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[rust.git] / compiler / rustc_interface / src / passes.rs
1 use crate::errors::{
2     CantEmitMIR, EmojiIdentifier, ErrorWritingDependencies, FerrisIdentifier,
3     GeneratedFileConflictsWithDirectory, InputFileWouldBeOverWritten, MixedBinCrate,
4     MixedProcMacroCrate, OutDirError, ProcMacroDocWithoutArg, TempsDirError,
5 };
6 use crate::interface::{Compiler, Result};
7 use crate::proc_macro_decls;
8 use crate::util;
9
10 use ast::CRATE_NODE_ID;
11 use rustc_ast::{self as ast, visit};
12 use rustc_borrowck as mir_borrowck;
13 use rustc_codegen_ssa::traits::CodegenBackend;
14 use rustc_data_structures::parallel;
15 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
16 use rustc_errors::{ErrorGuaranteed, PResult};
17 use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand};
18 use rustc_hir::def_id::StableCrateId;
19 use rustc_lint::{BufferedEarlyLint, EarlyCheckNode, LintStore};
20 use rustc_metadata::creader::CStore;
21 use rustc_middle::arena::Arena;
22 use rustc_middle::dep_graph::DepGraph;
23 use rustc_middle::ty::query::{ExternProviders, Providers};
24 use rustc_middle::ty::{self, GlobalCtxt, RegisteredTools, TyCtxt};
25 use rustc_mir_build as mir_build;
26 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str, validate_attr};
27 use rustc_passes::{self, hir_stats, layout_test};
28 use rustc_plugin_impl as plugin;
29 use rustc_query_impl::{OnDiskCache, Queries as TcxQueries};
30 use rustc_resolve::{Resolver, ResolverArenas};
31 use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType};
32 use rustc_session::cstore::{MetadataLoader, MetadataLoaderDyn};
33 use rustc_session::output::filename_for_input;
34 use rustc_session::search_paths::PathKind;
35 use rustc_session::{Limit, Session};
36 use rustc_span::symbol::{sym, Symbol};
37 use rustc_span::FileName;
38 use rustc_trait_selection::traits;
39
40 use std::any::Any;
41 use std::cell::RefCell;
42 use std::ffi::OsString;
43 use std::io::{self, BufWriter, Write};
44 use std::marker::PhantomPinned;
45 use std::path::{Path, PathBuf};
46 use std::pin::Pin;
47 use std::rc::Rc;
48 use std::sync::LazyLock;
49 use std::{env, fs, iter};
50
51 pub fn parse<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
52     let krate = sess.time("parse_crate", || match input {
53         Input::File(file) => parse_crate_from_file(file, &sess.parse_sess),
54         Input::Str { input, name } => {
55             parse_crate_from_source_str(name.clone(), input.clone(), &sess.parse_sess)
56         }
57     })?;
58
59     if sess.opts.unstable_opts.input_stats {
60         eprintln!("Lines of code:             {}", sess.source_map().count_lines());
61         eprintln!("Pre-expansion node count:  {}", count_nodes(&krate));
62     }
63
64     if let Some(ref s) = sess.opts.unstable_opts.show_span {
65         rustc_ast_passes::show_span::run(sess.diagnostic(), s, &krate);
66     }
67
68     if sess.opts.unstable_opts.hir_stats {
69         hir_stats::print_ast_stats(&krate, "PRE EXPANSION AST STATS", "ast-stats-1");
70     }
71
72     Ok(krate)
73 }
74
75 fn count_nodes(krate: &ast::Crate) -> usize {
76     let mut counter = rustc_ast_passes::node_count::NodeCounter::new();
77     visit::walk_crate(&mut counter, krate);
78     counter.count
79 }
80
81 pub use boxed_resolver::BoxedResolver;
82 mod boxed_resolver {
83     use super::*;
84
85     pub struct BoxedResolver(Pin<Box<BoxedResolverInner>>);
86
87     struct BoxedResolverInner {
88         session: Lrc<Session>,
89         resolver_arenas: Option<ResolverArenas<'static>>,
90         resolver: Option<Resolver<'static>>,
91         _pin: PhantomPinned,
92     }
93
94     // Note: Drop order is important to prevent dangling references. Resolver must be dropped first,
95     // then resolver_arenas and session.
96     impl Drop for BoxedResolverInner {
97         fn drop(&mut self) {
98             self.resolver.take();
99             self.resolver_arenas.take();
100         }
101     }
102
103     impl BoxedResolver {
104         pub(super) fn new(
105             session: Lrc<Session>,
106             make_resolver: impl for<'a> FnOnce(&'a Session, &'a ResolverArenas<'a>) -> Resolver<'a>,
107         ) -> BoxedResolver {
108             let mut boxed_resolver = Box::new(BoxedResolverInner {
109                 session,
110                 resolver_arenas: Some(Resolver::arenas()),
111                 resolver: None,
112                 _pin: PhantomPinned,
113             });
114             // SAFETY: `make_resolver` takes a resolver arena with an arbitrary lifetime and
115             // returns a resolver with the same lifetime as the arena. We ensure that the arena
116             // outlives the resolver in the drop impl and elsewhere so these transmutes are sound.
