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 use lint;
  17 use middle::cstore::CrateStore;
  18 use middle::dependency_format;
  19 use session::search_paths::PathKind;
  20 use session::config::DebugInfoLevel;
  21 use ty::tls;
  22 use util::nodemap::{FxHashMap, FxHashSet};
  23 use util::common::duration_to_secs_str;
  24 use mir::transform as mir_pass;
  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 llvm;
  42
  43 use std::path::{Path, PathBuf};
  44 use std::cell::{self, Cell, RefCell};
  45 use std::collections::HashMap;
  46 use std::env;
  47 use std::ffi::CString;
  48 use std::io::Write;
  49 use std::rc::Rc;
  50 use std::fmt;
  51 use std::time::Duration;
  52 use libc::c_int;
  53
  54 mod code_stats;
  55 pub mod config;
  56 pub mod filesearch;
  57 pub mod search_paths;
  58
  59 // Represents the data associated with a compilation
  60 // session for a single crate.
  61 pub struct Session {
  62     pub dep_graph: DepGraph,
  63     pub target: config::Config,
  64     pub host: Target,
  65     pub opts: config::Options,
  66     pub cstore: Rc<CrateStore>,
  67     pub parse_sess: ParseSess,
  68     // For a library crate, this is always none
  69     pub entry_fn: RefCell<Option<(NodeId, Span)>>,
  70     pub entry_type: Cell<Option<config::EntryFnType>>,
  71     pub plugin_registrar_fn: Cell<Option<ast::NodeId>>,
  72     pub derive_registrar_fn: Cell<Option<ast::NodeId>>,
  73     pub default_sysroot: Option<PathBuf>,
  74     // The name of the root source file of the crate, in the local file system.
  75     // The path is always expected to be absolute. `None` means that there is no
  76     // source file.
  77     pub local_crate_source_file: Option<PathBuf>,
  78     pub working_dir: PathBuf,
  79     pub lint_store: RefCell<lint::LintStore>,
  80     pub lints: RefCell<lint::LintTable>,
  81     /// Set of (LintId, span, message) tuples tracking lint (sub)diagnostics
  82     /// that have been set once, but should not be set again, in order to avoid
  83     /// redundantly verbose output (Issue #24690).
  84     pub one_time_diagnostics: RefCell<FxHashSet<(lint::LintId, Span, String)>>,
  85     pub plugin_llvm_passes: RefCell<Vec<String>>,
  86     pub mir_passes: RefCell<mir_pass::Passes>,
  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
 141 pub struct PerfStats {
 142     // The accumulated time needed for computing the SVH of the crate
 143     pub svh_time: Cell<Duration>,
 144     // The accumulated time spent on computing incr. comp. hashes
 145     pub incr_comp_hashes_time: Cell<Duration>,
 146     // The number of incr. comp. hash computations performed
 147     pub incr_comp_hashes_count: Cell<u64>,
 148     // The number of bytes hashed when computing ICH values
 149     pub incr_comp_bytes_hashed: Cell<u64>,
 150     // The accumulated time spent on computing symbol hashes
 151     pub symbol_hash_time: Cell<Duration>,
 152     // The accumulated time spent decoding def path tables from metadata
 153     pub decode_def_path_tables_time: Cell<Duration>,
 154 }
 155
 156 impl Session {
 157     pub fn local_crate_disambiguator(&self) -> Symbol {
 158         *self.crate_disambiguator.borrow()
 159     }
 160     pub fn struct_span_warn<'a, S: Into<MultiSpan>>(&'a self,
 161                                                     sp: S,
 162                                                     msg: &str)
 163                                                     -> DiagnosticBuilder<'a>  {
 164         self.diagnostic().struct_span_warn(sp, msg)
 165     }
 166     pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(&'a self,
 167                                                               sp: S,
 168                                                               msg: &str,
 169                                                               code: &str)
 170                                                               -> DiagnosticBuilder<'a>  {
 171         self.diagnostic().struct_span_warn_with_code(sp, msg, code)
 172     }
 173     pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 174         self.diagnostic().struct_warn(msg)
 175     }
 176     pub fn struct_span_err<'a, S: Into<MultiSpan>>(&'a self,
 177                                                    sp: S,
 178                                                    msg: &str)
 179                                                    -> DiagnosticBuilder<'a>  {
 180         self.diagnostic().struct_span_err(sp, msg)
 181     }
 182     pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(&'a self,
 183                                                              sp: S,
 184                                                              msg: &str,
 185                                                              code: &str)
 186                                                              -> DiagnosticBuilder<'a>  {
 187         self.diagnostic().struct_span_err_with_code(sp, msg, code)
 188     }
