[bigint/bigint.git] / Makefile

#
# Matt McCutchen's Big Integer Library
# http://mysite.verizon.net/mccutchen/bigint/
#

# The implicit rules we need
%.tag : %
	touch $@
%.o : %.cc
	g++ -c -O -Wall -Wextra -pedantic $<

# Default target
library : NumberlikeArray.hh.tag BigUnsigned.o BigInteger.o BigUnsignedInABase.o BigIntegerUtils.o

# Extra `include' dependencies
BigUnsigned.hh.tag : NumberlikeArray.hh.tag
BigUnsigned.o : BigUnsigned.hh.tag
BigInteger.hh.tag : BigUnsigned.hh.tag
BigInteger.o : BigInteger.hh.tag
BigUnsignedInABase.hh.tag : BigUnsigned.hh.tag
BigUnsignedInABase.o : BigUnsignedInABase.hh.tag
BigIntegerUtils.hh.tag : BigInteger.hh.tag
BigIntegerUtils.o : BigIntegerUtils.hh.tag

# sample program
sample : library sample.cc
	g++ -osample *.o sample.cc

clean :
	rm -f *.tag *.o sample

# The ``.tag'' mechanism allows for proper recompilation when a header file
# changes, considering that some header files may include others.
#
# If a header file X includes other header
# files Y and Z, we create a file X.tag that depends
# on X, Y.tag, and Z.tag.  Other headers that include X should
# depend on X.tag.
#
# Suppose Y is subsequently changed.  X doesn't get ``recompiled'',
# but anything that includes X should be recompiled.  Well, Y.tag becomes
# out-of-date, so X.tag becomes out-of-date, so anything depending on X.tag
# (that is, anything including X) becomes out-of-date.  Magic!
#
# In this system, the tag files are empty files used only for their
# timestamps.  If one wished to use precompiled headers, one could use
# ``.gch'' files exactly how ``.tag'' files are used now, except that
# their contents would be meaningful.
#
# However, the same sort of ``deadly diamond'' problem that surfaces with
# multiple inheritance also applies to precompiled headers.  The ``#ifndef''
# mechanism that prevents multiple inclusion doesn't work when headers are
# compiled independently in a hierarchical structure, since the second
# inclusion of a file won't even know there was a first inclusion.  For
# this reason, I just use ``.tag''s.
Commit	Line	Data
e67d6049 MM	1	#
e67d6049 MM	2	# Matt McCutchen's Big Integer Library
b3fe29df	3	# http://mysite.verizon.net/mccutchen/bigint/
e67d6049	4	#
e67d6049	5
05780f4b MM	6	# The implicit rules we need
	7	%.tag : %
	8	touch $@
	9	%.o : %.cc
	10	g++ -c -O -Wall -Wextra -pedantic $<
e67d6049	11
05780f4b MM	12	# Default target
05780f4b MM	13	library : NumberlikeArray.hh.tag BigUnsigned.o BigInteger.o BigUnsignedInABase.o BigIntegerUtils.o
e67d6049	14
05780f4b MM	15	# Extra `include' dependencies
	16	BigUnsigned.hh.tag : NumberlikeArray.hh.tag
	17	BigUnsigned.o : BigUnsigned.hh.tag
	18	BigInteger.hh.tag : BigUnsigned.hh.tag
	19	BigInteger.o : BigInteger.hh.tag
	20	BigUnsignedInABase.hh.tag : BigUnsigned.hh.tag
	21	BigUnsignedInABase.o : BigUnsignedInABase.hh.tag
	22	BigIntegerUtils.hh.tag : BigInteger.hh.tag
	23	BigIntegerUtils.o : BigIntegerUtils.hh.tag
e67d6049	24
05780f4b MM	25	# sample program
	26	sample : library sample.cc
	27	g++ -osample *.o sample.cc
e67d6049	28
05780f4b MM	29	clean :
05780f4b MM	30	rm -f .tag .o sample
e67d6049	31
05780f4b MM	32	# The ``.tag'' mechanism allows for proper recompilation when a header file
	33	# changes, considering that some header files may include others.
	34	#
	35	# If a header file X includes other header
	36	# files Y and Z, we create a file X.tag that depends
	37	# on X, Y.tag, and Z.tag. Other headers that include X should
	38	# depend on X.tag.
	39	#
	40	# Suppose Y is subsequently changed. X doesn't get ``recompiled'',
	41	# but anything that includes X should be recompiled. Well, Y.tag becomes
	42	# out-of-date, so X.tag becomes out-of-date, so anything depending on X.tag
	43	# (that is, anything including X) becomes out-of-date. Magic!
	44	#
	45	# In this system, the tag files are empty files used only for their
	46	# timestamps. If one wished to use precompiled headers, one could use
	47	# ``.gch'' files exactly how ``.tag'' files are used now, except that
	48	# their contents would be meaningful.
	49	#
	50	# However, the same sort of ``deadly diamond'' problem that surfaces with
	51	# multiple inheritance also applies to precompiled headers. The ``#ifndef''
	52	# mechanism that prevents multiple inclusion doesn't work when headers are
	53	# compiled independently in a hierarchical structure, since the second
	54	# inclusion of a file won't even know there was a first inclusion. For
	55	# this reason, I just use ``.tag''s.