Question

This code compiles, but no surprises, it fails while linking (no main found):

Listing 1:

void main();

Link error: \mingw\lib\libmingw32.a(main.o):main.c:(.text+0x106) undefined reference to _WinMain@16′

But, the code below compiles and links fine, with a warning:

Listing 2:

void (*main)();

warning: ‘main’ is usually a function

Questions:

1. In listing 1, linker should have
   complained for missing “main”. Why
   is it looking for _WinMain@16?

2. The executable generated from
   listing 2 simply crashes. What is
   the reason?

Thanks for your time.

Answer 1

Case 1. is Windows-specific – the compiler probably generates _WinMain symbol when main is properly defined.

Case 2. – you have a pointer, but as static variable it’s initialized to zero, thus the crash.