5 //! This API is completely unstable and subject to change.
7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
9 #![feature(box_syntax)]
10 #![cfg_attr(unix, feature(libc))]
12 #![feature(set_stdio)]
14 #![feature(integer_atomics)]
16 #![recursion_limit="256"]
18 pub extern crate getopts;
24 extern crate lazy_static;
26 pub extern crate rustc_plugin_impl as plugin;
28 //use rustc_resolve as resolve;
29 use rustc_save_analysis as save;
30 use rustc_save_analysis::DumpHandler;
31 use rustc::session::{config, Session, DiagnosticOutput};
32 use rustc::session::config::{Input, PrintRequest, ErrorOutputType, OutputType};
33 use rustc::session::config::nightly_options;
34 use rustc::session::{early_error, early_warn};
35 use rustc::lint::Lint;
37 use rustc::middle::cstore::MetadataLoader;
38 use rustc::hir::def_id::LOCAL_CRATE;
39 use rustc::ty::TyCtxt;
40 use rustc::util::common::{set_time_depth, time, print_time_passes_entry, ErrorReported};
41 use rustc_metadata::locator;
42 use rustc_codegen_utils::codegen_backend::CodegenBackend;
43 use errors::{PResult, registry::Registry};
44 use rustc_interface::interface;
45 use rustc_interface::util::get_codegen_sysroot;
46 use rustc_data_structures::sync::SeqCst;
48 use rustc_serialize::json::ToJson;
52 use std::default::Default;
54 use std::ffi::OsString;
55 use std::io::{self, Read, Write};
57 use std::panic::{self, catch_unwind};
58 use std::path::PathBuf;
59 use std::process::{self, Command, Stdio};
61 use std::time::Instant;
64 use syntax::source_map::FileLoader;
65 use syntax::feature_gate::{GatedCfg, UnstableFeatures};
66 use syntax::symbol::sym;
67 use syntax_pos::{DUMMY_SP, FileName};
72 /// Exit status code used for successful compilation and help output.
73 pub const EXIT_SUCCESS: i32 = 0;
75 /// Exit status code used for compilation failures and invalid flags.
76 pub const EXIT_FAILURE: i32 = 1;
78 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.\
81 const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["Z", "C", "crate-type"];
83 const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"];
85 const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"];
87 pub fn abort_on_err<T>(result: Result<T, ErrorReported>, sess: &Session) -> T {
90 sess.abort_if_errors();
91 panic!("error reported but abort_if_errors didn't abort???");
98 /// Called before creating the compiler instance
99 fn config(&mut self, _config: &mut interface::Config) {}
100 /// Called after parsing. Return value instructs the compiler whether to
101 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
102 fn after_parsing(&mut self, _compiler: &interface::Compiler) -> Compilation {
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(&mut self, _compiler: &interface::Compiler) -> Compilation {
108 Compilation::Continue
110 /// Called after analysis. Return value instructs the compiler whether to
111 /// continue the compilation afterwards (defaults to `Compilation::Continue`)
112 fn after_analysis(&mut self, _compiler: &interface::Compiler) -> Compilation {
113 Compilation::Continue
117 pub struct DefaultCallbacks;
119 impl Callbacks for DefaultCallbacks {}
122 pub struct TimePassesCallbacks {
126 impl Callbacks for TimePassesCallbacks {
127 fn config(&mut self, config: &mut interface::Config) {
128 // If a --prints=... option has been given, we don't print the "total"
129 // time because it will mess up the --prints output. See #64339.
131 config.opts.prints.is_empty() &&
132 (config.opts.debugging_opts.time_passes || config.opts.debugging_opts.time);
136 pub fn diagnostics_registry() -> Registry {
137 Registry::new(&rustc_error_codes::DIAGNOSTICS)
140 // Parse args and run the compiler. This is the primary entry point for rustc.
141 // See comments on CompilerCalls below for details about the callbacks argument.
142 // The FileLoader provides a way to load files from sources other than the file system.
