Re: [boost] [Test] boost_unit_test_framework and main()

From: Jürgen Hunold (juergen.hunold_at_[hidden])
Date: 2007-05-15 05:33:42

Hi ! 

An'n Dingsdag 15 Mai 2007 hett Vladimir Prus schreven:
> Douglas Gregor wrote:
> > Our tests pass because BBv2 decides to put the archive file on the
> > link line:
> >
> > g++ -fPIC -o algorithms_test algorithms_test.o
> > libboost_unit_test_framework.a

No, it uses the static library, which has _main.

> Further, in my testing putting 'main' in static library works. I believe
> that even works on Windows. Furthermore, previous testing reveals that on
> Linux, putting 'main' in shared library works as well.

Correct.

> > Why must main() be in a library? It seems a trivial matter to fix.
> The real issue is that there's no 'main()' in library, as shown below:
>
> ghost_at_wind:~/Work/Boost/boost-rc/stage/lib$ readelf --symbols
> libboost_unit_test_framework-gcc40-d.so | grep main 871: 00074a43    17
> OBJECT  WEAK   DEFAULT   12 _ZTSSt12domain_error 1253: 0007ed68    12
> OBJECT  WEAK   DEFAULT   22 _ZTISt12domain_error 165: 00000000     0 FILE  
>  LOCAL  DEFAULT  ABS unit_test_main.cpp 259: 0007ed98     4 OBJECT  LOCAL 
> HIDDEN   22 DW.ref._ZTISt12domain_err 1128: 00074a43    17 OBJECT  WEAK  
> DEFAULT   12 _ZTSSt12domain_error 1510: 0007ed68    12 OBJECT  WEAK  
> DEFAULT   22 _ZTISt12domain_error
>
> When both static and shared libraries are present, gcc picks shared
> on most platforms of note. Since shared library lacks 'main', you get
> linker error.

Right.

> I believe this is intentional change made in Boost.Test for 1.34, in the
> interest of making Linux (where 'main' can be in shared library) and
> Windows (where 'main' cannot be in shared library), uniform.

Yes, that was the intention

> However, you'd need to ask Gennadiy how to your tests work now.

Just #define BOOST_TEST_DYN_LINK

The autotest code then creates a main for you.

Taking a look at libs/test/build/Jamfile.v2 reveals
    : usage-requirements 
                   <define>BOOST_TEST_NO_AUTO_LINK=1
                   <link>shared:<define>BOOST_TEST_DYN_LINK=1

which Boost.Build applies automagically ;-))

Yours,

Jürgen

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