1 use rustc_ast::mut_visit::{visit_clobber, MutVisitor, *};
3 use rustc_ast::util::lev_distance::find_best_match_for_name;
4 use rustc_ast::{self as ast, AttrVec, BlockCheckMode};
5 use rustc_codegen_ssa::traits::CodegenBackend;
6 use rustc_data_structures::fingerprint::Fingerprint;
7 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
8 #[cfg(parallel_compiler)]
9 use rustc_data_structures::jobserver;
10 use rustc_data_structures::stable_hasher::StableHasher;
11 use rustc_data_structures::sync::Lrc;
12 use rustc_errors::registry::Registry;
13 use rustc_metadata::dynamic_lib::DynamicLibrary;
14 use rustc_resolve::{self, Resolver};
15 use rustc_session as session;
16 use rustc_session::config::{self, CrateType};
17 use rustc_session::config::{ErrorOutputType, Input, OutputFilenames};
18 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
19 use rustc_session::parse::CrateConfig;
20 use rustc_session::CrateDisambiguator;
21 use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session};
22 use rustc_span::edition::Edition;
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 if let Some(stderr) = stderr {
152 io::set_panic(Some(stderr.clone()));
158 scoped_thread(cfg, main_handler)
161 #[cfg(parallel_compiler)]
162 pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
165 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
168 use rustc_middle::ty;
169 crate::callbacks::setup_callbacks();
171 let mut config = rayon::ThreadPoolBuilder::new()
172 .thread_name(|_| "rustc".to_string())
173 .acquire_thread_handler(jobserver::acquire_thread)
174 .release_thread_handler(jobserver::release_thread)
175 .num_threads(threads)
176 .deadlock_handler(|| unsafe { ty::query::handle_deadlock() });
178 if let Some(size) = get_stack_size() {
179 config = config.stack_size(size);
182 let with_pool = move |pool: &rayon::ThreadPool| pool.install(f);
184 rustc_span::with_session_globals(edition, || {
185 rustc_span::SESSION_GLOBALS.with(|session_globals| {
186 // The main handler runs for each Rayon worker thread and sets up
187 // the thread local rustc uses. `session_globals` is captured and set
188 // on the new threads.
189 let main_handler = move |thread: rayon::ThreadBuilder| {
190 rustc_span::SESSION_GLOBALS.set(session_globals, || {
191 if let Some(stderr) = stderr {
192 io::set_panic(Some(stderr.clone()));
198 config.build_scoped(main_handler, with_pool).unwrap()
203 fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
204 let lib = DynamicLibrary::open(path).unwrap_or_else(|err| {
205 let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
206 early_error(ErrorOutputType::default(), &err);
209 match lib.symbol("__rustc_codegen_backend") {
212 mem::transmute::<*mut u8, _>(f)
216 "couldn't load codegen backend as it \
217 doesn't export the `__rustc_codegen_backend` \
221 early_error(ErrorOutputType::default(), &err);
227 pub fn get_codegen_backend(sopts: &config::Options) -> Box<dyn CodegenBackend> {
228 static INIT: Once = Once::new();
230 static mut LOAD: fn() -> Box<dyn CodegenBackend> = || unreachable!();
233 #[cfg(feature = "llvm")]
234 const DEFAULT_CODEGEN_BACKEND: &str = "llvm";
236 #[cfg(not(feature = "llvm"))]
237 const DEFAULT_CODEGEN_BACKEND: &str = "cranelift";
239 let codegen_name = sopts
243 .map(|name| &name[..])
244 .unwrap_or(DEFAULT_CODEGEN_BACKEND);
246 let backend = match codegen_name {
247 filename if filename.contains('.') => load_backend_from_dylib(filename.as_ref()),
248 codegen_name => get_builtin_codegen_backend(codegen_name),
258 // This is used for rustdoc, but it uses similar machinery to codegen backend
259 // loading, so we leave the code here. It is potentially useful for other tools
260 // that want to invoke the rustc binary while linking to rustc as well.
