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