[clang-format] Handle C# where clause in SeparateDefinitionBlocks

[owenca]

Fix #61956

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: Owen Pan (owenca)

Changes

Fix #61956

---

Full diff: https://github.com/llvm/llvm-project/pull/139034.diff

2 Files Affected:

• (modified) clang/lib/Format/DefinitionBlockSeparator.cpp (+6)
• (modified) clang/unittests/Format/DefinitionBlockSeparatorTest.cpp (+5)

diff --git a/clang/lib/Format/DefinitionBlockSeparator.cpp b/clang/lib/Format/DefinitionBlockSeparator.cpp
index 319236d3bd618..c4d609083977e 100644
--- a/clang/lib/Format/DefinitionBlockSeparator.cpp
+++ b/clang/lib/Format/DefinitionBlockSeparator.cpp
@@ -137,6 +137,12 @@ void DefinitionBlockSeparator::separateBlocks(
     const auto MayPrecedeDefinition = [&](const int Direction = -1) {
       assert(Direction >= -1);
       assert(Direction <= 1);
+
+      if (Style.isCSharp() &&
+          Lines[OpeningLineIndex]->First->is(TT_CSharpGenericTypeConstraint)) {
+        return true;
+      }
+
       const size_t OperateIndex = OpeningLineIndex + Direction;
       assert(OperateIndex < Lines.size());
       const auto &OperateLine = Lines[OperateIndex];
diff --git a/clang/unittests/Format/DefinitionBlockSeparatorTest.cpp b/clang/unittests/Format/DefinitionBlockSeparatorTest.cpp
index b26b9f4f4ff62..1f4245b703fb7 100644
--- a/clang/unittests/Format/DefinitionBlockSeparatorTest.cpp
+++ b/clang/unittests/Format/DefinitionBlockSeparatorTest.cpp
@@ -574,6 +574,11 @@ TEST_F(DefinitionBlockSeparatorTest, CSharp) {
                "\r\n"
                "public class FoobarClass {\r\n"
                "  int foobar;\r\n"
+               "}\r\n"
+               "\r\n"
+               "public class LogFactory<TLogger>\r\n"
+               "    where TLogger : class, new() {\r\n"
+               "  int i;\r\n"
                "}",
                Style);
 }