2 use rustc::session::config::{Input, OutputFilenames, ErrorOutputType};
3 use rustc::session::{self, config, early_error, filesearch, Session, DiagnosticOutput};
4 use rustc::session::CrateDisambiguator;
7 use rustc_codegen_utils::codegen_backend::CodegenBackend;
8 #[cfg(parallel_compiler)]
9 use rustc_data_structures::jobserver;
10 use rustc_data_structures::sync::{Lock, Lrc};
11 use rustc_data_structures::stable_hasher::StableHasher;
12 use rustc_data_structures::fingerprint::Fingerprint;
13 use rustc_data_structures::thin_vec::ThinVec;
14 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
15 use rustc_errors::registry::Registry;
17 use rustc_metadata::dynamic_lib::DynamicLibrary;
24 use std::collections::HashSet;
26 use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
27 use std::io::{self, Write};
29 use std::path::{Path, PathBuf};
30 use std::sync::atomic::{AtomicBool, Ordering};
31 use std::sync::{Arc, Mutex, Once};
32 use std::ops::DerefMut;
33 use smallvec::SmallVec;
35 use syntax::mut_visit::{*, MutVisitor, visit_clobber};
36 use syntax::ast::BlockCheckMode;
37 use syntax::util::lev_distance::find_best_match_for_name;
38 use syntax::source_map::{FileLoader, RealFileLoader, SourceMap};
39 use syntax::symbol::Symbol;
40 use syntax::{self, ast, attr};
41 #[cfg(not(parallel_compiler))]
42 use std::{thread, panic};
44 pub fn diagnostics_registry() -> Registry {
45 let mut all_errors = Vec::new();
46 all_errors.extend_from_slice(&rustc::DIAGNOSTICS);
47 all_errors.extend_from_slice(&rustc_typeck::DIAGNOSTICS);
48 all_errors.extend_from_slice(&rustc_resolve::DIAGNOSTICS);
49 all_errors.extend_from_slice(&rustc_privacy::DIAGNOSTICS);
50 // FIXME: need to figure out a way to get these back in here
51 // all_errors.extend_from_slice(get_codegen_backend(sess).diagnostics());
52 all_errors.extend_from_slice(&rustc_metadata::DIAGNOSTICS);
53 all_errors.extend_from_slice(&rustc_passes::DIAGNOSTICS);
54 all_errors.extend_from_slice(&rustc_plugin::DIAGNOSTICS);
55 all_errors.extend_from_slice(&rustc_mir::DIAGNOSTICS);
56 all_errors.extend_from_slice(&syntax::DIAGNOSTICS);
58 Registry::new(&all_errors)
61 /// Adds `target_feature = "..."` cfgs for a variety of platform
62 /// specific features (SSE, NEON etc.).
64 /// This is performed by checking whether a whitelisted set of
65 /// features is available on the target machine, by querying LLVM.
66 pub fn add_configuration(
67 cfg: &mut ast::CrateConfig,
69 codegen_backend: &dyn CodegenBackend,
71 let tf = Symbol::intern("target_feature");
75 .target_features(sess)
77 .map(|feat| (tf, Some(feat))),
80 if sess.crt_static_feature() {
81 cfg.insert((tf, Some(Symbol::intern("crt-static"))));
85 pub fn create_session(
86 sopts: config::Options,
87 cfg: FxHashSet<(String, Option<String>)>,
88 diagnostic_output: DiagnosticOutput,
89 file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
90 input_path: Option<PathBuf>,
91 lint_caps: FxHashMap<lint::LintId, lint::Level>,
92 ) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>, Lrc<SourceMap>) {
93 let descriptions = diagnostics_registry();
95 let loader = file_loader.unwrap_or(box RealFileLoader);
96 let source_map = Lrc::new(SourceMap::with_file_loader(
98 sopts.file_path_mapping(),
100 let mut sess = session::build_session_with_source_map(
109 let codegen_backend = get_codegen_backend(&sess);
111 rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
113 let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
114 add_configuration(&mut cfg, &sess, &*codegen_backend);
115 sess.parse_sess.config = cfg;
117 (Lrc::new(sess), Lrc::new(codegen_backend), source_map)
120 // Temporarily have stack size set to 32MB to deal with various crates with long method
121 // chains or deep syntax trees.
