//! The Rust compiler. //! //! # Note //! //! This API is completely unstable and subject to change. #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] #![feature(lazy_cell)] #![feature(decl_macro)] #![recursion_limit = "256"] #![allow(rustc::potential_query_instability)] #![deny(rustc::untranslatable_diagnostic)] #![deny(rustc::diagnostic_outside_of_impl)] #[macro_use] extern crate tracing; pub extern crate rustc_plugin_impl as plugin; use rustc_ast as ast; use rustc_codegen_ssa::{traits::CodegenBackend, CodegenErrors, CodegenResults}; use rustc_data_structures::profiling::{ get_resident_set_size, print_time_passes_entry, TimePassesFormat, }; use rustc_data_structures::sync::SeqCst; use rustc_errors::registry::{InvalidErrorCode, Registry}; use rustc_errors::{ DiagnosticMessage, ErrorGuaranteed, PResult, SubdiagnosticMessage, TerminalUrl, }; use rustc_feature::find_gated_cfg; use rustc_interface::util::{self, collect_crate_types, get_codegen_backend}; use rustc_interface::{interface, Queries}; use rustc_lint::LintStore; use rustc_macros::fluent_messages; use rustc_metadata::locator; use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS}; use rustc_session::config::{ErrorOutputType, Input, OutputType, PrintRequest, TrimmedDefPaths}; use rustc_session::cstore::MetadataLoader; use rustc_session::getopts::{self, Matches}; use rustc_session::lint::{Lint, LintId}; use rustc_session::{config, Session}; use rustc_session::{early_error, early_error_no_abort, early_warn}; use rustc_span::source_map::{FileLoader, FileName}; use rustc_span::symbol::sym; use rustc_target::json::ToJson; use rustc_target::spec::{Target, TargetTriple}; use std::cmp::max; use std::collections::BTreeMap; use std::env; use std::ffi::OsString; use std::fs; use std::io::{self, IsTerminal, Read, Write}; use std::panic::{self, catch_unwind}; use std::path::PathBuf; use std::process::{self, Command, Stdio}; use std::str; use std::sync::LazyLock; use std::time::Instant; pub mod args; pub mod pretty; mod session_diagnostics; use crate::session_diagnostics::{ RLinkEmptyVersionNumber, RLinkEncodingVersionMismatch, RLinkRustcVersionMismatch, RLinkWrongFileType, RlinkNotAFile, RlinkUnableToRead, }; fluent_messages! { "../messages.ftl" } pub static DEFAULT_LOCALE_RESOURCES: &[&str] = &[ // tidy-alphabetical-start crate::DEFAULT_LOCALE_RESOURCE, rustc_ast_lowering::DEFAULT_LOCALE_RESOURCE, rustc_ast_passes::DEFAULT_LOCALE_RESOURCE, rustc_attr::DEFAULT_LOCALE_RESOURCE, rustc_borrowck::DEFAULT_LOCALE_RESOURCE, rustc_builtin_macros::DEFAULT_LOCALE_RESOURCE, rustc_codegen_ssa::DEFAULT_LOCALE_RESOURCE, rustc_const_eval::DEFAULT_LOCALE_RESOURCE, rustc_error_messages::DEFAULT_LOCALE_RESOURCE, rustc_expand::DEFAULT_LOCALE_RESOURCE, rustc_hir_analysis::DEFAULT_LOCALE_RESOURCE, rustc_hir_typeck::DEFAULT_LOCALE_RESOURCE, rustc_incremental::DEFAULT_LOCALE_RESOURCE, rustc_infer::DEFAULT_LOCALE_RESOURCE, rustc_interface::DEFAULT_LOCALE_RESOURCE, rustc_lint::DEFAULT_LOCALE_RESOURCE, rustc_metadata::DEFAULT_LOCALE_RESOURCE, rustc_middle::DEFAULT_LOCALE_RESOURCE, rustc_mir_build::DEFAULT_LOCALE_RESOURCE, rustc_mir_dataflow::DEFAULT_LOCALE_RESOURCE, rustc_monomorphize::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE, rustc_passes::DEFAULT_LOCALE_RESOURCE, rustc_plugin_impl::DEFAULT_LOCALE_RESOURCE, rustc_privacy::DEFAULT_LOCALE_RESOURCE, rustc_query_system::DEFAULT_LOCALE_RESOURCE, rustc_resolve::DEFAULT_LOCALE_RESOURCE, rustc_session::DEFAULT_LOCALE_RESOURCE, rustc_symbol_mangling::DEFAULT_LOCALE_RESOURCE, rustc_trait_selection::DEFAULT_LOCALE_RESOURCE, rustc_ty_utils::DEFAULT_LOCALE_RESOURCE, // tidy-alphabetical-end ]; /// Exit status code used for successful compilation and help output. pub const EXIT_SUCCESS: i32 = 0; /// Exit status code used for compilation failures and invalid flags. pub const EXIT_FAILURE: i32 = 1; const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\ ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md"; const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["-Z", "-C", "--crate-type"]; const ICE_REPORT_COMPILER_FLAGS_EXCLUDE: &[&str] = &["metadata", "extra-filename"]; const ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE: &[&str] = &["incremental"]; pub fn abort_on_err(result: Result, sess: &Session) -> T { match result { Err(..) => { sess.abort_if_errors(); panic!