1 use rustc_ast::mut_visit::{visit_clobber, MutVisitor, *};
3 use rustc_ast::{self as ast, AttrVec, BlockCheckMode};
4 use rustc_codegen_ssa::traits::CodegenBackend;
5 use rustc_data_structures::fingerprint::Fingerprint;
6 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
7 #[cfg(parallel_compiler)]
8 use rustc_data_structures::jobserver;
9 use rustc_data_structures::stable_hasher::StableHasher;
10 use rustc_data_structures::sync::Lrc;
11 use rustc_errors::registry::Registry;
12 use rustc_metadata::dynamic_lib::DynamicLibrary;
13 use rustc_resolve::{self, Resolver};
14 use rustc_session as session;
15 use rustc_session::config::{self, CrateType};
16 use rustc_session::config::{ErrorOutputType, Input, OutputFilenames};
17 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
18 use rustc_session::parse::CrateConfig;
19 use rustc_session::CrateDisambiguator;
20 use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session};
21 use rustc_span::edition::Edition;
22 use rustc_span::lev_distance::find_best_match_for_name;
23 use rustc_span::source_map::FileLoader;
24 use rustc_span::symbol::{sym, Symbol};
25 use smallvec::SmallVec;
27 use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
29 use std::lazy::SyncOnceCell;
31 use std::ops::DerefMut;
32 use std::path::{Path, PathBuf};
33 use std::sync::atomic::{AtomicBool, Ordering};
34 use std::sync::{Arc, Mutex, Once};
35 #[cfg(not(parallel_compiler))]
36 use std::{panic, thread};
39 /// Adds `target_feature = "..."` cfgs for a variety of platform
40 /// specific features (SSE, NEON etc.).
42 /// This is performed by checking whether a set of permitted features
43 /// is available on the target machine, by querying LLVM.
44 pub fn add_configuration(
45 cfg: &mut CrateConfig,
47 codegen_backend: &dyn CodegenBackend,
49 let tf = sym::target_feature;
51 let target_features = codegen_backend.target_features(sess);
52 sess.target_features.extend(target_features.iter().cloned());
54 cfg.extend(target_features.into_iter().map(|feat| (tf, Some(feat))));
56 if sess.crt_static(None) {
57 cfg.insert((tf, Some(sym::crt_dash_static)));
61 pub fn create_session(
62 sopts: config::Options,
63 cfg: FxHashSet<(String, Option<String>)>,
64 diagnostic_output: DiagnosticOutput,
65 file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
66 input_path: Option<PathBuf>,
67 lint_caps: FxHashMap<lint::LintId, lint::Level>,
68 make_codegen_backend: Option<
69 Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
71 descriptions: Registry,
72 ) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>) {
73 let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
74 make_codegen_backend(&sopts)
76 get_codegen_backend(&sopts)
79 // target_override is documented to be called before init(), so this is okay
80 let target_override = codegen_backend.target_override(&sopts);
82 let mut sess = session::build_session(
92 codegen_backend.init(&sess);
94 let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
95 add_configuration(&mut cfg, &mut sess, &*codegen_backend);
96 sess.parse_sess.config = cfg;
98 (Lrc::new(sess), Lrc::new(codegen_backend))
101 const STACK_SIZE: usize = 8 * 1024 * 1024;
103 fn get_stack_size() -> Option<usize> {
104 // FIXME: Hacks on hacks. If the env is trying to override the stack size
105 // then *don't* set it explicitly.
106 env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE)
109 /// Like a `thread::Builder::spawn` followed by a `join()`, but avoids the need
110 /// for `'static` bounds.
