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 hir::def_id::{CrateNum, DefIndex};
  15
  16 use lint;
  17 use middle::allocator::AllocatorKind;
  18 use middle::dependency_format;
  19 use session::search_paths::PathKind;
  20 use session::config::DebugInfoLevel;
  21 use ty::tls;
  22 use util::nodemap::{FxHashMap, FxHashSet};
  23 use util::common::{duration_to_secs_str, ErrorReported};
  24
  25 use syntax::ast::NodeId;
  26 use errors::{self, DiagnosticBuilder};
  27 use errors::emitter::{Emitter, EmitterWriter};
  28 use syntax::json::JsonEmitter;
  29 use syntax::feature_gate;
  30 use syntax::parse;
  31 use syntax::parse::ParseSess;
  32 use syntax::symbol::Symbol;
  33 use syntax::{ast, codemap};
  34 use syntax::feature_gate::AttributeType;
  35 use syntax_pos::{Span, MultiSpan};
  36
  37 use rustc_back::{LinkerFlavor, PanicStrategy};
  38 use rustc_back::target::Target;
  39 use rustc_data_structures::flock;
  40 use jobserver::Client;
  41
  42 use std::cell::{self, Cell, RefCell};
  43 use std::collections::HashMap;
  44 use std::env;
  45 use std::fmt;
  46 use std::io::Write;
  47 use std::path::{Path, PathBuf};
  48 use std::rc::Rc;
  49 use std::sync::{Once, ONCE_INIT};
  50 use std::time::Duration;
  51
  52 mod code_stats;
  53 pub mod config;
  54 pub mod filesearch;
  55 pub mod search_paths;
  56
  57 // Represents the data associated with a compilation
  58 // session for a single crate.
  59 pub struct Session {
  60     pub target: config::Config,
  61     pub host: Target,
  62     pub opts: config::Options,
  63     pub parse_sess: ParseSess,
  64     // For a library crate, this is always none
  65     pub entry_fn: RefCell<Option<(NodeId, Span)>>,
  66     pub entry_type: Cell<Option<config::EntryFnType>>,
  67     pub plugin_registrar_fn: Cell<Option<ast::NodeId>>,
  68     pub derive_registrar_fn: Cell<Option<ast::NodeId>>,
  69     pub default_sysroot: Option<PathBuf>,
  70     // The name of the root source file of the crate, in the local file system.
  71     // The path is always expected to be absolute. `None` means that there is no
  72     // source file.
  73     pub local_crate_source_file: Option<String>,
  74     // The directory the compiler has been executed in plus a flag indicating
  75     // if the value stored here has been affected by path remapping.
  76     pub working_dir: (String, bool),
  77     pub lint_store: RefCell<lint::LintStore>,
  78     pub buffered_lints: RefCell<Option<lint::LintBuffer>>,
  79     /// Set of (LintId, Option<Span>, message) tuples tracking lint
  80     /// (sub)diagnostics that have been set once, but should not be set again,
  81     /// in order to avoid redundantly verbose output (Issue #24690).
  82     pub one_time_diagnostics: RefCell<FxHashSet<(lint::LintId, Option<Span>, String)>>,
  83     pub plugin_llvm_passes: RefCell<Vec<String>>,
  84     pub plugin_attributes: RefCell<Vec<(String, AttributeType)>>,
  85     pub crate_types: RefCell<Vec<config::CrateType>>,
  86     pub dependency_formats: RefCell<dependency_format::Dependencies>,
  87     // The crate_disambiguator is constructed out of all the `-C metadata`
  88     // arguments passed to the compiler. Its value together with the crate-name
  89     // forms a unique global identifier for the crate. It is used to allow
  90     // multiple crates with the same name to coexist. See the
  91     // trans::back::symbol_names module for more information.
  92     pub crate_disambiguator: RefCell<Option<Symbol>>,
  93     pub features: RefCell<feature_gate::Features>,
  94
  95     /// The maximum recursion limit for potentially infinitely recursive
  96     /// operations such as auto-dereference and monomorphization.
  97     pub recursion_limit: Cell<usize>,
  98
  99     /// The maximum length of types during monomorphization.
 100     pub type_length_limit: Cell<usize>,
 101
 102     /// The metadata::creader module may inject an allocator/panic_runtime
 103     /// dependency if it didn't already find one, and this tracks what was
 104     /// injected.
