[clang-format] Keep level of comment before an empty line

Summary:
This patch fixes bug https://bugs.llvm.org/show_bug.cgi?id=3313: a comment line
was aligned with the next #ifdef even in the presence of an empty line between
them.

Reviewers: djasper, klimek

Reviewed By: djasper

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D35296

llvm-svn: 307795

1 files changed, 24 insertions, 1 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index b5f959f9c1f..937362f5c9d 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -825,12 +825,35 @@ TEST_F(FormatTest, FormatsSwitchStatement) {
                "  case A:\n"
                "    f();\n"
                "    break;\n"
-               "  // On B:\n"
+               "    // fallthrough\n"
                "  case B:\n"
                "    g();\n"
                "    break;\n"
                "  }\n"
                "});");
+  EXPECT_EQ("DEBUG({\n"
+            "  switch (x) {\n"
+            "  case A:\n"
+            "    f();\n"
+            "    break;\n"
+            "  // On B:\n"
+            "  case B:\n"
+            "    g();\n"
+            "    break;\n"
+            "  }\n"
+            "});",
+            format("DEBUG({\n"
+                   "  switch (x) {\n"
+                   "  case A:\n"
+                   "    f();\n"
+                   "    break;\n"
+                   "  // On B:\n"
+                   "  case B:\n"
+                   "    g();\n"
+                   "    break;\n"
+                   "  }\n"
+                   "});",
+                   getLLVMStyle()));
   verifyFormat("switch (a) {\n"
                "case (b):\n"
                "  return;\n"