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::middle::allocator::AllocatorKind;
11 use crate::middle::dependency_format;
12 use crate::session::config::OutputType;
13 use crate::session::search_paths::{PathKind, SearchPath};
14 use crate::util::nodemap::{FxHashMap, FxHashSet};
15 use crate::util::common::{duration_to_secs_str, ErrorReported};
16 use crate::util::common::ProfileQueriesMsg;
18 use rustc_data_structures::base_n;
19 use rustc_data_structures::sync::{
20 self, Lrc, Lock, OneThread, Once, RwLock, AtomicU64, AtomicUsize, Ordering,
24 use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
25 use errors::emitter::{Emitter, EmitterWriter};
26 use syntax::ast::{self, NodeId};
27 use syntax::edition::Edition;
28 use syntax::feature_gate::{self, AttributeType};
29 use syntax::json::JsonEmitter;
30 use syntax::source_map;
31 use syntax::parse::{self, ParseSess};
32 use syntax_pos::{MultiSpan, Span};
33 use crate::util::profiling::SelfProfiler;
35 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
36 use rustc_data_structures::flock;
37 use rustc_data_structures::jobserver;
38 use ::jobserver::Client;
41 use std::cell::{self, Cell, RefCell};
45 use std::path::PathBuf;
46 use std::time::Duration;
54 pub struct OptimizationFuel {
55 /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
57 /// We're rejecting all further optimizations.
61 /// Represents the data associated with a compilation
62 /// session for a single crate.
64 pub target: config::Config,
66 pub opts: config::Options,
67 pub host_tlib_path: SearchPath,
68 /// `None` if the host and target are the same.
69 pub target_tlib_path: Option<SearchPath>,
70 pub parse_sess: ParseSess,
72 /// The name of the root source file of the crate, in the local file system.
73 /// `None` means that there is no source file.
74 pub local_crate_source_file: Option<PathBuf>,
75 /// The directory the compiler has been executed in plus a flag indicating
76 /// if the value stored here has been affected by path remapping.
77 pub working_dir: (PathBuf, bool),
79 // FIXME: lint_store and buffered_lints are not thread-safe,
80 // but are only used in a single thread
81 pub lint_store: RwLock<lint::LintStore>,
82 pub buffered_lints: Lock<Option<lint::LintBuffer>>,
84 /// Set of (DiagnosticId, Option<Span>, message) tuples tracking
85 /// (sub)diagnostics that have been set once, but should not be set again,
86 /// in order to avoid redundantly verbose output (Issue #24690, #44953).
87 pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
88 pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
89 pub plugin_attributes: Lock<Vec<(String, AttributeType)>>,
90 pub crate_types: Once<Vec<config::CrateType>>,
91 pub dependency_formats: Once<dependency_format::Dependencies>,
92 /// The crate_disambiguator is constructed out of all the `-C metadata`
93 /// arguments passed to the compiler. Its value together with the crate-name
94 /// forms a unique global identifier for the crate. It is used to allow
95 /// multiple crates with the same name to coexist. See the
96 /// rustc_codegen_llvm::back::symbol_names module for more information.
97 pub crate_disambiguator: Once<CrateDisambiguator>,
99 features: Once<feature_gate::Features>,
101 /// The maximum recursion limit for potentially infinitely recursive
102 /// operations such as auto-dereference and monomorphization.
103 pub recursion_limit: Once<usize>,
105 /// The maximum length of types during monomorphization.
106 pub type_length_limit: Once<usize>,
108 /// The maximum number of stackframes allowed in const eval.
109 pub const_eval_stack_frame_limit: usize,
111 /// The metadata::creader module may inject an allocator/panic_runtime
112 /// dependency if it didn't already find one, and this tracks what was
114 pub allocator_kind: Once<Option<AllocatorKind>>,
115 pub injected_panic_runtime: Once<Option<CrateNum>>,
117 /// Map from imported macro spans (which consist of
118 /// the localized span for the macro body) to the
119 /// macro name and definition span in the source crate.
120 pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
122 incr_comp_session: OneThread<RefCell<IncrCompSession>>,
123 /// Used for incremental compilation tests. Will only be populated if
124 /// `-Zquery-dep-graph` is specified.
125 pub cgu_reuse_tracker: CguReuseTracker,
127 /// Used by `-Z profile-queries` in `util::common`.
128 pub profile_channel: Lock<Option<mpsc::Sender<ProfileQueriesMsg>>>,
130 /// Used by `-Z self-profile`.
131 pub self_profiling_active: bool,
133 /// Used by `-Z self-profile`.
134 pub self_profiling: Lock<SelfProfiler>,
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>,
147 /// Tracks fuel info if `-zfuel=crate=n` is specified.
