Re: [Valgrind-users] hardcoded /usr/bin/gdb

[Philippe E. <ph...@wa...>]

Nicholas Nethercote wrote:
> On Thu, 20 Mar 2003, Ruben Garcia wrote:
> 
> 
>>In valgrind 1.0.4 (dont know if this is fixed in development)
>>the location of gdb is hardcoded in vg_main.c as /usr/bin/gdb.
>>
>>Gdb sources, on the other hand, install by default in /usr/local/bin/gdb.
>>Surely a patch to the ./configure to check where gdb is installed cannot
>>be difficult.
> 
> 
> I have this working, but I'm not certain if I've done it the best way.
> 
> Here's what I did:
> 
> - added this to configure.in:
> 
>     AC_PATH_PROG(GDB, gdb)
> 
> - added this to coregrind/Makefile.am:
> 
>     vg_main.o: CFLAGS += -DWHERE_IS_GDB=@GDB@
> 
> - changed coregrind/vg_main.c to use WHERE_IS_GDB for the path.
> 
> This works, but it would be better if the GDB variable was put into a .h
> file, so it's available everywhere -- that's better than having to feed it
> in to every file that needs it with -D.  This could be done by introducing
> eg. vg_skin.h.in, but that would be a pain, especially just for one
> variable.
> 
> I tried various ways to get the WHERE_IS_GDB variable put into config.h,
> but didn't manage... this would be a better solution.  Does anyone know
> how to do this?

Yes, it's a better way but the trivial:

AC_PATH_PROG(GDB, gdb)
AC_DEFINE(GDB_PATH, @GDB@, "gdb path")
AC_SUBST(GDB)

doesn't work cause configure don't do subsititution in
config.h.in when creating config.h, I don't think there is
any way to put it in config.h.in. I work around by doing:

** configure.in:

AC_PATH(GDB_PATH, gdb)
AC_SUBST(GDB_PATH)

AC_OUTPUT( .... \
	path-1.h)

AX_COPY_IF_CHANGE(path-1.h, path.h)


$ cat path-1.h.in

#define GDB_PATH @GDB_PATH@


$ cat copyifchange.m4

dnl AX_COPY_IF_CHANGE(source, dest)
dnl copy source to dest if they don't compare equally or if dest doesn't 
exist
AC_DEFUN(AX_COPY_IF_CHANGE, [
if test -r $2; then
	if cmp $1 $2 > /dev/null; then
		echo $2 is unchanged
	else
		cp -f $1 $2
	fi
else
	cp -f $1 $2
fi
])

I use path-1.h and  copyifchange to avoid spurious recompilation
when you configure and nothing change in path-1.h. (configure take
care to not change time stamp of config.h if unnecessary but
doesn't do the same thing for other .in translation)

Not very elegant but the only way I found

The only required file in cvs/tarball is path-1.h.in

regards,
Phil