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 abort_if_errors(&self) {
316 self.diagnostic().abort_if_errors();
318 pub fn compile_status(&self) -> Result<(), ErrorReported> {
319 if self.has_errors() {
320 self.diagnostic().emit_stashed_diagnostics();
326 // FIXME(matthewjasper) Remove this method, it should never be needed.
327 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
331 let old_count = self.err_count();
333 let errors = self.err_count() - old_count;
340 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
341 self.diagnostic().span_warn(sp, msg)
343 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
344 self.diagnostic().span_warn_with_code(sp, msg, code)
346 pub fn warn(&self, msg: &str) {
347 self.diagnostic().warn(msg)
349 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
351 Some(sp) => self.span_warn(sp, msg),
352 None => self.warn(msg),
355 /// Delay a span_bug() call until abort_if_errors()
356 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
357 self.diagnostic().delay_span_bug(sp, msg)
359 pub fn note_without_error(&self, msg: &str) {
360 self.diagnostic().note_without_error(msg)
362 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
363 self.diagnostic().span_note_without_error(sp, msg)
366 pub fn buffer_lint<S: Into<MultiSpan>>(
368 lint: &'static lint::Lint,
373 match *self.buffered_lints.borrow_mut() {
374 Some(ref mut buffer) => {
375 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
377 None => bug!("can't buffer lints after HIR lowering"),
381 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
383 lint: &'static lint::Lint,
387 diagnostic: BuiltinLintDiagnostics,
389 match *self.buffered_lints.borrow_mut() {
390 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
391 None => bug!("can't buffer lints after HIR lowering"),
395 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
396 let id = self.next_node_id.get();
398 match id.as_usize().checked_add(count) {
400 self.next_node_id.set(ast::NodeId::from_usize(next));
402 None => bug!("input too large; ran out of node-IDs!"),
407 pub fn next_node_id(&self) -> NodeId {
408 self.reserve_node_ids(1)
410 pub fn diagnostic(&self) -> &errors::Handler {
411 &self.parse_sess.span_diagnostic
414 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
415 /// deduplicates on lint ID, span (if any), and message for this `Session`
416 fn diag_once<'a, 'b>(
418 diag_builder: &'b mut DiagnosticBuilder<'a>,
419 method: DiagnosticBuilderMethod,
420 msg_id: DiagnosticMessageId,
422 span_maybe: Option<Span>,
424 let id_span_message = (msg_id, span_maybe, message.to_owned());
425 let fresh = self.one_time_diagnostics
427 .insert(id_span_message);
430 DiagnosticBuilderMethod::Note => {
431 diag_builder.note(message);
433 DiagnosticBuilderMethod::SpanNote => {
434 let span = span_maybe.expect("`span_note` needs a span");
435 diag_builder.span_note(span, message);
437 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
438 let span = span_maybe.expect("`span_suggestion_*` needs a span");
439 diag_builder.span_suggestion(
443 Applicability::Unspecified,
450 pub fn diag_span_note_once<'a, 'b>(
452 diag_builder: &'b mut DiagnosticBuilder<'a>,
453 msg_id: DiagnosticMessageId,
459 DiagnosticBuilderMethod::SpanNote,
466 pub fn diag_note_once<'a, 'b>(
468 diag_builder: &'b mut DiagnosticBuilder<'a>,
469 msg_id: DiagnosticMessageId,
474 DiagnosticBuilderMethod::Note,
481 pub fn diag_span_suggestion_once<'a, 'b>(
483 diag_builder: &'b mut DiagnosticBuilder<'a>,
484 msg_id: DiagnosticMessageId,
491 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
498 pub fn source_map(&self) -> &source_map::SourceMap {
499 self.parse_sess.source_map()
501 pub fn verbose(&self) -> bool {
502 self.opts.debugging_opts.verbose
504 pub fn time_passes(&self) -> bool {
505 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
507 pub fn time_extended(&self) -> bool {
508 self.opts.debugging_opts.time_passes
510 pub fn instrument_mcount(&self) -> bool {
511 self.opts.debugging_opts.instrument_mcount
513 pub fn time_llvm_passes(&self) -> bool {
514 self.opts.debugging_opts.time_llvm_passes
516 pub fn meta_stats(&self) -> bool {
517 self.opts.debugging_opts.meta_stats
519 pub fn asm_comments(&self) -> bool {
520 self.opts.debugging_opts.asm_comments
522 pub fn verify_llvm_ir(&self) -> bool {
523 self.opts.debugging_opts.verify_llvm_ir
524 || cfg!(always_verify_llvm_ir)
526 pub fn borrowck_stats(&self) -> bool {
527 self.opts.debugging_opts.borrowck_stats
529 pub fn print_llvm_passes(&self) -> bool {
530 self.opts.debugging_opts.print_llvm_passes
532 pub fn binary_dep_depinfo(&self) -> bool {
533 self.opts.debugging_opts.binary_dep_depinfo
536 /// Gets the features enabled for the current compilation session.