 105     pub injected_allocator: Cell<Option<CrateNum>>,
 106     pub allocator_kind: Cell<Option<AllocatorKind>>,
 107     pub injected_panic_runtime: Cell<Option<CrateNum>>,
 108
 109     /// Map from imported macro spans (which consist of
 110     /// the localized span for the macro body) to the
 111     /// macro name and definition span in the source crate.
 112     pub imported_macro_spans: RefCell<HashMap<Span, (String, Span)>>,
 113
 114     incr_comp_session: RefCell<IncrCompSession>,
 115
 116     /// Some measurements that are being gathered during compilation.
 117     pub perf_stats: PerfStats,
 118
 119     /// Data about code being compiled, gathered during compilation.
 120     pub code_stats: RefCell<CodeStats>,
 121
 122     next_node_id: Cell<ast::NodeId>,
 123
 124     /// If -zfuel=crate=n is specified, Some(crate).
 125     optimization_fuel_crate: Option<String>,
 126     /// If -zfuel=crate=n is specified, initially set to n. Otherwise 0.
 127     optimization_fuel_limit: Cell<u64>,
 128     /// We're rejecting all further optimizations.
 129     out_of_fuel: Cell<bool>,
 130
 131     // The next two are public because the driver needs to read them.
 132
 133     /// If -zprint-fuel=crate, Some(crate).
 134     pub print_fuel_crate: Option<String>,
 135     /// Always set to zero and incremented so that we can print fuel expended by a crate.
 136     pub print_fuel: Cell<u64>,
 137
 138     /// Loaded up early on in the initialization of this `Session` to avoid
 139     /// false positives about a job server in our environment.
 140     pub jobserver_from_env: Option<Client>,
 141
 142     /// Metadata about the allocators for the current crate being compiled
 143     pub has_global_allocator: Cell<bool>,
 144 }
 145
 146 pub struct PerfStats {
 147     // The accumulated time needed for computing the SVH of the crate
 148     pub svh_time: Cell<Duration>,
 149     // The accumulated time spent on computing incr. comp. hashes
 150     pub incr_comp_hashes_time: Cell<Duration>,
 151     // The number of incr. comp. hash computations performed
 152     pub incr_comp_hashes_count: Cell<u64>,
 153     // The number of bytes hashed when computing ICH values
 154     pub incr_comp_bytes_hashed: Cell<u64>,
 155     // The accumulated time spent on computing symbol hashes
 156     pub symbol_hash_time: Cell<Duration>,
 157     // The accumulated time spent decoding def path tables from metadata
 158     pub decode_def_path_tables_time: Cell<Duration>,
 159 }
 160
 161 /// Enum to support dispatch of one-time diagnostics (in Session.diag_once)
 162 enum DiagnosticBuilderMethod {
 163     Note,
 164     SpanNote,
 165     // add more variants as needed to support one-time diagnostics
 166 }
 167
 168 impl Session {
 169     pub fn local_crate_disambiguator(&self) -> Symbol {
 170         match *self.crate_disambiguator.borrow() {
 171             Some(sym) => sym,
 172             None => bug!("accessing disambiguator before initialization"),
 173         }
 174     }
 175     pub fn struct_span_warn<'a, S: Into<MultiSpan>>(&'a self,
 176                                                     sp: S,
 177                                                     msg: &str)
 178                                                     -> DiagnosticBuilder<'a> {
 179         self.diagnostic().struct_span_warn(sp, msg)
 180     }
 181     pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(&'a self,
 182                                                               sp: S,
 183                                                               msg: &str,
 184                                                               code: &str)
 185                                                               -> DiagnosticBuilder<'a> {
 186         self.diagnostic().struct_span_warn_with_code(sp, msg, code)
 187     }
 188     pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 189         self.diagnostic().struct_warn(msg)
 190     }
 191     pub fn struct_span_err<'a, S: Into<MultiSpan>>(&'a self,
 192                                                    sp: S,
 193                                                    msg: &str)
 194                                                    -> DiagnosticBuilder<'a> {
 195         self.diagnostic().struct_span_err(sp, msg)
 196     }
 197     pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(&'a self,
 198                                                              sp: S,
 199                                                              msg: &str,
 200                                                              code: &str)
 201                                                              -> DiagnosticBuilder<'a> {
 202         self.diagnostic().struct_span_err_with_code(sp, msg, code)
 203     }
 204     // FIXME: This method should be removed (every error should have an associated error code).
