[clang-format] Do not interpret C# deconstruction in a foreach as a cast

Reviewers: krasimir

Reviewed By: krasimir

Subscribers: cfe-commits, MyDeveloperDay

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D78295

clang/lib/Format/TokenAnnotator.cpp

@@ -1775,6 +1775,10 @@ class AnnotatingParser {
     if (Tok.Next->is(tok::question))
       return false;
 
+    // `foreach((A a, B b) in someList)` should not be seen as a cast.
+    if (Tok.Next->is(Keywords.kw_in) && Style.isCSharp())
+      return false;
+
     // Functions which end with decorations like volatile, noexcept are unlikely
     // to be casts.
     if (Tok.Next->isOneOf(tok::kw_noexcept, tok::kw_volatile, tok::kw_const,

clang/unittests/Format/FormatTestCSharp.cpp

@@ -624,6 +624,7 @@ TEST_F(FormatTestCSharp, CSharpSpaces) {
   Style.SpaceBeforeCpp11BracedList = true;
   Style.Cpp11BracedListStyle = false;
   Style.SpacesInContainerLiterals = false;
+  Style.SpaceAfterCStyleCast = false;
 
   verifyFormat(R"(new Car { "Door", 0.1 })", Style);
   verifyFormat(R"(new Car { 0.1, "Door" })", Style);
@@ -642,6 +643,12 @@ TEST_F(FormatTestCSharp, CSharpSpaces) {
 
   verifyFormat(R"(char[,,] rawCharArray = MakeCharacterGrid();)", Style);
 
+  // Not seen as a C-style cast.
+  verifyFormat(R"(//
+foreach ((A a, B b) in someList) {
+})",
+               Style);
+
   Style.SpacesInSquareBrackets = true;
   verifyFormat(R"(private float[ , ] Values;)", Style);
   verifyFormat(R"(string dirPath = args?[ 0 ];)", Style);