5 //! This API is completely unstable and subject to change.
7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
9 #![recursion_limit = "256"]
14 extern crate lazy_static;
16 pub extern crate rustc_plugin_impl as plugin;
19 use rustc_codegen_ssa::{traits::CodegenBackend, CodegenResults};
20 use rustc_data_structures::profiling::print_time_passes_entry;
21 use rustc_data_structures::sync::SeqCst;
22 use rustc_errors::registry::{InvalidErrorCode, Registry};
23 use rustc_errors::{ErrorReported, PResult};
24 use rustc_feature::{find_gated_cfg, UnstableFeatures};
25 use rustc_hir::def_id::LOCAL_CRATE;
26 use rustc_interface::util::{collect_crate_types, get_builtin_codegen_backend};
27 use rustc_interface::{interface, Queries};
28 use rustc_lint::LintStore;
29 use rustc_metadata::locator;
30 use rustc_middle::middle::cstore::MetadataLoader;
31 use rustc_middle::ty::TyCtxt;
32 use rustc_save_analysis as save;
33 use rustc_save_analysis::DumpHandler;
34 use rustc_serialize::json::{self, ToJson};
35 use rustc_session::config::nightly_options;
36 use rustc_session::config::{ErrorOutputType, Input, OutputType, PrintRequest};
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_warn};
41 use rustc_span::source_map::{FileLoader, FileName};
42 use rustc_span::symbol::sym;
46 use std::default::Default;
48 use std::ffi::OsString;
50 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::time::Instant;
61 /// Exit status code used for successful compilation and help output.
62 pub const EXIT_SUCCESS: i32 = 0;
64 /// Exit status code used for compilation failures and invalid flags.
65 pub const EXIT_FAILURE: i32 = 1;
67 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
68 ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md";
70 const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["Z", "C", "crate-type"];
72 const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"];
74 const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"];
76 pub fn abort_on_err<T>(result: Result<T, ErrorReported>, sess: &Session) -> T {
79 sess.abort_if_errors();
80 panic!("error reported but abort_if_errors didn't abort???");
87 /// Called before creating the compiler instance
88 fn config(&mut self, _config: &mut interface::Config) {}
89 /// Called after parsing. Return value instructs the compiler whether to
90 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
91 fn after_parsing<'tcx>(
93 _compiler: &interface::Compiler,
94 _queries: &'tcx Queries<'tcx>,
98 /// Called after expansion. Return value instructs the compiler whether to
99 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
100 fn after_expansion<'tcx>(
102 _compiler: &interface::Compiler,
103 _queries: &'tcx Queries<'tcx>,
105 Compilation::Continue
107 /// Called after analysis. Return value instructs the compiler whether to
108 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
109 fn after_analysis<'tcx>(
111 _compiler: &interface::Compiler,
112 _queries: &'tcx Queries<'tcx>,
114 Compilation::Continue
119 pub struct TimePassesCallbacks {
123 impl Callbacks for TimePassesCallbacks {
124 fn config(&mut self, config: &mut interface::Config) {
125 // If a --prints=... option has been given, we don't print the "total"
126 // time because it will mess up the --prints output. See #64339.
127 self.time_passes = config.opts.prints.is_empty()
128 && (config.opts.debugging_opts.time_passes || config.opts.debugging_opts.time);
132 pub fn diagnostics_registry() -> Registry {
133 Registry::new(&rustc_error_codes::DIAGNOSTICS)
136 // Parse args and run the compiler. This is the primary entry point for rustc.
137 // The FileLoader provides a way to load files from sources other than the file system.
