Fixed calculation of penalty when breaking tokens.

Summary:
Introduced two new style parameters: PenaltyBreakComment and
PenaltyBreakString. Add penalty for each character of a breakable token beyond
the column limit (this relates mainly to comments, as they are broken only on
whitespace). Tuned PenaltyBreakComment to prefer comment breaking over breaking
inside most binary expressions.
Fixed a bug that prevented *, & and && from being considered TT_BinaryOperator
in the presense of adjacent comments.

Reviewers: klimek, djasper

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D933

llvm-svn: 183530

1 files changed, 18 insertions, 4 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 9dd5e4a0f21..f61f1fbb3fb 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -96,6 +96,8 @@ template <> struct MappingTraits<clang::format::FormatStyle> {
     IO.mapOptional("MaxEmptyLinesToKeep", Style.MaxEmptyLinesToKeep);
     IO.mapOptional("ObjCSpaceBeforeProtocolList",
                    Style.ObjCSpaceBeforeProtocolList);
+    IO.mapOptional("PenaltyBreakComment", Style.PenaltyBreakComment);
+    IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
     IO.mapOptional("PenaltyExcessCharacter", Style.PenaltyExcessCharacter);
     IO.mapOptional("PenaltyReturnTypeOnItsOwnLine",
                    Style.PenaltyReturnTypeOnItsOwnLine);
@@ -130,6 +132,8 @@ FormatStyle getLLVMStyle() {
   LLVMStyle.IndentCaseLabels = false;
   LLVMStyle.MaxEmptyLinesToKeep = 1;
   LLVMStyle.ObjCSpaceBeforeProtocolList = true;
+  LLVMStyle.PenaltyBreakComment = 45;
+  LLVMStyle.PenaltyBreakString = 1000;
   LLVMStyle.PenaltyExcessCharacter = 1000000;
   LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 75;
   LLVMStyle.PointerBindsToType = false;
@@ -157,6 +161,8 @@ FormatStyle getGoogleStyle() {
   GoogleStyle.IndentCaseLabels = true;
   GoogleStyle.MaxEmptyLinesToKeep = 1;
   GoogleStyle.ObjCSpaceBeforeProtocolList = false;
+  GoogleStyle.PenaltyBreakComment = 45;
+  GoogleStyle.PenaltyBreakString = 1000;
   GoogleStyle.PenaltyExcessCharacter = 1000000;
   GoogleStyle.PenaltyReturnTypeOnItsOwnLine = 200;
   GoogleStyle.PointerBindsToType = true;
@@ -840,8 +846,8 @@ private:
                                        Whitespaces);
       }
       unsigned TailOffset = 0;
-      unsigned RemainingTokenColumns =
-          Token->getLineLengthAfterSplit(LineIndex, TailOffset);
+      unsigned RemainingTokenColumns = Token->getLineLengthAfterSplit(
+          LineIndex, TailOffset, StringRef::npos);
       while (RemainingTokenColumns > RemainingSpace) {
         BreakableToken::Split Split =
             Token->getSplit(LineIndex, TailOffset, getColumnLimit());
@@ -849,15 +855,23 @@ private:
           break;
         assert(Split.first != 0);
         unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
-            LineIndex, TailOffset + Split.first + Split.second);
+            LineIndex, TailOffset + Split.first + Split.second,
+            StringRef::npos);
         assert(NewRemainingTokenColumns < RemainingTokenColumns);
         if (!DryRun) {
           Token->insertBreak(LineIndex, TailOffset, Split, Line.InPPDirective,
                              Whitespaces);
         }
+        Penalty += Current.is(tok::string_literal) ? Style.PenaltyBreakString
+                                                   : Style.PenaltyBreakComment;
+        unsigned ColumnsUsed =
+            Token->getLineLengthAfterSplit(LineIndex, TailOffset, Split.first);
+        if (ColumnsUsed > getColumnLimit()) {
+          Penalty +=
+              Style.PenaltyExcessCharacter * (ColumnsUsed - getColumnLimit());
+        }
         TailOffset += Split.first + Split.second;
         RemainingTokenColumns = NewRemainingTokenColumns;
-        Penalty += Style.PenaltyExcessCharacter;
         BreakInserted = true;
       }
       PositionAfterLastLineInToken = RemainingTokenColumns;