Re: [boost] Support for Android

Subject: Re: [boost] Support for Android
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2014-01-22 02:29:35

2014/1/22 Vladimir Prus <ghost_at_[hidden]>

> On 22.01.2014 11:04, Antony Polukhin wrote:
>
>> 2014/1/22 Vladimir Prus <ghost_at_[hidden]>
>>
>>  On 22.01.2014 10:15, Antony Polukhin wrote:
>>>
>>>  Would your scripts take care of -lrt?
>>>>>
>>>>>> What about -lpthread?
>>>>>>
>>>>>
>>>>>
>>>> No. No. This must be fixed by bjam or Google (preferable).
>>>>
>>>>
>>> Would the below patch, along with using target-os=android when building,
>>> do the trick?
>>>
>>>
>> Looks like it will do the trick! Thanks a lot!
>>
>> However this arise a question:
>> Who is in charge of specifying platform specific thread libraries? Bjam or
>> each library developer?
>>
>
> It normally should be specified by Boost.Build.
>
>
>
>> For example Boost.Chrono has the following:
>> ./chrono/build/Jamfile.v2:        <target-os>freebsd:<linkflags>"-lrt"
>> ./chrono/build/Jamfile.v2:        <target-os>linux:<linkflags>"-lrt
>> -lpthread"
>> ./chrono/perf/Jamfile.v2:        <target-os>freebsd:<linkflags>"-lrt"
>> ./chrono/perf/Jamfile.v2:        <target-os>linux:<linkflags>"-lrt"
>> ./chrono/test/Jamfile.v2:        <target-os>freebsd:<linkflags>"-lrt"
>> ./chrono/test/Jamfile.v2:        <target-os>linux:<linkflags>"-lrt
>> -lpthread"
>>
>> While bjam has exactly the same rules:
>>          switch $(target)
>>          {
>>              case windows : option = -mthreads ;
>>              case cygwin  : option = -mthreads ;
>>              case solaris : option = -pthreads ; libs = rt ;
>>              case beos    : # No threading options.
>>              case *bsd    : option = -pthread ;  # There is no -lrt on
>> BSD.
>>              case sgi     : # gcc on IRIX does not support
>> multi-threading.
>>              case darwin  : # No threading options.
>>              case *       : option = -pthread ; libs = rt ;
>>          }
>>
>> And why do these rules do not work:
>> If I remove handwritten rules from one of the jamfiles, I'll get
>>
>> ../../../bin.v2/libs/variant/perf/move_perf.test/gcc-4.6/
>> release/link-static/move_perf.o:
>> In function `scope::~scope()':
>> move_perf.cpp:(.text._ZN5scopeD2Ev[_ZN5scopeD5Ev]+0x1b): undefined
>> reference to `clock_gettime'
>>
>
> That's because the above build is not threading=multi, it's just single
> threaded build. I think that the 'rt' library
> is not actually threading, it has some timer stuff, so if chrono needs to
> use such timer stuff specifically,
> there's nothing extremely wrong about specifying that separately.
>
> - Volodya
>

Great thanks for the explanations!
Then please merge the proposed patch.

-- 
Best regards,
Antony Polukhin