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1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 use ast::*;
12 use ast;
13 use codemap;
14 use codemap::Span;
15 use parse::token;
16 use print::pprust;
17 use ptr::P;
18 use visit::{FnKind, Visitor};
19 use visit;
20
21 use std::cmp;
22 use std::u32;
23
24 pub fn path_name_i(idents: &[Ident]) -> String {
25 // FIXME: Bad copies (#2543 -- same for everything else that says "bad")
26 idents.iter().map(|i| i.to_string()).collect::<Vec<String>>().join("::")
27 }
28
29 pub fn is_path(e: P<Expr>) -> bool {
30 match e.node { ExprKind::Path(..) => true, _ => false }
31 }
32
33
34 // convert a span and an identifier to the corresponding
35 // 1-segment path
36 pub fn ident_to_path(s: Span, identifier: Ident) -> Path {
37 ast::Path {
38 span: s,
39 global: false,
40 segments: vec!(
41 ast::PathSegment {
42 identifier: identifier,
43 parameters: ast::PathParameters::AngleBracketed(ast::AngleBracketedParameterData {
44 lifetimes: Vec::new(),
45 types: P::empty(),
46 bindings: P::empty(),
47 })
48 }
49 ),
50 }
51 }
52
53 // If path is a single segment ident path, return that ident. Otherwise, return
54 // None.
55 pub fn path_to_ident(path: &Path) -> Option<Ident> {
56 if path.segments.len() != 1 {
57 return None;
58 }
59
60 let segment = &path.segments[0];
61 if !segment.parameters.is_empty() {
62 return None;
63 }
64
65 Some(segment.identifier)
66 }
67
68 pub fn ident_to_pat(id: NodeId, s: Span, i: Ident) -> P<Pat> {
69 let spanned = codemap::Spanned{ span: s, node: i };
70 P(Pat {
71 id: id,
72 node: PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), spanned, None),
73 span: s
74 })
75 }
76
77 /// Generate a "pretty" name for an `impl` from its type and trait.
78 /// This is designed so that symbols of `impl`'d methods give some
79 /// hint of where they came from, (previously they would all just be
80 /// listed as `__extensions__::method_name::hash`, with no indication
81 /// of the type).
82 pub fn impl_pretty_name(trait_ref: &Option<TraitRef>, ty: Option<&Ty>) -> Ident {
83 let mut pretty = match ty {
84 Some(t) => pprust::ty_to_string(t),
85 None => String::from("..")
86 };
87
88 match *trait_ref {
89 Some(ref trait_ref) => {
90 pretty.push('.');
91 pretty.push_str(&pprust::path_to_string(&trait_ref.path));
92 }
93 None => {}
94 }
95 token::gensym_ident(&pretty[..])
96 }
97
98 pub fn struct_field_visibility(field: ast::StructField) -> Visibility {
99 match field.node.kind {
100 ast::NamedField(_, v) | ast::UnnamedField(v) => v
101 }
102 }
103
104 // ______________________________________________________________________
105 // Enumerating the IDs which appear in an AST
106
107 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
108 pub struct IdRange {
109 pub min: NodeId,
110 pub max: NodeId,
111 }
112
113 impl IdRange {
114 pub fn max() -> IdRange {
115 IdRange {
116 min: u32::MAX,
117 max: u32::MIN,
118 }
119 }
120
121 pub fn empty(&self) -> bool {
122 self.min >= self.max
123 }
124
125 pub fn add(&mut self, id: NodeId) {
126 self.min = cmp::min(self.min, id);
127 self.max = cmp::max(self.max, id + 1);
128 }
129 }
130
131 pub trait IdVisitingOperation {
132 fn visit_id(&mut self, node_id: NodeId);
133 }
134
135 /// A visitor that applies its operation to all of the node IDs
136 /// in a visitable thing.
