GDCC is an alternative ACS compiler, and also a standards-compliant compiler of the C programming language to ACS VM bytecode.

The ACS compiler part of GDCC is called GDCC-ACC. The rest is the C compiler.

• ZDoom forums: https://forum.zdoom.org/viewtopic.php?f=19&t=32078
• GitHub: https://github.com/DavidPH/GDCC

function int f(void)
{
    DoSomething();
    // accidentally wrote "int" instead of "void"
    // This function will now proceed to some other random function's code
}

Functions that return a value but don't have “return” in the code will execute some other random function's code due to the compiler ignoring the missing return statement.

function void f(void)
{
    int x = g(1, 2, 3);
    print(d:x);
}

function void g(void)
{
    // This function does NOT return a value
    // and does NOT accept 3 arguments.
}

If a function is used before it's declared, GDCC allows ANY call to the function, unlike ACC and BCC.

Some fatal compiler errors do not result in an error message, but in a compiled ACS file that is 0 bytes long.

Bad gen Retn means that the name of the function is already used elsewhere.