1//===--- CommentCommandTraits.cpp - Comment command properties --*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "clang/AST/CommentCommandTraits.h"
11#include "llvm/ADT/STLExtras.h"
12
13namespace clang {
14namespace comments {
15
16#include "clang/AST/CommentCommandInfo.inc"
17
18CommandTraits::CommandTraits(llvm::BumpPtrAllocator &Allocator,
19                             const CommentOptions &CommentOptions) :
20    NextID(llvm::array_lengthof(Commands)), Allocator(Allocator) {
21  registerCommentOptions(CommentOptions);
22}
23
24void CommandTraits::registerCommentOptions(
25    const CommentOptions &CommentOptions) {
26  for (CommentOptions::BlockCommandNamesTy::const_iterator
27           I = CommentOptions.BlockCommandNames.begin(),
28           E = CommentOptions.BlockCommandNames.end();
29       I != E; I++) {
30    registerBlockCommand(*I);
31  }
32}
33
34const CommandInfo *CommandTraits::getCommandInfoOrNULL(StringRef Name) const {
35  if (const CommandInfo *Info = getBuiltinCommandInfo(Name))
36    return Info;
37  return getRegisteredCommandInfo(Name);
38}
39
40const CommandInfo *CommandTraits::getCommandInfo(unsigned CommandID) const {
41  if (const CommandInfo *Info = getBuiltinCommandInfo(CommandID))
42    return Info;
43  return getRegisteredCommandInfo(CommandID);
44}
45
46const CommandInfo *
47CommandTraits::getTypoCorrectCommandInfo(StringRef Typo) const {
48  // Single-character command impostures, such as \t or \n, should not go
49  // through the fixit logic.
50  if (Typo.size() <= 1)
51    return nullptr;
52
53  // The maximum edit distance we're prepared to accept.
54  const unsigned MaxEditDistance = 1;
55
56  unsigned BestEditDistance = MaxEditDistance;
57  SmallVector<const CommandInfo *, 2> BestCommand;
58
59  auto ConsiderCorrection = [&](const CommandInfo *Command) {
60    StringRef Name = Command->Name;
61
62    unsigned MinPossibleEditDistance = abs((int)Name.size() - (int)Typo.size());
63    if (MinPossibleEditDistance <= BestEditDistance) {
64      unsigned EditDistance = Typo.edit_distance(Name, true, BestEditDistance);
65      if (EditDistance < BestEditDistance) {
66        BestEditDistance = EditDistance;
67        BestCommand.clear();
68      }
69      if (EditDistance == BestEditDistance)
70        BestCommand.push_back(Command);
71    }
72  };
73
74  for (const auto &Command : Commands)
75    ConsiderCorrection(&Command);
76
77  for (const auto *Command : RegisteredCommands)
78    if (!Command->IsUnknownCommand)
79      ConsiderCorrection(Command);
80
81  return BestCommand.size() == 1 ? BestCommand[0] : nullptr;
82}
83
84CommandInfo *CommandTraits::createCommandInfoWithName(StringRef CommandName) {
85  char *Name = Allocator.Allocate<char>(CommandName.size() + 1);
86  memcpy(Name, CommandName.data(), CommandName.size());
87  Name[CommandName.size()] = '\0';
88
89  // Value-initialize (=zero-initialize in this case) a new CommandInfo.
90  CommandInfo *Info = new (Allocator) CommandInfo();
91  Info->Name = Name;
92  Info->ID = NextID++;
93
94  RegisteredCommands.push_back(Info);
95
96  return Info;
97}
98
99const CommandInfo *CommandTraits::registerUnknownCommand(
100                                                  StringRef CommandName) {
101  CommandInfo *Info = createCommandInfoWithName(CommandName);
102  Info->IsUnknownCommand = true;
103  return Info;
104}
105
106const CommandInfo *CommandTraits::registerBlockCommand(StringRef CommandName) {
107  CommandInfo *Info = createCommandInfoWithName(CommandName);
108  Info->IsBlockCommand = true;
109  return Info;
110}
111
112const CommandInfo *CommandTraits::getBuiltinCommandInfo(
113                                                  unsigned CommandID) {
114  if (CommandID < llvm::array_lengthof(Commands))
115    return &Commands[CommandID];
116  return nullptr;
117}
118
119const CommandInfo *CommandTraits::getRegisteredCommandInfo(
120                                                  StringRef Name) const {
121  for (unsigned i = 0, e = RegisteredCommands.size(); i != e; ++i) {
122    if (RegisteredCommands[i]->Name == Name)
123      return RegisteredCommands[i];
124  }
125  return nullptr;
126}
127
128const CommandInfo *CommandTraits::getRegisteredCommandInfo(
129                                                  unsigned CommandID) const {
130  return RegisteredCommands[CommandID - llvm::array_lengthof(Commands)];
131}
132
133} // end namespace comments
134} // end namespace clang
135
136