 189     pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 190         self.diagnostic().struct_err(msg)
 191     }
 192     pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(&'a self,
 193                                                      sp: S,
 194                                                      msg: &str)
 195                                                      -> DiagnosticBuilder<'a>  {
 196         self.diagnostic().struct_span_fatal(sp, msg)
 197     }
 198     pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(&'a self,
 199                                                                sp: S,
 200                                                                msg: &str,
 201                                                                code: &str)
 202                                                                -> DiagnosticBuilder<'a>  {
 203         self.diagnostic().struct_span_fatal_with_code(sp, msg, code)
 204     }
 205     pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a>  {
 206         self.diagnostic().struct_fatal(msg)
 207     }
 208
 209     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 210         panic!(self.diagnostic().span_fatal(sp, msg))
 211     }
 212     pub fn span_fatal_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) -> ! {
 213         panic!(self.diagnostic().span_fatal_with_code(sp, msg, code))
 214     }
 215     pub fn fatal(&self, msg: &str) -> ! {
 216         panic!(self.diagnostic().fatal(msg))
 217     }
 218     pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
 219         if is_warning {
 220             self.span_warn(sp, msg);
 221         } else {
 222             self.span_err(sp, msg);
 223         }
 224     }
 225     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 226         self.diagnostic().span_err(sp, msg)
 227     }
 228     pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 229         self.diagnostic().span_err_with_code(sp, &msg, code)
 230     }
 231     pub fn err(&self, msg: &str) {
 232         self.diagnostic().err(msg)
 233     }
 234     pub fn err_count(&self) -> usize {
 235         self.diagnostic().err_count()
 236     }
 237     pub fn has_errors(&self) -> bool {
 238         self.diagnostic().has_errors()
 239     }
 240     pub fn abort_if_errors(&self) {
 241         self.diagnostic().abort_if_errors();
 242     }
 243     pub fn track_errors<F, T>(&self, f: F) -> Result<T, usize>
 244         where F: FnOnce() -> T
 245     {
 246         let old_count = self.err_count();
 247         let result = f();
 248         let errors = self.err_count() - old_count;
 249         if errors == 0 {
 250             Ok(result)
 251         } else {
 252             Err(errors)
 253         }
 254     }
 255     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 256         self.diagnostic().span_warn(sp, msg)
 257     }
 258     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: &str) {
 259         self.diagnostic().span_warn_with_code(sp, msg, code)
 260     }
 261     pub fn warn(&self, msg: &str) {
 262         self.diagnostic().warn(msg)
 263     }
 264     pub fn opt_span_warn<S: Into<MultiSpan>>(&self, opt_sp: Option<S>, msg: &str) {
 265         match opt_sp {
 266             Some(sp) => self.span_warn(sp, msg),
 267             None => self.warn(msg),
 268         }
 269     }
 270     /// Delay a span_bug() call until abort_if_errors()
 271     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 272         self.diagnostic().delay_span_bug(sp, msg)
 273     }
 274     pub fn note_without_error(&self, msg: &str) {
 275         self.diagnostic().note_without_error(msg)
 276     }
 277     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
 278         self.diagnostic().span_note_without_error(sp, msg)
 279     }
 280     pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
 281         self.diagnostic().span_unimpl(sp, msg)
 282     }
 283     pub fn unimpl(&self, msg: &str) -> ! {
 284         self.diagnostic().unimpl(msg)
 285     }
 286
 287     pub fn add_lint<S: Into<MultiSpan>>(&self,
 288                                         lint: &'static lint::Lint,
 289                                         id: ast::NodeId,
 290                                         sp: S,
 291                                         msg: String)
 292     {
 293         self.lints.borrow_mut().add_lint(lint, id, sp, msg);
 294     }
 295
 296     pub fn add_lint_diagnostic<M>(&self,
 297                                   lint: &'static lint::Lint,
 298                                   id: ast::NodeId,
 299                                   msg: M)
 300         where M: lint::IntoEarlyLint,
 301     {
 302         self.lints.borrow_mut().add_lint_diagnostic(lint, id, msg);
 303     }
 304
 305     pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
 306         let id = self.next_node_id.get();
 307
 308         match id.as_usize().checked_add(count) {
 309             Some(next) => {
 310                 self.next_node_id.set(ast::NodeId::new(next));
