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::fx::{FxHashMap, FxHashSet};
6 #[cfg(parallel_compiler)]
7 use rustc_data_structures::jobserver;
8 use rustc_data_structures::sync::Lrc;
9 use rustc_errors::registry::Registry;
10 use rustc_metadata::dynamic_lib::DynamicLibrary;
11 #[cfg(parallel_compiler)]
12 use rustc_middle::ty::tls;
13 use rustc_parse::validate_attr;
14 #[cfg(parallel_compiler)]
15 use rustc_query_impl::QueryCtxt;
16 use rustc_resolve::{self, Resolver};
17 use rustc_session as session;
18 use rustc_session::config::{self, CrateType};
19 use rustc_session::config::{ErrorOutputType, Input, OutputFilenames};
20 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
21 use rustc_session::parse::CrateConfig;
22 use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session};
23 use rustc_span::edition::Edition;
24 use rustc_span::lev_distance::find_best_match_for_name;
25 use rustc_span::source_map::FileLoader;
26 use rustc_span::symbol::{sym, Symbol};
27 use smallvec::SmallVec;
29 use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
31 use std::lazy::SyncOnceCell;
33 use std::ops::DerefMut;
34 #[cfg(not(parallel_compiler))]
36 use std::path::{Path, PathBuf};
37 use std::sync::atomic::{AtomicBool, Ordering};
38 use std::sync::{Arc, Mutex};
42 /// Adds `target_feature = "..."` cfgs for a variety of platform
43 /// specific features (SSE, NEON etc.).
45 /// This is performed by checking whether a set of permitted features
46 /// is available on the target machine, by querying LLVM.
47 pub fn add_configuration(
48 cfg: &mut CrateConfig,
50 codegen_backend: &dyn CodegenBackend,
52 let tf = sym::target_feature;
54 let target_features = codegen_backend.target_features(sess);
55 sess.target_features.extend(target_features.iter().cloned());
57 cfg.extend(target_features.into_iter().map(|feat| (tf, Some(feat))));
59 if sess.crt_static(None) {
60 cfg.insert((tf, Some(sym::crt_dash_static)));
64 pub fn create_session(
65 sopts: config::Options,
66 cfg: FxHashSet<(String, Option<String>)>,
67 diagnostic_output: DiagnosticOutput,
68 file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
69 input_path: Option<PathBuf>,
70 lint_caps: FxHashMap<lint::LintId, lint::Level>,
71 make_codegen_backend: Option<
72 Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
74 descriptions: Registry,
75 ) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>) {
76 let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
77 make_codegen_backend(&sopts)
81 sopts.debugging_opts.codegen_backend.as_ref().map(|name| &name[..]),
85 // target_override is documented to be called before init(), so this is okay
86 let target_override = codegen_backend.target_override(&sopts);
88 let mut sess = session::build_session(
98 codegen_backend.init(&sess);
100 let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
101 add_configuration(&mut cfg, &mut sess, &*codegen_backend);
102 sess.parse_sess.config = cfg;
104 (Lrc::new(sess), Lrc::new(codegen_backend))
107 const STACK_SIZE: usize = 8 * 1024 * 1024;
109 fn get_stack_size() -> Option<usize> {
110 // FIXME: Hacks on hacks. If the env is trying to override the stack size
111 // then *don't* set it explicitly.
112 env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE)
115 /// Like a `thread::Builder::spawn` followed by a `join()`, but avoids the need
116 /// for `'static` bounds.
117 #[cfg(not(parallel_compiler))]
118 pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
119 // SAFETY: join() is called immediately, so any closure captures are still
121 match unsafe { cfg.spawn_unchecked(f) }.unwrap().join() {
123 Err(e) => panic::resume_unwind(e),
127 #[cfg(not(parallel_compiler))]
128 pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
131 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
134 let mut cfg = thread::Builder::new().name("rustc".to_string());
136 if let Some(size) = get_stack_size() {
137 cfg = cfg.stack_size(size);
140 crate::callbacks::setup_callbacks();
142 let main_handler = move || {
143 rustc_span::create_session_globals_then(edition, || {
144 io::set_output_capture(stderr.clone());
149 scoped_thread(cfg, main_handler)
152 /// Creates a new thread and forwards information in thread locals to it.
