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::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
11 use crate::session::search_paths::{PathKind, SearchPath};
12 use crate::util::nodemap::{FxHashMap, FxHashSet};
13 use crate::util::common::{duration_to_secs_str, ErrorReported};
15 use rustc_data_structures::base_n;
16 use rustc_data_structures::sync::{
17 self, Lrc, Lock, OneThread, Once, AtomicU64, AtomicUsize, Ordering,
21 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
22 use errors::emitter::{Emitter, EmitterWriter};
23 use errors::emitter::HumanReadableErrorType;
24 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
25 use syntax::ast::{self, NodeId};
26 use syntax::edition::Edition;
27 use syntax::expand::allocator::AllocatorKind;
28 use syntax::feature_gate::{self, AttributeType};
29 use syntax::json::JsonEmitter;
30 use syntax::source_map;
31 use syntax::sess::ParseSess;
32 use syntax::symbol::Symbol;
33 use syntax_pos::{MultiSpan, Span};
34 use crate::util::profiling::{SelfProfiler, SelfProfilerRef};
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;
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 /// This is intended to be used from a single thread.
82 /// FIXME: there was a previous comment about this not being thread safe,
83 /// but it's not clear how or why that's the case. The LintBuffer itself is certainly thread
84 /// safe at least from a "Rust safety" standpoint.
85 pub buffered_lints: Lock<Option<lint::LintBuffer>>,
87 /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
88 /// (sub)diagnostics that have been set once, but should not be set again,
89 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
90 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
91 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
92 pub plugin_attributes: Lock<Vec<(Symbol, AttributeType)>>,
93 pub crate_types: Once<Vec<config::CrateType>>,
94 /// The `crate_disambiguator` is constructed out of all the `-C metadata`
95 /// arguments passed to the compiler. Its value together with the crate-name
96 /// forms a unique global identifier for the crate. It is used to allow
97 /// multiple crates with the same name to coexist. See the
98 /// `rustc_codegen_llvm::back::symbol_names` module for more information.
99 pub crate_disambiguator: Once<CrateDisambiguator>,
101 features: Once<feature_gate::Features>,
103 /// The maximum recursion limit for potentially infinitely recursive
104 /// operations such as auto-dereference and monomorphization.
105 pub recursion_limit: Once<usize>,
107 /// The maximum length of types during monomorphization.
108 pub type_length_limit: Once<usize>,
110 /// The maximum number of stackframes allowed in const eval.
111 pub const_eval_stack_frame_limit: usize,
113 /// The `metadata::creader` module may inject an allocator/`panic_runtime`
114 /// dependency if it didn't already find one, and this tracks what was
116 pub allocator_kind: Once<Option<AllocatorKind>>,
117 pub injected_panic_runtime: Once<Option<CrateNum>>,
119 /// Map from imported macro spans (which consist of
120 /// the localized span for the macro body) to the
121 /// macro name and definition span in the source crate.
122 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
124 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
125 /// Used for incremental compilation tests. Will only be populated if
126 /// `-Zquery-dep-graph` is specified.
127 pub cgu_reuse_tracker: CguReuseTracker,
129 /// Used by `-Z self-profile`.
130 pub prof: SelfProfilerRef,
132 /// Some measurements that are being gathered during compilation.
133 pub perf_stats: PerfStats,
135 /// Data about code being compiled, gathered during compilation.
136 pub code_stats: Lock<CodeStats>,
138 next_node_id: OneThread<Cell<ast::NodeId>>,
140 /// If `-zfuel=crate=n` is specified, `Some(crate)`.
141 optimization_fuel_crate: Option<String>,
143 /// Tracks fuel info if `-zfuel=crate=n` is specified.
144 optimization_fuel: Lock<OptimizationFuel>,
146 // The next two are public because the driver needs to read them.
147 /// If `-zprint-fuel=crate`, `Some(crate)`.
148 pub print_fuel_crate: Option<String>,
149 /// Always set to zero and incremented so that we can print fuel expended by a crate.
150 pub print_fuel: AtomicU64,
152 /// Loaded up early on in the initialization of this `Session` to avoid
153 /// false positives about a job server in our environment.
154 pub jobserver: Client,
156 /// Metadata about the allocators for the current crate being compiled.
157 pub has_global_allocator: Once<bool>,
159 /// Metadata about the panic handlers for the current crate being compiled.
