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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
use std::fmt::Debug;
use std::io::Write;

use measureme::{StringComponent, StringId};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::profiling::SelfProfiler;
use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, LOCAL_CRATE};
use rustc_hir::definitions::DefPathData;
use rustc_middle::ty::TyCtxt;
use rustc_query_system::query::QueryCache;

pub(crate) struct QueryKeyStringCache {
    def_id_cache: FxHashMap<DefId, StringId>,
}

impl QueryKeyStringCache {
    fn new() -> QueryKeyStringCache {
        QueryKeyStringCache { def_id_cache: Default::default() }
    }
}

struct QueryKeyStringBuilder<'p, 'tcx> {
    profiler: &'p SelfProfiler,
    tcx: TyCtxt<'tcx>,
    string_cache: &'p mut QueryKeyStringCache,
}

impl<'p, 'tcx> QueryKeyStringBuilder<'p, 'tcx> {
    fn new(
        profiler: &'p SelfProfiler,
        tcx: TyCtxt<'tcx>,
        string_cache: &'p mut QueryKeyStringCache,
    ) -> QueryKeyStringBuilder<'p, 'tcx> {
        QueryKeyStringBuilder { profiler, tcx, string_cache }
    }

    // The current implementation is rather crude. In the future it might be a
    // good idea to base this on `ty::print` in order to get nicer and more
    // efficient query keys.
    fn def_id_to_string_id(&mut self, def_id: DefId) -> StringId {
        if let Some(&string_id) = self.string_cache.def_id_cache.get(&def_id) {
            return string_id;
        }

        let def_key = self.tcx.def_key(def_id);

        let (parent_string_id, start_index) = match def_key.parent {
            Some(parent_index) => {
                let parent_def_id = DefId { index: parent_index, krate: def_id.krate };

                (self.def_id_to_string_id(parent_def_id), 0)
            }
            None => (StringId::INVALID, 2),
        };

        let dis_buffer = &mut [0u8; 16];
        let crate_name;
        let other_name;
        let name;
        let dis;
        let end_index;

        match def_key.disambiguated_data.data {
            DefPathData::CrateRoot => {
                crate_name = self.tcx.crate_name(def_id.krate);
                name = crate_name.as_str();
                dis = "";
                end_index = 3;
            }
            other => {
                other_name = other.to_string();
                name = other_name.as_str();
                if def_key.disambiguated_data.disambiguator == 0 {
                    dis = "";
                    end_index = 3;
                } else {
                    write!(&mut dis_buffer[..], "[{}]", def_key.disambiguated_data.disambiguator)
                        .unwrap();
                    let end_of_dis = dis_buffer.iter().position(|&c| c == b']').unwrap();
                    dis = std::str::from_utf8(&dis_buffer[..end_of_dis + 1]).unwrap();
                    end_index = 4;
                }
            }
        }

        let components = [
            StringComponent::Ref(parent_string_id),
            StringComponent::Value("::"),
            StringComponent::Value(name),
            StringComponent::Value(dis),
        ];

        let string_id = self.profiler.alloc_string(&components[start_index..end_index]);

        self.string_cache.def_id_cache.insert(def_id, string_id);

        string_id
    }
}

trait IntoSelfProfilingString {
    fn to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId;
}

// The default implementation of `IntoSelfProfilingString` just uses `Debug`
// which is slow and causes lots of duplication of string data.
// The specialized impls below take care of making the `DefId` case more
// efficient.
impl<T: Debug> IntoSelfProfilingString for T {
    default fn to_self_profile_string(
        &self,
        builder: &mut QueryKeyStringBuilder<'_, '_>,
    ) -> StringId {
        let s = format!("{self:?}");
        builder.profiler.alloc_string(&s[..])
    }
}

impl<T: SpecIntoSelfProfilingString> IntoSelfProfilingString for T {
    fn to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        self.spec_to_self_profile_string(builder)
    }
}

