rustc_expand/
build.rs

1use rustc_ast::token::Delimiter;
2use rustc_ast::tokenstream::TokenStream;
3use rustc_ast::util::literal;
4use rustc_ast::{
5    self as ast, AnonConst, AttrItem, AttrVec, BlockCheckMode, Expr, LocalKind, MatchKind, PatKind,
6    UnOp, attr, token, tokenstream,
7};
8use rustc_span::source_map::Spanned;
9use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
10use thin_vec::{ThinVec, thin_vec};
11
12use crate::base::ExtCtxt;
13
14impl<'a> ExtCtxt<'a> {
15    pub fn path(&self, span: Span, strs: Vec<Ident>) -> ast::Path {
16        self.path_all(span, false, strs, vec![])
17    }
18    pub fn path_ident(&self, span: Span, id: Ident) -> ast::Path {
19        self.path(span, vec![id])
20    }
21    pub fn path_global(&self, span: Span, strs: Vec<Ident>) -> ast::Path {
22        self.path_all(span, true, strs, vec![])
23    }
24    pub fn path_all(
25        &self,
26        span: Span,
27        global: bool,
28        mut idents: Vec<Ident>,
29        args: Vec<ast::GenericArg>,
30    ) -> ast::Path {
31        assert!(!idents.is_empty());
32        let add_root = global && !idents[0].is_path_segment_keyword();
33        let mut segments = ThinVec::with_capacity(idents.len() + add_root as usize);
34        if add_root {
35            segments.push(ast::PathSegment::path_root(span));
36        }
37        let last_ident = idents.pop().unwrap();
38        segments.extend(
39            idents.into_iter().map(|ident| ast::PathSegment::from_ident(ident.with_span_pos(span))),
40        );
41        let args = if !args.is_empty() {
42            let args = args.into_iter().map(ast::AngleBracketedArg::Arg).collect();
43            Some(ast::AngleBracketedArgs { args, span }.into())
44        } else {
45            None
46        };
47        segments.push(ast::PathSegment {
48            ident: last_ident.with_span_pos(span),
49            id: ast::DUMMY_NODE_ID,
50            args,
51        });
52        ast::Path { span, segments, tokens: None }
53    }
54
55    pub fn macro_call(
56        &self,
57        span: Span,
58        path: ast::Path,
59        delim: Delimiter,
60        tokens: TokenStream,
61    ) -> Box<ast::MacCall> {
62        Box::new(ast::MacCall {
63            path,
64            args: Box::new(ast::DelimArgs {
65                dspan: tokenstream::DelimSpan { open: span, close: span },
66                delim,
67                tokens,
68            }),
69        })
70    }
71
72    pub fn ty_mt(&self, ty: Box<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy {
73        ast::MutTy { ty, mutbl }
74    }
75
76    pub fn ty(&self, span: Span, kind: ast::TyKind) -> Box<ast::Ty> {
77        Box::new(ast::Ty { id: ast::DUMMY_NODE_ID, span, kind, tokens: None })
78    }
79
80    pub fn ty_infer(&self, span: Span) -> Box<ast::Ty> {
81        self.ty(span, ast::TyKind::Infer)
82    }
83
84    pub fn ty_path(&self, path: ast::Path) -> Box<ast::Ty> {
85        self.ty(path.span, ast::TyKind::Path(None, path))
86    }
87
88    // Might need to take bounds as an argument in the future, if you ever want
89    // to generate a bounded existential trait type.