 205     pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
 206         self.diagnostic().struct_err(msg)
 207     }
 208     pub fn struct_err_with_code<'a>(&'a self, msg: &str, code: &str) -> DiagnosticBuilder<'a> {
 209         self.diagnostic().struct_err_with_code(msg, code)
 210     }
 211     pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(&'a self,
 212                                                      sp: S,
 213                                                      msg: &str)
 214                                                      -> DiagnosticBuilder<'a> {
 215         self.diagnostic().struct_span_fatal(sp, msg)
 216     }
 217     pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(&'a self,
 218                                                                sp: S,
 219                                                                msg: &str,
 220                                                                code: &str)
 221                                                                -> DiagnosticBuilder<'a> {
 222         self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
 223     }
 224     pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 225         self.diagnostic().struct_fatal(msg)
 226     }
 227
 228     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 229         panic!(self.diagnostic().span_fatal(sp, msg))
 230     }
 231     pub fn span_fatal_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) -> ! {
 232         panic!(self.diagnostic().span_fatal_with_code(sp, msg, code))
 233     }
 234     pub fn fatal(&self, msg: &str) -> ! {
 235         panic!(self.diagnostic().fatal(msg))
 236     }
 237     pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
 238         if is_warning {
 239             self.span_warn(sp, msg);
 240         } else {
 241             self.span_err(sp, msg);
 242         }
 243     }
 244     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 245         self.diagnostic().span_err(sp, msg)
 246     }
 247     pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 248         self.diagnostic().span_err_with_code(sp, &msg, code)
 249     }
 250     pub fn err(&self, msg: &str) {
 251         self.diagnostic().err(msg)
 252     }
 253     pub fn err_count(&self) -> usize {
 254         self.diagnostic().err_count()
 255     }
 256     pub fn has_errors(&self) -> bool {
 257         self.diagnostic().has_errors()
 258     }
 259     pub fn abort_if_errors(&self) {
 260         self.diagnostic().abort_if_errors();
 261     }
 262     pub fn compile_status(&self) -> Result<(), CompileIncomplete> {
 263         compile_result_from_err_count(self.err_count())
 264     }
 265     pub fn track_errors<F, T>(&self, f: F) -> Result<T, ErrorReported>
 266         where F: FnOnce() -> T
 267     {
 268         let old_count = self.err_count();
 269         let result = f();
 270         let errors = self.err_count() - old_count;
 271         if errors == 0 {
 272             Ok(result)
 273         } else {
 274             Err(ErrorReported)
 275         }
 276     }
 277     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 278         self.diagnostic().span_warn(sp, msg)
 279     }
 280     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 281         self.diagnostic().span_warn_with_code(sp, msg, code)
 282     }
 283     pub fn warn(&self, msg: &str) {
 284         self.diagnostic().warn(msg)
 285     }
 286     pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
 287         match opt_sp {
 288             Some(sp) => self.span_warn(sp, msg),
 289             None => self.warn(msg),
 290         }
 291     }
 292     /// Delay a span_bug() call until abort_if_errors()
 293     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 294         self.diagnostic().delay_span_bug(sp, msg)
 295     }
 296     pub fn note_without_error(&self, msg: &str) {
 297         self.diagnostic().note_without_error(msg)
 298     }
 299     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 300         self.diagnostic().span_note_without_error(sp, msg)
 301     }
 302     pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 303         self.diagnostic().span_unimpl(sp, msg)
 304     }
 305     pub fn unimpl(&self, msg: &str) -> ! {
 306         self.diagnostic().unimpl(msg)
 307     }
 308
 309     pub fn buffer_lint<S: Into<MultiSpan>>(&self,
 310                                            lint: &'static lint::Lint,
 311                                            id: ast::NodeId,
 312                                            sp: S,
 313                                            msg: &str) {
 314         match *self.buffered_lints.borrow_mut() {
 315             Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg),
 316             None => bug!("can't buffer lints after HIR lowering"),
 317         }
 318     }
 319
 320     pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
 321         let id = self.next_node_id.get();
 322
 323         match id.as_usize().checked_add(count) {
 324             Some(next) => {
 325                 self.next_node_id.set(ast::NodeId::new(next));
 326             }
 327             None => bug!("Input too large, ran out of node ids!")
 328         }
 329
 330         id
 331     }
 332     pub fn next_node_id(&self) -> NodeId {
 333         self.reserve_node_ids(1)
 334     }
 335     pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
 336         &self.parse_sess.span_diagnostic
 337     }
 338
 339     /// Analogous to calling methods on the given `DiagnosticBuilder`, but
 340     /// deduplicates on lint ID, span (if any), and message for this `Session`
 341     /// if we're not outputting in JSON mode.
