Re: [PATCH, driver] -Wl, passing empty strings to ld

[Paolo Bonzini <bonzini at gnu dot org>]

On 04/15/2010 09:44 AM, Jim Wilson wrote:
> > >  What if an ld option makes sense with an empty argument, e.g. -Wl,-h, or
> > >  -Wl,-l, ?  It's a borderline case, I know, and I suppose you can do
> > >  -Xlinker '', but it seems like an arbitrary limitation for an option
> > >  that does pass-through by definition.
> The xgcc driver is constructing an argv array, and one of the entries in
> the argv array is pointing at a zero-length string.  There is no way to
> type such a thing on a shell command line.  You can certainly type
> something like '' which would be a 2 character string as an argument,

I don't follow, it would be a 0 character string in argv. '' or "" is 
exactly how you put a zero-length string on the command-line.

> but you can't type nothing in the middle of a command line and expect it
> to be interpreted as an argument to ld.

That's just how the shell works.  You can pass s/abc// or s,abc,, to sed 
or vi and it does exactly what you'd think, I don't see why gcc's 
-W[alp],arg1,arg2,...,argN options should be different.

Paolo