5 //! This API is completely unstable and subject to change.
7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
10 #![recursion_limit = "256"]
11 #![allow(rustc::potential_query_instability)]
12 #![deny(rustc::untranslatable_diagnostic)]
13 #![deny(rustc::diagnostic_outside_of_impl)]
18 pub extern crate rustc_plugin_impl as plugin;
21 use rustc_codegen_ssa::{traits::CodegenBackend, CodegenErrors, CodegenResults};
22 use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry};
23 use rustc_data_structures::sync::SeqCst;
24 use rustc_errors::registry::{InvalidErrorCode, Registry};
25 use rustc_errors::{ErrorGuaranteed, PResult};
26 use rustc_feature::find_gated_cfg;
27 use rustc_interface::util::{self, collect_crate_types, get_codegen_backend};
28 use rustc_interface::{interface, Queries};
29 use rustc_lint::LintStore;
30 use rustc_log::stdout_isatty;
31 use rustc_metadata::locator;
32 use rustc_save_analysis as save;
33 use rustc_save_analysis::DumpHandler;
34 use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS};
35 use rustc_session::config::{ErrorOutputType, Input, OutputType, PrintRequest, TrimmedDefPaths};
36 use rustc_session::cstore::MetadataLoader;
37 use rustc_session::getopts;
38 use rustc_session::lint::{Lint, LintId};
39 use rustc_session::{config, DiagnosticOutput, Session};
40 use rustc_session::{early_error, early_error_no_abort, early_warn};
41 use rustc_span::source_map::{FileLoader, FileName};
42 use rustc_span::symbol::sym;
43 use rustc_target::json::ToJson;
47 use std::default::Default;
49 use std::ffi::OsString;
51 use std::io::{self, Read, Write};
52 use std::panic::{self, catch_unwind};
53 use std::path::PathBuf;
54 use std::process::{self, Command, Stdio};
56 use std::sync::LazyLock;
57 use std::time::Instant;
61 mod session_diagnostics;
63 use crate::session_diagnostics::{
64 RLinkEmptyVersionNumber, RLinkEncodingVersionMismatch, RLinkRustcVersionMismatch,
65 RLinkWrongFileType, RlinkNotAFile, RlinkUnableToRead,
68 /// Exit status code used for successful compilation and help output.
69 pub const EXIT_SUCCESS: i32 = 0;
71 /// Exit status code used for compilation failures and invalid flags.
72 pub const EXIT_FAILURE: i32 = 1;
74 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
75 ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md";
77 const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["-Z", "-C", "--crate-type"];
79 const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"];
81 const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"];
83 pub fn abort_on_err<T>(result: Result<T, ErrorGuaranteed>, sess: &Session) -> T {
86 sess.abort_if_errors();
87 panic!("error reported but abort_if_errors didn't abort???");
94 /// Called before creating the compiler instance
95 fn config(&mut self, _config: &mut interface::Config) {}
96 /// Called after parsing. Return value instructs the compiler whether to
97 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
98 fn after_parsing<'tcx>(
100 _compiler: &interface::Compiler,
101 _queries: &'tcx Queries<'tcx>,
103 Compilation::Continue
105 /// Called after expansion. Return value instructs the compiler whether to
106 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
107 fn after_expansion<'tcx>(
109 _compiler: &interface::Compiler,
110 _queries: &'tcx Queries<'tcx>,
112 Compilation::Continue
114 /// Called after analysis. Return value instructs the compiler whether to
115 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
116 fn after_analysis<'tcx>(
118 _compiler: &interface::Compiler,
119 _queries: &'tcx Queries<'tcx>,
121 Compilation::Continue
126 pub struct TimePassesCallbacks {
130 impl Callbacks for TimePassesCallbacks {
131 fn config(&mut self, config: &mut interface::Config) {
132 // If a --prints=... option has been given, we don't print the "total"
133 // time because it will mess up the --prints output. See #64339.
134 self.time_passes = config.opts.prints.is_empty() && config.opts.time_passes();
135 config.opts.trimmed_def_paths = TrimmedDefPaths::GoodPath;
139 pub fn diagnostics_registry() -> Registry {
140 Registry::new(rustc_error_codes::DIAGNOSTICS)
143 /// This is the primary entry point for rustc.
144 pub struct RunCompiler<'a, 'b> {
145 at_args: &'a [String],
146 callbacks: &'b mut (dyn Callbacks + Send),
147 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
148 emitter: Option<Box<dyn Write + Send>>,
149 make_codegen_backend:
150 Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
153 impl<'a, 'b> RunCompiler<'a, 'b> {
154 pub fn new(at_args: &'a [String], callbacks: &'b mut (dyn Callbacks + Send)) -> Self {
155 Self { at_args, callbacks, file_loader: None, emitter: None, make_codegen_backend: None }
158 /// Set a custom codegen backend.
