1 #![recursion_limit = "256"]
2 #![deny(rustc::untranslatable_diagnostic)]
3 #![deny(rustc::diagnostic_outside_of_impl)]
4
5 use rustc_ast as ast;
6 use rustc_ast::util::parser::{self, AssocOp, Fixity};
7 use rustc_ast_pretty::pp::Breaks::{Consistent, Inconsistent};
8 use rustc_ast_pretty::pp::{self, Breaks};
9 use rustc_ast_pretty::pprust::{Comments, PrintState};
10 use rustc_hir as hir;
11 use rustc_hir::LifetimeParamKind;
12 use rustc_hir::{BindingAnnotation, ByRef, GenericArg, GenericParam, GenericParamKind, Node, Term};
13 use rustc_hir::{GenericBound, PatKind, RangeEnd, TraitBoundModifier};
14 use rustc_span::source_map::SourceMap;
15 use rustc_span::symbol::{kw, Ident, IdentPrinter, Symbol};
16 use rustc_span::{self, FileName};
17 use rustc_target::spec::abi::Abi;
18
19 use std::cell::Cell;
20 use std::vec;
21
id_to_string(map: &dyn rustc_hir::intravisit::Map<'_>, hir_id: hir::HirId) -> String22 pub fn id_to_string(map: &dyn rustc_hir::intravisit::Map<'_>, hir_id: hir::HirId) -> String {
23 to_string(&map, |s| s.print_node(map.find(hir_id).unwrap()))
24 }
25
26 pub enum AnnNode<'a> {
27 Name(&'a Symbol),
28 Block(&'a hir::Block<'a>),
29 Item(&'a hir::Item<'a>),
30 SubItem(hir::HirId),
31 Expr(&'a hir::Expr<'a>),
32 Pat(&'a hir::Pat<'a>),
33 Arm(&'a hir::Arm<'a>),
34 }
35
36 pub enum Nested {
37 Item(hir::ItemId),
38 TraitItem(hir::TraitItemId),
39 ImplItem(hir::ImplItemId),
40 ForeignItem(hir::ForeignItemId),
41 Body(hir::BodyId),
42 BodyParamPat(hir::BodyId, usize),
43 }
44
45 pub trait PpAnn {
nested(&self, _state: &mut State<'_>, _nested: Nested)46 fn nested(&self, _state: &mut State<'_>, _nested: Nested) {}
pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>)47 fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
post(&self, _state: &mut State<'_>, _node: AnnNode<'_>)48 fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
49 }
50
51 pub struct NoAnn;
52 impl PpAnn for NoAnn {}
53 pub const NO_ANN: &dyn PpAnn = &NoAnn;
54
55 /// Identical to the `PpAnn` implementation for `hir::Crate`,
56 /// except it avoids creating a dependency on the whole crate.
57 impl PpAnn for &dyn rustc_hir::intravisit::Map<'_> {
nested(&self, state: &mut State<'_>, nested: Nested)58 fn nested(&self, state: &mut State<'_>, nested: Nested) {
59 match nested {
60 Nested::Item(id) => state.print_item(self.item(id)),
61 Nested::TraitItem(id) => state.print_trait_item(self.trait_item(id)),
62 Nested::ImplItem(id) => state.print_impl_item(self.impl_item(id)),
63 Nested::ForeignItem(id) => state.print_foreign_item(self.foreign_item(id)),
64 Nested::Body(id) => state.print_expr(&self.body(id).value),
65 Nested::BodyParamPat(id, i) => state.print_pat(self.body(id).params[i].pat),
66 }
67 }
68 }
69
70 pub struct State<'a> {
71 pub s: pp::Printer,
72 comments: Option<Comments<'a>>,
73 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
74 ann: &'a (dyn PpAnn + 'a),
75 }
76
77 impl<'a> State<'a> {
print_node(&mut self, node: Node<'_>)78 pub fn print_node(&mut self, node: Node<'_>) {
79 match node {
80 Node::Param(a) => self.print_param(a),
81 Node::Item(a) => self.print_item(a),
82 Node::ForeignItem(a) => self.print_foreign_item(a),
83 Node::TraitItem(a) => self.print_trait_item(a),
84 Node::ImplItem(a) => self.print_impl_item(a),
85 Node::Variant(a) => self.print_variant(a),
86 Node::AnonConst(a) => self.print_anon_const(a),
87 Node::ConstBlock(a) => self.print_inline_const(a),
88 Node::Expr(a) => self.print_expr(a),
89 Node::ExprField(a) => self.print_expr_field(&a),
90 Node::Stmt(a) => self.print_stmt(a),
91 Node::PathSegment(a) => self.print_path_segment(a),
92 Node::Ty(a) => self.print_type(a),
93 Node::TypeBinding(a) => self.print_type_binding(a),
94 Node::TraitRef(a) => self.print_trait_ref(a),
95 Node::Pat(a) => self.print_pat(a),
96 Node::PatField(a) => self.print_patfield(&a),
97 Node::Arm(a) => self.print_arm(a),
98 Node::Infer(_) => self.word("_"),
99 Node::Block(a) => {
100 // Containing cbox, will be closed by print-block at `}`.
101 self.cbox(INDENT_UNIT);
102 // Head-ibox, will be closed by print-block after `{`.
103 self.ibox(0);
104 self.print_block(a);
105 }
106 Node::Lifetime(a) => self.print_lifetime(a),
107 Node::GenericParam(_) => panic!("cannot print Node::GenericParam"),
108 Node::Field(_) => panic!("cannot print Node::Field"),
109 // These cases do not carry enough information in the
110 // `hir_map` to reconstruct their full structure for pretty
111 // printing.
112 Node::Ctor(..) => panic!("cannot print isolated Ctor"),
113 Node::Local(a) => self.print_local_decl(a),
114 Node::Crate(..) => panic!("cannot print Crate"),
115 }
116 }
117 }
118
119 impl std::ops::Deref for State<'_> {
120 type Target = pp::Printer;
deref(&self) -> &Self::Target121 fn deref(&self) -> &Self::Target {
122 &self.s
123 }
124 }
125
126 impl std::ops::DerefMut for State<'_> {
deref_mut(&mut self) -> &mut Self::Target127 fn deref_mut(&mut self) -> &mut Self::Target {
128 &mut self.s
129 }
130 }
131
132 impl<'a> PrintState<'a> for State<'a> {
comments(&mut self) -> &mut Option<Comments<'a>>133 fn comments(&mut self) -> &mut Option<Comments<'a>> {
134 &mut self.comments
135 }
136
print_ident(&mut self, ident: Ident)137 fn print_ident(&mut self, ident: Ident) {
138 self.word(IdentPrinter::for_ast_ident(ident, ident.is_raw_guess()).to_string());
139 self.ann.post(self, AnnNode::Name(&ident.name))
140 }
141
print_generic_args(&mut self, _: &ast::GenericArgs, _colons_before_params: bool)142 fn print_generic_args(&mut self, _: &ast::GenericArgs, _colons_before_params: bool) {
143 panic!("AST generic args printed by HIR pretty-printer");
144 }
145 }
146
147 pub const INDENT_UNIT: isize = 4;
148
149 /// Requires you to pass an input filename and reader so that
150 /// it can scan the input text for comments to copy forward.
print_crate<'a>( sm: &'a SourceMap, krate: &hir::Mod<'_>, filename: FileName, input: String, attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute], ann: &'a dyn PpAnn, ) -> String151 pub fn print_crate<'a>(
152 sm: &'a SourceMap,
153 krate: &hir::Mod<'_>,
154 filename: FileName,
155 input: String,
156 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
157 ann: &'a dyn PpAnn,
158 ) -> String {
159 let mut s = State::new_from_input(sm, filename, input, attrs, ann);
160
161 // When printing the AST, we sometimes need to inject `#[no_std]` here.
162 // Since you can't compile the HIR, it's not necessary.
163
164 s.print_mod(krate, (*attrs)(hir::CRATE_HIR_ID));
165 s.print_remaining_comments();
166 s.s.eof()
167 }
168
169 impl<'a> State<'a> {
new_from_input( sm: &'a SourceMap, filename: FileName, input: String, attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute], ann: &'a dyn PpAnn, ) -> State<'a>170 pub fn new_from_input(
171 sm: &'a SourceMap,
172 filename: FileName,
173 input: String,
174 attrs: &'a dyn Fn(hir::HirId) -> &'a [ast::Attribute],
175 ann: &'a dyn PpAnn,
176 ) -> State<'a> {
177 State {
178 s: pp::Printer::new(),
179 comments: Some(Comments::new(sm, filename, input)),
180 attrs,
181 ann,
182 }
183 }
184
attrs(&self, id: hir::HirId) -> &'a [ast::Attribute]185 fn attrs(&self, id: hir::HirId) -> &'a [ast::Attribute] {
186 (self.attrs)(id)
187 }
188 }
189
to_string<F>(ann: &dyn PpAnn, f: F) -> String where F: FnOnce(&mut State<'_>),190 pub fn to_string<F>(ann: &dyn PpAnn, f: F) -> String
191 where
192 F: FnOnce(&mut State<'_>),
193 {
194 let mut printer = State { s: pp::Printer::new(), comments: None, attrs: &|_| &[], ann };
195 f(&mut printer);
196 printer.s.eof()
197 }
198
generic_params_to_string(generic_params: &[GenericParam<'_>]) -> String199 pub fn generic_params_to_string(generic_params: &[GenericParam<'_>]) -> String {
200 to_string(NO_ANN, |s| s.print_generic_params(generic_params))
201 }
202
bounds_to_string<'b>(bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>) -> String203 pub fn bounds_to_string<'b>(bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>) -> String {
204 to_string(NO_ANN, |s| s.print_bounds("", bounds))
205 }
206
ty_to_string(ty: &hir::Ty<'_>) -> String207 pub fn ty_to_string(ty: &hir::Ty<'_>) -> String {
208 to_string(NO_ANN, |s| s.print_type(ty))
209 }
210
path_segment_to_string(segment: &hir::PathSegment<'_>) -> String211 pub fn path_segment_to_string(segment: &hir::PathSegment<'_>) -> String {
212 to_string(NO_ANN, |s| s.print_path_segment(segment))
213 }
214
path_to_string(segment: &hir::Path<'_>) -> String215 pub fn path_to_string(segment: &hir::Path<'_>) -> String {
216 to_string(NO_ANN, |s| s.print_path(segment, false))
217 }
218
qpath_to_string(segment: &hir::QPath<'_>) -> String219 pub fn qpath_to_string(segment: &hir::QPath<'_>) -> String {
220 to_string(NO_ANN, |s| s.print_qpath(segment, false))
221 }
222
fn_to_string( decl: &hir::FnDecl<'_>, header: hir::FnHeader, name: Option<Symbol>, generics: &hir::Generics<'_>, arg_names: &[Ident], body_id: Option<hir::BodyId>, ) -> String223 pub fn fn_to_string(
224 decl: &hir::FnDecl<'_>,
225 header: hir::FnHeader,
226 name: Option<Symbol>,
227 generics: &hir::Generics<'_>,
228 arg_names: &[Ident],
229 body_id: Option<hir::BodyId>,
230 ) -> String {
231 to_string(NO_ANN, |s| s.print_fn(decl, header, name, generics, arg_names, body_id))
232 }
233
enum_def_to_string( enum_definition: &hir::EnumDef<'_>, generics: &hir::Generics<'_>, name: Symbol, span: rustc_span::Span, ) -> String234 pub fn enum_def_to_string(
235 enum_definition: &hir::EnumDef<'_>,
236 generics: &hir::Generics<'_>,
237 name: Symbol,
238 span: rustc_span::Span,
239 ) -> String {
240 to_string(NO_ANN, |s| s.print_enum_def(enum_definition, generics, name, span))
241 }
242
243 impl<'a> State<'a> {
bclose_maybe_open(&mut self, span: rustc_span::Span, close_box: bool)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);
247 self.word("}");
248 if close_box {
249 self.end(); // close the outer-box
250 }
251 }
252
bclose(&mut self, span: rustc_span::Span)253 pub fn bclose(&mut self, span: rustc_span::Span) {
254 self.bclose_maybe_open(span, true)
255 }
256
commasep_cmnt<T, F, G>(&mut self, b: Breaks, elts: &[T], mut op: F, mut get_span: G) where F: FnMut(&mut State<'_>, &T), G: FnMut(&T) -> rustc_span::Span,257 pub fn commasep_cmnt<T, F, G>(&mut self, b: Breaks, elts: &[T], mut op: F, mut get_span: G)
258 where
259 F: FnMut(&mut State<'_>, &T),
260 G: FnMut(&T) -> rustc_span::Span,
261 {
262 self.rbox(0, b);
263 let len = elts.len();
264 let mut i = 0;
265 for elt in elts {
266 self.maybe_print_comment(get_span(elt).hi());
267 op(self, elt);
268 i += 1;
269 if i < len {
270 self.word(",");
271 self.maybe_print_trailing_comment(get_span(elt), Some(get_span(&elts[i]).hi()));