 342     fn diag_once<'a, 'b>(&'a self,
 343                          diag_builder: &'b mut DiagnosticBuilder<'a>,
 344                          method: DiagnosticBuilderMethod,
 345                          lint: &'static lint::Lint, message: &str, span: Option<Span>) {
 346         let mut do_method = || {
 347             match method {
 348                 DiagnosticBuilderMethod::Note => {
 349                     diag_builder.note(message);
 350                 },
 351                 DiagnosticBuilderMethod::SpanNote => {
 352                     diag_builder.span_note(span.expect("span_note expects a span"), message);
 353                 }
 354             }
 355         };
 356
 357         match self.opts.error_format {
 358             // when outputting JSON for tool consumption, the tool might want
 359             // the duplicates
 360             config::ErrorOutputType::Json => {
 361                 do_method()
 362             },
 363             _ => {
 364                 let lint_id = lint::LintId::of(lint);
 365                 let id_span_message = (lint_id, span, message.to_owned());
 366                 let fresh = self.one_time_diagnostics.borrow_mut().insert(id_span_message);
 367                 if fresh {
 368                     do_method()
 369                 }
 370             }
 371         }
 372     }
 373
 374     pub fn diag_span_note_once<'a, 'b>(&'a self,
 375                                        diag_builder: &'b mut DiagnosticBuilder<'a>,
 376                                        lint: &'static lint::Lint, span: Span, message: &str) {
 377         self.diag_once(diag_builder, DiagnosticBuilderMethod::SpanNote, lint, message, Some(span));
 378     }
 379
 380     pub fn diag_note_once<'a, 'b>(&'a self,
 381                                   diag_builder: &'b mut DiagnosticBuilder<'a>,
 382                                   lint: &'static lint::Lint, message: &str) {
 383         self.diag_once(diag_builder, DiagnosticBuilderMethod::Note, lint, message, None);
 384     }
 385
 386     pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
 387         self.parse_sess.codemap()
 388     }
 389     pub fn verbose(&self) -> bool { self.opts.debugging_opts.verbose }
 390     pub fn time_passes(&self) -> bool { self.opts.debugging_opts.time_passes }
 391     pub fn profile_queries(&self) -> bool {
 392         self.opts.debugging_opts.profile_queries ||
 393             self.opts.debugging_opts.profile_queries_and_keys
 394     }
 395     pub fn profile_queries_and_keys(&self) -> bool {
 396         self.opts.debugging_opts.profile_queries_and_keys
 397     }
 398     pub fn count_llvm_insns(&self) -> bool {
 399         self.opts.debugging_opts.count_llvm_insns
 400     }
 401     pub fn time_llvm_passes(&self) -> bool {
 402         self.opts.debugging_opts.time_llvm_passes
 403     }
 404     pub fn trans_stats(&self) -> bool { self.opts.debugging_opts.trans_stats }
 405     pub fn meta_stats(&self) -> bool { self.opts.debugging_opts.meta_stats }
 406     pub fn asm_comments(&self) -> bool { self.opts.debugging_opts.asm_comments }
 407     pub fn no_verify(&self) -> bool { self.opts.debugging_opts.no_verify }
 408     pub fn borrowck_stats(&self) -> bool { self.opts.debugging_opts.borrowck_stats }
 409     pub fn print_llvm_passes(&self) -> bool {
 410         self.opts.debugging_opts.print_llvm_passes
 411     }
 412     pub fn emit_end_regions(&self) -> bool {
 413         self.opts.debugging_opts.emit_end_regions ||
 414             (self.opts.debugging_opts.mir_emit_validate > 0)
 415     }
 416     pub fn lto(&self) -> bool {
 417         self.opts.cg.lto
 418     }
 419     /// Returns the panic strategy for this compile session. If the user explicitly selected one
 420     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
 421     pub fn panic_strategy(&self) -> PanicStrategy {
 422         self.opts.cg.panic.unwrap_or(self.target.target.options.panic_strategy)
 423     }
 424     pub fn linker_flavor(&self) -> LinkerFlavor {
 425         self.opts.debugging_opts.linker_flavor.unwrap_or(self.target.target.linker_flavor)
 426     }
 427     pub fn no_landing_pads(&self) -> bool {
 428         self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
 429     }
 430     pub fn unstable_options(&self) -> bool {
 431         self.opts.debugging_opts.unstable_options
 432     }
 433     pub fn nonzeroing_move_hints(&self) -> bool {
 434         self.opts.debugging_opts.enable_nonzeroing_move_hints
 435     }
 436     pub fn overflow_checks(&self) -> bool {
 437         self.opts.cg.overflow_checks
 438             .or(self.opts.debugging_opts.force_overflow_checks)
 439             .unwrap_or(self.opts.debug_assertions)
 440     }
 441
 442     pub fn crt_static(&self) -> bool {
 443         // If the target does not opt in to crt-static support, use its default.
