1217739Sadrian//===--- CommentCommandTraits.cpp - Comment command properties --*- C++ -*-===//
2217739Sadrian//
3217739Sadrian// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4217739Sadrian// See https://llvm.org/LICENSE.txt for license information.
5217739Sadrian// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6217739Sadrian//
7217739Sadrian//===----------------------------------------------------------------------===//
8217739Sadrian
9217739Sadrian#include "clang/AST/CommentCommandTraits.h"
10217739Sadrian#include "llvm/ADT/STLExtras.h"
11217739Sadrian
12217739Sadriannamespace clang {
13217739Sadriannamespace comments {
14217739Sadrian
15217739Sadrian#include "clang/AST/CommentCommandInfo.inc"
16217739Sadrian
17217739SadrianCommandTraits::CommandTraits(llvm::BumpPtrAllocator &Allocator,
18217739Sadrian                             const CommentOptions &CommentOptions) :
19217739Sadrian    NextID(llvm::array_lengthof(Commands)), Allocator(Allocator) {
20217739Sadrian  registerCommentOptions(CommentOptions);
21217739Sadrian}
22217739Sadrian
23239161Sadrianvoid CommandTraits::registerCommentOptions(
24    const CommentOptions &CommentOptions) {
25  for (CommentOptions::BlockCommandNamesTy::const_iterator
26           I = CommentOptions.BlockCommandNames.begin(),
27           E = CommentOptions.BlockCommandNames.end();
28       I != E; I++) {
29    registerBlockCommand(*I);
30  }
31}
32
33const CommandInfo *CommandTraits::getCommandInfoOrNULL(StringRef Name) const {
34  if (const CommandInfo *Info = getBuiltinCommandInfo(Name))
35    return Info;
36  return getRegisteredCommandInfo(Name);
37}
38
39const CommandInfo *CommandTraits::getCommandInfo(unsigned CommandID) const {
40  if (const CommandInfo *Info = getBuiltinCommandInfo(CommandID))
41    return Info;
42  return getRegisteredCommandInfo(CommandID);
43}
44
45const CommandInfo *
46CommandTraits::getTypoCorrectCommandInfo(StringRef Typo) const {
47  // Single-character command impostures, such as \t or \n, should not go
48  // through the fixit logic.
49  if (Typo.size() <= 1)
50    return nullptr;
51
52  // The maximum edit distance we're prepared to accept.
53  const unsigned MaxEditDistance = 1;
54
55  unsigned BestEditDistance = MaxEditDistance;
56  SmallVector<const CommandInfo *, 2> BestCommand;
57
58  auto ConsiderCorrection = [&](const CommandInfo *Command) {
59    StringRef Name = Command->Name;
60
61    unsigned MinPossibleEditDistance = abs((int)Name.size() - (int)Typo.size());
62    if (MinPossibleEditDistance <= BestEditDistance) {
63      unsigned EditDistance = Typo.edit_distance(Name, true, BestEditDistance);
64      if (EditDistance < BestEditDistance) {
65        BestEditDistance = EditDistance;
66        BestCommand.clear();
67      }
68      if (EditDistance == BestEditDistance)
69        BestCommand.push_back(Command);
70    }
71  };
72
73  for (const auto &Command : Commands)
74    ConsiderCorrection(&Command);
75
76  for (const auto *Command : RegisteredCommands)
77    if (!Command->IsUnknownCommand)
78      ConsiderCorrection(Command);
79
80  return BestCommand.size() == 1 ? BestCommand[0] : nullptr;
81}
82
83CommandInfo *CommandTraits::createCommandInfoWithName(StringRef CommandName) {
84  char *Name = Allocator.Allocate<char>(CommandName.size() + 1);
85  memcpy(Name, CommandName.data(), CommandName.size());
86  Name[CommandName.size()] = '\0';
87
88  // Value-initialize (=zero-initialize in this case) a new CommandInfo.
89  CommandInfo *Info = new (Allocator) CommandInfo();
90  Info->Name = Name;
91  // We only have a limited number of bits to encode command IDs in the
92  // CommandInfo structure, so the ID numbers can potentially wrap around.
93  assert((NextID < (1 << CommandInfo::NumCommandIDBits))
94         && "Too many commands. We have limited bits for the command ID.");
95  Info->ID = NextID++;
96
97  RegisteredCommands.push_back(Info);
98
99  return Info;
100}
101
102const CommandInfo *CommandTraits::registerUnknownCommand(
103                                                  StringRef CommandName) {
104  CommandInfo *Info = createCommandInfoWithName(CommandName);
105  Info->IsUnknownCommand = true;
106  return Info;
107}
108
109const CommandInfo *CommandTraits::registerBlockCommand(StringRef CommandName) {
110  CommandInfo *Info = createCommandInfoWithName(CommandName);
111  Info->IsBlockCommand = true;
112  return Info;
113}
114
115const CommandInfo *CommandTraits::getBuiltinCommandInfo(
116                                                  unsigned CommandID) {
117  if (CommandID < llvm::array_lengthof(Commands))
118    return &Commands[CommandID];
119  return nullptr;
120}
121
122const CommandInfo *CommandTraits::getRegisteredCommandInfo(
123                                                  StringRef Name) const {
124  for (unsigned i = 0, e = RegisteredCommands.size(); i != e; ++i) {
125    if (RegisteredCommands[i]->Name == Name)
126      return RegisteredCommands[i];
127  }
128  return nullptr;
129}
130
131const CommandInfo *CommandTraits::getRegisteredCommandInfo(
132                                                  unsigned CommandID) const {
133  return RegisteredCommands[CommandID - llvm::array_lengthof(Commands)];
134}
135
136} // end namespace comments
137} // end namespace clang
138
139