90    pub fn ty_ident(&self, span: Span, ident: Ident) -> Box<ast::Ty> {
91        self.ty_path(self.path_ident(span, ident))
92    }
93
94    pub fn anon_const(&self, span: Span, kind: ast::ExprKind) -> ast::AnonConst {
95        ast::AnonConst {
96            id: ast::DUMMY_NODE_ID,
97            value: Box::new(ast::Expr {
98                id: ast::DUMMY_NODE_ID,
99                kind,
100                span,
101                attrs: AttrVec::new(),
102                tokens: None,
103            }),
104        }
105    }
106
107    pub fn anon_const_block(&self, b: Box<ast::Block>) -> Box<ast::AnonConst> {
108        Box::new(self.anon_const(b.span, ast::ExprKind::Block(b, None)))
109    }
110
111    pub fn const_ident(&self, span: Span, ident: Ident) -> ast::AnonConst {
112        self.anon_const(span, ast::ExprKind::Path(None, self.path_ident(span, ident)))
113    }
114
115    pub fn ty_ref(
116        &self,
117        span: Span,
118        ty: Box<ast::Ty>,
119        lifetime: Option<ast::Lifetime>,
120        mutbl: ast::Mutability,
121    ) -> Box<ast::Ty> {
122        self.ty(span, ast::TyKind::Ref(lifetime, self.ty_mt(ty, mutbl)))
123    }
124
125    pub fn ty_ptr(&self, span: Span, ty: Box<ast::Ty>, mutbl: ast::Mutability) -> Box<ast::Ty> {
126        self.ty(span, ast::TyKind::Ptr(self.ty_mt(ty, mutbl)))
127    }
128
129    pub fn typaram(
130        &self,
131        span: Span,
132        ident: Ident,
133        bounds: ast::GenericBounds,
134        default: Option<Box<ast::Ty>>,
135    ) -> ast::GenericParam {
136        ast::GenericParam {
137            ident: ident.with_span_pos(span),
138            id: ast::DUMMY_NODE_ID,
139            attrs: AttrVec::new(),
140            bounds,
141            kind: ast::GenericParamKind::Type { default },
142            is_placeholder: false,
143            colon_span: None,
144        }
145    }
146
147    pub fn lifetime_param(
148        &self,
149        span: Span,
150        ident: Ident,
151        bounds: ast::GenericBounds,
152    ) -> ast::GenericParam {
153        ast::GenericParam {
154            id: ast::DUMMY_NODE_ID,
155            ident: ident.with_span_pos(span),
156            attrs: AttrVec::new(),
157            bounds,
158            is_placeholder: false,
159            kind: ast::GenericParamKind::Lifetime,
160            colon_span: None,
161        }
162    }
163
164    pub fn const_param(
165        &self,
166        span: Span,
167        ident: Ident,
168        bounds: ast::GenericBounds,
169        ty: Box<ast::Ty>,
170        default: Option<AnonConst>,
171    ) -> ast::GenericParam {
172        ast::GenericParam {
173            id: ast::DUMMY_NODE_ID,
174            ident: ident.with_span_pos(span),
175            attrs: AttrVec::new(),
176            bounds,
177            is_placeholder: false,
178            kind: ast::GenericParamKind::Const { ty, span: DUMMY_SP, default },
179            colon_span: None,
180        }
181    }
182
183    pub fn trait_ref(&self, path: ast::Path) -> ast::TraitRef {
184        ast::TraitRef { path, ref_id: ast::DUMMY_NODE_ID }
185    }
186
187    pub fn poly_trait_ref(&self, span: Span, path: ast::Path, is_const: bool) -> ast::PolyTraitRef {
188        ast::PolyTraitRef {
189            bound_generic_params: ThinVec::new(),
190            modifiers: ast::TraitBoundModifiers {
191                polarity: ast::BoundPolarity::Positive,
192                constness: if is_const {
193                    ast::BoundConstness::Maybe(DUMMY_SP)
194                } else {
