1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 pub use self::code_stats::{CodeStats, DataTypeKind, FieldInfo};
12 pub use self::code_stats::{SizeKind, TypeSizeInfo, VariantInfo};
14 use hir::def_id::CrateNum;
19 use lint::builtin::BuiltinLintDiagnostics;
20 use middle::allocator::AllocatorKind;
21 use middle::dependency_format;
22 use session::search_paths::PathKind;
23 use session::config::{OutputType};
25 use util::nodemap::{FxHashMap, FxHashSet};
26 use util::common::{duration_to_secs_str, ErrorReported};
27 use util::common::ProfileQueriesMsg;
29 use rustc_data_structures::sync::{self, Lrc, Lock, LockCell, OneThread, Once, RwLock};
31 use syntax::ast::NodeId;
32 use errors::{self, DiagnosticBuilder, DiagnosticId};
33 use errors::emitter::{Emitter, EmitterWriter};
34 use syntax::edition::Edition;
35 use syntax::json::JsonEmitter;
36 use syntax::feature_gate;
37 use syntax::symbol::Symbol;
39 use syntax::parse::ParseSess;
40 use syntax::{ast, codemap};
41 use syntax::feature_gate::AttributeType;
42 use syntax_pos::{MultiSpan, Span};
44 use rustc_target::spec::{LinkerFlavor, PanicStrategy};
45 use rustc_target::spec::{Target, TargetTriple};
46 use rustc_data_structures::flock;
47 use jobserver::Client;
50 use std::cell::{self, Cell, RefCell};
51 use std::collections::HashMap;
55 use std::path::{Path, PathBuf};
56 use std::time::Duration;
58 use std::sync::atomic::{AtomicUsize, Ordering};
65 /// Represents the data associated with a compilation
66 /// session for a single crate.
68 pub target: config::Config,
70 pub opts: config::Options,
71 pub parse_sess: ParseSess,
72 /// For a library crate, this is always none
73 pub entry_fn: Once<Option<(NodeId, Span, config::EntryFnType)>>,
74 pub plugin_registrar_fn: Once<Option<ast::NodeId>>,
75 pub derive_registrar_fn: Once<Option<ast::NodeId>>,
76 pub default_sysroot: Option<PathBuf>,
77 /// The name of the root source file of the crate, in the local file system.
78 /// `None` means that there is no source file.
79 pub local_crate_source_file: Option<PathBuf>,
80 /// The directory the compiler has been executed in plus a flag indicating
81 /// if the value stored here has been affected by path remapping.
82 pub working_dir: (PathBuf, bool),
84 // FIXME: lint_store and buffered_lints are not thread-safe,
85 // but are only used in a single thread
86 pub lint_store: RwLock<lint::LintStore>,
87 pub buffered_lints: Lock<Option<lint::LintBuffer>>,
89 /// Set of (DiagnosticId, Option<Span>, message) tuples tracking
90 /// (sub)diagnostics that have been set once, but should not be set again,
91 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
92 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
93 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
94 pub plugin_attributes: OneThread<RefCell<Vec<(String, AttributeType)>>>,
95 pub crate_types: Once<Vec<config::CrateType>>,
96 pub dependency_formats: Once<dependency_format::Dependencies>,
97 /// The crate_disambiguator is constructed out of all the `-C metadata`
98 /// arguments passed to the compiler. Its value together with the crate-name
99 /// forms a unique global identifier for the crate. It is used to allow
100 /// multiple crates with the same name to coexist. See the
101 /// rustc_codegen_llvm::back::symbol_names module for more information.
102 pub crate_disambiguator: Once<CrateDisambiguator>,
104 features: Once<feature_gate::Features>,
106 /// The maximum recursion limit for potentially infinitely recursive
107 /// operations such as auto-dereference and monomorphization.
108 pub recursion_limit: Once<usize>,
110 /// The maximum length of types during monomorphization.
111 pub type_length_limit: Once<usize>,
113 /// The maximum number of stackframes allowed in const eval
114 pub const_eval_stack_frame_limit: usize,
116 /// The metadata::creader module may inject an allocator/panic_runtime
117 /// dependency if it didn't already find one, and this tracks what was
119 pub injected_allocator: Once<Option<CrateNum>>,
120 pub allocator_kind: Once<Option<AllocatorKind>>,
121 pub injected_panic_runtime: Once<Option<CrateNum>>,
123 /// Map from imported macro spans (which consist of
124 /// the localized span for the macro body) to the
125 /// macro name and definition span in the source crate.
