make: Special Targets
4.9 Special Built-in Target Names
=================================
Certain names have special meanings if they appear as targets.
'.PHONY'
The prerequisites of the special target '.PHONY' are considered to
be phony targets. When it is time to consider such a target,
'make' will run its recipe unconditionally, regardless of whether a
file with that name exists or what its last-modification time is.
Phony Targets Phony Targets.
'.SUFFIXES'
The prerequisites of the special target '.SUFFIXES' are the list of
suffixes to be used in checking for suffix rules.
Old-Fashioned Suffix Rules Suffix Rules.
'.DEFAULT'
The recipe specified for '.DEFAULT' is used for any target for
which no rules are found (either explicit rules or implicit rules).
Last Resort. If a '.DEFAULT' recipe is specified, every
file mentioned as a prerequisite, but not as a target in a rule,
will have that recipe executed on its behalf. Implicit Rule
Search Algorithm Implicit Rule Search.
'.PRECIOUS'
The targets which '.PRECIOUS' depends on are given the following
special treatment: if 'make' is killed or interrupted during the
execution of their recipes, the target is not deleted.
Interrupting or Killing 'make' Interrupts. Also, if the target is
an intermediate file, it will not be deleted after it is no longer
needed, as is normally done. Chains of Implicit Rules
Chained Rules. In this latter respect it overlaps with the
'.SECONDARY' special target.
You can also list the target pattern of an implicit rule (such as
'%.o') as a prerequisite file of the special target '.PRECIOUS' to
preserve intermediate files created by rules whose target patterns
match that file's name.
'.INTERMEDIATE'
The targets which '.INTERMEDIATE' depends on are treated as
intermediate files. Chains of Implicit Rules Chained Rules.
'.INTERMEDIATE' with no prerequisites has no effect.
'.SECONDARY'
The targets which '.SECONDARY' depends on are treated as
intermediate files, except that they are never automatically
deleted. Chains of Implicit Rules Chained Rules.
'.SECONDARY' with no prerequisites causes all targets to be treated
as secondary (i.e., no target is removed because it is considered
intermediate).
'.SECONDEXPANSION'
If '.SECONDEXPANSION' is mentioned as a target anywhere in the
makefile, then all prerequisite lists defined _after_ it appears
will be expanded a second time after all makefiles have been read
in. Secondary Expansion Secondary Expansion.
'.DELETE_ON_ERROR'
If '.DELETE_ON_ERROR' is mentioned as a target anywhere in the
makefile, then 'make' will delete the target of a rule if it has
changed and its recipe exits with a nonzero exit status, just as it
does when it receives a signal. Errors in Recipes Errors.
'.IGNORE'
If you specify prerequisites for '.IGNORE', then 'make' will ignore
errors in execution of the recipe for those particular files. The
recipe for '.IGNORE' (if any) is ignored.
If mentioned as a target with no prerequisites, '.IGNORE' says to
ignore errors in execution of recipes for all files. This usage of
'.IGNORE' is supported only for historical compatibility. Since
this affects every recipe in the makefile, it is not very useful;
we recommend you use the more selective ways to ignore errors in
specific recipes. Errors in Recipes Errors.
'.LOW_RESOLUTION_TIME'
If you specify prerequisites for '.LOW_RESOLUTION_TIME', 'make'
assumes that these files are created by commands that generate low
resolution time stamps. The recipe for the '.LOW_RESOLUTION_TIME'
target are ignored.
The high resolution file time stamps of many modern file systems
lessen the chance of 'make' incorrectly concluding that a file is
up to date. Unfortunately, some hosts do not provide a way to set
a high resolution file time stamp, so commands like 'cp -p' that
explicitly set a file's time stamp must discard its sub-second
part. If a file is created by such a command, you should list it
as a prerequisite of '.LOW_RESOLUTION_TIME' so that 'make' does not
mistakenly conclude that the file is out of date. For example:
.LOW_RESOLUTION_TIME: dst
dst: src
cp -p src dst
Since 'cp -p' discards the sub-second part of 'src''s time stamp,
'dst' is typically slightly older than 'src' even when it is up to
date. The '.LOW_RESOLUTION_TIME' line causes 'make' to consider
'dst' to be up to date if its time stamp is at the start of the
same second that 'src''s time stamp is in.
Due to a limitation of the archive format, archive member time
stamps are always low resolution. You need not list archive
members as prerequisites of '.LOW_RESOLUTION_TIME', as 'make' does
this automatically.
'.SILENT'
If you specify prerequisites for '.SILENT', then 'make' will not
print the recipe used to remake those particular files before
executing them. The recipe for '.SILENT' is ignored.
If mentioned as a target with no prerequisites, '.SILENT' says not
to print any recipes before executing them. This usage of
'.SILENT' is supported only for historical compatibility. We
recommend you use the more selective ways to silence specific
recipes. Recipe Echoing Echoing. If you want to silence
all recipes for a particular run of 'make', use the '-s' or
'--silent' option (Options Summary).
'.EXPORT_ALL_VARIABLES'
Simply by being mentioned as a target, this tells 'make' to export
all variables to child processes by default. Communicating
Variables to a Sub-'make' Variables/Recursion.
'.NOTPARALLEL'
If '.NOTPARALLEL' is mentioned as a target, then this invocation of
'make' will be run serially, even if the '-j' option is given. Any
recursively invoked 'make' command will still run recipes in
parallel (unless its makefile also contains this target). Any
prerequisites on this target are ignored.
'.ONESHELL'
If '.ONESHELL' is mentioned as a target, then when a target is
built all lines of the recipe will be given to a single invocation
of the shell rather than each line being invoked separately (
Recipe Execution Execution.).
'.POSIX'
If '.POSIX' is mentioned as a target, then the makefile will be
parsed and run in POSIX-conforming mode. This does _not_ mean that
only POSIX-conforming makefiles will be accepted: all advanced GNU
'make' features are still available. Rather, this target causes
'make' to behave as required by POSIX in those areas where 'make''s
default behavior differs.
In particular, if this target is mentioned then recipes will be
invoked as if the shell had been passed the '-e' flag: the first
failing command in a recipe will cause the recipe to fail
immediately.
Any defined implicit rule suffix also counts as a special target if
it appears as a target, and so does the concatenation of two suffixes,
such as '.c.o'. These targets are suffix rules, an obsolete way of
defining implicit rules (but a way still widely used). In principle,
any target name could be special in this way if you break it in two and
add both pieces to the suffix list. In practice, suffixes normally
begin with '.', so these special target names also begin with '.'.
Old-Fashioned Suffix Rules Suffix Rules.
Info Catalog
make: Empty Targets
make: Rules
make: Multiple Targets