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MAKE(1) DragonFly General Commands Manual MAKE(1)
NAME
make - maintain program dependencies
SYNOPSIS
make [-ABPSXeiknpqrstv] [-C directory] [-D variable] [-d flags]
[-E variable] [-f makefile] [-I directory] [-j max_jobs]
[-m directory] [-V variable] [-x warning_options] [variable=value]
[target ...]
DESCRIPTION
The make utility is a program designed to simplify the maintenance of
other programs. Its input is a list of specifications describing
dependency relationships between the generation of files and programs.
First of all, the initial list of specifications will be read from the
system makefile, sys.mk, unless inhibited with the -r option. The
standard sys.mk as shipped with FreeBSD also handles make.conf(5), the
default path to which can be altered via the make variable __MAKE_CONF.
Then the first of BSDmakefile, makefile, and Makefile that can be found
in the current directory, object directory (see .OBJDIR), or search path
(see the -I option) will be read for the main list of dependency
specifications. A different makefile or list of them can be supplied via
the -f option(s). Finally, if the file .depend can be found in any of
the aforesaid locations, it will also be read (see mkdep(1)).
When make searches for a makefile, its name takes precedence over its
location. For instance, BSDmakefile in the object directory will be
favored over Makefile in the current directory.
The options are as follows:
-A Make archive errors non-fatal, causing make to just skip the
remainder or all of the archive and continue after printing a
message.
-B Try to be backwards compatible by executing a single shell per
command and by executing the commands to make the sources of a
dependency line in sequence. This is turned on by default unless
-j is used.
-C directory
Change to directory before reading the makefiles or doing
anything else. If multiple -C options are specified, each is
interpreted relative to the previous one: -C / -C etc is
equivalent to -C /etc.
-D variable
Define variable to be 1, in the global context.
-d flags
Turn on debugging, and specify which portions of make are to
print debugging information. Argument flags is one or more of
the following:
A Print all possible debugging information; equivalent to
specifying all of the debugging flags.
a Print debugging information about archive searching and
caching.
c Print debugging information about conditional evaluation.
d Print debugging information about directory searching and
caching.
f Print debugging information about the execution of for
loops.
g1 Print the input graph before making anything.
g2 Print the input graph after making everything, or before
exiting on error.
j Print debugging information about running multiple
shells.
l Print commands in Makefiles regardless of whether or not
they are prefixed by @ or other "quiet" flags. Also
known as "loud" behavior.
m Print debugging information about making targets,
including modification dates.
s Print debugging information about suffix-transformation
rules.
t Print debugging information about target list
maintenance.
v Print debugging information about variable assignment.
-E variable
Specify a variable whose environment value (if any) will override
macro assignments within makefiles.
-e Specify that environment values override macro assignments within
makefiles for all variables.
-f makefile
Specify a makefile to read instead of the default one. If
makefile is not an absolute pathname, make will search for it as
described above. In case makefile is `-', standard input is
read. Multiple -f options can be supplied, and the makefiles
will be read in that order. Unlike the other command-line
options, -f is neither stored in .MAKEFLAGS nor pushed down to
sub-makes via MAKEFLAGS. See below for more details on these
variables.
-I directory
Specify a directory in which to search for makefiles and included
makefiles. Multiple -I options can be specified to form a search
path. The system makefile directory (or directories, see the -m
option) is automatically appended at the tail of this path.
-i Ignore non-zero exit of shell commands in the makefile.
Equivalent to specifying `-' before each command line in the
makefile.
-j max_jobs
Specify the maximum number of jobs that make may have running at
any one time. Turns compatibility mode off, unless the -B flag
is also specified.
-k Continue processing after errors are encountered, but only on
those targets that do not depend on the target whose creation
caused the error.
-m directory
Specify a directory in which to search for the system makefile
and makefiles included via the <...> style. Multiple -m options
can be specified to form a search path. This path will override
the default system include path, /usr/share/mk. The system
include path will always be appended to the search path used for
"..."-style inclusions and makefile searches (see the -I option).
