clang-format: Make alignment of trailing comments optional ..

.. in order to support WebKit style properly.

llvm-svn: 187549

clang/include/clang/Format/Format.h

@@ -131,6 +131,9 @@ struct FormatStyle {
   /// Foo <Protocol> instead of Foo<Protocol>.
   bool ObjCSpaceBeforeProtocolList;
 
+  /// \brief If \c true, aligns trailing comments.
+  bool AlignTrailingComments;
+
   /// \brief If \c true, aligns escaped newlines as far left as possible.
   /// Otherwise puts them into the right-most column.
   bool AlignEscapedNewlinesLeft;
@@ -188,6 +191,7 @@ struct FormatStyle {
   bool operator==(const FormatStyle &R) const {
     return AccessModifierOffset == R.AccessModifierOffset &&
            AlignEscapedNewlinesLeft == R.AlignEscapedNewlinesLeft &&
+           AlignTrailingComments == R.AlignTrailingComments &&
            AllowAllParametersOfDeclarationOnNextLine ==
                R.AllowAllParametersOfDeclarationOnNextLine &&
            AllowShortIfStatementsOnASingleLine ==

clang/lib/Format/Format.cpp

@@ -91,6 +91,7 @@ template <> struct MappingTraits<clang::format::FormatStyle> {
 
     IO.mapOptional("AccessModifierOffset", Style.AccessModifierOffset);
     IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlinesLeft);
+    IO.mapOptional("AlignTrailingComments", Style.AlignTrailingComments);
     IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
                    Style.AllowAllParametersOfDeclarationOnNextLine);
     IO.mapOptional("AllowShortIfStatementsOnASingleLine",
@@ -153,6 +154,7 @@ FormatStyle getLLVMStyle() {
   FormatStyle LLVMStyle;
   LLVMStyle.AccessModifierOffset = -2;
   LLVMStyle.AlignEscapedNewlinesLeft = false;
+  LLVMStyle.AlignTrailingComments = true;
   LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
   LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
   LLVMStyle.AllowShortLoopsOnASingleLine = false;
@@ -188,6 +190,7 @@ FormatStyle getGoogleStyle() {
   FormatStyle GoogleStyle;
   GoogleStyle.AccessModifierOffset = -1;
   GoogleStyle.AlignEscapedNewlinesLeft = true;
+  GoogleStyle.AlignTrailingComments = true;
   GoogleStyle.AllowAllParametersOfDeclarationOnNextLine = true;
   GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
   GoogleStyle.AllowShortLoopsOnASingleLine = true;
@@ -245,6 +248,7 @@ FormatStyle getMozillaStyle() {
 FormatStyle getWebKitStyle() {
   FormatStyle Style = getLLVMStyle();
   Style.AccessModifierOffset = -4;
+  Style.AlignTrailingComments = false;
   Style.BreakBeforeBinaryOperators = true;
   Style.BreakBeforeBraces = FormatStyle::BS_Stroustrup;
   Style.BreakConstructorInitializersBeforeComma = true;

clang/lib/Format/WhitespaceManager.cpp

@@ -124,6 +124,8 @@ void WhitespaceManager::alignTrailingComments() {
     unsigned ChangeMaxColumn = Style.ColumnLimit - Changes[i].TokenLength;
     Newlines += Changes[i].NewlinesBefore;
     if (Changes[i].IsTrailingComment) {
+      // If this comment follows an } in column 0, it probably documents the
+      // closing of a namespace and we don't want to align it.
       bool FollowsRBraceInColumn0 = i > 0 && Changes[i].NewlinesBefore == 0 &&
                                     Changes[i - 1].Kind == tok::r_brace &&
                                     Changes[i - 1].StartOfTokenColumn == 0;
@@ -140,9 +142,7 @@ void WhitespaceManager::alignTrailingComments() {
                Changes[i + 1].OriginalWhitespaceRange.getEnd())) &&
           // Which is not a comment itself.
           Changes[i + 1].Kind != tok::comment;
-      if (FollowsRBraceInColumn0) {
-        // If this comment follows an } in column 0, it probably documents the
-        // closing of a namespace and we don't want to align it.
+      if (!Style.AlignTrailingComments || FollowsRBraceInColumn0) {
         alignTrailingComments(StartOfSequence, i, MinColumn);
         MinColumn = ChangeMinColumn;
         MaxColumn = ChangeMinColumn;

clang/unittests/Format/FormatTest.cpp

@@ -5472,6 +5472,7 @@ TEST_F(FormatTest, ParsesConfiguration) {
   EXPECT_FALSE(Style.FIELD);
 
   CHECK_PARSE_BOOL(AlignEscapedNewlinesLeft);
+  CHECK_PARSE_BOOL(AlignTrailingComments);
   CHECK_PARSE_BOOL(AllowAllParametersOfDeclarationOnNextLine);
   CHECK_PARSE_BOOL(AllowShortIfStatementsOnASingleLine);
   CHECK_PARSE_BOOL(AllowShortLoopsOnASingleLine);
@@ -5679,9 +5680,9 @@ TEST_F(FormatTest, FormatsWithWebKitStyle) {
                Style);
 
   // Do not align comments.
-  // FIXME: Implement option to suppress comment alignment.
-  // verifyFormat("int a; // Do not\n"
-  //              "double b; // align comments.");
+  verifyFormat("int a; // Do not\n"
+               "double b; // align comments.",
+               Style);
 
   // Accept input's line breaks.
   EXPECT_EQ("if (aaaaaaaaaaaaaaa\n"