Re: [boost] Problem cross-compiling boost.context for Raspberry Pi (2)

Subject: Re: [boost] Problem cross-compiling boost.context for Raspberry Pi (2)
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2015-07-09 02:59:40

On 17/06/2015 18:30, Oliver Kowalke wrote:
>> - Compiler does not care much, it just uses the default one
>> - Boost.Build does not care either, since all ARM alternatives in
> boost.context
>>    have the same ABI
>>
>> What am I missing
>
> boost.context has to compile assemblerfiles/code. For this purpose it has
> asm files for combinations of architecture, abi, binary-format and
> address-model. The Jamfile of boost.context has rules for selecting the
> correct ASM file. In the case of cross compiling the rules get the wrong
> data. Theuser has to overwrite abi and the other properties guessed by
> context's Jamfile.

I think that Vladimir's suggestion is that:

1. The initial defaults for all properties should be auto-detected from 
the host OS as normal.
2. Specifying "architecture=arm" explicitly, also changes the default 
for "abi" to "aapcs" (but it can still be overruled by the command 
line), along with any other properties for which knowing the 
architecture is sufficient to overrule other auto-detection.

(Or, for another way to look at it: specifying the architecture makes it 
assume a certain abi without having to do any auto-detection, unless 
otherwise specified.)

I don't how easy it would be to convince B2 to do such a thing, however, 
or whether it's sufficiently worthwhile. :)