contrib/llvm-project/clang/utils/TableGen/ClangCommentHTMLNamedCharacterReferenceEmitter.cpp

   1 //===--- ClangCommentHTMLNamedCharacterReferenceEmitter.cpp -----------------=//
   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 // This tablegen backend emits an efficient function to translate HTML named
  10 // character references to UTF-8 sequences.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ADT/SmallString.h"
  15 #include "llvm/Support/ConvertUTF.h"
  16 #include "llvm/TableGen/Error.h"
  17 #include "llvm/TableGen/Record.h"
  18 #include "llvm/TableGen/StringMatcher.h"
  19 #include "llvm/TableGen/TableGenBackend.h"
  20 #include <vector>
  21
  22 using namespace llvm;
  23
  24 /// Convert a code point to the corresponding UTF-8 sequence represented
  25 /// as a C string literal.
  26 ///
  27 /// \returns true on success.
  28 static bool translateCodePointToUTF8(unsigned CodePoint,
  29                                      SmallVectorImpl<char> &CLiteral) {
  30   char Translated[UNI_MAX_UTF8_BYTES_PER_CODE_POINT];
  31   char *TranslatedPtr = Translated;
  32   if (!ConvertCodePointToUTF8(CodePoint, TranslatedPtr))
  33     return false;
  34
  35   StringRef UTF8(Translated, TranslatedPtr - Translated);
  36
  37   raw_svector_ostream OS(CLiteral);
  38   OS << "\"";
  39   for (size_t i = 0, e = UTF8.size(); i != e; ++i) {
  40     OS << "\\x";
  41     OS.write_hex(static_cast<unsigned char>(UTF8[i]));
  42   }
  43   OS << "\"";
  44
  45   return true;
  46 }
  47
  48 namespace clang {
  49 void EmitClangCommentHTMLNamedCharacterReferences(RecordKeeper &Records,
  50                                                   raw_ostream &OS) {
  51   std::vector<Record *> Tags = Records.getAllDerivedDefinitions("NCR");
  52   std::vector<StringMatcher::StringPair> NameToUTF8;
  53   SmallString<32> CLiteral;
  54   for (std::vector<Record *>::iterator I = Tags.begin(), E = Tags.end();
  55        I != E; ++I) {
  56     Record &Tag = **I;
  57     std::string Spelling = Tag.getValueAsString("Spelling");
  58     uint64_t CodePoint = Tag.getValueAsInt("CodePoint");
  59     CLiteral.clear();
  60     CLiteral.append("return ");
  61     if (!translateCodePointToUTF8(CodePoint, CLiteral)) {
  62       SrcMgr.PrintMessage(Tag.getLoc().front(),
  63                           SourceMgr::DK_Error,
  64                           Twine("invalid code point"));
  65       continue;
  66     }
  67     CLiteral.append(";");
  68
  69     StringMatcher::StringPair Match(Spelling, CLiteral.str());
  70     NameToUTF8.push_back(Match);
  71   }
  72
  73   emitSourceFileHeader("HTML named character reference to UTF-8 "
  74                        "translation", OS);
  75
  76   OS << "StringRef translateHTMLNamedCharacterReferenceToUTF8(\n"
  77         "                                             StringRef Name) {\n";
  78   StringMatcher("Name", NameToUTF8, OS).Emit();
  79   OS << "  return StringRef();\n"
  80      << "}\n\n";
  81 }
  82
  83 } // end namespace clang
  84