rustc_interface/
interface.rs

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1use std::path::PathBuf;
2use std::result;
3use std::sync::Arc;
4
5use rustc_ast::{LitKind, MetaItemKind, token};
6use rustc_codegen_ssa::traits::CodegenBackend;
7use rustc_data_structures::fx::{FxHashMap, FxHashSet};
8use rustc_data_structures::jobserver;
9use rustc_data_structures::stable_hasher::StableHasher;
10use rustc_errors::registry::Registry;
11use rustc_errors::{DiagCtxtHandle, ErrorGuaranteed};
12use rustc_lint::LintStore;
13use rustc_middle::ty;
14use rustc_middle::ty::CurrentGcx;
15use rustc_middle::util::Providers;
16use rustc_parse::new_parser_from_source_str;
17use rustc_parse::parser::attr::AllowLeadingUnsafe;
18use rustc_query_impl::QueryCtxt;
19use rustc_query_system::query::print_query_stack;
20use rustc_session::config::{self, Cfg, CheckCfg, ExpectedValues, Input, OutFileName};
21use rustc_session::filesearch::sysroot_candidates;
22use rustc_session::parse::ParseSess;
23use rustc_session::{CompilerIO, EarlyDiagCtxt, Session, lint};
24use rustc_span::source_map::{FileLoader, RealFileLoader, SourceMapInputs};
25use rustc_span::{FileName, sym};
26use tracing::trace;
27
28use crate::util;
29
30pub type Result<T> = result::Result<T, ErrorGuaranteed>;
31
32/// Represents a compiler session. Note that every `Compiler` contains a
33/// `Session`, but `Compiler` also contains some things that cannot be in
34/// `Session`, due to `Session` being in a crate that has many fewer
35/// dependencies than this crate.
36///
37/// Can be used to run `rustc_interface` queries.
38/// Created by passing [`Config`] to [`run_compiler`].
39pub struct Compiler {
40    pub sess: Session,
41    pub codegen_backend: Box<dyn CodegenBackend>,
42    pub(crate) override_queries: Option<fn(&Session, &mut Providers)>,
43    pub(crate) current_gcx: CurrentGcx,
44}
45
46/// Converts strings provided as `--cfg [cfgspec]` into a `Cfg`.
47pub(crate) fn parse_cfg(dcx: DiagCtxtHandle<'_>, cfgs: Vec<String>) -> Cfg {
48    cfgs.into_iter()
49        .map(|s| {
50            let psess = ParseSess::with_silent_emitter(
51                vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
52                format!("this error occurred on the command line: `--cfg={s}`"),
53                true,
54            );
55            let filename = FileName::cfg_spec_source_code(&s);
56
57            macro_rules! error {
58                ($reason: expr) => {
59                    #[allow(rustc::untranslatable_diagnostic)]
60                    #[allow(rustc::diagnostic_outside_of_impl)]
61                    dcx.fatal(format!(
62                        concat!("invalid `--cfg` argument: `{}` (", $reason, ")"),
63                        s
64                    ));
65                };
66            }
67
68            match new_parser_from_source_str(&psess, filename, s.to_string()) {
69                Ok(mut parser) => match parser.parse_meta_item(AllowLeadingUnsafe::No) {
70                    Ok(meta_item) if parser.token == token::Eof => {
71                        if meta_item.path.segments.len() != 1 {
72                            error!("argument key must be an identifier");
73                        }
74                        match &meta_item.kind {
75                            MetaItemKind::List(..) => {}
76                            MetaItemKind::NameValue(lit) if !lit.kind.is_str() => {
77                                error!("argument value must be a string");
78                            }
79                            MetaItemKind::NameValue(..) | MetaItemKind::Word => {
80                                let ident = meta_item.ident().expect("multi-segment cfg key");
81                                return (ident.name, meta_item.value_str());
82                            }
83                        }
84                    }
85                    Ok(..) => {}
86                    Err(err) => err.cancel(),
87                },
88                Err(errs) => errs.into_iter().for_each(|err| err.cancel()),
89            }
90
91            // If the user tried to use a key="value" flag, but is missing the quotes, provide
92            // a hint about how to resolve this.
93            if s.contains('=') && !s.contains("=\"") && !s.ends_with('"') {
94                error!(concat!(
95                    r#"expected `key` or `key="value"`, ensure escaping is appropriate"#,
96                    r#" for your shell, try 'key="value"' or key=\"value\""#
97                ));
98            } else {
99                error!(r#"expected `key` or `key="value"`"#);
100            }
101        })
102        .collect::<Cfg>()
103}
104
105/// Converts strings provided as `--check-cfg [specs]` into a `CheckCfg`.