 444         if self.target.target.options.crt_static_respected {
 445             self.crt_static_feature()
 446         } else {
 447             self.target.target.options.crt_static_default
 448         }
 449     }
 450
 451     pub fn crt_static_feature(&self) -> bool {
 452         let requested_features = self.opts.cg.target_feature.split(',');
 453         let found_negative = requested_features.clone().any(|r| r == "-crt-static");
 454         let found_positive = requested_features.clone().any(|r| r == "+crt-static");
 455
 456         // If the target we're compiling for requests a static crt by default,
 457         // then see if the `-crt-static` feature was passed to disable that.
 458         // Otherwise if we don't have a static crt by default then see if the
 459         // `+crt-static` feature was passed.
 460         if self.target.target.options.crt_static_default {
 461             !found_negative
 462         } else {
 463             found_positive
 464         }
 465     }
 466
 467     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
 468         self.opts.debuginfo != DebugInfoLevel::NoDebugInfo ||
 469         !self.target.target.options.eliminate_frame_pointer
 470     }
 471
 472     /// Returns the symbol name for the registrar function,
 473     /// given the crate Svh and the function DefIndex.
 474     pub fn generate_plugin_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 475                                             -> String {
 476         format!("__rustc_plugin_registrar__{}_{}", disambiguator, index.as_usize())
 477     }
 478
 479     pub fn generate_derive_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 480                                             -> String {
 481         format!("__rustc_derive_registrar__{}_{}", disambiguator, index.as_usize())
 482     }
 483
 484     pub fn sysroot<'a>(&'a self) -> &'a Path {
 485         match self.opts.maybe_sysroot {
 486             Some (ref sysroot) => sysroot,
 487             None => self.default_sysroot.as_ref()
 488                         .expect("missing sysroot and default_sysroot in Session")
 489         }
 490     }
 491     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 492         filesearch::FileSearch::new(self.sysroot(),
 493                                     &self.opts.target_triple,
 494                                     &self.opts.search_paths,
 495                                     kind)
 496     }
 497     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 498         filesearch::FileSearch::new(
 499             self.sysroot(),
 500             config::host_triple(),
 501             &self.opts.search_paths,
 502             kind)
 503     }
 504
 505     pub fn set_incr_session_load_dep_graph(&self, load: bool) {
 506         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 507
 508         match *incr_comp_session {
 509             IncrCompSession::Active { ref mut load_dep_graph, .. } => {
 510                 *load_dep_graph = load;
 511             }
 512             _ => {}
 513         }
 514     }
 515
 516     pub fn incr_session_load_dep_graph(&self) -> bool {
 517         let incr_comp_session = self.incr_comp_session.borrow();
 518         match *incr_comp_session {
 519             IncrCompSession::Active { load_dep_graph, .. } => load_dep_graph,
 520             _ => false,
 521         }
 522     }
 523
 524     pub fn init_incr_comp_session(&self,
 525                                   session_dir: PathBuf,
 526                                   lock_file: flock::Lock,
 527                                   load_dep_graph: bool) {
 528         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 529
 530         if let IncrCompSession::NotInitialized = *incr_comp_session { } else {
 531             bug!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session)
 532         }
 533
 534         *incr_comp_session = IncrCompSession::Active {
 535             session_directory: session_dir,
 536             lock_file,
 537             load_dep_graph,
 538         };
 539     }
 540
 541     pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
 542         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 543
 544         if let IncrCompSession::Active { .. } = *incr_comp_session { } else {
 545             bug!("Trying to finalize IncrCompSession `{:?}`", *incr_comp_session)
 546         }
 547
 548         // Note: This will also drop the lock file, thus unlocking the directory
 549         *incr_comp_session = IncrCompSession::Finalized {
 550             session_directory: new_directory_path,
 551         };
 552     }
 553
 554     pub fn mark_incr_comp_session_as_invalid(&self) {
 555         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 556
 557         let session_directory = match *incr_comp_session {
 558             IncrCompSession::Active { ref session_directory, .. } => {
 559                 session_directory.clone()
