text: // Copyright 2005, Google Inc.
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  // Authors: wan@google.com (Zhanyong Wan), eefacm@gmail.com (Sean Mcafee)
  //
  // The Google C++ Testing Framework (Google Test)
  //
  // This header file defines internal utilities needed for implementing
  // death tests.  They are subject to change without notice.
  
  #ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
  #define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
  
  #include "gtest-internal.h"
  
  #include <stdio.h>
  
  namespace testing {
  namespace internal {
  
  GTEST_DECLARE_string_(internal_run_death_test);
  
  // Names of the flags (needed for parsing Google Test flags).
  const char kDeathTestStyleFlag[] = "death_test_style";
  const char kDeathTestUseFork[] = "death_test_use_fork";
  const char kInternalRunDeathTestFlag[] = "internal_run_death_test";
  
  #if GTEST_HAS_DEATH_TEST
  
  // DeathTest is a class that hides much of the complexity of the
  // GTEST_DEATH_TEST_ macro.  It is abstract; its static Create method
  // returns a concrete class that depends on the prevailing death test
  // style, as defined by the --gtest_death_test_style and/or
  // --gtest_internal_run_death_test flags.
  
  // In describing the results of death tests, these terms are used with
  // the corresponding definitions:
  //
  // exit status:  The integer exit information in the format specified
  //               by wait(2)
  // exit code:    The integer code passed to exit(3), _exit(2), or
  //               returned from main()
  class GTEST_API_ DeathTest {
   public:
    // Create returns false if there was an error determining the
    // appropriate action to take for the current death test; for example,
    // if the gtest_death_test_style flag is set to an invalid value.
    // The LastMessage method will return a more detailed message in that
    // case.  Otherwise, the DeathTest pointer pointed to by the "test"
    // argument is set.  If the death test should be skipped, the pointer
    // is set to NULL; otherwise, it is set to the address of a new concrete
    // DeathTest object that controls the execution of the current test.
    static bool Create(const char* statement, const RE* regex,
                       const char* file, int line, DeathTest** test);
    DeathTest();
    virtual ~DeathTest() { }
  
    // A helper class that aborts a death test when it's deleted.
    class ReturnSentinel {
     public:
      explicit ReturnSentinel(DeathTest* test) : test_(test) { }
      ~ReturnSentinel() { test_->Abort(TEST_ENCOUNTERED_RETURN_STATEMENT); }
     private:
      DeathTest* const test_;
      GTEST_DISALLOW_COPY_AND_ASSIGN_(ReturnSentinel);
    } GTEST_ATTRIBUTE_UNUSED_;
  
    // An enumeration of possible roles that may be taken when a death
    // test is encountered.  EXECUTE means that the death test logic should
    // be executed immediately.  OVERSEE means that the program should prepare
    // the appropriate environment for a child process to execute the death
    // test, then wait for it to complete.
    enum TestRole { OVERSEE_TEST, EXECUTE_TEST };
  
    // An enumeration of the three reasons that a test might be aborted.
    enum AbortReason {
      TEST_ENCOUNTERED_RETURN_STATEMENT,
      TEST_THREW_EXCEPTION,
      TEST_DID_NOT_DIE
    };
  
    // Assumes one of the above roles.
    virtual TestRole AssumeRole() = 0;
  
    // Waits for the death test to finish and returns its status.
    virtual int Wait() = 0;
  
    // Returns true if the death test passed; that is, the test process
    // exited during the test, its exit status matches a user-supplied
    // predicate, and its stderr output matches a user-supplied regular
    // expression.
    // The user-supplied predicate may be a macro expression rather
    // than a function pointer or functor, or else Wait and Passed could
    // be combined.
    virtual bool Passed(bool exit_status_ok) = 0;
  
    // Signals that the death test did not die as expected.
    virtual void Abort(AbortReason reason) = 0;
  
    // Returns a human-readable outcome message regarding the outcome of
    // the last death test.
    static const char* LastMessage();
  
    static void set_last_death_test_message(const std::string& message);
  
   private:
    // A string containing a description of the outcome of the last death test.
    static std::string last_death_test_message_;
  
    GTEST_DISALLOW_COPY_AND_ASSIGN_(DeathTest);
  };
  
  // Factory interface for death tests.  May be mocked out for testing.
  class DeathTestFactory {
   public:
    virtual ~DeathTestFactory() { }
    virtual bool Create(const char* statement, const RE* regex,
                        const char* file, int line, DeathTest** test) = 0;
  };
  
  // A concrete DeathTestFactory implementation for normal use.
  class DefaultDeathTestFactory : public DeathTestFactory {
   public:
    virtual bool Create(const char* statement, const RE* regex,
                        const char* file, int line, DeathTest** test);
  };
  
  // Returns true if exit_status describes a process that was terminated
  // by a signal, or exited normally with a nonzero exit code.
  GTEST_API_ bool ExitedUnsuccessfully(int exit_status);
  
  // Traps C++ exceptions escaping statement and reports them as test
  // failures. Note that trapping SEH exceptions is not implemented here.
  # if GTEST_HAS_EXCEPTIONS
  #  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
    try { \
      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
    } catch (const ::std::exception& gtest_exception) { \
      fprintf(\
          stderr, \
          "\n%s: Caught std::exception-derived exception escaping the " \
          "death test statement. Exception message: %s\n", \
          ::testing::internal::FormatFileLocation(__FILE__, __LINE__).c_str(), \
          gtest_exception.what()); \
      fflush(stderr); \
      death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
    } catch (...) { \
      death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
    }
  