537 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
538 /// dependency tracking. Use tcx.features() instead.
540 pub fn features_untracked(&self) -> &feature_gate::Features {
544 pub fn init_features(&self, features: feature_gate::Features) {
545 self.features.set(features);
548 /// Calculates the flavor of LTO to use for this compilation.
549 pub fn lto(&self) -> config::Lto {
550 // If our target has codegen requirements ignore the command line
551 if self.target.target.options.requires_lto {
552 return config::Lto::Fat;
555 // If the user specified something, return that. If they only said `-C
556 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
557 // then ensure we can't use a ThinLTO.
558 match self.opts.cg.lto {
559 config::LtoCli::Unspecified => {
560 // The compiler was invoked without the `-Clto` flag. Fall
561 // through to the default handling
563 config::LtoCli::No => {
564 // The user explicitly opted out of any kind of LTO
565 return config::Lto::No;
567 config::LtoCli::Yes |
568 config::LtoCli::Fat |
569 config::LtoCli::NoParam => {
570 // All of these mean fat LTO
571 return config::Lto::Fat;
573 config::LtoCli::Thin => {
574 return if self.opts.cli_forced_thinlto_off {
582 // Ok at this point the target doesn't require anything and the user
583 // hasn't asked for anything. Our next decision is whether or not
584 // we enable "auto" ThinLTO where we use multiple codegen units and
585 // then do ThinLTO over those codegen units. The logic below will
586 // either return `No` or `ThinLocal`.
588 // If processing command line options determined that we're incompatible
589 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
590 if self.opts.cli_forced_thinlto_off {
591 return config::Lto::No;
594 // If `-Z thinlto` specified process that, but note that this is mostly
595 // a deprecated option now that `-C lto=thin` exists.
596 if let Some(enabled) = self.opts.debugging_opts.thinlto {
598 return config::Lto::ThinLocal;
600 return config::Lto::No;
604 // If there's only one codegen unit and LTO isn't enabled then there's
605 // no need for ThinLTO so just return false.
606 if self.codegen_units() == 1 {
607 return config::Lto::No;
610 // Now we're in "defaults" territory. By default we enable ThinLTO for
611 // optimized compiles (anything greater than O0).
612 match self.opts.optimize {
613 config::OptLevel::No => config::Lto::No,
614 _ => config::Lto::ThinLocal,
618 /// Returns the panic strategy for this compile session. If the user explicitly selected one
619 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
620 pub fn panic_strategy(&self) -> PanicStrategy {
624 .unwrap_or(self.target.target.options.panic_strategy)
626 pub fn fewer_names(&self) -> bool {
627 let more_names = self.opts
629 .contains_key(&OutputType::LlvmAssembly)
630 || self.opts.output_types.contains_key(&OutputType::Bitcode);
632 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
633 let more_names = match self.opts.debugging_opts.sanitizer {
634 Some(Sanitizer::Address) => true,
635 Some(Sanitizer::Memory) => true,
639 self.opts.debugging_opts.fewer_names || !more_names
642 pub fn no_landing_pads(&self) -> bool {
643 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
645 pub fn unstable_options(&self) -> bool {
646 self.opts.debugging_opts.unstable_options
648 pub fn overflow_checks(&self) -> bool {
652 .or(self.opts.debugging_opts.force_overflow_checks)
653 .unwrap_or(self.opts.debug_assertions)
656 pub fn crt_static(&self) -> bool {
657 // If the target does not opt in to crt-static support, use its default.
658 if self.target.target.options.crt_static_respected {
659 self.crt_static_feature()
661 self.target.target.options.crt_static_default
665 pub fn crt_static_feature(&self) -> bool {
666 let requested_features = self.opts.cg.target_feature.split(',');
667 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
668 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
670 // If the target we're compiling for requests a static crt by default,
671 // then see if the `-crt-static` feature was passed to disable that.
