]> git.lizzy.rs Git - rust.git/blob - src/librustc_interface/passes.rs
Rollup merge of #67936 - euclio:assoc-type-bad-style, r=Centril
[rust.git] / src / librustc_interface / passes.rs
1 use crate::interface::{Compiler, Result};
2 use crate::proc_macro_decls;
3 use crate::util;
4
5 use log::{info, log_enabled, warn};
6 use rustc::arena::Arena;
7 use rustc::dep_graph::DepGraph;
8 use rustc::hir::map;
9 use rustc::lint;
10 use rustc::middle;
11 use rustc::middle::cstore::{CrateStore, MetadataLoader, MetadataLoaderDyn};
12 use rustc::session::config::{self, CrateType, Input, OutputFilenames, OutputType};
13 use rustc::session::config::{PpMode, PpSourceMode};
14 use rustc::session::search_paths::PathKind;
15 use rustc::session::Session;
16 use rustc::traits;
17 use rustc::ty::steal::Steal;
18 use rustc::ty::{self, AllArenas, GlobalCtxt, ResolverOutputs, TyCtxt};
19 use rustc::util::common::ErrorReported;
20 use rustc_builtin_macros;
21 use rustc_codegen_ssa::back::link::emit_metadata;
22 use rustc_codegen_utils::codegen_backend::CodegenBackend;
23 use rustc_codegen_utils::link::filename_for_metadata;
24 use rustc_data_structures::sync::{par_iter, Lrc, Once, ParallelIterator, WorkerLocal};
25 use rustc_data_structures::{box_region_allow_access, declare_box_region_type, parallel};
26 use rustc_errors::PResult;
27 use rustc_expand::base::ExtCtxt;
28 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
29 use rustc_incremental;
30 use rustc_mir as mir;
31 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str};
32 use rustc_passes::{self, ast_validation, hir_stats, layout_test};
33 use rustc_plugin_impl as plugin;
34 use rustc_privacy;
35 use rustc_resolve::{Resolver, ResolverArenas};
36 use rustc_span::symbol::Symbol;
37 use rustc_span::FileName;
38 use rustc_traits;
39 use rustc_typeck as typeck;
40 use syntax::early_buffered_lints::BufferedEarlyLint;
41 use syntax::mut_visit::MutVisitor;
42 use syntax::util::node_count::NodeCounter;
43 use syntax::{self, ast, visit};
44
45 use rustc_serialize::json;
46 use tempfile::Builder as TempFileBuilder;
47
48 use std::any::Any;
49 use std::cell::RefCell;
50 use std::ffi::OsString;
51 use std::io::{self, Write};
52 use std::path::PathBuf;
53 use std::rc::Rc;
54 use std::{env, fs, iter, mem};
55
56 pub fn parse<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
57     sess.diagnostic().set_continue_after_error(sess.opts.debugging_opts.continue_parse_after_error);
58     let krate = sess.time("parsing", || match input {
59         Input::File(file) => parse_crate_from_file(file, &sess.parse_sess),
60         Input::Str { input, name } => {
61             parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
62         }
63     })?;
64
65     sess.diagnostic().set_continue_after_error(true);
66
67     if sess.opts.debugging_opts.ast_json_noexpand {
68         println!("{}", json::as_json(&krate));
69     }
70
71     if sess.opts.debugging_opts.input_stats {
72         println!("Lines of code:             {}", sess.source_map().count_lines());
73         println!("Pre-expansion node count:  {}", count_nodes(&krate));
74     }
75
76     if let Some(ref s) = sess.opts.debugging_opts.show_span {
77         syntax::show_span::run(sess.diagnostic(), s, &krate);
78     }
79
80     if sess.opts.debugging_opts.hir_stats {
81         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS");
82     }
83
84     Ok(krate)
85 }
86
87 fn count_nodes(krate: &ast::Crate) -> usize {
88     let mut counter = NodeCounter::new();
89     visit::walk_crate(&mut counter, krate);
90     counter.count
91 }
92
93 declare_box_region_type!(
94     pub BoxedResolver,
95     for(),
96     (&mut Resolver<'_>) -> (Result<ast::Crate>, ResolverOutputs)
97 );
98
99 /// Runs the "early phases" of the compiler: initial `cfg` processing, loading compiler plugins,
100 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
101 /// harness if one is to be provided, injection of a dependency on the
102 /// standard library and prelude, and name resolution.
103 ///
104 /// Returns `None` if we're aborting after handling -W help.
