src/librustc_session/session.rs

   1 use crate::code_stats::CodeStats;
   2 pub use crate::code_stats::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
   3
   4 use crate::cgu_reuse_tracker::CguReuseTracker;
   5 use rustc_data_structures::fingerprint::Fingerprint;
   6 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
   7
   8 use crate::config::{self, OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
   9 use crate::filesearch;
  10 use crate::lint;
  11 use crate::search_paths::{PathKind, SearchPath};
  12 use rustc_data_structures::profiling::duration_to_secs_str;
  13 use rustc_errors::ErrorReported;
  14
  15 use rustc_data_structures::base_n;
  16 use rustc_data_structures::impl_stable_hash_via_hash;
  17 use rustc_data_structures::sync::{
  18     self, AtomicU64, AtomicUsize, Lock, Lrc, Once, OneThread, Ordering, Ordering::SeqCst,
  19 };
  20
  21 use crate::parse::ParseSess;
  22 use rustc_errors::annotate_snippet_emitter_writer::AnnotateSnippetEmitterWriter;
  23 use rustc_errors::emitter::HumanReadableErrorType;
  24 use rustc_errors::emitter::{Emitter, EmitterWriter};
  25 use rustc_errors::json::JsonEmitter;
  26 use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticId};
  27 use rustc_span::edition::Edition;
  28 use rustc_span::source_map;
  29 use rustc_span::{MultiSpan, Span};
  30
  31 use rustc_data_structures::flock;
  32 use rustc_data_structures::jobserver::{self, Client};
  33 use rustc_data_structures::profiling::{SelfProfiler, SelfProfilerRef};
  34 use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
  35
  36 use std::cell::{self, RefCell};
  37 use std::env;
  38 use std::fmt;
  39 use std::io::Write;
  40 use std::num::NonZeroU32;
  41 use std::path::PathBuf;
  42 use std::sync::Arc;
  43 use std::time::Duration;
  44
  45 pub struct OptimizationFuel {
  46     /// If `-zfuel=crate=n` is specified, initially set to `n`, otherwise `0`.
  47     remaining: u64,
  48     /// We're rejecting all further optimizations.
  49     out_of_fuel: bool,
  50 }
  51
  52 /// Represents the data associated with a compilation
  53 /// session for a single crate.
  54 pub struct Session {
  55     pub target: config::Config,
  56     pub host: Target,
  57     pub opts: config::Options,
  58     pub host_tlib_path: SearchPath,
  59     /// `None` if the host and target are the same.
  60     pub target_tlib_path: Option<SearchPath>,
  61     pub parse_sess: ParseSess,
  62     pub sysroot: PathBuf,
  63     /// The name of the root source file of the crate, in the local file system.
  64     /// `None` means that there is no source file.
  65     pub local_crate_source_file: Option<PathBuf>,
  66     /// The directory the compiler has been executed in plus a flag indicating
  67     /// if the value stored here has been affected by path remapping.
  68     pub working_dir: (PathBuf, bool),
  69
  70     /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
  71     /// (sub)diagnostics that have been set once, but should not be set again,
  72     /// in order to avoid redundantly verbose output (Issue #24690, #44953).
  73     pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
  74     pub crate_types: Once<Vec<config::CrateType>>,
  75     /// The `crate_disambiguator` is constructed out of all the `-C metadata`
  76     /// arguments passed to the compiler. Its value together with the crate-name
  77     /// forms a unique global identifier for the crate. It is used to allow
  78     /// multiple crates with the same name to coexist. See the
  79     /// `rustc_codegen_llvm::back::symbol_names` module for more information.
  80     pub crate_disambiguator: Once<CrateDisambiguator>,
  81
  82     features: Once<rustc_feature::Features>,
  83
  84     /// The maximum recursion limit for potentially infinitely recursive
  85     /// operations such as auto-dereference and monomorphization.
  86     pub recursion_limit: Once<usize>,
  87
  88     /// The maximum length of types during monomorphization.
  89     pub type_length_limit: Once<usize>,
  90
  91     /// The maximum blocks a const expression can evaluate.
  92     pub const_eval_limit: Once<usize>,
  93
  94     /// Map from imported macro spans (which consist of
  95     /// the localized span for the macro body) to the
  96     /// macro name and definition span in the source crate.
  97     pub imported_macro_spans: OneThread<RefCell<FxHashMap<Span, (String, Span)>>>,
  98
  99     incr_comp_session: OneThread<RefCell<IncrCompSession>>,
 100     /// Used for incremental compilation tests. Will only be populated if
 101     /// `-Zquery-dep-graph` is specified.
 102     pub cgu_reuse_tracker: CguReuseTracker,
 103
 104     /// Used by `-Z self-profile`.
 105     pub prof: SelfProfilerRef,
 106
 107     /// Some measurements that are being gathered during compilation.
 108     pub perf_stats: PerfStats,
 109
 110     /// Data about code being compiled, gathered during compilation.
 111     pub code_stats: CodeStats,
 112
 113     /// If `-zfuel=crate=n` is specified, `Some(crate)`.
 114     optimization_fuel_crate: Option<String>,
 115
 116     /// Tracks fuel info if `-zfuel=crate=n` is specified.
 117     optimization_fuel: Lock<OptimizationFuel>,
 118
 119     // The next two are public because the driver needs to read them.
 120     /// If `-zprint-fuel=crate`, `Some(crate)`.
 121     pub print_fuel_crate: Option<String>,
 122     /// Always set to zero and incremented so that we can print fuel expended by a crate.
 123     pub print_fuel: AtomicU64,
 124
 125     /// Loaded up early on in the initialization of this `Session` to avoid
 126     /// false positives about a job server in our environment.
 127     pub jobserver: Client,
 128
 129     /// Cap lint level specified by a driver specifically.
 130     pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
 131
 132     /// `Span`s of trait methods that weren't found to avoid emitting object safety errors
 133     pub trait_methods_not_found: Lock<FxHashSet<Span>>,
 134
 135     /// Mapping from ident span to path span for paths that don't exist as written, but that
 136     /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
 137     pub confused_type_with_std_module: Lock<FxHashMap<Span, Span>>,
 138
 139     /// Path for libraries that will take preference over libraries shipped by Rust.
