src/librustc/session/mod.rs

   1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 pub use self::code_stats::{CodeStats, DataTypeKind, FieldInfo};
  12 pub use self::code_stats::{SizeKind, TypeSizeInfo, VariantInfo};
  13
  14 use dep_graph::DepGraph;
  15 use hir::def_id::{CrateNum, DefIndex};
  16
  17 use lint;
  18 use middle::allocator::AllocatorKind;
  19 use middle::dependency_format;
  20 use session::search_paths::PathKind;
  21 use session::config::DebugInfoLevel;
  22 use ty::tls;
  23 use util::nodemap::{FxHashMap, FxHashSet};
  24 use util::common::{duration_to_secs_str, ErrorReported};
  25
  26 use syntax::ast::NodeId;
  27 use errors::{self, DiagnosticBuilder};
  28 use errors::emitter::{Emitter, EmitterWriter};
  29 use syntax::json::JsonEmitter;
  30 use syntax::feature_gate;
  31 use syntax::parse;
  32 use syntax::parse::ParseSess;
  33 use syntax::symbol::Symbol;
  34 use syntax::{ast, codemap};
  35 use syntax::feature_gate::AttributeType;
  36 use syntax_pos::{Span, MultiSpan};
  37
  38 use rustc_back::{LinkerFlavor, PanicStrategy};
  39 use rustc_back::target::Target;
  40 use rustc_data_structures::flock;
  41 use jobserver::Client;
  42
  43 use std::cell::{self, Cell, RefCell};
  44 use std::collections::HashMap;
  45 use std::env;
  46 use std::fmt;
  47 use std::io::Write;
  48 use std::path::{Path, PathBuf};
  49 use std::rc::Rc;
  50 use std::sync::{Once, ONCE_INIT};
  51 use std::time::Duration;
  52
  53 mod code_stats;
  54 pub mod config;
  55 pub mod filesearch;
  56 pub mod search_paths;
  57
  58 // Represents the data associated with a compilation
  59 // session for a single crate.
  60 pub struct Session {
  61     pub dep_graph: DepGraph,
  62     pub target: config::Config,
  63     pub host: Target,
  64     pub opts: config::Options,
  65     pub parse_sess: ParseSess,
  66     // For a library crate, this is always none
  67     pub entry_fn: RefCell<Option<(NodeId, Span)>>,
  68     pub entry_type: Cell<Option<config::EntryFnType>>,
  69     pub plugin_registrar_fn: Cell<Option<ast::NodeId>>,
  70     pub derive_registrar_fn: Cell<Option<ast::NodeId>>,
  71     pub default_sysroot: Option<PathBuf>,
  72     // The name of the root source file of the crate, in the local file system.
  73     // The path is always expected to be absolute. `None` means that there is no
  74     // source file.
  75     pub local_crate_source_file: Option<String>,
  76     // The directory the compiler has been executed in plus a flag indicating
  77     // if the value stored here has been affected by path remapping.
  78     pub working_dir: (String, bool),
  79     pub lint_store: RefCell<lint::LintStore>,
  80     pub buffered_lints: RefCell<Option<lint::LintBuffer>>,
  81     /// Set of (LintId, Option<Span>, message) tuples tracking lint
  82     /// (sub)diagnostics that have been set once, but should not be set again,
  83     /// in order to avoid redundantly verbose output (Issue #24690).
  84     pub one_time_diagnostics: RefCell<FxHashSet<(lint::LintId, Option<Span>, String)>>,
  85     pub plugin_llvm_passes: RefCell<Vec<String>>,
  86     pub plugin_attributes: RefCell<Vec<(String, AttributeType)>>,
  87     pub crate_types: RefCell<Vec<config::CrateType>>,
  88     pub dependency_formats: RefCell<dependency_format::Dependencies>,
  89     // The crate_disambiguator is constructed out of all the `-C metadata`
  90     // arguments passed to the compiler. Its value together with the crate-name
  91     // forms a unique global identifier for the crate. It is used to allow
  92     // multiple crates with the same name to coexist. See the
  93     // trans::back::symbol_names module for more information.
  94     pub crate_disambiguator: RefCell<Symbol>,
  95     pub features: RefCell<feature_gate::Features>,
  96
  97     /// The maximum recursion limit for potentially infinitely recursive
  98     /// operations such as auto-dereference and monomorphization.
  99     pub recursion_limit: Cell<usize>,
 100
 101     /// The maximum length of types during monomorphization.
