1 use rustc_target::spec::abi::Abi;
3 use syntax::source_map::{SourceMap, Spanned};
4 use syntax::parse::ParseSess;
5 use syntax::print::pp::{self, Breaks};
6 use syntax::print::pp::Breaks::{Consistent, Inconsistent};
7 use syntax::print::pprust::{self, Comments, PrintState};
8 use syntax::symbol::kw;
9 use syntax::util::parser::{self, AssocOp, Fixity};
10 use syntax_pos::{self, BytePos, FileName};
13 use crate::hir::{PatKind, GenericBound, TraitBoundModifier, RangeEnd};
14 use crate::hir::{GenericParam, GenericParamKind, GenericArg};
15 use crate::hir::ptr::P;
21 pub enum AnnNode<'a> {
23 Block(&'a hir::Block),
33 TraitItem(hir::TraitItemId),
34 ImplItem(hir::ImplItemId),
36 BodyArgPat(hir::BodyId, usize)
40 fn nested(&self, _state: &mut State<'_>, _nested: Nested) {
42 fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {
44 fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {
46 fn try_fetch_item(&self, _: hir::HirId) -> Option<&hir::Item> {
52 impl PpAnn for NoAnn {}
53 pub const NO_ANN: &dyn PpAnn = &NoAnn;
55 impl PpAnn for hir::Crate {
56 fn try_fetch_item(&self, item: hir::HirId) -> Option<&hir::Item> {
59 fn nested(&self, state: &mut State<'_>, nested: Nested) {
61 Nested::Item(id) => state.print_item(self.item(id.id)),
62 Nested::TraitItem(id) => state.print_trait_item(self.trait_item(id)),
63 Nested::ImplItem(id) => state.print_impl_item(self.impl_item(id)),
64 Nested::Body(id) => state.print_expr(&self.body(id).value),
65 Nested::BodyArgPat(id, i) => state.print_pat(&self.body(id).arguments[i].pat)
70 pub struct State<'a> {
72 comments: Option<Comments<'a>>,
73 ann: &'a (dyn PpAnn + 'a),
76 impl std::ops::Deref for State<'_> {
77 type Target = pp::Printer;
78 fn deref(&self) -> &Self::Target {
83 impl std::ops::DerefMut for State<'_> {
84 fn deref_mut(&mut self) -> &mut Self::Target {
89 impl<'a> PrintState<'a> for State<'a> {
90 fn comments(&mut self) -> &mut Option<Comments<'a>> {
94 fn print_ident(&mut self, ident: ast::Ident) {
95 self.s.word(pprust::ast_ident_to_string(ident, ident.is_raw_guess()));
96 self.ann.post(self, AnnNode::Name(&ident.name))
99 fn print_generic_args(&mut self, args: &ast::GenericArgs, _colons_before_params: bool) {
100 span_bug!(args.span(), "AST generic args printed by HIR pretty-printer");
104 pub const INDENT_UNIT: usize = 4;
106 /// Requires you to pass an input filename and reader so that
107 /// it can scan the input text for comments to copy forward.
108 pub fn print_crate<'a>(cm: &'a SourceMap,
113 ann: &'a dyn PpAnn) -> String {
114 let mut s = State::new_from_input(cm, sess, filename, input, ann);
116 // When printing the AST, we sometimes need to inject `#[no_std]` here.
117 // Since you can't compile the HIR, it's not necessary.
119 s.print_mod(&krate.module, &krate.attrs);
120 s.print_remaining_comments();
125 pub fn new_from_input(cm: &'a SourceMap,
133 comments: Some(Comments::new(cm, sess, filename, input)),
139 pub fn to_string<F>(ann: &dyn PpAnn, f: F) -> String
140 where F: FnOnce(&mut State<'_>)
142 let mut printer = State {
151 pub fn visibility_qualified<S: Into<Cow<'static, str>>>(vis: &hir::Visibility, w: S) -> String {
152 to_string(NO_ANN, |s| {
153 s.print_visibility(vis);
159 pub fn cbox(&mut self, u: usize) {
163 pub fn nbsp(&mut self) {
167 pub fn word_nbsp<S: Into<Cow<'static, str>>>(&mut self, w: S) {
172 pub fn head<S: Into<Cow<'static, str>>>(&mut self, w: S) {
174 // outer-box is consistent
175 self.cbox(INDENT_UNIT);
176 // head-box is inconsistent
177 self.ibox(w.len() + 1);
178 // keyword that starts the head
184 pub fn bopen(&mut self) {
186 self.end(); // close the head-box
189 pub fn bclose_maybe_open(&mut self,
190 span: syntax_pos::Span,
193 self.maybe_print_comment(span.hi());
194 self.break_offset_if_not_bol(1, -(INDENT_UNIT as isize));
197 self.end(); // close the outer-box
201 pub fn bclose(&mut self, span: syntax_pos::Span) {
202 self.bclose_maybe_open(span, true)
205 pub fn space_if_not_bol(&mut self) {
206 if !self.s.is_beginning_of_line() {
211 pub fn break_offset_if_not_bol(&mut self, n: usize, off: isize) {
212 if !self.s.is_beginning_of_line() {
213 self.s.break_offset(n, off)
215 if off != 0 && self.s.last_token().is_hardbreak_tok() {
216 // We do something pretty sketchy here: tuck the nonzero
217 // offset-adjustment we were going to deposit along with the
218 // break into the previous hardbreak.