 140     /// Used by windows-gnu targets to priortize system mingw-w64 libraries.
 141     pub system_library_path: OneThread<RefCell<Option<Option<PathBuf>>>>,
 142 }
 143
 144 pub struct PerfStats {
 145     /// The accumulated time spent on computing symbol hashes.
 146     pub symbol_hash_time: Lock<Duration>,
 147     /// The accumulated time spent decoding def path tables from metadata.
 148     pub decode_def_path_tables_time: Lock<Duration>,
 149     /// Total number of values canonicalized queries constructed.
 150     pub queries_canonicalized: AtomicUsize,
 151     /// Number of times this query is invoked.
 152     pub normalize_ty_after_erasing_regions: AtomicUsize,
 153     /// Number of times this query is invoked.
 154     pub normalize_projection_ty: AtomicUsize,
 155 }
 156
 157 /// Enum to support dispatch of one-time diagnostics (in `Session.diag_once`).
 158 enum DiagnosticBuilderMethod {
 159     Note,
 160     SpanNote,
 161     SpanSuggestion(String), // suggestion
 162                             // Add more variants as needed to support one-time diagnostics.
 163 }
 164
 165 /// Diagnostic message ID, used by `Session.one_time_diagnostics` to avoid
 166 /// emitting the same message more than once.
 167 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 168 pub enum DiagnosticMessageId {
 169     ErrorId(u16), // EXXXX error code as integer
 170     LintId(lint::LintId),
 171     StabilityId(Option<NonZeroU32>), // issue number
 172 }
 173
 174 impl From<&'static lint::Lint> for DiagnosticMessageId {
 175     fn from(lint: &'static lint::Lint) -> Self {
 176         DiagnosticMessageId::LintId(lint::LintId::of(lint))
 177     }
 178 }
 179
 180 impl Session {
 181     pub fn local_crate_disambiguator(&self) -> CrateDisambiguator {
 182         *self.crate_disambiguator.get()
 183     }
 184
 185     pub fn struct_span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> DiagnosticBuilder<'_> {
 186         self.diagnostic().struct_span_warn(sp, msg)
 187     }
 188     pub fn struct_span_warn_with_code<S: Into<MultiSpan>>(
 189         &self,
 190         sp: S,
 191         msg: &str,
 192         code: DiagnosticId,
 193     ) -> DiagnosticBuilder<'_> {
 194         self.diagnostic().struct_span_warn_with_code(sp, msg, code)
 195     }
 196     pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
 197         self.diagnostic().struct_warn(msg)
 198     }
 199     pub fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> DiagnosticBuilder<'_> {
 200         self.diagnostic().struct_span_err(sp, msg)
 201     }
 202     pub fn struct_span_err_with_code<S: Into<MultiSpan>>(
 203         &self,
 204         sp: S,
 205         msg: &str,
 206         code: DiagnosticId,
 207     ) -> DiagnosticBuilder<'_> {
 208         self.diagnostic().struct_span_err_with_code(sp, msg, code)
 209     }
 210     // FIXME: This method should be removed (every error should have an associated error code).
 211     pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
 212         self.diagnostic().struct_err(msg)
 213     }
 214     pub fn struct_err_with_code(&self, msg: &str, code: DiagnosticId) -> DiagnosticBuilder<'_> {
 215         self.diagnostic().struct_err_with_code(msg, code)
 216     }
 217     pub fn struct_span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> DiagnosticBuilder<'_> {
 218         self.diagnostic().struct_span_fatal(sp, msg)
 219     }
 220     pub fn struct_span_fatal_with_code<S: Into<MultiSpan>>(
 221         &self,
 222         sp: S,
 223         msg: &str,
 224         code: DiagnosticId,
 225     ) -> DiagnosticBuilder<'_> {
 226         self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
 227     }
 228     pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
 229         self.diagnostic().struct_fatal(msg)
 230     }
 231
 232     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 233         self.diagnostic().span_fatal(sp, msg).raise()
 234     }
 235     pub fn span_fatal_with_code<S: Into<MultiSpan>>(
 236         &self,
 237         sp: S,
 238         msg: &str,
 239         code: DiagnosticId,
 240     ) -> ! {
 241         self.diagnostic().span_fatal_with_code(sp, msg, code).raise()
 242     }
 243     pub fn fatal(&self, msg: &str) -> ! {
 244         self.diagnostic().fatal(msg).raise()
 245     }
 246     pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
 247         if is_warning {
 248             self.span_warn(sp, msg);
 249         } else {
 250             self.span_err(sp, msg);
 251         }
 252     }
 253     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 254         self.diagnostic().span_err(sp, msg)
 255     }
 256     pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
 257         self.diagnostic().span_err_with_code(sp, &msg, code)
 258     }
 259     pub fn err(&self, msg: &str) {
 260         self.diagnostic().err(msg)
 261     }
 262     pub fn err_count(&self) -> usize {
 263         self.diagnostic().err_count()
 264     }
 265     pub fn has_errors(&self) -> bool {
 266         self.diagnostic().has_errors()
 267     }
 268     pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
 269         self.diagnostic().has_errors_or_delayed_span_bugs()
 270     }
 271     pub fn abort_if_errors(&self) {
 272         self.diagnostic().abort_if_errors();
 273     }
 274     pub fn compile_status(&self) -> Result<(), ErrorReported> {
 275         if self.has_errors() {
 276             self.diagnostic().emit_stashed_diagnostics();
 277             Err(ErrorReported)
 278         } else {
 279             Ok(())
 280         }
 281     }
 282     // FIXME(matthewjasper) Remove this method, it should never be needed.
