crate being compiled.
159 pub has_global_allocator: Once<bool>,
161 /// Metadata about the panic handlers for the current crate being compiled.
162 pub has_panic_handler: Once<bool>,
164 /// Cap lint level specified by a driver specifically.
165 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
167 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
168 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
170 /// Mapping from ident span to path span for paths that don't exist as written, but that
171 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
172 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
175 pub struct PerfStats {
176 /// The accumulated time spent on computing symbol hashes.
177 pub symbol_hash_time: Lock<Duration>,
178 /// The accumulated time spent decoding def path tables from metadata.
179 pub decode_def_path_tables_time: Lock<Duration>,
180 /// Total number of values canonicalized queries constructed.
181 pub queries_canonicalized: AtomicUsize,
182 /// Number of times this query is invoked.
183 pub normalize_ty_after_erasing_regions: AtomicUsize,
184 /// Number of times this query is invoked.
185 pub normalize_projection_ty: AtomicUsize,
188 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
189 enum DiagnosticBuilderMethod {
192 SpanSuggestion(String), // suggestion
193 // add more variants as needed to support one-time diagnostics
196 /// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
197 /// emitting the same message more than once
198 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
199 pub enum DiagnosticMessageId {
200 ErrorId(u16), // EXXXX error code as integer
201 LintId(lint::LintId),
202 StabilityId(u32), // issue number
205 impl From<&'static lint::Lint> for DiagnosticMessageId {
206 fn from(lint: &'static lint::Lint) -> Self {
207 DiagnosticMessageId::LintId(lint::LintId::of(lint))
212 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
213 *self.crate_disambiguator.get()
216 pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
220 ) -> DiagnosticBuilder<'a> {
221 self.diagnostic().struct_span_warn(sp, msg)
223 pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
228 ) -> DiagnosticBuilder<'a> {
229 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
231 pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
232 self.diagnostic().struct_warn(msg)
234 pub fn struct_span_err<'a, S: Into<MultiSpan>>(
238 ) -> DiagnosticBuilder<'a> {
239 self.diagnostic().struct_span_err(sp, msg)
241 pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
246 ) -> DiagnosticBuilder<'a> {
247 self.diagnostic().struct_span_err_with_code(sp, msg, code)
249 // FIXME: This method should be removed (every error should have an associated error code).
250 pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
251 self.diagnostic().struct_err(msg)
253 pub fn struct_err_with_code<'a>(
257 ) -> DiagnosticBuilder<'a> {
258 self.diagnostic().struct_err_with_code(msg, code)
260 pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
264 ) -> DiagnosticBuilder<'a> {
265 self.diagnostic().struct_span_fatal(sp, msg)
267 pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
272 ) -> DiagnosticBuilder<'a> {
273 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
275 pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
276 self.diagnostic().struct_fatal(msg)
279 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
280 self.diagnostic().span_fatal(sp, msg).raise()
282 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
289 .span_fatal_with_code(sp, msg, code)
292 pub fn fatal(&self, msg: &str) -> ! {
293 self.diagnostic().fatal(msg).raise()
295 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
297 self.span_warn(sp, msg);
299 self.span_err(sp, msg);
302 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
303 self.diagnostic().span_err(sp, msg)
305 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
306 self.diagnostic().span_err_with_code(sp, &msg, code)
308 pub fn err(&self, msg: &str) {
309 self.diagnostic().err(msg)
311 pub fn err_count(&self) -> usize {
312 self.diagnostic().err_count()
314 pub fn has_errors(&self) -> bool {
315 self.diagnostic().has_errors()
317 pub fn abort_if_errors(&self) {
318 self.diagnostic().abort_if_errors();
320 pub fn compile_status(&self) -> Result<(), ErrorReported> {
321 compile_result_from_err_count(self.err_count())
323 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
327 let old_count = self.err_count();
329 let errors = self.err_count() - old_count;
336 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
337 self.diagnostic().span_warn(sp, msg)
339 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
