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::{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>,
165 pub struct PerfStats {
166 /// The accumulated time spent on computing symbol hashes
167 pub symbol_hash_time: Lock<Duration>,
168 /// The accumulated time spent decoding def path tables from metadata
169 pub decode_def_path_tables_time: Lock<Duration>,
170 /// Total number of values canonicalized queries constructed.
171 pub queries_canonicalized: AtomicUsize,
172 /// Number of times this query is invoked.
173 pub normalize_ty_after_erasing_regions: AtomicUsize,
174 /// Number of times this query is invoked.
175 pub normalize_projection_ty: AtomicUsize,
178 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
179 enum DiagnosticBuilderMethod {
182 SpanSuggestion(String), // suggestion
183 // add more variants as needed to support one-time diagnostics
186 /// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
187 /// emitting the same message more than once
188 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
189 pub enum DiagnosticMessageId {
190 ErrorId(u16), // EXXXX error code as integer
191 LintId(lint::LintId),
192 StabilityId(u32), // issue number
195 impl From<&'static lint::Lint> for DiagnosticMessageId {
196 fn from(lint: &'static lint::Lint) -> Self {
197 DiagnosticMessageId::LintId(lint::LintId::of(lint))
202 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
203 *self.crate_disambiguator.get()
206 pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
210 ) -> DiagnosticBuilder<'a> {
211 self.diagnostic().struct_span_warn(sp, msg)
213 pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
218 ) -> DiagnosticBuilder<'a> {
219 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
221 pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
222 self.diagnostic().struct_warn(msg)
224 pub fn struct_span_err<'a, S: Into<MultiSpan>>(
228 ) -> DiagnosticBuilder<'a> {
229 self.diagnostic().struct_span_err(sp, msg)
231 pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
236 ) -> DiagnosticBuilder<'a> {
237 self.diagnostic().struct_span_err_with_code(sp, msg, code)
239 // FIXME: This method should be removed (every error should have an associated error code).
240 pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
241 self.diagnostic().struct_err(msg)
243 pub fn struct_err_with_code<'a>(
247 ) -> DiagnosticBuilder<'a> {
248 self.diagnostic().struct_err_with_code(msg, code)
250 pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
254 ) -> DiagnosticBuilder<'a> {
255 self.diagnostic().struct_span_fatal(sp, msg)
257 pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
262 ) -> DiagnosticBuilder<'a> {
263 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
265 pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
266 self.diagnostic().struct_fatal(msg)
269 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
270 self.diagnostic().span_fatal(sp, msg).raise()
272 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
279 .span_fatal_with_code(sp, msg, code)
282 pub fn fatal(&self, msg: &str) -> ! {
283 self.diagnostic().fatal(msg).raise()
285 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
287 self.span_warn(sp, msg);
289 self.span_err(sp, msg);
292 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
293 self.diagnostic().span_err(sp, msg)
295 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
296 self.diagnostic().span_err_with_code(sp, &msg, code)
298 pub fn err(&self, msg: &str) {
299 self.diagnostic().err(msg)
301 pub fn err_count(&self) -> usize {
302 self.diagnostic().err_count()
304 pub fn has_errors(&self) -> bool {
305 self.diagnostic().has_errors()
307 pub fn abort_if_errors(&self) {
308 self.diagnostic().abort_if_errors();
310 pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
311 compile_result_from_err_count(self.err_count())
313 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
317 let old_count = self.err_count();
319 let errors = self.err_count() - old_count;
326 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
327 self.diagnostic().span_warn(sp, msg)
329 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
330 self.diagnostic().span_warn_with_code(sp, msg, code)
332 pub fn warn(&self, msg: &str) {
333 self.diagnostic().warn(msg)
335 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