137
138 pub struct IdVisitor<'a, O:'a> {
139 pub operation: &'a mut O,
140 pub visited_outermost: bool,
141 }
142
143 impl<'a, O: IdVisitingOperation> IdVisitor<'a, O> {
144 fn visit_generics_helper(&mut self, generics: &Generics) {
145 for type_parameter in generics.ty_params.iter() {
146 self.operation.visit_id(type_parameter.id)
147 }
148 for lifetime in &generics.lifetimes {
149 self.operation.visit_id(lifetime.lifetime.id)
150 }
151 }
152 }
153
154 impl<'a, 'v, O: IdVisitingOperation> Visitor<'v> for IdVisitor<'a, O> {
155 fn visit_mod(&mut self,
156 module: &Mod,
157 _: Span,
158 node_id: NodeId) {
159 self.operation.visit_id(node_id);
160 visit::walk_mod(self, module)
161 }
162
163 fn visit_foreign_item(&mut self, foreign_item: &ForeignItem) {
164 self.operation.visit_id(foreign_item.id);
165 visit::walk_foreign_item(self, foreign_item)
166 }
167
168 fn visit_item(&mut self, item: &Item) {
169 if self.visited_outermost {
170 return
171 } else {
172 self.visited_outermost = true
173 }
174
175 self.operation.visit_id(item.id);
176 match item.node {
177 ItemKind::Use(ref view_path) => {
178 match view_path.node {
179 ViewPathSimple(_, _) |
180 ViewPathGlob(_) => {}
181 ViewPathList(_, ref paths) => {
182 for path in paths {
183 self.operation.visit_id(path.node.id())
184 }
185 }
186 }
187 }
188 _ => {}
189 }
190
191 visit::walk_item(self, item);
192
193 self.visited_outermost = false
194 }
195
196 fn visit_local(&mut self, local: &Local) {
197 self.operation.visit_id(local.id);
198 visit::walk_local(self, local)
199 }
200
201 fn visit_block(&mut self, block: &Block) {
202 self.operation.visit_id(block.id);
203 visit::walk_block(self, block)
204 }
205
206 fn visit_stmt(&mut self, statement: &Stmt) {
207 self.operation
208 .visit_id(statement.node.id().expect("attempted to visit unexpanded stmt"));
209 visit::walk_stmt(self, statement)
210 }
211
212 fn visit_pat(&mut self, pattern: &Pat) {
213 self.operation.visit_id(pattern.id);
214 visit::walk_pat(self, pattern)
215 }
216
217 fn visit_expr(&mut self, expression: &Expr) {
218 self.operation.visit_id(expression.id);
219 visit::walk_expr(self, expression)
220 }
221
222 fn visit_ty(&mut self, typ: &Ty) {
223 self.operation.visit_id(typ.id);
224 visit::walk_ty(self, typ)
225 }
226
227 fn visit_generics(&mut self, generics: &Generics) {
228 self.visit_generics_helper(generics);
229 visit::walk_generics(self, generics)
230 }
231
232 fn visit_fn(&mut self,
233 function_kind: visit::FnKind<'v>,
234 function_declaration: &'v FnDecl,
235 block: &'v Block,
236 span: Span,
237 node_id: NodeId) {
238 match function_kind {
239 FnKind::Method(..) if self.visited_outermost => return,
240 FnKind::Method(..) => self.visited_outermost = true,
241 _ => {}
242 }
243
244 self.operation.visit_id(node_id);
245
246 match function_kind {
247 FnKind::ItemFn(_, generics, _, _, _, _) => {
248 self.visit_generics_helper(generics)
249 }
250 FnKind::Method(_, sig, _) => {
251 self.visit_generics_helper(&sig.generics)
252 }
253 FnKind::Closure => {}
254 }
255
256 for argument in &function_declaration.inputs {
257 self.operation.visit_id(argument.id)
258 }
259
260 visit::walk_fn(self,
261 function_kind,
262 function_declaration,
263 block,
264 span);
265
266 if let FnKind::Method(..) = function_kind {
267 self.visited_outermost = false;
268 }
269 }
270
271 fn visit_struct_field(&mut self, struct_field: &StructField) {
272 self.operation.visit_id(struct_field.node.id);
273 visit::walk_struct_field(self, struct_field)
274 }
275
276 fn visit_variant_data(&mut self,
277 struct_def: &VariantData,
278 _: ast::Ident,
279 _: &ast::Generics,
280 _: NodeId,
281 _: Span) {