148 optimization_fuel: Lock<OptimizationFuel>,
150 // The next two are public because the driver needs to read them.
151 /// If `-zprint-fuel=crate`, `Some(crate)`.
152 pub print_fuel_crate: Option<String>,
153 /// Always set to zero and incremented so that we can print fuel expended by a crate.
154 pub print_fuel: AtomicU64,
156 /// Loaded up early on in the initialization of this `Session` to avoid
157 /// false positives about a job server in our environment.
158 pub jobserver: Client,
160 /// Metadata about the allocators for the current crate being compiled.
161 pub has_global_allocator: Once<bool>,
163 /// Metadata about the panic handlers for the current crate being compiled.
164 pub has_panic_handler: Once<bool>,
166 /// Cap lint level specified by a driver specifically.
167 pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
170 pub struct PerfStats {
171 /// The accumulated time spent on computing symbol hashes.
172 pub symbol_hash_time: Lock<Duration>,
173 /// The accumulated time spent decoding def path tables from metadata.
174 pub decode_def_path_tables_time: Lock<Duration>,
175 /// Total number of values canonicalized queries constructed.
176 pub queries_canonicalized: AtomicUsize,
177 /// Number of times this query is invoked.
178 pub normalize_ty_after_erasing_regions: AtomicUsize,
179 /// Number of times this query is invoked.
180 pub normalize_projection_ty: AtomicUsize,
183 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
184 enum DiagnosticBuilderMethod {
187 SpanSuggestion(String), // suggestion
188 // add more variants as needed to support one-time diagnostics
191 /// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
192 /// emitting the same message more than once
193 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
194 pub enum DiagnosticMessageId {
195 ErrorId(u16), // EXXXX error code as integer
196 LintId(lint::LintId),
197 StabilityId(u32), // issue number
200 impl From<&'static lint::Lint> for DiagnosticMessageId {
201 fn from(lint: &'static lint::Lint) -> Self {
202 DiagnosticMessageId::LintId(lint::LintId::of(lint))
207 pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
208 *self.crate_disambiguator.get()
211 pub fn struct_span_warn<'a, S: Into<MultiSpan>>(
215 ) -> DiagnosticBuilder<'a> {
216 self.diagnostic().struct_span_warn(sp, msg)
218 pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(
223 ) -> DiagnosticBuilder<'a> {
224 self.diagnostic().struct_span_warn_with_code(sp, msg, code)
226 pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
227 self.diagnostic().struct_warn(msg)
229 pub fn struct_span_err<'a, S: Into<MultiSpan>>(
233 ) -> DiagnosticBuilder<'a> {
234 self.diagnostic().struct_span_err(sp, msg)
236 pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(
241 ) -> DiagnosticBuilder<'a> {
242 self.diagnostic().struct_span_err_with_code(sp, msg, code)
244 // FIXME: This method should be removed (every error should have an associated error code).
245 pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
246 self.diagnostic().struct_err(msg)
248 pub fn struct_err_with_code<'a>(
252 ) -> DiagnosticBuilder<'a> {
253 self.diagnostic().struct_err_with_code(msg, code)
255 pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(
259 ) -> DiagnosticBuilder<'a> {
260 self.diagnostic().struct_span_fatal(sp, msg)
262 pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(
267 ) -> DiagnosticBuilder<'a> {
268 self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
270 pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
271 self.diagnostic().struct_fatal(msg)
274 pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
275 self.diagnostic().span_fatal(sp, msg).raise()
277 pub fn span_fatal_with_code<S: Into<MultiSpan>>(
284 .span_fatal_with_code(sp, msg, code)
287 pub fn fatal(&self, msg: &str) -> ! {
288 self.diagnostic().fatal(msg).raise()
290 pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
292 self.span_warn(sp, msg);
294 self.span_err(sp, msg);
297 pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
298 self.diagnostic().span_err(sp, msg)
300 pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
301 self.diagnostic().span_err_with_code(sp, &msg, code)
303 pub fn err(&self, msg: &str) {
304 self.diagnostic().err(msg)
306 pub fn err_count(&self) -> usize {
307 self.diagnostic().err_count()
309 pub fn has_errors(&self) -> bool {
310 self.diagnostic().has_errors()
312 pub fn abort_if_errors(&self) {
313 self.diagnostic().abort_if_errors();
315 pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
316 compile_result_from_err_count(self.err_count())
318 pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
322 let old_count = self.err_count();
324 let errors = self.err_count() - old_count;
331 pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
