clang-tools-extra/clangd/index/Symbol.cpp

   1 //===--- Symbol.cpp ----------------------------------------------*- C++-*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "Symbol.h"
  10
  11 #include <cmath>
  12
  13 namespace clang {
  14 namespace clangd {
  15
  16 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, Symbol::SymbolFlag F) {
  17   if (F == Symbol::None)
  18     return OS << "None";
  19   std::string S;
  20   if (F & Symbol::Deprecated)
  21     S += "deprecated|";
  22   if (F & Symbol::IndexedForCodeCompletion)
  23     S += "completion|";
  24   return OS << llvm::StringRef(S).rtrim('|');
  25 }
  26
  27 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Symbol &S) {
  28   return OS << S.Scope << S.Name;
  29 }
  30
  31 float quality(const Symbol &S) {
  32   // This avoids a sharp gradient for tail symbols, and also neatly avoids the
  33   // question of whether 0 references means a bad symbol or missing data.
  34   if (S.References < 3)
  35     return 1;
  36   return std::log(S.References);
  37 }
  38
  39 SymbolSlab::const_iterator SymbolSlab::find(const SymbolID &ID) const {
  40   auto It = llvm::partition_point(Symbols,
  41                                   [&](const Symbol &S) { return S.ID < ID; });
  42   if (It != Symbols.end() && It->ID == ID)
  43     return It;
  44   return Symbols.end();
  45 }
  46
  47 // Copy the underlying data of the symbol into the owned arena.
  48 static void own(Symbol &S, llvm::UniqueStringSaver &Strings) {
  49   visitStrings(S, [&](llvm::StringRef &V) { V = Strings.save(V); });
  50 }
  51
  52 void SymbolSlab::Builder::insert(const Symbol &S) {
  53   own(Symbols[S.ID] = S, UniqueStrings);
  54 }
  55
  56 SymbolSlab SymbolSlab::Builder::build() && {
  57   // Sort symbols into vector so the slab can binary search over them.
  58   std::vector<Symbol> SortedSymbols;
  59   SortedSymbols.reserve(Symbols.size());
  60   for (auto &Entry : Symbols)
  61     SortedSymbols.push_back(std::move(Entry.second));
  62   llvm::sort(SortedSymbols,
  63              [](const Symbol &L, const Symbol &R) { return L.ID < R.ID; });
  64   // We may have unused strings from overwritten symbols.
  65   // In practice, these are extremely small, it's not worth compacting.
  66   return SymbolSlab(std::move(Arena), std::move(SortedSymbols));
  67 }
  68
  69 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const SymbolSlab &Slab) {
  70   OS << "{";
  71   llvm::StringRef Sep = "";
  72   for (const auto &S : Slab) {
  73     OS << Sep << S;
  74     Sep = ", ";
  75   }
  76   OS << "}";
  77   return OS;
  78 }
  79 } // namespace clangd
  80 } // namespace clang