140 callbacks: &mut (dyn Callbacks + Send),
141 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
142 emitter: Option<Box<dyn Write + Send>>,
143 ) -> interface::Result<()> {
144 let mut args = Vec::new();
146 match args::arg_expand(arg.clone()) {
147 Ok(arg) => args.extend(arg),
148 Err(err) => early_error(
149 ErrorOutputType::default(),
150 &format!("Failed to load argument file: {}", err),
154 let diagnostic_output =
155 emitter.map(|emitter| DiagnosticOutput::Raw(emitter)).unwrap_or(DiagnosticOutput::Default);
156 let matches = match handle_options(&args) {
157 Some(matches) => matches,
158 None => return Ok(()),
161 let sopts = config::build_session_options(&matches);
162 let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg"));
164 let mut dummy_config = |sopts, cfg, diagnostic_output| {
165 let mut config = interface::Config {
168 input: Input::File(PathBuf::new()),
176 lint_caps: Default::default(),
177 register_lints: None,
178 override_queries: None,
179 registry: diagnostics_registry(),
181 callbacks.config(&mut config);
185 if let Some(ref code) = matches.opt_str("explain") {
186 handle_explain(diagnostics_registry(), code, sopts.error_format);
190 let (odir, ofile) = make_output(&matches);
191 let (input, input_file_path, input_err) = match make_input(&matches.free) {
193 None => match matches.free.len() {
195 let config = dummy_config(sopts, cfg, diagnostic_output);
196 interface::run_compiler(config, |compiler| {
197 let sopts = &compiler.session().opts;
198 if sopts.describe_lints {
199 let lint_store = rustc_lint::new_lint_store(
200 sopts.debugging_opts.no_interleave_lints,
201 compiler.session().unstable_options(),
203 describe_lints(compiler.session(), &lint_store, false);
206 let should_stop = RustcDefaultCalls::print_crate_info(
207 &***compiler.codegen_backend(),
214 if should_stop == Compilation::Stop {
217 early_error(sopts.error_format, "no input filename given")
221 1 => panic!("make_input should have provided valid inputs"),
225 "multiple input filenames provided (first two filenames are `{}` and `{}`)",
226 matches.free[0], matches.free[1],
232 if let Some(err) = input_err {
233 // Immediately stop compilation if there was an issue reading
234 // the input (for example if the input stream is not UTF-8).
235 interface::run_compiler(dummy_config(sopts, cfg, diagnostic_output), |compiler| {
236 compiler.session().err(&err.to_string());
238 return Err(ErrorReported);
241 let mut config = interface::Config {
245 input_path: input_file_path,
252 lint_caps: Default::default(),
253 register_lints: None,
254 override_queries: None,
255 registry: diagnostics_registry(),
258 callbacks.config(&mut config);
260 interface::run_compiler(config, |compiler| {
261 let sess = compiler.session();
262 let should_stop = RustcDefaultCalls::print_crate_info(
263 &***compiler.codegen_backend(),
265 Some(compiler.input()),
266 compiler.output_dir(),
267 compiler.output_file(),
270 RustcDefaultCalls::list_metadata(
272 &*compiler.codegen_backend().metadata_loader(),
277 .and_then(|| RustcDefaultCalls::try_process_rlink(sess, compiler));
279 if should_stop == Compilation::Stop {
280 return sess.compile_status();
283 let linker = compiler.enter(|queries| {
284 let early_exit = || sess.compile_status().map(|_| None);
287 if let Some(ppm) = &sess.opts.pretty {
288 if ppm.needs_ast_map() {
289 queries.global_ctxt()?.peek_mut().enter(|tcx| {
290 let expanded_crate = queries.expansion()?.take().0;
291 pretty::print_after_hir_lowering(
296 compiler.output_file().as_ref().map(|p| &**p),
301 let krate = queries.parse()?.take();
302 pretty::print_after_parsing(
307 compiler.output_file().as_ref().map(|p| &**p),
310 trace!("finished pretty-printing");
314 if callbacks.after_parsing(compiler, queries) == Compilation::Stop {
318 if sess.opts.debugging_opts.parse_only
319 || sess.opts.debugging_opts.show_span.is_some()
320 || sess.opts.debugging_opts.ast_json_noexpand
326 let (_, lint_store) = &*queries.register_plugins()?.peek();
328 // Lint plugins are registered; now we can process command line flags.
