Vendor import of clang release_34 branch r197841 (effectively, 3.4 RC3):

https://llvm.org/svn/llvm-project/cfe/branches/release_34@197841

1 files changed, 385 insertions, 119 deletions

diff --git a/lib/Format/BreakableToken.cpp b/lib/Format/BreakableToken.cpp
index 3e2e0ce..d720ce9 100644
--- a/lib/Format/BreakableToken.cpp
+++ b/lib/Format/BreakableToken.cpp
@@ -13,166 +13,432 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "format-token-breaker"
+
 #include "BreakableToken.h"
+#include "clang/Basic/CharInfo.h"
+#include "clang/Format/Format.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Debug.h"
 #include <algorithm>
 
 namespace clang {
 namespace format {
 
-BreakableToken::Split BreakableComment::getSplit(unsigned LineIndex,
-                                                 unsigned TailOffset,
-                                                 unsigned ColumnLimit) const {
-  StringRef Text = getLine(LineIndex).substr(TailOffset);
-  unsigned ContentStartColumn = getContentStartColumn(LineIndex, TailOffset);
+static const char *const Blanks = " \t\v\f\r";
+static bool IsBlank(char C) {
+  switch (C) {
+  case ' ':
+  case '\t':
+  case '\v':
+  case '\f':
+  case '\r':
+    return true;
+  default:
+    return false;
+  }
+}
+
+static BreakableToken::Split getCommentSplit(StringRef Text,
+                                             unsigned ContentStartColumn,
+                                             unsigned ColumnLimit,
+                                             unsigned TabWidth,
+                                             encoding::Encoding Encoding) {
   if (ColumnLimit <= ContentStartColumn + 1)
-    return Split(StringRef::npos, 0);
+    return BreakableToken::Split(StringRef::npos, 0);
 
   unsigned MaxSplit = ColumnLimit - ContentStartColumn + 1;
-  StringRef::size_type SpaceOffset = Text.rfind(' ', MaxSplit);
+  unsigned MaxSplitBytes = 0;
+
+  for (unsigned NumChars = 0;
+       NumChars < MaxSplit && MaxSplitBytes < Text.size();) {
+    unsigned BytesInChar =
+        encoding::getCodePointNumBytes(Text[MaxSplitBytes], Encoding);
+    NumChars +=
+        encoding::columnWidthWithTabs(Text.substr(MaxSplitBytes, BytesInChar),
+                                      ContentStartColumn, TabWidth, Encoding);
+    MaxSplitBytes += BytesInChar;
+  }
+
+  StringRef::size_type SpaceOffset = Text.find_last_of(Blanks, MaxSplitBytes);
   if (SpaceOffset == StringRef::npos ||
-      Text.find_last_not_of(' ', SpaceOffset) == StringRef::npos) {
-    SpaceOffset = Text.find(' ', MaxSplit);
+      // Don't break at leading whitespace.
+      Text.find_last_not_of(Blanks, SpaceOffset) == StringRef::npos) {
+    // Make sure that we don't break at leading whitespace that
+    // reaches past MaxSplit.
+    StringRef::size_type FirstNonWhitespace = Text.find_first_not_of(Blanks);
+    if (FirstNonWhitespace == StringRef::npos)
+      // If the comment is only whitespace, we cannot split.
+      return BreakableToken::Split(StringRef::npos, 0);
+    SpaceOffset = Text.find_first_of(
+        Blanks, std::max<unsigned>(MaxSplitBytes, FirstNonWhitespace));
   }
   if (SpaceOffset != StringRef::npos && SpaceOffset != 0) {
-    StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim();
-    StringRef AfterCut = Text.substr(SpaceOffset).ltrim();
+    StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim(Blanks);
+    StringRef AfterCut = Text.substr(SpaceOffset).ltrim(Blanks);
     return BreakableToken::Split(BeforeCut.size(),
                                  AfterCut.begin() - BeforeCut.end());
   }
   return BreakableToken::Split(StringRef::npos, 0);
 }
 
