Treat C# using as a control statement

Contributed by jbcoe!

Summary: Unless SpaceBeforeParensOptions is set to SBPO_Never, a space will be put between `using` and `(` in C# code.

Reviewers: klimek, MyDeveloperDay, krasimir

Reviewed By: krasimir

Subscribers: MyDeveloperDay, cfe-commits

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D72144

Author: krasimirgg

clang/lib/Format/TokenAnnotator.cpp

@@ -2869,7 +2869,8 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
     // space between keywords and paren e.g. "using ("
     if (Right.is(tok::l_paren))
       if (Left.is(tok::kw_using))
-        return spaceRequiredBeforeParens(Left);
+        return Style.SpaceBeforeParens == FormatStyle::SBPO_ControlStatements ||
+               spaceRequiredBeforeParens(Right);
   } else if (Style.Language == FormatStyle::LK_JavaScript) {
     if (Left.is(TT_JsFatArrow))
       return true;

clang/unittests/Format/FormatTestCSharp.cpp

@@ -235,20 +235,46 @@ TEST_F(FormatTestCSharp, CSharpUsing) {
   Style.SpaceBeforeParens = FormatStyle::SBPO_Always;
   verifyFormat("public void foo () {\n"
                "  using (StreamWriter sw = new StreamWriter (filenameA)) {}\n"
+               "  using () {}\n"
                "}",
                Style);
 
+  // Ensure clang-format affects top-level snippets correctly.
   verifyFormat("using (StreamWriter sw = new StreamWriter (filenameB)) {}",
                Style);
 
   Style.SpaceBeforeParens = FormatStyle::SBPO_Never;
   verifyFormat("public void foo() {\n"
                "  using(StreamWriter sw = new StreamWriter(filenameB)) {}\n"
+               "  using() {}\n"
                "}",
                Style);
 
+  // Ensure clang-format affects top-level snippets correctly.
   verifyFormat("using(StreamWriter sw = new StreamWriter(filenameB)) {}",
                Style);
+
+  Style.SpaceBeforeParens = FormatStyle::SBPO_ControlStatements;
+  verifyFormat("public void foo() {\n"
+               "  using (StreamWriter sw = new StreamWriter(filenameA)) {}\n"
+               "  using () {}\n"
+               "}",
+               Style);
+
+  // Ensure clang-format affects top-level snippets correctly.
+  verifyFormat("using (StreamWriter sw = new StreamWriter(filenameB)) {}",
+               Style);
+
+  Style.SpaceBeforeParens = FormatStyle::SBPO_NonEmptyParentheses;
+  verifyFormat("public void foo() {\n"
+               "  using (StreamWriter sw = new StreamWriter (filenameA)) {}\n"
+               "  using() {}\n"
+               "}",
+               Style);
+
+  // Ensure clang-format affects top-level snippets correctly.
+  verifyFormat("using (StreamWriter sw = new StreamWriter (filenameB)) {}",
+               Style);
 }
 
 TEST_F(FormatTestCSharp, CSharpRegions) {