 102     pub type_length_limit: Cell<usize>,
 103
 104     /// The metadata::creader module may inject an allocator/panic_runtime
 105     /// dependency if it didn't already find one, and this tracks what was
 106     /// injected.
 107     pub injected_allocator: Cell<Option<CrateNum>>,
 108     pub allocator_kind: Cell<Option<AllocatorKind>>,
 109     pub injected_panic_runtime: Cell<Option<CrateNum>>,
 110
 111     /// Map from imported macro spans (which consist of
 112     /// the localized span for the macro body) to the
 113     /// macro name and definition span in the source crate.
 114     pub imported_macro_spans: RefCell<HashMap<Span, (String, Span)>>,
 115
 116     incr_comp_session: RefCell<IncrCompSession>,
 117
 118     /// Some measurements that are being gathered during compilation.
 119     pub perf_stats: PerfStats,
 120
 121     /// Data about code being compiled, gathered during compilation.
 122     pub code_stats: RefCell<CodeStats>,
 123
 124     next_node_id: Cell<ast::NodeId>,
 125
 126     /// If -zfuel=crate=n is specified, Some(crate).
 127     optimization_fuel_crate: Option<String>,
 128     /// If -zfuel=crate=n is specified, initially set to n. Otherwise 0.
 129     optimization_fuel_limit: Cell<u64>,
 130     /// We're rejecting all further optimizations.
 131     out_of_fuel: Cell<bool>,
 132
 133     // The next two are public because the driver needs to read them.
 134
 135     /// If -zprint-fuel=crate, Some(crate).
 136     pub print_fuel_crate: Option<String>,
 137     /// Always set to zero and incremented so that we can print fuel expended by a crate.
 138     pub print_fuel: Cell<u64>,
 139
 140     /// Loaded up early on in the initialization of this `Session` to avoid
 141     /// false positives about a job server in our environment.
 142     pub jobserver_from_env: Option<Client>,
 143
 144     /// Metadata about the allocators for the current crate being compiled
 145     pub has_global_allocator: Cell<bool>,
 146 }
 147
 148 pub struct PerfStats {
 149     // The accumulated time needed for computing the SVH of the crate
 150     pub svh_time: Cell<Duration>,
 151     // The accumulated time spent on computing incr. comp. hashes
 152     pub incr_comp_hashes_time: Cell<Duration>,
 153     // The number of incr. comp. hash computations performed
 154     pub incr_comp_hashes_count: Cell<u64>,
 155     // The number of bytes hashed when computing ICH values
 156     pub incr_comp_bytes_hashed: Cell<u64>,
 157     // The accumulated time spent on computing symbol hashes
 158     pub symbol_hash_time: Cell<Duration>,
 159     // The accumulated time spent decoding def path tables from metadata
 160     pub decode_def_path_tables_time: Cell<Duration>,
 161 }
 162
 163 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
 164 enum DiagnosticBuilderMethod {
 165     Note,
 166     SpanNote,
 167     // add more variants as needed to support one-time diagnostics
 168 }
 169
 170 impl Session {
 171     pub fn local_crate_disambiguator(&self) -> Symbol {
 172         *self.crate_disambiguator.borrow()
 173     }
 174     pub fn struct_span_warn<'a, S: Into<MultiSpan>>(&'a self,
 175                                                     sp: S,
 176                                                     msg: &str)
 177                                                     -> DiagnosticBuilder<'a> {
 178         self.diagnostic().struct_span_warn(sp, msg)
 179     }
 180     pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(&'a self,
 181                                                               sp: S,
 182                                                               msg: &str,
 183                                                               code: &str)
 184                                                               -> DiagnosticBuilder<'a> {
 185         self.diagnostic().struct_span_warn_with_code(sp, msg, code)
 186     }
 187     pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 188         self.diagnostic().struct_warn(msg)
 189     }
 190     pub fn struct_span_err<'a, S: Into<MultiSpan>>(&'a self,
 191                                                    sp: S,
 192                                                    msg: &str)
 193                                                    -> DiagnosticBuilder<'a> {
 194         self.diagnostic().struct_span_err(sp, msg)
 195     }
 196     pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(&'a self,
 197                                                              sp: S,
 198                                                              msg: &str,
 199                                                              code: &str)
 200                                                              -> DiagnosticBuilder<'a> {
 201         self.diagnostic().struct_span_err_with_code(sp, msg, code)
 202     }
 203     // FIXME: This method should be removed (every error should have an associated error code).
