2 use rustc_ast::ast::{AttrVec, BlockCheckMode};
3 use rustc_ast::mut_visit::{visit_clobber, MutVisitor, *};
5 use rustc_ast::util::lev_distance::find_best_match_for_name;
6 use rustc_ast::{self, ast};
7 use rustc_codegen_ssa::traits::CodegenBackend;
8 use rustc_data_structures::fingerprint::Fingerprint;
9 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
10 #[cfg(parallel_compiler)]
11 use rustc_data_structures::jobserver;
12 use rustc_data_structures::stable_hasher::StableHasher;
13 use rustc_data_structures::sync::{Lock, Lrc};
14 use rustc_errors::registry::Registry;
15 use rustc_metadata::dynamic_lib::DynamicLibrary;
17 use rustc_resolve::{self, Resolver};
18 use rustc_session as session;
19 use rustc_session::config::{self, CrateType};
20 use rustc_session::config::{ErrorOutputType, Input, OutputFilenames};
21 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
22 use rustc_session::parse::CrateConfig;
23 use rustc_session::CrateDisambiguator;
24 use rustc_session::{early_error, filesearch, output, DiagnosticOutput, Session};
25 use rustc_span::edition::Edition;
26 use rustc_span::source_map::{FileLoader, SourceMap};
27 use rustc_span::symbol::{sym, Symbol};
28 use smallvec::SmallVec;
30 use std::io::{self, Write};
32 use std::ops::DerefMut;
33 use std::path::{Path, PathBuf};
34 use std::sync::{Arc, Mutex, Once};
35 #[cfg(not(parallel_compiler))]
36 use std::{panic, thread};
38 /// Adds `target_feature = "..."` cfgs for a variety of platform
39 /// specific features (SSE, NEON etc.).
41 /// This is performed by checking whether a whitelisted set of
42 /// features is available on the target machine, by querying LLVM.
43 pub fn add_configuration(
44 cfg: &mut CrateConfig,
46 codegen_backend: &dyn CodegenBackend,
48 let tf = sym::target_feature;
50 let target_features = codegen_backend.target_features(sess);
51 sess.target_features.extend(target_features.iter().cloned());
53 cfg.extend(target_features.into_iter().map(|feat| (tf, Some(feat))));
55 if sess.crt_static(None) {
56 cfg.insert((tf, Some(Symbol::intern("crt-static"))));
60 pub fn create_session(
61 sopts: config::Options,
62 cfg: FxHashSet<(String, Option<String>)>,
63 diagnostic_output: DiagnosticOutput,
64 file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
65 input_path: Option<PathBuf>,
66 lint_caps: FxHashMap<lint::LintId, lint::Level>,
67 descriptions: Registry,
68 ) -> (Lrc<Session>, Lrc<Box<dyn CodegenBackend>>, Lrc<SourceMap>) {
69 let (mut sess, source_map) = session::build_session_with_source_map(
78 let codegen_backend = get_codegen_backend(&sess);
80 let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
81 add_configuration(&mut cfg, &mut sess, &*codegen_backend);
82 sess.parse_sess.config = cfg;
84 (Lrc::new(sess), Lrc::new(codegen_backend), source_map)
87 const STACK_SIZE: usize = 8 * 1024 * 1024;
89 fn get_stack_size() -> Option<usize> {
90 // FIXME: Hacks on hacks. If the env is trying to override the stack size
91 // then *don't* set it explicitly.
