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.\" aegis - project change supervisor
.\" Copyright (C) 1998, 2006-2008, 2010, 2012 Peter Miller
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.nr PS 72
.nr VS 75000
.LP
.ad c
How Make Works
.br
.ad l
.sp 0.3i
.nr PS 36
.nr VS 37
.XP
\(bu
The Makefile is turned into pair\[hy]wise ordered dependencies.
.br
.ps 16
.vs 17
.sp 0.5
.TS
tab(;);
lf(CW) l.
prog: a.o b.o;prog \(<- a.o
    cc a.o b.o \-o prog;prog \(<- b.o
.sp 0.5
a.o: a.c a.h;a.o \(<- a.c
    cc \-c a.c;a.o \(<- a.h
.sp 0.5
b.o: b.c a.h;b.o \(<- b.c
    cc \-c b.c;b.o \(<- a.h
.sp 0.5
a.c a.h: a.y;a.c \(<- a.y
    yacc \-d a.y;a.h \(<- a.y
    \fImv \&...\fI
.TE
.XP
\(bu
The pairs are then shuffled to find a valid ordering.
.bp
.nr PS 24
.nr VS 25
.XP
\(bu
The Makefile is turned into pair\[hy]wise ordered dependencies.
.XP
\(bu
The order of appearance of the rules in the Makefile doesn't mean anything.
.XP
\(bu
There is more than one valid ordering.
.XP
\(bu
Recall \fIlorder\fP and \fItsort\fP from the days before \fIranlib\fP?
Same thing.
.br
\(dg Only nastier, because of pattern rules.
.\" vim: set ts=8 sw=4 et :