Re: [Boost-build] Specify assembly reference path in C++/CLI

From: Jurko Gospodnetić (jurko.gospodnetic_at_[hidden])
Date: 2008-06-03 03:08:45

   Hi Motonari.

> I have a question: how to pass the location to generated target to other
> target's build parameter?
> 
> My current case is an issue in C++/CLI compilation but it's not C++/CLI
> specific question. Anyway, let's see an example. Say you have these two
> files in C:\source:
> 
> [clr_lib.cpp]
> public ref class CLRLib {
> public:
>     static void Hello() {
>         System::Console::WriteLine("Hello World");
>     }
> };
> 
> [main.cpp]
> #using <clr_lib.dll>
> int main(){
>     CLRLib::Hello();
> }
> 
> 
> I can compile them with the following command line:
> 
> 1: cd C:\source
> 2: cl clr_lib.cpp /clr /LD
> 3: cl main.cpp /clr /AIC:\source
> 
> The /AI option in line 3 specifies the location of clr_lib.dll which is
> generated by the line (2).
> 
> Now, I want to use bjam to compile it.
> 
> [Jamfile]
> lib clr_lib : clr_lib.cpp
>             : <cxxflags>-clr
>               <asynch-exceptions>on
>               <link>shared
> ;
> 
> exe main : main.cpp
>          : <clr>clr
>            <cxxflags>-AI[?]
> ;
> 
> How to find the value of [?] so that it takes the location of
> clr_lib.dll?

   The option you are trying to use is not supported out of the box. :-(

   First, I am not completely sure what the option does. It's listed 
with other MSVC preprocessor commands so I assume preprocessor somehow 
parses those libraries for additional preprocessor symbols.

   Second, Boost Build expects all built files to be modeled as 
'targets' and then those 'targets' used to define sources for other 
targets, with Boost Build using those target and dependency definitions 
to fill in the actual target file paths to the actual tool command 
lines. I do not believe there is a way for you to directly say: 'place 
this target's path here'. I guess that could be implemented but I do not 
recall seeing it around nor do I have a precise idea of what the 
expected syntax for this would be or how hard it would be to implement. 
Note just that the path depends on the exact property set used when 
building the target so there seems little point in hard-coding just one 
path...

   One real ugly quick-fix is to hard-code paths in the command line 
like you do now but condition them on the properties affecting how those 
paths are constructed. This should work but would be exceedingly 
difficult to maintain as your project grows.

   Another dirty quick-fix would be to not use the exe rule but instead 
use the make rule (or define your own new target type or generator 
class) and construct the whole command line yourself. I guess that could 
be a bit cleaner than the previous solution but would still basically 
require that you duplicate much of the knowledge already contained in 
the msvc toolset.

   I guess the best way would be to improve the msvc toolset to know 
about this option. This would be the solution thats the easiest to 
maintain, however it might also be a bit tricky for someone relatively 
new to Boost Build. This group can offer assistance should you choose to 
do it this way, but basically you would have to:

   1. Declare a new feature, let us say <preprocessor-lib>.

   2. Use the toolset.flag rule to have this feature's values passed to 
the actual build actions used in the msvc toolset. For an example see 
how the library-file feature is linked to the 
LIBRARIES_MENTIONED_BY_FILE flag in the msvc toolset.

   2. Make Boost Build treat that feature's values as dependencies. I 
think specifying that the feature is a 'dependency' feature was meant 
for this but does not work correctly so you need to use the raw Jam 
DEPENDS command to make this work. For more information related to this 
see an example at 
http://www.boost.org/doc/tools/build/doc/html/bbv2/extending/features.html 
or how this done in the msvc toolset's compile-c-c++ rule for the 
PCH_HEADER flag.

   4. Modify the actual build actions in two ways:
     4.1. Make Jam 'bind' the new feature's values (i.e. so the actions 
get actual file names corresponding to the listed targets instead of 
just the target names). For an example see how the DEF_FLAG is used in 
the link action in the msvc module.
     4.2. Make the actions use the new values with the /AI option.

   From taking a quick look through the msvc toolset it seems like there 
are 3 relevant actions that you would need to modify but I am not 
completely sure what the difference is between them:
   actions compile-c-c++
   actions compile-c-c++-pch-s
   actions compile-c-c++-pch

   There might also be some already extracted helper rule to that could 
come in useful (CC_RSPLINE variable seems to hint that).

   Hope this helps.

   Best regards,
     Jurko Gospodnetić