 283     pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
 284     where
 285         F: FnOnce() -> T,
 286     {
 287         let old_count = self.err_count();
 288         let result = f();
 289         let errors = self.err_count() - old_count;
 290         if errors == 0 { Ok(result) } else { Err(ErrorReported) }
 291     }
 292     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 293         self.diagnostic().span_warn(sp, msg)
 294     }
 295     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
 296         self.diagnostic().span_warn_with_code(sp, msg, code)
 297     }
 298     pub fn warn(&self, msg: &str) {
 299         self.diagnostic().warn(msg)
 300     }
 301     pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
 302         match opt_sp {
 303             Some(sp) => self.span_warn(sp, msg),
 304             None => self.warn(msg),
 305         }
 306     }
 307     /// Delay a span_bug() call until abort_if_errors()
 308     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 309         self.diagnostic().delay_span_bug(sp, msg)
 310     }
 311     pub fn note_without_error(&self, msg: &str) {
 312         self.diagnostic().note_without_error(msg)
 313     }
 314     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 315         self.diagnostic().span_note_without_error(sp, msg)
 316     }
 317
 318     pub fn diagnostic(&self) -> &rustc_errors::Handler {
 319         &self.parse_sess.span_diagnostic
 320     }
 321
 322     /// Analogous to calling methods on the given `DiagnosticBuilder`, but
 323     /// deduplicates on lint ID, span (if any), and message for this `Session`
 324     fn diag_once<'a, 'b>(
 325         &'a self,
 326         diag_builder: &'b mut DiagnosticBuilder<'a>,
 327         method: DiagnosticBuilderMethod,
 328         msg_id: DiagnosticMessageId,
 329         message: &str,
 330         span_maybe: Option<Span>,
 331     ) {
 332         let id_span_message = (msg_id, span_maybe, message.to_owned());
 333         let fresh = self.one_time_diagnostics.borrow_mut().insert(id_span_message);
 334         if fresh {
 335             match method {
 336                 DiagnosticBuilderMethod::Note => {
 337                     diag_builder.note(message);
 338                 }
 339                 DiagnosticBuilderMethod::SpanNote => {
 340                     let span = span_maybe.expect("`span_note` needs a span");
 341                     diag_builder.span_note(span, message);
 342                 }
 343                 DiagnosticBuilderMethod::SpanSuggestion(suggestion) => {
 344                     let span = span_maybe.expect("`span_suggestion_*` needs a span");
 345                     diag_builder.span_suggestion(
 346                         span,
 347                         message,
 348                         suggestion,
 349                         Applicability::Unspecified,
 350                     );
 351                 }
 352             }
 353         }
 354     }
 355
 356     pub fn diag_span_note_once<'a, 'b>(
 357         &'a self,
 358         diag_builder: &'b mut DiagnosticBuilder<'a>,
 359         msg_id: DiagnosticMessageId,
 360         span: Span,
 361         message: &str,
 362     ) {
 363         self.diag_once(
 364             diag_builder,
 365             DiagnosticBuilderMethod::SpanNote,
 366             msg_id,
 367             message,
 368             Some(span),
 369         );
 370     }
 371
 372     pub fn diag_note_once<'a, 'b>(
 373         &'a self,
 374         diag_builder: &'b mut DiagnosticBuilder<'a>,
 375         msg_id: DiagnosticMessageId,
 376         message: &str,
 377     ) {
 378         self.diag_once(diag_builder, DiagnosticBuilderMethod::Note, msg_id, message, None);
 379     }
 380
 381     pub fn diag_span_suggestion_once<'a, 'b>(
 382         &'a self,
 383         diag_builder: &'b mut DiagnosticBuilder<'a>,
 384         msg_id: DiagnosticMessageId,
 385         span: Span,
 386         message: &str,
 387         suggestion: String,
 388     ) {
 389         self.diag_once(
 390             diag_builder,
 391             DiagnosticBuilderMethod::SpanSuggestion(suggestion),
 392             msg_id,
 393             message,
 394             Some(span),
 395         );
 396     }
 397
 398     #[inline]
 399     pub fn source_map(&self) -> &source_map::SourceMap {
 400         self.parse_sess.source_map()
 401     }
 402     pub fn verbose(&self) -> bool {
 403         self.opts.debugging_opts.verbose
 404     }
 405     pub fn time_passes(&self) -> bool {
 406         self.opts.debugging_opts.time_passes || self.opts.debugging_opts.time
 407     }
 408     pub fn instrument_mcount(&self) -> bool {
 409         self.opts.debugging_opts.instrument_mcount
 410     }
 411     pub fn time_llvm_passes(&self) -> bool {
 412         self.opts.debugging_opts.time_llvm_passes
 413     }
 414     pub fn meta_stats(&self) -> bool {
 415         self.opts.debugging_opts.meta_stats
 416     }
 417     pub fn asm_comments(&self) -> bool {
 418         self.opts.debugging_opts.asm_comments
 419     }
 420     pub fn verify_llvm_ir(&self) -> bool {
 421         self.opts.debugging_opts.verify_llvm_ir || cfg!(always_verify_llvm_ir)
 422     }
 423     pub fn borrowck_stats(&self) -> bool {
 424         self.opts.debugging_opts.borrowck_stats
 425     }
 426     pub fn print_llvm_passes(&self) -> bool {
 427         self.opts.debugging_opts.print_llvm_passes
 428     }
 429     pub fn binary_dep_depinfo(&self) -> bool {
 430         self.opts.debugging_opts.binary_dep_depinfo
 431     }
 432
 433     /// Gets the features enabled for the current compilation session.
 434     /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
 435     /// dependency tracking. Use tcx.features() instead.
 436     #[inline]
 437     pub fn features_untracked(&self) -> &rustc_feature::Features {
 438         self.features.get()
 439     }
 440
 441     pub fn init_features(&self, features: rustc_feature::Features) {
 442         self.features.set(features);
 443     }
 444
 445     /// Calculates the flavor of LTO to use for this compilation.
 446     pub fn lto(&self) -> config::Lto {
 447         // If our target has codegen requirements ignore the command line
 448         if self.target.target.options.requires_lto {
 449             return config::Lto::Fat;
 450         }
 451
 452         // If the user specified something, return that. If they only said `-C
 453         // lto` and we've for whatever reason forced off ThinLTO via the CLI,
 454         // then ensure we can't use a ThinLTO.