340 self.diagnostic().span_warn_with_code(sp, msg, code)
342 pub fn warn(&self, msg: &str) {
343 self.diagnostic().warn(msg)
345 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
347 Some(sp) => self.span_warn(sp, msg),
348 None => self.warn(msg),
351 /// Delay a span_bug() call until abort_if_errors()
352 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
353 self.diagnostic().delay_span_bug(sp, msg)
355 pub fn note_without_error(&self, msg: &str) {
356 self.diagnostic().note_without_error(msg)
358 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
359 self.diagnostic().span_note_without_error(sp, msg)
361 pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
362 self.diagnostic().span_unimpl(sp, msg)
364 pub fn unimpl(&self, msg: &str) -> ! {
365 self.diagnostic().unimpl(msg)
368 pub fn buffer_lint<S: Into<MultiSpan>>(
370 lint: &'static lint::Lint,
375 match *self.buffered_lints.borrow_mut() {
376 Some(ref mut buffer) => {
377 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
379 None => bug!("can't buffer lints after HIR lowering"),
383 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
385 lint: &'static lint::Lint,
389 diagnostic: BuiltinLintDiagnostics,
391 match *self.buffered_lints.borrow_mut() {
392 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
393 None => bug!("can't buffer lints after HIR lowering"),
397 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
398 let id = self.next_node_id.get();
400 match id.as_usize().checked_add(count) {
402 self.next_node_id.set(ast::NodeId::from_usize(next));
404 None => bug!("Input too large, ran out of node ids!"),
409 pub fn next_node_id(&self) -> NodeId {
410 self.reserve_node_ids(1)
412 pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
413 &self.parse_sess.span_diagnostic
416 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
417 /// deduplicates on lint ID, span (if any), and message for this `Session`
418 fn diag_once<'a, 'b>(
420 diag_builder: &'b mut DiagnosticBuilder<'a>,
421 method: DiagnosticBuilderMethod,
422 msg_id: DiagnosticMessageId,
424 span_maybe: Option<Span>,
426 let id_span_message = (msg_id, span_maybe, message.to_owned());
427 let fresh = self.one_time_diagnostics
429 .insert(id_span_message);
432 DiagnosticBuilderMethod::Note => {
433 diag_builder.note(message);
435 DiagnosticBuilderMethod::SpanNote => {
436 let span = span_maybe.expect("span_note needs a span");
437 diag_builder.span_note(span, message);
439 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
440 let span = span_maybe.expect("span_suggestion_* needs a span");
441 diag_builder.span_suggestion(
445 Applicability::Unspecified,
452 pub fn diag_span_note_once<'a, 'b>(
454 diag_builder: &'b mut DiagnosticBuilder<'a>,
455 msg_id: DiagnosticMessageId,
461 DiagnosticBuilderMethod::SpanNote,
468 pub fn diag_note_once<'a, 'b>(
470 diag_builder: &'b mut DiagnosticBuilder<'a>,
471 msg_id: DiagnosticMessageId,
476 DiagnosticBuilderMethod::Note,
483 pub fn diag_span_suggestion_once<'a, 'b>(
485 diag_builder: &'b mut DiagnosticBuilder<'a>,
486 msg_id: DiagnosticMessageId,
493 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
500 pub fn source_map<'a>(&'a self) -> &'a source_map::SourceMap {
501 self.parse_sess.source_map()
503 pub fn verbose(&self) -> bool {
504 self.opts.debugging_opts.verbose
506 pub fn time_passes(&self) -> bool {
507 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
509 pub fn time_extended(&self) -> bool {
510 self.opts.debugging_opts.time_passes
512 pub fn profile_queries(&self) -> bool {
513 self.opts.debugging_opts.profile_queries
514 || self.opts.debugging_opts.profile_queries_and_keys
516 pub fn profile_queries_and_keys(&self) -> bool {
517 self.opts.debugging_opts.profile_queries_and_keys
519 pub fn instrument_mcount(&self) -> bool {
520 self.opts.debugging_opts.instrument_mcount
522 pub fn count_llvm_insns(&self) -> bool {
523 self.opts.debugging_opts.count_llvm_insns
525 pub fn time_llvm_passes(&self) -> bool {
526 self.opts.debugging_opts.time_llvm_passes
528 pub fn codegen_stats(&self) -> bool {
529 self.opts.debugging_opts.codegen_stats
531 pub fn meta_stats(&self) -> bool {
532 self.opts.debugging_opts.meta_stats
534 pub fn asm_comments(&self) -> bool {
535 self.opts.debugging_opts.asm_comments
537 pub fn verify_llvm_ir(&self) -> bool {
538 self.opts.debugging_opts.verify_llvm_ir
539 || cfg!(always_verify_llvm_ir)
541 pub fn borrowck_stats(&self) -> bool {
542 self.opts.debugging_opts.borrowck_stats
544 pub fn print_llvm_passes(&self) -> bool {
545 self.opts.debugging_opts.print_llvm_passes
548 /// Gets the features enabled for the current compilation session.
