C++ ASTContext::AllocateCopy方法代码示例

static RawComment toRawComment(ASTContext &Context, CharSourceRange Range) {
  if (Range.isInvalid())
    return RawComment();

  auto &SourceMgr = Context.SourceMgr;
  unsigned BufferID = SourceMgr.findBufferContainingLoc(Range.getStart());
  unsigned Offset = SourceMgr.getLocOffsetInBuffer(Range.getStart(), BufferID);
  unsigned EndOffset = SourceMgr.getLocOffsetInBuffer(Range.getEnd(), BufferID);
  LangOptions FakeLangOpts;
  Lexer L(FakeLangOpts, SourceMgr, BufferID, nullptr, LexerMode::Swift,
          HashbangMode::Disallowed,
          CommentRetentionMode::ReturnAsTokens,
          TriviaRetentionMode::WithoutTrivia,
          Offset, EndOffset);
  SmallVector<SingleRawComment, 16> Comments;
  Token Tok;
  while (true) {
    L.lex(Tok);
    if (Tok.is(tok::eof))
      break;
    assert(Tok.is(tok::comment));
    addCommentToList(Comments, SingleRawComment(Tok.getRange(), SourceMgr));
  }
  RawComment Result;
  Result.Comments = Context.AllocateCopy(Comments);
  return Result;
}

/// Classify the given Clang enumeration to describe how to import it.
void EnumInfo::classifyEnum(ASTContext &ctx, const clang::EnumDecl *decl,
                            clang::Preprocessor &pp) {
  // Anonymous enumerations simply get mapped to constants of the
  // underlying type of the enum, because there is no way to conjure up a
  // name for the Swift type.
  if (!decl->hasNameForLinkage()) {
    kind = EnumKind::Constants;
    return;
  }

  // First, check for attributes that denote the classification
  if (auto domainAttr = decl->getAttr<clang::NSErrorDomainAttr>()) {
    kind = EnumKind::Enum;
    nsErrorDomain = ctx.AllocateCopy(domainAttr->getErrorDomain()->getName());
    return;
  }

  // Was the enum declared using *_ENUM or *_OPTIONS?
  // FIXME: Use Clang attributes instead of groveling the macro expansion loc.
  auto loc = decl->getLocStart();
  if (loc.isMacroID()) {
    StringRef MacroName = pp.getImmediateMacroName(loc);
    if (MacroName == "CF_ENUM" || MacroName == "__CF_NAMED_ENUM" ||
        MacroName == "OBJC_ENUM" || MacroName == "SWIFT_ENUM" ||
        MacroName == "SWIFT_ENUM_NAMED") {
      kind = EnumKind::Enum;
      return;
    }
    if (MacroName == "CF_OPTIONS" || MacroName == "OBJC_OPTIONS" ||
        MacroName == "SWIFT_OPTIONS") {
      kind = EnumKind::Options;
      return;
    }
  }

  // Hardcode a particular annoying case in the OS X headers.
  if (decl->getName() == "DYLD_BOOL") {
    kind = EnumKind::Enum;
    return;
  }

  // Fall back to the 'Unknown' path.
  kind = EnumKind::Unknown;
}

static StringRef extractBriefComment(ASTContext &Context, RawComment RC,
                                     const Decl *D) {
  PrettyStackTraceDecl StackTrace("extracting brief comment for", D);

  if (!D->canHaveComment())
    return StringRef();

  swift::markup::MarkupContext MC;
  auto DC = getCascadingDocComment(MC, D);
  if (!DC.hasValue())
    return StringRef();

  auto Brief = DC.getValue()->getBrief();
  if (!Brief.hasValue())
    return StringRef();

  SmallString<256> BriefStr("");
  llvm::raw_svector_ostream OS(BriefStr);
  swift::markup::printInlinesUnder(Brief.getValue(), OS);
  if (OS.str().empty())
    return StringRef();

  return Context.AllocateCopy(OS.str());
}

//.........这里部分代码省略.........
  if (ec == ecEnd)
    return;

  // Determine whether the given enumerator is non-deprecated and has no
  // specifically-provided name.
  auto isNonDeprecatedWithoutCustomName = [](
      const clang::EnumConstantDecl *elem) -> bool {
    if (elem->hasAttr<clang::SwiftNameAttr>())
      return false;

    clang::VersionTuple maxVersion{~0U, ~0U, ~0U};
    switch (elem->getAvailability(nullptr, maxVersion)) {
    case clang::AR_Available:
    case clang::AR_NotYetIntroduced:
      for (auto attr : elem->attrs()) {
        if (auto annotate = dyn_cast<clang::AnnotateAttr>(attr)) {
          if (annotate->getAnnotation() == "swift1_unavailable")
            return false;
        }
        if (auto avail = dyn_cast<clang::AvailabilityAttr>(attr)) {
          if (avail->getPlatform()->getName() == "swift")
            return false;
        }
      }
      return true;

    case clang::AR_Deprecated:
    case clang::AR_Unavailable:
      return false;
    }
  };

  // Move to the first non-deprecated enumerator, or non-swift_name'd
  // enumerator, if present.
  auto firstNonDeprecated =
      std::find_if(ec, ecEnd, isNonDeprecatedWithoutCustomName);
  bool hasNonDeprecated = (firstNonDeprecated != ecEnd);
  if (hasNonDeprecated) {
    ec = firstNonDeprecated;
  } else {
    // Advance to the first case without a custom name, deprecated or not.
    while (ec != ecEnd && (*ec)->hasAttr<clang::SwiftNameAttr>())
      ++ec;
    if (ec == ecEnd) {
      return;
    }
  }