106pub(crate) fn parse_check_cfg(dcx: DiagCtxtHandle<'_>, specs: Vec<String>) -> CheckCfg {
107    // If any --check-cfg is passed then exhaustive_values and exhaustive_names
108    // are enabled by default.
109    let exhaustive_names = !specs.is_empty();
110    let exhaustive_values = !specs.is_empty();
111    let mut check_cfg = CheckCfg { exhaustive_names, exhaustive_values, ..CheckCfg::default() };
112
113    for s in specs {
114        let psess = ParseSess::with_silent_emitter(
115            vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
116            format!("this error occurred on the command line: `--check-cfg={s}`"),
117            true,
118        );
119        let filename = FileName::cfg_spec_source_code(&s);
120
121        const VISIT: &str =
122            "visit <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more details";
123
124        macro_rules! error {
125            ($reason:expr) => {
126                #[allow(rustc::untranslatable_diagnostic)]
127                #[allow(rustc::diagnostic_outside_of_impl)]
128                {
129                    let mut diag =
130                        dcx.struct_fatal(format!("invalid `--check-cfg` argument: `{s}`"));
131                    diag.note($reason);
132                    diag.note(VISIT);
133                    diag.emit()
134                }
135            };
136            (in $arg:expr, $reason:expr) => {
137                #[allow(rustc::untranslatable_diagnostic)]
138                #[allow(rustc::diagnostic_outside_of_impl)]
139                {
140                    let mut diag =
141                        dcx.struct_fatal(format!("invalid `--check-cfg` argument: `{s}`"));
142
143                    let pparg = rustc_ast_pretty::pprust::meta_list_item_to_string($arg);
144                    if let Some(lit) = $arg.lit() {
145                        let (lit_kind_article, lit_kind_descr) = {
146                            let lit_kind = lit.as_token_lit().kind;
147                            (lit_kind.article(), lit_kind.descr())
148                        };
149                        diag.note(format!(
150                            "`{pparg}` is {lit_kind_article} {lit_kind_descr} literal"
151                        ));
152                    } else {
153                        diag.note(format!("`{pparg}` is invalid"));
154                    }
155
156                    diag.note($reason);
157                    diag.note(VISIT);
158                    diag.emit()
159                }
160            };
161        }
162
163        let expected_error = || -> ! {
164            error!("expected `cfg(name, values(\"value1\", \"value2\", ... \"valueN\"))`")
165        };
166
167        let mut parser = match new_parser_from_source_str(&psess, filename, s.to_string()) {
168            Ok(parser) => parser,
169            Err(errs) => {
170                errs.into_iter().for_each(|err| err.cancel());
171                expected_error();
172            }
173        };
174
175        let meta_item = match parser.parse_meta_item(AllowLeadingUnsafe::No) {
176            Ok(meta_item) if parser.token == token::Eof => meta_item,
177            Ok(..) => expected_error(),
178            Err(err) => {
179                err.cancel();
180                expected_error();
181            }
182        };
183
184        let Some(args) = meta_item.meta_item_list() else {
185            expected_error();
186        };
187
188        if !meta_item.has_name(sym::cfg) {
189            expected_error();
190        }
191
192        let mut names = Vec::new();
193        let mut values: FxHashSet<_> = Default::default();
194
195        let mut any_specified = false;
196        let mut values_specified = false;
197        let mut values_any_specified = false;
198
199        for arg in args {
200            if arg.is_word()
201                && let Some(ident) = arg.ident()
202            {
203                if values_specified {
204                    error!("`cfg()` names cannot be after values");
205                }
206                names.push(ident);
207            } else if let Some(boolean) = arg.boolean_literal() {
208                if values_specified {
209                    error!("`cfg()` names cannot be after values");
210                }
211                names.push(rustc_span::Ident::new(
212                    if boolean { rustc_span::kw::True } else { rustc_span::kw::False },
213                    arg.span(),
214                ));
215            } else if arg.has_name(sym::any)
216                && let Some(args) = arg.meta_item_list()
217            {
218                if any_specified {
219                    error!("`any()` cannot be specified multiple times");
220                }
221                any_specified = true;
222                if !args.is_empty() {
223                    error!(in arg, "`any()` takes no argument");
224                }
225            } else if arg.has_name(sym::values)
226                && let Some(args) = arg.meta_item_list()
227            {
228                if names.is_empty() {
229                    error!("`values()` cannot be specified before the names");
230                } else if values_specified {
231                    error!("`values()` cannot be specified multiple times");
232                }
233                values_specified = true;
234
235                for arg in args {
236                    if let Some(LitKind::Str(s, _)) = arg.lit().map(|lit| &lit.kind) {
