1 #![recursion_limit = "256"]
4 use rustc_ast::util::parser::{self, AssocOp, Fixity};
5 use rustc_ast_pretty::pp::Breaks::{Consistent, Inconsistent};
6 use rustc_ast_pretty::pp::{self, Breaks};
7 use rustc_ast_pretty::pprust::{Comments, PrintState};
9 use rustc_hir::{GenericArg, GenericParam, GenericParamKind, Node, Term};
10 use rustc_hir::{GenericBound, PatKind, RangeEnd, TraitBoundModifier};
11 use rustc_span::source_map::{SourceMap, Spanned};
12 use rustc_span::symbol::{kw, Ident, IdentPrinter, Symbol};
13 use rustc_span::{self, FileName};
14 use rustc_target::spec::abi::Abi;
20 pub fn id_to_string(map: &dyn rustc_hir::intravisit::Map<'_>, hir_id: hir::HirId) -> String {
21 to_string(&map, |s| s.print_node(map.find(hir_id).unwrap()))
24 pub enum AnnNode<'a> {
26 Block(&'a hir::Block<'a>),
27 Item(&'a hir::Item<'a>),
29 Expr(&'a hir::Expr<'a>),
30 Pat(&'a hir::Pat<'a>),
31 Arm(&'a hir::Arm<'a>),
36 TraitItem(hir::TraitItemId),
37 ImplItem(hir::ImplItemId),
38 ForeignItem(hir::ForeignItemId),
40 BodyParamPat(hir::BodyId, usize),
44 fn nested(&self, _state: &mut State<'_>, _nested: Nested) {}
45 fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
46 fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
50 impl PpAnn for NoAnn {}
51 pub const NO_ANN: &dyn PpAnn = &NoAnn;
53 /// Identical to the `PpAnn` implementation for `hir::Crate`,
54 /// except it avoids creating a dependency on the whole crate.
55 impl PpAnn for &dyn rustc_hir::intravisit::Map<'_> {
56 fn nested(&self, state: &mut State<'_>, nested: Nested) {
58 Nested::Item(id) => state.print_item(self.item(id)),
59 Nested::TraitItem(id) => state.print_trait_item(self.trait_item(id)),
60 Nested::ImplItem(id) => state.print_impl_item(self.impl_item(id)),
61 Nested::ForeignItem(id) => state.print_foreign_item(self.foreign_item(id)),
62 Nested::Body(id) => state.print_expr(&self.body(id).value),
63 Nested::BodyParamPat(id, i) => state.print_pat(&self.body(id).params[i].pat),
68 pub struct State<'a> {
70 comments: Option<Comments<'a>>,
71 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
72 ann: &'a (dyn PpAnn + 'a),
76 pub fn print_node(&mut self, node: Node<'_>) {
78 Node::Param(a) => self.print_param(&a),
79 Node::Item(a) => self.print_item(&a),
80 Node::ForeignItem(a) => self.print_foreign_item(&a),
81 Node::TraitItem(a) => self.print_trait_item(a),
82 Node::ImplItem(a) => self.print_impl_item(a),
83 Node::Variant(a) => self.print_variant(&a),
84 Node::AnonConst(a) => self.print_anon_const(&a),
85 Node::Expr(a) => self.print_expr(&a),
86 Node::Stmt(a) => self.print_stmt(&a),
87 Node::PathSegment(a) => self.print_path_segment(&a),
88 Node::Ty(a) => self.print_type(&a),
89 Node::TraitRef(a) => self.print_trait_ref(&a),
90 Node::Binding(a) | Node::Pat(a) => self.print_pat(&a),
91 Node::Arm(a) => self.print_arm(&a),
92 Node::Infer(_) => self.word("_"),
94 // Containing cbox, will be closed by print-block at `}`.
95 self.cbox(INDENT_UNIT);
96 // Head-ibox, will be closed by print-block after `{`.
100 Node::Lifetime(a) => self.print_lifetime(&a),
101 Node::Visibility(a) => self.print_visibility(&a),
102 Node::GenericParam(_) => panic!("cannot print Node::GenericParam"),
103 Node::Field(_) => panic!("cannot print Node::Field"),
104 // These cases do not carry enough information in the
105 // `hir_map` to reconstruct their full structure for pretty
107 Node::Ctor(..) => panic!("cannot print isolated Ctor"),
108 Node::Local(a) => self.print_local_decl(&a),
109 Node::Crate(..) => panic!("cannot print Crate"),
114 impl std::ops::Deref for State<'_> {
115 type Target = pp::Printer;
116 fn deref(&self) -> &Self::Target {
121 impl std::ops::DerefMut for State<'_> {
122 fn deref_mut(&mut self) -> &mut Self::Target {
127 impl<'a> PrintState<'a> for State<'a> {
128 fn comments(&mut self) -> &mut Option<Comments<'a>> {
132 fn print_ident(&mut self, ident: Ident) {
133 self.word(IdentPrinter::for_ast_ident(ident, ident.is_raw_guess()).to_string());
134 self.ann.post(self, AnnNode::Name(&ident.name))
137 fn print_generic_args(&mut self, _: &ast::GenericArgs, _colons_before_params: bool) {
138 panic!("AST generic args printed by HIR pretty-printer");
142 pub const INDENT_UNIT: isize = 4;
144 /// Requires you to pass an input filename and reader so that
145 /// it can scan the input text for comments to copy forward.
146 pub fn print_crate<'a>(
148 krate: &hir::Mod<'_>,
151 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
154 let mut s = State::new_from_input(sm, filename, input, attrs, ann);
156 // When printing the AST, we sometimes need to inject `#[no_std]` here.
157 // Since you can't compile the HIR, it's not necessary.
159 s.print_mod(krate, (*attrs)(hir::CRATE_HIR_ID));
160 s.print_remaining_comments();
165 pub fn new_from_input(
169 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
173 s: pp::Printer::new(),
174 comments: Some(Comments::new(sm, filename, input)),
180 fn attrs(&self, id: hir::HirId) -> &'a [ast::Attribute] {
185 pub fn to_string<F>(ann: &dyn PpAnn, f: F) -> String
187 F: FnOnce(&mut State<'_>),
189 let mut printer = State { s: pp::Printer::new(), comments: None, attrs: &|_| &[], ann };
194 pub fn visibility_qualified<S: Into<Cow<'static, str>>>(vis: &hir::Visibility<'_>, w: S) -> String {
195 to_string(NO_ANN, |s| {
196 s.print_visibility(vis);
201 pub fn generic_params_to_string(generic_params: &[GenericParam<'_>]) -> String {
202 to_string(NO_ANN, |s| s.print_generic_params(generic_params))
205 pub fn bounds_to_string<'b>(bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>) -> String {
206 to_string(NO_ANN, |s| s.print_bounds("", bounds))
209 pub fn ty_to_string(ty: &hir::Ty<'_>) -> String {
210 to_string(NO_ANN, |s| s.print_type(ty))
213 pub fn path_segment_to_string(segment: &hir::PathSegment<'_>) -> String {
214 to_string(NO_ANN, |s| s.print_path_segment(segment))
217 pub fn path_to_string(segment: &hir::Path<'_>) -> String {
218 to_string(NO_ANN, |s| s.print_path(segment, false))
222 decl: &hir::FnDecl<'_>,
223 header: hir::FnHeader,
224 name: Option<Symbol>,
225 generics: &hir::Generics<'_>,
226 vis: &hir::Visibility<'_>,
228 body_id: Option<hir::BodyId>,
230 to_string(NO_ANN, |s| s.print_fn(decl, header, name, generics, vis, arg_names, body_id))
233 pub fn enum_def_to_string(
234 enum_definition: &hir::EnumDef<'_>,
235 generics: &hir::Generics<'_>,
237 span: rustc_span::Span,
238 visibility: &hir::Visibility<'_>,
240 to_string(NO_ANN, |s| s.print_enum_def(enum_definition, generics, name, span, visibility))
244 pub fn bclose_maybe_open(&mut self, span: rustc_span::Span, close_box: bool) {
245 self.maybe_print_comment(span.hi());
246 self.break_offset_if_not_bol(1, -(INDENT_UNIT as isize));
249 self.end(); // close the outer-box
