ExcCrashRecoverOriginalException()

util/mach/exc_server_variants.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // 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
 //
 //     http://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,
@@ skipping 411 matching lines @@
                                        mach_msg_type_number_t old_state_count,
                                        thread_state_t new_state,
                                        mach_msg_type_number_t* new_state_count,
                                        bool* destroy_complex_request) override;
 
  private:
   internal::SimplifiedExcServer exc_server_;
   internal::SimplifiedMachExcServer mach_exc_server_;
 };
 
+//! \brief Recovers the original exception, first exception code, and signal
+//!     from the encoded form of the first exception code delivered with
+//!     `EXC_CRASH` exceptions.
+//!
+//! `EXC_CRASH` exceptions are generated when the kernel has committed to
+//! terminating a process as a result of a core-generating POSIX signal and, for
+//! hardware exceptions, an earlier Mach exception. Information about this
+//! earlier exception and signal is made available to the `EXC_CRASH` handler
+//! via its `code[0]` parameter. This function recovers the original exception,
+//! the value of `code[0]` from the original exception, and the value of the
+//! signal responsible for process termination.
+//!
+//! \param[in] code_0 The first exception code (`code[0]`) passed to a Mach
+//!     exception handler in an `EXC_CRASH` exception. It is invalid to call
+//!     this function with an exception code from any exception other than
+//!     `EXC_CRASH`.
+//! \param[out] original_code_0 The first exception code (`code[0]`) passed to
+//!     the Mach exception handler for a hardware exception that resulted in the
+//!     generation of a POSIX signal that caused process termination. If the
+//!     signal that caused termination was not sent as a result of a hardware
+//!     exception, this will be `0`. Callers that do not need this value may
+//!     pass `NULL`.
+//! \param[out] signal The POSIX signal that caused process termination. Callers
+//!     that do not need this value may pass `NULL`.
+//!
+//! \return The original exception for a hardware exception that resulted in the
+//!     generation of a POSIX signal that caused process termination. If the
+//!     signal that caused termination was not sent as a result of a hardware
+//!     exception, this will be `0`.
+exception_type_t ExcCrashRecoverOriginalException(
+    mach_exception_data_type_t code_0,
+    mach_exception_data_type_t* original_code_0,
+    int* signal);
+
 //! \brief Computes an approriate successful return value for an exception
 //!     handler function.
 //!
 //! For exception handlers that respond to state-carrying behaviors, when the
 //! handler is called by the kernel (as it is normally), the kernel will attempt
 //! to set a new thread state when the exception handler returns successfully.
 //! Other code that mimics the kernel’s exception-delivery semantics may
 //! implement the same or similar behavior. In some situations, it is
 //! undesirable to set a new thread state. If the exception handler were to
 //! return unsuccessfully, however, the kernel would continue searching for an
@@ skipping 33 matching lines @@
 //!     \a behavior is not a state-carrying behavior, or when it is a
 //!     state-carrying behavior and \a set_thread_state is `true`.
 //!     `MACH_RCV_PORT_DIED` is used when \a behavior is a state-carrying
 //!     behavior and \a set_thread_state is `false`.
 kern_return_t ExcServerSuccessfulReturnValue(exception_behavior_t behavior,
                                              bool set_thread_state);
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_MACH_EXC_SERVER_VARIANTS_H_