161 pub fn set_make_codegen_backend(
163 make_codegen_backend: Option<
164 Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
167 self.make_codegen_backend = make_codegen_backend;
171 /// Emit diagnostics to the specified location.
174 pub fn set_emitter(&mut self, emitter: Option<Box<dyn Write + Send>>) -> &mut Self {
175 self.emitter = emitter;
179 /// Load files from sources other than the file system.
182 pub fn set_file_loader(
184 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
186 self.file_loader = file_loader;
190 /// Parse args and run the compiler.
191 pub fn run(self) -> interface::Result<()> {
197 self.make_codegen_backend,
203 callbacks: &mut (dyn Callbacks + Send),
204 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
205 emitter: Option<Box<dyn Write + Send>>,
206 make_codegen_backend: Option<
207 Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
209 ) -> interface::Result<()> {
210 let args = args::arg_expand_all(at_args);
212 let diagnostic_output = emitter.map_or(DiagnosticOutput::Default, DiagnosticOutput::Raw);
213 let Some(matches) = handle_options(&args) else { return Ok(()) };
215 let sopts = config::build_session_options(&matches);
217 if let Some(ref code) = matches.opt_str("explain") {
218 handle_explain(diagnostics_registry(), code, sopts.error_format);
222 let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg"));
223 let check_cfg = interface::parse_check_cfg(matches.opt_strs("check-cfg"));
224 let (odir, ofile) = make_output(&matches);
225 let mut config = interface::Config {
228 crate_check_cfg: check_cfg,
229 input: Input::File(PathBuf::new()),
235 lint_caps: Default::default(),
236 parse_sess_created: None,
237 register_lints: None,
238 override_queries: None,
239 make_codegen_backend,
240 registry: diagnostics_registry(),
243 match make_input(config.opts.error_format, &matches.free) {
244 Err(reported) => return Err(reported),
245 Ok(Some((input, input_file_path))) => {
246 config.input = input;
247 config.input_path = input_file_path;
249 callbacks.config(&mut config);
251 Ok(None) => match matches.free.len() {
253 callbacks.config(&mut config);
254 interface::run_compiler(config, |compiler| {
255 let sopts = &compiler.session().opts;
256 if sopts.describe_lints {
257 let mut lint_store = rustc_lint::new_lint_store(
258 sopts.unstable_opts.no_interleave_lints,
259 compiler.session().enable_internal_lints(),
261 let registered_lints =
262 if let Some(register_lints) = compiler.register_lints() {
263 register_lints(compiler.session(), &mut lint_store);
268 describe_lints(compiler.session(), &lint_store, registered_lints);
271 let should_stop = print_crate_info(
272 &***compiler.codegen_backend(),
275 compiler.output_dir(),
276 compiler.output_file(),
277 compiler.temps_dir(),
280 if should_stop == Compilation::Stop {
283 early_error(sopts.error_format, "no input filename given")
287 1 => panic!("make_input should have provided valid inputs"),
289 config.opts.error_format,
291 "multiple input filenames provided (first two filenames are `{}` and `{}`)",
292 matches.free[0], matches.free[1],
298 interface::run_compiler(config, |compiler| {
299 let sess = compiler.session();
300 let should_stop = print_crate_info(
301 &***compiler.codegen_backend(),
303 Some(compiler.input()),
304 compiler.output_dir(),
305 compiler.output_file(),
306 compiler.temps_dir(),
309 list_metadata(sess, &*compiler.codegen_backend().metadata_loader(), compiler.input())
311 .and_then(|| try_process_rlink(sess, compiler));
313 if should_stop == Compilation::Stop {
314 return sess.compile_status();
317 let linker = compiler.enter(|queries| {
318 let early_exit = || sess.compile_status().map(|_| None);
321 if let Some(ppm) = &sess.opts.pretty {
322 if ppm.needs_ast_map() {
323 let expanded_crate = queries.expansion()?.peek().0.clone();
324 queries.global_ctxt()?.peek_mut().enter(|tcx| {
325 pretty::print_after_hir_lowering(
330 compiler.output_file().as_ref().map(|p| &**p),
335 let krate = queries.parse()?.take();
336 pretty::print_after_parsing(
341 compiler.output_file().as_ref().map(|p| &**p),
344 trace!("finished pretty-printing");
348 if callbacks.after_parsing(compiler, queries) == Compilation::Stop {
352 if sess.opts.unstable_opts.parse_only || sess.opts.unstable_opts.show_span.is_some() {
357 let (_, lint_store) = &*queries.register_plugins()?.peek();
359 // Lint plugins are registered; now we can process command line flags.