237                        values.insert(Some(*s));
238                    } else if arg.has_name(sym::any)
239                        && let Some(args) = arg.meta_item_list()
240                    {
241                        if values_any_specified {
242                            error!(in arg, "`any()` in `values()` cannot be specified multiple times");
243                        }
244                        values_any_specified = true;
245                        if !args.is_empty() {
246                            error!(in arg, "`any()` in `values()` takes no argument");
247                        }
248                    } else if arg.has_name(sym::none)
249                        && let Some(args) = arg.meta_item_list()
250                    {
251                        values.insert(None);
252                        if !args.is_empty() {
253                            error!(in arg, "`none()` in `values()` takes no argument");
254                        }
255                    } else {
256                        error!(in arg, "`values()` arguments must be string literals, `none()` or `any()`");
257                    }
258                }
259            } else {
260                error!(in arg, "`cfg()` arguments must be simple identifiers, `any()` or `values(...)`");
261            }
262        }
263
264        if !values_specified && !any_specified {
265            // `cfg(name)` is equivalent to `cfg(name, values(none()))` so add
266            // an implicit `none()`
267            values.insert(None);
268        } else if !values.is_empty() && values_any_specified {
269            error!(
270                "`values()` arguments cannot specify string literals and `any()` at the same time"
271            );
272        }
273
274        if any_specified {
275            if names.is_empty() && values.is_empty() && !values_specified && !values_any_specified {
276                check_cfg.exhaustive_names = false;
277            } else {
278                error!("`cfg(any())` can only be provided in isolation");
279            }
280        } else {
281            for name in names {
282                check_cfg
283                    .expecteds
284                    .entry(name.name)
285                    .and_modify(|v| match v {
286                        ExpectedValues::Some(v) if !values_any_specified => {
287                            v.extend(values.clone())
288                        }
289                        ExpectedValues::Some(_) => *v = ExpectedValues::Any,
290                        ExpectedValues::Any => {}
291                    })
292                    .or_insert_with(|| {
293                        if values_any_specified {
294                            ExpectedValues::Any
295                        } else {
296                            ExpectedValues::Some(values.clone())
297                        }
298                    });
299            }
300        }
301    }
302
303    check_cfg
304}
305
306/// The compiler configuration
307pub struct Config {
308    /// Command line options
309    pub opts: config::Options,
310
311    /// Unparsed cfg! configuration in addition to the default ones.
312    pub crate_cfg: Vec<String>,
313    pub crate_check_cfg: Vec<String>,
314
315    pub input: Input,
316    pub output_dir: Option<PathBuf>,
317    pub output_file: Option<OutFileName>,
318    pub ice_file: Option<PathBuf>,
319    /// Load files from sources other than the file system.
320    ///
321    /// Has no uses within this repository, but may be used in the future by
322    /// bjorn3 for "hooking rust-analyzer's VFS into rustc at some point for
323    /// running rustc without having to save". (See #102759.)
324    pub file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
325    /// The list of fluent resources, used for lints declared with
326    /// [`Diagnostic`](rustc_errors::Diagnostic) and [`LintDiagnostic`](rustc_errors::LintDiagnostic).
327    pub locale_resources: Vec<&'static str>,
328
329    pub lint_caps: FxHashMap<lint::LintId, lint::Level>,
330
331    /// This is a callback from the driver that is called when [`ParseSess`] is created.
332    pub psess_created: Option<Box<dyn FnOnce(&mut ParseSess) + Send>>,
333
334    /// This is a callback to hash otherwise untracked state used by the caller, if the
335    /// hash changes between runs the incremental cache will be cleared.
336    ///
337    /// e.g. used by Clippy to hash its config file
338    pub hash_untracked_state: Option<Box<dyn FnOnce(&Session, &mut StableHasher) + Send>>,
339
340    /// This is a callback from the driver that is called when we're registering lints;
341    /// it is called during lint loading when we have the LintStore in a non-shared state.
342    ///
343    /// Note that if you find a Some here you probably want to call that function in the new
344    /// function being registered.
345    pub register_lints: Option<Box<dyn Fn(&Session, &mut LintStore) + Send + Sync>>,
346
347    /// This is a callback from the driver that is called just after we have populated
348    /// the list of queries.
349    pub override_queries: Option<fn(&Session, &mut Providers)>,
350
351    /// An extra set of symbols to add to the symbol interner, the symbol indices
352    /// will start at [`PREDEFINED_SYMBOLS_COUNT`](rustc_span::symbol::PREDEFINED_SYMBOLS_COUNT)
353    pub extra_symbols: Vec<&'static str>,
354
355    /// This is a callback from the driver that is called to create a codegen backend.