105 pub fn configure_and_expand(
106     sess: Lrc<Session>,
107     lint_store: Lrc<lint::LintStore>,
108     metadata_loader: Box<MetadataLoaderDyn>,
109     krate: ast::Crate,
110     crate_name: &str,
111 ) -> Result<(ast::Crate, BoxedResolver)> {
112     // Currently, we ignore the name resolution data structures for the purposes of dependency
113     // tracking. Instead we will run name resolution and include its output in the hash of each
114     // item, much like we do for macro expansion. In other words, the hash reflects not just
115     // its contents but the results of name resolution on those contents. Hopefully we'll push
116     // this back at some point.
117     let crate_name = crate_name.to_string();
118     let (result, resolver) = BoxedResolver::new(static move || {
119         let sess = &*sess;
120         let resolver_arenas = Resolver::arenas();
121         let res = configure_and_expand_inner(
122             sess,
123             &lint_store,
124             krate,
125             &crate_name,
126             &resolver_arenas,
127             &*metadata_loader,
128         );
129         let mut resolver = match res {
130             Err(v) => {
131                 yield BoxedResolver::initial_yield(Err(v));
132                 panic!()
133             }
134             Ok((krate, resolver)) => {
135                 yield BoxedResolver::initial_yield(Ok(krate));
136                 resolver
137             }
138         };
139         box_region_allow_access!(for(), (&mut Resolver<'_>), (&mut resolver));
140         resolver.into_outputs()
141     });
142     result.map(|k| (k, resolver))
143 }
144
145 impl BoxedResolver {
146     pub fn to_resolver_outputs(resolver: Rc<RefCell<BoxedResolver>>) -> ResolverOutputs {
147         match Rc::try_unwrap(resolver) {
148             Ok(resolver) => resolver.into_inner().complete(),
149             Err(resolver) => resolver.borrow_mut().access(|resolver| resolver.clone_outputs()),
150         }
151     }
152 }
153
154 pub fn register_plugins<'a>(
155     sess: &'a Session,
156     metadata_loader: &'a dyn MetadataLoader,
157     register_lints: impl Fn(&Session, &mut lint::LintStore),
158     mut krate: ast::Crate,
159     crate_name: &str,
160 ) -> Result<(ast::Crate, Lrc<lint::LintStore>)> {
161     krate = sess.time("attributes injection", || {
162         rustc_builtin_macros::cmdline_attrs::inject(
163             krate,
164             &sess.parse_sess,
165             &sess.opts.debugging_opts.crate_attr,
166         )
167     });
168
169     let (krate, features) = rustc_expand::config::features(
170         krate,
171         &sess.parse_sess,
172         sess.edition(),
173         &sess.opts.debugging_opts.allow_features,
174     );
175     // these need to be set "early" so that expansion sees `quote` if enabled.
176     sess.init_features(features);
177
178     let crate_types = util::collect_crate_types(sess, &krate.attrs);
179     sess.crate_types.set(crate_types);
180
181     let disambiguator = util::compute_crate_disambiguator(sess);
182     sess.crate_disambiguator.set(disambiguator);
183     rustc_incremental::prepare_session_directory(sess, &crate_name, disambiguator);
184
185     if sess.opts.incremental.is_some() {
186         sess.time("garbage-collect incremental cache directory", || {
187             let _prof_timer =
188                 sess.prof.generic_activity("incr_comp_garbage_collect_session_directories");
189             if let Err(e) = rustc_incremental::garbage_collect_session_directories(sess) {
190                 warn!(
191                     "Error while trying to garbage collect incremental \
192                      compilation cache directory: {}",
193                     e
194                 );
195             }
196         });
197     }
198
199     sess.time("recursion limit", || {
200         middle::recursion_limit::update_limits(sess, &krate);
201     });
202
203     let mut lint_store = rustc_lint::new_lint_store(
204         sess.opts.debugging_opts.no_interleave_lints,
205         sess.unstable_options(),
206     );
207     register_lints(&sess, &mut lint_store);
208
209     let registrars =
210         sess.time("plugin loading", || plugin::load::load_plugins(sess, metadata_loader, &krate));
211     sess.time("plugin registration", || {
212         let mut registry = plugin::Registry { lint_store: &mut lint_store };
213         for registrar in registrars {
214             registrar(&mut registry);
215         }
216     });
217
218     Ok((krate, Lrc::new(lint_store)))
219 }
220
221 fn configure_and_expand_inner<'a>(
222     sess: &'a Session,
223     lint_store: &'a lint::LintStore,
224     mut krate: ast::Crate,
225     crate_name: &str,
226     resolver_arenas: &'a ResolverArenas<'a>,
227     metadata_loader: &'a MetadataLoaderDyn,
228 ) -> Result<(ast::Crate, Resolver<'a>)> {
229     sess.time("pre-AST-expansion lint checks", || {
230         rustc_lint::check_ast_crate(
231             sess,
232             lint_store,
233             &krate,
234             true,
235             None,
236             rustc_lint::BuiltinCombinedPreExpansionLintPass::new(),
237         );
238     });
239
240     let mut resolver = Resolver::new(sess, &krate, crate_name, metadata_loader, &resolver_arenas);
241     rustc_builtin_macros::register_builtin_macros(&mut resolver, sess.edition());
242
243     krate = sess.time("crate injection", || {
244         let alt_std_name = sess.opts.alt_std_name.as_ref().map(|s| Symbol::intern(s));
245         let (krate, name) = rustc_builtin_macros::standard_library_imports::inject(
246             krate,
247             &mut resolver,
248             &sess.parse_sess,
249             alt_std_name,
250         );
251         if let Some(name) = name {
252             sess.parse_sess.injected_crate_name.set(name);
253         }
254         krate
255     });
256
257     util::check_attr_crate_type(&krate.attrs, &mut resolver.lint_buffer());
258
259     // Expand all macros
260     krate = sess.time("expansion", || {
261         // Windows dlls do not have rpaths, so they don't know how to find their
262         // dependencies. It's up to us to tell the system where to find all the
263         // dependent dlls. Note that this uses cfg!(windows) as opposed to
264         // targ_cfg because syntax extensions are always loaded for the host
265         // compiler, not for the target.