 311             }
 312             None => bug!("Input too large, ran out of node ids!")
 313         }
 314
 315         id
 316     }
 317     pub fn next_node_id(&self) -> NodeId {
 318         self.reserve_node_ids(1)
 319     }
 320     pub fn diagnostic<'a>(&'a self) -> &'a errors::Handler {
 321         &self.parse_sess.span_diagnostic
 322     }
 323
 324     /// Analogous to calling `.span_note` on the given DiagnosticBuilder, but
 325     /// deduplicates on lint ID, span, and message for this `Session` if we're
 326     /// not outputting in JSON mode.
 327     //
 328     // FIXME: if the need arises for one-time diagnostics other than
 329     // `span_note`, we almost certainly want to generalize this
 330     // "check/insert-into the one-time diagnostics map, then set message if
 331     // it's not already there" code to accomodate all of them
 332     pub fn diag_span_note_once<'a, 'b>(&'a self,
 333                                        diag_builder: &'b mut DiagnosticBuilder<'a>,
 334                                        lint: &'static lint::Lint, span: Span, message: &str) {
 335         match self.opts.error_format {
 336             // when outputting JSON for tool consumption, the tool might want
 337             // the duplicates
 338             config::ErrorOutputType::Json => {
 339                 diag_builder.span_note(span, &message);
 340             },
 341             _ => {
 342                 let lint_id = lint::LintId::of(lint);
 343                 let id_span_message = (lint_id, span, message.to_owned());
 344                 let fresh = self.one_time_diagnostics.borrow_mut().insert(id_span_message);
 345                 if fresh {
 346                     diag_builder.span_note(span, &message);
 347                 }
 348             }
 349         }
 350     }
 351
 352     pub fn codemap<'a>(&'a self) -> &'a codemap::CodeMap {
 353         self.parse_sess.codemap()
 354     }
 355     pub fn verbose(&self) -> bool { self.opts.debugging_opts.verbose }
 356     pub fn time_passes(&self) -> bool { self.opts.debugging_opts.time_passes }
 357     pub fn count_llvm_insns(&self) -> bool {
 358         self.opts.debugging_opts.count_llvm_insns
 359     }
 360     pub fn time_llvm_passes(&self) -> bool {
 361         self.opts.debugging_opts.time_llvm_passes
 362     }
 363     pub fn trans_stats(&self) -> bool { self.opts.debugging_opts.trans_stats }
 364     pub fn meta_stats(&self) -> bool { self.opts.debugging_opts.meta_stats }
 365     pub fn asm_comments(&self) -> bool { self.opts.debugging_opts.asm_comments }
 366     pub fn no_verify(&self) -> bool { self.opts.debugging_opts.no_verify }
 367     pub fn borrowck_stats(&self) -> bool { self.opts.debugging_opts.borrowck_stats }
 368     pub fn print_llvm_passes(&self) -> bool {
 369         self.opts.debugging_opts.print_llvm_passes
 370     }
 371     pub fn lto(&self) -> bool {
 372         self.opts.cg.lto
 373     }
 374     /// Returns the panic strategy for this compile session. If the user explicitly selected one
 375     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
 376     pub fn panic_strategy(&self) -> PanicStrategy {
 377         self.opts.cg.panic.unwrap_or(self.target.target.options.panic_strategy)
 378     }
 379     pub fn linker_flavor(&self) -> LinkerFlavor {
 380         self.opts.debugging_opts.linker_flavor.unwrap_or(self.target.target.linker_flavor)
 381     }
 382     pub fn no_landing_pads(&self) -> bool {
 383         self.opts.debugging_opts.no_landing_pads || self.panic_strategy() == PanicStrategy::Abort
 384     }
 385     pub fn unstable_options(&self) -> bool {
 386         self.opts.debugging_opts.unstable_options
 387     }
 388     pub fn nonzeroing_move_hints(&self) -> bool {
 389         self.opts.debugging_opts.enable_nonzeroing_move_hints
 390     }
 391     pub fn overflow_checks(&self) -> bool {
 392         self.opts.cg.overflow_checks
 393             .or(self.opts.debugging_opts.force_overflow_checks)
 394             .unwrap_or(self.opts.debug_assertions)
 395     }
 396
 397     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
 398         self.opts.debuginfo != DebugInfoLevel::NoDebugInfo ||
 399         !self.target.target.options.eliminate_frame_pointer
 400     }
 401
 402     /// Returns the symbol name for the registrar function,
 403     /// given the crate Svh and the function DefIndex.