153 /// The new thread runs the deadlock handler.
154 /// Must only be called when a deadlock is about to happen.
155 #[cfg(parallel_compiler)]
156 unsafe fn handle_deadlock() {
157 let registry = rustc_rayon_core::Registry::current();
159 let context = tls::get_tlv();
160 assert!(context != 0);
161 rustc_data_structures::sync::assert_sync::<tls::ImplicitCtxt<'_, '_>>();
162 let icx: &tls::ImplicitCtxt<'_, '_> = &*(context as *const tls::ImplicitCtxt<'_, '_>);
164 let session_globals = rustc_span::with_session_globals(|sg| sg as *const _);
165 let session_globals = &*session_globals;
166 thread::spawn(move || {
167 tls::enter_context(icx, |_| {
168 rustc_span::set_session_globals_then(session_globals, || {
169 tls::with(|tcx| QueryCtxt::from_tcx(tcx).deadlock(®istry))
175 #[cfg(parallel_compiler)]
176 pub fn setup_callbacks_and_run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
179 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
182 crate::callbacks::setup_callbacks();
184 let mut config = rayon::ThreadPoolBuilder::new()
185 .thread_name(|_| "rustc".to_string())
186 .acquire_thread_handler(jobserver::acquire_thread)
187 .release_thread_handler(jobserver::release_thread)
188 .num_threads(threads)
189 .deadlock_handler(|| unsafe { handle_deadlock() });
191 if let Some(size) = get_stack_size() {
192 config = config.stack_size(size);
195 let with_pool = move |pool: &rayon::ThreadPool| pool.install(f);
197 rustc_span::create_session_globals_then(edition, || {
198 rustc_span::with_session_globals(|session_globals| {
199 // The main handler runs for each Rayon worker thread and sets up
200 // the thread local rustc uses. `session_globals` is captured and set
201 // on the new threads.
202 let main_handler = move |thread: rayon::ThreadBuilder| {
203 rustc_span::set_session_globals_then(session_globals, || {
204 io::set_output_capture(stderr.clone());
209 config.build_scoped(main_handler, with_pool).unwrap()
214 fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
215 let lib = DynamicLibrary::open(path).unwrap_or_else(|err| {
216 let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
217 early_error(ErrorOutputType::default(), &err);
220 match lib.symbol("__rustc_codegen_backend") {
223 mem::transmute::<*mut u8, _>(f)
227 "couldn't load codegen backend as it \
228 doesn't export the `__rustc_codegen_backend` \
232 early_error(ErrorOutputType::default(), &err);
238 /// Get the codegen backend based on the name and specified sysroot.
240 /// A name of `None` indicates that the default backend should be used.
241 pub fn get_codegen_backend(
242 maybe_sysroot: &Option<PathBuf>,
243 backend_name: Option<&str>,
244 ) -> Box<dyn CodegenBackend> {
245 static LOAD: SyncOnceCell<unsafe fn() -> Box<dyn CodegenBackend>> = SyncOnceCell::new();
247 let load = LOAD.get_or_init(|| {
248 #[cfg(feature = "llvm")]
249 const DEFAULT_CODEGEN_BACKEND: &str = "llvm";
251 #[cfg(not(feature = "llvm"))]
252 const DEFAULT_CODEGEN_BACKEND: &str = "cranelift";
254 match backend_name.unwrap_or(DEFAULT_CODEGEN_BACKEND) {
255 filename if filename.contains('.') => load_backend_from_dylib(filename.as_ref()),
256 #[cfg(feature = "llvm")]
257 "llvm" => rustc_codegen_llvm::LlvmCodegenBackend::new,
258 backend_name => get_codegen_sysroot(maybe_sysroot, backend_name),
262 // SAFETY: In case of a builtin codegen backend this is safe. In case of an external codegen
263 // backend we hope that the backend links against the same rustc_driver version. If this is not
264 // the case, we get UB.
268 // This is used for rustdoc, but it uses similar machinery to codegen backend
269 // loading, so we leave the code here. It is potentially useful for other tools
270 // that want to invoke the rustc binary while linking to rustc as well.