  # else
  #  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
  
  # endif
  
  // This macro is for implementing ASSERT_DEATH*, EXPECT_DEATH*,
  // ASSERT_EXIT*, and EXPECT_EXIT*.
  # define GTEST_DEATH_TEST_(statement, predicate, regex, fail) \
    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
    if (::testing::internal::AlwaysTrue()) { \
      const ::testing::internal::RE& gtest_regex = (regex); \
      ::testing::internal::DeathTest* gtest_dt; \
      if (!::testing::internal::DeathTest::Create(#statement, &gtest_regex, \
          __FILE__, __LINE__, &gtest_dt)) { \
        goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__); \
      } \
      if (gtest_dt != NULL) { \
        ::testing::internal::scoped_ptr< ::testing::internal::DeathTest> \
            gtest_dt_ptr(gtest_dt); \
        switch (gtest_dt->AssumeRole()) { \
          case ::testing::internal::DeathTest::OVERSEE_TEST: \
            if (!gtest_dt->Passed(predicate(gtest_dt->Wait()))) { \
              goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__); \
            } \
            break; \
          case ::testing::internal::DeathTest::EXECUTE_TEST: { \
            ::testing::internal::DeathTest::ReturnSentinel \
                gtest_sentinel(gtest_dt); \
            GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, gtest_dt); \
            gtest_dt->Abort(::testing::internal::DeathTest::TEST_DID_NOT_DIE); \
            break; \
          } \
          default: \
            break; \
        } \
      } \
    } else \
      GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__): \
        fail(::testing::internal::DeathTest::LastMessage())
  // The symbol "fail" here expands to something into which a message
  // can be streamed.
  
  // This macro is for implementing ASSERT/EXPECT_DEBUG_DEATH when compiled in
  // NDEBUG mode. In this case we need the statements to be executed, the regex is
  // ignored, and the macro must accept a streamed message even though the message
  // is never printed.
  # define GTEST_EXECUTE_STATEMENT_(statement, regex) \
    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
    if (::testing::internal::AlwaysTrue()) { \
       GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
    } else \
      ::testing::Message()
  
  // A class representing the parsed contents of the
  // --gtest_internal_run_death_test flag, as it existed when
  // RUN_ALL_TESTS was called.
  class InternalRunDeathTestFlag {
   public:
    InternalRunDeathTestFlag(const std::string& a_file,
                             int a_line,
                             int an_index,
                             int a_write_fd)
        : file_(a_file), line_(a_line), index_(an_index),
          write_fd_(a_write_fd) {}
  
    ~InternalRunDeathTestFlag() {
      if (write_fd_ >= 0)
        posix::Close(write_fd_);
    }
  
    const std::string& file() const { return file_; }
    int line() const { return line_; }
    int index() const { return index_; }
    int write_fd() const { return write_fd_; }
  
   private:
    std::string file_;
    int line_;
    int index_;
    int write_fd_;
  
    GTEST_DISALLOW_COPY_AND_ASSIGN_(InternalRunDeathTestFlag);
  };
  
  // Returns a newly created InternalRunDeathTestFlag object with fields
  // initialized from the GTEST_FLAG(internal_run_death_test) flag if
  // the flag is specified; otherwise returns NULL.
  InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag();
  
  #else  // GTEST_HAS_DEATH_TEST
  
  // This macro is used for implementing macros such as
  // EXPECT_DEATH_IF_SUPPORTED and ASSERT_DEATH_IF_SUPPORTED on systems where
  // death tests are not supported. Those macros must compile on such systems
  // iff EXPECT_DEATH and ASSERT_DEATH compile with the same parameters on
  // systems that support death tests. This allows one to write such a macro
  // on a system that does not support death tests and be sure that it will
  // compile on a death-test supporting system.
  //
  // Parameters:
  //   statement -  A statement that a macro such as EXPECT_DEATH would test
  //                for program termination. This macro has to make sure this
  //                statement is compiled but not executed, to ensure that
  //                EXPECT_DEATH_IF_SUPPORTED compiles with a certain
  //                parameter iff EXPECT_DEATH compiles with it.
  //   regex     -  A regex that a macro such as EXPECT_DEATH would use to test
  //                the output of statement.  This parameter has to be
  //                compiled but not evaluated by this macro, to ensure that
  //                this macro only accepts expressions that a macro such as
  //                EXPECT_DEATH would accept.
  //   terminator - Must be an empty statement for EXPECT_DEATH_IF_SUPPORTED
  //                and a return statement for ASSERT_DEATH_IF_SUPPORTED.
  //                This ensures that ASSERT_DEATH_IF_SUPPORTED will not
  //                compile inside functions where ASSERT_DEATH doesn't
  //                compile.
  //
  //  The branch that has an always false condition is used to ensure that
  //  statement and regex are compiled (and thus syntactically correct) but
  //  never executed. The unreachable code macro protects the terminator
  //  statement from generating an 'unreachable code' warning in case
  //  statement unconditionally returns or throws. The Message constructor at
  //  the end allows the syntax of streaming additional messages into the
  //  macro, for compilational compatibility with EXPECT_DEATH/ASSERT_DEATH.
  # define GTEST_UNSUPPORTED_DEATH_TEST_(statement, regex, terminator) \
      GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
      if (::testing::internal::AlwaysTrue()) { \
        GTEST_LOG_(WARNING) \
            << "Death tests are not supported on this platform.\n" \
            << "Statement '" #statement "' cannot be verified."; \
      } else if (::testing::internal::AlwaysFalse()) { \
        ::testing::internal::RE::PartialMatch(".*", (regex)); \
        GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
        terminator; \
      } else \
        ::testing::Message()
  
  #endif  // GTEST_HAS_DEATH_TEST
  
  }  // namespace internal
  }  // namespace testing
  
  #endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
  