145 callbacks: &mut (dyn Callbacks + Send),
146 file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
147 emitter: Option<Box<dyn Write + Send>>
148 ) -> interface::Result<()> {
149 let mut args = Vec::new();
151 match args::arg_expand(arg.clone()) {
152 Ok(arg) => args.extend(arg),
153 Err(err) => early_error(ErrorOutputType::default(),
154 &format!("Failed to load argument file: {}", err)),
157 let diagnostic_output = emitter.map(|emitter| DiagnosticOutput::Raw(emitter))
158 .unwrap_or(DiagnosticOutput::Default);
159 let matches = match handle_options(&args) {
160 Some(matches) => matches,
161 None => return Ok(()),
164 let sopts = config::build_session_options(&matches);
165 let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg"));
167 let mut dummy_config = |sopts, cfg, diagnostic_output| {
168 let mut config = interface::Config {
171 input: Input::File(PathBuf::new()),
179 lint_caps: Default::default(),
180 register_lints: None,
181 override_queries: None,
182 registry: diagnostics_registry(),
184 callbacks.config(&mut config);
188 if let Some(ref code) = matches.opt_str("explain") {
189 handle_explain(diagnostics_registry(), code, sopts.error_format);
193 let (odir, ofile) = make_output(&matches);
194 let (input, input_file_path, input_err) = match make_input(&matches.free) {
197 match matches.free.len() {
199 let config = dummy_config(sopts, cfg, diagnostic_output);
200 interface::run_compiler(config, |compiler| {
201 let sopts = &compiler.session().opts;
202 if sopts.describe_lints {
203 let lint_store = rustc_lint::new_lint_store(
204 sopts.debugging_opts.no_interleave_lints,
205 compiler.session().unstable_options(),
214 let should_stop = RustcDefaultCalls::print_crate_info(
215 &***compiler.codegen_backend(),
222 if should_stop == Compilation::Stop {
225 early_error(sopts.error_format, "no input filename given")
229 1 => panic!("make_input should have provided valid inputs"),
230 _ => early_error(sopts.error_format, &format!(
231 "multiple input filenames provided (first two filenames are `{}` and `{}`)",
239 if let Some(err) = input_err {
240 // Immediately stop compilation if there was an issue reading
241 // the input (for example if the input stream is not UTF-8).
242 interface::run_compiler(dummy_config(sopts, cfg, diagnostic_output), |compiler| {
243 compiler.session().err(&err.to_string());
245 return Err(ErrorReported);
248 let mut config = interface::Config {
252 input_path: input_file_path,
259 lint_caps: Default::default(),
260 register_lints: None,
261 override_queries: None,
262 registry: diagnostics_registry(),
265 callbacks.config(&mut config);
267 interface::run_compiler(config, |compiler| {
268 let sess = compiler.session();
269 let should_stop = RustcDefaultCalls::print_crate_info(
270 &***compiler.codegen_backend(),
272 Some(compiler.input()),
273 compiler.output_dir(),
274 compiler.output_file(),
275 ).and_then(|| RustcDefaultCalls::list_metadata(
277 &*compiler.codegen_backend().metadata_loader(),
282 if should_stop == Compilation::Stop {
283 return sess.compile_status();
288 if let Some(ppm) = &sess.opts.pretty {
289 if ppm.needs_ast_map() {
290 compiler.global_ctxt()?.peek_mut().enter(|tcx| {
291 let expanded_crate = compiler.expansion()?.take().0;
292 pretty::print_after_hir_lowering(
297 compiler.output_file().as_ref().map(|p| &**p),
302 let krate = compiler.parse()?.take();
303 pretty::print_after_parsing(
308 compiler.output_file().as_ref().map(|p| &**p),
311 return sess.compile_status();
314 if callbacks.after_parsing(compiler) == Compilation::Stop {
315 return sess.compile_status();
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 {
321 return sess.compile_status();
325 let (_, _, lint_store) = &*compiler.register_plugins()?.peek();
327 // Lint plugins are registered; now we can process command line flags.
