5 //! This API is completely unstable and subject to change.
7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
8 #![feature(box_syntax)]
9 #![cfg_attr(unix, feature(libc))]
11 #![feature(set_stdio)]
13 #![feature(integer_atomics)]
14 #![recursion_limit = "256"]
16 pub extern crate getopts;
22 extern crate lazy_static;
24 pub extern crate rustc_plugin_impl as plugin;
26 use rustc::lint::{Lint, LintId};
27 use rustc::middle::cstore::MetadataLoader;
28 use rustc::session::config::nightly_options;
29 use rustc::session::config::{ErrorOutputType, Input, OutputType, PrintRequest};
30 use rustc::session::{config, DiagnosticOutput, Session};
31 use rustc::session::{early_error, early_warn};
32 use rustc::ty::TyCtxt;
33 use rustc::util::common::ErrorReported;
34 use rustc_codegen_utils::codegen_backend::CodegenBackend;
35 use rustc_data_structures::profiling::print_time_passes_entry;
36 use rustc_data_structures::sync::SeqCst;
37 use rustc_errors::{registry::Registry, PResult};
38 use rustc_feature::{find_gated_cfg, UnstableFeatures};
39 use rustc_hir::def_id::LOCAL_CRATE;
40 use rustc_interface::util::get_builtin_codegen_backend;
41 use rustc_interface::{interface, Queries};
42 use rustc_lint::LintStore;
43 use rustc_metadata::locator;
44 use rustc_save_analysis as save;
45 use rustc_save_analysis::DumpHandler;
46 use rustc_serialize::json::ToJson;
50 use std::default::Default;
52 use std::ffi::OsString;
53 use std::io::{self, Read, Write};
55 use std::panic::{self, catch_unwind};
56 use std::path::PathBuf;
57 use std::process::{self, Command, Stdio};
59 use std::time::Instant;
61 use rustc_span::source_map::FileLoader;
62 use rustc_span::symbol::sym;
63 use rustc_span::FileName;
69 /// Exit status code used for successful compilation and help output.
70 pub const EXIT_SUCCESS: i32 = 0;
72 /// Exit status code used for compilation failures and invalid flags.
73 pub const EXIT_FAILURE: i32 = 1;
75 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
78 const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["Z", "C", "crate-type"];
80 const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"];
82 const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"];
84 pub fn abort_on_err<T>(result: Result<T, ErrorReported>, sess: &Session) -> T {
87 sess.abort_if_errors();
88 panic!("error reported but abort_if_errors didn't abort???");
95 /// Called before creating the compiler instance
96 fn config(&mut self, _config: &mut interface::Config) {}
97 /// Called after parsing. Return value instructs the compiler whether to
98 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
99 fn after_parsing<'tcx>(
101 _compiler: &interface::Compiler,
102 _queries: &'tcx Queries<'tcx>,
104 Compilation::Continue
106 /// Called after expansion. Return value instructs the compiler whether to
107 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
108 fn after_expansion<'tcx>(
110 _compiler: &interface::Compiler,
111 _queries: &'tcx Queries<'tcx>,
113 Compilation::Continue
115 /// Called after analysis. Return value instructs the compiler whether to
116 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
117 fn after_analysis<'tcx>(
119 _compiler: &interface::Compiler,
120 _queries: &'tcx Queries<'tcx>,
122 Compilation::Continue
126 pub struct DefaultCallbacks;
128 impl Callbacks for DefaultCallbacks {}
131 pub struct TimePassesCallbacks {
135 impl Callbacks for TimePassesCallbacks {
136 fn config(&mut self, config: &mut interface::Config) {
137 // If a --prints=... option has been given, we don't print the "total"
138 // time because it will mess up the --prints output. See #64339.
139 self.time_passes = config.opts.prints.is_empty()
140 && (config.opts.debugging_opts.time_passes || config.opts.debugging_opts.time);
144 pub fn diagnostics_registry() -> Registry {
145 Registry::new(&rustc_error_codes::DIAGNOSTICS)
148 // Parse args and run the compiler. This is the primary entry point for rustc.
