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;
  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 track_errors<F, T>(&self, f: F) -> Result<T, usize>
 259         where F: FnOnce() -> T
 260     {
 261         let old_count = self.err_count();
 262         let result = f();
 263         let errors = self.err_count() - old_count;
 264         if errors == 0 {
 265             Ok(result)
 266         } else {
 267             Err(errors)
 268         }
 269     }
 270     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 271         self.diagnostic().span_warn(sp, msg)
 272     }
 273     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 274         self.diagnostic().span_warn_with_code(sp, msg, code)
 275     }
 276     pub fn warn(&self, msg: &str) {
 277         self.diagnostic().warn(msg)
 278     }
 279     pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
 280         match opt_sp {
 281             Some(sp) => self.span_warn(sp, msg),
 282             None => self.warn(msg),
 283         }
 284     }
 285     /// Delay a span_bug() call until abort_if_errors()
 286     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 287         self.diagnostic().delay_span_bug(sp, msg)
 288     }
 289     pub fn note_without_error(&self, msg: &str) {
 290         self.diagnostic().note_without_error(msg)
 291     }
 292     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 293         self.diagnostic().span_note_without_error(sp, msg)
 294     }
 295     pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 296         self.diagnostic().span_unimpl(sp, msg)
 297     }
 298     pub fn unimpl(&self, msg: &str) -> ! {
 299         self.diagnostic().unimpl(msg)
 300     }
 301
 302     pub fn add_lint<S: Into<MultiSpan>>(&self,
 303                                         lint: &'static lint::Lint,
 304                                         id: ast::NodeId,
 305                                         sp: S,
 306                                         msg: String)
 307     {
 308         self.lints.borrow_mut().add_lint(lint, id, sp, msg);
 309     }
 310
 311     pub fn add_lint_diagnostic<M>(&self,
 312                                   lint: &'static lint::Lint,
 313                                   id: ast::NodeId,
 314                                   msg: M)
 315         where M: lint::IntoEarlyLint,
 316     {
 317         self.lints.borrow_mut().add_lint_diagnostic(lint, id, msg);
 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 count_llvm_insns(&self) -> bool {
 392         self.opts.debugging_opts.count_llvm_insns
 393     }
 394     pub fn time_llvm_passes(&self) -> bool {
 395         self.opts.debugging_opts.time_llvm_passes
 396     }
 397     pub fn trans_stats(&self) -> bool { self.opts.debugging_opts.trans_stats }
 398     pub fn meta_stats(&self) -> bool { self.opts.debugging_opts.meta_stats }
 399     pub fn asm_comments(&self) -> bool { self.opts.debugging_opts.asm_comments }
 400     pub fn no_verify(&self) -> bool { self.opts.debugging_opts.no_verify }
 401     pub fn borrowck_stats(&self) -> bool { self.opts.debugging_opts.borrowck_stats }
 402     pub fn print_llvm_passes(&self) -> bool {
 403         self.opts.debugging_opts.print_llvm_passes
 404     }
 405     pub fn lto(&self) -> bool {
 406         self.opts.cg.lto
 407     }
 408     /// Returns the panic strategy for this compile session. If the user explicitly selected one
 409     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
 410     pub fn panic_strategy(&self) -> PanicStrategy {
 411         self.opts.cg.panic.unwrap_or(self.target.target.options.panic_strategy)
 412     }
 413     pub fn linker_flavor(&self) -> LinkerFlavor {
 414         self.opts.debugging_opts.linker_flavor.unwrap_or(self.target.target.linker_flavor)
 415     }
 416     pub fn no_landing_pads(&self) -> bool {
 417         self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
 418     }
 419     pub fn unstable_options(&self) -> bool {
 420         self.opts.debugging_opts.unstable_options
 421     }
 422     pub fn nonzeroing_move_hints(&self) -> bool {
 423         self.opts.debugging_opts.enable_nonzeroing_move_hints
 424     }
 425     pub fn overflow_checks(&self) -> bool {
 426         self.opts.cg.overflow_checks
 427             .or(self.opts.debugging_opts.force_overflow_checks)
 428             .unwrap_or(self.opts.debug_assertions)
 429     }
 430
 431     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
 432         self.opts.debuginfo != DebugInfoLevel::NoDebugInfo ||
 433         !self.target.target.options.eliminate_frame_pointer
 434     }
 435
 436     /// Returns the symbol name for the registrar function,
 437     /// given the crate Svh and the function DefIndex.