  // Compute the common prefix.
  StringRef commonPrefix = (*ec)->getName();
  bool followedByNonIdentifier = false;
  for (++ec; ec != ecEnd; ++ec) {
    // Skip deprecated or swift_name'd enumerators.
    const clang::EnumConstantDecl *elem = *ec;
    if (hasNonDeprecated) {
      if (!isNonDeprecatedWithoutCustomName(elem))
        continue;
    } else {
      if (elem->hasAttr<clang::SwiftNameAttr>())
        continue;
    }

    commonPrefix = getCommonWordPrefix(commonPrefix, elem->getName(),
                                       followedByNonIdentifier);
    if (commonPrefix.empty())
      break;
  }

  if (!commonPrefix.empty()) {
    StringRef checkPrefix = commonPrefix;

    // Account for the 'kConstant' naming convention on enumerators.
    if (checkPrefix[0] == 'k') {
      bool canDropK;
      if (checkPrefix.size() >= 2)
        canDropK = clang::isUppercase(checkPrefix[1]);
      else
        canDropK = !followedByNonIdentifier;

      if (canDropK)
        checkPrefix = checkPrefix.drop_front();
    }

    // Don't use importFullName() here, we want to ignore the swift_name
    // and swift_private attributes.
    StringRef enumNameStr = decl->getName();
    StringRef commonWithEnum = getCommonPluralPrefix(checkPrefix, enumNameStr);
    size_t delta = commonPrefix.size() - checkPrefix.size();

    // Account for the 'EnumName_Constant' convention on enumerators.
    if (commonWithEnum.size() < checkPrefix.size() &&
        checkPrefix[commonWithEnum.size()] == '_' && !followedByNonIdentifier) {
      delta += 1;
    }

    commonPrefix = commonPrefix.slice(0, commonWithEnum.size() + delta);
  }

  constantNamePrefix = ctx.AllocateCopy(commonPrefix);
}

static StmtCondition exprToCond(Expr *C, ASTContext &Ctx) {
  StmtConditionElement Arr[] = { StmtConditionElement(C) };
  return Ctx.AllocateCopy(Arr);
}

/// Classify the given Clang enumeration to describe how to import it.
void EnumInfo::classifyEnum(ASTContext &ctx, const clang::EnumDecl *decl,
                            clang::Preprocessor &pp) {
  assert(decl);
  clang::PrettyStackTraceDecl trace(decl, clang::SourceLocation(),
                                    pp.getSourceManager(), "classifying");
  assert(decl->isThisDeclarationADefinition());

  // Anonymous enumerations simply get mapped to constants of the
  // underlying type of the enum, because there is no way to conjure up a
  // name for the Swift type.
  if (!decl->hasNameForLinkage()) {
    kind = EnumKind::Constants;
    return;
  }

  // First, check for attributes that denote the classification
  if (auto domainAttr = decl->getAttr<clang::NSErrorDomainAttr>()) {
    kind = EnumKind::Enum;
    nsErrorDomain = ctx.AllocateCopy(domainAttr->getErrorDomain()->getName());
    return;
  }
  if (decl->hasAttr<clang::FlagEnumAttr>()) {
    kind = EnumKind::Options;
    return;
  }
  if (decl->hasAttr<clang::EnumExtensibilityAttr>()) {
    // FIXME: Distinguish between open and closed enums.
    kind = EnumKind::Enum;
    return;
  }

  // If API notes have /removed/ a FlagEnum or EnumExtensibility attribute,
  // then we don't need to check the macros.
  for (auto *attr : decl->specific_attrs<clang::SwiftVersionedAttr>()) {
    if (!attr->getVersion().empty())
      continue;
    if (isa<clang::FlagEnumAttr>(attr->getAttrToAdd()) ||
        isa<clang::EnumExtensibilityAttr>(attr->getAttrToAdd())) {
      kind = EnumKind::Unknown;
      return;
    }
  }

  // Was the enum declared using *_ENUM or *_OPTIONS?
  // FIXME: Stop using these once flag_enum and enum_extensibility
  // have been adopted everywhere, or at least relegate them to Swift 3 mode
  // only.
  auto loc = decl->getLocStart();
  if (loc.isMacroID()) {
    StringRef MacroName = pp.getImmediateMacroName(loc);
    if (MacroName == "CF_ENUM" || MacroName == "__CF_NAMED_ENUM" ||
        MacroName == "OBJC_ENUM" || MacroName == "SWIFT_ENUM" ||
        MacroName == "SWIFT_ENUM_NAMED") {
      kind = EnumKind::Enum;
      return;
    }
    if (MacroName == "CF_OPTIONS" || MacroName == "OBJC_OPTIONS" ||
        MacroName == "SWIFT_OPTIONS") {
      kind = EnumKind::Options;
      return;
    }
  }

  // Hardcode a particular annoying case in the OS X headers.
  if (decl->getName() == "DYLD_BOOL") {
    kind = EnumKind::Enum;
    return;
  }

  // Fall back to the 'Unknown' path.
  kind = EnumKind::Unknown;
}