253 pub fn bclose(&mut self, span: rustc_span::Span) {
254 self.bclose_maybe_open(span, true)
257 pub fn commasep_cmnt<T, F, G>(&mut self, b: Breaks, elts: &[T], mut op: F, mut get_span: G)
259 F: FnMut(&mut State<'_>, &T),
260 G: FnMut(&T) -> rustc_span::Span,
263 let len = elts.len();
266 self.maybe_print_comment(get_span(elt).hi());
271 self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi()));
272 self.space_if_not_bol();
278 pub fn commasep_exprs(&mut self, b: Breaks, exprs: &[hir::Expr<'_>]) {
279 self.commasep_cmnt(b, exprs, |s, e| s.print_expr(&e), |e| e.span)
282 pub fn print_mod(&mut self, _mod: &hir::Mod<'_>, attrs: &[ast::Attribute]) {
283 self.print_inner_attributes(attrs);
284 for &item_id in _mod.item_ids {
285 self.ann.nested(self, Nested::Item(item_id));
289 pub fn print_opt_lifetime(&mut self, lifetime: &hir::Lifetime) {
290 if !lifetime.is_elided() {
291 self.print_lifetime(lifetime);
296 pub fn print_type(&mut self, ty: &hir::Ty<'_>) {
297 self.maybe_print_comment(ty.span.lo());
300 hir::TyKind::Slice(ref ty) => {
302 self.print_type(&ty);
305 hir::TyKind::Ptr(ref mt) => {
307 self.print_mt(mt, true);
309 hir::TyKind::Rptr(ref lifetime, ref mt) => {
311 self.print_opt_lifetime(lifetime);
312 self.print_mt(mt, false);
314 hir::TyKind::Never => {
317 hir::TyKind::Tup(ref elts) => {
319 self.commasep(Inconsistent, &elts, |s, ty| s.print_type(&ty));
325 hir::TyKind::BareFn(ref f) => {
335 hir::TyKind::OpaqueDef(..) => self.word("/*impl Trait*/"),
336 hir::TyKind::Path(ref qpath) => self.print_qpath(qpath, false),
337 hir::TyKind::TraitObject(bounds, ref lifetime, syntax) => {
338 if syntax == ast::TraitObjectSyntax::Dyn {
339 self.word_space("dyn");
341 let mut first = true;
342 for bound in bounds {
347 self.word_space("+");
349 self.print_poly_trait_ref(bound);
351 if !lifetime.is_elided() {
353 self.word_space("+");
354 self.print_lifetime(lifetime);
357 hir::TyKind::Array(ref ty, ref length) => {
359 self.print_type(&ty);
361 self.print_array_length(length);
364 hir::TyKind::Typeof(ref e) => {
365 self.word("typeof(");
366 self.print_anon_const(e);
369 hir::TyKind::Err => {
371 self.word("/*ERROR*/");
374 hir::TyKind::Infer => {
381 pub fn print_foreign_item(&mut self, item: &hir::ForeignItem<'_>) {
382 self.hardbreak_if_not_bol();
383 self.maybe_print_comment(item.span.lo());
384 self.print_outer_attributes(self.attrs(item.hir_id()));
386 hir::ForeignItemKind::Fn(ref decl, ref arg_names, ref generics) => {
391 unsafety: hir::Unsafety::Normal,
392 constness: hir::Constness::NotConst,
394 asyncness: hir::IsAsync::NotAsync,
396 Some(item.ident.name),
402 self.end(); // end head-ibox
404 self.end() // end the outer fn box
406 hir::ForeignItemKind::Static(ref t, m) => {
407 self.head(visibility_qualified(&item.vis, "static"));
408 if m == hir::Mutability::Mut {
409 self.word_space("mut");
411 self.print_ident(item.ident);
412 self.word_space(":");
415 self.end(); // end the head-ibox
416 self.end() // end the outer cbox
418 hir::ForeignItemKind::Type => {
419 self.head(visibility_qualified(&item.vis, "type"));
420 self.print_ident(item.ident);
422 self.end(); // end the head-ibox
423 self.end() // end the outer cbox
428 fn print_associated_const(
432 default: Option<hir::BodyId>,
433 vis: &hir::Visibility<'_>,
435 self.word(visibility_qualified(vis, ""));
436 self.word_space("const");
437 self.print_ident(ident);
438 self.word_space(":");
440 if let Some(expr) = default {
442 self.word_space("=");
443 self.ann.nested(self, Nested::Body(expr));
448 fn print_associated_type(
451 generics: &hir::Generics<'_>,
452 bounds: Option<hir::GenericBounds<'_>>,
453 ty: Option<&hir::Ty<'_>>,
455 self.word_space("type");
456 self.print_ident(ident);
457 self.print_generic_params(&generics.params);
458 if let Some(bounds) = bounds {
459 self.print_bounds(":", bounds);
461 self.print_where_clause(&generics.where_clause);
462 if let Some(ty) = ty {
464 self.word_space("=");
472 item: &hir::Item<'_>,
473 generics: &hir::Generics<'_>,
474 inner: impl Fn(&mut Self),
476 self.head(visibility_qualified(&item.vis, "type"));
477 self.print_ident(item.ident);
478 self.print_generic_params(&generics.params);
479 self.end(); // end the inner ibox
481 self.print_where_clause(&generics.where_clause);
485 self.end(); // end the outer ibox
488 /// Pretty-print an item
489 pub fn print_item(&mut self, item: &hir::Item<'_>) {
490 self.hardbreak_if_not_bol();
491 self.maybe_print_comment(item.span.lo());
492 let attrs = self.attrs(item.hir_id());
493 self.print_outer_attributes(attrs);
494 self.ann.pre(self, AnnNode::Item(item));
496 hir::ItemKind::ExternCrate(orig_name) => {
497 self.head(visibility_qualified(&item.vis, "extern crate"));
498 if let Some(orig_name) = orig_name {
499 self.print_name(orig_name);
504 self.print_ident(item.ident);
506 self.end(); // end inner head-block
507 self.end(); // end outer head-block
509 hir::ItemKind::Use(ref path, kind) => {
510 self.head(visibility_qualified(&item.vis, "use"));
511 self.print_path(path, false);
514 hir::UseKind::Single => {
515 if path.segments.last().unwrap().ident != item.ident {
517 self.word_space("as");
518 self.print_ident(item.ident);
522 hir::UseKind::Glob => self.word("::*;"),
523 hir::UseKind::ListStem => self.word("::{};"),
525 self.end(); // end inner head-block
526 self.end(); // end outer head-block
528 hir::ItemKind::Static(ref ty, m, expr) => {
529 self.head(visibility_qualified(&item.vis, "static"));
530 if m == hir::Mutability::Mut {
531 self.word_space("mut");
533 self.print_ident(item.ident);
534 self.word_space(":");
535 self.print_type(&ty);
537 self.end(); // end the head-ibox
539 self.word_space("=");
540 self.ann.nested(self, Nested::Body(expr));
542 self.end(); // end the outer cbox
544 hir::ItemKind::Const(ref ty, expr) => {
545 self.head(visibility_qualified(&item.vis, "const"));
546 self.print_ident(item.ident);
547 self.word_space(":");
548 self.print_type(&ty);
550 self.end(); // end the head-ibox
552 self.word_space("=");
553 self.ann.nested(self, Nested::Body(expr));
555 self.end(); // end the outer cbox
557 hir::ItemKind::Fn(ref sig, ref param_names, body) => {
562 Some(item.ident.name),
569 self.end(); // need to close a box
570 self.end(); // need to close a box
571 self.ann.nested(self, Nested::Body(body));
573 hir::ItemKind::Macro(ref macro_def, _) => {
574 self.print_mac_def(macro_def, &item.ident, item.span, |state| {
575 state.print_visibility(&item.vis)
578 hir::ItemKind::Mod(ref _mod) => {
579 self.head(visibility_qualified(&item.vis, "mod"));
580 self.print_ident(item.ident);
583 self.print_mod(_mod, attrs);
584 self.bclose(item.span);
586 hir::ItemKind::ForeignMod { abi, items } => {
588 self.word_nbsp(abi.to_string());
