1 // Copyright 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.
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.
11 use hir::def_id::CrateNum;
15 macro_rules! try_opt {
24 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
25 pub enum DepNode<D: Clone + Debug> {
26 // The `D` type is "how definitions are identified".
27 // During compilation, it is always `DefId`, but when serializing
28 // it is mapped to `DefPath`.
30 // Represents the `Krate` as a whole (the `hir::Krate` value) (as
31 // distinct from the krate module). This is basically a hash of
32 // the entire krate, so if you read from `Krate` (e.g., by calling
33 // `tcx.hir.krate()`), we will have to assume that any change
34 // means that you need to be recompiled. This is because the
35 // `Krate` value gives you access to all other items. To avoid
36 // this fate, do not call `tcx.hir.krate()`; instead, prefer
37 // wrappers like `tcx.visit_all_items_in_krate()`. If there is no
38 // suitable wrapper, you can use `tcx.dep_graph.ignore()` to gain
39 // access to the krate, but you must remember to add suitable
40 // edges yourself for the individual items that you read.
43 // Represents the HIR node with the given node-id
46 // Represents the body of a function or method. The def-id is that of the
50 // Represents the metadata for a given HIR node, typically found
51 // in an extern crate.
54 // Represents some artifact that we save to disk. Note that these
55 // do not have a def-id as part of their identifier.
56 WorkProduct(Arc<WorkProductId>),
58 // Represents different phases in the compiler.
62 CoherenceCheckTrait(D),
63 CoherenceCheckImpl(D),
64 CoherenceOverlapCheck(D),
65 CoherenceOverlapCheckSpecial(D),
67 PrivacyAccessLevels(CrateNum),
69 // Represents the MIR for a fn; also used as the task node for
70 // things read/modify that MIR.
85 // Nodes representing bits of computed IR in the tcx. Each shared
86 // table in the tcx (or elsewhere) maps to one of these
87 // nodes. Often we map multiple tables to the same node if there
88 // is no point in distinguishing them (e.g., both the type and
89 // predicates for an item wind up in `ItemSignature`).
93 TypeParamPredicates((D, D)),
97 AssociatedItemDefIds(D),
105 // The set of impls for a given trait. Ultimately, it would be
106 // nice to get more fine-grained here (e.g., to include a
107 // simplified type), but we can't do that until we restructure the
108 // HIR to distinguish the *header* of an impl from its body. This
109 // is because changes to the header may change the self-type of
110 // the impl and hence would require us to be more conservative
111 // than changes in the impl body.
114 // Nodes representing caches. To properly handle a true cache, we
115 // don't use a DepTrackingMap, but rather we push a task node.
116 // Otherwise the write into the map would be incorrectly
117 // attributed to the first task that happened to fill the cache,
118 // which would yield an overly conservative dep-graph.
122 // Trait selection cache is a little funny. Given a trait
123 // reference like `Foo: SomeTrait<Bar>`, there could be
124 // arbitrarily many def-ids to map on in there (e.g., `Foo`,
125 // `SomeTrait`, `Bar`). We could have a vector of them, but it
126 // requires heap-allocation, and trait sel in general can be a
127 // surprisingly hot path. So instead we pick two def-ids: the
128 // trait def-id, and the first def-id in the input types. If there
129 // is no def-id in the input types, then we use the trait def-id
130 // again. So for example:
132 // - `i32: Clone` -> `TraitSelect { trait_def_id: Clone, self_def_id: Clone }`
133 // - `u32: Clone` -> `TraitSelect { trait_def_id: Clone, self_def_id: Clone }`
134 // - `Clone: Clone` -> `TraitSelect { trait_def_id: Clone, self_def_id: Clone }`
135 // - `Vec<i32>: Clone` -> `TraitSelect { trait_def_id: Clone, self_def_id: Vec }`
136 // - `String: Clone` -> `TraitSelect { trait_def_id: Clone, self_def_id: String }`
137 // - `Foo: Trait<Bar>` -> `TraitSelect { trait_def_id: Trait, self_def_id: Foo }`
138 // - `Foo: Trait<i32>` -> `TraitSelect { trait_def_id: Trait, self_def_id: Foo }`
139 // - `(Foo, Bar): Trait` -> `TraitSelect { trait_def_id: Trait, self_def_id: Foo }`
140 // - `i32: Trait<Foo>` -> `TraitSelect { trait_def_id: Trait, self_def_id: Foo }`
142 // You can see that we map many trait refs to the same
143 // trait-select node. This is not a problem, it just means
144 // imprecision in our dep-graph tracking. The important thing is
145 // that for any given trait-ref, we always map to the **same**
146 // trait-select node.