328 if sess.opts.describe_lints {
329 describe_lints(&sess, &lint_store, true);
330 return sess.compile_status();
334 compiler.expansion()?;
335 if callbacks.after_expansion(compiler) == Compilation::Stop {
336 return sess.compile_status();
339 compiler.prepare_outputs()?;
341 if sess.opts.output_types.contains_key(&OutputType::DepInfo)
342 && sess.opts.output_types.len() == 1
344 return sess.compile_status();
347 compiler.global_ctxt()?;
349 if sess.opts.debugging_opts.no_analysis ||
350 sess.opts.debugging_opts.ast_json {
351 return sess.compile_status();
354 if sess.opts.debugging_opts.save_analysis {
355 let expanded_crate = &compiler.expansion()?.peek().0;
356 let crate_name = compiler.crate_name()?.peek().clone();
357 compiler.global_ctxt()?.peek_mut().enter(|tcx| {
358 let result = tcx.analysis(LOCAL_CRATE);
360 time(sess, "save analysis", || {
367 DumpHandler::new(compiler.output_dir().as_ref().map(|p| &**p), &crate_name)
372 // AST will be dropped *after* the `after_analysis` callback
373 // (needed by the RLS)
376 // Drop AST after creating GlobalCtxt to free memory
377 mem::drop(compiler.expansion()?.take());
380 compiler.global_ctxt()?.peek_mut().enter(|tcx| tcx.analysis(LOCAL_CRATE))?;
382 if callbacks.after_analysis(compiler) == Compilation::Stop {
383 return sess.compile_status();
386 if sess.opts.debugging_opts.save_analysis {
387 mem::drop(compiler.expansion()?.take());
390 compiler.ongoing_codegen()?;
392 // Drop GlobalCtxt after starting codegen to free memory
393 mem::drop(compiler.global_ctxt()?.take());
395 if sess.opts.debugging_opts.print_type_sizes {
396 sess.code_stats.print_type_sizes();
401 if sess.opts.debugging_opts.perf_stats {
402 sess.print_perf_stats();
405 if sess.print_fuel_crate.is_some() {
406 eprintln!("Fuel used by {}: {}",
407 sess.print_fuel_crate.as_ref().unwrap(),
408 sess.print_fuel.load(SeqCst));
416 pub fn set_sigpipe_handler() {
418 // Set the SIGPIPE signal handler, so that an EPIPE
419 // will cause rustc to terminate, as expected.
420 assert_ne!(libc::signal(libc::SIGPIPE, libc::SIG_DFL), libc::SIG_ERR);
425 pub fn set_sigpipe_handler() {}
427 // Extract output directory and file from matches.
428 fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<PathBuf>) {
429 let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
430 let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o));
434 // Extract input (string or file and optional path) from matches.
435 fn make_input(free_matches: &[String]) -> Option<(Input, Option<PathBuf>, Option<io::Error>)> {
436 if free_matches.len() == 1 {
437 let ifile = &free_matches[0];
439 let mut src = String::new();
440 let err = if io::stdin().read_to_string(&mut src).is_err() {
441 Some(io::Error::new(io::ErrorKind::InvalidData,
442 "couldn't read from stdin, as it did not contain valid UTF-8"))
446 if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
447 let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").
448 expect("when UNSTABLE_RUSTDOC_TEST_PATH is set \
449 UNSTABLE_RUSTDOC_TEST_LINE also needs to be set");
450 let line = isize::from_str_radix(&line, 10).
451 expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number");
452 let file_name = FileName::doc_test_source_code(PathBuf::from(path), line);
453 return Some((Input::Str { name: file_name, input: src }, None, err));
455 Some((Input::Str { name: FileName::anon_source_code(&src), input: src },
458 Some((Input::File(PathBuf::from(ifile)),
459 Some(PathBuf::from(ifile)), None))
466 // Whether to stop or continue compilation.