160 pub has_panic_handler: Once<bool>,
162 /// Cap lint level specified by a driver specifically.
163 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
165 /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
166 pub trait_methods_not_found: Lock<FxHashSet<Span>>,
168 /// Mapping from ident span to path span for paths that don't exist as written, but that
169 /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
170 pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
173 pub struct PerfStats {
174 /// The accumulated time spent on computing symbol hashes.
175 pub symbol_hash_time: Lock<Duration>,
176 /// The accumulated time spent decoding def path tables from metadata.
177 pub decode_def_path_tables_time: Lock<Duration>,
178 /// Total number of values canonicalized queries constructed.
179 pub queries_canonicalized: AtomicUsize,
180 /// Number of times this query is invoked.
181 pub normalize_ty_after_erasing_regions: AtomicUsize,
182 /// Number of times this query is invoked.
183 pub normalize_projection_ty: AtomicUsize,
186 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
187 enum DiagnosticBuilderMethod {
190 SpanSuggestion(String), // suggestion
191 // Add more variants as needed to support one-time diagnostics.
194 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
195 /// emitting the same message more than once.
196 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
197 pub enum DiagnosticMessageId {
198 ErrorId(u16), // EXXXX error code as integer
199 LintId(lint::LintId),
200 StabilityId(u32), // issue number
203 impl From<&'static lint::Lint> for DiagnosticMessageId {
204 fn from(lint: &'static lint::Lint) -> Self {
205 DiagnosticMessageId::LintId(lint::LintId::of(lint))
210 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
211 *self.crate_disambiguator.get()
214 pub fn struct_span_warn<S: Into<MultiSpan>>(
218 ) -> DiagnosticBuilder<'_> {
219 self.diagnostic().struct_span_warn(sp, msg)
221 pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
226 ) -> DiagnosticBuilder<'_> {
227 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
229 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
230 self.diagnostic().struct_warn(msg)
232 pub fn struct_span_err<S: Into<MultiSpan>>(
236 ) -> DiagnosticBuilder<'_> {
237 self.diagnostic().struct_span_err(sp, msg)
239 pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
244 ) -> DiagnosticBuilder<'_> {
245 self.diagnostic().struct_span_err_with_code(sp, msg, code)
247 // FIXME: This method should be removed (every error should have an associated error code).
248 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
249 self.diagnostic().struct_err(msg)
251 pub fn struct_err_with_code(
255 ) -> DiagnosticBuilder<'_> {
256 self.diagnostic().struct_err_with_code(msg, code)
258 pub fn struct_span_fatal<S: Into<MultiSpan>>(
262 ) -> DiagnosticBuilder<'_> {
263 self.diagnostic().struct_span_fatal(sp, msg)
265 pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
270 ) -> DiagnosticBuilder<'_> {
271 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
273 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
274 self.diagnostic().struct_fatal(msg)
277 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
278 self.diagnostic().span_fatal(sp, msg).raise()
280 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
287 .span_fatal_with_code(sp, msg, code)
290 pub fn fatal(&self, msg: &str) -> ! {
291 self.diagnostic().fatal(msg).raise()
293 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
295 self.span_warn(sp, msg);
297 self.span_err(sp, msg);
300 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
301 self.diagnostic().span_err(sp, msg)
303 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
304 self.diagnostic().span_err_with_code(sp, &msg, code)
306 pub fn err(&self, msg: &str) {
307 self.diagnostic().err(msg)
309 pub fn err_count(&self) -> usize {
310 self.diagnostic().err_count()
312 pub fn has_errors(&self) -> bool {
313 self.diagnostic().has_errors()
315 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
316 self.diagnostic().has_errors_or_delayed_span_bugs()
318 pub fn abort_if_errors(&self) {
319 self.diagnostic().abort_if_errors();
321 pub fn compile_status(&self) -> Result<(), ErrorReported> {
322 if self.has_errors() {
323 self.diagnostic().emit_stashed_diagnostics();
329 // FIXME(matthewjasper) Remove this method, it should never be needed.
