Re: [Boost-build] linking against external librarys

Subject: Re: [Boost-build] linking against external librarys
From: Gevorg Voskanyan (v_gevorg_at_[hidden])
Date: 2010-12-08 13:12:32

"HarrievA_at_[hidden]" wrote:
>Hey Guys,
>
>I want to link all my programs against one library. When i'm in a subdirectory i 
>
>get the error: "Unable to find file or target named"...
>
>This is what my Jamroot looks like:
>lib boostsystem : : <name>boost_system ;
>explicit boostsystem ;
>project : default-build release 
>        : requirements <cxxflags>"-std=gnu++0x" 
>        : requirements <include>.
>        : requirements <library>boostsystem
>        : build-dir ./bin
>        ;
>#exe sertest : samples/sertest.cpp ;
>build-project samples ;
>
>The samples/Jamfile contains only the line:
>exe sertest : sertest.cpp ;
>
>By typing bjam I get the errormessage:
>error: Unable to find file or target named
>error:     'boostsystem'
>error: referred from project at
>error:     'samples'
>
>When I uncomment the secondlast line of the Jamrootfilie, and comment  the 
>lastline, my sampleapplication compiles with no error. I know that  this is not 

>the way to link against boost, but this is only an  example... I tried so much. 

>Adding a slash( and much more) to the  <library> argument... It works too when I 
>
>add the dependency  ../boostsystem to the samples/Jamfile-line, but thats the 
>thing i want  to avoid with the default rule...
>
>I don't know where the problem is.

Consider your samples/Jamfile had this instead:
exe sertest : sertest.cpp : <library>boostsystem ;
This wouldn't work because boostsystem is not a target name visible in 
samples/Jamfile. In your case <library>boostsystem comes from the parent 
project's requirements rather than being specified explicitly, but the behavior 
is the same.

>I read so much documentation, and it  is so 
>frustrating. Maybe I'm to stupid too get the concept behind  boost-bind. I had 
>so many problems with setting different  compileroptions, crosscompilation, 
>seting the linkingpath....

I think you meant boost-build instead of boost-bind.
Well, if you have difficulties with Boost.Build, this list is the proper place 
to ask your questions, so feel free to ask them.

>I hope someone can help me...

There are several ways to solve this problem, two of which are:

Option 1. Have the following alias declaration in samples/Jamfile:
alias boostsystem : ..//boostsystem ;

Option 2. Give the top project a name, and use that name in the requirement:
project myproject : default-build release 
        : requirements <cxxflags>"-std=gnu++0x" 
        : requirements <include>.
        : requirements <library>/myproject//boostsystem
        : build-dir ./bin
        ;

Warning: I typed this directly in email client, so there may be some errors.

>Regards, Hendrik,

HTH,
Gevorg