117             unsafe {
118                 let resolver = make_resolver(
119                     std::mem::transmute::<&Session, &Session>(&boxed_resolver.session),
120                     std::mem::transmute::<&ResolverArenas<'_>, &ResolverArenas<'_>>(
121                         boxed_resolver.resolver_arenas.as_ref().unwrap(),
122                     ),
123                 );
124                 boxed_resolver.resolver = Some(resolver);
125                 BoxedResolver(Pin::new_unchecked(boxed_resolver))
126             }
127         }
128
129         pub fn access<F: for<'a> FnOnce(&mut Resolver<'a>) -> R, R>(&mut self, f: F) -> R {
130             // SAFETY: The resolver doesn't need to be pinned.
131             let mut resolver = unsafe {
132                 self.0.as_mut().map_unchecked_mut(|boxed_resolver| &mut boxed_resolver.resolver)
133             };
134             f((&mut *resolver).as_mut().unwrap())
135         }
136
137         pub fn to_resolver_outputs(resolver: Rc<RefCell<BoxedResolver>>) -> ty::ResolverOutputs {
138             match Rc::try_unwrap(resolver) {
139                 Ok(resolver) => {
140                     let mut resolver = resolver.into_inner();
141                     // SAFETY: The resolver doesn't need to be pinned.
142                     let mut resolver = unsafe {
143                         resolver
144                             .0
145                             .as_mut()
146                             .map_unchecked_mut(|boxed_resolver| &mut boxed_resolver.resolver)
147                     };
148                     resolver.take().unwrap().into_outputs()
149                 }
150                 Err(resolver) => resolver.borrow_mut().access(|resolver| resolver.clone_outputs()),
151             }
152         }
153     }
154 }
155
156 pub fn create_resolver(
157     sess: Lrc<Session>,
158     metadata_loader: Box<MetadataLoaderDyn>,
159     krate: &ast::Crate,
160     crate_name: &str,
161 ) -> BoxedResolver {
162     trace!("create_resolver");
163     BoxedResolver::new(sess, move |sess, resolver_arenas| {
164         Resolver::new(sess, krate, crate_name, metadata_loader, resolver_arenas)
165     })
166 }
167
168 pub fn register_plugins<'a>(
169     sess: &'a Session,
170     metadata_loader: &'a dyn MetadataLoader,
171     register_lints: impl Fn(&Session, &mut LintStore),
172     mut krate: ast::Crate,
173     crate_name: &str,
174 ) -> Result<(ast::Crate, LintStore)> {
175     krate = sess.time("attributes_injection", || {
176         rustc_builtin_macros::cmdline_attrs::inject(
177             krate,
178             &sess.parse_sess,
179             &sess.opts.unstable_opts.crate_attr,
180         )
181     });
182
183     let (krate, features) = rustc_expand::config::features(sess, krate, CRATE_NODE_ID);
184     // these need to be set "early" so that expansion sees `quote` if enabled.
185     sess.init_features(features);
186
187     let crate_types = util::collect_crate_types(sess, &krate.attrs);
188     sess.init_crate_types(crate_types);
189
190     let stable_crate_id = StableCrateId::new(
191         crate_name,
192         sess.crate_types().contains(&CrateType::Executable),
193         sess.opts.cg.metadata.clone(),
194     );
195     sess.stable_crate_id.set(stable_crate_id).expect("not yet initialized");
196     rustc_incremental::prepare_session_directory(sess, crate_name, stable_crate_id)?;
197
198     if sess.opts.incremental.is_some() {
199         sess.time("incr_comp_garbage_collect_session_directories", || {
200             if let Err(e) = rustc_incremental::garbage_collect_session_directories(sess) {
201                 warn!(
202                     "Error while trying to garbage collect incremental \
203                      compilation cache directory: {}",
204                     e
205                 );
206             }
207         });
208     }
209
210     let mut lint_store = rustc_lint::new_lint_store(
211         sess.opts.unstable_opts.no_interleave_lints,
212         sess.enable_internal_lints(),
213     );
214     register_lints(sess, &mut lint_store);
215
216     let registrars =
217         sess.time("plugin_loading", || plugin::load::load_plugins(sess, metadata_loader, &krate));
218     sess.time("plugin_registration", || {
219         let mut registry = plugin::Registry { lint_store: &mut lint_store };
220         for registrar in registrars {
221             registrar(&mut registry);
222         }
223     });
224
225     Ok((krate, lint_store))
226 }
227
228 fn pre_expansion_lint<'a>(
229     sess: &Session,
230     lint_store: &LintStore,
231     registered_tools: &RegisteredTools,
232     check_node: impl EarlyCheckNode<'a>,
233     node_name: &str,
234 ) {
235     sess.prof.generic_activity_with_arg("pre_AST_expansion_lint_checks", node_name).run(|| {
236         rustc_lint::check_ast_node(
237             sess,
238             true,
239             lint_store,
240             registered_tools,
241             None,
242             rustc_lint::BuiltinCombinedPreExpansionLintPass::new(),
243             check_node,
244         );
245     });
246 }
247
248 // Cannot implement directly for `LintStore` due to trait coherence.