195                    ast::BoundConstness::Never
196                },
197                asyncness: ast::BoundAsyncness::Normal,
198            },
199            trait_ref: self.trait_ref(path),
200            span,
201            parens: ast::Parens::No,
202        }
203    }
204
205    pub fn trait_bound(&self, path: ast::Path, is_const: bool) -> ast::GenericBound {
206        ast::GenericBound::Trait(self.poly_trait_ref(path.span, path, is_const))
207    }
208
209    pub fn lifetime(&self, span: Span, ident: Ident) -> ast::Lifetime {
210        ast::Lifetime { id: ast::DUMMY_NODE_ID, ident: ident.with_span_pos(span) }
211    }
212
213    pub fn lifetime_static(&self, span: Span) -> ast::Lifetime {
214        self.lifetime(span, Ident::new(kw::StaticLifetime, span))
215    }
216
217    pub fn stmt_expr(&self, expr: Box<ast::Expr>) -> ast::Stmt {
218        ast::Stmt { id: ast::DUMMY_NODE_ID, span: expr.span, kind: ast::StmtKind::Expr(expr) }
219    }
220
221    pub fn stmt_let(&self, sp: Span, mutbl: bool, ident: Ident, ex: Box<ast::Expr>) -> ast::Stmt {
222        self.stmt_let_ty(sp, mutbl, ident, None, ex)
223    }
224
225    pub fn stmt_let_ty(
226        &self,
227        sp: Span,
228        mutbl: bool,
229        ident: Ident,
230        ty: Option<Box<ast::Ty>>,
231        ex: Box<ast::Expr>,
232    ) -> ast::Stmt {
233        let pat = if mutbl {
234            self.pat_ident_binding_mode(sp, ident, ast::BindingMode::MUT)
235        } else {
236            self.pat_ident(sp, ident)
237        };
238        let local = Box::new(ast::Local {
239            super_: None,
240            pat: Box::new(pat),
241            ty,
242            id: ast::DUMMY_NODE_ID,
243            kind: LocalKind::Init(ex),
244            span: sp,
245            colon_sp: None,
246            attrs: AttrVec::new(),
247            tokens: None,
248        });
249        self.stmt_local(local, sp)
250    }
251
252    /// Generates `let _: Type;`, which is usually used for type assertions.
253    pub fn stmt_let_type_only(&self, span: Span, ty: Box<ast::Ty>) -> ast::Stmt {
254        let local = Box::new(ast::Local {
255            super_: None,
256            pat: Box::new(self.pat_wild(span)),
257            ty: Some(ty),
258            id: ast::DUMMY_NODE_ID,
259            kind: LocalKind::Decl,
260            span,
261            colon_sp: None,
262            attrs: AttrVec::new(),
263            tokens: None,
264        });
265        self.stmt_local(local, span)
266    }
267
268    pub fn stmt_semi(&self, expr: Box<ast::Expr>) -> ast::Stmt {
269        ast::Stmt { id: ast::DUMMY_NODE_ID, span: expr.span, kind: ast::StmtKind::Semi(expr) }
270    }
271
272    pub fn stmt_local(&self, local: Box<ast::Local>, span: Span) -> ast::Stmt {
273        ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Let(local), span }
274    }
275
276    pub fn stmt_item(&self, sp: Span, item: Box<ast::Item>) -> ast::Stmt {
277        ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Item(item), span: sp }
278    }
279
280    pub fn block_expr(&self, expr: Box<ast::Expr>) -> Box<ast::Block> {
281        self.block(
282            expr.span,
283            thin_vec![ast::Stmt {
284                id: ast::DUMMY_NODE_ID,
285                span: expr.span,
286                kind: ast::StmtKind::Expr(expr),
287            }],
288        )
289    }
290    pub fn block(&self, span: Span, stmts: ThinVec<ast::Stmt>) -> Box<ast::Block> {
291        Box::new(ast::Block {
292            stmts,
293            id: ast::DUMMY_NODE_ID,
294            rules: BlockCheckMode::Default,