272 self.space_if_not_bol();
273 }
274 }
275 self.end();
276 }
277
commasep_exprs(&mut self, b: Breaks, exprs: &[hir::Expr<'_>])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);
280 }
281
print_mod(&mut self, _mod: &hir::Mod<'_>, attrs: &[ast::Attribute])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));
286 }
287 }
288
print_opt_lifetime(&mut self, lifetime: &hir::Lifetime)289 pub fn print_opt_lifetime(&mut self, lifetime: &hir::Lifetime) {
290 if !lifetime.is_elided() {
291 self.print_lifetime(lifetime);
292 self.nbsp();
293 }
294 }
295
print_type(&mut self, ty: &hir::Ty<'_>)296 pub fn print_type(&mut self, ty: &hir::Ty<'_>) {
297 self.maybe_print_comment(ty.span.lo());
298 self.ibox(0);
299 match ty.kind {
300 hir::TyKind::Slice(ty) => {
301 self.word("[");
302 self.print_type(ty);
303 self.word("]");
304 }
305 hir::TyKind::Ptr(ref mt) => {
306 self.word("*");
307 self.print_mt(mt, true);
308 }
309 hir::TyKind::Ref(ref lifetime, ref mt) => {
310 self.word("&");
311 self.print_opt_lifetime(lifetime);
312 self.print_mt(mt, false);
313 }
314 hir::TyKind::Never => {
315 self.word("!");
316 }
317 hir::TyKind::Tup(elts) => {
318 self.popen();
319 self.commasep(Inconsistent, elts, |s, ty| s.print_type(ty));
320 if elts.len() == 1 {
321 self.word(",");
322 }
323 self.pclose();
324 }
325 hir::TyKind::BareFn(f) => {
326 self.print_ty_fn(f.abi, f.unsafety, f.decl, None, f.generic_params, f.param_names);
327 }
328 hir::TyKind::OpaqueDef(..) => self.word("/*impl Trait*/"),
329 hir::TyKind::Path(ref qpath) => self.print_qpath(qpath, false),
330 hir::TyKind::TraitObject(bounds, ref lifetime, syntax) => {
331 if syntax == ast::TraitObjectSyntax::Dyn {
332 self.word_space("dyn");
333 }
334 let mut first = true;
335 for bound in bounds {
336 if first {
337 first = false;
338 } else {
339 self.nbsp();
340 self.word_space("+");
341 }
342 self.print_poly_trait_ref(bound);
343 }
344 if !lifetime.is_elided() {
345 self.nbsp();
346 self.word_space("+");
347 self.print_lifetime(lifetime);
348 }
349 }
350 hir::TyKind::Array(ty, ref length) => {
351 self.word("[");
352 self.print_type(ty);
353 self.word("; ");
354 self.print_array_length(length);
355 self.word("]");
356 }
357 hir::TyKind::Typeof(ref e) => {
358 self.word("typeof(");
359 self.print_anon_const(e);
360 self.word(")");
361 }
362 hir::TyKind::Err(_) => {
363 self.popen();
364 self.word("/*ERROR*/");
365 self.pclose();
366 }
367 hir::TyKind::Infer => {
368 self.word("_");
369 }
370 }
371 self.end()
372 }
373
print_foreign_item(&mut self, item: &hir::ForeignItem<'_>)374 pub fn print_foreign_item(&mut self, item: &hir::ForeignItem<'_>) {
375 self.hardbreak_if_not_bol();
376 self.maybe_print_comment(item.span.lo());
377 self.print_outer_attributes(self.attrs(item.hir_id()));
378 match item.kind {
379 hir::ForeignItemKind::Fn(decl, arg_names, generics) => {
380 self.head("");
381 self.print_fn(
382 decl,
383 hir::FnHeader {
384 unsafety: hir::Unsafety::Normal,
385 constness: hir::Constness::NotConst,
386 abi: Abi::Rust,
387 asyncness: hir::IsAsync::NotAsync,
388 },
389 Some(item.ident.name),
390 generics,
391 arg_names,
392 None,
393 );
394 self.end(); // end head-ibox
395 self.word(";");
396 self.end() // end the outer fn box
397 }
398 hir::ForeignItemKind::Static(t, m) => {
399 self.head("static");
400 if m.is_mut() {
401 self.word_space("mut");
402 }
403 self.print_ident(item.ident);
404 self.word_space(":");
405 self.print_type(t);
406 self.word(";");
407 self.end(); // end the head-ibox
408 self.end() // end the outer cbox
409 }
410 hir::ForeignItemKind::Type => {
411 self.head("type");
412 self.print_ident(item.ident);
413 self.word(";");
414 self.end(); // end the head-ibox
415 self.end() // end the outer cbox
416 }
417 }
418 }
419
print_associated_const( &mut self, ident: Ident, ty: &hir::Ty<'_>, default: Option<hir::BodyId>, )420 fn print_associated_const(
421 &mut self,
422 ident: Ident,
423 ty: &hir::Ty<'_>,
424 default: Option<hir::BodyId>,
425 ) {
426 self.head("");
427 self.word_space("const");
428 self.print_ident(ident);
429 self.word_space(":");
430 self.print_type(ty);
431 if let Some(expr) = default {
432 self.space();
433 self.word_space("=");
434 self.ann.nested(self, Nested::Body(expr));
435 }
436 self.word(";")
437 }
438
print_associated_type( &mut self, ident: Ident, generics: &hir::Generics<'_>, bounds: Option<hir::GenericBounds<'_>>, ty: Option<&hir::Ty<'_>>, )439 fn print_associated_type(
440 &mut self,
441 ident: Ident,
442 generics: &hir::Generics<'_>,
443 bounds: Option<hir::GenericBounds<'_>>,
444 ty: Option<&hir::Ty<'_>>,
445 ) {
446 self.word_space("type");
447 self.print_ident(ident);
448 self.print_generic_params(generics.params);
449 if let Some(bounds) = bounds {
450 self.print_bounds(":", bounds);
451 }
452 self.print_where_clause(generics);
453 if let Some(ty) = ty {
454 self.space();
455 self.word_space("=");
456 self.print_type(ty);
457 }
458 self.word(";")
459 }
460
print_item_type( &mut self, item: &hir::Item<'_>, generics: &hir::Generics<'_>, inner: impl Fn(&mut Self), )461 fn print_item_type(
462 &mut self,
463 item: &hir::Item<'_>,
464 generics: &hir::Generics<'_>,
465 inner: impl Fn(&mut Self),
466 ) {
467 self.head("type");
468 self.print_ident(item.ident);
469 self.print_generic_params(generics.params);
470 self.end(); // end the inner ibox
471
472 self.print_where_clause(generics);
473 self.space();
474 inner(self);
475 self.word(";");
476 self.end(); // end the outer ibox
477 }
478
479 /// Pretty-print an item
print_item(&mut self, item: &hir::Item<'_>)480 pub fn print_item(&mut self, item: &hir::Item<'_>) {
481 self.hardbreak_if_not_bol();
482 self.maybe_print_comment(item.span.lo());
483 let attrs = self.attrs(item.hir_id());
484 self.print_outer_attributes(attrs);
485 self.ann.pre(self, AnnNode::Item(item));
486 match item.kind {
487 hir::ItemKind::ExternCrate(orig_name) => {
488 self.head("extern crate");
489 if let Some(orig_name) = orig_name {
490 self.print_name(orig_name);
491 self.space();
492 self.word("as");
493 self.space();
494 }
495 self.print_ident(item.ident);
496 self.word(";");
497 self.end(); // end inner head-block
498 self.end(); // end outer head-block
499 }
500 hir::ItemKind::Use(path, kind) => {
501 self.head("use");
502 self.print_path(path, false);
503
504 match kind {
505 hir::UseKind::Single => {
506 if path.segments.last().unwrap().ident != item.ident {
507 self.space();
508 self.word_space("as");
509 self.print_ident(item.ident);
510 }
511 self.word(";");
512 }
513 hir::UseKind::Glob => self.word("::*;"),
514 hir::UseKind::ListStem => self.word("::{};"),
515 }
516 self.end(); // end inner head-block
517 self.end(); // end outer head-block
518 }
519 hir::ItemKind::Static(ty, m, expr) => {
520 self.head("static");
521 if m.is_mut() {
522 self.word_space("mut");
523 }
524 self.print_ident(item.ident);
525 self.word_space(":");
526 self.print_type(ty);
527 self.space();
528 self.end(); // end the head-ibox
529
530 self.word_space("=");
531 self.ann.nested(self, Nested::Body(expr));
532 self.word(";");
533 self.end(); // end the outer cbox
534 }
535 hir::ItemKind::Const(ty, expr) => {
536 self.head("const");
537 self.print_ident(item.ident);
538 self.word_space(":");
539 self.print_type(ty);
540 self.space();
541 self.end(); // end the head-ibox
542
543 self.word_space("=");
544 self.ann.nested(self, Nested::Body(expr));
545 self.word(";");
546 self.end(); // end the outer cbox
547 }
548 hir::ItemKind::Fn(ref sig, param_names, body) => {
549 self.head("");
550 self.print_fn(
551 sig.decl,
552 sig.header,
553 Some(item.ident.name),
554 param_names,
555 &[],
556 Some(body),
557 );
558 self.word(" ");
559 self.end(); // need to close a box
560 self.end(); // need to close a box
561 self.ann.nested(self, Nested::Body(body));
562 }
563 hir::ItemKind::Macro(ref macro_def, _) => {
564 self.print_mac_def(macro_def, &item.ident, item.span, |_| {});
565 }
566 hir::ItemKind::Mod(ref _mod) => {
567 self.head("mod");
568 self.print_ident(item.ident);
569 self.nbsp();
570 self.bopen();
571 self.print_mod(_mod, attrs);
572 self.bclose(item.span);
573 }
574 hir::ItemKind::ForeignMod { abi, items } => {
575 self.head("extern");
576 self.word_nbsp(abi.to_string());
577 self.bopen();
578 self.print_inner_attributes(self.attrs(item.hir_id()));
579 for item in items {
580 self.ann.nested(self, Nested::ForeignItem(item.id));
581 }
582 self.bclose(item.span);
583 }
584 hir::ItemKind::GlobalAsm(asm) => {
585 self.head("global_asm!");
586 self.print_inline_asm(asm);
587 self.end()
588 }
589 hir::ItemKind::TyAlias(ty, generics) => {
590 self.print_item_type(item, generics, |state| {
591 state.word_space("=");
592 state.print_type(ty);
593 });
594 }
595 hir::ItemKind::OpaqueTy(ref opaque_ty) => {
596 self.print_item_type(item, opaque_ty.generics, |state| {
597 let mut real_bounds = Vec::with_capacity(opaque_ty.bounds.len());
598 for b in opaque_ty.bounds {
599 if let GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = b {
600 state.space();
601 state.word_space("for ?");
602 state.print_trait_ref(&ptr.trait_ref);
603 } else {
604 real_bounds.push(b);
605 }
606 }
607 state.print_bounds("= impl", real_bounds);
608 });
609 }
610 hir::ItemKind::Enum(ref enum_definition, params) => {
611 self.print_enum_def(enum_definition, params, item.ident.name, item.span);
612 }
613 hir::ItemKind::Struct(ref struct_def, generics) => {
614 self.head("struct");
615 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
616 }
617 hir::ItemKind::Union(ref struct_def, generics) => {
618 self.head("union");
619 self.print_struct(struct_def, generics, item.ident.name, item.span, true);
620 }
621 hir::ItemKind::Impl(&hir::Impl {
622 unsafety,
623 polarity,
624 defaultness,
625 constness,
626 defaultness_span: _,
627 generics,
628 ref of_trait,
629 self_ty,
630 items,
631 }) => {
632 self.head("");
633 self.print_defaultness(defaultness);
634 self.print_unsafety(unsafety);
635 self.word_nbsp("impl");
636
637 if !generics.params.is_empty() {
638 self.print_generic_params(generics.params);
639 self.space();
640 }
641
642 if constness == hir::Constness::Const {
643 self.word_nbsp("const");
644 }
645
646 if let hir::ImplPolarity::Negative(_) = polarity {
647 self.word("!");
648 }
649
650 if let Some(t) = of_trait {
651 self.print_trait_ref(t);
652 self.space();
653 self.word_space("for");
654 }
655
656 self.print_type(self_ty);
657 self.print_where_clause(generics);
658
659 self.space();
660 self.bopen();
661 self.print_inner_attributes(attrs);
662 for impl_item in items {
663 self.ann.nested(self, Nested::ImplItem(impl_item.id));