356    ///
357    /// Has no uses within this repository, but is used by bjorn3 for "the
358    /// hotswapping branch of cg_clif" for "setting the codegen backend from a
359    /// custom driver where the custom codegen backend has arbitrary data."
360    /// (See #102759.)
361    pub make_codegen_backend:
362        Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
363
364    /// Registry of diagnostics codes.
365    pub registry: Registry,
366
367    /// The inner atomic value is set to true when a feature marked as `internal` is
368    /// enabled. Makes it so that "please report a bug" is hidden, as ICEs with
369    /// internal features are wontfix, and they are usually the cause of the ICEs.
370    pub using_internal_features: &'static std::sync::atomic::AtomicBool,
371
372    /// All commandline args used to invoke the compiler, with @file args fully expanded.
373    /// This will only be used within debug info, e.g. in the pdb file on windows
374    /// This is mainly useful for other tools that reads that debuginfo to figure out
375    /// how to call the compiler with the same arguments.
376    pub expanded_args: Vec<String>,
377}
378
379/// Initialize jobserver before getting `jobserver::client` and `build_session`.
380pub(crate) fn initialize_checked_jobserver(early_dcx: &EarlyDiagCtxt) {
381    jobserver::initialize_checked(|err| {
382        #[allow(rustc::untranslatable_diagnostic)]
383        #[allow(rustc::diagnostic_outside_of_impl)]
384        early_dcx
385            .early_struct_warn(err)
386            .with_note("the build environment is likely misconfigured")
387            .emit()
388    });
389}
390
391// JUSTIFICATION: before session exists, only config
392#[allow(rustc::bad_opt_access)]
393pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Send) -> R {
394    trace!("run_compiler");
395
396    // Set parallel mode before thread pool creation, which will create `Lock`s.
397    rustc_data_structures::sync::set_dyn_thread_safe_mode(config.opts.unstable_opts.threads > 1);
398
399    // Check jobserver before run_in_thread_pool_with_globals, which call jobserver::acquire_thread
400    let early_dcx = EarlyDiagCtxt::new(config.opts.error_format);
401    initialize_checked_jobserver(&early_dcx);
402
403    crate::callbacks::setup_callbacks();
404
405    let sysroot = config.opts.sysroot.clone();
406    let target = config::build_target_config(&early_dcx, &config.opts.target_triple, &sysroot);
407    let file_loader = config.file_loader.unwrap_or_else(|| Box::new(RealFileLoader));
408    let path_mapping = config.opts.file_path_mapping();
409    let hash_kind = config.opts.unstable_opts.src_hash_algorithm(&target);
410    let checksum_hash_kind = config.opts.unstable_opts.checksum_hash_algorithm();
411
412    util::run_in_thread_pool_with_globals(
413        &early_dcx,
414        config.opts.edition,
415        config.opts.unstable_opts.threads,
416        &config.extra_symbols,
417        SourceMapInputs { file_loader, path_mapping, hash_kind, checksum_hash_kind },
418        |current_gcx| {
419            // The previous `early_dcx` can't be reused here because it doesn't
420            // impl `Send`. Creating a new one is fine.
421            let early_dcx = EarlyDiagCtxt::new(config.opts.error_format);
422
423            let codegen_backend = match config.make_codegen_backend {
424                None => util::get_codegen_backend(
425                    &early_dcx,
426                    &sysroot,
427                    config.opts.unstable_opts.codegen_backend.as_deref(),
428                    &target,
429                ),
430                Some(make_codegen_backend) => {
431                    // N.B. `make_codegen_backend` takes precedence over
432                    // `target.default_codegen_backend`, which is ignored in this case.
