[clang-format] Add a SortUsingDeclaration option and enable it by default

Summary:
This patch adds a `SortUsingDeclaration` style option and enables it for llvm
style.

Reviewers: klimek

Reviewed By: klimek

Subscribers: klimek

Differential Revision: https://reviews.llvm.org/D34453

llvm-svn: 306094

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index b43f735d4cb..64bb28e0be2 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -9333,6 +9333,7 @@ TEST_F(FormatTest, ParsesConfigurationBools) {
   CHECK_PARSE_BOOL(Cpp11BracedListStyle);
   CHECK_PARSE_BOOL(ReflowComments);
   CHECK_PARSE_BOOL(SortIncludes);
+  CHECK_PARSE_BOOL(SortUsingDeclarations);
   CHECK_PARSE_BOOL(SpacesInParentheses);
   CHECK_PARSE_BOOL(SpacesInSquareBrackets);
   CHECK_PARSE_BOOL(SpacesInAngles);
@@ -10874,6 +10875,13 @@ TEST_F(ReplacementTest, SortIncludesAfterReplacement) {
   EXPECT_EQ(Expected, *Result);
 }
 
+TEST_F(FormatTest, FormatSortsUsingDeclarations) {
+  EXPECT_EQ("using std::cin;\n"
+            "using std::cout;",
+            format("using std::cout;\n"
+                   "using std::cin;", getGoogleStyle()));
+}
+
 TEST_F(FormatTest, UTF8CharacterLiteralCpp03) {
   format::FormatStyle Style = format::getLLVMStyle();
   Style.Standard = FormatStyle::LS_Cpp03;