Hitchikers Guide to Porting Phobos / D Runtime to other architectures

[Iain Buclaw]

On 4 December 2013 01:38, Mike <none at none.com> wrote:
> On Tuesday, 3 December 2013 at 09:28:11 UTC, Iain Buclaw wrote:
>>
>> On 3 December 2013 02:43, Mike <none at none.com> wrote:
>>>>
>>>> Personally I feel that people porting to specific architectures should
>>>> maintain their differences in separate files under a /ports directory
>>>> structure - lets say core.stdc.stdio as a cod example. The version for
>>>> bionic would be under /ports/bionic/core/stdc/stdio.d, and that is the
>>>> module that gets compiled into the library when building for bionic.
>>>> When installing, the build process generates a header file of the
>>>> bionic version of core.stdc.stdio and puts the file in the correct
>>>> /include/core/stdc/stdio.di location.
>>>>
>>>> Though it is fine to say using version {} else version {} else static
>>>> assert(false); when dealing with a small set of architectures.  I feel
>>>> strongly this is not practical when considering there are 23+
>>>> architectures and 12+ platforms that could be in mixed combination.
>>>> The result would either be lots of code duplications everywhere, or
>>>> just a wiry long block of spaghetti code.  Every port in one file
>>>> would (eventually) make it difficult for maintainers IMO.
>>>
>>>
>>>
>>> I agree.  Submitted an enhancement here:
>>> https://d.puremagic.com/issues/show_bug.cgi?id=11666
>>
>>
>> Thanks.
>>
>> My name is Iain.
>
>
> Iain (sorry for the misspelling),
>
> I'm wondering if you could please elaborate on the following statement:
>
>
> "When installing, the build process generates a header file of the bionic
> version of core.stdc.stdio and puts the file in the correct
> /include/core/stdc/stdio.di location."
>
> Being new to D and the D Runtime build process, while I understand the
> general principle, I'm not seeing exactly how this can be implemented.
>
> * How are header files generated in the build process?
> * Once all the necessary files are generated, what need to be done to tell
> the compiler to "use this one"?
>
> Also, D has "header files"? Tell me it isn't so.  Did you mean a .di file?
> Are these called "header files"?

1. There are interface files installed in header locations on your
filesystem. ;-)
They used to be generated in the build process (ie: gdc -fsyntax-only
-fintfc) but now they are just installed from *.d -> *.di

2. You don't need to tell the compiler to *use this one* because ~only
one is installed~.  Which one to install depends on whatever some
configure script/make rules decides based on your target system when
you build/install the library.