-void BreakableComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
-                                   Split Split, bool InPPDirective,
-                                   WhitespaceManager &Whitespaces) {
-  StringRef Text = getLine(LineIndex).substr(TailOffset);
-  StringRef AdditionalPrefix = Decoration;
-  if (Text.size() == Split.first + Split.second) {
-    // For all but the last line handle trailing space in trimLine.
-    if (LineIndex < Lines.size() - 1)
-      return;
-    // For the last line we need to break before "*/", but not to add "* ".
-    AdditionalPrefix = "";
+static BreakableToken::Split getStringSplit(StringRef Text,
+                                            unsigned UsedColumns,
+                                            unsigned ColumnLimit,
+                                            unsigned TabWidth,
+                                            encoding::Encoding Encoding) {
+  // FIXME: Reduce unit test case.
+  if (Text.empty())
+    return BreakableToken::Split(StringRef::npos, 0);
+  if (ColumnLimit <= UsedColumns)
+    return BreakableToken::Split(StringRef::npos, 0);
+  unsigned MaxSplit = std::min<unsigned>(
+      ColumnLimit - UsedColumns,
+      encoding::columnWidthWithTabs(Text, UsedColumns, TabWidth, Encoding) - 1);
+  StringRef::size_type SpaceOffset = 0;
+  StringRef::size_type SlashOffset = 0;
+  StringRef::size_type WordStartOffset = 0;
+  StringRef::size_type SplitPoint = 0;
+  for (unsigned Chars = 0;;) {
+    unsigned Advance;
+    if (Text[0] == '\\') {
+      Advance = encoding::getEscapeSequenceLength(Text);
+      Chars += Advance;
+    } else {
+      Advance = encoding::getCodePointNumBytes(Text[0], Encoding);
+      Chars += encoding::columnWidthWithTabs(
+          Text.substr(0, Advance), UsedColumns + Chars, TabWidth, Encoding);
+    }
+
+    if (Chars > MaxSplit)
+      break;
+
+    if (IsBlank(Text[0]))
+      SpaceOffset = SplitPoint;
+    if (Text[0] == '/')
+      SlashOffset = SplitPoint;
+    if (Advance == 1 && !isAlphanumeric(Text[0]))
+      WordStartOffset = SplitPoint;
+
+    SplitPoint += Advance;
+    Text = Text.substr(Advance);
   }
 
-  unsigned WhitespaceStartColumn =
-      getContentStartColumn(LineIndex, TailOffset) + Split.first;
-  unsigned BreakOffset = Text.data() - TokenText.data() + Split.first;
-  unsigned CharsToRemove = Split.second;
-  Whitespaces.breakToken(Tok, BreakOffset, CharsToRemove, "", AdditionalPrefix,
-                         InPPDirective, IndentAtLineBreak,
-                         WhitespaceStartColumn);
+  if (SpaceOffset != 0)
+    return BreakableToken::Split(SpaceOffset + 1, 0);
+  if (SlashOffset != 0)
+    return BreakableToken::Split(SlashOffset + 1, 0);
+  if (WordStartOffset != 0)
+    return BreakableToken::Split(WordStartOffset + 1, 0);
+  if (SplitPoint != 0)
+    return BreakableToken::Split(SplitPoint, 0);
+  return BreakableToken::Split(StringRef::npos, 0);
 }
 