433                    make_codegen_backend(&config.opts)
434                }
435            };
436
437            let temps_dir = config.opts.unstable_opts.temps_dir.as_deref().map(PathBuf::from);
438
439            let bundle = match rustc_errors::fluent_bundle(
440                config.opts.sysroot.clone(),
441                sysroot_candidates().to_vec(),
442                config.opts.unstable_opts.translate_lang.clone(),
443                config.opts.unstable_opts.translate_additional_ftl.as_deref(),
444                config.opts.unstable_opts.translate_directionality_markers,
445            ) {
446                Ok(bundle) => bundle,
447                Err(e) => {
448                    // We can't translate anything if we failed to load translations
449                    #[allow(rustc::untranslatable_diagnostic)]
450                    early_dcx.early_fatal(format!("failed to load fluent bundle: {e}"))
451                }
452            };
453
454            let mut locale_resources = config.locale_resources;
455            locale_resources.push(codegen_backend.locale_resource());
456
457            let mut sess = rustc_session::build_session(
458                config.opts,
459                CompilerIO {
460                    input: config.input,
461                    output_dir: config.output_dir,
462                    output_file: config.output_file,
463                    temps_dir,
464                },
465                bundle,
466                config.registry,
467                locale_resources,
468                config.lint_caps,
469                target,
470                sysroot,
471                util::rustc_version_str().unwrap_or("unknown"),
472                config.ice_file,
473                config.using_internal_features,
474                config.expanded_args,
475            );
476
477            codegen_backend.init(&sess);
478
479            let cfg = parse_cfg(sess.dcx(), config.crate_cfg);
480            let mut cfg = config::build_configuration(&sess, cfg);
481            util::add_configuration(&mut cfg, &mut sess, &*codegen_backend);
482            sess.psess.config = cfg;
483
484            let mut check_cfg = parse_check_cfg(sess.dcx(), config.crate_check_cfg);
485            check_cfg.fill_well_known(&sess.target);
486            sess.psess.check_config = check_cfg;
487
488            if let Some(psess_created) = config.psess_created {
489                psess_created(&mut sess.psess);
490            }
491
492            if let Some(hash_untracked_state) = config.hash_untracked_state {
493                let mut hasher = StableHasher::new();
494                hash_untracked_state(&sess, &mut hasher);
495                sess.opts.untracked_state_hash = hasher.finish()
496            }
497
498            // Even though the session holds the lint store, we can't build the
499            // lint store until after the session exists. And we wait until now
500            // so that `register_lints` sees the fully initialized session.
501            let mut lint_store = rustc_lint::new_lint_store(sess.enable_internal_lints());
502            if let Some(register_lints) = config.register_lints.as_deref() {
503                register_lints(&sess, &mut lint_store);
504            }
505            sess.lint_store = Some(Arc::new(lint_store));
506
507            util::check_abi_required_features(&sess);
508
509            let compiler = Compiler {
510                sess,
511                codegen_backend,
512                override_queries: config.override_queries,
513                current_gcx,
514            };
515
516            // There are two paths out of `f`.
517            // - Normal exit.
518            // - Panic, e.g. triggered by `abort_if_errors` or a fatal error.
519            //
520            // We must run `finish_diagnostics` in both cases.
521            let res = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| f(&compiler)));
522
523            compiler.sess.finish_diagnostics();
524
525            // If error diagnostics have been emitted, we can't return an
526            // error directly, because the return type of this function
527            // is `R`, not `Result<R, E>`. But we need to communicate the
528            // errors' existence to the caller, otherwise the caller might
529            // mistakenly think that no errors occurred and return a zero
530            // exit code. So we abort (panic) instead, similar to if `f`
531            // had panicked.
532            if res.is_ok() {
533                compiler.sess.dcx().abort_if_errors();
534            }
535
536            // Also make sure to flush delayed bugs as if we panicked, the
537            // bugs would be flushed by the Drop impl of DiagCtxt while
538            // unwinding, which would result in an abort with
539            // "panic in a destructor during cleanup".
540            compiler.sess.dcx().flush_delayed();
541
542            let res = match res {
543                Ok(res) => res,
544                // Resume unwinding if a panic happened.
545                Err(err) => std::panic::resume_unwind(err),
546            };
547
548            let prof = compiler.sess.prof.clone();
549            prof.generic_activity("drop_compiler").run(move || drop(compiler));
550
551            res
552        },
553    )
554}
555
556pub fn try_print_query_stack(
557    dcx: DiagCtxtHandle<'_>,
558    limit_frames: Option<usize>,
559    file: Option<std::fs::File>,
560) {
561    eprintln!("query stack during panic:");
562
563    // Be careful relying on global state here: this code is called from
564    // a panic hook, which means that the global `DiagCtxt` may be in a weird
565    // state if it was responsible for triggering the panic.
566    let all_frames = ty::tls::with_context_opt(|icx| {
567        if let Some(icx) = icx {
568            ty::print::with_no_queries!(print_query_stack(
569                QueryCtxt::new(icx.tcx),
570                icx.query,
571                dcx,
572                limit_frames,
573                file,
574            ))
575        } else {
576            0
577        }
578    });
579
580    if let Some(limit_frames) = limit_frames
581        && all_frames > limit_frames
582    {
583        eprintln!(
584            "... and {} other queries... use `env RUST_BACKTRACE=1` to see the full query stack",
585            all_frames - limit_frames
586        );
587    } else {
588        eprintln!("end of query stack");
589    }
590}
rustc_interface/interface.rs

rustc_interface/
interface.rs