467 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
468 pub enum Compilation {
474 pub fn and_then<F: FnOnce() -> Compilation>(self, next: F) -> Compilation {
476 Compilation::Stop => Compilation::Stop,
477 Compilation::Continue => next(),
482 /// CompilerCalls instance for a regular rustc build.
483 #[derive(Copy, Clone)]
484 pub struct RustcDefaultCalls;
486 // FIXME remove these and use winapi 0.3 instead
487 // Duplicates: bootstrap/compile.rs, librustc_errors/emitter.rs
489 fn stdout_isatty() -> bool {
490 unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
494 fn stdout_isatty() -> bool {
497 type HANDLE = *mut u8;
498 type LPDWORD = *mut u32;
499 const STD_OUTPUT_HANDLE: DWORD = -11i32 as DWORD;
501 fn GetStdHandle(which: DWORD) -> HANDLE;
502 fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: LPDWORD) -> BOOL;
505 let handle = GetStdHandle(STD_OUTPUT_HANDLE);
507 GetConsoleMode(handle, &mut out) != 0
511 fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) {
512 let normalised = if code.starts_with("E") {
515 format!("E{0:0>4}", code)
517 match registry.find_description(&normalised) {
518 Some(ref description) => {
519 let mut is_in_code_block = false;
520 let mut text = String::new();
522 // Slice off the leading newline and print.
523 for line in description.lines() {
524 let indent_level = line.find(|c: char| !c.is_whitespace())
525 .unwrap_or_else(|| line.len());
526 let dedented_line = &line[indent_level..];
527 if dedented_line.starts_with("```") {
528 is_in_code_block = !is_in_code_block;
529 text.push_str(&line[..(indent_level + 3)]);
530 } else if is_in_code_block && dedented_line.starts_with("# ") {
539 show_content_with_pager(&text);
545 early_error(output, &format!("no extended information for {}", code));
550 fn show_content_with_pager(content: &String) {
551 let pager_name = env::var_os("PAGER").unwrap_or_else(|| if cfg!(windows) {
552 OsString::from("more.com")
554 OsString::from("less")
557 let mut fallback_to_println = false;
559 match Command::new(pager_name).stdin(Stdio::piped()).spawn() {
561 if let Some(pipe) = pager.stdin.as_mut() {
562 if pipe.write_all(content.as_bytes()).is_err() {
563 fallback_to_println = true;
567 if pager.wait().is_err() {
568 fallback_to_println = true;
572 fallback_to_println = true;
576 // If pager fails for whatever reason, we should still print the content
577 // to standard output
578 if fallback_to_println {
579 print!("{}", content);
583 impl RustcDefaultCalls {
584 pub fn list_metadata(sess: &Session,
585 metadata_loader: &dyn MetadataLoader,
586 matches: &getopts::Matches,
589 let r = matches.opt_strs("Z");
590 if r.iter().any(|s| *s == "ls") {
592 &Input::File(ref ifile) => {
593 let path = &(*ifile);
594 let mut v = Vec::new();
595 locator::list_file_metadata(&sess.target.target,
600 println!("{}", String::from_utf8(v).unwrap());
602 &Input::Str { .. } => {
603 early_error(ErrorOutputType::default(), "cannot list metadata for stdin");
606 return Compilation::Stop;
609 Compilation::Continue
613 fn print_crate_info(codegen_backend: &dyn CodegenBackend,
615 input: Option<&Input>,
616 odir: &Option<PathBuf>,
617 ofile: &Option<PathBuf>)
619 use rustc::session::config::PrintRequest::*;
620 // PrintRequest::NativeStaticLibs is special - printed during linking
621 // (empty iterator returns true)
622 if sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
623 return Compilation::Continue;
626 let attrs = match input {
629 let result = parse_crate_attrs(sess, input);
631 Ok(attrs) => Some(attrs),
632 Err(mut parse_error) => {
634 return Compilation::Stop;
639 for req in &sess.opts.prints {
642 let mut targets = rustc_target::spec::get_targets().collect::<Vec<String>>();
644 println!("{}", targets.join("\n"));
646 Sysroot => println!("{}", sess.sysroot.display()),
647 TargetSpec => println!("{}", sess.target.target.to_json().pretty()),
648 FileNames | CrateName => {
649 let input = input.unwrap_or_else(||
650 early_error(ErrorOutputType::default(), "no input file provided"));
