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Re: linking application with a library


Hi Mohammad,
The --gc-sections remove unwanted section. But I think it is implemented
only for ELF for some targets. For hms it does not work. Try with
h8300-elf-ld.
Regards,
Anita Kulkarni

----- Original Message -----
From: Mohammad Saleem <mosa@enea.se>
To: <cygwin@cygwin.com>; <crossgcc@sources.redhat.com>
Sent: Sunday, November 18, 2001 5:25 PM
Subject: Re: linking application with a library


> Hi David,
>
> Thanks for your input.
>
> I tried with the flags you mentioned in your mail like:
>
> # how to compile C source
> %.o: %.c
>     @echo compiling $<
>     $(CC) -ffunction-sections -fdata-sections $(CFLAGS)  $(INCLUDE) $<
> -o    $@
>
> Even with link I tried with a flag --gc-sections (found by searching in
> mail archives) like:
>
> test.srec: $(OBJ) appcon.o
>     $(LD) --gc-sections $(LDFLAGS)   $^ mylib.a $(LIBS) -o $@
>
>
>
> But still I get the same size of srec as before, i.e my application is
> increased by the size of mylib.a even without any function call from
> mylib.a, along with a number of warnings like:
>
> ********************************************
> compiling appcon.c
> h8300-hitachi-hms-ld: warning: no memory region specified for section
> `._init'
> h8300-hitachi-hms-ld: warning: no memory region specified for section
> `.configu'
> h8300-hitachi-hms-ld: warning: no memory region specified for section
> `.timerIn'
> *************************************************
>
> What am I doing something wrong?
>
> regards
>
> /Mohammad
>
>
>
> David Korn wrote:
>
> >>-----Original Message-----
> >>From: Mohammad Saleem [mailto:mosa@enea.se]
> >>Sent: 18 November 2001 10:36
> >>
> >
> >
> >>I have a lib mylib.a (20 kb) which I want to link with my application.
> >>My application gets 20 kb bigger as soon as I link it with mylib.a
> >>without any function being called from mylib.a.
> >>It seems to me that I have built mylib.a so that the whole lib
> >>is linked
> >>during linking process even if no one method is being called.
> >>Now my question is which flag should I use to build mylib.a so
> >>that only
> >>those functions are linked which are being called.
> >>If no function is called then linking mylib.a shouldn't affect
> >>the size
> >>of my application.
> >>
> >
> >  Alas, the linker is fairly dumb, and can only include or exclude parts
> >of a lib file on the basis of the section name (.text, .data or .bss).
> >
> >  Fortunately the compiler is fairly smart, and has an option
> >-ffunction-sections that puts every function in a different section.
This
> >should supposedly do the job you wish.
> >
> >      DaveK
> >
>
>
>
>
> ------
> Want more information?  See the CrossGCC FAQ,
http://www.objsw.com/CrossGCC/
> Want to unsubscribe? Send a note to
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>


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