Fixes error when splitting block comments.

When trying to fall back to search from the end onwards, we
would still find leading whitespace if the leading whitespace
went on after the end of the line.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182886 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/BreakableToken.cpp b/lib/Format/BreakableToken.cpp
index c102f8b1b2955fb5c4b3638e34a5f25b57ac487b..5c3ad9cee2bc3aed1e1389f07d02803cf34759c0 100644 (file)
--- a/lib/Format/BreakableToken.cpp
+++ b/lib/Format/BreakableToken.cpp
@@ -87,8 +87,16 @@ BreakableToken::Split getCommentSplit(StringRef Text,
   StringRef::size_type SpaceOffset = Text.rfind(' ', MaxSplit);
   if (SpaceOffset == StringRef::npos ||
       // Don't break at leading whitespace.
-      Text.find_last_not_of(' ', SpaceOffset) == StringRef::npos)
-    SpaceOffset = Text.find(' ', MaxSplit);
+      Text.find_last_not_of(' ', SpaceOffset) == StringRef::npos) {
+    // Make sure that we don't break at leading whitespace that
+    // reaches past MaxSplit.
+    StringRef::size_type FirstNonWhitespace = Text.find_first_not_of(" ");
+    if (FirstNonWhitespace == StringRef::npos)
+      // If the comment is only whitespace, we cannot split.
+      return BreakableToken::Split(StringRef::npos, 0);
+    SpaceOffset =
+        Text.find(' ', std::max<unsigned>(MaxSplit, FirstNonWhitespace));
+  }
   if (SpaceOffset != StringRef::npos && SpaceOffset != 0) {
     StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim();
     StringRef AfterCut = Text.substr(SpaceOffset).ltrim();

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 18a1a008582640a3fa2d3f1a589893b21680b607..1f4f4806c3b7f2c12b5c81aefc80499340cac68e 100644 (file)
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -3694,6 +3694,33 @@ TEST_F(FormatTest, BlockCommentsInMacros) {
                    getLLVMStyleWithColumns(20)));
 }
 
+TEST_F(FormatTest, BlockCommentsAtEndOfLine) {
+  EXPECT_EQ("a = {\n"
+            "  1111 /*    */\n"
+            "};",
+            format("a = {1111\n"
+                   "/*    */\n"
+                   "};",
+                   getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("a = {\n"
+            "  1111 /*      */\n"
+            "};",
+            format("a = {1111\n"
+                   "/*      */\n"
+                   "};",
+                   getLLVMStyleWithColumns(15)));
+
+  // FIXME: The formatting is still wrong here.
+  EXPECT_EQ("a = {\n"
+            "  1111 /*      a\n"
+            "          */\n"
+            "};",
+            format("a = {1111\n"
+                   "/*      a */\n"
+                   "};",
+                   getLLVMStyleWithColumns(15)));
+}
+
 TEST_F(FormatTest, IndentLineCommentsInStartOfBlockAtEndOfFile) {
   // FIXME: This is not what we want...
   verifyFormat("{\n"