 455         match self.opts.cg.lto {
 456             config::LtoCli::Unspecified => {
 457                 // The compiler was invoked without the `-Clto` flag. Fall
 458                 // through to the default handling
 459             }
 460             config::LtoCli::No => {
 461                 // The user explicitly opted out of any kind of LTO
 462                 return config::Lto::No;
 463             }
 464             config::LtoCli::Yes | config::LtoCli::Fat | config::LtoCli::NoParam => {
 465                 // All of these mean fat LTO
 466                 return config::Lto::Fat;
 467             }
 468             config::LtoCli::Thin => {
 469                 return if self.opts.cli_forced_thinlto_off {
 470                     config::Lto::Fat
 471                 } else {
 472                     config::Lto::Thin
 473                 };
 474             }
 475         }
 476
 477         // Ok at this point the target doesn't require anything and the user
 478         // hasn't asked for anything. Our next decision is whether or not
 479         // we enable "auto" ThinLTO where we use multiple codegen units and
 480         // then do ThinLTO over those codegen units. The logic below will
 481         // either return `No` or `ThinLocal`.
 482
 483         // If processing command line options determined that we're incompatible
 484         // with ThinLTO (e.g., `-C lto --emit llvm-ir`) then return that option.
 485         if self.opts.cli_forced_thinlto_off {
 486             return config::Lto::No;
 487         }
 488
 489         // If `-Z thinlto` specified process that, but note that this is mostly
 490         // a deprecated option now that `-C lto=thin` exists.
 491         if let Some(enabled) = self.opts.debugging_opts.thinlto {
 492             if enabled {
 493                 return config::Lto::ThinLocal;
 494             } else {
 495                 return config::Lto::No;
 496             }
 497         }
 498
 499         // If there's only one codegen unit and LTO isn't enabled then there's
 500         // no need for ThinLTO so just return false.
 501         if self.codegen_units() == 1 {
 502             return config::Lto::No;
 503         }
 504
 505         // Now we're in "defaults" territory. By default we enable ThinLTO for
 506         // optimized compiles (anything greater than O0).
 507         match self.opts.optimize {
 508             config::OptLevel::No => config::Lto::No,
 509             _ => config::Lto::ThinLocal,
 510         }
 511     }
 512
 513     /// Returns the panic strategy for this compile session. If the user explicitly selected one
 514     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
 515     pub fn panic_strategy(&self) -> PanicStrategy {
 516         self.opts.cg.panic.unwrap_or(self.target.target.options.panic_strategy)
 517     }
 518     pub fn fewer_names(&self) -> bool {
 519         let more_names = self.opts.output_types.contains_key(&OutputType::LlvmAssembly)
 520             || self.opts.output_types.contains_key(&OutputType::Bitcode);
 521
 522         // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
 523         let more_names = match self.opts.debugging_opts.sanitizer {
 524             Some(Sanitizer::Address) => true,
 525             Some(Sanitizer::Memory) => true,
 526             _ => more_names,
 527         };
 528
 529         self.opts.debugging_opts.fewer_names || !more_names
 530     }
 531
 532     pub fn no_landing_pads(&self) -> bool {
 533         self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
 534     }
 535     pub fn unstable_options(&self) -> bool {
 536         self.opts.debugging_opts.unstable_options
 537     }
 538     pub fn overflow_checks(&self) -> bool {
 539         self.opts
 540             .cg
 541             .overflow_checks
 542             .or(self.opts.debugging_opts.force_overflow_checks)
 543             .unwrap_or(self.opts.debug_assertions)
 544     }
 545
 546     pub fn crt_static(&self) -> bool {
 547         // If the target does not opt in to crt-static support, use its default.
 548         if self.target.target.options.crt_static_respected {
 549             self.crt_static_feature()
 550         } else {
 551             self.target.target.options.crt_static_default
 552         }
 553     }
 554
 555     pub fn crt_static_feature(&self) -> bool {
 556         let requested_features = self.opts.cg.target_feature.split(',');
 557         let found_negative = requested_features.clone().any(|r| r == "-crt-static");
 558         let found_positive = requested_features.clone().any(|r| r == "+crt-static");
 559
 560         // If the target we're compiling for requests a static crt by default,
 561         // then see if the `-crt-static` feature was passed to disable that.
 562         // Otherwise if we don't have a static crt by default then see if the
 563         // `+crt-static` feature was passed.
 564         if self.target.target.options.crt_static_default { !found_negative } else { found_positive }
 565     }
 566
 567     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
 568         // "mcount" function relies on stack pointer.
 569         // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
 570         if self.instrument_mcount() {
 571             true
 572         } else if let Some(x) = self.opts.cg.force_frame_pointers {
 573             x
 574         } else {
 575             !self.target.target.options.eliminate_frame_pointer
 576         }
 577     }
 578
 579     /// Returns the symbol name for the registrar function,
 580     /// given the crate `Svh` and the function `DefIndex`.
 581     pub fn generate_plugin_registrar_symbol(&self, disambiguator: CrateDisambiguator) -> String {
 582         format!("__rustc_plugin_registrar_{}__", disambiguator.to_fingerprint().to_hex())
 583     }
 584
 585     pub fn generate_proc_macro_decls_symbol(&self, disambiguator: CrateDisambiguator) -> String {
 586         format!("__rustc_proc_macro_decls_{}__", disambiguator.to_fingerprint().to_hex())
 587     }
 588
 589     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
 590         filesearch::FileSearch::new(
 591             &self.sysroot,
 592             self.opts.target_triple.triple(),
 593             &self.opts.search_paths,
 594             // `target_tlib_path == None` means it's the same as `host_tlib_path`.
 595             self.target_tlib_path.as_ref().unwrap_or(&self.host_tlib_path),
 596             kind,
 597         )
 598     }
 599     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch<'_> {
 600         filesearch::FileSearch::new(
 601             &self.sysroot,
 602             config::host_triple(),
 603             &self.opts.search_paths,
 604             &self.host_tlib_path,
 605             kind,
 606         )
 607     }
 608
 609     pub fn set_incr_session_load_dep_graph(&self, load: bool) {
 610         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 611
 612         if let IncrCompSession::Active { ref mut load_dep_graph, .. } = *incr_comp_session {
 613             *load_dep_graph = load;
 614         }
 615     }
 616
 617     pub fn incr_session_load_dep_graph(&self) -> bool {
 618         let incr_comp_session = self.incr_comp_session.borrow();
 619         match *incr_comp_session {
 620             IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
 621             _ => false,
 622         }
 623     }
 624
 625     pub fn init_incr_comp_session(
 626         &self,
 627         session_dir: PathBuf,
 628         lock_file: flock::Lock,
 629         load_dep_graph: bool,
 630     ) {
 631         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 632
 633         if let IncrCompSession::NotInitialized = *incr_comp_session {
 634         } else {
 635             panic!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session)
 636         }
 637
 638         *incr_comp_session =
 639             IncrCompSession::Active { session_directory: session_dir, lock_file, load_dep_graph };
 640     }
 641
 642     pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
 643         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 644
 645         if let IncrCompSession::Active { .. } = *incr_comp_session {
 646         } else {
 647             panic!("trying to finalize `IncrCompSession` `{:?}`", *incr_comp_session);
 648         }
 649
 650         // Note: this will also drop the lock file, thus unlocking the directory.
