allow #defines to be passed to the compilation process (aka -D option on GCC)

[markthepiggy]

I don't know if this can be done already but I haven't found a way.

I #define TESTING (for instance). If I want to change this, i have to remember to do it in every file. GCC lets me do this with the -D flag...

-D name
or
-D name=definition

Is there any way you can fix things to pass #defines through to the compiler?

[eried]

Why you don't define that in the sketch itself?

[Chris--A]

Consider libraries.

Serial Rx/Tx buffer sizes, pulseIn max pulse width (anything that is compiled before the sketch needs this).

I personally would like each sketch to have the ability to define a platform.txt with compiler.cpp.flags and compiler.c.flags

Then sketches can then default C++98 or C++11, change compiler options easy (not just adding defines). And possibly the addition of a default board/port which others have asked for.

I don't know how I got here, and only just realized, so I'm going to post anyway! But it is what I want for the original/upstream IDE.