92 env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE)
95 struct Sink(Arc<Mutex<Vec<u8>>>);
97 fn write(&mut self, data: &[u8]) -> io::Result<usize> {
98 Write::write(&mut *self.0.lock().unwrap(), data)
100 fn flush(&mut self) -> io::Result<()> {
105 #[cfg(not(parallel_compiler))]
106 pub fn scoped_thread<F: FnOnce() -> R + Send, R: Send>(cfg: thread::Builder, f: F) -> R {
108 unsafe impl Send for Ptr {}
109 unsafe impl Sync for Ptr {}
112 let run = Ptr(&mut f as *mut _ as *mut ());
113 let mut result = None;
114 let result_ptr = Ptr(&mut result as *mut _ as *mut ());
116 let thread = cfg.spawn(move || {
117 let run = unsafe { (*(run.0 as *mut Option<F>)).take().unwrap() };
118 let result = unsafe { &mut *(result_ptr.0 as *mut Option<R>) };
119 *result = Some(run());
122 match thread.unwrap().join() {
123 Ok(()) => result.unwrap(),
124 Err(p) => panic::resume_unwind(p),
128 #[cfg(not(parallel_compiler))]
129 pub fn spawn_thread_pool<F: FnOnce() -> R + Send, R: Send>(
132 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
135 let mut cfg = thread::Builder::new().name("rustc".to_string());
137 if let Some(size) = get_stack_size() {
138 cfg = cfg.stack_size(size);
141 crate::callbacks::setup_callbacks();
143 scoped_thread(cfg, || {
144 rustc_ast::with_globals(edition, || {
145 ty::tls::GCX_PTR.set(&Lock::new(0), || {
146 if let Some(stderr) = stderr {
147 io::set_panic(Some(box Sink(stderr.clone())));
155 #[cfg(parallel_compiler)]
156 pub fn spawn_thread_pool<F: FnOnce() -> R + Send, R: Send>(
159 stderr: &Option<Arc<Mutex<Vec<u8>>>>,
162 use rayon::{ThreadBuilder, ThreadPool, ThreadPoolBuilder};
164 let gcx_ptr = &Lock::new(0);
165 crate::callbacks::setup_callbacks();
167 let mut config = ThreadPoolBuilder::new()
168 .thread_name(|_| "rustc".to_string())
169 .acquire_thread_handler(jobserver::acquire_thread)
170 .release_thread_handler(jobserver::release_thread)
171 .num_threads(threads)
172 .deadlock_handler(|| unsafe { ty::query::handle_deadlock() });
174 if let Some(size) = get_stack_size() {
175 config = config.stack_size(size);
178 let with_pool = move |pool: &ThreadPool| pool.install(move || f());
180 rustc_ast::with_globals(edition, || {
181 rustc_ast::GLOBALS.with(|syntax_globals| {
182 rustc_span::GLOBALS.with(|rustc_span_globals| {
183 // The main handler runs for each Rayon worker thread and sets up
184 // the thread local rustc uses. syntax_globals and rustc_span_globals are
185 // captured and set on the new threads. ty::tls::with_thread_locals sets up
186 // thread local callbacks from librustc_ast
187 let main_handler = move |thread: ThreadBuilder| {
188 rustc_ast::GLOBALS.set(syntax_globals, || {
189 rustc_span::GLOBALS.set(rustc_span_globals, || {
190 if let Some(stderr) = stderr {
191 io::set_panic(Some(box Sink(stderr.clone())));
193 ty::tls::GCX_PTR.set(gcx_ptr, || thread.run())
198 config.build_scoped(main_handler, with_pool).unwrap()
204 fn load_backend_from_dylib(path: &Path) -> fn() -> Box<dyn CodegenBackend> {
205 let lib = DynamicLibrary::open(path).unwrap_or_else(|err| {
206 let err = format!("couldn't load codegen backend {:?}: {:?}", path, err);
207 early_error(ErrorOutputType::default(), &err);
210 match lib.symbol("__rustc_codegen_backend") {
213 mem::transmute::<*mut u8, _>(f)
217 "couldn't load codegen backend as it \
218 doesn't export the `__rustc_codegen_backend` \
222 early_error(ErrorOutputType::default(), &err);
228 pub fn get_codegen_backend(sess: &Session) -> Box<dyn CodegenBackend> {
229 static INIT: Once = Once::new();
231 static mut LOAD: fn() -> Box<dyn CodegenBackend> = || unreachable!();
234 let codegen_name = sess
239 .unwrap_or(&sess.target.target.options.codegen_backend);
240 let backend = match &codegen_name[..] {
241 filename if filename.contains('.') => load_backend_from_dylib(filename.as_ref()),
242 codegen_name => get_builtin_codegen_backend(codegen_name),
249 let backend = unsafe { LOAD() };
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: once_cell::sync::OnceCell<Option<PathBuf>> =
259 once_cell::sync::OnceCell::new();
261 const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
263 RUSTC_PATH.get_or_init(|| get_rustc_path_inner(BIN_PATH)).as_ref().map(|v| &**v)
266 fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
267 sysroot_candidates().iter().find_map(|sysroot| {
268 let candidate = sysroot.join(bin_path).join(if cfg!(target_os = "windows") {
273 candidate.exists().then_some(candidate)
277 fn sysroot_candidates() -> Vec<PathBuf> {
278 let target = session::config::host_triple();
279 let mut sysroot_candidates = vec![filesearch::get_or_default_sysroot()];
280 let path = current_dll_path().and_then(|s| s.canonicalize().ok());
281 if let Some(dll) = path {
282 // use `parent` twice to chop off the file name and then also the
283 // directory containing the dll which should be either `lib` or `bin`.
284 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
285 // The original `path` pointed at the `rustc_driver` crate's dll.