126 pub imported_macro_spans: OneThread<RefCell<HashMap<Span, (String, Span)>>>,
128 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
130 /// A cache of attributes ignored by StableHashingContext
131 pub ignored_attr_names: FxHashSet<Symbol>,
133 /// Used by -Z profile-queries in util::common
134 pub profile_channel: Lock<Option<mpsc::Sender<ProfileQueriesMsg>>>,
136 /// Some measurements that are being gathered during compilation.
137 pub perf_stats: PerfStats,
139 /// Data about code being compiled, gathered during compilation.
140 pub code_stats: Lock<CodeStats>,
142 next_node_id: OneThread<Cell<ast::NodeId>>,
144 /// If -zfuel=crate=n is specified, Some(crate).
145 optimization_fuel_crate: Option<String>,
146 /// If -zfuel=crate=n is specified, initially set to n. Otherwise 0.
147 optimization_fuel_limit: LockCell<u64>,
148 /// We're rejecting all further optimizations.
149 out_of_fuel: LockCell<bool>,
151 // The next two are public because the driver needs to read them.
152 /// If -zprint-fuel=crate, Some(crate).
153 pub print_fuel_crate: Option<String>,
154 /// Always set to zero and incremented so that we can print fuel expended by a crate.
155 pub print_fuel: LockCell<u64>,
157 /// Loaded up early on in the initialization of this `Session` to avoid
158 /// false positives about a job server in our environment.
159 pub jobserver: Client,
161 /// Metadata about the allocators for the current crate being compiled
162 pub has_global_allocator: Once<bool>,
164 /// Cap lint level specified by a driver specifically.
165 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
168 pub struct PerfStats {
169 /// The accumulated time spent on computing symbol hashes
170 pub symbol_hash_time: Lock<Duration>,
171 /// The accumulated time spent decoding def path tables from metadata
172 pub decode_def_path_tables_time: Lock<Duration>,
173 /// Total number of values canonicalized queries constructed.
174 pub queries_canonicalized: AtomicUsize,
175 /// Number of times this query is invoked.
176 pub normalize_ty_after_erasing_regions: AtomicUsize,
177 /// Number of times this query is invoked.
178 pub normalize_projection_ty: AtomicUsize,
181 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
182 enum DiagnosticBuilderMethod {
185 SpanSuggestion(String), // suggestion
186 // add more variants as needed to support one-time diagnostics
189 /// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
190 /// emitting the same message more than once
191 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
192 pub enum DiagnosticMessageId {
193 ErrorId(u16), // EXXXX error code as integer
194 LintId(lint::LintId),
195 StabilityId(u32), // issue number
198 impl From<&'static lint::Lint> for DiagnosticMessageId {
199 fn from(lint: &'static lint::Lint) -> Self {
200 DiagnosticMessageId::LintId(lint::LintId::of(lint))
205 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
206 *self.crate_disambiguator.get()
209 pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
213 ) -> DiagnosticBuilder<'a> {
214 self.diagnostic().struct_span_warn(sp, msg)
216 pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
221 ) -> DiagnosticBuilder<'a> {
222 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
224 pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
225 self.diagnostic().struct_warn(msg)
227 pub fn struct_span_err<'a, S: Into<MultiSpan>>(
231 ) -> DiagnosticBuilder<'a> {
232 self.diagnostic().struct_span_err(sp, msg)
234 pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
239 ) -> DiagnosticBuilder<'a> {
240 self.diagnostic().struct_span_err_with_code(sp, msg, code)
242 // FIXME: This method should be removed (every error should have an associated error code).