#[rustc_specialization_trait]
trait SpecIntoSelfProfilingString: Debug {
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId;
}

impl SpecIntoSelfProfilingString for DefId {
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        builder.def_id_to_string_id(*self)
    }
}

impl SpecIntoSelfProfilingString for CrateNum {
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        builder.def_id_to_string_id(self.as_def_id())
    }
}

impl SpecIntoSelfProfilingString for DefIndex {
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        builder.def_id_to_string_id(DefId { krate: LOCAL_CRATE, index: *self })
    }
}

impl SpecIntoSelfProfilingString for LocalDefId {
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        builder.def_id_to_string_id(DefId { krate: LOCAL_CRATE, index: self.local_def_index })
    }
}

impl<T0, T1> SpecIntoSelfProfilingString for (T0, T1)
where
    T0: SpecIntoSelfProfilingString,
    T1: SpecIntoSelfProfilingString,
{
    fn spec_to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_>) -> StringId {
        let val0 = self.0.to_self_profile_string(builder);
        let val1 = self.1.to_self_profile_string(builder);

        let components = &[
            StringComponent::Value("("),
            StringComponent::Ref(val0),
            StringComponent::Value(","),
            StringComponent::Ref(val1),
            StringComponent::Value(")"),
        ];

        builder.profiler.alloc_string(components)
    }
}

/// Allocate the self-profiling query strings for a single query cache. This
/// method is called from `alloc_self_profile_query_strings` which knows all
/// the queries via macro magic.
pub(crate) fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
    tcx: TyCtxt<'tcx>,
    query_name: &'static str,
    query_cache: &C,
    string_cache: &mut QueryKeyStringCache,
) where
    C: QueryCache,
    C::Key: Debug + Clone,
{
    tcx.prof.with_profiler(|profiler| {
        let event_id_builder = profiler.event_id_builder();

        // Walk the entire query cache and allocate the appropriate
        // string representations. Each cache entry is uniquely
        // identified by its dep_node_index.
        if profiler.query_key_recording_enabled() {
            let mut query_string_builder = QueryKeyStringBuilder::new(profiler, tcx, string_cache);

            let query_name = profiler.get_or_alloc_cached_string(query_name);

            // Since building the string representation of query keys might
            // need to invoke queries itself, we cannot keep the query caches
            // locked while doing so. Instead we copy out the
            // `(query_key, dep_node_index)` pairs and release the lock again.
            let mut query_keys_and_indices = Vec::new();
            query_cache.iter(&mut |k, _, i| query_keys_and_indices.push((*k, i)));

            // Now actually allocate the strings. If allocating the strings
            // generates new entries in the query cache, we'll miss them but
            // we don't actually care.
            for (query_key, dep_node_index) in query_keys_and_indices {
                // Translate the DepNodeIndex into a QueryInvocationId
                let query_invocation_id = dep_node_index.into();

                // Create the string version of the query-key
                let query_key = query_key.to_self_profile_string(&mut query_string_builder);
                let event_id = event_id_builder.from_label_and_arg(query_name, query_key);

                // Doing this in bulk might be a good idea:
                profiler.map_query_invocation_id_to_string(
                    query_invocation_id,
                    event_id.to_string_id(),
                );
            }
        } else {
            // In this branch we don't allocate query keys
            let query_name = profiler.get_or_alloc_cached_string(query_name);
            let event_id = event_id_builder.from_label(query_name).to_string_id();

            // FIXME(eddyb) make this O(1) by using a pre-cached query name `EventId`,
            // instead of passing the `DepNodeIndex` to `finish_with_query_invocation_id`,
            // when recording the event in the first place.
            let mut query_invocation_ids = Vec::new();
            query_cache.iter(&mut |_, _, i| {
                query_invocation_ids.push(i.into());
            });

            profiler.bulk_map_query_invocation_id_to_single_string(
                query_invocation_ids.into_iter(),
                event_id,
            );
        }
    });
}

/// All self-profiling events generated by the query engine use
/// virtual `StringId`s for their `event_id`. This method makes all
/// those virtual `StringId`s point to actual strings.
///
/// If we are recording only summary data, the ids will point to
/// just the query names. If we are recording query keys too, we
/// allocate the corresponding strings here.
pub fn alloc_self_profile_query_strings(tcx: TyCtxt<'_>) {
    if !tcx.prof.enabled() {
        return;
    }

    let mut string_cache = QueryKeyStringCache::new();

    for alloc in super::ALLOC_SELF_PROFILE_QUERY_STRINGS.iter() {
        alloc(tcx, &mut string_cache)
    }
}