329 if sess.opts.describe_lints {
330 describe_lints(&sess, &lint_store, true);
335 queries.expansion()?;
336 if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
340 queries.prepare_outputs()?;
342 if sess.opts.output_types.contains_key(&OutputType::DepInfo)
343 && sess.opts.output_types.len() == 1
348 queries.global_ctxt()?;
350 // Drop AST after creating GlobalCtxt to free memory
352 let _timer = sess.prof.generic_activity("drop_ast");
353 mem::drop(queries.expansion()?.take());
356 if sess.opts.debugging_opts.no_analysis || sess.opts.debugging_opts.ast_json {
360 if sess.opts.debugging_opts.save_analysis {
361 let crate_name = queries.crate_name()?.peek().clone();
362 queries.global_ctxt()?.peek_mut().enter(|tcx| {
363 let result = tcx.analysis(LOCAL_CRATE);
365 sess.time("save_analysis", || {
372 compiler.output_dir().as_ref().map(|p| &**p),
382 queries.global_ctxt()?.peek_mut().enter(|tcx| tcx.analysis(LOCAL_CRATE))?;
384 if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
388 queries.ongoing_codegen()?;
390 if sess.opts.debugging_opts.print_type_sizes {
391 sess.code_stats.print_type_sizes();
394 let linker = queries.linker()?;
398 if let Some(linker) = linker {
399 let _timer = sess.timer("link");
403 if sess.opts.debugging_opts.perf_stats {
404 sess.print_perf_stats();
407 if sess.print_fuel_crate.is_some() {
409 "Fuel used by {}: {}",
410 sess.print_fuel_crate.as_ref().unwrap(),
411 sess.print_fuel.load(SeqCst)
420 pub fn set_sigpipe_handler() {
422 // Set the SIGPIPE signal handler, so that an EPIPE
423 // will cause rustc to terminate, as expected.
424 assert_ne!(libc::signal(libc::SIGPIPE, libc::SIG_DFL), libc::SIG_ERR);
429 pub fn set_sigpipe_handler() {}
431 // Extract output directory and file from matches.
432 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
433 let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
434 let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
438 // Extract input (string or file and optional path) from matches.
439 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>, Option<io::Error>)> {
440 if free_matches.len() == 1 {
441 let ifile = &free_matches[0];
443 let mut src = String::new();
444 let err = if io::stdin().read_to_string(&mut src).is_err() {
446 io::ErrorKind::InvalidData,
447 "couldn't read from stdin, as it did not contain valid UTF-8",
452 if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
453 let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect(
454 "when UNSTABLE_RUSTDOC_TEST_PATH is set \
455 UNSTABLE_RUSTDOC_TEST_LINE also needs to be set",
457 let line = isize::from_str_radix(&line, 10)
458 .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number");
459 let file_name = FileName::doc_test_source_code(PathBuf::from(path), line);
460 return Some((Input::Str { name: file_name, input: src }, None, err));
462 Some((Input::Str { name: FileName::anon_source_code(&src), input: src }, None, err))
464 Some((Input::File(PathBuf::from(ifile)), Some(PathBuf::from(ifile)), None))
471 // Whether to stop or continue compilation.
472 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
473 pub enum Compilation {
479 pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
481 Compilation::Stop => Compilation::Stop,
482 Compilation::Continue => next(),
487 /// CompilerCalls instance for a regular rustc build.
488 #[derive(Copy, Clone)]
489 pub struct RustcDefaultCalls;
491 // FIXME remove these and use winapi 0.3 instead
492 // Duplicates: bootstrap/compile.rs, librustc_errors/emitter.rs
494 fn stdout_isatty() -> bool {
495 unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
499 fn stdout_isatty() -> bool {
500 use winapi::um::consoleapi::GetConsoleMode;
501 use winapi::um::processenv::GetStdHandle;
502 use winapi::um::winbase::STD_OUTPUT_HANDLE;
505 let handle = GetStdHandle(STD_OUTPUT_HANDLE);
507 GetConsoleMode(handle, &mut out) != 0
511 fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
513 if code.starts_with('E') { code.to_string() } else { format!("E{0:0>4}", code) };
514 match registry.try_find_description(&normalised) {
515 Ok(Some(description)) => {
516 let mut is_in_code_block = false;
517 let mut text = String::new();
518 // Slice off the leading newline and print.
