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| 1 | +// Copyright 2018 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 rustc::session::Session; |
| 12 | +use syntax::ast::*; |
| 13 | +use syntax::ptr::P; |
| 14 | +use syntax::fold; |
| 15 | +use syntax::fold::Folder; |
| 16 | +use syntax::symbol::keywords; |
| 17 | +use syntax::codemap::dummy_spanned; |
| 18 | +use syntax_pos::DUMMY_SP; |
| 19 | +use syntax_pos::symbol::Symbol; |
| 20 | + |
| 21 | +struct ModFolder<'a> { |
| 22 | + use_std: &'a Item, |
| 23 | + root: Option<Ident>, |
| 24 | + main: Symbol, |
| 25 | +} |
| 26 | + |
| 27 | +impl<'a> ModFolder<'a> { |
| 28 | + fn fold_qpath(&mut self, qself: &mut Option<QSelf>, path: &mut Path) { |
| 29 | + let old = path.segments.len(); |
| 30 | + *path = self.fold_path(path.clone()); |
| 31 | + let add = path.segments.len() - old; |
| 32 | + qself.as_mut().map(|qself| { |
| 33 | + qself.position += add; |
| 34 | + qself.ty = self.fold_ty(qself.ty.clone()); |
| 35 | + }); |
| 36 | + } |
| 37 | +} |
| 38 | + |
| 39 | +impl<'a> fold::Folder for ModFolder<'a> { |
| 40 | + fn fold_use_tree(&mut self, mut use_tree: UseTree) -> UseTree { |
| 41 | + if let Some(root) = self.root { |
| 42 | + let pos = { |
| 43 | + let get = |i| { |
| 44 | + use_tree.prefix.segments.get(i).map(|p: &PathSegment| p.identifier.name) |
| 45 | + }; |
| 46 | + if get(0) == Some(keywords::SelfValue.name()) || |
| 47 | + get(0) == Some(keywords::Super.name()) { |
| 48 | + None |
| 49 | + } else { |
| 50 | + let mut i = 0; |
| 51 | + if get(i) == Some(keywords::CrateRoot.name()) { |
| 52 | + i += 1; |
| 53 | + } |
| 54 | + if get(i) == Some(keywords::Crate.name()) { |
| 55 | + i += 1; |
| 56 | + } |
| 57 | + Some(i) |
| 58 | + } |
| 59 | + }; |
| 60 | + if let Some(pos) = pos { |
| 61 | + use_tree.prefix.segments.insert(pos, PathSegment { |
| 62 | + identifier: root, |
| 63 | + span: use_tree.span, |
| 64 | + parameters: None, |
| 65 | + }); |
| 66 | + } |
| 67 | + use_tree |
| 68 | + } else { |
| 69 | + fold::noop_fold_use_tree(use_tree, self) |
| 70 | + } |
| 71 | + } |
| 72 | + |
| 73 | + fn fold_path(&mut self, mut p: Path) -> Path { |
| 74 | + if let Some(root) = self.root { |
| 75 | + if let Some(first) = p.segments.first().cloned() { |
| 76 | + if first.identifier.name == keywords::CrateRoot.name() { |
| 77 | + let idx = if p.segments.get(1).map(|p| p.identifier.name) == |
| 78 | + Some(keywords::Crate.name()) { |
| 79 | + 2 |
| 80 | + } else { |
| 81 | + 1 |
| 82 | + }; |
| 83 | + p.segments.insert(idx, PathSegment { |
| 84 | + identifier: root, |
| 85 | + span: p.span, |
| 86 | + parameters: None, |
| 87 | + }); |
| 88 | + } |
| 89 | + } |
| 90 | + fold::noop_fold_path(p, self) |
| 91 | + } else { |
| 92 | + fold::noop_fold_path(p, self) |
| 93 | + } |
| 94 | + } |
| 95 | + |
| 96 | + fn fold_ty(&mut self, mut t: P<Ty>) -> P<Ty> { |
| 97 | + if match t.node { |
| 98 | + TyKind::Path(ref mut qself, ref mut path) => { |
| 99 | + self.fold_qpath(qself, path); |
| 100 | + true |
| 101 | + } |
| 102 | + _ => false, |
| 103 | + } { |
| 104 | + return t; |
| 105 | + } |
| 106 | + fold::noop_fold_ty(t, self) |
| 107 | + } |
| 108 | + |
