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