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