330 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
334 let old_count = self.err_count();
336 let errors = self.err_count() - old_count;
343 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
344 self.diagnostic().span_warn(sp, msg)
346 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
347 self.diagnostic().span_warn_with_code(sp, msg, code)
349 pub fn warn(&self, msg: &str) {
350 self.diagnostic().warn(msg)
352 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
354 Some(sp) => self.span_warn(sp, msg),
355 None => self.warn(msg),
358 /// Delay a span_bug() call until abort_if_errors()
359 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
360 self.diagnostic().delay_span_bug(sp, msg)
362 pub fn note_without_error(&self, msg: &str) {
363 self.diagnostic().note_without_error(msg)
365 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
366 self.diagnostic().span_note_without_error(sp, msg)
369 pub fn buffer_lint<S: Into<MultiSpan>>(
371 lint: &'static lint::Lint,
376 match *self.buffered_lints.borrow_mut() {
377 Some(ref mut buffer) => {
378 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
380 None => bug!("can't buffer lints after HIR lowering"),
384 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
386 lint: &'static lint::Lint,
390 diagnostic: BuiltinLintDiagnostics,
392 match *self.buffered_lints.borrow_mut() {
393 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
394 None => bug!("can't buffer lints after HIR lowering"),
398 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
399 let id = self.next_node_id.get();
401 match id.as_usize().checked_add(count) {
403 self.next_node_id.set(ast::NodeId::from_usize(next));
405 None => bug!("input too large; ran out of node-IDs!"),
410 pub fn next_node_id(&self) -> NodeId {
411 self.reserve_node_ids(1)
413 pub fn diagnostic(&self) -> &errors::Handler {
414 &self.parse_sess.span_diagnostic
417 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
418 /// deduplicates on lint ID, span (if any), and message for this `Session`
419 fn diag_once<'a, 'b>(
421 diag_builder: &'b mut DiagnosticBuilder<'a>,
422 method: DiagnosticBuilderMethod,
423 msg_id: DiagnosticMessageId,
425 span_maybe: Option<Span>,
427 let id_span_message = (msg_id, span_maybe, message.to_owned());
428 let fresh = self.one_time_diagnostics
430 .insert(id_span_message);
433 DiagnosticBuilderMethod::Note => {
434 diag_builder.note(message);
436 DiagnosticBuilderMethod::SpanNote => {
437 let span = span_maybe.expect("`span_note` needs a span");
438 diag_builder.span_note(span, message);
440 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
441 let span = span_maybe.expect("`span_suggestion_*` needs a span");
442 diag_builder.span_suggestion(
446 Applicability::Unspecified,
453 pub fn diag_span_note_once<'a, 'b>(
455 diag_builder: &'b mut DiagnosticBuilder<'a>,
456 msg_id: DiagnosticMessageId,
462 DiagnosticBuilderMethod::SpanNote,
469 pub fn diag_note_once<'a, 'b>(
471 diag_builder: &'b mut DiagnosticBuilder<'a>,
472 msg_id: DiagnosticMessageId,
477 DiagnosticBuilderMethod::Note,
484 pub fn diag_span_suggestion_once<'a, 'b>(
486 diag_builder: &'b mut DiagnosticBuilder<'a>,
487 msg_id: DiagnosticMessageId,
494 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
501 pub fn source_map(&self) -> &source_map::SourceMap {
502 self.parse_sess.source_map()
504 pub fn verbose(&self) -> bool {
505 self.opts.debugging_opts.verbose
507 pub fn time_passes(&self) -> bool {
508 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
510 pub fn time_extended(&self) -> bool {
511 self.opts.debugging_opts.time_passes
513 pub fn instrument_mcount(&self) -> bool {
514 self.opts.debugging_opts.instrument_mcount
516 pub fn time_llvm_passes(&self) -> bool {
517 self.opts.debugging_opts.time_llvm_passes
519 pub fn meta_stats(&self) -> bool {
520 self.opts.debugging_opts.meta_stats
522 pub fn asm_comments(&self) -> bool {
523 self.opts.debugging_opts.asm_comments
525 pub fn verify_llvm_ir(&self) -> bool {
526 self.opts.debugging_opts.verify_llvm_ir
527 || cfg!(always_verify_llvm_ir)
529 pub fn borrowck_stats(&self) -> bool {
530 self.opts.debugging_opts.borrowck_stats
532 pub fn print_llvm_passes(&self) -> bool {
533 self.opts.debugging_opts.print_llvm_passes
535 pub fn binary_dep_depinfo(&self) -> bool {
536 self.opts.debugging_opts.binary_dep_depinfo
539 /// Gets the features enabled for the current compilation session.