111 #[cfg(not(parallel_compiler))]
112 pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
114 unsafe impl Send for Ptr {}
115 unsafe impl Sync for Ptr {}
118 let run = Ptr(&mut f as *mut _ as *mut ());
119 let mut result = None;
120 let result_ptr = Ptr(&mut result as *mut _ as *mut ());
122 let thread = cfg.spawn(move || {
123 let run = unsafe { (*(run.0 as *mut Option<F>)).take().unwrap() };
124 let result = unsafe { &mut *(result_ptr.0 as *mut Option<R>) };
125 *result = Some(run());
128 match thread.unwrap().join() {
129 Ok(()) => result.unwrap(),
130 Err(p) => panic::resume_unwind(p),
134 #[cfg(not(parallel_compiler))]
135 pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
138 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
141 let mut cfg = thread::Builder::new().name("rustc".to_string());
143 if let Some(size) = get_stack_size() {
144 cfg = cfg.stack_size(size);
147 crate::callbacks::setup_callbacks();
149 let main_handler = move || {
150 rustc_span::with_session_globals(edition, || {
151 io::set_output_capture(stderr.clone());
156 scoped_thread(cfg, main_handler)
159 #[cfg(parallel_compiler)]
160 pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
163 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
166 use rustc_middle::ty;
167 crate::callbacks::setup_callbacks();
169 let mut config = rayon::ThreadPoolBuilder::new()
170 .thread_name(|_| "rustc".to_string())
171 .acquire_thread_handler(jobserver::acquire_thread)
172 .release_thread_handler(jobserver::release_thread)
173 .num_threads(threads)
174 .deadlock_handler(|| unsafe { ty::query::handle_deadlock() });
176 if let Some(size) = get_stack_size() {
177 config = config.stack_size(size);
180 let with_pool = move |pool: &rayon::ThreadPool| pool.install(f);
182 rustc_span::with_session_globals(edition, || {
183 rustc_span::SESSION_GLOBALS.with(|session_globals| {
184 // The main handler runs for each Rayon worker thread and sets up
185 // the thread local rustc uses. `session_globals` is captured and set
186 // on the new threads.
187 let main_handler = move |thread: rayon::ThreadBuilder| {
188 rustc_span::SESSION_GLOBALS.set(session_globals, || {
189 io::set_output_capture(stderr.clone());
194 config.build_scoped(main_handler, with_pool).unwrap()
199 fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
200 let lib = DynamicLibrary::open(path).unwrap_or_else(|err| {
201 let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
202 early_error(ErrorOutputType::default(), &err);
205 match lib.symbol("__rustc_codegen_backend") {
208 mem::transmute::<*mut u8, _>(f)
212 "couldn't load codegen backend as it \
213 doesn't export the `__rustc_codegen_backend` \
217 early_error(ErrorOutputType::default(), &err);
223 pub fn get_codegen_backend(sopts: &config::Options) -> Box<dyn CodegenBackend> {
224 static INIT: Once = Once::new();
226 static mut LOAD: fn() -> Box<dyn CodegenBackend> = || unreachable!();
229 #[cfg(feature = "llvm")]
230 const DEFAULT_CODEGEN_BACKEND: &str = "llvm";
232 #[cfg(not(feature = "llvm"))]
233 const DEFAULT_CODEGEN_BACKEND: &str = "cranelift";
235 let codegen_name = sopts
239 .map(|name| &name[..])
240 .unwrap_or(DEFAULT_CODEGEN_BACKEND);
242 let backend = match codegen_name {
243 filename if filename.contains('.') => load_backend_from_dylib(filename.as_ref()),
244 codegen_name => get_builtin_codegen_backend(codegen_name),
254 // This is used for rustdoc, but it uses similar machinery to codegen backend
255 // loading, so we leave the code here. It is potentially useful for other tools
256 // that want to invoke the rustc binary while linking to rustc as well.
257 pub fn rustc_path<'a>() -> Option<&'a Path> {
258 static RUSTC_PATH: SyncOnceCell<Option<PathBuf>> = SyncOnceCell::new();
260 const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
262 RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_ref().map(|v| &**v)
265 fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
266 sysroot_candidates().iter().find_map(|sysroot| {
267 let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
272 candidate.exists().then_some(candidate)
276 fn sysroot_candidates() -> Vec<PathBuf> {
277 let target = session::config::host_triple();
278 let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
279 let path = current_dll_path().and_then(|s| s.canonicalize().ok());
280 if let Some(dll) = path {
281 // use `parent` twice to chop off the file name and then also the
282 // directory containing the dll which should be either `lib` or `bin`.
