headers,declarations,definitons

spx2 · 08-23-2006, 10:07 AM

hello
i'm continuing a pretty big
project wich was not either
designed/thought/coded by me
earlier.

now i have to make some modules
to it.

for that purpose it is needed
to make .h and .c to accompany
the big project as a module.

the problem i am experiencing
is purely of convention ,but
it seems i cannot overcome it
by any means that i know of.

consider for example the following
files

<- will mean "contains"

main.c <- mi_core.h
mi_core.c <- mi_core.h

mi_fifo is a module wich
is structured like this

mi_fifo.c <- mi_fifo.h
mi_fifo.c <- tree.h
tree.c <- dbl_list.h
dbl_list.c<- dbl_list.h

this module mi_fifo is linked
and is separate from main.c.
mi_fifo is to be linked dynamically
with main.
(it is compiled as a .so file)

i have respected the convention that
all functions should be first declared
in .h and are to be defined(written) in
.c ,but i am keeping experiencing some
warnings at compilation(of mi_fifo).

../../mi_core.h:65: warning: ‘mi_trim_filename’ used but never defined

the above is the type of warning i keep
experiencing.

now if i include besides the .h the .c also
in this case i don't get the warning above
no more.

i should also mention that the .h is structured
as :

#ifndef _NAMEOFHEADERFILE_H
#define _NAMEOFHEADERFILE_H
<content_of_header_file>
#endif

this i understand that i must use so that this
header will not be processed twice,and it makes
sense to me

i would like to get some help on how to remedy
my problem
thank you

xhi · 08-23-2006, 10:19 AM

what does the declaration of mi_trim_filename look like? is it declared to be extern?

xhi · 08-23-2006, 10:22 AM

oh and what is up with writing like you are a poet? or is your monitor resolution set at 50x75? if not could you try to type clear across the screen. i had to scroll down three times to read two sentences, pretty annoying..

spx2 · 08-23-2006, 10:32 AM

static char *mi_trim_filename( char * file )

xhi · 08-23-2006, 11:20 AM

almost sounds like you have the declaration in one lib and the definition in another. it gives a warning but does not fail because the linker is able to find the function in another lib that is linked in.

something like

Code:

header.h:
static char *mi_trim_filename( char * file );

main.c:
#include <header.h>
int main()
{
...
    mi_trim_filename(...);
...
}

other.c
char *mi_trim_filename( char * file )
{
    ... definition
}

you compile other.c and then compile it in with main.c, main's compile says that mi_trim is not defined, but the linker is happy because it finds mi_trim in other.o..

?? maybe

spx2 · 08-24-2006, 04:46 AM

xhi first of all i would like to thank you for
looking at my post.

now let's hit the code,
mi_trim_filename is declared in a .h
and is defined in the corresponding .c(with
the same name as the .h),and in the same directory

xhi · 08-24-2006, 07:43 AM

which .h file is it declared in?

spx2 · 08-25-2006, 03:01 AM

mi_core.h is the header