295            span,
296            tokens: None,
297        })
298    }
299
300    pub fn expr(&self, span: Span, kind: ast::ExprKind) -> Box<ast::Expr> {
301        Box::new(ast::Expr {
302            id: ast::DUMMY_NODE_ID,
303            kind,
304            span,
305            attrs: AttrVec::new(),
306            tokens: None,
307        })
308    }
309
310    pub fn expr_path(&self, path: ast::Path) -> Box<ast::Expr> {
311        self.expr(path.span, ast::ExprKind::Path(None, path))
312    }
313
314    pub fn expr_ident(&self, span: Span, id: Ident) -> Box<ast::Expr> {
315        self.expr_path(self.path_ident(span, id))
316    }
317    pub fn expr_self(&self, span: Span) -> Box<ast::Expr> {
318        self.expr_ident(span, Ident::with_dummy_span(kw::SelfLower))
319    }
320
321    pub fn expr_macro_call(&self, span: Span, call: Box<ast::MacCall>) -> Box<ast::Expr> {
322        self.expr(span, ast::ExprKind::MacCall(call))
323    }
324
325    pub fn expr_binary(
326        &self,
327        sp: Span,
328        op: ast::BinOpKind,
329        lhs: Box<ast::Expr>,
330        rhs: Box<ast::Expr>,
331    ) -> Box<ast::Expr> {
332        self.expr(sp, ast::ExprKind::Binary(Spanned { node: op, span: sp }, lhs, rhs))
333    }
334
335    pub fn expr_deref(&self, sp: Span, e: Box<ast::Expr>) -> Box<ast::Expr> {
336        self.expr(sp, ast::ExprKind::Unary(UnOp::Deref, e))
337    }
338
339    pub fn expr_addr_of(&self, sp: Span, e: Box<ast::Expr>) -> Box<ast::Expr> {
340        self.expr(sp, ast::ExprKind::AddrOf(ast::BorrowKind::Ref, ast::Mutability::Not, e))
341    }
342
343    pub fn expr_paren(&self, sp: Span, e: Box<ast::Expr>) -> Box<ast::Expr> {
344        self.expr(sp, ast::ExprKind::Paren(e))
345    }
346
347    pub fn expr_method_call(
348        &self,
349        span: Span,
350        expr: Box<ast::Expr>,
351        ident: Ident,
352        args: ThinVec<Box<ast::Expr>>,
353    ) -> Box<ast::Expr> {
354        let seg = ast::PathSegment::from_ident(ident);
355        self.expr(
356            span,
357            ast::ExprKind::MethodCall(Box::new(ast::MethodCall {
358                seg,
359                receiver: expr,
360                args,
361                span,
362            })),
363        )
364    }
365
366    pub fn expr_call(
367        &self,
368        span: Span,
369        expr: Box<ast::Expr>,
370        args: ThinVec<Box<ast::Expr>>,
371    ) -> Box<ast::Expr> {
372        self.expr(span, ast::ExprKind::Call(expr, args))
373    }
374    pub fn expr_loop(&self, sp: Span, block: Box<ast::Block>) -> Box<ast::Expr> {
375        self.expr(sp, ast::ExprKind::Loop(block, None, sp))
376    }
377    pub fn expr_asm(&self, sp: Span, expr: Box<ast::InlineAsm>) -> Box<ast::Expr> {
378        self.expr(sp, ast::ExprKind::InlineAsm(expr))
379    }
380    pub fn expr_call_ident(
381        &self,
382        span: Span,
383        id: Ident,
384        args: ThinVec<Box<ast::Expr>>,
385    ) -> Box<ast::Expr> {
386        self.expr(span, ast::ExprKind::Call(self.expr_ident(span, id), args))
387    }
388    pub fn expr_call_global(
389        &self,
390        sp: Span,
391        fn_path: Vec<Ident>,
392        args: ThinVec<Box<ast::Expr>>,
393    ) -> Box<ast::Expr> {
394        let pathexpr = self.expr_path(self.path_global(sp, fn_path));
395        self.expr_call(sp, pathexpr, args)
396    }
397    pub fn expr_block(&self, b: Box<ast::Block>) -> Box<ast::Expr> {
398        self.expr(b.span, ast::ExprKind::Block(b, None))
399    }