590 self.print_inner_attributes(self.attrs(item.hir_id()));
592 self.ann.nested(self, Nested::ForeignItem(item.id));
594 self.bclose(item.span);
596 hir::ItemKind::GlobalAsm(ref asm) => {
597 self.head(visibility_qualified(&item.vis, "global_asm!"));
598 self.print_inline_asm(asm);
601 hir::ItemKind::TyAlias(ref ty, ref generics) => {
602 self.print_item_type(item, &generics, |state| {
603 state.word_space("=");
604 state.print_type(&ty);
607 hir::ItemKind::OpaqueTy(ref opaque_ty) => {
608 self.print_item_type(item, &opaque_ty.generics, |state| {
609 let mut real_bounds = Vec::with_capacity(opaque_ty.bounds.len());
610 for b in opaque_ty.bounds.iter() {
611 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
613 state.word_space("for ?");
614 state.print_trait_ref(&ptr.trait_ref);
619 state.print_bounds("= impl", real_bounds);
622 hir::ItemKind::Enum(ref enum_definition, ref params) => {
623 self.print_enum_def(enum_definition, params, item.ident.name, item.span, &item.vis);
625 hir::ItemKind::Struct(ref struct_def, ref generics) => {
626 self.head(visibility_qualified(&item.vis, "struct"));
627 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
629 hir::ItemKind::Union(ref struct_def, ref generics) => {
630 self.head(visibility_qualified(&item.vis, "union"));
631 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
633 hir::ItemKind::Impl(hir::Impl {
645 self.print_visibility(&item.vis);
646 self.print_defaultness(defaultness);
647 self.print_unsafety(unsafety);
648 self.word_nbsp("impl");
650 if !generics.params.is_empty() {
651 self.print_generic_params(&generics.params);
655 if constness == hir::Constness::Const {
656 self.word_nbsp("const");
659 if let hir::ImplPolarity::Negative(_) = polarity {
663 if let Some(ref t) = of_trait {
664 self.print_trait_ref(t);
666 self.word_space("for");
669 self.print_type(&self_ty);
670 self.print_where_clause(&generics.where_clause);
674 self.print_inner_attributes(attrs);
675 for impl_item in items {
676 self.ann.nested(self, Nested::ImplItem(impl_item.id));
678 self.bclose(item.span);
680 hir::ItemKind::Trait(is_auto, unsafety, ref generics, ref bounds, trait_items) => {
682 self.print_visibility(&item.vis);
683 self.print_is_auto(is_auto);
684 self.print_unsafety(unsafety);
685 self.word_nbsp("trait");
686 self.print_ident(item.ident);
687 self.print_generic_params(&generics.params);
688 let mut real_bounds = Vec::with_capacity(bounds.len());
689 for b in bounds.iter() {
690 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
692 self.word_space("for ?");
693 self.print_trait_ref(&ptr.trait_ref);
698 self.print_bounds(":", real_bounds);
699 self.print_where_clause(&generics.where_clause);
702 for trait_item in trait_items {
703 self.ann.nested(self, Nested::TraitItem(trait_item.id));
705 self.bclose(item.span);
707 hir::ItemKind::TraitAlias(ref generics, ref bounds) => {
708 self.head(visibility_qualified(&item.vis, "trait"));
709 self.print_ident(item.ident);
710 self.print_generic_params(&generics.params);
711 let mut real_bounds = Vec::with_capacity(bounds.len());
712 // FIXME(durka) this seems to be some quite outdated syntax
713 for b in bounds.iter() {
714 if let GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = *b {
716 self.word_space("for ?");
717 self.print_trait_ref(&ptr.trait_ref);
723 self.print_bounds("=", real_bounds);
724 self.print_where_clause(&generics.where_clause);
726 self.end(); // end inner head-block
727 self.end(); // end outer head-block
730 self.ann.post(self, AnnNode::Item(item))
733 pub fn print_trait_ref(&mut self, t: &hir::TraitRef<'_>) {
734 self.print_path(&t.path, false)
737 fn print_formal_generic_params(&mut self, generic_params: &[hir::GenericParam<'_>]) {
738 if !generic_params.is_empty() {
740 self.print_generic_params(generic_params);
745 fn print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef<'_>) {
746 self.print_formal_generic_params(&t.bound_generic_params);
747 self.print_trait_ref(&t.trait_ref)
750 pub fn print_enum_def(
752 enum_definition: &hir::EnumDef<'_>,
753 generics: &hir::Generics<'_>,
755 span: rustc_span::Span,
756 visibility: &hir::Visibility<'_>,
758 self.head(visibility_qualified(visibility, "enum"));
759 self.print_name(name);
760 self.print_generic_params(&generics.params);
761 self.print_where_clause(&generics.where_clause);
763 self.print_variants(&enum_definition.variants, span)
766 pub fn print_variants(&mut self, variants: &[hir::Variant<'_>], span: rustc_span::Span) {
769 self.space_if_not_bol();
770 self.maybe_print_comment(v.span.lo());
771 self.print_outer_attributes(self.attrs(v.id));
772 self.ibox(INDENT_UNIT);
773 self.print_variant(v);
776 self.maybe_print_trailing_comment(v.span, None);
781 pub fn print_visibility(&mut self, vis: &hir::Visibility<'_>) {
783 hir::VisibilityKind::Public => self.word_nbsp("pub"),
784 hir::VisibilityKind::Crate(ast::CrateSugar::JustCrate) => self.word_nbsp("crate"),
785 hir::VisibilityKind::Crate(ast::CrateSugar::PubCrate) => self.word_nbsp("pub(crate)"),
786 hir::VisibilityKind::Restricted { ref path, .. } => {
788 if path.segments.len() == 1 && path.segments[0].ident.name == kw::Super {
789 // Special case: `super` can print like `pub(super)`.
792 // Everything else requires `in` at present.
793 self.word_nbsp("in");
794 self.print_path(path, false);
798 hir::VisibilityKind::Inherited => (),
802 pub fn print_defaultness(&mut self, defaultness: hir::Defaultness) {
804 hir::Defaultness::Default { .. } => self.word_nbsp("default"),
805 hir::Defaultness::Final => (),
811 struct_def: &hir::VariantData<'_>,
812 generics: &hir::Generics<'_>,
814 span: rustc_span::Span,
815 print_finalizer: bool,
817 self.print_name(name);
818 self.print_generic_params(&generics.params);
820 hir::VariantData::Tuple(..) | hir::VariantData::Unit(..) => {
821 if let hir::VariantData::Tuple(..) = struct_def {
823 self.commasep(Inconsistent, struct_def.fields(), |s, field| {
824 s.maybe_print_comment(field.span.lo());
825 s.print_outer_attributes(s.attrs(field.hir_id));
826 s.print_visibility(&field.vis);
827 s.print_type(&field.ty)
831 self.print_where_clause(&generics.where_clause);
836 self.end() // close the outer-box
838 hir::VariantData::Struct(..) => {
839 self.print_where_clause(&generics.where_clause);
842 self.hardbreak_if_not_bol();
844 for field in struct_def.fields() {
845 self.hardbreak_if_not_bol();
846 self.maybe_print_comment(field.span.lo());
847 self.print_outer_attributes(self.attrs(field.hir_id));
848 self.print_visibility(&field.vis);
849 self.print_ident(field.ident);
851 self.print_type(&field.ty);
860 pub fn print_variant(&mut self, v: &hir::Variant<'_>) {
862 let generics = hir::Generics::empty();
863 self.print_struct(&v.data, &generics, v.ident.name, v.span, false);