 404     pub fn generate_plugin_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 405                                             -> String {
 406         format!("__rustc_plugin_registrar__{}_{}", disambiguator, index.as_usize())
 407     }
 408
 409     pub fn generate_derive_registrar_symbol(&self, disambiguator: Symbol, index: DefIndex)
 410                                             -> String {
 411         format!("__rustc_derive_registrar__{}_{}", disambiguator, index.as_usize())
 412     }
 413
 414     pub fn sysroot<'a>(&'a self) -> &'a Path {
 415         match self.opts.maybe_sysroot {
 416             Some (ref sysroot) => sysroot,
 417             None => self.default_sysroot.as_ref()
 418                         .expect("missing sysroot and default_sysroot in Session")
 419         }
 420     }
 421     pub fn target_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 422         filesearch::FileSearch::new(self.sysroot(),
 423                                     &self.opts.target_triple,
 424                                     &self.opts.search_paths,
 425                                     kind)
 426     }
 427     pub fn host_filesearch(&self, kind: PathKind) -> filesearch::FileSearch {
 428         filesearch::FileSearch::new(
 429             self.sysroot(),
 430             config::host_triple(),
 431             &self.opts.search_paths,
 432             kind)
 433     }
 434
 435     pub fn init_incr_comp_session(&self,
 436                                   session_dir: PathBuf,
 437                                   lock_file: flock::Lock) {
 438         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 439
 440         if let IncrCompSession::NotInitialized = *incr_comp_session { } else {
 441             bug!("Trying to initialize IncrCompSession `{:?}`", *incr_comp_session)
 442         }
 443
 444         *incr_comp_session = IncrCompSession::Active {
 445             session_directory: session_dir,
 446             lock_file: lock_file,
 447         };
 448     }
 449
 450     pub fn finalize_incr_comp_session(&self, new_directory_path: PathBuf) {
 451         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 452
 453         if let IncrCompSession::Active { .. } = *incr_comp_session { } else {
 454             bug!("Trying to finalize IncrCompSession `{:?}`", *incr_comp_session)
 455         }
 456
 457         // Note: This will also drop the lock file, thus unlocking the directory
 458         *incr_comp_session = IncrCompSession::Finalized {
 459             session_directory: new_directory_path,
 460         };
 461     }
 462
 463     pub fn mark_incr_comp_session_as_invalid(&self) {
 464         let mut incr_comp_session = self.incr_comp_session.borrow_mut();
 465
 466         let session_directory = match *incr_comp_session {
 467             IncrCompSession::Active { ref session_directory, .. } => {
 468                 session_directory.clone()
 469             }
 470             _ => bug!("Trying to invalidate IncrCompSession `{:?}`",
 471                       *incr_comp_session),
 472         };
 473
 474         // Note: This will also drop the lock file, thus unlocking the directory
 475         *incr_comp_session = IncrCompSession::InvalidBecauseOfErrors {
 476             session_directory: session_directory
 477         };
 478     }
 479
 480     pub fn incr_comp_session_dir(&self) -> cell::Ref<PathBuf> {
 481         let incr_comp_session = self.incr_comp_session.borrow();
 482         cell::Ref::map(incr_comp_session, |incr_comp_session| {
 483             match *incr_comp_session {
 484                 IncrCompSession::NotInitialized => {
 485                     bug!("Trying to get session directory from IncrCompSession `{:?}`",
 486                         *incr_comp_session)
 487                 }
 488                 IncrCompSession::Active { ref session_directory, .. } |