540 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
541 /// dependency tracking. Use tcx.features() instead.
543 pub fn features_untracked(&self) -> &feature_gate::Features {
547 pub fn init_features(&self, features: feature_gate::Features) {
548 self.features.set(features);
551 /// Calculates the flavor of LTO to use for this compilation.
552 pub fn lto(&self) -> config::Lto {
553 // If our target has codegen requirements ignore the command line
554 if self.target.target.options.requires_lto {
555 return config::Lto::Fat;
558 // If the user specified something, return that. If they only said `-C
559 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
560 // then ensure we can't use a ThinLTO.
561 match self.opts.cg.lto {
562 config::LtoCli::Unspecified => {
563 // The compiler was invoked without the `-Clto` flag. Fall
564 // through to the default handling
566 config::LtoCli::No => {
567 // The user explicitly opted out of any kind of LTO
568 return config::Lto::No;
570 config::LtoCli::Yes |
571 config::LtoCli::Fat |
572 config::LtoCli::NoParam => {
573 // All of these mean fat LTO
574 return config::Lto::Fat;
576 config::LtoCli::Thin => {
577 return if self.opts.cli_forced_thinlto_off {
585 // Ok at this point the target doesn't require anything and the user
586 // hasn't asked for anything. Our next decision is whether or not
587 // we enable "auto" ThinLTO where we use multiple codegen units and
588 // then do ThinLTO over those codegen units. The logic below will
589 // either return `No` or `ThinLocal`.
591 // If processing command line options determined that we're incompatible
592 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
593 if self.opts.cli_forced_thinlto_off {
594 return config::Lto::No;
597 // If `-Z thinlto` specified process that, but note that this is mostly
598 // a deprecated option now that `-C lto=thin` exists.
599 if let Some(enabled) = self.opts.debugging_opts.thinlto {
601 return config::Lto::ThinLocal;
603 return config::Lto::No;
607 // If there's only one codegen unit and LTO isn't enabled then there's
608 // no need for ThinLTO so just return false.
609 if self.codegen_units() == 1 {
610 return config::Lto::No;
613 // Now we're in "defaults" territory. By default we enable ThinLTO for
614 // optimized compiles (anything greater than O0).
615 match self.opts.optimize {
616 config::OptLevel::No => config::Lto::No,
617 _ => config::Lto::ThinLocal,
621 /// Returns the panic strategy for this compile session. If the user explicitly selected one
622 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
623 pub fn panic_strategy(&self) -> PanicStrategy {
627 .unwrap_or(self.target.target.options.panic_strategy)
629 pub fn fewer_names(&self) -> bool {
630 let more_names = self.opts
632 .contains_key(&OutputType::LlvmAssembly)
633 || self.opts.output_types.contains_key(&OutputType::Bitcode);
635 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
636 let more_names = match self.opts.debugging_opts.sanitizer {
637 Some(Sanitizer::Address) => true,
638 Some(Sanitizer::Memory) => true,
642 self.opts.debugging_opts.fewer_names || !more_names
645 pub fn no_landing_pads(&self) -> bool {
646 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
648 pub fn unstable_options(&self) -> bool {
649 self.opts.debugging_opts.unstable_options
651 pub fn overflow_checks(&self) -> bool {
655 .or(self.opts.debugging_opts.force_overflow_checks)
656 .unwrap_or(self.opts.debug_assertions)
659 pub fn crt_static(&self) -> bool {
660 // If the target does not opt in to crt-static support, use its default.
661 if self.target.target.options.crt_static_respected {
662 self.crt_static_feature()
664 self.target.target.options.crt_static_default
668 pub fn crt_static_feature(&self) -> bool {
669 let requested_features = self.opts.cg.target_feature.split(',');
670 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
671 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
673 // If the target we're compiling for requests a static crt by default,
674 // then see if the `-crt-static` feature was passed to disable that.
675 // Otherwise if we don't have a static crt by default then see if the
676 // `+crt-static` feature was passed.
677 if self.target.target.options.crt_static_default {
684 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
685 // "mcount" function relies on stack pointer.
686 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
687 if self.instrument_mcount() {
689 } else if let Some(x) = self.opts.cg.force_frame_pointers {
692 !self.target.target.options.eliminate_frame_pointer
696 /// Returns the symbol name for the registrar function,
697 /// given the crate `Svh` and the function `DefIndex`.
