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