651 let attrs = attrs.as_ref().unwrap();
652 let t_outputs = rustc_interface::util::build_output_filenames(
659 let id = rustc_codegen_utils::link::find_crate_name(Some(sess), attrs, input);
660 if *req == PrintRequest::CrateName {
664 let crate_types = rustc_interface::util::collect_crate_types(sess, attrs);
665 for &style in &crate_types {
666 let fname = rustc_codegen_utils::link::filename_for_input(
672 println!("{}", fname.file_name().unwrap().to_string_lossy());
676 let allow_unstable_cfg = UnstableFeatures::from_environment()
679 let mut cfgs = sess.parse_sess.config.iter().filter_map(|&(name, ref value)| {
680 let gated_cfg = GatedCfg::gate(&ast::MetaItem {
681 path: ast::Path::from_ident(ast::Ident::with_dummy_span(name)),
682 kind: ast::MetaItemKind::Word,
686 // Note that crt-static is a specially recognized cfg
687 // directive that's printed out here as part of
688 // rust-lang/rust#37406, but in general the
689 // `target_feature` cfg is gated under
690 // rust-lang/rust#29717. For now this is just
691 // specifically allowing the crt-static cfg and that's
692 // it, this is intended to get into Cargo and then go
693 // through to build scripts.
694 let value = value.as_ref().map(|s| s.as_str());
695 let value = value.as_ref().map(|s| s.as_ref());
696 if name != sym::target_feature || value != Some("crt-static") {
697 if !allow_unstable_cfg && gated_cfg.is_some() {
702 if let Some(value) = value {
703 Some(format!("{}=\"{}\"", name, value))
705 Some(name.to_string())
707 }).collect::<Vec<String>>();
714 RelocationModels | CodeModels | TlsModels | TargetCPUs | TargetFeatures => {
715 codegen_backend.print(*req, sess);
717 // Any output here interferes with Cargo's parsing of other printed output
718 PrintRequest::NativeStaticLibs => {}
721 return Compilation::Stop;
725 /// Returns a version string such as "0.12.0-dev".
726 fn release_str() -> Option<&'static str> {
727 option_env!("CFG_RELEASE")
730 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
731 fn commit_hash_str() -> Option<&'static str> {
732 option_env!("CFG_VER_HASH")
735 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
736 fn commit_date_str() -> Option<&'static str> {
737 option_env!("CFG_VER_DATE")
740 /// Prints version information
741 pub fn version(binary: &str, matches: &getopts::Matches) {
742 let verbose = matches.opt_present("verbose");
744 println!("{} {}", binary, option_env!("CFG_VERSION").unwrap_or("unknown version"));
747 fn unw(x: Option<&str>) -> &str {
748 x.unwrap_or("unknown")
750 println!("binary: {}", binary);
751 println!("commit-hash: {}", unw(commit_hash_str()));
752 println!("commit-date: {}", unw(commit_date_str()));
753 println!("host: {}", config::host_triple());
754 println!("release: {}", unw(release_str()));
755 get_codegen_sysroot("llvm")().print_version();
759 fn usage(verbose: bool, include_unstable_options: bool) {
760 let groups = if verbose {
761 config::rustc_optgroups()
763 config::rustc_short_optgroups()
765 let mut options = getopts::Options::new();
766 for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) {
767 (option.apply)(&mut options);
769 let message = "Usage: rustc [OPTIONS] INPUT";
770 let nightly_help = if nightly_options::is_nightly_build() {
771 "\n -Z help Print unstable compiler options"
775 let verbose_help = if verbose {
778 "\n --help -v Print the full set of options rustc accepts"
780 let at_path = if verbose && nightly_options::is_nightly_build() {
781 " @path Read newline separated options from `path`\n"
785 println!("{options}{at_path}\nAdditional help:
786 -C help Print codegen options
788 Print 'lint' options and default settings{nightly}{verbose}\n",
789 options = options.usage(message),
791 nightly = nightly_help,
792 verbose = verbose_help);
795 fn print_wall_help() {
797 The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
798 default. Use `rustc -W help` to see all available lints. It's more common to put
799 warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
800 the command line flag directly.
