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29.\"
30.\" from: @(#)make.1 8.4 (Berkeley) 3/19/94
31.\"
32.Dd February 19, 2016
33.Dt MAKE 1
34.Os
35.Sh NAME
36.Nm bmake
37.Nd maintain program dependencies
38.Sh SYNOPSIS
39.Nm
40.Op Fl BeikNnqrstWwX
41.Op Fl C Ar directory
42.Op Fl D Ar variable
43.Op Fl d Ar flags
44.Op Fl f Ar makefile
45.Op Fl I Ar directory
46.Op Fl J Ar private
47.Op Fl j Ar max_jobs
48.Op Fl m Ar directory
49.Op Fl T Ar file
50.Op Fl V Ar variable
51.Op Ar variable=value
52.Op Ar target ...
53.Sh DESCRIPTION
54.Nm
55is a program designed to simplify the maintenance of other programs.
56Its input is a list of specifications as to the files upon which programs
57and other files depend.
58If no
59.Fl f Ar makefile
60makefile option is given,
61.Nm
62will try to open
63.Ql Pa makefile
64then
65.Ql Pa Makefile
66in order to find the specifications.
67If the file
68.Ql Pa .depend
69exists, it is read (see
70.Xr mkdep 1 ) .
71.Pp
72This manual page is intended as a reference document only.
73For a more thorough description of
74.Nm
75and makefiles, please refer to
76.%T "PMake \- A Tutorial" .
77.Pp
78.Nm
79will prepend the contents of the
80.Va MAKEFLAGS
81environment variable to the command line arguments before parsing them.
82.Pp
83The options are as follows:
84.Bl -tag -width Ds
85.It Fl B
86Try to be backwards compatible by executing a single shell per command and
87by executing the commands to make the sources of a dependency line in sequence.
88.It Fl C Ar directory
89Change to
90.Ar directory
91before reading the makefiles or doing anything else.
92If multiple
93.Fl C
94options are specified, each is interpreted relative to the previous one:
95.Fl C Pa / Fl C Pa etc
96is equivalent to
97.Fl C Pa /etc .
98.It Fl D Ar variable
99Define
100.Ar variable
101to be 1, in the global context.
102.It Fl d Ar [-]flags
103Turn on debugging, and specify which portions of
104.Nm
105are to print debugging information.
106Unless the flags are preceded by
107.Ql \-
108they are added to the
109.Va MAKEFLAGS
110environment variable and will be processed by any child make processes.
111By default, debugging information is printed to standard error,
112but this can be changed using the
113.Ar F
114debugging flag.
115The debugging output is always unbuffered; in addition, if debugging
116is enabled but debugging output is not directed to standard output,
117then the standard output is line buffered.
118.Ar Flags
119is one or more of the following:
120.Bl -tag -width Ds
121.It Ar A
122Print all possible debugging information;
123equivalent to specifying all of the debugging flags.
124.It Ar a
125Print debugging information about archive searching and caching.
126.It Ar C
127Print debugging information about current working directory.
128.It Ar c
129Print debugging information about conditional evaluation.
130.It Ar d
131Print debugging information about directory searching and caching.
132.It Ar e
133Print debugging information about failed commands and targets.
134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename
135Specify where debugging output is written.
136This must be the last flag, because it consumes the remainder of
137the argument.
138If the character immediately after the
139.Ql F
140flag is
141.Ql \&+ ,
142then the file will be opened in append mode;
143otherwise the file will be overwritten.
144If the file name is
145.Ql stdout
146or
147.Ql stderr
148then debugging output will be written to the
149standard output or standard error output file descriptors respectively
150(and the
151.Ql \&+
152option has no effect).
153Otherwise, the output will be written to the named file.
154If the file name ends
155.Ql .%d
156then the
157.Ql %d
158is replaced by the pid.
159.It Ar f
160Print debugging information about loop evaluation.
161.It Ar "g1"
162Print the input graph before making anything.
163.It Ar "g2"
164Print the input graph after making everything, or before exiting
165on error.
166.It Ar "g3"
167Print the input graph before exiting on error.
168.It Ar j
169Print debugging information about running multiple shells.
170.It Ar l
171Print commands in Makefiles regardless of whether or not they are prefixed by
172.Ql @
173or other "quiet" flags.
174Also known as "loud" behavior.
175.It Ar M
176Print debugging information about "meta" mode decisions about targets.
177.It Ar m
178Print debugging information about making targets, including modification
179dates.
180.It Ar n
181Don't delete the temporary command scripts created when running commands.
182These temporary scripts are created in the directory
183referred to by the
184.Ev TMPDIR
185environment variable, or in
186.Pa /tmp
187if
188.Ev TMPDIR
189is unset or set to the empty string.
190The temporary scripts are created by
191.Xr mkstemp 3 ,
192and have names of the form
193.Pa makeXXXXXX .
194.Em NOTE :
195This can create many files in
196.Ev TMPDIR
197or
198.Pa /tmp ,
199so use with care.
200.It Ar p
201Print debugging information about makefile parsing.
202.It Ar s
203Print debugging information about suffix-transformation rules.
204.It Ar t
205Print debugging information about target list maintenance.
206.It Ar V
207Force the
208.Fl V
209option to print raw values of variables.
210.It Ar v
211Print debugging information about variable assignment.
212.It Ar x
213Run shell commands with
214.Fl x
215so the actual commands are printed as they are executed.
216.El
217.It Fl e
218Specify that environment variables override macro assignments within
219makefiles.
220.It Fl f Ar makefile
221Specify a makefile to read instead of the default
222.Ql Pa makefile .
223If
224.Ar makefile
225is
226.Ql Fl ,
227standard input is read.
228Multiple makefiles may be specified, and are read in the order specified.
229.It Fl I Ar directory
230Specify a directory in which to search for makefiles and included makefiles.
231The system makefile directory (or directories, see the
232.Fl m
233option) is automatically included as part of this list.
234.It Fl i
235Ignore non-zero exit of shell commands in the makefile.
236Equivalent to specifying
237.Ql Fl
238before each command line in the makefile.
239.It Fl J Ar private
240This option should
241.Em not
242be specified by the user.
243.Pp
244When the
245.Ar j
246option is in use in a recursive build, this option is passed by a make
247to child makes to allow all the make processes in the build to
248cooperate to avoid overloading the system.
249.It Fl j Ar max_jobs
250Specify the maximum number of jobs that
251.Nm
252may have running at any one time.
253The value is saved in
254.Va .MAKE.JOBS .
255Turns compatibility mode off, unless the
256.Ar B
257flag is also specified.
258When compatibility mode is off, all commands associated with a
259target are executed in a single shell invocation as opposed to the
260traditional one shell invocation per line.
261This can break traditional scripts which change directories on each
262command invocation and then expect to start with a fresh environment
263on the next line.
264It is more efficient to correct the scripts rather than turn backwards
265compatibility on.
266.It Fl k
267Continue processing after errors are encountered, but only on those targets
268that do not depend on the target whose creation caused the error.
269.It Fl m Ar directory
270Specify a directory in which to search for sys.mk and makefiles included
271via the
272.Ao Ar file Ac Ns -style
273include statement.
274The
275.Fl m
276option can be used multiple times to form a search path.
277This path will override the default system include path: /usr/share/mk.
278Furthermore the system include path will be appended to the search path used
279for
280.Qo Ar file Qc Ns -style
281include statements (see the
282.Fl I
283option).
284.Pp
285If a file or directory name in the
286.Fl m
287argument (or the
288.Ev MAKESYSPATH
289environment variable) starts with the string
290.Qq \&.../
291then
292.Nm
293will search for the specified file or directory named in the remaining part
294of the argument string.
295The search starts with the current directory of
296the Makefile and then works upward towards the root of the file system.
297If the search is successful, then the resulting directory replaces the
298.Qq \&.../
299specification in the
300.Fl m
301argument.
302If used, this feature allows
303.Nm
304to easily search in the current source tree for customized sys.mk files
305(e.g., by using
306.Qq \&.../mk/sys.mk
307as an argument).
308.It Fl n
309Display the commands that would have been executed, but do not
310actually execute them unless the target depends on the .MAKE special
311source (see below).
312.It Fl N
313Display the commands which would have been executed, but do not
314actually execute any of them; useful for debugging top-level makefiles
315without descending into subdirectories.
316.It Fl q
317Do not execute any commands, but exit 0 if the specified targets are
318up-to-date and 1, otherwise.
319.It Fl r
320Do not use the built-in rules specified in the system makefile.
321.It Fl s
322Do not echo any commands as they are executed.
323Equivalent to specifying
324.Ql Ic @
325before each command line in the makefile.
