rustc_driver_impl/
lib.rs

1//! The Rust compiler.
2//!
3//! # Note
4//!
5//! This API is completely unstable and subject to change.
6
7// tidy-alphabetical-start
8#![allow(internal_features)]
9#![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
10#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
11#![doc(rust_logo)]
12#![feature(decl_macro)]
13#![feature(panic_backtrace_config)]
14#![feature(panic_update_hook)]
15#![feature(rustdoc_internals)]
16#![feature(try_blocks)]
17// tidy-alphabetical-end
18
19use std::cmp::max;
20use std::collections::{BTreeMap, BTreeSet};
21use std::ffi::OsString;
22use std::fmt::Write as _;
23use std::fs::{self, File};
24use std::io::{self, IsTerminal, Read, Write};
25use std::panic::{self, PanicHookInfo, catch_unwind};
26use std::path::{Path, PathBuf};
27use std::process::{self, Command, Stdio};
28use std::sync::OnceLock;
29use std::sync::atomic::{AtomicBool, Ordering};
30use std::time::Instant;
31use std::{env, str};
32
33use rustc_ast as ast;
34use rustc_codegen_ssa::traits::CodegenBackend;
35use rustc_codegen_ssa::{CodegenErrors, CodegenResults};
36use rustc_data_structures::profiling::{
37    TimePassesFormat, get_resident_set_size, print_time_passes_entry,
38};
39use rustc_errors::emitter::stderr_destination;
40use rustc_errors::registry::Registry;
41use rustc_errors::translation::Translator;
42use rustc_errors::{ColorConfig, DiagCtxt, ErrCode, FatalError, PResult, markdown};
43use rustc_feature::find_gated_cfg;
44// This avoids a false positive with `-Wunused_crate_dependencies`.
45// `rust_index` isn't used in this crate's code, but it must be named in the
46// `Cargo.toml` for the `rustc_randomized_layouts` feature.
47use rustc_index as _;
48use rustc_interface::util::{self, get_codegen_backend};
49use rustc_interface::{Linker, create_and_enter_global_ctxt, interface, passes};
50use rustc_lint::unerased_lint_store;
51use rustc_metadata::creader::MetadataLoader;
52use rustc_metadata::locator;
53use rustc_middle::ty::TyCtxt;
54use rustc_parse::lexer::StripTokens;
55use rustc_parse::{new_parser_from_file, new_parser_from_source_str, unwrap_or_emit_fatal};
56use rustc_session::config::{
57    CG_OPTIONS, CrateType, ErrorOutputType, Input, OptionDesc, OutFileName, OutputType, Sysroot,
58    UnstableOptions, Z_OPTIONS, nightly_options, parse_target_triple,
59};
60use rustc_session::getopts::{self, Matches};
61use rustc_session::lint::{Lint, LintId};
62use rustc_session::output::{CRATE_TYPES, collect_crate_types, invalid_output_for_target};
63use rustc_session::{EarlyDiagCtxt, Session, config};
64use rustc_span::FileName;
65use rustc_span::def_id::LOCAL_CRATE;
66use rustc_target::json::ToJson;
67use rustc_target::spec::{Target, TargetTuple};
68use tracing::trace;
69
70#[allow(unused_macros)]
71macro do_not_use_print($($t:tt)*) {
72    std::compile_error!(
73        "Don't use `print` or `println` here, use `safe_print` or `safe_println` instead"
74    )
75}
76
77#[allow(unused_macros)]
78macro do_not_use_safe_print($($t:tt)*) {
79    std::compile_error!("Don't use `safe_print` or `safe_println` here, use `println_info` instead")
80}
81
82// This import blocks the use of panicking `print` and `println` in all the code
83// below. Please use `safe_print` and `safe_println` to avoid ICE when
84// encountering an I/O error during print.
85#[allow(unused_imports)]
86use {do_not_use_print as print, do_not_use_print as println};
87
88pub mod args;
89pub mod pretty;
90#[macro_use]
91mod print;
92mod session_diagnostics;
93
94// Keep the OS parts of this `cfg` in sync with the `cfg` on the `libc`
95// dependency in `compiler/rustc_driver/Cargo.toml`, to keep
96// `-Wunused-crated-dependencies` satisfied.
97#[cfg(all(not(miri), unix, any(target_env = "gnu", target_os = "macos")))]
98mod signal_handler;
99
100#[cfg(not(all(not(miri), unix, any(target_env = "gnu", target_os = "macos"))))]
101mod signal_handler {
102    /// On platforms which don't support our signal handler's requirements,
103    /// simply use the default signal handler provided by std.
104    pub(super) fn install() {}
105}
106
107use crate::session_diagnostics::{
108    CantEmitMIR, RLinkEmptyVersionNumber, RLinkEncodingVersionMismatch, RLinkRustcVersionMismatch,
109    RLinkWrongFileType, RlinkCorruptFile, RlinkNotAFile, RlinkUnableToRead, UnstableFeatureUsage,
110};
111
112rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
113
114pub fn default_translator() -> Translator {
115    Translator::with_fallback_bundle(DEFAULT_LOCALE_RESOURCES.to_vec(), false)
116}
117
118pub static DEFAULT_LOCALE_RESOURCES: &[&str] = &[
119    // tidy-alphabetical-start
120    crate::DEFAULT_LOCALE_RESOURCE,
121    rustc_ast_lowering::DEFAULT_LOCALE_RESOURCE,
122    rustc_ast_passes::DEFAULT_LOCALE_RESOURCE,
123    rustc_attr_parsing::DEFAULT_LOCALE_RESOURCE,
124    rustc_borrowck::DEFAULT_LOCALE_RESOURCE,
125    rustc_builtin_macros::DEFAULT_LOCALE_RESOURCE,
126    rustc_codegen_ssa::DEFAULT_LOCALE_RESOURCE,
127    rustc_const_eval::DEFAULT_LOCALE_RESOURCE,
128    rustc_errors::DEFAULT_LOCALE_RESOURCE,
129    rustc_expand::DEFAULT_LOCALE_RESOURCE,
130    rustc_hir_analysis::DEFAULT_LOCALE_RESOURCE,
131    rustc_hir_typeck::DEFAULT_LOCALE_RESOURCE,
132    rustc_incremental::DEFAULT_LOCALE_RESOURCE,
133    rustc_infer::DEFAULT_LOCALE_RESOURCE,
134    rustc_interface::DEFAULT_LOCALE_RESOURCE,
135    rustc_lint::DEFAULT_LOCALE_RESOURCE,
136    rustc_metadata::DEFAULT_LOCALE_RESOURCE,
137    rustc_middle::DEFAULT_LOCALE_RESOURCE,
138    rustc_mir_build::DEFAULT_LOCALE_RESOURCE,
139    rustc_mir_dataflow::DEFAULT_LOCALE_RESOURCE,
140    rustc_mir_transform::DEFAULT_LOCALE_RESOURCE,
141    rustc_monomorphize::DEFAULT_LOCALE_RESOURCE,
142    rustc_parse::DEFAULT_LOCALE_RESOURCE,
143    rustc_passes::DEFAULT_LOCALE_RESOURCE,
144    rustc_pattern_analysis::DEFAULT_LOCALE_RESOURCE,
145    rustc_privacy::DEFAULT_LOCALE_RESOURCE,
146    rustc_query_system::DEFAULT_LOCALE_RESOURCE,
147    rustc_resolve::DEFAULT_LOCALE_RESOURCE,
148    rustc_session::DEFAULT_LOCALE_RESOURCE,
149    rustc_trait_selection::DEFAULT_LOCALE_RESOURCE,
150    rustc_ty_utils::DEFAULT_LOCALE_RESOURCE,
151    // tidy-alphabetical-end
152];
153
154/// Exit status code used for successful compilation and help output.
155pub const EXIT_SUCCESS: i32 = 0;
156
157/// Exit status code used for compilation failures and invalid flags.