266         //
267         // This is somewhat of an inherently racy operation, however, as
268         // multiple threads calling this function could possibly continue
269         // extending PATH far beyond what it should. To solve this for now we
270         // just don't add any new elements to PATH which are already there
271         // within PATH. This is basically a targeted fix at #17360 for rustdoc
272         // which runs rustc in parallel but has been seen (#33844) to cause
273         // problems with PATH becoming too long.
274         let mut old_path = OsString::new();
275         if cfg!(windows) {
276             old_path = env::var_os("PATH").unwrap_or(old_path);
277             let mut new_path = sess.host_filesearch(PathKind::All).search_path_dirs();
278             for path in env::split_paths(&old_path) {
279                 if !new_path.contains(&path) {
280                     new_path.push(path);
281                 }
282             }
283             env::set_var(
284                 "PATH",
285                 &env::join_paths(
286                     new_path.iter().filter(|p| env::join_paths(iter::once(p)).is_ok()),
287                 )
288                 .unwrap(),
289             );
290         }
291
292         // Create the config for macro expansion
293         let features = sess.features_untracked();
294         let cfg = rustc_expand::expand::ExpansionConfig {
295             features: Some(&features),
296             recursion_limit: *sess.recursion_limit.get(),
297             trace_mac: sess.opts.debugging_opts.trace_macros,
298             should_test: sess.opts.test,
299             ..rustc_expand::expand::ExpansionConfig::default(crate_name.to_string())
300         };
301
302         let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
303
304         // Expand macros now!
305         let krate = sess.time("expand crate", || ecx.monotonic_expander().expand_crate(krate));
306
307         // The rest is error reporting
308
309         sess.time("check unused macros", || {
310             ecx.check_unused_macros();
311         });
312
313         let mut missing_fragment_specifiers: Vec<_> =
314             ecx.parse_sess.missing_fragment_specifiers.borrow().iter().cloned().collect();
315         missing_fragment_specifiers.sort();
316
317         for span in missing_fragment_specifiers {
318             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
319             let msg = "missing fragment specifier";
320             resolver.lint_buffer().buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
321         }
322         if cfg!(windows) {
323             env::set_var("PATH", &old_path);
324         }
325         krate
326     });
327
328     sess.time("maybe building test harness", || {
329         rustc_builtin_macros::test_harness::inject(
330             &sess.parse_sess,
331             &mut resolver,
332             sess.opts.test,
333             &mut krate,
334             sess.diagnostic(),
335             &sess.features_untracked(),
336             sess.panic_strategy(),
337             sess.target.target.options.panic_strategy,
338             sess.opts.debugging_opts.panic_abort_tests,
339         )
340     });
341
342     // If we're actually rustdoc then there's no need to actually compile
343     // anything, so switch everything to just looping
344     let mut should_loop = sess.opts.actually_rustdoc;
345     if let Some(PpMode::PpmSource(PpSourceMode::PpmEveryBodyLoops)) = sess.opts.pretty {
346         should_loop |= true;
347     }
348     if should_loop {
349         util::ReplaceBodyWithLoop::new(&mut resolver).visit_crate(&mut krate);
350     }
351
352     let has_proc_macro_decls = sess.time("AST validation", || {
353         ast_validation::check_crate(sess, &krate, &mut resolver.lint_buffer())
354     });
355
356     let crate_types = sess.crate_types.borrow();
357     let is_proc_macro_crate = crate_types.contains(&config::CrateType::ProcMacro);
358
359     // For backwards compatibility, we don't try to run proc macro injection
360     // if rustdoc is run on a proc macro crate without '--crate-type proc-macro' being
361     // specified. This should only affect users who manually invoke 'rustdoc', as
362     // 'cargo doc' will automatically pass the proper '--crate-type' flags.
