Heap error with Google mock test framework

Question

If you download the latest version of Google Mock (1.7.0) there are project files for VS2005 and 2010! The project to test is written in VS2008,so I opened the VS2005 file and converted it for VS2008 and compiled with

• Multi-threaded Debug (/MTd)
• Dynamic Library (.dll)

In the test solution:

Project to test:

Configuration type: Dynamic Library (.dll)

Runtime library: Multi-threaded Debug (/MTd)

UnitTest project:

#include <iostream>
#include "gmock/gmock.h"
#include "gtest/gtest.h"

int main(int argc, char **argv) 
{   
    ::testing::InitGoogleMock(&argc, argv); 
    return RUN_ALL_TESTS(); 
}

Additional Library Directories: ..\..\gmock\msvc\2005\Debug

Additional Dependencies: gmock.lib gmock_main.lib

Runtime library: Multi-threaded Debug (/MTd)

If I run the UnitTest project I get following error:

Windows has triggered a breakpoint in Program_UnitTests.exe.

This may be due to a corruption of the heap, which indicates a bug in Program_UnitTests.exe or any of the DLLs it has loaded.

in xmtx.c:

_RELIABILITY_CONTRACT
void  __CLRCALL_PURE_OR_CDECL _Mtxunlock(_Rmtx *_Mtx)
    {   /* unlock mutex */
    LeaveCriticalSection(_Mtx);
#ifdef _M_CEE
    System::Threading::Thread::EndThreadAffinity();
#endif
    } // <------- STOPPED HERE
 #endif /* !_MULTI_THREAD */

What is wrong here? Thank you for any help!

Answer 1

Super-short answer: compile googlemock as a static library instead of a dll; that might fix your problem.

Much longer answer:

Problems like this are typically the result of mismatched compiler settings. These kinds of problems are a pain to diagnose, which is a large part of the reason for the following guidance given in the googletest FAQ:

If you compile Google Test and your test code using different compiler flags, they may see different definitions of the same class/function/variable (e.g. due to the use of #if in Google Test). Therefore, for your sanity, we recommend to avoid installing pre-compiled Google Test libraries. Instead, each project should compile Google Test itself such that it can be sure that the same flags are used for both Google Test and the tests.

This applies equally to googlemock. Basically, they're suggesting that you compile the googletest & googlemock source code alongside your own code to avoid this problem. They also make this quite easy: check out the fused-src directory of the gmock distribution for a voltron .cc file and the corresponding headers, gmock.h and gtest.h.

If you'd like to continue linking against a completely separate library, you'll need to verify that all of the compiler settings match in the VS project. Basically you'll need to check every single configuration in the properties dialog, paying special attention to the toolset, exceptions, preprocessor definitions, RTTI, etc.