GCC -D equivalent for iarbuild.exe

I have a build machine server I am maintaining which is using Makefiles infrastructure.

As part of that infrastructure, I'm passing a few arguments to the Makefile from the build machine (example: user, build-server name, and various build variables known only when compiling for a specific project).

Some of these variables are aggregated to the code using gcc -D directive

-DSOME_VAR=VAL

I've now been asked to migrate an Iar Project into my build system. That is not a problem in itself, only I can't find any way to introduce preprocessor defines using iarbuild.exe command line tool.

I guess I could use an existing H file and edit it before compiling (using sed for example), but that's an ugly hack I would rather avoid if I can.

How do I properly achieve this with IAR?

Solution

To my understanding iarbuild does not support passing such parameters directly.

There are two possibilities that were suggested by IAR support and that both work for me (using 7.40.2):

1) Use a preinclude file

Go to Project->Options->C/C++ Compiler->Preprocessor
Add a preinclude file (e.g. preinclude.h)
Now have your build script generate that preinclude file before starting iarbuild

2) Use "Defined symbols"

Go to Project->Options->C/C++ Compiler->Preprocessor
Add an option to "Defined symbols" and use environment variable, e.g. "SOMEVAR=$_SOMEVAL_$"
On the cmd line, set the environment variable, e.g. "set SOMEVAR=myvalue"
Run iarbuild

The 2nd method is little more elegant, but the build will fail if the environment variable is not set, so I'll probably go with the 1st method.