672 // Otherwise if we don't have a static crt by default then see if the
673 // `+crt-static` feature was passed.
674 if self.target.target.options.crt_static_default {
681 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
682 // "mcount" function relies on stack pointer.
683 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
684 if self.instrument_mcount() {
686 } else if let Some(x) = self.opts.cg.force_frame_pointers {
689 !self.target.target.options.eliminate_frame_pointer
693 /// Returns the symbol name for the registrar function,
694 /// given the crate `Svh` and the function `DefIndex`.
695 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
697 "__rustc_plugin_registrar_{}__",
698 disambiguator.to_fingerprint().to_hex()
702 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
704 "__rustc_proc_macro_decls_{}__",
705 disambiguator.to_fingerprint().to_hex()
709 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
710 filesearch::FileSearch::new(
712 self.opts.target_triple.triple(),
713 &self.opts.search_paths,
714 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
715 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
719 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
720 filesearch::FileSearch::new(
722 config::host_triple(),
723 &self.opts.search_paths,
724 &self.host_tlib_path,
729 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
730 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
732 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
733 *load_dep_graph = load;
737 pub fn incr_session_load_dep_graph(&self) -> bool {
738 let incr_comp_session = self.incr_comp_session.borrow();
739 match *incr_comp_session {
740 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
745 pub fn init_incr_comp_session(
747 session_dir: PathBuf,
748 lock_file: flock::Lock,
749 load_dep_graph: bool,
751 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
753 if let IncrCompSession::NotInitialized = *incr_comp_session {
756 "Trying to initialize IncrCompSession `{:?}`",
761 *incr_comp_session = IncrCompSession::Active {
762 session_directory: session_dir,
768 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
769 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
771 if let IncrCompSession::Active { .. } = *incr_comp_session {
774 "trying to finalize `IncrCompSession` `{:?}`",
779 // Note: this will also drop the lock file, thus unlocking the directory.
780 *incr_comp_session = IncrCompSession::Finalized {
781 session_directory: new_directory_path,
785 pub fn mark_incr_comp_session_as_invalid(&self) {
786 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
788 let session_directory = match *incr_comp_session {
789 IncrCompSession::Active {
790 ref session_directory,
792 } => session_directory.clone(),
793 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
795 "trying to invalidate `IncrCompSession` `{:?}`",
800 // Note: this will also drop the lock file, thus unlocking the directory.
801 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
806 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
807 let incr_comp_session = self.incr_comp_session.borrow();
810 |incr_comp_session| match *incr_comp_session {
811 IncrCompSession::NotInitialized => bug!(
812 "trying to get session directory from `IncrCompSession`: {:?}",
815 IncrCompSession::Active {
816 ref session_directory,
819 | IncrCompSession::Finalized {
820 ref session_directory,
822 | IncrCompSession::InvalidBecauseOfErrors {
823 ref session_directory,
824 } => session_directory,
829 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
830 if self.opts.incremental.is_some() {
831 Some(self.incr_comp_session_dir())
837 pub fn print_perf_stats(&self) {
839 "Total time spent computing symbol hashes: {}",
840 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
843 "Total time spent decoding DefPath tables: {}",
844 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
846 println!("Total queries canonicalized: {}",
847 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
848 println!("normalize_ty_after_erasing_regions: {}",
849 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
850 println!("normalize_projection_ty: {}",
851 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
854 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
855 /// This expends fuel if applicable, and records fuel if applicable.
856 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
858 if let Some(ref c) = self.optimization_fuel_crate {
860 assert_eq!(self.threads(), 1);
861 let mut fuel = self.optimization_fuel.lock();
862 ret = fuel.remaining != 0;
863 if fuel.remaining == 0 && !fuel.out_of_fuel {
864 eprintln!("optimization-fuel-exhausted: {}", msg());
865 fuel.out_of_fuel = true;
866 } else if fuel.remaining > 0 {
871 if let Some(ref c) = self.print_fuel_crate {
873 assert_eq!(self.threads(), 1);
874 self.print_fuel.fetch_add(1, SeqCst);
880 /// Returns the number of query threads that should be used for this
882 pub fn threads(&self) -> usize {
883 self.opts.debugging_opts.threads
886 /// Returns the number of codegen units that should be used for this
888 pub fn codegen_units(&self) -> usize {
889 if let Some(n) = self.opts.cli_forced_codegen_units {
892 if let Some(n) = self.target.target.options.default_codegen_units {
896 // Why is 16 codegen units the default all the time?