332 self.diagnostic().span_warn(sp, msg)
334 pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
335 self.diagnostic().span_warn_with_code(sp, msg, code)
337 pub fn warn(&self, msg: &str) {
338 self.diagnostic().warn(msg)
340 pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
342 Some(sp) => self.span_warn(sp, msg),
343 None => self.warn(msg),
346 /// Delay a span_bug() call until abort_if_errors()
347 pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
348 self.diagnostic().delay_span_bug(sp, msg)
350 pub fn note_without_error(&self, msg: &str) {
351 self.diagnostic().note_without_error(msg)
353 pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
354 self.diagnostic().span_note_without_error(sp, msg)
356 pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
357 self.diagnostic().span_unimpl(sp, msg)
359 pub fn unimpl(&self, msg: &str) -> ! {
360 self.diagnostic().unimpl(msg)
363 pub fn buffer_lint<S: Into<MultiSpan>>(
365 lint: &'static lint::Lint,
370 match *self.buffered_lints.borrow_mut() {
371 Some(ref mut buffer) => {
372 buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
374 None => bug!("can't buffer lints after HIR lowering"),
378 pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
380 lint: &'static lint::Lint,
384 diagnostic: BuiltinLintDiagnostics,
386 match *self.buffered_lints.borrow_mut() {
387 Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
388 None => bug!("can't buffer lints after HIR lowering"),
392 pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
393 let id = self.next_node_id.get();
395 match id.as_usize().checked_add(count) {
397 self.next_node_id.set(ast::NodeId::from_usize(next));
399 None => bug!("Input too large, ran out of node ids!"),
404 pub fn next_node_id(&self) -> NodeId {
405 self.reserve_node_ids(1)
407 pub(crate) fn current_node_id_count(&self) -> usize {
408 self.next_node_id.get().as_u32() as usize
410 pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
411 &self.parse_sess.span_diagnostic
414 /// Analogous to calling methods on the given `DiagnosticBuilder`, but
415 /// deduplicates on lint ID, span (if any), and message for this `Session`
416 fn diag_once<'a, 'b>(
418 diag_builder: &'b mut DiagnosticBuilder<'a>,
419 method: DiagnosticBuilderMethod,
420 msg_id: DiagnosticMessageId,
422 span_maybe: Option<Span>,
424 let id_span_message = (msg_id, span_maybe, message.to_owned());
425 let fresh = self.one_time_diagnostics
427 .insert(id_span_message);
430 DiagnosticBuilderMethod::Note => {
431 diag_builder.note(message);
433 DiagnosticBuilderMethod::SpanNote => {
434 let span = span_maybe.expect("span_note needs a span");
435 diag_builder.span_note(span, message);
437 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
438 let span = span_maybe.expect("span_suggestion_* needs a span");
439 diag_builder.span_suggestion(
443 Applicability::Unspecified,
450 pub fn diag_span_note_once<'a, 'b>(
452 diag_builder: &'b mut DiagnosticBuilder<'a>,
453 msg_id: DiagnosticMessageId,
459 DiagnosticBuilderMethod::SpanNote,
466 pub fn diag_note_once<'a, 'b>(
468 diag_builder: &'b mut DiagnosticBuilder<'a>,
469 msg_id: DiagnosticMessageId,
474 DiagnosticBuilderMethod::Note,
481 pub fn diag_span_suggestion_once<'a, 'b>(
483 diag_builder: &'b mut DiagnosticBuilder<'a>,
484 msg_id: DiagnosticMessageId,
491 DiagnosticBuilderMethod::SpanSuggestion(suggestion),
498 pub fn source_map<'a>(&'a self) -> &'a source_map::SourceMap {
499 self.parse_sess.source_map()
501 pub fn verbose(&self) -> bool {
502 self.opts.debugging_opts.verbose
504 pub fn time_passes(&self) -> bool {
505 self.opts.debugging_opts.time_passes
507 pub fn profile_queries(&self) -> bool {
508 self.opts.debugging_opts.profile_queries
509 || self.opts.debugging_opts.profile_queries_and_keys
511 pub fn profile_queries_and_keys(&self) -> bool {
512 self.opts.debugging_opts.profile_queries_and_keys
514 pub fn instrument_mcount(&self) -> bool {
515 self.opts.debugging_opts.instrument_mcount
517 pub fn count_llvm_insns(&self) -> bool {
518 self.opts.debugging_opts.count_llvm_insns
520 pub fn time_llvm_passes(&self) -> bool {
521 self.opts.debugging_opts.time_llvm_passes
523 pub fn codegen_stats(&self) -> bool {
524 self.opts.debugging_opts.codegen_stats
526 pub fn meta_stats(&self) -> bool {
527 self.opts.debugging_opts.meta_stats
529 pub fn asm_comments(&self) -> bool {
530 self.opts.debugging_opts.asm_comments
532 pub fn verify_llvm_ir(&self) -> bool {
533 self.opts.debugging_opts.verify_llvm_ir
534 || cfg!(always_verify_llvm_ir)
536 pub fn borrowck_stats(&self) -> bool {
537 self.opts.debugging_opts.borrowck_stats
539 pub fn print_llvm_passes(&self) -> bool {
540 self.opts.debugging_opts.print_llvm_passes
543 /// Gets the features enabled for the current compilation session.