149 // See comments on CompilerCalls below for details about the callbacks argument.
150 // The FileLoader provides a way to load files from sources other than the file system.
153 callbacks: &mut (dyn Callbacks + Send),
154 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
155 emitter: Option<Box<dyn Write + Send>>,
156 ) -> interface::Result<()> {
157 let mut args = Vec::new();
159 match args::arg_expand(arg.clone()) {
160 Ok(arg) => args.extend(arg),
161 Err(err) => early_error(
162 ErrorOutputType::default(),
163 &format!("Failed to load argument file: {}", err),
167 let diagnostic_output =
168 emitter.map(|emitter| DiagnosticOutput::Raw(emitter)).unwrap_or(DiagnosticOutput::Default);
169 let matches = match handle_options(&args) {
170 Some(matches) => matches,
171 None => return Ok(()),
174 let sopts = config::build_session_options(&matches);
175 let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg"));
177 let mut dummy_config = |sopts, cfg, diagnostic_output| {
178 let mut config = interface::Config {
181 input: Input::File(PathBuf::new()),
189 lint_caps: Default::default(),
190 register_lints: None,
191 override_queries: None,
192 registry: diagnostics_registry(),
194 callbacks.config(&mut config);
198 if let Some(ref code) = matches.opt_str("explain") {
199 handle_explain(diagnostics_registry(), code, sopts.error_format);
203 let (odir, ofile) = make_output(&matches);
204 let (input, input_file_path, input_err) = match make_input(&matches.free) {
206 None => match matches.free.len() {
208 let config = dummy_config(sopts, cfg, diagnostic_output);
209 interface::run_compiler(config, |compiler| {
210 let sopts = &compiler.session().opts;
211 if sopts.describe_lints {
212 let lint_store = rustc_lint::new_lint_store(
213 sopts.debugging_opts.no_interleave_lints,
214 compiler.session().unstable_options(),
216 describe_lints(compiler.session(), &lint_store, false);
219 let should_stop = RustcDefaultCalls::print_crate_info(
220 &***compiler.codegen_backend(),
227 if should_stop == Compilation::Stop {
230 early_error(sopts.error_format, "no input filename given")
234 1 => panic!("make_input should have provided valid inputs"),
238 "multiple input filenames provided (first two filenames are `{}` and `{}`)",
239 matches.free[0], matches.free[1],
245 if let Some(err) = input_err {
246 // Immediately stop compilation if there was an issue reading
247 // the input (for example if the input stream is not UTF-8).
248 interface::run_compiler(dummy_config(sopts, cfg, diagnostic_output), |compiler| {
249 compiler.session().err(&err.to_string());
251 return Err(ErrorReported);
254 let mut config = interface::Config {
258 input_path: input_file_path,
265 lint_caps: Default::default(),
266 register_lints: None,
267 override_queries: None,
268 registry: diagnostics_registry(),
271 callbacks.config(&mut config);
273 interface::run_compiler(config, |compiler| {
274 let sess = compiler.session();
275 let should_stop = RustcDefaultCalls::print_crate_info(
276 &***compiler.codegen_backend(),
278 Some(compiler.input()),
279 compiler.output_dir(),
280 compiler.output_file(),
283 RustcDefaultCalls::list_metadata(
285 &*compiler.codegen_backend().metadata_loader(),
291 if should_stop == Compilation::Stop {
292 return sess.compile_status();
295 let linker = compiler.enter(|queries| {
296 let early_exit = || sess.compile_status().map(|_| None);
299 if let Some(ppm) = &sess.opts.pretty {
300 if ppm.needs_ast_map() {
301 queries.global_ctxt()?.peek_mut().enter(|tcx| {
302 let expanded_crate = queries.expansion()?.take().0;
303 pretty::print_after_hir_lowering(
308 compiler.output_file().as_ref().map(|p| &**p),
313 let krate = queries.parse()?.take();
314 pretty::print_after_parsing(
319 compiler.output_file().as_ref().map(|p| &**p),
325 if callbacks.after_parsing(compiler, queries) == Compilation::Stop {
329 if sess.opts.debugging_opts.parse_only
330 || sess.opts.debugging_opts.show_span.is_some()
331 || sess.opts.debugging_opts.ast_json_noexpand
337 let (_, lint_store) = &*queries.register_plugins()?.peek();
339 // Lint plugins are registered; now we can process command line flags.