122 // FIXME(oli-obk): get https://github.com/rust-lang/rust/pull/55617 the finish line
123 const STACK_SIZE: usize = 32 * 1024 * 1024; // 32MB
125 fn get_stack_size() -> Option<usize> {
126 // FIXME: Hacks on hacks. If the env is trying to override the stack size
127 // then *don't* set it explicitly.
128 if env::var_os("RUST_MIN_STACK").is_none() {
135 struct Sink(Arc<Mutex<Vec<u8>>>);
136 impl Write for Sink {
137 fn write(&mut self, data: &[u8]) -> io::Result<usize> {
138 Write::write(&mut *self.0.lock().unwrap(), data)
140 fn flush(&mut self) -> io::Result<()> { Ok(()) }
143 #[cfg(not(parallel_compiler))]
144 pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
146 unsafe impl Send for Ptr {}
147 unsafe impl Sync for Ptr {}
150 let run = Ptr(&mut f as *mut _ as *mut ());
151 let mut result = None;
152 let result_ptr = Ptr(&mut result as *mut _ as *mut ());
154 let thread = cfg.spawn(move || {
155 let run = unsafe { (*(run.0 as *mut Option<F>)).take().unwrap() };
156 let result = unsafe { &mut *(result_ptr.0 as *mut Option<R>) };
157 *result = Some(run());
160 match thread.unwrap().join() {
161 Ok(()) => result.unwrap(),
162 Err(p) => panic::resume_unwind(p),
166 #[cfg(not(parallel_compiler))]
167 pub fn spawn_thread_pool<F: FnOnce() -> R + Send, R: Send>(
168 _threads: Option<usize>,
169 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
172 let mut cfg = thread::Builder::new().name("rustc".to_string());
174 if let Some(size) = get_stack_size() {
175 cfg = cfg.stack_size(size);
178 scoped_thread(cfg, || {
179 syntax::with_globals( || {
180 ty::tls::GCX_PTR.set(&Lock::new(0), || {
181 if let Some(stderr) = stderr {
182 io::set_panic(Some(box Sink(stderr.clone())));
184 ty::tls::with_thread_locals(|| f())
190 #[cfg(parallel_compiler)]
191 pub fn spawn_thread_pool<F: FnOnce() -> R + Send, R: Send>(
192 threads: Option<usize>,
193 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
196 use rayon::{ThreadPool, ThreadPoolBuilder};
200 let gcx_ptr = &Lock::new(0);
202 let mut config = ThreadPoolBuilder::new()
203 .acquire_thread_handler(jobserver::acquire_thread)
204 .release_thread_handler(jobserver::release_thread)
205 .num_threads(Session::threads_from_count(threads))
206 .deadlock_handler(|| unsafe { ty::query::handle_deadlock() });
208 if let Some(size) = get_stack_size() {
209 config = config.stack_size(size);
212 let with_pool = move |pool: &ThreadPool| pool.install(move || f());
214 syntax::with_globals(|| {
215 syntax::GLOBALS.with(|syntax_globals| {
216 syntax_pos::GLOBALS.with(|syntax_pos_globals| {
217 // The main handler runs for each Rayon worker thread and sets up
218 // the thread local rustc uses. syntax_globals and syntax_pos_globals are
219 // captured and set on the new threads. ty::tls::with_thread_locals sets up
220 // thread local callbacks from libsyntax
221 let main_handler = move |worker: &mut dyn FnMut()| {
222 syntax::GLOBALS.set(syntax_globals, || {
223 syntax_pos::GLOBALS.set(syntax_pos_globals, || {
224 if let Some(stderr) = stderr {
225 io::set_panic(Some(box Sink(stderr.clone())));
227 ty::tls::with_thread_locals(|| {
228 ty::tls::GCX_PTR.set(gcx_ptr, || worker())
234 ThreadPool::scoped_pool(config, main_handler, with_pool).unwrap()
240 fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
241 let lib = DynamicLibrary::open(Some(path)).unwrap_or_else(|err| {
242 let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
243 early_error(ErrorOutputType::default(), &err);
246 match lib.symbol("__rustc_codegen_backend") {
249 mem::transmute::<*mut u8, _>(f)
252 let err = format!("couldn't load codegen backend as it \
253 doesn't export the `__rustc_codegen_backend` \
255 early_error(ErrorOutputType::default(), &err);
261 pub fn get_codegen_backend(sess: &Session) -> Box<dyn CodegenBackend> {
262 static INIT: Once = Once::new();
264 static mut LOAD: fn() -> Box<dyn CodegenBackend> = || unreachable!();
267 let codegen_name = sess.opts.debugging_opts.codegen_backend.as_ref()
268 .unwrap_or(&sess.target.target.options.codegen_backend);
269 let backend = match &codegen_name[..] {