249 struct LintStoreExpandImpl<'a>(&'a LintStore);
250
251 impl LintStoreExpand for LintStoreExpandImpl<'_> {
252     fn pre_expansion_lint(
253         &self,
254         sess: &Session,
255         registered_tools: &RegisteredTools,
256         node_id: ast::NodeId,
257         attrs: &[ast::Attribute],
258         items: &[rustc_ast::ptr::P<ast::Item>],
259         name: &str,
260     ) {
261         pre_expansion_lint(sess, self.0, registered_tools, (node_id, attrs, items), name);
262     }
263 }
264
265 /// Runs the "early phases" of the compiler: initial `cfg` processing, loading compiler plugins,
266 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
267 /// harness if one is to be provided, injection of a dependency on the
268 /// standard library and prelude, and name resolution.
269 pub fn configure_and_expand(
270     sess: &Session,
271     lint_store: &LintStore,
272     mut krate: ast::Crate,
273     crate_name: &str,
274     resolver: &mut Resolver<'_>,
275 ) -> Result<ast::Crate> {
276     trace!("configure_and_expand");
277     pre_expansion_lint(sess, lint_store, resolver.registered_tools(), &krate, crate_name);
278     rustc_builtin_macros::register_builtin_macros(resolver);
279
280     krate = sess.time("crate_injection", || {
281         rustc_builtin_macros::standard_library_imports::inject(krate, resolver, sess)
282     });
283
284     util::check_attr_crate_type(sess, &krate.attrs, &mut resolver.lint_buffer());
285
286     // Expand all macros
287     krate = sess.time("macro_expand_crate", || {
288         // Windows dlls do not have rpaths, so they don't know how to find their
289         // dependencies. It's up to us to tell the system where to find all the
290         // dependent dlls. Note that this uses cfg!(windows) as opposed to
291         // targ_cfg because syntax extensions are always loaded for the host
292         // compiler, not for the target.
293         //
294         // This is somewhat of an inherently racy operation, however, as
295         // multiple threads calling this function could possibly continue
296         // extending PATH far beyond what it should. To solve this for now we
297         // just don't add any new elements to PATH which are already there
298         // within PATH. This is basically a targeted fix at #17360 for rustdoc
299         // which runs rustc in parallel but has been seen (#33844) to cause
300         // problems with PATH becoming too long.
301         let mut old_path = OsString::new();
302         if cfg!(windows) {
303             old_path = env::var_os("PATH").unwrap_or(old_path);
304             let mut new_path = sess.host_filesearch(PathKind::All).search_path_dirs();
305             for path in env::split_paths(&old_path) {
306                 if !new_path.contains(&path) {
307                     new_path.push(path);
308                 }
309             }
310             env::set_var(
311                 "PATH",
312                 &env::join_paths(
313                     new_path.iter().filter(|p| env::join_paths(iter::once(p)).is_ok()),
314                 )
315                 .unwrap(),
316             );
317         }
318
319         // Create the config for macro expansion
320         let features = sess.features_untracked();
321         let recursion_limit = get_recursion_limit(&krate.attrs, sess);
322         let cfg = rustc_expand::expand::ExpansionConfig {
323             features: Some(features),
324             recursion_limit,
325             trace_mac: sess.opts.unstable_opts.trace_macros,
326             should_test: sess.opts.test,
327             span_debug: sess.opts.unstable_opts.span_debug,
328             proc_macro_backtrace: sess.opts.unstable_opts.proc_macro_backtrace,
329             ..rustc_expand::expand::ExpansionConfig::default(crate_name.to_string())
330         };
331
332         let lint_store = LintStoreExpandImpl(lint_store);
333         let mut ecx = ExtCtxt::new(sess, cfg, resolver, Some(&lint_store));
334         // Expand macros now!