698 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
700 "__rustc_plugin_registrar_{}__",
701 disambiguator.to_fingerprint().to_hex()
705 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
707 "__rustc_proc_macro_decls_{}__",
708 disambiguator.to_fingerprint().to_hex()
712 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
713 filesearch::FileSearch::new(
715 self.opts.target_triple.triple(),
716 &self.opts.search_paths,
717 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
718 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
722 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
723 filesearch::FileSearch::new(
725 config::host_triple(),
726 &self.opts.search_paths,
727 &self.host_tlib_path,
732 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
733 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
735 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
736 *load_dep_graph = load;
740 pub fn incr_session_load_dep_graph(&self) -> bool {
741 let incr_comp_session = self.incr_comp_session.borrow();
742 match *incr_comp_session {
743 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
748 pub fn init_incr_comp_session(
750 session_dir: PathBuf,
751 lock_file: flock::Lock,
752 load_dep_graph: bool,
754 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
756 if let IncrCompSession::NotInitialized = *incr_comp_session {
759 "Trying to initialize IncrCompSession `{:?}`",
764 *incr_comp_session = IncrCompSession::Active {
765 session_directory: session_dir,
771 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
772 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
774 if let IncrCompSession::Active { .. } = *incr_comp_session {
777 "trying to finalize `IncrCompSession` `{:?}`",
782 // Note: this will also drop the lock file, thus unlocking the directory.
783 *incr_comp_session = IncrCompSession::Finalized {
784 session_directory: new_directory_path,
788 pub fn mark_incr_comp_session_as_invalid(&self) {
789 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
791 let session_directory = match *incr_comp_session {
792 IncrCompSession::Active {
793 ref session_directory,
795 } => session_directory.clone(),
796 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
798 "trying to invalidate `IncrCompSession` `{:?}`",
803 // Note: this will also drop the lock file, thus unlocking the directory.
804 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
809 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
810 let incr_comp_session = self.incr_comp_session.borrow();
813 |incr_comp_session| match *incr_comp_session {
814 IncrCompSession::NotInitialized => bug!(
815 "trying to get session directory from `IncrCompSession`: {:?}",
818 IncrCompSession::Active {
819 ref session_directory,
822 | IncrCompSession::Finalized {
823 ref session_directory,
825 | IncrCompSession::InvalidBecauseOfErrors {
826 ref session_directory,
827 } => session_directory,
832 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
833 if self.opts.incremental.is_some() {
834 Some(self.incr_comp_session_dir())
840 pub fn print_perf_stats(&self) {
842 "Total time spent computing symbol hashes: {}",
843 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
846 "Total time spent decoding DefPath tables: {}",
847 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
849 println!("Total queries canonicalized: {}",
850 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
851 println!("normalize_ty_after_erasing_regions: {}",
852 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
853 println!("normalize_projection_ty: {}",
854 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
857 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
858 /// This expends fuel if applicable, and records fuel if applicable.
859 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
861 if let Some(ref c) = self.optimization_fuel_crate {
863 assert_eq!(self.threads(), 1);
864 let mut fuel = self.optimization_fuel.lock();
865 ret = fuel.remaining != 0;
866 if fuel.remaining == 0 && !fuel.out_of_fuel {
867 eprintln!("optimization-fuel-exhausted: {}", msg());
868 fuel.out_of_fuel = true;
869 } else if fuel.remaining > 0 {
874 if let Some(ref c) = self.print_fuel_crate {
876 assert_eq!(self.threads(), 1);
877 self.print_fuel.fetch_add(1, SeqCst);
883 /// Returns the number of query threads that should be used for this
885 pub fn threads(&self) -> usize {
886 self.opts.debugging_opts.threads
889 /// Returns the number of codegen units that should be used for this
891 pub fn codegen_units(&self) -> usize {
892 if let Some(n) = self.opts.cli_forced_codegen_units {
895 if let Some(n) = self.target.target.options.default_codegen_units {
899 // Why is 16 codegen units the default all the time?