 560             }
 561             _ => bug!("Trying to invalidate IncrCompSession `{:?}`",
 562                       *incr_comp_session),
 563         };
 564
 565         // Note: This will also drop the lock file, thus unlocking the directory
 566         *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
 567             session_directory,
 568         };
 569     }
 570
 571     pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
 572         let incr_comp_session = self.incr_comp_session.borrow();
 573         cell::Ref::map(incr_comp_session, |incr_comp_session| {
 574             match *incr_comp_session {
 575                 IncrCompSession::NotInitialized => {
 576                     bug!("Trying to get session directory from IncrCompSession `{:?}`",
 577                         *incr_comp_session)
 578                 }
 579                 IncrCompSession::Active { ref session_directory, .. } |
 580                 IncrCompSession::Finalized { ref session_directory } |
 581                 IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => {
 582                     session_directory
 583                 }
 584             }
 585         })
 586     }
 587
 588     pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
 589         if self.opts.incremental.is_some() {
 590             Some(self.incr_comp_session_dir())
 591         } else {
 592             None
 593         }
 594     }
 595
 596     pub fn print_perf_stats(&self) {
 597         println!("Total time spent computing SVHs:               {}",
 598                  duration_to_secs_str(self.perf_stats.svh_time.get()));
 599         println!("Total time spent computing incr. comp. hashes: {}",
 600                  duration_to_secs_str(self.perf_stats.incr_comp_hashes_time.get()));
 601         println!("Total number of incr. comp. hashes computed:   {}",
 602                  self.perf_stats.incr_comp_hashes_count.get());
 603         println!("Total number of bytes hashed for incr. comp.:  {}",
 604                  self.perf_stats.incr_comp_bytes_hashed.get());
 605         println!("Average bytes hashed per incr. comp. HIR node: {}",
 606                  self.perf_stats.incr_comp_bytes_hashed.get() /
 607                  self.perf_stats.incr_comp_hashes_count.get());
 608         println!("Total time spent computing symbol hashes:      {}",
 609                  duration_to_secs_str(self.perf_stats.symbol_hash_time.get()));
 610         println!("Total time spent decoding DefPath tables:      {}",
 611                  duration_to_secs_str(self.perf_stats.decode_def_path_tables_time.get()));
 612     }
 613
 614     /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
 615     /// This expends fuel if applicable, and records fuel if applicable.
 616     pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
 617         let mut ret = true;
 618         match self.optimization_fuel_crate {
 619             Some(ref c) if c == crate_name => {
 620                 let fuel = self.optimization_fuel_limit.get();
 621                 ret = fuel != 0;
 622                 if fuel == 0 && !self.out_of_fuel.get() {
 623                     println!("optimization-fuel-exhausted: {}", msg());
 624                     self.out_of_fuel.set(true);
 625                 } else if fuel > 0 {
 626                     self.optimization_fuel_limit.set(fuel-1);
 627                 }
 628             }
 629             _ => {}
 630         }
 631         match self.print_fuel_crate {
 632             Some(ref c) if c == crate_name=> {
 633                 self.print_fuel.set(self.print_fuel.get()+1);
 634             },
 635             _ => {}
 636         }
 637         ret
 638     }
 639 }
 640
 641 pub fn build_session(sopts: config::Options,
 642                      local_crate_source_file: Option<PathBuf>,
 643                      registry: errors::registry::Registry)
 644                      -> Session {
 645     let file_path_mapping = sopts.file_path_mapping();
 646
 647     build_session_with_codemap(sopts,
 648                                local_crate_source_file,
 649                                registry,
 650                                Rc::new(codemap::CodeMap::new(file_path_mapping)),
 651                                None)
 652 }
 653
 654 pub fn build_session_with_codemap(sopts: config::Options,
 655                                   local_crate_source_file: Option<PathBuf>,
 656                                   registry: errors::registry::Registry,
 657                                   codemap: Rc<codemap::CodeMap>,
 658                                   emitter_dest: Option<Box<Write + Send>>)
 659                                   -> Session {
 660     // FIXME: This is not general enough to make the warning lint completely override
 661     // normal diagnostic warnings, since the warning lint can also be denied and changed
 662     // later via the source code.