243 pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
244 self.diagnostic().struct_err(msg)
246 pub fn struct_err_with_code<'a>(
250 ) -> DiagnosticBuilder<'a> {
251 self.diagnostic().struct_err_with_code(msg, code)
253 pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
257 ) -> DiagnosticBuilder<'a> {
258 self.diagnostic().struct_span_fatal(sp, msg)
260 pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
265 ) -> DiagnosticBuilder<'a> {
266 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
268 pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
269 self.diagnostic().struct_fatal(msg)
272 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
273 self.diagnostic().span_fatal(sp, msg).raise()
275 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
282 .span_fatal_with_code(sp, msg, code)
285 pub fn fatal(&self, msg: &str) -> ! {
286 self.diagnostic().fatal(msg).raise()
288 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
290 self.span_warn(sp, msg);
292 self.span_err(sp, msg);
295 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
296 self.diagnostic().span_err(sp, msg)
298 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
299 self.diagnostic().span_err_with_code(sp, &msg, code)
301 pub fn err(&self, msg: &str) {
302 self.diagnostic().err(msg)
304 pub fn err_count(&self) -> usize {
305 self.diagnostic().err_count()
307 pub fn has_errors(&self) -> bool {
308 self.diagnostic().has_errors()
310 pub fn abort_if_errors(&self) {
311 self.diagnostic().abort_if_errors();
313 pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
314 compile_result_from_err_count(self.err_count())
316 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
320 let old_count = self.err_count();
322 let errors = self.err_count() - old_count;
329 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
330 self.diagnostic().span_warn(sp, msg)
332 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
333 self.diagnostic().span_warn_with_code(sp, msg, code)
335 pub fn warn(&self, msg: &str) {
336 self.diagnostic().warn(msg)
338 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
340 Some(sp) => self.span_warn(sp, msg),
341 None => self.warn(msg),
344 /// Delay a span_bug() call until abort_if_errors()
345 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
346 self.diagnostic().delay_span_bug(sp, msg)
348 pub fn note_without_error(&self, msg: &str) {
349 self.diagnostic().note_without_error(msg)
351 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
352 self.diagnostic().span_note_without_error(sp, msg)
354 pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
355 self.diagnostic().span_unimpl(sp, msg)
357 pub fn unimpl(&self, msg: &str) -> ! {
358 self.diagnostic().unimpl(msg)
361 pub fn buffer_lint<S: Into<MultiSpan>>(
363 lint: &'static lint::Lint,
368 match *self.buffered_lints.borrow_mut() {
369 Some(ref mut buffer) => {
370 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
372 None => bug!("can't buffer lints after HIR lowering"),
376 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
378 lint: &'static lint::Lint,
382 diagnostic: BuiltinLintDiagnostics,
384 match *self.buffered_lints.borrow_mut() {
385 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
386 None => bug!("can't buffer lints after HIR lowering"),
390 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
391 let id = self.next_node_id.get();
393 match id.as_usize().checked_add(count) {
395 self.next_node_id.set(ast::NodeId::new(next));
397 None => bug!("Input too large, ran out of node ids!"),
402 pub fn next_node_id(&self) -> NodeId {
403 self.reserve_node_ids(1)
405 pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
406 &self.parse_sess.span_diagnostic
409 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
410 /// deduplicates on lint ID, span (if any), and message for this `Session`
411 fn diag_once<'a, 'b>(
413 diag_builder: &'b mut DiagnosticBuilder<'a>,
414 method: DiagnosticBuilderMethod,
415 msg_id: DiagnosticMessageId,
417 span_maybe: Option<Span>,
419 let id_span_message = (msg_id, span_maybe, message.to_owned());
420 let fresh = self.one_time_diagnostics
422 .insert(id_span_message);
425 DiagnosticBuilderMethod::Note => {
426 diag_builder.note(message);
428 DiagnosticBuilderMethod::SpanNote => {
429 let span = span_maybe.expect("span_note needs a span");
430 diag_builder.span_note(span, message);
432 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
433 let span = span_maybe.expect("span_suggestion needs a span");
434 diag_builder.span_suggestion(span, message, suggestion);
440 pub fn diag_span_note_once<'a, 'b>(
442 diag_builder: &'b mut DiagnosticBuilder<'a>,
443 msg_id: DiagnosticMessageId,
449 DiagnosticBuilderMethod::SpanNote,
456 pub fn diag_note_once<'a, 'b>(
458 diag_builder: &'b mut DiagnosticBuilder<'a>,
459 msg_id: DiagnosticMessageId,
464 DiagnosticBuilderMethod::Note,
471 pub fn diag_span_suggestion_once<'a, 'b>(
473 diag_builder: &'b mut DiagnosticBuilder<'a>,
474 msg_id: DiagnosticMessageId,
481 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
488 pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
489 self.parse_sess.codemap()
491 pub fn verbose(&self) -> bool {
492 self.opts.debugging_opts.verbose
494 pub fn time_passes(&self) -> bool {
495 self.opts.debugging_opts.time_passes
497 pub fn profile_queries(&self) -> bool {
498 self.opts.debugging_opts.profile_queries
499 || self.opts.debugging_opts.profile_queries_and_keys
501 pub fn profile_queries_and_keys(&self) -> bool {
502 self.opts.debugging_opts.profile_queries_and_keys
504 pub fn count_llvm_insns(&self) -> bool {
505 self.opts.debugging_opts.count_llvm_insns
507 pub fn time_llvm_passes(&self) -> bool {
508 self.opts.debugging_opts.time_llvm_passes
510 pub fn codegen_stats(&self) -> bool {
511 self.opts.debugging_opts.codegen_stats
513 pub fn meta_stats(&self) -> bool {
514 self.opts.debugging_opts.meta_stats
516 pub fn asm_comments(&self) -> bool {
517 self.opts.debugging_opts.asm_comments
519 pub fn verify_llvm_ir(&self) -> bool {
520 self.opts.debugging_opts.verify_llvm_ir
522 pub fn borrowck_stats(&self) -> bool {
523 self.opts.debugging_opts.borrowck_stats
525 pub fn print_llvm_passes(&self) -> bool {
526 self.opts.debugging_opts.print_llvm_passes
529 /// Get the features enabled for the current compilation session.