326.It Fl T Ar tracefile
327When used with the
328.Fl j
329flag,
330append a trace record to
331.Ar tracefile
332for each job started and completed.
333.It Fl t
334Rather than re-building a target as specified in the makefile, create it
335or update its modification time to make it appear up-to-date.
336.It Fl V Ar variable
337Print
338.Nm Ns 's
339idea of the value of
340.Ar variable ,
341in the global context.
342Do not build any targets.
343Multiple instances of this option may be specified;
344the variables will be printed one per line,
345with a blank line for each null or undefined variable.
346If
347.Ar variable
348contains a
349.Ql \&$
350then the value will be expanded before printing.
351.It Fl W
352Treat any warnings during makefile parsing as errors.
353.It Fl w
354Print entering and leaving directory messages, pre and post processing.
355.It Fl X
356Don't export variables passed on the command line to the environment
357individually.
358Variables passed on the command line are still exported
359via the
360.Va MAKEFLAGS
361environment variable.
362This option may be useful on systems which have a small limit on the
363size of command arguments.
364.It Ar variable=value
365Set the value of the variable
366.Ar variable
367to
368.Ar value .
369Normally, all values passed on the command line are also exported to
370sub-makes in the environment.
371The
372.Fl X
373flag disables this behavior.
374Variable assignments should follow options for POSIX compatibility
375but no ordering is enforced.
376.El
377.Pp
378There are seven different types of lines in a makefile: file dependency
379specifications, shell commands, variable assignments, include statements,
380conditional directives, for loops, and comments.
381.Pp
382In general, lines may be continued from one line to the next by ending
383them with a backslash
384.Pq Ql \e .
385The trailing newline character and initial whitespace on the following
386line are compressed into a single space.
387.Sh FILE DEPENDENCY SPECIFICATIONS
388Dependency lines consist of one or more targets, an operator, and zero
389or more sources.
390This creates a relationship where the targets
391.Dq depend
392on the sources
393and are usually created from them.
394The exact relationship between the target and the source is determined
395by the operator that separates them.
396The three operators are as follows:
397.Bl -tag -width flag
398.It Ic \&:
399A target is considered out-of-date if its modification time is less than
400those of any of its sources.
401Sources for a target accumulate over dependency lines when this operator
402is used.
403The target is removed if
404.Nm
405is interrupted.
406.It Ic \&!
407Targets are always re-created, but not until all sources have been
408examined and re-created as necessary.
409Sources for a target accumulate over dependency lines when this operator
410is used.
411The target is removed if
412.Nm
413is interrupted.
414.It Ic \&::
415If no sources are specified, the target is always re-created.
416Otherwise, a target is considered out-of-date if any of its sources has
417been modified more recently than the target.
418Sources for a target do not accumulate over dependency lines when this
419operator is used.
420The target will not be removed if
421.Nm
422is interrupted.
423.El
424.Pp
425Targets and sources may contain the shell wildcard values
426.Ql \&? ,
427.Ql * ,
428.Ql [] ,
429and
430.Ql {} .
431The values
432.Ql \&? ,
433.Ql * ,
434and
435.Ql []
436may only be used as part of the final
437component of the target or source, and must be used to describe existing
438files.
439The value
440.Ql {}
441need not necessarily be used to describe existing files.
442Expansion is in directory order, not alphabetically as done in the shell.
443.Sh SHELL COMMANDS
444Each target may have associated with it one or more lines of shell
445commands, normally
446used to create the target.
447Each of the lines in this script
448.Em must
449be preceded by a tab.
450(For historical reasons, spaces are not accepted.)
451While targets can appear in many dependency lines if desired, by
452default only one of these rules may be followed by a creation
453script.
454If the
455.Ql Ic \&::
456operator is used, however, all rules may include scripts and the
457scripts are executed in the order found.
458.Pp
459Each line is treated as a separate shell command, unless the end of
460line is escaped with a backslash
461.Pq Ql \e
462in which case that line and the next are combined.
463.\" The escaped newline is retained and passed to the shell, which
464.\" normally ignores it.
465.\" However, the tab at the beginning of the following line is removed.
466If the first characters of the command are any combination of
467.Ql Ic @ ,
468.Ql Ic + ,
469or
470.Ql Ic \- ,
471the command is treated specially.
472A
473.Ql Ic @
474causes the command not to be echoed before it is executed.
475A
476.Ql Ic +
477causes the command to be executed even when
478.Fl n
479is given.
480This is similar to the effect of the .MAKE special source,
481except that the effect can be limited to a single line of a script.
482A
483.Ql Ic \-
484in compatibility mode
485causes any non-zero exit status of the command line to be ignored.
486.Pp
487When
488.Nm
489is run in jobs mode with
490.Fl j Ar max_jobs ,
491the entire script for the target is fed to a
492single instance of the shell.
493In compatibility (non-jobs) mode, each command is run in a separate process.
494If the command contains any shell meta characters
495.Pq Ql #=|^(){};&<>*?[]:$`\e\en
496it will be passed to the shell; otherwise
497.Nm
498will attempt direct execution.
499If a line starts with
500.Ql Ic \-
501and the shell has ErrCtl enabled then failure of the command line
502will be ignored as in compatibility mode.
503Otherwise
504.Ql Ic \-
505affects the entire job;
506the script will stop at the first command line that fails,
507but the target will not be deemed to have failed.
508.Pp
509Makefiles should be written so that the mode of
510.Nm
511operation does not change their behavior.
512For example, any command which needs to use
513.Dq cd
514or
515.Dq chdir
516without potentially changing the directory for subsequent commands
517should be put in parentheses so it executes in a subshell.
518To force the use of one shell, escape the line breaks so as to make
519the whole script one command.
520For example:
521.Bd -literal -offset indent
522avoid-chdir-side-effects:
523 @echo Building $@ in `pwd`
524 @(cd ${.CURDIR} && ${MAKE} $@)
525 @echo Back in `pwd`
526
527ensure-one-shell-regardless-of-mode:
528 @echo Building $@ in `pwd`; \e
529 (cd ${.CURDIR} && ${MAKE} $@); \e
530 echo Back in `pwd`
531.Ed
532.Pp
533Since
534.Nm
535will
536.Xr chdir 2
537to
538.Ql Va .OBJDIR
539before executing any targets, each child process
540starts with that as its current working directory.
541.Sh VARIABLE ASSIGNMENTS
542Variables in make are much like variables in the shell, and, by tradition,
543consist of all upper-case letters.
544.Ss Variable assignment modifiers
545The five operators that can be used to assign values to variables are as
546follows:
547.Bl -tag -width Ds
548.It Ic \&=
549Assign the value to the variable.
550Any previous value is overridden.
551.It Ic \&+=
552Append the value to the current value of the variable.
553.It Ic \&?=
554Assign the value to the variable if it is not already defined.
555.It Ic \&:=
556Assign with expansion, i.e. expand the value before assigning it
557to the variable.
558Normally, expansion is not done until the variable is referenced.
559.Em NOTE :
560References to undefined variables are
561.Em not
562expanded.
563This can cause problems when variable modifiers are used.
564.It Ic \&!=
565Expand the value and pass it to the shell for execution and assign
566the result to the variable.
567Any newlines in the result are replaced with spaces.
568.El
569.Pp
570Any white-space before the assigned
571.Ar value
572is removed; if the value is being appended, a single space is inserted
573between the previous contents of the variable and the appended value.
574.Pp
575Variables are expanded by surrounding the variable name with either
576curly braces
577.Pq Ql {}
578or parentheses
579.Pq Ql ()
580and preceding it with
581a dollar sign
582.Pq Ql \&$ .
583If the variable name contains only a single letter, the surrounding
584braces or parentheses are not required.
585This shorter form is not recommended.
586.Pp
587If the variable name contains a dollar, then the name itself is expanded first.
588This allows almost arbitrary variable names, however names containing dollar,
589braces, parenthesis, or whitespace are really best avoided!
590.Pp
591If the result of expanding a variable contains a dollar sign
592.Pq Ql \&$
593the string is expanded again.
594.Pp
595Variable substitution occurs at three distinct times, depending on where
596the variable is being used.
597.Bl -enum
598.It
599Variables in dependency lines are expanded as the line is read.
600.It
601Variables in shell commands are expanded when the shell command is
602executed.
603.It
604.Dq .for
605loop index variables are expanded on each loop iteration.