("error reported but abort_if_errors didn't abort???"); } Ok(x) => x, } } pub trait Callbacks { /// Called before creating the compiler instance fn config(&mut self, _config: &mut interface::Config) {} /// Called after parsing. Return value instructs the compiler whether to /// continue the compilation afterwards (defaults to `Compilation::Continue`) fn after_parsing<'tcx>( &mut self, _compiler: &interface::Compiler, _queries: &'tcx Queries<'tcx>, ) -> Compilation { Compilation::Continue } /// Called after expansion. Return value instructs the compiler whether to /// continue the compilation afterwards (defaults to `Compilation::Continue`) fn after_expansion<'tcx>( &mut self, _compiler: &interface::Compiler, _queries: &'tcx Queries<'tcx>, ) -> Compilation { Compilation::Continue } /// Called after analysis. Return value instructs the compiler whether to /// continue the compilation afterwards (defaults to `Compilation::Continue`) fn after_analysis<'tcx>( &mut self, _compiler: &interface::Compiler, _queries: &'tcx Queries<'tcx>, ) -> Compilation { Compilation::Continue } } #[derive(Default)] pub struct TimePassesCallbacks { time_passes: Option, } impl Callbacks for TimePassesCallbacks { // JUSTIFICATION: the session doesn't exist at this point. #[allow(rustc::bad_opt_access)] fn config(&mut self, config: &mut interface::Config) { // If a --print=... option has been given, we don't print the "total" // time because it will mess up the --print output. See #64339. // self.time_passes = (config.opts.prints.is_empty() && config.opts.unstable_opts.time_passes) .then(|| config.opts.unstable_opts.time_passes_format); config.opts.trimmed_def_paths = TrimmedDefPaths::GoodPath; } } pub fn diagnostics_registry() -> Registry { Registry::new(rustc_error_codes::DIAGNOSTICS) } /// This is the primary entry point for rustc. pub struct RunCompiler<'a, 'b> { at_args: &'a [String], callbacks: &'b mut (dyn Callbacks + Send), file_loader: Option>, make_codegen_backend: Option Box + Send>>, } impl<'a, 'b> RunCompiler<'a, 'b> { pub fn new(at_args: &'a [String], callbacks: &'b mut (dyn Callbacks + Send)) -> Self { Self { at_args, callbacks, file_loader: None, make_codegen_backend: None } } /// Set a custom codegen backend. /// /// Has no uses within this repository, but is used by bjorn3 for "the /// hotswapping branch of cg_clif" for "setting the codegen backend from a /// custom driver where the custom codegen backend has arbitrary data." /// (See #102759.) pub fn set_make_codegen_backend( &mut self, make_codegen_backend: Option< Box Box + Send>, >, ) -> &mut Self { self.make_codegen_backend = make_codegen_backend; self } /// Load files from sources other than the file system. /// /// Has no uses within this repository, but may be used in the future by /// bjorn3 for "hooking rust-analyzer's VFS into rustc at some point for /// running rustc without having to save". (See #102759.) pub fn set_file_loader( &mut self, file_loader: Option>, ) -> &mut Self { self.file_loader = file_loader; self } /// Parse args and run the compiler. pub fn run(self) -> interface::Result<()> { run_compiler(self.at_args, self.callbacks, self.file_loader, self.make_codegen_backend) } } fn run_compiler( at_args: &[String], callbacks: &mut (dyn Callbacks + Send), file_loader: Option>, make_codegen_backend: Option< Box Box + Send>, >, ) -> interface::Result<()> { let args = args::arg_expand_all(at_args); let Some(matches) = handle_options(&args) else { return Ok(()) }; let sopts = config::build_session_options(&matches); if let Some(ref code) = matches.opt_str("explain") { handle_explain(diagnostics_registry(), code, sopts.error_format); return Ok(()); } let cfg = interface::parse_cfgspecs(matches.opt_strs("cfg")); let check_cfg = interface::parse_check_cfg(matches.opt_strs("check-cfg")); let (odir, ofile) = make_output(&matches); let mut config = interface::Config { opts: sopts, crate_cfg: cfg, crate_check_cfg: check_cfg, input: Input::File(PathBuf::new()), output_file: ofile, output_dir: odir, file_loader, locale_resources: DEFAULT_LOCALE_RESOURCES, lint_caps: Default::default(), parse_sess_created: None, register_lints: None, override_queries: None, make_codegen_backend, registry: diagnostics_registry(), }; match make_input(config.opts.error_format, &matches.free) { Err(reported) => return Err(reported), Ok(Some(input)) => { config.input = input; callbacks.config(&mut config); } Ok(None) => match matches.free.len() { 0 => { callbacks.config(&mut config); interface::run_compiler(config, |compiler| { let sopts = &compiler.session().opts; if sopts.describe_lints { let mut lint_store = rustc_lint::new_lint_store(compiler.session().enable_internal_lints()); let registered_lints = if let Some(register_lints) = compiler.register_lints() { register_lints(compiler.session(), &mut lint_store); true } else { false }; describe_lints(compiler.session(), &lint_store, registered_lints); return; } let should_stop = print_crate_info(&***compiler.codegen_backend(), compiler.session(), false); if should_stop == Compilation::Stop { return; } early_error(sopts.error_format, "no input filename given") }); return Ok(()); } 1 => panic!("make_input should have provided valid inputs"), _ => early_error( config.opts.error_format, &format!