270 filename if filename.contains(".") => {
271 load_backend_from_dylib(filename.as_ref())
273 codegen_name => get_codegen_sysroot(codegen_name),
280 let backend = unsafe { LOAD() };
285 pub fn get_codegen_sysroot(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
286 // For now we only allow this function to be called once as it'll dlopen a
287 // few things, which seems to work best if we only do that once. In
288 // general this assertion never trips due to the once guard in `get_codegen_backend`,
289 // but there's a few manual calls to this function in this file we protect
291 static LOADED: AtomicBool = AtomicBool::new(false);
292 assert!(!LOADED.fetch_or(true, Ordering::SeqCst),
293 "cannot load the default codegen backend twice");
295 let target = session::config::host_triple();
296 let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
297 let path = current_dll_path()
298 .and_then(|s| s.canonicalize().ok());
299 if let Some(dll) = path {
300 // use `parent` twice to chop off the file name and then also the
301 // directory containing the dll which should be either `lib` or `bin`.
302 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
303 // The original `path` pointed at the `rustc_driver` crate's dll.
304 // Now that dll should only be in one of two locations. The first is
305 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
306 // other is the target's libdir, for example
307 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
309 // We don't know which, so let's assume that if our `path` above
310 // ends in `$target` we *could* be in the target libdir, and always
311 // assume that we may be in the main libdir.
312 sysroot_candidates.push(path.to_owned());
314 if path.ends_with(target) {
315 sysroot_candidates.extend(path.parent() // chop off `$target`
316 .and_then(|p| p.parent()) // chop off `rustlib`
317 .and_then(|p| p.parent()) // chop off `lib`
318 .map(|s| s.to_owned()));
323 let sysroot = sysroot_candidates.iter()
325 let libdir = filesearch::relative_target_lib_path(&sysroot, &target);
326 sysroot.join(libdir).with_file_name(
327 option_env!("CFG_CODEGEN_BACKENDS_DIR").unwrap_or("codegen-backends"))
330 info!("codegen backend candidate: {}", f.display());
334 let sysroot = sysroot.unwrap_or_else(|| {
335 let candidates = sysroot_candidates.iter()
336 .map(|p| p.display().to_string())
339 let err = format!("failed to find a `codegen-backends` folder \
340 in the sysroot candidates:\n* {}", candidates);
341 early_error(ErrorOutputType::default(), &err);
343 info!("probing {} for a codegen backend", sysroot.display());
345 let d = sysroot.read_dir().unwrap_or_else(|e| {
346 let err = format!("failed to load default codegen backend, couldn't \
347 read `{}`: {}", sysroot.display(), e);
348 early_error(ErrorOutputType::default(), &err);
351 let mut file: Option<PathBuf> = None;
353 let expected_name = format!("rustc_codegen_llvm-{}", backend_name);
354 for entry in d.filter_map(|e| e.ok()) {
355 let path = entry.path();
356 let filename = match path.file_name().and_then(|s| s.to_str()) {
360 if !(filename.starts_with(DLL_PREFIX) && filename.ends_with(DLL_SUFFIX)) {
363 let name = &filename[DLL_PREFIX.len() .. filename.len() - DLL_SUFFIX.len()];
364 if name != expected_name {
367 if let Some(ref prev) = file {
368 let err = format!("duplicate codegen backends found\n\
371 ", prev.display(), path.display());
372 early_error(ErrorOutputType::default(), &err);
374 file = Some(path.clone());
378 Some(ref s) => return load_backend_from_dylib(s),
380 let err = format!("failed to load default codegen backend for `{}`, \
381 no appropriate codegen dylib found in `{}`",
382 backend_name, sysroot.display());
383 early_error(ErrorOutputType::default(), &err);
388 fn current_dll_path() -> Option<PathBuf> {
389 use std::ffi::{OsStr, CStr};
390 use std::os::unix::prelude::*;
393 let addr = current_dll_path as usize as *mut _;
394 let mut info = mem::zeroed();
395 if libc::dladdr(addr, &mut info) == 0 {
396 info!("dladdr failed");
399 if info.dli_fname.is_null() {
400 info!("dladdr returned null pointer");