 489                 IncrCompSession::Finalized { ref session_directory } |
 490                 IncrCompSession::InvalidBecauseOfErrors { ref session_directory } => {
 491                     session_directory
 492                 }
 493             }
 494         })
 495     }
 496
 497     pub fn incr_comp_session_dir_opt(&self) -> Option<cell::Ref<PathBuf>> {
 498         if self.opts.incremental.is_some() {
 499             Some(self.incr_comp_session_dir())
 500         } else {
 501             None
 502         }
 503     }
 504
 505     pub fn print_perf_stats(&self) {
 506         println!("Total time spent computing SVHs:               {}",
 507                  duration_to_secs_str(self.perf_stats.svh_time.get()));
 508         println!("Total time spent computing incr. comp. hashes: {}",
 509                  duration_to_secs_str(self.perf_stats.incr_comp_hashes_time.get()));
 510         println!("Total number of incr. comp. hashes computed:   {}",
 511                  self.perf_stats.incr_comp_hashes_count.get());
 512         println!("Total number of bytes hashed for incr. comp.:  {}",
 513                  self.perf_stats.incr_comp_bytes_hashed.get());
 514         println!("Average bytes hashed per incr. comp. HIR node: {}",
 515                  self.perf_stats.incr_comp_bytes_hashed.get() /
 516                  self.perf_stats.incr_comp_hashes_count.get());
 517         println!("Total time spent computing symbol hashes:      {}",
 518                  duration_to_secs_str(self.perf_stats.symbol_hash_time.get()));
 519         println!("Total time spent decoding DefPath tables:      {}",
 520                  duration_to_secs_str(self.perf_stats.decode_def_path_tables_time.get()));
 521     }
 522
 523     /// We want to know if we're allowed to do an optimization for crate foo from -z fuel=foo=n.
 524     /// This expends fuel if applicable, and records fuel if applicable.
 525     pub fn consider_optimizing<T: Fn() -> String>(&self, crate_name: &str, msg: T) -> bool {
 526         let mut ret = true;
 527         match self.optimization_fuel_crate {
 528             Some(ref c) if c == crate_name => {
 529                 let fuel = self.optimization_fuel_limit.get();
 530                 ret = fuel != 0;
 531                 if fuel == 0 && !self.out_of_fuel.get() {
 532                     println!("optimization-fuel-exhausted: {}", msg());
 533                     self.out_of_fuel.set(true);
 534                 } else if fuel > 0 {
 535                     self.optimization_fuel_limit.set(fuel-1);
 536                 }
 537             }
 538             _ => {}
 539         }
 540         match self.print_fuel_crate {
 541             Some(ref c) if c == crate_name=> {
 542                 self.print_fuel.set(self.print_fuel.get()+1);
 543             },
 544             _ => {}
 545         }
 546         ret
 547     }
 548 }
 549
 550 pub fn build_session(sopts: config::Options,
 551                      dep_graph: &DepGraph,
 552                      local_crate_source_file: Option<PathBuf>,
 553                      registry: errors::registry::Registry,
 554                      cstore: Rc<CrateStore>)
 555                      -> Session {
 556     build_session_with_codemap(sopts,
 557                                dep_graph,
 558                                local_crate_source_file,
 559                                registry,
 560                                cstore,
 561                                Rc::new(codemap::CodeMap::new()),
 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     let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap);
 629     let default_sysroot = match sopts.maybe_sysroot {
 630         Some(_) => None,
 631         None => Some(filesearch::get_or_default_sysroot())
 632     };
 633
 634     // Make the path absolute, if necessary
 635     let local_crate_source_file = local_crate_source_file.map(|path|