337 Some(sp) => self.span_warn(sp, msg),
338 None => self.warn(msg),
341 /// Delay a span_bug() call until abort_if_errors()
342 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
343 self.diagnostic().delay_span_bug(sp, msg)
345 pub fn note_without_error(&self, msg: &str) {
346 self.diagnostic().note_without_error(msg)
348 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
349 self.diagnostic().span_note_without_error(sp, msg)
351 pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
352 self.diagnostic().span_unimpl(sp, msg)
354 pub fn unimpl(&self, msg: &str) -> ! {
355 self.diagnostic().unimpl(msg)
358 pub fn buffer_lint<S: Into<MultiSpan>>(
360 lint: &'static lint::Lint,
365 match *self.buffered_lints.borrow_mut() {
366 Some(ref mut buffer) => {
367 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
369 None => bug!("can't buffer lints after HIR lowering"),
373 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
375 lint: &'static lint::Lint,
379 diagnostic: BuiltinLintDiagnostics,
381 match *self.buffered_lints.borrow_mut() {
382 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
383 None => bug!("can't buffer lints after HIR lowering"),
387 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
388 let id = self.next_node_id.get();
390 match id.as_usize().checked_add(count) {
392 self.next_node_id.set(ast::NodeId::new(next));
394 None => bug!("Input too large, ran out of node ids!"),
399 pub fn next_node_id(&self) -> NodeId {
400 self.reserve_node_ids(1)
402 pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
403 &self.parse_sess.span_diagnostic
406 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
407 /// deduplicates on lint ID, span (if any), and message for this `Session`
408 fn diag_once<'a, 'b>(
410 diag_builder: &'b mut DiagnosticBuilder<'a>,
411 method: DiagnosticBuilderMethod,
412 msg_id: DiagnosticMessageId,
414 span_maybe: Option<Span>,
416 let id_span_message = (msg_id, span_maybe, message.to_owned());
417 let fresh = self.one_time_diagnostics
419 .insert(id_span_message);
422 DiagnosticBuilderMethod::Note => {
423 diag_builder.note(message);
425 DiagnosticBuilderMethod::SpanNote => {
426 let span = span_maybe.expect("span_note needs a span");
427 diag_builder.span_note(span, message);
429 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
430 let span = span_maybe.expect("span_suggestion needs a span");
431 diag_builder.span_suggestion(span, message, suggestion);
437 pub fn diag_span_note_once<'a, 'b>(
439 diag_builder: &'b mut DiagnosticBuilder<'a>,
440 msg_id: DiagnosticMessageId,
446 DiagnosticBuilderMethod::SpanNote,
453 pub fn diag_note_once<'a, 'b>(
455 diag_builder: &'b mut DiagnosticBuilder<'a>,
456 msg_id: DiagnosticMessageId,
461 DiagnosticBuilderMethod::Note,
468 pub fn diag_span_suggestion_once<'a, 'b>(
470 diag_builder: &'b mut DiagnosticBuilder<'a>,
471 msg_id: DiagnosticMessageId,
478 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
485 pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
486 self.parse_sess.codemap()
488 pub fn verbose(&self) -> bool {
489 self.opts.debugging_opts.verbose
491 pub fn time_passes(&self) -> bool {
492 self.opts.debugging_opts.time_passes
494 pub fn profile_queries(&self) -> bool {
495 self.opts.debugging_opts.profile_queries
496 || self.opts.debugging_opts.profile_queries_and_keys
498 pub fn profile_queries_and_keys(&self) -> bool {
499 self.opts.debugging_opts.profile_queries_and_keys
501 pub fn count_llvm_insns(&self) -> bool {
502 self.opts.debugging_opts.count_llvm_insns
504 pub fn time_llvm_passes(&self) -> bool {
505 self.opts.debugging_opts.time_llvm_passes
507 pub fn codegen_stats(&self) -> bool {
508 self.opts.debugging_opts.codegen_stats
510 pub fn meta_stats(&self) -> bool {
511 self.opts.debugging_opts.meta_stats
513 pub fn asm_comments(&self) -> bool {
514 self.opts.debugging_opts.asm_comments
516 pub fn no_verify(&self) -> bool {
517 self.opts.debugging_opts.no_verify
519 pub fn borrowck_stats(&self) -> bool {
520 self.opts.debugging_opts.borrowck_stats
522 pub fn print_llvm_passes(&self) -> bool {
523 self.opts.debugging_opts.print_llvm_passes
526 /// Get the features enabled for the current compilation session.
527 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
528 /// dependency tracking. Use tcx.features() instead.