403 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
404 let os = OsStr::from_bytes(bytes);
405 Some(PathBuf::from(os))
410 fn current_dll_path() -> Option<PathBuf> {
411 use std::ffi::OsString;
412 use std::os::windows::prelude::*;
415 fn GetModuleHandleExW(dwFlags: u32,
417 phModule: *mut usize) -> i32;
418 fn GetModuleFileNameW(hModule: usize,
419 lpFilename: *mut u16,
423 const GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS: u32 = 0x00000004;
427 let r = GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
428 current_dll_path as usize,
431 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
434 let mut space = Vec::with_capacity(1024);
435 let r = GetModuleFileNameW(module,
437 space.capacity() as u32);
439 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
443 if r >= space.capacity() {
444 info!("our buffer was too small? {}",
445 io::Error::last_os_error());
449 let os = OsString::from_wide(&space);
450 Some(PathBuf::from(os))
455 pub(crate) fn compute_crate_disambiguator(session: &Session) -> CrateDisambiguator {
456 use std::hash::Hasher;
458 // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
459 // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
460 // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
461 // should still be safe enough to avoid collisions in practice.
462 let mut hasher = StableHasher::<Fingerprint>::new();
464 let mut metadata = session.opts.cg.metadata.clone();
465 // We don't want the crate_disambiguator to dependent on the order
466 // -C metadata arguments, so sort them:
468 // Every distinct -C metadata value is only incorporated once:
471 hasher.write(b"metadata");
473 // Also incorporate the length of a metadata string, so that we generate
474 // different values for `-Cmetadata=ab -Cmetadata=c` and
475 // `-Cmetadata=a -Cmetadata=bc`
476 hasher.write_usize(s.len());
477 hasher.write(s.as_bytes());
480 // Also incorporate crate type, so that we don't get symbol conflicts when
481 // linking against a library of the same name, if this is an executable.
485 .contains(&config::CrateType::Executable);
486 hasher.write(if is_exe { b"exe" } else { b"lib" });
488 CrateDisambiguator::from(hasher.finish())
491 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<config::CrateType> {
492 // Unconditionally collect crate types from attributes to make them used
493 let attr_types: Vec<config::CrateType> = attrs
496 if a.check_name("crate_type") {
497 match a.value_str() {
498 Some(ref n) if *n == "rlib" => Some(config::CrateType::Rlib),
499 Some(ref n) if *n == "dylib" => Some(config::CrateType::Dylib),
500 Some(ref n) if *n == "cdylib" => Some(config::CrateType::Cdylib),
501 Some(ref n) if *n == "lib" => Some(config::default_lib_output()),
502 Some(ref n) if *n == "staticlib" => Some(config::CrateType::Staticlib),
503 Some(ref n) if *n == "proc-macro" => Some(config::CrateType::ProcMacro),
504 Some(ref n) if *n == "bin" => Some(config::CrateType::Executable),
506 let crate_types = vec![
507 Symbol::intern("rlib"),
508 Symbol::intern("dylib"),
509 Symbol::intern("cdylib"),
510 Symbol::intern("lib"),
511 Symbol::intern("staticlib"),
512 Symbol::intern("proc-macro"),
513 Symbol::intern("bin")
516 if let ast::MetaItemKind::NameValue(spanned) = a.meta().unwrap().node {
517 let span = spanned.span;
518 let lev_candidate = find_best_match_for_name(
523 if let Some(candidate) = lev_candidate {
524 session.buffer_lint_with_diagnostic(
525 lint::builtin::UNKNOWN_CRATE_TYPES,
528 "invalid `crate_type` value",
529 lint::builtin::BuiltinLintDiagnostics::
532 "did you mean".to_string(),
533 format!("\"{}\"", candidate)
538 lint::builtin::UNKNOWN_CRATE_TYPES,
541 "invalid `crate_type` value"
555 // If we're generating a test executable, then ignore all other output
556 // styles at all other locations
557 if session.opts.test {
558 return vec![config::CrateType::Executable];
561 // Only check command line flags if present. If no types are specified by
562 // command line, then reuse the empty `base` Vec to hold the types that
563 // will be found in crate attributes.