664 }
665 self.bclose(item.span);
666 }
667 hir::ItemKind::Trait(is_auto, unsafety, generics, bounds, trait_items) => {
668 self.head("");
669 self.print_is_auto(is_auto);
670 self.print_unsafety(unsafety);
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 for b in bounds {
676 if let GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = b {
677 self.space();
678 self.word_space("for ?");
679 self.print_trait_ref(&ptr.trait_ref);
680 } else {
681 real_bounds.push(b);
682 }
683 }
684 self.print_bounds(":", real_bounds);
685 self.print_where_clause(generics);
686 self.word(" ");
687 self.bopen();
688 for trait_item in trait_items {
689 self.ann.nested(self, Nested::TraitItem(trait_item.id));
690 }
691 self.bclose(item.span);
692 }
693 hir::ItemKind::TraitAlias(generics, bounds) => {
694 self.head("trait");
695 self.print_ident(item.ident);
696 self.print_generic_params(generics.params);
697 self.nbsp();
698 self.print_bounds("=", bounds);
699 self.print_where_clause(generics);
700 self.word(";");
701 self.end(); // end inner head-block
702 self.end(); // end outer head-block
703 }
704 }
705 self.ann.post(self, AnnNode::Item(item))
706 }
707
print_trait_ref(&mut self, t: &hir::TraitRef<'_>)708 pub fn print_trait_ref(&mut self, t: &hir::TraitRef<'_>) {
709 self.print_path(t.path, false);
710 }
711
print_formal_generic_params(&mut self, generic_params: &[hir::GenericParam<'_>])712 fn print_formal_generic_params(&mut self, generic_params: &[hir::GenericParam<'_>]) {
713 if !generic_params.is_empty() {
714 self.word("for");
715 self.print_generic_params(generic_params);
716 self.nbsp();
717 }
718 }
719
print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef<'_>)720 fn print_poly_trait_ref(&mut self, t: &hir::PolyTraitRef<'_>) {
721 self.print_formal_generic_params(t.bound_generic_params);
722 self.print_trait_ref(&t.trait_ref);
723 }
724
print_enum_def( &mut self, enum_definition: &hir::EnumDef<'_>, generics: &hir::Generics<'_>, name: Symbol, span: rustc_span::Span, )725 pub fn print_enum_def(
726 &mut self,
727 enum_definition: &hir::EnumDef<'_>,
728 generics: &hir::Generics<'_>,
729 name: Symbol,
730 span: rustc_span::Span,
731 ) {
732 self.head("enum");
733 self.print_name(name);
734 self.print_generic_params(generics.params);
735 self.print_where_clause(generics);
736 self.space();
737 self.print_variants(enum_definition.variants, span);
738 }
739
print_variants(&mut self, variants: &[hir::Variant<'_>], span: rustc_span::Span)740 pub fn print_variants(&mut self, variants: &[hir::Variant<'_>], span: rustc_span::Span) {
741 self.bopen();
742 for v in variants {
743 self.space_if_not_bol();
744 self.maybe_print_comment(v.span.lo());
745 self.print_outer_attributes(self.attrs(v.hir_id));
746 self.ibox(INDENT_UNIT);
747 self.print_variant(v);
748 self.word(",");
749 self.end();
750 self.maybe_print_trailing_comment(v.span, None);
751 }
752 self.bclose(span)
753 }
754
print_defaultness(&mut self, defaultness: hir::Defaultness)755 pub fn print_defaultness(&mut self, defaultness: hir::Defaultness) {
756 match defaultness {
757 hir::Defaultness::Default { .. } => self.word_nbsp("default"),
758 hir::Defaultness::Final => (),
759 }
760 }
761
print_struct( &mut self, struct_def: &hir::VariantData<'_>, generics: &hir::Generics<'_>, name: Symbol, span: rustc_span::Span, print_finalizer: bool, )762 pub fn print_struct(
763 &mut self,
764 struct_def: &hir::VariantData<'_>,
765 generics: &hir::Generics<'_>,
766 name: Symbol,
767 span: rustc_span::Span,
768 print_finalizer: bool,
769 ) {
770 self.print_name(name);
771 self.print_generic_params(generics.params);
772 match struct_def {
773 hir::VariantData::Tuple(..) | hir::VariantData::Unit(..) => {
774 if let hir::VariantData::Tuple(..) = struct_def {
775 self.popen();
776 self.commasep(Inconsistent, struct_def.fields(), |s, field| {
777 s.maybe_print_comment(field.span.lo());
778 s.print_outer_attributes(s.attrs(field.hir_id));
779 s.print_type(field.ty);
780 });
781 self.pclose();
782 }
783 self.print_where_clause(generics);
784 if print_finalizer {
785 self.word(";");
786 }
787 self.end();
788 self.end() // close the outer-box
789 }
790 hir::VariantData::Struct(..) => {
791 self.print_where_clause(generics);
792 self.nbsp();
793 self.bopen();
794 self.hardbreak_if_not_bol();
795
796 for field in struct_def.fields() {
797 self.hardbreak_if_not_bol();
798 self.maybe_print_comment(field.span.lo());
799 self.print_outer_attributes(self.attrs(field.hir_id));
800 self.print_ident(field.ident);
801 self.word_nbsp(":");
802 self.print_type(field.ty);
803 self.word(",");
804 }
805
806 self.bclose(span)
807 }
808 }
809 }
810
print_variant(&mut self, v: &hir::Variant<'_>)811 pub fn print_variant(&mut self, v: &hir::Variant<'_>) {
812 self.head("");
813 let generics = hir::Generics::empty();
814 self.print_struct(&v.data, generics, v.ident.name, v.span, false);
815 if let Some(ref d) = v.disr_expr {
816 self.space();
817 self.word_space("=");
818 self.print_anon_const(d);
819 }
820 }
print_method_sig( &mut self, ident: Ident, m: &hir::FnSig<'_>, generics: &hir::Generics<'_>, arg_names: &[Ident], body_id: Option<hir::BodyId>, )821 pub fn print_method_sig(
822 &mut self,
823 ident: Ident,
824 m: &hir::FnSig<'_>,
825 generics: &hir::Generics<'_>,
826 arg_names: &[Ident],
827 body_id: Option<hir::BodyId>,
828 ) {
829 self.print_fn(m.decl, m.header, Some(ident.name), generics, arg_names, body_id);
830 }
831
print_trait_item(&mut self, ti: &hir::TraitItem<'_>)832 pub fn print_trait_item(&mut self, ti: &hir::TraitItem<'_>) {
833 self.ann.pre(self, AnnNode::SubItem(ti.hir_id()));
834 self.hardbreak_if_not_bol();
835 self.maybe_print_comment(ti.span.lo());
836 self.print_outer_attributes(self.attrs(ti.hir_id()));
837 match ti.kind {
838 hir::TraitItemKind::Const(ty, default) => {
839 self.print_associated_const(ti.ident, ty, default);
840 }
841 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(arg_names)) => {
842 self.print_method_sig(ti.ident, sig, ti.generics, arg_names, None);
843 self.word(";");
844 }
845 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
846 self.head("");
847 self.print_method_sig(ti.ident, sig, ti.generics, &[], Some(body));
848 self.nbsp();
849 self.end(); // need to close a box
850 self.end(); // need to close a box
851 self.ann.nested(self, Nested::Body(body));
852 }
853 hir::TraitItemKind::Type(bounds, default) => {
854 self.print_associated_type(ti.ident, ti.generics, Some(bounds), default);
855 }
856 }
857 self.ann.post(self, AnnNode::SubItem(ti.hir_id()))
858 }
859
print_impl_item(&mut self, ii: &hir::ImplItem<'_>)860 pub fn print_impl_item(&mut self, ii: &hir::ImplItem<'_>) {
861 self.ann.pre(self, AnnNode::SubItem(ii.hir_id()));
862 self.hardbreak_if_not_bol();
863 self.maybe_print_comment(ii.span.lo());
864 self.print_outer_attributes(self.attrs(ii.hir_id()));
865
866 match ii.kind {
867 hir::ImplItemKind::Const(ty, expr) => {
868 self.print_associated_const(ii.ident, ty, Some(expr));
869 }
870 hir::ImplItemKind::Fn(ref sig, body) => {
871 self.head("");
872 self.print_method_sig(ii.ident, sig, ii.generics, &[], Some(body));
873 self.nbsp();
874 self.end(); // need to close a box
875 self.end(); // need to close a box
876 self.ann.nested(self, Nested::Body(body));
877 }
878 hir::ImplItemKind::Type(ty) => {
879 self.print_associated_type(ii.ident, ii.generics, None, Some(ty));
880 }
881 }
882 self.ann.post(self, AnnNode::SubItem(ii.hir_id()))
883 }
884
print_local( &mut self, init: Option<&hir::Expr<'_>>, els: Option<&hir::Block<'_>>, decl: impl Fn(&mut Self), )885 pub fn print_local(
886 &mut self,
887 init: Option<&hir::Expr<'_>>,
888 els: Option<&hir::Block<'_>>,
889 decl: impl Fn(&mut Self),
890 ) {
891 self.space_if_not_bol();
892 self.ibox(INDENT_UNIT);
893 self.word_nbsp("let");
894
895 self.ibox(INDENT_UNIT);
896 decl(self);
897 self.end();
898
899 if let Some(init) = init {
900 self.nbsp();
901 self.word_space("=");
902 self.print_expr(init);
903 }
904
905 if let Some(els) = els {
906 self.nbsp();
907 self.word_space("else");
908 // containing cbox, will be closed by print-block at `}`
909 self.cbox(0);
910 // head-box, will be closed by print-block after `{`
911 self.ibox(0);
912 self.print_block(els);
913 }
914
915 self.end()
916 }
917
print_stmt(&mut self, st: &hir::Stmt<'_>)918 pub fn print_stmt(&mut self, st: &hir::Stmt<'_>) {
919 self.maybe_print_comment(st.span.lo());
920 match st.kind {
921 hir::StmtKind::Local(loc) => {
922 self.print_local(loc.init, loc.els, |this| this.print_local_decl(loc));
923 }
924 hir::StmtKind::Item(item) => self.ann.nested(self, Nested::Item(item)),
925 hir::StmtKind::Expr(expr) => {
926 self.space_if_not_bol();
927 self.print_expr(expr);
928 }
929 hir::StmtKind::Semi(expr) => {
930 self.space_if_not_bol();
931 self.print_expr(expr);
932 self.word(";");
933 }
934 }
935 if stmt_ends_with_semi(&st.kind) {
936 self.word(";");
937 }
938 self.maybe_print_trailing_comment(st.span, None)
939 }
940
print_block(&mut self, blk: &hir::Block<'_>)941 pub fn print_block(&mut self, blk: &hir::Block<'_>) {
942 self.print_block_with_attrs(blk, &[])
943 }
944
print_block_unclosed(&mut self, blk: &hir::Block<'_>)945 pub fn print_block_unclosed(&mut self, blk: &hir::Block<'_>) {
946 self.print_block_maybe_unclosed(blk, &[], false)
947 }
948
print_block_with_attrs(&mut self, blk: &hir::Block<'_>, attrs: &[ast::Attribute])949 pub fn print_block_with_attrs(&mut self, blk: &hir::Block<'_>, attrs: &[ast::Attribute]) {
950 self.print_block_maybe_unclosed(blk, attrs, true)
951 }
952
print_block_maybe_unclosed( &mut self, blk: &hir::Block<'_>, attrs: &[ast::Attribute], close_box: bool, )953 pub fn print_block_maybe_unclosed(
954 &mut self,
955 blk: &hir::Block<'_>,
956 attrs: &[ast::Attribute],
957 close_box: bool,
958 ) {
959 match blk.rules {
960 hir::BlockCheckMode::UnsafeBlock(..) => self.word_space("unsafe"),
961 hir::BlockCheckMode::DefaultBlock => (),
962 }
963 self.maybe_print_comment(blk.span.lo());
964 self.ann.pre(self, AnnNode::Block(blk));
965 self.bopen();
966
967 self.print_inner_attributes(attrs);
968
969 for st in blk.stmts {
970 self.print_stmt(st);
971 }
972 if let Some(expr) = blk.expr {
973 self.space_if_not_bol();
974 self.print_expr(expr);
975 self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi()));
976 }
977 self.bclose_maybe_open(blk.span, close_box);
978 self.ann.post(self, AnnNode::Block(blk))
979 }
980
print_else(&mut self, els: Option<&hir::Expr<'_>>)981 fn print_else(&mut self, els: Option<&hir::Expr<'_>>) {
982 if let Some(els_inner) = els {
983 match els_inner.kind {
984 // Another `else if` block.
