Debugging load time error in C++ SDL2 program compiled with VS2015 on Win10

Question

I\'m writing a project in C++ with SDL2 on 64-bit Windows 10 using Visual Studio 2015. I recently purchased a new Windows 10 laptop and cloned my project from github. My pro

Answer 1

This is by no means completely reliable, but you can give it a try. It requires dumpbin.exe, which is included with Visual Studio.

First, get a list of dependent DLLs for your program, resolved against your path:

del dlls.txt
for /f %d in ('dumpbin /dependents Questless.exe ^| findstr /ic:".dll"') do @echo %~$PATH:d >> dlls.txt

Then get the bitness of each:

for /f "delims=" %d in (dlls.txt) do @echo %d & dumpbin /headers "%d" | findstr /c:"machine (x"

This will produce output like:

C:\Windows\System32\kernel32.dll
            8664 machine (x64)
C:\programs\ed23\bin\hydra.dll
             14C machine (x86)

Note that this is incorrectly using the kernel32.dll from System32, rather than the WOW6432 one, so it shows that as x64. That's because it just used the path, when the Windows loader will actually use the WOW6432 mapper, SxS, the application manifest, and only fall back on the path if none of those resolve the dependency. It also doesn't find dependents of dependents (you could script recursing through the dependents, but be sure to filter out duplicates), and of course doesn't know anything about run-time explicit dynamic loads.

Nevertheless, it's a quick way to get a short list to check, and might identify your problem.

Answer 2

Note that Dependency Walker has 32 and 64 bit version. If your application is 32-bit you should use the 32 bit version. Otherwise the Dependency Walker will see the libs to System32 and not SisWOW64. You image show 32bit and 64bit libs mixed, where 64 has error.

Answer 3

I feel profoundly dumb, but I finally figured out the real problem. I'm using the SDL font library SDL2_ttf, and I simply hadn't copied zlib.dll from the SDL2_ttf lib directory into my build directory. I don't understand why the error message was so cryptic; in the past missing DLLs have given me a helpful "foo.dll is missing" error message.

Anyway, thank you all for your help. At least I've learned a useful lesson: always make sure all the required DLLs are present before suspecting a more complex problem.