[cmake-developers] Apple tests for target_link_libraries failing

[Stephen Kelly]

Bill Hoffman wrote:

> So, basically we this:
> 
> 
> set(CMAKE_LINK_INTERFACE_LIBRARIES "")
> 
> add_library(libA SHARED classA.cpp)
> add_library(libB SHARED classB.cpp)
> add_library(libC SHARED classC.cpp)
> 
> generate_export_header(libA)
> generate_export_header(libB)
> generate_export_header(libC)
> 
> target_link_libraries(libB libA)
> target_link_libraries(libC libA libB)
> 
> add_executable(exec
>    "main.cpp"
> )
> target_link_libraries(exec libC )
> 
> 
> So, setting CMAKE_LINK_INTERFACE_LIBRARIES to "" is supposed to make the
> transitive linking of A and B not happen when linking C.  I tried adding
> some print stuff in the code.  But, I am not sure where to look.
> 
> I added the following:
> 
>   void cmTarget::SetPropertyDefault(const char* property,
>                                     const char* default_value)
>   {
> +  bool debug = false;
> +  if(strcmp("LINK_INTERFACE_LIBRARIES", property) == 0)
> +    debug = true;
> +  if(debug) std::cerr << this->GetName() << "\n";
>     // Compute the name of the variable holding the default value.
>     std::string var = "CMAKE_";
>     var += property;
> -
> +  if(debug) std::cerr << var << "\n";
>     if(const char* value = this->Makefile->GetDefinition(var.c_str()))
>       {
> +    if(debug) std::cerr << "found it " << value << "\n";
>       this->SetProperty(property, value);
>       }
>     else if(default_value)
>       {
> +    if(debug) std::cerr << "not found " << default_value << "\n";
>       this->SetProperty(property, default_value);
>       }
>   }
> diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLin
> kLibrariesCommand.cxx
> index 805959d..d2be3fa 100644
> --- a/Source/cmTargetLinkLibrariesCommand.cxx
> +++ b/Source/cmTargetLinkLibrariesCommand.cxx
> @@ -219,6 +219,7 @@ cmTargetLinkLibrariesCommand::HandleLibrary(const cha
> r* lib,
>     // Handle normal case first.
>     if(!this->DoingInterface)
>       {
> +    std::cerr << this->Target->GetName() << " Not doing interface" << "\
> n";
>       this->Makefile
> 
> 
> I ended up with this:
> 
> libA
> CMAKE_LINK_INTERFACE_LIBRARIES
> found it
> libB
> CMAKE_LINK_INTERFACE_LIBRARIES
> found it
> libC
> CMAKE_LINK_INTERFACE_LIBRARIES
> found it
> 
> 
> libB Not doing interface
> libC Not doing interface
> libC Not doing interface
> 
> 
> Do you have other prints that I should add?  How is this supposed to work?
> 
> -Bill
> 

How exactly it works I am not entirely certain. I followed the suggestion in 
this thread:

http://thread.gmane.org/gmane.comp.programming.tools.cmake.devel/1865/focus=1868

and it just worked for me.

I assume the contents of LINK_INTERFACE_LIBRARIES gets read somewhere else 
to create the actual link line. each of libA libB and libC do not get added 
to the link_interfaces, and using set(CMAKE_LINK_INTERFACE_LIBRARIES "") 
should be the same as using 

target_link_libraries(libA LINK_INTERFACE_LIBRARIES "")

for each library.

It works for me, but I don't know why it doesn't work for you. Maybe Brad 
can have some insight?

Thanks,

Steve.