contrib/llvm/tools/clang/utils/TableGen/ClangCommentHTMLNamedCharacterReferenceEmitter.cpp

   1 //===--- ClangCommentHTMLNamedCharacterReferenceEmitter.cpp -----------------=//
   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 // This tablegen backend emits an fficient function to translate HTML named
  11 // character references to UTF-8 sequences.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ADT/SmallString.h"
  16 #include "llvm/Support/ConvertUTF.h"
  17 #include "llvm/TableGen/Error.h"
  18 #include "llvm/TableGen/Record.h"
  19 #include "llvm/TableGen/StringMatcher.h"
  20 #include "llvm/TableGen/TableGenBackend.h"
  21 #include <vector>
  22
  23 using namespace llvm;
  24
  25 /// \brief Convert a code point to the corresponding UTF-8 sequence represented
  26 /// as a C string literal.
  27 ///
  28 /// \returns true on success.
  29 static bool translateCodePointToUTF8(unsigned CodePoint,
  30                                      SmallVectorImpl<char> &CLiteral) {
  31   char Translated[UNI_MAX_UTF8_BYTES_PER_CODE_POINT];
  32   char *TranslatedPtr = Translated;
  33   if (!ConvertCodePointToUTF8(CodePoint, TranslatedPtr))
  34     return false;
  35
  36   StringRef UTF8(Translated, TranslatedPtr - Translated);
  37
  38   raw_svector_ostream OS(CLiteral);
  39   OS << "\"";
  40   for (size_t i = 0, e = UTF8.size(); i != e; ++i) {
  41     OS << "\\x";
  42     OS.write_hex(static_cast<unsigned char>(UTF8[i]));
  43   }
  44   OS << "\"";
  45
  46   return true;
  47 }
  48
  49 namespace clang {
  50 void EmitClangCommentHTMLNamedCharacterReferences(RecordKeeper &Records,
  51                                                   raw_ostream &OS) {
  52   std::vector<Record *> Tags = Records.getAllDerivedDefinitions("NCR");
  53   std::vector<StringMatcher::StringPair> NameToUTF8;
  54   SmallString<32> CLiteral;
  55   for (std::vector<Record *>::iterator I = Tags.begin(), E = Tags.end();
  56        I != E; ++I) {
  57     Record &Tag = **I;
  58     std::string Spelling = Tag.getValueAsString("Spelling");
  59     uint64_t CodePoint = Tag.getValueAsInt("CodePoint");
  60     CLiteral.clear();
  61     CLiteral.append("return ");
  62     if (!translateCodePointToUTF8(CodePoint, CLiteral)) {
  63       SrcMgr.PrintMessage(Tag.getLoc().front(),
  64                           SourceMgr::DK_Error,
  65                           Twine("invalid code point"));
  66       continue;
  67     }
  68     CLiteral.append(";");
  69
  70     StringMatcher::StringPair Match(Spelling, CLiteral.str());
  71     NameToUTF8.push_back(Match);
  72   }
  73
  74   emitSourceFileHeader("HTML named character reference to UTF-8 "
  75                        "translation", OS);
  76
  77   OS << "StringRef translateHTMLNamedCharacterReferenceToUTF8(\n"
  78         "                                             StringRef Name) {\n";
  79   StringMatcher("Name", NameToUTF8, OS).Emit();
  80   OS << "  return StringRef();\n"
  81      << "}\n\n";
  82 }
  83
  84 } // end namespace clang
  85