Normally, yes. But main() is special and implicitly returns 0, for whatever reason.
int main()
{
int a = 12;
}
$ gcc maintest.c
$ ./a.out
$ echo $?
148 $ cat test.c
int main(void) {int a = 12;}
$ gcc-6 test.c -o test --std=c89; ./test; echo $?
162
$ gcc-6 test.c -o test --std=c99; ./test; echo $?
0
int main(void)
{
__asm {
mov eax, 123
}
}
// visual studio command line
// cl testc.c
// cl testcpp.cpp
// testc.exe
// echo C %errorlevel%
// testcpp.exe
// echo CPP %errorlevel%
For those not familiar with MSVC. The C compiler is not C99 compliant and the C++ compiler is.
Often this is as easy as coding to an older standard, like C89 with a few selected features from later standards, and adding some compatibility features / problem detection in the build system.
And don't rely on features that are difficult to explain and/or add only questionable value. Just return 0 from main, it's the obvious simple thing to do.