864 if let Some(ref d) = v.disr_expr {
866 self.word_space("=");
867 self.print_anon_const(d);
870 pub fn print_method_sig(
874 generics: &hir::Generics<'_>,
875 vis: &hir::Visibility<'_>,
877 body_id: Option<hir::BodyId>,
879 self.print_fn(&m.decl, m.header, Some(ident.name), generics, vis, arg_names, body_id)
882 pub fn print_trait_item(&mut self, ti: &hir::TraitItem<'_>) {
883 self.ann.pre(self, AnnNode::SubItem(ti.hir_id()));
884 self.hardbreak_if_not_bol();
885 self.maybe_print_comment(ti.span.lo());
886 self.print_outer_attributes(self.attrs(ti.hir_id()));
888 hir::TraitItemKind::Const(ref ty, default) => {
890 Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
891 self.print_associated_const(ti.ident, &ty, default, &vis);
893 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref arg_names)) => {
895 Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
896 self.print_method_sig(ti.ident, sig, &ti.generics, &vis, arg_names, None);
899 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
901 Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
903 self.print_method_sig(ti.ident, sig, &ti.generics, &vis, &[], Some(body));
905 self.end(); // need to close a box
906 self.end(); // need to close a box
907 self.ann.nested(self, Nested::Body(body));
909 hir::TraitItemKind::Type(ref bounds, ref default) => {
910 self.print_associated_type(
914 default.as_ref().map(|ty| &**ty),
918 self.ann.post(self, AnnNode::SubItem(ti.hir_id()))
921 pub fn print_impl_item(&mut self, ii: &hir::ImplItem<'_>) {
922 self.ann.pre(self, AnnNode::SubItem(ii.hir_id()));
923 self.hardbreak_if_not_bol();
924 self.maybe_print_comment(ii.span.lo());
925 self.print_outer_attributes(self.attrs(ii.hir_id()));
928 hir::ImplItemKind::Const(ref ty, expr) => {
929 self.print_associated_const(ii.ident, &ty, Some(expr), &ii.vis);
931 hir::ImplItemKind::Fn(ref sig, body) => {
933 self.print_method_sig(ii.ident, sig, &ii.generics, &ii.vis, &[], Some(body));
935 self.end(); // need to close a box
936 self.end(); // need to close a box
937 self.ann.nested(self, Nested::Body(body));
939 hir::ImplItemKind::TyAlias(ref ty) => {
940 self.print_associated_type(ii.ident, &ii.generics, None, Some(ty));
943 self.ann.post(self, AnnNode::SubItem(ii.hir_id()))
946 pub fn print_local(&mut self, init: Option<&hir::Expr<'_>>, decl: impl Fn(&mut Self)) {
947 self.space_if_not_bol();
948 self.ibox(INDENT_UNIT);
949 self.word_nbsp("let");
951 self.ibox(INDENT_UNIT);
955 if let Some(ref init) = init {
957 self.word_space("=");
958 self.print_expr(&init);
963 pub fn print_stmt(&mut self, st: &hir::Stmt<'_>) {
964 self.maybe_print_comment(st.span.lo());
966 hir::StmtKind::Local(ref loc) => {
967 self.print_local(loc.init, |this| this.print_local_decl(&loc));
969 hir::StmtKind::Item(item) => self.ann.nested(self, Nested::Item(item)),
970 hir::StmtKind::Expr(ref expr) => {
971 self.space_if_not_bol();
972 self.print_expr(&expr);
974 hir::StmtKind::Semi(ref expr) => {
975 self.space_if_not_bol();
976 self.print_expr(&expr);
980 if stmt_ends_with_semi(&st.kind) {
983 self.maybe_print_trailing_comment(st.span, None)
986 pub fn print_block(&mut self, blk: &hir::Block<'_>) {
987 self.print_block_with_attrs(blk, &[])
990 pub fn print_block_unclosed(&mut self, blk: &hir::Block<'_>) {
991 self.print_block_maybe_unclosed(blk, &[], false)
994 pub fn print_block_with_attrs(&mut self, blk: &hir::Block<'_>, attrs: &[ast::Attribute]) {
995 self.print_block_maybe_unclosed(blk, attrs, true)
998 pub fn print_block_maybe_unclosed(
1000 blk: &hir::Block<'_>,
1001 attrs: &[ast::Attribute],
1005 hir::BlockCheckMode::UnsafeBlock(..) => self.word_space("unsafe"),
1006 hir::BlockCheckMode::DefaultBlock => (),
1008 self.maybe_print_comment(blk.span.lo());
1009 self.ann.pre(self, AnnNode::Block(blk));
1012 self.print_inner_attributes(attrs);
1014 for st in blk.stmts {
1015 self.print_stmt(st);
1017 if let Some(ref expr) = blk.expr {
1018 self.space_if_not_bol();
1019 self.print_expr(&expr);
1020 self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi()));
1022 self.bclose_maybe_open(blk.span, close_box);
1023 self.ann.post(self, AnnNode::Block(blk))
1026 fn print_else(&mut self, els: Option<&hir::Expr<'_>>) {
1027 if let Some(els_inner) = els {
1028 match els_inner.kind {
1029 // Another `else if` block.
1030 hir::ExprKind::If(ref i, ref then, ref e) => {
1031 self.cbox(INDENT_UNIT - 1);
1033 self.word(" else if ");
1034 self.print_expr_as_cond(&i);
1036 self.print_expr(&then);
1037 self.print_else(e.as_ref().map(|e| &**e))
1039 // Final `else` block.
1040 hir::ExprKind::Block(ref b, _) => {
1041 self.cbox(INDENT_UNIT - 1);
1043 self.word(" else ");
1044 self.print_block(&b)
1046 // Constraints would be great here!
1048 panic!("print_if saw if with weird alternative");
1056 test: &hir::Expr<'_>,
1057 blk: &hir::Expr<'_>,
1058 elseopt: Option<&hir::Expr<'_>>,
1061 self.print_expr_as_cond(test);
1063 self.print_expr(blk);
1064 self.print_else(elseopt)
1067 pub fn print_array_length(&mut self, len: &hir::ArrayLen) {
1069 hir::ArrayLen::Infer(_, _) => self.word("_"),
1070 hir::ArrayLen::Body(ct) => self.print_anon_const(ct),
1074 pub fn print_anon_const(&mut self, constant: &hir::AnonConst) {
1075 self.ann.nested(self, Nested::Body(constant.body))
1078 fn print_call_post(&mut self, args: &[hir::Expr<'_>]) {
1080 self.commasep_exprs(Inconsistent, args);
1084 fn print_expr_maybe_paren(&mut self, expr: &hir::Expr<'_>, prec: i8) {
1085 self.print_expr_cond_paren(expr, expr.precedence().order() < prec)
1088 /// Prints an expr using syntax that's acceptable in a condition position, such as the `cond` in
1089 /// `if cond { ... }`.
1090 pub fn print_expr_as_cond(&mut self, expr: &hir::Expr<'_>) {
1091 self.print_expr_cond_paren(expr, Self::cond_needs_par(expr))
1094 /// Prints `expr` or `(expr)` when `needs_par` holds.
1095 fn print_expr_cond_paren(&mut self, expr: &hir::Expr<'_>, needs_par: bool) {
1099 if let hir::ExprKind::DropTemps(ref actual_expr) = expr.kind {
1100 self.print_expr(actual_expr);
1102 self.print_expr(expr);
1109 /// Print a `let pat = expr` expression.
1110 fn print_let(&mut self, pat: &hir::Pat<'_>, ty: Option<&hir::Ty<'_>>, init: &hir::Expr<'_>) {
1111 self.word_space("let");
1112 self.print_pat(pat);
1113 if let Some(ty) = ty {
1114 self.word_space(":");
1115 self.print_type(ty);
1118 self.word_space("=");
1119 let npals = || parser::needs_par_as_let_scrutinee(init.precedence().order());
1120 self.print_expr_cond_paren(init, Self::cond_needs_par(init) || npals())
1123 // Does `expr` need parentheses when printed in a condition position?
1125 // These cases need parens due to the parse error observed in #26461: `if return {}`
1126 // parses as the erroneous construct `if (return {})`, not `if (return) {}`.