283 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
284 // The original `path` pointed at the `rustc_driver` crate's dll.
285 // Now that dll should only be in one of two locations. The first is
286 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
287 // other is the target's libdir, for example
288 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
290 // We don't know which, so let's assume that if our `path` above
291 // ends in `$target` we *could* be in the target libdir, and always
292 // assume that we may be in the main libdir.
293 sysroot_candidates.push(path.to_owned());
295 if path.ends_with(target) {
296 sysroot_candidates.extend(
297 path.parent() // chop off `$target`
298 .and_then(|p| p.parent()) // chop off `rustlib`
299 .and_then(|p| p.parent()) // chop off `lib`
300 .map(|s| s.to_owned()),
306 return sysroot_candidates;
309 fn current_dll_path() -> Option<PathBuf> {
310 use std::ffi::{CStr, OsStr};
311 use std::os::unix::prelude::*;
314 let addr = current_dll_path as usize as *mut _;
315 let mut info = mem::zeroed();
316 if libc::dladdr(addr, &mut info) == 0 {
317 info!("dladdr failed");
320 if info.dli_fname.is_null() {
321 info!("dladdr returned null pointer");
324 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
325 let os = OsStr::from_bytes(bytes);
326 Some(PathBuf::from(os))
331 fn current_dll_path() -> Option<PathBuf> {
332 use std::ffi::OsString;
333 use std::os::windows::prelude::*;
336 use winapi::um::libloaderapi::{
337 GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
341 let mut module = ptr::null_mut();
342 let r = GetModuleHandleExW(
343 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
344 current_dll_path as usize as *mut _,
348 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
351 let mut space = Vec::with_capacity(1024);
352 let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
354 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
358 if r >= space.capacity() {
359 info!("our buffer was too small? {}", io::Error::last_os_error());
363 let os = OsString::from_wide(&space);
364 Some(PathBuf::from(os))
369 pub fn get_builtin_codegen_backend(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
371 #[cfg(feature = "llvm")]
372 "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
373 _ => get_codegen_sysroot(backend_name),
377 pub fn get_codegen_sysroot(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
378 // For now we only allow this function to be called once as it'll dlopen a
379 // few things, which seems to work best if we only do that once. In
380 // general this assertion never trips due to the once guard in `get_codegen_backend`,
381 // but there's a few manual calls to this function in this file we protect
383 static LOADED: AtomicBool = AtomicBool::new(false);
385 !LOADED.fetch_or(true, Ordering::SeqCst),
386 "cannot load the default codegen backend twice"
389 let target = session::config::host_triple();
390 let sysroot_candidates = sysroot_candidates();
392 let sysroot = sysroot_candidates
395 let libdir = filesearch::relative_target_lib_path(&sysroot, &target);
396 sysroot.join(libdir).with_file_name("codegen-backends")
399 info!("codegen backend candidate: {}", f.display());
402 let sysroot = sysroot.unwrap_or_else(|| {
403 let candidates = sysroot_candidates
405 .map(|p| p.display().to_string())
409 "failed to find a `codegen-backends` folder \
410 in the sysroot candidates:\n* {}",
413 early_error(ErrorOutputType::default(), &err);
415 info!("probing {} for a codegen backend", sysroot.display());
417 let d = sysroot.read_dir().unwrap_or_else(|e| {
419 "failed to load default codegen backend, couldn't \
424 early_error(ErrorOutputType::default(), &err);
427 let mut file: Option<PathBuf> = None;
430 format!("rustc_codegen_{}-{}", backend_name, release_str().expect("CFG_RELEASE"));
431 for entry in d.filter_map(|e| e.ok()) {
432 let path = entry.path();
433 let filename = match path.file_name().and_then(|s| s.to_str()) {
437 if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) {
440 let name = &filename[DLL_PREFIX.len()..filename.len() - DLL_SUFFIX.len()];
441 if name != expected_name {
444 if let Some(ref prev) = file {
446 "duplicate codegen backends found\n\
453 early_error(ErrorOutputType::default(), &err);
455 file = Some(path.clone());
459 Some(ref s) => load_backend_from_dylib(s),
461 let err = format!("unsupported builtin codegen backend `{}`", backend_name);
462 early_error(ErrorOutputType::default(), &err);
467 pub(crate) fn compute_crate_disambiguator(session: &Session) -> CrateDisambiguator {
468 use std::hash::Hasher;
470 // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
471 // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
472 // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
473 // should still be safe enough to avoid collisions in practice.