519 for line in description.lines() {
521 line.find(|c: char| !c.is_whitespace()).unwrap_or_else(|| line.len());
522 let dedented_line = &line[indent_level..];
523 if dedented_line.starts_with("```") {
524 is_in_code_block = !is_in_code_block;
525 text.push_str(&line[..(indent_level + 3)]);
526 } else if is_in_code_block && dedented_line.starts_with("# ") {
534 show_content_with_pager(&text);
540 early_error(output, &format!("no extended information for {}", code));
542 Err(InvalidErrorCode) => {
543 early_error(output, &format!("{} is not a valid error code", code));
548 fn show_content_with_pager(content: &String) {
549 let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
550 if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
553 let mut fallback_to_println = false;
555 match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
557 if let Some(pipe) = pager.stdin.as_mut() {
558 if pipe.write_all(content.as_bytes()).is_err() {
559 fallback_to_println = true;
563 if pager.wait().is_err() {
564 fallback_to_println = true;
568 fallback_to_println = true;
572 // If pager fails for whatever reason, we should still print the content
573 // to standard output
574 if fallback_to_println {
575 print!("{}", content);
579 impl RustcDefaultCalls {
580 fn process_rlink(sess: &Session, compiler: &interface::Compiler) -> Result<(), ErrorReported> {
581 if let Input::File(file) = compiler.input() {
582 // FIXME: #![crate_type] and #![crate_name] support not implemented yet
584 sess.init_crate_types(collect_crate_types(sess, &attrs));
585 let outputs = compiler.build_output_filenames(&sess, &attrs);
586 let rlink_data = fs::read_to_string(file).unwrap_or_else(|err| {
587 sess.fatal(&format!("failed to read rlink file: {}", err));
589 let codegen_results: CodegenResults = json::decode(&rlink_data).unwrap_or_else(|err| {
590 sess.fatal(&format!("failed to decode rlink: {}", err));
592 compiler.codegen_backend().link(&sess, Box::new(codegen_results), &outputs)
594 sess.fatal("rlink must be a file")
598 pub fn try_process_rlink(sess: &Session, compiler: &interface::Compiler) -> Compilation {
599 if sess.opts.debugging_opts.link_only {
600 let result = RustcDefaultCalls::process_rlink(sess, compiler);
601 abort_on_err(result, sess);
604 Compilation::Continue
608 pub fn list_metadata(
610 metadata_loader: &dyn MetadataLoader,
611 matches: &getopts::Matches,
614 let r = matches.opt_strs("Z");
615 if r.iter().any(|s| *s == "ls") {
617 Input::File(ref ifile) => {
618 let path = &(*ifile);
619 let mut v = Vec::new();
620 locator::list_file_metadata(&sess.target.target, path, metadata_loader, &mut v)
622 println!("{}", String::from_utf8(v).unwrap());
624 Input::Str { .. } => {
625 early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
628 return Compilation::Stop;
631 Compilation::Continue
635 codegen_backend: &dyn CodegenBackend,
637 input: Option<&Input>,
638 odir: &Option<PathBuf>,
639 ofile: &Option<PathBuf>,
641 use rustc_session::config::PrintRequest::*;
642 // PrintRequest::NativeStaticLibs is special - printed during linking
643 // (empty iterator returns true)
644 if sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
645 return Compilation::Continue;
648 let attrs = match input {
651 let result = parse_crate_attrs(sess, input);
653 Ok(attrs) => Some(attrs),
654 Err(mut parse_error) => {
656 return Compilation::Stop;
661 for req in &sess.opts.prints {
664 let mut targets = rustc_target::spec::get_targets().collect::<Vec<String>>();
666 println!("{}", targets.join("\n"));
668 Sysroot => println!("{}", sess.sysroot.display()),
669 TargetLibdir => println!(
671 sess.target_tlib_path.as_ref().unwrap_or(&sess.host_tlib_path).dir.display()
673 TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
674 FileNames | CrateName => {
675 let input = input.unwrap_or_else(|| {