 204     pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
 205         self.diagnostic().struct_err(msg)
 206     }
 207     pub fn struct_err_with_code<'a>(&'a self, msg: &str, code: &str) -> DiagnosticBuilder<'a> {
 208         self.diagnostic().struct_err_with_code(msg, code)
 209     }
 210     pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(&'a self,
 211                                                      sp: S,
 212                                                      msg: &str)
 213                                                      -> DiagnosticBuilder<'a> {
 214         self.diagnostic().struct_span_fatal(sp, msg)
 215     }
 216     pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(&'a self,
 217                                                                sp: S,
 218                                                                msg: &str,
 219                                                                code: &str)
 220                                                                -> DiagnosticBuilder<'a> {
 221         self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
 222     }
 223     pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 224         self.diagnostic().struct_fatal(msg)
 225     }
 226
 227     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 228         panic!(self.diagnostic().span_fatal(sp, msg))
 229     }
 230     pub fn span_fatal_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) -> ! {
 231         panic!(self.diagnostic().span_fatal_with_code(sp, msg, code))
 232     }
 233     pub fn fatal(&self, msg: &str) -> ! {
 234         panic!(self.diagnostic().fatal(msg))
 235     }
 236     pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
 237         if is_warning {
 238             self.span_warn(sp, msg);
 239         } else {
 240             self.span_err(sp, msg);
 241         }
 242     }
 243     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 244         self.diagnostic().span_err(sp, msg)
 245     }
 246     pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 247         self.diagnostic().span_err_with_code(sp, &msg, code)
 248     }
 249     pub fn err(&self, msg: &str) {
 250         self.diagnostic().err(msg)
 251     }
 252     pub fn err_count(&self) -> usize {
 253         self.diagnostic().err_count()
 254     }
 255     pub fn has_errors(&self) -> bool {
 256         self.diagnostic().has_errors()
 257     }
 258     pub fn abort_if_errors(&self) {
 259         self.diagnostic().abort_if_errors();
 260     }
 261     pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
 262         compile_result_from_err_count(self.err_count())
 263     }
 264     pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
 265         where F: FnOnce() -> T
 266     {
 267         let old_count = self.err_count();
 268         let result = f();
 269         let errors = self.err_count() - old_count;
 270         if errors == 0 {
 271             Ok(result)
 272         } else {
 273             Err(ErrorReported)
 274         }
 275     }
 276     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 277         self.diagnostic().span_warn(sp, msg)
 278     }
 279     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 280         self.diagnostic().span_warn_with_code(sp, msg, code)
 281     }
 282     pub fn warn(&self, msg: &str) {
 283         self.diagnostic().warn(msg)
 284     }
 285     pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
 286         match opt_sp {
 287             Some(sp) => self.span_warn(sp, msg),
 288             None => self.warn(msg),
 289         }
 290     }
 291     /// Delay a span_bug() call until abort_if_errors()
 292     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 293         self.diagnostic().delay_span_bug(sp, msg)
 294     }
 295     pub fn note_without_error(&self, msg: &str) {
 296         self.diagnostic().note_without_error(msg)
 297     }
 298     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 299         self.diagnostic().span_note_without_error(sp, msg)
 300     }
 301     pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 302         self.diagnostic().span_unimpl(sp, msg)
 303     }
 304     pub fn unimpl(&self, msg: &str) -> ! {
 305         self.diagnostic().unimpl(msg)
 306     }
 307
 308     pub fn buffer_lint<S: Into<MultiSpan>>(&self,
 309                                            lint: &'static lint::Lint,
 310                                            id: ast::NodeId,
 311                                            sp: S,
 312                                            msg: &str) {
 313         match *self.buffered_lints.borrow_mut() {
 314             Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg),
 315             None => bug!("can't buffer lints after HIR lowering"),
 316         }
 317     }
 318
 319     pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
 320         let id = self.next_node_id.get();
 321
 322         match id.as_usize().checked_add(count) {
 323             Some(next) => {
 324                 self.next_node_id.set(ast::NodeId::new(next));
 325             }
 326             None => bug!("Input too large, ran out of node ids!")
 327         }
 328
 329         id
 330     }
 331     pub fn next_node_id(&self) -> NodeId {
 332         self.reserve_node_ids(1)
 333     }
 334     pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
 335         &self.parse_sess.span_diagnostic
 336     }
 337
 338     /// Analogous to calling methods on the given `DiagnosticBuilder`, but
 339     /// deduplicates on lint ID, span (if any), and message for this `Session`
 340     /// if we're not outputting in JSON mode.