 651         *incr_comp_session = IncrCompSession::Finalized { session_directory: new_directory_path };
 652     }
 653
 654     pub fn mark_incr_comp_session_as_invalid(&self) {
 655         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 656
 657         let session_directory = match *incr_comp_session {
 658             IncrCompSession::Active { ref session_directory, .. } => session_directory.clone(),
 659             IncrCompSession::InvalidBecauseOfErrors { .. } => return,
 660             _ => panic!("trying to invalidate `IncrCompSession` `{:?}`", *incr_comp_session),
 661         };
 662
 663         // Note: this will also drop the lock file, thus unlocking the directory.
 664         *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors { session_directory };
 665     }
 666
 667     pub fn incr_comp_session_dir(&self) -> cell::Ref<'_, PathBuf> {
 668         let incr_comp_session = self.incr_comp_session.borrow();
 669         cell::Ref::map(incr_comp_session, |incr_comp_session| match *incr_comp_session {
 670             IncrCompSession::NotInitialized => panic!(
 671                 "trying to get session directory from `IncrCompSession`: {:?}",
 672                 *incr_comp_session,
 673             ),
 674             IncrCompSession::Active { ref session_directory, .. }
 675             | IncrCompSession::Finalized { ref session_directory }
 676             | IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => {
 677                 session_directory
 678             }
 679         })
 680     }
 681
 682     pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<'_, PathBuf>> {
 683         self.opts.incremental.as_ref().map(|_| self.incr_comp_session_dir())
 684     }
 685
 686     pub fn print_perf_stats(&self) {
 687         println!(
 688             "Total time spent computing symbol hashes:      {}",
 689             duration_to_secs_str(*self.perf_stats.symbol_hash_time.lock())
 690         );
 691         println!(
 692             "Total time spent decoding DefPath tables:      {}",
 693             duration_to_secs_str(*self.perf_stats.decode_def_path_tables_time.lock())
 694         );
 695         println!(
 696             "Total queries canonicalized:                   {}",
 697             self.perf_stats.queries_canonicalized.load(Ordering::Relaxed)
 698         );
 699         println!(
 700             "normalize_ty_after_erasing_regions:            {}",
 701             self.perf_stats.normalize_ty_after_erasing_regions.load(Ordering::Relaxed)
 702         );
 703         println!(
 704             "normalize_projection_ty:                       {}",
 705             self.perf_stats.normalize_projection_ty.load(Ordering::Relaxed)
 706         );
 707     }
 708
 709     /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
 710     /// This expends fuel if applicable, and records fuel if applicable.
 711     pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
 712         let mut ret = true;
 713         if let Some(ref c) = self.optimization_fuel_crate {
 714             if c == crate_name {
 715                 assert_eq!(self.threads(), 1);
 716                 let mut fuel = self.optimization_fuel.lock();
 717                 ret = fuel.remaining != 0;
 718                 if fuel.remaining == 0 && !fuel.out_of_fuel {
 719                     eprintln!("optimization-fuel-exhausted: {}", msg());
 720                     fuel.out_of_fuel = true;
 721                 } else if fuel.remaining > 0 {
 722                     fuel.remaining -= 1;
 723                 }
 724             }
 725         }
 726         if let Some(ref c) = self.print_fuel_crate {
 727             if c == crate_name {
 728                 assert_eq!(self.threads(), 1);
 729                 self.print_fuel.fetch_add(1, SeqCst);
 730             }
 731         }
 732         ret
 733     }
 734
 735     /// Returns the number of query threads that should be used for this
 736     /// compilation
 737     pub fn threads(&self) -> usize {
 738         self.opts.debugging_opts.threads
 739     }
 740
 741     /// Returns the number of codegen units that should be used for this
 742     /// compilation
 743     pub fn codegen_units(&self) -> usize {
 744         if let Some(n) = self.opts.cli_forced_codegen_units {
 745             return n;
 746         }
 747         if let Some(n) = self.target.target.options.default_codegen_units {
 748             return n as usize;
 749         }
 750
 751         // Why is 16 codegen units the default all the time?
 752         //
 753         // The main reason for enabling multiple codegen units by default is to
 754         // leverage the ability for the codegen backend to do codegen and
 755         // optimization in parallel. This allows us, especially for large crates, to
 756         // make good use of all available resources on the machine once we've
 757         // hit that stage of compilation. Large crates especially then often
 758         // take a long time in codegen/optimization and this helps us amortize that
 759         // cost.
 760         //
 761         // Note that a high number here doesn't mean that we'll be spawning a
 762         // large number of threads in parallel. The backend of rustc contains
 763         // global rate limiting through the `jobserver` crate so we'll never
 764         // overload the system with too much work, but rather we'll only be
 765         // optimizing when we're otherwise cooperating with other instances of
 766         // rustc.
 767         //
 768         // Rather a high number here means that we should be able to keep a lot
 769         // of idle cpus busy. By ensuring that no codegen unit takes *too* long
 770         // to build we'll be guaranteed that all cpus will finish pretty closely
 771         // to one another and we should make relatively optimal use of system
 772         // resources
 773         //
 774         // Note that the main cost of codegen units is that it prevents LLVM
 775         // from inlining across codegen units. Users in general don't have a lot
 776         // of control over how codegen units are split up so it's our job in the
 777         // compiler to ensure that undue performance isn't lost when using
 778         // codegen units (aka we can't require everyone to slap `#[inline]` on
 779         // everything).
 780         //
 781         // If we're compiling at `-O0` then the number doesn't really matter too
 782         // much because performance doesn't matter and inlining is ok to lose.