If a file or directory name in the -m argument (or the
MAKESYSPATH environment variable) starts with the string ".../"
then make will search for the specified file or directory named
in the remaining part of the argument string. The search starts
with the current directory of the Makefile and then works upward
towards the root of the filesystem. If the search is successful,
then the resulting directory replaces the ".../" specification in
the -m argument. If used, this feature allows make to easily
search in the current source tree for customized sys.mk files
(e.g. by using ".../mk/sys.mk" as an argument). Note that a -C
that are earlier on the command line affect where -m ".../"
searches.
-n Display the commands that would have been executed, but do not
actually execute them.
-P Collate the output of a given job and display it only when the
job finishes, instead of mixing the output of parallel jobs
together. This option has no effect unless -j is used too.
-p Only print the input graph, not executing any commands. The
output is the same as -d g1. When combined with -f /dev/null,
only the builtin rules of make are displayed.
-Q Be extra quiet. For multi-job makes, this will cause file
banners not to be generated.
-q Do not execute any commands, but exit 0 if the specified targets
are up-to-date and 1, otherwise.
-r Do not process the system makefile.
-S Stop processing when an error is encountered. Default behaviour.
This is needed to negate the -k option during recursive builds.
-s Do not echo any commands as they are executed. Equivalent to
specifying `@' before each command line in the makefile.
-t Rather than re-building a target as specified in the makefile,
create it or update its modification time to make it appear up-
to-date.
-V variable
Print make's idea of the value of variable, in the global
context. Do not build any targets. Multiple instances of this
option may be specified; the variables will be printed one per
line, with a blank line for each null or undefined variable. If
variable contains a `$' then the value will be expanded before
printing.
-v Be extra verbose. Print any extra information.
-X When using the -V option to print the values of variables, do not
recursively expand the values.
variable=value
Set the value of the variable variable to value.
-x warning_options
Specify extended warning options. This option may be specified
several times. A warning_option can be prefixed with "no" in
which case the warning is switched off. The currently available
options are:
dirsyntax
Warn if anything except blanks and comments follows an
.endif or .else directive.
See also the .WARN special target.
There are seven different types of lines in a makefile: file dependency
specifications, shell commands, variable assignments, include statements,
conditional directives, for loops, and comments.
In general, lines may be continued from one line to the next by ending
them with a backslash (`\'). The trailing newline character and initial
whitespace on the following line are compressed into a single space.
FILE DEPENDENCY SPECIFICATIONS
Dependency lines consist of one or more targets, an operator, and zero or
more sources. This creates a relationship where the targets "depend" on
the sources and are usually created from them. The exact relationship
between the target and the source is determined by the operator that
separates them. The three operators are as follows:
: A target is considered out-of-date if its modification time is less
than those of any of its sources. Sources for a target accumulate
over dependency lines when this operator is used. The target is
removed if make is interrupted.
! Targets are always re-created, but not until all sources have been
examined and re-created as necessary. Sources for a target
accumulate over dependency lines when this operator is used. The
target is removed if make is interrupted.
:: If no sources are specified, the target is always re-created.
Otherwise, a target is considered out-of-date if any of its sources
has been modified more recently than the target. Sources for a
target do not accumulate over dependency lines when this operator
is used. The target will not be removed if make is interrupted.
Targets and sources may contain the shell wildcard expressions `?', `*',
`[]' and `{}'. The expressions `?', `*' and `[]' may only be used as
part of the final component of the target or source, and must be used to
describe existing files. The expression `{}' need not necessarily be
used to describe existing files. Expansion is in directory order, not
alphabetically as done in the shell.
SHELL COMMANDS
Each target may have associated with it a series of shell commands,
normally used to create the target. Each of the commands in this script
must be preceded by a tab. While any target may appear on a dependency
line, only one of these dependencies may be followed by a creation
script, unless the `::' operator is used.
If the first characters of the command line are `@', `-', and/or `*', the
command is treated specially. A `@' causes the command not to be echoed
before it is executed. A `-' causes any non-zero exit status of the
command line to be ignored. A `*' causes the command to be executed even
if -n is specified on the command line.
VARIABLE ASSIGNMENTS
Variables in make are much like variables in the shell, and, by
tradition, consist of all upper-case letters. The five operators that
can be used to assign values to variables are as follows:
= Assign the value to the variable. Any previous value is
overridden.
+= Append the value to the current value of the variable.