158pub const EXIT_FAILURE: i32 = 1;
159
160pub const DEFAULT_BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
161    ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md";
162
163pub trait Callbacks {
164    /// Called before creating the compiler instance
165    fn config(&mut self, _config: &mut interface::Config) {}
166    /// Called after parsing the crate root. Submodules are not yet parsed when
167    /// this callback is called. Return value instructs the compiler whether to
168    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
169    fn after_crate_root_parsing(
170        &mut self,
171        _compiler: &interface::Compiler,
172        _krate: &mut ast::Crate,
173    ) -> Compilation {
174        Compilation::Continue
175    }
176    /// Called after expansion. Return value instructs the compiler whether to
177    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
178    fn after_expansion<'tcx>(
179        &mut self,
180        _compiler: &interface::Compiler,
181        _tcx: TyCtxt<'tcx>,
182    ) -> Compilation {
183        Compilation::Continue
184    }
185    /// Called after analysis. Return value instructs the compiler whether to
186    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
187    fn after_analysis<'tcx>(
188        &mut self,
189        _compiler: &interface::Compiler,
190        _tcx: TyCtxt<'tcx>,
191    ) -> Compilation {
192        Compilation::Continue
193    }
194}
195
196#[derive(Default)]
197pub struct TimePassesCallbacks {
198    time_passes: Option<TimePassesFormat>,
199}
200
201impl Callbacks for TimePassesCallbacks {
202    // JUSTIFICATION: the session doesn't exist at this point.
203    #[allow(rustc::bad_opt_access)]
204    fn config(&mut self, config: &mut interface::Config) {
205        // If a --print=... option has been given, we don't print the "total"
206        // time because it will mess up the --print output. See #64339.
207        //
208        self.time_passes = (config.opts.prints.is_empty() && config.opts.unstable_opts.time_passes)
209            .then_some(config.opts.unstable_opts.time_passes_format);
210        config.opts.trimmed_def_paths = true;
211    }
212}
213
214pub fn diagnostics_registry() -> Registry {
215    Registry::new(rustc_errors::codes::DIAGNOSTICS)
216}
217
218/// This is the primary entry point for rustc.
219pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send)) {
220    let mut default_early_dcx = EarlyDiagCtxt::new(ErrorOutputType::default());
221
222    // Throw away the first argument, the name of the binary.
223    // In case of at_args being empty, as might be the case by
224    // passing empty argument array to execve under some platforms,
225    // just use an empty slice.
226    //
227    // This situation was possible before due to arg_expand_all being
228    // called before removing the argument, enabling a crash by calling
229    // the compiler with @empty_file as argv[0] and no more arguments.
230    let at_args = at_args.get(1..).unwrap_or_default();
231
232    let args = args::arg_expand_all(&default_early_dcx, at_args);
233
234    let Some(matches) = handle_options(&default_early_dcx, &args) else {
235        return;
236    };
237
238    let sopts = config::build_session_options(&mut default_early_dcx, &matches);
239    // fully initialize ice path static once unstable options are available as context
240    let ice_file = ice_path_with_config(Some(&sopts.unstable_opts)).clone();
241
242    if let Some(ref code) = matches.opt_str("explain") {
243        handle_explain(&default_early_dcx, diagnostics_registry(), code, sopts.color);
244        return;
245    }
246
247    let input = make_input(&default_early_dcx, &matches.free);
248    let has_input = input.is_some();
249    let (odir, ofile) = make_output(&matches);
250
251    drop(default_early_dcx);
252
253    let mut config = interface::Config {
254        opts: sopts,
255        crate_cfg: matches.opt_strs("cfg"),
256        crate_check_cfg: matches.opt_strs("check-cfg"),
257        input: input.unwrap_or(Input::File(PathBuf::new())),
258        output_file: ofile,
259        output_dir: odir,
260        ice_file,
261        file_loader: None,
262        locale_resources: DEFAULT_LOCALE_RESOURCES.to_vec(),
263        lint_caps: Default::default(),
264        psess_created: None,
265        hash_untracked_state: None,
266        register_lints: None,
267        override_queries: None,
268        extra_symbols: Vec::new(),
269        make_codegen_backend: None,
270        registry: diagnostics_registry(),
271        using_internal_features: &USING_INTERNAL_FEATURES,
272        expanded_args: args,
273    };
274
275    callbacks.config(&mut config);
276
277    let registered_lints = config.register_lints.is_some();
278
279    interface::run_compiler(config, |compiler| {
280        let sess = &compiler.sess;
281        let codegen_backend = &*compiler.codegen_backend;
282
283        // This is used for early exits unrelated to errors. E.g. when just
284        // printing some information without compiling, or exiting immediately
285        // after parsing, etc.
286        let early_exit = || {
287            sess.dcx().abort_if_errors();
288        };
289
290        // This implements `-Whelp`. It should be handled very early, like
291        // `--help`/`-Zhelp`/`-Chelp`. This is the earliest it can run, because
292        // it must happen after lints are registered, during session creation.
293        if sess.opts.describe_lints {
294            describe_lints(sess, registered_lints);
295            return early_exit();
296        }
297
298        if print_crate_info(codegen_backend, sess, has_input) == Compilation::Stop {
299            return early_exit();
300        }
301
302        if !has_input {
303            #[allow(rustc::diagnostic_outside_of_impl)]
304            sess.dcx().fatal("no input filename given"); // this is fatal
305        }
306
307        if !sess.opts.unstable_opts.ls.is_empty() {
308            list_metadata(sess, &*codegen_backend.metadata_loader());
309            return early_exit();
310        }
311
312        if sess.opts.unstable_opts.link_only {
313            process_rlink(sess, compiler);
314            return early_exit();
315        }
316
317        // Parse the crate root source code (doesn't parse submodules yet)
318        // Everything else is parsed during macro expansion.
319        let mut krate = passes::parse(sess);
320
321        // If pretty printing is requested: Figure out the representation, print it and exit
322        if let Some(pp_mode) = sess.opts.pretty {
323            if pp_mode.needs_ast_map() {
324                create_and_enter_global_ctxt(compiler, krate, |tcx| {
325                    tcx.ensure_ok().early_lint_checks(());
326                    pretty::print(sess, pp_mode, pretty::PrintExtra::NeedsAstMap { tcx });
327                    passes::write_dep_info(tcx);
328                });
329            } else {
330                pretty::print(sess, pp_mode, pretty::PrintExtra::AfterParsing { krate: &krate });
331            }
332            trace!("finished pretty-printing");
333            return early_exit();
334        }
335
336        if callbacks.after_crate_root_parsing(compiler, &mut krate) == Compilation::Stop {
337            return early_exit();
338        }
339
340        if sess.opts.unstable_opts.parse_crate_root_only {
341            return early_exit();
342        }
343
344        let linker = create_and_enter_global_ctxt(compiler, krate, |tcx| {
345            let early_exit = || {
346                sess.dcx().abort_if_errors();
347                None
348            };
349
350            // Make sure name resolution and macro expansion is run.
351            let _ = tcx.resolver_for_lowering();
352
353            if callbacks.after_expansion(compiler, tcx) == Compilation::Stop {
354                return early_exit();
355            }
356
357            passes::write_dep_info(tcx);
358
359            passes::write_interface(tcx);
360
361            if sess.opts.output_types.contains_key(&OutputType::DepInfo)
362                && sess.opts.output_types.len() == 1
363            {
364                return early_exit();
365            }
366
367            if sess.opts.unstable_opts.no_analysis {
368                return early_exit();
369            }
370
371            tcx.ensure_ok().analysis(());
372
373            if let Some(metrics_dir) = &sess.opts.unstable_opts.metrics_dir {
374                dump_feature_usage_metrics(tcx, metrics_dir);
375            }
376
377            if callbacks.after_analysis(compiler, tcx) == Compilation::Stop {
378                return early_exit();
379            }
380
381            if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
382                if let Err(error) = rustc_mir_transform::dump_mir::emit_mir(tcx) {
383                    tcx.dcx().emit_fatal(CantEmitMIR { error });
384                }
385            }
386
387            Some(Linker::codegen_and_build_linker(tcx, &*compiler.codegen_backend))
388        });
389
390        // Linking is done outside the `compiler.enter()` so that the
391        // `GlobalCtxt` within `Queries` can be freed as early as possible.