 783         // In debug mode we just want to try to guarantee that no cpu is stuck
 784         // doing work that could otherwise be farmed to others.
 785         //
 786         // In release mode, however (O1 and above) performance does indeed
 787         // matter! To recover the loss in performance due to inlining we'll be
 788         // enabling ThinLTO by default (the function for which is just below).
 789         // This will ensure that we recover any inlining wins we otherwise lost
 790         // through codegen unit partitioning.
 791         //
 792         // ---
 793         //
 794         // Ok that's a lot of words but the basic tl;dr; is that we want a high
 795         // number here -- but not too high. Additionally we're "safe" to have it
 796         // always at the same number at all optimization levels.
 797         //
 798         // As a result 16 was chosen here! Mostly because it was a power of 2
 799         // and most benchmarks agreed it was roughly a local optimum. Not very
 800         // scientific.
 801         16
 802     }
 803
 804     pub fn teach(&self, code: &DiagnosticId) -> bool {
 805         self.opts.debugging_opts.teach && self.diagnostic().must_teach(code)
 806     }
 807
 808     pub fn rust_2015(&self) -> bool {
 809         self.opts.edition == Edition::Edition2015
 810     }
 811
 812     /// Are we allowed to use features from the Rust 2018 edition?
 813     pub fn rust_2018(&self) -> bool {
 814         self.opts.edition >= Edition::Edition2018
 815     }
 816
 817     pub fn edition(&self) -> Edition {
 818         self.opts.edition
 819     }
 820
 821     /// Returns `true` if we cannot skip the PLT for shared library calls.
 822     pub fn needs_plt(&self) -> bool {
 823         // Check if the current target usually needs PLT to be enabled.
 824         // The user can use the command line flag to override it.
 825         let needs_plt = self.target.target.options.needs_plt;
 826
 827         let dbg_opts = &self.opts.debugging_opts;
 828
 829         let relro_level = dbg_opts.relro_level.unwrap_or(self.target.target.options.relro_level);
 830
 831         // Only enable this optimization by default if full relro is also enabled.
 832         // In this case, lazy binding was already unavailable, so nothing is lost.
 833         // This also ensures `-Wl,-z,now` is supported by the linker.
 834         let full_relro = RelroLevel::Full == relro_level;
 835
 836         // If user didn't explicitly forced us to use / skip the PLT,
 837         // then try to skip it where possible.
 838         dbg_opts.plt.unwrap_or(needs_plt || !full_relro)
 839     }
 840 }
 841
 842 pub fn build_session(
 843     sopts: config::Options,
 844     local_crate_source_file: Option<PathBuf>,
 845     registry: rustc_errors::registry::Registry,
 846 ) -> Session {
 847     let file_path_mapping = sopts.file_path_mapping();
 848
 849     build_session_with_source_map(
 850         sopts,
 851         local_crate_source_file,
 852         registry,
 853         Lrc::new(source_map::SourceMap::new(file_path_mapping)),
 854         DiagnosticOutput::Default,
 855         Default::default(),
 856     )
 857 }
 858
 859 fn default_emitter(
 860     sopts: &config::Options,
 861     registry: rustc_errors::registry::Registry,
 862     source_map: &Lrc<source_map::SourceMap>,
 863     emitter_dest: Option<Box<dyn Write + Send>>,
 864 ) -> Box<dyn Emitter + sync::Send> {
 865     let macro_backtrace = sopts.debugging_opts.macro_backtrace;
 866     match (sopts.error_format, emitter_dest) {
 867         (config::ErrorOutputType::HumanReadable(kind), dst) => {
 868             let (short, color_config) = kind.unzip();
 869
 870             if let HumanReadableErrorType::AnnotateSnippet(_) = kind {
 871                 let emitter = AnnotateSnippetEmitterWriter::new(
 872                     Some(source_map.clone()),
 873                     short,
 874                     macro_backtrace,
 875                 );
 876                 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing()))
 877             } else {
 878                 let emitter = match dst {
 879                     None => EmitterWriter::stderr(
 880                         color_config,
 881                         Some(source_map.clone()),
 882                         short,
 883                         sopts.debugging_opts.teach,
 884                         sopts.debugging_opts.terminal_width,
 885                         macro_backtrace,
 886                     ),
 887                     Some(dst) => EmitterWriter::new(
 888                         dst,
 889                         Some(source_map.clone()),
 890                         short,
 891                         false, // no teach messages when writing to a buffer
 892                         false, // no colors when writing to a buffer
 893                         None,  // no terminal width
 894                         macro_backtrace,
 895                     ),
 896                 };
 897                 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing()))
 898             }
 899         }
 900         (config::ErrorOutputType::Json { pretty, json_rendered }, None) => Box::new(
 901             JsonEmitter::stderr(
 902                 Some(registry),
 903                 source_map.clone(),
 904                 pretty,
 905                 json_rendered,
 906                 macro_backtrace,
 907             )
 908             .ui_testing(sopts.debugging_opts.ui_testing()),
 909         ),
 910         (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
 911             JsonEmitter::new(
 912                 dst,
 913                 Some(registry),
 914                 source_map.clone(),
 915                 pretty,
 916                 json_rendered,
 917                 macro_backtrace,
 918             )
 919             .ui_testing(sopts.debugging_opts.ui_testing()),
 920         ),
 921     }
 922 }
 923
 924 pub enum DiagnosticOutput {
 925     Default,
 926     Raw(Box<dyn Write + Send>),
 927 }
 928
 929 pub fn build_session_with_source_map(
 930     sopts: config::Options,
 931     local_crate_source_file: Option<PathBuf>,
 932     registry: rustc_errors::registry::Registry,
 933     source_map: Lrc<source_map::SourceMap>,
 934     diagnostics_output: DiagnosticOutput,
 935     lint_caps: FxHashMap<lint::LintId, lint::Level>,
 936 ) -> Session {
 937     // FIXME: This is not general enough to make the warning lint completely override
 938     // normal diagnostic warnings, since the warning lint can also be denied and changed
 939     // later via the source code.
