Unable to inject build option (e.g. -fPIC) on Linux

[paniq]

I need to build NFD as part of a shared object on Linux, which makes it necessary to build libnfd.a with the -fPIC option; For Makefile-, CMake- or Premake-based projects, I usually just set CFLAGS/CXXFLAGS in the environment, and that propagates to the Makefile. However, SCons seems to ignore environment variables.

Is there a possibility to build the library with -fPIC or other manual build options without patching SConstruct?

[mlabbe]

Scons doesn't permit environment variables to override its internal environment by default. However, I can see why that would be useful as a vendor providing a library to a third party.

I have a fix which I'm in the process of testing on my array of build servers now. I am exposing the following:

'CC', 'CXX', 'CFLAGS', 'CXXFLAGS', 'ARFLAGS'

[paniq]

that sounds pretty good!

[mlabbe]

Okay, I pushed the improvement after testing in 5 build environments. I think having the ability to set these values from the command line is useful, but I don't think it gets you all the way to a shared lib. We've been talking on Twitter, but for the sake of others who come across this, there are a couple of challenges related to getting NFD compiling as a shared library.

As far as Scons is concerened, turning the nfd_env.StaticLibrary() call into nfd_env.SharedLibrary() should do the trick.

As you mentioned, the free() call would fail on Windows, as DLLs do not share heap space.

If someone wants to take the plunge and do a full .so patch, I would take a good look at merging that!

[paniq]

Thanks :)