-BreakableBlockComment::BreakableBlockComment(const SourceManager &SourceMgr,
-                                             const AnnotatedToken &Token,
-                                             unsigned StartColumn)
-    : BreakableComment(SourceMgr, Token.FormatTok, StartColumn + 2) {
-  assert(TokenText.startswith("/*") && TokenText.endswith("*/"));
+unsigned BreakableSingleLineToken::getLineCount() const { return 1; }
+
+unsigned BreakableSingleLineToken::getLineLengthAfterSplit(
+    unsigned LineIndex, unsigned Offset, StringRef::size_type Length) const {
+  return StartColumn + Prefix.size() + Postfix.size() +
+         encoding::columnWidthWithTabs(Line.substr(Offset, Length),
+                                       StartColumn + Prefix.size(),
+                                       Style.TabWidth, Encoding);
+}
+
+BreakableSingleLineToken::BreakableSingleLineToken(
+    const FormatToken &Tok, unsigned IndentLevel, unsigned StartColumn,
+    StringRef Prefix, StringRef Postfix, bool InPPDirective,
+    encoding::Encoding Encoding, const FormatStyle &Style)
+    : BreakableToken(Tok, IndentLevel, InPPDirective, Encoding, Style),
+      StartColumn(StartColumn), Prefix(Prefix), Postfix(Postfix) {
+  assert(Tok.TokenText.startswith(Prefix) && Tok.TokenText.endswith(Postfix));
+  Line = Tok.TokenText.substr(
+      Prefix.size(), Tok.TokenText.size() - Prefix.size() - Postfix.size());
+}
+
+BreakableStringLiteral::BreakableStringLiteral(
+    const FormatToken &Tok, unsigned IndentLevel, unsigned StartColumn,
+    StringRef Prefix, StringRef Postfix, bool InPPDirective,
+    encoding::Encoding Encoding, const FormatStyle &Style)
+    : BreakableSingleLineToken(Tok, IndentLevel, StartColumn, Prefix, Postfix,
+                               InPPDirective, Encoding, Style) {}
+
+BreakableToken::Split
+BreakableStringLiteral::getSplit(unsigned LineIndex, unsigned TailOffset,
+                                 unsigned ColumnLimit) const {
+  return getStringSplit(Line.substr(TailOffset),
+                        StartColumn + Prefix.size() + Postfix.size(),
+                        ColumnLimit, Style.TabWidth, Encoding);
+}
+
+void BreakableStringLiteral::insertBreak(unsigned LineIndex,
+                                         unsigned TailOffset, Split Split,
+                                         WhitespaceManager &Whitespaces) {
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, Prefix.size() + TailOffset + Split.first, Split.second, Postfix,
+      Prefix, InPPDirective, 1, IndentLevel, StartColumn);
+}
+
+static StringRef getLineCommentPrefix(StringRef Comment) {
+  static const char *const KnownPrefixes[] = { "/// ", "///", "// ", "//" };
+  for (size_t i = 0, e = llvm::array_lengthof(KnownPrefixes); i != e; ++i)
+    if (Comment.startswith(KnownPrefixes[i]))
+      return KnownPrefixes[i];
+  return "";
+}
+
+BreakableLineComment::BreakableLineComment(
+    const FormatToken &Token, unsigned IndentLevel, unsigned StartColumn,
+    bool InPPDirective, encoding::Encoding Encoding, const FormatStyle &Style)
+    : BreakableSingleLineToken(Token, IndentLevel, StartColumn,
+                               getLineCommentPrefix(Token.TokenText), "",
+                               InPPDirective, Encoding, Style) {
+  OriginalPrefix = Prefix;
+  if (Token.TokenText.size() > Prefix.size() &&
+      isAlphanumeric(Token.TokenText[Prefix.size()])) {
+    if (Prefix == "//")
+      Prefix = "// ";
+    else if (Prefix == "///")
+      Prefix = "/// ";
+  }
+}
+
+BreakableToken::Split
+BreakableLineComment::getSplit(unsigned LineIndex, unsigned TailOffset,
+                               unsigned ColumnLimit) const {
+  return getCommentSplit(Line.substr(TailOffset), StartColumn + Prefix.size(),
+                         ColumnLimit, Style.TabWidth, Encoding);
+}
+
+void BreakableLineComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
+                                       Split Split,
+                                       WhitespaceManager &Whitespaces) {
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, OriginalPrefix.size() + TailOffset + Split.first, Split.second,
+      Postfix, Prefix, InPPDirective, /*Newlines=*/1, IndentLevel, StartColumn);
+}
+
+void BreakableLineComment::replaceWhitespace(unsigned LineIndex,
+                                             unsigned TailOffset, Split Split,
+                                             WhitespaceManager &Whitespaces) {
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, OriginalPrefix.size() + TailOffset + Split.first, Split.second, "",
+      "", /*InPPDirective=*/false, /*Newlines=*/0, /*IndentLevel=*/0,
+      /*Spaces=*/1);
+}
 
