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rustc_mir_dataflow/framework/
visitor.rs

1use rustc_middle::mir::{self, BasicBlock, Location, traversal};
2
3use super::{Analysis, Direction, Results};
4
5/// Calls the corresponding method in `ResultsVisitor` for every location in a `mir::Body` with the
6/// dataflow state at that location.
7pub fn visit_results<'mir, 'tcx, A>(
8    body: &'mir mir::Body<'tcx>,
9    blocks: impl IntoIterator<Item = BasicBlock>,
10    results: &Results<'tcx, A>,
11    vis: &mut impl ResultsVisitor<'tcx, A>,
12) where
13    A: Analysis<'tcx>,
14{
15    let mut state = results.analysis.bottom_value(body);
16
17    #[cfg(debug_assertions)]
18    let reachable_blocks = mir::traversal::reachable_as_bitset(body);
19
20    for block in blocks {
21        #[cfg(debug_assertions)]
22        if !reachable_blocks.contains(block) {
    ::core::panicking::panic("assertion failed: reachable_blocks.contains(block)")
};assert!(reachable_blocks.contains(block));
23
24        let block_data = &body[block];
25        state.clone_from(&results.entry_states[block]);
26        A::Direction::visit_results_in_block(&results.analysis, &mut state, block, block_data, vis);
27    }
28}
29
30/// Like `visit_results`, but only for reachable blocks.
31pub fn visit_reachable_results<'mir, 'tcx, A>(
32    body: &'mir mir::Body<'tcx>,
33    results: &Results<'tcx, A>,
34    vis: &mut impl ResultsVisitor<'tcx, A>,
35) where
36    A: Analysis<'tcx>,
37{
38    let blocks = traversal::reachable(body).map(|(bb, _)| bb);
39    visit_results(body, blocks, results, vis)
40}
41
42/// A visitor over the results of an `Analysis`. Use this when you want to inspect domain values in
43/// many or all locations; use `ResultsCursor` if you want to inspect domain values only in certain
44/// locations.
45pub trait ResultsVisitor<'tcx, A>
46where
47    A: Analysis<'tcx>,
48{
49    /// Called after the "early" effect of the given statement is applied to `state`.
50    fn visit_after_early_statement_effect(
51        &mut self,
52        _analysis: &A,
53        _state: &A::Domain,
54        _statement: &mir::Statement<'tcx>,
55        _location: Location,
56    ) {
57    }
58
59    /// Called after the "primary" effect of the given statement is applied to `state`.
60    fn visit_after_primary_statement_effect(
61        &mut self,
62        _analysis: &A,
63        _state: &A::Domain,
64        _statement: &mir::Statement<'tcx>,
65        _location: Location,
66    ) {
67    }
68
69    /// Called after the "early" effect of the given terminator is applied to `state`.
70    fn visit_after_early_terminator_effect(
71        &mut self,
72        _analysis: &A,
73        _state: &A::Domain,
74        _terminator: &mir::Terminator<'tcx>,
75        _location: Location,
76    ) {
77    }
78
79    /// Called after the "primary" effect of the given terminator is applied to `state`.
80    ///
81    /// The `call_return_effect` (if one exists) will *not* be applied to `state`.
82    fn visit_after_primary_terminator_effect(
83        &mut self,
84        _analysis: &A,
85        _state: &A::Domain,
86        _terminator: &mir::Terminator<'tcx>,
87        _location: Location,
88    ) {
89    }
90}