219 self.s.replace_last_token(pp::Printer::hardbreak_tok_offset(off));
224 // Synthesizes a comment that was not textually present in the original source
226 pub fn synth_comment(&mut self, text: String) {
234 pub fn commasep_cmnt<T, F, G>(&mut self,
239 where F: FnMut(&mut State<'_>, &T),
240 G: FnMut(&T) -> syntax_pos::Span
243 let len = elts.len();
246 self.maybe_print_comment(get_span(elt).hi());
251 self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi()));
252 self.space_if_not_bol();
258 pub fn commasep_exprs(&mut self, b: Breaks, exprs: &[hir::Expr]) {
259 self.commasep_cmnt(b, exprs, |s, e| s.print_expr(&e), |e| e.span)
262 pub fn print_mod(&mut self, _mod: &hir::Mod, attrs: &[ast::Attribute]) {
263 self.print_inner_attributes(attrs);
264 for &item_id in &_mod.item_ids {
265 self.ann.nested(self, Nested::Item(item_id));
269 pub fn print_foreign_mod(&mut self,
270 nmod: &hir::ForeignMod,
271 attrs: &[ast::Attribute])
273 self.print_inner_attributes(attrs);
274 for item in &nmod.items {
275 self.print_foreign_item(item);
279 pub fn print_opt_lifetime(&mut self, lifetime: &hir::Lifetime) {
280 if !lifetime.is_elided() {
281 self.print_lifetime(lifetime);
286 pub fn print_type(&mut self, ty: &hir::Ty) {
287 self.maybe_print_comment(ty.span.lo());
290 hir::TyKind::Slice(ref ty) => {
292 self.print_type(&ty);
295 hir::TyKind::Ptr(ref mt) => {
298 hir::MutMutable => self.word_nbsp("mut"),
299 hir::MutImmutable => self.word_nbsp("const"),
301 self.print_type(&mt.ty);
303 hir::TyKind::Rptr(ref lifetime, ref mt) => {
305 self.print_opt_lifetime(lifetime);
308 hir::TyKind::Never => {
311 hir::TyKind::Tup(ref elts) => {
313 self.commasep(Inconsistent, &elts[..], |s, ty| s.print_type(&ty));
319 hir::TyKind::BareFn(ref f) => {
320 self.print_ty_fn(f.abi, f.unsafety, &f.decl, None, &f.generic_params,
323 hir::TyKind::Def(..) => {},
324 hir::TyKind::Path(ref qpath) => {
325 self.print_qpath(qpath, false)
327 hir::TyKind::TraitObject(ref bounds, ref lifetime) => {
328 let mut first = true;
329 for bound in bounds {
334 self.word_space("+");
336 self.print_poly_trait_ref(bound);
338 if !lifetime.is_elided() {
340 self.word_space("+");
341 self.print_lifetime(lifetime);
344 hir::TyKind::Array(ref ty, ref length) => {
346 self.print_type(&ty);
348 self.print_anon_const(length);
351 hir::TyKind::Typeof(ref e) => {
352 self.s.word("typeof(");
353 self.print_anon_const(e);
356 hir::TyKind::Infer => {
359 hir::TyKind::Err => {
361 self.s.word("/*ERROR*/");
364 hir::TyKind::CVarArgs(_) => {
371 pub fn print_foreign_item(&mut self, item: &hir::ForeignItem) {
372 self.hardbreak_if_not_bol();
373 self.maybe_print_comment(item.span.lo());
374 self.print_outer_attributes(&item.attrs);
376 hir::ForeignItemKind::Fn(ref decl, ref arg_names, ref generics) => {
380 unsafety: hir::Unsafety::Normal,
381 constness: hir::Constness::NotConst,
383 asyncness: hir::IsAsync::NotAsync,
385 Some(item.ident.name),
390 self.end(); // end head-ibox
392 self.end() // end the outer fn box
394 hir::ForeignItemKind::Static(ref t, m) => {
395 self.head(visibility_qualified(&item.vis, "static"));
396 if m == hir::MutMutable {
397 self.word_space("mut");
399 self.print_ident(item.ident);
400 self.word_space(":");
403 self.end(); // end the head-ibox
404 self.end() // end the outer cbox
406 hir::ForeignItemKind::Type => {
407 self.head(visibility_qualified(&item.vis, "type"));
408 self.print_ident(item.ident);
410 self.end(); // end the head-ibox
411 self.end() // end the outer cbox
416 fn print_associated_const(&mut self,
419 default: Option<hir::BodyId>,
420 vis: &hir::Visibility)
422 self.s.word(visibility_qualified(vis, ""));
423 self.word_space("const");
424 self.print_ident(ident);
425 self.word_space(":");
427 if let Some(expr) = default {
429 self.word_space("=");
430 self.ann.nested(self, Nested::Body(expr));
435 fn print_associated_type(&mut self,
437 bounds: Option<&hir::GenericBounds>,
438 ty: Option<&hir::Ty>)
440 self.word_space("type");
441 self.print_ident(ident);
442 if let Some(bounds) = bounds {
443 self.print_bounds(":", bounds);
445 if let Some(ty) = ty {
447 self.word_space("=");
453 /// Pretty-print an item
454 pub fn print_item(&mut self, item: &hir::Item) {
455 self.hardbreak_if_not_bol();
456 self.maybe_print_comment(item.span.lo());
457 self.print_outer_attributes(&item.attrs);
458 self.ann.pre(self, AnnNode::Item(item));
460 hir::ItemKind::ExternCrate(orig_name) => {
461 self.head(visibility_qualified(&item.vis, "extern crate"));
462 if let Some(orig_name) = orig_name {
463 self.print_name(orig_name);
468 self.print_ident(item.ident);
470 self.end(); // end inner head-block
471 self.end(); // end outer head-block
473 hir::ItemKind::Use(ref path, kind) => {
474 self.head(visibility_qualified(&item.vis, "use"));
475 self.print_path(path, false);
478 hir::UseKind::Single => {
479 if path.segments.last().unwrap().ident != item.ident {
481 self.word_space("as");
482 self.print_ident(item.ident);
486 hir::UseKind::Glob => self.s.word("::*;"),
487 hir::UseKind::ListStem => self.s.word("::{};")
489 self.end(); // end inner head-block
490 self.end(); // end outer head-block
492 hir::ItemKind::Static(ref ty, m, expr) => {
493 self.head(visibility_qualified(&item.vis, "static"));
494 if m == hir::MutMutable {
495 self.word_space("mut");
497 self.print_ident(item.ident);
498 self.word_space(":");
499 self.print_type(&ty);
501 self.end(); // end the head-ibox
503 self.word_space("=");
504 self.ann.nested(self, Nested::Body(expr));
506 self.end(); // end the outer cbox
508 hir::ItemKind::Const(ref ty, expr) => {
509 self.head(visibility_qualified(&item.vis, "const"));
510 self.print_ident(item.ident);
511 self.word_space(":");
512 self.print_type(&ty);
514 self.end(); // end the head-ibox
516 self.word_space("=");
517 self.ann.nested(self, Nested::Body(expr));
519 self.end(); // end the outer cbox
521 hir::ItemKind::Fn(ref decl, header, ref param_names, body) => {
525 Some(item.ident.name),
531 self.end(); // need to close a box
532 self.end(); // need to close a box
533 self.ann.nested(self, Nested::Body(body));
535 hir::ItemKind::Mod(ref _mod) => {
536 self.head(visibility_qualified(&item.vis, "mod"));
537 self.print_ident(item.ident);
540 self.print_mod(_mod, &item.attrs);
541 self.bclose(item.span);
543 hir::ItemKind::ForeignMod(ref nmod) => {
545 self.word_nbsp(nmod.abi.to_string());
547 self.print_foreign_mod(nmod, &item.attrs);
548 self.bclose(item.span);
550 hir::ItemKind::GlobalAsm(ref ga) => {
551 self.head(visibility_qualified(&item.vis, "global asm"));
552 self.s.word(ga.asm.as_str().to_string());
555 hir::ItemKind::Ty(ref ty, ref generics) => {
556 self.head(visibility_qualified(&item.vis, "type"));
557 self.print_ident(item.ident);
558 self.print_generic_params(&generics.params);
559 self.end(); // end the inner ibox
561 self.print_where_clause(&generics.where_clause);
563 self.word_space("=");
564 self.print_type(&ty);
566 self.end(); // end the outer ibox