400    pub fn field_imm(&self, span: Span, ident: Ident, e: Box<ast::Expr>) -> ast::ExprField {
401        ast::ExprField {
402            ident: ident.with_span_pos(span),
403            expr: e,
404            span,
405            is_shorthand: false,
406            attrs: AttrVec::new(),
407            id: ast::DUMMY_NODE_ID,
408            is_placeholder: false,
409        }
410    }
411    pub fn expr_struct(
412        &self,
413        span: Span,
414        path: ast::Path,
415        fields: ThinVec<ast::ExprField>,
416    ) -> Box<ast::Expr> {
417        self.expr(
418            span,
419            ast::ExprKind::Struct(Box::new(ast::StructExpr {
420                qself: None,
421                path,
422                fields,
423                rest: ast::StructRest::None,
424            })),
425        )
426    }
427    pub fn expr_struct_ident(
428        &self,
429        span: Span,
430        id: Ident,
431        fields: ThinVec<ast::ExprField>,
432    ) -> Box<ast::Expr> {
433        self.expr_struct(span, self.path_ident(span, id), fields)
434    }
435
436    pub fn expr_usize(&self, span: Span, n: usize) -> Box<ast::Expr> {
437        let suffix = Some(ast::UintTy::Usize.name());
438        let lit = token::Lit::new(token::Integer, sym::integer(n), suffix);
439        self.expr(span, ast::ExprKind::Lit(lit))
440    }
441
442    pub fn expr_u32(&self, span: Span, n: u32) -> Box<ast::Expr> {
443        let suffix = Some(ast::UintTy::U32.name());
444        let lit = token::Lit::new(token::Integer, sym::integer(n), suffix);
445        self.expr(span, ast::ExprKind::Lit(lit))
446    }
447
448    pub fn expr_bool(&self, span: Span, value: bool) -> Box<ast::Expr> {
449        let lit = token::Lit::new(token::Bool, if value { kw::True } else { kw::False }, None);
450        self.expr(span, ast::ExprKind::Lit(lit))
451    }
452
453    pub fn expr_str(&self, span: Span, s: Symbol) -> Box<ast::Expr> {
454        let lit = token::Lit::new(token::Str, literal::escape_string_symbol(s), None);
455        self.expr(span, ast::ExprKind::Lit(lit))
456    }
457
458    pub fn expr_byte_str(&self, span: Span, bytes: Vec<u8>) -> Box<ast::Expr> {
459        let lit = token::Lit::new(token::ByteStr, literal::escape_byte_str_symbol(&bytes), None);
460        self.expr(span, ast::ExprKind::Lit(lit))
461    }
462
463    /// `[expr1, expr2, ...]`
464    pub fn expr_array(&self, sp: Span, exprs: ThinVec<Box<ast::Expr>>) -> Box<ast::Expr> {
465        self.expr(sp, ast::ExprKind::Array(exprs))
466    }
467
468    /// `&[expr1, expr2, ...]`
469    pub fn expr_array_ref(&self, sp: Span, exprs: ThinVec<Box<ast::Expr>>) -> Box<ast::Expr> {
470        self.expr_addr_of(sp, self.expr_array(sp, exprs))
471    }
472
473    pub fn expr_some(&self, sp: Span, expr: Box<ast::Expr>) -> Box<ast::Expr> {
474        let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
475        self.expr_call_global(sp, some, thin_vec![expr])
476    }
477
478    pub fn expr_none(&self, sp: Span) -> Box<ast::Expr> {
479        let none = self.std_path(&[sym::option, sym::Option, sym::None]);
480        self.expr_path(self.path_global(sp, none))
481    }
482    pub fn expr_tuple(&self, sp: Span, exprs: ThinVec<Box<ast::Expr>>) -> Box<ast::Expr> {
483        self.expr(sp, ast::ExprKind::Tup(exprs))
484    }
485
486    pub fn expr_unreachable(&self, span: Span) -> Box<ast::Expr> {
487        self.expr_macro_call(
488            span,
489            self.macro_call(
490                span,
491                self.path_global(
492                    span,