335         let krate = sess.time("expand_crate", || ecx.monotonic_expander().expand_crate(krate));
336
337         // The rest is error reporting
338
339         sess.parse_sess.buffered_lints.with_lock(|buffered_lints: &mut Vec<BufferedEarlyLint>| {
340             buffered_lints.append(&mut ecx.buffered_early_lint);
341         });
342
343         sess.time("check_unused_macros", || {
344             ecx.check_unused_macros();
345         });
346
347         let recursion_limit_hit = ecx.reduced_recursion_limit.is_some();
348
349         if cfg!(windows) {
350             env::set_var("PATH", &old_path);
351         }
352
353         if recursion_limit_hit {
354             // If we hit a recursion limit, exit early to avoid later passes getting overwhelmed
355             // with a large AST
356             Err(ErrorGuaranteed::unchecked_claim_error_was_emitted())
357         } else {
358             Ok(krate)
359         }
360     })?;
361
362     sess.time("maybe_building_test_harness", || {
363         rustc_builtin_macros::test_harness::inject(sess, resolver, &mut krate)
364     });
365
366     let has_proc_macro_decls = sess.time("AST_validation", || {
367         rustc_ast_passes::ast_validation::check_crate(sess, &krate, resolver.lint_buffer())
368     });
369
370     let crate_types = sess.crate_types();
371     let is_executable_crate = crate_types.contains(&CrateType::Executable);
372     let is_proc_macro_crate = crate_types.contains(&CrateType::ProcMacro);
373
374     if crate_types.len() > 1 {
375         if is_executable_crate {
376             sess.emit_err(MixedBinCrate);
377         }
378         if is_proc_macro_crate {
379             sess.emit_err(MixedProcMacroCrate);
380         }
381     }
382
383     // For backwards compatibility, we don't try to run proc macro injection
384     // if rustdoc is run on a proc macro crate without '--crate-type proc-macro' being
385     // specified. This should only affect users who manually invoke 'rustdoc', as
386     // 'cargo doc' will automatically pass the proper '--crate-type' flags.
387     // However, we do emit a warning, to let such users know that they should
388     // start passing '--crate-type proc-macro'
389     if has_proc_macro_decls && sess.opts.actually_rustdoc && !is_proc_macro_crate {
390         sess.emit_warning(ProcMacroDocWithoutArg);
391     } else {
392         krate = sess.time("maybe_create_a_macro_crate", || {
393             let is_test_crate = sess.opts.test;
394             rustc_builtin_macros::proc_macro_harness::inject(
395                 sess,
396                 resolver,
397                 krate,
398                 is_proc_macro_crate,
399                 has_proc_macro_decls,
400                 is_test_crate,
401                 sess.diagnostic(),
402             )
403         });
404     }
405
406     // Done with macro expansion!
407
408     if sess.opts.unstable_opts.input_stats {
409         eprintln!("Post-expansion node count: {}", count_nodes(&krate));
410     }
411
412     if sess.opts.unstable_opts.hir_stats {
413         hir_stats::print_ast_stats(&krate, "POST EXPANSION AST STATS", "ast-stats-2");
414     }
415
416     resolver.resolve_crate(&krate);
417
418     // Needs to go *after* expansion to be able to check the results of macro expansion.
419     sess.time("complete_gated_feature_checking", || {
420         rustc_ast_passes::feature_gate::check_crate(&krate, sess);
421     });
422
423     // Add all buffered lints from the `ParseSess` to the `Session`.
424     sess.parse_sess.buffered_lints.with_lock(|buffered_lints| {
425         info!("{} parse sess buffered_lints", buffered_lints.len());
426         for early_lint in buffered_lints.drain(..) {
427             resolver.lint_buffer().add_early_lint(early_lint);
428         }
429     });
430
431     // Gate identifiers containing invalid Unicode codepoints that were recovered during lexing.
432     sess.parse_sess.bad_unicode_identifiers.with_lock(|identifiers| {
433         let mut identifiers: Vec<_> = identifiers.drain().collect();
434         identifiers.sort_by_key(|&(key, _)| key);
435         for (ident, mut spans) in identifiers.into_iter() {
436             spans.sort();
437             if ident == sym::ferris {
438                 let first_span = spans[0];
439                 sess.emit_err(FerrisIdentifier { spans, first_span });
440             } else {
441                 sess.emit_err(EmojiIdentifier { spans, ident });
442             }
443         }
444     });
445
446     sess.time("early_lint_checks", || {
447         let lint_buffer = Some(std::mem::take(resolver.lint_buffer()));
448         rustc_lint::check_ast_node(
449             sess,
450             false,
451             lint_store,
452             resolver.registered_tools(),
453             lint_buffer,
454             rustc_lint::BuiltinCombinedEarlyLintPass::new(),
455             &krate,
456         )
457     });
458
459     Ok(krate)
460 }
461
462 // Returns all the paths that correspond to generated files.
463 fn generated_output_paths(
464     sess: &Session,
465     outputs: &OutputFilenames,
466     exact_name: bool,
467     crate_name: &str,
468 ) -> Vec<PathBuf> {
469     let mut out_filenames = Vec::new();
470     for output_type in sess.opts.output_types.keys() {
471         let file = outputs.path(*output_type);
472         match *output_type {
473             // If the filename has been overridden using `-o`, it will not be modified
474             // by appending `.rlib`, `.exe`, etc., so we can skip this transformation.
475             OutputType::Exe if !exact_name => {
476                 for crate_type in sess.crate_types().iter() {
477                     let p = filename_for_input(sess, *crate_type, crate_name, outputs);
478                     out_filenames.push(p);
479                 }
480             }
481             OutputType::DepInfo if sess.opts.unstable_opts.dep_info_omit_d_target => {
482                 // Don't add the dep-info output when omitting it from dep-info targets
483             }
484             _ => {
485                 out_filenames.push(file);
486             }
487         }
488     }
489     out_filenames
490 }
491
492 // Runs `f` on every output file path and returns the first non-None result, or None if `f`
493 // returns None for every file path.