 438     pub fn generate_plugin_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 439                                             -> String {
 440         format!("__rustc_plugin_registrar__{}_{}", disambiguator, index.as_usize())
 441     }
 442
 443     pub fn generate_derive_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 444                                             -> String {
 445         format!("__rustc_derive_registrar__{}_{}", disambiguator, index.as_usize())
 446     }
 447
 448     pub fn sysroot<'a>(&'a self) -> &'a Path {
 449         match self.opts.maybe_sysroot {
 450             Some (ref sysroot) => sysroot,
 451             None => self.default_sysroot.as_ref()
 452                         .expect("missing sysroot and default_sysroot in Session")
 453         }
 454     }
 455     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 456         filesearch::FileSearch::new(self.sysroot(),
 457                                     &self.opts.target_triple,
 458                                     &self.opts.search_paths,
 459                                     kind)
 460     }
 461     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 462         filesearch::FileSearch::new(
 463             self.sysroot(),
 464             config::host_triple(),
 465             &self.opts.search_paths,
 466             kind)
 467     }
 468
 469     pub fn init_incr_comp_session(&self,
 470                                   session_dir: PathBuf,
 471                                   lock_file: flock::Lock) {
 472         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 473
 474         if let IncrCompSession::NotInitialized = *incr_comp_session { } else {
 475             bug!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session)
 476         }
 477
 478         *incr_comp_session = IncrCompSession::Active {
 479             session_directory: session_dir,
 480             lock_file: lock_file,
 481         };
 482     }
 483
 484     pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
 485         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 486
 487         if let IncrCompSession::Active { .. } = *incr_comp_session { } else {
 488             bug!("Trying to finalize IncrCompSession `{:?}`", *incr_comp_session)
 489         }
 490
 491         // Note: This will also drop the lock file, thus unlocking the directory
 492         *incr_comp_session = IncrCompSession::Finalized {
 493             session_directory: new_directory_path,
 494         };
 495     }
 496
 497     pub fn mark_incr_comp_session_as_invalid(&self) {
 498         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 499
 500         let session_directory = match *incr_comp_session {
 501             IncrCompSession::Active { ref session_directory, .. } => {
 502                 session_directory.clone()
 503             }
 504             _ => bug!("Trying to invalidate IncrCompSession `{:?}`",
 505                       *incr_comp_session),
 506         };
 507
 508         // Note: This will also drop the lock file, thus unlocking the directory
 509         *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
 510             session_directory: session_directory
 511         };
 512     }
 513
 514     pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
 515         let incr_comp_session = self.incr_comp_session.borrow();
 516         cell::Ref::map(incr_comp_session, |incr_comp_session| {
 517             match *incr_comp_session {
 518                 IncrCompSession::NotInitialized => {
 519                     bug!("Trying to get session directory from IncrCompSession `{:?}`",
 520                         *incr_comp_session)
 521                 }
 522                 IncrCompSession::Active { ref session_directory, .. } |
 523                 IncrCompSession::Finalized { ref session_directory } |
 524                 IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => {
 525                     session_directory
 526                 }
 527             }
 528         })
 529     }
 530
 531     pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
 532         if self.opts.incremental.is_some() {
 533             Some(self.incr_comp_session_dir())
 534         } else {
 535             None
 536         }
 537     }
 538
 539     pub fn print_perf_stats(&self) {
 540         println!("Total time spent computing SVHs:               {}",
 541                  duration_to_secs_str(self.perf_stats.svh_time.get()));
 542         println!("Total time spent computing incr. comp. hashes: {}",
 543                  duration_to_secs_str(self.perf_stats.incr_comp_hashes_time.get()));
 544         println!("Total number of incr. comp. hashes computed:   {}",
 545                  self.perf_stats.incr_comp_hashes_count.get());
 546         println!("Total number of bytes hashed for incr. comp.:  {}",
 547                  self.perf_stats.incr_comp_bytes_hashed.get());
 548         println!("Average bytes hashed per incr. comp. HIR node: {}",
 549                  self.perf_stats.incr_comp_bytes_hashed.get() /
 550                  self.perf_stats.incr_comp_hashes_count.get());
 551         println!("Total time spent computing symbol hashes:      {}",
 552                  duration_to_secs_str(self.perf_stats.symbol_hash_time.get()));
 553         println!("Total time spent decoding DefPath tables:      {}",
 554                  duration_to_secs_str(self.perf_stats.decode_def_path_tables_time.get()));
 555     }
 556
 557     /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
 558     /// This expends fuel if applicable, and records fuel if applicable.