( "multiple input filenames provided (first two filenames are `{}` and `{}`)", matches.free[0], matches.free[1], ), ), }, }; interface::run_compiler(config, |compiler| { let sess = compiler.session(); let should_stop = print_crate_info(&***compiler.codegen_backend(), sess, true) .and_then(|| list_metadata(sess, &*compiler.codegen_backend().metadata_loader())) .and_then(|| try_process_rlink(sess, compiler)); if should_stop == Compilation::Stop { return sess.compile_status(); } let linker = compiler.enter(|queries| { let early_exit = || sess.compile_status().map(|_| None); queries.parse()?; if let Some(ppm) = &sess.opts.pretty { if ppm.needs_ast_map() { queries.global_ctxt()?.enter(|tcx| { tcx.ensure().early_lint_checks(()); pretty::print_after_hir_lowering(tcx, *ppm); Ok(()) })?; } else { let krate = queries.parse()?.steal(); pretty::print_after_parsing(sess, &krate, *ppm); } trace!("finished pretty-printing"); return early_exit(); } if callbacks.after_parsing(compiler, queries) == Compilation::Stop { return early_exit(); } if sess.opts.unstable_opts.parse_only || sess.opts.unstable_opts.show_span.is_some() { return early_exit(); } { let plugins = queries.register_plugins()?; let (.., lint_store) = &*plugins.borrow(); // Lint plugins are registered; now we can process command line flags. if sess.opts.describe_lints { describe_lints(sess, lint_store, true); return early_exit(); } } // Make sure name resolution and macro expansion is run. queries.global_ctxt()?.enter(|tcx| tcx.resolver_for_lowering(())); if callbacks.after_expansion(compiler, queries) == Compilation::Stop { return early_exit(); } // Make sure the `output_filenames` query is run for its side // effects of writing the dep-info and reporting errors. queries.global_ctxt()?.enter(|tcx| tcx.output_filenames(())); if sess.opts.output_types.contains_key(&OutputType::DepInfo) && sess.opts.output_types.len() == 1 { return early_exit(); } if sess.opts.unstable_opts.no_analysis { return early_exit(); } queries.global_ctxt()?.enter(|tcx| tcx.analysis(()))?; if callbacks.after_analysis(compiler, queries) == Compilation::Stop { return early_exit(); } queries.ongoing_codegen()?; if sess.opts.unstable_opts.print_type_sizes { sess.code_stats.print_type_sizes(); } let linker = queries.linker()?; Ok(Some(linker)) })?; if let Some(linker) = linker { let _timer = sess.timer("link"); linker.link()? } if sess.opts.unstable_opts.perf_stats { sess.print_perf_stats(); } if sess.opts.unstable_opts.print_fuel.is_some() { eprintln!( "Fuel used by {}: {}", sess.opts.unstable_opts.print_fuel.as_ref().unwrap(), sess.print_fuel.load(SeqCst) ); } Ok(()) }) } // Extract output directory and file from matches. fn make_output(matches: &getopts::Matches) -> (Option, Option) { let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o)); let ofile = matches.opt_str("o").map(|o| PathBuf::from(&o)); (odir, ofile) } // Extract input (string or file and optional path) from matches. fn make_input( error_format: ErrorOutputType, free_matches: &[String], ) -> Result, ErrorGuaranteed> { if free_matches.len() == 1 { let ifile = &free_matches[0]; if ifile == "-" { let mut src = String::new(); if io::stdin().read_to_string(&mut src).is_err() { // Immediately stop compilation if there was an issue reading // the input (for example if the input stream is not UTF-8). let reported = early_error_no_abort( error_format, "couldn't read from stdin, as it did not contain valid UTF-8", ); return Err(reported); } if let Ok(path) = env::var("UNSTABLE_RUSTDOC_TEST_PATH") { let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect( "when UNSTABLE_RUSTDOC_TEST_PATH is set \ UNSTABLE_RUSTDOC_TEST_LINE also needs to be set", ); let line = isize::from_str_radix(&line, 10) .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be an number"); let file_name = FileName::doc_test_source_code(PathBuf::from(path), line); Ok(Some(Input::Str { name: file_name, input: src })) } else { Ok(Some(Input::Str { name: FileName::anon_source_code(&src), input: src })) } } else { Ok(Some(Input::File(PathBuf::from(ifile)))) } } else { Ok(None) } } /// Whether to stop or continue compilation. #[derive(Copy, Clone, Debug, Eq, PartialEq)] pub enum Compilation { Stop, Continue, } impl Compilation { pub fn and_then Compilation>(self, next: F) -> Compilation { match self { Compilation::Stop => Compilation::Stop, Compilation::Continue => next(), } } } fn handle_explain(registry: Registry, code: &str, output: ErrorOutputType) { let upper_cased_code = code.to_ascii_uppercase(); let normalised = if upper_cased_code.starts_with('E') { upper_cased_code } else { format!("E{code:0>4}") }; match registry.try_find_description(&normalised) { Ok(description) => { let mut is_in_code_block = false; let mut text = String::new(); // Slice off the leading newline and print. for line in description.lines() { let indent_level = line.find(|c: char| !c.is_whitespace()).unwrap_or_else(|| line.len()); let dedented_line = &line[indent_level..]; if dedented_line.starts_with("```") { is_in_code_block = !is_in_code_block; text.push_str(&line[..(indent_level + 3)]); } else if is_in_code_block && dedented_line.starts_with("# ") { continue; } else { text.push_str(line); } text.push('\n'); } if io::stdout().is_terminal() { show_content_with_pager(&text); } else { print!