676 early_error(ErrorOutputType::default(), "no input file provided")
678 let attrs = attrs.as_ref().unwrap();
679 let t_outputs = rustc_interface::util::build_output_filenames(
680 input, odir, ofile, attrs, sess,
682 let id = rustc_session::output::find_crate_name(sess, attrs, input);
683 if *req == PrintRequest::CrateName {
687 let crate_types = collect_crate_types(sess, attrs);
688 for &style in &crate_types {
690 rustc_session::output::filename_for_input(sess, style, &id, &t_outputs);
691 println!("{}", fname.file_name().unwrap().to_string_lossy());
695 let allow_unstable_cfg =
696 UnstableFeatures::from_environment().is_nightly_build();
702 .filter_map(|&(name, value)| {
703 // Note that crt-static is a specially recognized cfg
704 // directive that's printed out here as part of
705 // rust-lang/rust#37406, but in general the
706 // `target_feature` cfg is gated under
707 // rust-lang/rust#29717. For now this is just
708 // specifically allowing the crt-static cfg and that's
709 // it, this is intended to get into Cargo and then go
710 // through to build scripts.
711 if (name != sym::target_feature || value != Some(sym::crt_dash_static))
712 && !allow_unstable_cfg
713 && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
718 if let Some(value) = value {
719 Some(format!("{}=\"{}\"", name, value))
721 Some(name.to_string())
724 .collect::<Vec<String>>();
731 RelocationModels | CodeModels | TlsModels | TargetCPUs | TargetFeatures => {
732 codegen_backend.print(*req, sess);
734 // Any output here interferes with Cargo's parsing of other printed output
735 PrintRequest::NativeStaticLibs => {}
742 /// Returns a version string such as "0.12.0-dev".
743 fn release_str() -> Option<&'static str> {
744 option_env!("CFG_RELEASE")
747 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
748 fn commit_hash_str() -> Option<&'static str> {
749 option_env!("CFG_VER_HASH")
752 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
753 fn commit_date_str() -> Option<&'static str> {
754 option_env!("CFG_VER_DATE")
757 /// Prints version information
758 pub fn version(binary: &str, matches: &getopts::Matches) {
759 let verbose = matches.opt_present("verbose");
761 println!("{} {}", binary, option_env!("CFG_VERSION").unwrap_or("unknown version"));
764 fn unw(x: Option<&str>) -> &str {
765 x.unwrap_or("unknown")
767 println!("binary: {}", binary);
768 println!("commit-hash: {}", unw(commit_hash_str()));
769 println!("commit-date: {}", unw(commit_date_str()));
770 println!("host: {}", config::host_triple());
771 println!("release: {}", unw(release_str()));
772 get_builtin_codegen_backend("llvm")().print_version();
776 fn usage(verbose: bool, include_unstable_options: bool) {
777 let groups = if verbose { config::rustc_optgroups() } else { config::rustc_short_optgroups() };
778 let mut options = getopts::Options::new();
779 for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
780 (option.apply)(&mut options);
782 let message = "Usage: rustc [OPTIONS] INPUT";
783 let nightly_help = if nightly_options::is_nightly_build() {
784 "\n -Z help Print unstable compiler options"
788 let verbose_help = if verbose {
791 "\n --help -v Print the full set of options rustc accepts"
793 let at_path = if verbose && nightly_options::is_nightly_build() {
794 " @path Read newline separated options from `path`\n"
799 "{options}{at_path}\nAdditional help:
800 -C help Print codegen options
802 Print 'lint' options and default settings{nightly}{verbose}\n",
803 options = options.usage(message),
805 nightly = nightly_help,
806 verbose = verbose_help
810 fn print_wall_help() {
813 The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
814 default. Use `rustc -W help` to see all available lints. It's more common to put
815 warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
816 the command line flag directly.
