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_late<S: Into<MultiSpan>>(
371 lint: &'static lint::Lint,
376 match *self.buffered_lints.borrow_mut() {
377 Some(ref mut buffer) => {
378 buffer.buffer_lint(lint, id, sp, msg);
380 None => bug!("can't buffer lints after HIR lowering"),
384 pub fn buffer_lint_with_diagnostic_late<S: Into<MultiSpan>>(
386 lint: &'static lint::Lint,
390 diagnostic: BuiltinLintDiagnostics,
392 match *self.buffered_lints.borrow_mut() {
393 Some(ref mut buffer) => buffer.buffer_lint_with_diagnostic(
394 lint, id, sp.into(), msg, diagnostic,
396 None => bug!("can't buffer lints after HIR lowering"),
400 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
401 let id = self.next_node_id.get();
403 match id.as_usize().checked_add(count) {
405 self.next_node_id.set(ast::NodeId::from_usize(next));
407 None => bug!("input too large; ran out of node-IDs!"),
412 pub fn next_node_id(&self) -> NodeId {
413 self.reserve_node_ids(1)
415 pub fn diagnostic(&self) -> &errors::Handler {
416 &self.parse_sess.span_diagnostic
419 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
420 /// deduplicates on lint ID, span (if any), and message for this `Session`
421 fn diag_once<'a, 'b>(
423 diag_builder: &'b mut DiagnosticBuilder<'a>,
424 method: DiagnosticBuilderMethod,
425 msg_id: DiagnosticMessageId,
427 span_maybe: Option<Span>,
429 let id_span_message = (msg_id, span_maybe, message.to_owned());
430 let fresh = self.one_time_diagnostics
432 .insert(id_span_message);
435 DiagnosticBuilderMethod::Note => {
436 diag_builder.note(message);
438 DiagnosticBuilderMethod::SpanNote => {
439 let span = span_maybe.expect("`span_note` needs a span");
440 diag_builder.span_note(span, message);
442 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
443 let span = span_maybe.expect("`span_suggestion_*` needs a span");
444 diag_builder.span_suggestion(
448 Applicability::Unspecified,
455 pub fn diag_span_note_once<'a, 'b>(
457 diag_builder: &'b mut DiagnosticBuilder<'a>,
458 msg_id: DiagnosticMessageId,
464 DiagnosticBuilderMethod::SpanNote,
471 pub fn diag_note_once<'a, 'b>(
473 diag_builder: &'b mut DiagnosticBuilder<'a>,
474 msg_id: DiagnosticMessageId,
479 DiagnosticBuilderMethod::Note,
486 pub fn diag_span_suggestion_once<'a, 'b>(
488 diag_builder: &'b mut DiagnosticBuilder<'a>,
489 msg_id: DiagnosticMessageId,
496 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
503 pub fn source_map(&self) -> &source_map::SourceMap {
504 self.parse_sess.source_map()
506 pub fn verbose(&self) -> bool {
507 self.opts.debugging_opts.verbose
509 pub fn time_passes(&self) -> bool {
510 self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
512 pub fn time_extended(&self) -> bool {
513 self.opts.debugging_opts.time_passes
515 pub fn instrument_mcount(&self) -> bool {
516 self.opts.debugging_opts.instrument_mcount
518 pub fn time_llvm_passes(&self) -> bool {
519 self.opts.debugging_opts.time_llvm_passes
521 pub fn meta_stats(&self) -> bool {
522 self.opts.debugging_opts.meta_stats
524 pub fn asm_comments(&self) -> bool {
525 self.opts.debugging_opts.asm_comments
527 pub fn verify_llvm_ir(&self) -> bool {
528 self.opts.debugging_opts.verify_llvm_ir
529 || cfg!(always_verify_llvm_ir)
531 pub fn borrowck_stats(&self) -> bool {
532 self.opts.debugging_opts.borrowck_stats
534 pub fn print_llvm_passes(&self) -> bool {
535 self.opts.debugging_opts.print_llvm_passes
537 pub fn binary_dep_depinfo(&self) -> bool {
538 self.opts.debugging_opts.binary_dep_depinfo
541 /// Gets the features enabled for the current compilation session.
542 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
543 /// dependency tracking. Use tcx.features() instead.
545 pub fn features_untracked(&self) -> &feature_gate::Features {
549 pub fn init_features(&self, features: feature_gate::Features) {
550 self.features.set(features);
553 /// Calculates the flavor of LTO to use for this compilation.