363     // However, we do emit a warning, to let such users know that they should
364     // start passing '--crate-type proc-macro'
365     if has_proc_macro_decls && sess.opts.actually_rustdoc && !is_proc_macro_crate {
366         let mut msg = sess.diagnostic().struct_warn(
367             &"Trying to document proc macro crate \
368             without passing '--crate-type proc-macro to rustdoc",
369         );
370
371         msg.warn("The generated documentation may be incorrect");
372         msg.emit()
373     } else {
374         krate = sess.time("maybe creating a macro crate", || {
375             let num_crate_types = crate_types.len();
376             let is_test_crate = sess.opts.test;
377             rustc_builtin_macros::proc_macro_harness::inject(
378                 &sess.parse_sess,
379                 &mut resolver,
380                 krate,
381                 is_proc_macro_crate,
382                 has_proc_macro_decls,
383                 is_test_crate,
384                 num_crate_types,
385                 sess.diagnostic(),
386             )
387         });
388     }
389
390     // Done with macro expansion!
391
392     if sess.opts.debugging_opts.input_stats {
393         println!("Post-expansion node count: {}", count_nodes(&krate));
394     }
395
396     if sess.opts.debugging_opts.hir_stats {
397         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS");
398     }
399
400     if sess.opts.debugging_opts.ast_json {
401         println!("{}", json::as_json(&krate));
402     }
403
404     sess.time("name resolution", || {
405         resolver.resolve_crate(&krate);
406     });
407
408     // Needs to go *after* expansion to be able to check the results of macro expansion.
409     sess.time("complete gated feature checking", || {
410         syntax::feature_gate::check_crate(
411             &krate,
412             &sess.parse_sess,
413             &sess.features_untracked(),
414             sess.opts.unstable_features,
415         );
416     });
417
418     // Add all buffered lints from the `ParseSess` to the `Session`.
419     sess.parse_sess.buffered_lints.with_lock(|buffered_lints| {
420         info!("{} parse sess buffered_lints", buffered_lints.len());
421         for BufferedEarlyLint { id, span, msg, lint_id } in buffered_lints.drain(..) {
422             resolver.lint_buffer().buffer_lint(lint_id, id, span, &msg);
423         }
424     });
425
426     Ok((krate, resolver))
427 }
428
429 pub fn lower_to_hir<'res, 'tcx>(
430     sess: &'tcx Session,
431     lint_store: &lint::LintStore,
432     resolver: &'res mut Resolver<'_>,
433     dep_graph: &'res DepGraph,
434     krate: &'res ast::Crate,
435     arena: &'tcx Arena<'tcx>,
436 ) -> Result<map::Forest<'tcx>> {
437     // Lower AST to HIR.
438     let hir_forest = sess.time("lowering AST -> HIR", || {
439         let hir_crate = rustc_ast_lowering::lower_crate(
440             sess,
441             &dep_graph,
442             &krate,
443             resolver,
444             rustc_parse::nt_to_tokenstream,
445             arena,
446         );
447
448         if sess.opts.debugging_opts.hir_stats {
449             hir_stats::print_hir_stats(&hir_crate);
450         }
451
452         map::Forest::new(hir_crate, &dep_graph)
453     });
454
455     sess.time("early lint checks", || {
456         rustc_lint::check_ast_crate(
457             sess,
458             lint_store,
459             &krate,
460             false,
461             Some(std::mem::take(resolver.lint_buffer())),
462             rustc_lint::BuiltinCombinedEarlyLintPass::new(),
463         )
464     });
465
466     // Discard hygiene data, which isn't required after lowering to HIR.
467     if !sess.opts.debugging_opts.keep_hygiene_data {
468         rustc_span::hygiene::clear_syntax_context_map();
469     }
470
471     Ok(hir_forest)
472 }
473
474 // Returns all the paths that correspond to generated files.
475 fn generated_output_paths(
476     sess: &Session,
477     outputs: &OutputFilenames,
478     exact_name: bool,
479     crate_name: &str,
480 ) -> Vec<PathBuf> {
481     let mut out_filenames = Vec::new();
482     for output_type in sess.opts.output_types.keys() {
483         let file = outputs.path(*output_type);
484         match *output_type {
485             // If the filename has been overridden using `-o`, it will not be modified
486             // by appending `.rlib`, `.exe`, etc., so we can skip this transformation.
