msbuild, defining Conditional Compilation Symbols

Question

I'm possibly just blind, but is there a command line to specify conditional compilation symbols in MSBUILD?

I currently have this Line in my buildscript:

SET MSBUILD=C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\MSBuild.exe SET CONFIG=Debug %MSBUILD% /p:Configuration=%CONFIG% /p:OutputPath=..\..\output source\MyProject\MyProject.csproj 

And I'd like to add a condition. In Visual Studio, i can just go into Project Properties => Build => Conditional compilation symbols, but I have not seen that option for msbuild?

Bonus Karma if you know if I can completely override all symbols already specified in the .csproj files to make sure that only the conditionals from my Buildscript go in.

Answer 1

Have you seen this? (most info is in the penultimate post)

/p:DefineConstants="MYSYMBOL1;MYSYMBOL2" 

Answer 2

I had to use a space instead of a semicolon a la this post by Björn Lasar: http://www.linqinpark.net/2009/01/13/MSBuildWithMultipleDefineConstants.aspx

Update: the blog has disappeared; retrieved via Internet Archive:

Recently I had to use MSBuild directly to automate some builds. I also had to configure some preprocessor defines based upon a configuration. This is usually done by an Argument like this

"/p:DefineConstants=MY_PREPROC_FLAG" 

Nothing special here since there are enough comments on the web about that. Today I needed one Flag more and I used the commandline syntax similar to how I knew it from the IDE:

"/p:DefineConstants=MY_PREPROC_FLAG;YET_ANOTHER_FLAG" 

but this one didn't work.

So the point is that if you want to support multiple defines to a project by commandline you'll have to separate them by simple spaces...

"/p:DefineConstants=MY_PREPROC_FLAG YET_ANOTHER_FLAG"  

and it will be added to the (semicolon-separated) Defines from the IDE. Good to know I think...