360 if sess.opts.describe_lints {
361 describe_lints(sess, lint_store, true);
366 queries.expansion()?;
367 if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
371 queries.prepare_outputs()?;
373 if sess.opts.output_types.contains_key(&OutputType::DepInfo)
374 && sess.opts.output_types.len() == 1
379 queries.global_ctxt()?;
381 if sess.opts.unstable_opts.no_analysis {
385 queries.global_ctxt()?.peek_mut().enter(|tcx| {
386 let result = tcx.analysis(());
387 if sess.opts.unstable_opts.save_analysis {
388 let crate_name = queries.crate_name()?.peek().clone();
389 sess.time("save_analysis", || {
396 compiler.output_dir().as_ref().map(|p| &**p),
405 if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
409 queries.ongoing_codegen()?;
411 if sess.opts.unstable_opts.print_type_sizes {
412 sess.code_stats.print_type_sizes();
415 let linker = queries.linker()?;
419 if let Some(linker) = linker {
420 let _timer = sess.timer("link");
424 if sess.opts.unstable_opts.perf_stats {
425 sess.print_perf_stats();
428 if sess.opts.unstable_opts.print_fuel.is_some() {
430 "Fuel used by {}: {}",
431 sess.opts.unstable_opts.print_fuel.as_ref().unwrap(),
432 sess.print_fuel.load(SeqCst)
441 pub fn set_sigpipe_handler() {
443 // Set the SIGPIPE signal handler, so that an EPIPE
444 // will cause rustc to terminate, as expected.
445 assert_ne!(libc::signal(libc::SIGPIPE, libc::SIG_DFL), libc::SIG_ERR);
450 pub fn set_sigpipe_handler() {}
452 // Extract output directory and file from matches.
453 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
454 let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
455 let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
459 // Extract input (string or file and optional path) from matches.
461 error_format: ErrorOutputType,
462 free_matches: &[String],
463 ) -> Result<Option<(Input, Option<PathBuf>)>, ErrorGuaranteed> {
464 if free_matches.len() == 1 {
465 let ifile = &free_matches[0];
467 let mut src = String::new();
468 if io::stdin().read_to_string(&mut src).is_err() {
469 // Immediately stop compilation if there was an issue reading
470 // the input (for example if the input stream is not UTF-8).
471 let reported = early_error_no_abort(
473 "couldn't read from stdin, as it did not contain valid UTF-8",
475 return Err(reported);
477 if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
478 let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect(
479 "when UNSTABLE_RUSTDOC_TEST_PATH is set \
480 UNSTABLE_RUSTDOC_TEST_LINE also needs to be set",
482 let line = isize::from_str_radix(&line, 10)
483 .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number");
484 let file_name = FileName::doc_test_source_code(PathBuf::from(path), line);
485 Ok(Some((Input::Str { name: file_name, input: src }, None)))
487 Ok(Some((Input::Str { name: FileName::anon_source_code(&src), input: src }, None)))
490 Ok(Some((Input::File(PathBuf::from(ifile)), Some(PathBuf::from(ifile)))))
497 /// Whether to stop or continue compilation.
498 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
499 pub enum Compilation {
505 pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
507 Compilation::Stop => Compilation::Stop,
508 Compilation::Continue => next(),
513 fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
514 let upper_cased_code = code.to_ascii_uppercase();
515 let normalised = if upper_cased_code.starts_with('E') {
518 format!("E{0:0>4}", code)
520 match registry.try_find_description(&normalised) {
521 Ok(Some(description)) => {
522 let mut is_in_code_block = false;
523 let mut text = String::new();
524 // Slice off the leading newline and print.