530 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
531 /// dependency tracking. Use tcx.features() instead.
533 pub fn features_untracked(&self) -> &feature_gate::Features {
537 pub fn init_features(&self, features: feature_gate::Features) {
538 self.features.set(features);
541 /// Calculates the flavor of LTO to use for this compilation.
542 pub fn lto(&self) -> config::Lto {
543 // If our target has codegen requirements ignore the command line
544 if self.target.target.options.requires_lto {
545 return config::Lto::Fat;
548 // If the user specified something, return that. If they only said `-C
549 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
550 // then ensure we can't use a ThinLTO.
551 match self.opts.cg.lto {
552 config::Lto::No => {}
553 config::Lto::Yes if self.opts.cli_forced_thinlto_off => return config::Lto::Fat,
554 other => return other,
557 // Ok at this point the target doesn't require anything and the user
558 // hasn't asked for anything. Our next decision is whether or not
559 // we enable "auto" ThinLTO where we use multiple codegen units and
560 // then do ThinLTO over those codegen units. The logic below will
561 // either return `No` or `ThinLocal`.
563 // If processing command line options determined that we're incompatible
564 // with ThinLTO (e.g. `-C lto --emit llvm-ir`) then return that option.
565 if self.opts.cli_forced_thinlto_off {
566 return config::Lto::No;
569 // If `-Z thinlto` specified process that, but note that this is mostly
570 // a deprecated option now that `-C lto=thin` exists.
571 if let Some(enabled) = self.opts.debugging_opts.thinlto {
573 return config::Lto::ThinLocal;
575 return config::Lto::No;
579 // If there's only one codegen unit and LTO isn't enabled then there's
580 // no need for ThinLTO so just return false.
581 if self.codegen_units() == 1 {
582 return config::Lto::No;
585 // Right now ThinLTO isn't compatible with incremental compilation.
586 if self.opts.incremental.is_some() {
587 return config::Lto::No;
590 // Now we're in "defaults" territory. By default we enable ThinLTO for
591 // optimized compiles (anything greater than O0).
592 match self.opts.optimize {
593 config::OptLevel::No => config::Lto::No,
594 _ => config::Lto::ThinLocal,
598 /// Returns the panic strategy for this compile session. If the user explicitly selected one
599 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
600 pub fn panic_strategy(&self) -> PanicStrategy {
604 .unwrap_or(self.target.target.options.panic_strategy)
606 pub fn linker_flavor(&self) -> LinkerFlavor {
610 .unwrap_or(self.target.target.linker_flavor)
613 pub fn fewer_names(&self) -> bool {
614 let more_names = self.opts
616 .contains_key(&OutputType::LlvmAssembly)
617 || self.opts.output_types.contains_key(&OutputType::Bitcode);
618 self.opts.debugging_opts.fewer_names || !more_names
621 pub fn no_landing_pads(&self) -> bool {
622 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
624 pub fn unstable_options(&self) -> bool {
625 self.opts.debugging_opts.unstable_options
627 pub fn nonzeroing_move_hints(&self) -> bool {
628 self.opts.debugging_opts.enable_nonzeroing_move_hints
630 pub fn overflow_checks(&self) -> bool {
634 .or(self.opts.debugging_opts.force_overflow_checks)
635 .unwrap_or(self.opts.debug_assertions)
638 pub fn crt_static(&self) -> bool {
639 // If the target does not opt in to crt-static support, use its default.