 940     let warnings_allow = sopts
 941         .lint_opts
 942         .iter()
 943         .filter(|&&(ref key, _)| *key == "warnings")
 944         .map(|&(_, ref level)| *level == lint::Allow)
 945         .last()
 946         .unwrap_or(false);
 947     let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
 948     let can_emit_warnings = !(warnings_allow || cap_lints_allow);
 949
 950     let write_dest = match diagnostics_output {
 951         DiagnosticOutput::Default => None,
 952         DiagnosticOutput::Raw(write) => Some(write),
 953     };
 954     let emitter = default_emitter(&sopts, registry, &source_map, write_dest);
 955
 956     let diagnostic_handler = rustc_errors::Handler::with_emitter_and_flags(
 957         emitter,
 958         sopts.debugging_opts.diagnostic_handler_flags(can_emit_warnings),
 959     );
 960
 961     build_session_(sopts, local_crate_source_file, diagnostic_handler, source_map, lint_caps)
 962 }
 963
 964 fn build_session_(
 965     sopts: config::Options,
 966     local_crate_source_file: Option<PathBuf>,
 967     span_diagnostic: rustc_errors::Handler,
 968     source_map: Lrc<source_map::SourceMap>,
 969     driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
 970 ) -> Session {
 971     let self_profiler = if let SwitchWithOptPath::Enabled(ref d) = sopts.debugging_opts.self_profile
 972     {
 973         let directory =
 974             if let Some(ref directory) = d { directory } else { std::path::Path::new(".") };
 975
 976         let profiler = SelfProfiler::new(
 977             directory,
 978             sopts.crate_name.as_ref().map(|s| &s[..]),
 979             &sopts.debugging_opts.self_profile_events,
 980         );
 981         match profiler {
 982             Ok(profiler) => Some(Arc::new(profiler)),
 983             Err(e) => {
 984                 early_warn(sopts.error_format, &format!("failed to create profiler: {}", e));
 985                 None
 986             }
 987         }
 988     } else {
 989         None
 990     };
 991
 992     let host_triple = TargetTriple::from_triple(config::host_triple());
 993     let host = Target::search(&host_triple).unwrap_or_else(|e| {
 994         span_diagnostic.fatal(&format!("Error loading host specification: {}", e)).raise()
 995     });
 996     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 997
 998     let parse_sess = ParseSess::with_span_handler(span_diagnostic, source_map);
 999     let sysroot = match &sopts.maybe_sysroot {
1000         Some(sysroot) => sysroot.clone(),
1001         None => filesearch::get_or_default_sysroot(),
1002     };
1003
1004     let host_triple = config::host_triple();
1005     let target_triple = sopts.target_triple.triple();
1006     let host_tlib_path = SearchPath::from_sysroot_and_triple(&sysroot, host_triple);
1007     let target_tlib_path = if host_triple == target_triple {
1008         None
1009     } else {
1010         Some(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
1011     };
1012
1013     let file_path_mapping = sopts.file_path_mapping();
1014
1015     let local_crate_source_file =
1016         local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
1017
1018     let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
1019     let optimization_fuel = Lock::new(OptimizationFuel {
1020         remaining: sopts.debugging_opts.fuel.as_ref().map(|i| i.1).unwrap_or(0),
1021         out_of_fuel: false,
1022     });
1023     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
1024     let print_fuel = AtomicU64::new(0);
1025
1026     let working_dir = env::current_dir().unwrap_or_else(|e| {
1027         parse_sess.span_diagnostic.fatal(&format!("Current directory is invalid: {}", e)).raise()
1028     });
1029     let working_dir = file_path_mapping.map_prefix(working_dir);
1030
1031     let cgu_reuse_tracker = if sopts.debugging_opts.query_dep_graph {
1032         CguReuseTracker::new()
1033     } else {
1034         CguReuseTracker::new_disabled()
1035     };
1036
1037     let prof = SelfProfilerRef::new(
1038         self_profiler,
1039         sopts.debugging_opts.time_passes || sopts.debugging_opts.time,
1040         sopts.debugging_opts.time_passes,
1041     );
1042
1043     let sess = Session {
1044         target: target_cfg,
1045         host,
1046         opts: sopts,
1047         host_tlib_path,
1048         target_tlib_path,
1049         parse_sess,
1050         sysroot,
1051         local_crate_source_file,
1052         working_dir,
1053         one_time_diagnostics: Default::default(),
1054         crate_types: Once::new(),
1055         crate_disambiguator: Once::new(),
1056         features: Once::new(),
1057         recursion_limit: Once::new(),
1058         type_length_limit: Once::new(),
1059         const_eval_limit: Once::new(),
1060         imported_macro_spans: OneThread::new(RefCell::new(FxHashMap::default())),
1061         incr_comp_session: OneThread::new(RefCell::new(IncrCompSession::NotInitialized)),
1062         cgu_reuse_tracker,
1063         prof,
1064         perf_stats: PerfStats {
1065             symbol_hash_time: Lock::new(Duration::from_secs(0)),
1066             decode_def_path_tables_time: Lock::new(Duration::from_secs(0)),
1067             queries_canonicalized: AtomicUsize::new(0),
1068             normalize_ty_after_erasing_regions: AtomicUsize::new(0),
1069             normalize_projection_ty: AtomicUsize::new(0),
1070         },
1071         code_stats: Default::default(),
1072         optimization_fuel_crate,
1073         optimization_fuel,
1074         print_fuel_crate,
1075         print_fuel,
1076         jobserver: jobserver::client(),
1077         driver_lint_caps,
1078         trait_methods_not_found: Lock::new(Default::default()),
1079         confused_type_with_std_module: Lock::new(Default::default()),
1080         system_library_path: OneThread::new(RefCell::new(Default::default())),
1081     };
1082
1083     validate_commandline_args_with_session_available(&sess);
1084
1085     sess
1086 }
1087
1088 // If it is useful to have a Session available already for validating a
1089 // commandline argument, you can do so here.
1090 fn validate_commandline_args_with_session_available(sess: &Session) {
1091     // Since we don't know if code in an rlib will be linked to statically or
1092     // dynamically downstream, rustc generates `__imp_` symbols that help the
1093     // MSVC linker deal with this lack of knowledge (#27438). Unfortunately,
1094     // these manually generated symbols confuse LLD when it tries to merge
1095     // bitcode during ThinLTO. Therefore we disallow dynamic linking on MSVC
1096     // when compiling for LLD ThinLTO. This way we can validly just not generate
1097     // the `dllimport` attributes and `__imp_` symbols in that case.