525 for line in description.lines() {
527 line.find(|c: char| !c.is_whitespace()).unwrap_or_else(|| line.len());
528 let dedented_line = &line[indent_level..];
529 if dedented_line.starts_with("```") {
530 is_in_code_block = !is_in_code_block;
531 text.push_str(&line[..(indent_level + 3)]);
532 } else if is_in_code_block && dedented_line.starts_with("# ") {
540 show_content_with_pager(&text);
546 early_error(output, &format!("no extended information for {}", code));
548 Err(InvalidErrorCode) => {
549 early_error(output, &format!("{} is not a valid error code", code));
554 fn show_content_with_pager(content: &str) {
555 let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
556 if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
559 let mut fallback_to_println = false;
561 match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
563 if let Some(pipe) = pager.stdin.as_mut() {
564 if pipe.write_all(content.as_bytes()).is_err() {
565 fallback_to_println = true;
569 if pager.wait().is_err() {
570 fallback_to_println = true;
574 fallback_to_println = true;
578 // If pager fails for whatever reason, we should still print the content
579 // to standard output
580 if fallback_to_println {
581 print!("{}", content);
585 pub fn try_process_rlink(sess: &Session, compiler: &interface::Compiler) -> Compilation {
586 if sess.opts.unstable_opts.link_only {
587 if let Input::File(file) = compiler.input() {
588 // FIXME: #![crate_type] and #![crate_name] support not implemented yet
589 sess.init_crate_types(collect_crate_types(sess, &[]));
590 let outputs = compiler.build_output_filenames(sess, &[]);
591 let rlink_data = fs::read(file).unwrap_or_else(|err| {
592 sess.emit_fatal(RlinkUnableToRead { err });
594 let codegen_results = match CodegenResults::deserialize_rlink(rlink_data) {
595 Ok(codegen) => codegen,
598 CodegenErrors::WrongFileType => sess.emit_fatal(RLinkWrongFileType),
599 CodegenErrors::EmptyVersionNumber => {
600 sess.emit_fatal(RLinkEmptyVersionNumber)
602 CodegenErrors::EncodingVersionMismatch { version_array, rlink_version } => {
603 sess.emit_fatal(RLinkEncodingVersionMismatch {
608 CodegenErrors::RustcVersionMismatch { rustc_version, current_version } => {
609 sess.emit_fatal(RLinkRustcVersionMismatch {
617 let result = compiler.codegen_backend().link(sess, codegen_results, &outputs);
618 abort_on_err(result, sess);
620 sess.emit_fatal(RlinkNotAFile {})
624 Compilation::Continue
628 pub fn list_metadata(
630 metadata_loader: &dyn MetadataLoader,
633 if sess.opts.unstable_opts.ls {
635 Input::File(ref ifile) => {
636 let path = &(*ifile);
637 let mut v = Vec::new();
638 locator::list_file_metadata(&sess.target, path, metadata_loader, &mut v).unwrap();
639 println!("{}", String::from_utf8(v).unwrap());
641 Input::Str { .. } => {
642 early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
645 return Compilation::Stop;
648 Compilation::Continue
652 codegen_backend: &dyn CodegenBackend,
654 input: Option<&Input>,
655 odir: &Option<PathBuf>,
656 ofile: &Option<PathBuf>,
657 temps_dir: &Option<PathBuf>,
659 use rustc_session::config::PrintRequest::*;
660 // NativeStaticLibs and LinkArgs are special - printed during linking
661 // (empty iterator returns true)
662 if sess.opts.prints.iter().all(|&p| p == NativeStaticLibs || p == LinkArgs) {
663 return Compilation::Continue;
666 let attrs = match input {
669 let result = parse_crate_attrs(sess, input);
671 Ok(attrs) => Some(attrs),
672 Err(mut parse_error) => {
674 return Compilation::Stop;
679 for req in &sess.opts.prints {
682 let mut targets = rustc_target::spec::TARGETS.iter().copied().collect::<Vec<_>>();
683 targets.sort_unstable();
684 println!("{}", targets.join("\n"));
686 Sysroot => println!("{}", sess.sysroot.display()),
687 TargetLibdir => println!("{}", sess.target_tlib_path.dir.display()),
689 println!("{}", serde_json::to_string_pretty(&sess.target.to_json()).unwrap());
691 FileNames | CrateName => {
692 let input = input.unwrap_or_else(|| {
693 early_error(ErrorOutputType::default(), "no input file provided")
695 let attrs = attrs.as_ref().unwrap();
696 let t_outputs = rustc_interface::util::build_output_filenames(
697 input, odir, ofile, temps_dir, attrs, sess,
699 let id = rustc_session::output::find_crate_name(sess, attrs, input);
700 if *req == PrintRequest::CrateName {
704 let crate_types = collect_crate_types(sess, attrs);
705 for &style in &crate_types {
707 rustc_session::output::filename_for_input(sess, style, &id, &t_outputs);
708 println!("{}", fname.file_name().unwrap().to_string_lossy());
716 .filter_map(|&(name, value)| {
717 // Note that crt-static is a specially recognized cfg
718 // directive that's printed out here as part of
719 // rust-lang/rust#37406, but in general the
720 // `target_feature` cfg is gated under
721 // rust-lang/rust#29717. For now this is just
722 // specifically allowing the crt-static cfg and that's
723 // it, this is intended to get into Cargo and then go
724 // through to build scripts.