1127 fn cond_needs_par(expr: &hir::Expr<'_>) -> bool {
1129 hir::ExprKind::Break(..) | hir::ExprKind::Closure(..) | hir::ExprKind::Ret(..) => true,
1130 _ => contains_exterior_struct_lit(expr),
1134 fn print_expr_vec(&mut self, exprs: &[hir::Expr<'_>]) {
1135 self.ibox(INDENT_UNIT);
1137 self.commasep_exprs(Inconsistent, exprs);
1142 fn print_expr_anon_const(&mut self, anon_const: &hir::AnonConst) {
1143 self.ibox(INDENT_UNIT);
1144 self.word_space("const");
1145 self.print_anon_const(anon_const);
1149 fn print_expr_repeat(&mut self, element: &hir::Expr<'_>, count: &hir::ArrayLen) {
1150 self.ibox(INDENT_UNIT);
1152 self.print_expr(element);
1153 self.word_space(";");
1154 self.print_array_length(count);
1159 fn print_expr_struct(
1161 qpath: &hir::QPath<'_>,
1162 fields: &[hir::ExprField<'_>],
1163 wth: &Option<&hir::Expr<'_>>,
1165 self.print_qpath(qpath, true);
1171 s.ibox(INDENT_UNIT);
1172 if !field.is_shorthand {
1173 s.print_ident(field.ident);
1176 s.print_expr(&field.expr);
1183 self.ibox(INDENT_UNIT);
1184 if !fields.is_empty() {
1189 self.print_expr(&expr);
1193 if !fields.is_empty() {
1201 fn print_expr_tup(&mut self, exprs: &[hir::Expr<'_>]) {
1203 self.commasep_exprs(Inconsistent, exprs);
1204 if exprs.len() == 1 {
1210 fn print_expr_call(&mut self, func: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
1211 let prec = match func.kind {
1212 hir::ExprKind::Field(..) => parser::PREC_FORCE_PAREN,
1213 _ => parser::PREC_POSTFIX,
1216 self.print_expr_maybe_paren(func, prec);
1217 self.print_call_post(args)
1220 fn print_expr_method_call(&mut self, segment: &hir::PathSegment<'_>, args: &[hir::Expr<'_>]) {
1221 let base_args = &args[1..];
1222 self.print_expr_maybe_paren(&args[0], parser::PREC_POSTFIX);
1224 self.print_ident(segment.ident);
1226 let generic_args = segment.args();
1227 if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
1228 self.print_generic_args(generic_args, segment.infer_args, true);
1231 self.print_call_post(base_args)
1234 fn print_expr_binary(&mut self, op: hir::BinOp, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>) {
1235 let assoc_op = bin_op_to_assoc_op(op.node);
1236 let prec = assoc_op.precedence() as i8;
1237 let fixity = assoc_op.fixity();
1239 let (left_prec, right_prec) = match fixity {
1240 Fixity::Left => (prec, prec + 1),
1241 Fixity::Right => (prec + 1, prec),
1242 Fixity::None => (prec + 1, prec + 1),
1245 let left_prec = match (&lhs.kind, op.node) {
1246 // These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
1247 // the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
1248 // of `(x as i32) < ...`. We need to convince it _not_ to do that.
1249 (&hir::ExprKind::Cast { .. }, hir::BinOpKind::Lt | hir::BinOpKind::Shl) => {
1250 parser::PREC_FORCE_PAREN
1252 (&hir::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(prec) => {
1253 parser::PREC_FORCE_PAREN
1258 self.print_expr_maybe_paren(lhs, left_prec);
1260 self.word_space(op.node.as_str());
1261 self.print_expr_maybe_paren(rhs, right_prec)
1264 fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr<'_>) {
1265 self.word(op.as_str());
1266 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1269 fn print_expr_addr_of(
1271 kind: hir::BorrowKind,
1272 mutability: hir::Mutability,
1273 expr: &hir::Expr<'_>,
1277 hir::BorrowKind::Ref => self.print_mutability(mutability, false),
1278 hir::BorrowKind::Raw => {
1279 self.word_nbsp("raw");
1280 self.print_mutability(mutability, true);
1283 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1286 fn print_literal(&mut self, lit: &hir::Lit) {
1287 self.maybe_print_comment(lit.span.lo());
1288 self.word(lit.node.to_lit_token().to_string())
1291 fn print_inline_asm(&mut self, asm: &hir::InlineAsm<'_>) {
1294 Operand(&'a hir::InlineAsmOperand<'a>),
1295 Options(ast::InlineAsmOptions),
1299 vec![AsmArg::Template(ast::InlineAsmTemplatePiece::to_string(&asm.template))];
1300 args.extend(asm.operands.iter().map(|(o, _)| AsmArg::Operand(o)));
1301 if !asm.options.is_empty() {
1302 args.push(AsmArg::Options(asm.options));
1306 self.commasep(Consistent, &args, |s, arg| match arg {
1307 AsmArg::Template(template) => s.print_string(&template, ast::StrStyle::Cooked),
1308 AsmArg::Operand(op) => match op {
1309 hir::InlineAsmOperand::In { reg, expr } => {
1312 s.word(format!("{}", reg));
1317 hir::InlineAsmOperand::Out { reg, late, expr } => {
1318 s.word(if *late { "lateout" } else { "out" });
1320 s.word(format!("{}", reg));
1324 Some(expr) => s.print_expr(expr),
1325 None => s.word("_"),
1328 hir::InlineAsmOperand::InOut { reg, late, expr } => {
1329 s.word(if *late { "inlateout" } else { "inout" });
1331 s.word(format!("{}", reg));
1336 hir::InlineAsmOperand::SplitInOut { reg, late, in_expr, out_expr } => {
1337 s.word(if *late { "inlateout" } else { "inout" });
1339 s.word(format!("{}", reg));
1342 s.print_expr(in_expr);
1346 Some(out_expr) => s.print_expr(out_expr),
1347 None => s.word("_"),
1350 hir::InlineAsmOperand::Const { anon_const } => {
1353 s.print_anon_const(anon_const);
1355 hir::InlineAsmOperand::Sym { expr } => {
1361 AsmArg::Options(opts) => {
1364 let mut options = vec![];
1365 if opts.contains(ast::InlineAsmOptions::PURE) {
1366 options.push("pure");
1368 if opts.contains(ast::InlineAsmOptions::NOMEM) {
1369 options.push("nomem");
1371 if opts.contains(ast::InlineAsmOptions::READONLY) {
1372 options.push("readonly");
1374 if opts.contains(ast::InlineAsmOptions::PRESERVES_FLAGS) {
1375 options.push("preserves_flags");
1377 if opts.contains(ast::InlineAsmOptions::NORETURN) {
1378 options.push("noreturn");
1380 if opts.contains(ast::InlineAsmOptions::NOSTACK) {
1381 options.push("nostack");
1383 if opts.contains(ast::InlineAsmOptions::ATT_SYNTAX) {
1384 options.push("att_syntax");
1386 if opts.contains(ast::InlineAsmOptions::RAW) {
1387 options.push("raw");
1389 if opts.contains(ast::InlineAsmOptions::MAY_UNWIND) {
1390 options.push("may_unwind");
1392 s.commasep(Inconsistent, &options, |s, &opt| {
1401 pub fn print_expr(&mut self, expr: &hir::Expr<'_>) {
1402 self.maybe_print_comment(expr.span.lo());
1403 self.print_outer_attributes(self.attrs(expr.hir_id));
1404 self.ibox(INDENT_UNIT);
1405 self.ann.pre(self, AnnNode::Expr(expr));
1407 hir::ExprKind::Box(ref expr) => {
1408 self.word_space("box");
1409 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX);
1411 hir::ExprKind::Array(ref exprs) => {
1412 self.print_expr_vec(exprs);
1414 hir::ExprKind::ConstBlock(ref anon_const) => {
1415 self.print_expr_anon_const(anon_const);
1417 hir::ExprKind::Repeat(ref element, ref count) => {
1418 self.print_expr_repeat(&element, count);
1420 hir::ExprKind::Struct(ref qpath, fields, ref wth) => {
1421 self.print_expr_struct(qpath, fields, wth);
1423 hir::ExprKind::Tup(ref exprs) => {
1424 self.print_expr_tup(exprs);
1426 hir::ExprKind::Call(ref func, ref args) => {
1427 self.print_expr_call(&func, args);
1429 hir::ExprKind::MethodCall(ref segment, ref args, _) => {
1430 self.print_expr_method_call(segment, args);
1432 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
1433 self.print_expr_binary(op, &lhs, &rhs);
1435 hir::ExprKind::Unary(op, ref expr) => {
1436 self.print_expr_unary(op, &expr);
1438 hir::ExprKind::AddrOf(k, m, ref expr) => {
1439 self.print_expr_addr_of(k, m, &expr);
1441 hir::ExprKind::Lit(ref lit) => {
1442 self.print_literal(&lit);
1444 hir::ExprKind::Cast(ref expr, ref ty) => {
1445 let prec = AssocOp::As.precedence() as i8;
1446 self.print_expr_maybe_paren(&expr, prec);
1448 self.word_space("as");
1449 self.print_type(&ty);
1451 hir::ExprKind::Type(ref expr, ref ty) => {
1452 let prec = AssocOp::Colon.precedence() as i8;
1453 self.print_expr_maybe_paren(&expr, prec);
1454 self.word_space(":");
1455 self.print_type(&ty);
1457 hir::ExprKind::DropTemps(ref init) => {
1459 self.cbox(INDENT_UNIT);
1463 // Print `let _t = $init;`:
1464 let temp = Ident::from_str("_t");
1465 self.print_local(Some(init), |this| this.print_ident(temp));
1469 self.space_if_not_bol();
1470 self.print_ident(temp);
1473 self.bclose_maybe_open(expr.span, true);
1475 hir::ExprKind::Let(hir::Let { pat, ty, init, .. }) => {
1476 self.print_let(pat, *ty, init);
1478 hir::ExprKind::If(ref test, ref blk, ref elseopt) => {
1479 self.print_if(&test, &blk, elseopt.as_ref().map(|e| &**e));
1481 hir::ExprKind::Loop(ref blk, opt_label, _, _) => {
1482 if let Some(label) = opt_label {
1483 self.print_ident(label.ident);
1484 self.word_space(":");
1487 self.print_block(&blk);
1489 hir::ExprKind::Match(ref expr, arms, _) => {
1490 self.cbox(INDENT_UNIT);
1491 self.ibox(INDENT_UNIT);
1492 self.word_nbsp("match");
1493 self.print_expr_as_cond(&expr);
1497 self.print_arm(arm);
1499 self.bclose(expr.span);
1501 hir::ExprKind::Closure(capture_clause, ref decl, body, _fn_decl_span, _gen) => {
1502 self.print_capture_clause(capture_clause);
1504 self.print_closure_params(&decl, body);
1507 // This is a bare expression.