?= Assign the value to the variable if it is not already defined.
:= Assign with expansion, i.e., expand the value before assigning it
to the variable. Normally, expansion is not done until the
variable is referenced.
!= Expand the value and pass it to the shell for execution and
assign the result to the variable. Any newlines in the result
are replaced with spaces.
Any whitespace before the assigned value is removed; if the value is
being appended, a single space is inserted between the previous contents
of the variable and the appended value.
Variables are expanded by surrounding the variable name with either curly
braces (`{}') or parentheses (`()') and preceding it with a dollar sign
(`$'). If the variable name contains only a single letter, the
surrounding braces or parentheses are not required. This shorter form is
not recommended.
Variable substitution occurs at two distinct times, depending on where
the variable is being used. Variables in dependency lines are expanded
as the line is read. Variables in shell commands are expanded when the
shell command is executed.
The four different classes of variables (in order of increasing
precedence) are:
Environment variables
Variables defined as part of make's environment.
Global variables
Variables defined in the makefile or in included makefiles.
Command line variables
Variables defined as part of the command line and variables
obtained from the MAKEFLAGS environment variable or the
.MAKEFLAGS target.
Local variables
Variables that are defined specific to a certain target.
If the name of an environment variable appears in a makefile on the left-
hand side of an assignment, a global variable with the same name is
created, and the latter shadows the former as per their relative
precedences. The environment is not changed in this case, and the change
is not exported to programs executed by make. However, a command-line
variable actually replaces the environment variable of the same name if
the latter exists, which is visible to child programs.
There are seven local variables in make:
.ALLSRC The list of all sources for this target; also known as `>'.
.ARCHIVE The name of the archive file; also known as `!'.
.IMPSRC The name/path of the source from which the target is to be
transformed (the "implied" source); also known as `<'.
.MEMBER The name of the archive member; also known as `%'.
.OODATE The list of sources for this target that were deemed out-of-
date; also known as `?'.
.PREFIX The file prefix of the file, containing only the file portion,
no suffix or preceding directory components; also known as `*'.
.TARGET The name of the target; also known as `@'.
The shorter forms `@', `!', `<', `%', `?', `>', and `*' are permitted for
backward compatibility and are not recommended. The six variables `@F',
`@D', `<F', `<D', `*F', and `*D' are permitted for compatibility with
AT&T System V UNIX makefiles and are not recommended.
Four of the local variables may be used in sources on dependency lines
because they expand to the proper value for each target on the line.
These variables are .TARGET, .PREFIX, .ARCHIVE, and .MEMBER.
In addition, make sets or knows about the following internal variables or
environment variables:
$ A single dollar sign `$', i.e. `$$' expands to a
single dollar sign.
MAKE The name that make was executed with (argv[0]).
.CURDIR A path to the directory where make was executed. The
make utility sets .CURDIR to the canonical path given
by getcwd(3).
.OBJDIR A path to the directory where the targets are built.
At startup, make searches for an alternate directory
to place target files. It will attempt to change
into this special directory and will search this
directory for makefiles not found in the current
directory. The following directories are tried in
order:
1. ${MAKEOBJDIRPREFIX}/`pwd -P`
2. ${MAKEOBJDIR}
3. obj.${MACHINE}
4. obj
5. /usr/obj/`pwd -P`
The first directory that make successfully changes
into is used. If either MAKEOBJDIRPREFIX or
MAKEOBJDIR is set in the environment but make is
unable to change into the corresponding directory,
then the current directory is used without checking
the remainder of the list. If they are undefined and
make is unable to change into any of the remaining
three directories, then the current directory is
used. Note, that MAKEOBJDIRPREFIX and MAKEOBJDIR
must be environment variables and should not be set
on make's command line.
The make utility sets .OBJDIR to the canonical path
given by getcwd(3).
.MAKEFILE_LIST As make reads various makefiles, including the
default files and any obtained from the command line
and .include and .sinclude directives, their names
will be automatically appended to the .MAKEFILE_LIST
variable. They are added right before make begins to
parse them, so that the name of the current makefile
is the last word in this variable.
MAKEFLAGS The environment variable MAKEFLAGS may initially
contain anything that may be specified on make's
command line, including -f option(s). After
processing, its contents are stored in the .MAKEFLAGS
global variable, although any -f options are omitted.
