How to pass flag to GCC?

[Paulo Alexandre Regis]

I'm compiling ns-3 on a raspberry pi. It compiles ok, but it spits a lot of messages like this: "note: parameter passing for argument of type '...' will change in GCC 7.1"

I googled around and from [1] looks like if I pass the flag '-Wno-psabi' to GCC it should silence that message.

I tried adding this command to the wscript: add_gcc_flag('-Wno-psabi') right where a bunch of this commands are called, but the note message keeps appearing when compiling.

Is there another way to hide those annoying messages?

[Paulo Alexandre Regis]

[1] https://github.com/nlohmann/json/issues/658

[Ahmed Khalifa]

Simply, ns3 must be compiled using -std=c++0x.