549 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
550 /// dependency tracking. Use tcx.features() instead.
552 pub fn features_untracked(&self) -> &feature_gate::Features {
556 pub fn init_features(&self, features: feature_gate::Features) {
557 self.features.set(features);
560 /// Calculates the flavor of LTO to use for this compilation.
561 pub fn lto(&self) -> config::Lto {
562 // If our target has codegen requirements ignore the command line
563 if self.target.target.options.requires_lto {
564 return config::Lto::Fat;
567 // If the user specified something, return that. If they only said `-C
568 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
569 // then ensure we can't use a ThinLTO.
570 match self.opts.cg.lto {
571 config::LtoCli::Unspecified => {
572 // The compiler was invoked without the `-Clto` flag. Fall
573 // through to the default handling
575 config::LtoCli::No => {
576 // The user explicitly opted out of any kind of LTO
577 return config::Lto::No;
579 config::LtoCli::Yes |
580 config::LtoCli::Fat |
581 config::LtoCli::NoParam => {
582 // All of these mean fat LTO
583 return config::Lto::Fat;
585 config::LtoCli::Thin => {
586 return if self.opts.cli_forced_thinlto_off {
594 // Ok at this point the target doesn't require anything and the user
595 // hasn't asked for anything. Our next decision is whether or not
596 // we enable "auto" ThinLTO where we use multiple codegen units and
597 // then do ThinLTO over those codegen units. The logic below will
598 // either return `No` or `ThinLocal`.
600 // If processing command line options determined that we're incompatible
601 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
602 if self.opts.cli_forced_thinlto_off {
603 return config::Lto::No;
606 // If `-Z thinlto` specified process that, but note that this is mostly
607 // a deprecated option now that `-C lto=thin` exists.
608 if let Some(enabled) = self.opts.debugging_opts.thinlto {
610 return config::Lto::ThinLocal;
612 return config::Lto::No;
616 // If there's only one codegen unit and LTO isn't enabled then there's
617 // no need for ThinLTO so just return false.
618 if self.codegen_units() == 1 {
619 return config::Lto::No;
622 // Now we're in "defaults" territory. By default we enable ThinLTO for
623 // optimized compiles (anything greater than O0).
624 match self.opts.optimize {
625 config::OptLevel::No => config::Lto::No,
626 _ => config::Lto::ThinLocal,
630 /// Returns the panic strategy for this compile session. If the user explicitly selected one
631 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
632 pub fn panic_strategy(&self) -> PanicStrategy {
636 .unwrap_or(self.target.target.options.panic_strategy)
638 pub fn fewer_names(&self) -> bool {
639 let more_names = self.opts
641 .contains_key(&OutputType::LlvmAssembly)
642 || self.opts.output_types.contains_key(&OutputType::Bitcode);
643 self.opts.debugging_opts.fewer_names || !more_names
646 pub fn no_landing_pads(&self) -> bool {
647 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
649 pub fn unstable_options(&self) -> bool {
650 self.opts.debugging_opts.unstable_options
652 pub fn overflow_checks(&self) -> bool {
656 .or(self.opts.debugging_opts.force_overflow_checks)
657 .unwrap_or(self.opts.debug_assertions)
660 pub fn crt_static(&self) -> bool {
661 // If the target does not opt in to crt-static support, use its default.
662 if self.target.target.options.crt_static_respected {
663 self.crt_static_feature()
665 self.target.target.options.crt_static_default
669 pub fn crt_static_feature(&self) -> bool {
670 let requested_features = self.opts.cg.target_feature.split(',');
671 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
672 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
674 // If the target we're compiling for requests a static crt by default,
675 // then see if the `-crt-static` feature was passed to disable that.
676 // Otherwise if we don't have a static crt by default then see if the
677 // `+crt-static` feature was passed.
678 if self.target.target.options.crt_static_default {
685 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
686 // "mcount" function relies on stack pointer.