271 pub fn rustc_path<'a>() -> Option<&'a Path> {
272 static RUSTC_PATH: SyncOnceCell<Option<PathBuf>> = SyncOnceCell::new();
274 const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
276 RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_ref().map(|v| &**v)
279 fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
280 sysroot_candidates().iter().find_map(|sysroot| {
281 let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
286 candidate.exists().then_some(candidate)
290 fn sysroot_candidates() -> Vec<PathBuf> {
291 let target = session::config::host_triple();
292 let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
293 let path = current_dll_path().and_then(|s| s.canonicalize().ok());
294 if let Some(dll) = path {
295 // use `parent` twice to chop off the file name and then also the
296 // directory containing the dll which should be either `lib` or `bin`.
297 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
298 // The original `path` pointed at the `rustc_driver` crate's dll.
299 // Now that dll should only be in one of two locations. The first is
300 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
301 // other is the target's libdir, for example
302 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
304 // We don't know which, so let's assume that if our `path` above
305 // ends in `$target` we *could* be in the target libdir, and always
306 // assume that we may be in the main libdir.
307 sysroot_candidates.push(path.to_owned());
309 if path.ends_with(target) {
310 sysroot_candidates.extend(
311 path.parent() // chop off `$target`
312 .and_then(|p| p.parent()) // chop off `rustlib`
313 .and_then(|p| p.parent()) // chop off `lib`
314 .map(|s| s.to_owned()),
320 return sysroot_candidates;
323 fn current_dll_path() -> Option<PathBuf> {
324 use std::ffi::{CStr, OsStr};
325 use std::os::unix::prelude::*;
328 let addr = current_dll_path as usize as *mut _;
329 let mut info = mem::zeroed();
330 if libc::dladdr(addr, &mut info) == 0 {
331 info!("dladdr failed");
334 if info.dli_fname.is_null() {
335 info!("dladdr returned null pointer");
338 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
339 let os = OsStr::from_bytes(bytes);
340 Some(PathBuf::from(os))
345 fn current_dll_path() -> Option<PathBuf> {
346 use std::ffi::OsString;
347 use std::os::windows::prelude::*;
350 use winapi::um::libloaderapi::{
351 GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
355 let mut module = ptr::null_mut();
356 let r = GetModuleHandleExW(
357 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
358 current_dll_path as usize as *mut _,
362 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
365 let mut space = Vec::with_capacity(1024);
366 let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
368 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
372 if r >= space.capacity() {
373 info!("our buffer was too small? {}", io::Error::last_os_error());
377 let os = OsString::from_wide(&space);
378 Some(PathBuf::from(os))
383 pub fn get_codegen_sysroot(
384 maybe_sysroot: &Option<PathBuf>,
386 ) -> fn() -> Box<dyn CodegenBackend> {
387 // For now we only allow this function to be called once as it'll dlopen a
388 // few things, which seems to work best if we only do that once. In
389 // general this assertion never trips due to the once guard in `get_codegen_backend`,
390 // but there's a few manual calls to this function in this file we protect
392 static LOADED: AtomicBool = AtomicBool::new(false);
394 !LOADED.fetch_or(true, Ordering::SeqCst),
395 "cannot load the default codegen backend twice"
398 let target = session::config::host_triple();
399 let sysroot_candidates = sysroot_candidates();
401 let sysroot = maybe_sysroot
403 .chain(sysroot_candidates.iter())
405 filesearch::make_target_lib_path(sysroot, target).with_file_name("codegen-backends")
408 info!("codegen backend candidate: {}", f.display());
411 let sysroot = sysroot.unwrap_or_else(|| {
412 let candidates = sysroot_candidates
414 .map(|p| p.display().to_string())
418 "failed to find a `codegen-backends` folder \
419 in the sysroot candidates:\n* {}",
422 early_error(ErrorOutputType::default(), &err);
424 info!("probing {} for a codegen backend", sysroot.display());