554 pub fn lto(&self) -> config::Lto {
555 // If our target has codegen requirements ignore the command line
556 if self.target.target.options.requires_lto {
557 return config::Lto::Fat;
560 // If the user specified something, return that. If they only said `-C
561 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
562 // then ensure we can't use a ThinLTO.
563 match self.opts.cg.lto {
564 config::LtoCli::Unspecified => {
565 // The compiler was invoked without the `-Clto` flag. Fall
566 // through to the default handling
568 config::LtoCli::No => {
569 // The user explicitly opted out of any kind of LTO
570 return config::Lto::No;
572 config::LtoCli::Yes |
573 config::LtoCli::Fat |
574 config::LtoCli::NoParam => {
575 // All of these mean fat LTO
576 return config::Lto::Fat;
578 config::LtoCli::Thin => {
579 return if self.opts.cli_forced_thinlto_off {
587 // Ok at this point the target doesn't require anything and the user
588 // hasn't asked for anything. Our next decision is whether or not
589 // we enable "auto" ThinLTO where we use multiple codegen units and
590 // then do ThinLTO over those codegen units. The logic below will
591 // either return `No` or `ThinLocal`.
593 // If processing command line options determined that we're incompatible
594 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
595 if self.opts.cli_forced_thinlto_off {
596 return config::Lto::No;
599 // If `-Z thinlto` specified process that, but note that this is mostly
600 // a deprecated option now that `-C lto=thin` exists.
601 if let Some(enabled) = self.opts.debugging_opts.thinlto {
603 return config::Lto::ThinLocal;
605 return config::Lto::No;
609 // If there's only one codegen unit and LTO isn't enabled then there's
610 // no need for ThinLTO so just return false.
611 if self.codegen_units() == 1 {
612 return config::Lto::No;
615 // Now we're in "defaults" territory. By default we enable ThinLTO for
616 // optimized compiles (anything greater than O0).
617 match self.opts.optimize {
618 config::OptLevel::No => config::Lto::No,
619 _ => config::Lto::ThinLocal,
623 /// Returns the panic strategy for this compile session. If the user explicitly selected one
624 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
625 pub fn panic_strategy(&self) -> PanicStrategy {
629 .unwrap_or(self.target.target.options.panic_strategy)
631 pub fn fewer_names(&self) -> bool {
632 let more_names = self.opts
634 .contains_key(&OutputType::LlvmAssembly)
635 || self.opts.output_types.contains_key(&OutputType::Bitcode);
637 // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
638 let more_names = match self.opts.debugging_opts.sanitizer {
639 Some(Sanitizer::Address) => true,
640 Some(Sanitizer::Memory) => true,
644 self.opts.debugging_opts.fewer_names || !more_names
647 pub fn no_landing_pads(&self) -> bool {
648 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
650 pub fn unstable_options(&self) -> bool {
651 self.opts.debugging_opts.unstable_options
653 pub fn overflow_checks(&self) -> bool {
657 .or(self.opts.debugging_opts.force_overflow_checks)
658 .unwrap_or(self.opts.debug_assertions)
661 pub fn crt_static(&self) -> bool {
662 // If the target does not opt in to crt-static support, use its default.
663 if self.target.target.options.crt_static_respected {
664 self.crt_static_feature()
666 self.target.target.options.crt_static_default
670 pub fn crt_static_feature(&self) -> bool {
671 let requested_features = self.opts.cg.target_feature.split(',');
672 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
673 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
675 // If the target we're compiling for requests a static crt by default,
676 // then see if the `-crt-static` feature was passed to disable that.
677 // Otherwise if we don't have a static crt by default then see if the
678 // `+crt-static` feature was passed.
679 if self.target.target.options.crt_static_default {
686 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
687 // "mcount" function relies on stack pointer.
688 // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
689 if self.instrument_mcount() {
691 } else if let Some(x) = self.opts.cg.force_frame_pointers {
694 !self.target.target.options.eliminate_frame_pointer
698 /// Returns the symbol name for the registrar function,
699 /// given the crate `Svh` and the function `DefIndex`.
700 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
702 "__rustc_plugin_registrar_{}__",
703 disambiguator.to_fingerprint().to_hex()
707 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
709 "__rustc_proc_macro_decls_{}__",
710 disambiguator.to_fingerprint().to_hex()
714 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
715 filesearch::FileSearch::new(
717 self.opts.target_triple.triple(),
718 &self.opts.search_paths,
719 // `target_tlib_path == None` means it's the same as `host_tlib_path`.