725 if (name != sym::target_feature || value != Some(sym::crt_dash_static))
726 && !sess.is_nightly_build()
727 && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
732 if let Some(value) = value {
733 Some(format!("{}=\"{}\"", name, value))
735 Some(name.to_string())
738 .collect::<Vec<String>>();
749 | StackProtectorStrategies
750 | TargetFeatures => {
751 codegen_backend.print(*req, sess);
753 // Any output here interferes with Cargo's parsing of other printed output
754 NativeStaticLibs => {}
761 /// Prints version information
762 pub fn version(binary: &str, matches: &getopts::Matches) {
763 let verbose = matches.opt_present("verbose");
765 println!("{} {}", binary, util::version_str().unwrap_or("unknown version"));
768 fn unw(x: Option<&str>) -> &str {
769 x.unwrap_or("unknown")
771 println!("binary: {}", binary);
772 println!("commit-hash: {}", unw(util::commit_hash_str()));
773 println!("commit-date: {}", unw(util::commit_date_str()));
774 println!("host: {}", config::host_triple());
775 println!("release: {}", unw(util::release_str()));
777 let debug_flags = matches.opt_strs("Z");
778 let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
779 get_codegen_backend(&None, backend_name).print_version();
783 fn usage(verbose: bool, include_unstable_options: bool, nightly_build: bool) {
784 let groups = if verbose { config::rustc_optgroups() } else { config::rustc_short_optgroups() };
785 let mut options = getopts::Options::new();
786 for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
787 (option.apply)(&mut options);
789 let message = "Usage: rustc [OPTIONS] INPUT";
790 let nightly_help = if nightly_build {
791 "\n -Z help Print unstable compiler options"
795 let verbose_help = if verbose {
798 "\n --help -v Print the full set of options rustc accepts"
800 let at_path = if verbose {
801 " @path Read newline separated options from `path`\n"
806 "{options}{at_path}\nAdditional help:
807 -C help Print codegen options
809 Print 'lint' options and default settings{nightly}{verbose}\n",
810 options = options.usage(message),
812 nightly = nightly_help,
813 verbose = verbose_help
817 fn print_wall_help() {
820 The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
821 default. Use `rustc -W help` to see all available lints. It's more common to put
822 warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
823 the command line flag directly.
828 /// Write to stdout lint command options, together with a list of all available lints
829 pub fn describe_lints(sess: &Session, lint_store: &LintStore, loaded_plugins: bool) {
832 Available lint options:
833 -W <foo> Warn about <foo>
837 -F <foo> Forbid <foo> \
838 (deny <foo> and all attempts to override)
843 fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
844 // The sort doesn't case-fold but it's doubtful we care.
845 lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name));
850 lints: Vec<(&'static str, Vec<LintId>, bool)>,
851 ) -> Vec<(&'static str, Vec<LintId>)> {
852 let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
853 lints.sort_by_key(|l| l.0);
857 let (plugin, builtin): (Vec<_>, _) =
858 lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_plugin);
859 let plugin = sort_lints(sess, plugin);
860 let builtin = sort_lints(sess, builtin);
862 let (plugin_groups, builtin_groups): (Vec<_>, _) =
863 lint_store.get_lint_groups().partition(|&(.., p)| p);
864 let plugin_groups = sort_lint_groups(plugin_groups);
865 let builtin_groups = sort_lint_groups(builtin_groups);
868 plugin.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0);
869 let padded = |x: &str| {
870 let mut s = " ".repeat(max_name_len - x.chars().count());
875 println!("Lint checks provided by rustc:\n");
877 let print_lints = |lints: Vec<&Lint>| {
878 println!(" {} {:7.7} {}", padded("name"), "default", "meaning");
879 println!(" {} {:7.7} {}", padded("----"), "-------", "-------");
881 let name = lint.name_lower().replace('_', "-");
885 lint.default_level(sess.edition()).as_str(),
892 print_lints(builtin);
894 let max_name_len = max(
898 .chain(&builtin_groups)
899 .map(|&(s, _)| s.chars().count())
904 let padded = |x: &str| {
905 let mut s = " ".repeat(max_name_len - x.chars().count());
910 println!("Lint groups provided by rustc:\n");
912 let print_lint_groups = |lints: Vec<(&'static str, Vec<LintId>)>, all_warnings| {
913 println!(" {} sub-lints", padded("name"));
914 println!(" {} ---------", padded("----"));
917 println!(" {} all lints that are set to issue warnings", padded("warnings"));
920 for (name, to) in lints {
921 let name = name.to_lowercase().replace('_', "-");
924 .map(|x| x.to_string().replace('_', "-"))
925 .collect::<Vec<String>>()
927 println!(" {} {}", padded(&name), desc);