564 let mut base = session.opts.crate_types.clone();
566 base.extend(attr_types);
568 base.push(::rustc_codegen_utils::link::default_output_for_target(
577 base.retain(|crate_type| {
578 let res = !::rustc_codegen_utils::link::invalid_output_for_target(session, *crate_type);
581 session.warn(&format!(
582 "dropping unsupported crate type `{}` for target `{}`",
583 *crate_type, session.opts.target_triple
593 pub fn build_output_filenames(
595 odir: &Option<PathBuf>,
596 ofile: &Option<PathBuf>,
597 attrs: &[ast::Attribute],
599 ) -> OutputFilenames {
602 // "-" as input file will cause the parser to read from stdin so we
603 // have to make up a name
604 // We want to toss everything after the final '.'
605 let dirpath = (*odir).as_ref().cloned().unwrap_or_default();
607 // If a crate name is present, we use it as the link name
611 .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
612 .unwrap_or_else(|| input.filestem().to_owned());
615 out_directory: dirpath,
617 single_output_file: None,
618 extra: sess.opts.cg.extra_filename.clone(),
619 outputs: sess.opts.output_types.clone(),
623 Some(ref out_file) => {
624 let unnamed_output_types = sess.opts
627 .filter(|a| a.is_none())
629 let ofile = if unnamed_output_types > 1 {
631 "due to multiple output types requested, the explicitly specified \
632 output file name will be adapted for each output type",
636 Some(out_file.clone())
639 sess.warn("ignoring --out-dir flag due to -o flag");
641 if !sess.opts.cg.extra_filename.is_empty() {
642 sess.warn("ignoring -C extra-filename flag due to -o flag");
646 out_directory: out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
647 out_filestem: out_file
653 single_output_file: ofile,
654 extra: sess.opts.cg.extra_filename.clone(),
655 outputs: sess.opts.output_types.clone(),
661 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
663 // FIXME: Currently the `everybody_loops` transformation is not applied to:
664 // * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
665 // waiting for miri to fix that.
666 // * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
667 // Solving this may require `!` to implement every trait, which relies on the an even more
668 // ambitious form of the closed RFC #1637. See also [#34511].