-  OriginalStartColumn =
-      SourceMgr.getSpellingColumnNumber(Tok.getStartOfNonWhitespace()) - 1;
+void
+BreakableLineComment::replaceWhitespaceBefore(unsigned LineIndex,
+                                              WhitespaceManager &Whitespaces) {
+  if (OriginalPrefix != Prefix) {
+    Whitespaces.replaceWhitespaceInToken(Tok, OriginalPrefix.size(), 0, "", "",
+                                         /*InPPDirective=*/false,
+                                         /*Newlines=*/0, /*IndentLevel=*/0,
+                                         /*Spaces=*/1);
+  }
+}
 
+BreakableBlockComment::BreakableBlockComment(
+    const FormatToken &Token, unsigned IndentLevel, unsigned StartColumn,
+    unsigned OriginalStartColumn, bool FirstInLine, bool InPPDirective,
+    encoding::Encoding Encoding, const FormatStyle &Style)
+    : BreakableToken(Token, IndentLevel, InPPDirective, Encoding, Style) {
+  StringRef TokenText(Token.TokenText);
+  assert(TokenText.startswith("/*") && TokenText.endswith("*/"));
   TokenText.substr(2, TokenText.size() - 4).split(Lines, "\n");
 
-  bool NeedsStar = true;
-  CommonPrefixLength = UINT_MAX;
-  if (Lines.size() == 1) {
-    if (Token.Parent == 0) {
-      // Standalone block comments will be aligned and prefixed with *s.
-      CommonPrefixLength = OriginalStartColumn + 1;
-    } else {
-      // Trailing comments can start on arbitrary column, and available
-      // horizontal space can be too small to align consecutive lines with
-      // the first one. We could, probably, align them to current
-      // indentation level, but now we just wrap them without indentation
-      // and stars.
-      CommonPrefixLength = 0;
-      NeedsStar = false;
-    }
-  } else {
-    for (size_t i = 1; i < Lines.size(); ++i) {
-      size_t FirstNonWhitespace = Lines[i].find_first_not_of(" ");
-      if (FirstNonWhitespace != StringRef::npos) {
-        NeedsStar = NeedsStar && (Lines[i][FirstNonWhitespace] == '*');
-        CommonPrefixLength =
-            std::min<unsigned>(CommonPrefixLength, FirstNonWhitespace);
+  int IndentDelta = StartColumn - OriginalStartColumn;
+  LeadingWhitespace.resize(Lines.size());
+  StartOfLineColumn.resize(Lines.size());
+  StartOfLineColumn[0] = StartColumn + 2;
+  for (size_t i = 1; i < Lines.size(); ++i)
+    adjustWhitespace(i, IndentDelta);
+
+  Decoration = "* ";
+  if (Lines.size() == 1 && !FirstInLine) {
+    // Comments for which FirstInLine is false can start on arbitrary column,
+    // and available horizontal space can be too small to align consecutive
+    // lines with the first one.
+    // FIXME: We could, probably, align them to current indentation level, but
+    // now we just wrap them without stars.
+    Decoration = "";
+  }
+  for (size_t i = 1, e = Lines.size(); i < e && !Decoration.empty(); ++i) {
+    // If the last line is empty, the closing "*/" will have a star.
+    if (i + 1 == e && Lines[i].empty())
+      break;
+    while (!Lines[i].startswith(Decoration))
+      Decoration = Decoration.substr(0, Decoration.size() - 1);
+  }
+
+  LastLineNeedsDecoration = true;
+  IndentAtLineBreak = StartOfLineColumn[0] + 1;
+  for (size_t i = 1; i < Lines.size(); ++i) {
+    if (Lines[i].empty()) {
