about main must return "int"

[Ben Davis]

On Monday 7 July 2003 8:53 pm, Amy Lin wrote:
> Hi, I am new with this list, and I need your help.
>
> After installing Redhat 8.0 which has gcc 3.2, I ran into a problem when
> recompiling a project. with c++.  It errors out on "main" must return
> "int".  All my old codes with "void" main.  I used c++ from egcs-1.1-2
> (redhat 7.3) and it was no problem there.  My question is: Is this a bug
> of gcc 3.2, or this is a permanent change and I will have to change my
> codes?

I can't answer your question about how the GCC project is handling this 
mistake, but I can tell you that main should return int and your code is 
wrong if your main function returns void. So yes, you should change your 
code.

The use of the return value is to let the parent process know if your program 
did what it was supposed to do successfully. For instance, GCC itself will 
return zero if it was capable of producing valid output. This can be used by 
GNU Make; if GCC returns nonzero, GNU Make will know that something went 
wrong, and it will not try to complete the build.

Ben