Re: [ros-kernel] Two questions about GCC...

[KJK::Hyperion <no...@li...>]

At 19.17 18/05/2002, you wrote:
> > testfork.o(.text+0x43):testfork.c: undefined reference to `__main'
> > make: *** [testfork.nostrip.exe] Error 1
>well, you need your custom __main function then.

erm... why exactly? I checked, and it's the damn *compiler* that inserts a 
"call ___main" just after the stack frame setup in main():

         .file   "testmain.c"
gcc2_compiled.:
___gnu_compiled_c:
         .def    ___main;        .scl    2;      .type   32;     .endef
.text
         .align 4
.globl _main
         .def    _main;  .scl    2;      .type   32;     .endef
_main:
         pushl %ebp
         movl %esp,%ebp
         subl $8,%esp
         call ___main
         xorl %eax,%eax
         jmp L2
         .align 4
L2:
         leave
         ret

Why the hell does it do this? Why does the compiler try to be smarter than 
me? How can I tell the compiler to compile *exactly* what I say, and not 
generate useless/superfluous code? Borland C++ doesn't do it, for example:

         .386p
         ifdef ??version
         if    ??version GT 500H
         .mmx
         endif
         endif
         model flat
         ifndef  ??version
         ?debug  macro
         endm
         endif
         ?debug  S "testmain.c"
         ?debug  T "testmain.c"
_TEXT   segment dword public use32 'CODE'
_TEXT   ends
_DATA   segment dword public use32 'DATA'
_DATA   ends
_BSS    segment dword public use32 'BSS'
_BSS    ends
DGROUP  group   _BSS,_DATA
_TEXT   segment dword public use32 'CODE'
_main   proc    near
?live1@0:
    ;
    ;    int main(void)
    ;
         push      ebp
         mov       ebp,esp
    ;
    ;    {
    ;     return (0);
    ;
@1:
         xor       eax,eax
    ;
    ;    }
    ;
@3:
@2:
         pop       ebp
         ret
_main   endp
_TEXT   ends
         public  _main
         ?debug  D "testmain.c" 11442 44081
         end