340 if sess.opts.describe_lints {
341 describe_lints(&sess, &lint_store, true);
346 queries.expansion()?;
347 if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
351 queries.prepare_outputs()?;
353 if sess.opts.output_types.contains_key(&OutputType::DepInfo)
354 && sess.opts.output_types.len() == 1
359 queries.global_ctxt()?;
361 if sess.opts.debugging_opts.no_analysis || sess.opts.debugging_opts.ast_json {
365 if sess.opts.debugging_opts.save_analysis {
366 let expanded_crate = &queries.expansion()?.peek().0;
367 let crate_name = queries.crate_name()?.peek().clone();
368 queries.global_ctxt()?.peek_mut().enter(|tcx| {
369 let result = tcx.analysis(LOCAL_CRATE);
371 sess.time("save_analysis", || {
379 compiler.output_dir().as_ref().map(|p| &**p),
386 // AST will be dropped *after* the `after_analysis` callback
387 // (needed by the RLS)
390 // Drop AST after creating GlobalCtxt to free memory
391 let _timer = sess.prof.generic_activity("drop_ast");
392 mem::drop(queries.expansion()?.take());
395 queries.global_ctxt()?.peek_mut().enter(|tcx| tcx.analysis(LOCAL_CRATE))?;
397 if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
401 if sess.opts.debugging_opts.save_analysis {
402 mem::drop(queries.expansion()?.take());
405 queries.ongoing_codegen()?;
407 if sess.opts.debugging_opts.print_type_sizes {
408 sess.code_stats.print_type_sizes();
411 let linker = queries.linker()?;
415 if let Some(linker) = linker {
416 let _timer = sess.timer("link");
420 if sess.opts.debugging_opts.perf_stats {
421 sess.print_perf_stats();
424 if sess.print_fuel_crate.is_some() {
426 "Fuel used by {}: {}",
427 sess.print_fuel_crate.as_ref().unwrap(),
428 sess.print_fuel.load(SeqCst)
437 pub fn set_sigpipe_handler() {
439 // Set the SIGPIPE signal handler, so that an EPIPE
440 // will cause rustc to terminate, as expected.
441 assert_ne!(libc::signal(libc::SIGPIPE, libc::SIG_DFL), libc::SIG_ERR);
446 pub fn set_sigpipe_handler() {}
448 // Extract output directory and file from matches.
449 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
450 let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
451 let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
455 // Extract input (string or file and optional path) from matches.
456 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>, Option<io::Error>)> {
457 if free_matches.len() == 1 {
458 let ifile = &free_matches[0];
460 let mut src = String::new();
461 let err = if io::stdin().read_to_string(&mut src).is_err() {
463 io::ErrorKind::InvalidData,
464 "couldn't read from stdin, as it did not contain valid UTF-8",
469 if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
470 let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect(
471 "when UNSTABLE_RUSTDOC_TEST_PATH is set \
472 UNSTABLE_RUSTDOC_TEST_LINE also needs to be set",
474 let line = isize::from_str_radix(&line, 10)
475 .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number");
476 let file_name = FileName::doc_test_source_code(PathBuf::from(path), line);
477 return Some((Input::Str { name: file_name, input: src }, None, err));
479 Some((Input::Str { name: FileName::anon_source_code(&src), input: src }, None, err))
481 Some((Input::File(PathBuf::from(ifile)), Some(PathBuf::from(ifile)), None))
488 // Whether to stop or continue compilation.