392        if let Some(linker) = linker {
393            linker.link(sess, codegen_backend);
394        }
395    })
396}
397
398fn dump_feature_usage_metrics(tcxt: TyCtxt<'_>, metrics_dir: &Path) {
399    let hash = tcxt.crate_hash(LOCAL_CRATE);
400    let crate_name = tcxt.crate_name(LOCAL_CRATE);
401    let metrics_file_name = format!("unstable_feature_usage_metrics-{crate_name}-{hash}.json");
402    let metrics_path = metrics_dir.join(metrics_file_name);
403    if let Err(error) = tcxt.features().dump_feature_usage_metrics(metrics_path) {
404        // FIXME(yaahc): once metrics can be enabled by default we will want "failure to emit
405        // default metrics" to only produce a warning when metrics are enabled by default and emit
406        // an error only when the user manually enables metrics
407        tcxt.dcx().emit_err(UnstableFeatureUsage { error });
408    }
409}
410
411/// Extract output directory and file from matches.
412fn make_output(matches: &getopts::Matches) -> (Option<PathBuf>, Option<OutFileName>) {
413    let odir = matches.opt_str("out-dir").map(|o| PathBuf::from(&o));
414    let ofile = matches.opt_str("o").map(|o| match o.as_str() {
415        "-" => OutFileName::Stdout,
416        path => OutFileName::Real(PathBuf::from(path)),
417    });
418    (odir, ofile)
419}
420
421/// Extract input (string or file and optional path) from matches.
422/// This handles reading from stdin if `-` is provided.
423fn make_input(early_dcx: &EarlyDiagCtxt, free_matches: &[String]) -> Option<Input> {
424    match free_matches {
425        [] => None, // no input: we will exit early,
426        [ifile] if ifile == "-" => {
427            // read from stdin as `Input::Str`
428            let mut input = String::new();
429            if io::stdin().read_to_string(&mut input).is_err() {
430                // Immediately stop compilation if there was an issue reading
431                // the input (for example if the input stream is not UTF-8).
432                early_dcx
433                    .early_fatal("couldn't read from stdin, as it did not contain valid UTF-8");
434            }
435
436            let name = match env::var("UNSTABLE_RUSTDOC_TEST_PATH") {
437                Ok(path) => {
438                    let line = env::var("UNSTABLE_RUSTDOC_TEST_LINE").expect(
439                        "when UNSTABLE_RUSTDOC_TEST_PATH is set \
440                                    UNSTABLE_RUSTDOC_TEST_LINE also needs to be set",
441                    );
442                    let line = line
443                        .parse::<isize>()
444                        .expect("UNSTABLE_RUSTDOC_TEST_LINE needs to be a number");
445                    FileName::doc_test_source_code(PathBuf::from(path), line)
446                }
447                Err(_) => FileName::anon_source_code(&input),
448            };
449
450            Some(Input::Str { name, input })
451        }
452        [ifile] => Some(Input::File(PathBuf::from(ifile))),
453        [ifile1, ifile2, ..] => early_dcx.early_fatal(format!(
454            "multiple input filenames provided (first two filenames are `{}` and `{}`)",
455            ifile1, ifile2
456        )),
457    }
458}
459
460/// Whether to stop or continue compilation.
461#[derive(Copy, Clone, Debug, Eq, PartialEq)]
462pub enum Compilation {
463    Stop,
464    Continue,
465}
466
467fn handle_explain(early_dcx: &EarlyDiagCtxt, registry: Registry, code: &str, color: ColorConfig) {
468    // Allow "E0123" or "0123" form.
469    let upper_cased_code = code.to_ascii_uppercase();
470    if let Ok(code) = upper_cased_code.strip_prefix('E').unwrap_or(&upper_cased_code).parse::<u32>()
471        && code <= ErrCode::MAX_AS_U32
472        && let Ok(description) = registry.try_find_description(ErrCode::from_u32(code))
473    {
474        let mut is_in_code_block = false;
475        let mut text = String::new();
476        // Slice off the leading newline and print.
477        for line in description.lines() {
478            let indent_level = line.find(|c: char| !c.is_whitespace()).unwrap_or(line.len());
479            let dedented_line = &line[indent_level..];
480            if dedented_line.starts_with("```") {
481                is_in_code_block = !is_in_code_block;
482                text.push_str(&line[..(indent_level + 3)]);
483            } else if is_in_code_block && dedented_line.starts_with("# ") {
484                continue;
485            } else {
486                text.push_str(line);
487            }
488            text.push('\n');
489        }
490        if io::stdout().is_terminal() {
491            show_md_content_with_pager(&text, color);
492        } else {
493            safe_print!("{text}");
494        }
495    } else {
496        early_dcx.early_fatal(format!("{code} is not a valid error code"));
497    }
498}
499
500/// If `color` is `always` or `auto`, try to print pretty (formatted & colorized) markdown. If
501/// that fails or `color` is `never`, print the raw markdown.
502///
503/// Uses a pager if possible, falls back to stdout.
504fn show_md_content_with_pager(content: &str, color: ColorConfig) {
505    let pager_name = env::var_os("PAGER").unwrap_or_else(|| {
506        if cfg!(windows) { OsString::from("more.com") } else { OsString::from("less") }
507    });
508
509    let mut cmd = Command::new(&pager_name);
510    if pager_name == "less" {
511        cmd.arg("-R"); // allows color escape sequences
512    }
513
514    let pretty_on_pager = match color {
515        ColorConfig::Auto => {
516            // Add other pagers that accept color escape sequences here.
517            ["less", "bat", "batcat", "delta"].iter().any(|v| *v == pager_name)
518        }
519        ColorConfig::Always => true,
520        ColorConfig::Never => false,
521    };
522
523    // Try to prettify the raw markdown text. The result can be used by the pager or on stdout.
524    let pretty_data = {
525        let mdstream = markdown::MdStream::parse_str(content);
526        let bufwtr = markdown::create_stdout_bufwtr();
527        let mut mdbuf = bufwtr.buffer();
528        if mdstream.write_termcolor_buf(&mut mdbuf).is_ok() { Some((bufwtr, mdbuf)) } else { None }
529    };
530
531    // Try to print via the pager, pretty output if possible.
532    let pager_res: Option<()> = try {
533        let mut pager = cmd.stdin(Stdio::piped()).spawn().ok()?;
534
535        let pager_stdin = pager.stdin.as_mut()?;
536        if pretty_on_pager && let Some((_, mdbuf)) = &pretty_data {
537            pager_stdin.write_all(mdbuf.as_slice()).ok()?;
538        } else {
539            pager_stdin.write_all(content.as_bytes()).ok()?;
540        };
541
542        pager.wait().ok()?;
543    };
544    if pager_res.is_some() {
545        return;
546    }
547
548    // The pager failed. Try to print pretty output to stdout.
549    if let Some((bufwtr, mdbuf)) = &pretty_data
550        && bufwtr.print(mdbuf).is_ok()
551    {
552        return;
553    }
554
555    // Everything failed. Print the raw markdown text.
556    safe_print!("{content}");
557}
558
559fn process_rlink(sess: &Session, compiler: &interface::Compiler) {
560    assert!(sess.opts.unstable_opts.link_only);
561    let dcx = sess.dcx();
562    if let Input::File(file) = &sess.io.input {
563        let rlink_data = fs::read(file).unwrap_or_else(|err| {
564            dcx.emit_fatal(RlinkUnableToRead { err });
565        });
566        let (codegen_results, metadata, outputs) =
567            match CodegenResults::deserialize_rlink(sess, rlink_data) {
568                Ok((codegen, metadata, outputs)) => (codegen, metadata, outputs),
569                Err(err) => {
570                    match err {
571                        CodegenErrors::WrongFileType => dcx.emit_fatal(RLinkWrongFileType),
572                        CodegenErrors::EmptyVersionNumber => {
573                            dcx.emit_fatal(RLinkEmptyVersionNumber)
574                        }
575                        CodegenErrors::EncodingVersionMismatch { version_array, rlink_version } => {
576                            dcx.emit_fatal(RLinkEncodingVersionMismatch {
577                                version_array,
578                                rlink_version,
579                            })
580                        }
581                        CodegenErrors::RustcVersionMismatch { rustc_version } => {
582                            dcx.emit_fatal(RLinkRustcVersionMismatch {
583                                rustc_version,
584                                current_version: sess.cfg_version,
585                            })
586                        }
587                        CodegenErrors::CorruptFile => {
588                            dcx.emit_fatal(RlinkCorruptFile { file });
589                        }
590                    };
591                }
592            };
593        compiler.codegen_backend.link(sess, codegen_results, metadata, &outputs);
594    } else {
595        dcx.emit_fatal(RlinkNotAFile {});
596    }
597}
598
599fn list_metadata(sess: &Session, metadata_loader: &dyn MetadataLoader) {
600    match sess.io.input {
601        Input::File(ref path) => {
602            let mut v = Vec::new();
603            locator::list_file_metadata(
604                &sess.target,
605                path,
606                metadata_loader,
607                &mut v,
608                &sess.opts.unstable_opts.ls,
609                sess.cfg_version,
610            )
611            .unwrap();
612            safe_println!("{}", String::from_utf8(v).unwrap());
613        }
614        Input::Str { .. } => {
615            #[allow(rustc::diagnostic_outside_of_impl)]
616            sess.dcx().fatal("cannot list metadata for stdin");
617        }
618    }
619}
620
621fn print_crate_info(
622    codegen_backend: &dyn CodegenBackend,
623    sess: &Session,
624    parse_attrs: bool,
625) -> Compilation {
626    use rustc_session::config::PrintKind::*;
627    // This import prevents the following code from using the printing macros
628    // used by the rest of the module. Within this function, we only write to
629    // the output specified by `sess.io.output_file`.
