[CodeGen][counted_by] Support use of the comma operator (#151776)

Writing something like this:

  __builtin_dynamic_object_size((0, p->array), 0)

is equivalent to writing this:

  __builtin_dynamic_object_size(p->array, 0)

though the former will give a warning about the first value being
unused.

1 files changed, 3 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index e1f7ea0..a648bde 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -973,6 +973,9 @@ public:
     AddrOfSeen = false;
     return Visit(E->getSubExpr());
   }
+  const Expr *VisitBinaryOperator(const clang::BinaryOperator *Op) {
+    return Op->isCommaOp() ? Visit(Op->getRHS()) : nullptr;
+  }
 };
 
 } // end anonymous namespace