640 if self.target.target.options.crt_static_respected {
641 self.crt_static_feature()
643 self.target.target.options.crt_static_default
647 pub fn crt_static_feature(&self) -> bool {
648 let requested_features = self.opts.cg.target_feature.split(',');
649 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
650 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
652 // If the target we're compiling for requests a static crt by default,
653 // then see if the `-crt-static` feature was passed to disable that.
654 // Otherwise if we don't have a static crt by default then see if the
655 // `+crt-static` feature was passed.
656 if self.target.target.options.crt_static_default {
663 pub fn target_cpu(&self) -> &str {
664 match self.opts.cg.target_cpu {
666 None => &*self.target.target.options.cpu
670 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
671 if let Some(x) = self.opts.cg.force_frame_pointers {
674 !self.target.target.options.eliminate_frame_pointer
678 /// Returns the symbol name for the registrar function,
679 /// given the crate Svh and the function DefIndex.
680 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
682 "__rustc_plugin_registrar_{}__",
683 disambiguator.to_fingerprint().to_hex()
687 pub fn generate_derive_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
689 "__rustc_derive_registrar_{}__",
690 disambiguator.to_fingerprint().to_hex()
694 pub fn sysroot<'a>(&'a self) -> &'a Path {
695 match self.opts.maybe_sysroot {
696 Some(ref sysroot) => sysroot,
697 None => self.default_sysroot
699 .expect("missing sysroot and default_sysroot in Session"),
702 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
703 filesearch::FileSearch::new(
705 self.opts.target_triple.triple(),
706 &self.opts.search_paths,
710 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
711 filesearch::FileSearch::new(
713 config::host_triple(),
714 &self.opts.search_paths,
719 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
720 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
722 match *incr_comp_session {
723 IncrCompSession::Active {
724 ref mut load_dep_graph,
727 *load_dep_graph = load;
733 pub fn incr_session_load_dep_graph(&self) -> bool {
734 let incr_comp_session = self.incr_comp_session.borrow();
735 match *incr_comp_session {
736 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
741 pub fn init_incr_comp_session(
743 session_dir: PathBuf,
744 lock_file: flock::Lock,
745 load_dep_graph: bool,
747 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
749 if let IncrCompSession::NotInitialized = *incr_comp_session {
752 "Trying to initialize IncrCompSession `{:?}`",
757 *incr_comp_session = IncrCompSession::Active {
758 session_directory: session_dir,
764 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
765 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
767 if let IncrCompSession::Active { .. } = *incr_comp_session {
770 "Trying to finalize IncrCompSession `{:?}`",
775 // Note: This will also drop the lock file, thus unlocking the directory
776 *incr_comp_session = IncrCompSession::Finalized {
777 session_directory: new_directory_path,
781 pub fn mark_incr_comp_session_as_invalid(&self) {
782 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
784 let session_directory = match *incr_comp_session {
785 IncrCompSession::Active {
786 ref session_directory,
788 } => session_directory.clone(),
789 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
791 "Trying to invalidate IncrCompSession `{:?}`",
796 // Note: This will also drop the lock file, thus unlocking the directory
797 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
800 pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
801 let incr_comp_session = self.incr_comp_session.borrow();
804 |incr_comp_session| match *incr_comp_session {
805 IncrCompSession::NotInitialized => bug!(
806 "Trying to get session directory from IncrCompSession `{:?}`",
809 IncrCompSession::Active {
810 ref session_directory,
813 | IncrCompSession::Finalized {
814 ref session_directory,
816 | IncrCompSession::InvalidBecauseOfErrors {
817 ref session_directory,
818 } => session_directory,
823 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
824 if self.opts.incremental.is_some() {
825 Some(self.incr_comp_session_dir())
831 pub fn print_perf_stats(&self) {
833 "Total time spent computing symbol hashes: {}",
834 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
837 "Total time spent decoding DefPath tables: {}",
838 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
840 println!("Total queries canonicalized: {}",
841 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
842 println!("normalize_ty_after_erasing_regions: {}",
843 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
844 println!("normalize_projection_ty: {}",
845 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
848 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
849 /// This expends fuel if applicable, and records fuel if applicable.