426 let d = sysroot.read_dir().unwrap_or_else(|e| {
428 "failed to load default codegen backend, couldn't \
433 early_error(ErrorOutputType::default(), &err);
436 let mut file: Option<PathBuf> = None;
438 let expected_names = &[
439 format!("rustc_codegen_{}-{}", backend_name, release_str().expect("CFG_RELEASE")),
440 format!("rustc_codegen_{}", backend_name),
442 for entry in d.filter_map(|e| e.ok()) {
443 let path = entry.path();
444 let filename = match path.file_name().and_then(|s| s.to_str()) {
448 if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) {
451 let name = &filename[DLL_PREFIX.len()..filename.len() - DLL_SUFFIX.len()];
452 if !expected_names.iter().any(|expected| expected == name) {
455 if let Some(ref prev) = file {
457 "duplicate codegen backends found\n\
464 early_error(ErrorOutputType::default(), &err);
466 file = Some(path.clone());
470 Some(ref s) => load_backend_from_dylib(s),
472 let err = format!("unsupported builtin codegen backend `{}`", backend_name);
473 early_error(ErrorOutputType::default(), &err);
478 pub(crate) fn check_attr_crate_type(
480 attrs: &[ast::Attribute],
481 lint_buffer: &mut LintBuffer,
483 // Unconditionally collect crate types from attributes to make them used
484 for a in attrs.iter() {
485 if a.has_name(sym::crate_type) {
486 if let Some(n) = a.value_str() {
487 if categorize_crate_type(n).is_some() {
491 if let ast::MetaItemKind::NameValue(spanned) = a.meta().unwrap().kind {
492 let span = spanned.span;
493 let lev_candidate = find_best_match_for_name(
494 &CRATE_TYPES.iter().map(|(k, _)| *k).collect::<Vec<_>>(),
498 if let Some(candidate) = lev_candidate {
499 lint_buffer.buffer_lint_with_diagnostic(
500 lint::builtin::UNKNOWN_CRATE_TYPES,
503 "invalid `crate_type` value",
504 BuiltinLintDiagnostics::UnknownCrateTypes(
506 "did you mean".to_string(),
507 format!("\"{}\"", candidate),
511 lint_buffer.buffer_lint(
512 lint::builtin::UNKNOWN_CRATE_TYPES,
515 "invalid `crate_type` value",
520 // This is here mainly to check for using a macro, such as
521 // #![crate_type = foo!()]. That is not supported since the
522 // crate type needs to be known very early in compilation long
523 // before expansion. Otherwise, validation would normally be
524 // caught in AstValidator (via `check_builtin_attribute`), but
525 // by the time that runs the macro is expanded, and it doesn't
527 validate_attr::emit_fatal_malformed_builtin_attribute(
537 const CRATE_TYPES: &[(Symbol, CrateType)] = &[
538 (sym::rlib, CrateType::Rlib),
539 (sym::dylib, CrateType::Dylib),
540 (sym::cdylib, CrateType::Cdylib),
541 (sym::lib, config::default_lib_output()),
542 (sym::staticlib, CrateType::Staticlib),
543 (sym::proc_dash_macro, CrateType::ProcMacro),
544 (sym::bin, CrateType::Executable),
547 fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
548 Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
551 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
552 // Unconditionally collect crate types from attributes to make them used
553 let attr_types: Vec<CrateType> = attrs
556 if a.has_name(sym::crate_type) {
557 match a.value_str() {
558 Some(s) => categorize_crate_type(s),
567 // If we're generating a test executable, then ignore all other output
568 // styles at all other locations
569 if session.opts.test {
570 return vec![CrateType::Executable];
573 // Only check command line flags if present. If no types are specified by
574 // command line, then reuse the empty `base` Vec to hold the types that
575 // will be found in crate attributes.
576 let mut base = session.opts.crate_types.clone();
578 base.extend(attr_types);
580 base.push(output::default_output_for_target(session));
587 base.retain(|crate_type| {
588 let res = !output::invalid_output_for_target(session, *crate_type);
591 session.warn(&format!(
592 "dropping unsupported crate type `{}` for target `{}`",
593 *crate_type, session.opts.target_triple
603 pub fn build_output_filenames(
605 odir: &Option<PathBuf>,
606 ofile: &Option<PathBuf>,
607 temps_dir: &Option<PathBuf>,
608 attrs: &[ast::Attribute],
610 ) -> OutputFilenames {
613 // "-" as input file will cause the parser to read from stdin so we
614 // have to make up a name
615 // We want to toss everything after the final '.'