544 /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
545 /// dependency tracking. Use tcx.features() instead.
547 pub fn features_untracked(&self) -> &feature_gate::Features {
551 pub fn init_features(&self, features: feature_gate::Features) {
552 self.features.set(features);
555 /// Calculates the flavor of LTO to use for this compilation.
556 pub fn lto(&self) -> config::Lto {
557 // If our target has codegen requirements ignore the command line
558 if self.target.target.options.requires_lto {
559 return config::Lto::Fat;
562 // If the user specified something, return that. If they only said `-C
563 // lto` and we've for whatever reason forced off ThinLTO via the CLI,
564 // then ensure we can't use a ThinLTO.
565 match self.opts.cg.lto {
566 config::LtoCli::Unspecified => {
567 // The compiler was invoked without the `-Clto` flag. Fall
568 // through to the default handling
570 config::LtoCli::No => {
571 // The user explicitly opted out of any kind of LTO
572 return config::Lto::No;
574 config::LtoCli::Yes |
575 config::LtoCli::Fat |
576 config::LtoCli::NoParam => {
577 // All of these mean fat LTO
578 return config::Lto::Fat;
580 config::LtoCli::Thin => {
581 return if self.opts.cli_forced_thinlto_off {
589 // Ok at this point the target doesn't require anything and the user
590 // hasn't asked for anything. Our next decision is whether or not
591 // we enable "auto" ThinLTO where we use multiple codegen units and
592 // then do ThinLTO over those codegen units. The logic below will
593 // either return `No` or `ThinLocal`.
595 // If processing command line options determined that we're incompatible
596 // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
597 if self.opts.cli_forced_thinlto_off {
598 return config::Lto::No;
601 // If `-Z thinlto` specified process that, but note that this is mostly
602 // a deprecated option now that `-C lto=thin` exists.
603 if let Some(enabled) = self.opts.debugging_opts.thinlto {
605 return config::Lto::ThinLocal;
607 return config::Lto::No;
611 // If there's only one codegen unit and LTO isn't enabled then there's
612 // no need for ThinLTO so just return false.
613 if self.codegen_units() == 1 {
614 return config::Lto::No;
617 // Now we're in "defaults" territory. By default we enable ThinLTO for
618 // optimized compiles (anything greater than O0).
619 match self.opts.optimize {
620 config::OptLevel::No => config::Lto::No,
621 _ => config::Lto::ThinLocal,
625 /// Returns the panic strategy for this compile session. If the user explicitly selected one
626 /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
627 pub fn panic_strategy(&self) -> PanicStrategy {
631 .unwrap_or(self.target.target.options.panic_strategy)
633 pub fn fewer_names(&self) -> bool {
634 let more_names = self.opts
636 .contains_key(&OutputType::LlvmAssembly)
637 || self.opts.output_types.contains_key(&OutputType::Bitcode);
638 self.opts.debugging_opts.fewer_names || !more_names
641 pub fn no_landing_pads(&self) -> bool {
642 self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
644 pub fn unstable_options(&self) -> bool {
645 self.opts.debugging_opts.unstable_options
647 pub fn overflow_checks(&self) -> bool {
651 .or(self.opts.debugging_opts.force_overflow_checks)
652 .unwrap_or(self.opts.debug_assertions)
655 pub fn crt_static(&self) -> bool {
656 // If the target does not opt in to crt-static support, use its default.
657 if self.target.target.options.crt_static_respected {
658 self.crt_static_feature()
660 self.target.target.options.crt_static_default
664 pub fn crt_static_feature(&self) -> bool {
665 let requested_features = self.opts.cg.target_feature.split(',');
666 let found_negative = requested_features.clone().any(|r| r == "-crt-static");
667 let found_positive = requested_features.clone().any(|r| r == "+crt-static");
669 // If the target we're compiling for requests a static crt by default,
670 // then see if the `-crt-static` feature was passed to disable that.
671 // Otherwise if we don't have a static crt by default then see if the
672 // `+crt-static` feature was passed.
673 if self.target.target.options.crt_static_default {
680 pub fn must_not_eliminate_frame_pointers(&self) -> bool {
681 // "mcount" function relies on stack pointer.
682 // See https://sourceware.org/binutils/docs/gprof/Implementation.html
683 if self.instrument_mcount() {
685 } else if let Some(x) = self.opts.cg.force_frame_pointers {
688 !self.target.target.options.eliminate_frame_pointer
692 /// Returns the symbol name for the registrar function,
693 /// given the crate Svh and the function DefIndex.