 636         if path.is_absolute() {
 637             path.clone()
 638         } else {
 639             env::current_dir().unwrap().join(&path)
 640         }
 641     );
 642
 643     let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone());
 644     let optimization_fuel_limit = Cell::new(sopts.debugging_opts.fuel.as_ref()
 645         .map(|i| i.1).unwrap_or(0));
 646     let print_fuel_crate = sopts.debugging_opts.print_fuel.clone();
 647     let print_fuel = Cell::new(0);
 648
 649     let sess = Session {
 650         dep_graph: dep_graph.clone(),
 651         target: target_cfg,
 652         host: host,
 653         opts: sopts,
 654         cstore: cstore,
 655         parse_sess: p_s,
 656         // For a library crate, this is always none
 657         entry_fn: RefCell::new(None),
 658         entry_type: Cell::new(None),
 659         plugin_registrar_fn: Cell::new(None),
 660         derive_registrar_fn: Cell::new(None),
 661         default_sysroot: default_sysroot,
 662         local_crate_source_file: local_crate_source_file,
 663         working_dir: env::current_dir().unwrap(),
 664         lint_store: RefCell::new(lint::LintStore::new()),
 665         lints: RefCell::new(lint::LintTable::new()),
 666         one_time_diagnostics: RefCell::new(FxHashSet()),
 667         plugin_llvm_passes: RefCell::new(Vec::new()),
 668         mir_passes: RefCell::new(mir_pass::Passes::new()),
 669         plugin_attributes: RefCell::new(Vec::new()),
 670         crate_types: RefCell::new(Vec::new()),
 671         dependency_formats: RefCell::new(FxHashMap()),
 672         crate_disambiguator: RefCell::new(Symbol::intern("")),
 673         features: RefCell::new(feature_gate::Features::new()),
 674         recursion_limit: Cell::new(64),
 675         type_length_limit: Cell::new(1048576),
 676         next_node_id: Cell::new(NodeId::new(1)),
 677         injected_allocator: Cell::new(None),
 678         injected_panic_runtime: Cell::new(None),
 679         imported_macro_spans: RefCell::new(HashMap::new()),
 680         incr_comp_session: RefCell::new(IncrCompSession::NotInitialized),
 681         perf_stats: PerfStats {
 682             svh_time: Cell::new(Duration::from_secs(0)),
 683             incr_comp_hashes_time: Cell::new(Duration::from_secs(0)),
 684             incr_comp_hashes_count: Cell::new(0),
 685             incr_comp_bytes_hashed: Cell::new(0),
 686             symbol_hash_time: Cell::new(Duration::from_secs(0)),
 687             decode_def_path_tables_time: Cell::new(Duration::from_secs(0)),
 688         },
 689         code_stats: RefCell::new(CodeStats::new()),
 690         optimization_fuel_crate: optimization_fuel_crate,
 691         optimization_fuel_limit: optimization_fuel_limit,
 692         print_fuel_crate: print_fuel_crate,
 693         print_fuel: print_fuel,
 694         out_of_fuel: Cell::new(false),
 695     };
 696
 697     init_llvm(&sess);
 698
 699     sess
 700 }
 701
 702 /// Holds data on the current incremental compilation session, if there is one.
 703 #[derive(Debug)]
 704 pub enum IncrCompSession {
 705     // This is the state the session will be in until the incr. comp. dir is
 706     // needed.
 707     NotInitialized,
 708     // This is the state during which the session directory is private and can
 709     // be modified.
 710     Active {
 711         session_directory: PathBuf,
 712         lock_file: flock::Lock,
 713     },
 714     // This is the state after the session directory has been finalized. In this
 715     // state, the contents of the directory must not be modified any more.
 716     Finalized {
 717         session_directory: PathBuf,
 718     },
 719     // This is an error state that is reached when some compilation error has
 720     // occurred. It indicates that the contents of the session directory must
 721     // not be used, since they might be invalid.