568 hir::ItemKind::Existential(ref exist) => {
569 self.head(visibility_qualified(&item.vis, "existential type"));
570 self.print_ident(item.ident);
571 self.print_generic_params(&exist.generics.params);
572 self.end(); // end the inner ibox
574 self.print_where_clause(&exist.generics.where_clause);
576 let mut real_bounds = Vec::with_capacity(exist.bounds.len());
577 for b in exist.bounds.iter() {
578 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
580 self.word_space("for ?");
581 self.print_trait_ref(&ptr.trait_ref);
586 self.print_bounds(":", real_bounds);
588 self.end(); // end the outer ibox
590 hir::ItemKind::Enum(ref enum_definition, ref params) => {
591 self.print_enum_def(enum_definition, params, item.ident.name, item.span,
594 hir::ItemKind::Struct(ref struct_def, ref generics) => {
595 self.head(visibility_qualified(&item.vis, "struct"));
596 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
598 hir::ItemKind::Union(ref struct_def, ref generics) => {
599 self.head(visibility_qualified(&item.vis, "union"));
600 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
602 hir::ItemKind::Impl(unsafety,
610 self.print_visibility(&item.vis);
611 self.print_defaultness(defaultness);
612 self.print_unsafety(unsafety);
613 self.word_nbsp("impl");
615 if !generics.params.is_empty() {
616 self.print_generic_params(&generics.params);
620 if let hir::ImplPolarity::Negative = polarity {
624 if let Some(ref t) = opt_trait {
625 self.print_trait_ref(t);
627 self.word_space("for");
630 self.print_type(&ty);
631 self.print_where_clause(&generics.where_clause);
635 self.print_inner_attributes(&item.attrs);
636 for impl_item in impl_items {
637 self.ann.nested(self, Nested::ImplItem(impl_item.id));
639 self.bclose(item.span);
641 hir::ItemKind::Trait(is_auto, unsafety, ref generics, ref bounds, ref trait_items) => {
643 self.print_visibility(&item.vis);
644 self.print_is_auto(is_auto);
645 self.print_unsafety(unsafety);
646 self.word_nbsp("trait");
647 self.print_ident(item.ident);
648 self.print_generic_params(&generics.params);
649 let mut real_bounds = Vec::with_capacity(bounds.len());
650 for b in bounds.iter() {
651 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
653 self.word_space("for ?");
654 self.print_trait_ref(&ptr.trait_ref);
659 self.print_bounds(":", real_bounds);
660 self.print_where_clause(&generics.where_clause);
663 for trait_item in trait_items {
664 self.ann.nested(self, Nested::TraitItem(trait_item.id));
666 self.bclose(item.span);
668 hir::ItemKind::TraitAlias(ref generics, ref bounds) => {
670 self.print_visibility(&item.vis);
671 self.word_nbsp("trait");
672 self.print_ident(item.ident);
673 self.print_generic_params(&generics.params);
674 let mut real_bounds = Vec::with_capacity(bounds.len());
675 // FIXME(durka) this seems to be some quite outdated syntax
676 for b in bounds.iter() {
677 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
679 self.word_space("for ?");
680 self.print_trait_ref(&ptr.trait_ref);
686 self.print_bounds("=", real_bounds);
687 self.print_where_clause(&generics.where_clause);
691 self.ann.post(self, AnnNode::Item(item))
694 pub fn print_trait_ref(&mut self, t: &hir::TraitRef) {
695 self.print_path(&t.path, false)
698 fn print_formal_generic_params(
700 generic_params: &[hir::GenericParam]
702 if !generic_params.is_empty() {
704 self.print_generic_params(generic_params);
709 fn print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef) {
710 self.print_formal_generic_params(&t.bound_generic_params);
711 self.print_trait_ref(&t.trait_ref)
714 pub fn print_enum_def(&mut self,
715 enum_definition: &hir::EnumDef,
716 generics: &hir::Generics,
718 span: syntax_pos::Span,
719 visibility: &hir::Visibility)
721 self.head(visibility_qualified(visibility, "enum"));
722 self.print_name(name);
723 self.print_generic_params(&generics.params);
724 self.print_where_clause(&generics.where_clause);
726 self.print_variants(&enum_definition.variants, span)
729 pub fn print_variants(&mut self,
730 variants: &[hir::Variant],
731 span: syntax_pos::Span)
735 self.space_if_not_bol();
736 self.maybe_print_comment(v.span.lo());
737 self.print_outer_attributes(&v.node.attrs);
738 self.ibox(INDENT_UNIT);
739 self.print_variant(v);
742 self.maybe_print_trailing_comment(v.span, None);
747 pub fn print_visibility(&mut self, vis: &hir::Visibility) {
749 hir::VisibilityKind::Public => self.word_nbsp("pub"),
750 hir::VisibilityKind::Crate(ast::CrateSugar::JustCrate) => self.word_nbsp("crate"),
751 hir::VisibilityKind::Crate(ast::CrateSugar::PubCrate) => self.word_nbsp("pub(crate)"),
752 hir::VisibilityKind::Restricted { ref path, .. } => {
754 if path.segments.len() == 1 &&
755 path.segments[0].ident.name == kw::Super {
756 // Special case: `super` can print like `pub(super)`.
757 self.s.word("super");
759 // Everything else requires `in` at present.
760 self.word_nbsp("in");
761 self.print_path(path, false);
765 hir::VisibilityKind::Inherited => ()
769 pub fn print_defaultness(&mut self, defaultness: hir::Defaultness) {
771 hir::Defaultness::Default { .. } => self.word_nbsp("default"),
772 hir::Defaultness::Final => (),
776 pub fn print_struct(&mut self,
777 struct_def: &hir::VariantData,
778 generics: &hir::Generics,
780 span: syntax_pos::Span,
781 print_finalizer: bool)
783 self.print_name(name);
784 self.print_generic_params(&generics.params);
786 hir::VariantData::Tuple(..) | hir::VariantData::Unit(..) => {
787 if let hir::VariantData::Tuple(..) = struct_def {
789 self.commasep(Inconsistent, struct_def.fields(), |s, field| {
790 s.maybe_print_comment(field.span.lo());
791 s.print_outer_attributes(&field.attrs);
792 s.print_visibility(&field.vis);
793 s.print_type(&field.ty)
797 self.print_where_clause(&generics.where_clause);
802 self.end() // close the outer-box
804 hir::VariantData::Struct(..) => {
805 self.print_where_clause(&generics.where_clause);
808 self.hardbreak_if_not_bol();
810 for field in struct_def.fields() {
811 self.hardbreak_if_not_bol();
812 self.maybe_print_comment(field.span.lo());
813 self.print_outer_attributes(&field.attrs);
814 self.print_visibility(&field.vis);
815 self.print_ident(field.ident);
817 self.print_type(&field.ty);
826 pub fn print_variant(&mut self, v: &hir::Variant) {
828 let generics = hir::Generics::empty();
829 self.print_struct(&v.node.data, &generics, v.node.ident.name, v.span, false);
830 if let Some(ref d) = v.node.disr_expr {
832 self.word_space("=");
833 self.print_anon_const(d);
836 pub fn print_method_sig(&mut self,
839 generics: &hir::Generics,
840 vis: &hir::Visibility,
841 arg_names: &[ast::Ident],
842 body_id: Option<hir::BodyId>)
844 self.print_fn(&m.decl,
853 pub fn print_trait_item(&mut self, ti: &hir::TraitItem) {
854 self.ann.pre(self, AnnNode::SubItem(ti.hir_id));
855 self.hardbreak_if_not_bol();
856 self.maybe_print_comment(ti.span.lo());
857 self.print_outer_attributes(&ti.attrs);
859 hir::TraitItemKind::Const(ref ty, default) => {
