shows bundled dlls as 'needed'

[Min RK]

I'm so pleased to see a Windows wheel repair tool!

I'm trying this out because I've just made a pyzmq release with missing DLL dependencies and I'd like to use your tool to help not make that mistake in the future. However, my existing bundling is resulting in some unexpected behavior. Running on pyzmq 21 wheel for Python 3.8, I get:

Analyzing pyzmq-21.0.0-cp38-cp38-win_amd64.whl

The following dependent DLLs will be copied into the wheel.
    vcruntime140.dll (C:\Program Files\Python38\vcruntime140.dll)
    vcruntime140_1.dll (C:\Program Files\Python38\vcruntime140_1.dll)
    libzmq.cp38-win_amd64.pyd (Error: Not Found)
    msvcp140.dll (Error: Not Found)

The following dependent DLLs will not be copied into the wheel.
    advapi32.dll
    api-ms-win-crt-convert-l1-1-0.dll
    api-ms-win-crt-heap-l1-1-0.dll
    api-ms-win-crt-runtime-l1-1-0.dll
    api-ms-win-crt-stdio-l1-1-0.dll
    api-ms-win-crt-string-l1-1-0.dll
    api-ms-win-crt-utility-l1-1-0.dll
    iphlpapi.dll
    kernel32.dll
    python38.dll
    ws2_32.dll

The problem is that msvcp140.dll and libzmq.cp38-win_amd64.pyd are already present in the top-level of the wheel due to my own incomplete steps to bundle dependencies, so should be found and not added for bundling. I would also expect msvcp140.dll to be found, since it's in the compiler's runtime-redist directory. Is this not searched by default?

It can be found with:

from setuptools import msvc
from distutils.util import get_platform

vcvars = msvc.msvc14_get_vc_env(get_platform())
vcruntime = vcvars["py_vcruntime_redist"]
redist_dir, _ = os.path.split(vcruntime)

where all the vc++ redist dlls such as msvcp140.dll, vcruntime, etc. are in redist_dir. It seems like it would make sense to add this to the default search path if it exists.

[adang1345]

At the moment, ctypes.util.find_library() is used to search for dependent shared libraries. As far as I can tell, this just looks through the PATH environment variable. I agree that it makes sense to add the compiler's runtime-redist directory as well to the search path by default.

We also don't check whether a needed DLL is already in the wheel. I agree that to work with other bundling tools or techniques that already place some DLLs into the wheel, we should better handle this situation.

[Min RK]

Makes sense, thanks! I also think copying the vcruntime files from the Python root directory isn't the right thing to do, as they don't need to be shipped as a duplicate if they come with Python itself. That indicates the following changes should be made, if I understand correctly:

• if a dll is in the Python install directory, treat as "will not be copied" (should change vcruntime140, vcruntime140_1 from "will be copied" to "not copied" for Python 3.8, only vcruntime140 for Python 3.6)
• if a dll is already in the wheel, treat as "will not be copied" (pyzmq.pyd should change from "not found" to "will not be copied"). Maybe this means a general "ignore_dirs" parameter to ignore dlls if they are found in specified directories.
• maybe *\.pyd should be added to ignore_regex?
• find and add vcredist directory to PATH so that any vcredist files not already bundled with Python (or the wheel) can be bundled. I guess this is handled easily enough by setting PATH before calling the tool, but would be convenient to do by default (should change msvcp from "Not found" to "will be copied")