 559     pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
 560         let mut ret = true;
 561         match self.optimization_fuel_crate {
 562             Some(ref c) if c == crate_name => {
 563                 let fuel = self.optimization_fuel_limit.get();
 564                 ret = fuel != 0;
 565                 if fuel == 0 && !self.out_of_fuel.get() {
 566                     println!("optimization-fuel-exhausted: {}", msg());
 567                     self.out_of_fuel.set(true);
 568                 } else if fuel > 0 {
 569                     self.optimization_fuel_limit.set(fuel-1);
 570                 }
 571             }
 572             _ => {}
 573         }
 574         match self.print_fuel_crate {
 575             Some(ref c) if c == crate_name=> {
 576                 self.print_fuel.set(self.print_fuel.get()+1);
 577             },
 578             _ => {}
 579         }
 580         ret
 581     }
 582 }
 583
 584 pub fn build_session(sopts: config::Options,
 585                      dep_graph: &DepGraph,
 586                      local_crate_source_file: Option<PathBuf>,
 587                      registry: errors::registry::Registry,
 588                      cstore: Rc<CrateStore>)
 589                      -> Session {
 590     let file_path_mapping = sopts.file_path_mapping();
 591
 592     build_session_with_codemap(sopts,
 593                                dep_graph,
 594                                local_crate_source_file,
 595                                registry,
 596                                cstore,
 597                                Rc::new(codemap::CodeMap::new(file_path_mapping)),
 598                                None)
 599 }
 600
 601 pub fn build_session_with_codemap(sopts: config::Options,
 602                                   dep_graph: &DepGraph,
 603                                   local_crate_source_file: Option<PathBuf>,
 604                                   registry: errors::registry::Registry,
 605                                   cstore: Rc<CrateStore>,
 606                                   codemap: Rc<codemap::CodeMap>,
 607                                   emitter_dest: Option<Box<Write + Send>>)
 608                                   -> Session {
 609     // FIXME: This is not general enough to make the warning lint completely override
 610     // normal diagnostic warnings, since the warning lint can also be denied and changed
 611     // later via the source code.