616 let dirpath = (*odir).as_ref().cloned().unwrap_or_default();
618 // If a crate name is present, we use it as the link name
623 .or_else(|| rustc_attr::find_crate_name(sess, attrs).map(|n| n.to_string()))
624 .unwrap_or_else(|| input.filestem().to_owned());
626 OutputFilenames::new(
631 sess.opts.cg.extra_filename.clone(),
632 sess.opts.output_types.clone(),
636 Some(ref out_file) => {
637 let unnamed_output_types =
638 sess.opts.output_types.values().filter(|a| a.is_none()).count();
639 let ofile = if unnamed_output_types > 1 {
641 "due to multiple output types requested, the explicitly specified \
642 output file name will be adapted for each output type",
646 if !sess.opts.cg.extra_filename.is_empty() {
647 sess.warn("ignoring -C extra-filename flag due to -o flag");
649 Some(out_file.clone())
652 sess.warn("ignoring --out-dir flag due to -o flag");
655 OutputFilenames::new(
656 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
657 out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(),
660 sess.opts.cg.extra_filename.clone(),
661 sess.opts.output_types.clone(),
667 #[cfg(not(target_os = "linux"))]
668 pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> {
669 std::fs::rename(src, dst)
672 /// This function attempts to bypass the auto_da_alloc heuristic implemented by some filesystems
673 /// such as btrfs and ext4. When renaming over a file that already exists then they will "helpfully"
674 /// write back the source file before committing the rename in case a developer forgot some of
675 /// the fsyncs in the open/write/fsync(file)/rename/fsync(dir) dance for atomic file updates.
677 /// To avoid triggering this heuristic we delete the destination first, if it exists.
678 /// The cost of an extra syscall is much lower than getting descheduled for the sync IO.
679 #[cfg(target_os = "linux")]
680 pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> {
681 let _ = std::fs::remove_file(dst);
682 std::fs::rename(src, dst)
685 /// Replaces function bodies with `loop {}` (an infinite loop). This gets rid of
686 /// all semantic errors in the body while still satisfying the return type,
687 /// except in certain cases, see below for more.
689 /// This pass is known as `everybody_loops`. Very punny.
691 /// As of March 2021, `everybody_loops` is only used for the
692 /// `-Z unpretty=everybody_loops` debugging option.
694 /// FIXME: Currently the `everybody_loops` transformation is not applied to:
695 /// * `const fn`; support could be added, but hasn't. Originally `const fn`
696 /// was skipped due to issue #43636 that `loop` was not supported for
697 /// const evaluation.
698 /// * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
699 /// Solving this may require `!` to implement every trait, which relies on the an even more
700 /// ambitious form of the closed RFC #1637. See also [#34511].
702 /// [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
703 pub struct ReplaceBodyWithLoop<'a, 'b> {
704 within_static_or_const: bool,
705 nested_blocks: Option<Vec<ast::Block>>,
706 resolver: &'a mut Resolver<'b>,
709 impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
710 pub fn new(resolver: &'a mut Resolver<'b>) -> ReplaceBodyWithLoop<'a, 'b> {
711 ReplaceBodyWithLoop { within_static_or_const: false, nested_blocks: None, resolver }
714 fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
715 let old_const = mem::replace(&mut self.within_static_or_const, is_const);
716 let old_blocks = self.nested_blocks.take();
717 let ret = action(self);
718 self.within_static_or_const = old_const;
719 self.nested_blocks = old_blocks;
723 fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
724 if let ast::FnRetTy::Ty(ref ty) = ret_ty {
725 fn involves_impl_trait(ty: &ast::Ty) -> bool {
727 ast::TyKind::ImplTrait(..) => true,
728 ast::TyKind::Slice(ref subty)
729 | ast::TyKind::Array(ref subty, _)
730 | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
731 | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
732 | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
733 ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
734 ast::TyKind::Path(_, ref path) => {
735 path.segments.iter().any(|seg| match seg.args.as_deref() {
737 Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
738 data.args.iter().any(|arg| match arg {