630    #[allow(unused_imports)]
631    use {do_not_use_safe_print as safe_print, do_not_use_safe_print as safe_println};
632
633    // NativeStaticLibs and LinkArgs are special - printed during linking
634    // (empty iterator returns true)
635    if sess.opts.prints.iter().all(|p| p.kind == NativeStaticLibs || p.kind == LinkArgs) {
636        return Compilation::Continue;
637    }
638
639    let attrs = if parse_attrs {
640        let result = parse_crate_attrs(sess);
641        match result {
642            Ok(attrs) => Some(attrs),
643            Err(parse_error) => {
644                parse_error.emit();
645                return Compilation::Stop;
646            }
647        }
648    } else {
649        None
650    };
651
652    for req in &sess.opts.prints {
653        let mut crate_info = String::new();
654        macro println_info($($arg:tt)*) {
655            crate_info.write_fmt(format_args!("{}\n", format_args!($($arg)*))).unwrap()
656        }
657
658        match req.kind {
659            TargetList => {
660                let mut targets = rustc_target::spec::TARGETS.to_vec();
661                targets.sort_unstable();
662                println_info!("{}", targets.join("\n"));
663            }
664            HostTuple => println_info!("{}", rustc_session::config::host_tuple()),
665            Sysroot => println_info!("{}", sess.opts.sysroot.path().display()),
666            TargetLibdir => println_info!("{}", sess.target_tlib_path.dir.display()),
667            TargetSpecJson => {
668                println_info!("{}", serde_json::to_string_pretty(&sess.target.to_json()).unwrap());
669            }
670            TargetSpecJsonSchema => {
671                let schema = rustc_target::spec::json_schema();
672                println_info!("{}", serde_json::to_string_pretty(&schema).unwrap());
673            }
674            AllTargetSpecsJson => {
675                let mut targets = BTreeMap::new();
676                for name in rustc_target::spec::TARGETS {
677                    let triple = TargetTuple::from_tuple(name);
678                    let target = Target::expect_builtin(&triple);
679                    targets.insert(name, target.to_json());
680                }
681                println_info!("{}", serde_json::to_string_pretty(&targets).unwrap());
682            }
683            FileNames => {
684                let Some(attrs) = attrs.as_ref() else {
685                    // no crate attributes, print out an error and exit
686                    return Compilation::Continue;
687                };
688                let t_outputs = rustc_interface::util::build_output_filenames(attrs, sess);
689                let crate_name = passes::get_crate_name(sess, attrs);
690                let crate_types = collect_crate_types(sess, attrs);
691                for &style in &crate_types {
692                    let fname = rustc_session::output::filename_for_input(
693                        sess, style, crate_name, &t_outputs,
694                    );
695                    println_info!("{}", fname.as_path().file_name().unwrap().to_string_lossy());
696                }
697            }
698            CrateName => {
699                let Some(attrs) = attrs.as_ref() else {
700                    // no crate attributes, print out an error and exit
701                    return Compilation::Continue;
702                };
703                println_info!("{}", passes::get_crate_name(sess, attrs));
704            }
705            CrateRootLintLevels => {
706                let Some(attrs) = attrs.as_ref() else {
707                    // no crate attributes, print out an error and exit
708                    return Compilation::Continue;
709                };
710                let crate_name = passes::get_crate_name(sess, attrs);
711                let lint_store = crate::unerased_lint_store(sess);
712                let registered_tools = rustc_resolve::registered_tools_ast(sess.dcx(), attrs);
713                let features = rustc_expand::config::features(sess, attrs, crate_name);
714                let lint_levels = rustc_lint::LintLevelsBuilder::crate_root(
715                    sess,
716                    &features,
717                    true,
718                    lint_store,
719                    &registered_tools,
720                    attrs,
721                );
722                for lint in lint_store.get_lints() {
723                    if let Some(feature_symbol) = lint.feature_gate
724                        && !features.enabled(feature_symbol)
725                    {
726                        // lint is unstable and feature gate isn't active, don't print
727                        continue;
728                    }
729                    let level = lint_levels.lint_level(lint).level;
730                    println_info!("{}={}", lint.name_lower(), level.as_str());
731                }
732            }
733            Cfg => {
734                let mut cfgs = sess
735                    .psess
736                    .config
737                    .iter()
738                    .filter_map(|&(name, value)| {
739                        // On stable, exclude unstable flags.
740                        if !sess.is_nightly_build()
741                            && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
742                        {
743                            return None;
744                        }
745
746                        if let Some(value) = value {
747                            Some(format!("{name}=\"{value}\""))
748                        } else {
749                            Some(name.to_string())
750                        }
751                    })
752                    .collect::<Vec<String>>();
753
754                cfgs.sort();
755                for cfg in cfgs {
756                    println_info!("{cfg}");
757                }
758            }
759            CheckCfg => {
760                let mut check_cfgs: Vec<String> = Vec::with_capacity(410);
761
762                // INSTABILITY: We are sorting the output below.
763                #[allow(rustc::potential_query_instability)]
764                for (name, expected_values) in &sess.psess.check_config.expecteds {
765                    use crate::config::ExpectedValues;
766                    match expected_values {
767                        ExpectedValues::Any => check_cfgs.push(format!("{name}=any()")),
768                        ExpectedValues::Some(values) => {
769                            if !values.is_empty() {
770                                check_cfgs.extend(values.iter().map(|value| {
771                                    if let Some(value) = value {
772                                        format!("{name}=\"{value}\"")
773                                    } else {
774                                        name.to_string()
775                                    }
776                                }))
777                            } else {
778                                check_cfgs.push(format!("{name}="))
779                            }
780                        }
781                    }
782                }
783
784                check_cfgs.sort_unstable();
785                if !sess.psess.check_config.exhaustive_names {
786                    if !sess.psess.check_config.exhaustive_values {
787                        println_info!("any()=any()");
788                    } else {
789                        println_info!("any()");
790                    }
791                }
792                for check_cfg in check_cfgs {
793                    println_info!("{check_cfg}");
794                }
795            }
796            CallingConventions => {
797                let calling_conventions = rustc_abi::all_names();
798                println_info!("{}", calling_conventions.join("\n"));
799            }
800            RelocationModels
801            | CodeModels
802            | TlsModels
803            | TargetCPUs
804            | StackProtectorStrategies
805            | TargetFeatures => {
806                codegen_backend.print(req, &mut crate_info, sess);
807            }
808            // Any output here interferes with Cargo's parsing of other printed output
809            NativeStaticLibs => {}
810            LinkArgs => {}
811            SplitDebuginfo => {
812                use rustc_target::spec::SplitDebuginfo::{Off, Packed, Unpacked};
813
814                for split in &[Off, Packed, Unpacked] {
815                    if sess.target.options.supported_split_debuginfo.contains(split) {
816                        println_info!("{split}");
817                    }
818                }
819            }
820            DeploymentTarget => {
821                if sess.target.is_like_darwin {
822                    println_info!(
823                        "{}={}",
824                        rustc_target::spec::apple::deployment_target_env_var(&sess.target.os),
825                        sess.apple_deployment_target().fmt_pretty(),
826                    )
827                } else {
828                    #[allow(rustc::diagnostic_outside_of_impl)]
829                    sess.dcx().fatal("only Apple targets currently support deployment version info")
830                }
831            }
832            SupportedCrateTypes => {
833                let supported_crate_types = CRATE_TYPES
834                    .iter()
835                    .filter(|(_, crate_type)| !invalid_output_for_target(sess, *crate_type))
836                    .filter(|(_, crate_type)| *crate_type != CrateType::Sdylib)
837                    .map(|(crate_type_sym, _)| *crate_type_sym)
838                    .collect::<BTreeSet<_>>();
839                for supported_crate_type in supported_crate_types {
840                    println_info!("{}", supported_crate_type.as_str());
841                }
842            }
843        }
844
845        req.out.overwrite(&crate_info, sess);
846    }
847    Compilation::Stop
848}
849
850/// Prints version information
851///
852/// NOTE: this is a macro to support drivers built at a different time than the main `rustc_driver` crate.
