Compilers are just as vulnerable to defects as any other software. When I worked on VS COBOL II at IBM we had a several levels of people devoted to answering cu

Compilers are just as vulnerable to defects as any other software. When I worked on VS COBOL II at IBM we had a several levels of people devoted to answering customer bug reports and fixing compiler code. I think the difference is is that compilers tend to be the kind of software that is written a little more carefully, better reviewed, and more comprehensively tested because of the implications of compiler bugs getting out in the wild through compiled apps. Compilers are hard to write and hard to make money with, too, and I think it's safe to say the reliability of the compiler is a big factor in its success.