474 let mut hasher = StableHasher::new();
476 let mut metadata = session.opts.cg.metadata.clone();
477 // We don't want the crate_disambiguator to dependent on the order
478 // -C metadata arguments, so sort them:
480 // Every distinct -C metadata value is only incorporated once:
483 hasher.write(b"metadata");
485 // Also incorporate the length of a metadata string, so that we generate
486 // different values for `-Cmetadata=ab -Cmetadata=c` and
487 // `-Cmetadata=a -Cmetadata=bc`
488 hasher.write_usize(s.len());
489 hasher.write(s.as_bytes());
492 // Also incorporate crate type, so that we don't get symbol conflicts when
493 // linking against a library of the same name, if this is an executable.
494 let is_exe = session.crate_types().contains(&CrateType::Executable);
495 hasher.write(if is_exe { b"exe" } else { b"lib" });
497 CrateDisambiguator::from(hasher.finish::<Fingerprint>())
500 pub(crate) fn check_attr_crate_type(
502 attrs: &[ast::Attribute],
503 lint_buffer: &mut LintBuffer,
505 // Unconditionally collect crate types from attributes to make them used
506 for a in attrs.iter() {
507 if sess.check_name(a, sym::crate_type) {
508 if let Some(n) = a.value_str() {
509 if categorize_crate_type(n).is_some() {
513 if let ast::MetaItemKind::NameValue(spanned) = a.meta().unwrap().kind {
514 let span = spanned.span;
515 let lev_candidate = find_best_match_for_name(
516 &CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(),
520 if let Some(candidate) = lev_candidate {
521 lint_buffer.buffer_lint_with_diagnostic(
522 lint::builtin::UNKNOWN_CRATE_TYPES,
525 "invalid `crate_type` value",
526 BuiltinLintDiagnostics::UnknownCrateTypes(
528 "did you mean".to_string(),
529 format!("\"{}\"", candidate),
533 lint_buffer.buffer_lint(
534 lint::builtin::UNKNOWN_CRATE_TYPES,
537 "invalid `crate_type` value",
546 const CRATE_TYPES: &[(Symbol, CrateType)] = &[
547 (sym::rlib, CrateType::Rlib),
548 (sym::dylib, CrateType::Dylib),
549 (sym::cdylib, CrateType::Cdylib),
550 (sym::lib, config::default_lib_output()),
551 (sym::staticlib, CrateType::Staticlib),
552 (sym::proc_dash_macro, CrateType::ProcMacro),
553 (sym::bin, CrateType::Executable),
556 fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
557 Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
560 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
561 // Unconditionally collect crate types from attributes to make them used
562 let attr_types: Vec<CrateType> = attrs
565 if session.check_name(a, sym::crate_type) {
566 match a.value_str() {
567 Some(s) => categorize_crate_type(s),
576 // If we're generating a test executable, then ignore all other output
577 // styles at all other locations
578 if session.opts.test {
579 return vec![CrateType::Executable];
582 // Only check command line flags if present. If no types are specified by
583 // command line, then reuse the empty `base` Vec to hold the types that
584 // will be found in crate attributes.