1098     if sess.opts.cg.linker_plugin_lto.enabled()
1099         && sess.opts.cg.prefer_dynamic
1100         && sess.target.target.options.is_like_msvc
1101     {
1102         sess.err(
1103             "Linker plugin based LTO is not supported together with \
1104                   `-C prefer-dynamic` when targeting MSVC",
1105         );
1106     }
1107
1108     // Make sure that any given profiling data actually exists so LLVM can't
1109     // decide to silently skip PGO.
1110     if let Some(ref path) = sess.opts.cg.profile_use {
1111         if !path.exists() {
1112             sess.err(&format!(
1113                 "File `{}` passed to `-C profile-use` does not exist.",
1114                 path.display()
1115             ));
1116         }
1117     }
1118
1119     // PGO does not work reliably with panic=unwind on Windows. Let's make it
1120     // an error to combine the two for now. It always runs into an assertions
1121     // if LLVM is built with assertions, but without assertions it sometimes
1122     // does not crash and will probably generate a corrupted binary.
1123     // We should only display this error if we're actually going to run PGO.
1124     // If we're just supposed to print out some data, don't show the error (#61002).
1125     if sess.opts.cg.profile_generate.enabled()
1126         && sess.target.target.options.is_like_msvc
1127         && sess.panic_strategy() == PanicStrategy::Unwind
1128         && sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs)
1129     {
1130         sess.err(
1131             "Profile-guided optimization does not yet work in conjunction \
1132                   with `-Cpanic=unwind` on Windows when targeting MSVC. \
1133                   See issue #61002 <https://github.com/rust-lang/rust/issues/61002> \
1134                   for more information.",
1135         );
1136     }
1137
1138     // Sanitizers can only be used on some tested platforms.
1139     if let Some(ref sanitizer) = sess.opts.debugging_opts.sanitizer {
1140         const ASAN_SUPPORTED_TARGETS: &[&str] = &[
1141             "x86_64-unknown-linux-gnu",
1142             "x86_64-apple-darwin",
1143             "x86_64-fuchsia",
1144             "aarch64-fuchsia",
1145         ];
1146         const TSAN_SUPPORTED_TARGETS: &[&str] =
1147             &["x86_64-unknown-linux-gnu", "x86_64-apple-darwin"];
1148         const LSAN_SUPPORTED_TARGETS: &[&str] =
1149             &["x86_64-unknown-linux-gnu", "x86_64-apple-darwin"];
1150         const MSAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu"];
1151
1152         let supported_targets = match *sanitizer {
1153             Sanitizer::Address => ASAN_SUPPORTED_TARGETS,
1154             Sanitizer::Thread => TSAN_SUPPORTED_TARGETS,
1155             Sanitizer::Leak => LSAN_SUPPORTED_TARGETS,
1156             Sanitizer::Memory => MSAN_SUPPORTED_TARGETS,
1157         };
1158
1159         if !supported_targets.contains(&&*sess.opts.target_triple.triple()) {
1160             sess.err(&format!(
1161                 "{:?}Sanitizer only works with the `{}` target",
1162                 sanitizer,
1163                 supported_targets.join("` or `")
1164             ));
1165         }
1166     }
1167 }
1168
1169 /// Hash value constructed out of all the `-C metadata` arguments passed to the
1170 /// compiler. Together with the crate-name forms a unique global identifier for
1171 /// the crate.
1172 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, RustcEncodable, RustcDecodable)]
1173 pub struct CrateDisambiguator(Fingerprint);
1174
1175 impl CrateDisambiguator {
1176     pub fn to_fingerprint(self) -> Fingerprint {
1177         self.0
1178     }
1179 }
1180
1181 impl fmt::Display for CrateDisambiguator {
1182     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
1183         let (a, b) = self.0.as_value();
1184         let as_u128 = a as u128 | ((b as u128) << 64);
1185         f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
1186     }
1187 }
1188
1189 impl From<Fingerprint> for CrateDisambiguator {
1190     fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
1191         CrateDisambiguator(fingerprint)
1192     }
1193 }
1194
1195 impl_stable_hash_via_hash!(CrateDisambiguator);
1196
1197 /// Holds data on the current incremental compilation session, if there is one.
1198 #[derive(Debug)]
1199 pub enum IncrCompSession {
1200     /// This is the state the session will be in until the incr. comp. dir is
1201     /// needed.
1202     NotInitialized,
1203     /// This is the state during which the session directory is private and can
1204     /// be modified.
1205     Active { session_directory: PathBuf, lock_file: flock::Lock, load_dep_graph: bool },
1206     /// This is the state after the session directory has been finalized. In this
1207     /// state, the contents of the directory must not be modified any more.
1208     Finalized { session_directory: PathBuf },
1209     /// This is an error state that is reached when some compilation error has
1210     /// occurred. It indicates that the contents of the session directory must
1211     /// not be used, since they might be invalid.
1212     InvalidBecauseOfErrors { session_directory: PathBuf },
1213 }
1214
1215 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
1216     let emitter: Box<dyn Emitter + sync::Send> = match output {
1217         config::ErrorOutputType::HumanReadable(kind) => {
1218             let (short, color_config) = kind.unzip();
1219             Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1220         }
1221         config::ErrorOutputType::Json { pretty, json_rendered } => {
1222             Box::new(JsonEmitter::basic(pretty, json_rendered, false))
1223         }
1224     };
1225     let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
1226     handler.struct_fatal(msg).emit();
1227     rustc_errors::FatalError.raise();
1228 }
1229
1230 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
1231     let emitter: Box<dyn Emitter + sync::Send> = match output {
1232         config::ErrorOutputType::HumanReadable(kind) => {
1233             let (short, color_config) = kind.unzip();
1234             Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
1235         }
1236         config::ErrorOutputType::Json { pretty, json_rendered } => {
1237             Box::new(JsonEmitter::basic(pretty, json_rendered, false))
1238         }
1239     };
1240     let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
1241     handler.struct_warn(msg).emit();
1242 }
1243
1244 pub type CompileResult = Result<(), ErrorReported>;