 341     fn diag_once<'a, 'b>(&'a self,
 342                          diag_builder: &'b mut DiagnosticBuilder<'a>,
 343                          method: DiagnosticBuilderMethod,
 344                          lint: &'static lint::Lint, message: &str, span: Option<Span>) {
 345         let mut do_method = || {
 346             match method {
 347                 DiagnosticBuilderMethod::Note => {
 348                     diag_builder.note(message);
 349                 },
 350                 DiagnosticBuilderMethod::SpanNote => {
 351                     diag_builder.span_note(span.expect("span_note expects a span"), message);
 352                 }
 353             }
 354         };
 355
 356         match self.opts.error_format {
 357             // when outputting JSON for tool consumption, the tool might want
 358             // the duplicates
 359             config::ErrorOutputType::Json => {
 360                 do_method()
 361             },
 362             _ => {
 363                 let lint_id = lint::LintId::of(lint);
 364                 let id_span_message = (lint_id, span, message.to_owned());
 365                 let fresh = self.one_time_diagnostics.borrow_mut().insert(id_span_message);
 366                 if fresh {
 367                     do_method()
 368                 }
 369             }
 370         }
 371     }
 372
 373     pub fn diag_span_note_once<'a, 'b>(&'a self,
 374                                        diag_builder: &'b mut DiagnosticBuilder<'a>,
 375                                        lint: &'static lint::Lint, span: Span, message: &str) {
 376         self.diag_once(diag_builder, DiagnosticBuilderMethod::SpanNote, lint, message, Some(span));
 377     }
 378
 379     pub fn diag_note_once<'a, 'b>(&'a self,
 380                                   diag_builder: &'b mut DiagnosticBuilder<'a>,
 381                                   lint: &'static lint::Lint, message: &str) {
 382         self.diag_once(diag_builder, DiagnosticBuilderMethod::Note, lint, message, None);
 383     }
 384
 385     pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
 386         self.parse_sess.codemap()
 387     }
 388     pub fn verbose(&self) -> bool { self.opts.debugging_opts.verbose }
 389     pub fn time_passes(&self) -> bool { self.opts.debugging_opts.time_passes }
 390     pub fn profile_queries(&self) -> bool {
 391         self.opts.debugging_opts.profile_queries ||
 392             self.opts.debugging_opts.profile_queries_and_keys
 393     }
 394     pub fn profile_queries_and_keys(&self) -> bool {
 395         self.opts.debugging_opts.profile_queries_and_keys
 396     }
 397     pub fn count_llvm_insns(&self) -> bool {
 398         self.opts.debugging_opts.count_llvm_insns
 399     }
 400     pub fn time_llvm_passes(&self) -> bool {
 401         self.opts.debugging_opts.time_llvm_passes
 402     }
 403     pub fn trans_stats(&self) -> bool { self.opts.debugging_opts.trans_stats }
 404     pub fn meta_stats(&self) -> bool { self.opts.debugging_opts.meta_stats }
 405     pub fn asm_comments(&self) -> bool { self.opts.debugging_opts.asm_comments }
 406     pub fn no_verify(&self) -> bool { self.opts.debugging_opts.no_verify }
 407     pub fn borrowck_stats(&self) -> bool { self.opts.debugging_opts.borrowck_stats }
 408     pub fn print_llvm_passes(&self) -> bool {
 409         self.opts.debugging_opts.print_llvm_passes
 410     }
 411     pub fn emit_end_regions(&self) -> bool {
 412         self.opts.debugging_opts.emit_end_regions ||
 413             (self.opts.debugging_opts.mir_emit_validate > 0)
 414     }
 415     pub fn lto(&self) -> bool {
 416         self.opts.cg.lto
 417     }
 418     /// Returns the panic strategy for this compile session. If the user explicitly selected one
 419     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
 420     pub fn panic_strategy(&self) -> PanicStrategy {
 421         self.opts.cg.panic.unwrap_or(self.target.target.options.panic_strategy)
 422     }
 423     pub fn linker_flavor(&self) -> LinkerFlavor {
 424         self.opts.debugging_opts.linker_flavor.unwrap_or(self.target.target.linker_flavor)
 425     }
 426     pub fn no_landing_pads(&self) -> bool {
 427         self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
 428     }
 429     pub fn unstable_options(&self) -> bool {
 430         self.opts.debugging_opts.unstable_options
 431     }
 432     pub fn nonzeroing_move_hints(&self) -> bool {
 433         self.opts.debugging_opts.enable_nonzeroing_move_hints
 434     }
 435     pub fn overflow_checks(&self) -> bool {
 436         self.opts.cg.overflow_checks
 437             .or(self.opts.debugging_opts.force_overflow_checks)
 438             .unwrap_or(self.opts.debug_assertions)
 439     }
 440
 441     pub fn crt_static(&self) -> bool {
 442         // If the target does not opt in to crt-static support, use its default.