493                    [sym::std, sym::unreachable].map(|s| Ident::new(s, span)).to_vec(),
494                ),
495                Delimiter::Parenthesis,
496                TokenStream::default(),
497            ),
498        )
499    }
500
501    pub fn expr_ok(&self, sp: Span, expr: Box<ast::Expr>) -> Box<ast::Expr> {
502        let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
503        self.expr_call_global(sp, ok, thin_vec![expr])
504    }
505
506    pub fn expr_try(&self, sp: Span, head: Box<ast::Expr>) -> Box<ast::Expr> {
507        let ok = self.std_path(&[sym::result, sym::Result, sym::Ok]);
508        let ok_path = self.path_global(sp, ok);
509        let err = self.std_path(&[sym::result, sym::Result, sym::Err]);
510        let err_path = self.path_global(sp, err);
511
512        let binding_variable = Ident::new(sym::__try_var, sp);
513        let binding_pat = self.pat_ident(sp, binding_variable);
514        let binding_expr = self.expr_ident(sp, binding_variable);
515
516        // `Ok(__try_var)` pattern
517        let ok_pat = self.pat_tuple_struct(sp, ok_path, thin_vec![binding_pat.clone()]);
518
519        // `Err(__try_var)` (pattern and expression respectively)
520        let err_pat = self.pat_tuple_struct(sp, err_path.clone(), thin_vec![binding_pat]);
521        let err_inner_expr =
522            self.expr_call(sp, self.expr_path(err_path), thin_vec![binding_expr.clone()]);
523        // `return Err(__try_var)`
524        let err_expr = self.expr(sp, ast::ExprKind::Ret(Some(err_inner_expr)));
525
526        // `Ok(__try_var) => __try_var`
527        let ok_arm = self.arm(sp, ok_pat, binding_expr);
528        // `Err(__try_var) => return Err(__try_var)`
529        let err_arm = self.arm(sp, err_pat, err_expr);
530
531        // `match head { Ok() => ..., Err() => ... }`
532        self.expr_match(sp, head, thin_vec![ok_arm, err_arm])
533    }
534
535    pub fn pat(&self, span: Span, kind: PatKind) -> ast::Pat {
536        ast::Pat { id: ast::DUMMY_NODE_ID, kind, span, tokens: None }
537    }
538    pub fn pat_wild(&self, span: Span) -> ast::Pat {
539        self.pat(span, PatKind::Wild)
540    }
541    pub fn pat_lit(&self, span: Span, expr: Box<ast::Expr>) -> ast::Pat {
542        self.pat(span, PatKind::Expr(expr))
543    }
544    pub fn pat_ident(&self, span: Span, ident: Ident) -> ast::Pat {
545        self.pat_ident_binding_mode(span, ident, ast::BindingMode::NONE)
546    }
547
548    pub fn pat_ident_binding_mode(
549        &self,
550        span: Span,
551        ident: Ident,
552        ann: ast::BindingMode,
553    ) -> ast::Pat {
554        let pat = PatKind::Ident(ann, ident.with_span_pos(span), None);
555        self.pat(span, pat)
556    }
557    pub fn pat_path(&self, span: Span, path: ast::Path) -> ast::Pat {
558        self.pat(span, PatKind::Path(None, path))
559    }
560    pub fn pat_tuple_struct(
561        &self,
562        span: Span,
563        path: ast::Path,
564        subpats: ThinVec<ast::Pat>,
565    ) -> ast::Pat {
566        self.pat(span, PatKind::TupleStruct(None, path, subpats))
567    }
568    pub fn pat_struct(
569        &self,
570        span: Span,
571        path: ast::Path,
572        field_pats: ThinVec<ast::PatField>,
573    ) -> ast::Pat {
574        self.pat(span, PatKind::Struct(None, path, field_pats, ast::PatFieldsRest::None))
575    }
576    pub fn pat_tuple(&self, span: Span, pats: ThinVec<ast::Pat>) -> ast::Pat {
577        self.pat(span, PatKind::Tuple(pats))
578    }
579
580    pub fn pat_some(&self, span: Span, pat: ast::Pat) -> ast::Pat {
