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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
//! Custom formatting traits used when outputting Graphviz diagrams with the results of a dataflow
//! analysis.

use super::lattice::MaybeReachable;
use rustc_index::bit_set::{BitSet, ChunkedBitSet, HybridBitSet};
use rustc_index::Idx;
use std::fmt;

/// An extension to `fmt::Debug` for data that can be better printed with some auxiliary data `C`.
pub trait DebugWithContext<C>: Eq + fmt::Debug {
    fn fmt_with(&self, _ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Debug::fmt(self, f)
    }

    /// Print the difference between `self` and `old`.
    ///
    /// This should print nothing if `self == old`.
    ///
    /// `+` and `-` are typically used to indicate differences. However, these characters are
    /// fairly common and may be needed to print a types representation. If using them to indicate
    /// a diff, prefix them with the "Unit Separator"  control character (␟  U+001F).
    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        if self == old {
            return Ok(());
        }

        write!(f, "\u{001f}+")?;
        self.fmt_with(ctxt, f)?;

        if f.alternate() {
            write!(f, "\n")?;
        } else {
            write!(f, "\t")?;
        }

        write!(f, "\u{001f}-")?;
        old.fmt_with(ctxt, f)
    }
}

/// Implements `fmt::Debug` by deferring to `<T as DebugWithContext<C>>::fmt_with`.
pub struct DebugWithAdapter<'a, T, C> {
    pub this: T,
    pub ctxt: &'a C,
}

impl<T, C> fmt::Debug for DebugWithAdapter<'_, T, C>
where
    T: DebugWithContext<C>,
{
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.this.fmt_with(self.ctxt, f)
    }
}

/// Implements `fmt::Debug` by deferring to `<T as DebugWithContext<C>>::fmt_diff_with`.
pub struct DebugDiffWithAdapter<'a, T, C> {
    pub new: T,
    pub old: T,
    pub ctxt: &'a C,
}

impl<T, C> fmt::Debug for DebugDiffWithAdapter<'_, T, C>
where
    T: DebugWithContext<C>,
{
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.new.fmt_diff_with(&self.old, self.ctxt, f)
    }
}

// Impls

impl<T, C> DebugWithContext<C> for BitSet<T>
where
    T: Idx + DebugWithContext<C>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_set().entries(self.iter().map(|i| DebugWithAdapter { this: i, ctxt })).finish()
    }

    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let size = self.domain_size();
        assert_eq!(size, old.domain_size());

        let mut set_in_self = HybridBitSet::new_empty(size);
        let mut cleared_in_self = HybridBitSet::new_empty(size);

        for i in (0..size).map(T::new) {
            match (self.contains(i), old.contains(i)) {
                (true, false) => set_in_self.insert(i),
                (false, true) => cleared_in_self.insert(i),
                _ => continue,
            };
        }

        fmt_diff(&set_in_self, &cleared_in_self, ctxt, f)
    }
}

impl<T, C> DebugWithContext<C> for ChunkedBitSet<T>
where
    T: Idx + DebugWithContext<C>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_set().entries(self.iter().map(|i| DebugWithAdapter { this: i, ctxt })).finish()
    }

    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let size = self.domain_size();
        assert_eq!(size, old.domain_size());

        let mut set_in_self = HybridBitSet::new_empty(size);
        let mut cleared_in_self = HybridBitSet::new_empty(size);

        for i in (0..size).map(T::new) {
            match (self.contains(i), old.contains(i)) {
                (true, false) => set_in_self.insert(i),
                (false, true) => cleared_in_self.insert(i),
                _ => continue,
            };
        }

        fmt_diff(&set_in_self, &cleared_in_self, ctxt, f)
    }
}

impl<S, C> DebugWithContext<C> for MaybeReachable<S>
where
    S: DebugWithContext<C>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            MaybeReachable::Unreachable => {
                write!(f, "unreachable")
            }
            MaybeReachable::Reachable(set) => set.fmt_with(ctxt, f),
        }
    }

    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match (self, old) {
            (MaybeReachable::Unreachable, MaybeReachable::Unreachable) => Ok(()),
            (MaybeReachable::Unreachable, MaybeReachable::Reachable(set)) => {
                write!(f, "\u{001f}+")?;
                set.fmt_with(ctxt, f)
            }
            (MaybeReachable::Reachable(set), MaybeReachable::Unreachable) => {
                write!(f, "\u{001f}-")?;
                set.fmt_with(ctxt, f)
            }
            (MaybeReachable::Reachable(this), MaybeReachable::Reachable(old)) => {
                this.fmt_diff_with(old, ctxt, f)
            }
        }
    }
}

fn fmt_diff<T, C>(
    inserted: &HybridBitSet<T>,
    removed: &HybridBitSet<T>,
    ctxt: &C,
    f: &mut fmt::Formatter<'_>,
) -> fmt::Result
where
    T: Idx + DebugWithContext<C>,
{
    let mut first = true;
    for idx in inserted.iter() {
        let delim = if first {
            "\u{001f}+"
        } else if f.alternate() {
            "\n\u{001f}+"
        } else {
            ", "
        };

        write!(f, "{delim}")?;
        idx.fmt_with(ctxt, f)?;
        first = false;
    }

    if !f.alternate() {
        first = true;
        if !inserted.is_empty() && !removed.is_empty() {
            write!(f, "\t")?;
        }
    }

    for idx in removed.iter() {
        let delim = if first {
            "\u{001f}-"
        } else if f.alternate() {
            "\n\u{001f}-"
        } else {
            ", "
        };

        write!(f, "{delim}")?;
        idx.fmt_with(ctxt, f)?;
        first = false;
    }

    Ok(())
}

impl<T, C> DebugWithContext<C> for &'_ T
where
    T: DebugWithContext<C>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        (*self).fmt_with(ctxt, f)
    }

    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        (*self).fmt_diff_with(*old, ctxt, f)
    }
}

impl<C> DebugWithContext<C> for rustc_middle::mir::Local {}
impl<C> DebugWithContext<C> for crate::move_paths::InitIndex {}

impl<'tcx, C> DebugWithContext<C> for crate::move_paths::MovePathIndex
where
    C: crate::move_paths::HasMoveData<'tcx>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", ctxt.move_data().move_paths[*self])
    }
}

impl<T, C> DebugWithContext<C> for crate::lattice::Dual<T>
where
    T: DebugWithContext<C>,
{
    fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        (self.0).fmt_with(ctxt, f)
    }

    fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        (self.0).fmt_diff_with(&old.0, ctxt, f)
    }
}