Simplified unit testing of sandboxing code.

sandbox/linux/seccomp-bpf/die.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SANDBOX_LINUX_SECCOMP_BPF_DIE_H__
+#define SANDBOX_LINUX_SECCOMP_BPF_DIE_H__
+
+namespace playground2 {
+
+class Die {
+ public:
+  // This is the main API for using this file. Prints a error message and
+  // exits with a fatal error.
+  #define SANDBOX_DIE(m) Die::SandboxDie(m, __FILE__, __LINE__)
+
+  // Terminate the program, even if the current sandbox policy prevents some
+  // of the more commonly used functions used for exiting.
+  // Most users would want to call SANDBOX_DIE() instead, as it logs extra
+  // information. But calling ExitGroup() is correct and in some rare cases
+  // preferable. So, we make it part of the public API.
+  static void ExitGroup() __attribute__((noreturn));
+
+  // This method gets called by SANDBOX_DIE(). There is normally no reason
+  // to call it directly unless you are defining your own exiting macro.
+  static void SandboxDie(const char *msg, const char *file, int line)
+    __attribute__((noreturn));
+
+  // Writes a message to stderr. Used as a fall-back choice, if we don't have
+  // any other way to report an error.
+  static void LogToStderr(const char *msg, const char *file, int line);
+
+  // We generally want to run all exit handlers. This means, on SANDBOX_DIE()
+  // we should be calling LOG(FATAL). But there are some situations where
+  // we just need to print a message and then terminate. This would typically
+  // happen in cases where we consume the error message internally (e.g. in
+  // unit tests or in the supportsSeccompSandbox() method).
+  static void EnableSimpleExit() { simple_exit_ = true; }
+
+ private:
+  static bool simple_exit_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Die);
+};
+
+}  // namespace
+
+#endif  // SANDBOX_LINUX_SECCOMP_BPF_DIE_H__