985 hir::ExprKind::If(i, then, e) => {
986 self.cbox(INDENT_UNIT - 1);
987 self.ibox(0);
988 self.word(" else if ");
989 self.print_expr_as_cond(i);
990 self.space();
991 self.print_expr(then);
992 self.print_else(e);
993 }
994 // Final `else` block.
995 hir::ExprKind::Block(b, _) => {
996 self.cbox(INDENT_UNIT - 1);
997 self.ibox(0);
998 self.word(" else ");
999 self.print_block(b);
1000 }
1001 // Constraints would be great here!
1002 _ => {
1003 panic!("print_if saw if with weird alternative");
1004 }
1005 }
1006 }
1007 }
1008
print_if( &mut self, test: &hir::Expr<'_>, blk: &hir::Expr<'_>, elseopt: Option<&hir::Expr<'_>>, )1009 pub fn print_if(
1010 &mut self,
1011 test: &hir::Expr<'_>,
1012 blk: &hir::Expr<'_>,
1013 elseopt: Option<&hir::Expr<'_>>,
1014 ) {
1015 self.head("if");
1016 self.print_expr_as_cond(test);
1017 self.space();
1018 self.print_expr(blk);
1019 self.print_else(elseopt)
1020 }
1021
print_array_length(&mut self, len: &hir::ArrayLen)1022 pub fn print_array_length(&mut self, len: &hir::ArrayLen) {
1023 match len {
1024 hir::ArrayLen::Infer(_, _) => self.word("_"),
1025 hir::ArrayLen::Body(ct) => self.print_anon_const(ct),
1026 }
1027 }
1028
print_anon_const(&mut self, constant: &hir::AnonConst)1029 pub fn print_anon_const(&mut self, constant: &hir::AnonConst) {
1030 self.ann.nested(self, Nested::Body(constant.body))
1031 }
1032
print_call_post(&mut self, args: &[hir::Expr<'_>])1033 fn print_call_post(&mut self, args: &[hir::Expr<'_>]) {
1034 self.popen();
1035 self.commasep_exprs(Inconsistent, args);
1036 self.pclose()
1037 }
1038
print_expr_maybe_paren(&mut self, expr: &hir::Expr<'_>, prec: i8)1039 fn print_expr_maybe_paren(&mut self, expr: &hir::Expr<'_>, prec: i8) {
1040 self.print_expr_cond_paren(expr, expr.precedence().order() < prec)
1041 }
1042
1043 /// Prints an expr using syntax that's acceptable in a condition position, such as the `cond` in
1044 /// `if cond { ... }`.
print_expr_as_cond(&mut self, expr: &hir::Expr<'_>)1045 pub fn print_expr_as_cond(&mut self, expr: &hir::Expr<'_>) {
1046 self.print_expr_cond_paren(expr, Self::cond_needs_par(expr))
1047 }
1048
1049 /// Prints `expr` or `(expr)` when `needs_par` holds.
print_expr_cond_paren(&mut self, expr: &hir::Expr<'_>, needs_par: bool)1050 fn print_expr_cond_paren(&mut self, expr: &hir::Expr<'_>, needs_par: bool) {
1051 if needs_par {
1052 self.popen();
1053 }
1054 if let hir::ExprKind::DropTemps(actual_expr) = expr.kind {
1055 self.print_expr(actual_expr);
1056 } else {
1057 self.print_expr(expr);
1058 }
1059 if needs_par {
1060 self.pclose();
1061 }
1062 }
1063
1064 /// Print a `let pat = expr` expression.
print_let(&mut self, pat: &hir::Pat<'_>, ty: Option<&hir::Ty<'_>>, init: &hir::Expr<'_>)1065 fn print_let(&mut self, pat: &hir::Pat<'_>, ty: Option<&hir::Ty<'_>>, init: &hir::Expr<'_>) {
1066 self.word_space("let");
1067 self.print_pat(pat);
1068 if let Some(ty) = ty {
1069 self.word_space(":");
1070 self.print_type(ty);
1071 }
1072 self.space();
1073 self.word_space("=");
1074 let npals = || parser::needs_par_as_let_scrutinee(init.precedence().order());
1075 self.print_expr_cond_paren(init, Self::cond_needs_par(init) || npals())
1076 }
1077
1078 // Does `expr` need parentheses when printed in a condition position?
1079 //
1080 // These cases need parens due to the parse error observed in #26461: `if return {}`
1081 // parses as the erroneous construct `if (return {})`, not `if (return) {}`.
cond_needs_par(expr: &hir::Expr<'_>) -> bool1082 fn cond_needs_par(expr: &hir::Expr<'_>) -> bool {
1083 match expr.kind {
1084 hir::ExprKind::Break(..) | hir::ExprKind::Closure { .. } | hir::ExprKind::Ret(..) => {
1085 true
1086 }
1087 _ => contains_exterior_struct_lit(expr),
1088 }
1089 }
1090
print_expr_vec(&mut self, exprs: &[hir::Expr<'_>])1091 fn print_expr_vec(&mut self, exprs: &[hir::Expr<'_>]) {
1092 self.ibox(INDENT_UNIT);
1093 self.word("[");
1094 self.commasep_exprs(Inconsistent, exprs);
1095 self.word("]");
1096 self.end()
1097 }
1098
print_inline_const(&mut self, constant: &hir::ConstBlock)1099 fn print_inline_const(&mut self, constant: &hir::ConstBlock) {
1100 self.ibox(INDENT_UNIT);
1101 self.word_space("const");
1102 self.ann.nested(self, Nested::Body(constant.body));
1103 self.end()
1104 }
1105
print_expr_repeat(&mut self, element: &hir::Expr<'_>, count: &hir::ArrayLen)1106 fn print_expr_repeat(&mut self, element: &hir::Expr<'_>, count: &hir::ArrayLen) {
1107 self.ibox(INDENT_UNIT);
1108 self.word("[");
1109 self.print_expr(element);
1110 self.word_space(";");
1111 self.print_array_length(count);
1112 self.word("]");
1113 self.end()
1114 }
1115
print_expr_struct( &mut self, qpath: &hir::QPath<'_>, fields: &[hir::ExprField<'_>], wth: Option<&hir::Expr<'_>>, )1116 fn print_expr_struct(
1117 &mut self,
1118 qpath: &hir::QPath<'_>,
1119 fields: &[hir::ExprField<'_>],
1120 wth: Option<&hir::Expr<'_>>,
1121 ) {
1122 self.print_qpath(qpath, true);
1123 self.word("{");
1124 self.commasep_cmnt(Consistent, fields, |s, field| s.print_expr_field(field), |f| f.span);
1125 if let Some(expr) = wth {
1126 self.ibox(INDENT_UNIT);
1127 if !fields.is_empty() {
1128 self.word(",");
1129 self.space();
1130 }
1131 self.word("..");
1132 self.print_expr(expr);
1133 self.end();
1134 } else if !fields.is_empty() {
1135 self.word(",");
1136 }
1137
1138 self.word("}");
1139 }
1140
print_expr_field(&mut self, field: &hir::ExprField<'_>)1141 fn print_expr_field(&mut self, field: &hir::ExprField<'_>) {
1142 if self.attrs(field.hir_id).is_empty() {
1143 self.space();
1144 }
1145 self.cbox(INDENT_UNIT);
1146 self.print_outer_attributes(&self.attrs(field.hir_id));
1147 if !field.is_shorthand {
1148 self.print_ident(field.ident);
1149 self.word_space(":");
1150 }
1151 self.print_expr(&field.expr);
1152 self.end()
1153 }
1154
print_expr_tup(&mut self, exprs: &[hir::Expr<'_>])1155 fn print_expr_tup(&mut self, exprs: &[hir::Expr<'_>]) {
1156 self.popen();
1157 self.commasep_exprs(Inconsistent, exprs);
1158 if exprs.len() == 1 {
1159 self.word(",");
1160 }
1161 self.pclose()
1162 }
1163
print_expr_call(&mut self, func: &hir::Expr<'_>, args: &[hir::Expr<'_>])1164 fn print_expr_call(&mut self, func: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
1165 let prec = match func.kind {
1166 hir::ExprKind::Field(..) => parser::PREC_FORCE_PAREN,
1167 _ => parser::PREC_POSTFIX,
1168 };
1169
1170 self.print_expr_maybe_paren(func, prec);
1171 self.print_call_post(args)
1172 }
1173
print_expr_method_call( &mut self, segment: &hir::PathSegment<'_>, receiver: &hir::Expr<'_>, args: &[hir::Expr<'_>], )1174 fn print_expr_method_call(
1175 &mut self,
1176 segment: &hir::PathSegment<'_>,
1177 receiver: &hir::Expr<'_>,
1178 args: &[hir::Expr<'_>],
1179 ) {
1180 let base_args = args;
1181 self.print_expr_maybe_paren(&receiver, parser::PREC_POSTFIX);
1182 self.word(".");
1183 self.print_ident(segment.ident);
1184
1185 let generic_args = segment.args();
1186 if !generic_args.args.is_empty() || !generic_args.bindings.is_empty() {
1187 self.print_generic_args(generic_args, true);
1188 }
1189
1190 self.print_call_post(base_args)
1191 }
1192
print_expr_binary(&mut self, op: hir::BinOp, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>)1193 fn print_expr_binary(&mut self, op: hir::BinOp, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>) {
1194 let assoc_op = bin_op_to_assoc_op(op.node);
1195 let prec = assoc_op.precedence() as i8;
1196 let fixity = assoc_op.fixity();
1197
1198 let (left_prec, right_prec) = match fixity {
1199 Fixity::Left => (prec, prec + 1),
1200 Fixity::Right => (prec + 1, prec),
1201 Fixity::None => (prec + 1, prec + 1),
1202 };
1203
1204 let left_prec = match (&lhs.kind, op.node) {
1205 // These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
1206 // the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
1207 // of `(x as i32) < ...`. We need to convince it _not_ to do that.
