1 files changed, 94 insertions, 0 deletions
diff --git a/clangd/index/SymbolLocation.h b/clangd/index/SymbolLocation.h
new file mode 100644
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+++ b/clangd/index/SymbolLocation.h
@@ -0,0 +1,94 @@
+//===--- SymbolLocation.h ----------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstdint>
+
+namespace clang {
+namespace clangd {
+
+struct SymbolLocation {
+  // Specify a position (Line, Column) of symbol. Using Line/Column allows us to
+  // build LSP responses without reading the file content.
+  //
+  // clangd uses the following definitions, which differ slightly from LSP:
+  //  - Line is the number of newline characters (\n) before the point.
+  //  - Column is (by default) the number of UTF-16 code between the last \n
+  //    (or start of file) and the point.
+  //    If the `offsetEncoding` protocol extension is used to negotiate UTF-8,
+  //    then it is instead the number of *bytes* since the last \n.
+  //
+  // Position is encoded into 32 bits to save space.
+  // If Line/Column overflow, the value will be their maximum value.
+  struct Position {
+    Position() : Line(0), Column(0) {}
+    void setLine(uint32_t Line);
+    uint32_t line() const { return Line; }
+    void setColumn(uint32_t Column);
+    uint32_t column() const { return Column; }
+
+    bool hasOverflow() const {
+      return Line >= MaxLine || Column >= MaxColumn;
+    }
+
+    static constexpr uint32_t MaxLine = (1 << 20) - 1;
+    static constexpr uint32_t MaxColumn = (1 << 12) - 1;
+
+  private:
+    uint32_t Line : 20;   // 0-based
+    uint32_t Column : 12; // 0-based
+  };
+
+  /// The symbol range, using half-open range [Start, End).
+  Position Start;
+  Position End;
+
+  explicit operator bool() const { return !llvm::StringRef(FileURI).empty(); }
+
+  // The URI of the source file where a symbol occurs.
+  // The string must be null-terminated.
+  //
+  // We avoid using llvm::StringRef here to save memory.
+  // WARNING: unless you know what you are doing, it is recommended to use it
+  // via llvm::StringRef.
+  const char *FileURI = "";
+};
+
+inline bool operator==(const SymbolLocation::Position &L,
+                       const SymbolLocation::Position &R) {
+  return std::make_tuple(L.line(), L.column()) ==
+         std::make_tuple(R.line(), R.column());
+}
+inline bool operator<(const SymbolLocation::Position &L,
+                      const SymbolLocation::Position &R) {
+  return std::make_tuple(L.line(), L.column()) <
+         std::make_tuple(R.line(), R.column());
+}
+inline bool operator==(const SymbolLocation &L, const SymbolLocation &R) {
+  assert(L.FileURI && R.FileURI);
+  return !std::strcmp(L.FileURI, R.FileURI) &&
+         std::tie(L.Start, L.End) == std::tie(R.Start, R.End);
+}
+inline bool operator<(const SymbolLocation &L, const SymbolLocation &R) {
+  assert(L.FileURI && R.FileURI);
+  int Cmp = std::strcmp(L.FileURI, R.FileURI);
+  if (Cmp != 0)
+    return Cmp < 0;
+  return std::tie(L.Start, L.End) < std::tie(R.Start, R.End);
+}
+
+llvm::raw_ostream &operator<<(llvm::raw_ostream &, const SymbolLocation &);
+
+} // namespace clangd
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H