898 // The main reason for enabling multiple codegen units by default is to
899 // leverage the ability for the codegen backend to do codegen and
900 // optimization in parallel. This allows us, especially for large crates, to
901 // make good use of all available resources on the machine once we've
902 // hit that stage of compilation. Large crates especially then often
903 // take a long time in codegen/optimization and this helps us amortize that
906 // Note that a high number here doesn't mean that we'll be spawning a
907 // large number of threads in parallel. The backend of rustc contains
908 // global rate limiting through the `jobserver` crate so we'll never
909 // overload the system with too much work, but rather we'll only be
910 // optimizing when we're otherwise cooperating with other instances of
913 // Rather a high number here means that we should be able to keep a lot
914 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
915 // to build we'll be guaranteed that all cpus will finish pretty closely
916 // to one another and we should make relatively optimal use of system
919 // Note that the main cost of codegen units is that it prevents LLVM
920 // from inlining across codegen units. Users in general don't have a lot
921 // of control over how codegen units are split up so it's our job in the
922 // compiler to ensure that undue performance isn't lost when using
923 // codegen units (aka we can't require everyone to slap `#[inline]` on
926 // If we're compiling at `-O0` then the number doesn't really matter too
927 // much because performance doesn't matter and inlining is ok to lose.
928 // In debug mode we just want to try to guarantee that no cpu is stuck
929 // doing work that could otherwise be farmed to others.
931 // In release mode, however (O1 and above) performance does indeed
932 // matter! To recover the loss in performance due to inlining we'll be
933 // enabling ThinLTO by default (the function for which is just below).
934 // This will ensure that we recover any inlining wins we otherwise lost
935 // through codegen unit partitioning.
939 // Ok that's a lot of words but the basic tl;dr; is that we want a high
940 // number here -- but not too high. Additionally we're "safe" to have it
941 // always at the same number at all optimization levels.
943 // As a result 16 was chosen here! Mostly because it was a power of 2
944 // and most benchmarks agreed it was roughly a local optimum. Not very
949 pub fn teach(&self, code: &DiagnosticId) -> bool {
950 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
953 pub fn rust_2015(&self) -> bool {
954 self.opts.edition == Edition::Edition2015
957 /// Are we allowed to use features from the Rust 2018 edition?
958 pub fn rust_2018(&self) -> bool {
959 self.opts.edition >= Edition::Edition2018
962 pub fn edition(&self) -> Edition {
966 /// Returns `true` if we cannot skip the PLT for shared library calls.
967 pub fn needs_plt(&self) -> bool {
968 // Check if the current target usually needs PLT to be enabled.
969 // The user can use the command line flag to override it.
970 let needs_plt = self.target.target.options.needs_plt;
972 let dbg_opts = &self.opts.debugging_opts;
974 let relro_level = dbg_opts.relro_level
975 .unwrap_or(self.target.target.options.relro_level);
977 // Only enable this optimization by default if full relro is also enabled.
978 // In this case, lazy binding was already unavailable, so nothing is lost.
979 // This also ensures `-Wl,-z,now` is supported by the linker.
980 let full_relro = RelroLevel::Full == relro_level;
982 // If user didn't explicitly forced us to use / skip the PLT,
983 // then try to skip it where possible.