606Note that other variables are not expanded inside loops so
607the following example code:
608.Bd -literal -offset indent
609
610.Dv .for i in 1 2 3
611a+= ${i}
612j= ${i}
613b+= ${j}
614.Dv .endfor
615
616all:
617 @echo ${a}
618 @echo ${b}
619
620.Ed
621will print:
622.Bd -literal -offset indent
6231 2 3
6243 3 3
625
626.Ed
627Because while ${a} contains
628.Dq 1 2 3
629after the loop is executed, ${b}
630contains
631.Dq ${j} ${j} ${j}
632which expands to
633.Dq 3 3 3
634since after the loop completes ${j} contains
635.Dq 3 .
636.El
637.Ss Variable classes
638The four different classes of variables (in order of increasing precedence)
639are:
640.Bl -tag -width Ds
641.It Environment variables
642Variables defined as part of
643.Nm Ns 's
644environment.
645.It Global variables
646Variables defined in the makefile or in included makefiles.
647.It Command line variables
648Variables defined as part of the command line.
649.It Local variables
650Variables that are defined specific to a certain target.
651.El
652.Pp
653Local variables are all built in and their values vary magically from
654target to target.
655It is not currently possible to define new local variables.
656The seven local variables are as follows:
657.Bl -tag -width ".ARCHIVE" -offset indent
658.It Va .ALLSRC
659The list of all sources for this target; also known as
660.Ql Va \&\*[Gt] .
661.It Va .ARCHIVE
662The name of the archive file; also known as
663.Ql Va \&! .
664.It Va .IMPSRC
665In suffix-transformation rules, the name/path of the source from which the
666target is to be transformed (the
667.Dq implied
668source); also known as
669.Ql Va \&\*[Lt] .
670It is not defined in explicit rules.
671.It Va .MEMBER
672The name of the archive member; also known as
673.Ql Va % .
674.It Va .OODATE
675The list of sources for this target that were deemed out-of-date; also
676known as
677.Ql Va \&? .
678.It Va .PREFIX
679The file prefix of the target, containing only the file portion, no suffix
680or preceding directory components; also known as
681.Ql Va * .
682The suffix must be one of the known suffixes declared with
683.Ic .SUFFIXES
684or it will not be recognized.
685.It Va .TARGET
686The name of the target; also known as
687.Ql Va @ .
688For compatibility with other makes this is an alias for
689.Ic .ARCHIVE
690in archive member rules.
691.El
692.Pp
693The shorter forms
694.Ql ( Va \*[Gt] ,
695.Ql Va \&! ,
696.Ql Va \*[Lt] ,
697.Ql Va % ,
698.Ql Va \&? ,
699.Ql Va * ,
700and
701.Ql Va @ )
702are permitted for backward
703compatibility with historical makefiles and legacy POSIX make and are
704not recommended.
705.Pp
706Variants of these variables with the punctuation followed immediately by
707.Ql D
708or
709.Ql F ,
710e.g.
711.Ql Va $(@D) ,
712are legacy forms equivalent to using the
713.Ql :H
714and
715.Ql :T
716modifiers.
717These forms are accepted for compatibility with
718.At V
719makefiles and POSIX but are not recommended.
720.Pp
721Four of the local variables may be used in sources on dependency lines
722because they expand to the proper value for each target on the line.
723These variables are
724.Ql Va .TARGET ,
725.Ql Va .PREFIX ,
726.Ql Va .ARCHIVE ,
727and
728.Ql Va .MEMBER .
729.Ss Additional built-in variables
730In addition,
731.Nm
732sets or knows about the following variables:
733.Bl -tag -width .MAKEOVERRIDES
734.It Va \&$
735A single dollar sign
736.Ql \&$ ,
737i.e.
738.Ql \&$$
739expands to a single dollar
740sign.
741.It Va .ALLTARGETS
742The list of all targets encountered in the Makefile.
743If evaluated during
744Makefile parsing, lists only those targets encountered thus far.
745.It Va .CURDIR
746A path to the directory where
747.Nm
748was executed.
749Refer to the description of
750.Ql Ev PWD
751for more details.
752.It Va .INCLUDEDFROMDIR
753The directory of the file this Makefile was included from.
754.It Va .INCLUDEDFROMFILE
755The filename of the file this Makefile was included from.
756.It Ev MAKE
757The name that
758.Nm
759was executed with
760.Pq Va argv[0] .
761For compatibility
762.Nm
763also sets
764.Va .MAKE
765with the same value.
766The preferred variable to use is the environment variable
767.Ev MAKE
768because it is more compatible with other versions of
769.Nm
770and cannot be confused with the special target with the same name.
771.It Va .MAKE.DEPENDFILE
772Names the makefile (default
773.Ql Pa .depend )
774from which generated dependencies are read.
775.It Va .MAKE.EXPAND_VARIABLES
776A boolean that controls the default behavior of the
777.Fl V
778option.
779.It Va .MAKE.EXPORTED
780The list of variables exported by
781.Nm .
782.It Va .MAKE.JOBS
783The argument to the
784.Fl j
785option.
786.It Va .MAKE.JOB.PREFIX
787If
788.Nm
789is run with
790.Ar j
791then output for each target is prefixed with a token
792.Ql --- target ---
793the first part of which can be controlled via
794.Va .MAKE.JOB.PREFIX .
795If
796.Va .MAKE.JOB.PREFIX
797is empty, no token is printed.
798.br
799For example:
800.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
801would produce tokens like
802.Ql ---make[1234] target ---
803making it easier to track the degree of parallelism being achieved.
804.It Ev MAKEFLAGS
805The environment variable
806.Ql Ev MAKEFLAGS
807may contain anything that
808may be specified on
809.Nm Ns 's
810command line.
811Anything specified on
812.Nm Ns 's
813command line is appended to the
814.Ql Ev MAKEFLAGS
815variable which is then
816entered into the environment for all programs which
817.Nm
818executes.
819.It Va .MAKE.LEVEL
820The recursion depth of
821.Nm .
822The initial instance of
823.Nm
824will be 0, and an incremented value is put into the environment
825to be seen by the next generation.
826This allows tests like:
827.Li .if ${.MAKE.LEVEL} == 0
828to protect things which should only be evaluated in the initial instance of
829.Nm .
830.It Va .MAKE.MAKEFILE_PREFERENCE
831The ordered list of makefile names
832(default
833.Ql Pa makefile ,
834.Ql Pa Makefile )
835that
836.Nm
837will look for.
838.It Va .MAKE.MAKEFILES
839The list of makefiles read by
840.Nm ,
841which is useful for tracking dependencies.
842Each makefile is recorded only once, regardless of the number of times read.
843.It Va .MAKE.MODE
844Processed after reading all makefiles.
845Can affect the mode that
846.Nm
847runs in.
848It can contain a number of keywords:
849.Bl -hang -width ignore-cmd
850.It Pa compat
851Like
852.Fl B ,
853puts
854.Nm
855into "compat" mode.
856.It Pa meta
857Puts
858.Nm
859into "meta" mode, where meta files are created for each target
860to capture the command run, the output generated and if
861.Xr filemon 4
862is available, the system calls which are of interest to
863.Nm .
864The captured output can be very useful when diagnosing errors.
865.It Pa curdirOk= Ar bf
866Normally
867.Nm
868will not create .meta files in
869.Ql Va .CURDIR .
870This can be overridden by setting
871.Va bf
872to a value which represents True.
873.It Pa env
874For debugging, it can be useful to include the environment
875in the .meta file.
876.It Pa verbose
877If in "meta" mode, print a clue about the target being built.
878This is useful if the build is otherwise running silently.
879The message printed the value of:
880.Va .MAKE.META.PREFIX .
881.It Pa ignore-cmd
882Some makefiles have commands which are simply not stable.
883This keyword causes them to be ignored for
884determining whether a target is out of date in "meta" mode.
885See also
886.Ic .NOMETA_CMP .
887.It Pa silent= Ar bf
888If
889.Va bf
890is True, when a .meta file is created, mark the target
891.Ic .SILENT .
892.El
893.It Va .MAKE.META.BAILIWICK
894In "meta" mode, provides a list of prefixes which
895match the directories controlled by
896.Nm .
897If a file that was generated outside of
898.Va .OBJDIR
899but within said bailiwick is missing,
900the current target is considered out-of-date.
901.It Va .MAKE.META.CREATED
902In "meta" mode, this variable contains a list of all the meta files
903updated.
904If not empty, it can be used to trigger processing of
905.Va .MAKE.META.FILES .
906.It Va .MAKE.META.FILES
907In "meta" mode, this variable contains a list of all the meta files
908used (updated or not).
909This list can be used to process the meta files to extract dependency
910information.
911.It Va .MAKE.META.IGNORE_PATHS
912Provides a list of path prefixes that should be ignored;
913because the contents are expected to change over time.