286 // Now that dll should only be in one of two locations. The first is
287 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
288 // other is the target's libdir, for example
289 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
291 // We don't know which, so let's assume that if our `path` above
292 // ends in `$target` we *could* be in the target libdir, and always
293 // assume that we may be in the main libdir.
294 sysroot_candidates.push(path.to_owned());
296 if path.ends_with(target) {
297 sysroot_candidates.extend(
298 path.parent() // chop off `$target`
299 .and_then(|p| p.parent()) // chop off `rustlib`
300 .and_then(|p| p.parent()) // chop off `lib`
301 .map(|s| s.to_owned()),
307 return sysroot_candidates;
310 fn current_dll_path() -> Option<PathBuf> {
311 use std::ffi::{CStr, OsStr};
312 use std::os::unix::prelude::*;
315 let addr = current_dll_path as usize as *mut _;
316 let mut info = mem::zeroed();
317 if libc::dladdr(addr, &mut info) == 0 {
318 info!("dladdr failed");
321 if info.dli_fname.is_null() {
322 info!("dladdr returned null pointer");
325 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
326 let os = OsStr::from_bytes(bytes);
327 Some(PathBuf::from(os))
332 fn current_dll_path() -> Option<PathBuf> {
333 use std::ffi::OsString;
334 use std::os::windows::prelude::*;
337 use winapi::um::libloaderapi::{
338 GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
342 let mut module = ptr::null_mut();
343 let r = GetModuleHandleExW(
344 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
345 current_dll_path as usize as *mut _,
349 info!("GetModuleHandleExW failed: {}", io::Error::last_os_error());
352 let mut space = Vec::with_capacity(1024);
353 let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
355 info!("GetModuleFileNameW failed: {}", io::Error::last_os_error());
359 if r >= space.capacity() {
360 info!("our buffer was too small? {}", io::Error::last_os_error());
364 let os = OsString::from_wide(&space);
365 Some(PathBuf::from(os))
370 pub fn get_builtin_codegen_backend(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
371 #[cfg(feature = "llvm")]
373 if backend_name == "llvm" {
374 return rustc_codegen_llvm::LlvmCodegenBackend::new;
378 let err = format!("unsupported builtin codegen backend `{}`", backend_name);
379 early_error(ErrorOutputType::default(), &err);
382 pub(crate) fn compute_crate_disambiguator(session: &Session) -> CrateDisambiguator {
383 use std::hash::Hasher;
385 // The crate_disambiguator is a 128 bit hash. The disambiguator is fed
386 // into various other hashes quite a bit (symbol hashes, incr. comp. hashes,
387 // debuginfo type IDs, etc), so we don't want it to be too wide. 128 bits
388 // should still be safe enough to avoid collisions in practice.
389 let mut hasher = StableHasher::new();
391 let mut metadata = session.opts.cg.metadata.clone();
392 // We don't want the crate_disambiguator to dependent on the order
393 // -C metadata arguments, so sort them:
395 // Every distinct -C metadata value is only incorporated once:
398 hasher.write(b"metadata");
400 // Also incorporate the length of a metadata string, so that we generate
401 // different values for `-Cmetadata=ab -Cmetadata=c` and
402 // `-Cmetadata=a -Cmetadata=bc`
403 hasher.write_usize(s.len());
404 hasher.write(s.as_bytes());
407 // Also incorporate crate type, so that we don't get symbol conflicts when
408 // linking against a library of the same name, if this is an executable.