 443         if self.target.target.options.crt_static_respected {
 444             self.crt_static_feature()
 445         } else {
 446             self.target.target.options.crt_static_default
 447         }
 448     }
 449
 450     pub fn crt_static_feature(&self) -> bool {
 451         let requested_features = self.opts.cg.target_feature.split(',');
 452         let found_negative = requested_features.clone().any(|r| r == "-crt-static");
 453         let found_positive = requested_features.clone().any(|r| r == "+crt-static");
 454
 455         // If the target we're compiling for requests a static crt by default,
 456         // then see if the `-crt-static` feature was passed to disable that.
 457         // Otherwise if we don't have a static crt by default then see if the
 458         // `+crt-static` feature was passed.
 459         if self.target.target.options.crt_static_default {
 460             !found_negative
 461         } else {
 462             found_positive
 463         }
 464     }
 465
 466     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
 467         self.opts.debuginfo != DebugInfoLevel::NoDebugInfo ||
 468         !self.target.target.options.eliminate_frame_pointer
 469     }
 470
 471     /// Returns the symbol name for the registrar function,
 472     /// given the crate Svh and the function DefIndex.
 473     pub fn generate_plugin_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 474                                             -> String {
 475         format!("__rustc_plugin_registrar__{}_{}", disambiguator, index.as_usize())
 476     }
 477
 478     pub fn generate_derive_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 479                                             -> String {
 480         format!("__rustc_derive_registrar__{}_{}", disambiguator, index.as_usize())
 481     }
 482
 483     pub fn sysroot<'a>(&'a self) -> &'a Path {
 484         match self.opts.maybe_sysroot {
 485             Some (ref sysroot) => sysroot,
 486             None => self.default_sysroot.as_ref()
 487                         .expect("missing sysroot and default_sysroot in Session")
 488         }
 489     }
 490     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 491         filesearch::FileSearch::new(self.sysroot(),
 492                                     &self.opts.target_triple,
 493                                     &self.opts.search_paths,
 494                                     kind)
 495     }
 496     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 497         filesearch::FileSearch::new(
 498             self.sysroot(),
 499             config::host_triple(),
 500             &self.opts.search_paths,
 501             kind)
 502     }
 503
 504     pub fn init_incr_comp_session(&self,
 505                                   session_dir: PathBuf,
 506                                   lock_file: flock::Lock) {
 507         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 508
 509         if let IncrCompSession::NotInitialized = *incr_comp_session { } else {
 510             bug!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session)
 511         }
 512
 513         *incr_comp_session = IncrCompSession::Active {
 514             session_directory: session_dir,
 515             lock_file,
 516         };
 517     }
 518
 519     pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
 520         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 521
 522         if let IncrCompSession::Active { .. } = *incr_comp_session { } else {
 523             bug!("Trying to finalize IncrCompSession `{:?}`", *incr_comp_session)
 524         }
 525
 526         // Note: This will also drop the lock file, thus unlocking the directory
 527         *incr_comp_session = IncrCompSession::Finalized {
 528             session_directory: new_directory_path,
 529         };
 530     }
 531
 532     pub fn mark_incr_comp_session_as_invalid(&self) {
 533         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 534
 535         let session_directory = match *incr_comp_session {
 536             IncrCompSession::Active { ref session_directory, .. } => {
 537                 session_directory.clone()
 538             }
 539             _ => bug!("Trying to invalidate IncrCompSession `{:?}`",
 540                       *incr_comp_session),
 541         };
 542
 543         // Note: This will also drop the lock file, thus unlocking the directory
 544         *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
 545             session_directory,
 546         };
 547     }
 548
 549     pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
