The Source Integrity Professional Edition User Guide - MKS

and
$(TEST:+".c")
expands to
main.c func1.c func2.c
Controlling MKS Make
If the prefix and suffix strings themselves consist of a list of tokens
separated by blanks, the resulting expansion provides the cross
product of both lists. Consider the following example using a
different value for the TEST macro.
TEST = a b c
$(TEST:^"1 2 3")
expands to
and
1a 1b 1c 2a 2b 2c 3a 3b 3c
$(TEST:+"1 2 3")
expands to
a1 b1 c1 a2 b2 c2 a3 b3 c3
If you combine these two references
$(TEST:^"1 2 3":+"1 2 3")
expands to
Controlling MKS Make
For a complete technical
description, see the man page
for the make command.
Attributes
1a1 1b1 1c1 2a1 2b1 2c1 3a1 3b1 3c1
1a2 1b2 1c2 2a2 2b2 2c2 3a2 3b2 3c2
1a3 1b3 1c3 2a3 2b3 2c3 3a3 3b3 3c3
This chapter has covered a few ways to control the way MKS Make
proceeds when rebuilding a file. To really control its behavior, you
need to understand how to use attributes, special targets, and special
macros.
This section introduces you to these concepts and describes some
commonly used examples.
Attributes represent qualities that you can attach to targets. When
make updates a target, it triggers any attributes associated with that
target.
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