530 pub fn features_untracked(&self) -> &feature_gate::Features {
534 pub fn init_features(&self, features: feature_gate::Features) {
535 self.features.set(features);
538 /// Calculates the flavor of LTO to use for this compilation.
539 pub fn lto(&self) -> config::Lto {
540 // If our target has codegen requirements ignore the command line
541 if self.target.target.options.requires_lto {
542 return config::Lto::Fat;
545 // If the user specified something, return that. If they only said `-C
546 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
547 // then ensure we can't use a ThinLTO.
548 match self.opts.cg.lto {
549 config::Lto::No => {}
550 config::Lto::Yes if self.opts.cli_forced_thinlto_off => return config::Lto::Fat,
551 other => return other,
554 // Ok at this point the target doesn't require anything and the user
555 // hasn't asked for anything. Our next decision is whether or not
556 // we enable "auto" ThinLTO where we use multiple codegen units and
557 // then do ThinLTO over those codegen units. The logic below will
558 // either return `No` or `ThinLocal`.
560 // If processing command line options determined that we're incompatible
561 // with ThinLTO (e.g. `-C lto --emit llvm-ir`) then return that option.
562 if self.opts.cli_forced_thinlto_off {
563 return config::Lto::No;
566 // If `-Z thinlto` specified process that, but note that this is mostly
567 // a deprecated option now that `-C lto=thin` exists.
568 if let Some(enabled) = self.opts.debugging_opts.thinlto {
570 return config::Lto::ThinLocal;
572 return config::Lto::No;
576 // If there's only one codegen unit and LTO isn't enabled then there's
577 // no need for ThinLTO so just return false.
578 if self.codegen_units() == 1 {
579 return config::Lto::No;
582 // Right now ThinLTO isn't compatible with incremental compilation.
583 if self.opts.incremental.is_some() {
584 return config::Lto::No;
587 // Now we're in "defaults" territory. By default we enable ThinLTO for
588 // optimized compiles (anything greater than O0).
589 match self.opts.optimize {
590 config::OptLevel::No => config::Lto::No,
591 _ => config::Lto::ThinLocal,
595 /// Returns the panic strategy for this compile session. If the user explicitly selected one
596 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
597 pub fn panic_strategy(&self) -> PanicStrategy {
601 .unwrap_or(self.target.target.options.panic_strategy)
603 pub fn linker_flavor(&self) -> LinkerFlavor {
607 .unwrap_or(self.target.target.linker_flavor)
610 pub fn fewer_names(&self) -> bool {
611 let more_names = self.opts
613 .contains_key(&OutputType::LlvmAssembly)
614 || self.opts.output_types.contains_key(&OutputType::Bitcode);
615 self.opts.debugging_opts.fewer_names || !more_names
618 pub fn no_landing_pads(&self) -> bool {
619 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
621 pub fn unstable_options(&self) -> bool {
622 self.opts.debugging_opts.unstable_options
624 pub fn nonzeroing_move_hints(&self) -> bool {
625 self.opts.debugging_opts.enable_nonzeroing_move_hints
627 pub fn overflow_checks(&self) -> bool {
631 .or(self.opts.debugging_opts.force_overflow_checks)
632 .unwrap_or(self.opts.debug_assertions)
635 pub fn crt_static(&self) -> bool {
636 // If the target does not opt in to crt-static support, use its default.
637 if self.target.target.options.crt_static_respected {
638 self.crt_static_feature()
640 self.target.target.options.crt_static_default
644 pub fn crt_static_feature(&self) -> bool {
645 let requested_features = self.opts.cg.target_feature.split(',');
646 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
647 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
649 // If the target we're compiling for requests a static crt by default,
650 // then see if the `-crt-static` feature was passed to disable that.
651 // Otherwise if we don't have a static crt by default then see if the
652 // `+crt-static` feature was passed.
653 if self.target.target.options.crt_static_default {
660 pub fn target_cpu(&self) -> &str {
661 match self.opts.cg.target_cpu {
663 None => &*self.target.target.options.cpu
667 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
668 if let Some(x) = self.opts.cg.force_frame_pointers {
671 !self.target.target.options.eliminate_frame_pointer
675 /// Returns the symbol name for the registrar function,
676 /// given the crate Svh and the function DefIndex.
