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Diffstat (limited to 'base/check_handler.h')
| -rw-r--r-- | base/check_handler.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/base/check_handler.h b/base/check_handler.h new file mode 100644 index 0000000..cf6dd67 --- /dev/null +++ b/base/check_handler.h @@ -0,0 +1,112 @@ +// Copyright 2008, 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. + +#ifndef BASE_CHECK_HANDLER_H__ +#define BASE_CHECK_HANDLER_H__ + +#include <windows.h> + +#include "base/logging.h" + +// This class allows temporary handling of assert firing. When a CHECK() +// or DCHECK() assertion happens it will in turn generate a SEH exception +// which can be can captured using a windows SEH hander __try .. _except +// block. One practical use of this class is for unit tests that make sure +// CHECK conditions are appropriately handled. For example: +// +// TEST(TestGroup, VerifyAssert) { +// CheckAssertHandler expect_exception; +// __try { +// MyClass object; // MyClass dtor will not be called. +// Param some_bad_param; +// object.Method(some_bad_param); // Should triggers a CHECK(). +// ADD_FAILURE(); // If we get here the test failed. +// } __except(EXCEPTION_EXECUTE_HANDLER) { +// DWORD ecode = GetExceptionCode(); +// EXPECT_EQ(CheckAssertHandler::seh_exception_code(), ecode); +// } +// } +// +// You can put MyClass outside the __try block so its destructor will be +// called which could lead to a crash if the state of the object is +// corrupted by the CHECK you are testing. If that is the case you should +// fix the state of the object inside the __except block. +// +// Since the above code is Windows specific, two helper macros are provided +// that hide the implementation details. Using the macros the code becomes: +// +// TEST(TestGroup, VerifyAssert) { +// CHECK_HANDLER_BEGIN +// MyClass object; // MyClass dtor will not be called. +// Param some_bad_param; +// object.Method(some_bad_param); // Should triggers a CHECK(). +// CHECK_HANDLER_END +// } +// +// Depending on the compiler settings you might have issue this pragma arround +// the code that uses this class: +// #pragma warning(disable: 4509) +// Which tells the compiler that is ok that some dtors will not be called. +// +// Create this object on the stack always.Do not create it inside the +// __try block itself or the dtor will never be called. Create only one +// on each scope. +// +// The key detail here is the RaiseException() call which transfers +// program control away from the code that caused the assertion and back +// into the _except block. + +class CheckAssertHandler { + public: + // Installs the assert handler. The dtor will remove the handler. + CheckAssertHandler() { + logging::SetLogAssertHandler(&CheckAssertHandler::LogAssertHandler); + } + ~CheckAssertHandler() { + logging::SetLogAssertHandler(NULL); + } + static DWORD seh_exception_code() { return 0x1765413; } + private: + static void LogAssertHandler(const std::string&) { + ::RaiseException(seh_exception_code(), 0, 0, NULL); + } +}; + +#define CHECK_HANDLER_BEGIN \ + CheckAssertHandler chk_ex_handler; \ + __try { + +#define CHECK_HANDLER_END \ + ADD_FAILURE(); \ + } __except(EXCEPTION_EXECUTE_HANDLER) { \ + DWORD ecode = GetExceptionCode(); \ + EXPECT_EQ(CheckAssertHandler::seh_exception_code(), ecode); \ + } + +#endif // BASE_CHECK_HANDLER_H__ |