("{text}"); } } Err(InvalidErrorCode) => { early_error(output, &format!("{code} is not a valid error code")); } } } fn show_content_with_pager(content: &str) { let pager_name = env::var_os("PAGER").unwrap_or_else(|| { if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") } }); let mut fallback_to_println = false; match Command::new(pager_name).stdin(Stdio::piped()).spawn() { Ok(mut pager) => { if let Some(pipe) = pager.stdin.as_mut() { if pipe.write_all(content.as_bytes()).is_err() { fallback_to_println = true; } } if pager.wait().is_err() { fallback_to_println = true; } } Err(_) => { fallback_to_println = true; } } // If pager fails for whatever reason, we should still print the content // to standard output if fallback_to_println { print!("{content}"); } } pub fn try_process_rlink(sess: &Session, compiler: &interface::Compiler) -> Compilation { if sess.opts.unstable_opts.link_only { if let Input::File(file) = &sess.io.input { // FIXME: #![crate_type] and #![crate_name] support not implemented yet sess.init_crate_types(collect_crate_types(sess, &[])); let outputs = compiler.build_output_filenames(sess, &[]); let rlink_data = fs::read(file).unwrap_or_else(|err| { sess.emit_fatal(RlinkUnableToRead { err }); }); let codegen_results = match CodegenResults::deserialize_rlink(rlink_data) { Ok(codegen) => codegen, Err(err) => { match err { CodegenErrors::WrongFileType => sess.emit_fatal(RLinkWrongFileType), CodegenErrors::EmptyVersionNumber => { sess.emit_fatal(RLinkEmptyVersionNumber) } CodegenErrors::EncodingVersionMismatch { version_array, rlink_version } => { sess.emit_fatal(RLinkEncodingVersionMismatch { version_array, rlink_version, }) } CodegenErrors::RustcVersionMismatch { rustc_version, current_version } => { sess.emit_fatal(RLinkRustcVersionMismatch { rustc_version, current_version, }) } }; } }; let result = compiler.codegen_backend().link(sess, codegen_results, &outputs); abort_on_err(result, sess); } else { sess.emit_fatal(RlinkNotAFile {}) } Compilation::Stop } else { Compilation::Continue } } pub fn list_metadata(sess: &Session, metadata_loader: &dyn MetadataLoader) -> Compilation { if sess.opts.unstable_opts.ls { match sess.io.input { Input::File(ref ifile) => { let path = &(*ifile); let mut v = Vec::new(); locator::list_file_metadata(&sess.target, path, metadata_loader, &mut v).unwrap(); println!("{}", String::from_utf8(v).unwrap()); } Input::Str { .. } => { early_error(ErrorOutputType::default(), "cannot list metadata for stdin"); } } return Compilation::Stop; } Compilation::Continue } fn print_crate_info( codegen_backend: &dyn CodegenBackend, sess: &Session, parse_attrs: bool, ) -> Compilation { use rustc_session::config::PrintRequest::*; // NativeStaticLibs and LinkArgs are special - printed during linking // (empty iterator returns true) if sess.opts.prints.iter().all(|&p| p == NativeStaticLibs || p == LinkArgs) { return Compilation::Continue; } let attrs = if parse_attrs { let result = parse_crate_attrs(sess); match result { Ok(attrs) => Some(attrs), Err(mut parse_error) => { parse_error.emit(); return Compilation::Stop; } } } else { None }; for req in &sess.opts.prints { match *req { TargetList => { let mut targets = rustc_target::spec::TARGETS.to_vec(); targets.sort_unstable(); println!("{}", targets.join("\n")); } Sysroot => println!("{}", sess.sysroot.display()), TargetLibdir => println!("{}", sess.target_tlib_path.dir.display()), TargetSpec => { println!("{}", serde_json::to_string_pretty(&sess.target.to_json()).unwrap()); } AllTargetSpecs => { let mut targets = BTreeMap::new(); for name in rustc_target::spec::TARGETS { let triple = TargetTriple::from_triple(name); let target = Target::expect_builtin(&triple); targets.insert(name, target.to_json()); } println!("{}", serde_json::to_string_pretty(&targets).unwrap()); } FileNames | CrateName => { let Some(attrs) = attrs.as_ref() else { // no crate attributes, print out an error and exit return Compilation::Continue; }; let t_outputs = rustc_interface::util::build_output_filenames(attrs, sess); let id = rustc_session::output::find_crate_name(sess, attrs); if *req == PrintRequest::CrateName { println!("{id}"); continue; } let crate_types = collect_crate_types(sess, attrs); for &style in &crate_types { let fname = rustc_session::output::filename_for_input(sess, style, id, &t_outputs); println!("{}", fname.file_name().unwrap().to_string_lossy()); } } Cfg => { let mut cfgs = sess .parse_sess .config .iter() .filter_map(|&(name, value)| { // Note that crt-static is a specially recognized cfg // directive that's printed out here as part of // rust-lang/rust#37406, but in general the // `target_feature` cfg is gated under // rust-lang/rust#29717. For now this is just // specifically allowing the crt-static cfg and that's // it, this is intended to get into Cargo and then go // through to build scripts. if (name != sym::target_feature || value != Some(sym::crt_dash_static)) && !sess.is_nightly_build() && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some() { return None; } if let Some(value) = value { Some(format!