Is there way to specify compiler flags (e.g., preprocessor macro definitions) on the node-gyp command line?

Question

I'm trying to integrate a Node.js addon into an existing build system based on CMake. The addon build requires a large number of preprocessor macro definitions and library dependencies that are available in the CMake context. I would like to be able to pass these into node-gyp when it is invoked by CMake. Unfortunately, I have not been able to find a simple way to do so.

I've tried using the approach used for plain old gyp like this:

node-gyp configure -d -DPOSIX=1

but the -D option doesn't seem to be passed on by node-gyp. Looking at the source for node-gyp, this isn't entirely surprising. Is there a straightforward, direct way to do this, or am I stuck with generating the entries in binding.gyp programmatically, pulling in this information from the environment or something else along those lines?

Answer 1

Use "defines".

{
  "targets": [
    {
      "target_name": "MyAddon",
      "sources": [ "File1.cpp", "File2.cpp" ],
      "libraries": [ "MyNeeded.lib" ],
      "defines": [ "_UNICODE", "UNICODE" ]
    }
  ]
}

This adds the defines to the in your config.gypi when running node-gyp configure

Answer 2

I'm not sure why you see a downside to using the cflags setting in binding.gyp - but I just make something similar work by setting the flags using .bashrc

export CFLAGS='-m32' export CXXFLAGS='-m32' export LDFLAGS='-m3'