585 let mut base = session.opts.crate_types.clone();
587 base.extend(attr_types);
589 base.push(output::default_output_for_target(session));
596 base.retain(|crate_type| {
597 let res = !output::invalid_output_for_target(session, *crate_type);
600 session.warn(&format!(
601 "dropping unsupported crate type `{}` for target `{}`",
602 *crate_type, session.opts.target_triple
612 pub fn build_output_filenames(
614 odir: &Option<PathBuf>,
615 ofile: &Option<PathBuf>,
616 attrs: &[ast::Attribute],
618 ) -> OutputFilenames {
621 // "-" as input file will cause the parser to read from stdin so we
622 // have to make up a name
623 // We want to toss everything after the final '.'
624 let dirpath = (*odir).as_ref().cloned().unwrap_or_default();
626 // If a crate name is present, we use it as the link name
631 .or_else(|| rustc_attr::find_crate_name(&sess, attrs).map(|n| n.to_string()))
632 .unwrap_or_else(|| input.filestem().to_owned());
634 OutputFilenames::new(
638 sess.opts.cg.extra_filename.clone(),
639 sess.opts.output_types.clone(),
643 Some(ref out_file) => {
644 let unnamed_output_types =
645 sess.opts.output_types.values().filter(|a| a.is_none()).count();
646 let ofile = if unnamed_output_types > 1 {
648 "due to multiple output types requested, the explicitly specified \
649 output file name will be adapted for each output type",
653 if !sess.opts.cg.extra_filename.is_empty() {
654 sess.warn("ignoring -C extra-filename flag due to -o flag");
656 Some(out_file.clone())
659 sess.warn("ignoring --out-dir flag due to -o flag");
662 OutputFilenames::new(
663 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
664 out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(),
666 sess.opts.cg.extra_filename.clone(),
667 sess.opts.output_types.clone(),
673 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
675 // FIXME: Currently the `everybody_loops` transformation is not applied to:
676 // * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
677 // waiting for miri to fix that.
678 // * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
679 // Solving this may require `!` to implement every trait, which relies on the an even more
680 // ambitious form of the closed RFC #1637. See also [#34511].
682 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
683 pub struct ReplaceBodyWithLoop<'a, 'b> {
684 within_static_or_const: bool,
685 nested_blocks: Option<Vec<ast::Block>>,
686 resolver: &'a mut Resolver<'b>,
689 impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
690 pub fn new(resolver: &'a mut Resolver<'b>) -> ReplaceBodyWithLoop<'a, 'b> {
691 ReplaceBodyWithLoop { within_static_or_const: false, nested_blocks: None, resolver }
694 fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
695 let old_const = mem::replace(&mut self.within_static_or_const, is_const);
696 let old_blocks = self.nested_blocks.take();
697 let ret = action(self);
698 self.within_static_or_const = old_const;
699 self.nested_blocks = old_blocks;
703 fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
704 if let ast::FnRetTy::Ty(ref ty) = ret_ty {
705 fn involves_impl_trait(ty: &ast::Ty) -> bool {
707 ast::TyKind::ImplTrait(..) => true,
708 ast::TyKind::Slice(ref subty)
709 | ast::TyKind::Array(ref subty, _)
710 | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
711 | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
712 | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
713 ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
714 ast::TyKind::Path(_, ref path) => {
715 path.segments.iter().any(|seg| match seg.args.as_deref() {
717 Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
718 data.args.iter().any(|arg| match arg {
719 ast::AngleBracketedArg::Arg(arg) => match arg {
720 ast::GenericArg::Type(ty) => involves_impl_trait(ty),
721 ast::GenericArg::Lifetime(_)
722 | ast::GenericArg::Const(_) => false,
724 ast::AngleBracketedArg::Constraint(c) => match c.kind {