494 fn check_output<F, T>(output_paths: &[PathBuf], f: F) -> Option<T>
495 where
496     F: Fn(&PathBuf) -> Option<T>,
497 {
498     for output_path in output_paths {
499         if let Some(result) = f(output_path) {
500             return Some(result);
501         }
502     }
503     None
504 }
505
506 fn output_contains_path(output_paths: &[PathBuf], input_path: &Path) -> bool {
507     let input_path = input_path.canonicalize().ok();
508     if input_path.is_none() {
509         return false;
510     }
511     let check = |output_path: &PathBuf| {
512         if output_path.canonicalize().ok() == input_path { Some(()) } else { None }
513     };
514     check_output(output_paths, check).is_some()
515 }
516
517 fn output_conflicts_with_dir(output_paths: &[PathBuf]) -> Option<PathBuf> {
518     let check = |output_path: &PathBuf| output_path.is_dir().then(|| output_path.clone());
519     check_output(output_paths, check)
520 }
521
522 fn escape_dep_filename(filename: &str) -> String {
523     // Apparently clang and gcc *only* escape spaces:
524     // https://llvm.org/klaus/clang/commit/9d50634cfc268ecc9a7250226dd5ca0e945240d4
525     filename.replace(' ', "\\ ")
526 }
527
528 // Makefile comments only need escaping newlines and `\`.
529 // The result can be unescaped by anything that can unescape `escape_default` and friends.
530 fn escape_dep_env(symbol: Symbol) -> String {
531     let s = symbol.as_str();
532     let mut escaped = String::with_capacity(s.len());
533     for c in s.chars() {
534         match c {
535             '\n' => escaped.push_str(r"\n"),
536             '\r' => escaped.push_str(r"\r"),
537             '\\' => escaped.push_str(r"\\"),
538             _ => escaped.push(c),
539         }
540     }
541     escaped
542 }
543
544 fn write_out_deps(
545     sess: &Session,
546     boxed_resolver: &RefCell<BoxedResolver>,
547     outputs: &OutputFilenames,
548     out_filenames: &[PathBuf],
549 ) {
550     // Write out dependency rules to the dep-info file if requested
551     if !sess.opts.output_types.contains_key(&OutputType::DepInfo) {
552         return;
553     }
554     let deps_filename = outputs.path(OutputType::DepInfo);
555
556     let result = (|| -> io::Result<()> {
557         // Build a list of files used to compile the output and
558         // write Makefile-compatible dependency rules
559         let mut files: Vec<String> = sess
560             .source_map()
561             .files()
562             .iter()
563             .filter(|fmap| fmap.is_real_file())
564             .filter(|fmap| !fmap.is_imported())
565             .map(|fmap| escape_dep_filename(&fmap.name.prefer_local().to_string()))
566             .collect();
567
568         // Account for explicitly marked-to-track files
569         // (e.g. accessed in proc macros).
570         let file_depinfo = sess.parse_sess.file_depinfo.borrow();
571
572         let normalize_path = |path: PathBuf| {
573             let file = FileName::from(path);
574             escape_dep_filename(&file.prefer_local().to_string())
575         };
576
577         let extra_tracked_files =
578             file_depinfo.iter().map(|path_sym| normalize_path(PathBuf::from(path_sym.as_str())));
579         files.extend(extra_tracked_files);
580
581         // We also need to track used PGO profile files
582         if let Some(ref profile_instr) = sess.opts.cg.profile_use {
583             files.push(normalize_path(profile_instr.as_path().to_path_buf()));
584         }
585         if let Some(ref profile_sample) = sess.opts.unstable_opts.profile_sample_use {
586             files.push(normalize_path(profile_sample.as_path().to_path_buf()));
587         }
588
589         if sess.binary_dep_depinfo() {
590             if let Some(ref backend) = sess.opts.unstable_opts.codegen_backend {
591                 if backend.contains('.') {
592                     // If the backend name contain a `.`, it is the path to an external dynamic
593                     // library. If not, it is not a path.
594                     files.push(backend.to_string());
595                 }
596             }
597
598             boxed_resolver.borrow_mut().access(|resolver| {
599                 for cnum in resolver.cstore().crates_untracked() {
600                     let source = resolver.cstore().crate_source_untracked(cnum);
601                     if let Some((path, _)) = &source.dylib {
602                         files.push(escape_dep_filename(&path.display().to_string()));
603                     }
604                     if let Some((path, _)) = &source.rlib {
605                         files.push(escape_dep_filename(&path.display().to_string()));
606                     }
607                     if let Some((path, _)) = &source.rmeta {
608                         files.push(escape_dep_filename(&path.display().to_string()));
609                     }
610                 }
611             });
612         }
613
614         let mut file = BufWriter::new(fs::File::create(&deps_filename)?);
615         for path in out_filenames {
616             writeln!(file, "{}: {}\n", path.display(), files.join(" "))?;
617         }
618
619         // Emit a fake target for each input file to the compilation. This
620         // prevents `make` from spitting out an error if a file is later
621         // deleted. For more info see #28735
622         for path in files {
623             writeln!(file, "{}:", path)?;
624         }
625
626         // Emit special comments with information about accessed environment variables.