261 pub fn rustc_path<'a>() -> Option<&'a Path> {
262 static RUSTC_PATH: SyncOnceCell<Option<PathBuf>> = SyncOnceCell::new();
264 const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
266 RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_ref().map(|v| &**v)
269 fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
270 sysroot_candidates().iter().find_map(|sysroot| {
271 let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
276 candidate.exists().then_some(candidate)
280 fn sysroot_candidates() -> Vec<PathBuf> {
281 let target = session::config::host_triple();
282 let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
283 let path = current_dll_path().and_then(|s| s.canonicalize().ok());
284 if let Some(dll) = path {
285 // use `parent` twice to chop off the file name and then also the
286 // directory containing the dll which should be either `lib` or `bin`.
287 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
288 // The original `path` pointed at the `rustc_driver` crate's dll.
289 // Now that dll should only be in one of two locations. The first is
290 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
291 // other is the target's libdir, for example
292 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
294 // We don't know which, so let's assume that if our `path` above
295 // ends in `$target` we *could* be in the target libdir, and always
296 // assume that we may be in the main libdir.
297 sysroot_candidates.push(path.to_owned());
299 if path.ends_with(target) {
300 sysroot_candidates.extend(
301 path.parent() // chop off `$target`
302 .and_then(|p| p.parent()) // chop off `rustlib`
303 .and_then(|p| p.parent()) // chop off `lib`
304 .map(|s| s.to_owned()),
310 return sysroot_candidates;
313 fn current_dll_path() -> Option<PathBuf> {
314 use std::ffi::{CStr, OsStr};
315 use std::os::unix::prelude::*;
318 let addr = current_dll_path as usize as *mut _;
319 let mut info = mem::zeroed();
320 if libc::dladdr(addr, &mut info) == 0 {
321 info!("dladdr failed");
324 if info.dli_fname.is_null() {
325 info!("dladdr returned null pointer");
328 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
329 let os = OsStr::from_bytes(bytes);
330 Some(PathBuf::from(os))
335 fn current_dll_path() -> Option<PathBuf> {
336 use std::ffi::OsString;
337 use std::os::windows::prelude::*;
340 use winapi::um::libloaderapi::{
341 GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
345 let mut module = ptr::null_mut();
346 let r = GetModuleHandleExW(
347 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
348 current_dll_path as usize as *mut _,
352 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
355 let mut space = Vec::with_capacity(1024);
356 let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
358 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
362 if r >= space.capacity() {
363 info!("our buffer was too small? {}", io::Error::last_os_error());
367 let os = OsString::from_wide(&space);
368 Some(PathBuf::from(os))
373 pub fn get_builtin_codegen_backend(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
375 #[cfg(feature = "llvm")]
376 "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
377 _ => get_codegen_sysroot(backend_name),
381 pub fn get_codegen_sysroot(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
382 // For now we only allow this function to be called once as it'll dlopen a
383 // few things, which seems to work best if we only do that once. In
384 // general this assertion never trips due to the once guard in `get_codegen_backend`,
385 // but there's a few manual calls to this function in this file we protect
387 static LOADED: AtomicBool = AtomicBool::new(false);
389 !LOADED.fetch_or(true, Ordering::SeqCst),
390 "cannot load the default codegen backend twice"
393 let target = session::config::host_triple();
394 let sysroot_candidates = sysroot_candidates();
396 let sysroot = sysroot_candidates
399 let libdir = filesearch::relative_target_lib_path(&sysroot, &target);
400 sysroot.join(libdir).with_file_name("codegen-backends")
403 info!("codegen backend candidate: {}", f.display());
406 let sysroot = sysroot.unwrap_or_else(|| {
407 let candidates = sysroot_candidates
409 .map(|p| p.display().to_string())
413 "failed to find a `codegen-backends` folder \
414 in the sysroot candidates:\n* {}",
417 early_error(ErrorOutputType::default(), &err);
419 info!("probing {} for a codegen backend", sysroot.display());
421 let d = sysroot.read_dir().unwrap_or_else(|e| {
423 "failed to load default codegen backend, couldn't \
428 early_error(ErrorOutputType::default(), &err);
431 let mut file: Option<PathBuf> = None;
434 format!("rustc_codegen_{}-{}", backend_name, release_str().expect("CFG_RELEASE"));
435 for entry in d.filter_map(|e| e.ok()) {
436 let path = entry.path();
437 let filename = match path.file_name().and_then(|s| s.to_str()) {
441 if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) {
444 let name = &filename[DLL_PREFIX.len()..filename.len() - DLL_SUFFIX.len()];
445 if name != expected_name {
448 if let Some(ref prev) = file {
450 "duplicate codegen backends found\n\
457 early_error(ErrorOutputType::default(), &err);
459 file = Some(path.clone());
463 Some(ref s) => load_backend_from_dylib(s),
465 let err = format!("unsupported builtin codegen backend `{}`", backend_name);
466 early_error(ErrorOutputType::default(), &err);
471 pub(crate) fn compute_crate_disambiguator(session: &Session) -> CrateDisambiguator {
472 use std::hash::Hasher;
474 // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
475 // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
476 // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
477 // should still be safe enough to avoid collisions in practice.
