Re: Python recompile

On 04/03/2025 17:42, Kaz Kylheku wrote:
> On 2025-03-04, [email protected] <[email protected]> wrote:
>> On Tue, 4 Mar 2025 09:57:16 +0000
>> Richard Heathfield <[email protected]> wibbled:
>>> On 04/03/2025 09:23, [email protected] wrote:
>>>> because plenty of compilation issues are caused by code issues.
>>>
>>> Undoubtedly true, and equally undoubtedly irrelevant in this
>>> case. Were it relevant, the OP would by now have shown us the
>>> problem code.
>>
>> So what you're saying is you can't troubleshoot linking problems. Do you
>> get someone else to compile your code for you?
> 
> Python is not "your code" for any value of "your" referring to any
> regular here in comp.lang.c.
> 
>> A compiler is a compiler, a linker is a linker. Troubleshooting both is part
>> of the development process of any competent C dev. But we know already you
>> don't consider that to be the case because its beyond your abilities.
> 
> Troubleshooting an open source package build problem is often a complex
> problem that in most cases requires direct access to the environment
> where the problem is happening.
> 

The CPython source bundle doesn't come with any makefiles. The first 
step appears to be to run a 35,000-line 'configure' script. Part of its 
job appears to be generate the necessary makefiles. I see options like 
"-fPIC" inside it set according to platform type and other settings.


Maybe the OP was trying to build it independently. I tried it once on 
Windows; I was told by the people at comp.lang.python that it was a 
piece of cake; it wasn't. (I notice this is cross-posted there; I will 
keep that in.)

On Windows, CPython must be built via MSVC, not gcc.

That involving installing VS20xx, a 6GB download, which itself first 
needed a 4GB .NET update. Then I needed GIT. Then SVN. Then MSBUILD 
tools. Then something else...

Whatever I fixed, it always found something else to fail on. After 
several hours and a lot of downloads, I gave up.


> It's actually a case of porting. When Python does not build in some OS
> distro with certain compilers, that's a kind of porting challenge.

Yet CPython exists on Windows; it must work for somebody!

I'd been interested in fiddling with the source to make it faster, but 
the first thing I discovered was that on Linux, CPython makes use of 
gcc's extensions to use computed-gotos for its dispatch loop.

MSVC doesn't have that feature, so on Windows, CPython is a little bit 
slower than on Linux as it has to use a regular 'switch', because the 
developers couldn't manage to build it with gcc on Windows.