932 print_lint_groups(builtin_groups, true);
934 match (loaded_plugins, plugin.len(), plugin_groups.len()) {
935 (false, 0, _) | (false, _, 0) => {
936 println!("Lint tools like Clippy can provide additional lints and lint groups.");
938 (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
939 (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
942 println!("Lint checks provided by plugins loaded by this crate:\n");
946 println!("Lint groups provided by plugins loaded by this crate:\n");
947 print_lint_groups(plugin_groups, false);
953 fn describe_debug_flags() {
954 println!("\nAvailable options:\n");
955 print_flag_list("-Z", config::Z_OPTIONS);
958 fn describe_codegen_flags() {
959 println!("\nAvailable codegen options:\n");
960 print_flag_list("-C", config::CG_OPTIONS);
963 pub fn print_flag_list<T>(
965 flag_list: &[(&'static str, T, &'static str, &'static str)],
967 let max_len = flag_list.iter().map(|&(name, _, _, _)| name.chars().count()).max().unwrap_or(0);
969 for &(name, _, _, desc) in flag_list {
971 " {} {:>width$}=val -- {}",
973 name.replace('_', "-"),
980 /// Process command line options. Emits messages as appropriate. If compilation
981 /// should continue, returns a getopts::Matches object parsed from args,
982 /// otherwise returns `None`.
984 /// The compiler's handling of options is a little complicated as it ties into
985 /// our stability story. The current intention of each compiler option is to
986 /// have one of two modes:
988 /// 1. An option is stable and can be used everywhere.
989 /// 2. An option is unstable, and can only be used on nightly.
991 /// Like unstable library and language features, however, unstable options have
992 /// always required a form of "opt in" to indicate that you're using them. This
993 /// provides the easy ability to scan a code base to check to see if anything
994 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
996 /// All options behind `-Z` are considered unstable by default. Other top-level
997 /// options can also be considered unstable, and they were unlocked through the
998 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
999 /// instability in both cases, though.
1001 /// So with all that in mind, the comments below have some more detail about the
1002 /// contortions done here to get things to work out correctly.
1003 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
1004 // Throw away the first argument, the name of the binary
1005 let args = &args[1..];
1007 if args.is_empty() {
1008 // user did not write `-v` nor `-Z unstable-options`, so do not
1009 // include that extra information.
1011 rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build();
1012 usage(false, false, nightly_build);
1016 // Parse with *all* options defined in the compiler, we don't worry about
1017 // option stability here we just want to parse as much as possible.
1018 let mut options = getopts::Options::new();
1019 for option in config::rustc_optgroups() {
1020 (option.apply)(&mut options);
1022 let matches = options.parse(args).unwrap_or_else(|e| {
1024 getopts::Fail::UnrecognizedOption(ref opt) => CG_OPTIONS
1026 .map(|&(name, ..)| ('C', name))
1027 .chain(Z_OPTIONS.iter().map(|&(name, ..)| ('Z', name)))
1028 .find(|&(_, name)| *opt == name.replace('_', "-"))
1029 .map(|(flag, _)| format!("{}. Did you mean `-{} {}`?", e, flag, opt)),
1032 early_error(ErrorOutputType::default(), &msg.unwrap_or_else(|| e.to_string()));
1035 // For all options we just parsed, we check a few aspects:
1037 // * If the option is stable, we're all good
1038 // * If the option wasn't passed, we're all good
1039 // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1040 // ourselves), then we require the `-Z unstable-options` flag to unlock
1041 // this option that was passed.
1042 // * If we're a nightly compiler, then unstable options are now unlocked, so
1043 // we're good to go.
1044 // * Otherwise, if we're an unstable option then we generate an error
1045 // (unstable option being used on stable)
1046 nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
1048 if matches.opt_present("h") || matches.opt_present("help") {
1049 // Only show unstable options in --help if we accept unstable options.
1050 let unstable_enabled = nightly_options::is_unstable_enabled(&matches);
1051 let nightly_build = nightly_options::match_is_nightly_build(&matches);
1052 usage(matches.opt_present("verbose"), unstable_enabled, nightly_build);
1056 // Handle the special case of -Wall.
1057 let wall = matches.opt_strs("W");
1058 if wall.iter().any(|x| *x == "all") {
1060 rustc_errors::FatalError.raise();
1063 // Don't handle -W help here, because we might first load plugins.