 550         let incr_comp_session = self.incr_comp_session.borrow();
 551         cell::Ref::map(incr_comp_session, |incr_comp_session| {
 552             match *incr_comp_session {
 553                 IncrCompSession::NotInitialized => {
 554                     bug!("Trying to get session directory from IncrCompSession `{:?}`",
 555                         *incr_comp_session)
 556                 }
 557                 IncrCompSession::Active { ref session_directory, .. } |
 558                 IncrCompSession::Finalized { ref session_directory } |
 559                 IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => {
 560                     session_directory
 561                 }
 562             }
 563         })
 564     }
 565
 566     pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
 567         if self.opts.incremental.is_some() {
 568             Some(self.incr_comp_session_dir())
 569         } else {
 570             None
 571         }
 572     }
 573
 574     pub fn print_perf_stats(&self) {
 575         println!("Total time spent computing SVHs:               {}",
 576                  duration_to_secs_str(self.perf_stats.svh_time.get()));
 577         println!("Total time spent computing incr. comp. hashes: {}",
 578                  duration_to_secs_str(self.perf_stats.incr_comp_hashes_time.get()));
 579         println!("Total number of incr. comp. hashes computed:   {}",
 580                  self.perf_stats.incr_comp_hashes_count.get());
 581         println!("Total number of bytes hashed for incr. comp.:  {}",
 582                  self.perf_stats.incr_comp_bytes_hashed.get());
 583         println!("Average bytes hashed per incr. comp. HIR node: {}",
 584                  self.perf_stats.incr_comp_bytes_hashed.get() /
 585                  self.perf_stats.incr_comp_hashes_count.get());
 586         println!("Total time spent computing symbol hashes:      {}",
 587                  duration_to_secs_str(self.perf_stats.symbol_hash_time.get()));
 588         println!("Total time spent decoding DefPath tables:      {}",
 589                  duration_to_secs_str(self.perf_stats.decode_def_path_tables_time.get()));
 590     }
 591
 592     /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
 593     /// This expends fuel if applicable, and records fuel if applicable.
 594     pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
 595         let mut ret = true;
 596         match self.optimization_fuel_crate {
 597             Some(ref c) if c == crate_name => {
 598                 let fuel = self.optimization_fuel_limit.get();
 599                 ret = fuel != 0;
 600                 if fuel == 0 && !self.out_of_fuel.get() {
 601                     println!("optimization-fuel-exhausted: {}", msg());
 602                     self.out_of_fuel.set(true);
 603                 } else if fuel > 0 {
 604                     self.optimization_fuel_limit.set(fuel-1);
 605                 }
 606             }
 607             _ => {}
 608         }
 609         match self.print_fuel_crate {
 610             Some(ref c) if c == crate_name=> {
 611                 self.print_fuel.set(self.print_fuel.get()+1);
 612             },
 613             _ => {}
 614         }
 615         ret
 616     }
 617 }
 618
 619 pub fn build_session(sopts: config::Options,
 620                      dep_graph: &DepGraph,
 621                      local_crate_source_file: Option<PathBuf>,
 622                      registry: errors::registry::Registry)
 623                      -> Session {
 624     let file_path_mapping = sopts.file_path_mapping();
 625
 626     build_session_with_codemap(sopts,
 627                                dep_graph,
 628                                local_crate_source_file,
 629                                registry,
 630                                Rc::new(codemap::CodeMap::new(file_path_mapping)),
 631                                None)
 632 }
 633
 634 pub fn build_session_with_codemap(sopts: config::Options,
 635                                   dep_graph: &DepGraph,
 636                                   local_crate_source_file: Option<PathBuf>,
 637                                   registry: errors::registry::Registry,
 638                                   codemap: Rc<codemap::CodeMap>,
 639                                   emitter_dest: Option<Box<Write + Send>>)
 640                                   -> Session {
 641     // FIXME: This is not general enough to make the warning lint completely override
 642     // normal diagnostic warnings, since the warning lint can also be denied and changed
 643     // later via the source code.