581        let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
582        let path = self.path_global(span, some);
583        self.pat_tuple_struct(span, path, thin_vec![pat])
584    }
585
586    pub fn arm(&self, span: Span, pat: ast::Pat, expr: Box<ast::Expr>) -> ast::Arm {
587        ast::Arm {
588            attrs: AttrVec::new(),
589            pat: Box::new(pat),
590            guard: None,
591            body: Some(expr),
592            span,
593            id: ast::DUMMY_NODE_ID,
594            is_placeholder: false,
595        }
596    }
597
598    pub fn arm_unreachable(&self, span: Span) -> ast::Arm {
599        self.arm(span, self.pat_wild(span), self.expr_unreachable(span))
600    }
601
602    pub fn expr_match(
603        &self,
604        span: Span,
605        arg: Box<ast::Expr>,
606        arms: ThinVec<ast::Arm>,
607    ) -> Box<Expr> {
608        self.expr(span, ast::ExprKind::Match(arg, arms, MatchKind::Prefix))
609    }
610
611    pub fn expr_if(
612        &self,
613        span: Span,
614        cond: Box<ast::Expr>,
615        then: Box<ast::Expr>,
616        els: Option<Box<ast::Expr>>,
617    ) -> Box<ast::Expr> {
618        let els = els.map(|x| self.expr_block(self.block_expr(x)));
619        self.expr(span, ast::ExprKind::If(cond, self.block_expr(then), els))
620    }
621
622    pub fn lambda(&self, span: Span, ids: Vec<Ident>, body: Box<ast::Expr>) -> Box<ast::Expr> {
623        let fn_decl = self.fn_decl(
624            ids.iter().map(|id| self.param(span, *id, self.ty(span, ast::TyKind::Infer))).collect(),
625            ast::FnRetTy::Default(span),
626        );
627
628        // FIXME -- We are using `span` as the span of the `|...|`
629        // part of the lambda, but it probably (maybe?) corresponds to
630        // the entire lambda body. Probably we should extend the API
631        // here, but that's not entirely clear.
632        self.expr(
633            span,
634            ast::ExprKind::Closure(Box::new(ast::Closure {
635                binder: ast::ClosureBinder::NotPresent,
636                capture_clause: ast::CaptureBy::Ref,
637                constness: ast::Const::No,
638                coroutine_kind: None,
639                movability: ast::Movability::Movable,
640                fn_decl,
641                body,
642                fn_decl_span: span,
643                // FIXME(SarthakSingh31): This points to the start of the declaration block and
644                // not the span of the argument block.
645                fn_arg_span: span,
646            })),
647        )
648    }
649
650    pub fn lambda0(&self, span: Span, body: Box<ast::Expr>) -> Box<ast::Expr> {
651        self.lambda(span, Vec::new(), body)
652    }
653
654    pub fn lambda1(&self, span: Span, body: Box<ast::Expr>, ident: Ident) -> Box<ast::Expr> {
655        self.lambda(span, vec![ident], body)
656    }
657
658    pub fn lambda_stmts_1(
659        &self,
660        span: Span,
661        stmts: ThinVec<ast::Stmt>,
662        ident: Ident,
663    ) -> Box<ast::Expr> {
664        self.lambda1(span, self.expr_block(self.block(span, stmts)), ident)
665    }
666
667    pub fn param(&self, span: Span, ident: Ident, ty: Box<ast::Ty>) -> ast::Param {
668        let pat = Box::new(self.pat_ident(span, ident));
669        ast::Param {
670            attrs: AttrVec::default(),
671            id: ast::DUMMY_NODE_ID,
672            pat,
673            span,
674            ty,
675            is_placeholder: false,
676        }
677    }
678
679    // `self` is unused but keep it as method for the convenience use.