850 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
852 match self.optimization_fuel_crate {
853 Some(ref c) if c == crate_name => {
854 assert!(self.query_threads() == 1);
855 let fuel = self.optimization_fuel_limit.get();
857 if fuel == 0 && !self.out_of_fuel.get() {
858 println!("optimization-fuel-exhausted: {}", msg());
859 self.out_of_fuel.set(true);
861 self.optimization_fuel_limit.set(fuel - 1);
866 match self.print_fuel_crate {
867 Some(ref c) if c == crate_name => {
868 assert!(self.query_threads() == 1);
869 self.print_fuel.set(self.print_fuel.get() + 1);
876 /// Returns the number of query threads that should be used for this
878 pub fn query_threads_from_opts(opts: &config::Options) -> usize {
879 opts.debugging_opts.query_threads.unwrap_or(1)
882 /// Returns the number of query threads that should be used for this
884 pub fn query_threads(&self) -> usize {
885 Self::query_threads_from_opts(&self.opts)
888 /// Returns the number of codegen units that should be used for this
890 pub fn codegen_units(&self) -> usize {
891 if let Some(n) = self.opts.cli_forced_codegen_units {
894 if let Some(n) = self.target.target.options.default_codegen_units {
898 // Why is 16 codegen units the default all the time?
900 // The main reason for enabling multiple codegen units by default is to
901 // leverage the ability for the codegen backend to do codegen and
902 // optimization in parallel. This allows us, especially for large crates, to
903 // make good use of all available resources on the machine once we've
904 // hit that stage of compilation. Large crates especially then often
905 // take a long time in codegen/optimization and this helps us amortize that
908 // Note that a high number here doesn't mean that we'll be spawning a
909 // large number of threads in parallel. The backend of rustc contains
910 // global rate limiting through the `jobserver` crate so we'll never
911 // overload the system with too much work, but rather we'll only be
912 // optimizing when we're otherwise cooperating with other instances of
915 // Rather a high number here means that we should be able to keep a lot
916 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
917 // to build we'll be guaranteed that all cpus will finish pretty closely
918 // to one another and we should make relatively optimal use of system
921 // Note that the main cost of codegen units is that it prevents LLVM
922 // from inlining across codegen units. Users in general don't have a lot
923 // of control over how codegen units are split up so it's our job in the
924 // compiler to ensure that undue performance isn't lost when using
925 // codegen units (aka we can't require everyone to slap `#[inline]` on
928 // If we're compiling at `-O0` then the number doesn't really matter too
929 // much because performance doesn't matter and inlining is ok to lose.
930 // In debug mode we just want to try to guarantee that no cpu is stuck
931 // doing work that could otherwise be farmed to others.
933 // In release mode, however (O1 and above) performance does indeed
934 // matter! To recover the loss in performance due to inlining we'll be
935 // enabling ThinLTO by default (the function for which is just below).
936 // This will ensure that we recover any inlining wins we otherwise lost
937 // through codegen unit partitioning.
941 // Ok that's a lot of words but the basic tl;dr; is that we want a high
942 // number here -- but not too high. Additionally we're "safe" to have it
943 // always at the same number at all optimization levels.
945 // As a result 16 was chosen here! Mostly because it was a power of 2
946 // and most benchmarks agreed it was roughly a local optimum. Not very
951 pub fn teach(&self, code: &DiagnosticId) -> bool {
952 self.opts.debugging_opts.teach && self.parse_sess.span_diagnostic.must_teach(code)
955 /// Are we allowed to use features from the Rust 2018 edition?
956 pub fn rust_2018(&self) -> bool {
957 self.opts.edition >= Edition::Edition2018
960 pub fn edition(&self) -> Edition {
965 pub fn build_session(
966 sopts: config::Options,
967 local_crate_source_file: Option<PathBuf>,
968 registry: errors::registry::Registry,
970 let file_path_mapping = sopts.file_path_mapping();
972 build_session_with_codemap(
974 local_crate_source_file,
976 Lrc::new(codemap::CodeMap::new(file_path_mapping)),
981 pub fn build_session_with_codemap(
982 sopts: config::Options,
983 local_crate_source_file: Option<PathBuf>,
984 registry: errors::registry::Registry,
985 codemap: Lrc<codemap::CodeMap>,
986 emitter_dest: Option<Box<dyn Write + Send>>,
988 // FIXME: This is not general enough to make the warning lint completely override
989 // normal diagnostic warnings, since the warning lint can also be denied and changed
990 // later via the source code.