860 let vis = Spanned { span: syntax_pos::DUMMY_SP,
861 node: hir::VisibilityKind::Inherited };
862 self.print_associated_const(ti.ident, &ty, default, &vis);
864 hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Required(ref arg_names)) => {
865 let vis = Spanned { span: syntax_pos::DUMMY_SP,
866 node: hir::VisibilityKind::Inherited };
867 self.print_method_sig(ti.ident, sig, &ti.generics, &vis, arg_names, None);
870 hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Provided(body)) => {
871 let vis = Spanned { span: syntax_pos::DUMMY_SP,
872 node: hir::VisibilityKind::Inherited };
874 self.print_method_sig(ti.ident, sig, &ti.generics, &vis, &[], Some(body));
876 self.end(); // need to close a box
877 self.end(); // need to close a box
878 self.ann.nested(self, Nested::Body(body));
880 hir::TraitItemKind::Type(ref bounds, ref default) => {
881 self.print_associated_type(ti.ident,
883 default.as_ref().map(|ty| &**ty));
886 self.ann.post(self, AnnNode::SubItem(ti.hir_id))
889 pub fn print_impl_item(&mut self, ii: &hir::ImplItem) {
890 self.ann.pre(self, AnnNode::SubItem(ii.hir_id));
891 self.hardbreak_if_not_bol();
892 self.maybe_print_comment(ii.span.lo());
893 self.print_outer_attributes(&ii.attrs);
894 self.print_defaultness(ii.defaultness);
897 hir::ImplItemKind::Const(ref ty, expr) => {
898 self.print_associated_const(ii.ident, &ty, Some(expr), &ii.vis);
900 hir::ImplItemKind::Method(ref sig, body) => {
902 self.print_method_sig(ii.ident, sig, &ii.generics, &ii.vis, &[], Some(body));
904 self.end(); // need to close a box
905 self.end(); // need to close a box
906 self.ann.nested(self, Nested::Body(body));
908 hir::ImplItemKind::Type(ref ty) => {
909 self.print_associated_type(ii.ident, None, Some(ty));
911 hir::ImplItemKind::Existential(ref bounds) => {
912 self.word_space("existential");
913 self.print_associated_type(ii.ident, Some(bounds), None);
916 self.ann.post(self, AnnNode::SubItem(ii.hir_id))
921 init: Option<&hir::Expr>,
922 decl: impl Fn(&mut Self)
924 self.space_if_not_bol();
925 self.ibox(INDENT_UNIT);
926 self.word_nbsp("let");
928 self.ibox(INDENT_UNIT);
932 if let Some(ref init) = init {
934 self.word_space("=");
935 self.print_expr(&init);
940 pub fn print_stmt(&mut self, st: &hir::Stmt) {
941 self.maybe_print_comment(st.span.lo());
943 hir::StmtKind::Local(ref loc) => {
944 self.print_local(loc.init.as_deref(), |this| this.print_local_decl(&loc));
946 hir::StmtKind::Item(item) => {
947 self.ann.nested(self, Nested::Item(item))
949 hir::StmtKind::Expr(ref expr) => {
950 self.space_if_not_bol();
951 self.print_expr(&expr);
953 hir::StmtKind::Semi(ref expr) => {
954 self.space_if_not_bol();
955 self.print_expr(&expr);
959 if stmt_ends_with_semi(&st.node) {
962 self.maybe_print_trailing_comment(st.span, None)
965 pub fn print_block(&mut self, blk: &hir::Block) {
966 self.print_block_with_attrs(blk, &[])
969 pub fn print_block_unclosed(&mut self, blk: &hir::Block) {
970 self.print_block_maybe_unclosed(blk, &[], false)
973 pub fn print_block_with_attrs(&mut self,
975 attrs: &[ast::Attribute])
977 self.print_block_maybe_unclosed(blk, attrs, true)
980 pub fn print_block_maybe_unclosed(&mut self,
982 attrs: &[ast::Attribute],
986 hir::UnsafeBlock(..) => self.word_space("unsafe"),
987 hir::PushUnsafeBlock(..) => self.word_space("push_unsafe"),
988 hir::PopUnsafeBlock(..) => self.word_space("pop_unsafe"),
989 hir::DefaultBlock => (),
991 self.maybe_print_comment(blk.span.lo());
992 self.ann.pre(self, AnnNode::Block(blk));
995 self.print_inner_attributes(attrs);
997 for st in &blk.stmts {
1000 if let Some(ref expr) = blk.expr {
1001 self.space_if_not_bol();
1002 self.print_expr(&expr);
1003 self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi()));
1005 self.bclose_maybe_open(blk.span, close_box);
1006 self.ann.post(self, AnnNode::Block(blk))
1009 pub fn print_anon_const(&mut self, constant: &hir::AnonConst) {
1010 self.ann.nested(self, Nested::Body(constant.body))
1013 fn print_call_post(&mut self, args: &[hir::Expr]) {
1015 self.commasep_exprs(Inconsistent, args);
1019 pub fn print_expr_maybe_paren(&mut self, expr: &hir::Expr, prec: i8) {
1020 let needs_par = expr.precedence().order() < prec;
1024 self.print_expr(expr);
1030 /// Print an expr using syntax that's acceptable in a condition position, such as the `cond` in
1031 /// `if cond { ... }`.
1032 pub fn print_expr_as_cond(&mut self, expr: &hir::Expr) {
1033 let needs_par = match expr.node {
1034 // These cases need parens due to the parse error observed in #26461: `if return {}`
1035 // parses as the erroneous construct `if (return {})`, not `if (return) {}`.
1036 hir::ExprKind::Closure(..) |
1037 hir::ExprKind::Ret(..) |
1038 hir::ExprKind::Break(..) => true,
1040 _ => contains_exterior_struct_lit(expr),
1046 self.print_expr(expr);
1052 fn print_expr_vec(&mut self, exprs: &[hir::Expr]) {
1053 self.ibox(INDENT_UNIT);
1055 self.commasep_exprs(Inconsistent, exprs);
1060 fn print_expr_repeat(&mut self, element: &hir::Expr, count: &hir::AnonConst) {
1061 self.ibox(INDENT_UNIT);
1063 self.print_expr(element);
1064 self.word_space(";");
1065 self.print_anon_const(count);
1070 fn print_expr_struct(&mut self,
1072 fields: &[hir::Field],
1073 wth: &Option<P<hir::Expr>>)
1075 self.print_qpath(qpath, true);
1077 self.commasep_cmnt(Consistent,
1080 s.ibox(INDENT_UNIT);
1081 if !field.is_shorthand {
1082 s.print_ident(field.ident);
1085 s.print_expr(&field.expr);
1091 self.ibox(INDENT_UNIT);
1092 if !fields.is_empty() {
1097 self.print_expr(&expr);
1100 _ => if !fields.is_empty() {
1107 fn print_expr_tup(&mut self, exprs: &[hir::Expr]) {
1109 self.commasep_exprs(Inconsistent, exprs);
1110 if exprs.len() == 1 {
1116 fn print_expr_call(&mut self, func: &hir::Expr, args: &[hir::Expr]) {
1119 hir::ExprKind::Field(..) => parser::PREC_FORCE_PAREN,
1120 _ => parser::PREC_POSTFIX,
1123 self.print_expr_maybe_paren(func, prec);
1124 self.print_call_post(args)
1127 fn print_expr_method_call(&mut self,
1128 segment: &hir::PathSegment,
1131 let base_args = &args[1..];
1132 self.print_expr_maybe_paren(&args[0], parser::PREC_POSTFIX);
1134 self.print_ident(segment.ident);
1136 let generic_args = segment.generic_args();
1137 if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
1138 self.print_generic_args(generic_args, segment.infer_args, true);
1141 self.print_call_post(base_args)
1144 fn print_expr_binary(&mut self,
1149 let assoc_op = bin_op_to_assoc_op(op.node);
1150 let prec = assoc_op.precedence() as i8;
1151 let fixity = assoc_op.fixity();
1153 let (left_prec, right_prec) = match fixity {
1154 Fixity::Left => (prec, prec + 1),
1155 Fixity::Right => (prec + 1, prec),
1156 Fixity::None => (prec + 1, prec + 1),
1159 let left_prec = match (&lhs.node, op.node) {
1160 // These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
1161 // the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
1162 // of `(x as i32) < ...`. We need to convince it _not_ to do that.