 663     let can_print_warnings = sopts.lint_opts
 664         .iter()
 665         .filter(|&&(ref key, _)| *key == "warnings")
 666         .map(|&(_, ref level)| *level != lint::Allow)
 667         .last()
 668         .unwrap_or(true);
 669     let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
 670
 671     let emitter: Box<Emitter> = match (sopts.error_format, emitter_dest) {
 672         (config::ErrorOutputType::HumanReadable(color_config), None) => {
 673             Box::new(EmitterWriter::stderr(color_config,
 674                                            Some(codemap.clone())))
 675         }
 676         (config::ErrorOutputType::HumanReadable(_), Some(dst)) => {
 677             Box::new(EmitterWriter::new(dst,
 678                                         Some(codemap.clone())))
 679         }
 680         (config::ErrorOutputType::Json, None) => {
 681             Box::new(JsonEmitter::stderr(Some(registry), codemap.clone()))
 682         }
 683         (config::ErrorOutputType::Json, Some(dst)) => {
 684             Box::new(JsonEmitter::new(dst, Some(registry), codemap.clone()))
 685         }
 686     };
 687
 688     let diagnostic_handler =
 689         errors::Handler::with_emitter(can_print_warnings,
 690                                       treat_err_as_bug,
 691                                       emitter);
 692
 693     build_session_(sopts,
 694                    local_crate_source_file,
 695                    diagnostic_handler,
 696                    codemap)
 697 }
 698
 699 pub fn build_session_(sopts: config::Options,
 700                       local_crate_source_file: Option<PathBuf>,
 701                       span_diagnostic: errors::Handler,
 702                       codemap: Rc<codemap::CodeMap>)
 703                       -> Session {
 704     let host = match Target::search(config::host_triple()) {
 705         Ok(t) => t,
 706         Err(e) => {
 707             panic!(span_diagnostic.fatal(&format!("Error loading host specification: {}", e)));
 708         }
 709     };
 710     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 711
 712     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
 713     let default_sysroot = match sopts.maybe_sysroot {
 714         Some(_) => None,
 715         None => Some(filesearch::get_or_default_sysroot())
 716     };
 717
 718     let file_path_mapping = sopts.file_path_mapping();
 719
 720     // Make the path absolute, if necessary
 721     let local_crate_source_file = local_crate_source_file.map(|path| {
 722         file_path_mapping.map_prefix(path.to_string_lossy().into_owned()).0
 723     });
 724
 725     let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
 726     let optimization_fuel_limit = Cell::new(sopts.debugging_opts.fuel.as_ref()
 727         .map(|i| i.1).unwrap_or(0));
 728     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
 729     let print_fuel = Cell::new(0);
 730
 731     let working_dir = env::current_dir().unwrap().to_string_lossy().into_owned();
 732     let working_dir = file_path_mapping.map_prefix(working_dir);
 733
 734     let sess = Session {
 735         target: target_cfg,
 736         host,
 737         opts: sopts,
 738         parse_sess: p_s,
 739         // For a library crate, this is always none
 740         entry_fn: RefCell::new(None),
 741         entry_type: Cell::new(None),
 742         plugin_registrar_fn: Cell::new(None),
 743         derive_registrar_fn: Cell::new(None),
 744         default_sysroot,
 745         local_crate_source_file,
 746         working_dir,
 747         lint_store: RefCell::new(lint::LintStore::new()),
 748         buffered_lints: RefCell::new(Some(lint::LintBuffer::new())),
 749         one_time_diagnostics: RefCell::new(FxHashSet()),
 750         plugin_llvm_passes: RefCell::new(Vec::new()),
 751         plugin_attributes: RefCell::new(Vec::new()),
 752         crate_types: RefCell::new(Vec::new()),
 753         dependency_formats: RefCell::new(FxHashMap()),
 754         crate_disambiguator: RefCell::new(None),
 755         features: RefCell::new(feature_gate::Features::new()),
 756         recursion_limit: Cell::new(64),
 757         type_length_limit: Cell::new(1048576),
 758         next_node_id: Cell::new(NodeId::new(1)),
 759         injected_allocator: Cell::new(None),
 760         allocator_kind: Cell::new(None),
 761         injected_panic_runtime: Cell::new(None),
 762         imported_macro_spans: RefCell::new(HashMap::new()),
 763         incr_comp_session: RefCell::new(IncrCompSession::NotInitialized),
 764         perf_stats: PerfStats {
 765             svh_time: Cell::new(Duration::from_secs(0)),
 766             incr_comp_hashes_time: Cell::new(Duration::from_secs(0)),
 767             incr_comp_hashes_count: Cell::new(0),
 768             incr_comp_bytes_hashed: Cell::new(0),
 769             symbol_hash_time: Cell::new(Duration::from_secs(0)),
 770             decode_def_path_tables_time: Cell::new(Duration::from_secs(0)),
 771         },
 772         code_stats: RefCell::new(CodeStats::new()),
 773         optimization_fuel_crate,
 774         optimization_fuel_limit,
 775         print_fuel_crate,
 776         print_fuel,
 777         out_of_fuel: Cell::new(false),
 778         // Note that this is unsafe because it may misinterpret file descriptors
 779         // on Unix as jobserver file descriptors. We hopefully execute this near
 780         // the beginning of the process though to ensure we don't get false
 781         // positives, or in other words we try to execute this before we open
 782         // any file descriptors ourselves.
