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, Lto};
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 crate::errors::{self, DiagnosticBuilder, DiagnosticId, Applicability};
25 use crate::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_pos::{MultiSpan, Span};
33 use crate::util::profiling::SelfProfiler;
35 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
36 use rustc_data_structures::flock;
37 use jobserver::Client;
40 use std::cell::{self, Cell, RefCell};
44 use std::path::PathBuf;
45 use std::time::Duration;
53 pub struct OptimizationFuel {
54 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
56 /// We're rejecting all further optimizations.
60 /// Represents the data associated with a compilation
61 /// session for a single crate.
63 pub target: config::Config,
65 pub opts: config::Options,
66 pub host_tlib_path: SearchPath,
67 /// `None` if the host and target are the same.
68 pub target_tlib_path: Option<SearchPath>,
69 pub parse_sess: ParseSess,
71 /// The name of the root source file of the crate, in the local file system.
72 /// `None` means that there is no source file.
73 pub local_crate_source_file: Option<PathBuf>,
74 /// The directory the compiler has been executed in plus a flag indicating
75 /// if the value stored here has been affected by path remapping.
76 pub working_dir: (PathBuf, bool),
78 // FIXME: lint_store and buffered_lints are not thread-safe,
79 // but are only used in a single thread
80 pub lint_store: RwLock<lint::LintStore>,
81 pub buffered_lints: Lock<Option<lint::LintBuffer>>,
83 /// Set of (DiagnosticId, Option<Span>, message) tuples tracking
84 /// (sub)diagnostics that have been set once, but should not be set again,
85 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
86 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
87 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
88 pub plugin_attributes: Lock<Vec<(String, AttributeType)>>,
89 pub crate_types: Once<Vec<config::CrateType>>,
90 pub dependency_formats: Once<dependency_format::Dependencies>,
91 /// The crate_disambiguator is constructed out of all the `-C metadata`
92 /// arguments passed to the compiler. Its value together with the crate-name
93 /// forms a unique global identifier for the crate. It is used to allow
94 /// multiple crates with the same name to coexist. See the
95 /// rustc_codegen_llvm::back::symbol_names module for more information.
96 pub crate_disambiguator: Once<CrateDisambiguator>,
98 features: Once<feature_gate::Features>,
100 /// The maximum recursion limit for potentially infinitely recursive
101 /// operations such as auto-dereference and monomorphization.
102 pub recursion_limit: Once<usize>,
104 /// The maximum length of types during monomorphization.
105 pub type_length_limit: Once<usize>,
107 /// The maximum number of stackframes allowed in const eval.
108 pub const_eval_stack_frame_limit: usize,
110 /// The metadata::creader module may inject an allocator/panic_runtime
111 /// dependency if it didn't already find one, and this tracks what was
113 pub allocator_kind: Once<Option<AllocatorKind>>,
114 pub injected_panic_runtime: Once<Option<CrateNum>>,
116 /// Map from imported macro spans (which consist of
117 /// the localized span for the macro body) to the
118 /// macro name and definition span in the source crate.
119 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
121 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
122 /// Used for incremental compilation tests. Will only be populated if
123 /// `-Zquery-dep-graph` is specified.
124 pub cgu_reuse_tracker: CguReuseTracker,
126 /// Used by `-Z profile-queries` in `util::common`.
127 pub profile_channel: Lock<Option<mpsc::Sender<ProfileQueriesMsg>>>,
129 /// Used by `-Z self-profile`.
130 pub self_profiling_active: bool,
132 /// Used by `-Z self-profile`.
133 pub self_profiling: Lock<SelfProfiler>,
135 /// Some measurements that are being gathered during compilation.
136 pub perf_stats: PerfStats,
138 /// Data about code being compiled, gathered during compilation.
139 pub code_stats: Lock<CodeStats>,
141 next_node_id: OneThread<Cell<ast::NodeId>>,
143 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
144 optimization_fuel_crate: Option<String>,
146 /// Tracks fuel info if `-zfuel=crate=n` is specified.
147 optimization_fuel: Lock<OptimizationFuel>,
149 // The next two are public because the driver needs to read them.
150 /// If `-zprint-fuel=crate`, `Some(crate)`.
151 pub print_fuel_crate: Option<String>,
152 /// Always set to zero and incremented so that we can print fuel expended by a crate.
153 pub print_fuel: AtomicU64,
155 /// Loaded up early on in the initialization of this `Session` to avoid
156 /// false positives about a job server in our environment.