914The default list includes:
915.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
916.It Va .MAKE.META.PREFIX
917Defines the message printed for each meta file updated in "meta verbose" mode.
918The default value is:
919.Dl Building ${.TARGET:H:tA}/${.TARGET:T}
920.It Va .MAKEOVERRIDES
921This variable is used to record the names of variables assigned to
922on the command line, so that they may be exported as part of
923.Ql Ev MAKEFLAGS .
924This behavior can be disabled by assigning an empty value to
925.Ql Va .MAKEOVERRIDES
926within a makefile.
927Extra variables can be exported from a makefile
928by appending their names to
929.Ql Va .MAKEOVERRIDES .
930.Ql Ev MAKEFLAGS
931is re-exported whenever
932.Ql Va .MAKEOVERRIDES
933is modified.
934.It Va .MAKE.PATH_FILEMON
935If
936.Nm
937was built with
938.Xr filemon 4
939support, this is set to the path of the device node.
940This allows makefiles to test for this support.
941.It Va .MAKE.PID
942The process-id of
943.Nm .
944.It Va .MAKE.PPID
945The parent process-id of
946.Nm .
947.It Va .MAKE.SAVE_DOLLARS
948value should be a boolean that controls whether
949.Ql $$
950are preserved when doing
951.Ql :=
952assignments.
953The default is false, for backwards compatibility.
954Set to true for compatability with other makes.
955If set to false,
956.Ql $$
957becomes
958.Ql $
959per normal evaluation rules.
960.It Va MAKE_PRINT_VAR_ON_ERROR
961When
962.Nm
963stops due to an error, it prints its name and the value of
964.Ql Va .CURDIR
965as well as the value of any variables named in
966.Ql Va MAKE_PRINT_VAR_ON_ERROR .
967.It Va .newline
968This variable is simply assigned a newline character as its value.
969This allows expansions using the
970.Cm \&:@
971modifier to put a newline between
972iterations of the loop rather than a space.
973For example, the printing of
974.Ql Va MAKE_PRINT_VAR_ON_ERROR
975could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
976.It Va .OBJDIR
977A path to the directory where the targets are built.
978Its value is determined by trying to
979.Xr chdir 2
980to the following directories in order and using the first match:
981.Bl -enum
982.It
983.Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
984.Pp
985(Only if
986.Ql Ev MAKEOBJDIRPREFIX
987is set in the environment or on the command line.)
988.It
989.Ev ${MAKEOBJDIR}
990.Pp
991(Only if
992.Ql Ev MAKEOBJDIR
993is set in the environment or on the command line.)
994.It
995.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
996.It
997.Ev ${.CURDIR} Ns Pa /obj
998.It
999.Pa /usr/obj/ Ns Ev ${.CURDIR}
1000.It
1001.Ev ${.CURDIR}
1002.El
1003.Pp
1004Variable expansion is performed on the value before it's used,
1005so expressions such as
1006.Dl ${.CURDIR:S,^/usr/src,/var/obj,}
1007may be used.
1008This is especially useful with
1009.Ql Ev MAKEOBJDIR .
1010.Pp
1011.Ql Va .OBJDIR
1012may be modified in the makefile via the special target
1013.Ql Ic .OBJDIR .
1014In all cases,
1015.Nm
1016will
1017.Xr chdir 2
1018to the specified directory if it exists, and set
1019.Ql Va .OBJDIR
1020and
1021.Ql Ev PWD
1022to that directory before executing any targets.
1023.
1024.It Va .PARSEDIR
1025A path to the directory of the current
1026.Ql Pa Makefile
1027being parsed.
1028.It Va .PARSEFILE
1029The basename of the current
1030.Ql Pa Makefile
1031being parsed.
1032This variable and
1033.Ql Va .PARSEDIR
1034are both set only while the
1035.Ql Pa Makefiles
1036are being parsed.
1037If you want to retain their current values, assign them to a variable
1038using assignment with expansion:
1039.Pq Ql Cm \&:= .
1040.It Va .PATH
1041A variable that represents the list of directories that
1042.Nm
1043will search for files.
1044The search list should be updated using the target
1045.Ql Va .PATH
1046rather than the variable.
1047.It Ev PWD
1048Alternate path to the current directory.
1049.Nm
1050normally sets
1051.Ql Va .CURDIR
1052to the canonical path given by
1053.Xr getcwd 3 .
1054However, if the environment variable
1055.Ql Ev PWD
1056is set and gives a path to the current directory, then
1057.Nm
1058sets
1059.Ql Va .CURDIR
1060to the value of
1061.Ql Ev PWD
1062instead.
1063This behavior is disabled if
1064.Ql Ev MAKEOBJDIRPREFIX
1065is set or
1066.Ql Ev MAKEOBJDIR
1067contains a variable transform.
1068.Ql Ev PWD
1069is set to the value of
1070.Ql Va .OBJDIR
1071for all programs which
1072.Nm
1073executes.
1074.It Ev .TARGETS
1075The list of targets explicitly specified on the command line, if any.
1076.It Ev VPATH
1077Colon-separated
1078.Pq Dq \&:
1079lists of directories that
1080.Nm
1081will search for files.
1082The variable is supported for compatibility with old make programs only,
1083use
1084.Ql Va .PATH
1085instead.
1086.El
1087.Ss Variable modifiers
1088Variable expansion may be modified to select or modify each word of the
1089variable (where a
1090.Dq word
1091is white-space delimited sequence of characters).
1092The general format of a variable expansion is as follows:
1093.Pp
1094.Dl ${variable[:modifier[:...]]}
1095.Pp
1096Each modifier begins with a colon,
1097which may be escaped with a backslash
1098.Pq Ql \e .
1099.Pp
1100A set of modifiers can be specified via a variable, as follows:
1101.Pp
1102.Dl modifier_variable=modifier[:...]
1103.Dl ${variable:${modifier_variable}[:...]}
1104.Pp
1105In this case the first modifier in the modifier_variable does not
1106start with a colon, since that must appear in the referencing
1107variable.
1108If any of the modifiers in the modifier_variable contain a dollar sign
1109.Pq Ql $ ,
1110these must be doubled to avoid early expansion.
1111.Pp
1112The supported modifiers are:
1113.Bl -tag -width EEE
1114.It Cm \&:E
1115Replaces each word in the variable with its suffix.
1116.It Cm \&:H
1117Replaces each word in the variable with everything but the last component.
1118.It Cm \&:M Ns Ar pattern
1119Select only those words that match
1120.Ar pattern .
1121The standard shell wildcard characters
1122.Pf ( Ql * ,
1123.Ql \&? ,
1124and
1125.Ql Oo Oc )
1126may
1127be used.
1128The wildcard characters may be escaped with a backslash
1129.Pq Ql \e .
1130As a consequence of the way values are split into words, matched,
1131and then joined, a construct like
1132.Dl ${VAR:M*}
1133will normalize the inter-word spacing, removing all leading and
1134trailing space, and converting multiple consecutive spaces
1135to single spaces.
1136.
1137.It Cm \&:N Ns Ar pattern
1138This is identical to
1139.Ql Cm \&:M ,
1140but selects all words which do not match
1141.Ar pattern .
1142.It Cm \&:O
1143Order every word in variable alphabetically.
1144To sort words in
1145reverse order use the
1146.Ql Cm \&:O:[-1..1]
1147combination of modifiers.
1148.It Cm \&:Ox
1149Randomize words in variable.
1150The results will be different each time you are referring to the
1151modified variable; use the assignment with expansion
1152.Pq Ql Cm \&:=
1153to prevent such behavior.
1154For example,
1155.Bd -literal -offset indent
1156LIST= uno due tre quattro
1157RANDOM_LIST= ${LIST:Ox}
1158STATIC_RANDOM_LIST:= ${LIST:Ox}
1159
1160all:
1161 @echo "${RANDOM_LIST}"
1162 @echo "${RANDOM_LIST}"
1163 @echo "${STATIC_RANDOM_LIST}"
1164 @echo "${STATIC_RANDOM_LIST}"
1165.Ed
1166may produce output similar to:
1167.Bd -literal -offset indent
1168quattro due tre uno
1169tre due quattro uno
1170due uno quattro tre
1171due uno quattro tre
1172.Ed
1173.It Cm \&:Q
1174Quotes every shell meta-character in the variable, so that it can be passed
1175safely through recursive invocations of
1176.Nm .
1177.It Cm \&:R
1178Replaces each word in the variable with everything but its suffix.
1179.It Cm \&:gmtime
1180The value is a format string for
1181.Xr strftime 3 ,
1182using the current
1183.Xr gmtime 3 .
1184.It Cm \&:hash
1185Compute a 32-bit hash of the value and encode it as hex digits.