+      if (i + 1 == Lines.size()) {
+        // Empty last line means that we already have a star as a part of the
+        // trailing */. We also need to preserve whitespace, so that */ is
+        // correctly indented.
+        LastLineNeedsDecoration = false;
+      } else if (Decoration.empty()) {
+        // For all other lines, set the start column to 0 if they're empty, so
+        // we do not insert trailing whitespace anywhere.
+        StartOfLineColumn[i] = 0;
       }
+      continue;
     }
+    // The first line already excludes the star.
+    // For all other lines, adjust the line to exclude the star and
+    // (optionally) the first whitespace.
+    StartOfLineColumn[i] += Decoration.size();
+    Lines[i] = Lines[i].substr(Decoration.size());
+    LeadingWhitespace[i] += Decoration.size();
+    IndentAtLineBreak = std::min<int>(IndentAtLineBreak, StartOfLineColumn[i]);
   }
-  if (CommonPrefixLength == UINT_MAX)
-    CommonPrefixLength = 0;
+  IndentAtLineBreak = std::max<unsigned>(IndentAtLineBreak, Decoration.size());
+  DEBUG({
+    llvm::dbgs() << "IndentAtLineBreak " << IndentAtLineBreak << "\n";
+    for (size_t i = 0; i < Lines.size(); ++i) {
+      llvm::dbgs() << i << " |" << Lines[i] << "| " << LeadingWhitespace[i]
+                   << "\n";
+    }
+  });
+}
+
+void BreakableBlockComment::adjustWhitespace(unsigned LineIndex,
+                                             int IndentDelta) {
+  // When in a preprocessor directive, the trailing backslash in a block comment
+  // is not needed, but can serve a purpose of uniformity with necessary escaped
+  // newlines outside the comment. In this case we remove it here before
+  // trimming the trailing whitespace. The backslash will be re-added later when
+  // inserting a line break.
+  size_t EndOfPreviousLine = Lines[LineIndex - 1].size();
+  if (InPPDirective && Lines[LineIndex - 1].endswith("\\"))
+    --EndOfPreviousLine;
 
-  Decoration = NeedsStar ? "* " : "";
+  // Calculate the end of the non-whitespace text in the previous line.
+  EndOfPreviousLine =
+      Lines[LineIndex - 1].find_last_not_of(Blanks, EndOfPreviousLine);
+  if (EndOfPreviousLine == StringRef::npos)
+    EndOfPreviousLine = 0;
+  else
+    ++EndOfPreviousLine;
+  // Calculate the start of the non-whitespace text in the current line.
+  size_t StartOfLine = Lines[LineIndex].find_first_not_of(Blanks);
+  if (StartOfLine == StringRef::npos)
+    StartOfLine = Lines[LineIndex].size();
 
-  IndentAtLineBreak =
-      std::max<int>(StartColumn - OriginalStartColumn + CommonPrefixLength, 0);
+  StringRef Whitespace = Lines[LineIndex].substr(0, StartOfLine);
+  // Adjust Lines to only contain relevant text.
+  Lines[LineIndex - 1] = Lines[LineIndex - 1].substr(0, EndOfPreviousLine);
+  Lines[LineIndex] = Lines[LineIndex].substr(StartOfLine);
+  // Adjust LeadingWhitespace to account all whitespace between the lines
+  // to the current line.
+  LeadingWhitespace[LineIndex] =
+      Lines[LineIndex].begin() - Lines[LineIndex - 1].end();
+
+  // Adjust the start column uniformly accross all lines.
+  StartOfLineColumn[LineIndex] = std::max<int>(
+      0,
+      encoding::columnWidthWithTabs(Whitespace, 0, Style.TabWidth, Encoding) +
+          IndentDelta);
 }
 