1064 let debug_flags = matches.opt_strs("Z");
1065 if debug_flags.iter().any(|x| *x == "help") {
1066 describe_debug_flags();
1070 let cg_flags = matches.opt_strs("C");
1072 if cg_flags.iter().any(|x| *x == "help") {
1073 describe_codegen_flags();
1077 if cg_flags.iter().any(|x| *x == "no-stack-check") {
1079 ErrorOutputType::default(),
1080 "the --no-stack-check flag is deprecated and does nothing",
1084 if cg_flags.iter().any(|x| *x == "passes=list") {
1085 let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend="));
1086 get_codegen_backend(&None, backend_name).print_passes();
1090 if matches.opt_present("version") {
1091 version("rustc", &matches);
1098 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::AttrVec> {
1100 Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess),
1101 Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str(
1109 /// Gets a list of extra command-line flags provided by the user, as strings.
1111 /// This function is used during ICEs to show more information useful for
1112 /// debugging, since some ICEs only happens with non-default compiler flags
1113 /// (and the users don't always report them).
1114 fn extra_compiler_flags() -> Option<(Vec<String>, bool)> {
1115 let mut args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).peekable();
1117 let mut result = Vec::new();
1118 let mut excluded_cargo_defaults = false;
1119 while let Some(arg) = args.next() {
1120 if let Some(a) = ICE_REPORT_COMPILER_FLAGS.iter().find(|a| arg.starts_with(*a)) {
1121 let content = if arg.len() == a.len() {
1123 Some(arg) => arg.to_string(),
1126 } else if arg.get(a.len()..a.len() + 1) == Some("=") {
1127 arg[a.len() + 1..].to_string()
1129 arg[a.len()..].to_string()
1131 if ICE_REPORT_COMPILER_FLAGS_EXCLUDE.iter().any(|exc| content.starts_with(exc)) {
1132 excluded_cargo_defaults = true;
1134 result.push(a.to_string());
1135 match ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.iter().find(|s| content.starts_with(*s))
1137 Some(s) => result.push(s.to_string()),
1138 None => result.push(content),
1144 if !result.is_empty() { Some((result, excluded_cargo_defaults)) } else { None }
1147 /// Runs a closure and catches unwinds triggered by fatal errors.
1149 /// The compiler currently unwinds with a special sentinel value to abort
1150 /// compilation on fatal errors. This function catches that sentinel and turns
1151 /// the panic into a `Result` instead.
1152 pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorGuaranteed> {
1153 catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
1154 if value.is::<rustc_errors::FatalErrorMarker>() {
1155 ErrorGuaranteed::unchecked_claim_error_was_emitted()
1157 panic::resume_unwind(value);
1162 /// Variant of `catch_fatal_errors` for the `interface::Result` return type
1163 /// that also computes the exit code.
1164 pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
1165 let result = catch_fatal_errors(f).and_then(|result| result);
1167 Ok(()) => EXIT_SUCCESS,
1168 Err(_) => EXIT_FAILURE,
1172 static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
1174 let hook = panic::take_hook();
1175 panic::set_hook(Box::new(|info| {
1176 // If the error was caused by a broken pipe then this is not a bug.
1177 // Write the error and return immediately. See #98700.
1179 if let Some(msg) = info.payload().downcast_ref::<String>() {
1180 if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)")
1182 early_error_no_abort(ErrorOutputType::default(), &msg);
1187 // Invoke the default handler, which prints the actual panic message and optionally a backtrace
1188 (*DEFAULT_HOOK)(info);
1190 // Separate the output with an empty line
1193 // Print the ICE message
1194 report_ice(info, BUG_REPORT_URL);
1199 /// Prints the ICE message, including query stack, but without backtrace.
1201 /// The message will point the user at `bug_report_url` to report the ICE.
1203 /// When `install_ice_hook` is called, this function will be called as the panic
1205 pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
1206 let fallback_bundle =
1207 rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
1208 let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
1209 rustc_errors::ColorConfig::Auto,
1218 let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
1220 // a .span_bug or .bug call has already printed what
1221 // it wants to print.