1186.It Cm \&:localtime
1187The value is a format string for
1188.Xr strftime 3 ,
1189using the current
1190.Xr localtime 3 .
1191.It Cm \&:tA
1192Attempt to convert variable to an absolute path using
1193.Xr realpath 3 ,
1194if that fails, the value is unchanged.
1195.It Cm \&:tl
1196Converts variable to lower-case letters.
1197.It Cm \&:ts Ns Ar c
1198Words in the variable are normally separated by a space on expansion.
1199This modifier sets the separator to the character
1200.Ar c .
1201If
1202.Ar c
1203is omitted, then no separator is used.
1204The common escapes (including octal numeric codes), work as expected.
1205.It Cm \&:tu
1206Converts variable to upper-case letters.
1207.It Cm \&:tW
1208Causes the value to be treated as a single word
1209(possibly containing embedded white space).
1210See also
1211.Ql Cm \&:[*] .
1212.It Cm \&:tw
1213Causes the value to be treated as a sequence of
1214words delimited by white space.
1215See also
1216.Ql Cm \&:[@] .
1217.Sm off
1218.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1219.Sm on
1220Modify the first occurrence of
1221.Ar old_string
1222in the variable's value, replacing it with
1223.Ar new_string .
1224If a
1225.Ql g
1226is appended to the last slash of the pattern, all occurrences
1227in each word are replaced.
1228If a
1229.Ql 1
1230is appended to the last slash of the pattern, only the first word
1231is affected.
1232If a
1233.Ql W
1234is appended to the last slash of the pattern,
1235then the value is treated as a single word
1236(possibly containing embedded white space).
1237If
1238.Ar old_string
1239begins with a caret
1240.Pq Ql ^ ,
1241.Ar old_string
1242is anchored at the beginning of each word.
1243If
1244.Ar old_string
1245ends with a dollar sign
1246.Pq Ql \&$ ,
1247it is anchored at the end of each word.
1248Inside
1249.Ar new_string ,
1250an ampersand
1251.Pq Ql \*[Am]
1252is replaced by
1253.Ar old_string
1254(without any
1255.Ql ^
1256or
1257.Ql \&$ ) .
1258Any character may be used as a delimiter for the parts of the modifier
1259string.
1260The anchoring, ampersand and delimiter characters may be escaped with a
1261backslash
1262.Pq Ql \e .
1263.Pp
1264Variable expansion occurs in the normal fashion inside both
1265.Ar old_string
1266and
1267.Ar new_string
1268with the single exception that a backslash is used to prevent the expansion
1269of a dollar sign
1270.Pq Ql \&$ ,
1271not a preceding dollar sign as is usual.
1272.Sm off
1273.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1274.Sm on
1275The
1276.Cm \&:C
1277modifier is just like the
1278.Cm \&:S
1279modifier except that the old and new strings, instead of being
1280simple strings, are an extended regular expression (see
1281.Xr regex 3 )
1282string
1283.Ar pattern
1284and an
1285.Xr ed 1 Ns \-style
1286string
1287.Ar replacement .
1288Normally, the first occurrence of the pattern
1289.Ar pattern
1290in each word of the value is substituted with
1291.Ar replacement .
1292The
1293.Ql 1
1294modifier causes the substitution to apply to at most one word; the
1295.Ql g
1296modifier causes the substitution to apply to as many instances of the
1297search pattern
1298.Ar pattern
1299as occur in the word or words it is found in; the
1300.Ql W
1301modifier causes the value to be treated as a single word
1302(possibly containing embedded white space).
1303Note that
1304.Ql 1
1305and
1306.Ql g
1307are orthogonal; the former specifies whether multiple words are
1308potentially affected, the latter whether multiple substitutions can
1309potentially occur within each affected word.
1310.Pp
1311As for the
1312.Cm \&:S
1313modifier, the
1314.Ar pattern
1315and
1316.Ar replacement
1317are subjected to variable expansion before being parsed as
1318regular expressions.
1319.It Cm \&:T
1320Replaces each word in the variable with its last component.
1321.It Cm \&:u
1322Remove adjacent duplicate words (like
1323.Xr uniq 1 ) .
1324.Sm off
1325.It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1326.Sm on
1327If the variable name (not its value), when parsed as a .if conditional
1328expression, evaluates to true, return as its value the
1329.Ar true_string ,
1330otherwise return the
1331.Ar false_string .
1332Since the variable name is used as the expression, \&:\&? must be the
1333first modifier after the variable name itself - which will, of course,
1334usually contain variable expansions.
1335A common error is trying to use expressions like
1336.Dl ${NUMBERS:M42:?match:no}
1337which actually tests defined(NUMBERS),
1338to determine is any words match "42" you need to use something like:
1339.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1340.It Ar :old_string=new_string
1341This is the
1342.At V
1343style variable substitution.
1344It must be the last modifier specified.
1345If
1346.Ar old_string
1347or
1348.Ar new_string
1349do not contain the pattern matching character
1350.Ar %
1351then it is assumed that they are
1352anchored at the end of each word, so only suffixes or entire
1353words may be replaced.
1354Otherwise
1355.Ar %
1356is the substring of
1357.Ar old_string
1358to be replaced in
1359.Ar new_string .
1360.Pp
1361Variable expansion occurs in the normal fashion inside both
1362.Ar old_string
1363and
1364.Ar new_string
1365with the single exception that a backslash is used to prevent the
1366expansion of a dollar sign
1367.Pq Ql \&$ ,
1368not a preceding dollar sign as is usual.
1369.Sm off
1370.It Cm \&:@ Ar temp Cm @ Ar string Cm @
1371.Sm on
1372This is the loop expansion mechanism from the OSF Development
1373Environment (ODE) make.
1374Unlike
1375.Cm \&.for
1376loops expansion occurs at the time of
1377reference.
1378Assign
1379.Ar temp
1380to each word in the variable and evaluate
1381.Ar string .
1382The ODE convention is that
1383.Ar temp
1384should start and end with a period.
1385For example.
1386.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1387.Pp
1388However a single character variable is often more readable:
1389.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1390.It Cm \&:U Ns Ar newval
1391If the variable is undefined
1392.Ar newval
1393is the value.
1394If the variable is defined, the existing value is returned.
1395This is another ODE make feature.
1396It is handy for setting per-target CFLAGS for instance:
1397.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1398If a value is only required if the variable is undefined, use:
1399.Dl ${VAR:D:Unewval}
1400.It Cm \&:D Ns Ar newval
1401If the variable is defined
1402.Ar newval
1403is the value.
1404.It Cm \&:L
1405The name of the variable is the value.
1406.It Cm \&:P
1407The path of the node which has the same name as the variable
1408is the value.
1409If no such node exists or its path is null, then the
1410name of the variable is used.
1411In order for this modifier to work, the name (node) must at least have
1412appeared on the rhs of a dependency.
1413.Sm off
1414.It Cm \&:\&! Ar cmd Cm \&!
1415.Sm on
1416The output of running
1417.Ar cmd
1418is the value.
1419.It Cm \&:sh
1420If the variable is non-empty it is run as a command and the output
1421becomes the new value.
1422.It Cm \&::= Ns Ar str
1423The variable is assigned the value
1424.Ar str
1425after substitution.
1426This modifier and its variations are useful in
1427obscure situations such as wanting to set a variable when shell commands
1428are being parsed.
1429These assignment modifiers always expand to
1430nothing, so if appearing in a rule line by themselves should be
1431preceded with something to keep
1432.Nm
1433happy.
1434.Pp
1435The
1436.Ql Cm \&::
1437helps avoid false matches with the
1438.At V
1439style
1440.Cm \&:=
1441modifier and since substitution always occurs the
1442.Cm \&::=
1443form is vaguely appropriate.
1444.It Cm \&::?= Ns Ar str
1445As for
1446.Cm \&::=
1447but only if the variable does not already have a value.
1448.It Cm \&::+= Ns Ar str
1449Append
1450.Ar str
1451to the variable.
1452.It Cm \&::!= Ns Ar cmd
1453Assign the output of
1454.Ar cmd
1455to the variable.
1456.It Cm \&:\&[ Ns Ar range Ns Cm \&]
1457Selects one or more words from the value,
1458or performs other operations related to the way in which the
1459value is divided into words.
1460.Pp
1461Ordinarily, a value is treated as a sequence of words
1462delimited by white space.
1463Some modifiers suppress this behavior,
1464causing a value to be treated as a single word
1465(possibly containing embedded white space).
1466An empty value, or a value that consists entirely of white-space,
1467is treated as a single word.