Then all options and variable assignments specified
on make's command line, except for -f, are appended
to the .MAKEFLAGS variable.
Whenever make executes a program, it sets MAKEFLAGS
in the program's environment to the current value of
the .MAKEFLAGS global variable. Thus, if MAKEFLAGS
in make's environment contains any -f options, they
will not be pushed down to child programs
automatically. The make utility effectively filters
out -f options from the environment and command line
although it passes the rest of its options down to
sub-makes via MAKEFLAGS by default.
When passing macro definitions and flag arguments in
the MAKEFLAGS environment variable, space and tab
characters are quoted by preceding them with a
backslash. When reading the MAKEFLAGS variable from
the environment, all sequences of a backslash and one
of space or tab are replaced just with their second
character without causing a word break. Any other
occurrences of a backslash are retained. Groups of
unquoted space, tab and newline characters cause word
breaking.
.MAKEFLAGS Initially, this global variable contains make's
current run-time options from the environment and
command line as described above, under MAKEFLAGS. By
modifying the contents of the .MAKEFLAGS global
variable, the makefile can alter the contents of the
MAKEFLAGS environment variable made available for all
programs which make executes. This includes adding
-f option(s). The current value of .MAKEFLAGS is
just copied verbatim to MAKEFLAGS in the environment
of child programs.
Note that any options entered to .MAKEFLAGS neither
affect the current instance of make nor show up in
its own copy of MAKEFLAGS instantly. However, they
do show up in the MAKEFLAGS environment variable of
programs executed by make. On the other hand, a
direct assignment to MAKEFLAGS neither affects the
current instance of make nor is passed down to make's
children. Compare with the .MAKEFLAGS special target
below.
MFLAGS This variable is provided for backward compatibility
and contains all the options from the MAKEFLAGS
environment variable plus any options specified on
make's command line.
.MAKE.PID The process-id of make.
.MAKE.PPID The parent process-id of make.
.MAKE.JOB.PREFIX If make is run with -j -v then output for each target
is prefixed with a token `--- target ---' the first
part of which can be controlled via .MAKE.JOB.PREFIX.
For example:
.MAKE.JOB.PREFIX=${.newline}---${MAKE:T}[${.MAKE.PID}]
would produce tokens like `---make[1234] target ---'
or
.MAKE.JOB.PREFIX=---pid[${.MAKE.PID}],ppid[${.MAKE.PPID}]
would produce tokens like `---pid[56789],ppid[1234]
target ---' making it easier to track the degree of
parallelism being achieved.
.TARGETS List of targets make is currently building.
.INCLUDES See .INCLUDES special target.
.LIBS See .LIBS special target.
MACHINE Name of the machine architecture make is running on,
obtained from the MACHINE environment variable, or
through uname(3) if not defined.
MACHINE_ARCH Name of the machine architecture make was compiled
for, defined at compilation time.
VPATH Makefiles may assign a colon-delimited list of
directories to VPATH. These directories will be
searched for source files by make after it has
finished parsing all input makefiles.
Variable Modifiers
Variable expansion may be modified to select or modify each word of the
variable (where a "word" is whitespace-delimited sequence of characters).
The general format of a variable expansion is as follows:
{variable[:modifier[:...]]}
Each modifier begins with a colon and one of the following special
characters. The colon may be escaped with a backslash (`\').
:C/pattern/replacement/[1g]
Modify each word of the value, substituting every match of
the extended regular expression pattern (see re_format(7))
with the ed(1)-style replacement string. Normally, the first
occurrence of the pattern in each word of the value is
changed. The `1' modifier causes the substitution to apply
to at most one word; the `g' modifier causes the substitution
to apply to as many instances of the search pattern as occur
in the word or words it is found in. Note that `1' and `g'
are orthogonal; the former specifies whether multiple words
are potentially affected, the latter whether multiple
substitutions can potentially occur within each affected
word.
:E Replaces each word in the variable with its suffix.
:H Replaces each word in the variable with everything but the
last component.
:L Converts variable to lower-case letters. (deprecated)
:Mpattern Select only those words that match the rest of the modifier.