 783         //
 784         // Also note that we stick this in a global because there could be
 785         // multiple `Session` instances in this process, and the jobserver is
 786         // per-process.
 787         jobserver_from_env: unsafe {
 788             static mut GLOBAL_JOBSERVER: *mut Option<Client> = 0 as *mut _;
 789             static INIT: Once = ONCE_INIT;
 790             INIT.call_once(|| {
 791                 GLOBAL_JOBSERVER = Box::into_raw(Box::new(Client::from_env()));
 792             });
 793             (*GLOBAL_JOBSERVER).clone()
 794         },
 795         has_global_allocator: Cell::new(false),
 796     };
 797
 798     sess
 799 }
 800
 801 /// Holds data on the current incremental compilation session, if there is one.
 802 #[derive(Debug)]
 803 pub enum IncrCompSession {
 804     // This is the state the session will be in until the incr. comp. dir is
 805     // needed.
 806     NotInitialized,
 807     // This is the state during which the session directory is private and can
 808     // be modified.
 809     Active {
 810         session_directory: PathBuf,
 811         lock_file: flock::Lock,
 812         load_dep_graph: bool,
 813     },
 814     // This is the state after the session directory has been finalized. In this
 815     // state, the contents of the directory must not be modified any more.
 816     Finalized {
 817         session_directory: PathBuf,
 818     },
 819     // This is an error state that is reached when some compilation error has
 820     // occurred. It indicates that the contents of the session directory must
 821     // not be used, since they might be invalid.
 822     InvalidBecauseOfErrors {
 823         session_directory: PathBuf,
 824     }
 825 }
 826
 827 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
 828     let emitter: Box<Emitter> = match output {
 829         config::ErrorOutputType::HumanReadable(color_config) => {
 830             Box::new(EmitterWriter::stderr(color_config,
 831                                            None))
 832         }
 833         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 834     };
 835     let handler = errors::Handler::with_emitter(true, false, emitter);
 836     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
 837     panic!(errors::FatalError);
 838 }
 839
 840 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
 841     let emitter: Box<Emitter> = match output {
 842         config::ErrorOutputType::HumanReadable(color_config) => {
 843             Box::new(EmitterWriter::stderr(color_config,
 844                                            None))
 845         }
 846         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 847     };
 848     let handler = errors::Handler::with_emitter(true, false, emitter);
 849     handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
 850 }
 851
 852 #[derive(Copy, Clone, Debug)]
 853 pub enum CompileIncomplete {
 854     Stopped,
 855     Errored(ErrorReported)
 856 }
 857 impl From<ErrorReported> for CompileIncomplete {
 858     fn from(err: ErrorReported) -> CompileIncomplete {
 859         CompileIncomplete::Errored(err)
 860     }
 861 }
 862 pub type CompileResult = Result<(), CompileIncomplete>;
 863
 864 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
 865     if err_count == 0 {
 866         Ok(())
 867     } else {
 868         Err(CompileIncomplete::Errored(ErrorReported))
 869     }
 870 }
 871
 872 #[cold]
 873 #[inline(never)]
 874 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
 875     // this wrapper mostly exists so I don't have to write a fully
 876     // qualified path of None::<Span> inside the bug!() macro definition
 877     opt_span_bug_fmt(file, line, None::<Span>, args);
 878 }
 879
 880 #[cold]
 881 #[inline(never)]
 882 pub fn span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 883                                         line: u32,
 884                                         span: S,
 885                                         args: fmt::Arguments) -> ! {
 886     opt_span_bug_fmt(file, line, Some(span), args);
 887 }
 888
 889 fn opt_span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 890                                         line: u32,
 891                                         span: Option<S>,
 892                                         args: fmt::Arguments) -> ! {
 893     tls::with_opt(move |tcx| {
 894         let msg = format!("{}:{}: {}", file, line, args);
 895         match (tcx, span) {
 896             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
 897             (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
 898             (None, _) => panic!(msg)
 899         }
 900     });
 901     unreachable!();
 902 }