1163 (&hir::ExprKind::Cast { .. }, hir::BinOpKind::Lt) |
1164 (&hir::ExprKind::Cast { .. }, hir::BinOpKind::Shl) => parser::PREC_FORCE_PAREN,
1168 self.print_expr_maybe_paren(lhs, left_prec);
1170 self.word_space(op.node.as_str());
1171 self.print_expr_maybe_paren(rhs, right_prec)
1174 fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr) {
1175 self.s.word(op.as_str());
1176 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1179 fn print_expr_addr_of(&mut self,
1180 mutability: hir::Mutability,
1184 self.print_mutability(mutability);
1185 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1188 fn print_literal(&mut self, lit: &hir::Lit) {
1189 self.maybe_print_comment(lit.span.lo());
1190 self.word(lit.node.to_lit_token().to_string())
1193 pub fn print_expr(&mut self, expr: &hir::Expr) {
1194 self.maybe_print_comment(expr.span.lo());
1195 self.print_outer_attributes(&expr.attrs);
1196 self.ibox(INDENT_UNIT);
1197 self.ann.pre(self, AnnNode::Expr(expr));
1199 hir::ExprKind::Box(ref expr) => {
1200 self.word_space("box");
1201 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX);
1203 hir::ExprKind::Array(ref exprs) => {
1204 self.print_expr_vec(exprs);
1206 hir::ExprKind::Repeat(ref element, ref count) => {
1207 self.print_expr_repeat(&element, count);
1209 hir::ExprKind::Struct(ref qpath, ref fields, ref wth) => {
1210 self.print_expr_struct(qpath, &fields[..], wth);
1212 hir::ExprKind::Tup(ref exprs) => {
1213 self.print_expr_tup(exprs);
1215 hir::ExprKind::Call(ref func, ref args) => {
1216 self.print_expr_call(&func, args);
1218 hir::ExprKind::MethodCall(ref segment, _, ref args) => {
1219 self.print_expr_method_call(segment, args);
1221 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
1222 self.print_expr_binary(op, &lhs, &rhs);
1224 hir::ExprKind::Unary(op, ref expr) => {
1225 self.print_expr_unary(op, &expr);
1227 hir::ExprKind::AddrOf(m, ref expr) => {
1228 self.print_expr_addr_of(m, &expr);
1230 hir::ExprKind::Lit(ref lit) => {
1231 self.print_literal(&lit);
1233 hir::ExprKind::Cast(ref expr, ref ty) => {
1234 let prec = AssocOp::As.precedence() as i8;
1235 self.print_expr_maybe_paren(&expr, prec);
1237 self.word_space("as");
1238 self.print_type(&ty);
1240 hir::ExprKind::Type(ref expr, ref ty) => {
1241 let prec = AssocOp::Colon.precedence() as i8;
1242 self.print_expr_maybe_paren(&expr, prec);
1243 self.word_space(":");
1244 self.print_type(&ty);
1246 hir::ExprKind::DropTemps(ref init) => {
1248 self.cbox(INDENT_UNIT);
1252 // Print `let _t = $init;`:
1253 let temp = ast::Ident::from_str("_t");
1254 self.print_local(Some(init), |this| this.print_ident(temp));
1258 self.space_if_not_bol();
1259 self.print_ident(temp);
1262 self.bclose_maybe_open(expr.span, true);
1264 hir::ExprKind::Loop(ref blk, opt_label, _) => {
1265 if let Some(label) = opt_label {
1266 self.print_ident(label.ident);
1267 self.word_space(":");
1271 self.print_block(&blk);
1273 hir::ExprKind::Match(ref expr, ref arms, _) => {
1274 self.cbox(INDENT_UNIT);
1275 self.ibox(INDENT_UNIT);
1276 self.word_nbsp("match");
1277 self.print_expr_as_cond(&expr);
1281 self.print_arm(arm);
1283 self.bclose(expr.span);
1285 hir::ExprKind::Closure(capture_clause, ref decl, body, _fn_decl_span, _gen) => {
1286 self.print_capture_clause(capture_clause);
1288 self.print_closure_args(&decl, body);
1291 // this is a bare expression
1292 self.ann.nested(self, Nested::Body(body));
1293 self.end(); // need to close a box
1295 // a box will be closed by print_expr, but we didn't want an overall
1296 // wrapper so we closed the corresponding opening. so create an
1297 // empty box to satisfy the close.
1300 hir::ExprKind::Block(ref blk, opt_label) => {
1301 if let Some(label) = opt_label {
1302 self.print_ident(label.ident);
1303 self.word_space(":");
1305 // containing cbox, will be closed by print-block at }
1306 self.cbox(INDENT_UNIT);
1307 // head-box, will be closed by print-block after {
1309 self.print_block(&blk);
1311 hir::ExprKind::Assign(ref lhs, ref rhs) => {
1312 let prec = AssocOp::Assign.precedence() as i8;
1313 self.print_expr_maybe_paren(&lhs, prec + 1);
1315 self.word_space("=");
1316 self.print_expr_maybe_paren(&rhs, prec);
1318 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
1319 let prec = AssocOp::Assign.precedence() as i8;
1320 self.print_expr_maybe_paren(&lhs, prec + 1);
1322 self.s.word(op.node.as_str());
1323 self.word_space("=");
1324 self.print_expr_maybe_paren(&rhs, prec);
1326 hir::ExprKind::Field(ref expr, ident) => {
1327 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
1329 self.print_ident(ident);
1331 hir::ExprKind::Index(ref expr, ref index) => {
1332 self.print_expr_maybe_paren(&expr, parser::PREC_POSTFIX);
1334 self.print_expr(&index);
1337 hir::ExprKind::Path(ref qpath) => {
1338 self.print_qpath(qpath, true)
1340 hir::ExprKind::Break(destination, ref opt_expr) => {
1341 self.s.word("break");
1343 if let Some(label) = destination.label {
1344 self.print_ident(label.ident);
1347 if let Some(ref expr) = *opt_expr {
1348 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
1352 hir::ExprKind::Continue(destination) => {
1353 self.s.word("continue");
1355 if let Some(label) = destination.label {
1356 self.print_ident(label.ident);
1360 hir::ExprKind::Ret(ref result) => {
1361 self.s.word("return");
1362 if let Some(ref expr) = *result {
1364 self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
1367 hir::ExprKind::InlineAsm(ref a, ref outputs, ref inputs) => {
1368 self.s.word("asm!");
1370 self.print_string(&a.asm.as_str(), a.asm_str_style);
1371 self.word_space(":");
1373 let mut out_idx = 0;
1374 self.commasep(Inconsistent, &a.outputs, |s, out| {
1375 let constraint = out.constraint.as_str();
1376 let mut ch = constraint.chars();
1378 Some('=') if out.is_rw => {
1379 s.print_string(&format!("+{}", ch.as_str()),
1380 ast::StrStyle::Cooked)
1382 _ => s.print_string(&constraint, ast::StrStyle::Cooked),
1385 s.print_expr(&outputs[out_idx]);
1390 self.word_space(":");
