Add the ability to defer the initialization of the SyzyAsan crash reporter.

syzygy/agent/asan/rtl_impl.h

 // Copyright 2012 Google Inc. 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 87 matching lines @@
 
 // @name Experiment state enumerator, used to expose SyzyASAN experiments to
 //     the client and from there to e.g. finch.
 // @{
 // Called once for each experiment.
 // @param experiment_name the name of the experiement.
 // @param experiment_group the selected group for this instance of this
 //    experiement.
 typedef void(WINAPI* AsanExperimentCallback)(const char* experiment_name,
                                              const char* experiment_group);
-// Calls @p callback once for each experiement this runtime is performing.
+// Calls @p callback once for each experiment this runtime is performing.
 // @param callback a function that will be invoked recursively zero or more
 //     times to enumerate the experiments and their state.
 void WINAPI asan_EnumExperiments(AsanExperimentCallback callback);
 // @}
 
 int asan_CrashForException(EXCEPTION_POINTERS* exception);
 
+// This functions allows to manually initialize the crash reporter used by the

[chrisha, 2017/01/13 18:16:26]

allows manually initializing* and* is* used

[Sébastien Marchand, 2017/01/13 20:56:02]

Done.

+// runtime.
+//
+// It should only be used if the deferred initialization flag has been used by
+// the instrumented image (via the corresponding environment variable or at
+// instrumentation time) and should only be called once, trying to initialize

[chrisha, 2017/01/13 18:16:26]

once. Trying to initialize the crash handler a second time will result in
undefined behaviour.

[Sébastien Marchand, 2017/01/13 20:56:02]

Done.

+// the crash handler will result in a crash of the runtime library.
+//
+// Manually controlling the initialization of the crash reporter is useful when
+// there's no crash reporter available at initialization time (i.e. the
+// instrumented process hasn't initialized it yet). E.g. the instrumented image
+// should do something like this (additionally to using the deferred
+// initialization flag):

[chrisha, 2017/01/13 18:16:26]

In addition to instrumenting with the deferred initialization flag, the
instrumented image should do something like the following:

...

[Sébastien Marchand, 2017/01/13 20:56:02]

Done.

+//
+//   InitializeCrashReporter();
+//   typedef VOID(WINAPI* SyzyAsanInitializeCrashHandlerFn)();
+//   HMODULE handle = ::GetModuleHandle(L"syzyasan_rtl.dll");
+//   SyzyAsanInitializeCrashHandlerFn syzyasan_init_crash_handler =
+//       reinterpret_cast<SyzyAsanInitializeCrashHandlerFn>(
+//             ::GetProcAddress(handle, "asan_InitializeCrashHandler"));
+//   syzyasan_init_crash_handler();
+void WINAPI asan_InitializeCrashReporter();
+
 }  // extern "C"
 
 #endif  // SYZYGY_AGENT_ASAN_RTL_IMPL_H_