-void BreakableBlockComment::alignLines(WhitespaceManager &Whitespaces) {
-  SourceLocation TokenLoc = Tok.getStartOfNonWhitespace();
-  int IndentDelta = (StartColumn - 2) - OriginalStartColumn;
-  if (IndentDelta > 0) {
-    std::string WhiteSpace(IndentDelta, ' ');
-    for (size_t i = 1; i < Lines.size(); ++i) {
-      Whitespaces.addReplacement(
-          TokenLoc.getLocWithOffset(Lines[i].data() - TokenText.data()), 0,
-          WhiteSpace);
-    }
-  } else if (IndentDelta < 0) {
-    std::string WhiteSpace(-IndentDelta, ' ');
-    // Check that the line is indented enough.
-    for (size_t i = 1; i < Lines.size(); ++i) {
-      if (!Lines[i].startswith(WhiteSpace))
-        return;
-    }
-    for (size_t i = 1; i < Lines.size(); ++i) {
-      Whitespaces.addReplacement(
-          TokenLoc.getLocWithOffset(Lines[i].data() - TokenText.data()),
-          -IndentDelta, "");
-    }
+unsigned BreakableBlockComment::getLineCount() const { return Lines.size(); }
+
+unsigned BreakableBlockComment::getLineLengthAfterSplit(
+    unsigned LineIndex, unsigned Offset, StringRef::size_type Length) const {
+  unsigned ContentStartColumn = getContentStartColumn(LineIndex, Offset);
+  return ContentStartColumn +
+         encoding::columnWidthWithTabs(Lines[LineIndex].substr(Offset, Length),
+                                       ContentStartColumn, Style.TabWidth,
+                                       Encoding) +
+         // The last line gets a "*/" postfix.
+         (LineIndex + 1 == Lines.size() ? 2 : 0);
+}
+
+BreakableToken::Split
+BreakableBlockComment::getSplit(unsigned LineIndex, unsigned TailOffset,
+                                unsigned ColumnLimit) const {
+  return getCommentSplit(Lines[LineIndex].substr(TailOffset),
+                         getContentStartColumn(LineIndex, TailOffset),
+                         ColumnLimit, Style.TabWidth, Encoding);
+}
+
+void BreakableBlockComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
+                                        Split Split,
+                                        WhitespaceManager &Whitespaces) {
+  StringRef Text = Lines[LineIndex].substr(TailOffset);
+  StringRef Prefix = Decoration;
+  if (LineIndex + 1 == Lines.size() &&
+      Text.size() == Split.first + Split.second) {
+    // For the last line we need to break before "*/", but not to add "* ".
+    Prefix = "";
   }
 
-  for (unsigned i = 1; i < Lines.size(); ++i)
-    Lines[i] = Lines[i].substr(CommonPrefixLength + Decoration.size());
+  unsigned BreakOffsetInToken =
+      Text.data() - Tok.TokenText.data() + Split.first;
+  unsigned CharsToRemove = Split.second;
+  assert(IndentAtLineBreak >= Decoration.size());
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, BreakOffsetInToken, CharsToRemove, "", Prefix, InPPDirective, 1,
+      IndentLevel, IndentAtLineBreak - Decoration.size());
 }
 