853pub macro version($early_dcx: expr, $binary: literal, $matches: expr) {
854    fn unw(x: Option<&str>) -> &str {
855        x.unwrap_or("unknown")
856    }
857    $crate::version_at_macro_invocation(
858        $early_dcx,
859        $binary,
860        $matches,
861        unw(option_env!("CFG_VERSION")),
862        unw(option_env!("CFG_VER_HASH")),
863        unw(option_env!("CFG_VER_DATE")),
864        unw(option_env!("CFG_RELEASE")),
865    )
866}
867
868#[doc(hidden)] // use the macro instead
869pub fn version_at_macro_invocation(
870    early_dcx: &EarlyDiagCtxt,
871    binary: &str,
872    matches: &getopts::Matches,
873    version: &str,
874    commit_hash: &str,
875    commit_date: &str,
876    release: &str,
877) {
878    let verbose = matches.opt_present("verbose");
879
880    let mut version = version;
881    let mut release = release;
882    let tmp;
883    if let Ok(force_version) = std::env::var("RUSTC_OVERRIDE_VERSION_STRING") {
884        tmp = force_version;
885        version = &tmp;
886        release = &tmp;
887    }
888
889    safe_println!("{binary} {version}");
890
891    if verbose {
892        safe_println!("binary: {binary}");
893        safe_println!("commit-hash: {commit_hash}");
894        safe_println!("commit-date: {commit_date}");
895        safe_println!("host: {}", config::host_tuple());
896        safe_println!("release: {release}");
897
898        get_backend_from_raw_matches(early_dcx, matches).print_version();
899    }
900}
901
902fn usage(verbose: bool, include_unstable_options: bool, nightly_build: bool) {
903    let mut options = getopts::Options::new();
904    for option in config::rustc_optgroups()
905        .iter()
906        .filter(|x| verbose || !x.is_verbose_help_only)
907        .filter(|x| include_unstable_options || x.is_stable())
908    {
909        option.apply(&mut options);
910    }
911    let message = "Usage: rustc [OPTIONS] INPUT";
912    let nightly_help = if nightly_build {
913        "\n    -Z help             Print unstable compiler options"
914    } else {
915        ""
916    };
917    let verbose_help = if verbose {
918        ""
919    } else {
920        "\n    --help -v           Print the full set of options rustc accepts"
921    };
922    let at_path = if verbose {
923        "    @path               Read newline separated options from `path`\n"
924    } else {
925        ""
926    };
927    safe_println!(
928        "{options}{at_path}\nAdditional help:
929    -C help             Print codegen options
930    -W help             \
931              Print 'lint' options and default settings{nightly}{verbose}\n",
932        options = options.usage(message),
933        at_path = at_path,
934        nightly = nightly_help,
935        verbose = verbose_help
936    );
937}
938
939fn print_wall_help() {
940    safe_println!(
941        "
942The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by
943default. Use `rustc -W help` to see all available lints. It's more common to put
944warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
945the command line flag directly.
946"
947    );
948}
949
950/// Write to stdout lint command options, together with a list of all available lints
951pub fn describe_lints(sess: &Session, registered_lints: bool) {
952    safe_println!(
953        "
954Available lint options:
955    -W <foo>           Warn about <foo>
956    -A <foo>           Allow <foo>
957    -D <foo>           Deny <foo>
958    -F <foo>           Forbid <foo> (deny <foo> and all attempts to override)
959
960"
961    );
962
963    fn sort_lints(sess: &Session, mut lints: Vec<&'static Lint>) -> Vec<&'static Lint> {
964        // The sort doesn't case-fold but it's doubtful we care.
965        lints.sort_by_cached_key(|x: &&Lint| (x.default_level(sess.edition()), x.name));
966        lints
967    }
968
969    fn sort_lint_groups(
970        lints: Vec<(&'static str, Vec<LintId>, bool)>,
971    ) -> Vec<(&'static str, Vec<LintId>)> {
972        let mut lints: Vec<_> = lints.into_iter().map(|(x, y, _)| (x, y)).collect();
973        lints.sort_by_key(|l| l.0);
974        lints
975    }
976
977    let lint_store = unerased_lint_store(sess);
978    let (loaded, builtin): (Vec<_>, _) =
979        lint_store.get_lints().iter().cloned().partition(|&lint| lint.is_externally_loaded);
980    let loaded = sort_lints(sess, loaded);
981    let builtin = sort_lints(sess, builtin);
982
983    let (loaded_groups, builtin_groups): (Vec<_>, _) =
984        lint_store.get_lint_groups().partition(|&(.., p)| p);
985    let loaded_groups = sort_lint_groups(loaded_groups);
986    let builtin_groups = sort_lint_groups(builtin_groups);
987
988    let max_name_len =
989        loaded.iter().chain(&builtin).map(|&s| s.name.chars().count()).max().unwrap_or(0);
990    let padded = |x: &str| {
991        let mut s = " ".repeat(max_name_len - x.chars().count());
992        s.push_str(x);
993        s
994    };
995
996    safe_println!("Lint checks provided by rustc:\n");
997
998    let print_lints = |lints: Vec<&Lint>| {
999        safe_println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
1000        safe_println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
1001        for lint in lints {
1002            let name = lint.name_lower().replace('_', "-");
1003            safe_println!(
1004                "    {}  {:7.7}  {}",
1005                padded(&name),
1006                lint.default_level(sess.edition()).as_str(),
1007                lint.desc
1008            );
1009        }
1010        safe_println!("\n");
1011    };
1012
1013    print_lints(builtin);
1014
1015    let max_name_len = max(
1016        "warnings".len(),
1017        loaded_groups
1018            .iter()
1019            .chain(&builtin_groups)
1020            .map(|&(s, _)| s.chars().count())
1021            .max()
1022            .unwrap_or(0),
1023    );
1024
1025    let padded = |x: &str| {
1026        let mut s = " ".repeat(max_name_len - x.chars().count());
1027        s.push_str(x);
1028        s
1029    };
1030
1031    safe_println!("Lint groups provided by rustc:\n");
1032
1033    let print_lint_groups = |lints: Vec<(&'static str, Vec<LintId>)>, all_warnings| {
1034        safe_println!("    {}  sub-lints", padded("name"));
1035        safe_println!("    {}  ---------", padded("----"));
1036
1037        if all_warnings {
1038            safe_println!("    {}  all lints that are set to issue warnings", padded("warnings"));
1039        }
1040
1041        for (name, to) in lints {
1042            let name = name.to_lowercase().replace('_', "-");
1043            let desc = to
1044                .into_iter()
1045                .map(|x| x.to_string().replace('_', "-"))
1046                .collect::<Vec<String>>()
1047                .join(", ");
1048            safe_println!("    {}  {}", padded(&name), desc);
1049        }
1050        safe_println!("\n");
1051    };
1052
1053    print_lint_groups(builtin_groups, true);
1054
1055    match (registered_lints, loaded.len(), loaded_groups.len()) {
1056        (false, 0, _) | (false, _, 0) => {
1057            safe_println!("Lint tools like Clippy can load additional lints and lint groups.");
1058        }
1059        (false, ..) => panic!("didn't load additional lints but got them anyway!"),
1060        (true, 0, 0) => {
1061            safe_println!("This crate does not load any additional lints or lint groups.")
1062        }
1063        (true, l, g) => {
1064            if l > 0 {
1065                safe_println!("Lint checks loaded by this crate:\n");
1066                print_lints(loaded);
1067            }
1068            if g > 0 {
1069                safe_println!("Lint groups loaded by this crate:\n");
1070                print_lint_groups(loaded_groups, false);
1071            }
1072        }
1073    }
1074}
1075
1076/// Show help for flag categories shared between rustdoc and rustc.