1393 self.commasep(Inconsistent, &a.inputs, |s, co| {
1394 s.print_string(&co.as_str(), ast::StrStyle::Cooked);
1396 s.print_expr(&inputs[in_idx]);
1401 self.word_space(":");
1403 self.commasep(Inconsistent, &a.clobbers, |s, co| {
1404 s.print_string(&co.as_str(), ast::StrStyle::Cooked);
1407 let mut options = vec![];
1409 options.push("volatile");
1412 options.push("alignstack");
1414 if a.dialect == ast::AsmDialect::Intel {
1415 options.push("intel");
1418 if !options.is_empty() {
1420 self.word_space(":");
1421 self.commasep(Inconsistent, &options, |s, &co| {
1422 s.print_string(co, ast::StrStyle::Cooked);
1428 hir::ExprKind::Yield(ref expr, _) => {
1429 self.word_space("yield");
1430 self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
1432 hir::ExprKind::Err => {
1434 self.s.word("/*ERROR*/");
1438 self.ann.post(self, AnnNode::Expr(expr));
1442 pub fn print_local_decl(&mut self, loc: &hir::Local) {
1443 self.print_pat(&loc.pat);
1444 if let Some(ref ty) = loc.ty {
1445 self.word_space(":");
1446 self.print_type(&ty);
1450 pub fn print_usize(&mut self, i: usize) {
1451 self.s.word(i.to_string())
1454 pub fn print_name(&mut self, name: ast::Name) {
1455 self.print_ident(ast::Ident::with_empty_ctxt(name))
1458 pub fn print_for_decl(&mut self, loc: &hir::Local, coll: &hir::Expr) {
1459 self.print_local_decl(loc);
1461 self.word_space("in");
1462 self.print_expr(coll)
1465 pub fn print_path(&mut self,
1467 colons_before_params: bool)
1469 self.maybe_print_comment(path.span.lo());
1471 for (i, segment) in path.segments.iter().enumerate() {
1475 if segment.ident.name != kw::PathRoot {
1476 self.print_ident(segment.ident);
1477 self.print_generic_args(segment.generic_args(), segment.infer_args,
1478 colons_before_params);
1483 pub fn print_path_segment(&mut self, segment: &hir::PathSegment) {
1484 if segment.ident.name != kw::PathRoot {
1485 self.print_ident(segment.ident);
1486 self.print_generic_args(segment.generic_args(), segment.infer_args, false);
1490 pub fn print_qpath(&mut self,
1492 colons_before_params: bool)
1495 hir::QPath::Resolved(None, ref path) => {
1496 self.print_path(path, colons_before_params)
1498 hir::QPath::Resolved(Some(ref qself), ref path) => {
1500 self.print_type(qself);
1502 self.word_space("as");
1504 for (i, segment) in path.segments[..path.segments.len() - 1].iter().enumerate() {
1508 if segment.ident.name != kw::PathRoot {
1509 self.print_ident(segment.ident);
1510 self.print_generic_args(segment.generic_args(),
1512 colons_before_params);
1518 let item_segment = path.segments.last().unwrap();
1519 self.print_ident(item_segment.ident);
1520 self.print_generic_args(item_segment.generic_args(),
1521 item_segment.infer_args,
1522 colons_before_params)
1524 hir::QPath::TypeRelative(ref qself, ref item_segment) => {
1526 self.print_type(qself);
1529 self.print_ident(item_segment.ident);
1530 self.print_generic_args(item_segment.generic_args(),
1531 item_segment.infer_args,
1532 colons_before_params)
1537 fn print_generic_args(&mut self,
1538 generic_args: &hir::GenericArgs,
1540 colons_before_params: bool)
1542 if generic_args.parenthesized {
1544 self.commasep(Inconsistent, generic_args.inputs(), |s, ty| s.print_type(&ty));
1547 self.space_if_not_bol();
1548 self.word_space("->");
1549 self.print_type(generic_args.bindings[0].ty());
1551 let start = if colons_before_params { "::<" } else { "<" };
1552 let empty = Cell::new(true);
1553 let start_or_comma = |this: &mut Self| {
1558 this.word_space(",")
1562 let mut nonelided_generic_args: bool = false;
1563 let elide_lifetimes = generic_args.args.iter().all(|arg| match arg {
1564 GenericArg::Lifetime(lt) => lt.is_elided(),
1566 nonelided_generic_args = true;
1571 if nonelided_generic_args {
1572 start_or_comma(self);
1573 self.commasep(Inconsistent, &generic_args.args, |s, generic_arg| {
1575 GenericArg::Lifetime(lt) if !elide_lifetimes => s.print_lifetime(lt),
1576 GenericArg::Lifetime(_) => {},
1577 GenericArg::Type(ty) => s.print_type(ty),
1578 GenericArg::Const(ct) => s.print_anon_const(&ct.value),
1583 // FIXME(eddyb): this would leak into error messages (e.g.,
1584 // "non-exhaustive patterns: `Some::<..>(_)` not covered").
1585 if infer_args && false {
1586 start_or_comma(self);
1590 for binding in generic_args.bindings.iter() {
1591 start_or_comma(self);
1592 self.print_ident(binding.ident);
1594 match generic_args.bindings[0].kind {
1595 hir::TypeBindingKind::Equality { ref ty } => {
1596 self.word_space("=");
1597 self.print_type(ty);
1599 hir::TypeBindingKind::Constraint { ref bounds } => {
1600 self.print_bounds(":", bounds);
1611 pub fn print_pat(&mut self, pat: &hir::Pat) {
1612 self.maybe_print_comment(pat.span.lo());
1613 self.ann.pre(self, AnnNode::Pat(pat));
1614 // Pat isn't normalized, but the beauty of it
1615 // is that it doesn't matter
1617 PatKind::Wild => self.s.word("_"),
1618 PatKind::Binding(binding_mode, _, ident, ref sub) => {
1619 match binding_mode {
1620 hir::BindingAnnotation::Ref => {
1621 self.word_nbsp("ref");
1622 self.print_mutability(hir::MutImmutable);
1624 hir::BindingAnnotation::RefMut => {
1625 self.word_nbsp("ref");
1626 self.print_mutability(hir::MutMutable);
1628 hir::BindingAnnotation::Unannotated => {}
1629 hir::BindingAnnotation::Mutable => {
1630 self.word_nbsp("mut");
1633 self.print_ident(ident);
1634 if let Some(ref p) = *sub {
1639 PatKind::TupleStruct(ref qpath, ref elts, ddpos) => {
1640 self.print_qpath(qpath, true);
1642 if let Some(ddpos) = ddpos {
1643 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
1645 self.word_space(",");
1648 if ddpos != elts.len() {
1650 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
1653 self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p));
1657 PatKind::Path(ref qpath) => {
1658 self.print_qpath(qpath, true);
1660 PatKind::Struct(ref qpath, ref fields, etc) => {
1661 self.print_qpath(qpath, true);
1663 self.word_space("{");
1664 self.commasep_cmnt(Consistent,
1667 s.cbox(INDENT_UNIT);
1668 if !f.node.is_shorthand {