489 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
490 pub enum Compilation {
496 pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
498 Compilation::Stop => Compilation::Stop,
499 Compilation::Continue => next(),
504 /// CompilerCalls instance for a regular rustc build.
505 #[derive(Copy, Clone)]
506 pub struct RustcDefaultCalls;
508 // FIXME remove these and use winapi 0.3 instead
509 // Duplicates: bootstrap/compile.rs, librustc_errors/emitter.rs
511 fn stdout_isatty() -> bool {
512 unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
516 fn stdout_isatty() -> bool {
519 type HANDLE = *mut u8;
520 type LPDWORD = *mut u32;
521 const STD_OUTPUT_HANDLE: DWORD = -11i32 as DWORD;
523 fn GetStdHandle(which: DWORD) -> HANDLE;
524 fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: LPDWORD) -> BOOL;
527 let handle = GetStdHandle(STD_OUTPUT_HANDLE);
529 GetConsoleMode(handle, &mut out) != 0
533 fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
535 if code.starts_with("E") { code.to_string() } else { format!("E{0:0>4}", code) };
536 match registry.find_description(&normalised) {
537 Some(ref description) => {
538 let mut is_in_code_block = false;
539 let mut text = String::new();
541 // Slice off the leading newline and print.
542 for line in description.lines() {
544 line.find(|c: char| !c.is_whitespace()).unwrap_or_else(|| line.len());
545 let dedented_line = &line[indent_level..];
546 if dedented_line.starts_with("```") {
547 is_in_code_block = !is_in_code_block;
548 text.push_str(&line[..(indent_level + 3)]);
549 } else if is_in_code_block && dedented_line.starts_with("# ") {
558 show_content_with_pager(&text);
564 early_error(output, &format!("no extended information for {}", code));
569 fn show_content_with_pager(content: &String) {
570 let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
571 if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
574 let mut fallback_to_println = false;
576 match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
578 if let Some(pipe) = pager.stdin.as_mut() {
579 if pipe.write_all(content.as_bytes()).is_err() {
580 fallback_to_println = true;
584 if pager.wait().is_err() {
585 fallback_to_println = true;
589 fallback_to_println = true;
593 // If pager fails for whatever reason, we should still print the content
594 // to standard output
595 if fallback_to_println {
596 print!("{}", content);
600 impl RustcDefaultCalls {
601 pub fn list_metadata(
603 metadata_loader: &dyn MetadataLoader,
604 matches: &getopts::Matches,
607 let r = matches.opt_strs("Z");
608 if r.iter().any(|s| *s == "ls") {
610 &Input::File(ref ifile) => {
611 let path = &(*ifile);
612 let mut v = Vec::new();
613 locator::list_file_metadata(&sess.target.target, path, metadata_loader, &mut v)
615 println!("{}", String::from_utf8(v).unwrap());
617 &Input::Str { .. } => {
618 early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
621 return Compilation::Stop;
624 Compilation::Continue
628 codegen_backend: &dyn CodegenBackend,
630 input: Option<&Input>,
631 odir: &Option<PathBuf>,
632 ofile: &Option<PathBuf>,
634 use rustc::session::config::PrintRequest::*;
635 // PrintRequest::NativeStaticLibs is special - printed during linking
636 // (empty iterator returns true)
637 if sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
638 return Compilation::Continue;
641 let attrs = match input {
644 let result = parse_crate_attrs(sess, input);
646 Ok(attrs) => Some(attrs),
647 Err(mut parse_error) => {
649 return Compilation::Stop;
654 for req in &sess.opts.prints {
657 let mut targets = rustc_target::spec::get_targets().collect::<Vec<String>>();
659 println!("{}", targets.join("\n"));
661 Sysroot => println!("{}", sess.sysroot.display()),
662 TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
663 FileNames | CrateName => {
664 let input = input.unwrap_or_else(|| {
665 early_error(ErrorOutputType::default(), "no input file provided")