627         let env_depinfo = sess.parse_sess.env_depinfo.borrow();
628         if !env_depinfo.is_empty() {
629             let mut envs: Vec<_> = env_depinfo
630                 .iter()
631                 .map(|(k, v)| (escape_dep_env(*k), v.map(escape_dep_env)))
632                 .collect();
633             envs.sort_unstable();
634             writeln!(file)?;
635             for (k, v) in envs {
636                 write!(file, "# env-dep:{}", k)?;
637                 if let Some(v) = v {
638                     write!(file, "={}", v)?;
639                 }
640                 writeln!(file)?;
641             }
642         }
643
644         Ok(())
645     })();
646
647     match result {
648         Ok(_) => {
649             if sess.opts.json_artifact_notifications {
650                 sess.parse_sess
651                     .span_diagnostic
652                     .emit_artifact_notification(&deps_filename, "dep-info");
653             }
654         }
655         Err(error) => {
656             sess.emit_fatal(ErrorWritingDependencies { path: &deps_filename, error });
657         }
658     }
659 }
660
661 pub fn prepare_outputs(
662     sess: &Session,
663     compiler: &Compiler,
664     krate: &ast::Crate,
665     boxed_resolver: &RefCell<BoxedResolver>,
666     crate_name: &str,
667 ) -> Result<OutputFilenames> {
668     let _timer = sess.timer("prepare_outputs");
669
670     // FIXME: rustdoc passes &[] instead of &krate.attrs here
671     let outputs = util::build_output_filenames(
672         &compiler.input,
673         &compiler.output_dir,
674         &compiler.output_file,
675         &compiler.temps_dir,
676         &krate.attrs,
677         sess,
678     );
679
680     let output_paths =
681         generated_output_paths(sess, &outputs, compiler.output_file.is_some(), crate_name);
682
683     // Ensure the source file isn't accidentally overwritten during compilation.
684     if let Some(ref input_path) = compiler.input_path {
685         if sess.opts.will_create_output_file() {
686             if output_contains_path(&output_paths, input_path) {
687                 let reported = sess.emit_err(InputFileWouldBeOverWritten { path: input_path });
688                 return Err(reported);
689             }
690             if let Some(ref dir_path) = output_conflicts_with_dir(&output_paths) {
691                 let reported =
692                     sess.emit_err(GeneratedFileConflictsWithDirectory { input_path, dir_path });
693                 return Err(reported);
694             }
695         }
696     }
697
698     if let Some(ref dir) = compiler.temps_dir {
699         if fs::create_dir_all(dir).is_err() {
700             let reported = sess.emit_err(TempsDirError);
701             return Err(reported);
702         }
703     }
704
705     write_out_deps(sess, boxed_resolver, &outputs, &output_paths);
706
707     let only_dep_info = sess.opts.output_types.contains_key(&OutputType::DepInfo)
708         && sess.opts.output_types.len() == 1;
709
710     if !only_dep_info {
711         if let Some(ref dir) = compiler.output_dir {
712             if fs::create_dir_all(dir).is_err() {
713                 let reported = sess.emit_err(OutDirError);
714                 return Err(reported);
715             }
716         }
717     }
718
719     Ok(outputs)
720 }
721
722 pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
723     let providers = &mut Providers::default();
724     providers.analysis = analysis;
725     providers.hir_crate = rustc_ast_lowering::lower_to_hir;
726     proc_macro_decls::provide(providers);
727     rustc_const_eval::provide(providers);
728     rustc_middle::hir::provide(providers);
729     mir_borrowck::provide(providers);
730     mir_build::provide(providers);
731     rustc_mir_transform::provide(providers);
732     rustc_monomorphize::provide(providers);
733     rustc_privacy::provide(providers);
734     rustc_hir_analysis::provide(providers);
735     rustc_hir_typeck::provide(providers);
736     ty::provide(providers);
737     traits::provide(providers);
738     rustc_passes::provide(providers);
739     rustc_traits::provide(providers);
740     rustc_ty_utils::provide(providers);
741     rustc_metadata::provide(providers);
742     rustc_lint::provide(providers);
743     rustc_symbol_mangling::provide(providers);
744     rustc_codegen_ssa::provide(providers);
745     *providers
746 });
747
748 pub static DEFAULT_EXTERN_QUERY_PROVIDERS: LazyLock<ExternProviders> = LazyLock::new(|| {
749     let mut extern_providers = ExternProviders::default();
750     rustc_metadata::provide_extern(&mut extern_providers);
751     rustc_codegen_ssa::provide_extern(&mut extern_providers);
752     extern_providers
753 });
754
755 pub struct QueryContext<'tcx> {
756     gcx: &'tcx GlobalCtxt<'tcx>,
757 }
758
759 impl<'tcx> QueryContext<'tcx> {
760     pub fn enter<F, R>(&mut self, f: F) -> R
761     where
762         F: FnOnce(TyCtxt<'tcx>) -> R,
763     {
764         let icx = ty::tls::ImplicitCtxt::new(self.gcx);
765         ty::tls::enter_context(&icx, |_| f(icx.tcx))
766     }
767 }
768
769 pub fn create_global_ctxt<'tcx>(
770     compiler: &'tcx Compiler,
771     lint_store: Lrc<LintStore>,
772     krate: Lrc<ast::Crate>,
773     dep_graph: DepGraph,
774     resolver: Rc<RefCell<BoxedResolver>>,
775     outputs: OutputFilenames,
776     crate_name: &str,
777     queries: &'tcx OnceCell<TcxQueries<'tcx>>,
778     global_ctxt: &'tcx OnceCell<GlobalCtxt<'tcx>>,
779     arena: &'tcx WorkerLocal<Arena<'tcx>>,
780     hir_arena: &'tcx WorkerLocal<rustc_hir::Arena<'tcx>>,
781 ) -> QueryContext<'tcx> {
782     // We're constructing the HIR here; we don't care what we will
783     // read, since we haven't even constructed the *input* to
784     // incr. comp. yet.