739 ast::AngleBracketedArg::Arg(arg) => match arg {
740 ast::GenericArg::Type(ty) => involves_impl_trait(ty),
741 ast::GenericArg::Lifetime(_)
742 | ast::GenericArg::Const(_) => false,
744 ast::AngleBracketedArg::Constraint(c) => match c.kind {
745 ast::AssocTyConstraintKind::Bound { .. } => true,
746 ast::AssocTyConstraintKind::Equality { ref ty } => {
747 involves_impl_trait(ty)
752 Some(&ast::GenericArgs::Parenthesized(ref data)) => {
753 any_involves_impl_trait(data.inputs.iter())
754 || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
762 fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
763 it.any(|subty| involves_impl_trait(subty))
766 involves_impl_trait(ty)
772 fn is_sig_const(sig: &ast::FnSig) -> bool {
773 matches!(sig.header.constness, ast::Const::Yes(_))
774 || ReplaceBodyWithLoop::should_ignore_fn(&sig.decl.output)
778 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
779 fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
780 let is_const = match i {
781 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
782 ast::ItemKind::Fn(box ast::Fn { ref sig, .. }) => Self::is_sig_const(sig),
785 self.run(is_const, |s| noop_visit_item_kind(i, s))
788 fn flat_map_trait_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
789 let is_const = match i.kind {
790 ast::AssocItemKind::Const(..) => true,
791 ast::AssocItemKind::Fn(box ast::Fn { ref sig, .. }) => Self::is_sig_const(sig),
794 self.run(is_const, |s| noop_flat_map_assoc_item(i, s))
797 fn flat_map_impl_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
798 self.flat_map_trait_item(i)
801 fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
802 self.run(true, |s| noop_visit_anon_const(c, s))
805 fn visit_block(&mut self, b: &mut P<ast::Block>) {
807 rules: ast::BlockCheckMode,
808 s: Option<ast::Stmt>,
809 resolver: &mut Resolver<'_>,
812 stmts: s.into_iter().collect(),
814 id: resolver.next_node_id(),
815 span: rustc_span::DUMMY_SP,
817 could_be_bare_literal: false,
821 fn block_to_stmt(b: ast::Block, resolver: &mut Resolver<'_>) -> ast::Stmt {
822 let expr = P(ast::Expr {
823 id: resolver.next_node_id(),
824 kind: ast::ExprKind::Block(P(b), None),
825 span: rustc_span::DUMMY_SP,
826 attrs: AttrVec::new(),
831 id: resolver.next_node_id(),
832 kind: ast::StmtKind::Expr(expr),
833 span: rustc_span::DUMMY_SP,
837 let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.resolver);
838 let loop_expr = P(ast::Expr {
839 kind: ast::ExprKind::Loop(P(empty_block), None),
840 id: self.resolver.next_node_id(),
841 span: rustc_span::DUMMY_SP,
842 attrs: AttrVec::new(),
846 let loop_stmt = ast::Stmt {
847 id: self.resolver.next_node_id(),
848 span: rustc_span::DUMMY_SP,
849 kind: ast::StmtKind::Expr(loop_expr),
852 if self.within_static_or_const {
853 noop_visit_block(b, self)
855 visit_clobber(b.deref_mut(), |b| {
856 let mut stmts = vec![];
858 let old_blocks = self.nested_blocks.replace(vec![]);
860 stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
862 // we put a Some in there earlier with that replace(), so this is valid
863 let new_blocks = self.nested_blocks.take().unwrap();
864 self.nested_blocks = old_blocks;
865 stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, self.resolver)));
868 let mut new_block = ast::Block { stmts, ..b };
870 if let Some(old_blocks) = self.nested_blocks.as_mut() {
871 //push our fresh block onto the cache and yield an empty block with `loop {}`
872 if !new_block.stmts.is_empty() {
873 old_blocks.push(new_block);
876 stmt_to_block(b.rules, Some(loop_stmt), &mut self.resolver)
878 //push `loop {}` onto the end of our fresh block and yield that
879 new_block.stmts.push(loop_stmt);
888 /// Returns a version string such as "1.46.0 (04488afe3 2020-08-24)"
889 pub fn version_str() -> Option<&'static str> {
890 option_env!("CFG_VERSION")
893 /// Returns a version string such as "0.12.0-dev".
894 pub fn release_str() -> Option<&'static str> {
895 option_env!("CFG_RELEASE")
898 /// Returns the full SHA1 hash of HEAD of the Git repo from which rustc was built.
899 pub fn commit_hash_str() -> Option<&'static str> {
900 option_env!("CFG_VER_HASH")
903 /// Returns the "commit date" of HEAD of the Git repo from which rustc was built as a static string.
904 pub fn commit_date_str() -> Option<&'static str> {
905 option_env!("CFG_VER_DATE")