1077///
1078/// Returns whether a help option was printed.
1079pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) -> bool {
1080    // Handle the special case of -Wall.
1081    let wall = matches.opt_strs("W");
1082    if wall.iter().any(|x| *x == "all") {
1083        print_wall_help();
1084        return true;
1085    }
1086
1087    // Don't handle -W help here, because we might first load additional lints.
1088    let debug_flags = matches.opt_strs("Z");
1089    if debug_flags.iter().any(|x| *x == "help") {
1090        describe_debug_flags();
1091        return true;
1092    }
1093
1094    let cg_flags = matches.opt_strs("C");
1095    if cg_flags.iter().any(|x| *x == "help") {
1096        describe_codegen_flags();
1097        return true;
1098    }
1099
1100    if cg_flags.iter().any(|x| *x == "passes=list") {
1101        get_backend_from_raw_matches(early_dcx, matches).print_passes();
1102        return true;
1103    }
1104
1105    false
1106}
1107
1108/// Get the codegen backend based on the raw [`Matches`].
1109///
1110/// `rustc -vV` and `rustc -Cpasses=list` need to get the codegen backend before we have parsed all
1111/// arguments and created a [`Session`]. This function reads `-Zcodegen-backend`, `--target` and
1112/// `--sysroot` without validating any other arguments and loads the codegen backend based on these
1113/// arguments.
1114fn get_backend_from_raw_matches(
1115    early_dcx: &EarlyDiagCtxt,
1116    matches: &Matches,
1117) -> Box<dyn CodegenBackend> {
1118    let debug_flags = matches.opt_strs("Z");
1119    let backend_name = debug_flags
1120        .iter()
1121        .find_map(|x| x.strip_prefix("codegen-backend=").or(x.strip_prefix("codegen_backend=")));
1122    let target = parse_target_triple(early_dcx, matches);
1123    let sysroot = Sysroot::new(matches.opt_str("sysroot").map(PathBuf::from));
1124    let target = config::build_target_config(early_dcx, &target, sysroot.path());
1125
1126    get_codegen_backend(early_dcx, &sysroot, backend_name, &target)
1127}
1128
1129fn describe_debug_flags() {
1130    safe_println!("\nAvailable options:\n");
1131    print_flag_list("-Z", config::Z_OPTIONS);
1132}
1133
1134fn describe_codegen_flags() {
1135    safe_println!("\nAvailable codegen options:\n");
1136    print_flag_list("-C", config::CG_OPTIONS);
1137}
1138
1139fn print_flag_list<T>(cmdline_opt: &str, flag_list: &[OptionDesc<T>]) {
1140    let max_len =
1141        flag_list.iter().map(|opt_desc| opt_desc.name().chars().count()).max().unwrap_or(0);
1142
1143    for opt_desc in flag_list {
1144        safe_println!(
1145            "    {} {:>width$}=val -- {}",
1146            cmdline_opt,
1147            opt_desc.name().replace('_', "-"),
1148            opt_desc.desc(),
1149            width = max_len
1150        );
1151    }
1152}
1153
1154/// Process command line options. Emits messages as appropriate. If compilation
1155/// should continue, returns a getopts::Matches object parsed from args,
1156/// otherwise returns `None`.
1157///
1158/// The compiler's handling of options is a little complicated as it ties into
1159/// our stability story. The current intention of each compiler option is to
1160/// have one of two modes:
1161///
1162/// 1. An option is stable and can be used everywhere.
1163/// 2. An option is unstable, and can only be used on nightly.
1164///
1165/// Like unstable library and language features, however, unstable options have
1166/// always required a form of "opt in" to indicate that you're using them. This
1167/// provides the easy ability to scan a code base to check to see if anything
1168/// unstable is being used. Currently, this "opt in" is the `-Z` "zed" flag.
1169///
1170/// All options behind `-Z` are considered unstable by default. Other top-level
1171/// options can also be considered unstable, and they were unlocked through the
1172/// `-Z unstable-options` flag. Note that `-Z` remains to be the root of
1173/// instability in both cases, though.
1174///
1175/// So with all that in mind, the comments below have some more detail about the
1176/// contortions done here to get things to work out correctly.
1177///
1178/// This does not need to be `pub` for rustc itself, but @chaosite needs it to
1179/// be public when using rustc as a library, see
1180/// <https://github.com/rust-lang/rust/commit/2b4c33817a5aaecabf4c6598d41e190080ec119e>
1181pub fn handle_options(early_dcx: &EarlyDiagCtxt, args: &[String]) -> Option<getopts::Matches> {
1182    // Parse with *all* options defined in the compiler, we don't worry about
1183    // option stability here we just want to parse as much as possible.
1184    let mut options = getopts::Options::new();
1185    let optgroups = config::rustc_optgroups();
1186    for option in &optgroups {
1187        option.apply(&mut options);
1188    }
1189    let matches = options.parse(args).unwrap_or_else(|e| {
1190        let msg: Option<String> = match e {
1191            getopts::Fail::UnrecognizedOption(ref opt) => CG_OPTIONS
1192                .iter()
1193                .map(|opt_desc| ('C', opt_desc.name()))
1194                .chain(Z_OPTIONS.iter().map(|opt_desc| ('Z', opt_desc.name())))
1195                .find(|&(_, name)| *opt == name.replace('_', "-"))
1196                .map(|(flag, _)| format!("{e}. Did you mean `-{flag} {opt}`?")),
1197            getopts::Fail::ArgumentMissing(ref opt) => {
1198                optgroups.iter().find(|option| option.name == opt).map(|option| {
1199                    // Print the help just for the option in question.
1200                    let mut options = getopts::Options::new();
1201                    option.apply(&mut options);
1202                    // getopt requires us to pass a function for joining an iterator of
1203                    // strings, even though in this case we expect exactly one string.
1204                    options.usage_with_format(|it| {
1205                        it.fold(format!("{e}\nUsage:"), |a, b| a + "\n" + &b)
1206                    })
1207                })
1208            }
1209            _ => None,
1210        };
1211        early_dcx.early_fatal(msg.unwrap_or_else(|| e.to_string()));
1212    });
1213
1214    // For all options we just parsed, we check a few aspects:
1215    //
1216    // * If the option is stable, we're all good
1217    // * If the option wasn't passed, we're all good
1218    // * If `-Z unstable-options` wasn't passed (and we're not a -Z option
1219    //   ourselves), then we require the `-Z unstable-options` flag to unlock
1220    //   this option that was passed.
1221    // * If we're a nightly compiler, then unstable options are now unlocked, so
1222    //   we're good to go.
1223    // * Otherwise, if we're an unstable option then we generate an error
1224    //   (unstable option being used on stable)
1225    nightly_options::check_nightly_options(early_dcx, &matches, &config::rustc_optgroups());
1226
1227    if args.is_empty() || matches.opt_present("h") || matches.opt_present("help") {
1228        // Only show unstable options in --help if we accept unstable options.
1229        let unstable_enabled = nightly_options::is_unstable_enabled(&matches);
1230        let nightly_build = nightly_options::match_is_nightly_build(&matches);
1231        usage(matches.opt_present("verbose"), unstable_enabled, nightly_build);
1232        return None;
1233    }
1234
1235    if describe_flag_categories(early_dcx, &matches) {
1236        return None;
1237    }
1238
1239    if matches.opt_present("version") {
1240        version!(early_dcx, "rustc", &matches);
1241        return None;
1242    }
1243
1244    warn_on_confusing_output_filename_flag(early_dcx, &matches, args);
1245
1246    Some(matches)
1247}
1248
1249/// Warn if `-o` is used without a space between the flag name and the value
1250/// and the value is a high-value confusables,
1251/// e.g. `-optimize` instead of `-o optimize`, see issue #142812.
