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36 GNU make

If none of the explicit rules for a target has a recipe, then make searches for an applicable

implicit rule to ﬁnd one see Chapter 10 [Using Implicit Rules], page 111).

4.11 Static Pattern Rules

Static pattern rules are rules which specify multiple targets and construct the prerequisite

names for each target based on the target name. They are more general than ordinary rules

with multiple targets because the targets do not have to have identical prerequisites. Their

prerequisites must be analogous, but not necessarily identical.

4.11.1 Syntax of Static Pattern Rules

Here is the syntax of a static pattern rule:

targets ...: target-pattern: prereq-patterns ...

recipe

...

The targets list speciﬁes the targets that the rule applies to. The targets can contain

wildcard characters, just like the targets of ordinary rules (see Section 4.3 [Using Wildcard

Characters in File Names], page 23).

The target-pattern and prereq-patterns say how to compute the prerequisites of each

target. Each target is matched against the target-pattern to extract a part of the target

name, called the stem. This stem is substituted into each of the prereq-patterns to make

the prerequisite names (one from each prereq-pattern).

Each pattern normally contains the character ‘%’ just once. When the target-pattern

matches a target, the ‘%’ can match any part of the target name; this part is called the

stem. The rest of the pattern must match exactly. For example, the target foo.o matches

the pattern ‘%.o’, with ‘foo’ as the stem. The targets foo.c and foo.out do not match

that pattern.

The prerequisite names for each target are made by substituting the stem for the ‘%’ in

each prerequisite pattern. For example, if one prerequisite pattern is %.c, then substitution

of the stem ‘foo’ gives the prerequisite name foo.c. It is legitimate to write a prerequisite

pattern that does not contain ‘%’; then this prerequisite is the same for all targets.

‘%’ characters in pattern rules can be quoted with preceding backslashes (‘\’). Back-

slashes that would otherwise quote ‘%’ characters can be quoted with more backslashes.

Backslashes that quote ‘%’ characters or other backslashes are removed from the pattern

before it is compared to ﬁle names or has a stem substituted into it. Backslashes that

are not in danger of quoting ‘%’ characters go unmolested. For example, the pattern

the\%weird\\%pattern\\ has ‘the%weird\’ preceding the operative ‘%’ character, and

‘pattern\\’ following it. The ﬁnal two backslashes are left alone because they cannot

aﬀect any ‘%’ character.

Here is an example, which compiles each of foo.o and bar.o from the corresponding .c

ﬁle:

1 2 ... 41 42 43 44 45 46 47 48 49 50 51 ... 211 212

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Roland Ver. 4.5 Informações Técnicas Página 46