478 let mut hasher = StableHasher::new();
480 let mut metadata = session.opts.cg.metadata.clone();
481 // We don't want the crate_disambiguator to dependent on the order
482 // -C metadata arguments, so sort them:
484 // Every distinct -C metadata value is only incorporated once:
487 hasher.write(b"metadata");
489 // Also incorporate the length of a metadata string, so that we generate
490 // different values for `-Cmetadata=ab -Cmetadata=c` and
491 // `-Cmetadata=a -Cmetadata=bc`
492 hasher.write_usize(s.len());
493 hasher.write(s.as_bytes());
496 // Also incorporate crate type, so that we don't get symbol conflicts when
497 // linking against a library of the same name, if this is an executable.
498 let is_exe = session.crate_types().contains(&CrateType::Executable);
499 hasher.write(if is_exe { b"exe" } else { b"lib" });
501 CrateDisambiguator::from(hasher.finish::<Fingerprint>())
504 pub(crate) fn check_attr_crate_type(
506 attrs: &[ast::Attribute],
507 lint_buffer: &mut LintBuffer,
509 // Unconditionally collect crate types from attributes to make them used
510 for a in attrs.iter() {
511 if sess.check_name(a, sym::crate_type) {
512 if let Some(n) = a.value_str() {
513 if categorize_crate_type(n).is_some() {
517 if let ast::MetaItemKind::NameValue(spanned) = a.meta().unwrap().kind {
518 let span = spanned.span;
520 find_best_match_for_name(CRATE_TYPES.iter().map(|(k, _)| k), n, None);
521 if let Some(candidate) = lev_candidate {
522 lint_buffer.buffer_lint_with_diagnostic(
523 lint::builtin::UNKNOWN_CRATE_TYPES,
526 "invalid `crate_type` value",
527 BuiltinLintDiagnostics::UnknownCrateTypes(
529 "did you mean".to_string(),
530 format!("\"{}\"", candidate),
534 lint_buffer.buffer_lint(
535 lint::builtin::UNKNOWN_CRATE_TYPES,
538 "invalid `crate_type` value",
547 const CRATE_TYPES: &[(Symbol, CrateType)] = &[
548 (sym::rlib, CrateType::Rlib),
549 (sym::dylib, CrateType::Dylib),
550 (sym::cdylib, CrateType::Cdylib),
551 (sym::lib, config::default_lib_output()),
552 (sym::staticlib, CrateType::Staticlib),
553 (sym::proc_dash_macro, CrateType::ProcMacro),
554 (sym::bin, CrateType::Executable),
557 fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
558 Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
561 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
562 // Unconditionally collect crate types from attributes to make them used
563 let attr_types: Vec<CrateType> = attrs
566 if session.check_name(a, sym::crate_type) {
567 match a.value_str() {
568 Some(s) => categorize_crate_type(s),
577 // If we're generating a test executable, then ignore all other output
578 // styles at all other locations
579 if session.opts.test {
580 return vec![CrateType::Executable];
583 // Only check command line flags if present. If no types are specified by
584 // command line, then reuse the empty `base` Vec to hold the types that
585 // will be found in crate attributes.