694 pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
696 "__rustc_plugin_registrar_{}__",
697 disambiguator.to_fingerprint().to_hex()
701 pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
703 "__rustc_proc_macro_decls_{}__",
704 disambiguator.to_fingerprint().to_hex()
708 pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
709 filesearch::FileSearch::new(
711 self.opts.target_triple.triple(),
712 &self.opts.search_paths,
713 // target_tlib_path==None means it's the same as host_tlib_path.
714 self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
718 pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
719 filesearch::FileSearch::new(
721 config::host_triple(),
722 &self.opts.search_paths,
723 &self.host_tlib_path,
728 pub fn set_incr_session_load_dep_graph(&self, load: bool) {
729 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
731 if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
732 *load_dep_graph = load;
736 pub fn incr_session_load_dep_graph(&self) -> bool {
737 let incr_comp_session = self.incr_comp_session.borrow();
738 match *incr_comp_session {
739 IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
744 pub fn init_incr_comp_session(
746 session_dir: PathBuf,
747 lock_file: flock::Lock,
748 load_dep_graph: bool,
750 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
752 if let IncrCompSession::NotInitialized = *incr_comp_session {
755 "Trying to initialize IncrCompSession `{:?}`",
760 *incr_comp_session = IncrCompSession::Active {
761 session_directory: session_dir,
767 pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
768 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
770 if let IncrCompSession::Active { .. } = *incr_comp_session {
773 "Trying to finalize IncrCompSession `{:?}`",
778 // Note: This will also drop the lock file, thus unlocking the directory
779 *incr_comp_session = IncrCompSession::Finalized {
780 session_directory: new_directory_path,
784 pub fn mark_incr_comp_session_as_invalid(&self) {
785 let mut incr_comp_session = self.incr_comp_session.borrow_mut();
787 let session_directory = match *incr_comp_session {
788 IncrCompSession::Active {
789 ref session_directory,
791 } => session_directory.clone(),
792 IncrCompSession::InvalidBecauseOfErrors { .. } => return,
794 "Trying to invalidate IncrCompSession `{:?}`",
799 // Note: This will also drop the lock file, thus unlocking the directory
800 *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
803 pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
804 let incr_comp_session = self.incr_comp_session.borrow();
807 |incr_comp_session| match *incr_comp_session {
808 IncrCompSession::NotInitialized => bug!(
809 "Trying to get session directory from IncrCompSession `{:?}`",
812 IncrCompSession::Active {
813 ref session_directory,
816 | IncrCompSession::Finalized {
817 ref session_directory,
819 | IncrCompSession::InvalidBecauseOfErrors {
820 ref session_directory,
821 } => session_directory,
826 pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
827 if self.opts.incremental.is_some() {
828 Some(self.incr_comp_session_dir())
836 fn profiler_active<F: FnOnce(&mut SelfProfiler) -> ()>(&self, f: F) {
837 let mut profiler = self.self_profiling.borrow_mut();
842 pub fn profiler<F: FnOnce(&mut SelfProfiler) -> ()>(&self, f: F) {
843 if unlikely!(self.self_profiling_active) {
844 self.profiler_active(f)
848 pub fn print_profiler_results(&self) {
849 let mut profiler = self.self_profiling.borrow_mut();
850 profiler.print_results(&self.opts);
853 pub fn save_json_results(&self) {
854 let profiler = self.self_profiling.borrow();
855 profiler.save_results(&self.opts);
858 pub fn print_perf_stats(&self) {
860 "Total time spent computing symbol hashes: {}",
861 duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
864 "Total time spent decoding DefPath tables: {}",
865 duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
867 println!("Total queries canonicalized: {}",
868 self.perf_stats.queries_canonicalized.load(Ordering::Relaxed));
869 println!("normalize_ty_after_erasing_regions: {}",
870 self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed));
871 println!("normalize_projection_ty: {}",
872 self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed));
875 /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
876 /// This expends fuel if applicable, and records fuel if applicable.
877 pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
879 if let Some(ref c) = self.optimization_fuel_crate {
881 assert_eq!(self.threads(), 1);
882 let mut fuel = self.optimization_fuel.lock();
883 ret = fuel.remaining != 0;
884 if fuel.remaining == 0 && !fuel.out_of_fuel {
885 eprintln!("optimization-fuel-exhausted: {}", msg());
886 fuel.out_of_fuel = true;
887 } else if fuel.remaining > 0 {
892 if let Some(ref c) = self.print_fuel_crate {
894 assert_eq!(self.threads(), 1);
895 self.print_fuel.fetch_add(1, SeqCst);
901 /// Returns the number of query threads that should be used for this
903 pub fn threads_from_count(query_threads: Option<usize>) -> usize {
904 query_threads.unwrap_or(::num_cpus::get())
907 /// Returns the number of query threads that should be used for this
909 pub fn threads(&self) -> usize {
910 Self::threads_from_count(self.opts.debugging_opts.threads)
913 /// Returns the number of codegen units that should be used for this
915 pub fn codegen_units(&self) -> usize {
916 if let Some(n) = self.opts.cli_forced_codegen_units {
919 if let Some(n) = self.target.target.options.default_codegen_units {
923 // Why is 16 codegen units the default all the time?