1208 (&hir::ExprKind::Cast { .. }, hir::BinOpKind::Lt | hir::BinOpKind::Shl) => {
1209 parser::PREC_FORCE_PAREN
1210 }
1211 (&hir::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(prec) => {
1212 parser::PREC_FORCE_PAREN
1213 }
1214 _ => left_prec,
1215 };
1216
1217 self.print_expr_maybe_paren(lhs, left_prec);
1218 self.space();
1219 self.word_space(op.node.as_str());
1220 self.print_expr_maybe_paren(rhs, right_prec)
1221 }
1222
print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr<'_>)1223 fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr<'_>) {
1224 self.word(op.as_str());
1225 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1226 }
1227
print_expr_addr_of( &mut self, kind: hir::BorrowKind, mutability: hir::Mutability, expr: &hir::Expr<'_>, )1228 fn print_expr_addr_of(
1229 &mut self,
1230 kind: hir::BorrowKind,
1231 mutability: hir::Mutability,
1232 expr: &hir::Expr<'_>,
1233 ) {
1234 self.word("&");
1235 match kind {
1236 hir::BorrowKind::Ref => self.print_mutability(mutability, false),
1237 hir::BorrowKind::Raw => {
1238 self.word_nbsp("raw");
1239 self.print_mutability(mutability, true);
1240 }
1241 }
1242 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
1243 }
1244
print_literal(&mut self, lit: &hir::Lit)1245 fn print_literal(&mut self, lit: &hir::Lit) {
1246 self.maybe_print_comment(lit.span.lo());
1247 self.word(lit.node.to_string())
1248 }
1249
print_inline_asm(&mut self, asm: &hir::InlineAsm<'_>)1250 fn print_inline_asm(&mut self, asm: &hir::InlineAsm<'_>) {
1251 enum AsmArg<'a> {
1252 Template(String),
1253 Operand(&'a hir::InlineAsmOperand<'a>),
1254 Options(ast::InlineAsmOptions),
1255 }
1256
1257 let mut args = vec![AsmArg::Template(ast::InlineAsmTemplatePiece::to_string(asm.template))];
1258 args.extend(asm.operands.iter().map(|(o, _)| AsmArg::Operand(o)));
1259 if !asm.options.is_empty() {
1260 args.push(AsmArg::Options(asm.options));
1261 }
1262
1263 self.popen();
1264 self.commasep(Consistent, &args, |s, arg| match *arg {
1265 AsmArg::Template(ref template) => s.print_string(template, ast::StrStyle::Cooked),
1266 AsmArg::Operand(op) => match *op {
1267 hir::InlineAsmOperand::In { reg, ref expr } => {
1268 s.word("in");
1269 s.popen();
1270 s.word(format!("{reg}"));
1271 s.pclose();
1272 s.space();
1273 s.print_expr(expr);
1274 }
1275 hir::InlineAsmOperand::Out { reg, late, ref expr } => {
1276 s.word(if late { "lateout" } else { "out" });
1277 s.popen();
1278 s.word(format!("{reg}"));
1279 s.pclose();
1280 s.space();
1281 match expr {
1282 Some(expr) => s.print_expr(expr),
1283 None => s.word("_"),
1284 }
1285 }
1286 hir::InlineAsmOperand::InOut { reg, late, ref expr } => {
1287 s.word(if late { "inlateout" } else { "inout" });
1288 s.popen();
1289 s.word(format!("{reg}"));
1290 s.pclose();
1291 s.space();
1292 s.print_expr(expr);
1293 }
1294 hir::InlineAsmOperand::SplitInOut { reg, late, ref in_expr, ref out_expr } => {
1295 s.word(if late { "inlateout" } else { "inout" });
1296 s.popen();
1297 s.word(format!("{reg}"));
1298 s.pclose();
1299 s.space();
1300 s.print_expr(in_expr);
1301 s.space();
1302 s.word_space("=>");
1303 match out_expr {
1304 Some(out_expr) => s.print_expr(out_expr),
1305 None => s.word("_"),
1306 }
1307 }
1308 hir::InlineAsmOperand::Const { ref anon_const } => {
1309 s.word("const");
1310 s.space();
1311 s.print_anon_const(anon_const);
1312 }
1313 hir::InlineAsmOperand::SymFn { ref anon_const } => {
1314 s.word("sym_fn");
1315 s.space();
1316 s.print_anon_const(anon_const);
1317 }
1318 hir::InlineAsmOperand::SymStatic { ref path, def_id: _ } => {
1319 s.word("sym_static");
1320 s.space();
1321 s.print_qpath(path, true);
1322 }
1323 },
1324 AsmArg::Options(opts) => {
1325 s.word("options");
1326 s.popen();
1327 let mut options = vec![];
1328 if opts.contains(ast::InlineAsmOptions::PURE) {
1329 options.push("pure");
1330 }
1331 if opts.contains(ast::InlineAsmOptions::NOMEM) {
1332 options.push("nomem");
1333 }
1334 if opts.contains(ast::InlineAsmOptions::READONLY) {
1335 options.push("readonly");
1336 }
1337 if opts.contains(ast::InlineAsmOptions::PRESERVES_FLAGS) {
1338 options.push("preserves_flags");
1339 }
1340 if opts.contains(ast::InlineAsmOptions::NORETURN) {
1341 options.push("noreturn");
1342 }
1343 if opts.contains(ast::InlineAsmOptions::NOSTACK) {
1344 options.push("nostack");
1345 }
1346 if opts.contains(ast::InlineAsmOptions::ATT_SYNTAX) {
1347 options.push("att_syntax");
1348 }
1349 if opts.contains(ast::InlineAsmOptions::RAW) {
1350 options.push("raw");
1351 }
1352 if opts.contains(ast::InlineAsmOptions::MAY_UNWIND) {
1353 options.push("may_unwind");
1354 }
1355 s.commasep(Inconsistent, &options, |s, &opt| {
1356 s.word(opt);
1357 });
1358 s.pclose();
1359 }
1360 });
1361 self.pclose();
1362 }
1363
print_expr(&mut self, expr: &hir::Expr<'_>)1364 pub fn print_expr(&mut self, expr: &hir::Expr<'_>) {
1365 self.maybe_print_comment(expr.span.lo());
1366 self.print_outer_attributes(self.attrs(expr.hir_id));
1367 self.ibox(INDENT_UNIT);
1368 self.ann.pre(self, AnnNode::Expr(expr));
1369 match expr.kind {
1370 hir::ExprKind::Array(exprs) => {
1371 self.print_expr_vec(exprs);
1372 }
1373 hir::ExprKind::ConstBlock(ref anon_const) => {
1374 self.print_inline_const(anon_const);
1375 }
1376 hir::ExprKind::Repeat(element, ref count) => {
1377 self.print_expr_repeat(element, count);
1378 }
1379 hir::ExprKind::Struct(qpath, fields, wth) => {
1380 self.print_expr_struct(qpath, fields, wth);
1381 }
1382 hir::ExprKind::Tup(exprs) => {
1383 self.print_expr_tup(exprs);
1384 }
1385 hir::ExprKind::Call(func, args) => {
1386 self.print_expr_call(func, args);
1387 }
1388 hir::ExprKind::MethodCall(segment, receiver, args, _) => {
1389 self.print_expr_method_call(segment, receiver, args);
1390 }
1391 hir::ExprKind::Binary(op, lhs, rhs) => {
1392 self.print_expr_binary(op, lhs, rhs);
1393 }
1394 hir::ExprKind::Unary(op, expr) => {
1395 self.print_expr_unary(op, expr);
1396 }
1397 hir::ExprKind::AddrOf(k, m, expr) => {
1398 self.print_expr_addr_of(k, m, expr);
1399 }
1400 hir::ExprKind::Lit(ref lit) => {
1401 self.print_literal(lit);
1402 }
1403 hir::ExprKind::Cast(expr, ty) => {
1404 let prec = AssocOp::As.precedence() as i8;
1405 self.print_expr_maybe_paren(expr, prec);
1406 self.space();
1407 self.word_space("as");
1408 self.print_type(ty);
1409 }
1410 hir::ExprKind::Type(expr, ty) => {
1411 self.word("type_ascribe!(");
1412 self.ibox(0);
1413 self.print_expr(expr);
1414
1415 self.word(",");
1416 self.space_if_not_bol();
1417 self.print_type(ty);
1418
1419 self.end();
1420 self.word(")");
1421 }
1422 hir::ExprKind::DropTemps(init) => {
1423 // Print `{`:
1424 self.cbox(INDENT_UNIT);
1425 self.ibox(0);
1426 self.bopen();
1427
1428 // Print `let _t = $init;`:
1429 let temp = Ident::from_str("_t");
1430 self.print_local(Some(init), None, |this| this.print_ident(temp));
1431 self.word(";");
1432
1433 // Print `_t`:
1434 self.space_if_not_bol();
1435 self.print_ident(temp);
1436
1437 // Print `}`:
1438 self.bclose_maybe_open(expr.span, true);
1439 }
1440 hir::ExprKind::Let(&hir::Let { pat, ty, init, .. }) => {
1441 self.print_let(pat, ty, init);
1442 }
1443 hir::ExprKind::If(test, blk, elseopt) => {
1444 self.print_if(test, blk, elseopt);
1445 }
1446 hir::ExprKind::Loop(blk, opt_label, _, _) => {
1447 if let Some(label) = opt_label {
1448 self.print_ident(label.ident);
1449 self.word_space(":");
1450 }
1451 self.head("loop");
1452 self.print_block(blk);
1453 }
1454 hir::ExprKind::Match(expr, arms, _) => {
1455 self.cbox(INDENT_UNIT);
1456 self.ibox(INDENT_UNIT);
1457 self.word_nbsp("match");
1458 self.print_expr_as_cond(expr);
1459 self.space();
1460 self.bopen();
1461 for arm in arms {
1462 self.print_arm(arm);
1463 }
1464 self.bclose(expr.span);
1465 }
1466 hir::ExprKind::Closure(&hir::Closure {
1467 binder,
1468 constness,
1469 capture_clause,
1470 bound_generic_params,
1471 fn_decl,
1472 body,
1473 fn_decl_span: _,
1474 fn_arg_span: _,
1475 movability: _,
1476 def_id: _,
1477 }) => {
1478 self.print_closure_binder(binder, bound_generic_params);
1479 self.print_constness(constness);
1480 self.print_capture_clause(capture_clause);
1481
1482 self.print_closure_params(fn_decl, body);
1483 self.space();
1484
1485 // This is a bare expression.