804 fn describe_lints(sess: &Session, lint_store: &lint::LintStore, loaded_plugins: bool) {
806 Available lint options:
807 -W <foo> Warn about <foo>
811 -F <foo> Forbid <foo> \
812 (deny <foo> and all attempts to override)
816 fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
817 // The sort doesn't case-fold but it's doubtful we care.
818 lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess), x.name));
822 fn sort_lint_groups(lints: Vec<(&'static str, Vec<lint::LintId>, bool)>)
823 -> Vec<(&'static str, Vec<lint::LintId>)> {
824 let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
825 lints.sort_by_key(|l| l.0);
829 let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints()
832 .partition(|&lint| lint.is_plugin);
833 let plugin = sort_lints(sess, plugin);
834 let builtin = sort_lints(sess, builtin);
836 let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups()
839 .partition(|&(.., p)| p);
840 let plugin_groups = sort_lint_groups(plugin_groups);
841 let builtin_groups = sort_lint_groups(builtin_groups);
843 let max_name_len = plugin.iter()
845 .map(|&s| s.name.chars().count())
848 let padded = |x: &str| {
849 let mut s = " ".repeat(max_name_len - x.chars().count());
854 println!("Lint checks provided by rustc:\n");
855 println!(" {} {:7.7} {}", padded("name"), "default", "meaning");
856 println!(" {} {:7.7} {}", padded("----"), "-------", "-------");
858 let print_lints = |lints: Vec<&Lint>| {
860 let name = lint.name_lower().replace("_", "-");
861 println!(" {} {:7.7} {}",
863 lint.default_level.as_str(),
869 print_lints(builtin);
871 let max_name_len = max("warnings".len(),
873 .chain(&builtin_groups)
874 .map(|&(s, _)| s.chars().count())
878 let padded = |x: &str| {
879 let mut s = " ".repeat(max_name_len - x.chars().count());
884 println!("Lint groups provided by rustc:\n");
885 println!(" {} {}", padded("name"), "sub-lints");
886 println!(" {} {}", padded("----"), "---------");
887 println!(" {} {}", padded("warnings"), "all lints that are set to issue warnings");
889 let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
890 for (name, to) in lints {
891 let name = name.to_lowercase().replace("_", "-");
892 let desc = to.into_iter()
893 .map(|x| x.to_string().replace("_", "-"))
894 .collect::<Vec<String>>()
896 println!(" {} {}", padded(&name), desc);
901 print_lint_groups(builtin_groups);
903 match (loaded_plugins, plugin.len(), plugin_groups.len()) {
904 (false, 0, _) | (false, _, 0) => {
905 println!("Compiler plugins can provide additional lints and lint groups. To see a \
906 listing of these, re-run `rustc -W help` with a crate filename.");
908 (false, ..) => panic!("didn't load lint plugins but got them anyway!"),
909 (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."),
912 println!("Lint checks provided by plugins loaded by this crate:\n");
916 println!("Lint groups provided by plugins loaded by this crate:\n");
917 print_lint_groups(plugin_groups);
923 fn describe_debug_flags() {
924 println!("\nAvailable options:\n");
925 print_flag_list("-Z", config::DB_OPTIONS);
928 fn describe_codegen_flags() {
929 println!("\nAvailable codegen options:\n");
930 print_flag_list("-C", config::CG_OPTIONS);
933 fn print_flag_list<T>(cmdline_opt: &str,
934 flag_list: &[(&'static str, T, Option<&'static str>, &'static str)]) {
935 let max_len = flag_list.iter()
936 .map(|&(name, _, opt_type_desc, _)| {
937 let extra_len = match opt_type_desc {
941 name.chars().count() + extra_len
946 for &(name, _, opt_type_desc, desc) in flag_list {
947 let (width, extra) = match opt_type_desc {
948 Some(..) => (max_len - 4, "=val"),
949 None => (max_len, ""),
951 println!(" {} {:>width$}{} -- {}",
953 name.replace("_", "-"),
960 /// Process command line options. Emits messages as appropriate. If compilation
961 /// should continue, returns a getopts::Matches object parsed from args,
962 /// otherwise returns `None`.