667 let attrs = attrs.as_ref().unwrap();
668 let t_outputs = rustc_interface::util::build_output_filenames(
669 input, odir, ofile, attrs, sess,
671 let id = rustc_codegen_utils::link::find_crate_name(Some(sess), attrs, input);
672 if *req == PrintRequest::CrateName {
676 let crate_types = rustc_interface::util::collect_crate_types(sess, attrs);
677 for &style in &crate_types {
678 let fname = rustc_codegen_utils::link::filename_for_input(
679 sess, style, &id, &t_outputs,
681 println!("{}", fname.file_name().unwrap().to_string_lossy());
685 let allow_unstable_cfg =
686 UnstableFeatures::from_environment().is_nightly_build();
692 .filter_map(|&(name, ref value)| {
693 // Note that crt-static is a specially recognized cfg
694 // directive that's printed out here as part of
695 // rust-lang/rust#37406, but in general the
696 // `target_feature` cfg is gated under
697 // rust-lang/rust#29717. For now this is just
698 // specifically allowing the crt-static cfg and that's
699 // it, this is intended to get into Cargo and then go
700 // through to build scripts.
701 let value = value.as_ref().map(|s| s.as_str());
702 let value = value.as_ref().map(|s| s.as_ref());
703 if (name != sym::target_feature || value != Some("crt-static"))
704 && !allow_unstable_cfg
705 && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
710 if let Some(value) = value {
711 Some(format!("{}=\"{}\"", name, value))
713 Some(name.to_string())
716 .collect::<Vec<String>>();
723 RelocationModels | CodeModels | TlsModels | TargetCPUs | TargetFeatures => {
724 codegen_backend.print(*req, sess);
726 // Any output here interferes with Cargo's parsing of other printed output
727 PrintRequest::NativeStaticLibs => {}
730 return Compilation::Stop;
734 /// Returns a version string such as "0.12.0-dev".
735 fn release_str() -> Option<&'static str> {
736 option_env!("CFG_RELEASE")
739 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
740 fn commit_hash_str() -> Option<&'static str> {
741 option_env!("CFG_VER_HASH")
744 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
745 fn commit_date_str() -> Option<&'static str> {
746 option_env!("CFG_VER_DATE")
749 /// Prints version information
750 pub fn version(binary: &str, matches: &getopts::Matches) {
751 let verbose = matches.opt_present("verbose");
753 println!("{} {}", binary, option_env!("CFG_VERSION").unwrap_or("unknown version"));
756 fn unw(x: Option<&str>) -> &str {
757 x.unwrap_or("unknown")
759 println!("binary: {}", binary);
760 println!("commit-hash: {}", unw(commit_hash_str()));
761 println!("commit-date: {}", unw(commit_date_str()));
762 println!("host: {}", config::host_triple());
763 println!("release: {}", unw(release_str()));
764 get_builtin_codegen_backend("llvm")().print_version();
768 fn usage(verbose: bool, include_unstable_options: bool) {
769 let groups = if verbose { config::rustc_optgroups() } else { config::rustc_short_optgroups() };
770 let mut options = getopts::Options::new();
771 for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
772 (option.apply)(&mut options);
774 let message = "Usage: rustc [OPTIONS] INPUT";
775 let nightly_help = if nightly_options::is_nightly_build() {
776 "\n -Z help Print unstable compiler options"
780 let verbose_help = if verbose {
783 "\n --help -v Print the full set of options rustc accepts"
785 let at_path = if verbose && nightly_options::is_nightly_build() {
786 " @path Read newline separated options from `path`\n"
791 "{options}{at_path}\nAdditional help:
792 -C help Print codegen options
794 Print 'lint' options and default settings{nightly}{verbose}\n",
795 options = options.usage(message),
797 nightly = nightly_help,
798 verbose = verbose_help
802 fn print_wall_help() {
805 The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
806 default. Use `rustc -W help` to see all available lints. It's more common to put
807 warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
808 the command line flag directly.