821 fn describe_lints(sess: &Session, lint_store: &LintStore, loaded_plugins: bool) {
824 Available lint options:
825 -W <foo> Warn about <foo>
829 -F <foo> Forbid <foo> \
830 (deny <foo> and all attempts to override)
835 fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
836 // The sort doesn't case-fold but it's doubtful we care.
837 lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name));
842 lints: Vec<(&'static str, Vec<LintId>, bool)>,
843 ) -> Vec<(&'static str, Vec<LintId>)> {
844 let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
845 lints.sort_by_key(|l| l.0);
849 let (plugin, builtin): (Vec<_>, _) =
850 lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_plugin);
851 let plugin = sort_lints(sess, plugin);
852 let builtin = sort_lints(sess, builtin);
854 let (plugin_groups, builtin_groups): (Vec<_>, _) =
855 lint_store.get_lint_groups().iter().cloned().partition(|&(.., p)| p);
856 let plugin_groups = sort_lint_groups(plugin_groups);
857 let builtin_groups = sort_lint_groups(builtin_groups);
860 plugin.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0);
861 let padded = |x: &str| {
862 let mut s = " ".repeat(max_name_len - x.chars().count());
867 println!("Lint checks provided by rustc:\n");
868 println!(" {} {:7.7} {}", padded("name"), "default", "meaning");
869 println!(" {} {:7.7} {}", padded("----"), "-------", "-------");
871 let print_lints = |lints: Vec<&Lint>| {
873 let name = lint.name_lower().replace("_", "-");
874 println!(" {} {:7.7} {}", padded(&name), lint.default_level.as_str(), lint.desc);
879 print_lints(builtin);
881 let max_name_len = max(
885 .chain(&builtin_groups)
886 .map(|&(s, _)| s.chars().count())
891 let padded = |x: &str| {
892 let mut s = " ".repeat(max_name_len - x.chars().count());
897 println!("Lint groups provided by rustc:\n");
898 println!(" {} {}", padded("name"), "sub-lints");
899 println!(" {} {}", padded("----"), "---------");
900 println!(" {} {}", padded("warnings"), "all lints that are set to issue warnings");
902 let print_lint_groups = |lints: Vec<(&'static str, Vec<LintId>)>| {
903 for (name, to) in lints {
904 let name = name.to_lowercase().replace("_", "-");
907 .map(|x| x.to_string().replace("_", "-"))
908 .collect::<Vec<String>>()
910 println!(" {} {}", padded(&name), desc);
915 print_lint_groups(builtin_groups);
917 match (loaded_plugins, plugin.len(), plugin_groups.len()) {
918 (false, 0, _) | (false, _, 0) => {
920 "Compiler plugins can provide additional lints and lint groups. To see a \
921 listing of these, re-run `rustc -W help` with a crate filename."
924 (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
925 (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
928 println!("Lint checks provided by plugins loaded by this crate:\n");
932 println!("Lint groups provided by plugins loaded by this crate:\n");
933 print_lint_groups(plugin_groups);
939 fn describe_debug_flags() {
940 println!("\nAvailable options:\n");
941 print_flag_list("-Z", config::DB_OPTIONS);
944 fn describe_codegen_flags() {
945 println!("\nAvailable codegen options:\n");
946 print_flag_list("-C", config::CG_OPTIONS);
949 fn print_flag_list<T>(
951 flag_list: &[(&'static str, T, &'static str, &'static str)],
953 let max_len = flag_list.iter().map(|&(name, _, _, _)| name.chars().count()).max().unwrap_or(0);
955 for &(name, _, _, desc) in flag_list {
957 " {} {:>width$}=val -- {}",
959 name.replace("_", "-"),
966 /// Process command line options. Emits messages as appropriate. If compilation
967 /// should continue, returns a getopts::Matches object parsed from args,
968 /// otherwise returns `None`.
970 /// The compiler's handling of options is a little complicated as it ties into
971 /// our stability story. The current intention of each compiler option is to
972 /// have one of two modes:
974 /// 1. An option is stable and can be used everywhere.
975 /// 2. An option is unstable, and can only be used on nightly.
