compiler/rustc_middle/src/ty/query/profiling_support.rs

   1 use crate::ty::context::TyCtxt;
   2 use crate::ty::WithOptConstParam;
   3 use measureme::{StringComponent, StringId};
   4 use rustc_data_structures::fx::FxHashMap;
   5 use rustc_data_structures::profiling::SelfProfiler;
   6 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
   7 use rustc_hir::definitions::DefPathData;
   8 use rustc_query_system::query::{QueryCache, QueryContext, QueryState};
   9 use std::fmt::Debug;
  10 use std::io::Write;
  11
  12 pub struct QueryKeyStringCache {
  13     def_id_cache: FxHashMap<DefId, StringId>,
  14 }
  15
  16 impl QueryKeyStringCache {
  17     pub fn new() -> QueryKeyStringCache {
  18         QueryKeyStringCache { def_id_cache: Default::default() }
  19     }
  20 }
  21
  22 pub struct QueryKeyStringBuilder<'p, 'c, 'tcx> {
  23     profiler: &'p SelfProfiler,
  24     tcx: TyCtxt<'tcx>,
  25     string_cache: &'c mut QueryKeyStringCache,
  26 }
  27
  28 impl<'p, 'c, 'tcx> QueryKeyStringBuilder<'p, 'c, 'tcx> {
  29     pub fn new(
  30         profiler: &'p SelfProfiler,
  31         tcx: TyCtxt<'tcx>,
  32         string_cache: &'c mut QueryKeyStringCache,
  33     ) -> QueryKeyStringBuilder<'p, 'c, 'tcx> {
  34         QueryKeyStringBuilder { profiler, tcx, string_cache }
  35     }
  36
  37     // The current implementation is rather crude. In the future it might be a
  38     // good idea to base this on `ty::print` in order to get nicer and more
  39     // efficient query keys.
  40     fn def_id_to_string_id(&mut self, def_id: DefId) -> StringId {
  41         if let Some(&string_id) = self.string_cache.def_id_cache.get(&def_id) {
  42             return string_id;
  43         }
  44
  45         let def_key = self.tcx.def_key(def_id);
  46
  47         let (parent_string_id, start_index) = match def_key.parent {
  48             Some(parent_index) => {
  49                 let parent_def_id = DefId { index: parent_index, krate: def_id.krate };
  50
  51                 (self.def_id_to_string_id(parent_def_id), 0)
  52             }
  53             None => (StringId::INVALID, 2),
  54         };
  55
  56         let dis_buffer = &mut [0u8; 16];
  57         let crate_name;
  58         let other_name;
  59         let name;
  60         let dis;
  61         let end_index;
  62
  63         match def_key.disambiguated_data.data {
  64             DefPathData::CrateRoot => {
  65                 crate_name = self.tcx.original_crate_name(def_id.krate).as_str();
  66                 name = &*crate_name;
  67                 dis = "";
  68                 end_index = 3;
  69             }
  70             other => {
  71                 other_name = other.to_string();
  72                 name = other_name.as_str();
  73                 if def_key.disambiguated_data.disambiguator == 0 {
  74                     dis = "";
  75                     end_index = 3;
  76                 } else {
  77                     write!(&mut dis_buffer[..], "[{}]", def_key.disambiguated_data.disambiguator)
  78                         .unwrap();
  79                     let end_of_dis = dis_buffer.iter().position(|&c| c == b']').unwrap();
  80                     dis = std::str::from_utf8(&dis_buffer[..end_of_dis + 1]).unwrap();
  81                     end_index = 4;
  82                 }
  83             }
  84         }
  85
  86         let components = [
  87             StringComponent::Ref(parent_string_id),
  88             StringComponent::Value("::"),
  89             StringComponent::Value(name),
  90             StringComponent::Value(dis),
  91         ];
  92
  93         let string_id = self.profiler.alloc_string(&components[start_index..end_index]);
  94
  95         self.string_cache.def_id_cache.insert(def_id, string_id);
  96
  97         string_id
  98     }
  99 }
 100
 101 pub trait IntoSelfProfilingString {
 102     fn to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_, '_>) -> StringId;
 103 }
 104
 105 // The default implementation of `IntoSelfProfilingString` just uses `Debug`
 106 // which is slow and causes lots of duplication of string data.
 107 // The specialized impls below take care of making the `DefId` case more
 108 // efficient.
 109 impl<T: Debug> IntoSelfProfilingString for T {
 110     default fn to_self_profile_string(
 111         &self,
 112         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 113     ) -> StringId {
 114         let s = format!("{:?}", self);
 115         builder.profiler.alloc_string(&s[..])
