Split long strings on word boundaries.

Summary: Split strings at word boundaries, when there are no spaces and slashes.

Reviewers: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1003

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184304 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/BreakableToken.cpp b/lib/Format/BreakableToken.cpp
index 48c1dee..2b559cf 100644
--- a/lib/Format/BreakableToken.cpp
+++ b/lib/Format/BreakableToken.cpp
@@ -77,6 +77,7 @@
                          encoding::getCodePointCount(Text, 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;
@@ -95,6 +96,8 @@
       SpaceOffset = SplitPoint;
     if (Text[0] == '/')
       SlashOffset = SplitPoint;
+    if (Text[0] != '\\' && !isAlphanumeric(Text[0]))
+      WordStartOffset = SplitPoint;
 
     SplitPoint += Advance;
     Text = Text.substr(Advance);
@@ -104,6 +107,8 @@
     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);
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 8454af3..15a5d6b 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -4636,6 +4636,26 @@
       "\"slashes\"",
       format("\"split/pathat/slashes\"", getLLVMStyleWithColumns(10)));
 
+  EXPECT_EQ(
+      "\"split/\"\n"
+      "\"pathat/\"\n"
+      "\"slashes\"",
+      format("\"split/pathat/slashes\"", getLLVMStyleWithColumns(10)));
+  EXPECT_EQ("\"split at \"\n"
+            "\"spaces/at/\"\n"
+            "\"slashes.at.any$\"\n"
+            "\"non-alphanumeric%\"\n"
+            "\"1111111111characte\"\n"
+            "\"rs\"",
+            format("\"split at "
+                   "spaces/at/"
+                   "slashes.at."
+                   "any$non-"
+                   "alphanumeric%"
+                   "1111111111characte"
+                   "rs\"",
+                   getLLVMStyleWithColumns(20)));
+
   FormatStyle AlignLeft = getLLVMStyleWithColumns(12);
   AlignLeft.AlignEscapedNewlinesLeft = true;
   EXPECT_EQ(