The standard shell wildcard characters (`*', `?', and `[]')
may be used. The wildcard characters may be escaped with a
backslash (`\').
:Npattern This is identical to :M, but selects all words which do not
match the rest of the modifier.
:O Order every word in the variable alphabetically.
:Q Quotes every shell meta-character in the variable, so that it
can be passed safely through recursive invocations of make.
:R Replaces each word in the variable with everything but its
suffix.
:S/old_string/new_string/[g]
Modify the first occurrence of old_string in each word of the
variable's value, replacing it with new_string. If a `g' is
appended to the last slash of the pattern, all occurrences in
each word are replaced. If old_string begins with a caret
(`^'), old_string is anchored at the beginning of each word.
If old_string ends with a dollar sign (`$'), it is anchored
at the end of each word. Inside new_string, an ampersand
(`&') is replaced by old_string. Any character may be used
as a delimiter for the parts of the modifier string. The
anchoring, ampersand, and delimiter characters may be escaped
with a backslash (`\').
Variable expansion occurs in the normal fashion inside both
old_string and new_string with the single exception that a
backslash is used to prevent the expansion of a dollar sign
(`$'), not a preceding dollar sign as is usual.
:old_string=new_string
This is the AT&T System V UNIX style variable substitution.
It must be the last modifier specified. If old_string or
new_string do not contain the pattern matching character %
then it is assumed that they are anchored at the end of each
word, so only suffixes or entire words may be replaced.
Otherwise % is the substring of old_string to be replaced in
new_string.
:T Replaces each word in the variable with its last component.
:tl Converts variable to lower-case letters.
:tu Converts variable to upper-case letters.
:U Converts variable to upper-case letters. (deprecated)
:u Remove adjacent duplicate words (like uniq(1)).
DIRECTIVES, CONDITIONALS, AND FOR LOOPS
Directives, conditionals, and for loops reminiscent of the C programming
language are provided in make. All such structures are identified by a
line beginning with a single dot (`.') character. The following
directives are supported:
.include <file>
.include "file"
Include the specified makefile. Variables between the angle
brackets or double quotes are expanded to form the file name. If
angle brackets are used, the included makefile is expected to be
in the system makefile directory. If double quotes are used, the
including makefile's directory and any directories specified
using the -I option are searched before the system makefile
directory.
.sinclude <file>
.sinclude "file"
Like .include, but silently ignored if the file cannot be found
and opened.
.undef variable
Un-define the specified global variable. Only global variables
may be un-defined.
.error message
Terminate processing of the makefile immediately. The filename
of the makefile, the line on which the error was encountered and
the specified message are printed to the standard error output
and make terminates with exit code 1. Variables in the message
are expanded.
.warning message
Emit a warning message. The filename of the makefile, the line
on which the warning was encountered, and the specified message
are printed to the standard error output. Variables in the
message are expanded.
Conditionals are used to determine which parts of the Makefile to
process. They are used similarly to the conditionals supported by the C
pre-processor. The following conditionals are supported:
.if [!]expression [operator expression ...]
Test the value of an expression.
.ifdef [!]variable [operator variable ...]
Test the value of a variable.
.ifndef [!]variable [operator variable ...]
Test the value of a variable.
.ifmake [!]target [operator target ...]
Test the target being built.
.ifnmake [!]target [operator target ...]
Test the target being built.
.else Reverse the sense of the last conditional.
.elif [!]expression [operator expression ...]
A combination of .else followed by .if.
.elifdef [!]variable [operator variable ...]
A combination of .else followed by .ifdef.
.elifndef [!]variable [operator variable ...]
A combination of .else followed by .ifndef.
.elifmake [!]target [operator target ...]
A combination of .else followed by .ifmake.
.elifnmake [!]target [operator target ...]
A combination of .else followed by .ifnmake.
.endif End the body of the conditional.
The operator may be any one of the following:
|| Logical OR
&& Logical AND; of higher precedence than `||'.
As in C, make will only evaluate a conditional as far as is necessary to
determine its value. Parentheses may be used to change the order of
evaluation. The boolean operator `!' may be used to logically negate an
entire conditional. It is of higher precedence than `&&'.