785     dep_graph.assert_ignored();
786
787     let resolver_outputs = BoxedResolver::to_resolver_outputs(resolver);
788
789     let sess = &compiler.session();
790     let query_result_on_disk_cache = rustc_incremental::load_query_result_cache(sess);
791
792     let codegen_backend = compiler.codegen_backend();
793     let mut local_providers = *DEFAULT_QUERY_PROVIDERS;
794     codegen_backend.provide(&mut local_providers);
795
796     let mut extern_providers = *DEFAULT_EXTERN_QUERY_PROVIDERS;
797     codegen_backend.provide_extern(&mut extern_providers);
798
799     if let Some(callback) = compiler.override_queries {
800         callback(sess, &mut local_providers, &mut extern_providers);
801     }
802
803     let queries = queries.get_or_init(|| {
804         TcxQueries::new(local_providers, extern_providers, query_result_on_disk_cache)
805     });
806
807     let gcx = sess.time("setup_global_ctxt", || {
808         global_ctxt.get_or_init(move || {
809             TyCtxt::create_global_ctxt(
810                 sess,
811                 lint_store,
812                 arena,
813                 hir_arena,
814                 resolver_outputs,
815                 krate,
816                 dep_graph,
817                 queries.on_disk_cache.as_ref().map(OnDiskCache::as_dyn),
818                 queries.as_dyn(),
819                 rustc_query_impl::query_callbacks(arena),
820                 crate_name,
821                 outputs,
822             )
823         })
824     });
825
826     QueryContext { gcx }
827 }
828
829 /// Runs the resolution, type-checking, region checking and other
830 /// miscellaneous analysis passes on the crate.
831 fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
832     rustc_passes::hir_id_validator::check_crate(tcx);
833
834     let sess = tcx.sess;
835     let mut entry_point = None;
836
837     sess.time("misc_checking_1", || {
838         parallel!(
839             {
840                 entry_point = sess.time("looking_for_entry_point", || tcx.entry_fn(()));
841
842                 sess.time("looking_for_derive_registrar", || {
843                     tcx.ensure().proc_macro_decls_static(())
844                 });
845
846                 CStore::from_tcx(tcx).report_unused_deps(tcx);
847             },
848             {
849                 tcx.hir().par_for_each_module(|module| {
850                     tcx.ensure().check_mod_loops(module);
851                     tcx.ensure().check_mod_attrs(module);
852                     tcx.ensure().check_mod_naked_functions(module);
853                     tcx.ensure().check_mod_unstable_api_usage(module);
854                     tcx.ensure().check_mod_const_bodies(module);
855                 });
856             },
857             {
858                 sess.time("unused_lib_feature_checking", || {
859                     rustc_passes::stability::check_unused_or_stable_features(tcx)
860                 });
861             },
862             {
863                 // We force these queries to run,
864                 // since they might not otherwise get called.
865                 // This marks the corresponding crate-level attributes
866                 // as used, and ensures that their values are valid.
867                 tcx.ensure().limits(());
868                 tcx.ensure().stability_index(());
869             }
870         );
871     });
872
873     // passes are timed inside typeck
874     rustc_hir_analysis::check_crate(tcx)?;
875
876     sess.time("misc_checking_2", || {
877         parallel!(
878             {
879                 sess.time("match_checking", || {
880                     tcx.hir().par_body_owners(|def_id| tcx.ensure().check_match(def_id.to_def_id()))
881                 });
882             },
883             {
884                 sess.time("liveness_checking", || {
885                     tcx.hir().par_body_owners(|def_id| {
886                         // this must run before MIR dump, because
887                         // "not all control paths return a value" is reported here.
