summaryrefslogtreecommitdiffstats
path: root/compiler/rustc_query_system/src/ich/hcx.rs
blob: a09b8ca30e138068118f6b086164379448744c1e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
use crate::ich;

use rustc_ast as ast;
use rustc_data_structures::sorted_map::SortedMap;
use rustc_data_structures::stable_hasher::{HashStable, HashingControls, StableHasher};
use rustc_data_structures::sync::Lrc;
use rustc_hir as hir;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::definitions::{DefPathHash, Definitions};
use rustc_index::vec::IndexVec;
use rustc_session::cstore::CrateStore;
use rustc_session::Session;
use rustc_span::source_map::SourceMap;
use rustc_span::symbol::Symbol;
use rustc_span::{BytePos, CachingSourceMapView, SourceFile, Span, SpanData};

/// This is the context state available during incr. comp. hashing. It contains
/// enough information to transform `DefId`s and `HirId`s into stable `DefPath`s (i.e.,
/// a reference to the `TyCtxt`) and it holds a few caches for speeding up various
/// things (e.g., each `DefId`/`DefPath` is only hashed once).
#[derive(Clone)]
pub struct StableHashingContext<'a> {
    definitions: &'a Definitions,
    cstore: &'a dyn CrateStore,
    source_span: &'a IndexVec<LocalDefId, Span>,
    // The value of `-Z incremental-ignore-spans`.
    // This field should only be used by `unstable_opts_incremental_ignore_span`
    incremental_ignore_spans: bool,
    pub(super) body_resolver: BodyResolver<'a>,
    // Very often, we are hashing something that does not need the
    // `CachingSourceMapView`, so we initialize it lazily.
    raw_source_map: &'a SourceMap,
    caching_source_map: Option<CachingSourceMapView<'a>>,
    pub(super) hashing_controls: HashingControls,
}

/// The `BodyResolver` allows mapping a `BodyId` to the corresponding `hir::Body`.
/// We could also just store a plain reference to the `hir::Crate` but we want
/// to avoid that the crate is used to get untracked access to all of the HIR.
#[derive(Clone, Copy)]
pub(super) enum BodyResolver<'tcx> {
    Forbidden,
    Ignore,
    Traverse { owner: LocalDefId, bodies: &'tcx SortedMap<hir::ItemLocalId, &'tcx hir::Body<'tcx>> },
}

impl<'a> StableHashingContext<'a> {
    #[inline]
    fn new_with_or_without_spans(
        sess: &'a Session,
        definitions: &'a Definitions,
        cstore: &'a dyn CrateStore,
        source_span: &'a IndexVec<LocalDefId, Span>,
        always_ignore_spans: bool,
    ) -> Self {
        let hash_spans_initial =
            !always_ignore_spans && !sess.opts.unstable_opts.incremental_ignore_spans;

        StableHashingContext {
            body_resolver: BodyResolver::Forbidden,
            definitions,
            cstore,
            source_span,
            incremental_ignore_spans: sess.opts.unstable_opts.incremental_ignore_spans,
            caching_source_map: None,
            raw_source_map: sess.source_map(),
            hashing_controls: HashingControls { hash_spans: hash_spans_initial },
        }
    }

    #[inline]
    pub fn new(
        sess: &'a Session,
        definitions: &'a Definitions,
        cstore: &'a dyn CrateStore,
        source_span: &'a IndexVec<LocalDefId, Span>,
    ) -> Self {
        Self::new_with_or_without_spans(
            sess,
            definitions,
            cstore,
            source_span,
            /*always_ignore_spans=*/ false,
        )
    }

    #[inline]
    pub fn ignore_spans(
        sess: &'a Session,
        definitions: &'a Definitions,
        cstore: &'a dyn CrateStore,
        source_span: &'a IndexVec<LocalDefId, Span>,
    ) -> Self {
        let always_ignore_spans = true;
        Self::new_with_or_without_spans(sess, definitions, cstore, source_span, always_ignore_spans)
    }

    #[inline]
    pub fn without_hir_bodies(&mut self, f: impl FnOnce(&mut StableHashingContext<'_>)) {
        f(&mut StableHashingContext { body_resolver: BodyResolver::Ignore, ..self.clone() });
    }

    #[inline]
    pub fn with_hir_bodies(
        &mut self,
        owner: LocalDefId,
        bodies: &SortedMap<hir::ItemLocalId, &hir::Body<'_>>,
        f: impl FnOnce(&mut StableHashingContext<'_>),
    ) {
        f(&mut StableHashingContext {
            body_resolver: BodyResolver::Traverse { owner, bodies },
            ..self.clone()
        });
    }

    #[inline]
    pub fn while_hashing_spans<F: FnOnce(&mut Self)>(&mut self, hash_spans: bool, f: F) {
        let prev_hash_spans = self.hashing_controls.hash_spans;
        self.hashing_controls.hash_spans = hash_spans;
        f(self);
        self.hashing_controls.hash_spans = prev_hash_spans;
    }

    #[inline]
    pub fn def_path_hash(&self, def_id: DefId) -> DefPathHash {
        if let Some(def_id) = def_id.as_local() {
            self.local_def_path_hash(def_id)
        } else {
            self.cstore.def_path_hash(def_id)
        }
    }

    #[inline]
    pub fn local_def_path_hash(&self, def_id: LocalDefId) -> DefPathHash {
        self.definitions.def_path_hash(def_id)
    }

    #[inline]
    pub fn source_map(&mut self) -> &mut CachingSourceMapView<'a> {
        match self.caching_source_map {
            Some(ref mut sm) => sm,
            ref mut none => {
                *none = Some(CachingSourceMapView::new(self.raw_source_map));
                none.as_mut().unwrap()
            }
        }
    }

    #[inline]
    pub fn is_ignored_attr(&self, name: Symbol) -> bool {
        ich::IGNORED_ATTRIBUTES.contains(&name)
    }

    #[inline]
    pub fn hashing_controls(&self) -> HashingControls {
        self.hashing_controls.clone()
    }
}

impl<'a> HashStable<StableHashingContext<'a>> for ast::NodeId {
    #[inline]
    fn hash_stable(&self, _: &mut StableHashingContext<'a>, _: &mut StableHasher) {
        panic!("Node IDs should not appear in incremental state");
    }
}

impl<'a> rustc_span::HashStableContext for StableHashingContext<'a> {
    #[inline]
    fn hash_spans(&self) -> bool {
        self.hashing_controls.hash_spans
    }

    #[inline]
    fn unstable_opts_incremental_ignore_spans(&self) -> bool {
        self.incremental_ignore_spans
    }

    #[inline]
    fn def_path_hash(&self, def_id: DefId) -> DefPathHash {
        self.def_path_hash(def_id)
    }

    #[inline]
    fn def_span(&self, def_id: LocalDefId) -> Span {
        self.source_span[def_id]
    }

    #[inline]
    fn span_data_to_lines_and_cols(
        &mut self,
        span: &SpanData,
    ) -> Option<(Lrc<SourceFile>, usize, BytePos, usize, BytePos)> {
        self.source_map().span_data_to_lines_and_cols(span)
    }

    #[inline]
    fn hashing_controls(&self) -> HashingControls {
        self.hashing_controls.clone()
    }
}

impl<'a> rustc_data_structures::intern::InternedHashingContext for StableHashingContext<'a> {
    fn with_def_path_and_no_spans(&mut self, f: impl FnOnce(&mut Self)) {
        self.while_hashing_spans(false, f);
    }
}

impl<'a> rustc_session::HashStableContext for StableHashingContext<'a> {}