977 /// Like unstable library and language features, however, unstable options have
978 /// always required a form of "opt in" to indicate that you're using them. This
979 /// provides the easy ability to scan a code base to check to see if anything
980 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
982 /// All options behind `-Z` are considered unstable by default. Other top-level
983 /// options can also be considered unstable, and they were unlocked through the
984 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
985 /// instability in both cases, though.
987 /// So with all that in mind, the comments below have some more detail about the
988 /// contortions done here to get things to work out correctly.
989 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
990 // Throw away the first argument, the name of the binary
991 let args = &args[1..];
994 // user did not write `-v` nor `-Z unstable-options`, so do not
995 // include that extra information.
1000 // Parse with *all* options defined in the compiler, we don't worry about
1001 // option stability here we just want to parse as much as possible.
1002 let mut options = getopts::Options::new();
1003 for option in config::rustc_optgroups() {
1004 (option.apply)(&mut options);
1006 let matches = options
1008 .unwrap_or_else(|f| early_error(ErrorOutputType::default(), &f.to_string()));
1010 // For all options we just parsed, we check a few aspects:
1012 // * If the option is stable, we're all good
1013 // * If the option wasn't passed, we're all good
1014 // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1015 // ourselves), then we require the `-Z unstable-options` flag to unlock
1016 // this option that was passed.
1017 // * If we're a nightly compiler, then unstable options are now unlocked, so
1018 // we're good to go.
1019 // * Otherwise, if we're an unstable option then we generate an error
1020 // (unstable option being used on stable)
1021 nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
1023 if matches.opt_present("h") || matches.opt_present("help") {
1024 // Only show unstable options in --help if we accept unstable options.
1025 usage(matches.opt_present("verbose"), nightly_options::is_unstable_enabled(&matches));
1029 // Handle the special case of -Wall.
1030 let wall = matches.opt_strs("W");
1031 if wall.iter().any(|x| *x == "all") {
1036 // Don't handle -W help here, because we might first load plugins.
1037 let r = matches.opt_strs("Z");
1038 if r.iter().any(|x| *x == "help") {
1039 describe_debug_flags();
1043 let cg_flags = matches.opt_strs("C");
1045 if cg_flags.iter().any(|x| *x == "help") {
1046 describe_codegen_flags();
1050 if cg_flags.iter().any(|x| *x == "no-stack-check") {
1052 ErrorOutputType::default(),
1053 "the --no-stack-check flag is deprecated and does nothing",
1057 if cg_flags.iter().any(|x| *x == "passes=list") {
1058 get_builtin_codegen_backend("llvm")().print_passes();
1062 if matches.opt_present("version") {
1063 version("rustc", &matches);
1070 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1072 Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess),
1073 Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str(
1081 /// Gets a list of extra command-line flags provided by the user, as strings.
1083 /// This function is used during ICEs to show more information useful for
1084 /// debugging, since some ICEs only happens with non-default compiler flags
1085 /// (and the users don't always report them).
1086 fn extra_compiler_flags() -> Option<(Vec<String>, bool)> {
1087 let args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).collect::<Vec<_>>();
1089 // Avoid printing help because of empty args. This can suggest the compiler
1090 // itself is not the program root (consider RLS).
1095 let matches = handle_options(&args)?;
1096 let mut result = Vec::new();
1097 let mut excluded_cargo_defaults = false;
1098 for flag in ICE_REPORT_COMPILER_FLAGS {
1099 let prefix = if flag.len() == 1 { "-" } else { "--" };
1101 for content in &matches.opt_strs(flag) {
1102 // Split always returns the first element
1103 let name = if let Some(first) = content.split('=').next() { first } else { &content };
1106 if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) { name } else { content };
1108 if !ICE_REPORT_COMPILER_FLAGS_EXCLUDE.contains(&name) {
1109 result.push(format!("{}{} {}", prefix, flag, content));
1111 excluded_cargo_defaults = true;
1116 if !result.is_empty() { Some((result, excluded_cargo_defaults)) } else { None }
1119 /// Runs a closure and catches unwinds triggered by fatal errors.