720 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
724 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
725 filesearch::FileSearch::new(
727 config::host_triple(),
728 &self.opts.search_paths,
729 &self.host_tlib_path,
734 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
735 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
737 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
738 *load_dep_graph = load;
742 pub fn incr_session_load_dep_graph(&self) -> bool {
743 let incr_comp_session = self.incr_comp_session.borrow();
744 match *incr_comp_session {
745 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
750 pub fn init_incr_comp_session(
752 session_dir: PathBuf,
753 lock_file: flock::Lock,
754 load_dep_graph: bool,
756 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
758 if let IncrCompSession::NotInitialized = *incr_comp_session {
761 "Trying to initialize IncrCompSession `{:?}`",
766 *incr_comp_session = IncrCompSession::Active {
767 session_directory: session_dir,
773 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
774 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
776 if let IncrCompSession::Active { .. } = *incr_comp_session {
779 "trying to finalize `IncrCompSession` `{:?}`",
784 // Note: this will also drop the lock file, thus unlocking the directory.
785 *incr_comp_session = IncrCompSession::Finalized {
786 session_directory: new_directory_path,
790 pub fn mark_incr_comp_session_as_invalid(&self) {
791 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
793 let session_directory = match *incr_comp_session {
794 IncrCompSession::Active {
795 ref session_directory,
797 } => session_directory.clone(),
798 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
800 "trying to invalidate `IncrCompSession` `{:?}`",
805 // Note: this will also drop the lock file, thus unlocking the directory.
806 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
811 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
812 let incr_comp_session = self.incr_comp_session.borrow();
815 |incr_comp_session| match *incr_comp_session {
816 IncrCompSession::NotInitialized => bug!(
817 "trying to get session directory from `IncrCompSession`: {:?}",
820 IncrCompSession::Active {
821 ref session_directory,
824 | IncrCompSession::Finalized {
825 ref session_directory,
827 | IncrCompSession::InvalidBecauseOfErrors {
828 ref session_directory,
829 } => session_directory,
834 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
835 if self.opts.incremental.is_some() {
836 Some(self.incr_comp_session_dir())
842 pub fn print_perf_stats(&self) {
844 "Total time spent computing symbol hashes: {}",
845 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
848 "Total time spent decoding DefPath tables: {}",
849 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
851 println!("Total queries canonicalized: {}",
852 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
853 println!("normalize_ty_after_erasing_regions: {}",
854 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
855 println!("normalize_projection_ty: {}",
856 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
859 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
860 /// This expends fuel if applicable, and records fuel if applicable.
861 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
863 if let Some(ref c) = self.optimization_fuel_crate {
865 assert_eq!(self.threads(), 1);
866 let mut fuel = self.optimization_fuel.lock();
867 ret = fuel.remaining != 0;
868 if fuel.remaining == 0 && !fuel.out_of_fuel {
869 eprintln!("optimization-fuel-exhausted: {}", msg());
870 fuel.out_of_fuel = true;
871 } else if fuel.remaining > 0 {
876 if let Some(ref c) = self.print_fuel_crate {
878 assert_eq!(self.threads(), 1);
879 self.print_fuel.fetch_add(1, SeqCst);
885 /// Returns the number of query threads that should be used for this
887 pub fn threads(&self) -> usize {
888 self.opts.debugging_opts.threads
891 /// Returns the number of codegen units that should be used for this
893 pub fn codegen_units(&self) -> usize {
894 if let Some(n) = self.opts.cli_forced_codegen_units {
897 if let Some(n) = self.target.target.options.default_codegen_units {
901 // Why is 16 codegen units the default all the time?