147 TraitSelect { trait_def_id: D, input_def_id: D },
149 // For proj. cache, we just keep a list of all def-ids, since it is
151 ProjectionCache { def_ids: Vec<D> },
157 impl<D: Clone + Debug> DepNode<D> {
159 pub fn from_label_string(label: &str, data: D) -> Result<DepNode<D>, ()> {
161 ($($name:ident,)*) => {
163 $(stringify!($name) => Ok(DepNode::$name(data)),)*
169 if label == "Krate" {
171 return Ok(DepNode::Krate);
182 AssociatedItemDefIds,
191 pub fn map_def<E, OP>(&self, mut op: OP) -> Option<DepNode<E>>
192 where OP: FnMut(&D) -> Option<E>, E: Clone + Debug
194 use self::DepNode::*;
197 Krate => Some(Krate),
198 BorrowCheckKrate => Some(BorrowCheckKrate),
199 MirKrate => Some(MirKrate),
200 TypeckBodiesKrate => Some(TypeckBodiesKrate),
201 Coherence => Some(Coherence),
202 Resolve => Some(Resolve),
203 Variance => Some(Variance),
204 PrivacyAccessLevels(k) => Some(PrivacyAccessLevels(k)),
205 Reachability => Some(Reachability),
206 MirKeys => Some(MirKeys),
207 LateLintCheck => Some(LateLintCheck),
208 TransWriteMetadata => Some(TransWriteMetadata),
210 // work product names do not need to be mapped, because
211 // they are always absolute.
212 WorkProduct(ref id) => Some(WorkProduct(id.clone())),
214 Hir(ref d) => op(d).map(Hir),
215 HirBody(ref d) => op(d).map(HirBody),
216 MetaData(ref d) => op(d).map(MetaData),
217 CoherenceCheckTrait(ref d) => op(d).map(CoherenceCheckTrait),
218 CoherenceCheckImpl(ref d) => op(d).map(CoherenceCheckImpl),
219 CoherenceOverlapCheck(ref d) => op(d).map(CoherenceOverlapCheck),
220 CoherenceOverlapCheckSpecial(ref d) => op(d).map(CoherenceOverlapCheckSpecial),
221 Mir(ref d) => op(d).map(Mir),
222 MirShim(ref def_ids) => {
223 let def_ids: Option<Vec<E>> = def_ids.iter().map(op).collect();
226 BorrowCheck(ref d) => op(d).map(BorrowCheck),
227 RegionMaps(ref d) => op(d).map(RegionMaps),
228 RvalueCheck(ref d) => op(d).map(RvalueCheck),
229 TransCrateItem(ref d) => op(d).map(TransCrateItem),
230 TransInlinedItem(ref d) => op(d).map(TransInlinedItem),
231 AssociatedItems(ref d) => op(d).map(AssociatedItems),
232 ItemSignature(ref d) => op(d).map(ItemSignature),
233 IsForeignItem(ref d) => op(d).map(IsForeignItem),
234 TypeParamPredicates((ref item, ref param)) => {
235 Some(TypeParamPredicates((try_opt!(op(item)), try_opt!(op(param)))))
237 SizedConstraint(ref d) => op(d).map(SizedConstraint),
238 DtorckConstraint(ref d) => op(d).map(DtorckConstraint),
239 AdtDestructor(ref d) => op(d).map(AdtDestructor),
240 AssociatedItemDefIds(ref d) => op(d).map(AssociatedItemDefIds),
241 InherentImpls(ref d) => op(d).map(InherentImpls),
242 TypeckTables(ref d) => op(d).map(TypeckTables),
243 UsedTraitImports(ref d) => op(d).map(UsedTraitImports),
244 ConstEval(ref d) => op(d).map(ConstEval),
245 SymbolName(ref d) => op(d).map(SymbolName),
246 TraitImpls(ref d) => op(d).map(TraitImpls),
247 TraitItems(ref d) => op(d).map(TraitItems),
248 ReprHints(ref d) => op(d).map(ReprHints),
249 TraitSelect { ref trait_def_id, ref input_def_id } => {
250 op(trait_def_id).and_then(|trait_def_id| {
251 op(input_def_id).and_then(|input_def_id| {
252 Some(TraitSelect { trait_def_id: trait_def_id,
253 input_def_id: input_def_id })
257 ProjectionCache { ref def_ids } => {
258 let def_ids: Option<Vec<E>> = def_ids.iter().map(op).collect();
259 def_ids.map(|d| ProjectionCache { def_ids: d })
261 DescribeDef(ref d) => op(d).map(DescribeDef),
262 DefSpan(ref d) => op(d).map(DefSpan),
267 /// A "work product" corresponds to a `.o` (or other) file that we
268 /// save in between runs. These ids do not have a DefId but rather
269 /// some independent path or string that persists between runs without
270 /// the need to be mapped or unmapped. (This ensures we can serialize
271 /// them even in the absence of a tcx.)
272 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
273 pub struct WorkProductId(pub String);