windows support

[dsd]

Would be great to have.

Some initial efforts here:
​https://sourceforge.net/tracker/?func=detail&aid=2819318&group_id=1674&atid=101674

[dsd]

That link is broken, here are the contents:

I began an attempt to create a libusb backend for Windows using WinUSB
which would give libusb support for >=WinXP. I began by creating a nulled
out backend struct for WinUSB to get my development environment (MSVC)
compiling properly. It turns out that though some of the functionality for
USB device access has been abstracted away, there are a lot of dependencies
that don't exist on Windows and coding semantics that aren't supported by
MSVC.

I think I've not finally got it compiling by finding or writing wrappers
for the dependencies and changing some of the code semantics. I haven't
tested my changes yet so I don't know if it still buil

I thought I would hit the compatibility bullet points here, to see if there
is a better way to abstract these incompatibilities:
* pthreads - pthreads is used for its mutex and cond variable
functionality; Windows has an incompatible set of syncro primitives, I
worked around this with http://sourceware.org/pthreads-win32/ but this
project hasn't been updated since '06
* poll - Windows doesn't have poll, it has mechanisms for similar
functionality such as WaitForMultipleObjects etc... I stole some code from
glib to make a fake poll() using those windows funcs.
* sys/time.h - This isn't even a POSIX header, it's BSD, the definitions
are pretty simple so I just patched a time.h together from some defs in
winsock2.h and the original.
* stdint.h - I know this is in the C99 standard, but MSVC doesn't have it,
I grabbed a copy made by paul hsieh
http://www.azillionmonkeys.com/qed/pstdint.h
* variadic macros - these are used for some logging functionality. I'm not
familiar with the syntax for variadic macros in GCC but I changed these
definitions to work in MSVC, I'll have to test them in GCC to see if it is
compatible.
* typeof - This is a GCC extension not supported by MSVC, I changed the
list-walking macros that used this to just take a last parameter of the
type.
* pipes - again the WinAPI has a different piping API, I worked around this
by using io.h that defines a _pipe function and a macro from glib that
defines a compatible POSIX pipe. This is the only point I had to use an
ifdef in the code to include io.h and fcntl.h instead of unistd.h on MSVC.

I would love to maybe abstract these dependencies away instead of creating
such a fragile framework of stand-ins. Perhaps using alternatives that are
cross-platform, or pulling the platform specific pieces out into different
source files so that the implementation can be swapped out easily.

I'm going to see if I can rig something up for testing so that I can tell
if this port actually works properly (it compiles! now whats a segfault?).
Once I've verified the functionality I can send in a patch for the changes
I've made.

I would love to hear some input on how you guys think this should proceed,
I really want to make libUSB work for my projects on all platforms!

- Josh Perry

[stuge]

Is there an email address for Josh Perry in the SF tracker archive? He should be added to this ticket.

It would be awesome to have his code!

[xiaofan]

Status here: it is now code-frozen and waiting for integration into the main branch. Pete Batard is the main developer.
​http://www.libusb.org/wiki/windows_backend

[pbatard]

In [bb108cbe39802785d10fe025b74ca5ee19734151/libusb]:

Windows: MS project files part 4 - MSVC6 project files

Fixes #57 and #1.