Here is an interesting problem I've stumbled on. I have an application. We are adding support for a new version of a low level third party library. The previous release required me to link against Linux Streams.

Our new prototype system doesn't need Linux Streams. I don't want to have two Makefile for this single discrepency; but if I try to link to Linux Streams on the new prototype, the applications no longer compiles.

Basically, in make, I'd like to call a script (to determine whether I need Linux Streams), and edit my library listing accordingly. I wrote the script easy enough (for this example named isver.sh), but…

ATTEMPT (A)

So, given:

LIBLIST = -ldxxx -ldti -ldl -lsrl

switch : $(OBJECTS)
         ./isver.sh DLGCcom 6 || $(eval LIBLIST += -lLiS)
         gcc $(OBJECTS) $(LIBLIST)  -o switch

RESULT: This looked promising by doesn't work since the eval is not in the Makefile context.

ATTEMPT (B)

The closest I could get was:…

RESULT: This gets the job done but is excruciatingly UGLY!

> Q:Does anyone know a better "outside the box" method for accomplishing
> something like this?

$ cat Makefile

LIBLIST := -ldxxx -ldti -ldl -lsrl $(shell ./isver.sh || echo "-lLiS")

all:
        @echo "LIBLIST = $(LIBLIST)"

$ ln -sf /bin/true isver.sh && make
LIBLIST = -ldxxx -ldti -ldl -lsrl
$ ln -sf /bin/false isver.sh && make
LIBLIST = -ldxxx -ldti -ldl -lsrl -lLiS

LIBLIST := -ldxxx -ldti -ldl -lsrl $(shell ./isver.sh)