The value of expression may be any of the following:
defined Takes a variable name as an argument and evaluates to true if
the variable has been defined.
make Takes a target name as an argument and evaluates to true if
the target was specified as part of make's command line or
was declared the default target (either implicitly or
explicitly, see .MAIN) before the line containing the
conditional.
empty Takes a variable, with possible modifiers, and evaluates to
true if the expansion of the variable would result in an
empty string.
exists Takes a file name as an argument and evaluates to true if the
file exists. The file is searched for on the system search
path (see .PATH).
target Takes a target name as an argument and evaluates to true if
the target has been defined.
An expression may also be a numeric or string comparison: in this case,
the left-hand side must be a variable expansion, whereas the right-hand
side can be a constant or a variable expansion. Variable expansion is
performed on both sides, after which the resulting values are compared.
A value is interpreted as hexadecimal if it is preceded by 0x, otherwise
it is decimal; octal numbers are not supported.
String comparison can only use the `==' or `!=' operators, whereas
numeric values (both integer and floating point) can also be compared
using the `>', `>=', `<' and `<=' operators.
If no relational operator (and right-hand value) are given, an implicit
`!= 0' is used. However be very careful in using this feature especially
when the left-hand side variable expansion returns a string.
When make is evaluating one of these conditional expressions, and it
encounters a word it does not recognize, either the "make" or "defined"
expression is applied to it, depending on the form of the conditional.
If the form is .if, .ifdef or .ifndef, the "defined" expression is
applied. Similarly, if the form is .ifmake or .ifnmake, the "make"
expression is applied.
If the conditional evaluates to true the parsing of the makefile
continues as before. If it evaluates to false, the following lines are
skipped. In both cases this continues until a .else or .endif is found.
For loops are typically used to apply a set of rules to a list of files.
The syntax of a for loop is:
.for variable in expression
<make-rules>
.endfor
After the for expression is evaluated, it is split into words. The
iteration variable is successively set to each word, and substituted in
the make-rules inside the body of the for loop.
COMMENTS
Comments begin with a hash (`#') character, anywhere but in a shell
command line, and continue to the end of the line.
SPECIAL SOURCES
.IGNORE Ignore any errors from the commands associated with this
target, exactly as if they all were preceded by a dash (`-').
.MAKE Execute the commands associated with this target even if the
-n or -t options were specified. Normally used to mark
recursive make's.
.NOTMAIN Normally make selects the first target it encounters as the
default target to be built if no target was specified. This
source prevents this target from being selected.
.OPTIONAL If a target is marked with this attribute and make cannot
figure out how to create it, it will ignore this fact and
assume the file is not needed or already exists.
.PRECIOUS When make is interrupted, it removes any partially made
targets. This source prevents the target from being removed.
.SILENT Do not echo any of the commands associated with this target,
exactly as if they all were preceded by an at sign (`@').
.USE Turn the target into make's version of a macro. When the
target is used as a source for another target, the other
target acquires the commands, sources, and attributes (except
for .USE) of the source. If the target already has commands,
the .USE target's commands are appended to them.
.WAIT If special .WAIT source appears in a dependency line, the
sources that precede it are made before the sources that
succeed it in the line. Loops are not being detected and
targets that form loops will be silently ignored.
SPECIAL TARGETS
Special targets may not be included with other targets, i.e., they must
be the only target specified.
.BEGIN Any command lines attached to this target are executed before
anything else is done.
.DEFAULT This is sort of a .USE rule for any target (that was used
only as a source) that make cannot figure out any other way
to create. Only the shell script is used. The .IMPSRC
variable of a target that inherits .DEFAULT's commands is set
to the target's own name.
.END Any command lines attached to this target are executed after
everything else is done.
.IGNORE Mark each of the sources with the .IGNORE attribute. If no
sources are specified, this is the equivalent of specifying
the -i option.
.INCLUDES A list of suffixes that indicate files that can be included
in a source file. The suffix must have already been declared
with .SUFFIXES; any suffix so declared will have the
directories on its search path (see .PATH) placed in the
.INCLUDES special variable, each preceded by a -I flag.
.INTERRUPT If make is interrupted, the commands for this target will be
executed.
.LIBS This does for libraries what .INCLUDES does for include
files, except that the flag used is -L.