409 let is_exe = session.crate_types().contains(&CrateType::Executable);
410 hasher.write(if is_exe { b"exe" } else { b"lib" });
412 CrateDisambiguator::from(hasher.finish::<Fingerprint>())
415 pub(crate) fn check_attr_crate_type(attrs: &[ast::Attribute], lint_buffer: &mut LintBuffer) {
416 // Unconditionally collect crate types from attributes to make them used
417 for a in attrs.iter() {
418 if a.check_name(sym::crate_type) {
419 if let Some(n) = a.value_str() {
420 if categorize_crate_type(n).is_some() {
424 if let ast::MetaItemKind::NameValue(spanned) = a.meta().unwrap().kind {
425 let span = spanned.span;
426 let lev_candidate = find_best_match_for_name(
427 CRATE_TYPES.iter().map(|(k, _)| k),
431 if let Some(candidate) = lev_candidate {
432 lint_buffer.buffer_lint_with_diagnostic(
433 lint::builtin::UNKNOWN_CRATE_TYPES,
436 "invalid `crate_type` value",
437 BuiltinLintDiagnostics::UnknownCrateTypes(
439 "did you mean".to_string(),
440 format!("\"{}\"", candidate),
444 lint_buffer.buffer_lint(
445 lint::builtin::UNKNOWN_CRATE_TYPES,
448 "invalid `crate_type` value",
457 const CRATE_TYPES: &[(Symbol, CrateType)] = &[
458 (sym::rlib, CrateType::Rlib),
459 (sym::dylib, CrateType::Dylib),
460 (sym::cdylib, CrateType::Cdylib),
461 (sym::lib, config::default_lib_output()),
462 (sym::staticlib, CrateType::Staticlib),
463 (sym::proc_dash_macro, CrateType::ProcMacro),
464 (sym::bin, CrateType::Executable),
467 fn categorize_crate_type(s: Symbol) -> Option<CrateType> {
468 Some(CRATE_TYPES.iter().find(|(key, _)| *key == s)?.1)
471 pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<CrateType> {
472 // Unconditionally collect crate types from attributes to make them used
473 let attr_types: Vec<CrateType> = attrs
476 if a.check_name(sym::crate_type) {
477 match a.value_str() {
478 Some(s) => categorize_crate_type(s),
487 // If we're generating a test executable, then ignore all other output
488 // styles at all other locations
489 if session.opts.test {
490 return vec![CrateType::Executable];
493 // Only check command line flags if present. If no types are specified by
494 // command line, then reuse the empty `base` Vec to hold the types that
495 // will be found in crate attributes.
496 let mut base = session.opts.crate_types.clone();
498 base.extend(attr_types);
500 base.push(output::default_output_for_target(session));
507 base.retain(|crate_type| {
508 let res = !output::invalid_output_for_target(session, *crate_type);
511 session.warn(&format!(
512 "dropping unsupported crate type `{}` for target `{}`",
513 *crate_type, session.opts.target_triple
523 pub fn build_output_filenames(
525 odir: &Option<PathBuf>,
526 ofile: &Option<PathBuf>,
527 attrs: &[ast::Attribute],
529 ) -> OutputFilenames {
532 // "-" as input file will cause the parser to read from stdin so we
533 // have to make up a name
534 // We want to toss everything after the final '.'
535 let dirpath = (*odir).as_ref().cloned().unwrap_or_default();
537 // If a crate name is present, we use it as the link name
542 .or_else(|| rustc_attr::find_crate_name(attrs).map(|n| n.to_string()))
543 .unwrap_or_else(|| input.filestem().to_owned());
545 OutputFilenames::new(
549 sess.opts.cg.extra_filename.clone(),
550 sess.opts.output_types.clone(),
554 Some(ref out_file) => {
555 let unnamed_output_types =
556 sess.opts.output_types.values().filter(|a| a.is_none()).count();
557 let ofile = if unnamed_output_types > 1 {
559 "due to multiple output types requested, the explicitly specified \
560 output file name will be adapted for each output type",
564 if !sess.opts.cg.extra_filename.is_empty() {
565 sess.warn("ignoring -C extra-filename flag due to -o flag");
567 Some(out_file.clone())
570 sess.warn("ignoring --out-dir flag due to -o flag");
573 OutputFilenames::new(
574 out_file.parent().unwrap_or_else(|| Path::new("")).to_path_buf(),
575 out_file.file_stem().unwrap_or_default().to_str().unwrap().to_string(),
577 sess.opts.cg.extra_filename.clone(),
578 sess.opts.output_types.clone(),
584 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
586 // FIXME: Currently the `everybody_loops` transformation is not applied to:
587 // * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
588 // waiting for miri to fix that.
589 // * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
590 // Solving this may require `!` to implement every trait, which relies on the an even more
591 // ambitious form of the closed RFC #1637. See also [#34511].