1508 self.ann.nested(self, Nested::Body(body));
1509 self.end(); // need to close a box
1511 // A box will be closed by `print_expr`, but we didn't want an overall
1512 // wrapper so we closed the corresponding opening. so create an
1513 // empty box to satisfy the close.
1516 hir::ExprKind::Block(ref blk, opt_label) => {
1517 if let Some(label) = opt_label {
1518 self.print_ident(label.ident);
1519 self.word_space(":");
1521 // containing cbox, will be closed by print-block at `}`
1522 self.cbox(INDENT_UNIT);
1523 // head-box, will be closed by print-block after `{`
1525 self.print_block(&blk);
1527 hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
1528 let prec = AssocOp::Assign.precedence() as i8;
1529 self.print_expr_maybe_paren(&lhs, prec + 1);
1531 self.word_space("=");
1532 self.print_expr_maybe_paren(&rhs, prec);
1534 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
1535 let prec = AssocOp::Assign.precedence() as i8;
1536 self.print_expr_maybe_paren(&lhs, prec + 1);
1538 self.word(op.node.as_str());
1539 self.word_space("=");
1540 self.print_expr_maybe_paren(&rhs, prec);
1542 hir::ExprKind::Field(ref expr, ident) => {
1543 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
1545 self.print_ident(ident);
1547 hir::ExprKind::Index(ref expr, ref index) => {
1548 self.print_expr_maybe_paren(&expr, parser::PREC_POSTFIX);
1550 self.print_expr(&index);
1553 hir::ExprKind::Path(ref qpath) => self.print_qpath(qpath, true),
1554 hir::ExprKind::Break(destination, ref opt_expr) => {
1556 if let Some(label) = destination.label {
1558 self.print_ident(label.ident);
1560 if let Some(ref expr) = *opt_expr {
1562 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
1565 hir::ExprKind::Continue(destination) => {
1566 self.word("continue");
1567 if let Some(label) = destination.label {
1569 self.print_ident(label.ident);
1572 hir::ExprKind::Ret(ref result) => {
1573 self.word("return");
1574 if let Some(ref expr) = *result {
1576 self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
1579 hir::ExprKind::InlineAsm(ref asm) => {
1581 self.print_inline_asm(asm);
1583 hir::ExprKind::Yield(ref expr, _) => {
1584 self.word_space("yield");
1585 self.print_expr_maybe_paren(&expr, parser::PREC_JUMP);
1587 hir::ExprKind::Err => {
1589 self.word("/*ERROR*/");
1593 self.ann.post(self, AnnNode::Expr(expr));
1597 pub fn print_local_decl(&mut self, loc: &hir::Local<'_>) {
1598 self.print_pat(&loc.pat);
1599 if let Some(ref ty) = loc.ty {
1600 self.word_space(":");
1601 self.print_type(&ty);
1605 pub fn print_name(&mut self, name: Symbol) {
1606 self.print_ident(Ident::with_dummy_span(name))
1609 pub fn print_path(&mut self, path: &hir::Path<'_>, colons_before_params: bool) {
1610 self.maybe_print_comment(path.span.lo());
1612 for (i, segment) in path.segments.iter().enumerate() {
1616 if segment.ident.name != kw::PathRoot {
1617 self.print_ident(segment.ident);
1618 self.print_generic_args(segment.args(), segment.infer_args, colons_before_params);
1623 pub fn print_path_segment(&mut self, segment: &hir::PathSegment<'_>) {
1624 if segment.ident.name != kw::PathRoot {
1625 self.print_ident(segment.ident);
1626 self.print_generic_args(segment.args(), segment.infer_args, false);
1630 pub fn print_qpath(&mut self, qpath: &hir::QPath<'_>, colons_before_params: bool) {
1632 hir::QPath::Resolved(None, ref path) => self.print_path(path, colons_before_params),
1633 hir::QPath::Resolved(Some(ref qself), ref path) => {
1635 self.print_type(qself);
1637 self.word_space("as");
1639 for (i, segment) in path.segments[..path.segments.len() - 1].iter().enumerate() {
1643 if segment.ident.name != kw::PathRoot {
1644 self.print_ident(segment.ident);
1645 self.print_generic_args(
1648 colons_before_params,
1655 let item_segment = path.segments.last().unwrap();
1656 self.print_ident(item_segment.ident);
1657 self.print_generic_args(
1658 item_segment.args(),
1659 item_segment.infer_args,
1660 colons_before_params,
1663 hir::QPath::TypeRelative(ref qself, ref item_segment) => {
1664 // If we've got a compound-qualified-path, let's push an additional pair of angle
1665 // brackets, so that we pretty-print `<<A::B>::C>` as `<A::B>::C`, instead of just
1666 // `A::B::C` (since the latter could be ambiguous to the user)
1667 if let hir::TyKind::Path(hir::QPath::Resolved(None, _)) = &qself.kind {
1668 self.print_type(qself);
1671 self.print_type(qself);
1676 self.print_ident(item_segment.ident);
1677 self.print_generic_args(
1678 item_segment.args(),
1679 item_segment.infer_args,
1680 colons_before_params,
1683 hir::QPath::LangItem(lang_item, span, _) => {
1684 self.word("#[lang = \"");
1685 self.print_ident(Ident::new(lang_item.name(), span));
1691 fn print_generic_args(
1693 generic_args: &hir::GenericArgs<'_>,
1695 colons_before_params: bool,
1697 if generic_args.parenthesized {
1699 self.commasep(Inconsistent, generic_args.inputs(), |s, ty| s.print_type(&ty));
1702 self.space_if_not_bol();
1703 self.word_space("->");
1704 self.print_type(generic_args.bindings[0].ty());
1706 let start = if colons_before_params { "::<" } else { "<" };
1707 let empty = Cell::new(true);
1708 let start_or_comma = |this: &mut Self| {
1713 this.word_space(",")
1717 let mut nonelided_generic_args: bool = false;
1718 let elide_lifetimes = generic_args.args.iter().all(|arg| match arg {
1719 GenericArg::Lifetime(lt) => lt.is_elided(),
1721 nonelided_generic_args = true;
1726 if nonelided_generic_args {
1727 start_or_comma(self);
1731 |s, generic_arg| match generic_arg {
1732 GenericArg::Lifetime(lt) if !elide_lifetimes => s.print_lifetime(lt),
1733 GenericArg::Lifetime(_) => {}
1734 GenericArg::Type(ty) => s.print_type(ty),
1735 GenericArg::Const(ct) => s.print_anon_const(&ct.value),
1736 GenericArg::Infer(_inf) => s.word("_"),
1741 // FIXME(eddyb): this would leak into error messages (e.g.,
1742 // "non-exhaustive patterns: `Some::<..>(_)` not covered").
