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44 # out-of-date, so X.tag becomes out-of-date, so anything depending on X.tag
45 # (that is, anything including X) becomes out-of-date.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