677 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
679 "__rustc_plugin_registrar_{}__",
680 disambiguator.to_fingerprint().to_hex()
684 pub fn generate_derive_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
686 "__rustc_derive_registrar_{}__",
687 disambiguator.to_fingerprint().to_hex()
691 pub fn sysroot<'a>(&'a self) -> &'a Path {
692 match self.opts.maybe_sysroot {
693 Some(ref sysroot) => sysroot,
694 None => self.default_sysroot
696 .expect("missing sysroot and default_sysroot in Session"),
699 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
700 filesearch::FileSearch::new(
702 self.opts.target_triple.triple(),
703 &self.opts.search_paths,
707 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
708 filesearch::FileSearch::new(
710 config::host_triple(),
711 &self.opts.search_paths,
716 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
717 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
719 match *incr_comp_session {
720 IncrCompSession::Active {
721 ref mut load_dep_graph,
724 *load_dep_graph = load;
730 pub fn incr_session_load_dep_graph(&self) -> bool {
731 let incr_comp_session = self.incr_comp_session.borrow();
732 match *incr_comp_session {
733 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
738 pub fn init_incr_comp_session(
740 session_dir: PathBuf,
741 lock_file: flock::Lock,
742 load_dep_graph: bool,
744 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
746 if let IncrCompSession::NotInitialized = *incr_comp_session {
749 "Trying to initialize IncrCompSession `{:?}`",
754 *incr_comp_session = IncrCompSession::Active {
755 session_directory: session_dir,
761 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
762 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
764 if let IncrCompSession::Active { .. } = *incr_comp_session {
767 "Trying to finalize IncrCompSession `{:?}`",
772 // Note: This will also drop the lock file, thus unlocking the directory
773 *incr_comp_session = IncrCompSession::Finalized {
774 session_directory: new_directory_path,
778 pub fn mark_incr_comp_session_as_invalid(&self) {
779 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
781 let session_directory = match *incr_comp_session {
782 IncrCompSession::Active {
783 ref session_directory,
785 } => session_directory.clone(),
786 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
788 "Trying to invalidate IncrCompSession `{:?}`",
793 // Note: This will also drop the lock file, thus unlocking the directory
794 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
797 pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
798 let incr_comp_session = self.incr_comp_session.borrow();
801 |incr_comp_session| match *incr_comp_session {
802 IncrCompSession::NotInitialized => bug!(
803 "Trying to get session directory from IncrCompSession `{:?}`",
806 IncrCompSession::Active {
807 ref session_directory,
810 | IncrCompSession::Finalized {
811 ref session_directory,
813 | IncrCompSession::InvalidBecauseOfErrors {
814 ref session_directory,
815 } => session_directory,
820 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
821 if self.opts.incremental.is_some() {
822 Some(self.incr_comp_session_dir())
828 pub fn print_perf_stats(&self) {
830 "Total time spent computing symbol hashes: {}",
831 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
834 "Total time spent decoding DefPath tables: {}",
835 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
837 println!("Total queries canonicalized: {}",
838 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
839 println!("normalize_ty_after_erasing_regions: {}",
840 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
841 println!("normalize_projection_ty: {}",
842 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
845 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
846 /// This expends fuel if applicable, and records fuel if applicable.
847 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
849 match self.optimization_fuel_crate {
850 Some(ref c) if c == crate_name => {
851 assert!(self.query_threads() == 1);
852 let fuel = self.optimization_fuel_limit.get();
854 if fuel == 0 && !self.out_of_fuel.get() {
855 println!("optimization-fuel-exhausted: {}", msg());
856 self.out_of_fuel.set(true);
858 self.optimization_fuel_limit.set(fuel - 1);
863 match self.print_fuel_crate {
864 Some(ref c) if c == crate_name => {
865 assert!(self.query_threads() == 1);
866 self.print_fuel.set(self.print_fuel.get() + 1);
873 /// Returns the number of query threads that should be used for this
875 pub fn query_threads_from_opts(opts: &config::Options) -> usize {
876 opts.debugging_opts.query_threads.unwrap_or(1)
879 /// Returns the number of query threads that should be used for this
881 pub fn query_threads(&self) -> usize {
882 Self::query_threads_from_opts(&self.opts)
885 /// Returns the number of codegen units that should be used for this
887 pub fn codegen_units(&self) -> usize {
888 if let Some(n) = self.opts.cli_forced_codegen_units {
891 if let Some(n) = self.target.target.options.default_codegen_units {
895 // Why is 16 codegen units the default all the time?
