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 namespace clang {
  12 namespace clangd {
  13
  14 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, Symbol::SymbolFlag F) {
  15   if (F == Symbol::None)
  16     return OS << "None";
  17   std::string S;
  18   if (F & Symbol::Deprecated)
  19     S += "deprecated|";
  20   if (F & Symbol::IndexedForCodeCompletion)
  21     S += "completion|";
  22   return OS << llvm::StringRef(S).rtrim('|');
  23 }
  24
  25 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Symbol &S) {
  26   return OS << S.Scope << S.Name;
  27 }
  28
  29 float quality(const Symbol &S) {
  30   // This avoids a sharp gradient for tail symbols, and also neatly avoids the
  31   // question of whether 0 references means a bad symbol or missing data.
  32   if (S.References < 3)
  33     return 1;
  34   return std::log(S.References);
  35 }
  36
  37 SymbolSlab::const_iterator SymbolSlab::find(const SymbolID &ID) const {
  38   auto It = llvm::partition_point(Symbols,
  39                                   [&](const Symbol &S) { return S.ID < ID; });
  40   if (It != Symbols.end() && It->ID == ID)
  41     return It;
  42   return Symbols.end();
  43 }
  44
  45 // Copy the underlying data of the symbol into the owned arena.
  46 static void own(Symbol &S, llvm::UniqueStringSaver &Strings) {
  47   visitStrings(S, [&](llvm::StringRef &V) { V = Strings.save(V); });
  48 }
  49
  50 void SymbolSlab::Builder::insert(const Symbol &S) {
  51   own(Symbols[S.ID] = S, UniqueStrings);
  52 }
  53
  54 SymbolSlab SymbolSlab::Builder::build() && {
  55   // Sort symbols into vector so the slab can binary search over them.
  56   std::vector<Symbol> SortedSymbols;
  57   SortedSymbols.reserve(Symbols.size());
  58   for (auto &Entry : Symbols)
  59     SortedSymbols.push_back(std::move(Entry.second));
  60   llvm::sort(SortedSymbols,
  61              [](const Symbol &L, const Symbol &R) { return L.ID < R.ID; });
  62   // We may have unused strings from overwritten symbols. Build a new arena.
  63   llvm::BumpPtrAllocator NewArena;
  64   llvm::UniqueStringSaver Strings(NewArena);
  65   for (auto &S : SortedSymbols)
  66     own(S, Strings);
  67   return SymbolSlab(std::move(NewArena), std::move(SortedSymbols));
  68 }
  69
  70 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const SymbolSlab &Slab) {
  71   OS << "{";
  72   llvm::StringRef Sep = "";
  73   for (const auto &S : Slab) {
  74     OS << Sep << S;
  75     Sep = ", ";
  76   }
  77   OS << "}";
  78   return OS;
  79 }
  80 } // namespace clangd
  81 } // namespace clang