1669 s.print_ident(f.node.ident);
1672 s.print_pat(&f.node.pat);
1675 |f| f.node.pat.span);
1677 if !fields.is_empty() {
1678 self.word_space(",");
1685 PatKind::Tuple(ref elts, ddpos) => {
1687 if let Some(ddpos) = ddpos {
1688 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
1690 self.word_space(",");
1693 if ddpos != elts.len() {
1695 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
1698 self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p));
1699 if elts.len() == 1 {
1705 PatKind::Box(ref inner) => {
1706 let is_range_inner = match inner.node {
1707 PatKind::Range(..) => true,
1710 self.s.word("box ");
1714 self.print_pat(&inner);
1719 PatKind::Ref(ref inner, mutbl) => {
1720 let is_range_inner = match inner.node {
1721 PatKind::Range(..) => true,
1725 if mutbl == hir::MutMutable {
1726 self.s.word("mut ");
1731 self.print_pat(&inner);
1736 PatKind::Lit(ref e) => self.print_expr(&e),
1737 PatKind::Range(ref begin, ref end, ref end_kind) => {
1738 self.print_expr(&begin);
1741 RangeEnd::Included => self.s.word("..."),
1742 RangeEnd::Excluded => self.s.word(".."),
1744 self.print_expr(&end);
1746 PatKind::Slice(ref before, ref slice, ref after) => {
1748 self.commasep(Inconsistent, &before[..], |s, p| s.print_pat(&p));
1749 if let Some(ref p) = *slice {
1750 if !before.is_empty() {
1751 self.word_space(",");
1753 if let PatKind::Wild = p.node {
1759 if !after.is_empty() {
1760 self.word_space(",");
1763 self.commasep(Inconsistent, &after[..], |s, p| s.print_pat(&p));
1767 self.ann.post(self, AnnNode::Pat(pat))
1770 pub fn print_arm(&mut self, arm: &hir::Arm) {
1771 // I have no idea why this check is necessary, but here it
1773 if arm.attrs.is_empty() {
1776 self.cbox(INDENT_UNIT);
1777 self.ann.pre(self, AnnNode::Arm(arm));
1779 self.print_outer_attributes(&arm.attrs);
1780 let mut first = true;
1781 for p in &arm.pats {
1786 self.word_space("|");
1791 if let Some(ref g) = arm.guard {
1793 hir::Guard::If(e) => {
1794 self.word_space("if");
1795 self.print_expr(&e);
1800 self.word_space("=>");
1802 match arm.body.node {
1803 hir::ExprKind::Block(ref blk, opt_label) => {
1804 if let Some(label) = opt_label {
1805 self.print_ident(label.ident);
1806 self.word_space(":");
1808 // the block will close the pattern's ibox
1809 self.print_block_unclosed(&blk);
1811 // If it is a user-provided unsafe block, print a comma after it
1812 if let hir::UnsafeBlock(hir::UserProvided) = blk.rules {
1817 self.end(); // close the ibox for the pattern
1818 self.print_expr(&arm.body);
1822 self.ann.post(self, AnnNode::Arm(arm));
1823 self.end() // close enclosing cbox
1826 pub fn print_fn(&mut self,
1828 header: hir::FnHeader,
1829 name: Option<ast::Name>,
1830 generics: &hir::Generics,
1831 vis: &hir::Visibility,
1832 arg_names: &[ast::Ident],
1833 body_id: Option<hir::BodyId>)
1835 self.print_fn_header_info(header, vis);
1837 if let Some(name) = name {
1839 self.print_name(name);
1841 self.print_generic_params(&generics.params);
1845 // Make sure we aren't supplied *both* `arg_names` and `body_id`.
1846 assert!(arg_names.is_empty() || body_id.is_none());
1847 self.commasep(Inconsistent, &decl.inputs, |s, ty| {
1848 s.ibox(INDENT_UNIT);
1849 if let Some(arg_name) = arg_names.get(i) {
1850 s.s.word(arg_name.as_str().to_string());
1853 } else if let Some(body_id) = body_id {
1854 s.ann.nested(s, Nested::BodyArgPat(body_id, i));
1862 if decl.c_variadic {
1863 self.s.word(", ...");
1867 self.print_fn_output(decl);
1868 self.print_where_clause(&generics.where_clause)
1871 fn print_closure_args(&mut self, decl: &hir::FnDecl, body_id: hir::BodyId) {
1874 self.commasep(Inconsistent, &decl.inputs, |s, ty| {
1875 s.ibox(INDENT_UNIT);
1877 s.ann.nested(s, Nested::BodyArgPat(body_id, i));
1880 if let hir::TyKind::Infer = ty.node {
1891 if let hir::DefaultReturn(..) = decl.output {
1895 self.space_if_not_bol();
1896 self.word_space("->");
1898 hir::Return(ref ty) => {
1899 self.print_type(&ty);
1900 self.maybe_print_comment(ty.span.lo())
1902 hir::DefaultReturn(..) => unreachable!(),
1906 pub fn print_capture_clause(&mut self, capture_clause: hir::CaptureClause) {
1907 match capture_clause {
1908 hir::CaptureByValue => self.word_space("move"),
1909 hir::CaptureByRef => {},
1913 pub fn print_bounds<'b>(
1915 prefix: &'static str,
1916 bounds: impl IntoIterator<Item = &'b hir::GenericBound>,
1918 let mut first = true;
1919 for bound in bounds {
1921 self.s.word(prefix);
1923 if !(first && prefix.is_empty()) {
1929 self.word_space("+");
1933 GenericBound::Trait(tref, modifier) => {
1934 if modifier == &TraitBoundModifier::Maybe {
1937 self.print_poly_trait_ref(tref);
1939 GenericBound::Outlives(lt) => {
1940 self.print_lifetime(lt);
1946 pub fn print_generic_params(&mut self, generic_params: &[GenericParam]) {
1947 if !generic_params.is_empty() {
1950 self.commasep(Inconsistent, generic_params, |s, param| {
1951 s.print_generic_param(param)
1958 pub fn print_generic_param(&mut self, param: &GenericParam) {
1959 if let GenericParamKind::Const { .. } = param.kind {
1960 self.word_space("const");
1963 self.print_ident(param.name.ident());
1966 GenericParamKind::Lifetime { .. } => {
1968 for bound in ¶m.bounds {
1970 GenericBound::Outlives(lt) => {
1972 self.print_lifetime(lt);
1979 GenericParamKind::Type { ref default, .. } => {
1980 self.print_bounds(":", ¶m.bounds);
1984 self.word_space("=");
1985 self.print_type(&default)
1990 GenericParamKind::Const { ref ty } => {
1991 self.word_space(":");
1997 pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) {
1998 self.print_ident(lifetime.name.ident())
2001 pub fn print_where_clause(&mut self, where_clause: &hir::WhereClause) {
2002 if where_clause.predicates.is_empty() {
2007 self.word_space("where");
2009 for (i, predicate) in where_clause.predicates.iter().enumerate() {
2011 self.word_space(",");
2015 &hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
2016 ref bound_generic_params,
2021 self.print_formal_generic_params(bound_generic_params);
2022 self.print_type(&bounded_ty);