925 // The main reason for enabling multiple codegen units by default is to
926 // leverage the ability for the codegen backend to do codegen and
927 // optimization in parallel. This allows us, especially for large crates, to
928 // make good use of all available resources on the machine once we've
929 // hit that stage of compilation. Large crates especially then often
930 // take a long time in codegen/optimization and this helps us amortize that
933 // Note that a high number here doesn't mean that we'll be spawning a
934 // large number of threads in parallel. The backend of rustc contains
935 // global rate limiting through the `jobserver` crate so we'll never
936 // overload the system with too much work, but rather we'll only be
937 // optimizing when we're otherwise cooperating with other instances of
940 // Rather a high number here means that we should be able to keep a lot
941 // of idle cpus busy. By ensuring that no codegen unit takes *too* long
942 // to build we'll be guaranteed that all cpus will finish pretty closely
943 // to one another and we should make relatively optimal use of system
946 // Note that the main cost of codegen units is that it prevents LLVM
947 // from inlining across codegen units. Users in general don't have a lot
948 // of control over how codegen units are split up so it's our job in the
949 // compiler to ensure that undue performance isn't lost when using
950 // codegen units (aka we can't require everyone to slap `#[inline]` on
953 // If we're compiling at `-O0` then the number doesn't really matter too
954 // much because performance doesn't matter and inlining is ok to lose.
955 // In debug mode we just want to try to guarantee that no cpu is stuck
956 // doing work that could otherwise be farmed to others.
958 // In release mode, however (O1 and above) performance does indeed
959 // matter! To recover the loss in performance due to inlining we'll be
960 // enabling ThinLTO by default (the function for which is just below).
961 // This will ensure that we recover any inlining wins we otherwise lost
962 // through codegen unit partitioning.
966 // Ok that's a lot of words but the basic tl;dr; is that we want a high
967 // number here -- but not too high. Additionally we're "safe" to have it
968 // always at the same number at all optimization levels.
970 // As a result 16 was chosen here! Mostly because it was a power of 2
971 // and most benchmarks agreed it was roughly a local optimum. Not very
976 pub fn teach(&self, code: &DiagnosticId) -> bool {
977 self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
980 pub fn rust_2015(&self) -> bool {
981 self.opts.edition == Edition::Edition2015
984 /// Are we allowed to use features from the Rust 2018 edition?
985 pub fn rust_2018(&self) -> bool {
986 self.opts.edition >= Edition::Edition2018
989 pub fn edition(&self) -> Edition {
993 /// Returns `true` if we cannot skip the PLT for shared library calls.
994 pub fn needs_plt(&self) -> bool {
995 // Check if the current target usually needs PLT to be enabled.
996 // The user can use the command line flag to override it.
997 let needs_plt = self.target.target.options.needs_plt;
999 let dbg_opts = &self.opts.debugging_opts;
1001 let relro_level = dbg_opts.relro_level
1002 .unwrap_or(self.target.target.options.relro_level);
1004 // Only enable this optimization by default if full relro is also enabled.
1005 // In this case, lazy binding was already unavailable, so nothing is lost.
1006 // This also ensures `-Wl,-z,now` is supported by the linker.
1007 let full_relro = RelroLevel::Full == relro_level;
1009 // If user didn't explicitly forced us to use / skip the PLT,
1010 // then try to skip it where possible.