487             OutputType::Exe if !exact_name => {
488                 for crate_type in sess.crate_types.borrow().iter() {
489                     let p = ::rustc_codegen_utils::link::filename_for_input(
490                         sess,
491                         *crate_type,
492                         crate_name,
493                         outputs,
494                     );
495                     out_filenames.push(p);
496                 }
497             }
498             OutputType::DepInfo if sess.opts.debugging_opts.dep_info_omit_d_target => {
499                 // Don't add the dep-info output when omitting it from dep-info targets
500             }
501             _ => {
502                 out_filenames.push(file);
503             }
504         }
505     }
506     out_filenames
507 }
508
509 // Runs `f` on every output file path and returns the first non-None result, or None if `f`
510 // returns None for every file path.
511 fn check_output<F, T>(output_paths: &[PathBuf], f: F) -> Option<T>
512 where
513     F: Fn(&PathBuf) -> Option<T>,
514 {
515     for output_path in output_paths {
516         if let Some(result) = f(output_path) {
517             return Some(result);
518         }
519     }
520     None
521 }
522
523 fn output_contains_path(output_paths: &[PathBuf], input_path: &PathBuf) -> bool {
524     let input_path = input_path.canonicalize().ok();
525     if input_path.is_none() {
526         return false;
527     }
528     let check = |output_path: &PathBuf| {
529         if output_path.canonicalize().ok() == input_path { Some(()) } else { None }
530     };
531     check_output(output_paths, check).is_some()
532 }
533
534 fn output_conflicts_with_dir(output_paths: &[PathBuf]) -> Option<PathBuf> {
535     let check = |output_path: &PathBuf| output_path.is_dir().then(|| output_path.clone());
536     check_output(output_paths, check)
537 }
538
539 fn escape_dep_filename(filename: &FileName) -> String {
540     // Apparently clang and gcc *only* escape spaces:
541     // http://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
542     filename.to_string().replace(" ", "\\ ")
543 }
544
545 fn write_out_deps(
546     sess: &Session,
547     boxed_resolver: &Steal<Rc<RefCell<BoxedResolver>>>,
548     outputs: &OutputFilenames,
549     out_filenames: &[PathBuf],
550 ) {
551     // Write out dependency rules to the dep-info file if requested
552     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
553         return;
554     }
555     let deps_filename = outputs.path(OutputType::DepInfo);
556
557     let result = (|| -> io::Result<()> {
558         // Build a list of files used to compile the output and
559         // write Makefile-compatible dependency rules
560         let mut files: Vec<String> = sess
561             .source_map()
562             .files()
563             .iter()
564             .filter(|fmap| fmap.is_real_file())
565             .filter(|fmap| !fmap.is_imported())
566             .map(|fmap| escape_dep_filename(&fmap.unmapped_path.as_ref().unwrap_or(&fmap.name)))
567             .collect();
568
569         if sess.binary_dep_depinfo() {
570             boxed_resolver.borrow().borrow_mut().access(|resolver| {
571                 for cnum in resolver.cstore().crates_untracked() {
572                     let source = resolver.cstore().crate_source_untracked(cnum);
573                     if let Some((path, _)) = source.dylib {
574                         files.push(escape_dep_filename(&FileName::Real(path)));
575                     }
576                     if let Some((path, _)) = source.rlib {
577                         files.push(escape_dep_filename(&FileName::Real(path)));
578                     }
579                     if let Some((path, _)) = source.rmeta {
580                         files.push(escape_dep_filename(&FileName::Real(path)));
581                     }
582                 }
583             });
584         }
585
586         let mut file = fs::File::create(&deps_filename)?;
587         for path in out_filenames {
588             writeln!(file, "{}: {}\n", path.display(), files.join(" "))?;
589         }
590
591         // Emit a fake target for each input file to the compilation. This
592         // prevents `make` from spitting out an error if a file is later
593         // deleted. For more info see #28735
594         for path in files {
595             writeln!(file, "{}:", path)?;
596         }
597         Ok(())
598     })();
599
600     match result {
601         Ok(_) => {
602             if sess.opts.json_artifact_notifications {
603                 sess.parse_sess
604                     .span_diagnostic
605                     .emit_artifact_notification(&deps_filename, "dep-info");
606             }
607         }
608         Err(e) => sess.fatal(&format!(
609             "error writing dependencies to `{}`: {}",
610             deps_filename.display(),
611             e
612         )),
613     }
614 }
615
616 pub fn prepare_outputs(
617     sess: &Session,
618     compiler: &Compiler,
619     krate: &ast::Crate,
620     boxed_resolver: &Steal<Rc<RefCell<BoxedResolver>>>,
621     crate_name: &str,
622 ) -> Result<OutputFilenames> {
623     // FIXME: rustdoc passes &[] instead of &krate.attrs here
624     let outputs = util::build_output_filenames(
625         &compiler.input,
626         &compiler.output_dir,
627         &compiler.output_file,
628         &krate.attrs,
629         sess,
630     );
631
632     let output_paths =
633         generated_output_paths(sess, &outputs, compiler.output_file.is_some(), &crate_name);
634
635     // Ensure the source file isn't accidentally overwritten during compilation.