813 fn describe_lints(sess: &Session, lint_store: &LintStore, loaded_plugins: bool) {
816 Available lint options:
817 -W <foo> Warn about <foo>
821 -F <foo> Forbid <foo> \
822 (deny <foo> and all attempts to override)
827 fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
828 // The sort doesn't case-fold but it's doubtful we care.
829 lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name));
834 lints: Vec<(&'static str, Vec<LintId>, bool)>,
835 ) -> Vec<(&'static str, Vec<LintId>)> {
836 let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
837 lints.sort_by_key(|l| l.0);
841 let (plugin, builtin): (Vec<_>, _) =
842 lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_plugin);
843 let plugin = sort_lints(sess, plugin);
844 let builtin = sort_lints(sess, builtin);
846 let (plugin_groups, builtin_groups): (Vec<_>, _) =
847 lint_store.get_lint_groups().iter().cloned().partition(|&(.., p)| p);
848 let plugin_groups = sort_lint_groups(plugin_groups);
849 let builtin_groups = sort_lint_groups(builtin_groups);
852 plugin.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0);
853 let padded = |x: &str| {
854 let mut s = " ".repeat(max_name_len - x.chars().count());
859 println!("Lint checks provided by rustc:\n");
860 println!(" {} {:7.7} {}", padded("name"), "default", "meaning");
861 println!(" {} {:7.7} {}", padded("----"), "-------", "-------");
863 let print_lints = |lints: Vec<&Lint>| {
865 let name = lint.name_lower().replace("_", "-");
866 println!(" {} {:7.7} {}", padded(&name), lint.default_level.as_str(), lint.desc);
871 print_lints(builtin);
873 let max_name_len = max(
877 .chain(&builtin_groups)
878 .map(|&(s, _)| s.chars().count())
883 let padded = |x: &str| {
884 let mut s = " ".repeat(max_name_len - x.chars().count());
889 println!("Lint groups provided by rustc:\n");
890 println!(" {} {}", padded("name"), "sub-lints");
891 println!(" {} {}", padded("----"), "---------");
892 println!(" {} {}", padded("warnings"), "all lints that are set to issue warnings");
894 let print_lint_groups = |lints: Vec<(&'static str, Vec<LintId>)>| {
895 for (name, to) in lints {
896 let name = name.to_lowercase().replace("_", "-");
899 .map(|x| x.to_string().replace("_", "-"))
900 .collect::<Vec<String>>()
902 println!(" {} {}", padded(&name), desc);
907 print_lint_groups(builtin_groups);
909 match (loaded_plugins, plugin.len(), plugin_groups.len()) {
910 (false, 0, _) | (false, _, 0) => {
912 "Compiler plugins can provide additional lints and lint groups. To see a \
913 listing of these, re-run `rustc -W help` with a crate filename."
916 (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
917 (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
920 println!("Lint checks provided by plugins loaded by this crate:\n");
924 println!("Lint groups provided by plugins loaded by this crate:\n");
925 print_lint_groups(plugin_groups);
931 fn describe_debug_flags() {
932 println!("\nAvailable options:\n");
933 print_flag_list("-Z", config::DB_OPTIONS);
936 fn describe_codegen_flags() {
937 println!("\nAvailable codegen options:\n");
938 print_flag_list("-C", config::CG_OPTIONS);
941 fn print_flag_list<T>(
943 flag_list: &[(&'static str, T, Option<&'static str>, &'static str)],
945 let max_len = flag_list
947 .map(|&(name, _, opt_type_desc, _)| {
948 let extra_len = match opt_type_desc {
952 name.chars().count() + extra_len
957 for &(name, _, opt_type_desc, desc) in flag_list {
958 let (width, extra) = match opt_type_desc {
959 Some(..) => (max_len - 4, "=val"),
960 None => (max_len, ""),
963 " {} {:>width$}{} -- {}",
965 name.replace("_", "-"),
973 /// Process command line options. Emits messages as appropriate. If compilation
974 /// should continue, returns a getopts::Matches object parsed from args,
975 /// otherwise returns `None`.