| 109 | + fn fold_pat(&mut self, mut p: P<Pat>) -> P<Pat> { |
| 110 | + if match p.node { |
| 111 | + PatKind::Path(ref mut qself, ref mut path) => { |
| 112 | + self.fold_qpath(qself, path); |
| 113 | + true |
| 114 | + } |
| 115 | + _ => false, |
| 116 | + } { |
| 117 | + return p; |
| 118 | + } |
| 119 | + fold::noop_fold_pat(p, self) |
| 120 | + } |
| 121 | + |
| 122 | + fn fold_expr(&mut self, mut e: P<Expr>) -> P<Expr> { |
| 123 | + if match e.node { |
| 124 | + ExprKind::Path(ref mut qself, ref mut path) => { |
| 125 | + self.fold_qpath(qself, path); |
| 126 | + true |
| 127 | + } |
| 128 | + _ => false, |
| 129 | + } { |
| 130 | + return e; |
| 131 | + } |
| 132 | + e.map(|e| fold::noop_fold_expr(e, self)) |
| 133 | + } |
| 134 | + |
| 135 | + fn fold_item_simple(&mut self, mut item: Item) -> Item { |
| 136 | + if self.root.is_some() { |
| 137 | + fold::noop_fold_item_simple(item, self) |
| 138 | + } else { |
| 139 | + let is_root = match item.node { |
| 140 | + ItemKind::Mod(ref mut module) => { |
| 141 | + for mut item in &mut module.items { |
| 142 | + if item.ident.name == self.main { |
| 143 | + item.vis = dummy_spanned(VisibilityKind::Public); |
| 144 | + } |
| 145 | + } |
| 146 | + true |
| 147 | + } |
| 148 | + _ => false, |
| 149 | + }; |
| 150 | + |
| 151 | + if is_root { |
| 152 | + let mut folder = ModFolder { |
| 153 | + use_std: self.use_std, |
| 154 | + root: Some(item.ident), |
| 155 | + main: self.main, |
| 156 | + }; |
| 157 | + |
| 158 | + let mut item = fold::noop_fold_item_simple(item, &mut folder); |
| 159 | + match item.node { |
| 160 | + ItemKind::Mod(ref mut module) => { |
| 161 | + module.items.push(P(self.use_std.clone())); |
| 162 | + } |
| 163 | + _ => (), |
| 164 | + } |
| 165 | + item |
| 166 | + } else { |
| 167 | + fold::noop_fold_item_simple(item, self) |
| 168 | + } |
| 169 | + } |
| 170 | + } |
| 171 | + |
| 172 | + fn fold_mac(&mut self, _mac: Mac) -> Mac { |
| 173 | + fold::noop_fold_mac(_mac, self) |
| 174 | + } |
| 175 | +} |
| 176 | + |
| 177 | +pub fn modify_crate(_session: &Session, krate: Crate) -> Crate { |
| 178 | + let std_i = Ident::from_str("std"); |
| 179 | + let use_std = Item { |
| 180 | + ident: keywords::Invalid.ident(), |
| 181 | + attrs: Vec::new(), |
| 182 | + id: DUMMY_NODE_ID, |
| 183 | + node: ItemKind::Use(P(UseTree { |
| 184 | + span: DUMMY_SP, |
| 185 | + kind: UseTreeKind::Simple(Some(std_i)), |
| 186 | + prefix: Path { |
| 187 | + segments: vec![PathSegment { |
| 188 | + identifier: std_i, |
| 189 | + span: DUMMY_SP, |
| 190 | + parameters: None, |
| 191 | + }], |
| 192 | + span: DUMMY_SP, |
| 193 | + }, |
| 194 | + })), |
| 195 | + vis: dummy_spanned(VisibilityKind::Inherited), |
| 196 | + span: DUMMY_SP, |
| 197 | + tokens: None, |
| 198 | + }; |
| 199 | + let Crate { |
| 200 | + module, |
| 201 | + attrs, |
| 202 | + span, |
| 203 | + } = krate; |
| 204 | + let module = ModFolder { |
| 205 | + use_std: &use_std, |
| 206 | + root: None, |
| 207 | + main: Symbol::intern("main"), |
| 208 | + }.fold_mod(module); |
| 209 | + Crate { |
| 210 | + module, |
| 211 | + attrs, |
| 212 | + span, |
| 213 | + } |
| 214 | +} |
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