991 let warnings_allow = sopts
994 .filter(|&&(ref key, _)| *key == "warnings")
995 .map(|&(_, ref level)| *level == lint::Allow)
998 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1000 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1002 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1004 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1006 let emitter: Box<dyn Emitter + sync::Send> =
1007 match (sopts.error_format, emitter_dest) {
1008 (config::ErrorOutputType::HumanReadable(color_config), None) => Box::new(
1009 EmitterWriter::stderr(
1011 Some(codemap.clone()),
1013 sopts.debugging_opts.teach,
1014 ).ui_testing(sopts.debugging_opts.ui_testing),
1016 (config::ErrorOutputType::HumanReadable(_), Some(dst)) => Box::new(
1017 EmitterWriter::new(dst, Some(codemap.clone()), false, false)
1018 .ui_testing(sopts.debugging_opts.ui_testing),
1020 (config::ErrorOutputType::Json(pretty), None) => Box::new(
1021 JsonEmitter::stderr(
1025 ).ui_testing(sopts.debugging_opts.ui_testing),
1027 (config::ErrorOutputType::Json(pretty), Some(dst)) => Box::new(
1033 ).ui_testing(sopts.debugging_opts.ui_testing),
1035 (config::ErrorOutputType::Short(color_config), None) => Box::new(
1036 EmitterWriter::stderr(color_config, Some(codemap.clone()), true, false),
1038 (config::ErrorOutputType::Short(_), Some(dst)) => {
1039 Box::new(EmitterWriter::new(dst, Some(codemap.clone()), true, false))
1043 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1045 errors::HandlerFlags {
1048 external_macro_backtrace,
1049 ..Default::default()
1053 build_session_(sopts, local_crate_source_file, diagnostic_handler, codemap)
1056 pub fn build_session_(
1057 sopts: config::Options,
1058 local_crate_source_file: Option<PathBuf>,
1059 span_diagnostic: errors::Handler,
1060 codemap: Lrc<codemap::CodeMap>,
1062 let host_triple = TargetTriple::from_triple(config::host_triple());
1063 let host = match Target::search(&host_triple) {
1067 .fatal(&format!("Error loading host specification: {}", e))
1071 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1073 let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
1074 let default_sysroot = match sopts.maybe_sysroot {
1076 None => Some(filesearch::get_or_default_sysroot()),
1079 let file_path_mapping = sopts.file_path_mapping();
1081 let local_crate_source_file =
1082 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1084 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1085 let optimization_fuel_limit =
1086 LockCell::new(sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0));
1087 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1088 let print_fuel = LockCell::new(0);
1090 let working_dir = match env::current_dir() {
1092 Err(e) => p_s.span_diagnostic
1093 .fatal(&format!("Current directory is invalid: {}", e))
1096 let working_dir = file_path_mapping.map_prefix(working_dir);
1098 let sess = Session {
1103 // For a library crate, this is always none
1104 entry_fn: Once::new(),
1105 plugin_registrar_fn: Once::new(),
1106 derive_registrar_fn: Once::new(),
1108 local_crate_source_file,
1110 lint_store: RwLock::new(lint::LintStore::new()),
1111 buffered_lints: Lock::new(Some(lint::LintBuffer::new())),
1112 one_time_diagnostics: Lock::new(FxHashSet()),
1113 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1114 plugin_attributes: OneThread::new(RefCell::new(Vec::new())),
1115 crate_types: Once::new(),
1116 dependency_formats: Once::new(),
1117 crate_disambiguator: Once::new(),
1118 features: Once::new(),
1119 recursion_limit: Once::new(),
1120 type_length_limit: Once::new(),
1121 const_eval_stack_frame_limit: 100,
1122 next_node_id: OneThread::new(Cell::new(NodeId::new(1))),
1123 injected_allocator: Once::new(),
1124 allocator_kind: Once::new(),
1125 injected_panic_runtime: Once::new(),
1126 imported_macro_spans: OneThread::new(RefCell::new(HashMap::new())),
1127 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1128 ignored_attr_names: ich::compute_ignored_attr_names(),
1129 profile_channel: Lock::new(None),
1130 perf_stats: PerfStats {
1131 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1132 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1133 queries_canonicalized: AtomicUsize::new(0),
1134 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1135 normalize_projection_ty: AtomicUsize::new(0),
1137 code_stats: Lock::new(CodeStats::new()),
1138 optimization_fuel_crate,
1139 optimization_fuel_limit,
1142 out_of_fuel: LockCell::new(false),
1143 // Note that this is unsafe because it may misinterpret file descriptors
1144 // on Unix as jobserver file descriptors. We hopefully execute this near
1145 // the beginning of the process though to ensure we don't get false
1146 // positives, or in other words we try to execute this before we open
1147 // any file descriptors ourselves.