670 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
671 pub struct ReplaceBodyWithLoop<'a> {
672 within_static_or_const: bool,
673 nested_blocks: Option<Vec<ast::Block>>,
677 impl<'a> ReplaceBodyWithLoop<'a> {
678 pub fn new(sess: &'a Session) -> ReplaceBodyWithLoop<'a> {
679 ReplaceBodyWithLoop {
680 within_static_or_const: false,
686 fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
687 let old_const = mem::replace(&mut self.within_static_or_const, is_const);
688 let old_blocks = self.nested_blocks.take();
689 let ret = action(self);
690 self.within_static_or_const = old_const;
691 self.nested_blocks = old_blocks;
695 fn should_ignore_fn(ret_ty: &ast::FnDecl) -> bool {
696 if let ast::FunctionRetTy::Ty(ref ty) = ret_ty.output {
697 fn involves_impl_trait(ty: &ast::Ty) -> bool {
699 ast::TyKind::ImplTrait(..) => true,
700 ast::TyKind::Slice(ref subty) |
701 ast::TyKind::Array(ref subty, _) |
702 ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. }) |
703 ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. }) |
704 ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
705 ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
706 ast::TyKind::Path(_, ref path) => path.segments.iter().any(|seg| {
707 match seg.args.as_ref().map(|generic_arg| &**generic_arg) {
709 Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
710 let types = data.args.iter().filter_map(|arg| match arg {
711 ast::GenericArg::Type(ty) => Some(ty),
714 any_involves_impl_trait(types.into_iter()) ||
715 any_involves_impl_trait(data.bindings.iter().map(|b| &b.ty))
717 Some(&ast::GenericArgs::Parenthesized(ref data)) => {
718 any_involves_impl_trait(data.inputs.iter()) ||
719 any_involves_impl_trait(data.output.iter())
727 fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
728 it.any(|subty| involves_impl_trait(subty))
731 involves_impl_trait(ty)
738 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a> {
739 fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
740 let is_const = match i {
741 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
742 ast::ItemKind::Fn(ref decl, ref header, _, _) =>
743 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
746 self.run(is_const, |s| noop_visit_item_kind(i, s))
749 fn flat_map_trait_item(&mut self, i: ast::TraitItem) -> SmallVec<[ast::TraitItem; 1]> {
750 let is_const = match i.node {
751 ast::TraitItemKind::Const(..) => true,
752 ast::TraitItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
753 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
756 self.run(is_const, |s| noop_flat_map_trait_item(i, s))
759 fn flat_map_impl_item(&mut self, i: ast::ImplItem) -> SmallVec<[ast::ImplItem; 1]> {
760 let is_const = match i.node {
761 ast::ImplItemKind::Const(..) => true,
762 ast::ImplItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
763 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
766 self.run(is_const, |s| noop_flat_map_impl_item(i, s))
769 fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
770 self.run(true, |s| noop_visit_anon_const(c, s))
773 fn visit_block(&mut self, b: &mut P<ast::Block>) {
774 fn stmt_to_block(rules: ast::BlockCheckMode,
775 s: Option<ast::Stmt>,
776 sess: &Session) -> ast::Block {
778 stmts: s.into_iter().collect(),
780 id: sess.next_node_id(),
781 span: syntax_pos::DUMMY_SP,
785 fn block_to_stmt(b: ast::Block, sess: &Session) -> ast::Stmt {
786 let expr = P(ast::Expr {
787 id: sess.next_node_id(),
788 node: ast::ExprKind::Block(P(b), None),
789 span: syntax_pos::DUMMY_SP,
790 attrs: ThinVec::new(),
794 id: sess.next_node_id(),
795 node: ast::StmtKind::Expr(expr),
796 span: syntax_pos::DUMMY_SP,
800 let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.sess);
801 let loop_expr = P(ast::Expr {
802 node: ast::ExprKind::Loop(P(empty_block), None),
803 id: self.sess.next_node_id(),
804 span: syntax_pos::DUMMY_SP,
805 attrs: ThinVec::new(),
808 let loop_stmt = ast::Stmt {
809 id: self.sess.next_node_id(),
810 span: syntax_pos::DUMMY_SP,
811 node: ast::StmtKind::Expr(loop_expr),
814 if self.within_static_or_const {
815 noop_visit_block(b, self)
817 visit_clobber(b.deref_mut(), |b| {
818 let mut stmts = vec![];
820 let old_blocks = self.nested_blocks.replace(vec![]);
822 stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
824 // we put a Some in there earlier with that replace(), so this is valid
825 let new_blocks = self.nested_blocks.take().unwrap();
826 self.nested_blocks = old_blocks;
827 stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, &self.sess)));
830 let mut new_block = ast::Block {
835 if let Some(old_blocks) = self.nested_blocks.as_mut() {
836 //push our fresh block onto the cache and yield an empty block with `loop {}`
837 if !new_block.stmts.is_empty() {
838 old_blocks.push(new_block);
841 stmt_to_block(b.rules, Some(loop_stmt), self.sess)
843 //push `loop {}` onto the end of our fresh block and yield that
844 new_block.stmts.push(loop_stmt);
852 // in general the pretty printer processes unexpanded code, so
853 // we override the default `visit_mac` method which panics.
854 fn visit_mac(&mut self, mac: &mut ast::Mac) {
855 noop_visit_mac(mac, self)