node-gyp ignores (c++17) cflag

[JlnWntr]

• Node Version: via package-manager
• Platform: Ubuntu 16.04
• Compiler: gcc-8
• Module: my own

I try to configure & build a node.js C++ addon with this
binding.gyp file:

{ 
  "targets": [
    {
      "target_name": "addon",
      "sources": [ "addon.cpp" ],
      "cflags": [
        "-std=c++17"
      ]          
    }
  ]
}

But when I run node-gyp configure and node-gype rebuild
I always get messages like

warning: ‘if constexpr’ only available with -std=c++17 or -std=gnu++17

The build also fails, because I really depend on these c++17 features. What am I doing wrong?

[richardlau]

Maybe try cflags_cc instead of cflags? It's what common.gypi uses: https://github.com/nodejs/node/blob/eaaee92d9b0be82d7f40b2abb67f30ce525d4bc4/common.gypi#L371

[JlnWntr]

This works. Thanks.

[luizperes]

If you are on Mac, it is actually

...
"xcode_settings": {
  ...
  "OTHER_CFLAGS": [ "-std=c++17"],
},

It wouldn't work for me otherwise...

[mceIdo]

In case anyone reaches here and can't get windows builds to work - see #1662 (comment)