1486 self.ann.nested(self, Nested::Body(body));
1487 self.end(); // need to close a box
1488
1489 // A box will be closed by `print_expr`, but we didn't want an overall
1490 // wrapper so we closed the corresponding opening. so create an
1491 // empty box to satisfy the close.
1492 self.ibox(0);
1493 }
1494 hir::ExprKind::Block(blk, opt_label) => {
1495 if let Some(label) = opt_label {
1496 self.print_ident(label.ident);
1497 self.word_space(":");
1498 }
1499 // containing cbox, will be closed by print-block at `}`
1500 self.cbox(INDENT_UNIT);
1501 // head-box, will be closed by print-block after `{`
1502 self.ibox(0);
1503 self.print_block(blk);
1504 }
1505 hir::ExprKind::Assign(lhs, rhs, _) => {
1506 let prec = AssocOp::Assign.precedence() as i8;
1507 self.print_expr_maybe_paren(lhs, prec + 1);
1508 self.space();
1509 self.word_space("=");
1510 self.print_expr_maybe_paren(rhs, prec);
1511 }
1512 hir::ExprKind::AssignOp(op, lhs, rhs) => {
1513 let prec = AssocOp::Assign.precedence() as i8;
1514 self.print_expr_maybe_paren(lhs, prec + 1);
1515 self.space();
1516 self.word(op.node.as_str());
1517 self.word_space("=");
1518 self.print_expr_maybe_paren(rhs, prec);
1519 }
1520 hir::ExprKind::Field(expr, ident) => {
1521 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
1522 self.word(".");
1523 self.print_ident(ident);
1524 }
1525 hir::ExprKind::Index(expr, index) => {
1526 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
1527 self.word("[");
1528 self.print_expr(index);
1529 self.word("]");
1530 }
1531 hir::ExprKind::Path(ref qpath) => self.print_qpath(qpath, true),
1532 hir::ExprKind::Break(destination, opt_expr) => {
1533 self.word("break");
1534 if let Some(label) = destination.label {
1535 self.space();
1536 self.print_ident(label.ident);
1537 }
1538 if let Some(expr) = opt_expr {
1539 self.space();
1540 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
1541 }
1542 }
1543 hir::ExprKind::Continue(destination) => {
1544 self.word("continue");
1545 if let Some(label) = destination.label {
1546 self.space();
1547 self.print_ident(label.ident);
1548 }
1549 }
1550 hir::ExprKind::Ret(result) => {
1551 self.word("return");
1552 if let Some(expr) = result {
1553 self.word(" ");
1554 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
1555 }
1556 }
1557 hir::ExprKind::Become(result) => {
1558 self.word("become");
1559 self.word(" ");
1560 self.print_expr_maybe_paren(result, parser::PREC_JUMP);
1561 }
1562 hir::ExprKind::InlineAsm(asm) => {
1563 self.word("asm!");
1564 self.print_inline_asm(asm);
1565 }
1566 hir::ExprKind::OffsetOf(container, ref fields) => {
1567 self.word("offset_of!(");
1568 self.print_type(container);
1569 self.word(",");
1570 self.space();
1571
1572 if let Some((&first, rest)) = fields.split_first() {
1573 self.print_ident(first);
1574
1575 for &field in rest {
1576 self.word(".");
1577 self.print_ident(field);
1578 }
1579 }
1580
1581 self.word(")");
1582 }
1583 hir::ExprKind::Yield(expr, _) => {
1584 self.word_space("yield");
1585 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
1586 }
1587 hir::ExprKind::Err(_) => {
1588 self.popen();
1589 self.word("/*ERROR*/");
1590 self.pclose();
1591 }
1592 }
1593 self.ann.post(self, AnnNode::Expr(expr));
1594 self.end()
1595 }
1596
print_local_decl(&mut self, loc: &hir::Local<'_>)1597 pub fn print_local_decl(&mut self, loc: &hir::Local<'_>) {
1598 self.print_pat(loc.pat);
1599 if let Some(ty) = loc.ty {
1600 self.word_space(":");
1601 self.print_type(ty);
1602 }
1603 }
1604
print_name(&mut self, name: Symbol)1605 pub fn print_name(&mut self, name: Symbol) {
1606 self.print_ident(Ident::with_dummy_span(name))
1607 }
1608
print_path<R>(&mut self, path: &hir::Path<'_, R>, colons_before_params: bool)1609 pub fn print_path<R>(&mut self, path: &hir::Path<'_, R>, colons_before_params: bool) {
1610 self.maybe_print_comment(path.span.lo());
1611
1612 for (i, segment) in path.segments.iter().enumerate() {
1613 if i > 0 {
1614 self.word("::")
1615 }
1616 if segment.ident.name != kw::PathRoot {
1617 self.print_ident(segment.ident);
1618 self.print_generic_args(segment.args(), colons_before_params);
1619 }
1620 }
1621 }
1622
print_path_segment(&mut self, segment: &hir::PathSegment<'_>)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(), false);
1627 }
1628 }
1629
print_qpath(&mut self, qpath: &hir::QPath<'_>, colons_before_params: bool)1630 pub fn print_qpath(&mut self, qpath: &hir::QPath<'_>, colons_before_params: bool) {
1631 match *qpath {
1632 hir::QPath::Resolved(None, path) => self.print_path(path, colons_before_params),
1633 hir::QPath::Resolved(Some(qself), path) => {
1634 self.word("<");
1635 self.print_type(qself);
1636 self.space();
1637 self.word_space("as");
1638
1639 for (i, segment) in path.segments[..path.segments.len() - 1].iter().enumerate() {
1640 if i > 0 {
1641 self.word("::")
1642 }
1643 if segment.ident.name != kw::PathRoot {
1644 self.print_ident(segment.ident);
1645 self.print_generic_args(segment.args(), colons_before_params);
1646 }
1647 }
1648
1649 self.word(">");
1650 self.word("::");
1651 let item_segment = path.segments.last().unwrap();
1652 self.print_ident(item_segment.ident);
1653 self.print_generic_args(item_segment.args(), colons_before_params)
1654 }
1655 hir::QPath::TypeRelative(qself, item_segment) => {
1656 // If we've got a compound-qualified-path, let's push an additional pair of angle
1657 // brackets, so that we pretty-print `<<A::B>::C>` as `<A::B>::C`, instead of just
1658 // `A::B::C` (since the latter could be ambiguous to the user)
1659 if let hir::TyKind::Path(hir::QPath::Resolved(None, _)) = qself.kind {
1660 self.print_type(qself);
1661 } else {
1662 self.word("<");
1663 self.print_type(qself);
1664 self.word(">");
1665 }
1666
1667 self.word("::");
1668 self.print_ident(item_segment.ident);
1669 self.print_generic_args(item_segment.args(), colons_before_params)
1670 }
1671 hir::QPath::LangItem(lang_item, span, _) => {
1672 self.word("#[lang = \"");
1673 self.print_ident(Ident::new(lang_item.name(), span));
1674 self.word("\"]");
1675 }
1676 }
1677 }
1678
print_generic_args( &mut self, generic_args: &hir::GenericArgs<'_>, colons_before_params: bool, )1679 fn print_generic_args(
1680 &mut self,
1681 generic_args: &hir::GenericArgs<'_>,
1682 colons_before_params: bool,
1683 ) {
1684 match generic_args.parenthesized {
1685 hir::GenericArgsParentheses::No => {
1686 let start = if colons_before_params { "::<" } else { "<" };
1687 let empty = Cell::new(true);
1688 let start_or_comma = |this: &mut Self| {
1689 if empty.get() {
1690 empty.set(false);
1691 this.word(start)
1692 } else {
1693 this.word_space(",")
1694 }
1695 };
1696
1697 let mut nonelided_generic_args: bool = false;
1698 let elide_lifetimes = generic_args.args.iter().all(|arg| match arg {
1699 GenericArg::Lifetime(lt) if lt.is_elided() => true,
1700 GenericArg::Lifetime(_) => {
1701 nonelided_generic_args = true;
1702 false
1703 }
1704 _ => {
1705 nonelided_generic_args = true;
1706 true
1707 }
1708 });
1709
1710 if nonelided_generic_args {
1711 start_or_comma(self);
1712 self.commasep(Inconsistent, generic_args.args, |s, generic_arg| {
1713 match generic_arg {
1714 GenericArg::Lifetime(lt) if !elide_lifetimes => s.print_lifetime(lt),
1715 GenericArg::Lifetime(_) => {}
1716 GenericArg::Type(ty) => s.print_type(ty),
1717 GenericArg::Const(ct) => s.print_anon_const(&ct.value),
1718 GenericArg::Infer(_inf) => s.word("_"),
1719 }
1720 });
1721 }
1722
1723 for binding in generic_args.bindings {
1724 start_or_comma(self);
1725 self.print_type_binding(binding);
1726 }
1727
1728 if !empty.get() {
1729 self.word(">")
1730 }
1731 }
1732 hir::GenericArgsParentheses::ParenSugar => {
1733 self.word("(");
1734 self.commasep(Inconsistent, generic_args.inputs(), |s, ty| s.print_type(ty));
1735 self.word(")");
1736
1737 self.space_if_not_bol();
1738 self.word_space("->");
1739 self.print_type(generic_args.bindings[0].ty());
1740 }
1741 hir::GenericArgsParentheses::ReturnTypeNotation => {
1742 self.word("(..)");
1743 }
1744 }
1745 }
1746
print_type_binding(&mut self, binding: &hir::TypeBinding<'_>)1747 pub fn print_type_binding(&mut self, binding: &hir::TypeBinding<'_>) {
1748 self.print_ident(binding.ident);
1749 self.print_generic_args(binding.gen_args, false);
1750 self.space();
1751 match binding.kind {
1752 hir::TypeBindingKind::Equality { ref term } => {
1753 self.word_space("=");
1754 match term {
1755 Term::Ty(ty) => self.print_type(ty),
1756 Term::Const(ref c) => self.print_anon_const(c),
1757 }
1758 }
1759 hir::TypeBindingKind::Constraint { bounds } => {
1760 self.print_bounds(":", bounds);
1761 }
1762 }
1763 }
1764
print_pat(&mut self, pat: &hir::Pat<'_>)1765 pub fn print_pat(&mut self, pat: &hir::Pat<'_>) {
1766 self.maybe_print_comment(pat.span.lo());
1767 self.ann.pre(self, AnnNode::Pat(pat));
1768 // Pat isn't normalized, but the beauty of it
1769 // is that it doesn't matter
1770 match pat.kind {
1771 PatKind::Wild => self.word("_"),
1772 PatKind::Binding(BindingAnnotation(by_ref, mutbl), _, ident, sub) => {
1773 if by_ref == ByRef::Yes {
1774 self.word_nbsp("ref");
1775 }
1776 if mutbl.is_mut() {
1777 self.word_nbsp("mut");
1778 }
1779 self.print_ident(ident);
1780 if let Some(p) = sub {
1781 self.word("@");
1782 self.print_pat(p);
1783 }
1784 }
1785 PatKind::TupleStruct(ref qpath, elts, ddpos) => {
1786 self.print_qpath(qpath, true);
1787 self.popen();
1788 if let Some(ddpos) = ddpos.as_opt_usize() {
1789 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(p));
1790 if ddpos != 0 {
1791 self.word_space(",");
1792 }
1793 self.word("..");
1794 if ddpos != elts.len() {
1795 self.word(",");
1796 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(p));
1797 }
1798 } else {
1799 self.commasep(Inconsistent, elts, |s, p| s.print_pat(p));
1800 }
1801 self.pclose();
1802 }
1803 PatKind::Path(ref qpath) => {
1804 self.print_qpath(qpath, true);
1805 }
1806 PatKind::Struct(ref qpath, fields, etc) => {
1807 self.print_qpath(qpath, true);
1808 self.nbsp();
1809 self.word("{");
1810 let empty = fields.is_empty() && !etc;
1811 if !empty {
1812 self.space();
1813 }
1814 self.commasep_cmnt(Consistent, &fields, |s, f| s.print_patfield(f), |f| f.pat.span);
1815 if etc {
1816 if !fields.is_empty() {
1817 self.word_space(",");
1818 }
1819 self.word("..");
1820 }
1821 if !empty {
1822 self.space();
1823 }
1824 self.word("}");
1825 }
1826 PatKind::Or(pats) => {
1827 self.strsep("|", true, Inconsistent, pats, |s, p| s.print_pat(p));
1828 }
1829 PatKind::Tuple(elts, ddpos) => {
1830 self.popen();
1831 if let Some(ddpos) = ddpos.as_opt_usize() {
1832 self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(p));
1833 if ddpos != 0 {
1834 self.word_space(",");
1835 }
1836 self.word("..");
1837 if ddpos != elts.len() {
1838 self.word(",");
1839 self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(p));
1840 }
1841 } else {
1842 self.commasep(Inconsistent, elts, |s, p| s.print_pat(p));
1843 if elts.len() == 1 {
1844 self.word(",");
1845 }
1846 }
1847 self.pclose();
1848 }
1849 PatKind::Box(inner) => {
1850 let is_range_inner = matches!(inner.kind, PatKind::Range(..));
1851 self.word("box ");
1852 if is_range_inner {
1853 self.popen();
1854 }
1855 self.print_pat(inner);
1856 if is_range_inner {
1857 self.pclose();
1858 }
1859 }
1860 PatKind::Ref(inner, mutbl) => {
1861 let is_range_inner = matches!(inner.kind, PatKind::Range(..));
1862 self.word("&");
1863 self.word(mutbl.prefix_str());
1864 if is_range_inner {
1865 self.popen();
1866 }
1867 self.print_pat(inner);
1868 if is_range_inner {
1869 self.pclose();
1870 }
1871 }
1872 PatKind::Lit(e) => self.print_expr(e),
1873 PatKind::Range(begin, end, end_kind) => {
1874 if let Some(expr) = begin {
1875 self.print_expr(expr);
1876 }
1877 match end_kind {
1878 RangeEnd::Included => self.word("..."),
1879 RangeEnd::Excluded => self.word(".."),
1880 }
1881 if let Some(expr) = end {
1882 self.print_expr(expr);
1883 }
1884 }
1885 PatKind::Slice(before, slice, after) => {
1886 self.word("[");
1887 self.commasep(Inconsistent, before, |s, p| s.print_pat(p));
1888 if let Some(p) = slice {
1889 if !before.is_empty() {
1890 self.word_space(",");
1891 }
1892 if let PatKind::Wild = p.kind {
1893 // Print nothing.