897 // The main reason for enabling multiple codegen units by default is to
898 // leverage the ability for the codegen backend to do codegen and
899 // optimization in parallel. This allows us, especially for large crates, to
900 // make good use of all available resources on the machine once we've
901 // hit that stage of compilation. Large crates especially then often
902 // take a long time in codegen/optimization and this helps us amortize that
905 // Note that a high number here doesn't mean that we'll be spawning a
906 // large number of threads in parallel. The backend of rustc contains
907 // global rate limiting through the `jobserver` crate so we'll never
908 // overload the system with too much work, but rather we'll only be
909 // optimizing when we're otherwise cooperating with other instances of
912 // Rather a high number here means that we should be able to keep a lot
913 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
914 // to build we'll be guaranteed that all cpus will finish pretty closely
915 // to one another and we should make relatively optimal use of system
918 // Note that the main cost of codegen units is that it prevents LLVM
919 // from inlining across codegen units. Users in general don't have a lot
920 // of control over how codegen units are split up so it's our job in the
921 // compiler to ensure that undue performance isn't lost when using
922 // codegen units (aka we can't require everyone to slap `#[inline]` on
925 // If we're compiling at `-O0` then the number doesn't really matter too
926 // much because performance doesn't matter and inlining is ok to lose.
927 // In debug mode we just want to try to guarantee that no cpu is stuck
928 // doing work that could otherwise be farmed to others.
930 // In release mode, however (O1 and above) performance does indeed
931 // matter! To recover the loss in performance due to inlining we'll be
932 // enabling ThinLTO by default (the function for which is just below).
933 // This will ensure that we recover any inlining wins we otherwise lost
934 // through codegen unit partitioning.
938 // Ok that's a lot of words but the basic tl;dr; is that we want a high
939 // number here -- but not too high. Additionally we're "safe" to have it
940 // always at the same number at all optimization levels.
942 // As a result 16 was chosen here! Mostly because it was a power of 2
943 // and most benchmarks agreed it was roughly a local optimum. Not very
948 pub fn teach(&self, code: &DiagnosticId) -> bool {
949 self.opts.debugging_opts.teach && self.parse_sess.span_diagnostic.must_teach(code)
952 /// Are we allowed to use features from the Rust 2018 edition?
953 pub fn rust_2018(&self) -> bool {
954 self.opts.edition >= Edition::Edition2018
957 pub fn edition(&self) -> Edition {
962 pub fn build_session(
963 sopts: config::Options,
964 local_crate_source_file: Option<PathBuf>,
965 registry: errors::registry::Registry,
967 let file_path_mapping = sopts.file_path_mapping();
969 build_session_with_codemap(
971 local_crate_source_file,
973 Lrc::new(codemap::CodeMap::new(file_path_mapping)),
978 pub fn build_session_with_codemap(
979 sopts: config::Options,
980 local_crate_source_file: Option<PathBuf>,
981 registry: errors::registry::Registry,
982 codemap: Lrc<codemap::CodeMap>,
983 emitter_dest: Option<Box<dyn Write + Send>>,
985 // FIXME: This is not general enough to make the warning lint completely override
986 // normal diagnostic warnings, since the warning lint can also be denied and changed
987 // later via the source code.