725 ast::AssocTyConstraintKind::Bound { .. } => true,
726 ast::AssocTyConstraintKind::Equality { ref ty } => {
727 involves_impl_trait(ty)
732 Some(&ast::GenericArgs::Parenthesized(ref data)) => {
733 any_involves_impl_trait(data.inputs.iter())
734 || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
742 fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
743 it.any(|subty| involves_impl_trait(subty))
746 involves_impl_trait(ty)
752 fn is_sig_const(sig: &ast::FnSig) -> bool {
753 matches!(sig.header.constness, ast::Const::Yes(_))
754 || ReplaceBodyWithLoop::should_ignore_fn(&sig.decl.output)
758 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
759 fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
760 let is_const = match i {
761 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
762 ast::ItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
765 self.run(is_const, |s| noop_visit_item_kind(i, s))
768 fn flat_map_trait_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
769 let is_const = match i.kind {
770 ast::AssocItemKind::Const(..) => true,
771 ast::AssocItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
774 self.run(is_const, |s| noop_flat_map_assoc_item(i, s))
777 fn flat_map_impl_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
778 self.flat_map_trait_item(i)
781 fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
782 self.run(true, |s| noop_visit_anon_const(c, s))
785 fn visit_block(&mut self, b: &mut P<ast::Block>) {
787 rules: ast::BlockCheckMode,
788 s: Option<ast::Stmt>,
789 resolver: &mut Resolver<'_>,
792 stmts: s.into_iter().collect(),
794 id: resolver.next_node_id(),
795 span: rustc_span::DUMMY_SP,
800 fn block_to_stmt(b: ast::Block, resolver: &mut Resolver<'_>) -> ast::Stmt {
801 let expr = P(ast::Expr {
802 id: resolver.next_node_id(),
803 kind: ast::ExprKind::Block(P(b), None),
804 span: rustc_span::DUMMY_SP,
805 attrs: AttrVec::new(),
810 id: resolver.next_node_id(),
811 kind: ast::StmtKind::Expr(expr),
812 span: rustc_span::DUMMY_SP,
816 let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.resolver);
817 let loop_expr = P(ast::Expr {
818 kind: ast::ExprKind::Loop(P(empty_block), None),
819 id: self.resolver.next_node_id(),
820 span: rustc_span::DUMMY_SP,
821 attrs: AttrVec::new(),
825 let loop_stmt = ast::Stmt {
826 id: self.resolver.next_node_id(),
827 span: rustc_span::DUMMY_SP,
828 kind: ast::StmtKind::Expr(loop_expr),
831 if self.within_static_or_const {
832 noop_visit_block(b, self)
834 visit_clobber(b.deref_mut(), |b| {
835 let mut stmts = vec![];
837 let old_blocks = self.nested_blocks.replace(vec![]);
839 stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
841 // we put a Some in there earlier with that replace(), so this is valid
842 let new_blocks = self.nested_blocks.take().unwrap();
843 self.nested_blocks = old_blocks;
844 stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, self.resolver)));
847 let mut new_block = ast::Block { stmts, ..b };
849 if let Some(old_blocks) = self.nested_blocks.as_mut() {
850 //push our fresh block onto the cache and yield an empty block with `loop {}`
851 if !new_block.stmts.is_empty() {
852 old_blocks.push(new_block);
855 stmt_to_block(b.rules, Some(loop_stmt), &mut self.resolver)
857 //push `loop {}` onto the end of our fresh block and yield that
858 new_block.stmts.push(loop_stmt);
867 /// Returns a version string such as "rustc 1.46.0 (04488afe3 2020-08-24)"
868 pub fn version_str() -> Option<&'static str> {
869 option_env!("CFG_VERSION")
872 /// Returns a version string such as "0.12.0-dev".
873 pub fn release_str() -> Option<&'static str> {
874 option_env!("CFG_RELEASE")
877 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
878 pub fn commit_hash_str() -> Option<&'static str> {
879 option_env!("CFG_VER_HASH")
882 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
883 pub fn commit_date_str() -> Option<&'static str> {
884 option_env!("CFG_VER_DATE")