1743 if infer_args && false {
1744 start_or_comma(self);
1748 for binding in generic_args.bindings.iter() {
1749 start_or_comma(self);
1750 self.print_ident(binding.ident);
1751 self.print_generic_args(binding.gen_args, false, false);
1753 match generic_args.bindings[0].kind {
1754 hir::TypeBindingKind::Equality { ref term } => {
1755 self.word_space("=");
1757 Term::Ty(ref ty) => self.print_type(ty),
1758 Term::Const(ref c) => self.print_anon_const(c),
1761 hir::TypeBindingKind::Constraint { bounds } => {
1762 self.print_bounds(":", bounds);
1773 pub fn print_pat(&mut self, pat: &hir::Pat<'_>) {
1774 self.maybe_print_comment(pat.span.lo());
1775 self.ann.pre(self, AnnNode::Pat(pat));
1776 // Pat isn't normalized, but the beauty of it
1777 // is that it doesn't matter
1779 PatKind::Wild => self.word("_"),
1780 PatKind::Binding(binding_mode, _, ident, ref sub) => {
1781 match binding_mode {
1782 hir::BindingAnnotation::Ref => {
1783 self.word_nbsp("ref");
1784 self.print_mutability(hir::Mutability::Not, false);
1786 hir::BindingAnnotation::RefMut => {
1787 self.word_nbsp("ref");
1788 self.print_mutability(hir::Mutability::Mut, false);
1790 hir::BindingAnnotation::Unannotated => {}
1791 hir::BindingAnnotation::Mutable => {
1792 self.word_nbsp("mut");
1795 self.print_ident(ident);
1796 if let Some(ref p) = *sub {
1801 PatKind::TupleStruct(ref qpath, ref elts, ddpos) => {
1802 self.print_qpath(qpath, true);
1804 if let Some(ddpos) = ddpos {
1805 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
1807 self.word_space(",");
1810 if ddpos != elts.len() {
1812 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
1815 self.commasep(Inconsistent, &elts, |s, p| s.print_pat(&p));
1819 PatKind::Path(ref qpath) => {
1820 self.print_qpath(qpath, true);
1822 PatKind::Struct(ref qpath, ref fields, etc) => {
1823 self.print_qpath(qpath, true);
1826 let empty = fields.is_empty() && !etc;
1834 s.cbox(INDENT_UNIT);
1835 if !f.is_shorthand {
1836 s.print_ident(f.ident);
1839 s.print_pat(&f.pat);
1845 if !fields.is_empty() {
1846 self.word_space(",");
1855 PatKind::Or(ref pats) => {
1856 self.strsep("|", true, Inconsistent, &pats, |s, p| s.print_pat(&p));
1858 PatKind::Tuple(ref elts, ddpos) => {
1860 if let Some(ddpos) = ddpos {
1861 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p));
1863 self.word_space(",");
1866 if ddpos != elts.len() {
1868 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p));
1871 self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p));
1872 if elts.len() == 1 {
1878 PatKind::Box(ref inner) => {
1879 let is_range_inner = matches!(inner.kind, PatKind::Range(..));
1884 self.print_pat(&inner);
1889 PatKind::Ref(ref inner, mutbl) => {
1890 let is_range_inner = matches!(inner.kind, PatKind::Range(..));
1892 self.word(mutbl.prefix_str());
1896 self.print_pat(&inner);
1901 PatKind::Lit(ref e) => self.print_expr(&e),
1902 PatKind::Range(ref begin, ref end, ref end_kind) => {
1903 if let Some(expr) = begin {
1904 self.print_expr(expr);
1907 RangeEnd::Included => self.word("..."),
1908 RangeEnd::Excluded => self.word(".."),
1910 if let Some(expr) = end {
1911 self.print_expr(expr);
1914 PatKind::Slice(ref before, ref slice, ref after) => {
1916 self.commasep(Inconsistent, &before, |s, p| s.print_pat(&p));
1917 if let Some(ref p) = *slice {
1918 if !before.is_empty() {
1919 self.word_space(",");
1921 if let PatKind::Wild = p.kind {
1927 if !after.is_empty() {
1928 self.word_space(",");
1931 self.commasep(Inconsistent, &after, |s, p| s.print_pat(&p));
1935 self.ann.post(self, AnnNode::Pat(pat))
1938 pub fn print_param(&mut self, arg: &hir::Param<'_>) {
1939 self.print_outer_attributes(self.attrs(arg.hir_id));
1940 self.print_pat(&arg.pat);
1943 pub fn print_arm(&mut self, arm: &hir::Arm<'_>) {
1944 // I have no idea why this check is necessary, but here it
1946 if self.attrs(arm.hir_id).is_empty() {
1949 self.cbox(INDENT_UNIT);
1950 self.ann.pre(self, AnnNode::Arm(arm));
1952 self.print_outer_attributes(&self.attrs(arm.hir_id));
1953 self.print_pat(&arm.pat);
1955 if let Some(ref g) = arm.guard {
1957 hir::Guard::If(e) => {
1958 self.word_space("if");
1959 self.print_expr(&e);
1962 hir::Guard::IfLet(pat, e) => {
1963 self.word_nbsp("if");
1964 self.word_nbsp("let");
1965 self.print_pat(&pat);
1967 self.word_space("=");
1968 self.print_expr(&e);
1973 self.word_space("=>");
1975 match arm.body.kind {
1976 hir::ExprKind::Block(ref blk, opt_label) => {
1977 if let Some(label) = opt_label {
1978 self.print_ident(label.ident);
1979 self.word_space(":");
1981 // the block will close the pattern's ibox
1982 self.print_block_unclosed(&blk);
1984 // If it is a user-provided unsafe block, print a comma after it
1985 if let hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::UserProvided) = blk.rules
1991 self.end(); // close the ibox for the pattern
1992 self.print_expr(&arm.body);
1996 self.ann.post(self, AnnNode::Arm(arm));
1997 self.end() // close enclosing cbox
2002 decl: &hir::FnDecl<'_>,
2003 header: hir::FnHeader,
2004 name: Option<Symbol>,
2005 generics: &hir::Generics<'_>,
2006 vis: &hir::Visibility<'_>,
2007 arg_names: &[Ident],
2008 body_id: Option<hir::BodyId>,
2010 self.print_fn_header_info(header, vis);
2012 if let Some(name) = name {
2014 self.print_name(name);
2016 self.print_generic_params(&generics.params);
2020 // Make sure we aren't supplied *both* `arg_names` and `body_id`.