1894 } else {
1895 self.print_pat(p);
1896 }
1897 self.word("..");
1898 if !after.is_empty() {
1899 self.word_space(",");
1900 }
1901 }
1902 self.commasep(Inconsistent, after, |s, p| s.print_pat(p));
1903 self.word("]");
1904 }
1905 }
1906 self.ann.post(self, AnnNode::Pat(pat))
1907 }
1908
print_patfield(&mut self, field: &hir::PatField<'_>)1909 pub fn print_patfield(&mut self, field: &hir::PatField<'_>) {
1910 if self.attrs(field.hir_id).is_empty() {
1911 self.space();
1912 }
1913 self.cbox(INDENT_UNIT);
1914 self.print_outer_attributes(&self.attrs(field.hir_id));
1915 if !field.is_shorthand {
1916 self.print_ident(field.ident);
1917 self.word_nbsp(":");
1918 }
1919 self.print_pat(field.pat);
1920 self.end();
1921 }
1922
print_param(&mut self, arg: &hir::Param<'_>)1923 pub fn print_param(&mut self, arg: &hir::Param<'_>) {
1924 self.print_outer_attributes(self.attrs(arg.hir_id));
1925 self.print_pat(arg.pat);
1926 }
1927
print_arm(&mut self, arm: &hir::Arm<'_>)1928 pub fn print_arm(&mut self, arm: &hir::Arm<'_>) {
1929 // I have no idea why this check is necessary, but here it
1930 // is :(
1931 if self.attrs(arm.hir_id).is_empty() {
1932 self.space();
1933 }
1934 self.cbox(INDENT_UNIT);
1935 self.ann.pre(self, AnnNode::Arm(arm));
1936 self.ibox(0);
1937 self.print_outer_attributes(self.attrs(arm.hir_id));
1938 self.print_pat(arm.pat);
1939 self.space();
1940 if let Some(ref g) = arm.guard {
1941 match *g {
1942 hir::Guard::If(e) => {
1943 self.word_space("if");
1944 self.print_expr(e);
1945 self.space();
1946 }
1947 hir::Guard::IfLet(&hir::Let { pat, ty, init, .. }) => {
1948 self.word_nbsp("if");
1949 self.print_let(pat, ty, init);
1950 }
1951 }
1952 }
1953 self.word_space("=>");
1954
1955 match arm.body.kind {
1956 hir::ExprKind::Block(blk, opt_label) => {
1957 if let Some(label) = opt_label {
1958 self.print_ident(label.ident);
1959 self.word_space(":");
1960 }
1961 // the block will close the pattern's ibox
1962 self.print_block_unclosed(blk);
1963
1964 // If it is a user-provided unsafe block, print a comma after it
1965 if let hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::UserProvided) = blk.rules
1966 {
1967 self.word(",");
1968 }
1969 }
1970 _ => {
1971 self.end(); // close the ibox for the pattern
1972 self.print_expr(arm.body);
1973 self.word(",");
1974 }
1975 }
1976 self.ann.post(self, AnnNode::Arm(arm));
1977 self.end() // close enclosing cbox
1978 }
1979
print_fn( &mut self, decl: &hir::FnDecl<'_>, header: hir::FnHeader, name: Option<Symbol>, generics: &hir::Generics<'_>, arg_names: &[Ident], body_id: Option<hir::BodyId>, )1980 pub fn print_fn(
1981 &mut self,
1982 decl: &hir::FnDecl<'_>,
1983 header: hir::FnHeader,
1984 name: Option<Symbol>,
1985 generics: &hir::Generics<'_>,
1986 arg_names: &[Ident],
1987 body_id: Option<hir::BodyId>,
1988 ) {
1989 self.print_fn_header_info(header);
1990
1991 if let Some(name) = name {
1992 self.nbsp();
1993 self.print_name(name);
1994 }
1995 self.print_generic_params(generics.params);
1996
1997 self.popen();
1998 let mut i = 0;
1999 // Make sure we aren't supplied *both* `arg_names` and `body_id`.
2000 assert!(arg_names.is_empty() || body_id.is_none());
2001 self.commasep(Inconsistent, decl.inputs, |s, ty| {
2002 s.ibox(INDENT_UNIT);
2003 if let Some(arg_name) = arg_names.get(i) {
2004 s.word(arg_name.to_string());
2005 s.word(":");
2006 s.space();
2007 } else if let Some(body_id) = body_id {
2008 s.ann.nested(s, Nested::BodyParamPat(body_id, i));
2009 s.word(":");
2010 s.space();
2011 }
2012 i += 1;
2013 s.print_type(ty);
2014 s.end()
2015 });
2016 if decl.c_variadic {
2017 self.word(", ...");
2018 }
2019 self.pclose();
2020
2021 self.print_fn_output(decl);
2022 self.print_where_clause(generics)
2023 }
2024
print_closure_params(&mut self, decl: &hir::FnDecl<'_>, body_id: hir::BodyId)2025 fn print_closure_params(&mut self, decl: &hir::FnDecl<'_>, body_id: hir::BodyId) {
2026 self.word("|");
2027 let mut i = 0;
2028 self.commasep(Inconsistent, decl.inputs, |s, ty| {
2029 s.ibox(INDENT_UNIT);
2030
2031 s.ann.nested(s, Nested::BodyParamPat(body_id, i));
2032 i += 1;
2033
2034 if let hir::TyKind::Infer = ty.kind {
2035 // Print nothing.
2036 } else {
2037 s.word(":");
2038 s.space();
2039 s.print_type(ty);
2040 }
2041 s.end();
2042 });
2043 self.word("|");
2044
2045 if let hir::FnRetTy::DefaultReturn(..) = decl.output {
2046 return;
2047 }
2048
2049 self.space_if_not_bol();
2050 self.word_space("->");
2051 match decl.output {
2052 hir::FnRetTy::Return(ty) => {
2053 self.print_type(ty);
2054 self.maybe_print_comment(ty.span.lo());
2055 }
2056 hir::FnRetTy::DefaultReturn(..) => unreachable!(),
2057 }
2058 }
2059
print_capture_clause(&mut self, capture_clause: hir::CaptureBy)2060 pub fn print_capture_clause(&mut self, capture_clause: hir::CaptureBy) {
2061 match capture_clause {
2062 hir::CaptureBy::Value => self.word_space("move"),
2063 hir::CaptureBy::Ref => {}
2064 }
2065 }
2066
print_closure_binder( &mut self, binder: hir::ClosureBinder, generic_params: &[GenericParam<'_>], )2067 pub fn print_closure_binder(
2068 &mut self,
2069 binder: hir::ClosureBinder,
2070 generic_params: &[GenericParam<'_>],
2071 ) {
2072 let generic_params = generic_params
2073 .iter()
2074 .filter(|p| {
2075 matches!(
2076 p,
2077 GenericParam {
2078 kind: GenericParamKind::Lifetime { kind: LifetimeParamKind::Explicit },
2079 ..
