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