593 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
594 pub struct ReplaceBodyWithLoop<'a, 'b> {
595 within_static_or_const: bool,
596 nested_blocks: Option<Vec<ast::Block>>,
597 resolver: &'a mut Resolver<'b>,
600 impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
601 pub fn new(resolver: &'a mut Resolver<'b>) -> ReplaceBodyWithLoop<'a, 'b> {
602 ReplaceBodyWithLoop { within_static_or_const: false, nested_blocks: None, resolver }
605 fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
606 let old_const = mem::replace(&mut self.within_static_or_const, is_const);
607 let old_blocks = self.nested_blocks.take();
608 let ret = action(self);
609 self.within_static_or_const = old_const;
610 self.nested_blocks = old_blocks;
614 fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
615 if let ast::FnRetTy::Ty(ref ty) = ret_ty {
616 fn involves_impl_trait(ty: &ast::Ty) -> bool {
618 ast::TyKind::ImplTrait(..) => true,
619 ast::TyKind::Slice(ref subty)
620 | ast::TyKind::Array(ref subty, _)
621 | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
622 | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
623 | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
624 ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
625 ast::TyKind::Path(_, ref path) => {
626 path.segments.iter().any(|seg| match seg.args.as_deref() {
628 Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
629 data.args.iter().any(|arg| match arg {
630 ast::AngleBracketedArg::Arg(arg) => match arg {
631 ast::GenericArg::Type(ty) => involves_impl_trait(ty),
632 ast::GenericArg::Lifetime(_)
633 | ast::GenericArg::Const(_) => false,
635 ast::AngleBracketedArg::Constraint(c) => match c.kind {
636 ast::AssocTyConstraintKind::Bound { .. } => true,
637 ast::AssocTyConstraintKind::Equality { ref ty } => {
638 involves_impl_trait(ty)
643 Some(&ast::GenericArgs::Parenthesized(ref data)) => {
644 any_involves_impl_trait(data.inputs.iter())
645 || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
653 fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
654 it.any(|subty| involves_impl_trait(subty))
657 involves_impl_trait(ty)
663 fn is_sig_const(sig: &ast::FnSig) -> bool {
664 matches!(sig.header.constness, ast::Const::Yes(_))
665 || ReplaceBodyWithLoop::should_ignore_fn(&sig.decl.output)
669 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
670 fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
671 let is_const = match i {
672 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
673 ast::ItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
676 self.run(is_const, |s| noop_visit_item_kind(i, s))
679 fn flat_map_trait_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
680 let is_const = match i.kind {
681 ast::AssocItemKind::Const(..) => true,
682 ast::AssocItemKind::Fn(_, ref sig, _, _) => Self::is_sig_const(sig),
685 self.run(is_const, |s| noop_flat_map_assoc_item(i, s))
688 fn flat_map_impl_item(&mut self, i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
689 self.flat_map_trait_item(i)
692 fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
693 self.run(true, |s| noop_visit_anon_const(c, s))
696 fn visit_block(&mut self, b: &mut P<ast::Block>) {
698 rules: ast::BlockCheckMode,
699 s: Option<ast::Stmt>,
700 resolver: &mut Resolver<'_>,
703 stmts: s.into_iter().collect(),
705 id: resolver.next_node_id(),
706 span: rustc_span::DUMMY_SP,
710 fn block_to_stmt(b: ast::Block, resolver: &mut Resolver<'_>) -> ast::Stmt {
711 let expr = P(ast::Expr {
712 id: resolver.next_node_id(),
713 kind: ast::ExprKind::Block(P(b), None),
714 span: rustc_span::DUMMY_SP,
715 attrs: AttrVec::new(),
720 id: resolver.next_node_id(),
721 kind: ast::StmtKind::Expr(expr),
722 span: rustc_span::DUMMY_SP,
726 let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.resolver);
727 let loop_expr = P(ast::Expr {
728 kind: ast::ExprKind::Loop(P(empty_block), None),
729 id: self.resolver.next_node_id(),
730 span: rustc_span::DUMMY_SP,
731 attrs: AttrVec::new(),
735 let loop_stmt = ast::Stmt {
736 id: self.resolver.next_node_id(),
737 span: rustc_span::DUMMY_SP,
738 kind: ast::StmtKind::Expr(loop_expr),
741 if self.within_static_or_const {
742 noop_visit_block(b, self)
744 visit_clobber(b.deref_mut(), |b| {
745 let mut stmts = vec![];
747 let old_blocks = self.nested_blocks.replace(vec![]);
749 stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
751 // we put a Some in there earlier with that replace(), so this is valid
752 let new_blocks = self.nested_blocks.take().unwrap();
753 self.nested_blocks = old_blocks;
754 stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, self.resolver)));
757 let mut new_block = ast::Block { stmts, ..b };
759 if let Some(old_blocks) = self.nested_blocks.as_mut() {
760 //push our fresh block onto the cache and yield an empty block with `loop {}`
761 if !new_block.stmts.is_empty() {
762 old_blocks.push(new_block);
765 stmt_to_block(b.rules, Some(loop_stmt), &mut self.resolver)
767 //push `loop {}` onto the end of our fresh block and yield that
768 new_block.stmts.push(loop_stmt);
776 // in general the pretty printer processes unexpanded code, so
777 // we override the default `visit_mac` method which panics.
778 fn visit_mac(&mut self, mac: &mut ast::MacCall) {
779 noop_visit_mac(mac, self)