What is the difference between a normal compiler error and a fatal compiler error? [duplicate]

Question

What is the main difference between fatal errors and non-fatal errors dipslayed in an IDE when one tries to compile the code?

In both cases the compiler shows an error message and the program is not compiled. Are fatal errors the undefined compiler errors in a compiler or linker?

Answer 1

A fatal error would probably stop compilation of that translation unit immediately.

A compiler may continue compiling after an error in order to reveal to you a more comprehensive list of issues.

Although in your case it appears that the preprocessor has issued the fatal error. Perhaps it's simply down to the mood of the compiler writer.

Answer 2

The difference is this:

• on a normal error, the compiler can continue its parsing, it's just a local problem (undeclared variable for instance, but the compiler knows how to recover from it. Some compilers go far in that process, adding missing ; and such)
• on a fatal error, the compiler (or preprocessor) cannot possibly know how to continue (like it's "lost") because of a structural error (loses the context)

Which explains that sometimes you fix all your compiling errors, and new ones appear.

Answer 3

The IDE is not the compiler. It generally starts another program (like GCC...) in command line to compile. Your IDE is simply a glorified editor (and on Linux the emacs editor is often better than an IDE).

Most compilers don't give fatal errors, except on compiler bugs, lacking resources at compile time, or when the source input cannot be further compiled: think of #include-ing a non existent header file.

BTW, sometimes a compiler gives so many errors (for instance, try to compile an English or French literature text disguised as a C file) that further compilation is meaning less.