 644     let can_print_warnings = sopts.lint_opts
 645         .iter()
 646         .filter(|&&(ref key, _)| *key == "warnings")
 647         .map(|&(_, ref level)| *level != lint::Allow)
 648         .last()
 649         .unwrap_or(true);
 650     let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
 651
 652     let emitter: Box<Emitter> = match (sopts.error_format, emitter_dest) {
 653         (config::ErrorOutputType::HumanReadable(color_config), None) => {
 654             Box::new(EmitterWriter::stderr(color_config,
 655                                            Some(codemap.clone())))
 656         }
 657         (config::ErrorOutputType::HumanReadable(_), Some(dst)) => {
 658             Box::new(EmitterWriter::new(dst,
 659                                         Some(codemap.clone())))
 660         }
 661         (config::ErrorOutputType::Json, None) => {
 662             Box::new(JsonEmitter::stderr(Some(registry), codemap.clone()))
 663         }
 664         (config::ErrorOutputType::Json, Some(dst)) => {
 665             Box::new(JsonEmitter::new(dst, Some(registry), codemap.clone()))
 666         }
 667     };
 668
 669     let diagnostic_handler =
 670         errors::Handler::with_emitter(can_print_warnings,
 671                                       treat_err_as_bug,
 672                                       emitter);
 673
 674     build_session_(sopts,
 675                    dep_graph,
 676                    local_crate_source_file,
 677                    diagnostic_handler,
 678                    codemap)
 679 }
 680
 681 pub fn build_session_(sopts: config::Options,
 682                       dep_graph: &DepGraph,
 683                       local_crate_source_file: Option<PathBuf>,
 684                       span_diagnostic: errors::Handler,
 685                       codemap: Rc<codemap::CodeMap>)
 686                       -> Session {
 687     let host = match Target::search(config::host_triple()) {
 688         Ok(t) => t,
 689         Err(e) => {
 690             panic!(span_diagnostic.fatal(&format!("Error loading host specification: {}", e)));
 691         }
 692     };
 693     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 694
 695     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
 696     let default_sysroot = match sopts.maybe_sysroot {
 697         Some(_) => None,
 698         None => Some(filesearch::get_or_default_sysroot())
 699     };
 700
 701     let file_path_mapping = sopts.file_path_mapping();
 702
 703     // Make the path absolute, if necessary
 704     let local_crate_source_file = local_crate_source_file.map(|path| {
 705         file_path_mapping.map_prefix(path.to_string_lossy().into_owned()).0
 706     });
 707
 708     let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
 709     let optimization_fuel_limit = Cell::new(sopts.debugging_opts.fuel.as_ref()
 710         .map(|i| i.1).unwrap_or(0));
 711     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
 712     let print_fuel = Cell::new(0);
 713
 714     let working_dir = env::current_dir().unwrap().to_string_lossy().into_owned();
 715     let working_dir = file_path_mapping.map_prefix(working_dir);
 716
 717     let sess = Session {
 718         dep_graph: dep_graph.clone(),
 719         target: target_cfg,
 720         host,
 721         opts: sopts,
 722         parse_sess: p_s,
 723         // For a library crate, this is always none
 724         entry_fn: RefCell::new(None),
 725         entry_type: Cell::new(None),
 726         plugin_registrar_fn: Cell::new(None),
 727         derive_registrar_fn: Cell::new(None),
 728         default_sysroot,
 729         local_crate_source_file,
 730         working_dir,
 731         lint_store: RefCell::new(lint::LintStore::new()),
 732         buffered_lints: RefCell::new(Some(lint::LintBuffer::new())),
 733         one_time_diagnostics: RefCell::new(FxHashSet()),
 734         plugin_llvm_passes: RefCell::new(Vec::new()),
 735         plugin_attributes: RefCell::new(Vec::new()),
 736         crate_types: RefCell::new(Vec::new()),
 737         dependency_formats: RefCell::new(FxHashMap()),
 738         crate_disambiguator: RefCell::new(Symbol::intern("")),
 739         features: RefCell::new(feature_gate::Features::new()),
 740         recursion_limit: Cell::new(64),
 741         type_length_limit: Cell::new(1048576),
 742         next_node_id: Cell::new(NodeId::new(1)),
 743         injected_allocator: Cell::new(None),
 744         allocator_kind: Cell::new(None),
 745         injected_panic_runtime: Cell::new(None),
 746         imported_macro_spans: RefCell::new(HashMap::new()),
 747         incr_comp_session: RefCell::new(IncrCompSession::NotInitialized),
 748         perf_stats: PerfStats {
 749             svh_time: Cell::new(Duration::from_secs(0)),
 750             incr_comp_hashes_time: Cell::new(Duration::from_secs(0)),
 751             incr_comp_hashes_count: Cell::new(0),
 752             incr_comp_bytes_hashed: Cell::new(0),
 753             symbol_hash_time: Cell::new(Duration::from_secs(0)),
 754             decode_def_path_tables_time: Cell::new(Duration::from_secs(0)),
 755         },
 756         code_stats: RefCell::new(CodeStats::new()),
 757         optimization_fuel_crate,
 758         optimization_fuel_limit,
 759         print_fuel_crate,
 760         print_fuel,
 761         out_of_fuel: Cell::new(false),
 762         // Note that this is unsafe because it may misinterpret file descriptors
 763         // on Unix as jobserver file descriptors. We hopefully execute this near
 764         // the beginning of the process though to ensure we don't get false
 765         // positives, or in other words we try to execute this before we open
 766         // any file descriptors ourselves.
