Add exception macros

internal/BUILD

@@ -107,6 +107,12 @@ cc_test(
     ],
 )
 
+cc_library(
+    name = "exceptions",
+    hdrs = ["exceptions.h"],
+    deps = ["@com_google_absl//absl/base:config"],
+)
+
 cc_library(
     name = "overloaded",
     hdrs = ["overloaded.h"],

internal/exceptions.h

@@ -0,0 +1,35 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef THIRD_PARTY_CEL_CPP_INTERNAL_EXCEPTIONS_H_
+#define THIRD_PARTY_CEL_CPP_INTERNAL_EXCEPTIONS_H_
+
+#include "absl/base/config.h"  // IWYU pragma: keep
+
+#ifdef ABSL_HAVE_EXCEPTIONS
+#define CEL_INTERNAL_TRY try
+#define CEL_INTERNAL_CATCH_ANY catch (...)
+#define CEL_INTERNAL_RETHROW \
+  do {                       \
+    throw;                   \
+  } while (false)
+#else
+#define CEL_INTERNAL_TRY if (true)
+#define CEL_INTERNAL_CATCH_ANY else if (false)
+#define CEL_INTERNAL_RETHROW \
+  do {                       \
+  } while (false)
+#endif
+
+#endif  // THIRD_PARTY_CEL_CPP_INTERNAL_EXCEPTIONS_H_