Conditional compilation for working at home

Question

I code C++ using MS Dev Studio and I work from home two days per week. I use CVS to keep my sources synchronized between the two computers but there are difference between the environments the machines are in.

Can anyone suggest a way I can conditionally modify constants in my code depending on whether I am compiling on my home box or not ?

What I am after is a way of defining a symbol, let's call it _ATHOME, automatically so I can do this:

#ifdef _ATHOME
#  define TEST_FILES  "E:\\Test"
#  define TEST_SERVER "192.168.0.1"
#else
#  define TEST_FILE   "Z:\\Project\\Blah\\Test"
#  define TEST_SERVER "212.45.68.43"
#endif

NB: This is for development and debugging purposes of course, I would never release software with hard coded constants like this.

Answer 1

You can set preproccesor variables in the properties->c++->preprocessor
in visual studio settings you can use $(enviromentvariable)

Answer 2

I generally use config files, then just create a symlink to the appropriate configuration.

Answer 3

On your home and work machines, set an environment variable LOCATION that is either "1" for home or "2" for work.

Then in the preprocessor options, add a preprocessor define /DLOCATION=$(LOCATION). This will evaluate to either the "home" or "work" string that you set in the environment variable.

Then in your code:

#if LOCATION==1
  // home
#else
  // work
#endif

Answer 4

If the only difference between work and home is where the test files are located... then (IMHO) you shouldn't pollute your build files with a bunch of static paths & IPs.

For the example you showed, I would simply map drives on both work and home. I.e. at work map a drive T: that points to \\212.45.68.43\Project\Blah\Test, at home map a drive T: that points to \\192.168.0.1\Test.

Then your build process uses the path "T:\" to refer to where tests reside.

Of course, if you need to change something more drastic, setting environment variables is probably the best way to go.