636     if let Some(ref input_path) = compiler.input_path {
637         if sess.opts.will_create_output_file() {
638             if output_contains_path(&output_paths, input_path) {
639                 sess.err(&format!(
640                     "the input file \"{}\" would be overwritten by the generated \
641                         executable",
642                     input_path.display()
643                 ));
644                 return Err(ErrorReported);
645             }
646             if let Some(dir_path) = output_conflicts_with_dir(&output_paths) {
647                 sess.err(&format!(
648                     "the generated executable for the input file \"{}\" conflicts with the \
649                         existing directory \"{}\"",
650                     input_path.display(),
651                     dir_path.display()
652                 ));
653                 return Err(ErrorReported);
654             }
655         }
656     }
657
658     write_out_deps(sess, boxed_resolver, &outputs, &output_paths);
659
660     let only_dep_info = sess.opts.output_types.contains_key(&OutputType::DepInfo)
661         && sess.opts.output_types.len() == 1;
662
663     if !only_dep_info {
664         if let Some(ref dir) = compiler.output_dir {
665             if fs::create_dir_all(dir).is_err() {
666                 sess.err("failed to find or create the directory specified by `--out-dir`");
667                 return Err(ErrorReported);
668             }
669         }
670     }
671
672     Ok(outputs)
673 }
674
675 pub fn default_provide(providers: &mut ty::query::Providers<'_>) {
676     providers.analysis = analysis;
677     proc_macro_decls::provide(providers);
678     plugin::build::provide(providers);
679     rustc::hir::provide(providers);
680     mir::provide(providers);
681     rustc_privacy::provide(providers);
682     typeck::provide(providers);
683     ty::provide(providers);
684     traits::provide(providers);
685     rustc_passes::provide(providers);
686     rustc_resolve::provide(providers);
687     rustc_traits::provide(providers);
688     rustc_metadata::provide(providers);
689     rustc_lint::provide(providers);
690     rustc_codegen_utils::provide(providers);
691     rustc_codegen_ssa::provide(providers);
692 }
693
694 pub fn default_provide_extern(providers: &mut ty::query::Providers<'_>) {
695     rustc_metadata::provide_extern(providers);
696     rustc_codegen_ssa::provide_extern(providers);
697 }
698
699 pub struct QueryContext<'tcx>(&'tcx GlobalCtxt<'tcx>);
700
701 impl<'tcx> QueryContext<'tcx> {
702     pub fn enter<F, R>(&mut self, f: F) -> R
703     where
704         F: FnOnce(TyCtxt<'tcx>) -> R,
705     {
706         ty::tls::enter_global(self.0, |tcx| f(tcx))
707     }
708
709     pub fn print_stats(&self) {
710         self.0.queries.print_stats()
711     }
712 }
713
714 pub fn create_global_ctxt<'tcx>(
715     compiler: &'tcx Compiler,
716     lint_store: Lrc<lint::LintStore>,
717     hir_forest: &'tcx map::Forest<'tcx>,
718     mut resolver_outputs: ResolverOutputs,
719     outputs: OutputFilenames,
720     crate_name: &str,
721     global_ctxt: &'tcx Once<GlobalCtxt<'tcx>>,
722     all_arenas: &'tcx AllArenas,
723     arena: &'tcx WorkerLocal<Arena<'tcx>>,
724 ) -> QueryContext<'tcx> {
725     let sess = &compiler.session();
726     let defs = mem::take(&mut resolver_outputs.definitions);
727
728     // Construct the HIR map.