("{name}=\"{value}\"")) } else { Some(name.to_string()) } }) .collect::>(); cfgs.sort(); for cfg in cfgs { println!("{cfg}"); } } CallingConventions => { let mut calling_conventions = rustc_target::spec::abi::all_names(); calling_conventions.sort_unstable(); println!("{}", calling_conventions.join("\n")); } RelocationModels | CodeModels | TlsModels | TargetCPUs | StackProtectorStrategies | TargetFeatures => { codegen_backend.print(*req, sess); } // Any output here interferes with Cargo's parsing of other printed output NativeStaticLibs => {} LinkArgs => {} SplitDebuginfo => { use rustc_target::spec::SplitDebuginfo::{Off, Packed, Unpacked}; for split in &[Off, Packed, Unpacked] { let stable = sess.target.options.supported_split_debuginfo.contains(split); let unstable_ok = sess.unstable_options(); if stable || unstable_ok { println!("{split}"); } } } } } Compilation::Stop } /// Prints version information /// /// NOTE: this is a macro to support drivers built at a different time than the main `rustc_driver` crate. pub macro version($binary: literal, $matches: expr) { fn unw(x: Option<&str>) -> &str { x.unwrap_or("unknown") } $crate::version_at_macro_invocation( $binary, $matches, unw(option_env!("CFG_VERSION")), unw(option_env!("CFG_VER_HASH")), unw(option_env!("CFG_VER_DATE")), unw(option_env!("CFG_RELEASE")), ) } #[doc(hidden)] // use the macro instead pub fn version_at_macro_invocation( binary: &str, matches: &getopts::Matches, version: &str, commit_hash: &str, commit_date: &str, release: &str, ) { let verbose = matches.opt_present("verbose"); println!("{binary} {version}"); if verbose { println!("binary: {binary}"); println!("commit-hash: {commit_hash}"); println!("commit-date: {commit_date}"); println!("host: {}", config::host_triple()); println!("release: {release}"); let debug_flags = matches.opt_strs("Z"); let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend=")); get_codegen_backend(&None, backend_name).print_version(); } } fn usage(verbose: bool, include_unstable_options: bool, nightly_build: bool) { let groups = if verbose { config::rustc_optgroups() } else { config::rustc_short_optgroups() }; let mut options = getopts::Options::new(); for option in groups.iter().filter(|x| include_unstable_options || x.is_stable()) { (option.apply)(&mut options); } let message = "Usage: rustc [OPTIONS] INPUT"; let nightly_help = if nightly_build { "\n -Z help Print unstable compiler options" } else { "" }; let verbose_help = if verbose { "" } else { "\n --help -v Print the full set of options rustc accepts" }; let at_path = if verbose { " @path Read newline separated options from `path`\n" } else { "" }; println!( "{options}{at_path}\nAdditional help: -C help Print codegen options -W help \ Print 'lint' options and default settings{nightly}{verbose}\n", options = options.usage(message), at_path = at_path, nightly = nightly_help, verbose = verbose_help ); } fn print_wall_help() { println!( " The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by default. Use `rustc -W help` to see all available lints. It's more common to put warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using the command line flag directly. " ); } /// Write to stdout lint command options, together with a list of all available lints pub fn describe_lints(sess: &Session, lint_store: &LintStore, loaded_plugins: bool) { println!( " Available lint options: -W Warn about -A \ Allow -D Deny -F Forbid \ (deny and all attempts to override) " ); fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> { // The sort doesn't case-fold but it's doubtful we care. lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name)); lints } fn sort_lint_groups( lints: Vec<(&'static str, Vec, bool)>, ) -> Vec<(&'static str, Vec)> { let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect(); lints.sort_by_key(|l| l.0); lints } let (plugin, builtin): (Vec<_>, _) = lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_plugin); let plugin = sort_lints(sess, plugin); let builtin = sort_lints(sess, builtin); let (plugin_groups, builtin_groups): (Vec<_>, _) = lint_store.get_lint_groups().partition(|&(.., p)| p); let plugin_groups = sort_lint_groups(plugin_groups); let builtin_groups = sort_lint_groups(builtin_groups); let max_name_len = plugin.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0); let padded = |x: &str| { let mut s = " ".repeat(max_name_len - x.chars().count()); s.push_str(x); s }; println!("Lint checks provided by rustc:\n"); let print_lints = |lints: Vec<&Lint>| { println!(" {} {:7.7} {}", padded("name"), "default", "meaning"); println!(" {} {:7.7} {}", padded("----"), "-------", "-------"); for lint in lints { let name = lint.name_lower().replace('_', "-"); println!( " {} {:7.7} {}", padded(&name), lint.default_level(sess.edition()).as_str(), lint.desc ); } println!