-void BreakableBlockComment::trimLine(unsigned LineIndex, unsigned TailOffset,
-                                     unsigned InPPDirective,
-                                     WhitespaceManager &Whitespaces) {
-  if (LineIndex == Lines.size() - 1)
-    return;
+void BreakableBlockComment::replaceWhitespace(unsigned LineIndex,
+                                              unsigned TailOffset, Split Split,
+                                              WhitespaceManager &Whitespaces) {
   StringRef Text = Lines[LineIndex].substr(TailOffset);
-  if (!Text.endswith(" ") && !InPPDirective)
+  unsigned BreakOffsetInToken =
+      Text.data() - Tok.TokenText.data() + Split.first;
+  unsigned CharsToRemove = Split.second;
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, BreakOffsetInToken, CharsToRemove, "", "", /*InPPDirective=*/false,
+      /*Newlines=*/0, /*IndentLevel=*/0, /*Spaces=*/1);
+}
+
+void
+BreakableBlockComment::replaceWhitespaceBefore(unsigned LineIndex,
+                                               WhitespaceManager &Whitespaces) {
+  if (LineIndex == 0)
     return;
+  StringRef Prefix = Decoration;
+  if (Lines[LineIndex].empty()) {
+    if (LineIndex + 1 == Lines.size()) {
+      if (!LastLineNeedsDecoration) {
+        // If the last line was empty, we don't need a prefix, as the */ will
+        // line up with the decoration (if it exists).
+        Prefix = "";
+      }
+    } else if (!Decoration.empty()) {
+      // For other empty lines, if we do have a decoration, adapt it to not
+      // contain a trailing whitespace.
+      Prefix = Prefix.substr(0, 1);
+    }
+  } else {
+    if (StartOfLineColumn[LineIndex] == 1) {
+      // This line starts immediately after the decorating *.
+      Prefix = Prefix.substr(0, 1);
+    }
+  }
 
-  StringRef TrimmedLine = Text.rtrim();
-  unsigned WhitespaceStartColumn =
-      getLineLengthAfterSplit(LineIndex, TailOffset);
-  unsigned BreakOffset = TrimmedLine.end() - TokenText.data();
-  unsigned CharsToRemove = Text.size() - TrimmedLine.size() + 1;
-  Whitespaces.breakToken(Tok, BreakOffset, CharsToRemove, "", "", InPPDirective,
-                         0, WhitespaceStartColumn);
-}
-
-BreakableLineComment::BreakableLineComment(const SourceManager &SourceMgr,
-                                           const AnnotatedToken &Token,
-                                           unsigned StartColumn)
-    : BreakableComment(SourceMgr, Token.FormatTok, StartColumn) {
-  assert(TokenText.startswith("//"));
-  Decoration = getLineCommentPrefix(TokenText);
-  Lines.push_back(TokenText.substr(Decoration.size()));
-  IndentAtLineBreak = StartColumn;
-  this->StartColumn += Decoration.size(); // Start column of the contents.
-}
-
-StringRef BreakableLineComment::getLineCommentPrefix(StringRef Comment) {
-  const char *KnownPrefixes[] = { "/// ", "///", "// ", "//" };
-  for (size_t i = 0; i < llvm::array_lengthof(KnownPrefixes); ++i)
-    if (Comment.startswith(KnownPrefixes[i]))
-      return KnownPrefixes[i];
-  return "";
+  unsigned WhitespaceOffsetInToken = Lines[LineIndex].data() -
+                                     Tok.TokenText.data() -
+                                     LeadingWhitespace[LineIndex];
+  assert(StartOfLineColumn[LineIndex] >= Prefix.size());
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, WhitespaceOffsetInToken, LeadingWhitespace[LineIndex], "", Prefix,
+      InPPDirective, 1, IndentLevel,
+      StartOfLineColumn[LineIndex] - Prefix.size());
+}
+
+unsigned
+BreakableBlockComment::getContentStartColumn(unsigned LineIndex,
+                                             unsigned TailOffset) const {
+  // If we break, we always break at the predefined indent.
+  if (TailOffset != 0)
+    return IndentAtLineBreak;
+  return StartOfLineColumn[LineIndex];
 }
 
 } // namespace format