903 // The main reason for enabling multiple codegen units by default is to
904 // leverage the ability for the codegen backend to do codegen and
905 // optimization in parallel. This allows us, especially for large crates, to
906 // make good use of all available resources on the machine once we've
907 // hit that stage of compilation. Large crates especially then often
908 // take a long time in codegen/optimization and this helps us amortize that
911 // Note that a high number here doesn't mean that we'll be spawning a
912 // large number of threads in parallel. The backend of rustc contains
913 // global rate limiting through the `jobserver` crate so we'll never
914 // overload the system with too much work, but rather we'll only be
915 // optimizing when we're otherwise cooperating with other instances of
918 // Rather a high number here means that we should be able to keep a lot
919 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
920 // to build we'll be guaranteed that all cpus will finish pretty closely
921 // to one another and we should make relatively optimal use of system
924 // Note that the main cost of codegen units is that it prevents LLVM
925 // from inlining across codegen units. Users in general don't have a lot
926 // of control over how codegen units are split up so it's our job in the
927 // compiler to ensure that undue performance isn't lost when using
928 // codegen units (aka we can't require everyone to slap `#[inline]` on
931 // If we're compiling at `-O0` then the number doesn't really matter too
932 // much because performance doesn't matter and inlining is ok to lose.
933 // In debug mode we just want to try to guarantee that no cpu is stuck
934 // doing work that could otherwise be farmed to others.
936 // In release mode, however (O1 and above) performance does indeed
937 // matter! To recover the loss in performance due to inlining we'll be
938 // enabling ThinLTO by default (the function for which is just below).
939 // This will ensure that we recover any inlining wins we otherwise lost
940 // through codegen unit partitioning.
944 // Ok that's a lot of words but the basic tl;dr; is that we want a high
945 // number here -- but not too high. Additionally we're "safe" to have it
946 // always at the same number at all optimization levels.
948 // As a result 16 was chosen here! Mostly because it was a power of 2
949 // and most benchmarks agreed it was roughly a local optimum. Not very
954 pub fn teach(&self, code: &DiagnosticId) -> bool {
955 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
958 pub fn rust_2015(&self) -> bool {
959 self.opts.edition == Edition::Edition2015
962 /// Are we allowed to use features from the Rust 2018 edition?
963 pub fn rust_2018(&self) -> bool {
964 self.opts.edition >= Edition::Edition2018
967 pub fn edition(&self) -> Edition {
971 /// Returns `true` if we cannot skip the PLT for shared library calls.
972 pub fn needs_plt(&self) -> bool {
973 // Check if the current target usually needs PLT to be enabled.
974 // The user can use the command line flag to override it.
975 let needs_plt = self.target.target.options.needs_plt;
977 let dbg_opts = &self.opts.debugging_opts;
979 let relro_level = dbg_opts.relro_level
980 .unwrap_or(self.target.target.options.relro_level);
982 // Only enable this optimization by default if full relro is also enabled.
983 // In this case, lazy binding was already unavailable, so nothing is lost.
984 // This also ensures `-Wl,-z,now` is supported by the linker.
985 let full_relro = RelroLevel::Full == relro_level;
987 // If user didn't explicitly forced us to use / skip the PLT,
988 // then try to skip it where possible.
989 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
993 pub fn build_session(
994 sopts: config::Options,
995 local_crate_source_file: Option<PathBuf>,
996 registry: errors::registry::Registry,
998 let file_path_mapping = sopts.file_path_mapping();
1000 build_session_with_source_map(
1002 local_crate_source_file,
1004 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
1005 DiagnosticOutput::Default,
1011 sopts: &config::Options,
1012 registry: errors::registry::Registry,
1013 source_map: &Lrc<source_map::SourceMap>,
1014 emitter_dest: Option<Box<dyn Write + Send>>,
1015 ) -> Box<dyn Emitter + sync::Send> {
1016 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1017 match (sopts.error_format, emitter_dest) {
1018 (config::ErrorOutputType::HumanReadable(kind), dst) => {
1019 let (short, color_config) = kind.unzip();
1021 if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
1022 let emitter = AnnotateSnippetEmitterWriter::new(
1023 Some(source_map.clone()),
1025 external_macro_backtrace,
1027 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1029 let emitter = match dst {
1030 None => EmitterWriter::stderr(
1032 Some(source_map.clone()),
1034 sopts.debugging_opts.teach,
1035 sopts.debugging_opts.terminal_width,
1036 external_macro_backtrace,
1038 Some(dst) => EmitterWriter::new(
1040 Some(source_map.clone()),
1042 false, // no teach messages when writing to a buffer
1043 false, // no colors when writing to a buffer
1044 None, // no terminal width
1045 external_macro_backtrace,
1048 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
1051 (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
1052 JsonEmitter::stderr(
1057 external_macro_backtrace,
1058 ).ui_testing(sopts.debugging_opts.ui_testing),
1060 (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
1067 external_macro_backtrace,
1068 ).ui_testing(sopts.debugging_opts.ui_testing),
1073 pub enum DiagnosticOutput {
1075 Raw(Box<dyn Write + Send>)
1078 pub fn build_session_with_source_map(
1079 sopts: config::Options,
1080 local_crate_source_file: Option<PathBuf>,
1081 registry: errors::registry::Registry,
1082 source_map: Lrc<source_map::SourceMap>,
1083 diagnostics_output: DiagnosticOutput,
1084 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1086 // FIXME: This is not general enough to make the warning lint completely override
1087 // normal diagnostic warnings, since the warning lint can also be denied and changed
1088 // later via the source code.
