Why are my Custom Build steps not running in Visual Studio 2010?

Question

I have a Visual Studio project with several Custom Build steps in it, but some of them are simply failing to run. There are no errors and no warnings, and according to the build logs they are running, but they're definitely not.

It was all working in older versions of Visual Studio, but it's now going wrong in Visual Studio 2010.

Answer 1

The reason it's failing is that there's another custom build step in the same project that's calling a batch file, like this:

Command Line: buildsomething.bat something.h
Description: Building something
Outputs: something.h

Visual Studio 2010 concatenates all the custom build commands into a single batch file, which it then runs. When a batch file runs another batch file, Windows doesn't return control to the first batch file. It's like a goto, not a function call. So to fix the problem, you need to use call like this:

Command Line: call buildsomething.bat something.h

call makes the flow of control return to Visual Studio's batch file, and hence lets your other Custom Build steps run.

_{(I'm answering my own question so that future searchers can find the answer.)}