1011 dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
1015 pub fn build_session(
1016 sopts: config::Options,
1017 local_crate_source_file: Option<PathBuf>,
1018 registry: errors::registry::Registry,
1020 let file_path_mapping = sopts.file_path_mapping();
1022 build_session_with_source_map(
1024 local_crate_source_file,
1026 Lrc::new(source_map::SourceMap::new(file_path_mapping)),
1027 DiagnosticOutput::Default,
1033 sopts: &config::Options,
1034 registry: errors::registry::Registry,
1035 source_map: &Lrc<source_map::SourceMap>,
1036 emitter_dest: Option<Box<dyn Write + Send>>,
1037 ) -> Box<dyn Emitter + sync::Send> {
1038 match (sopts.error_format, emitter_dest) {
1039 (config::ErrorOutputType::HumanReadable(color_config), None) => Box::new(
1040 EmitterWriter::stderr(
1042 Some(source_map.clone()),
1044 sopts.debugging_opts.teach,
1045 ).ui_testing(sopts.debugging_opts.ui_testing),
1047 (config::ErrorOutputType::HumanReadable(_), Some(dst)) => Box::new(
1048 EmitterWriter::new(dst, Some(source_map.clone()), false, false)
1049 .ui_testing(sopts.debugging_opts.ui_testing),
1051 (config::ErrorOutputType::Json(pretty), None) => Box::new(
1052 JsonEmitter::stderr(
1056 ).ui_testing(sopts.debugging_opts.ui_testing),
1058 (config::ErrorOutputType::Json(pretty), Some(dst)) => Box::new(
1064 ).ui_testing(sopts.debugging_opts.ui_testing),
1066 (config::ErrorOutputType::Short(color_config), None) => Box::new(
1067 EmitterWriter::stderr(color_config, Some(source_map.clone()), true, false),
1069 (config::ErrorOutputType::Short(_), Some(dst)) => {
1070 Box::new(EmitterWriter::new(dst, Some(source_map.clone()), true, false))
1075 pub enum DiagnosticOutput {
1077 Raw(Box<dyn Write + Send>),
1078 Emitter(Box<dyn Emitter + Send + sync::Send>)
1081 pub fn build_session_with_source_map(
1082 sopts: config::Options,
1083 local_crate_source_file: Option<PathBuf>,
1084 registry: errors::registry::Registry,
1085 source_map: Lrc<source_map::SourceMap>,
1086 diagnostics_output: DiagnosticOutput,
1087 lint_caps: FxHashMap<lint::LintId, lint::Level>,
1089 // FIXME: This is not general enough to make the warning lint completely override
1090 // normal diagnostic warnings, since the warning lint can also be denied and changed
1091 // later via the source code.
1092 let warnings_allow = sopts
1095 .filter(|&&(ref key, _)| *key == "warnings")
1096 .map(|&(_, ref level)| *level == lint::Allow)
1099 let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
1101 let can_emit_warnings = !(warnings_allow || cap_lints_allow);
1103 let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
1104 let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
1105 let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
1107 let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
1109 let emitter = match diagnostics_output {
1110 DiagnosticOutput::Default => default_emitter(&sopts, registry, &source_map, None),
1111 DiagnosticOutput::Raw(write) => {
1112 default_emitter(&sopts, registry, &source_map, Some(write))
1114 DiagnosticOutput::Emitter(emitter) => emitter,
1117 let diagnostic_handler = errors::Handler::with_emitter_and_flags(
1119 errors::HandlerFlags {
1122 report_delayed_bugs,
1123 dont_buffer_diagnostics,
1124 external_macro_backtrace,
1125 ..Default::default()
1129 build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
1132 pub fn build_session_(
1133 sopts: config::Options,
1134 local_crate_source_file: Option<PathBuf>,
1135 span_diagnostic: errors::Handler,
1136 source_map: Lrc<source_map::SourceMap>,
1137 driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
1139 let host_triple = TargetTriple::from_triple(config::host_triple());
1140 let host = Target::search(&host_triple).unwrap_or_else(|e|
1142 .fatal(&format!("Error loading host specification: {}", e))
1145 let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
1147 let p_s = parse::ParseSess::with_span_handler(span_diagnostic, source_map);
1148 let sysroot = match &sopts.maybe_sysroot {
1149 Some(sysroot) => sysroot.clone(),
1150 None => filesearch::get_or_default_sysroot(),
1153 let host_triple = config::host_triple();
1154 let target_triple = sopts.target_triple.triple();
1155 let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1156 let target_tlib_path = if host_triple == target_triple {
1159 Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1162 let file_path_mapping = sopts.file_path_mapping();
1164 let local_crate_source_file =
1165 local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1167 let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1168 let optimization_fuel = Lock::new(OptimizationFuel {
1169 remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1172 let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1173 let print_fuel = AtomicU64::new(0);
1175 let working_dir = env::current_dir().unwrap_or_else(|e|
1177 .fatal(&format!("Current directory is invalid: {}", e))
1180 let working_dir = file_path_mapping.map_prefix(working_dir);
1182 let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1183 CguReuseTracker::new()
1185 CguReuseTracker::new_disabled()
1188 let self_profiling_active = sopts.debugging_opts.self_profile ||
1189 sopts.debugging_opts.profile_json;
1191 let sess = Session {
1199 local_crate_source_file,
1201 lint_store: RwLock::new(lint::LintStore::new()),
1202 buffered_lints: Lock::new(Some(Default::default())),
1203 one_time_diagnostics: Default::default(),
1204 plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
1205 plugin_attributes: Lock::new(Vec::new()),
1206 crate_types: Once::new(),
1207 dependency_formats: Once::new(),
1208 crate_disambiguator: Once::new(),
1209 features: Once::new(),
1210 recursion_limit: Once::new(),
1211 type_length_limit: Once::new(),
1212 const_eval_stack_frame_limit: 100,
1213 next_node_id: OneThread::new(Cell::new(NodeId::from_u32(1))),
1214 allocator_kind: Once::new(),
1215 injected_panic_runtime: Once::new(),
1216 imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1217 incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1219 self_profiling_active,
1220 self_profiling: Lock::new(SelfProfiler::new()),
1221 profile_channel: Lock::new(None),
1222 perf_stats: PerfStats {
1223 symbol_hash_time: Lock::new(Duration::from_secs(0)),
1224 decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1225 queries_canonicalized: AtomicUsize::new(0),
1226 normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1227 normalize_projection_ty: AtomicUsize::new(0),
1229 code_stats: Default::default(),
1230 optimization_fuel_crate,
1234 jobserver: jobserver::client(),
1235 has_global_allocator: Once::new(),
1236 has_panic_handler: Once::new(),
1240 validate_commandline_args_with_session_available(&sess);
1245 // If it is useful to have a Session available already for validating a
1246 // commandline argument, you can do so here.
