RE: [Dev-C++] #DEFINE versus cont variables in array inicializations

Please.

I'm not talking about C++ standard.
I'm talking about a real gcc 3.2 behaviour.
This isn't what I think but what my compiler does:

--- def.cc ---
const int x = 7;
--- ref.cc ---
#include <stdio.h>
extern const int x;
int main() {
    printf("value x = %d\n",x);
    printf("addr x = %p\n",&x);
    return 0;
}
--- build ---
>g++ -c def.c
>g++ -c ref.c
>g++ def.o ref.o -lstdc++ -o test.exe
--- result ---
ref.o(.text+0x3f):ref.cc: undefined reference to `x'
ref.o(.text+0x54):ref.cc: undefined reference to `x'
--- def.s ---
        .file   "def.cc"
        .text
        .align 4
_x:
        .long   7
--- ref.s ---
        .file   "ref.cc"
        .def    ___main;        .scl    2;      .type   32;     .endef
        .text
LC0:
        .ascii "value x = %d\12\0"
LC1:
        .ascii "addr x = %p\12\0"
        .align 2
.globl _main
        .def    _main;  .scl    2;      .type   32;     .endef
_main:
LFB1:
        pushl   %ebp
LCFI0:
        movl    %esp, %ebp
LCFI1:
        subl    $8, %esp
LCFI2:
        andl    $-16, %esp
        movl    $0, %eax
        movl    %eax, -4(%ebp)
        movl    -4(%ebp), %eax
        call    __alloca
        call    ___main
        subl    $8, %esp
        pushl   _x
        pushl   $LC0
LCFI3:
        call    _printf
        addl    $16, %esp
        subl    $8, %esp
        pushl   $_x
        pushl   $LC1
        call    _printf
        addl    $16, %esp
        movl    $0, %eax
        leave
        ret
LFE1:
        .def    _printf;        .scl    2;      .type   32;     .endef
--- end ---

As you can see, def.cc doesn't export the const int x.

If I instead make the following change, everything will work ok, since
now, x is exported from def.o.

--- def.cc ---
extern int x = 7;
--- def.s ---
        .file   "def.cc"
.globl _x
        .text
        .align 4
_x:
        .long   7
--- end ---

/Per W

On Sat, 31 May 2003, Ioannis Vranos wrote:

> > -----Original Message-----
> > From: Per Westermark [mailto:pw...@ia...]
> > Sent: Saturday, May 31, 2003 6:38 AM
> > To: Ioannis Vranos
> > Cc: Dev-C++ Mailing List
> > Subject: RE: [Dev-C++] #DEFINE versus cont variables in array
> > inicializations
> >
> >
> > See below
> >
> >
> > If you know that you need to take the address in another file, then
> > declare it as:
> >     extern const int SIZE = 7;
>
>
> I am sorry to tell you this, but this is *nonsense*. The C++ standard
> doesn't require to define it like this.
>
>
> I can define a const object in the global namespace:
>
> const int x=7;
>
>
>
> and in another file I can do this:
>
>
> #include <iostream>
>
>
> extern const int x;
>
> // ...
>
>
> void f()
> {
>    const unsigned char *p=reinterpret_cast<const unsigned char *>(&x);
>
>
>  // Shows SIZE representation in memory in byte values
>  // including padding bits
>    for(unsigned long i=0; i<sizeof(x); ++i)
>       std::cout<<static_cast<short>(p[i])<<" ";
> }
>
>
>
>
>
>
>
> > It doesn't. Either make sure that the file that declares SIZE
> > takes it's
> > address, or declare it as 'extern const int SIZE = 7;'
>
>
>
> Please direct me in the C++ standard where it mentions such a requirement.
>
>
>
>
> Ioannis Vranos
>
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>
>
>
>
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