1149 // Pick a "reasonable maximum" if we don't otherwise have
1150 // a jobserver in our environment, capping out at 32 so we
1151 // don't take everything down by hogging the process run queue.
1152 // The fixed number is used to have deterministic compilation
1155 // Also note that we stick this in a global because there could be
1156 // multiple `Session` instances in this process, and the jobserver is
1159 static mut GLOBAL_JOBSERVER: *mut Client = 0 as *mut _;
1160 static INIT: std::sync::Once = std::sync::ONCE_INIT;
1162 let client = Client::from_env().unwrap_or_else(|| {
1163 Client::new(32).expect("failed to create jobserver")
1165 GLOBAL_JOBSERVER = Box::into_raw(Box::new(client));
1167 (*GLOBAL_JOBSERVER).clone()
1169 has_global_allocator: Once::new(),
1170 driver_lint_caps: FxHashMap(),
1176 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1177 /// compiler. Together with the crate-name forms a unique global identifier for
1179 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1180 pub struct CrateDisambiguator(Fingerprint);
1182 impl CrateDisambiguator {
1183 pub fn to_fingerprint(self) -> Fingerprint {
1188 impl From<Fingerprint> for CrateDisambiguator {
1189 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1190 CrateDisambiguator(fingerprint)
1194 impl_stable_hash_for!(tuple_struct CrateDisambiguator { fingerprint });
1196 /// Holds data on the current incremental compilation session, if there is one.
1198 pub enum IncrCompSession {
1199 /// This is the state the session will be in until the incr. comp. dir is
1202 /// This is the state during which the session directory is private and can
1205 session_directory: PathBuf,
1206 lock_file: flock::Lock,
1207 load_dep_graph: bool,
1209 /// This is the state after the session directory has been finalized. In this
1210 /// state, the contents of the directory must not be modified any more.
1211 Finalized { session_directory: PathBuf },
1212 /// This is an error state that is reached when some compilation error has
1213 /// occurred. It indicates that the contents of the session directory must
1214 /// not be used, since they might be invalid.
1215 InvalidBecauseOfErrors { session_directory: PathBuf },
1218 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1219 let emitter: Box<dyn Emitter + sync::Send> = match output {
1220 config::ErrorOutputType::HumanReadable(color_config) => {
1221 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1223 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1224 config::ErrorOutputType::Short(color_config) => {
1225 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1228 let handler = errors::Handler::with_emitter(true, false, emitter);
1229 handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
1230 errors::FatalError.raise();
1233 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1234 let emitter: Box<dyn Emitter + sync::Send> = match output {
1235 config::ErrorOutputType::HumanReadable(color_config) => {
1236 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1238 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1239 config::ErrorOutputType::Short(color_config) => {
1240 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1243 let handler = errors::Handler::with_emitter(true, false, emitter);
1244 handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
1247 #[derive(Copy, Clone, Debug)]
1248 pub enum CompileIncomplete {
1250 Errored(ErrorReported),
1252 impl From<ErrorReported> for CompileIncomplete {
1253 fn from(err: ErrorReported) -> CompileIncomplete {
1254 CompileIncomplete::Errored(err)
1257 pub type CompileResult = Result<(), CompileIncomplete>;
1259 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
1263 Err(CompileIncomplete::Errored(ErrorReported))
1269 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
1270 // this wrapper mostly exists so I don't have to write a fully
1271 // qualified path of None::<Span> inside the bug!() macro definition
1272 opt_span_bug_fmt(file, line, None::<Span>, args);
1277 pub fn span_bug_fmt<S: Into<MultiSpan>>(
1281 args: fmt::Arguments,
1283 opt_span_bug_fmt(file, line, Some(span), args);
1286 fn opt_span_bug_fmt<S: Into<MultiSpan>>(
1290 args: fmt::Arguments,
1292 tls::with_opt(move |tcx| {
1293 let msg = format!("{}:{}: {}", file, line, args);
1295 (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
1296 (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
1297 (None, _) => panic!(msg),