1 files changed, 71 insertions, 0 deletions
diff --git a/clangd/index/Symbol.cpp b/clangd/index/Symbol.cpp
new file mode 100644
index 00000000..137f90df
--- /dev/null
+++ b/clangd/index/Symbol.cpp
@@ -0,0 +1,71 @@
+//===--- Symbol.cpp ----------------------------------------------*- C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Symbol.h"
+
+namespace clang {
+namespace clangd {
+
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, Symbol::SymbolFlag F) {
+  if (F == Symbol::None)
+    return OS << "None";
+  std::string S;
+  if (F & Symbol::Deprecated)
+    S += "deprecated|";
+  if (F & Symbol::IndexedForCodeCompletion)
+    S += "completion|";
+  return OS << llvm::StringRef(S).rtrim('|');
+}
+
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Symbol &S) {
+  return OS << S.Scope << S.Name;
+}
+
+float quality(const Symbol &S) {
+  // This avoids a sharp gradient for tail symbols, and also neatly avoids the
+  // question of whether 0 references means a bad symbol or missing data.
+  if (S.References < 3)
+    return 1;
+  return std::log(S.References);
+}
+
+SymbolSlab::const_iterator SymbolSlab::find(const SymbolID &ID) const {
+  auto It =
+      llvm::bsearch(Symbols, [&](const Symbol &S) { return !(S.ID < ID); });
+  if (It != Symbols.end() && It->ID == ID)
+    return It;
+  return Symbols.end();
+}
+
+// Copy the underlying data of the symbol into the owned arena.
+static void own(Symbol &S, llvm::UniqueStringSaver &Strings) {
+  visitStrings(S, [&](llvm::StringRef &V) { V = Strings.save(V); });
+}
+
+void SymbolSlab::Builder::insert(const Symbol &S) {
+  own(Symbols[S.ID] = S, UniqueStrings);
+}
+
+SymbolSlab SymbolSlab::Builder::build() && {
+  // Sort symbols into vector so the slab can binary search over them.
+  std::vector<Symbol> SortedSymbols;
+  SortedSymbols.reserve(Symbols.size());
+  for (auto &Entry : Symbols)
+    SortedSymbols.push_back(std::move(Entry.second));
+  llvm::sort(SortedSymbols,
+             [](const Symbol &L, const Symbol &R) { return L.ID < R.ID; });
+  // We may have unused strings from overwritten symbols. Build a new arena.
+  llvm::BumpPtrAllocator NewArena;
+  llvm::UniqueStringSaver Strings(NewArena);
+  for (auto &S : SortedSymbols)
+    own(S, Strings);
+  return SymbolSlab(std::move(NewArena), std::move(SortedSymbols));
+}
+
+} // namespace clangd
+} // namespace clang