680    pub fn fn_decl(&self, inputs: ThinVec<ast::Param>, output: ast::FnRetTy) -> Box<ast::FnDecl> {
681        Box::new(ast::FnDecl { inputs, output })
682    }
683
684    pub fn item(&self, span: Span, attrs: ast::AttrVec, kind: ast::ItemKind) -> Box<ast::Item> {
685        Box::new(ast::Item {
686            attrs,
687            id: ast::DUMMY_NODE_ID,
688            kind,
689            vis: ast::Visibility {
690                span: span.shrink_to_lo(),
691                kind: ast::VisibilityKind::Inherited,
692                tokens: None,
693            },
694            span,
695            tokens: None,
696        })
697    }
698
699    pub fn item_static(
700        &self,
701        span: Span,
702        ident: Ident,
703        ty: Box<ast::Ty>,
704        mutability: ast::Mutability,
705        expr: Box<ast::Expr>,
706    ) -> Box<ast::Item> {
707        self.item(
708            span,
709            AttrVec::new(),
710            ast::ItemKind::Static(
711                ast::StaticItem {
712                    ident,
713                    ty,
714                    safety: ast::Safety::Default,
715                    mutability,
716                    expr: Some(expr),
717                    define_opaque: None,
718                }
719                .into(),
720            ),
721        )
722    }
723
724    pub fn item_const(
725        &self,
726        span: Span,
727        ident: Ident,
728        ty: Box<ast::Ty>,
729        rhs: ast::ConstItemRhs,
730    ) -> Box<ast::Item> {
731        let defaultness = ast::Defaultness::Final;
732        self.item(
733            span,
734            AttrVec::new(),
735            ast::ItemKind::Const(
736                ast::ConstItem {
737                    defaultness,
738                    ident,
739                    // FIXME(generic_const_items): Pass the generics as a parameter.
740                    generics: ast::Generics::default(),
741                    ty,
742                    rhs: Some(rhs),
743                    define_opaque: None,
744                }
745                .into(),
746            ),
747        )
748    }
749
750    // Builds `#[name]`.
751    pub fn attr_word(&self, name: Symbol, span: Span) -> ast::Attribute {
752        let g = &self.sess.psess.attr_id_generator;
753        attr::mk_attr_word(g, ast::AttrStyle::Outer, ast::Safety::Default, name, span)
754    }
755
756    // Builds `#[name = val]`.
757    //
758    // Note: `span` is used for both the identifier and the value.
759    pub fn attr_name_value_str(&self, name: Symbol, val: Symbol, span: Span) -> ast::Attribute {
760        let g = &self.sess.psess.attr_id_generator;
761        attr::mk_attr_name_value_str(
762            g,
763            ast::AttrStyle::Outer,
764            ast::Safety::Default,
765            name,
766            val,
767            span,
768        )
769    }
770
771    // Builds `#[outer(inner)]`.
772    pub fn attr_nested_word(&self, outer: Symbol, inner: Symbol, span: Span) -> ast::Attribute {
773        let g = &self.sess.psess.attr_id_generator;
774        attr::mk_attr_nested_word(
775            g,
776            ast::AttrStyle::Outer,
777            ast::Safety::Default,
778            outer,
779            inner,
780            span,
781        )
782    }
783
784    // Builds an attribute fully manually.
785    pub fn attr_nested(&self, inner: AttrItem, span: Span) -> ast::Attribute {
786        let g = &self.sess.psess.attr_id_generator;
787        attr::mk_attr_from_item(g, inner, None, ast::AttrStyle::Outer, span)
788    }
789}
rustc_expand/build.rs

rustc_expand/
build.rs