1468For the purposes of the
1469.Ql Cm \&:[]
1470modifier, the words are indexed both forwards using positive integers
1471(where index 1 represents the first word),
1472and backwards using negative integers
1473(where index \-1 represents the last word).
1474.Pp
1475The
1476.Ar range
1477is subjected to variable expansion, and the expanded result is
1478then interpreted as follows:
1479.Bl -tag -width index
1480.\" :[n]
1481.It Ar index
1482Selects a single word from the value.
1483.\" :[start..end]
1484.It Ar start Ns Cm \&.. Ns Ar end
1485Selects all words from
1486.Ar start
1487to
1488.Ar end ,
1489inclusive.
1490For example,
1491.Ql Cm \&:[2..-1]
1492selects all words from the second word to the last word.
1493If
1494.Ar start
1495is greater than
1496.Ar end ,
1497then the words are output in reverse order.
1498For example,
1499.Ql Cm \&:[-1..1]
1500selects all the words from last to first.
1501.\" :[*]
1502.It Cm \&*
1503Causes subsequent modifiers to treat the value as a single word
1504(possibly containing embedded white space).
1505Analogous to the effect of
1506\&"$*\&"
1507in Bourne shell.
1508.\" :[0]
1509.It 0
1510Means the same as
1511.Ql Cm \&:[*] .
1512.\" :[*]
1513.It Cm \&@
1514Causes subsequent modifiers to treat the value as a sequence of words
1515delimited by white space.
1516Analogous to the effect of
1517\&"$@\&"
1518in Bourne shell.
1519.\" :[#]
1520.It Cm \&#
1521Returns the number of words in the value.
1522.El \" :[range]
1523.El
1524.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1525Makefile inclusion, conditional structures and for loops reminiscent
1526of the C programming language are provided in
1527.Nm .
1528All such structures are identified by a line beginning with a single
1529dot
1530.Pq Ql \&.
1531character.
1532Files are included with either
1533.Cm \&.include Aq Ar file
1534or
1535.Cm \&.include Pf \*q Ar file Ns \*q .
1536Variables between the angle brackets or double quotes are expanded
1537to form the file name.
1538If angle brackets are used, the included makefile is expected to be in
1539the system makefile directory.
1540If double quotes are used, the including makefile's directory and any
1541directories specified using the
1542.Fl I
1543option are searched before the system
1544makefile directory.
1545For compatibility with other versions of
1546.Nm
1547.Ql include file ...
1548is also accepted.
1549.Pp
1550If the include statement is written as
1551.Cm .-include
1552or as
1553.Cm .sinclude
1554then errors locating and/or opening include files are ignored.
1555.Pp
1556If the include statement is written as
1557.Cm .dinclude
1558not only are errors locating and/or opening include files ignored,
1559but stale dependencies within the included file will be ignored
1560just like
1561.Va .MAKE.DEPENDFILE .
1562.Pp
1563Conditional expressions are also preceded by a single dot as the first
1564character of a line.
1565The possible conditionals are as follows:
1566.Bl -tag -width Ds
1567.It Ic .error Ar message
1568The message is printed along with the name of the makefile and line number,
1569then
1570.Nm
1571will exit.
1572.It Ic .export Ar variable ...
1573Export the specified global variable.
1574If no variable list is provided, all globals are exported
1575except for internal variables (those that start with
1576.Ql \&. ) .
1577This is not affected by the
1578.Fl X
1579flag, so should be used with caution.
1580For compatibility with other
1581.Nm
1582programs
1583.Ql export variable=value
1584is also accepted.
1585.Pp
1586Appending a variable name to
1587.Va .MAKE.EXPORTED
1588is equivalent to exporting a variable.
1589.It Ic .export-env Ar variable ...
1590The same as
1591.Ql .export ,
1592except that the variable is not appended to
1593.Va .MAKE.EXPORTED .
1594This allows exporting a value to the environment which is different from that
1595used by
1596.Nm
1597internally.
1598.It Ic .export-literal Ar variable ...
1599The same as
1600.Ql .export-env ,
1601except that variables in the value are not expanded.
1602.It Ic .info Ar message
1603The message is printed along with the name of the makefile and line number.
1604.It Ic .undef Ar variable
1605Un-define the specified global variable.
1606Only global variables may be un-defined.
1607.It Ic .unexport Ar variable ...
1608The opposite of
1609.Ql .export .
1610The specified global
1611.Va variable
1612will be removed from
1613.Va .MAKE.EXPORTED .
1614If no variable list is provided, all globals are unexported,
1615and
1616.Va .MAKE.EXPORTED
1617deleted.
1618.It Ic .unexport-env
1619Unexport all globals previously exported and
1620clear the environment inherited from the parent.
1621This operation will cause a memory leak of the original environment,
1622so should be used sparingly.
1623Testing for
1624.Va .MAKE.LEVEL
1625being 0, would make sense.
1626Also note that any variables which originated in the parent environment
1627should be explicitly preserved if desired.
1628For example:
1629.Bd -literal -offset indent
1630.Li .if ${.MAKE.LEVEL} == 0
1631PATH := ${PATH}
1632.Li .unexport-env
1633.Li .export PATH
1634.Li .endif
1635.Pp
1636.Ed
1637Would result in an environment containing only
1638.Ql Ev PATH ,
1639which is the minimal useful environment.
1640Actually
1641.Ql Ev .MAKE.LEVEL
1642will also be pushed into the new environment.
1643.It Ic .warning Ar message
1644The message prefixed by
1645.Ql Pa warning:
1646is printed along with the name of the makefile and line number.
1647.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1648Test the value of an expression.
1649.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1650Test the value of a variable.
1651.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1652Test the value of a variable.
1653.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1654Test the target being built.
1655.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1656Test the target being built.
1657.It Ic .else
1658Reverse the sense of the last conditional.
1659.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1660A combination of
1661.Ql Ic .else
1662followed by
1663.Ql Ic .if .
1664.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1665A combination of
1666.Ql Ic .else
1667followed by
1668.Ql Ic .ifdef .
1669.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1670A combination of
1671.Ql Ic .else
1672followed by
1673.Ql Ic .ifndef .
1674.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1675A combination of
1676.Ql Ic .else
1677followed by
1678.Ql Ic .ifmake .
1679.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1680A combination of
1681.Ql Ic .else
1682followed by
1683.Ql Ic .ifnmake .
1684.It Ic .endif
1685End the body of the conditional.
1686.El
1687.Pp
1688The
1689.Ar operator
1690may be any one of the following:
1691.Bl -tag -width "Cm XX"
1692.It Cm \&|\&|
1693Logical OR.
1694.It Cm \&\*[Am]\*[Am]
1695Logical
1696.Tn AND ;
1697of higher precedence than
1698.Dq \&|\&| .
1699.El
1700.Pp
1701As in C,
1702.Nm
1703will only evaluate a conditional as far as is necessary to determine
1704its value.
1705Parentheses may be used to change the order of evaluation.
1706The boolean operator
1707.Ql Ic \&!
1708may be used to logically negate an entire
1709conditional.
1710It is of higher precedence than
1711.Ql Ic \&\*[Am]\*[Am] .
1712.Pp
1713The value of
1714.Ar expression
1715may be any of the following:
1716.Bl -tag -width defined
1717.It Ic defined
1718Takes a variable name as an argument and evaluates to true if the variable
1719has been defined.
1720.It Ic make
1721Takes a target name as an argument and evaluates to true if the target
1722was specified as part of
1723.Nm Ns 's
1724command line or was declared the default target (either implicitly or
1725explicitly, see
1726.Va .MAIN )
1727before the line containing the conditional.
1728.It Ic empty
1729Takes a variable, with possible modifiers, and evaluates to true if
1730the expansion of the variable would result in an empty string.
1731.It Ic exists
1732Takes a file name as an argument and evaluates to true if the file exists.
1733The file is searched for on the system search path (see
1734.Va .PATH ) .
1735.It Ic target
1736Takes a target name as an argument and evaluates to true if the target
1737has been defined.
1738.It Ic commands
1739Takes a target name as an argument and evaluates to true if the target
1740has been defined and has commands associated with it.
1741.El
1742.Pp
1743.Ar Expression
1744may also be an arithmetic or string comparison.
1745Variable expansion is
1746performed on both sides of the comparison, after which the integral
1747values are compared.
1748A value is interpreted as hexadecimal if it is
1749preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1750The standard C relational operators are all supported.
1751If after
1752variable expansion, either the left or right hand side of a
1753.Ql Ic ==
1754or
1755.Ql Ic "!="
1756operator is not an integral value, then
1757string comparison is performed between the expanded
1758variables.
