Multiple Builds From Same Source

[cramerj]

Hello,

I am trying to build a 32-bit and 64-bit library using the same source with 
just one invocation of Make.  Unfortunately, I can't seem to figure out how to 
tell Make to delete the intermediate files before trying to build the second 
library.  The object files persist in Make's database so that it performs the 
archive of the second target using the first target's object files.  Only after 
that is done, Make will then delete the object files (as expected).  Also, if 
you have any "facepalm" moments with this example, feel free to let me know. :)

...

$ cat Makefile
CPPFLAGS += -O3
NATIVE_ARCH := $(shell uname -m)

ifeq "$(NATIVE_ARCH)" "x86_64"
COMPAT_FLAG := -m32
TARGETS := i386 x86_64
else
TARGETS := i386
endif

SOURCES := a.cpp b.cpp c.cpp
MEMBERS := $(SOURCES:.cpp=.o)

ARFLAGS := rcs

all: $(TARGETS)

i386: CXXFLAGS += $(COMPAT_FLAG)
i386: path/to/32b/library.a($(MEMBERS))

x86_64: path/to/64b/library.a($(MEMBERS))


$ make
g++ -m32 -O3  -c -o a.o a.cpp
ar rcs path/to/32b/library.a a.o
g++ -m32 -O3  -c -o b.o b.cpp
ar rcs path/to/32b/library.a b.o
g++ -m32 -O3  -c -o c.o c.cpp
ar rcs path/to/32b/library.a c.o
ar rcs path/to/64b/library.a a.o
ar rcs path/to/64b/library.a b.o
ar rcs path/to/64b/library.a c.o
rm a.o b.o c.o

...

I tried adding i386 and x86_64 to the .PHONY target just as a stab in the dark, 
but no luck.

Thanks,
-Jeb