("\n"); }; print_lints(builtin); let max_name_len = max( "warnings".len(), plugin_groups .iter() .chain(&builtin_groups) .map(|&(s, _)| s.chars().count()) .max() .unwrap_or(0), ); let padded = |x: &str| { let mut s = " ".repeat(max_name_len - x.chars().count()); s.push_str(x); s }; println!("Lint groups provided by rustc:\n"); let print_lint_groups = |lints: Vec<(&'static str, Vec)>, all_warnings| { println!(" {} sub-lints", padded("name")); println!(" {} ---------", padded("----")); if all_warnings { println!(" {} all lints that are set to issue warnings", padded("warnings")); } for (name, to) in lints { let name = name.to_lowercase().replace('_', "-"); let desc = to .into_iter() .map(|x| x.to_string().replace('_', "-")) .collect::>() .join(", "); println!(" {} {}", padded(&name), desc); } println!("\n"); }; print_lint_groups(builtin_groups, true); match (loaded_plugins, plugin.len(), plugin_groups.len()) { (false, 0, _) | (false, _, 0) => { println!("Lint tools like Clippy can provide additional lints and lint groups."); } (false, ..) => panic!("didn't load lint plugins but got them anyway!"), (true, 0, 0) => println!("This crate does not load any lint plugins or lint groups."), (true, l, g) => { if l > 0 { println!("Lint checks provided by plugins loaded by this crate:\n"); print_lints(plugin); } if g > 0 { println!("Lint groups provided by plugins loaded by this crate:\n"); print_lint_groups(plugin_groups, false); } } } } /// Show help for flag categories shared between rustdoc and rustc. /// /// Returns whether a help option was printed. pub fn describe_flag_categories(matches: &Matches) -> bool { // Handle the special case of -Wall. let wall = matches.opt_strs("W"); if wall.iter().any(|x| *x == "all") { print_wall_help(); rustc_errors::FatalError.raise(); } // Don't handle -W help here, because we might first load plugins. let debug_flags = matches.opt_strs("Z"); if debug_flags.iter().any(|x| *x == "help") { describe_debug_flags(); return true; } let cg_flags = matches.opt_strs("C"); if cg_flags.iter().any(|x| *x == "help") { describe_codegen_flags(); return true; } if cg_flags.iter().any(|x| *x == "no-stack-check") { early_warn( ErrorOutputType::default(), "the --no-stack-check flag is deprecated and does nothing", ); } if cg_flags.iter().any(|x| *x == "passes=list") { let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend=")); get_codegen_backend(&None, backend_name).print_passes(); return true; } false } fn describe_debug_flags() { println!("\nAvailable options:\n"); print_flag_list("-Z", config::Z_OPTIONS); } fn describe_codegen_flags() { println!("\nAvailable codegen options:\n"); print_flag_list("-C", config::CG_OPTIONS); } fn print_flag_list( cmdline_opt: &str, flag_list: &[(&'static str, T, &'static str, &'static str)], ) { let max_len = flag_list.iter().map(|&(name, _, _, _)| name.chars().count()).max().unwrap_or(0); for &(name, _, _, desc) in flag_list { println!( " {} {:>width$}=val -- {}", cmdline_opt, name.replace('_', "-"), desc, width = max_len ); } } /// Process command line options. Emits messages as appropriate. If compilation /// should continue, returns a getopts::Matches object parsed from args, /// otherwise returns `None`. /// /// The compiler's handling of options is a little complicated as it ties into /// our stability story. The current intention of each compiler option is to /// have one of two modes: /// /// 1. An option is stable and can be used everywhere. /// 2. An option is unstable, and can only be used on nightly. /// /// Like unstable library and language features, however, unstable options have /// always required a form of "opt in" to indicate that you're using them. This /// provides the easy ability to scan a code base to check to see if anything /// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag. /// /// All options behind `-Z` are considered unstable by default. Other top-level /// options can also be considered unstable, and they were unlocked through the /// `-Z unstable-options` flag. Note that `-Z` remains to be the root of /// instability in both cases, though. /// /// So with all that in mind, the comments below have some more detail about the /// contortions done here to get things to work out correctly. pub fn handle_options(args: &[String]) -> Option { // Throw away the first argument, the name of the binary let args = &args[1..]; if args.is_empty() { // user did not write `-v` nor `-Z unstable-options`, so do not // include that extra information. let nightly_build = rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build(); usage(false, false, nightly_build); return None; } // Parse with *all* options defined in the compiler, we don't worry about // option stability here we just want to parse as much as possible. let mut options = getopts::Options::new(); for option in config::rustc_optgroups() { (option.apply)(&mut options); } let matches = options.parse(args).unwrap_or_else(|e| { let msg = match e { getopts::Fail::UnrecognizedOption(ref opt) => CG_OPTIONS .iter() .map(|&(name, ..)