make(1) questions

[Paul Chamberlain]

cpcahil at virtech.uucp (Conor P. Cahill) writes:
>pefv700 at perv.pe.utexas.edu writes:
>>I have 2 executables that are "made" using the same sources files.  The only
>>difference is that for one a cpp(1) macro is defined, for the other it is not.
>The easiest way to do this is to create a new rule:

That's alot better than my way.  But just to give an alternative method:

Well, I got it figured out.  Below I have included a makefile for
two hypothetical executables that use the same .c's.  A fringe
benefit is that even if you only have one executable, using this
style of make file will allow you to remove all the .o's and it
still won't recompile anything unless a .c or .h changed.

Paul Chamberlain | I do NOT speak for IBM.          IBM VNET: PAULCC AT AUSTIN
512/838-9662     | ...!cs.utexas.edu!ibmchs!auschs!doorstop.austin.ibm.com!tif

# This is a really bizarre makefile that allows two executables to be made
# from one set of source.  In this example, the exe's are to be compiled
# with slightly different compile lines and libraries.  This should handle
# all manner of interrupted and restarted compiles.

OBJ	= obj1.o obj2.o obj3.o
HFILES	= local1.h local2.h
CFLAGS	= -O $(NAME)
LDFLAGS	= $(OTHER_LIB)

# by default, make both executables
all:	exe1 exe2

clean:
	rm -f *.o making.exe1 making.exe2

# This will prevent recompilation if everything is
# up to date even if no .o's are around.
exe1:	$(OBJ:.o=.c) exe1.c $(HFILES)
	if test ! -f making.exe1;then make clean;fi
	touch making.exe1
	$(MAKE) NAME=-DEXE1 OTHER_LIB=-lx exe1.make

exe1.make:	$(OBJ) exe1.o
	$(CC) $(CFLAGS) $(OBJ) exe1.o $(LDFLAGS) -o exe1

# This will prevent recompilation if everything is
# up to date even if no .o's are around.
exe2:	$(OBJ:.o=.c) exe2.c $(HFILES)
	if test ! -f making.exe2;then make clean;fi
	touch making.exe2
	$(MAKE) NAME=-DEXE2 exe2.make

exe2.make:	$(OBJ) exe2.o
	$(CC) $(CFLAGS) $(OBJ) exe2.o $(LDFLAGS) -o exe2