586 let mut base = session.opts.crate_types.clone();
588 base.extend(attr_types);
590 base.push(output::default_output_for_target(session));
597 base.retain(|crate_type| {
598 let res = !output::invalid_output_for_target(session, *crate_type);
601 session.warn(&format!(
602 "dropping unsupported crate type `{}` for target `{}`",
603 *crate_type, session.opts.target_triple
613 pub fn build_output_filenames(
615 odir: &Option<PathBuf>,
616 ofile: &Option<PathBuf>,
617 attrs: &[ast::Attribute],
619 ) -> OutputFilenames {
622 // "-" as input file will cause the parser to read from stdin so we
623 // have to make up a name
624 // We want to toss everything after the final '.'
625 let dirpath = (*odir).as_ref().cloned().unwrap_or_default();
627 // If a crate name is present, we use it as the link name
632 .or_else(|| rustc_attr::find_crate_name(&sess, attrs).map(|n| n.to_string()))
633 .unwrap_or_else(|| input.filestem().to_owned());
635 OutputFilenames::new(
639 sess.opts.cg.extra_filename.clone(),
640 sess.opts.output_types.clone(),
644 Some(ref out_file) => {
645 let unnamed_output_types =
646 sess.opts.output_types.values().filter(|a| a.is_none()).count();
647 let ofile = if unnamed_output_types > 1 {
649 "due to multiple output types requested, the explicitly specified \
650 output file name will be adapted for each output type",
654 if !sess.opts.cg.extra_filename.is_empty() {
655 sess.warn("ignoring -C extra-filename flag due to -o flag");
657 Some(out_file.clone())
660 sess.warn("ignoring --out-dir flag due to -o flag");
663 OutputFilenames::new(
664 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
665 out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(),
667 sess.opts.cg.extra_filename.clone(),
668 sess.opts.output_types.clone(),
674 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
676 // FIXME: Currently the `everybody_loops` transformation is not applied to:
677 // * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
678 // waiting for miri to fix that.
679 // * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
680 // Solving this may require `!` to implement every trait, which relies on the an even more
681 // ambitious form of the closed RFC #1637. See also [#34511].
683 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
684 pub struct ReplaceBodyWithLoop<'a, 'b> {
685 within_static_or_const: bool,
686 nested_blocks: Option<Vec<ast::Block>>,
687 resolver: &'a mut Resolver<'b>,
690 impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
691 pub fn new(resolver: &'a mut Resolver<'b>) -> ReplaceBodyWithLoop<'a, 'b> {
692 ReplaceBodyWithLoop { within_static_or_const: false, nested_blocks: None, resolver }
695 fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
696 let old_const = mem::replace(&mut self.within_static_or_const, is_const);
697 let old_blocks = self.nested_blocks.take();
698 let ret = action(self);
699 self.within_static_or_const = old_const;
700 self.nested_blocks = old_blocks;
704 fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
705 if let ast::FnRetTy::Ty(ref ty) = ret_ty {
706 fn involves_impl_trait(ty: &ast::Ty) -> bool {
708 ast::TyKind::ImplTrait(..) => true,
709 ast::TyKind::Slice(ref subty)
710 | ast::TyKind::Array(ref subty, _)
711 | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
712 | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
713 | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
714 ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
715 ast::TyKind::Path(_, ref path) => {
716 path.segments.iter().any(|seg| match seg.args.as_deref() {
718 Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
719 data.args.iter().any(|arg| match arg {
720 ast::AngleBracketedArg::Arg(arg) => match arg {
721 ast::GenericArg::Type(ty) => involves_impl_trait(ty),
722 ast::GenericArg::Lifetime(_)
723 | ast::GenericArg::Const(_) => false,
725 ast::AngleBracketedArg::Constraint(c) => match c.kind {