 612     let can_print_warnings = sopts.lint_opts
 613         .iter()
 614         .filter(|&&(ref key, _)| *key == "warnings")
 615         .map(|&(_, ref level)| *level != lint::Allow)
 616         .last()
 617         .unwrap_or(true);
 618     let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
 619
 620     let emitter: Box<Emitter> = match (sopts.error_format, emitter_dest) {
 621         (config::ErrorOutputType::HumanReadable(color_config), None) => {
 622             Box::new(EmitterWriter::stderr(color_config,
 623                                            Some(codemap.clone())))
 624         }
 625         (config::ErrorOutputType::HumanReadable(_), Some(dst)) => {
 626             Box::new(EmitterWriter::new(dst,
 627                                         Some(codemap.clone())))
 628         }
 629         (config::ErrorOutputType::Json, None) => {
 630             Box::new(JsonEmitter::stderr(Some(registry), codemap.clone()))
 631         }
 632         (config::ErrorOutputType::Json, Some(dst)) => {
 633             Box::new(JsonEmitter::new(dst, Some(registry), codemap.clone()))
 634         }
 635     };
 636
 637     let diagnostic_handler =
 638         errors::Handler::with_emitter(can_print_warnings,
 639                                       treat_err_as_bug,
 640                                       emitter);
 641
 642     build_session_(sopts,
 643                    dep_graph,
 644                    local_crate_source_file,
 645                    diagnostic_handler,
 646                    codemap,
 647                    cstore)
 648 }
 649
 650 pub fn build_session_(sopts: config::Options,
 651                       dep_graph: &DepGraph,
 652                       local_crate_source_file: Option<PathBuf>,
 653                       span_diagnostic: errors::Handler,
 654                       codemap: Rc<codemap::CodeMap>,
 655                       cstore: Rc<CrateStore>)
 656                       -> Session {
 657     let host = match Target::search(config::host_triple()) {
 658         Ok(t) => t,
 659         Err(e) => {
 660             panic!(span_diagnostic.fatal(&format!("Error loading host specification: {}", e)));
 661         }
 662     };
 663     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
 664
 665     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
 666     let default_sysroot = match sopts.maybe_sysroot {
 667         Some(_) => None,
 668         None => Some(filesearch::get_or_default_sysroot())
 669     };
 670
 671     let file_path_mapping = sopts.file_path_mapping();
 672
 673     // Make the path absolute, if necessary
 674     let local_crate_source_file = local_crate_source_file.map(|path| {
 675         file_path_mapping.map_prefix(path.to_string_lossy().into_owned()).0
 676     });
 677
 678     let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
 679     let optimization_fuel_limit = Cell::new(sopts.debugging_opts.fuel.as_ref()
 680         .map(|i| i.1).unwrap_or(0));
 681     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
 682     let print_fuel = Cell::new(0);
 683
 684     let working_dir = env::current_dir().unwrap().to_string_lossy().into_owned();
 685     let working_dir = file_path_mapping.map_prefix(working_dir);
 686
 687     let sess = Session {
 688         dep_graph: dep_graph.clone(),
 689         target: target_cfg,
 690         host: host,
 691         opts: sopts,
 692         cstore: cstore,
 693         parse_sess: p_s,
 694         // For a library crate, this is always none
 695         entry_fn: RefCell::new(None),
 696         entry_type: Cell::new(None),
 697         plugin_registrar_fn: Cell::new(None),
 698         derive_registrar_fn: Cell::new(None),
 699         default_sysroot: default_sysroot,
 700         local_crate_source_file: local_crate_source_file,
 701         working_dir: working_dir,
 702         lint_store: RefCell::new(lint::LintStore::new()),
 703         lints: RefCell::new(lint::LintTable::new()),
 704         one_time_diagnostics: RefCell::new(FxHashSet()),
 705         plugin_llvm_passes: RefCell::new(Vec::new()),
 706         plugin_attributes: RefCell::new(Vec::new()),
 707         crate_types: RefCell::new(Vec::new()),
 708         dependency_formats: RefCell::new(FxHashMap()),
 709         crate_disambiguator: RefCell::new(Symbol::intern("")),
 710         features: RefCell::new(feature_gate::Features::new()),
 711         recursion_limit: Cell::new(64),
 712         type_length_limit: Cell::new(1048576),
 713         next_node_id: Cell::new(NodeId::new(1)),
 714         injected_allocator: Cell::new(None),
 715         injected_panic_runtime: Cell::new(None),
 716         imported_macro_spans: RefCell::new(HashMap::new()),
 717         incr_comp_session: RefCell::new(IncrCompSession::NotInitialized),
 718         perf_stats: PerfStats {
 719             svh_time: Cell::new(Duration::from_secs(0)),
 720             incr_comp_hashes_time: Cell::new(Duration::from_secs(0)),
 721             incr_comp_hashes_count: Cell::new(0),
 722             incr_comp_bytes_hashed: Cell::new(0),
 723             symbol_hash_time: Cell::new(Duration::from_secs(0)),
 724             decode_def_path_tables_time: Cell::new(Duration::from_secs(0)),
 725         },
 726         code_stats: RefCell::new(CodeStats::new()),
 727         optimization_fuel_crate: optimization_fuel_crate,
 728         optimization_fuel_limit: optimization_fuel_limit,
 729         print_fuel_crate: print_fuel_crate,
 730         print_fuel: print_fuel,
 731         out_of_fuel: Cell::new(false),
 732
 733         // Note that this is unsafe because it may misinterpret file descriptors
 734         // on Unix as jobserver file descriptors. We hopefully execute this near
 735         // the beginning of the process though to ensure we don't get false
 736         // positives, or in other words we try to execute this before we open
 737         // any file descriptors ourselves.