| ('C', name)) .chain(Z_OPTIONS.iter().map(|&(name, ..)| ('Z', name))) .find(|&(_, name)| *opt == name.replace('_', "-")) .map(|(flag, _)| format!("{e}. Did you mean `-{flag} {opt}`?")), _ => None, }; early_error(ErrorOutputType::default(), &msg.unwrap_or_else(|| e.to_string())); }); // For all options we just parsed, we check a few aspects: // // * If the option is stable, we're all good // * If the option wasn't passed, we're all good // * If `-Z unstable-options` wasn't passed (and we're not a -Z option // ourselves), then we require the `-Z unstable-options` flag to unlock // this option that was passed. // * If we're a nightly compiler, then unstable options are now unlocked, so // we're good to go. // * Otherwise, if we're an unstable option then we generate an error // (unstable option being used on stable) nightly_options::check_nightly_options(&matches, &config::rustc_optgroups()); if matches.opt_present("h") || matches.opt_present("help") { // Only show unstable options in --help if we accept unstable options. let unstable_enabled = nightly_options::is_unstable_enabled(&matches); let nightly_build = nightly_options::match_is_nightly_build(&matches); usage(matches.opt_present("verbose"), unstable_enabled, nightly_build); return None; } if describe_flag_categories(&matches) { return None; } if matches.opt_present("version") { version!("rustc", &matches); return None; } Some(matches) } fn parse_crate_attrs<'a>(sess: &'a Session) -> PResult<'a, ast::AttrVec> { match &sess.io.input { Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess), Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str( name.clone(), input.clone(), &sess.parse_sess, ), } } /// Gets a list of extra command-line flags provided by the user, as strings. /// /// This function is used during ICEs to show more information useful for /// debugging, since some ICEs only happens with non-default compiler flags /// (and the users don't always report them). fn extra_compiler_flags() -> Option<(Vec, bool)> { let mut args = env::args_os().map(|arg| arg.to_string_lossy().to_string()).peekable(); let mut result = Vec::new(); let mut excluded_cargo_defaults = false; while let Some(arg) = args.next() { if let Some(a) = ICE_REPORT_COMPILER_FLAGS.iter().find(|a| arg.starts_with(*a)) { let content = if arg.len() == a.len() { // A space-separated option, like `-C incremental=foo` or `--crate-type rlib` match args.next() { Some(arg) => arg.to_string(), None => continue, } } else if arg.get(a.len()..a.len() + 1) == Some("=") { // An equals option, like `--crate-type=rlib` arg[a.len() + 1..].to_string() } else { // A non-space option, like `-Cincremental=foo` arg[a.len()..].to_string() }; let option = content.split_once('=').map(|s| s.0).unwrap_or(&content); if ICE_REPORT_COMPILER_FLAGS_EXCLUDE.iter().any(|exc| option == *exc) { excluded_cargo_defaults = true; } else { result.push(a.to_string()); match ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.iter().find(|s| option == **s) { Some(s) => result.push(format!("{s}=[REDACTED]")), None => result.push(content), } } } } if !result.is_empty() { Some((result, excluded_cargo_defaults)) } else { None } } /// Runs a closure and catches unwinds triggered by fatal errors. /// /// The compiler currently unwinds with a special sentinel value to abort /// compilation on fatal errors. This function catches that sentinel and turns /// the panic into a `Result` instead. pub fn catch_fatal_errors R, R>(f: F) -> Result { catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| { if value.is::() { ErrorGuaranteed::unchecked_claim_error_was_emitted() } else { panic::resume_unwind(value); } }) } /// Variant of `catch_fatal_errors` for the `interface::Result` return type /// that also computes the exit code. pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 { let result = catch_fatal_errors(f).and_then(|result| result); match result { Ok(()) => EXIT_SUCCESS, Err(_) => EXIT_FAILURE, } } static DEFAULT_HOOK: LazyLock) + Sync + Send + 'static>> = LazyLock::new(|| { let hook = panic::take_hook(); panic::set_hook(Box::new(|info| { // If the error was caused by a broken pipe then this is not a bug. // Write the error and return immediately. See #98700. #[cfg(windows)] if let Some(msg) = info.payload().downcast_ref::() { if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)") { early_error_no_abort(ErrorOutputType::default(), &msg); return; } }; // Invoke the default handler, which prints the actual panic message and optionally a backtrace // Don't do this for delayed bugs, which already emit their own more useful backtrace. if !info.payload().is::() { (*DEFAULT_HOOK)(info); // Separate the output with an empty line eprintln!