988 let warnings_allow = sopts
991 .filter(|&&(ref key, _)| *key == "warnings")
992 .map(|&(_, ref level)| *level == lint::Allow)
995 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
997 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
999 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1001 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1003 let emitter: Box<dyn Emitter + sync::Send> =
1004 match (sopts.error_format, emitter_dest) {
1005 (config::ErrorOutputType::HumanReadable(color_config), None) => Box::new(
1006 EmitterWriter::stderr(
1008 Some(codemap.clone()),
1010 sopts.debugging_opts.teach,
1011 ).ui_testing(sopts.debugging_opts.ui_testing),
1013 (config::ErrorOutputType::HumanReadable(_), Some(dst)) => Box::new(
1014 EmitterWriter::new(dst, Some(codemap.clone()), false, false)
1015 .ui_testing(sopts.debugging_opts.ui_testing),
1017 (config::ErrorOutputType::Json(pretty), None) => Box::new(
1018 JsonEmitter::stderr(
1022 ).ui_testing(sopts.debugging_opts.ui_testing),
1024 (config::ErrorOutputType::Json(pretty), Some(dst)) => Box::new(
1030 ).ui_testing(sopts.debugging_opts.ui_testing),
1032 (config::ErrorOutputType::Short(color_config), None) => Box::new(
1033 EmitterWriter::stderr(color_config, Some(codemap.clone()), true, false),
1035 (config::ErrorOutputType::Short(_), Some(dst)) => {
1036 Box::new(EmitterWriter::new(dst, Some(codemap.clone()), true, false))
1040 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1042 errors::HandlerFlags {
1045 external_macro_backtrace,
1046 ..Default::default()
1050 build_session_(sopts, local_crate_source_file, diagnostic_handler, codemap)
1053 pub fn build_session_(
1054 sopts: config::Options,
1055 local_crate_source_file: Option<PathBuf>,
1056 span_diagnostic: errors::Handler,
1057 codemap: Lrc<codemap::CodeMap>,
1059 let host_triple = TargetTriple::from_triple(config::host_triple());
1060 let host = match Target::search(&host_triple) {
1064 .fatal(&format!("Error loading host specification: {}", e))
1068 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1070 let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
1071 let default_sysroot = match sopts.maybe_sysroot {
1073 None => Some(filesearch::get_or_default_sysroot()),
1076 let file_path_mapping = sopts.file_path_mapping();
1078 let local_crate_source_file =
1079 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1081 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1082 let optimization_fuel_limit =
1083 LockCell::new(sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0));
1084 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1085 let print_fuel = LockCell::new(0);
1087 let working_dir = match env::current_dir() {
1089 Err(e) => p_s.span_diagnostic
1090 .fatal(&format!("Current directory is invalid: {}", e))
1093 let working_dir = file_path_mapping.map_prefix(working_dir);
1095 let sess = Session {
1100 // For a library crate, this is always none
1101 entry_fn: Once::new(),
1102 plugin_registrar_fn: Once::new(),
1103 derive_registrar_fn: Once::new(),
1105 local_crate_source_file,
1107 lint_store: RwLock::new(lint::LintStore::new()),
1108 buffered_lints: Lock::new(Some(lint::LintBuffer::new())),
1109 one_time_diagnostics: Lock::new(FxHashSet()),
1110 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1111 plugin_attributes: OneThread::new(RefCell::new(Vec::new())),
1112 crate_types: Once::new(),
1113 dependency_formats: Once::new(),
1114 crate_disambiguator: Once::new(),
1115 features: Once::new(),
1116 recursion_limit: Once::new(),
1117 type_length_limit: Once::new(),
1118 const_eval_stack_frame_limit: 100,
1119 next_node_id: OneThread::new(Cell::new(NodeId::new(1))),
1120 injected_allocator: Once::new(),
1121 allocator_kind: Once::new(),
1122 injected_panic_runtime: Once::new(),
1123 imported_macro_spans: OneThread::new(RefCell::new(HashMap::new())),
1124 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1125 ignored_attr_names: ich::compute_ignored_attr_names(),
1126 profile_channel: Lock::new(None),
1127 perf_stats: PerfStats {
1128 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1129 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1130 queries_canonicalized: AtomicUsize::new(0),
1131 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1132 normalize_projection_ty: AtomicUsize::new(0),
1134 code_stats: Lock::new(CodeStats::new()),
1135 optimization_fuel_crate,
1136 optimization_fuel_limit,
1139 out_of_fuel: LockCell::new(false),
1140 // Note that this is unsafe because it may misinterpret file descriptors
1141 // on Unix as jobserver file descriptors. We hopefully execute this near
1142 // the beginning of the process though to ensure we don't get false
1143 // positives, or in other words we try to execute this before we open
1144 // any file descriptors ourselves.
