Certain names have special meanings if they appear as targets.
.PHONY.PHONY are considered to
be phony targets. When it is time to consider such a target,
make will run its commands unconditionally, regardless of
whether a file with that name exists or what its last-modification
time is. See Phony Targets.
.SUFFIXES.SUFFIXES are the list
of suffixes to be used in checking for suffix rules.
See Old-Fashioned Suffix Rules.
.DEFAULT.DEFAULT are used for any target for
which no rules are found (either explicit rules or implicit rules).
See Last Resort. If .DEFAULT commands are specified, every
file mentioned as a prerequisite, but not as a target in a rule, will have
these commands executed on its behalf. See Implicit Rule Search Algorithm.
.PRECIOUS.PRECIOUS depends on are given the following
special treatment: if make is killed or interrupted during the
execution of their commands, the target is not deleted.
See Interrupting or Killing make. Also, if the
target is an intermediate file, it will not be deleted after it is no
longer needed, as is normally done. See Chains of Implicit 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.INTERMEDIATE depends on are treated as
intermediate files. See Chains of Implicit Rules.
.INTERMEDIATE with no prerequisites has no effect.
.SECONDARY.SECONDARY depends on are treated as
intermediate files, except that they are never automatically deleted.
See Chains of Implicit 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.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.
See Secondary Expansion.
The prerequisites of the special target .SUFFIXES are the list
of suffixes to be used in checking for suffix rules.
See Old-Fashioned Suffix Rules.
.DELETE_ON_ERROR.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 commands exit with a nonzero exit status, just as it
does when it receives a signal. See Errors in Commands.
.IGNORE.IGNORE, then make will
ignore errors in execution of the commands run for those particular
files. The commands for .IGNORE are not meaningful.
If mentioned as a target with no prerequisites, .IGNORE says to
ignore errors in execution of commands for all files. This usage of
‘.IGNORE’ is supported only for historical compatibility. Since
this affects every command in the makefile, it is not very useful; we
recommend you use the more selective ways to ignore errors in specific
commands. See Errors in Commands.
.LOW_RESOLUTION_TIME.LOW_RESOLUTION_TIME,
make assumes that these files are created by commands that
generate low resolution time stamps. The commands for
.LOW_RESOLUTION_TIME are not meaningful.
The high resolution file time stamps of many modern hosts lessen the
chance of make incorrectly concluding that a file is up to
date. Unfortunately, these hosts provide no 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 subsecond 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 subsecond 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.SILENT, then make will
not print the commands to remake those particular files before executing
them. The commands for .SILENT are not meaningful.
If mentioned as a target with no prerequisites, .SILENT says not
to print any commands before executing them. This usage of
‘.SILENT’ is supported only for historical compatibility. We
recommend you use the more selective ways to silence specific commands.
See Command Echoing. If you want to silence all commands
for a particular run of make, use the ‘-s’ or
‘--silent’ option (see Options Summary).
.EXPORT_ALL_VARIABLESmake to
export all variables to child processes by default.
See Communicating Variables to a Sub-make.
.NOTPARALLEL.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 be run in
parallel (unless its makefile contains this target). Any prerequisites
on this target are ignored.
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 ‘.’. See Old-Fashioned Suffix Rules.