Runtime macros

Runtime macros receive values as make is making targets. They take on different values for each target. These are the recognized runtime macros:

$@

Evaluates to the full name of the target, when building a normal target. When building a library, it expands to the name of the archive library. For example, if the target is mylib(member), $@ expands to mylib.

$%

Also evaluates to the full name of the target, when building a normal target. When building a library, it expands to the name of the archive member. In the previous example, $% expands to member.

$&

Evaluates to the list of all prerequisites, in all rules that apply to the target.

$?

Evaluates to the list of all prerequisites that are newer than the target. In inference rules, however, this macro evaluates to the same value as the $^ macro.

$>

Evaluates to the name of the library if the current target is a library member. For example, if the target is mylib(member), $> expands to mylib.

$^

Evaluates to the list of prerequisites given in the rule that contains the recipe make is executing.

$<

In normal rules, it evaluates the same as $?. In inference rules it evaluates to the single prerequisite that causes the execution of the rule.

$*

Is equivalent to $(%:db). This expands to the target name with no suffix.

$$

Expands to $.

The following example illustrates the difference between these:

a.o : a.c
a.o : b.h c.h
      recipe for making a.o

Assume a.c and c.h are newer than a.o, whereas b.h is not. When make executes the recipe for a.o, the macros expand to the following values:

$@  →  a.o
$*  →  a
$&  →  a.c b.h c.h
$?  →  a.c c.h
$^  →  b.h c.h
$<  →  b.h c.h

Consider this example of a library target:

mylib(mem1.o):
	recipe…

For this target, the internal macros then expand to:

$@  →  mylib
$*  →  mem1
$>  →  mylib