1146 // Pick a "reasonable maximum" if we don't otherwise have
1147 // a jobserver in our environment, capping out at 32 so we
1148 // don't take everything down by hogging the process run queue.
1149 // The fixed number is used to have deterministic compilation
1152 // Also note that we stick this in a global because there could be
1153 // multiple `Session` instances in this process, and the jobserver is
1156 static mut GLOBAL_JOBSERVER: *mut Client = 0 as *mut _;
1157 static INIT: std::sync::Once = std::sync::ONCE_INIT;
1159 let client = Client::from_env().unwrap_or_else(|| {
1160 Client::new(32).expect("failed to create jobserver")
1162 GLOBAL_JOBSERVER = Box::into_raw(Box::new(client));
1164 (*GLOBAL_JOBSERVER).clone()
1166 has_global_allocator: Once::new(),
1172 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1173 /// compiler. Together with the crate-name forms a unique global identifier for
1175 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1176 pub struct CrateDisambiguator(Fingerprint);
1178 impl CrateDisambiguator {
1179 pub fn to_fingerprint(self) -> Fingerprint {
1184 impl From<Fingerprint> for CrateDisambiguator {
1185 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1186 CrateDisambiguator(fingerprint)
1190 impl_stable_hash_for!(tuple_struct CrateDisambiguator { fingerprint });
1192 /// Holds data on the current incremental compilation session, if there is one.
1194 pub enum IncrCompSession {
1195 /// This is the state the session will be in until the incr. comp. dir is
1198 /// This is the state during which the session directory is private and can
1201 session_directory: PathBuf,
1202 lock_file: flock::Lock,
1203 load_dep_graph: bool,
1205 /// This is the state after the session directory has been finalized. In this
1206 /// state, the contents of the directory must not be modified any more.
1207 Finalized { session_directory: PathBuf },
1208 /// This is an error state that is reached when some compilation error has
1209 /// occurred. It indicates that the contents of the session directory must
1210 /// not be used, since they might be invalid.
1211 InvalidBecauseOfErrors { session_directory: PathBuf },
1214 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1215 let emitter: Box<dyn Emitter + sync::Send> = match output {
1216 config::ErrorOutputType::HumanReadable(color_config) => {
1217 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1219 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1220 config::ErrorOutputType::Short(color_config) => {
1221 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1224 let handler = errors::Handler::with_emitter(true, false, emitter);
1225 handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
1226 errors::FatalError.raise();
1229 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1230 let emitter: Box<dyn Emitter + sync::Send> = match output {
1231 config::ErrorOutputType::HumanReadable(color_config) => {
1232 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1234 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1235 config::ErrorOutputType::Short(color_config) => {
1236 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1239 let handler = errors::Handler::with_emitter(true, false, emitter);
1240 handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
1243 #[derive(Copy, Clone, Debug)]
1244 pub enum CompileIncomplete {
1246 Errored(ErrorReported),
1248 impl From<ErrorReported> for CompileIncomplete {
1249 fn from(err: ErrorReported) -> CompileIncomplete {
1250 CompileIncomplete::Errored(err)
1253 pub type CompileResult = Result<(), CompileIncomplete>;
1255 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
1259 Err(CompileIncomplete::Errored(ErrorReported))
1265 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
1266 // this wrapper mostly exists so I don't have to write a fully
1267 // qualified path of None::<Span> inside the bug!() macro definition
1268 opt_span_bug_fmt(file, line, None::<Span>, args);
1273 pub fn span_bug_fmt<S: Into<MultiSpan>>(
1277 args: fmt::Arguments,
1279 opt_span_bug_fmt(file, line, Some(span), args);
1282 fn opt_span_bug_fmt<S: Into<MultiSpan>>(
1286 args: fmt::Arguments,
1288 tls::with_opt(move |tcx| {
1289 let msg = format!("{}:{}: {}", file, line, args);
1291 (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
1292 (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
1293 (None, _) => panic!(msg),