977 /// The compiler's handling of options is a little complicated as it ties into
978 /// our stability story. The current intention of each compiler option is to
979 /// have one of two modes:
981 /// 1. An option is stable and can be used everywhere.
982 /// 2. An option is unstable, and can only be used on nightly.
984 /// Like unstable library and language features, however, unstable options have
985 /// always required a form of "opt in" to indicate that you're using them. This
986 /// provides the easy ability to scan a code base to check to see if anything
987 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
989 /// All options behind `-Z` are considered unstable by default. Other top-level
990 /// options can also be considered unstable, and they were unlocked through the
991 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
992 /// instability in both cases, though.
994 /// So with all that in mind, the comments below have some more detail about the
995 /// contortions done here to get things to work out correctly.
996 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
997 // Throw away the first argument, the name of the binary
998 let args = &args[1..];
1000 if args.is_empty() {
1001 // user did not write `-v` nor `-Z unstable-options`, so do not
1002 // include that extra information.
1003 usage(false, false);
1007 // Parse with *all* options defined in the compiler, we don't worry about
1008 // option stability here we just want to parse as much as possible.
1009 let mut options = getopts::Options::new();
1010 for option in config::rustc_optgroups() {
1011 (option.apply)(&mut options);
1013 let matches = options
1015 .unwrap_or_else(|f| early_error(ErrorOutputType::default(), &f.to_string()));
1017 // For all options we just parsed, we check a few aspects:
1019 // * If the option is stable, we're all good
1020 // * If the option wasn't passed, we're all good
1021 // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1022 // ourselves), then we require the `-Z unstable-options` flag to unlock
1023 // this option that was passed.
1024 // * If we're a nightly compiler, then unstable options are now unlocked, so
1025 // we're good to go.
1026 // * Otherwise, if we're an unstable option then we generate an error
1027 // (unstable option being used on stable)
1028 nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
1030 if matches.opt_present("h") || matches.opt_present("help") {
1031 // Only show unstable options in --help if we accept unstable options.
1032 usage(matches.opt_present("verbose"), nightly_options::is_unstable_enabled(&matches));
1036 // Handle the special case of -Wall.
1037 let wall = matches.opt_strs("W");
1038 if wall.iter().any(|x| *x == "all") {
1043 // Don't handle -W help here, because we might first load plugins.
1044 let r = matches.opt_strs("Z");
1045 if r.iter().any(|x| *x == "help") {
1046 describe_debug_flags();
1050 let cg_flags = matches.opt_strs("C");
1052 if cg_flags.iter().any(|x| *x == "help") {
1053 describe_codegen_flags();
1057 if cg_flags.iter().any(|x| *x == "no-stack-check") {
1059 ErrorOutputType::default(),
1060 "the --no-stack-check flag is deprecated and does nothing",
1064 if cg_flags.iter().any(|x| *x == "passes=list") {
1065 get_builtin_codegen_backend("llvm")().print_passes();
1069 if matches.opt_present("version") {
1070 version("rustc", &matches);
1077 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1079 Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess),
1080 Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str(
1088 /// Gets a list of extra command-line flags provided by the user, as strings.
1090 /// This function is used during ICEs to show more information useful for
1091 /// debugging, since some ICEs only happens with non-default compiler flags
1092 /// (and the users don't always report them).
1093 fn extra_compiler_flags() -> Option<(Vec<String>, bool)> {
1094 let args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).collect::<Vec<_>>();
1096 // Avoid printing help because of empty args. This can suggest the compiler
1097 // itself is not the program root (consider RLS).