282 self.operation.visit_id(struct_def.id());
283 visit::walk_struct_def(self, struct_def);
284 }
285
286 fn visit_trait_item(&mut self, ti: &ast::TraitItem) {
287 self.operation.visit_id(ti.id);
288 visit::walk_trait_item(self, ti);
289 }
290
291 fn visit_impl_item(&mut self, ii: &ast::ImplItem) {
292 self.operation.visit_id(ii.id);
293 visit::walk_impl_item(self, ii);
294 }
295
296 fn visit_lifetime(&mut self, lifetime: &Lifetime) {
297 self.operation.visit_id(lifetime.id);
298 }
299
300 fn visit_lifetime_def(&mut self, def: &LifetimeDef) {
301 self.visit_lifetime(&def.lifetime);
302 }
303
304 fn visit_trait_ref(&mut self, trait_ref: &TraitRef) {
305 self.operation.visit_id(trait_ref.ref_id);
306 visit::walk_trait_ref(self, trait_ref);
307 }
308 }
309
310 pub struct IdRangeComputingVisitor {
311 pub result: IdRange,
312 }
313
314 impl IdRangeComputingVisitor {
315 pub fn new() -> IdRangeComputingVisitor {
316 IdRangeComputingVisitor { result: IdRange::max() }
317 }
318
319 pub fn result(&self) -> IdRange {
320 self.result
321 }
322 }
323
324 impl IdVisitingOperation for IdRangeComputingVisitor {
325 fn visit_id(&mut self, id: NodeId) {
326 self.result.add(id);
327 }
328 }
329
330 /// Computes the id range for a single fn body, ignoring nested items.
331 pub fn compute_id_range_for_fn_body(fk: FnKind,
332 decl: &FnDecl,
333 body: &Block,
334 sp: Span,
335 id: NodeId)
336 -> IdRange
337 {
338 let mut visitor = IdRangeComputingVisitor::new();
339 let mut id_visitor = IdVisitor {
340 operation: &mut visitor,
341 visited_outermost: false,
342 };
343 id_visitor.visit_fn(fk, decl, body, sp, id);
344 id_visitor.operation.result
345 }
346
347 /// Returns true if the given pattern consists solely of an identifier
348 /// and false otherwise.
349 pub fn pat_is_ident(pat: P<ast::Pat>) -> bool {
350 match pat.node {
351 PatKind::Ident(..) => true,
352 _ => false,
353 }
354 }
355
356 // are two paths equal when compared unhygienically?
357 // since I'm using this to replace ==, it seems appropriate
358 // to compare the span, global, etc. fields as well.
359 pub fn path_name_eq(a : &ast::Path, b : &ast::Path) -> bool {
360 (a.span.source_equal(&b.span))
361 && (a.global == b.global)
362 && (segments_name_eq(&a.segments[..], &b.segments[..]))
363 }
364
365 // are two arrays of segments equal when compared unhygienically?
366 pub fn segments_name_eq(a : &[ast::PathSegment], b : &[ast::PathSegment]) -> bool {
367 a.len() == b.len() &&
368 a.iter().zip(b).all(|(s, t)| {
369 s.identifier.name == t.identifier.name &&
370 // FIXME #7743: ident -> name problems in lifetime comparison?
371 // can types contain idents?
372 s.parameters == t.parameters
373 })
374 }
375
376 #[cfg(test)]
377 mod tests {
378 use ast::*;
379 use super::*;
380
381 fn ident_to_segment(id: Ident) -> PathSegment {
382 PathSegment {identifier: id,
383 parameters: PathParameters::none()}
384 }
385
386 #[test] fn idents_name_eq_test() {
387 assert!(segments_name_eq(
388 &[Ident::new(Name(3),SyntaxContext(4)), Ident::new(Name(78),SyntaxContext(82))]
389 .iter().cloned().map(ident_to_segment).collect::<Vec<PathSegment>>(),
390 &[Ident::new(Name(3),SyntaxContext(104)), Ident::new(Name(78),SyntaxContext(182))]
391 .iter().cloned().map(ident_to_segment).collect::<Vec<PathSegment>>()));
392 assert!(!segments_name_eq(
393 &[Ident::new(Name(3),SyntaxContext(4)), Ident::new(Name(78),SyntaxContext(82))]
394 .iter().cloned().map(ident_to_segment).collect::<Vec<PathSegment>>(),
395 &[Ident::new(Name(3),SyntaxContext(104)), Ident::new(Name(77),SyntaxContext(182))]
396 .iter().cloned().map(ident_to_segment).collect::<Vec<PathSegment>>()));
397 }
398 }