Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/clang-tools-extra/test/clang-tidy/cert-dcl58-cpp.cpp

@@ -0,0 +1,67 @@
+// RUN: %check_clang_tidy %s cert-dcl58-cpp %t -- -- -std=c++1z -I %S/Inputs/Headers
+
+#include "system-header-simulation.h"
+
+namespace A {
+  namespace B {
+    int b;
+  }
+}
+
+namespace A {
+  namespace B {
+    int c;
+  }
+}
+
+namespace posix {
+// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: modification of 'posix' namespace can result in undefined behavior [cert-dcl58-cpp]
+  namespace vmi {
+  }
+}
+
+namespace std {
+// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: modification of 'std' namespace can
+  int stdInt;
+}
+
+namespace foobar {
+  namespace std {
+    int bar;
+  }
+}
+
+namespace posix::a {
+// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: modification of 'posix' namespace 
+}
+
+enum class MyError {
+  ErrorA,
+  ErrorB
+};
+
+namespace std {
+template <>
+struct is_error_code_enum<MyError> : std::true_type {};
+
+template<>
+void swap<MyError>(MyError &a, MyError &b);
+}
+
+enum class MyError2 {
+  Error2A,
+  Error2B
+};
+
+namespace std {
+// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: modification of 'std' namespace 
+template <>
+struct is_error_code_enum<MyError2> : std::true_type {};
+
+int foobar;
+}
+
+using namespace std;
+
+int x;
+