687 // See https://sourceware.org/binutils/docs/gprof/Implementation.html
688 if self.instrument_mcount() {
690 } else if let Some(x) = self.opts.cg.force_frame_pointers {
693 !self.target.target.options.eliminate_frame_pointer
697 /// Returns the symbol name for the registrar function,
698 /// given the crate Svh and the function DefIndex.
699 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
701 "__rustc_plugin_registrar_{}__",
702 disambiguator.to_fingerprint().to_hex()
706 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
708 "__rustc_proc_macro_decls_{}__",
709 disambiguator.to_fingerprint().to_hex()
713 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
714 filesearch::FileSearch::new(
716 self.opts.target_triple.triple(),
717 &self.opts.search_paths,
718 // target_tlib_path==None means it's the same as host_tlib_path.
719 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
723 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
724 filesearch::FileSearch::new(
726 config::host_triple(),
727 &self.opts.search_paths,
728 &self.host_tlib_path,
733 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
734 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
736 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
737 *load_dep_graph = load;
741 pub fn incr_session_load_dep_graph(&self) -> bool {
742 let incr_comp_session = self.incr_comp_session.borrow();
743 match *incr_comp_session {
744 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
749 pub fn init_incr_comp_session(
751 session_dir: PathBuf,
752 lock_file: flock::Lock,
753 load_dep_graph: bool,
755 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
757 if let IncrCompSession::NotInitialized = *incr_comp_session {
760 "Trying to initialize IncrCompSession `{:?}`",
765 *incr_comp_session = IncrCompSession::Active {
766 session_directory: session_dir,
772 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
773 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
775 if let IncrCompSession::Active { .. } = *incr_comp_session {
778 "Trying to finalize IncrCompSession `{:?}`",
783 // Note: This will also drop the lock file, thus unlocking the directory
784 *incr_comp_session = IncrCompSession::Finalized {
785 session_directory: new_directory_path,
789 pub fn mark_incr_comp_session_as_invalid(&self) {
790 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
792 let session_directory = match *incr_comp_session {
793 IncrCompSession::Active {
794 ref session_directory,
796 } => session_directory.clone(),
797 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
799 "Trying to invalidate IncrCompSession `{:?}`",
804 // Note: This will also drop the lock file, thus unlocking the directory
805 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
808 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
809 let incr_comp_session = self.incr_comp_session.borrow();
812 |incr_comp_session| match *incr_comp_session {
813 IncrCompSession::NotInitialized => bug!(
814 "Trying to get session directory from IncrCompSession `{:?}`",
817 IncrCompSession::Active {
818 ref session_directory,
821 | IncrCompSession::Finalized {
822 ref session_directory,
824 | IncrCompSession::InvalidBecauseOfErrors {
825 ref session_directory,
826 } => session_directory,
831 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
832 if self.opts.incremental.is_some() {
833 Some(self.incr_comp_session_dir())
841 fn profiler_active<F: FnOnce(&SelfProfiler) -> ()>(&self, f: F) {
842 match &self.self_profiling {
843 None => bug!("profiler_active() called but there was no profiler active"),
851 pub fn profiler<F: FnOnce(&SelfProfiler) -> ()>(&self, f: F) {
852 if unlikely!(self.self_profiling.is_some()) {
853 self.profiler_active(f)
857 pub fn print_perf_stats(&self) {
859 "Total time spent computing symbol hashes: {}",
860 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
863 "Total time spent decoding DefPath tables: {}",
864 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
866 println!("Total queries canonicalized: {}",
867 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
868 println!("normalize_ty_after_erasing_regions: {}",
869 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
870 println!("normalize_projection_ty: {}",
871 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
874 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
875 /// This expends fuel if applicable, and records fuel if applicable.
876 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
878 if let Some(ref c) = self.optimization_fuel_crate {
880 assert_eq!(self.threads(), 1);
881 let mut fuel = self.optimization_fuel.lock();
882 ret = fuel.remaining != 0;
883 if fuel.remaining == 0 && !fuel.out_of_fuel {
884 eprintln!("optimization-fuel-exhausted: {}", msg());
885 fuel.out_of_fuel = true;
886 } else if fuel.remaining > 0 {
891 if let Some(ref c) = self.print_fuel_crate {
893 assert_eq!(self.threads(), 1);
894 self.print_fuel.fetch_add(1, SeqCst);
900 /// Returns the number of query threads that should be used for this
902 pub fn threads_from_count(query_threads: Option<usize>) -> usize {
903 query_threads.unwrap_or(::num_cpus::get())
906 /// Returns the number of query threads that should be used for this
908 pub fn threads(&self) -> usize {
909 Self::threads_from_count(self.opts.debugging_opts.threads)
912 /// Returns the number of codegen units that should be used for this
914 pub fn codegen_units(&self) -> usize {
915 if let Some(n) = self.opts.cli_forced_codegen_units {
918 if let Some(n) = self.target.target.options.default_codegen_units {
922 // Why is 16 codegen units the default all the time?
