clang-tools-extra/clang-tidy/misc/ConfusableTable/BuildConfusableTable.cpp

   1 //===--- BuildConfusableTable.cpp - clang-tidy---------------------------===//
   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 #include "llvm/ADT/STLExtras.h"
  10 #include "llvm/ADT/StringExtras.h"
  11 #include "llvm/Support/ConvertUTF.h"
  12 #include "llvm/Support/MemoryBuffer.h"
  13 #include "llvm/Support/raw_ostream.h"
  14
  15 using namespace llvm;
  16
  17 int main(int argc, char *argv[]) {
  18   auto ErrorOrBuffer = MemoryBuffer::getFile(argv[1], true);
  19   if (!ErrorOrBuffer)
  20     return 1;
  21   std::unique_ptr<MemoryBuffer> Buffer = std::move(ErrorOrBuffer.get());
  22   StringRef Content = Buffer->getBuffer();
  23   Content = Content.drop_until([](char c) { return c == '#'; });
  24   SmallVector<StringRef> Lines;
  25   SplitString(Content, Lines, "\r\n");
  26
  27   std::vector<std::pair<llvm::UTF32, SmallVector<llvm::UTF32>>> Entries;
  28   SmallVector<StringRef> Values;
  29   for (StringRef Line : Lines) {
  30     if (Line.starts_with("#"))
  31       continue;
  32
  33     Values.clear();
  34     Line.split(Values, ';');
  35     if (Values.size() < 2) {
  36       errs() << "Failed to parse: " << Line << "\n";
  37       return 2;
  38     }
  39
  40     llvm::StringRef From = Values[0].trim();
  41     llvm::UTF32 CodePoint = 0;
  42     From.getAsInteger(16, CodePoint);
  43
  44     SmallVector<llvm::UTF32> To;
  45     SmallVector<StringRef> ToN;
  46     Values[1].split(ToN, ' ', -1, false);
  47     for (StringRef To_ : ToN) {
  48       llvm::UTF32 ToCodePoint = 0;
  49       To_.trim().getAsInteger(16, ToCodePoint);
  50       To.push_back(ToCodePoint);
  51     }
  52     // Sentinel
  53     To.push_back(0);
  54
  55     Entries.emplace_back(CodePoint, To);
  56   }
  57   llvm::sort(Entries);
  58
  59   unsigned LargestValue =
  60       std::max_element(Entries.begin(), Entries.end(),
  61                        [](const auto &Entry0, const auto &Entry1) {
  62                          return Entry0.second.size() < Entry1.second.size();
  63                        })
  64           ->second.size();
  65
  66   std::error_code ec;
  67   llvm::raw_fd_ostream os(argv[2], ec);
  68
  69   // FIXME: If memory consumption and/or lookup time becomes a constraint, it
  70   // maybe worth using a more elaborate data structure.
  71   os << "struct {llvm::UTF32 codepoint; llvm::UTF32 values[" << LargestValue
  72      << "];} "
  73         "ConfusableEntries[] = {\n";
  74   for (const auto &Values : Entries) {
  75     os << "  { ";
  76     os << Values.first;
  77     os << ", {";
  78     for (auto CP : Values.second)
  79       os << CP << ", ";
  80
  81     os << "}},\n";
  82   }
  83   os << "};\n";
  84   return 0;
  85 }