2021 assert!(arg_names.is_empty() || body_id.is_none());
2022 self.commasep(Inconsistent, &decl.inputs, |s, ty| {
2023 s.ibox(INDENT_UNIT);
2024 if let Some(arg_name) = arg_names.get(i) {
2025 s.word(arg_name.to_string());
2028 } else if let Some(body_id) = body_id {
2029 s.ann.nested(s, Nested::BodyParamPat(body_id, i));
2037 if decl.c_variadic {
2042 self.print_fn_output(decl);
2043 self.print_where_clause(&generics.where_clause)
2046 fn print_closure_params(&mut self, decl: &hir::FnDecl<'_>, body_id: hir::BodyId) {
2049 self.commasep(Inconsistent, &decl.inputs, |s, ty| {
2050 s.ibox(INDENT_UNIT);
2052 s.ann.nested(s, Nested::BodyParamPat(body_id, i));
2055 if let hir::TyKind::Infer = ty.kind {
2066 if let hir::FnRetTy::DefaultReturn(..) = decl.output {
2070 self.space_if_not_bol();
2071 self.word_space("->");
2073 hir::FnRetTy::Return(ref ty) => {
2074 self.print_type(&ty);
2075 self.maybe_print_comment(ty.span.lo());
2077 hir::FnRetTy::DefaultReturn(..) => unreachable!(),
2081 pub fn print_capture_clause(&mut self, capture_clause: hir::CaptureBy) {
2082 match capture_clause {
2083 hir::CaptureBy::Value => self.word_space("move"),
2084 hir::CaptureBy::Ref => {}
2088 pub fn print_bounds<'b>(
2090 prefix: &'static str,
2091 bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>,
2093 let mut first = true;
2094 for bound in bounds {
2098 if !(first && prefix.is_empty()) {
2104 self.word_space("+");
2108 GenericBound::Trait(tref, modifier) => {
2109 if modifier == &TraitBoundModifier::Maybe {
2112 self.print_poly_trait_ref(tref);
2114 GenericBound::LangItemTrait(lang_item, span, ..) => {
2115 self.word("#[lang = \"");
2116 self.print_ident(Ident::new(lang_item.name(), *span));
2119 GenericBound::Outlives(lt) => {
2120 self.print_lifetime(lt);
2126 pub fn print_generic_params(&mut self, generic_params: &[GenericParam<'_>]) {
2127 if !generic_params.is_empty() {
2130 self.commasep(Inconsistent, generic_params, |s, param| s.print_generic_param(param));
2136 pub fn print_generic_param(&mut self, param: &GenericParam<'_>) {
2137 if let GenericParamKind::Const { .. } = param.kind {
2138 self.word_space("const");
2141 self.print_ident(param.name.ident());
2144 GenericParamKind::Lifetime { .. } => {
2146 for bound in param.bounds {
2148 GenericBound::Outlives(ref lt) => {
2150 self.print_lifetime(lt);
2157 GenericParamKind::Type { ref default, .. } => {
2158 self.print_bounds(":", param.bounds);
2159 if let Some(default) = default {
2161 self.word_space("=");
2162 self.print_type(&default)
2165 GenericParamKind::Const { ref ty, ref default } => {
2166 self.word_space(":");
2167 self.print_type(ty);
2168 if let Some(ref default) = default {
2170 self.word_space("=");
2171 self.print_anon_const(&default)
2177 pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) {
2178 self.print_ident(lifetime.name.ident())
2181 pub fn print_where_clause(&mut self, where_clause: &hir::WhereClause<'_>) {
2182 if where_clause.predicates.is_empty() {
2187 self.word_space("where");
2189 for (i, predicate) in where_clause.predicates.iter().enumerate() {
2191 self.word_space(",");
2195 hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
2196 bound_generic_params,
2201 self.print_formal_generic_params(bound_generic_params);
2202 self.print_type(&bounded_ty);
2203 self.print_bounds(":", *bounds);
2205 hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate {
2210 self.print_lifetime(lifetime);
2213 for (i, bound) in bounds.iter().enumerate() {
2215 GenericBound::Outlives(lt) => {
2216 self.print_lifetime(lt);
2226 hir::WherePredicate::EqPredicate(hir::WhereEqPredicate {
2229 self.print_type(lhs_ty);
2231 self.word_space("=");
2232 self.print_type(rhs_ty);
2238 pub fn print_mutability(&mut self, mutbl: hir::Mutability, print_const: bool) {
2240 hir::Mutability::Mut => self.word_nbsp("mut"),
2241 hir::Mutability::Not => {
2243 self.word_nbsp("const")
2249 pub fn print_mt(&mut self, mt: &hir::MutTy<'_>, print_const: bool) {
2250 self.print_mutability(mt.mutbl, print_const);
2251 self.print_type(&mt.ty)
2254 pub fn print_fn_output(&mut self, decl: &hir::FnDecl<'_>) {
2255 if let hir::FnRetTy::DefaultReturn(..) = decl.output {
2259 self.space_if_not_bol();
2260 self.ibox(INDENT_UNIT);
2261 self.word_space("->");
2263 hir::FnRetTy::DefaultReturn(..) => unreachable!(),
2264 hir::FnRetTy::Return(ref ty) => self.print_type(&ty),
2268 if let hir::FnRetTy::Return(ref output) = decl.output {
2269 self.maybe_print_comment(output.span.lo());
2276 unsafety: hir::Unsafety,
2277 decl: &hir::FnDecl<'_>,
2278 name: Option<Symbol>,
2279 generic_params: &[hir::GenericParam<'_>],
2280 arg_names: &[Ident],
2282 self.ibox(INDENT_UNIT);
2283 self.print_formal_generic_params(generic_params);
2284 let generics = hir::Generics {
2286 where_clause: hir::WhereClause { predicates: &[], span: rustc_span::DUMMY_SP },
2287 span: rustc_span::DUMMY_SP,
2294 constness: hir::Constness::NotConst,
2295 asyncness: hir::IsAsync::NotAsync,
2299 &Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited },
2306 pub fn print_fn_header_info(&mut self, header: hir::FnHeader, vis: &hir::Visibility<'_>) {
2307 self.word(visibility_qualified(vis, ""));
2309 match header.constness {
2310 hir::Constness::NotConst => {}
2311 hir::Constness::Const => self.word_nbsp("const"),
2314 match header.asyncness {
2315 hir::IsAsync::NotAsync => {}
2316 hir::IsAsync::Async => self.word_nbsp("async"),
2319 self.print_unsafety(header.unsafety);
2321 if header.abi != Abi::Rust {
2322 self.word_nbsp("extern");
2323 self.word_nbsp(header.abi.to_string());
2329 pub fn print_unsafety(&mut self, s: hir::Unsafety) {
2331 hir::Unsafety::Normal => {}
2332 hir::Unsafety::Unsafe => self.word_nbsp("unsafe"),
2336 pub fn print_is_auto(&mut self, s: hir::IsAuto) {
2338 hir::IsAuto::Yes => self.word_nbsp("auto"),
2339 hir::IsAuto::No => {}
2344 /// Does this expression require a semicolon to be treated
2345 /// as a statement? The negation of this: 'can this expression
2346 /// be used as a statement without a semicolon' -- is used
2347 /// as an early-bail-out in the parser so that, for instance,
2348 /// if true {...} else {...}
2350 /// isn't parsed as (if true {...} else {...} | x) | 5
2352 // Duplicated from `parse::classify`, but adapted for the HIR.
2353 fn expr_requires_semi_to_be_stmt(e: &hir::Expr<'_>) -> bool {
2356 hir::ExprKind::If(..)
2357 | hir::ExprKind::Match(..)
2358 | hir::ExprKind::Block(..)
2359 | hir::ExprKind::Loop(..)
2363 /// This statement requires a semicolon after it.
2364 /// note that in one case (stmt_semi), we've already
2365 /// seen the semicolon, and thus don't need another.
2366 fn stmt_ends_with_semi(stmt: &hir::StmtKind<'_>) -> bool {
2368 hir::StmtKind::Local(_) => true,
2369 hir::StmtKind::Item(_) => false,
2370 hir::StmtKind::Expr(ref e) => expr_requires_semi_to_be_stmt(&e),
2371 hir::StmtKind::Semi(..) => false,
2375 fn bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp {
2376 use crate::hir::BinOpKind::*;
2378 Add => AssocOp::Add,
2379 Sub => AssocOp::Subtract,
2380 Mul => AssocOp::Multiply,
2381 Div => AssocOp::Divide,
2382 Rem => AssocOp::Modulus,
2384 And => AssocOp::LAnd,
2387 BitXor => AssocOp::BitXor,
2388 BitAnd => AssocOp::BitAnd,
2389 BitOr => AssocOp::BitOr,
2390 Shl => AssocOp::ShiftLeft,
2391 Shr => AssocOp::ShiftRight,
2393 Eq => AssocOp::Equal,
2394 Lt => AssocOp::Less,
2395 Le => AssocOp::LessEqual,
2396 Ne => AssocOp::NotEqual,
2397 Ge => AssocOp::GreaterEqual,
2398 Gt => AssocOp::Greater,
2402 /// Expressions that syntactically contain an "exterior" struct literal, i.e., not surrounded by any
2403 /// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
2404 /// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.
2405 fn contains_exterior_struct_lit(value: &hir::Expr<'_>) -> bool {
2407 hir::ExprKind::Struct(..) => true,
2409 hir::ExprKind::Assign(ref lhs, ref rhs, _)
2410 | hir::ExprKind::AssignOp(_, ref lhs, ref rhs)
2411 | hir::ExprKind::Binary(_, ref lhs, ref rhs) => {
2412 // `X { y: 1 } + X { y: 2 }`
2413 contains_exterior_struct_lit(&lhs) || contains_exterior_struct_lit(&rhs)
2415 hir::ExprKind::Unary(_, ref x)
2416 | hir::ExprKind::Cast(ref x, _)
2417 | hir::ExprKind::Type(ref x, _)
2418 | hir::ExprKind::Field(ref x, _)
2419 | hir::ExprKind::Index(ref x, _) => {
2420 // `&X { y: 1 }, X { y: 1 }.y`
2421 contains_exterior_struct_lit(&x)
2424 hir::ExprKind::MethodCall(.., ref exprs, _) => {
2425 // `X { y: 1 }.bar(...)`
2426 contains_exterior_struct_lit(&exprs[0])