Avoid column limit violation in block comments in certain cases.

Summary:
Add penalty when an excessively long line in a block comment can not be
broken on a leading whitespace. Lack of this addition can lead to severe column
width violations when they can be easily avoided.

Reviewers: djasper

Reviewed By: djasper

CC: cfe-commits, klimek
Differential Revision: http://llvm-reviews.chandlerc.com/D1071

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185337 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/Format.cpp b/lib/Format/Format.cpp
index 7b9950a43b0151fe4611bfbc97c6a5262fef9fbf..9cfb04162e8b1135ad648b411a5733579458d56c 100644 (file)
--- a/lib/Format/Format.cpp
+++ b/lib/Format/Format.cpp
@@ -806,9 +806,10 @@ private:
   ///
   /// \returns An extra penalty if a token was broken, otherwise 0.
   ///
-  /// Note that the penalty of the token protruding the allowed line length is
-  /// already handled in \c addNextStateToQueue; the returned penalty will only
-  /// cover the cost of the additional line breaks.
+  /// The returned penalty will cover the cost of the additional line breaks and
+  /// column limit violation in all lines except for the last one. The penalty
+  /// for the column limit violation in the last line (and in single line
+  /// tokens) is handled in \c addNextStateToQueue.
   unsigned breakProtrudingToken(const FormatToken &Current, LineState &State,
                                 bool DryRun) {
     llvm::OwningPtr<BreakableToken> Token;
@@ -854,8 +855,13 @@ private:
       while (RemainingTokenColumns > RemainingSpace) {
         BreakableToken::Split Split =
             Token->getSplit(LineIndex, TailOffset, getColumnLimit());
-        if (Split.first == StringRef::npos)
+        if (Split.first == StringRef::npos) {
+          // The last line's penalty is handled in addNextStateToQueue().
+          if (LineIndex < EndIndex - 1)
+            Penalty += Style.PenaltyExcessCharacter *
+                       (RemainingTokenColumns - RemainingSpace);
           break;
+        }
         assert(Split.first != 0);
         unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
             LineIndex, TailOffset + Split.first + Split.second,

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 5227554d65c7f81fab7978c08e0a025374e326fd..affec47121482d5661065f5c341cf3e5f9eaefea 100644 (file)
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -844,6 +844,23 @@ TEST_F(FormatTest, CorrectlyHandlesLengthOfBlockComments) {
             "              aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa */",
             format("double *x; /* aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
                    "              aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa */"));
+  EXPECT_EQ(
+      "void ffffffffffff(\n"
+      "    int aaaaaaaa, int bbbbbbbb,\n"
+      "    int cccccccccccc) { /*\n"
+      "                           aaaaaaaaaa\n"
+      "                           aaaaaaaaaaaaa\n"
+      "                           bbbbbbbbbbbbbb\n"
+      "                           bbbbbbbbbb\n"
+      "                         */\n"
+      "}",
+      format("void ffffffffffff(int aaaaaaaa, int bbbbbbbb, int cccccccccccc)\n"
+             "{ /*\n"
+             "     aaaaaaaaaa aaaaaaaaaaaaa\n"
+             "     bbbbbbbbbbbbbb bbbbbbbbbb\n"
+             "   */\n"
+             "}",
+             getLLVMStyleWithColumns(40)));
 }
 
 TEST_F(FormatTest, SplitsLongCxxComments) {