Intel XENIX 286 Programmers Guide (86) - Tenox.tc

make: Program Maintainer XENIX Programming
If a dependency line is too long, you can continue it by typing a backslash (\)
immediately followed by a newline character.
The makefile should be kept in the same directory as the given source files. For
convenience, the file names makefile, Makefile, s.makefile, and s.Makefile are provided
as default file names used by make if no explicit name is given at invocation. You may
use one of these names for your makefile or choose one of your own. If the file name
begins with the s. prefix, make assumes that it is an sees file and invokes the
appropriate sees command to retrieve the latest version of the file.
To illustrate dependency lines, consider the following example. A program named prog
is made by linking three object files, x.o, y.o, and z.o. These object files are created by
compiling the e language source files x.c, y.c, and z.c. Furthermore, the files x.c and
y.c contain the line
#include "defs"
This means that prog depends on the three object files, the object files depend on the e
source files, and two of the source files depend on the include file defs. You can
represent these relationships in a makefile with the following lines
prog : x.o y.o z.o
cc x.o y.o z.o -o prog
x.o: x.c defs
cc -c x.c
y.o: y.c defs
cc -c y.c
z.o: z.c
cc -c z.c
In the first dependency line, prog is the target file and x.o, y.o, and z.o are its
dependents. The command sequence
cc x.o y.o z.o -o prog
on the next line tells how to create prog if it is out of date. The program is out of date
if any one of its dependents has been modified since prog was last created.
The second, third, and fourth dependency lines have the same form, with the x.o, y.o,
and z.o files as targets and x.c, y.c, z.c, and defs files as dependents. Each dependency
line has one command sequence that defines how to update the given target file.
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