 738         //
 739         // Also note that we stick this in a global because there could be
 740         // multiple `Session` instances in this process, and the jobserver is
 741         // per-process.
 742         jobserver_from_env: unsafe {
 743             static mut GLOBAL_JOBSERVER: *mut Option<Client> = 0 as *mut _;
 744             static INIT: Once = ONCE_INIT;
 745             INIT.call_once(|| {
 746                 GLOBAL_JOBSERVER = Box::into_raw(Box::new(Client::from_env()));
 747             });
 748             (*GLOBAL_JOBSERVER).clone()
 749         },
 750     };
 751
 752     sess
 753 }
 754
 755 /// Holds data on the current incremental compilation session, if there is one.
 756 #[derive(Debug)]
 757 pub enum IncrCompSession {
 758     // This is the state the session will be in until the incr. comp. dir is
 759     // needed.
 760     NotInitialized,
 761     // This is the state during which the session directory is private and can
 762     // be modified.
 763     Active {
 764         session_directory: PathBuf,
 765         lock_file: flock::Lock,
 766     },
 767     // This is the state after the session directory has been finalized. In this
 768     // state, the contents of the directory must not be modified any more.
 769     Finalized {
 770         session_directory: PathBuf,
 771     },
 772     // This is an error state that is reached when some compilation error has
 773     // occurred. It indicates that the contents of the session directory must
 774     // not be used, since they might be invalid.
 775     InvalidBecauseOfErrors {
 776         session_directory: PathBuf,
 777     }
 778 }
 779
 780 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
 781     let emitter: Box<Emitter> = match output {
 782         config::ErrorOutputType::HumanReadable(color_config) => {
 783             Box::new(EmitterWriter::stderr(color_config,
 784                                            None))
 785         }
 786         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 787     };
 788     let handler = errors::Handler::with_emitter(true, false, emitter);
 789     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
 790     panic!(errors::FatalError);
 791 }
 792
 793 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
 794     let emitter: Box<Emitter> = match output {
 795         config::ErrorOutputType::HumanReadable(color_config) => {
 796             Box::new(EmitterWriter::stderr(color_config,
 797                                            None))
 798         }
 799         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 800     };
 801     let handler = errors::Handler::with_emitter(true, false, emitter);
 802     handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
 803 }
 804
 805 // Err(0) means compilation was stopped, but no errors were found.
 806 // This would be better as a dedicated enum, but using try! is so convenient.
 807 pub type CompileResult = Result<(), usize>;
 808
 809 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
 810     if err_count == 0 {
 811         Ok(())
 812     } else {
 813         Err(err_count)
 814     }
 815 }
 816
 817 #[cold]
 818 #[inline(never)]
 819 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
 820     // this wrapper mostly exists so I don't have to write a fully
 821     // qualified path of None::<Span> inside the bug!() macro defintion
 822     opt_span_bug_fmt(file, line, None::<Span>, args);
 823 }
 824
 825 #[cold]
 826 #[inline(never)]
 827 pub fn span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 828                                         line: u32,
 829                                         span: S,
 830                                         args: fmt::Arguments) -> ! {
 831     opt_span_bug_fmt(file, line, Some(span), args);
 832 }
 833
 834 fn opt_span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 835                                         line: u32,
 836                                         span: Option<S>,
 837                                         args: fmt::Arguments) -> ! {
 838     tls::with_opt(move |tcx| {
 839         let msg = format!("{}:{}: {}", file, line, args);
 840         match (tcx, span) {
 841             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
 842             (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
 843             (None, _) => panic!(msg)
 844         }
 845     });
 846     unreachable!();
 847 }