• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===--- SymbolLocation.h ----------------------------------------*- 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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H
11 
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/Support/raw_ostream.h"
14 #include <cstdint>
15 
16 namespace clang {
17 namespace clangd {
18 
19 struct SymbolLocation {
20   // Specify a position (Line, Column) of symbol. Using Line/Column allows us to
21   // build LSP responses without reading the file content.
22   //
23   // clangd uses the following definitions, which differ slightly from LSP:
24   //  - Line is the number of newline characters (\n) before the point.
25   //  - Column is (by default) the number of UTF-16 code between the last \n
26   //    (or start of file) and the point.
27   //    If the `offsetEncoding` protocol extension is used to negotiate UTF-8,
28   //    then it is instead the number of *bytes* since the last \n.
29   //
30   // Position is encoded into 32 bits to save space.
31   // If Line/Column overflow, the value will be their maximum value.
32   struct Position {
PositionSymbolLocation::Position33     Position() : LineColumnPacked(0) {}
34     void setLine(uint32_t Line);
lineSymbolLocation::Position35     uint32_t line() const { return LineColumnPacked >> ColumnBits; }
36     void setColumn(uint32_t Column);
columnSymbolLocation::Position37     uint32_t column() const { return LineColumnPacked & MaxColumn; }
repSymbolLocation::Position38     uint32_t rep() const { return LineColumnPacked; }
39 
hasOverflowSymbolLocation::Position40     bool hasOverflow() const {
41       return line() == MaxLine || column() == MaxColumn;
42     }
43 
44     static constexpr unsigned ColumnBits = 12;
45     static constexpr uint32_t MaxLine = (1 << (32 - ColumnBits)) - 1;
46     static constexpr uint32_t MaxColumn = (1 << ColumnBits) - 1;
47 
48   private:
49     uint32_t LineColumnPacked; // Top 20 bit line, bottom 12 bits column.
50   };
51 
52   /// The symbol range, using half-open range [Start, End).
53   Position Start;
54   Position End;
55 
56   explicit operator bool() const { return !llvm::StringRef(FileURI).empty(); }
57 
58   // The URI of the source file where a symbol occurs.
59   // The string must be null-terminated.
60   //
61   // We avoid using llvm::StringRef here to save memory.
62   // WARNING: unless you know what you are doing, it is recommended to use it
63   // via llvm::StringRef.
64   const char *FileURI = "";
65 };
66 
67 inline bool operator==(const SymbolLocation::Position &L,
68                        const SymbolLocation::Position &R) {
69   return std::make_tuple(L.line(), L.column()) ==
70          std::make_tuple(R.line(), R.column());
71 }
72 inline bool operator<(const SymbolLocation::Position &L,
73                       const SymbolLocation::Position &R) {
74   return std::make_tuple(L.line(), L.column()) <
75          std::make_tuple(R.line(), R.column());
76 }
77 inline bool operator==(const SymbolLocation &L, const SymbolLocation &R) {
78   assert(L.FileURI && R.FileURI);
79   return !std::strcmp(L.FileURI, R.FileURI) &&
80          std::tie(L.Start, L.End) == std::tie(R.Start, R.End);
81 }
82 inline bool operator<(const SymbolLocation &L, const SymbolLocation &R) {
83   assert(L.FileURI && R.FileURI);
84   int Cmp = std::strcmp(L.FileURI, R.FileURI);
85   if (Cmp != 0)
86     return Cmp < 0;
87   return std::tie(L.Start, L.End) < std::tie(R.Start, R.End);
88 }
89 
90 llvm::raw_ostream &operator<<(llvm::raw_ostream &, const SymbolLocation &);
91 
92 } // namespace clangd
93 } // namespace clang
94 
95 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOL_LOCATION_H
96