901 // The main reason for enabling multiple codegen units by default is to
902 // leverage the ability for the codegen backend to do codegen and
903 // optimization in parallel. This allows us, especially for large crates, to
904 // make good use of all available resources on the machine once we've
905 // hit that stage of compilation. Large crates especially then often
906 // take a long time in codegen/optimization and this helps us amortize that
909 // Note that a high number here doesn't mean that we'll be spawning a
910 // large number of threads in parallel. The backend of rustc contains
911 // global rate limiting through the `jobserver` crate so we'll never
912 // overload the system with too much work, but rather we'll only be
913 // optimizing when we're otherwise cooperating with other instances of
916 // Rather a high number here means that we should be able to keep a lot
917 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
918 // to build we'll be guaranteed that all cpus will finish pretty closely
919 // to one another and we should make relatively optimal use of system
922 // Note that the main cost of codegen units is that it prevents LLVM
923 // from inlining across codegen units. Users in general don't have a lot
924 // of control over how codegen units are split up so it's our job in the
925 // compiler to ensure that undue performance isn't lost when using
926 // codegen units (aka we can't require everyone to slap `#[inline]` on
929 // If we're compiling at `-O0` then the number doesn't really matter too
930 // much because performance doesn't matter and inlining is ok to lose.
931 // In debug mode we just want to try to guarantee that no cpu is stuck
932 // doing work that could otherwise be farmed to others.
934 // In release mode, however (O1 and above) performance does indeed
935 // matter! To recover the loss in performance due to inlining we'll be
936 // enabling ThinLTO by default (the function for which is just below).
937 // This will ensure that we recover any inlining wins we otherwise lost
938 // through codegen unit partitioning.
942 // Ok that's a lot of words but the basic tl;dr; is that we want a high
943 // number here -- but not too high. Additionally we're "safe" to have it
944 // always at the same number at all optimization levels.
946 // As a result 16 was chosen here! Mostly because it was a power of 2
947 // and most benchmarks agreed it was roughly a local optimum. Not very
952 pub fn teach(&self, code: &DiagnosticId) -> bool {
953 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
956 pub fn rust_2015(&self) -> bool {
957 self.opts.edition == Edition::Edition2015
960 /// Are we allowed to use features from the Rust 2018 edition?
961 pub fn rust_2018(&self) -> bool {
962 self.opts.edition >= Edition::Edition2018
965 pub fn edition(&self) -> Edition {
969 /// Returns `true` if we cannot skip the PLT for shared library calls.
970 pub fn needs_plt(&self) -> bool {
971 // Check if the current target usually needs PLT to be enabled.
972 // The user can use the command line flag to override it.
973 let needs_plt = self.target.target.options.needs_plt;
975 let dbg_opts = &self.opts.debugging_opts;
977 let relro_level = dbg_opts.relro_level
978 .unwrap_or(self.target.target.options.relro_level);
980 // Only enable this optimization by default if full relro is also enabled.
981 // In this case, lazy binding was already unavailable, so nothing is lost.
982 // This also ensures `-Wl,-z,now` is supported by the linker.
983 let full_relro = RelroLevel::Full == relro_level;
985 // If user didn't explicitly forced us to use / skip the PLT,
986 // then try to skip it where possible.
987 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
991 pub fn build_session(
992 sopts: config::Options,
993 local_crate_source_file: Option<PathBuf>,
994 registry: errors::registry::Registry,
996 let file_path_mapping = sopts.file_path_mapping();
998 build_session_with_source_map(
1000 local_crate_source_file,
1002 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
1003 DiagnosticOutput::Default,
1009 sopts: &config::Options,
1010 registry: errors::registry::Registry,
1011 source_map: &Lrc<source_map::SourceMap>,
1012 emitter_dest: Option<Box<dyn Write + Send>>,
1013 ) -> Box<dyn Emitter + sync::Send> {
1014 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1015 match (sopts.error_format, emitter_dest) {
1016 (config::ErrorOutputType::HumanReadable(kind), dst) => {
1017 let (short, color_config) = kind.unzip();
1019 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
1020 let emitter = AnnotateSnippetEmitterWriter::new(
1021 Some(source_map.clone()),
1023 external_macro_backtrace,
1025 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1027 let emitter = match dst {
1028 None => EmitterWriter::stderr(
1030 Some(source_map.clone()),
1032 sopts.debugging_opts.teach,
1033 sopts.debugging_opts.terminal_width,
1034 external_macro_backtrace,
1036 Some(dst) => EmitterWriter::new(
1038 Some(source_map.clone()),
1040 false, // no teach messages when writing to a buffer
1041 false, // no colors when writing to a buffer
1042 None, // no terminal width
1043 external_macro_backtrace,
1046 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1049 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1050 JsonEmitter::stderr(
1055 external_macro_backtrace,
1056 ).ui_testing(sopts.debugging_opts.ui_testing),
1058 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1065 external_macro_backtrace,
1066 ).ui_testing(sopts.debugging_opts.ui_testing),
1071 pub enum DiagnosticOutput {
1073 Raw(Box<dyn Write + Send>)
1076 pub fn build_session_with_source_map(
1077 sopts: config::Options,
1078 local_crate_source_file: Option<PathBuf>,
1079 registry: errors::registry::Registry,
1080 source_map: Lrc<source_map::SourceMap>,
1081 diagnostics_output: DiagnosticOutput,
1082 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1084 // FIXME: This is not general enough to make the warning lint completely override
1085 // normal diagnostic warnings, since the warning lint can also be denied and changed
1086 // later via the source code.