1759If no relational operator is given, it is assumed that the expanded
1760variable is being compared against 0 or an empty string in the case
1761of a string comparison.
1762.Pp
1763When
1764.Nm
1765is evaluating one of these conditional expressions, and it encounters
1766a (white-space separated) word it doesn't recognize, either the
1767.Dq make
1768or
1769.Dq defined
1770expression is applied to it, depending on the form of the conditional.
1771If the form is
1772.Ql Ic .ifdef ,
1773.Ql Ic .ifndef ,
1774or
1775.Ql Ic .if
1776the
1777.Dq defined
1778expression is applied.
1779Similarly, if the form is
1780.Ql Ic .ifmake
1781or
1782.Ql Ic .ifnmake , the
1783.Dq make
1784expression is applied.
1785.Pp
1786If the conditional evaluates to true the parsing of the makefile continues
1787as before.
1788If it evaluates to false, the following lines are skipped.
1789In both cases this continues until a
1790.Ql Ic .else
1791or
1792.Ql Ic .endif
1793is found.
1794.Pp
1795For loops are typically used to apply a set of rules to a list of files.
1796The syntax of a for loop is:
1797.Pp
1798.Bl -tag -compact -width Ds
1799.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1800.It Aq make-rules
1801.It Ic \&.endfor
1802.El
1803.Pp
1804After the for
1805.Ic expression
1806is evaluated, it is split into words.
1807On each iteration of the loop, one word is taken and assigned to each
1808.Ic variable ,
1809in order, and these
1810.Ic variables
1811are substituted into the
1812.Ic make-rules
1813inside the body of the for loop.
1814The number of words must come out even; that is, if there are three
1815iteration variables, the number of words provided must be a multiple
1816of three.
1817.Sh COMMENTS
1818Comments begin with a hash
1819.Pq Ql \&#
1820character, anywhere but in a shell
1821command line, and continue to the end of an unescaped new line.
1822.Sh SPECIAL SOURCES (ATTRIBUTES)
1823.Bl -tag -width .IGNOREx
1824.It Ic .EXEC
1825Target is never out of date, but always execute commands anyway.
1826.It Ic .IGNORE
1827Ignore any errors from the commands associated with this target, exactly
1828as if they all were preceded by a dash
1829.Pq Ql \- .
1830.\" .It Ic .INVISIBLE
1831.\" XXX
1832.\" .It Ic .JOIN
1833.\" XXX
1834.It Ic .MADE
1835Mark all sources of this target as being up-to-date.
1836.It Ic .MAKE
1837Execute the commands associated with this target even if the
1838.Fl n
1839or
1840.Fl t
1841options were specified.
1842Normally used to mark recursive
1843.Nm Ns s .
1844.It Ic .META
1845Create a meta file for the target, even if it is flagged as
1846.Ic .PHONY ,
1847.Ic .MAKE ,
1848or
1849.Ic .SPECIAL .
1850Usage in conjunction with
1851.Ic .MAKE
1852is the most likely case.
1853In "meta" mode, the target is out-of-date if the meta file is missing.
1854.It Ic .NOMETA
1855Do not create a meta file for the target.
1856Meta files are also not created for
1857.Ic .PHONY ,
1858.Ic .MAKE ,
1859or
1860.Ic .SPECIAL
1861targets.
1862.It Ic .NOMETA_CMP
1863Ignore differences in commands when deciding if target is out of date.
1864This is useful if the command contains a value which always changes.
1865If the number of commands change, though, the target will still be out of date.
1866The same effect applies to any command line that uses the variable
1867.Va .OODATE ,
1868which can be used for that purpose even when not otherwise needed or desired:
1869.Bd -literal -offset indent
1870
1871skip-compare-for-some:
1872 @echo this will be compared
1873 @echo this will not ${.OODATE:M.NOMETA_CMP}
1874 @echo this will also be compared
1875
1876.Ed
1877The
1878.Cm \&:M
1879pattern suppresses any expansion of the unwanted variable.
1880.It Ic .NOPATH
1881Do not search for the target in the directories specified by
1882.Ic .PATH .
1883.It Ic .NOTMAIN
1884Normally
1885.Nm
1886selects the first target it encounters as the default target to be built
1887if no target was specified.
1888This source prevents this target from being selected.
1889.It Ic .OPTIONAL
1890If a target is marked with this attribute and
1891.Nm
1892can't figure out how to create it, it will ignore this fact and assume
1893the file isn't needed or already exists.
1894.It Ic .PHONY
1895The target does not
1896correspond to an actual file; it is always considered to be out of date,
1897and will not be created with the
1898.Fl t
1899option.
1900Suffix-transformation rules are not applied to
1901.Ic .PHONY
1902targets.
1903.It Ic .PRECIOUS
1904When
1905.Nm
1906is interrupted, it normally removes any partially made targets.
1907This source prevents the target from being removed.
1908.It Ic .RECURSIVE
1909Synonym for
1910.Ic .MAKE .
1911.It Ic .SILENT
1912Do not echo any of the commands associated with this target, exactly
1913as if they all were preceded by an at sign
1914.Pq Ql @ .
1915.It Ic .USE
1916Turn the target into
1917.Nm Ns 's
1918version of a macro.
1919When the target is used as a source for another target, the other target
1920acquires the commands, sources, and attributes (except for
1921.Ic .USE )
1922of the
1923source.
1924If the target already has commands, the
1925.Ic .USE
1926target's commands are appended
1927to them.
1928.It Ic .USEBEFORE
1929Exactly like
1930.Ic .USE ,
1931but prepend the
1932.Ic .USEBEFORE
1933target commands to the target.
1934.It Ic .WAIT
1935If
1936.Ic .WAIT
1937appears in a dependency line, the sources that precede it are
1938made before the sources that succeed it in the line.
1939Since the dependents of files are not made until the file itself
1940could be made, this also stops the dependents being built unless they
1941are needed for another branch of the dependency tree.
1942So given:
1943.Bd -literal
1944x: a .WAIT b
1945 echo x
1946a:
1947 echo a
1948b: b1
1949 echo b
1950b1:
1951 echo b1
1952
1953.Ed
1954the output is always
1955.Ql a ,
1956.Ql b1 ,
1957.Ql b ,
1958.Ql x .
1959.br
1960The ordering imposed by
1961.Ic .WAIT
1962is only relevant for parallel makes.
1963.El
1964.Sh SPECIAL TARGETS
1965Special targets may not be included with other targets, i.e. they must be
1966the only target specified.
1967.Bl -tag -width .BEGINx
1968.It Ic .BEGIN
1969Any command lines attached to this target are executed before anything
1970else is done.
1971.It Ic .DEFAULT
1972This is sort of a
1973.Ic .USE
1974rule for any target (that was used only as a
1975source) that
1976.Nm
1977can't figure out any other way to create.
1978Only the shell script is used.
1979The
1980.Ic .IMPSRC
1981variable of a target that inherits
1982.Ic .DEFAULT Ns 's
1983commands is set
1984to the target's own name.
1985.It Ic .END
1986Any command lines attached to this target are executed after everything
1987else is done.
1988.It Ic .ERROR
1989Any command lines attached to this target are executed when another target fails.
1990The
1991.Ic .ERROR_TARGET
1992variable is set to the target that failed.
1993See also
1994.Ic MAKE_PRINT_VAR_ON_ERROR .
1995.It Ic .IGNORE
1996Mark each of the sources with the
1997.Ic .IGNORE
1998attribute.
1999If no sources are specified, this is the equivalent of specifying the
2000.Fl i
2001option.
2002.It Ic .INTERRUPT
2003If
2004.Nm
2005is interrupted, the commands for this target will be executed.
2006.It Ic .MAIN
2007If no target is specified when
2008.Nm
2009is invoked, this target will be built.
2010.It Ic .MAKEFLAGS
2011This target provides a way to specify flags for
2012.Nm
2013when the makefile is used.
2014The flags are as if typed to the shell, though the
2015.Fl f
2016option will have
2017no effect.
2018.\" XXX: NOT YET!!!!
2019.\" .It Ic .NOTPARALLEL
2020.\" The named targets are executed in non parallel mode.
2021.\" If no targets are
2022.\" specified, then all targets are executed in non parallel mode.
2023.It Ic .NOPATH
2024Apply the
2025.Ic .NOPATH
2026attribute to any specified sources.
2027.It Ic .NOTPARALLEL
2028Disable parallel mode.
2029.It Ic .NO_PARALLEL
2030Synonym for
2031.Ic .NOTPARALLEL ,
2032for compatibility with other pmake variants.
2033.It Ic .OBJDIR
2034The source is a new value for
2035.Ql Va .OBJDIR .