157 pub jobserver: Client,
159 /// Metadata about the allocators for the current crate being compiled.
160 pub has_global_allocator: Once<bool>,
162 /// Metadata about the panic handlers for the current crate being compiled.
163 pub has_panic_handler: Once<bool>,
165 /// Cap lint level specified by a driver specifically.
166 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
169 pub struct PerfStats {
170 /// The accumulated time spent on computing symbol hashes.
171 pub symbol_hash_time: Lock<Duration>,
172 /// The accumulated time spent decoding def path tables from metadata.
173 pub decode_def_path_tables_time: Lock<Duration>,
174 /// Total number of values canonicalized queries constructed.
175 pub queries_canonicalized: AtomicUsize,
176 /// Number of times this query is invoked.
177 pub normalize_ty_after_erasing_regions: AtomicUsize,
178 /// Number of times this query is invoked.
179 pub normalize_projection_ty: AtomicUsize,
182 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
183 enum DiagnosticBuilderMethod {
186 SpanSuggestion(String), // suggestion
187 // add more variants as needed to support one-time diagnostics
190 /// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
191 /// emitting the same message more than once
192 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
193 pub enum DiagnosticMessageId {
194 ErrorId(u16), // EXXXX error code as integer
195 LintId(lint::LintId),
196 StabilityId(u32), // issue number
199 impl From<&'static lint::Lint> for DiagnosticMessageId {
200 fn from(lint: &'static lint::Lint) -> Self {
201 DiagnosticMessageId::LintId(lint::LintId::of(lint))
206 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
207 *self.crate_disambiguator.get()
210 pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
214 ) -> DiagnosticBuilder<'a> {
215 self.diagnostic().struct_span_warn(sp, msg)
217 pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
222 ) -> DiagnosticBuilder<'a> {
223 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
225 pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
226 self.diagnostic().struct_warn(msg)
228 pub fn struct_span_err<'a, S: Into<MultiSpan>>(
232 ) -> DiagnosticBuilder<'a> {
233 self.diagnostic().struct_span_err(sp, msg)
235 pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
240 ) -> DiagnosticBuilder<'a> {
241 self.diagnostic().struct_span_err_with_code(sp, msg, code)
243 // FIXME: This method should be removed (every error should have an associated error code).
244 pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
245 self.diagnostic().struct_err(msg)
247 pub fn struct_err_with_code<'a>(
251 ) -> DiagnosticBuilder<'a> {
252 self.diagnostic().struct_err_with_code(msg, code)
254 pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
258 ) -> DiagnosticBuilder<'a> {
259 self.diagnostic().struct_span_fatal(sp, msg)
261 pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
266 ) -> DiagnosticBuilder<'a> {
267 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
269 pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
270 self.diagnostic().struct_fatal(msg)
273 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
274 self.diagnostic().span_fatal(sp, msg).raise()
276 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
283 .span_fatal_with_code(sp, msg, code)
286 pub fn fatal(&self, msg: &str) -> ! {
287 self.diagnostic().fatal(msg).raise()
289 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
291 self.span_warn(sp, msg);
293 self.span_err(sp, msg);
296 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
297 self.diagnostic().span_err(sp, msg)
299 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
300 self.diagnostic().span_err_with_code(sp, &msg, code)
302 pub fn err(&self, msg: &str) {
303 self.diagnostic().err(msg)
305 pub fn err_count(&self) -> usize {
306 self.diagnostic().err_count()
308 pub fn has_errors(&self) -> bool {
309 self.diagnostic().has_errors()
311 pub fn abort_if_errors(&self) {
312 self.diagnostic().abort_if_errors();
314 pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
315 compile_result_from_err_count(self.err_count())
317 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
321 let old_count = self.err_count();
323 let errors = self.err_count() - old_count;
330 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
331 self.diagnostic().span_warn(sp, msg)
333 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
334 self.diagnostic().span_warn_with_code(sp, msg, code)
336 pub fn warn(&self, msg: &str) {
337 self.diagnostic().warn(msg)
339 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
341 Some(sp) => self.span_warn(sp, msg),
342 None => self.warn(msg),
345 /// Delay a span_bug() call until abort_if_errors()
346 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
347 self.diagnostic().delay_span_bug(sp, msg)
349 pub fn note_without_error(&self, msg: &str) {
350 self.diagnostic().note_without_error(msg)
352 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
353 self.diagnostic().span_note_without_error(sp, msg)
355 pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
356 self.diagnostic().span_unimpl(sp, msg)
358 pub fn unimpl(&self, msg: &str) -> ! {
359 self.diagnostic().unimpl(msg)
362 pub fn buffer_lint<S: Into<MultiSpan>>(
364 lint: &'static lint::Lint,
369 match *self.buffered_lints.borrow_mut() {
370 Some(ref mut buffer) => {
371 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
373 None => bug!("can't buffer lints after HIR lowering"),
377 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
379 lint: &'static lint::Lint,
383 diagnostic: BuiltinLintDiagnostics,
385 match *self.buffered_lints.borrow_mut() {
386 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
387 None => bug!("can't buffer lints after HIR lowering"),
391 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
392 let id = self.next_node_id.get();
394 match id.as_usize().checked_add(count) {
396 self.next_node_id.set(ast::NodeId::from_usize(next));
398 None => bug!("Input too large, ran out of node ids!"),
403 pub fn next_node_id(&self) -> NodeId {
404 self.reserve_node_ids(1)
406 pub(crate) fn current_node_id_count(&self) -> usize {
407 self.next_node_id.get().as_u32() as usize
409 pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
410 &self.parse_sess.span_diagnostic
413 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
414 /// deduplicates on lint ID, span (if any), and message for this `Session`
415 fn diag_once<'a, 'b>(
417 diag_builder: &'b mut DiagnosticBuilder<'a>,
418 method: DiagnosticBuilderMethod,
419 msg_id: DiagnosticMessageId,
421 span_maybe: Option<Span>,
423 let id_span_message = (msg_id, span_maybe, message.to_owned());
424 let fresh = self.one_time_diagnostics
426 .insert(id_span_message);
429 DiagnosticBuilderMethod::Note => {
430 diag_builder.note(message);
432 DiagnosticBuilderMethod::SpanNote => {
433 let span = span_maybe.expect("span_note needs a span");
434 diag_builder.span_note(span, message);
436 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
437 let span = span_maybe.expect("span_suggestion_* needs a span");
438 diag_builder.span_suggestion(
442 Applicability::Unspecified,
449 pub fn diag_span_note_once<'a, 'b>(
451 diag_builder: &'b mut DiagnosticBuilder<'a>,
452 msg_id: DiagnosticMessageId,
458 DiagnosticBuilderMethod::SpanNote,
465 pub fn diag_note_once<'a, 'b>(
467 diag_builder: &'b mut DiagnosticBuilder<'a>,
468 msg_id: DiagnosticMessageId,
473 DiagnosticBuilderMethod::Note,
480 pub fn diag_span_suggestion_once<'a, 'b>(
482 diag_builder: &'b mut DiagnosticBuilder<'a>,
483 msg_id: DiagnosticMessageId,
490 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
497 pub fn source_map<'a>(&'a self) -> &'a source_map::SourceMap {
498 self.parse_sess.source_map()
500 pub fn verbose(&self) -> bool {
501 self.opts.debugging_opts.verbose
503 pub fn time_passes(&self) -> bool {
504 self.opts.debugging_opts.time_passes
506 pub fn profile_queries(&self) -> bool {
507 self.opts.debugging_opts.profile_queries
508 || self.opts.debugging_opts.profile_queries_and_keys
510 pub fn profile_queries_and_keys(&self) -> bool {
511 self.opts.debugging_opts.profile_queries_and_keys
513 pub fn instrument_mcount(&self) -> bool {
514 self.opts.debugging_opts.instrument_mcount
516 pub fn count_llvm_insns(&self) -> bool {
517 self.opts.debugging_opts.count_llvm_insns
519 pub fn time_llvm_passes(&self) -> bool {
520 self.opts.debugging_opts.time_llvm_passes
522 pub fn codegen_stats(&self) -> bool {
523 self.opts.debugging_opts.codegen_stats
525 pub fn meta_stats(&self) -> bool {
526 self.opts.debugging_opts.meta_stats
528 pub fn asm_comments(&self) -> bool {
529 self.opts.debugging_opts.asm_comments
531 pub fn verify_llvm_ir(&self) -> bool {
532 self.opts.debugging_opts.verify_llvm_ir
533 || cfg!(always_verify_llvm_ir)
535 pub fn borrowck_stats(&self) -> bool {
536 self.opts.debugging_opts.borrowck_stats
538 pub fn print_llvm_passes(&self) -> bool {
539 self.opts.debugging_opts.print_llvm_passes
542 /// Gets the features enabled for the current compilation session.
543 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
544 /// dependency tracking. Use tcx.features() instead.
546 pub fn features_untracked(&self) -> &feature_gate::Features {
550 pub fn init_features(&self, features: feature_gate::Features) {
551 self.features.set(features);
554 /// Calculates the flavor of LTO to use for this compilation.
555 pub fn lto(&self) -> config::Lto {
556 // If our target has codegen requirements ignore the command line
557 if self.target.target.options.requires_lto {
558 return config::Lto::Fat;
561 // If the user specified something, return that. If they only said `-C
562 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
563 // then ensure we can't use a ThinLTO.
564 match self.opts.cg.lto {
565 config::LtoCli::Unspecified => {
566 // The compiler was invoked without the `-Clto` flag. Fall
567 // through to the default handling
569 config::LtoCli::No => {
570 // The user explicitly opted out of any kind of LTO
571 return config::Lto::No;
573 config::LtoCli::Yes |
574 config::LtoCli::Fat |
575 config::LtoCli::NoParam => {
576 // All of these mean fat LTO
577 return config::Lto::Fat;
579 config::LtoCli::Thin => {
580 return if self.opts.cli_forced_thinlto_off {
588 // Ok at this point the target doesn't require anything and the user
589 // hasn't asked for anything. Our next decision is whether or not
590 // we enable "auto" ThinLTO where we use multiple codegen units and
591 // then do ThinLTO over those codegen units. The logic below will
592 // either return `No` or `ThinLocal`.
594 // If processing command line options determined that we're incompatible
595 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
596 if self.opts.cli_forced_thinlto_off {
597 return config::Lto::No;
600 // If `-Z thinlto` specified process that, but note that this is mostly
601 // a deprecated option now that `-C lto=thin` exists.
602 if let Some(enabled) = self.opts.debugging_opts.thinlto {
604 return config::Lto::ThinLocal;
606 return config::Lto::No;
610 // If there's only one codegen unit and LTO isn't enabled then there's
611 // no need for ThinLTO so just return false.
612 if self.codegen_units() == 1 {
613 return config::Lto::No;
616 // Now we're in "defaults" territory. By default we enable ThinLTO for
617 // optimized compiles (anything greater than O0).
618 match self.opts.optimize {
619 config::OptLevel::No => config::Lto::No,
620 _ => config::Lto::ThinLocal,
624 /// Returns the panic strategy for this compile session. If the user explicitly selected one
625 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
626 pub fn panic_strategy(&self) -> PanicStrategy {
630 .unwrap_or(self.target.target.options.panic_strategy)
632 pub fn fewer_names(&self) -> bool {
633 let more_names = self.opts
635 .contains_key(&OutputType::LlvmAssembly)
636 || self.opts.output_types.contains_key(&OutputType::Bitcode);
637 self.opts.debugging_opts.fewer_names || !more_names
640 pub fn no_landing_pads(&self) -> bool {
641 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
643 pub fn unstable_options(&self) -> bool {
644 self.opts.debugging_opts.unstable_options
646 pub fn overflow_checks(&self) -> bool {
650 .or(self.opts.debugging_opts.force_overflow_checks)
651 .unwrap_or(self.opts.debug_assertions)
654 pub fn crt_static(&self) -> bool {
655 // If the target does not opt in to crt-static support, use its default.
656 if self.target.target.options.crt_static_respected {
657 self.crt_static_feature()
659 self.target.target.options.crt_static_default
663 pub fn crt_static_feature(&self) -> bool {
664 let requested_features = self.opts.cg.target_feature.split(',');
665 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
666 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
668 // If the target we're compiling for requests a static crt by default,
669 // then see if the `-crt-static` feature was passed to disable that.
670 // Otherwise if we don't have a static crt by default then see if the
671 // `+crt-static` feature was passed.
672 if self.target.target.options.crt_static_default {
679 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
680 // "mcount" function relies on stack pointer.
681 // See https://sourceware.org/binutils/docs/gprof/Implementation.html
682 if self.instrument_mcount() {
684 } else if let Some(x) = self.opts.cg.force_frame_pointers {
687 !self.target.target.options.eliminate_frame_pointer
691 /// Returns the symbol name for the registrar function,
692 /// given the crate Svh and the function DefIndex.
693 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
695 "__rustc_plugin_registrar_{}__",
696 disambiguator.to_fingerprint().to_hex()
700 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
702 "__rustc_proc_macro_decls_{}__",
703 disambiguator.to_fingerprint().to_hex()
707 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
708 filesearch::FileSearch::new(
710 self.opts.target_triple.triple(),
711 &self.opts.search_paths,
712 // target_tlib_path==None means it's the same as host_tlib_path.
713 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
717 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
718 filesearch::FileSearch::new(
720 config::host_triple(),
721 &self.opts.search_paths,
722 &self.host_tlib_path,
727 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
728 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
730 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
731 *load_dep_graph = load;
735 pub fn incr_session_load_dep_graph(&self) -> bool {
736 let incr_comp_session = self.incr_comp_session.borrow();
737 match *incr_comp_session {
738 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
743 pub fn init_incr_comp_session(
745 session_dir: PathBuf,
746 lock_file: flock::Lock,
747 load_dep_graph: bool,
749 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
751 if let IncrCompSession::NotInitialized = *incr_comp_session {
754 "Trying to initialize IncrCompSession `{:?}`",
759 *incr_comp_session = IncrCompSession::Active {
760 session_directory: session_dir,
766 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
767 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
769 if let IncrCompSession::Active { .. } = *incr_comp_session {
772 "Trying to finalize IncrCompSession `{:?}`",
777 // Note: This will also drop the lock file, thus unlocking the directory
778 *incr_comp_session = IncrCompSession::Finalized {
779 session_directory: new_directory_path,
783 pub fn mark_incr_comp_session_as_invalid(&self) {
784 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
786 let session_directory = match *incr_comp_session {
787 IncrCompSession::Active {
788 ref session_directory,
790 } => session_directory.clone(),
791 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
793 "Trying to invalidate IncrCompSession `{:?}`",
798 // Note: This will also drop the lock file, thus unlocking the directory
799 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
802 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
803 let incr_comp_session = self.incr_comp_session.borrow();
806 |incr_comp_session| match *incr_comp_session {
807 IncrCompSession::NotInitialized => bug!(
808 "Trying to get session directory from IncrCompSession `{:?}`",
811 IncrCompSession::Active {
812 ref session_directory,
815 | IncrCompSession::Finalized {
816 ref session_directory,
818 | IncrCompSession::InvalidBecauseOfErrors {
819 ref session_directory,
820 } => session_directory,
825 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
826 if self.opts.incremental.is_some() {
827 Some(self.incr_comp_session_dir())
835 fn profiler_active<F: FnOnce(&mut SelfProfiler) -> ()>(&self, f: F) {
836 let mut profiler = self.self_profiling.borrow_mut();
841 pub fn profiler<F: FnOnce(&mut SelfProfiler) -> ()>(&self, f: F) {
842 if unlikely!(self.self_profiling_active) {
843 self.profiler_active(f)
847 pub fn print_profiler_results(&self) {
848 let mut profiler = self.self_profiling.borrow_mut();
849 profiler.print_results(&self.opts);
852 pub fn save_json_results(&self) {
853 let profiler = self.self_profiling.borrow();
854 profiler.save_results(&self.opts);
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_opts(opts: &config::Options) -> usize {
903 opts.debugging_opts.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_opts(&self.opts)
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)),
1030 pub fn build_session_with_source_map(
1031 sopts: config::Options,
1032 local_crate_source_file: Option<PathBuf>,
1033 registry: errors::registry::Registry,
1034 source_map: Lrc<source_map::SourceMap>,
1035 emitter_dest: Option<Box<dyn Write + Send>>,
1037 // FIXME: This is not general enough to make the warning lint completely override
1038 // normal diagnostic warnings, since the warning lint can also be denied and changed
1039 // later via the source code.
1040 let warnings_allow = sopts
1043 .filter(|&&(ref key, _)| *key == "warnings")
1044 .map(|&(_, ref level)| *level == lint::Allow)
1047 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1049 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1051 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1052 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1053 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1055 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1057 let emitter: Box<dyn Emitter + sync::Send> =
1058 match (sopts.error_format, emitter_dest) {
1059 (config::ErrorOutputType::HumanReadable(color_config), None) => Box::new(
1060 EmitterWriter::stderr(
1062 Some(source_map.clone()),
1064 sopts.debugging_opts.teach,
1065 ).ui_testing(sopts.debugging_opts.ui_testing),
1067 (config::ErrorOutputType::HumanReadable(_), Some(dst)) => Box::new(
1068 EmitterWriter::new(dst, Some(source_map.clone()), false, false)
1069 .ui_testing(sopts.debugging_opts.ui_testing),
1071 (config::ErrorOutputType::Json(pretty), None) => Box::new(
1072 JsonEmitter::stderr(
1076 ).ui_testing(sopts.debugging_opts.ui_testing),
1078 (config::ErrorOutputType::Json(pretty), Some(dst)) => Box::new(
1084 ).ui_testing(sopts.debugging_opts.ui_testing),
1086 (config::ErrorOutputType::Short(color_config), None) => Box::new(
1087 EmitterWriter::stderr(color_config, Some(source_map.clone()), true, false),
1089 (config::ErrorOutputType::Short(_), Some(dst)) => {
1090 Box::new(EmitterWriter::new(dst, Some(source_map.clone()), true, false))
1094 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1096 errors::HandlerFlags {
1099 report_delayed_bugs,
1100 dont_buffer_diagnostics,
1101 external_macro_backtrace,
1102 ..Default::default()
1106 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map)
1109 pub fn build_session_(
1110 sopts: config::Options,
1111 local_crate_source_file: Option<PathBuf>,
1112 span_diagnostic: errors::Handler,
1113 source_map: Lrc<source_map::SourceMap>,
1115 let host_triple = TargetTriple::from_triple(config::host_triple());
1116 let host = Target::search(&host_triple).unwrap_or_else(|e|
1118 .fatal(&format!("Error loading host specification: {}", e))
1121 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1123 let p_s = parse::ParseSess::with_span_handler(span_diagnostic, source_map);
1124 let sysroot = match &sopts.maybe_sysroot {
1125 Some(sysroot) => sysroot.clone(),
1126 None => filesearch::get_or_default_sysroot(),
1129 let host_triple = config::host_triple();
1130 let target_triple = sopts.target_triple.triple();
1131 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1132 let target_tlib_path = if host_triple == target_triple {
1135 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1138 let file_path_mapping = sopts.file_path_mapping();
1140 let local_crate_source_file =
1141 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1143 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1144 let optimization_fuel = Lock::new(OptimizationFuel {
1145 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1148 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1149 let print_fuel = AtomicU64::new(0);
1151 let working_dir = env::current_dir().unwrap_or_else(|e|
1153 .fatal(&format!("Current directory is invalid: {}", e))
1156 let working_dir = file_path_mapping.map_prefix(working_dir);
1158 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1159 CguReuseTracker::new()
1161 CguReuseTracker::new_disabled()
1164 let self_profiling_active = sopts.debugging_opts.self_profile ||
1165 sopts.debugging_opts.profile_json;
1167 let sess = Session {
1175 local_crate_source_file,
1177 lint_store: RwLock::new(lint::LintStore::new()),
1178 buffered_lints: Lock::new(Some(Default::default())),
1179 one_time_diagnostics: Default::default(),
1180 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1181 plugin_attributes: Lock::new(Vec::new()),
1182 crate_types: Once::new(),
1183 dependency_formats: Once::new(),
1184 crate_disambiguator: Once::new(),
1185 features: Once::new(),
1186 recursion_limit: Once::new(),
1187 type_length_limit: Once::new(),
1188 const_eval_stack_frame_limit: 100,
1189 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1190 allocator_kind: Once::new(),
1191 injected_panic_runtime: Once::new(),
1192 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1193 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1195 self_profiling_active,
1196 self_profiling: Lock::new(SelfProfiler::new()),
1197 profile_channel: Lock::new(None),
1198 perf_stats: PerfStats {
1199 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1200 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1201 queries_canonicalized: AtomicUsize::new(0),
1202 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1203 normalize_projection_ty: AtomicUsize::new(0),
1205 code_stats: Default::default(),
1206 optimization_fuel_crate,
1210 // Note that this is unsafe because it may misinterpret file descriptors
1211 // on Unix as jobserver file descriptors. We hopefully execute this near
1212 // the beginning of the process though to ensure we don't get false
1213 // positives, or in other words we try to execute this before we open
1214 // any file descriptors ourselves.
1216 // Pick a "reasonable maximum" if we don't otherwise have
1217 // a jobserver in our environment, capping out at 32 so we
1218 // don't take everything down by hogging the process run queue.
1219 // The fixed number is used to have deterministic compilation
1222 // Also note that we stick this in a global because there could be
1223 // multiple `Session` instances in this process, and the jobserver is
1226 static mut GLOBAL_JOBSERVER: *mut Client = 0 as *mut _;
1227 static INIT: std::sync::Once = std::sync::ONCE_INIT;
1229 let client = Client::from_env().unwrap_or_else(|| {
1230 Client::new(32).expect("failed to create jobserver")
1232 GLOBAL_JOBSERVER = Box::into_raw(Box::new(client));
1234 (*GLOBAL_JOBSERVER).clone()
1236 has_global_allocator: Once::new(),
1237 has_panic_handler: Once::new(),
1238 driver_lint_caps: Default::default(),
1241 validate_commandline_args_with_session_available(&sess);
1246 // If it is useful to have a Session available already for validating a
1247 // commandline argument, you can do so here.
1248 fn validate_commandline_args_with_session_available(sess: &Session) {
1250 if sess.opts.incremental.is_some() {
1254 sess.err("can't perform LTO when compiling incrementally");
1263 // Since we don't know if code in an rlib will be linked to statically or
1264 // dynamically downstream, rustc generates `__imp_` symbols that help the
1265 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1266 // these manually generated symbols confuse LLD when it tries to merge
1267 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1268 // when compiling for LLD ThinLTO. This way we can validly just not generate
1269 // the `dllimport` attributes and `__imp_` symbols in that case.
1270 if sess.opts.cg.linker_plugin_lto.enabled() &&
1271 sess.opts.cg.prefer_dynamic &&
1272 sess.target.target.options.is_like_msvc {
1273 sess.err("Linker plugin based LTO is not supported together with \
1274 `-C prefer-dynamic` when targeting MSVC");
1278 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1279 /// compiler. Together with the crate-name forms a unique global identifier for
1281 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1282 pub struct CrateDisambiguator(Fingerprint);
1284 impl CrateDisambiguator {
1285 pub fn to_fingerprint(self) -> Fingerprint {
1290 impl fmt::Display for CrateDisambiguator {
1291 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1292 let (a, b) = self.0.as_value();
1293 let as_u128 = a as u128 | ((b as u128) << 64);
1294 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1298 impl From<Fingerprint> for CrateDisambiguator {
1299 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1300 CrateDisambiguator(fingerprint)
1304 impl_stable_hash_via_hash!(CrateDisambiguator);
1306 /// Holds data on the current incremental compilation session, if there is one.
1308 pub enum IncrCompSession {
1309 /// This is the state the session will be in until the incr. comp. dir is
1312 /// This is the state during which the session directory is private and can
1315 session_directory: PathBuf,
1316 lock_file: flock::Lock,
1317 load_dep_graph: bool,
1319 /// This is the state after the session directory has been finalized. In this
1320 /// state, the contents of the directory must not be modified any more.
1321 Finalized { session_directory: PathBuf },
1322 /// This is an error state that is reached when some compilation error has
1323 /// occurred. It indicates that the contents of the session directory must
1324 /// not be used, since they might be invalid.
1325 InvalidBecauseOfErrors { session_directory: PathBuf },
1328 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1329 let emitter: Box<dyn Emitter + sync::Send> = match output {
1330 config::ErrorOutputType::HumanReadable(color_config) => {
1331 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1333 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1334 config::ErrorOutputType::Short(color_config) => {
1335 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1338 let handler = errors::Handler::with_emitter(true, false, emitter);
1339 handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
1340 errors::FatalError.raise();
1343 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1344 let emitter: Box<dyn Emitter + sync::Send> = match output {
1345 config::ErrorOutputType::HumanReadable(color_config) => {
1346 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1348 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1349 config::ErrorOutputType::Short(color_config) => {
1350 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1353 let handler = errors::Handler::with_emitter(true, false, emitter);
1354 handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
1357 #[derive(Copy, Clone, Debug)]
1358 pub enum CompileIncomplete {
1360 Errored(ErrorReported),
1362 impl From<ErrorReported> for CompileIncomplete {
1363 fn from(err: ErrorReported) -> CompileIncomplete {
1364 CompileIncomplete::Errored(err)
1367 pub type CompileResult = Result<(), CompileIncomplete>;
1369 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
1373 Err(CompileIncomplete::Errored(ErrorReported))