[aur-general] Conventions on packages for cross-compiling

[Vojtech Horky]

Allan McRae napsal(a):
> Vojtech Horky wrote:
>> 2009/10/13 Allan McRae <allan at archlinux.org>:
>>  
>>> Vojtech Horky wrote:
>>>    
>>>> 2009/10/8 bardo <ilbardo at gmail.com>:
>>>>
>>>>      
>>>>> 2009/10/7 Vojtech Horky <vojta.horky at seznam.cz>:
>>>>>
>>>>>        
>>>>>> Hi all,
>>>>>> I am seeking advice how to write correct PKGBUILDs for 
>>>>>> cross-compilers.
>>>>>>
>>>>>> The thing I am not sure about is where to install them.
>>>>>> Trouble is that even the binary packages use different locations 
>>>>>> and I
>>>>>> haven't found any other source where to get information from (for
>>>>>> example, cross-arm-wince-cegcc-binutils uses prefix /opt/cegcc/ while
>>>>>> mingw32-gcc uses /usr).
>>>>>> So, which location would you recommend/is better?
>>>>>>
>>>>>>           
>>>>> Some time ago I asked the same question about my AVR toolchain, which
>>>>> is now in [community]. I think the original thread can be interesting
>>>>> to you:
>>>>>
>>>>> http://mailman.archlinux.org/pipermail/aur-general/2008-January/thread.html#611 
>>>>>
>>>>>
>>>>>
>>>>>        
>>>>>> Another thing - is the correct naming convention
>>>>>> 'cross-<arch>-<pkgname>'?
>>>>>>
>>>>>>           
>>>>> As you see, I just stuck with the '-arch' postfix =)
>>>>>
>>>>> Corrado
>>>>>
>>>>>
>>>>>         
>>>> Hi,
>>>> first of all - thanks everybody for the suggestions and the links.
>>>>
>>>> I read them through, (again and again) looked around how others do it
>>>> and finally decided to really write that wiki page as Loui proposed. I
>>>> put the guidelines proposal on
>>>>
>>>> http://wiki.archlinux.org/index.php/Cross_Compiling_Tools_Package_Guidelines_Proposal 
>>>>
>>>> I and would be really glad if someone would find some time to read it
>>>> and express his opinion.
>>>>       
>>> I have been looking into cross-compilers a lot lately, and I think 
>>> the best
>>> place to put _all_ their files is /usr/lib/cross-*-*-* and then symlink
>>> needed stuff or add wrapper scripts in /usr/bin/.  This is more FHS
>>> compliant than the /usr/i486-mingw32 that is used in mingw32 and 
>>> /usr/avr in
>>> the avr one.
>>>     
>> I agree that it is more FHS compliant but I would prefer to have files
>> directly (i.e. no symlinks) where they are supposed to be (e.g. put
>> executables into /usr/bin rather than symlinking them from
>> /usr/lib/cross*).
>>   
> 
> I found an issue with just using /usr directly...  see below.
> 
>>> Does your proposed build process lead to any "interesting"
>>> directories in /usr?
>>>     
>> No. But sometimes a small hack is needed (e.g. the tooldir settings
>> for binutils). Possible conflicts are solved by adding architecture
>> prefix and duplicate files are not installed at all (e.g. man pages or
>> READMEs).
>> BTW, the MIPS cross-compilers
>> (http://aur.archlinux.org/packages.php?O=0&K=cross-mips) now follow
>> the proposed guidelines from the wiki.
>>   
> 
> Are there no headers needed for mips?  Seems weird...
Some headers are installed into 
/usr/lib/gcc/mipsel-linux-gnu/4.3.2/include/ and these are found 
correctly and do not interfere with the native gcc:
~$mipsel-linux-gnu-cpp -v
...
#include "..." search starts here:
#include <...> search starts here:
  /usr/lib/gcc/mipsel-linux-gnu/4.3.2/include
  /usr/lib/gcc/mipsel-linux-gnu/4.3.2/include-fixed
End of search list.
~$cpp -v
...
#include "..." search starts here:
#include <...> search starts here:
  /usr/local/include
  /usr/lib/gcc/x86_64-unknown-linux-gnu/4.4.1/include
  /usr/lib/gcc/x86_64-unknown-linux-gnu/4.4.1/include-fixed
  /usr/include
End of search list.

 > and this may be
> an issue with other cross compilers.  If the mingw headers go in 
> /usr/include there will be lots of conflicts.
Probably I am completely wrong, but won't the headers be the same for 
all architectures? Of course, except for the very low-level macros that 
are stored outside /usr/include anyway (I mean those files in 
/usr/lib/gcc/<arch>/include/).
> Allan
> 
- Vojta