1089 let warnings_allow = sopts
1092 .filter(|&&(ref key, _)| *key == "warnings")
1093 .map(|&(_, ref level)| *level == lint::Allow)
1096 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1098 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1100 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1101 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1102 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1104 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1106 let emitter = match diagnostics_output {
1107 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1108 DiagnosticOutput::Raw(write) => {
1109 default_emitter(&sopts, registry, &source_map, Some(write))
1113 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1115 errors::HandlerFlags {
1118 report_delayed_bugs,
1119 dont_buffer_diagnostics,
1120 external_macro_backtrace,
1121 ..Default::default()
1125 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1129 sopts: config::Options,
1130 local_crate_source_file: Option<PathBuf>,
1131 span_diagnostic: errors::Handler,
1132 source_map: Lrc<source_map::SourceMap>,
1133 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1136 if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile {
1137 let directory = if let Some(ref directory) = d {
1140 std::path::Path::new(".")
1143 let profiler = SelfProfiler::new(
1145 sopts.crate_name.as_ref().map(|s| &s[..]),
1146 &sopts.debugging_opts.self_profile_events
1150 crate::ty::query::QueryName::register_with_profiler(&profiler);
1151 Some(Arc::new(profiler))
1154 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
1161 let host_triple = TargetTriple::from_triple(config::host_triple());
1162 let host = Target::search(&host_triple).unwrap_or_else(|e|
1164 .fatal(&format!("Error loading host specification: {}", e))
1167 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1169 let parse_sess = ParseSess::with_span_handler(
1173 let sysroot = match &sopts.maybe_sysroot {
1174 Some(sysroot) => sysroot.clone(),
1175 None => filesearch::get_or_default_sysroot(),
1178 let host_triple = config::host_triple();
1179 let target_triple = sopts.target_triple.triple();
1180 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1181 let target_tlib_path = if host_triple == target_triple {
1184 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1187 let file_path_mapping = sopts.file_path_mapping();
1189 let local_crate_source_file =
1190 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1192 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1193 let optimization_fuel = Lock::new(OptimizationFuel {
1194 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1197 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1198 let print_fuel = AtomicU64::new(0);
1200 let working_dir = env::current_dir().unwrap_or_else(|e|
1201 parse_sess.span_diagnostic
1202 .fatal(&format!("Current directory is invalid: {}", e))
1205 let working_dir = file_path_mapping.map_prefix(working_dir);
1207 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1208 CguReuseTracker::new()
1210 CguReuseTracker::new_disabled()
1213 let sess = Session {
1221 local_crate_source_file,
1223 buffered_lints: Lock::new(Some(Default::default())),
1224 one_time_diagnostics: Default::default(),
1225 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1226 plugin_attributes: Lock::new(Vec::new()),
1227 crate_types: Once::new(),
1228 crate_disambiguator: Once::new(),
1229 features: Once::new(),
1230 recursion_limit: Once::new(),
1231 type_length_limit: Once::new(),
1232 const_eval_stack_frame_limit: 100,
1233 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1234 allocator_kind: Once::new(),
1235 injected_panic_runtime: Once::new(),
1236 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1237 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1239 prof: SelfProfilerRef::new(self_profiler),
1240 perf_stats: PerfStats {
1241 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1242 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1243 queries_canonicalized: AtomicUsize::new(0),
1244 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1245 normalize_projection_ty: AtomicUsize::new(0),
1247 code_stats: Default::default(),
1248 optimization_fuel_crate,
1252 jobserver: jobserver::client(),
1253 has_global_allocator: Once::new(),
1254 has_panic_handler: Once::new(),
1256 trait_methods_not_found: Lock::new(Default::default()),
1257 confused_type_with_std_module: Lock::new(Default::default()),
1260 validate_commandline_args_with_session_available(&sess);
1265 // If it is useful to have a Session available already for validating a
1266 // commandline argument, you can do so here.
