Hi,
I've been using Eigen in my software, and I've run into an issue today, caused by changing my code from building a static library to dynamic library in Windows, using Visual Studio 2013. The reason for this switch was not related to Eigen.

I am embedding Eigen in my own library file, which itself is then linked into my application(s). As mentioned before, this library had been a static library until today; I have just updated my codebase to generate a DLL file instead.

Since making this change, I am now getting the following error message from Visual Studio:

The Block at -------------------- was allocated by aligned routines, use _aligned_free()

(that this message pops up numerous times with different addresses each time; I've used dashes above, as I don't believe that the specific addresses are relevant to this issue).

choosing "retry" opens the debugger to line 255 on Memory.h

Visual studio IntelliSense (when not debugging) suggests that EIGEN_ALIGN and EIGEN_HAS_MM_MALLOC are both defined as 1, EIGEN_MALLOC_ALREADY_ALIGNED and EIGEN_HAS_POSIX_MEMALIGN are both undefined. Accordingly, it should be running _mm_free(ptr), which (again-based from IntelliSense) is an alias for _aligned_free(a). As such, it appears that this code should be running the correct function, but it isn't.

When I change the code back to a static library, this issue goes away.

The only thing remotely relevant that I found from numerous Google searches was an article from Intel Fortran Compiler saying that this error message might come from a library which was compiled in an earlier version that is called by code compiled with the latest version. Aside from the fact that I am using Visual Studio C++ 2013, I have rebuilt the code numerous times to be sure that it is all fully recompiled from a clean state and this error message persists.

I have downloaded the latest code from the mercurial repo (default branch), but this did not solve the problem.

Edit:
A short additional bit of context and clarification:
I am not trying to allocate the memory in the DLL file and de-allocate it from the client application, or something else similarly evil. The client app is my unit test framework (I'm using Google Test, although I don't think that matters in this context). The code crashes after running a specific test -- i.e. running a destructor for a temporary object.

I've tried to be as thorough as I could be. If you need any more information, please let me know.

Thanks-
Shmuel

Can you tell us the precise version of Eigen so that we can known which line corresponds line 255. Also make sure you tried with latest Eigen version.