2036If it exists,
2037.Nm
2038will
2039.Xr chdir 2
2040to it and update the value of
2041.Ql Va .OBJDIR .
2042.It Ic .ORDER
2043The named targets are made in sequence.
2044This ordering does not add targets to the list of targets to be made.
2045Since the dependents of a target do not get built until the target itself
2046could be built, unless
2047.Ql a
2048is built by another part of the dependency graph,
2049the following is a dependency loop:
2050.Bd -literal
2051\&.ORDER: b a
2052b: a
2053.Ed
2054.Pp
2055The ordering imposed by
2056.Ic .ORDER
2057is only relevant for parallel makes.
2058.\" XXX: NOT YET!!!!
2059.\" .It Ic .PARALLEL
2060.\" The named targets are executed in parallel mode.
2061.\" If no targets are
2062.\" specified, then all targets are executed in parallel mode.
2063.It Ic .PATH
2064The sources are directories which are to be searched for files not
2065found in the current directory.
2066If no sources are specified, any previously specified directories are
2067deleted.
2068If the source is the special
2069.Ic .DOTLAST
2070target, then the current working
2071directory is searched last.
2072.It Ic .PATH. Ns Va suffix
2073Like
2074.Ic .PATH
2075but applies only to files with a particular suffix.
2076The suffix must have been previously declared with
2077.Ic .SUFFIXES .
2078.It Ic .PHONY
2079Apply the
2080.Ic .PHONY
2081attribute to any specified sources.
2082.It Ic .PRECIOUS
2083Apply the
2084.Ic .PRECIOUS
2085attribute to any specified sources.
2086If no sources are specified, the
2087.Ic .PRECIOUS
2088attribute is applied to every
2089target in the file.
2090.It Ic .SHELL
2091Sets the shell that
2092.Nm
2093will use to execute commands.
2094The sources are a set of
2095.Ar field=value
2096pairs.
2097.Bl -tag -width hasErrCtls
2098.It Ar name
2099This is the minimal specification, used to select one of the built-in
2100shell specs;
2101.Ar sh ,
2102.Ar ksh ,
2103and
2104.Ar csh .
2105.It Ar path
2106Specifies the path to the shell.
2107.It Ar hasErrCtl
2108Indicates whether the shell supports exit on error.
2109.It Ar check
2110The command to turn on error checking.
2111.It Ar ignore
2112The command to disable error checking.
2113.It Ar echo
2114The command to turn on echoing of commands executed.
2115.It Ar quiet
2116The command to turn off echoing of commands executed.
2117.It Ar filter
2118The output to filter after issuing the
2119.Ar quiet
2120command.
2121It is typically identical to
2122.Ar quiet .
2123.It Ar errFlag
2124The flag to pass the shell to enable error checking.
2125.It Ar echoFlag
2126The flag to pass the shell to enable command echoing.
2127.It Ar newline
2128The string literal to pass the shell that results in a single newline
2129character when used outside of any quoting characters.
2130.El
2131Example:
2132.Bd -literal
2133\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2134 check="set \-e" ignore="set +e" \e
2135 echo="set \-v" quiet="set +v" filter="set +v" \e
2136 echoFlag=v errFlag=e newline="'\en'"
2137.Ed
2138.It Ic .SILENT
2139Apply the
2140.Ic .SILENT
2141attribute to any specified sources.
2142If no sources are specified, the
2143.Ic .SILENT
2144attribute is applied to every
2145command in the file.
2146.It Ic .STALE
2147This target gets run when a dependency file contains stale entries, having
2148.Va .ALLSRC
2149set to the name of that dependency file.
2150.It Ic .SUFFIXES
2151Each source specifies a suffix to
2152.Nm .
2153If no sources are specified, any previously specified suffixes are deleted.
2154It allows the creation of suffix-transformation rules.
2155.Pp
2156Example:
2157.Bd -literal
2158\&.SUFFIXES: .o
2159\&.c.o:
2160 cc \-o ${.TARGET} \-c ${.IMPSRC}
2161.Ed
2162.El
2163.Sh ENVIRONMENT
2164.Nm
2165uses the following environment variables, if they exist:
2166.Ev MACHINE ,
2167.Ev MACHINE_ARCH ,
2168.Ev MAKE ,
2169.Ev MAKEFLAGS ,
2170.Ev MAKEOBJDIR ,
2171.Ev MAKEOBJDIRPREFIX ,
2172.Ev MAKESYSPATH ,
2173.Ev PWD ,
2174and
2175.Ev TMPDIR .
2176.Pp
2177.Ev MAKEOBJDIRPREFIX
2178and
2179.Ev MAKEOBJDIR
2180may only be set in the environment or on the command line to
2181.Nm
2182and not as makefile variables;
2183see the description of
2184.Ql Va .OBJDIR
2185for more details.
2186.Sh FILES
2187.Bl -tag -width /usr/share/mk -compact
2188.It .depend
2189list of dependencies
2190.It Makefile
2191list of dependencies
2192.It makefile
2193list of dependencies
2194.It sys.mk
2195system makefile
2196.It /usr/share/mk
2197system makefile directory
2198.El
2199.Sh COMPATIBILITY
2200The basic make syntax is compatible between different versions of make;
2201however the special variables, variable modifiers and conditionals are not.
2202.Ss Older versions
2203An incomplete list of changes in older versions of
2204.Nm :
2205.Pp
2206The way that .for loop variables are substituted changed after
2207NetBSD 5.0
2208so that they still appear to be variable expansions.
2209In particular this stops them being treated as syntax, and removes some
2210obscure problems using them in .if statements.
2211.Pp
2212The way that parallel makes are scheduled changed in
2213NetBSD 4.0
2214so that .ORDER and .WAIT apply recursively to the dependent nodes.
2215The algorithms used may change again in the future.
2216.Ss Other make dialects
2217Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not
2218support most of the features of
2219.Nm
2220as described in this manual.
2221Most notably:
2222.Bl -bullet -offset indent
2223.It
2224The
2225.Ic .WAIT
2226and
2227.Ic .ORDER
2228declarations and most functionality pertaining to parallelization.
2229(GNU make supports parallelization but lacks these features needed to
2230control it effectively.)
2231.It
2232Directives, including for loops and conditionals and most of the
2233forms of include files.
2234(GNU make has its own incompatible and less powerful syntax for
2235conditionals.)
2236.It
2237All built-in variables that begin with a dot.
2238.It
2239Most of the special sources and targets that begin with a dot,
2240with the notable exception of
2241.Ic .PHONY ,
2242.Ic .PRECIOUS ,
2243and
2244.Ic .SUFFIXES .
2245.It
2246Variable modifiers, except for the
2247.Dl :old=new
2248string substitution, which does not portably support globbing with
2249.Ql %
2250and historically only works on declared suffixes.
2251.It
2252The
2253.Ic $>
2254variable even in its short form; most makes support this functionality
2255but its name varies.
2256.El
2257.Pp
2258Some features are somewhat more portable, such as assignment with
2259.Ic += ,
2260.Ic ?= ,
2261and
2262.Ic != .
2263The
2264.Ic .PATH
2265functionality is based on an older feature
2266.Ic VPATH
2267found in GNU make and many versions of SVR4 make; however,
2268historically its behavior is too ill-defined (and too buggy) to rely
2269upon.
2270.Pp
2271The
2272.Ic $@
2273and
2274.Ic $<
2275variables are more or less universally portable, as is the
2276.Ic $(MAKE)
2277variable.
2278Basic use of suffix rules (for files only in the current directory,
2279not trying to chain transformations together, etc.) is also reasonably
2280portable.
2281.Sh SEE ALSO
2282.Xr mkdep 1
2283.Sh HISTORY
2284.Nm
2285is derived from NetBSD
2286.Xr make 1 .
2287It uses autoconf to facilitate portability to other platforms.
2288.Pp
2289A
2290make
2291command appeared in
2292.At v7 .
2293This
2294make
2295implementation is based on Adam De Boor's pmake program which was written
2296for Sprite at Berkeley.
2297It was designed to be a parallel distributed make running jobs on different
2298machines using a daemon called
2299.Dq customs .
2300.Pp
2301Historically the target/dependency
2302.Dq FRC
2303has been used to FoRCe rebuilding (since the target/dependency
2304does not exist... unless someone creates an
2305.Dq FRC
2306file).
2307.Sh BUGS
2308The
2309make
2310syntax is difficult to parse without actually acting of the data.
2311For instance finding the end of a variable use should involve scanning each
2312the modifiers using the correct terminator for each field.
2313In many places
2314make
2315just counts {} and () in order to find the end of a variable expansion.
2316.Pp
2317There is no way of escaping a space character in a filename.