Solution-wide #define

Question

Is there a way to globally declare a #define?

Like I want to have a file that has for instance,

#define MONO

and I want all source-

Answer 1

Years later, and similar to Alexei's answer but supported innately

One can make a Directory.Build.props similar to a NuGet.Config file as per

https://docs.microsoft.com/en-us/visualstudio/msbuild/customize-your-build?view=vs-2019

Ours looks like:

<Project>
    <PropertyGroup>
        <DefineConstants>RC_427</DefineConstants>
    </PropertyGroup>
</Project>

And it effectively includes this into all CSPROJ files in your SLN. For some reason that particular solution is insanely hard to find via google. Been around since MSBuild 15

Answer 2

I don't think there is a way to create a solution-wide #define. You can create one for each project/assembly, as the other answers have described, but you'll need to do this for each and every project in the solution if you need all source code files to know of that #define.

Answer 3

In case you have both C# and C++ projects in the solution and need to share preprocessor definitions among them. Create some SolutionDefines.targets file near your *.sln as follows

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <DefineConstants>$(DefineConstants);MY_DEFINITION</DefineConstants>
    </PropertyGroup>
  <ItemDefinitionGroup>
    <ClCompile>
      <PreprocessorDefinitions>MY_DEFINITION;%(PreprocessorDefinitions)</PreprocessorDefinitions>
    </ClCompile>
  </ItemDefinitionGroup>
</Project>

Then add to C/C++/C# *.vcproj/*.vcxproj/*.csproj project files this line somewhere in the end

<Import Project="$(SolutionDir)SolutionDefines.targets" Condition="exists('$(SolutionDir)SolutionDefines.targets')" />

Ok, now you can enjoy #if MY_DEFINITION in C# and #ifdef MY_DEFINITION in C/C++. Visual Studio C# editor doesn't like this way and tells there is no MY_DEFINITION defined. But, C# compiler csc.exe gets the symbol properly.

Answer 4

in vs 2013 you can use /define:x or /d:x http://msdn.microsoft.com/en-us/library/0feaad6z.aspx

Answer 5

Update: You cannot do a "solution-wide" define afaik, however the answer below is workable on a per-project basis.

You set them in your Compilation Properties or Build options:

http://msdn.microsoft.com/en-US/library/76zdzba1(v=VS.80).aspx (VS2008) http://msdn.microsoft.com/en-US/library/76zdzba1(v=VS.100).aspx (VS2010)

see the "To set a custom constant" heading.

Update

Microsoft Documentation on Build Options

You get to the build options by right-clicking the project and selecting properties from the menu.