c++ - Adding preprocessor to CL in command line and build *.sln by MSBuild

Question

I need to compile and build c++ project in command-line using MSBiuld without using vs2019 IDE, some preprocessors must be added by command-line!

for example, how to define PO preprocessor and run MSBuild to compile below code?

#include <iostream>

using namespace std;

int main()
{
#ifdef PO
    cout << "PO is defined";
#else
    cout << "PO not defined";
#endif
    
    return 0;
}

question from:https://stackoverflow.com/questions/65927984/adding-preprocessor-to-cl-in-command-line-and-build-sln-by-msbuild

Answer 1

You can use CL environment variables to set the /D option.

For example, to define PO, you can do

SET CL=/DPO

on the command line before invoking MSBuild.

Just be sure to read those docs, because you'll probably need to use the number sign (#) instead of the equal sign (=) if you want to define a preprocessor constant with an explicit value. Also (depending on the context) the quotes (") may need to be escaped (like ") if you want to define a string constant.