> The compiler is supposed to compile programs that comply with the spec Yes. > and not compile programs that don't. No, there is no limitation on what a com

> The compiler is supposed to compile programs that comply with the spec Yes. > and not compile programs that don't. No, there is no limitation on what a compiler does in this case. > The concept of "compiling a program that doesn't comply with the spec" doesn't even exist! It does, it is called "undefined behaviour". > A text file that doesn't comply with the C spec isn't a C program. That's the point. A program that contains UB is not a valid C program. That's what UB means.