964 /// The compiler's handling of options is a little complicated as it ties into
965 /// our stability story. The current intention of each compiler option is to
966 /// have one of two modes:
968 /// 1. An option is stable and can be used everywhere.
969 /// 2. An option is unstable, and can only be used on nightly.
971 /// Like unstable library and language features, however, unstable options have
972 /// always required a form of "opt in" to indicate that you're using them. This
973 /// provides the easy ability to scan a code base to check to see if anything
974 /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
976 /// All options behind `-Z` are considered unstable by default. Other top-level
977 /// options can also be considered unstable, and they were unlocked through the
978 /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
979 /// instability in both cases, though.
981 /// So with all that in mind, the comments below have some more detail about the
982 /// contortions done here to get things to work out correctly.
983 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
984 // Throw away the first argument, the name of the binary
985 let args = &args[1..];
988 // user did not write `-v` nor `-Z unstable-options`, so do not
989 // include that extra information.
994 // Parse with *all* options defined in the compiler, we don't worry about
995 // option stability here we just want to parse as much as possible.
996 let mut options = getopts::Options::new();
997 for option in config::rustc_optgroups() {
998 (option.apply)(&mut options);
1000 let matches = options.parse(args).unwrap_or_else(|f|
1001 early_error(ErrorOutputType::default(), &f.to_string()));
1003 // For all options we just parsed, we check a few aspects:
1005 // * If the option is stable, we're all good
1006 // * If the option wasn't passed, we're all good
1007 // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1008 // ourselves), then we require the `-Z unstable-options` flag to unlock
1009 // this option that was passed.
1010 // * If we're a nightly compiler, then unstable options are now unlocked, so
1011 // we're good to go.
1012 // * Otherwise, if we're an unstable option then we generate an error
1013 // (unstable option being used on stable)
1014 nightly_options::check_nightly_options(&matches, &config::rustc_optgroups());
1016 if matches.opt_present("h") || matches.opt_present("help") {
1017 // Only show unstable options in --help if we accept unstable options.
1018 usage(matches.opt_present("verbose"), nightly_options::is_unstable_enabled(&matches));
1022 // Handle the special case of -Wall.
1023 let wall = matches.opt_strs("W");
1024 if wall.iter().any(|x| *x == "all") {
1029 // Don't handle -W help here, because we might first load plugins.
1030 let r = matches.opt_strs("Z");
1031 if r.iter().any(|x| *x == "help") {
1032 describe_debug_flags();
1036 let cg_flags = matches.opt_strs("C");
1038 if cg_flags.iter().any(|x| *x == "help") {
1039 describe_codegen_flags();
1043 if cg_flags.iter().any(|x| *x == "no-stack-check") {
1044 early_warn(ErrorOutputType::default(),
1045 "the --no-stack-check flag is deprecated and does nothing");
1048 if cg_flags.iter().any(|x| *x == "passes=list") {
1049 get_codegen_sysroot("llvm")().print_passes();
1053 if matches.opt_present("version") {
1054 version("rustc", &matches);
1061 fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
1063 Input::File(ifile) => {
1064 rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess)
1066 Input::Str { name, input } => {
1067 rustc_parse::parse_crate_attrs_from_source_str(
1076 /// Gets a list of extra command-line flags provided by the user, as strings.
1078 /// This function is used during ICEs to show more information useful for
1079 /// debugging, since some ICEs only happens with non-default compiler flags
1080 /// (and the users don't always report them).