2080 }
2081 )
2082 })
2083 .collect::<Vec<_>>();
2084
2085 match binder {
2086 hir::ClosureBinder::Default => {}
2087 // we need to distinguish `|...| {}` from `for<> |...| {}` as `for<>` adds additional restrictions
2088 hir::ClosureBinder::For { .. } if generic_params.is_empty() => self.word("for<>"),
2089 hir::ClosureBinder::For { .. } => {
2090 self.word("for");
2091 self.word("<");
2092
2093 self.commasep(Inconsistent, &generic_params, |s, param| {
2094 s.print_generic_param(param)
2095 });
2096
2097 self.word(">");
2098 self.nbsp();
2099 }
2100 }
2101 }
2102
print_bounds<'b>( &mut self, prefix: &'static str, bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>, )2103 pub fn print_bounds<'b>(
2104 &mut self,
2105 prefix: &'static str,
2106 bounds: impl IntoIterator<Item = &'b hir::GenericBound<'b>>,
2107 ) {
2108 let mut first = true;
2109 for bound in bounds {
2110 if first {
2111 self.word(prefix);
2112 }
2113 if !(first && prefix.is_empty()) {
2114 self.nbsp();
2115 }
2116 if first {
2117 first = false;
2118 } else {
2119 self.word_space("+");
2120 }
2121
2122 match bound {
2123 GenericBound::Trait(tref, modifier) => {
2124 if modifier == &TraitBoundModifier::Maybe {
2125 self.word("?");
2126 }
2127 self.print_poly_trait_ref(tref);
2128 }
2129 GenericBound::LangItemTrait(lang_item, span, ..) => {
2130 self.word("#[lang = \"");
2131 self.print_ident(Ident::new(lang_item.name(), *span));
2132 self.word("\"]");
2133 }
2134 GenericBound::Outlives(lt) => {
2135 self.print_lifetime(lt);
2136 }
2137 }
2138 }
2139 }
2140
print_generic_params(&mut self, generic_params: &[GenericParam<'_>])2141 pub fn print_generic_params(&mut self, generic_params: &[GenericParam<'_>]) {
2142 if !generic_params.is_empty() {
2143 self.word("<");
2144
2145 self.commasep(Inconsistent, generic_params, |s, param| s.print_generic_param(param));
2146
2147 self.word(">");
2148 }
2149 }
2150
print_generic_param(&mut self, param: &GenericParam<'_>)2151 pub fn print_generic_param(&mut self, param: &GenericParam<'_>) {
2152 if let GenericParamKind::Const { .. } = param.kind {
2153 self.word_space("const");
2154 }
2155
2156 self.print_ident(param.name.ident());
2157
2158 match param.kind {
2159 GenericParamKind::Lifetime { .. } => {}
2160 GenericParamKind::Type { default, .. } => {
2161 if let Some(default) = default {
2162 self.space();
2163 self.word_space("=");
2164 self.print_type(default);
2165 }
2166 }
2167 GenericParamKind::Const { ty, ref default } => {
2168 self.word_space(":");
2169 self.print_type(ty);
2170 if let Some(default) = default {
2171 self.space();
2172 self.word_space("=");
2173 self.print_anon_const(default);
2174 }
2175 }
2176 }
2177 }
2178
print_lifetime(&mut self, lifetime: &hir::Lifetime)2179 pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) {
2180 self.print_ident(lifetime.ident)
2181 }
2182
print_where_clause(&mut self, generics: &hir::Generics<'_>)2183 pub fn print_where_clause(&mut self, generics: &hir::Generics<'_>) {
2184 if generics.predicates.is_empty() {
2185 return;
2186 }
2187
2188 self.space();
2189 self.word_space("where");
2190
2191 for (i, predicate) in generics.predicates.iter().enumerate() {
2192 if i != 0 {
2193 self.word_space(",");
2194 }
2195
2196 match *predicate {
2197 hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
2198 bound_generic_params,
2199 bounded_ty,
2200 bounds,
2201 ..
2202 }) => {
2203 self.print_formal_generic_params(bound_generic_params);
2204 self.print_type(bounded_ty);
2205 self.print_bounds(":", bounds);
2206 }
2207 hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate {
2208 ref lifetime,
2209 bounds,
2210 ..
2211 }) => {
2212 self.print_lifetime(lifetime);
2213 self.word(":");
2214
2215 for (i, bound) in bounds.iter().enumerate() {
2216 match bound {
2217 GenericBound::Outlives(lt) => {
2218 self.print_lifetime(lt);
2219 }
2220 _ => panic!(),
2221 }
2222
2223 if i != 0 {
2224 self.word(":");
2225 }
2226 }
2227 }
2228 hir::WherePredicate::EqPredicate(hir::WhereEqPredicate {
2229 lhs_ty, rhs_ty, ..
2230 }) => {
2231 self.print_type(lhs_ty);
2232 self.space();
2233 self.word_space("=");
2234 self.print_type(rhs_ty);
2235 }
2236 }
2237 }
2238 }
2239
print_mutability(&mut self, mutbl: hir::Mutability, print_const: bool)2240 pub fn print_mutability(&mut self, mutbl: hir::Mutability, print_const: bool) {
2241 match mutbl {
2242 hir::Mutability::Mut => self.word_nbsp("mut"),
2243 hir::Mutability::Not => {
2244 if print_const {
2245 self.word_nbsp("const")
2246 }
2247 }
2248 }
2249 }
2250
print_mt(&mut self, mt: &hir::MutTy<'_>, print_const: bool)2251 pub fn print_mt(&mut self, mt: &hir::MutTy<'_>, print_const: bool) {
2252 self.print_mutability(mt.mutbl, print_const);
2253 self.print_type(mt.ty);
2254 }
2255
print_fn_output(&mut self, decl: &hir::FnDecl<'_>)2256 pub fn print_fn_output(&mut self, decl: &hir::FnDecl<'_>) {
2257 if let hir::FnRetTy::DefaultReturn(..) = decl.output {
2258 return;
2259 }
2260
2261 self.space_if_not_bol();
2262 self.ibox(INDENT_UNIT);
2263 self.word_space("->");
2264 match decl.output {
2265 hir::FnRetTy::DefaultReturn(..) => unreachable!(),
2266 hir::FnRetTy::Return(ty) => self.print_type(ty),
2267 }
2268 self.end();
2269
2270 if let hir::FnRetTy::Return(output) = decl.output {
2271 self.maybe_print_comment(output.span.lo());
2272 }
2273 }
2274
print_ty_fn( &mut self, abi: Abi, unsafety: hir::Unsafety, decl: &hir::FnDecl<'_>, name: Option<Symbol>, generic_params: &[hir::GenericParam<'_>], arg_names: &[Ident], )2275 pub fn print_ty_fn(
2276 &mut self,
2277 abi: Abi,
2278 unsafety: hir::Unsafety,
2279 decl: &hir::FnDecl<'_>,
2280 name: Option<Symbol>,
2281 generic_params: &[hir::GenericParam<'_>],
2282 arg_names: &[Ident],
2283 ) {
2284 self.ibox(INDENT_UNIT);
2285 self.print_formal_generic_params(generic_params);
2286 let generics = hir::Generics::empty();
2287 self.print_fn(
2288 decl,
2289 hir::FnHeader {
2290 unsafety,
2291 abi,
2292 constness: hir::Constness::NotConst,
2293 asyncness: hir::IsAsync::NotAsync,
2294 },
2295 name,
2296 generics,
2297 arg_names,
2298 None,
2299 );
2300 self.end();
2301 }
2302
print_fn_header_info(&mut self, header: hir::FnHeader)2303 pub fn print_fn_header_info(&mut self, header: hir::FnHeader) {
2304 self.print_constness(header.constness);
2305
2306 match header.asyncness {
2307 hir::IsAsync::NotAsync => {}
2308 hir::IsAsync::Async => self.word_nbsp("async"),
2309 }
2310
2311 self.print_unsafety(header.unsafety);
2312
2313 if header.abi != Abi::Rust {
2314 self.word_nbsp("extern");
2315 self.word_nbsp(header.abi.to_string());
2316 }
2317
2318 self.word("fn")
2319 }
2320
print_constness(&mut self, s: hir::Constness)2321 pub fn print_constness(&mut self, s: hir::Constness) {
2322 match s {
2323 hir::Constness::NotConst => {}
2324 hir::Constness::Const => self.word_nbsp("const"),
2325 }
2326 }
2327
print_unsafety(&mut self, s: hir::Unsafety)2328 pub fn print_unsafety(&mut self, s: hir::Unsafety) {
2329 match s {
2330 hir::Unsafety::Normal => {}
2331 hir::Unsafety::Unsafe => self.word_nbsp("unsafe"),
2332 }
2333 }
2334
print_is_auto(&mut self, s: hir::IsAuto)2335 pub fn print_is_auto(&mut self, s: hir::IsAuto) {
2336 match s {
2337 hir::IsAuto::Yes => self.word_nbsp("auto"),
2338 hir::IsAuto::No => {}
2339 }
2340 }
2341 }
2342
2343 /// Does this expression require a semicolon to be treated
2344 /// as a statement? The negation of this: 'can this expression
2345 /// be used as a statement without a semicolon' -- is used
2346 /// as an early-bail-out in the parser so that, for instance,
2347 /// if true {...} else {...}
2348 /// |x| 5
2349 /// isn't parsed as (if true {...} else {...} | x) | 5
2350 //
2351 // Duplicated from `parse::classify`, but adapted for the HIR.
expr_requires_semi_to_be_stmt(e: &hir::Expr<'_>) -> bool2352 fn expr_requires_semi_to_be_stmt(e: &hir::Expr<'_>) -> bool {
2353 !matches!(
2354 e.kind,
2355 hir::ExprKind::If(..)
2356 | hir::ExprKind::Match(..)
2357 | hir::ExprKind::Block(..)
2358 | hir::ExprKind::Loop(..)
2359 )
2360 }
2361
2362 /// This statement requires a semicolon after it.
2363 /// note that in one case (stmt_semi), we've already
2364 /// seen the semicolon, and thus don't need another.
stmt_ends_with_semi(stmt: &hir::StmtKind<'_>) -> bool2365 fn stmt_ends_with_semi(stmt: &hir::StmtKind<'_>) -> bool {
2366 match *stmt {
2367 hir::StmtKind::Local(_) => true,
2368 hir::StmtKind::Item(_) => false,
2369 hir::StmtKind::Expr(e) => expr_requires_semi_to_be_stmt(e),
2370 hir::StmtKind::Semi(..) => false,
2371 }
2372 }
2373
bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp2374 fn bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp {
2375 use crate::hir::BinOpKind::*;
2376 match op {
2377 Add => AssocOp::Add,
2378 Sub => AssocOp::Subtract,
2379 Mul => AssocOp::Multiply,
2380 Div => AssocOp::Divide,
2381 Rem => AssocOp::Modulus,
2382
2383 And => AssocOp::LAnd,
2384 Or => AssocOp::LOr,
2385
2386 BitXor => AssocOp::BitXor,
2387 BitAnd => AssocOp::BitAnd,
2388 BitOr => AssocOp::BitOr,
2389 Shl => AssocOp::ShiftLeft,
2390 Shr => AssocOp::ShiftRight,
2391
2392 Eq => AssocOp::Equal,
2393 Lt => AssocOp::Less,
2394 Le => AssocOp::LessEqual,
2395 Ne => AssocOp::NotEqual,
2396 Ge => AssocOp::GreaterEqual,
2397 Gt => AssocOp::Greater,
2398 }
2399 }
2400
2401 /// Expressions that syntactically contain an "exterior" struct literal, i.e., not surrounded by any
2402 /// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
2403 /// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.
contains_exterior_struct_lit(value: &hir::Expr<'_>) -> bool2404 fn contains_exterior_struct_lit(value: &hir::Expr<'_>) -> bool {
2405 match value.kind {
2406 hir::ExprKind::Struct(..) => true,
2407
2408 hir::ExprKind::Assign(lhs, rhs, _)
2409 | hir::ExprKind::AssignOp(_, lhs, rhs)
2410 | hir::ExprKind::Binary(_, lhs, rhs) => {
2411 // `X { y: 1 } + X { y: 2 }`
2412 contains_exterior_struct_lit(lhs) || contains_exterior_struct_lit(rhs)
2413 }
2414 hir::ExprKind::Unary(_, x)
2415 | hir::ExprKind::Cast(x, _)
2416 | hir::ExprKind::Type(x, _)
2417 | hir::ExprKind::Field(x, _)
2418 | hir::ExprKind::Index(x, _) => {
2419 // `&X { y: 1 }, X { y: 1 }.y`
2420 contains_exterior_struct_lit(x)
2421 }
2422
2423 hir::ExprKind::MethodCall(_, receiver, ..) => {
2424 // `X { y: 1 }.bar(...)`
2425 contains_exterior_struct_lit(receiver)
2426 }
2427
2428 _ => false,
2429 }
2430 }
2431