1102 let matches = if let Some(matches) = handle_options(&args) {
1108 let mut result = Vec::new();
1109 let mut excluded_cargo_defaults = false;
1110 for flag in ICE_REPORT_COMPILER_FLAGS {
1111 let prefix = if flag.len() == 1 { "-" } else { "--" };
1113 for content in &matches.opt_strs(flag) {
1114 // Split always returns the first element
1115 let name = if let Some(first) = content.split('=').next() { first } else { &content };
1118 if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) { name } else { content };
1120 if !ICE_REPORT_COMPILER_FLAGS_EXCLUDE.contains(&name) {
1121 result.push(format!("{}{} {}", prefix, flag, content));
1123 excluded_cargo_defaults = true;
1128 if !result.is_empty() { Some((result, excluded_cargo_defaults)) } else { None }
1131 /// Runs a closure and catches unwinds triggered by fatal errors.
1133 /// The compiler currently unwinds with a special sentinel value to abort
1134 /// compilation on fatal errors. This function catches that sentinel and turns
1135 /// the panic into a `Result` instead.
1136 pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorReported> {
1137 catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
1138 if value.is::<rustc_errors::FatalErrorMarker>() {
1141 panic::resume_unwind(value);
1147 static ref DEFAULT_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
1148 let hook = panic::take_hook();
1149 panic::set_hook(Box::new(|info| report_ice(info, BUG_REPORT_URL)));
1154 /// Prints the ICE message, including backtrace and query stack.
1156 /// The message will point the user at `bug_report_url` to report the ICE.
1158 /// When `install_ice_hook` is called, this function will be called as the panic
1160 pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
1161 // Invoke the default handler, which prints the actual panic message and optionally a backtrace
1162 (*DEFAULT_HOOK)(info);
1164 // Separate the output with an empty line
1167 let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
1168 rustc_errors::ColorConfig::Auto,
1175 let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
1177 // a .span_bug or .bug call has already printed what
1178 // it wants to print.
1179 if !info.payload().is::<rustc_errors::ExplicitBug>() {
1180 let d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
1181 handler.emit_diagnostic(&d);
1184 let mut xs: Vec<Cow<'static, str>> = vec![
1185 "the compiler unexpectedly panicked. this is a bug.".into(),
1186 format!("we would appreciate a bug report: {}", bug_report_url).into(),
1188 "rustc {} running on {}",
1189 option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1190 config::host_triple()
1195 if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
1196 xs.push(format!("compiler flags: {}", flags.join(" ")).into());
1198 if excluded_cargo_defaults {
1199 xs.push("some of the compiler flags provided by cargo are hidden".into());
1204 handler.note_without_error(¬e);
1207 // If backtraces are enabled, also print the query stack
1208 let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
1211 TyCtxt::try_print_query_stack(&handler);
1216 if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
1220 // Trigger a debugger if we crashed during bootstrap
1226 /// Installs a panic hook that will print the ICE message on unexpected panics.
1228 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
1229 pub fn install_ice_hook() {
1230 lazy_static::initialize(&DEFAULT_HOOK);
1233 /// This allows tools to enable rust logging without having to magically match rustc's
1234 /// log crate version
1235 pub fn init_rustc_env_logger() {
1236 env_logger::init_from_env("RUSTC_LOG");
1240 let start = Instant::now();
1241 init_rustc_env_logger();
1242 let mut callbacks = TimePassesCallbacks::default();
1244 let result = catch_fatal_errors(|| {
1245 let args = env::args_os()
1248 arg.into_string().unwrap_or_else(|arg| {
1250 ErrorOutputType::default(),
1251 &format!("Argument {} is not valid Unicode: {:?}", i, arg),
1255 .collect::<Vec<_>>();
1256 run_compiler(&args, &mut callbacks, None, None)
1258 .and_then(|result| result);
1259 let exit_code = match result {
1260 Ok(_) => EXIT_SUCCESS,
1261 Err(_) => EXIT_FAILURE,
1263 // The extra `\t` is necessary to align this label with the others.
1264 print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
1265 process::exit(exit_code);