1247 fn validate_commandline_args_with_session_available(sess: &Session) {
1248 // Since we don't know if code in an rlib will be linked to statically or
1249 // dynamically downstream, rustc generates `__imp_` symbols that help the
1250 // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1251 // these manually generated symbols confuse LLD when it tries to merge
1252 // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1253 // when compiling for LLD ThinLTO. This way we can validly just not generate
1254 // the `dllimport` attributes and `__imp_` symbols in that case.
1255 if sess.opts.cg.linker_plugin_lto.enabled() &&
1256 sess.opts.cg.prefer_dynamic &&
1257 sess.target.target.options.is_like_msvc {
1258 sess.err("Linker plugin based LTO is not supported together with \
1259 `-C prefer-dynamic` when targeting MSVC");
1263 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1264 /// compiler. Together with the crate-name forms a unique global identifier for
1266 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1267 pub struct CrateDisambiguator(Fingerprint);
1269 impl CrateDisambiguator {
1270 pub fn to_fingerprint(self) -> Fingerprint {
1275 impl fmt::Display for CrateDisambiguator {
1276 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1277 let (a, b) = self.0.as_value();
1278 let as_u128 = a as u128 | ((b as u128) << 64);
1279 f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1283 impl From<Fingerprint> for CrateDisambiguator {
1284 fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1285 CrateDisambiguator(fingerprint)
1289 impl_stable_hash_via_hash!(CrateDisambiguator);
1291 /// Holds data on the current incremental compilation session, if there is one.
1293 pub enum IncrCompSession {
1294 /// This is the state the session will be in until the incr. comp. dir is
1297 /// This is the state during which the session directory is private and can
1300 session_directory: PathBuf,
1301 lock_file: flock::Lock,
1302 load_dep_graph: bool,
1304 /// This is the state after the session directory has been finalized. In this
1305 /// state, the contents of the directory must not be modified any more.
1306 Finalized { session_directory: PathBuf },
1307 /// This is an error state that is reached when some compilation error has
1308 /// occurred. It indicates that the contents of the session directory must
1309 /// not be used, since they might be invalid.
1310 InvalidBecauseOfErrors { session_directory: PathBuf },
1313 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1314 let emitter: Box<dyn Emitter + sync::Send> = match output {
1315 config::ErrorOutputType::HumanReadable(color_config) => {
1316 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1318 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1319 config::ErrorOutputType::Short(color_config) => {
1320 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1323 let handler = errors::Handler::with_emitter(true, false, emitter);
1324 handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
1325 errors::FatalError.raise();
1328 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1329 let emitter: Box<dyn Emitter + sync::Send> = match output {
1330 config::ErrorOutputType::HumanReadable(color_config) => {
1331 Box::new(EmitterWriter::stderr(color_config, None, false, false))
1333 config::ErrorOutputType::Json(pretty) => Box::new(JsonEmitter::basic(pretty)),
1334 config::ErrorOutputType::Short(color_config) => {
1335 Box::new(EmitterWriter::stderr(color_config, None, true, false))
1338 let handler = errors::Handler::with_emitter(true, false, emitter);
1339 handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
1342 #[derive(Copy, Clone, Debug)]
1343 pub enum CompileIncomplete {
1345 Errored(ErrorReported),
1347 impl From<ErrorReported> for CompileIncomplete {
1348 fn from(err: ErrorReported) -> CompileIncomplete {
1349 CompileIncomplete::Errored(err)
1352 pub type CompileResult = Result<(), CompileIncomplete>;
1354 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
1358 Err(CompileIncomplete::Errored(ErrorReported))