1222 if !info.payload().is::<rustc_errors::ExplicitBug>() {
1223 let mut d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
1224 handler.emit_diagnostic(&mut d);
1227 let mut xs: Vec<Cow<'static, str>> = vec![
1228 "the compiler unexpectedly panicked. this is a bug.".into(),
1229 format!("we would appreciate a bug report: {}", bug_report_url).into(),
1231 "rustc {} running on {}",
1232 util::version_str().unwrap_or("unknown_version"),
1233 config::host_triple()
1238 if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
1239 xs.push(format!("compiler flags: {}", flags.join(" ")).into());
1241 if excluded_cargo_defaults {
1242 xs.push("some of the compiler flags provided by cargo are hidden".into());
1247 handler.note_without_error(note.as_ref());
1250 // If backtraces are enabled, also print the query stack
1251 let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
1253 let num_frames = if backtrace { None } else { Some(2) };
1255 interface::try_print_query_stack(&handler, num_frames);
1259 if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
1260 // Trigger a debugger if we crashed during bootstrap
1261 winapi::um::debugapi::DebugBreak();
1266 /// Installs a panic hook that will print the ICE message on unexpected panics.
1268 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
1269 pub fn install_ice_hook() {
1270 // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
1271 // full backtraces. When a compiler ICE happens, we want to gather
1272 // as much information as possible to present in the issue opened
1273 // by the user. Compiler developers and other rustc users can
1274 // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE"
1275 // (e.g. `RUST_BACKTRACE=1`)
1276 if std::env::var("RUST_BACKTRACE").is_err() {
1277 std::env::set_var("RUST_BACKTRACE", "full");
1279 LazyLock::force(&DEFAULT_HOOK);
1282 /// This allows tools to enable rust logging without having to magically match rustc's
1283 /// tracing crate version.
1284 pub fn init_rustc_env_logger() {
1285 if let Err(error) = rustc_log::init_rustc_env_logger() {
1286 early_error(ErrorOutputType::default(), &error.to_string());
1290 /// This allows tools to enable rust logging without having to magically match rustc's
1291 /// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose an env var
1292 /// other than `RUSTC_LOG`.
1293 pub fn init_env_logger(env: &str) {
1294 if let Err(error) = rustc_log::init_env_logger(env) {
1295 early_error(ErrorOutputType::default(), &error.to_string());
1299 #[cfg(all(unix, any(target_env = "gnu", target_os = "macos")))]
1300 mod signal_handler {
1302 fn backtrace_symbols_fd(
1303 buffer: *const *mut libc::c_void,
1309 extern "C" fn print_stack_trace(_: libc::c_int) {
1310 const MAX_FRAMES: usize = 256;
1311 static mut STACK_TRACE: [*mut libc::c_void; MAX_FRAMES] =
1312 [std::ptr::null_mut(); MAX_FRAMES];
1314 let depth = libc::backtrace(STACK_TRACE.as_mut_ptr(), MAX_FRAMES as i32);
1318 backtrace_symbols_fd(STACK_TRACE.as_ptr(), depth, 2);
1322 // When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
1323 // process, print a stack trace and then exit.
1324 pub(super) fn install() {
1326 const ALT_STACK_SIZE: usize = libc::MINSIGSTKSZ + 64 * 1024;
1327 let mut alt_stack: libc::stack_t = std::mem::zeroed();
1329 std::alloc::alloc(std::alloc::Layout::from_size_align(ALT_STACK_SIZE, 1).unwrap())
1330 as *mut libc::c_void;
1331 alt_stack.ss_size = ALT_STACK_SIZE;
1332 libc::sigaltstack(&alt_stack, std::ptr::null_mut());
1334 let mut sa: libc::sigaction = std::mem::zeroed();
1335 sa.sa_sigaction = print_stack_trace as libc::sighandler_t;
1336 sa.sa_flags = libc::SA_NODEFER | libc::SA_RESETHAND | libc::SA_ONSTACK;
1337 libc::sigemptyset(&mut sa.sa_mask);
1338 libc::sigaction(libc::SIGSEGV, &sa, std::ptr::null_mut());
1343 #[cfg(not(all(unix, any(target_env = "gnu", target_os = "macos"))))]
1344 mod signal_handler {
1345 pub(super) fn install() {}
1348 pub fn main() -> ! {
1349 let start_time = Instant::now();
1350 let start_rss = get_resident_set_size();
1351 init_rustc_env_logger();
1352 signal_handler::install();
1353 let mut callbacks = TimePassesCallbacks::default();
1355 let exit_code = catch_with_exit_code(|| {
1356 let args = env::args_os()
1359 arg.into_string().unwrap_or_else(|arg| {
1361 ErrorOutputType::default(),
1362 &format!("argument {} is not valid Unicode: {:?}", i, arg),
1366 .collect::<Vec<_>>();
1367 RunCompiler::new(&args, &mut callbacks).run()
1370 if callbacks.time_passes {
1371 let end_rss = get_resident_set_size();
1372 print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss);
1375 process::exit(exit_code)