924 // The main reason for enabling multiple codegen units by default is to
925 // leverage the ability for the codegen backend to do codegen and
926 // optimization in parallel. This allows us, especially for large crates, to
927 // make good use of all available resources on the machine once we've
928 // hit that stage of compilation. Large crates especially then often
929 // take a long time in codegen/optimization and this helps us amortize that
932 // Note that a high number here doesn't mean that we'll be spawning a
933 // large number of threads in parallel. The backend of rustc contains
934 // global rate limiting through the `jobserver` crate so we'll never
935 // overload the system with too much work, but rather we'll only be
936 // optimizing when we're otherwise cooperating with other instances of
939 // Rather a high number here means that we should be able to keep a lot
940 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
941 // to build we'll be guaranteed that all cpus will finish pretty closely
942 // to one another and we should make relatively optimal use of system
945 // Note that the main cost of codegen units is that it prevents LLVM
946 // from inlining across codegen units. Users in general don't have a lot
947 // of control over how codegen units are split up so it's our job in the
948 // compiler to ensure that undue performance isn't lost when using
949 // codegen units (aka we can't require everyone to slap `#[inline]` on
952 // If we're compiling at `-O0` then the number doesn't really matter too
953 // much because performance doesn't matter and inlining is ok to lose.
954 // In debug mode we just want to try to guarantee that no cpu is stuck
955 // doing work that could otherwise be farmed to others.
957 // In release mode, however (O1 and above) performance does indeed
958 // matter! To recover the loss in performance due to inlining we'll be
959 // enabling ThinLTO by default (the function for which is just below).
960 // This will ensure that we recover any inlining wins we otherwise lost
961 // through codegen unit partitioning.
965 // Ok that's a lot of words but the basic tl;dr; is that we want a high
966 // number here -- but not too high. Additionally we're "safe" to have it
967 // always at the same number at all optimization levels.
969 // As a result 16 was chosen here! Mostly because it was a power of 2
970 // and most benchmarks agreed it was roughly a local optimum. Not very
975 pub fn teach(&self, code: &DiagnosticId) -> bool {
976 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
979 pub fn rust_2015(&self) -> bool {
980 self.opts.edition == Edition::Edition2015
983 /// Are we allowed to use features from the Rust 2018 edition?
984 pub fn rust_2018(&self) -> bool {
985 self.opts.edition >= Edition::Edition2018
988 pub fn edition(&self) -> Edition {
992 /// Returns `true` if we cannot skip the PLT for shared library calls.
993 pub fn needs_plt(&self) -> bool {
994 // Check if the current target usually needs PLT to be enabled.
995 // The user can use the command line flag to override it.
996 let needs_plt = self.target.target.options.needs_plt;
998 let dbg_opts = &self.opts.debugging_opts;
1000 let relro_level = dbg_opts.relro_level
1001 .unwrap_or(self.target.target.options.relro_level);
1003 // Only enable this optimization by default if full relro is also enabled.
1004 // In this case, lazy binding was already unavailable, so nothing is lost.
1005 // This also ensures `-Wl,-z,now` is supported by the linker.
1006 let full_relro = RelroLevel::Full == relro_level;
1008 // If user didn't explicitly forced us to use / skip the PLT,
1009 // then try to skip it where possible.