2023 self.print_bounds(":", bounds);
2025 &hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate{ref lifetime,
2028 self.print_lifetime(lifetime);
2031 for (i, bound) in bounds.iter().enumerate() {
2033 GenericBound::Outlives(lt) => {
2034 self.print_lifetime(lt);
2044 &hir::WherePredicate::EqPredicate(hir::WhereEqPredicate{ref lhs_ty,
2047 self.print_type(lhs_ty);
2049 self.word_space("=");
2050 self.print_type(rhs_ty);
2056 pub fn print_mutability(&mut self, mutbl: hir::Mutability) {
2058 hir::MutMutable => self.word_nbsp("mut"),
2059 hir::MutImmutable => {},
2063 pub fn print_mt(&mut self, mt: &hir::MutTy) {
2064 self.print_mutability(mt.mutbl);
2065 self.print_type(&mt.ty)
2068 pub fn print_fn_output(&mut self, decl: &hir::FnDecl) {
2069 if let hir::DefaultReturn(..) = decl.output {
2073 self.space_if_not_bol();
2074 self.ibox(INDENT_UNIT);
2075 self.word_space("->");
2077 hir::DefaultReturn(..) => unreachable!(),
2078 hir::Return(ref ty) => self.print_type(&ty),
2083 hir::Return(ref output) => self.maybe_print_comment(output.span.lo()),
2088 pub fn print_ty_fn(&mut self,
2090 unsafety: hir::Unsafety,
2092 name: Option<ast::Name>,
2093 generic_params: &[hir::GenericParam],
2094 arg_names: &[ast::Ident])
2096 self.ibox(INDENT_UNIT);
2097 if !generic_params.is_empty() {
2099 self.print_generic_params(generic_params);
2101 let generics = hir::Generics {
2102 params: hir::HirVec::new(),
2103 where_clause: hir::WhereClause {
2104 predicates: hir::HirVec::new(),
2105 span: syntax_pos::DUMMY_SP,
2107 span: syntax_pos::DUMMY_SP,
2113 constness: hir::Constness::NotConst,
2114 asyncness: hir::IsAsync::NotAsync,
2118 &Spanned { span: syntax_pos::DUMMY_SP,
2119 node: hir::VisibilityKind::Inherited },
2125 pub fn maybe_print_trailing_comment(&mut self,
2126 span: syntax_pos::Span,
2127 next_pos: Option<BytePos>)
2129 if let Some(cmnts) = self.comments() {
2130 if let Some(cmnt) = cmnts.trailing_comment(span, next_pos) {
2131 self.print_comment(&cmnt);
2136 pub fn print_remaining_comments(&mut self) {
2137 // If there aren't any remaining comments, then we need to manually
2138 // make sure there is a line break at the end.
2139 if self.next_comment().is_none() {
2142 while let Some(ref cmnt) = self.next_comment() {
2143 self.print_comment(cmnt)
2147 pub fn print_opt_abi_and_extern_if_nondefault(&mut self,
2148 opt_abi: Option<Abi>)
2151 Some(Abi::Rust) => {},
2153 self.word_nbsp("extern");
2154 self.word_nbsp(abi.to_string())
2160 pub fn print_extern_opt_abi(&mut self, opt_abi: Option<Abi>) {
2163 self.word_nbsp("extern");
2164 self.word_nbsp(abi.to_string())
2170 pub fn print_fn_header_info(&mut self,
2171 header: hir::FnHeader,
2172 vis: &hir::Visibility)
2174 self.s.word(visibility_qualified(vis, ""));
2176 match header.constness {
2177 hir::Constness::NotConst => {}
2178 hir::Constness::Const => self.word_nbsp("const"),
2181 match header.asyncness {
2182 hir::IsAsync::NotAsync => {}
2183 hir::IsAsync::Async => self.word_nbsp("async"),
2186 self.print_unsafety(header.unsafety);
2188 if header.abi != Abi::Rust {
2189 self.word_nbsp("extern");
2190 self.word_nbsp(header.abi.to_string());
2196 pub fn print_unsafety(&mut self, s: hir::Unsafety) {
2198 hir::Unsafety::Normal => {}
2199 hir::Unsafety::Unsafe => self.word_nbsp("unsafe"),
2203 pub fn print_is_auto(&mut self, s: hir::IsAuto) {
2205 hir::IsAuto::Yes => self.word_nbsp("auto"),
2206 hir::IsAuto::No => {},
2211 // Dup'ed from parse::classify, but adapted for the HIR.
2212 /// Does this expression require a semicolon to be treated
2213 /// as a statement? The negation of this: 'can this expression
2214 /// be used as a statement without a semicolon' -- is used
2215 /// as an early-bail-out in the parser so that, for instance,
2216 /// if true {...} else {...}
2218 /// isn't parsed as (if true {...} else {...} | x) | 5
2219 fn expr_requires_semi_to_be_stmt(e: &hir::Expr) -> bool {
2221 hir::ExprKind::Match(..) |
2222 hir::ExprKind::Block(..) |
2223 hir::ExprKind::Loop(..) => false,
2228 /// this statement requires a semicolon after it.
2229 /// note that in one case (stmt_semi), we've already
2230 /// seen the semicolon, and thus don't need another.
2231 fn stmt_ends_with_semi(stmt: &hir::StmtKind) -> bool {
2233 hir::StmtKind::Local(_) => true,
2234 hir::StmtKind::Item(_) => false,
2235 hir::StmtKind::Expr(ref e) => expr_requires_semi_to_be_stmt(&e),
2236 hir::StmtKind::Semi(..) => false,
2240 fn bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp {
2241 use crate::hir::BinOpKind::*;
2243 Add => AssocOp::Add,
2244 Sub => AssocOp::Subtract,
2245 Mul => AssocOp::Multiply,
2246 Div => AssocOp::Divide,
2247 Rem => AssocOp::Modulus,
2249 And => AssocOp::LAnd,
2252 BitXor => AssocOp::BitXor,
2253 BitAnd => AssocOp::BitAnd,
2254 BitOr => AssocOp::BitOr,
2255 Shl => AssocOp::ShiftLeft,
2256 Shr => AssocOp::ShiftRight,
2258 Eq => AssocOp::Equal,
2259 Lt => AssocOp::Less,
2260 Le => AssocOp::LessEqual,
2261 Ne => AssocOp::NotEqual,
2262 Ge => AssocOp::GreaterEqual,
2263 Gt => AssocOp::Greater,
2267 /// Expressions that syntactically contain an "exterior" struct literal i.e., not surrounded by any
2268 /// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
2269 /// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.
2270 fn contains_exterior_struct_lit(value: &hir::Expr) -> bool {
2272 hir::ExprKind::Struct(..) => true,
2274 hir::ExprKind::Assign(ref lhs, ref rhs) |
2275 hir::ExprKind::AssignOp(_, ref lhs, ref rhs) |
2276 hir::ExprKind::Binary(_, ref lhs, ref rhs) => {
2277 // X { y: 1 } + X { y: 2 }
2278 contains_exterior_struct_lit(&lhs) || contains_exterior_struct_lit(&rhs)
2280 hir::ExprKind::Unary(_, ref x) |
2281 hir::ExprKind::Cast(ref x, _) |
2282 hir::ExprKind::Type(ref x, _) |
2283 hir::ExprKind::Field(ref x, _) |
2284 hir::ExprKind::Index(ref x, _) => {
2285 // &X { y: 1 }, X { y: 1 }.y
2286 contains_exterior_struct_lit(&x)
2289 hir::ExprKind::MethodCall(.., ref exprs) => {
2290 // X { y: 1 }.bar(...)
2291 contains_exterior_struct_lit(&exprs[0])