1087 let warnings_allow = sopts
1090 .filter(|&&(ref key, _)| *key == "warnings")
1091 .map(|&(_, ref level)| *level == lint::Allow)
1094 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1096 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1098 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1099 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1100 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1102 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1104 let emitter = match diagnostics_output {
1105 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1106 DiagnosticOutput::Raw(write) => {
1107 default_emitter(&sopts, registry, &source_map, Some(write))
1111 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1113 errors::HandlerFlags {
1116 report_delayed_bugs,
1117 dont_buffer_diagnostics,
1118 external_macro_backtrace,
1119 ..Default::default()
1123 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1127 sopts: config::Options,
1128 local_crate_source_file: Option<PathBuf>,
1129 span_diagnostic: errors::Handler,
1130 source_map: Lrc<source_map::SourceMap>,
1131 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1134 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1135 let directory = if let Some(ref directory) = d {
1138 std::path::Path::new(".")
1141 let profiler = SelfProfiler::new(
1143 sopts.crate_name.as_ref().map(|s| &s[..]),
1144 &sopts.debugging_opts.self_profile_events
1148 crate::ty::query::QueryName::register_with_profiler(&profiler);
1149 Some(Arc::new(profiler))
1152 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1159 let host_triple = TargetTriple::from_triple(config::host_triple());
1160 let host = Target::search(&host_triple).unwrap_or_else(|e|
1162 .fatal(&format!("Error loading host specification: {}", e))
1165 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1167 let parse_sess = ParseSess::with_span_handler(
1171 let sysroot = match &sopts.maybe_sysroot {
1172 Some(sysroot) => sysroot.clone(),
1173 None => filesearch::get_or_default_sysroot(),
1176 let host_triple = config::host_triple();
1177 let target_triple = sopts.target_triple.triple();
1178 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1179 let target_tlib_path = if host_triple == target_triple {
1182 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1185 let file_path_mapping = sopts.file_path_mapping();
1187 let local_crate_source_file =
1188 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1190 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1191 let optimization_fuel = Lock::new(OptimizationFuel {
1192 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1195 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1196 let print_fuel = AtomicU64::new(0);
1198 let working_dir = env::current_dir().unwrap_or_else(|e|
1199 parse_sess.span_diagnostic
1200 .fatal(&format!("Current directory is invalid: {}", e))
1203 let working_dir = file_path_mapping.map_prefix(working_dir);
1205 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1206 CguReuseTracker::new()
1208 CguReuseTracker::new_disabled()
1211 let sess = Session {
1219 local_crate_source_file,
1221 buffered_lints: Lock::new(Some(Default::default())),
1222 one_time_diagnostics: Default::default(),
1223 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1224 plugin_attributes: Lock::new(Vec::new()),
1225 crate_types: Once::new(),
1226 crate_disambiguator: Once::new(),
1227 features: Once::new(),
1228 recursion_limit: Once::new(),
1229 type_length_limit: Once::new(),
1230 const_eval_stack_frame_limit: 100,
1231 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1232 allocator_kind: Once::new(),
1233 injected_panic_runtime: Once::new(),
1234 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1235 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1237 prof: SelfProfilerRef::new(self_profiler),
1238 perf_stats: PerfStats {
1239 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1240 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1241 queries_canonicalized: AtomicUsize::new(0),
1242 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1243 normalize_projection_ty: AtomicUsize::new(0),
1245 code_stats: Default::default(),
1246 optimization_fuel_crate,
1250 jobserver: jobserver::client(),
1251 has_global_allocator: Once::new(),
1252 has_panic_handler: Once::new(),
1254 trait_methods_not_found: Lock::new(Default::default()),
1255 confused_type_with_std_module: Lock::new(Default::default()),
1258 validate_commandline_args_with_session_available(&sess);
1263 // If it is useful to have a Session available already for validating a
1264 // commandline argument, you can do so here.