1010 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
1014 pub fn build_session(
1015 sopts: config::Options,
1016 local_crate_source_file: Option<PathBuf>,
1017 registry: errors::registry::Registry,
1019 let file_path_mapping = sopts.file_path_mapping();
1021 build_session_with_source_map(
1023 local_crate_source_file,
1025 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
1026 DiagnosticOutput::Default,
1032 sopts: &config::Options,
1033 registry: errors::registry::Registry,
1034 source_map: &Lrc<source_map::SourceMap>,
1035 emitter_dest: Option<Box<dyn Write + Send>>,
1036 ) -> Box<dyn Emitter + sync::Send> {
1037 match (sopts.error_format, emitter_dest) {
1038 (config::ErrorOutputType::HumanReadable(kind), dst) => {
1039 let (short, color_config) = kind.unzip();
1040 let emitter = match dst {
1041 None => EmitterWriter::stderr(
1043 Some(source_map.clone()),
1045 sopts.debugging_opts.teach,
1047 Some(dst) => EmitterWriter::new(
1049 Some(source_map.clone()),
1051 false, // no teach messages when writing to a buffer
1052 false, // no colors when writing to a buffer
1055 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1057 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1058 JsonEmitter::stderr(
1063 ).ui_testing(sopts.debugging_opts.ui_testing),
1065 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1072 ).ui_testing(sopts.debugging_opts.ui_testing),
1077 pub enum DiagnosticOutput {
1079 Raw(Box<dyn Write + Send>)
1082 pub fn build_session_with_source_map(
1083 sopts: config::Options,
1084 local_crate_source_file: Option<PathBuf>,
1085 registry: errors::registry::Registry,
1086 source_map: Lrc<source_map::SourceMap>,
1087 diagnostics_output: DiagnosticOutput,
1088 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1090 // FIXME: This is not general enough to make the warning lint completely override
1091 // normal diagnostic warnings, since the warning lint can also be denied and changed
1092 // later via the source code.
1093 let warnings_allow = sopts
1096 .filter(|&&(ref key, _)| *key == "warnings")
1097 .map(|&(_, ref level)| *level == lint::Allow)
1100 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1102 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1104 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1105 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1106 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1108 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1110 let emitter = match diagnostics_output {
1111 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1112 DiagnosticOutput::Raw(write) => {
1113 default_emitter(&sopts, registry, &source_map, Some(write))
1117 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1119 errors::HandlerFlags {
1122 report_delayed_bugs,
1123 dont_buffer_diagnostics,
1124 external_macro_backtrace,
1125 ..Default::default()
1129 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1133 sopts: config::Options,
1134 local_crate_source_file: Option<PathBuf>,
1135 span_diagnostic: errors::Handler,
1136 source_map: Lrc<source_map::SourceMap>,
1137 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1140 if sopts.debugging_opts.self_profile {
1141 let profiler = SelfProfiler::new(&sopts.debugging_opts.self_profile_events);
1144 crate::ty::query::QueryName::register_with_profiler(&profiler);
1145 Some(Arc::new(profiler))
1148 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1155 let host_triple = TargetTriple::from_triple(config::host_triple());
1156 let host = Target::search(&host_triple).unwrap_or_else(|e|
1158 .fatal(&format!("Error loading host specification: {}", e))
1161 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1163 let p_s = parse::ParseSess::with_span_handler(span_diagnostic, source_map);
1164 let sysroot = match &sopts.maybe_sysroot {
1165 Some(sysroot) => sysroot.clone(),
1166 None => filesearch::get_or_default_sysroot(),
1169 let host_triple = config::host_triple();
1170 let target_triple = sopts.target_triple.triple();
1171 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1172 let target_tlib_path = if host_triple == target_triple {
1175 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1178 let file_path_mapping = sopts.file_path_mapping();
1180 let local_crate_source_file =
1181 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1183 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1184 let optimization_fuel = Lock::new(OptimizationFuel {
1185 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1188 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1189 let print_fuel = AtomicU64::new(0);
1191 let working_dir = env::current_dir().unwrap_or_else(|e|
1193 .fatal(&format!("Current directory is invalid: {}", e))
1196 let working_dir = file_path_mapping.map_prefix(working_dir);
1198 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1199 CguReuseTracker::new()
1201 CguReuseTracker::new_disabled()
1204 let sess = Session {
1212 local_crate_source_file,
1214 lint_store: RwLock::new(lint::LintStore::new()),
1215 buffered_lints: Lock::new(Some(Default::default())),
1216 one_time_diagnostics: Default::default(),
1217 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1218 plugin_attributes: Lock::new(Vec::new()),
1219 crate_types: Once::new(),
1220 dependency_formats: Once::new(),
1221 crate_disambiguator: Once::new(),
1222 features: Once::new(),
1223 recursion_limit: Once::new(),
1224 type_length_limit: Once::new(),
1225 const_eval_stack_frame_limit: 100,
1226 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1227 allocator_kind: Once::new(),
1228 injected_panic_runtime: Once::new(),
1229 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1230 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1232 self_profiling: self_profiler,
1233 profile_channel: Lock::new(None),
1234 perf_stats: PerfStats {
1235 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1236 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1237 queries_canonicalized: AtomicUsize::new(0),
1238 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1239 normalize_projection_ty: AtomicUsize::new(0),
1241 code_stats: Default::default(),
1242 optimization_fuel_crate,
1246 jobserver: jobserver::client(),
1247 has_global_allocator: Once::new(),
1248 has_panic_handler: Once::new(),
1250 trait_methods_not_found: Lock::new(Default::default()),
1251 confused_type_with_std_module: Lock::new(Default::default()),
1254 validate_commandline_args_with_session_available(&sess);
1259 // If it is useful to have a Session available already for validating a
1260 // commandline argument, you can do so here.
