-Wall option less picky in c++ than in c?

[bixtuelista]

I'm somewhat dangerous in C, not an expert by any means. I decided to rip off the bandaid and learn c++ as I want to use the Qt libraries. So I've been going thru and messing with the tutorials here which are really nice.

gcc -Wall has really helped me a lot in the past... but I noticed I just wasn't I'm not getting many warnings I to use it with g++, so I tried:

given code in file testwall.c:

int main(int argc, char **argv)
{
}

gcc -Wall testwall.c gives a: warning: control reaches end of non-void function [-Wreturn-type]

g++ -Wall says nothing at all about this.

Is there a way to ask for maximum warning level that I should know about?

[MiiNiPaa]

g++ -Wall says nothing at all about this.

In C++ main has an implicit return 0 at the end, so in C++ it is legal (unlike C) and not require diagnostic.

-Wall do not shows all warnings. At least add -Wextra and -pedantic. Or:
http://stackoverflow.com/questions/399850/best-compiler-warning-level-for-c-c-compilers

[JLBorges]

> In C++ main has an implicit return 0 at the end, so in C++ it is legal (unlike C) and not require diagnostic.

The implicit return 0 for main() is there in standard C too.
http://coliru.stacked-crooked.com/a/5e4b1cf8948a7208

[MiiNiPaa]

Oh, cool. Guess you just need to turn on C99 (or C11) to get rid of the warning then.

[JLBorges]

Yes. C89 did not have this provision.

In any case, unless both -std=<some actual standard> and -pedantic-errors are present, GNU compilers assume that the code is in some non-standard GNU dialect.