Re: gcc with glib

[Brian Dessent <brian at dessent dot net>]

PRIEUR Christophe RD-TECH-ISS wrote:

> Okay!  You're right, it works.  I guess some versions of gcc are a bit
> more open-minded on this issue (trying to save my self-esteem of old C
> programmer).

It has nothing to do with gcc.  It's a property of the linker (ld) which
is a separate external program, and this behavior is as old as unix,
i.e. it's been this way forever.

What you might have been trying to say is that on some ELF systems such
as Linux or Solaris the order doesn't matter, but this is true only when
linking with shared libraries.  The order must still be correct even on
these systems when linking with static archives.  Try the following on
Linux:

$ echo "int foo (void) { return 42; }" > foo.c && \
cc -c foo.c -o foo.o && \
ar rcs libfoo.a foo.o && \
echo 'extern int foo (void);
int main (int c, char **v) { return foo (); }' > main.c && \
cc -c main.c -o main.o && \
cc -L. -lfoo main.o -o main
main.o: In function `main':
main.c:(.text+0x1d): undefined reference to `foo'
collect2: ld returned 1 exit status

$ cc main.o -L. -lfoo -o main && ./main ; echo $?
42

Brian

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