.MAIN If no target is specified when make is invoked, this target
will be built. This is always set, either explicitly, or
implicitly when make selects the default target, to give the
user a way to refer to the default target on the command
line.
.MAKEFILEDEPS
Enable the "Remaking Makefiles" functionality, as explained
in the REMAKING MAKEFILES section below.
.MAKEFLAGS This target provides a way to specify flags for make when the
makefile is used. The flags are as if typed to the shell,
though the -f option will have no effect. Flags (except for
-f) and variable assignments specified as the source for this
target are also appended to the .MAKEFLAGS internal variable.
Please note the difference between this target and the
.MAKEFLAGS internal variable: specifying an option or
variable assignment as the source for this target will affect
both the current makefile and all processes that make
executes.
.MFLAGS Same as above, for backward compatibility.
.NOTPARALLEL
Disable parallel mode.
.NO_PARALLEL
Same as above, for compatibility with other pmake variants.
.ORDER The named targets are made in sequence.
.PATH The sources are directories which are to be searched for
files not found in the current directory. If no sources are
specified, any previously specified directories are deleted.
Where possible, use of .PATH is preferred over use of the
VPATH variable.
.PATHsuffix
The sources are directories which are to be searched for
suffixed files not found in the current directory. The make
utility first searches the suffixed search path, before
reverting to the default path if the file is not found there.
This form is required for .LIBS and .INCLUDES to work.
.PHONY Apply the .PHONY attribute to any specified sources. Targets
with this attribute are always considered to be out of date.
.POSIX Adjust make's behavior to match the applicable POSIX
specifications. (Note this disables the "Remaking Makefiles"
feature.)
.PRECIOUS Apply the .PRECIOUS attribute to any specified sources. If
no sources are specified, the .PRECIOUS attribute is applied
to every target in the file.
.SHELL Select another shell. The sources of this target have the
format key=value. The key is one of:
path Specify the path to the new shell.
name Specify the name of the new shell. This may
be either one of the three builtin shells (see
below) or any other name.
quiet Specify the shell command to turn echoing off.
echo Specify the shell command to turn echoing on.
filter Usually shells print the echo off command
before turning echoing off. This is the exact
string that will be printed by the shell and
is used to filter the shell output to remove
the echo off command.
echoFlag The shell option that turns echoing on.
errFlag The shell option to turn on error checking.
If error checking is on, the shell should exit
if a command returns a non-zero status.
hasErrCtl True if the shell has error control.
check If hasErrCtl is true then this is the shell
command to turn error checking on. If
hasErrCtl is false then this is a command
template to echo commands for which error
checking is disabled. The template must
contain a `%s'.
ignore If hasErrCtl is true, this is the shell
command to turn error checking off. If
hasErrCtl is false, this is a command template
to execute a command so that errors are
ignored. The template must contain a `%s'.
meta This is a string of meta characters of the
shell.
builtins This is a string holding all the shell's
builtin commands separated by blanks. The
meta and builtins strings are used in compat
mode. When a command line contains neither a
meta character nor starts with a shell
builtin, it is executed directly without
invoking a shell. When one of these strings
(or both) is empty all commands are executed
through a shell.
unsetenv If true, remove the ENV environment variable
before executing any command. This is useful
for the Korn-shell (ksh).
Values that are strings must be surrounded by double quotes.
Boolean values are specified as `T' or `Y' (in either case)
to mean true. Any other value is taken to mean false.
There are several uses of the .SHELL target:
* Selecting one of the builtin shells. This is done by
just specifying the name of the shell with the name
keyword. It is also possible to modify the parameters of
the builtin shell by just specifying other keywords
(except for path).
* Using another executable for one of the builtin shells.
This is done by specifying the path to the executable
with the path keyword. If the last component is the same
as the name of the builtin shell, no name needs to be
specified; if it is different, the name must be given:
.SHELL: path="/usr/local/bin/sh"
selects the builtin shell "sh" but will execute it from
/usr/local/bin/sh. Like in the previous case, it is
possible to modify parameters of the builtin shell by
just specifying them.
* Using an entirely different shell. This is done by
specifying all keywords.