1267 fn validate_commandline_args_with_session_available(sess: &Session) {
1268 // Since we don't know if code in an rlib will be linked to statically or
1269 // dynamically downstream, rustc generates `__imp_` symbols that help the
1270 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1271 // these manually generated symbols confuse LLD when it tries to merge
1272 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1273 // when compiling for LLD ThinLTO. This way we can validly just not generate
1274 // the `dllimport` attributes and `__imp_` symbols in that case.
1275 if sess.opts.cg.linker_plugin_lto.enabled() &&
1276 sess.opts.cg.prefer_dynamic &&
1277 sess.target.target.options.is_like_msvc {
1278 sess.err("Linker plugin based LTO is not supported together with \
1279 `-C prefer-dynamic` when targeting MSVC");
1282 // Make sure that any given profiling data actually exists so LLVM can't
1283 // decide to silently skip PGO.
1284 if let Some(ref path) = sess.opts.cg.profile_use {
1286 sess.err(&format!("File `{}` passed to `-C profile-use` does not exist.",
1291 // PGO does not work reliably with panic=unwind on Windows. Let's make it
1292 // an error to combine the two for now. It always runs into an assertions
1293 // if LLVM is built with assertions, but without assertions it sometimes
1294 // does not crash and will probably generate a corrupted binary.
1295 // We should only display this error if we're actually going to run PGO.
1296 // If we're just supposed to print out some data, don't show the error (#61002).
1297 if sess.opts.cg.profile_generate.enabled() &&
1298 sess.target.target.options.is_like_msvc &&
1299 sess.panic_strategy() == PanicStrategy::Unwind &&
1300 sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
1301 sess.err("Profile-guided optimization does not yet work in conjunction \
1302 with `-Cpanic=unwind` on Windows when targeting MSVC. \
1303 See https://github.com/rust-lang/rust/issues/61002 for details.");
1307 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1308 /// compiler. Together with the crate-name forms a unique global identifier for
1310 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1311 pub struct CrateDisambiguator(Fingerprint);
1313 impl CrateDisambiguator {
1314 pub fn to_fingerprint(self) -> Fingerprint {
1319 impl fmt::Display for CrateDisambiguator {
1320 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1321 let (a, b) = self.0.as_value();
1322 let as_u128 = a as u128 | ((b as u128) << 64);
1323 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1327 impl From<Fingerprint> for CrateDisambiguator {
1328 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1329 CrateDisambiguator(fingerprint)
1333 impl_stable_hash_via_hash!(CrateDisambiguator);
1335 /// Holds data on the current incremental compilation session, if there is one.
1337 pub enum IncrCompSession {
1338 /// This is the state the session will be in until the incr. comp. dir is
1341 /// This is the state during which the session directory is private and can
1344 session_directory: PathBuf,
1345 lock_file: flock::Lock,
1346 load_dep_graph: bool,
1348 /// This is the state after the session directory has been finalized. In this
1349 /// state, the contents of the directory must not be modified any more.
1350 Finalized { session_directory: PathBuf },
1351 /// This is an error state that is reached when some compilation error has
1352 /// occurred. It indicates that the contents of the session directory must
1353 /// not be used, since they might be invalid.
1354 InvalidBecauseOfErrors { session_directory: PathBuf },
1357 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1358 let emitter: Box<dyn Emitter + sync::Send> = match output {
1359 config::ErrorOutputType::HumanReadable(kind) => {
1360 let (short, color_config) = kind.unzip();
1361 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1363 config::ErrorOutputType::Json { pretty, json_rendered } =>
1364 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1366 let handler = errors::Handler::with_emitter(true, None, emitter);
1367 handler.struct_fatal(msg).emit();
1368 errors::FatalError.raise();
1371 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1372 let emitter: Box<dyn Emitter + sync::Send> = match output {
1373 config::ErrorOutputType::HumanReadable(kind) => {
1374 let (short, color_config) = kind.unzip();
1375 Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1377 config::ErrorOutputType::Json { pretty, json_rendered } =>
1378 Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
1380 let handler = errors::Handler::with_emitter(true, None, emitter);
1381 handler.struct_warn(msg).emit();
1384 pub type CompileResult = Result<(), ErrorReported>;