🚀 go-pugleaf

I'm not sure if this is a bug or a feature.  You tell me:

    I am trying to use a construct like the one demonstrated in the
following makefile.  "all" depends on some program, and that program
depends on the program being built in some other directory ($(BIN)/prog).
Whenever $(BIN)/prog is up-to-date, prog is up-to-date (by my definition).

    This all works fine except for one thing: After gnu make has satisfied
itself that all the dependencies for prog have been met, it then tries to
generate a program called "prog", using some default rule from somewhere.
I explicitely do not want make to take any action of this sort, and the
fact that I've put no commands in the "prog:" target should signify that,
shouldn't it?  HP make and Sun make both do what I consider to be the right
thing (ie, once the prog1 dependency is satisfied, they exit).  (Yes, I
realize that just because HP and Sun do something doesn't make it right ...
and in fact usually indicates otherwise).  I suspect the problem is
aggravated by the fact that there is a prog.c in the current directory.

    I have a workaround in that putting ANY command in the prog: rule
causes it not to attempt to build a "prog".  Even the null command "@" will
prevent it.  But, I have a group here with a hierarchy of Makefiles that
use this feature with HP and Sun make, and they don't want to change the
makefiles, so the workaround does me no good.  I have another group here
that needs some features that GNU make supplies that HP and Sun make don't,
so I'd rather install GNU make all around.

So, is this a bug in gnu make?  Or just a feature? 

Mark

Here's the makefile I mentioned above:
------------------------------------------------------------------------------
# Test makefile to demonstate bug in gnu make.

.SUFFIXES:.o .c

DIR     =       /tmp
BIN     =       $(DIR)/bin
OBJ     =       $(DIR)/obj
CC      =       cc
CFLAGS  =       -g

.c.o:
                $(CC) $(CFLAGS) -c $*.c -o $(OBJ)/$*.o

all:            prog

$(BIN)/prog:    prog.o
                cc -g -o $(BIN)/prog $(OBJ)/prog.o

prog:           $(BIN)/prog

------------------------------------------------------------------------------

Here's a sample run with HP make:

<argon> [825] ->make -f makefile.test
        cc -g -c prog.c -o /tmp/obj/prog.o
        cc -g -o /tmp/bin/prog /tmp/obj/prog.o


-------------------------------------------------------------------------
And here's a sample run with GNU make:

<argon> [827] ->gmake -v -f makefile.test
GNU Make version 3.58, by Richard Stallman and Roland McGrath.
Copyright (C) 1988, 1989, 1990 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

cc -g -c prog.c -o /tmp/obj/prog.o
cc -g -o /tmp/bin/prog /tmp/obj/prog.o
cc   prog.o /tmp/bin/prog   -o prog      <<<<------- This is the funky line
ld: file prog.o cannot be opened
ld: (Warning) did not generate an output file
gmake: *** [prog] Error 1

-------------------------------------------------------------------------

The line marked funky above is where gnu make decided it wasn't done
and invoked some rule from God-knows-where.

Any input appreciated

Mark

cheeks@edsr.eds.com    or     ...uunet!edsr!cheeks