1261 fn validate_commandline_args_with_session_available(sess: &Session) {
1262 // Since we don't know if code in an rlib will be linked to statically or
1263 // dynamically downstream, rustc generates `__imp_` symbols that help the
1264 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1265 // these manually generated symbols confuse LLD when it tries to merge
1266 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1267 // when compiling for LLD ThinLTO. This way we can validly just not generate
1268 // the `dllimport` attributes and `__imp_` symbols in that case.
1269 if sess.opts.cg.linker_plugin_lto.enabled() &&
1270 sess.opts.cg.prefer_dynamic &&
1271 sess.target.target.options.is_like_msvc {
1272 sess.err("Linker plugin based LTO is not supported together with \
1273 `-C prefer-dynamic` when targeting MSVC");
1277 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1278 /// compiler. Together with the crate-name forms a unique global identifier for
1280 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1281 pub struct CrateDisambiguator(Fingerprint);
1283 impl CrateDisambiguator {
1284 pub fn to_fingerprint(self) -> Fingerprint {
1289 impl fmt::Display for CrateDisambiguator {
1290 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1291 let (a, b) = self.0.as_value();
1292 let as_u128 = a as u128 | ((b as u128) << 64);
1293 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1297 impl From<Fingerprint> for CrateDisambiguator {
1298 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1299 CrateDisambiguator(fingerprint)
1303 impl_stable_hash_via_hash!(CrateDisambiguator);
1305 /// Holds data on the current incremental compilation session, if there is one.
1307 pub enum IncrCompSession {
1308 /// This is the state the session will be in until the incr. comp. dir is
1311 /// This is the state during which the session directory is private and can
1314 session_directory: PathBuf,
1315 lock_file: flock::Lock,
1316 load_dep_graph: bool,
1318 /// This is the state after the session directory has been finalized. In this
1319 /// state, the contents of the directory must not be modified any more.
1320 Finalized { session_directory: PathBuf },
1321 /// This is an error state that is reached when some compilation error has
1322 /// occurred. It indicates that the contents of the session directory must
1323 /// not be used, since they might be invalid.
1324 InvalidBecauseOfErrors { session_directory: PathBuf },
1327 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1328 let emitter: Box<dyn Emitter + sync::Send> = match output {
1329 config::ErrorOutputType::HumanReadable(kind) => {
1330 let (short, color_config) = kind.unzip();
1331 Box::new(EmitterWriter::stderr(color_config, None, short, false))
1333 config::ErrorOutputType::Json { pretty, json_rendered } =>
1334 Box::new(JsonEmitter::basic(pretty, json_rendered)),
1336 let handler = errors::Handler::with_emitter(true, None, emitter);
1337 handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
1338 errors::FatalError.raise();
1341 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1342 let emitter: Box<dyn Emitter + sync::Send> = match output {
1343 config::ErrorOutputType::HumanReadable(kind) => {
1344 let (short, color_config) = kind.unzip();
1345 Box::new(EmitterWriter::stderr(color_config, None, short, false))
1347 config::ErrorOutputType::Json { pretty, json_rendered } =>
1348 Box::new(JsonEmitter::basic(pretty, json_rendered)),
1350 let handler = errors::Handler::with_emitter(true, None, emitter);
1351 handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
1354 pub type CompileResult = Result<(), ErrorReported>;
1356 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {