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 /// Cap lint level specified by a driver specifically.
152 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
154 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
155 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
157 /// Mapping from ident span to path span for paths that don't exist as written, but that
158 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
159 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
162 pub struct PerfStats {
163 /// The accumulated time spent on computing symbol hashes.
164 pub symbol_hash_time: Lock<Duration>,
165 /// The accumulated time spent decoding def path tables from metadata.
166 pub decode_def_path_tables_time: Lock<Duration>,
167 /// Total number of values canonicalized queries constructed.
168 pub queries_canonicalized: AtomicUsize,
169 /// Number of times this query is invoked.
170 pub normalize_ty_after_erasing_regions: AtomicUsize,
171 /// Number of times this query is invoked.
172 pub normalize_projection_ty: AtomicUsize,
175 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
176 enum DiagnosticBuilderMethod {
179 SpanSuggestion(String), // suggestion
180 // Add more variants as needed to support one-time diagnostics.
183 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
184 /// emitting the same message more than once.
185 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
186 pub enum DiagnosticMessageId {
187 ErrorId(u16), // EXXXX error code as integer
188 LintId(lint::LintId),
189 StabilityId(u32), // issue number
192 impl From<&'static lint::Lint> for DiagnosticMessageId {
193 fn from(lint: &'static lint::Lint) -> Self {
194 DiagnosticMessageId::LintId(lint::LintId::of(lint))
199 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
200 *self.crate_disambiguator.get()
203 pub fn struct_span_warn<S: Into<MultiSpan>>(
207 ) -> DiagnosticBuilder<'_> {
208 self.diagnostic().struct_span_warn(sp, msg)
210 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
215 ) -> DiagnosticBuilder<'_> {
216 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
218 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
219 self.diagnostic().struct_warn(msg)
221 pub fn struct_span_err<S: Into<MultiSpan>>(
225 ) -> DiagnosticBuilder<'_> {
226 self.diagnostic().struct_span_err(sp, msg)
228 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
233 ) -> DiagnosticBuilder<'_> {
234 self.diagnostic().struct_span_err_with_code(sp, msg, code)
236 // FIXME: This method should be removed (every error should have an associated error code).
237 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
238 self.diagnostic().struct_err(msg)
240 pub fn struct_err_with_code(
244 ) -> DiagnosticBuilder<'_> {
245 self.diagnostic().struct_err_with_code(msg, code)
247 pub fn struct_span_fatal<S: Into<MultiSpan>>(
251 ) -> DiagnosticBuilder<'_> {
252 self.diagnostic().struct_span_fatal(sp, msg)
254 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
259 ) -> DiagnosticBuilder<'_> {
260 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
262 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
263 self.diagnostic().struct_fatal(msg)
266 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
267 self.diagnostic().span_fatal(sp, msg).raise()
269 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
276 .span_fatal_with_code(sp, msg, code)
279 pub fn fatal(&self, msg: &str) -> ! {
280 self.diagnostic().fatal(msg).raise()
282 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
284 self.span_warn(sp, msg);
286 self.span_err(sp, msg);
289 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
290 self.diagnostic().span_err(sp, msg)
292 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
293 self.diagnostic().span_err_with_code(sp, &msg, code)
295 pub fn err(&self, msg: &str) {
296 self.diagnostic().err(msg)
298 pub fn err_count(&self) -> usize {
299 self.diagnostic().err_count()
301 pub fn has_errors(&self) -> bool {
302 self.diagnostic().has_errors()
304 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
305 self.diagnostic().has_errors_or_delayed_span_bugs()
307 pub fn abort_if_errors(&self) {
308 self.diagnostic().abort_if_errors();
310 pub fn compile_status(&self) -> Result<(), ErrorReported> {
311 if self.has_errors() {
312 self.diagnostic().emit_stashed_diagnostics();
318 // FIXME(matthewjasper) Remove this method, it should never be needed.
319 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
323 let old_count = self.err_count();
325 let errors = self.err_count() - old_count;
332 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
333 self.diagnostic().span_warn(sp, msg)
335 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
336 self.diagnostic().span_warn_with_code(sp, msg, code)
338 pub fn warn(&self, msg: &str) {
339 self.diagnostic().warn(msg)
341 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
343 Some(sp) => self.span_warn(sp, msg),
344 None => self.warn(msg),
347 /// Delay a span_bug() call until abort_if_errors()
348 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
349 self.diagnostic().delay_span_bug(sp, msg)
351 pub fn note_without_error(&self, msg: &str) {
352 self.diagnostic().note_without_error(msg)
354 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
355 self.diagnostic().span_note_without_error(sp, msg)
358 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
359 let id = self.next_node_id.get();
361 match id.as_usize().checked_add(count) {
363 self.next_node_id.set(ast::NodeId::from_usize(next));
365 None => bug!("input too large; ran out of node-IDs!"),
370 pub fn next_node_id(&self) -> NodeId {
371 self.reserve_node_ids(1)
373 pub fn diagnostic(&self) -> &errors::Handler {
374 &self.parse_sess.span_diagnostic
377 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
378 /// deduplicates on lint ID, span (if any), and message for this `Session`
379 fn diag_once<'a, 'b>(
381 diag_builder: &'b mut DiagnosticBuilder<'a>,
382 method: DiagnosticBuilderMethod,
383 msg_id: DiagnosticMessageId,
385 span_maybe: Option<Span>,
387 let id_span_message = (msg_id, span_maybe, message.to_owned());
388 let fresh = self.one_time_diagnostics
390 .insert(id_span_message);
393 DiagnosticBuilderMethod::Note => {
394 diag_builder.note(message);
396 DiagnosticBuilderMethod::SpanNote => {
397 let span = span_maybe.expect("`span_note` needs a span");
398 diag_builder.span_note(span, message);
400 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
401 let span = span_maybe.expect("`span_suggestion_*` needs a span");
402 diag_builder.span_suggestion(
406 Applicability::Unspecified,
413 pub fn diag_span_note_once<'a, 'b>(
415 diag_builder: &'b mut DiagnosticBuilder<'a>,
416 msg_id: DiagnosticMessageId,
422 DiagnosticBuilderMethod::SpanNote,
429 pub fn diag_note_once<'a, 'b>(
431 diag_builder: &'b mut DiagnosticBuilder<'a>,
432 msg_id: DiagnosticMessageId,
437 DiagnosticBuilderMethod::Note,
444 pub fn diag_span_suggestion_once<'a, 'b>(
446 diag_builder: &'b mut DiagnosticBuilder<'a>,
447 msg_id: DiagnosticMessageId,
454 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
461 pub fn source_map(&self) -> &source_map::SourceMap {
462 self.parse_sess.source_map()
464 pub fn verbose(&self) -> bool {
465 self.opts.debugging_opts.verbose
467 pub fn time_passes(&self) -> bool {
468 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
470 pub fn time_extended(&self) -> bool {
471 self.opts.debugging_opts.time_passes
473 pub fn instrument_mcount(&self) -> bool {
474 self.opts.debugging_opts.instrument_mcount
476 pub fn time_llvm_passes(&self) -> bool {
477 self.opts.debugging_opts.time_llvm_passes
479 pub fn meta_stats(&self) -> bool {
480 self.opts.debugging_opts.meta_stats
482 pub fn asm_comments(&self) -> bool {
483 self.opts.debugging_opts.asm_comments
485 pub fn verify_llvm_ir(&self) -> bool {
486 self.opts.debugging_opts.verify_llvm_ir
487 || cfg!(always_verify_llvm_ir)
489 pub fn borrowck_stats(&self) -> bool {
490 self.opts.debugging_opts.borrowck_stats
492 pub fn print_llvm_passes(&self) -> bool {
493 self.opts.debugging_opts.print_llvm_passes
495 pub fn binary_dep_depinfo(&self) -> bool {
496 self.opts.debugging_opts.binary_dep_depinfo
499 /// Gets the features enabled for the current compilation session.
500 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
501 /// dependency tracking. Use tcx.features() instead.
503 pub fn features_untracked(&self) -> &feature_gate::Features {
507 pub fn init_features(&self, features: feature_gate::Features) {
508 self.features.set(features);
511 /// Calculates the flavor of LTO to use for this compilation.
512 pub fn lto(&self) -> config::Lto {
513 // If our target has codegen requirements ignore the command line
514 if self.target.target.options.requires_lto {
515 return config::Lto::Fat;
518 // If the user specified something, return that. If they only said `-C
519 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
520 // then ensure we can't use a ThinLTO.
521 match self.opts.cg.lto {
522 config::LtoCli::Unspecified => {
523 // The compiler was invoked without the `-Clto` flag. Fall
524 // through to the default handling
526 config::LtoCli::No => {
527 // The user explicitly opted out of any kind of LTO
528 return config::Lto::No;
530 config::LtoCli::Yes |
531 config::LtoCli::Fat |
532 config::LtoCli::NoParam => {
533 // All of these mean fat LTO
534 return config::Lto::Fat;
536 config::LtoCli::Thin => {
537 return if self.opts.cli_forced_thinlto_off {
545 // Ok at this point the target doesn't require anything and the user
546 // hasn't asked for anything. Our next decision is whether or not
547 // we enable "auto" ThinLTO where we use multiple codegen units and
548 // then do ThinLTO over those codegen units. The logic below will
549 // either return `No` or `ThinLocal`.
551 // If processing command line options determined that we're incompatible
552 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
553 if self.opts.cli_forced_thinlto_off {
554 return config::Lto::No;
557 // If `-Z thinlto` specified process that, but note that this is mostly
558 // a deprecated option now that `-C lto=thin` exists.
559 if let Some(enabled) = self.opts.debugging_opts.thinlto {
561 return config::Lto::ThinLocal;
563 return config::Lto::No;
567 // If there's only one codegen unit and LTO isn't enabled then there's
568 // no need for ThinLTO so just return false.
569 if self.codegen_units() == 1 {
570 return config::Lto::No;
573 // Now we're in "defaults" territory. By default we enable ThinLTO for
574 // optimized compiles (anything greater than O0).
575 match self.opts.optimize {
576 config::OptLevel::No => config::Lto::No,
577 _ => config::Lto::ThinLocal,
581 /// Returns the panic strategy for this compile session. If the user explicitly selected one
582 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
583 pub fn panic_strategy(&self) -> PanicStrategy {
587 .unwrap_or(self.target.target.options.panic_strategy)
589 pub fn fewer_names(&self) -> bool {
590 let more_names = self.opts
592 .contains_key(&OutputType::LlvmAssembly)
593 || self.opts.output_types.contains_key(&OutputType::Bitcode);
595 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
596 let more_names = match self.opts.debugging_opts.sanitizer {
597 Some(Sanitizer::Address) => true,
598 Some(Sanitizer::Memory) => true,
602 self.opts.debugging_opts.fewer_names || !more_names
605 pub fn no_landing_pads(&self) -> bool {
606 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
608 pub fn unstable_options(&self) -> bool {
609 self.opts.debugging_opts.unstable_options
611 pub fn overflow_checks(&self) -> bool {
615 .or(self.opts.debugging_opts.force_overflow_checks)
616 .unwrap_or(self.opts.debug_assertions)
619 pub fn crt_static(&self) -> bool {
620 // If the target does not opt in to crt-static support, use its default.
621 if self.target.target.options.crt_static_respected {
622 self.crt_static_feature()
624 self.target.target.options.crt_static_default
628 pub fn crt_static_feature(&self) -> bool {
629 let requested_features = self.opts.cg.target_feature.split(',');
630 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
631 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
633 // If the target we're compiling for requests a static crt by default,
634 // then see if the `-crt-static` feature was passed to disable that.
635 // Otherwise if we don't have a static crt by default then see if the
636 // `+crt-static` feature was passed.
637 if self.target.target.options.crt_static_default {
644 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
645 // "mcount" function relies on stack pointer.
646 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
647 if self.instrument_mcount() {
649 } else if let Some(x) = self.opts.cg.force_frame_pointers {
652 !self.target.target.options.eliminate_frame_pointer
656 /// Returns the symbol name for the registrar function,
657 /// given the crate `Svh` and the function `DefIndex`.
658 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
660 "__rustc_plugin_registrar_{}__",
661 disambiguator.to_fingerprint().to_hex()
665 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
667 "__rustc_proc_macro_decls_{}__",
668 disambiguator.to_fingerprint().to_hex()
672 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
673 filesearch::FileSearch::new(
675 self.opts.target_triple.triple(),
676 &self.opts.search_paths,
677 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
678 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
682 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
683 filesearch::FileSearch::new(
685 config::host_triple(),
686 &self.opts.search_paths,
687 &self.host_tlib_path,
692 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
693 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
695 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
696 *load_dep_graph = load;
700 pub fn incr_session_load_dep_graph(&self) -> bool {
701 let incr_comp_session = self.incr_comp_session.borrow();
702 match *incr_comp_session {
703 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
708 pub fn init_incr_comp_session(
710 session_dir: PathBuf,
711 lock_file: flock::Lock,
712 load_dep_graph: bool,
714 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
716 if let IncrCompSession::NotInitialized = *incr_comp_session {
719 "Trying to initialize IncrCompSession `{:?}`",
724 *incr_comp_session = IncrCompSession::Active {
725 session_directory: session_dir,
731 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
732 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
734 if let IncrCompSession::Active { .. } = *incr_comp_session {
737 "trying to finalize `IncrCompSession` `{:?}`",
742 // Note: this will also drop the lock file, thus unlocking the directory.
743 *incr_comp_session = IncrCompSession::Finalized {
744 session_directory: new_directory_path,
748 pub fn mark_incr_comp_session_as_invalid(&self) {
749 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
751 let session_directory = match *incr_comp_session {
752 IncrCompSession::Active {
753 ref session_directory,
755 } => session_directory.clone(),
756 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
758 "trying to invalidate `IncrCompSession` `{:?}`",
763 // Note: this will also drop the lock file, thus unlocking the directory.
764 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
769 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
770 let incr_comp_session = self.incr_comp_session.borrow();
773 |incr_comp_session| match *incr_comp_session {
774 IncrCompSession::NotInitialized => bug!(
775 "trying to get session directory from `IncrCompSession`: {:?}",
778 IncrCompSession::Active {
779 ref session_directory,
782 | IncrCompSession::Finalized {
783 ref session_directory,
785 | IncrCompSession::InvalidBecauseOfErrors {
786 ref session_directory,
787 } => session_directory,
792 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
793 if self.opts.incremental.is_some() {
794 Some(self.incr_comp_session_dir())
800 pub fn print_perf_stats(&self) {
802 "Total time spent computing symbol hashes: {}",
803 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
806 "Total time spent decoding DefPath tables: {}",
807 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
809 println!("Total queries canonicalized: {}",
810 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
811 println!("normalize_ty_after_erasing_regions: {}",
812 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
813 println!("normalize_projection_ty: {}",
814 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
817 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
818 /// This expends fuel if applicable, and records fuel if applicable.
819 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
821 if let Some(ref c) = self.optimization_fuel_crate {
823 assert_eq!(self.threads(), 1);
824 let mut fuel = self.optimization_fuel.lock();
825 ret = fuel.remaining != 0;
826 if fuel.remaining == 0 && !fuel.out_of_fuel {
827 eprintln!("optimization-fuel-exhausted: {}", msg());
828 fuel.out_of_fuel = true;
829 } else if fuel.remaining > 0 {
834 if let Some(ref c) = self.print_fuel_crate {
836 assert_eq!(self.threads(), 1);
837 self.print_fuel.fetch_add(1, SeqCst);
843 /// Returns the number of query threads that should be used for this
845 pub fn threads(&self) -> usize {
846 self.opts.debugging_opts.threads
849 /// Returns the number of codegen units that should be used for this
851 pub fn codegen_units(&self) -> usize {
852 if let Some(n) = self.opts.cli_forced_codegen_units {
855 if let Some(n) = self.target.target.options.default_codegen_units {
859 // Why is 16 codegen units the default all the time?
861 // The main reason for enabling multiple codegen units by default is to
862 // leverage the ability for the codegen backend to do codegen and
863 // optimization in parallel. This allows us, especially for large crates, to
864 // make good use of all available resources on the machine once we've
865 // hit that stage of compilation. Large crates especially then often
866 // take a long time in codegen/optimization and this helps us amortize that
869 // Note that a high number here doesn't mean that we'll be spawning a
870 // large number of threads in parallel. The backend of rustc contains
871 // global rate limiting through the `jobserver` crate so we'll never
872 // overload the system with too much work, but rather we'll only be
873 // optimizing when we're otherwise cooperating with other instances of
876 // Rather a high number here means that we should be able to keep a lot
877 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
878 // to build we'll be guaranteed that all cpus will finish pretty closely
879 // to one another and we should make relatively optimal use of system
882 // Note that the main cost of codegen units is that it prevents LLVM
883 // from inlining across codegen units. Users in general don't have a lot
884 // of control over how codegen units are split up so it's our job in the
885 // compiler to ensure that undue performance isn't lost when using
886 // codegen units (aka we can't require everyone to slap `#[inline]` on
889 // If we're compiling at `-O0` then the number doesn't really matter too
890 // much because performance doesn't matter and inlining is ok to lose.
891 // In debug mode we just want to try to guarantee that no cpu is stuck
892 // doing work that could otherwise be farmed to others.
894 // In release mode, however (O1 and above) performance does indeed
895 // matter! To recover the loss in performance due to inlining we'll be
896 // enabling ThinLTO by default (the function for which is just below).
897 // This will ensure that we recover any inlining wins we otherwise lost
898 // through codegen unit partitioning.
902 // Ok that's a lot of words but the basic tl;dr; is that we want a high
903 // number here -- but not too high. Additionally we're "safe" to have it
904 // always at the same number at all optimization levels.
906 // As a result 16 was chosen here! Mostly because it was a power of 2
907 // and most benchmarks agreed it was roughly a local optimum. Not very
912 pub fn teach(&self, code: &DiagnosticId) -> bool {
913 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
916 pub fn rust_2015(&self) -> bool {
917 self.opts.edition == Edition::Edition2015
920 /// Are we allowed to use features from the Rust 2018 edition?
921 pub fn rust_2018(&self) -> bool {
922 self.opts.edition >= Edition::Edition2018
925 pub fn edition(&self) -> Edition {
929 /// Returns `true` if we cannot skip the PLT for shared library calls.
930 pub fn needs_plt(&self) -> bool {
931 // Check if the current target usually needs PLT to be enabled.
932 // The user can use the command line flag to override it.
933 let needs_plt = self.target.target.options.needs_plt;
935 let dbg_opts = &self.opts.debugging_opts;
937 let relro_level = dbg_opts.relro_level
938 .unwrap_or(self.target.target.options.relro_level);
940 // Only enable this optimization by default if full relro is also enabled.
941 // In this case, lazy binding was already unavailable, so nothing is lost.
942 // This also ensures `-Wl,-z,now` is supported by the linker.
943 let full_relro = RelroLevel::Full == relro_level;
945 // If user didn't explicitly forced us to use / skip the PLT,
946 // then try to skip it where possible.
947 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
951 pub fn build_session(
952 sopts: config::Options,
953 local_crate_source_file: Option<PathBuf>,
954 registry: errors::registry::Registry,
956 let file_path_mapping = sopts.file_path_mapping();
958 build_session_with_source_map(
960 local_crate_source_file,
962 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
963 DiagnosticOutput::Default,
969 sopts: &config::Options,
970 registry: errors::registry::Registry,
971 source_map: &Lrc<source_map::SourceMap>,
972 emitter_dest: Option<Box<dyn Write + Send>>,
973 ) -> Box<dyn Emitter + sync::Send> {
974 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
975 match (sopts.error_format, emitter_dest) {
976 (config::ErrorOutputType::HumanReadable(kind), dst) => {
977 let (short, color_config) = kind.unzip();
979 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
980 let emitter = AnnotateSnippetEmitterWriter::new(
981 Some(source_map.clone()),
983 external_macro_backtrace,
985 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
987 let emitter = match dst {
988 None => EmitterWriter::stderr(
990 Some(source_map.clone()),
992 sopts.debugging_opts.teach,
993 sopts.debugging_opts.terminal_width,
994 external_macro_backtrace,
996 Some(dst) => EmitterWriter::new(
998 Some(source_map.clone()),
1000 false, // no teach messages when writing to a buffer
1001 false, // no colors when writing to a buffer
1002 None, // no terminal width
1003 external_macro_backtrace,
1006 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1009 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1010 JsonEmitter::stderr(
1015 external_macro_backtrace,
1016 ).ui_testing(sopts.debugging_opts.ui_testing),
1018 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1025 external_macro_backtrace,
1026 ).ui_testing(sopts.debugging_opts.ui_testing),
1031 pub enum DiagnosticOutput {
1033 Raw(Box<dyn Write + Send>)
1036 pub fn build_session_with_source_map(
1037 sopts: config::Options,
1038 local_crate_source_file: Option<PathBuf>,
1039 registry: errors::registry::Registry,
1040 source_map: Lrc<source_map::SourceMap>,
1041 diagnostics_output: DiagnosticOutput,
1042 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1044 // FIXME: This is not general enough to make the warning lint completely override
1045 // normal diagnostic warnings, since the warning lint can also be denied and changed
1046 // later via the source code.
1047 let warnings_allow = sopts
1050 .filter(|&&(ref key, _)| *key == "warnings")
1051 .map(|&(_, ref level)| *level == lint::Allow)
1054 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1056 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1058 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1059 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1060 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1062 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1064 let emitter = match diagnostics_output {
1065 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1066 DiagnosticOutput::Raw(write) => {
1067 default_emitter(&sopts, registry, &source_map, Some(write))
1071 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1073 errors::HandlerFlags {
1076 report_delayed_bugs,
1077 dont_buffer_diagnostics,
1078 external_macro_backtrace,
1079 ..Default::default()
1083 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1087 sopts: config::Options,
1088 local_crate_source_file: Option<PathBuf>,
1089 span_diagnostic: errors::Handler,
1090 source_map: Lrc<source_map::SourceMap>,
1091 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1094 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1095 let directory = if let Some(ref directory) = d {
1098 std::path::Path::new(".")
1101 let profiler = SelfProfiler::new(
1103 sopts.crate_name.as_ref().map(|s| &s[..]),
1104 &sopts.debugging_opts.self_profile_events
1108 crate::ty::query::QueryName::register_with_profiler(&profiler);
1109 Some(Arc::new(profiler))
1112 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1119 let host_triple = TargetTriple::from_triple(config::host_triple());
1120 let host = Target::search(&host_triple).unwrap_or_else(|e|
1122 .fatal(&format!("Error loading host specification: {}", e))
1125 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1127 let parse_sess = ParseSess::with_span_handler(
1131 let sysroot = match &sopts.maybe_sysroot {
1132 Some(sysroot) => sysroot.clone(),
1133 None => filesearch::get_or_default_sysroot(),
1136 let host_triple = config::host_triple();
1137 let target_triple = sopts.target_triple.triple();
1138 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1139 let target_tlib_path = if host_triple == target_triple {
1142 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1145 let file_path_mapping = sopts.file_path_mapping();
1147 let local_crate_source_file =
1148 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1150 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1151 let optimization_fuel = Lock::new(OptimizationFuel {
1152 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1155 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1156 let print_fuel = AtomicU64::new(0);
1158 let working_dir = env::current_dir().unwrap_or_else(|e|
1159 parse_sess.span_diagnostic
1160 .fatal(&format!("Current directory is invalid: {}", e))
1163 let working_dir = file_path_mapping.map_prefix(working_dir);
1165 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1166 CguReuseTracker::new()
1168 CguReuseTracker::new_disabled()
1171 let sess = Session {
1179 local_crate_source_file,
1181 one_time_diagnostics: Default::default(),
1182 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1183 plugin_attributes: Lock::new(Vec::new()),
1184 crate_types: Once::new(),
1185 crate_disambiguator: Once::new(),
1186 features: Once::new(),
1187 recursion_limit: Once::new(),
1188 type_length_limit: Once::new(),
1189 const_eval_stack_frame_limit: 100,
1190 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1191 allocator_kind: Once::new(),
1192 injected_panic_runtime: Once::new(),
1193 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1194 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1196 prof: SelfProfilerRef::new(self_profiler),
1197 perf_stats: PerfStats {
1198 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1199 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1200 queries_canonicalized: AtomicUsize::new(0),
1201 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1202 normalize_projection_ty: AtomicUsize::new(0),
1204 code_stats: Default::default(),
1205 optimization_fuel_crate,
1209 jobserver: jobserver::client(),
1210 has_global_allocator: Once::new(),
1212 trait_methods_not_found: Lock::new(Default::default()),
1213 confused_type_with_std_module: Lock::new(Default::default()),
1216 validate_commandline_args_with_session_available(&sess);
1221 // If it is useful to have a Session available already for validating a
1222 // commandline argument, you can do so here.
1223 fn validate_commandline_args_with_session_available(sess: &Session) {
1224 // Since we don't know if code in an rlib will be linked to statically or
1225 // dynamically downstream, rustc generates `__imp_` symbols that help the
1226 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1227 // these manually generated symbols confuse LLD when it tries to merge
1228 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1229 // when compiling for LLD ThinLTO. This way we can validly just not generate
1230 // the `dllimport` attributes and `__imp_` symbols in that case.
1231 if sess.opts.cg.linker_plugin_lto.enabled() &&
1232 sess.opts.cg.prefer_dynamic &&
1233 sess.target.target.options.is_like_msvc {
1234 sess.err("Linker plugin based LTO is not supported together with \
1235 `-C prefer-dynamic` when targeting MSVC");
1238 // Make sure that any given profiling data actually exists so LLVM can't
1239 // decide to silently skip PGO.
1240 if let Some(ref path) = sess.opts.cg.profile_use {
1242 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1247 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1248 // an error to combine the two for now. It always runs into an assertions
1249 // if LLVM is built with assertions, but without assertions it sometimes
1250 // does not crash and will probably generate a corrupted binary.
1251 // We should only display this error if we're actually going to run PGO.
1252 // If we're just supposed to print out some data, don't show the error (#61002).
1253 if sess.opts.cg.profile_generate.enabled() &&
1254 sess.target.target.options.is_like_msvc &&
1255 sess.panic_strategy() == PanicStrategy::Unwind &&
1256 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1257 sess.err("Profile-guided optimization does not yet work in conjunction \
1258 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1259 See https://github.com/rust-lang/rust/issues/61002 for details.");
1263 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1264 /// compiler. Together with the crate-name forms a unique global identifier for
1266 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1267 pub struct CrateDisambiguator(Fingerprint);
1269 impl CrateDisambiguator {
1270 pub fn to_fingerprint(self) -> Fingerprint {
1275 impl fmt::Display for CrateDisambiguator {
1276 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1277 let (a, b) = self.0.as_value();
1278 let as_u128 = a as u128 | ((b as u128) << 64);
1279 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1283 impl From<Fingerprint> for CrateDisambiguator {
1284 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1285 CrateDisambiguator(fingerprint)
1289 impl_stable_hash_via_hash!(CrateDisambiguator);
1291 /// Holds data on the current incremental compilation session, if there is one.
1293 pub enum IncrCompSession {
1294 /// This is the state the session will be in until the incr. comp. dir is
1297 /// This is the state during which the session directory is private and can
1300 session_directory: PathBuf,
1301 lock_file: flock::Lock,
1302 load_dep_graph: bool,
1304 /// This is the state after the session directory has been finalized. In this
1305 /// state, the contents of the directory must not be modified any more.
1306 Finalized { session_directory: PathBuf },
1307 /// This is an error state that is reached when some compilation error has
1308 /// occurred. It indicates that the contents of the session directory must
1309 /// not be used, since they might be invalid.
1310 InvalidBecauseOfErrors { session_directory: PathBuf },
1313 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1314 let emitter: Box<dyn Emitter + sync::Send> = match output {
1315 config::ErrorOutputType::HumanReadable(kind) => {
1316 let (short, color_config) = kind.unzip();
1317 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1319 config::ErrorOutputType::Json { pretty, json_rendered } =>
1320 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1322 let handler = errors::Handler::with_emitter(true, None, emitter);
1323 handler.struct_fatal(msg).emit();
1324 errors::FatalError.raise();
1327 pub fn early_warn(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, None, false))
1333 config::ErrorOutputType::Json { pretty, json_rendered } =>
1334 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1336 let handler = errors::Handler::with_emitter(true, None, emitter);
1337 handler.struct_warn(msg).emit();
1340 pub type CompileResult = Result<(), ErrorReported>;