888                         //
889                         // maybe move the check to a MIR pass?
890                         tcx.ensure().check_liveness(def_id.to_def_id());
891                     });
892                 });
893             }
894         );
895     });
896
897     sess.time("MIR_borrow_checking", || {
898         tcx.hir().par_body_owners(|def_id| tcx.ensure().mir_borrowck(def_id));
899     });
900
901     sess.time("MIR_effect_checking", || {
902         for def_id in tcx.hir().body_owners() {
903             tcx.ensure().thir_check_unsafety(def_id);
904             if !tcx.sess.opts.unstable_opts.thir_unsafeck {
905                 rustc_mir_transform::check_unsafety::check_unsafety(tcx, def_id);
906             }
907             tcx.ensure().has_ffi_unwind_calls(def_id);
908
909             if tcx.hir().body_const_context(def_id).is_some() {
910                 tcx.ensure()
911                     .mir_drops_elaborated_and_const_checked(ty::WithOptConstParam::unknown(def_id));
912             }
913         }
914     });
915
916     sess.time("layout_testing", || layout_test::test_layout(tcx));
917
918     // Avoid overwhelming user with errors if borrow checking failed.
919     // I'm not sure how helpful this is, to be honest, but it avoids a
920     // lot of annoying errors in the ui tests (basically,
921     // lint warnings and so on -- kindck used to do this abort, but
922     // kindck is gone now). -nmatsakis
923     if let Some(reported) = sess.has_errors() {
924         return Err(reported);
925     }
926
927     sess.time("misc_checking_3", || {
928         parallel!(
929             {
930                 tcx.ensure().effective_visibilities(());
931
932                 parallel!(
933                     {
934                         tcx.ensure().check_private_in_public(());
935                     },
936                     {
937                         tcx.hir()
938                             .par_for_each_module(|module| tcx.ensure().check_mod_deathness(module));
939                     },
940                     {
941                         sess.time("lint_checking", || {
942                             rustc_lint::check_crate(tcx, || {
943                                 rustc_lint::BuiltinCombinedLateLintPass::new()
944                             });
945                         });
946                     }
947                 );
948             },
949             {
950                 sess.time("privacy_checking_modules", || {
951                     tcx.hir().par_for_each_module(|module| {
952                         tcx.ensure().check_mod_privacy(module);
953                     });
954                 });
955             }
956         );
957
958         // This check has to be run after all lints are done processing. We don't
959         // define a lint filter, as all lint checks should have finished at this point.
960         sess.time("check_lint_expectations", || tcx.check_expectations(None));
961     });
962
963     Ok(())
964 }
965
966 /// Runs the codegen backend, after which the AST and analysis can
967 /// be discarded.
968 pub fn start_codegen<'tcx>(
969     codegen_backend: &dyn CodegenBackend,
970     tcx: TyCtxt<'tcx>,
971     outputs: &OutputFilenames,
972 ) -> Box<dyn Any> {
973     info!("Pre-codegen\n{:?}", tcx.debug_stats());
974
975     let (metadata, need_metadata_module) =
976         rustc_metadata::fs::encode_and_write_metadata(tcx, outputs);
977
978     let codegen = tcx.sess.time("codegen_crate", move || {
979         codegen_backend.codegen_crate(tcx, metadata, need_metadata_module)
980     });
981
982     // Don't run these test assertions when not doing codegen. Compiletest tries to build
983     // build-fail tests in check mode first and expects it to not give an error in that case.
984     if tcx.sess.opts.output_types.should_codegen() {
985         rustc_incremental::assert_module_sources::assert_module_sources(tcx);
986         rustc_symbol_mangling::test::report_symbol_names(tcx);
987     }
988
989     info!("Post-codegen\n{:?}", tcx.debug_stats());
990
991     if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
992         if let Err(error) = rustc_mir_transform::dump_mir::emit_mir(tcx, outputs) {
993             tcx.sess.emit_err(CantEmitMIR { error });
994             tcx.sess.abort_if_errors();
995         }
996     }
997
998     codegen
999 }
1000
1001 fn get_recursion_limit(krate_attrs: &[ast::Attribute], sess: &Session) -> Limit {
1002     if let Some(attr) = krate_attrs
1003         .iter()
1004         .find(|attr| attr.has_name(sym::recursion_limit) && attr.value_str().is_none())
1005     {
1006         // This is here mainly to check for using a macro, such as
1007         // #![recursion_limit = foo!()]. That is not supported since that
1008         // would require expanding this while in the middle of expansion,
1009         // which needs to know the limit before expanding. Otherwise,
1010         // validation would normally be caught in AstValidator (via
1011         // `check_builtin_attribute`), but by the time that runs the macro
1012         // is expanded, and it doesn't give an error.
1013         validate_attr::emit_fatal_malformed_builtin_attribute(
1014             &sess.parse_sess,
1015             attr,
1016             sym::recursion_limit,
1017         );
1018     }
1019     rustc_middle::middle::limits::get_recursion_limit(krate_attrs, sess)
1020 }