The builtin shells are "sh", "csh" and "ksh". Because
FreeBSD has no ksh in /bin, it is unwise to specify
name="ksh" without also specifying a path.
.SILENT Apply the .SILENT attribute to any specified sources. If no
sources are specified, the .SILENT attribute is applied to
every command in the file.
.SUFFIXES Each source specifies a suffix to make. If no sources are
specified, any previous specified suffixes are deleted.
.WARN Each source specifies a warning flag as previously described
for the -x command line option. Warning flags specified on
the command line take precedence over flags specified in the
makefile. Also, command line warning flags are pushed to
sub-makes through the MAKEFLAGS environment variables so that
a warning flag specified on the command line will influence
all sub-makes. Several flags can be specified on a single
.WARN target by separating them with blanks.
REMAKING MAKEFILES
If the special target .MAKEFILEDEPS exists in the Makefile, make enables
the "Remaking Makefiles" feature. After reading Makefile and all the
files that are included using .include or .sinclude directives (source
Makefiles) make considers each source Makefile as a target and tries to
rebuild it. Both explicit and implicit rules are checked and all source
Makefiles are updated if necessary. If any of the source Makefiles were
rebuilt, make restarts from clean state.
To prevent infinite loops the following source Makefile targets are
ignored:
* :: targets that have no prerequisites
* ! targets
* targets that have .PHONY or .EXEC attributes
* targets without prerequisites and without commands
When remaking a source Makefile options -t (touch target), -q (query
mode), and -n (no exec) do not take effect, unless source Makefile is
specified explicitly as a target in make command line.
Additionally, system makefiles and .depend are not considered as
Makefiles that can be rebuilt.
ENVIRONMENT
The make utility uses the following environment variables, if they exist:
MACHINE, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, and MAKESYSPATH.
FILES
.depend list of dependencies
Makefile list of dependencies
makefile list of dependencies
obj object directory
sys.mk system makefile
/usr/share/mk default system makefile directory
/usr/share/doc/psd/12.make PMake tutorial
/usr/obj default MAKEOBJDIRPREFIX directory.
/etc/make.conf default path to make.conf(5)
EXAMPLES
List all included makefiles in order visited:
make -V .MAKEFILE_LIST | tr \ \\n
COMPATIBILITY
Older versions of make used MAKE instead of MAKEFLAGS. This was removed
for POSIX compatibility. The internal variable MAKE is set to the same
value as .MAKE; support for this may be removed in the future.
The use of the :L and :U modifiers are deprecated in FreeBSD 10.0 and the
more portable (among Pmake decedents) :tl and :tu should be used instead.
Most of the more esoteric features of make should probably be avoided for
greater compatibility.
SEE ALSO
mkdep(1), make.conf(5)
PMake - A Tutorial. in /usr/share/doc/psd/12.make
HISTORY
A make command appeared in PWB UNIX.
BUGS
The determination of .OBJDIR is contorted to the point of absurdity.
In the presence of several .MAIN special targets, make silently ignores
all but the first.
.TARGETS is not set to the default target when make is invoked without a
target name and no .MAIN special target exists.
The evaluation of expression in a test is very simple-minded. Currently,
the only form that works is `.if ${VAR} op something'. For instance, you
should write tests as `.if ${VAR} == string' not the other way around,
which would give you an error.
For loops are expanded before tests, so a fragment such as:
.for ARCH in ${SHARED_ARCHS}
.if ${ARCH} == ${MACHINE}
...
.endif
.endfor
will not work, and should be rewritten as:
.for ARCH in ${SHARED_ARCHS}
.if ${MACHINE} == ${ARCH}
...
.endif
.endfor
The parsing code is broken with respect to handling a semicolon after a
colon, so a fragment like this will fail:
HDRS= foo.h bar.h
all:
.for h in ${HDRS:S;^;${.CURDIR}/;}
...
.endfor
A trailing backslash in a variable value defined on the command line
causes the delimiting space in the MAKEFLAGS environment variable to be
preceded by that backslash. That causes a submake to not treat that
space as a word delimiter. Fixing this requires a larger rewrite of the
code handling command line macros and assignments to .MAKEFLAGS.
DragonFly 6.5-DEVELOPMENT May 30, 2012 DragonFly 6.5-DEVELOPMENT