1081 fn extra_compiler_flags() -> Option<(Vec<String>, bool)> {
1082 let args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).collect::<Vec<_>>();
1084 // Avoid printing help because of empty args. This can suggest the compiler
1085 // itself is not the program root (consider RLS).
1090 let matches = if let Some(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() {
1109 let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
1115 if !ICE_REPORT_COMPILER_FLAGS_EXCLUDE.contains(&name) {
1116 result.push(format!("{}{} {}", prefix, flag, content));
1118 excluded_cargo_defaults = true;
1123 if !result.is_empty() {
1124 Some((result, excluded_cargo_defaults))
1130 /// Runs a closure and catches unwinds triggered by fatal errors.
1132 /// The compiler currently unwinds with a special sentinel value to abort
1133 /// compilation on fatal errors. This function catches that sentinel and turns
1134 /// the panic into a `Result` instead.
1135 pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorReported> {
1136 catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
1137 if value.is::<errors::FatalErrorMarker>() {
1140 panic::resume_unwind(value);
1146 static ref DEFAULT_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
1147 let hook = panic::take_hook();
1148 panic::set_hook(Box::new(|info| report_ice(info, BUG_REPORT_URL)));
1153 /// Prints the ICE message, including backtrace and query stack.
1155 /// The message will point the user at `bug_report_url` to report the ICE.
1157 /// When `install_ice_hook` is called, this function will be called as the panic
1159 pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
1160 // Invoke the default handler, which prints the actual panic message and optionally a backtrace
1161 (*DEFAULT_HOOK)(info);
1163 // Separate the output with an empty line
1166 let emitter = Box::new(errors::emitter::EmitterWriter::stderr(
1167 errors::ColorConfig::Auto,
1174 let handler = errors::Handler::with_emitter(true, None, emitter);
1176 // a .span_bug or .bug call has already printed what
1177 // it wants to print.
1178 if !info.payload().is::<errors::ExplicitBug>() {
1179 let d = errors::Diagnostic::new(errors::Level::Bug, "unexpected panic");
1180 handler.emit_diagnostic(&d);
1181 handler.abort_if_errors_and_should_abort();
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(),
1187 format!("rustc {} running on {}",
1188 option_env!("CFG_VERSION").unwrap_or("unknown_version"),
1189 config::host_triple()).into(),
1192 if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
1193 xs.push(format!("compiler flags: {}", flags.join(" ")).into());
1195 if excluded_cargo_defaults {
1196 xs.push("some of the compiler flags provided by cargo are hidden".into());
1201 handler.note_without_error(¬e);
1204 // If backtraces are enabled, also print the query stack
1205 let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
1208 TyCtxt::try_print_query_stack(&handler);
1213 if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
1217 // Trigger a debugger if we crashed during bootstrap
1223 /// Installs a panic hook that will print the ICE message on unexpected panics.
1225 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
1226 pub fn install_ice_hook() {
1227 lazy_static::initialize(&DEFAULT_HOOK);
1230 /// This allows tools to enable rust logging without having to magically match rustc's
1231 /// log crate version
1232 pub fn init_rustc_env_logger() {
1233 env_logger::init_from_env("RUSTC_LOG");
1237 let start = Instant::now();
1238 init_rustc_env_logger();
1239 let mut callbacks = TimePassesCallbacks::default();
1241 let result = catch_fatal_errors(|| {
1242 let args = env::args_os().enumerate()
1243 .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
1244 early_error(ErrorOutputType::default(),
1245 &format!("Argument {} is not valid Unicode: {:?}", i, arg))
1247 .collect::<Vec<_>>();
1248 run_compiler(&args, &mut callbacks, None, None)
1249 }).and_then(|result| result);
1250 let exit_code = match result {
1251 Ok(_) => EXIT_SUCCESS,
1252 Err(_) => EXIT_FAILURE,
1254 // The extra `\t` is necessary to align this label with the others.
1256 print_time_passes_entry(callbacks.time_passes, "\ttotal", start.elapsed());
1257 process::exit(exit_code);