1252fn warn_on_confusing_output_filename_flag(
1253    early_dcx: &EarlyDiagCtxt,
1254    matches: &getopts::Matches,
1255    args: &[String],
1256) {
1257    fn eq_ignore_separators(s1: &str, s2: &str) -> bool {
1258        let s1 = s1.replace('-', "_");
1259        let s2 = s2.replace('-', "_");
1260        s1 == s2
1261    }
1262
1263    if let Some(name) = matches.opt_str("o")
1264        && let Some(suspect) = args.iter().find(|arg| arg.starts_with("-o") && *arg != "-o")
1265    {
1266        let filename = suspect.strip_prefix("-").unwrap_or(suspect);
1267        let optgroups = config::rustc_optgroups();
1268        let fake_args = ["optimize", "o0", "o1", "o2", "o3", "ofast", "og", "os", "oz"];
1269
1270        // Check if provided filename might be confusing in conjunction with `-o` flag,
1271        // i.e. consider `-o{filename}` such as `-optimize` with `filename` being `ptimize`.
1272        // There are high-value confusables, for example:
1273        // - Long name of flags, e.g. `--out-dir` vs `-out-dir`
1274        // - C compiler flag, e.g. `optimize`, `o0`, `o1`, `o2`, `o3`, `ofast`.
1275        // - Codegen flags, e.g. `pt-level` of `-opt-level`.
1276        if optgroups.iter().any(|option| eq_ignore_separators(option.long_name(), filename))
1277            || config::CG_OPTIONS.iter().any(|option| eq_ignore_separators(option.name(), filename))
1278            || fake_args.iter().any(|arg| eq_ignore_separators(arg, filename))
1279        {
1280            early_dcx.early_warn(
1281                "option `-o` has no space between flag name and value, which can be confusing",
1282            );
1283            early_dcx.early_note(format!(
1284                "output filename `-o {name}` is applied instead of a flag named `o{name}`"
1285            ));
1286            early_dcx.early_help(format!(
1287                "insert a space between `-o` and `{name}` if this is intentional: `-o {name}`"
1288            ));
1289        }
1290    }
1291}
1292
1293fn parse_crate_attrs<'a>(sess: &'a Session) -> PResult<'a, ast::AttrVec> {
1294    let mut parser = unwrap_or_emit_fatal(match &sess.io.input {
1295        Input::File(file) => {
1296            new_parser_from_file(&sess.psess, file, StripTokens::ShebangAndFrontmatter, None)
1297        }
1298        Input::Str { name, input } => new_parser_from_source_str(
1299            &sess.psess,
1300            name.clone(),
1301            input.clone(),
1302            StripTokens::ShebangAndFrontmatter,
1303        ),
1304    });
1305    parser.parse_inner_attributes()
1306}
1307
1308/// Runs a closure and catches unwinds triggered by fatal errors.
1309///
1310/// The compiler currently unwinds with a special sentinel value to abort
1311/// compilation on fatal errors. This function catches that sentinel and turns
1312/// the panic into a `Result` instead.
1313pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, FatalError> {
1314    catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
1315        if value.is::<rustc_errors::FatalErrorMarker>() {
1316            FatalError
1317        } else {
1318            panic::resume_unwind(value);
1319        }
1320    })
1321}
1322
1323/// Variant of `catch_fatal_errors` for the `interface::Result` return type
1324/// that also computes the exit code.
1325pub fn catch_with_exit_code(f: impl FnOnce()) -> i32 {
1326    match catch_fatal_errors(f) {
1327        Ok(()) => EXIT_SUCCESS,
1328        _ => EXIT_FAILURE,
1329    }
1330}
1331
1332static ICE_PATH: OnceLock<Option<PathBuf>> = OnceLock::new();
1333
1334// This function should only be called from the ICE hook.
1335//
1336// The intended behavior is that `run_compiler` will invoke `ice_path_with_config` early in the
1337// initialization process to properly initialize the ICE_PATH static based on parsed CLI flags.
1338//
1339// Subsequent calls to either function will then return the proper ICE path as configured by
1340// the environment and cli flags
1341fn ice_path() -> &'static Option<PathBuf> {
1342    ice_path_with_config(None)
1343}
1344
1345fn ice_path_with_config(config: Option<&UnstableOptions>) -> &'static Option<PathBuf> {
1346    if ICE_PATH.get().is_some() && config.is_some() && cfg!(debug_assertions) {
1347        tracing::warn!(
1348            "ICE_PATH has already been initialized -- files may be emitted at unintended paths"
1349        )
1350    }
1351
1352    ICE_PATH.get_or_init(|| {
1353        if !rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build() {
1354            return None;
1355        }
1356        let mut path = match std::env::var_os("RUSTC_ICE") {
1357            Some(s) => {
1358                if s == "0" {
1359                    // Explicitly opting out of writing ICEs to disk.
1360                    return None;
1361                }
1362                if let Some(unstable_opts) = config && unstable_opts.metrics_dir.is_some() {
1363                    tracing::warn!("ignoring -Zerror-metrics in favor of RUSTC_ICE for destination of ICE report files");
1364                }
1365                PathBuf::from(s)
1366            }
1367            None => config
1368                .and_then(|unstable_opts| unstable_opts.metrics_dir.to_owned())
1369                .or_else(|| std::env::current_dir().ok())
1370                .unwrap_or_default(),
1371        };
1372        // Don't use a standard datetime format because Windows doesn't support `:` in paths
1373        let file_now = jiff::Zoned::now().strftime("%Y-%m-%dT%H_%M_%S");
1374        let pid = std::process::id();
1375        path.push(format!("rustc-ice-{file_now}-{pid}.txt"));
1376        Some(path)
1377    })
1378}
1379
1380pub static USING_INTERNAL_FEATURES: AtomicBool = AtomicBool::new(false);
1381
1382/// Installs a panic hook that will print the ICE message on unexpected panics.
1383///
1384/// The hook is intended to be useable even by external tools. You can pass a custom
1385/// `bug_report_url`, or report arbitrary info in `extra_info`. Note that `extra_info` is called in
1386/// a context where *the thread is currently panicking*, so it must not panic or the process will
1387/// abort.
1388///
1389/// If you have no extra info to report, pass the empty closure `|_| ()` as the argument to
1390/// extra_info.
1391///
1392/// A custom rustc driver can skip calling this to set up a custom ICE hook.
1393pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&DiagCtxt)) {
1394    // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
1395    // full backtraces. When a compiler ICE happens, we want to gather
1396    // as much information as possible to present in the issue opened
1397    // by the user. Compiler developers and other rustc users can
1398    // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE"
1399    // (e.g. `RUST_BACKTRACE=1`)
1400    if env::var_os("RUST_BACKTRACE").is_none() {
1401        // HACK: this check is extremely dumb, but we don't really need it to be smarter since this should only happen in the test suite anyway.
1402        let ui_testing = std::env::args().any(|arg| arg == "-Zui-testing");
1403        if env!("CFG_RELEASE_CHANNEL") == "dev" && !ui_testing {
1404            panic::set_backtrace_style(panic::BacktraceStyle::Short);
1405        } else {
1406            panic::set_backtrace_style(panic::BacktraceStyle::Full);
1407        }
1408    }
1409
1410    panic::update_hook(Box::new(
1411        move |default_hook: &(dyn Fn(&PanicHookInfo<'_>) + Send + Sync + 'static),
1412              info: &PanicHookInfo<'_>| {
1413            // Lock stderr to prevent interleaving of concurrent panics.
1414            let _guard = io::stderr().lock();
1415            // If the error was caused by a broken pipe then this is not a bug.
1416            // Write the error and return immediately. See #98700.
1417            #[cfg(windows)]
1418            if let Some(msg) = info.payload().downcast_ref::<String>() {
1419                if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)")
1420                {
1421                    // the error code is already going to be reported when the panic unwinds up the stack
1422                    let early_dcx = EarlyDiagCtxt::new(ErrorOutputType::default());
1423                    let _ = early_dcx.early_err(msg.clone());
1424                    return;
1425                }
1426            };
1427
1428            // Invoke the default handler, which prints the actual panic message and optionally a backtrace
1429            // Don't do this for delayed bugs, which already emit their own more useful backtrace.
1430            if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
1431                default_hook(info);
1432                // Separate the output with an empty line
1433                eprintln!();
1434
1435                if let Some(ice_path) = ice_path()
1436                    && let Ok(mut out) = File::options().create(true).append(true).open(ice_path)
1437                {
1438                    // The current implementation always returns `Some`.