 722     InvalidBecauseOfErrors {
 723         session_directory: PathBuf,
 724     }
 725 }
 726
 727 fn init_llvm(sess: &Session) {
 728     unsafe {
 729         // Before we touch LLVM, make sure that multithreading is enabled.
 730         use std::sync::Once;
 731         static INIT: Once = Once::new();
 732         static mut POISONED: bool = false;
 733         INIT.call_once(|| {
 734             if llvm::LLVMStartMultithreaded() != 1 {
 735                 // use an extra bool to make sure that all future usage of LLVM
 736                 // cannot proceed despite the Once not running more than once.
 737                 POISONED = true;
 738             }
 739
 740             configure_llvm(sess);
 741         });
 742
 743         if POISONED {
 744             bug!("couldn't enable multi-threaded LLVM");
 745         }
 746     }
 747 }
 748
 749 unsafe fn configure_llvm(sess: &Session) {
 750     let mut llvm_c_strs = Vec::new();
 751     let mut llvm_args = Vec::new();
 752
 753     {
 754         let mut add = |arg: &str| {
 755             let s = CString::new(arg).unwrap();
 756             llvm_args.push(s.as_ptr());
 757             llvm_c_strs.push(s);
 758         };
 759         add("rustc"); // fake program name
 760         if sess.time_llvm_passes() { add("-time-passes"); }
 761         if sess.print_llvm_passes() { add("-debug-pass=Structure"); }
 762
 763         for arg in &sess.opts.cg.llvm_args {
 764             add(&(*arg));
 765         }
 766     }
 767
 768     llvm::LLVMInitializePasses();
 769
 770     llvm::initialize_available_targets();
 771
 772     llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int,
 773                                  llvm_args.as_ptr());
 774 }
 775
 776 pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
 777     let emitter: Box<Emitter> = match output {
 778         config::ErrorOutputType::HumanReadable(color_config) => {
 779             Box::new(EmitterWriter::stderr(color_config,
 780                                            None))
 781         }
 782         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 783     };
 784     let handler = errors::Handler::with_emitter(true, false, emitter);
 785     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
 786     panic!(errors::FatalError);
 787 }
 788
 789 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
 790     let emitter: Box<Emitter> = match output {
 791         config::ErrorOutputType::HumanReadable(color_config) => {
 792             Box::new(EmitterWriter::stderr(color_config,
 793                                            None))
 794         }
 795         config::ErrorOutputType::Json => Box::new(JsonEmitter::basic()),
 796     };
 797     let handler = errors::Handler::with_emitter(true, false, emitter);
 798     handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
 799 }
 800
 801 // Err(0) means compilation was stopped, but no errors were found.
 802 // This would be better as a dedicated enum, but using try! is so convenient.
 803 pub type CompileResult = Result<(), usize>;
 804
 805 pub fn compile_result_from_err_count(err_count: usize) -> CompileResult {
 806     if err_count == 0 {
 807         Ok(())
 808     } else {
 809         Err(err_count)
 810     }
 811 }
 812
 813 #[cold]
 814 #[inline(never)]
 815 pub fn bug_fmt(file: &'static str, line: u32, args: fmt::Arguments) -> ! {
 816     // this wrapper mostly exists so I don't have to write a fully
 817     // qualified path of None::<Span> inside the bug!() macro defintion
 818     opt_span_bug_fmt(file, line, None::<Span>, args);
 819 }
 820
 821 #[cold]
 822 #[inline(never)]
 823 pub fn span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 824                                         line: u32,
 825                                         span: S,
 826                                         args: fmt::Arguments) -> ! {
 827     opt_span_bug_fmt(file, line, Some(span), args);
 828 }
 829
 830 fn opt_span_bug_fmt<S: Into<MultiSpan>>(file: &'static str,
 831                                         line: u32,
 832                                         span: Option<S>,
 833                                         args: fmt::Arguments) -> ! {
 834     tls::with_opt(move |tcx| {
 835         let msg = format!("{}:{}: {}", file, line, args);
 836         match (tcx, span) {
 837             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
 838             (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
 839             (None, _) => panic!(msg)
 840         }
 841     });
 842     unreachable!();
 843 }