Re: how to fully qualify entries in a "-I" list?

[Robert P. J. Day]

On Tue, 20 Nov 2007, Greg Chicares wrote:

> On 2007-11-20 11:02Z, Robert P. J. Day wrote:
> >   wanted:  a simple way to transform the string (and its entries):
> >
> >     -Ia -I/b -Ic -I/d
> >
> > to
> >
> >     -I/src/a -I/b -I/src/c -I/d
> >
> > in short, wherever an entry represents a location that is *not*
> > fully-qualified, i want to replace that entry with one that is now
> > fully-qualified (and for which i will supply the appropriate prefix).
>
> /tmp[0]$cat subst.make
> original := -Ia -I/b -Ic -I/d
> modified := $(shell echo $(original) | sed -e 's|-I\([^/]\)|-I/src/\1|g')
>
> .PHONY: all
> all:
>       @echo original: $(original)
>       @echo modified: $(modified)
>
> /tmp[0]$make -f subst.make
> original: -Ia -I/b -Ic -I/d
> modified: -I/src/a -I/b -I/src/c -I/d
>
> >   is there a simple way to do with one "patsubst" operator?
>
> I don't see how to do it with just one.

actually, i came up with this, which is done in two parts, but needs
only one patsubst:

        $(patsubst -I%,-I$(srctree)/%,$(filter-out -I/%,$(1))) \
        $(filter -I/%,$(1))

obviously, the first line handles the cases where there is *no* slash
and applies the transformation i want, while the second simply scarfs
up the remainder unchanged.

> > i can see
> > a couple obvious ways with "foreach", but the tricky bit is that i'm
> > trying to invoke patsubst in places that *don't* match a given pattern
> > (that being "-I/").
>
> What transformation do you want for "-I/"?

none at all but, as you can see, i have something that appears to
work.

rday

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Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://crashcourse.ca
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