 767         //
 768         // Also note that we stick this in a global because there could be
 769         // multiple `Session` instances in this process, and the jobserver is
 770         // per-process.
 771         jobserver_from_env: unsafe {
 772             static mut GLOBAL_JOBSERVER: *mut Option<Client> = 0 as *mut _;
 773             static INIT: Once = ONCE_INIT;
 774             INIT.call_once(|| {
 775                 GLOBAL_JOBSERVER = Box::into_raw(Box::new(Client::from_env()));
 776             });
 777             (*GLOBAL_JOBSERVER).clone()
 778         },
 779         has_global_allocator: Cell::new(false),
 780     };
 781
 782     sess
 783 }
 784
 785 /// Holds data on the current incremental compilation session, if there is one.
 786 #[derive(Debug)]
 787 pub enum IncrCompSession {
 788     // This is the state the session will be in until the incr. comp. dir is
 789     // needed.
 790     NotInitialized,
 791     // This is the state during which the session directory is private and can
 792     // be modified.
 793     Active {
 794         session_directory: PathBuf,
 795         lock_file: flock::Lock,
 796     },
 797     // This is the state after the session directory has been finalized. In this
 798     // state, the contents of the directory must not be modified any more.
 799     Finalized {
 800         session_directory: PathBuf,
 801     },
 802     // This is an error state that is reached when some compilation error has
 803     // occurred. It indicates that the contents of the session directory must
 804     // not be used, since they might be invalid.
 805     InvalidBecauseOfErrors {
 806         session_directory: PathBuf,
 807     }
 808 }
 809
 810 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
 811     let emitter: Box<Emitter> = match output {
 812         config::ErrorOutputType::HumanReadable(color_config) => {
 813             Box::new(EmitterWriter::stderr(color_config,
 814                                            None))
 815         }
 816         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 817     };
 818     let handler = errors::Handler::with_emitter(true, false, emitter);
 819     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
 820     panic!(errors::FatalError);
 821 }
 822
 823 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
 824     let emitter: Box<Emitter> = match output {
 825         config::ErrorOutputType::HumanReadable(color_config) => {
 826             Box::new(EmitterWriter::stderr(color_config,
 827                                            None))
 828         }
 829         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 830     };
 831     let handler = errors::Handler::with_emitter(true, false, emitter);
 832     handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
 833 }
 834
 835 #[derive(Copy, Clone, Debug)]
 836 pub enum CompileIncomplete {
 837     Stopped,
 838     Errored(ErrorReported)
 839 }
 840 impl From<ErrorReported> for CompileIncomplete {
 841     fn from(err: ErrorReported) -> CompileIncomplete {
 842         CompileIncomplete::Errored(err)
 843     }
 844 }
 845 pub type CompileResult = Result<(), CompileIncomplete>;
 846
 847 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
 848     if err_count == 0 {
 849         Ok(())
 850     } else {
 851         Err(CompileIncomplete::Errored(ErrorReported))
 852     }
 853 }
 854
 855 #[cold]
 856 #[inline(never)]
 857 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
 858     // this wrapper mostly exists so I don't have to write a fully
 859     // qualified path of None::<Span> inside the bug!() macro definition
 860     opt_span_bug_fmt(file, line, None::<Span>, args);
 861 }
 862
 863 #[cold]
 864 #[inline(never)]
 865 pub fn span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 866                                         line: u32,
 867                                         span: S,
 868                                         args: fmt::Arguments) -> ! {
 869     opt_span_bug_fmt(file, line, Some(span), args);
 870 }
 871
 872 fn opt_span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 873                                         line: u32,
 874                                         span: Option<S>,
 875                                         args: fmt::Arguments) -> ! {
 876     tls::with_opt(move |tcx| {
 877         let msg = format!("{}:{}: {}", file, line, args);
 878         match (tcx, span) {
 879             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
 880             (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
 881             (None, _) => panic!(msg)
 882         }
 883     });
 884     unreachable!();
 885 }