 116     }
 117 }
 118
 119 impl<T: SpecIntoSelfProfilingString> IntoSelfProfilingString for T {
 120     fn to_self_profile_string(&self, builder: &mut QueryKeyStringBuilder<'_, '_, '_>) -> StringId {
 121         self.spec_to_self_profile_string(builder)
 122     }
 123 }
 124
 125 #[rustc_specialization_trait]
 126 pub trait SpecIntoSelfProfilingString: Debug {
 127     fn spec_to_self_profile_string(
 128         &self,
 129         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 130     ) -> StringId;
 131 }
 132
 133 impl SpecIntoSelfProfilingString for DefId {
 134     fn spec_to_self_profile_string(
 135         &self,
 136         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 137     ) -> StringId {
 138         builder.def_id_to_string_id(*self)
 139     }
 140 }
 141
 142 impl SpecIntoSelfProfilingString for CrateNum {
 143     fn spec_to_self_profile_string(
 144         &self,
 145         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 146     ) -> StringId {
 147         builder.def_id_to_string_id(DefId { krate: *self, index: CRATE_DEF_INDEX })
 148     }
 149 }
 150
 151 impl SpecIntoSelfProfilingString for DefIndex {
 152     fn spec_to_self_profile_string(
 153         &self,
 154         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 155     ) -> StringId {
 156         builder.def_id_to_string_id(DefId { krate: LOCAL_CRATE, index: *self })
 157     }
 158 }
 159
 160 impl SpecIntoSelfProfilingString for LocalDefId {
 161     fn spec_to_self_profile_string(
 162         &self,
 163         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 164     ) -> StringId {
 165         builder.def_id_to_string_id(DefId { krate: LOCAL_CRATE, index: self.local_def_index })
 166     }
 167 }
 168
 169 impl<T: SpecIntoSelfProfilingString> SpecIntoSelfProfilingString for WithOptConstParam<T> {
 170     fn spec_to_self_profile_string(
 171         &self,
 172         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 173     ) -> StringId {
 174         // We print `WithOptConstParam` values as tuples to make them shorter
 175         // and more readable, without losing information:
 176         //
 177         // "WithOptConstParam { did: foo::bar, const_param_did: Some(foo::baz) }"
 178         // becomes "(foo::bar, foo::baz)" and
 179         // "WithOptConstParam { did: foo::bar, const_param_did: None }"
 180         // becomes "(foo::bar, _)".
 181
 182         let did = StringComponent::Ref(self.did.to_self_profile_string(builder));
 183
 184         let const_param_did = if let Some(const_param_did) = self.const_param_did {
 185             let const_param_did = builder.def_id_to_string_id(const_param_did);
 186             StringComponent::Ref(const_param_did)
 187         } else {
 188             StringComponent::Value("_")
 189         };
 190
 191         let components = [
 192             StringComponent::Value("("),
 193             did,
 194             StringComponent::Value(", "),
 195             const_param_did,
 196             StringComponent::Value(")"),
 197         ];
 198
 199         builder.profiler.alloc_string(&components[..])
 200     }
 201 }
 202
 203 impl<T0, T1> SpecIntoSelfProfilingString for (T0, T1)
 204 where
 205     T0: SpecIntoSelfProfilingString,
 206     T1: SpecIntoSelfProfilingString,
 207 {
 208     fn spec_to_self_profile_string(
 209         &self,
 210         builder: &mut QueryKeyStringBuilder<'_, '_, '_>,
 211     ) -> StringId {
 212         let val0 = self.0.to_self_profile_string(builder);
 213         let val1 = self.1.to_self_profile_string(builder);
 214
 215         let components = &[
 216             StringComponent::Value("("),
 217             StringComponent::Ref(val0),
 218             StringComponent::Value(","),
 219             StringComponent::Ref(val1),
 220             StringComponent::Value(")"),
 221         ];
 222
 223         builder.profiler.alloc_string(components)
 224     }
 225 }
 226
 227 /// Allocate the self-profiling query strings for a single query cache. This
 228 /// method is called from `alloc_self_profile_query_strings` which knows all
 229 /// the queries via macro magic.
 230 pub(super) fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
 231     tcx: TyCtxt<'tcx>,
 232     query_name: &'static str,
 233     query_state: &QueryState<crate::dep_graph::DepKind, <TyCtxt<'tcx> as QueryContext>::Query, C>,
 234     string_cache: &mut QueryKeyStringCache,
 235 ) where
 236     C: QueryCache,
 237     C::Key: Debug + Clone,
 238 {
 239     tcx.prof.with_profiler(|profiler| {
 240         let event_id_builder = profiler.event_id_builder();
 241
 242         // Walk the entire query cache and allocate the appropriate
 243         // string representations. Each cache entry is uniquely
 244         // identified by its dep_node_index.
 245         if profiler.query_key_recording_enabled() {
 246             let mut query_string_builder = QueryKeyStringBuilder::new(profiler, tcx, string_cache);
 247
 248             let query_name = profiler.get_or_alloc_cached_string(query_name);
 249
 250             // Since building the string representation of query keys might
 251             // need to invoke queries itself, we cannot keep the query caches
 252             // locked while doing so. Instead we copy out the
 253             // `(query_key, dep_node_index)` pairs and release the lock again.
 254             let query_keys_and_indices: Vec<_> = query_state
 255                 .iter_results(|results| results.map(|(k, _, i)| (k.clone(), i)).collect());
 256
 257             // Now actually allocate the strings. If allocating the strings
 258             // generates new entries in the query cache, we'll miss them but
 259             // we don't actually care.
 260             for (query_key, dep_node_index) in query_keys_and_indices {
 261                 // Translate the DepNodeIndex into a QueryInvocationId
 262                 let query_invocation_id = dep_node_index.into();
 263
 264                 // Create the string version of the query-key
 265                 let query_key = query_key.to_self_profile_string(&mut query_string_builder);
 266                 let event_id = event_id_builder.from_label_and_arg(query_name, query_key);
 267
 268                 // Doing this in bulk might be a good idea:
 269                 profiler.map_query_invocation_id_to_string(
 270                     query_invocation_id,
 271                     event_id.to_string_id(),
 272                 );
 273             }
 274         } else {
 275             // In this branch we don't allocate query keys
 276             let query_name = profiler.get_or_alloc_cached_string(query_name);
 277             let event_id = event_id_builder.from_label(query_name).to_string_id();
 278
 279             query_state.iter_results(|results| {
 280                 let query_invocation_ids: Vec<_> = results.map(|v| v.2.into()).collect();
 281
 282                 profiler.bulk_map_query_invocation_id_to_single_string(
 283                     query_invocation_ids.into_iter(),
 284                     event_id,
 285                 );
 286             });
 287         }
 288     });
 289 }