clang-format: Slightly adapt decision of when to break before <<.

Before:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa) << aaaaaaaaaaaaaaaaaaaaaaaaa(
                                              aaaaaaaaaaaaa);

After:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaa);

llvm-svn: 197690

2 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index c840c4557f5..366d26d479a 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -338,7 +338,7 @@ unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
   // short. Also always add the penalty if the LHS is split over mutliple lines
   // to avoid unncessary line breaks that just work around this penalty.
   if (Current.is(tok::lessless) && State.Stack.back().FirstLessLess == 0 &&
-      (State.Column <= Style.ColumnLimit / 2 ||
+      (State.Column <= Style.ColumnLimit / 3 ||
        State.Stack.back().BreakBeforeParameter))
     Penalty += Style.PenaltyBreakFirstLessLess;
 
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 7d58ec2ed96..db105ee3233 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -3800,6 +3800,8 @@ TEST_F(FormatTest, AlignsPipes) {
                getLLVMStyleWithColumns(70));
 
   // But sometimes, breaking before the first "<<" is desirable.
+  verifyFormat("Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)\n"
+               "    << aaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaa);");
   verifyFormat("Diag(aaaaaaaaaaaaaaaaaaaaaaaaaaaaa, bbbbbbbbb)\n"
                "    << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
                "    << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa;");