1265 fn validate_commandline_args_with_session_available(sess: &Session) {
1266 // Since we don't know if code in an rlib will be linked to statically or
1267 // dynamically downstream, rustc generates `__imp_` symbols that help the
1268 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1269 // these manually generated symbols confuse LLD when it tries to merge
1270 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1271 // when compiling for LLD ThinLTO. This way we can validly just not generate
1272 // the `dllimport` attributes and `__imp_` symbols in that case.
1273 if sess.opts.cg.linker_plugin_lto.enabled() &&
1274 sess.opts.cg.prefer_dynamic &&
1275 sess.target.target.options.is_like_msvc {
1276 sess.err("Linker plugin based LTO is not supported together with \
1277 `-C prefer-dynamic` when targeting MSVC");
1280 // Make sure that any given profiling data actually exists so LLVM can't
1281 // decide to silently skip PGO.
1282 if let Some(ref path) = sess.opts.cg.profile_use {
1284 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1289 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1290 // an error to combine the two for now. It always runs into an assertions
1291 // if LLVM is built with assertions, but without assertions it sometimes
1292 // does not crash and will probably generate a corrupted binary.
1293 // We should only display this error if we're actually going to run PGO.
1294 // If we're just supposed to print out some data, don't show the error (#61002).
1295 if sess.opts.cg.profile_generate.enabled() &&
1296 sess.target.target.options.is_like_msvc &&
1297 sess.panic_strategy() == PanicStrategy::Unwind &&
1298 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1299 sess.err("Profile-guided optimization does not yet work in conjunction \
1300 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1301 See https://github.com/rust-lang/rust/issues/61002 for details.");
1305 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1306 /// compiler. Together with the crate-name forms a unique global identifier for
1308 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1309 pub struct CrateDisambiguator(Fingerprint);
1311 impl CrateDisambiguator {
1312 pub fn to_fingerprint(self) -> Fingerprint {
1317 impl fmt::Display for CrateDisambiguator {
1318 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1319 let (a, b) = self.0.as_value();
1320 let as_u128 = a as u128 | ((b as u128) << 64);
1321 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1325 impl From<Fingerprint> for CrateDisambiguator {
1326 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1327 CrateDisambiguator(fingerprint)
1331 impl_stable_hash_via_hash!(CrateDisambiguator);
1333 /// Holds data on the current incremental compilation session, if there is one.
1335 pub enum IncrCompSession {
1336 /// This is the state the session will be in until the incr. comp. dir is
1339 /// This is the state during which the session directory is private and can
1342 session_directory: PathBuf,
1343 lock_file: flock::Lock,
1344 load_dep_graph: bool,
1346 /// This is the state after the session directory has been finalized. In this
1347 /// state, the contents of the directory must not be modified any more.
1348 Finalized { session_directory: PathBuf },
1349 /// This is an error state that is reached when some compilation error has
1350 /// occurred. It indicates that the contents of the session directory must
1351 /// not be used, since they might be invalid.
1352 InvalidBecauseOfErrors { session_directory: PathBuf },
1355 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1356 let emitter: Box<dyn Emitter + sync::Send> = match output {
1357 config::ErrorOutputType::HumanReadable(kind) => {
1358 let (short, color_config) = kind.unzip();
1359 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1361 config::ErrorOutputType::Json { pretty, json_rendered } =>
1362 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1364 let handler = errors::Handler::with_emitter(true, None, emitter);
1365 handler.struct_fatal(msg).emit();
1366 errors::FatalError.raise();
1369 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1370 let emitter: Box<dyn Emitter + sync::Send> = match output {
1371 config::ErrorOutputType::HumanReadable(kind) => {
1372 let (short, color_config) = kind.unzip();
1373 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1375 config::ErrorOutputType::Json { pretty, json_rendered } =>
1376 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1378 let handler = errors::Handler::with_emitter(true, None, emitter);
1379 handler.struct_warn(msg).emit();
1382 pub type CompileResult = Result<(), ErrorReported>;