Windows support

[dgrunwald]

I actually started writing rust-cpython on Windows, but had to give up due to strange issues when linking against the official python binaries. Now that the x86_64-pc-windows-msvc target exists, we should give it another try.

[novocaine]

I've started working on at least getting the build script to be correct.

[dgrunwald]

Have you had any success linking against the official python27.dll on Windows?

[novocaine]

python27-sys appeared to compile fine, but there may still be issues that I didn't see because I didn't try to get rust-cpython itself to work yet.

some interesting comments here about what .rlibs actually contain: rust-lang/rust#25820

so would make sense that the issues would only come up when trying to actually create an executable, which I didn't do.

also some chatter here: https://mail.mozilla.org/pipermail/rust-dev/2014-July/010702.html

[novocaine]

okay, so once I moved the python.org's python27.dll into C:\Program Files\Rust nightly 1.2\bin\rustlib\x86_64-pc-windows-gnu\lib, the linker was able to locate but it rejects it with this when running cargo test:

note: ld: skipping incompatible C:\Program Files\Rust nightly 1.2\bin\rustlib\x86_64-pc-windows-gnu\lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:\Program Files\Rust nightly 1.2\bin\rustlib\x86_64-pc-windows-gnu\lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:/Program Files/Rust nightly 1.2/bin/rustlib/x86_64-pc-windows-gnu/bin/../lib/gcc/x86_64-w64-mingw32/4.9.1/../../../../lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:/Program Files/Rust nightly 1.2/bin/rustlib/x86_64-pc-windows-gnu/bin/../lib/gcc/x86_64-w64-mingw32/4.9.1/../../../python27.dll when searching for -lpython27
ld: skipping incompatible C:\Program Files\Rust nightly 1.2\bin\rustlib\x86_64-pc-windows-gnu\lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:\Program Files\Rust nightly 1.2\bin\rustlib\x86_64-pc-windows-gnu\lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:/Program Files/Rust nightly 1.2/bin/rustlib/x86_64-pc-windows-gnu/bin/../lib/gcc/x86_64-w64-mingw32/4.9.1/../../../../lib/python27.dll when searching for -lpython27
ld: skipping incompatible C:/Program Files/Rust nightly 1.2/bin/rustlib/x86_64-pc-windows-gnu/bin/../lib/gcc/x86_64-w64-mingw32/4.9.1/../../../python27.dll when
searching for -lpython27
ld: cannot find -lpython27

I suspect this is because I have a 64-bit rust with a 32-bit python, but the error message is opaque.

[dgrunwald]

I tried using a x86_64-pc-windows-msvc rustc, but I'm getting some missing symbols:

python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PyByteArray_Type referenced in function _ZN15bytearrayobject17PyByteArray_Check20h8e69401868e4196bTDbE
python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PyFrozenSet_Type referenced in function _ZN9setobject22PyFrozenSet_CheckExact20h7aaa0fe8c1c5aefaaTbE
python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PySet_Type referenced in function _ZN9setobject19PyAnySet_CheckExact20ha41476a56e29f32exTbE
python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PyClass_Type referenced in function _ZN11classobject13PyClass_Check20h19fdd48fccf38ff578bE
python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PyInstance_Type referenced in function _ZN11classobject16PyInstance_Check20h66ff2a8ae590f7abu9bE
python27_sys-c1b521149f9904e3.o : error LNK2019: unresolved external symbol PyCapsule_Type referenced in function _ZN9pycapsule20PyCapsule_CheckExact20h92843e2bc63353cdwicE
c:\work\rust\cpython\python27-sys\target\debug\python27_sys-c1b521149f9904e3.exe : fatal error LNK1120: 6 unresolved externals

But those symbols are exported by the .lib:

python27-sys>dumpbin /exports "c:\Program Files\Python27\libs\python27.lib" | grep PyByteArray_Type
                  PyByteArray_Type

[dgrunwald]

The missing symbols seem to always be global variables.

Looks like this is caused by missing __dllspec(dllimport) support in rust: rust-lang/rust#7196

[yunge]

Hi,

I get some issues when try the test code in windows, so windows support is not finished yet?

E:\dev\msys32\home\fu.cargo\registry\src\github.com-121aea75f9ef2ce2\cpython-0.0.3\src/python.rs:156: undefined reference to `_Py_NoneStruct'

[dgrunwald]

For the msys-version of rust (x86_64-pc-windows-gnu), I have no idea how to get the msys linker to link against pythonXY.dll.

For the msvc-version of rust (x86_64-pc-windows-msvc), I think it's currently impossible to link against pythonXY.dll due to Rust's lack of __declspec(dllimport). The linker seems to find functions but not global variables, but global variables like _Py_NoneStruct are pretty critical for python.

I've given up on Windows support for now. Feel free to dig deeper into the linker troubles.

[yunge]

Ok, I'll play it with linux. Anyway, thanks for the cool project!

[novocaine]

rust-lang/rust#25350

[dgrunwald]

The #[linked_from] attribute might help here.

[Eh2406]

Is this still "given up" on?