729     let hir_map = sess.time("indexing HIR", || {
730         map::map_crate(sess, &*resolver_outputs.cstore, &hir_forest, defs)
731     });
732
733     let query_result_on_disk_cache =
734         sess.time("load query result cache", || rustc_incremental::load_query_result_cache(sess));
735
736     let codegen_backend = compiler.codegen_backend();
737     let mut local_providers = ty::query::Providers::default();
738     default_provide(&mut local_providers);
739     codegen_backend.provide(&mut local_providers);
740
741     let mut extern_providers = local_providers;
742     default_provide_extern(&mut extern_providers);
743     codegen_backend.provide_extern(&mut extern_providers);
744
745     if let Some(callback) = compiler.override_queries {
746         callback(sess, &mut local_providers, &mut extern_providers);
747     }
748
749     let gcx = global_ctxt.init_locking(|| {
750         TyCtxt::create_global_ctxt(
751             sess,
752             lint_store,
753             local_providers,
754             extern_providers,
755             &all_arenas,
756             arena,
757             resolver_outputs,
758             hir_map,
759             query_result_on_disk_cache,
760             &crate_name,
761             &outputs,
762         )
763     });
764
765     // Do some initialization of the DepGraph that can only be done with the tcx available.
766     ty::tls::enter_global(&gcx, |tcx| {
767         tcx.sess.time("dep graph tcx init", || rustc_incremental::dep_graph_tcx_init(tcx));
768     });
769
770     QueryContext(gcx)
771 }
772
773 /// Runs the resolution, type-checking, region checking and other
774 /// miscellaneous analysis passes on the crate.
775 fn analysis(tcx: TyCtxt<'_>, cnum: CrateNum) -> Result<()> {
776     assert_eq!(cnum, LOCAL_CRATE);
777
778     let sess = tcx.sess;
779     let mut entry_point = None;
780
781     sess.time("misc checking 1", || {
782         parallel!(
783             {
784                 entry_point = sess
785                     .time("looking for entry point", || rustc_passes::entry::find_entry_point(tcx));
786
787                 sess.time("looking for plugin registrar", || {
788                     plugin::build::find_plugin_registrar(tcx)
789                 });
790
791                 sess.time("looking for derive registrar", || proc_macro_decls::find(tcx));
792             },
793             {
794                 par_iter(&tcx.hir().krate().modules).for_each(|(&module, _)| {
795                     let local_def_id = tcx.hir().local_def_id(module);
796                     tcx.ensure().check_mod_loops(local_def_id);
797                     tcx.ensure().check_mod_attrs(local_def_id);
798                     tcx.ensure().check_mod_unstable_api_usage(local_def_id);
799                     tcx.ensure().check_mod_const_bodies(local_def_id);
800                 });
801             }
802         );
803     });
804
805     // passes are timed inside typeck
806     typeck::check_crate(tcx)?;
807
808     sess.time("misc checking 2", || {
809         parallel!(
810             {
811                 sess.time("match checking", || {
812                     tcx.par_body_owners(|def_id| {
813                         tcx.ensure().check_match(def_id);
814                     });
815                 });
816             },
817             {
818                 sess.time("liveness checking + intrinsic checking", || {
819                     par_iter(&tcx.hir().krate().modules).for_each(|(&module, _)| {
820                         // this must run before MIR dump, because
821                         // "not all control paths return a value" is reported here.
822                         //
823                         // maybe move the check to a MIR pass?
824                         let local_def_id = tcx.hir().local_def_id(module);
825
826                         tcx.ensure().check_mod_liveness(local_def_id);
827                         tcx.ensure().check_mod_intrinsics(local_def_id);
828                     });
829                 });
830             }
831         );
832     });
833
834     sess.time("MIR borrow checking", || {
835         tcx.par_body_owners(|def_id| tcx.ensure().mir_borrowck(def_id));
836     });
837
838     sess.time("dumping Chalk-like clauses", || {
839         rustc_traits::lowering::dump_program_clauses(tcx);
840     });
841
842     sess.time("MIR effect checking", || {
843         for def_id in tcx.body_owners() {
844             mir::transform::check_unsafety::check_unsafety(tcx, def_id)
845         }
846     });
847
848     sess.time("layout testing", || layout_test::test_layout(tcx));
849
850     // Avoid overwhelming user with errors if borrow checking failed.