984 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
988 pub fn build_session(
989 sopts: config::Options,
990 local_crate_source_file: Option<PathBuf>,
991 registry: errors::registry::Registry,
993 let file_path_mapping = sopts.file_path_mapping();
995 build_session_with_source_map(
997 local_crate_source_file,
999 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
1000 DiagnosticOutput::Default,
1006 sopts: &config::Options,
1007 registry: errors::registry::Registry,
1008 source_map: &Lrc<source_map::SourceMap>,
1009 emitter_dest: Option<Box<dyn Write + Send>>,
1010 ) -> Box<dyn Emitter + sync::Send> {
1011 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1012 match (sopts.error_format, emitter_dest) {
1013 (config::ErrorOutputType::HumanReadable(kind), dst) => {
1014 let (short, color_config) = kind.unzip();
1016 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
1017 let emitter = AnnotateSnippetEmitterWriter::new(
1018 Some(source_map.clone()),
1020 external_macro_backtrace,
1022 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1024 let emitter = match dst {
1025 None => EmitterWriter::stderr(
1027 Some(source_map.clone()),
1029 sopts.debugging_opts.teach,
1030 sopts.debugging_opts.terminal_width,
1031 external_macro_backtrace,
1033 Some(dst) => EmitterWriter::new(
1035 Some(source_map.clone()),
1037 false, // no teach messages when writing to a buffer
1038 false, // no colors when writing to a buffer
1039 None, // no terminal width
1040 external_macro_backtrace,
1043 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1046 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1047 JsonEmitter::stderr(
1052 external_macro_backtrace,
1053 ).ui_testing(sopts.debugging_opts.ui_testing),
1055 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1062 external_macro_backtrace,
1063 ).ui_testing(sopts.debugging_opts.ui_testing),
1068 pub enum DiagnosticOutput {
1070 Raw(Box<dyn Write + Send>)
1073 pub fn build_session_with_source_map(
1074 sopts: config::Options,
1075 local_crate_source_file: Option<PathBuf>,
1076 registry: errors::registry::Registry,
1077 source_map: Lrc<source_map::SourceMap>,
1078 diagnostics_output: DiagnosticOutput,
1079 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1081 // FIXME: This is not general enough to make the warning lint completely override
1082 // normal diagnostic warnings, since the warning lint can also be denied and changed
1083 // later via the source code.
1084 let warnings_allow = sopts
1087 .filter(|&&(ref key, _)| *key == "warnings")
1088 .map(|&(_, ref level)| *level == lint::Allow)
1091 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1093 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1095 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1096 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1097 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1099 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1101 let emitter = match diagnostics_output {
1102 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1103 DiagnosticOutput::Raw(write) => {
1104 default_emitter(&sopts, registry, &source_map, Some(write))
1108 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1110 errors::HandlerFlags {
1113 report_delayed_bugs,
1114 dont_buffer_diagnostics,
1115 external_macro_backtrace,
1116 ..Default::default()
1120 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1124 sopts: config::Options,
1125 local_crate_source_file: Option<PathBuf>,
1126 span_diagnostic: errors::Handler,
1127 source_map: Lrc<source_map::SourceMap>,
1128 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1131 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1132 let directory = if let Some(ref directory) = d {
1135 std::path::Path::new(".")
1138 let profiler = SelfProfiler::new(
1140 sopts.crate_name.as_ref().map(|s| &s[..]),
1141 &sopts.debugging_opts.self_profile_events
1145 crate::ty::query::QueryName::register_with_profiler(&profiler);
1146 Some(Arc::new(profiler))
1149 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1156 let host_triple = TargetTriple::from_triple(config::host_triple());
1157 let host = Target::search(&host_triple).unwrap_or_else(|e|
1159 .fatal(&format!("Error loading host specification: {}", e))
1162 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1164 let parse_sess = ParseSess::with_span_handler(
1168 let sysroot = match &sopts.maybe_sysroot {
1169 Some(sysroot) => sysroot.clone(),
1170 None => filesearch::get_or_default_sysroot(),
1173 let host_triple = config::host_triple();
1174 let target_triple = sopts.target_triple.triple();
1175 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1176 let target_tlib_path = if host_triple == target_triple {
1179 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1182 let file_path_mapping = sopts.file_path_mapping();
1184 let local_crate_source_file =
1185 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1187 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1188 let optimization_fuel = Lock::new(OptimizationFuel {
1189 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1192 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1193 let print_fuel = AtomicU64::new(0);
1195 let working_dir = env::current_dir().unwrap_or_else(|e|
1196 parse_sess.span_diagnostic
1197 .fatal(&format!("Current directory is invalid: {}", e))
1200 let working_dir = file_path_mapping.map_prefix(working_dir);
1202 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1203 CguReuseTracker::new()
1205 CguReuseTracker::new_disabled()
1208 let sess = Session {
1216 local_crate_source_file,
1218 buffered_lints: Lock::new(Some(Default::default())),
1219 one_time_diagnostics: Default::default(),
1220 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1221 plugin_attributes: Lock::new(Vec::new()),
1222 crate_types: Once::new(),
1223 crate_disambiguator: Once::new(),
1224 features: Once::new(),
1225 recursion_limit: Once::new(),
1226 type_length_limit: Once::new(),
1227 const_eval_stack_frame_limit: 100,
1228 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1229 allocator_kind: Once::new(),
1230 injected_panic_runtime: Once::new(),
1231 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1232 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1234 prof: SelfProfilerRef::new(self_profiler),
1235 perf_stats: PerfStats {
1236 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1237 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1238 queries_canonicalized: AtomicUsize::new(0),
1239 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1240 normalize_projection_ty: AtomicUsize::new(0),
1242 code_stats: Default::default(),
1243 optimization_fuel_crate,
1247 jobserver: jobserver::client(),
1248 has_global_allocator: Once::new(),
1249 has_panic_handler: Once::new(),
1251 trait_methods_not_found: Lock::new(Default::default()),
1252 confused_type_with_std_module: Lock::new(Default::default()),
1255 validate_commandline_args_with_session_available(&sess);
1260 // If it is useful to have a Session available already for validating a
1261 // commandline argument, you can do so here.