726 ast::AssocTyConstraintKind::Bound { .. } => true,
727 ast::AssocTyConstraintKind::Equality { ref ty } => {
728 involves_impl_trait(ty)
733 Some(&ast::GenericArgs::Parenthesized(ref data)) => {
734 any_involves_impl_trait(data.inputs.iter())
735 || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
743 fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
744 it.any(|subty| involves_impl_trait(subty))
747 involves_impl_trait(ty)
753 fn is_sig_const(sig: &ast::FnSig) -> bool {
754 matches!(sig.header.constness, ast::Const::Yes(_))
755 || ReplaceBodyWithLoop::should_ignore_fn(&sig.decl.output)
759 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
760 fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
761 let is_const = match i {
762 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
763 ast::ItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
766 self.run(is_const, |s| noop_visit_item_kind(i, s))
769 fn flat_map_trait_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
770 let is_const = match i.kind {
771 ast::AssocItemKind::Const(..) => true,
772 ast::AssocItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
775 self.run(is_const, |s| noop_flat_map_assoc_item(i, s))
778 fn flat_map_impl_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
779 self.flat_map_trait_item(i)
782 fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
783 self.run(true, |s| noop_visit_anon_const(c, s))
786 fn visit_block(&mut self, b: &mut P<ast::Block>) {
788 rules: ast::BlockCheckMode,
789 s: Option<ast::Stmt>,
790 resolver: &mut Resolver<'_>,
793 stmts: s.into_iter().collect(),
795 id: resolver.next_node_id(),
796 span: rustc_span::DUMMY_SP,
801 fn block_to_stmt(b: ast::Block, resolver: &mut Resolver<'_>) -> ast::Stmt {
802 let expr = P(ast::Expr {
803 id: resolver.next_node_id(),
804 kind: ast::ExprKind::Block(P(b), None),
805 span: rustc_span::DUMMY_SP,
806 attrs: AttrVec::new(),
811 id: resolver.next_node_id(),
812 kind: ast::StmtKind::Expr(expr),
813 span: rustc_span::DUMMY_SP,
818 let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.resolver);
819 let loop_expr = P(ast::Expr {
820 kind: ast::ExprKind::Loop(P(empty_block), None),
821 id: self.resolver.next_node_id(),
822 span: rustc_span::DUMMY_SP,
823 attrs: AttrVec::new(),
827 let loop_stmt = ast::Stmt {
828 id: self.resolver.next_node_id(),
829 span: rustc_span::DUMMY_SP,
830 kind: ast::StmtKind::Expr(loop_expr),
834 if self.within_static_or_const {
835 noop_visit_block(b, self)
837 visit_clobber(b.deref_mut(), |b| {
838 let mut stmts = vec![];
840 let old_blocks = self.nested_blocks.replace(vec![]);
842 stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
844 // we put a Some in there earlier with that replace(), so this is valid
845 let new_blocks = self.nested_blocks.take().unwrap();
846 self.nested_blocks = old_blocks;
847 stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, self.resolver)));
850 let mut new_block = ast::Block { stmts, ..b };
852 if let Some(old_blocks) = self.nested_blocks.as_mut() {
853 //push our fresh block onto the cache and yield an empty block with `loop {}`
854 if !new_block.stmts.is_empty() {
855 old_blocks.push(new_block);
858 stmt_to_block(b.rules, Some(loop_stmt), &mut self.resolver)
860 //push `loop {}` onto the end of our fresh block and yield that
861 new_block.stmts.push(loop_stmt);
870 /// Returns a version string such as "rustc 1.46.0 (04488afe3 2020-08-24)"
871 pub fn version_str() -> Option<&'static str> {
872 option_env!("CFG_VERSION")
875 /// Returns a version string such as "0.12.0-dev".
876 pub fn release_str() -> Option<&'static str> {
877 option_env!("CFG_RELEASE")
880 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
881 pub fn commit_hash_str() -> Option<&'static str> {
882 option_env!("CFG_VER_HASH")
885 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
886 pub fn commit_date_str() -> Option<&'static str> {
887 option_env!("CFG_VER_DATE")