851     // I'm not sure how helpful this is, to be honest, but it avoids a
852     // lot of annoying errors in the compile-fail tests (basically,
853     // lint warnings and so on -- kindck used to do this abort, but
854     // kindck is gone now). -nmatsakis
855     if sess.has_errors() {
856         return Err(ErrorReported);
857     }
858
859     sess.time("misc checking 3", || {
860         parallel!(
861             {
862                 sess.time("privacy access levels", || {
863                     tcx.ensure().privacy_access_levels(LOCAL_CRATE);
864                 });
865                 parallel!(
866                     {
867                         sess.time("private in public", || {
868                             tcx.ensure().check_private_in_public(LOCAL_CRATE);
869                         });
870                     },
871                     {
872                         sess.time("death checking", || rustc_passes::dead::check_crate(tcx));
873                     },
874                     {
875                         sess.time("unused lib feature checking", || {
876                             rustc_passes::stability::check_unused_or_stable_features(tcx)
877                         });
878                     },
879                     {
880                         sess.time("lint checking", || {
881                             rustc_lint::check_crate(tcx, || {
882                                 rustc_lint::BuiltinCombinedLateLintPass::new()
883                             });
884                         });
885                     }
886                 );
887             },
888             {
889                 sess.time("privacy checking modules", || {
890                     par_iter(&tcx.hir().krate().modules).for_each(|(&module, _)| {
891                         tcx.ensure().check_mod_privacy(tcx.hir().local_def_id(module));
892                     });
893                 });
894             }
895         );
896     });
897
898     Ok(())
899 }
900
901 fn encode_and_write_metadata(
902     tcx: TyCtxt<'_>,
903     outputs: &OutputFilenames,
904 ) -> (middle::cstore::EncodedMetadata, bool) {
905     #[derive(PartialEq, Eq, PartialOrd, Ord)]
906     enum MetadataKind {
907         None,
908         Uncompressed,
909         Compressed,
910     }
911
912     let metadata_kind = tcx
913         .sess
914         .crate_types
915         .borrow()
916         .iter()
917         .map(|ty| match *ty {
918             CrateType::Executable | CrateType::Staticlib | CrateType::Cdylib => MetadataKind::None,
919
920             CrateType::Rlib => MetadataKind::Uncompressed,
921
922             CrateType::Dylib | CrateType::ProcMacro => MetadataKind::Compressed,
923         })
924         .max()
925         .unwrap_or(MetadataKind::None);
926
927     let metadata = match metadata_kind {
928         MetadataKind::None => middle::cstore::EncodedMetadata::new(),
929         MetadataKind::Uncompressed | MetadataKind::Compressed => tcx.encode_metadata(),
930     };
931
932     let need_metadata_file = tcx.sess.opts.output_types.contains_key(&OutputType::Metadata);
933     if need_metadata_file {
934         let crate_name = &tcx.crate_name(LOCAL_CRATE).as_str();
935         let out_filename = filename_for_metadata(tcx.sess, crate_name, outputs);
936         // To avoid races with another rustc process scanning the output directory,
937         // we need to write the file somewhere else and atomically move it to its
938         // final destination, with an `fs::rename` call. In order for the rename to
939         // always succeed, the temporary file needs to be on the same filesystem,
940         // which is why we create it inside the output directory specifically.
941         let metadata_tmpdir = TempFileBuilder::new()
942             .prefix("rmeta")
943             .tempdir_in(out_filename.parent().unwrap())
944             .unwrap_or_else(|err| tcx.sess.fatal(&format!("couldn't create a temp dir: {}", err)));
945         let metadata_filename = emit_metadata(tcx.sess, &metadata, &metadata_tmpdir);
946         if let Err(e) = fs::rename(&metadata_filename, &out_filename) {
947             tcx.sess.fatal(&format!("failed to write {}: {}", out_filename.display(), e));
948         }
949         if tcx.sess.opts.json_artifact_notifications {
950             tcx.sess
951                 .parse_sess
952                 .span_diagnostic
953                 .emit_artifact_notification(&out_filename, "metadata");
954         }
955     }
956
957     let need_metadata_module = metadata_kind == MetadataKind::Compressed;
958
959     (metadata, need_metadata_module)
960 }
961
962 /// Runs the codegen backend, after which the AST and analysis can
963 /// be discarded.
964 pub fn start_codegen<'tcx>(
965     codegen_backend: &dyn CodegenBackend,
966     tcx: TyCtxt<'tcx>,
967     outputs: &OutputFilenames,
968 ) -> Box<dyn Any> {
969     if log_enabled!(::log::Level::Info) {
970         println!("Pre-codegen");
971         tcx.print_debug_stats();
972     }
973
974     let (metadata, need_metadata_module) =
975         tcx.sess.time("metadata encoding and writing", || encode_and_write_metadata(tcx, outputs));
976
977     let codegen = tcx.sess.time("codegen", move || {
978         codegen_backend.codegen_crate(tcx, metadata, need_metadata_module)
979     });
980
981     if log_enabled!(::log::Level::Info) {
982         println!("Post-codegen");
983         tcx.print_debug_stats();
984     }
985
986     if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
987         if let Err(e) = mir::transform::dump_mir::emit_mir(tcx, outputs) {
988             tcx.sess.err(&format!("could not emit MIR: {}", e));
989             tcx.sess.abort_if_errors();
990         }
991     }
992
993     codegen
994 }