1262 fn validate_commandline_args_with_session_available(sess: &Session) {
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");
1277 // Make sure that any given profiling data actually exists so LLVM can't
1278 // decide to silently skip PGO.
1279 if let Some(ref path) = sess.opts.cg.profile_use {
1281 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1286 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1287 // an error to combine the two for now. It always runs into an assertions
1288 // if LLVM is built with assertions, but without assertions it sometimes
1289 // does not crash and will probably generate a corrupted binary.
1290 // We should only display this error if we're actually going to run PGO.
1291 // If we're just supposed to print out some data, don't show the error (#61002).
1292 if sess.opts.cg.profile_generate.enabled() &&
1293 sess.target.target.options.is_like_msvc &&
1294 sess.panic_strategy() == PanicStrategy::Unwind &&
1295 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1296 sess.err("Profile-guided optimization does not yet work in conjunction \
1297 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1298 See https://github.com/rust-lang/rust/issues/61002 for details.");
1302 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1303 /// compiler. Together with the crate-name forms a unique global identifier for
1305 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1306 pub struct CrateDisambiguator(Fingerprint);
1308 impl CrateDisambiguator {
1309 pub fn to_fingerprint(self) -> Fingerprint {
1314 impl fmt::Display for CrateDisambiguator {
1315 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1316 let (a, b) = self.0.as_value();
1317 let as_u128 = a as u128 | ((b as u128) << 64);
1318 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1322 impl From<Fingerprint> for CrateDisambiguator {
1323 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1324 CrateDisambiguator(fingerprint)
1328 impl_stable_hash_via_hash!(CrateDisambiguator);
1330 /// Holds data on the current incremental compilation session, if there is one.
1332 pub enum IncrCompSession {
1333 /// This is the state the session will be in until the incr. comp. dir is
1336 /// This is the state during which the session directory is private and can
1339 session_directory: PathBuf,
1340 lock_file: flock::Lock,
1341 load_dep_graph: bool,
1343 /// This is the state after the session directory has been finalized. In this
1344 /// state, the contents of the directory must not be modified any more.
1345 Finalized { session_directory: PathBuf },
1346 /// This is an error state that is reached when some compilation error has
1347 /// occurred. It indicates that the contents of the session directory must
1348 /// not be used, since they might be invalid.
1349 InvalidBecauseOfErrors { session_directory: PathBuf },
1352 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1353 let emitter: Box<dyn Emitter + sync::Send> = match output {
1354 config::ErrorOutputType::HumanReadable(kind) => {
1355 let (short, color_config) = kind.unzip();
1356 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1358 config::ErrorOutputType::Json { pretty, json_rendered } =>
1359 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1361 let handler = errors::Handler::with_emitter(true, None, emitter);
1362 handler.struct_fatal(msg).emit();
1363 errors::FatalError.raise();
1366 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1367 let emitter: Box<dyn Emitter + sync::Send> = match output {
1368 config::ErrorOutputType::HumanReadable(kind) => {
1369 let (short, color_config) = kind.unzip();
1370 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1372 config::ErrorOutputType::Json { pretty, json_rendered } =>
1373 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1375 let handler = errors::Handler::with_emitter(true, None, emitter);
1376 handler.struct_warn(msg).emit();
1379 pub type CompileResult = Result<(), ErrorReported>;