1439                    let location = info.location().unwrap();
1440                    let msg = match info.payload().downcast_ref::<&'static str>() {
1441                        Some(s) => *s,
1442                        None => match info.payload().downcast_ref::<String>() {
1443                            Some(s) => &s[..],
1444                            None => "Box<dyn Any>",
1445                        },
1446                    };
1447                    let thread = std::thread::current();
1448                    let name = thread.name().unwrap_or("<unnamed>");
1449                    let _ = write!(
1450                        &mut out,
1451                        "thread '{name}' panicked at {location}:\n\
1452                        {msg}\n\
1453                        stack backtrace:\n\
1454                        {:#}",
1455                        std::backtrace::Backtrace::force_capture()
1456                    );
1457                }
1458            }
1459
1460            // Print the ICE message
1461            report_ice(info, bug_report_url, extra_info, &USING_INTERNAL_FEATURES);
1462        },
1463    ));
1464}
1465
1466/// Prints the ICE message, including query stack, but without backtrace.
1467///
1468/// The message will point the user at `bug_report_url` to report the ICE.
1469///
1470/// When `install_ice_hook` is called, this function will be called as the panic
1471/// hook.
1472fn report_ice(
1473    info: &panic::PanicHookInfo<'_>,
1474    bug_report_url: &str,
1475    extra_info: fn(&DiagCtxt),
1476    using_internal_features: &AtomicBool,
1477) {
1478    let translator = default_translator();
1479    let emitter = Box::new(rustc_errors::emitter::HumanEmitter::new(
1480        stderr_destination(rustc_errors::ColorConfig::Auto),
1481        translator,
1482    ));
1483    let dcx = rustc_errors::DiagCtxt::new(emitter);
1484    let dcx = dcx.handle();
1485
1486    // a .span_bug or .bug call has already printed what
1487    // it wants to print.
1488    if !info.payload().is::<rustc_errors::ExplicitBug>()
1489        && !info.payload().is::<rustc_errors::DelayedBugPanic>()
1490    {
1491        dcx.emit_err(session_diagnostics::Ice);
1492    }
1493
1494    if using_internal_features.load(std::sync::atomic::Ordering::Relaxed) {
1495        dcx.emit_note(session_diagnostics::IceBugReportInternalFeature);
1496    } else {
1497        dcx.emit_note(session_diagnostics::IceBugReport { bug_report_url });
1498
1499        // Only emit update nightly hint for users on nightly builds.
1500        if rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build() {
1501            dcx.emit_note(session_diagnostics::UpdateNightlyNote);
1502        }
1503    }
1504
1505    let version = util::version_str!().unwrap_or("unknown_version");
1506    let tuple = config::host_tuple();
1507
1508    static FIRST_PANIC: AtomicBool = AtomicBool::new(true);
1509
1510    let file = if let Some(path) = ice_path() {
1511        // Create the ICE dump target file.
1512        match crate::fs::File::options().create(true).append(true).open(path) {
1513            Ok(mut file) => {
1514                dcx.emit_note(session_diagnostics::IcePath { path: path.clone() });
1515                if FIRST_PANIC.swap(false, Ordering::SeqCst) {
1516                    let _ = write!(file, "\n\nrustc version: {version}\nplatform: {tuple}");
1517                }
1518                Some(file)
1519            }
1520            Err(err) => {
1521                // The path ICE couldn't be written to disk, provide feedback to the user as to why.
1522                dcx.emit_warn(session_diagnostics::IcePathError {
1523                    path: path.clone(),
1524                    error: err.to_string(),
1525                    env_var: std::env::var_os("RUSTC_ICE")
1526                        .map(PathBuf::from)
1527                        .map(|env_var| session_diagnostics::IcePathErrorEnv { env_var }),
1528                });
1529                dcx.emit_note(session_diagnostics::IceVersion { version, triple: tuple });
1530                None
1531            }
1532        }
1533    } else {
1534        dcx.emit_note(session_diagnostics::IceVersion { version, triple: tuple });
1535        None
1536    };
1537
1538    if let Some((flags, excluded_cargo_defaults)) = rustc_session::utils::extra_compiler_flags() {
1539        dcx.emit_note(session_diagnostics::IceFlags { flags: flags.join(" ") });
1540        if excluded_cargo_defaults {
1541            dcx.emit_note(session_diagnostics::IceExcludeCargoDefaults);
1542        }
1543    }
1544
1545    // If backtraces are enabled, also print the query stack
1546    let backtrace = env::var_os("RUST_BACKTRACE").is_some_and(|x| &x != "0");
1547
1548    let limit_frames = if backtrace { None } else { Some(2) };
1549
1550    interface::try_print_query_stack(dcx, limit_frames, file);
1551
1552    // We don't trust this callback not to panic itself, so run it at the end after we're sure we've
1553    // printed all the relevant info.
1554    extra_info(&dcx);
1555
1556    #[cfg(windows)]
1557    if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
1558        // Trigger a debugger if we crashed during bootstrap
1559        unsafe { windows::Win32::System::Diagnostics::Debug::DebugBreak() };
1560    }
1561}
1562
1563/// This allows tools to enable rust logging without having to magically match rustc's
1564/// tracing crate version.
1565pub fn init_rustc_env_logger(early_dcx: &EarlyDiagCtxt) {
1566    init_logger(early_dcx, rustc_log::LoggerConfig::from_env("RUSTC_LOG"));
1567}
1568
1569/// This allows tools to enable rust logging without having to magically match rustc's
1570/// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose
1571/// the logger config directly rather than having to set an environment variable.
1572pub fn init_logger(early_dcx: &EarlyDiagCtxt, cfg: rustc_log::LoggerConfig) {
1573    if let Err(error) = rustc_log::init_logger(cfg) {
1574        early_dcx.early_fatal(error.to_string());
1575    }
1576}
1577
1578/// This allows tools to enable rust logging without having to magically match rustc's
1579/// tracing crate version. In contrast to `init_rustc_env_logger`, it allows you to
1580/// choose the logger config directly rather than having to set an environment variable.
1581/// Moreover, in contrast to `init_logger`, it allows you to add a custom tracing layer
1582/// via `build_subscriber`, for example `|| Registry::default().with(custom_layer)`.
1583pub fn init_logger_with_additional_layer<F, T>(
1584    early_dcx: &EarlyDiagCtxt,
1585    cfg: rustc_log::LoggerConfig,
1586    build_subscriber: F,
1587) where
1588    F: FnOnce() -> T,
1589    T: rustc_log::BuildSubscriberRet,
1590{
1591    if let Err(error) = rustc_log::init_logger_with_additional_layer(cfg, build_subscriber) {
1592        early_dcx.early_fatal(error.to_string());
1593    }
1594}
1595
1596/// Install our usual `ctrlc` handler, which sets [`rustc_const_eval::CTRL_C_RECEIVED`].
1597/// Making this handler optional lets tools can install a different handler, if they wish.
1598pub fn install_ctrlc_handler() {
1599    #[cfg(all(not(miri), not(target_family = "wasm")))]
1600    ctrlc::set_handler(move || {
1601        // Indicate that we have been signaled to stop, then give the rest of the compiler a bit of
1602        // time to check CTRL_C_RECEIVED and run its own shutdown logic, but after a short amount
1603        // of time exit the process. This sleep+exit ensures that even if nobody is checking
1604        // CTRL_C_RECEIVED, the compiler exits reasonably promptly.
1605        rustc_const_eval::CTRL_C_RECEIVED.store(true, Ordering::Relaxed);
1606        std::thread::sleep(std::time::Duration::from_millis(100));
1607        std::process::exit(1);
1608    })
1609    .expect("Unable to install ctrlc handler");
1610}
1611
1612pub fn main() -> ! {
1613    let start_time = Instant::now();
1614    let start_rss = get_resident_set_size();
1615
1616    let early_dcx = EarlyDiagCtxt::new(ErrorOutputType::default());
1617
1618    init_rustc_env_logger(&early_dcx);
1619    signal_handler::install();
1620    let mut callbacks = TimePassesCallbacks::default();
1621    install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
1622    install_ctrlc_handler();
1623
1624    let exit_code =
1625        catch_with_exit_code(|| run_compiler(&args::raw_args(&early_dcx), &mut callbacks));
1626
1627    if let Some(format) = callbacks.time_passes {
1628        let end_rss = get_resident_set_size();
1629        print_time_passes_entry("total", start_time.elapsed(), start_rss, end_rss, format);
1630    }
1631
1632    process::exit(exit_code)
1633}