Home | History | Annotate | Download | only in AST 
      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 
     13 namespace clang {
     14 namespace comments {
     15 
     16 #include "clang/AST/CommentCommandInfo.inc"
     17 
     18 CommandTraits::CommandTraits(llvm::BumpPtrAllocator &Allocator,
     19                              const CommentOptions &CommentOptions) :
     20     NextID(llvm::array_lengthof(Commands)), Allocator(Allocator) {
     21   registerCommentOptions(CommentOptions);
     22 }
     23 
     24 void 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 
     34 const CommandInfo *CommandTraits::getCommandInfoOrNULL(StringRef Name) const {
     35   if (const CommandInfo *Info = getBuiltinCommandInfo(Name))
     36     return Info;
     37   return getRegisteredCommandInfo(Name);
     38 }
     39 
     40 const CommandInfo *CommandTraits::getCommandInfo(unsigned CommandID) const {
     41   if (const CommandInfo *Info = getBuiltinCommandInfo(CommandID))
     42     return Info;
     43   return getRegisteredCommandInfo(CommandID);
     44 }
     45 
     46 const CommandInfo *
     47 CommandTraits::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 
     84 CommandInfo *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 
     99 const CommandInfo *CommandTraits::registerUnknownCommand(
    100                                                   StringRef CommandName) {
    101   CommandInfo *Info = createCommandInfoWithName(CommandName);
    102   Info->IsUnknownCommand = true;
    103   return Info;
    104 }
    105 
    106 const CommandInfo *CommandTraits::registerBlockCommand(StringRef CommandName) {
    107   CommandInfo *Info = createCommandInfoWithName(CommandName);
    108   Info->IsBlockCommand = true;
    109   return Info;
    110 }
    111 
    112 const CommandInfo *CommandTraits::getBuiltinCommandInfo(
    113                                                   unsigned CommandID) {
    114   if (CommandID < llvm::array_lengthof(Commands))
    115     return &Commands[CommandID];
    116   return nullptr;
    117 }
    118 
    119 const 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 
    128 const 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