1121 /// The compiler currently unwinds with a special sentinel value to abort
1122 /// compilation on fatal errors. This function catches that sentinel and turns
1123 /// the panic into a `Result` instead.
1124 pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorReported> {
1125 catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
1126 if value.is::<rustc_errors::FatalErrorMarker>() {
1129 panic::resume_unwind(value);
1134 /// Variant of `catch_fatal_errors` for the `interface::Result` return type
1135 /// that also computes the exit code.
1136 pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
1137 let result = catch_fatal_errors(f).and_then(|result| result);
1139 Ok(()) => EXIT_SUCCESS,
1140 Err(_) => EXIT_FAILURE,
1145 static ref DEFAULT_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
1146 let hook = panic::take_hook();
1147 panic::set_hook(Box::new(|info| report_ice(info, BUG_REPORT_URL)));
1152 /// Prints the ICE message, including backtrace and query stack.
1154 /// The message will point the user at `bug_report_url` to report the ICE.
1156 /// When `install_ice_hook` is called, this function will be called as the panic
1158 pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
1159 // Invoke the default handler, which prints the actual panic message and optionally a backtrace
1160 (*DEFAULT_HOOK)(info);
1162 // Separate the output with an empty line
1165 let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
1166 rustc_errors::ColorConfig::Auto,
1173 let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
1175 // a .span_bug or .bug call has already printed what
1176 // it wants to print.
1177 if !info.payload().is::<rustc_errors::ExplicitBug>() {
1178 let d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
1179 handler.emit_diagnostic(&d);
1182 let mut xs: Vec<Cow<'static, str>> = vec![
1183 "the compiler unexpectedly panicked. this is a bug.".into(),
1184 format!("we would appreciate a bug report: {}", bug_report_url).into(),
1186 "rustc {} running on {}",
1187 option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1188 config::host_triple()
1193 if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
1194 xs.push(format!("compiler flags: {}", flags.join(" ")).into());
1196 if excluded_cargo_defaults {
1197 xs.push("some of the compiler flags provided by cargo are hidden".into());
1202 handler.note_without_error(¬e);
1205 // If backtraces are enabled, also print the query stack
1206 let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
1209 TyCtxt::try_print_query_stack(&handler);
1214 if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
1215 // Trigger a debugger if we crashed during bootstrap
1216 winapi::um::debugapi::DebugBreak();
1221 /// Installs a panic hook that will print the ICE message on unexpected panics.
1223 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
1224 pub fn install_ice_hook() {
1225 lazy_static::initialize(&DEFAULT_HOOK);
1228 /// This allows tools to enable rust logging without having to magically match rustc's
1229 /// tracing crate version.
1230 pub fn init_rustc_env_logger() {
1231 init_env_logger("RUSTC_LOG")
1234 /// This allows tools to enable rust logging without having to magically match rustc's
1235 /// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose an env var
1236 /// other than `RUSTC_LOG`.
1237 pub fn init_env_logger(env: &str) {
1238 // Don't register a dispatcher if there's no filter to print anything
1239 match std::env::var(env) {
1241 Ok(s) if s.is_empty() => return,
1244 let builder = tracing_subscriber::FmtSubscriber::builder();
1246 let builder = builder.with_env_filter(tracing_subscriber::EnvFilter::from_env(env));
1251 pub fn main() -> ! {
1252 let start = Instant::now();
1253 init_rustc_env_logger();
1254 let mut callbacks = TimePassesCallbacks::default();
1256 let exit_code = catch_with_exit_code(|| {
1257 let args = env::args_os()
1260 arg.into_string().unwrap_or_else(|arg| {
1262 ErrorOutputType::default(),
1263 &format!("Argument {} is not valid Unicode: {:?}", i, arg),
1267 .collect::<Vec<_>>();
1268 run_compiler(&args, &mut callbacks, None, None)
1270 // The extra `\t` is necessary to align this label with the others.
1271 print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
1272 process::exit(exit_code)