(); } // Print the ICE message report_ice(info, BUG_REPORT_URL); })); hook }); /// Prints the ICE message, including query stack, but without backtrace. /// /// The message will point the user at `bug_report_url` to report the ICE. /// /// When `install_ice_hook` is called, this function will be called as the panic /// hook. pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) { let fallback_bundle = rustc_errors::fallback_fluent_bundle(crate::DEFAULT_LOCALE_RESOURCES.to_vec(), false); let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr( rustc_errors::ColorConfig::Auto, None, None, fallback_bundle, false, false, None, false, false, TerminalUrl::No, )); let handler = rustc_errors::Handler::with_emitter(true, None, emitter); // a .span_bug or .bug call has already printed what // it wants to print. if !info.payload().is::() && !info.payload().is::() { handler.emit_err(session_diagnostics::Ice); } handler.emit_note(session_diagnostics::IceBugReport { bug_report_url }); handler.emit_note(session_diagnostics::IceVersion { version: util::version_str!().unwrap_or("unknown_version"), triple: config::host_triple(), }); if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() { handler.emit_note(session_diagnostics::IceFlags { flags: flags.join(" ") }); if excluded_cargo_defaults { handler.emit_note(session_diagnostics::IceExcludeCargoDefaults); } } // If backtraces are enabled, also print the query stack let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0"); let num_frames = if backtrace { None } else { Some(2) }; interface::try_print_query_stack(&handler, num_frames); #[cfg(windows)] if env::var("RUSTC_BREAK_ON_ICE").is_ok() { // Trigger a debugger if we crashed during bootstrap unsafe { windows::Win32::System::Diagnostics::Debug::DebugBreak() }; } } /// Installs a panic hook that will print the ICE message on unexpected panics. /// /// A custom rustc driver can skip calling this to set up a custom ICE hook. pub fn install_ice_hook() { // If the user has not explicitly overridden "RUST_BACKTRACE", then produce // full backtraces. When a compiler ICE happens, we want to gather // as much information as possible to present in the issue opened // by the user. Compiler developers and other rustc users can // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE" // (e.g. `RUST_BACKTRACE=1`) if std::env::var("RUST_BACKTRACE").is_err() { std::env::set_var("RUST_BACKTRACE", "full"); } LazyLock::force(&DEFAULT_HOOK); } /// This allows tools to enable rust logging without having to magically match rustc's /// tracing crate version. pub fn init_rustc_env_logger() { init_env_logger("RUSTC_LOG"); } /// This allows tools to enable rust logging without having to magically match rustc's /// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose an env var /// other than `RUSTC_LOG`. pub fn init_env_logger(env: &str) { if let Err(error) = rustc_log::init_env_logger(env) { early_error(ErrorOutputType::default(), &error.to_string()); } } #[cfg(all(unix, any(target_env = "gnu", target_os = "macos")))] mod signal_handler { extern "C" { fn backtrace_symbols_fd( buffer: *const *mut libc::c_void, size: libc::c_int, fd: libc::c_int, ); } extern "C" fn print_stack_trace(_: libc::c_int) { const MAX_FRAMES: usize = 256; static mut STACK_TRACE: [*mut libc::c_void; MAX_FRAMES] = [std::ptr::null_mut(); MAX_FRAMES]; unsafe { let depth = libc::backtrace(STACK_TRACE.as_mut_ptr(), MAX_FRAMES as i32); if depth == 0 { return; } backtrace_symbols_fd(STACK_TRACE.as_ptr(), depth, 2); } } /// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the /// process, print a stack trace and then exit. pub(super) fn install() { unsafe { const ALT_STACK_SIZE: usize = libc::MINSIGSTKSZ + 64 * 1024; let mut alt_stack: libc::stack_t = std::mem::zeroed(); alt_stack.ss_sp = std::alloc::alloc(std::alloc::Layout::from_size_align(ALT_STACK_SIZE, 1).unwrap()) as *mut libc::c_void; alt_stack.ss_size = ALT_STACK_SIZE; libc::sigaltstack(&alt_stack, std::ptr::null_mut()); let mut sa: libc::sigaction = std::mem::zeroed(); sa.sa_sigaction = print_stack_trace as libc::sighandler_t; sa.sa_flags = libc::SA_NODEFER | libc::SA_RESETHAND | libc::SA_ONSTACK; libc::sigemptyset(&mut sa.sa_mask); libc::sigaction(libc::SIGSEGV, &sa, std::ptr::null_mut()); } } } #[cfg(not(all(unix, any(target_env = "gnu", target_os = "macos"))))] mod signal_handler { pub(super) fn install() {} } pub fn main() -> ! { let start_time = Instant::now(); let start_rss = get_resident_set_size(); init_rustc_env_logger(); signal_handler::install(); let mut callbacks = TimePassesCallbacks::default(); install_ice_hook(); let exit_code = catch_with_exit_code(|| { let args = env::args_os() .enumerate() .map(|(i, arg)| { arg.into_string().unwrap_or_else(|arg| { early_error( ErrorOutputType::default(), &format!("argument {i} is not valid Unicode: {arg:?}"), ) }) }) .collect::>(); RunCompiler::new(&args, &mut callbacks).run() }); if let Some(format) = callbacks.time_passes { let end_rss = get_resident_set_size(); print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss, format); } process::exit(exit_code) }