xref: /freebsd/contrib/bmake/make.1 (revision 9e5787d2284e187abb5b654d924394a65772e004)
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30.\"	from: @(#)make.1	8.4 (Berkeley) 3/19/94
31.\"
32.Dd June 5, 2020
33.Dt MAKE 1
34.Os
35.Sh NAME
36.Nm make
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 Fl v Ar variable
52.Op Ar variable=value
53.Op Ar target ...
54.Sh DESCRIPTION
55.Nm
56is a program designed to simplify the maintenance of other programs.
57Its input is a list of specifications as to the files upon which programs
58and other files depend.
59If no
60.Fl f Ar makefile
61makefile option is given,
62.Nm
63will try to open
64.Ql Pa makefile
65then
66.Ql Pa Makefile
67in order to find the specifications.
68If the file
69.Ql Pa .depend
70exists, it is read (see
71.Xr mkdep 1 ) .
72.Pp
73This manual page is intended as a reference document only.
74For a more thorough description of
75.Nm
76and makefiles, please refer to
77.%T "PMake \- A Tutorial" .
78.Pp
79.Nm
80will prepend the contents of the
81.Va MAKEFLAGS
82environment variable to the command line arguments before parsing them.
83.Pp
84The options are as follows:
85.Bl -tag -width Ds
86.It Fl B
87Try to be backwards compatible by executing a single shell per command and
88by executing the commands to make the sources of a dependency line in sequence.
89.It Fl C Ar directory
90Change to
91.Ar directory
92before reading the makefiles or doing anything else.
93If multiple
94.Fl C
95options are specified, each is interpreted relative to the previous one:
96.Fl C Pa / Fl C Pa etc
97is equivalent to
98.Fl C Pa /etc .
99.It Fl D Ar variable
100Define
101.Ar variable
102to be 1, in the global context.
103.It Fl d Ar [-]flags
104Turn on debugging, and specify which portions of
105.Nm
106are to print debugging information.
107Unless the flags are preceded by
108.Ql \-
109they are added to the
110.Va MAKEFLAGS
111environment variable and will be processed by any child make processes.
112By default, debugging information is printed to standard error,
113but this can be changed using the
114.Ar F
115debugging flag.
116The debugging output is always unbuffered; in addition, if debugging
117is enabled but debugging output is not directed to standard output,
118then the standard output is line buffered.
119.Ar Flags
120is one or more of the following:
121.Bl -tag -width Ds
122.It Ar A
123Print all possible debugging information;
124equivalent to specifying all of the debugging flags.
125.It Ar a
126Print debugging information about archive searching and caching.
127.It Ar C
128Print debugging information about current working directory.
129.It Ar c
130Print debugging information about conditional evaluation.
131.It Ar d
132Print debugging information about directory searching and caching.
133.It Ar e
134Print debugging information about failed commands and targets.
135.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename
136Specify where debugging output is written.
137This must be the last flag, because it consumes the remainder of
138the argument.
139If the character immediately after the
140.Ql F
141flag is
142.Ql \&+ ,
143then the file will be opened in append mode;
144otherwise the file will be overwritten.
145If the file name is
146.Ql stdout
147or
148.Ql stderr
149then debugging output will be written to the
150standard output or standard error output file descriptors respectively
151(and the
152.Ql \&+
153option has no effect).
154Otherwise, the output will be written to the named file.
155If the file name ends
156.Ql .%d
157then the
158.Ql %d
159is replaced by the pid.
160.It Ar f
161Print debugging information about loop evaluation.
162.It Ar "g1"
163Print the input graph before making anything.
164.It Ar "g2"
165Print the input graph after making everything, or before exiting
166on error.
167.It Ar "g3"
168Print the input graph before exiting on error.
169.It Ar j
170Print debugging information about running multiple shells.
171.It Ar l
172Print commands in Makefiles regardless of whether or not they are prefixed by
173.Ql @
174or other "quiet" flags.
175Also known as "loud" behavior.
176.It Ar M
177Print debugging information about "meta" mode decisions about targets.
178.It Ar m
179Print debugging information about making targets, including modification
180dates.
181.It Ar n
182Don't delete the temporary command scripts created when running commands.
183These temporary scripts are created in the directory
184referred to by the
185.Ev TMPDIR
186environment variable, or in
187.Pa /tmp
188if
189.Ev TMPDIR
190is unset or set to the empty string.
191The temporary scripts are created by
192.Xr mkstemp 3 ,
193and have names of the form
194.Pa makeXXXXXX .
195.Em NOTE :
196This can create many files in
197.Ev TMPDIR
198or
199.Pa /tmp ,
200so use with care.
201.It Ar p
202Print debugging information about makefile parsing.
203.It Ar s
204Print debugging information about suffix-transformation rules.
205.It Ar t
206Print debugging information about target list maintenance.
207.It Ar V
208Force the
209.Fl V
210option to print raw values of variables, overriding the default behavior
211set via
212.Va .MAKE.EXPAND_VARIABLES .
213.It Ar v
214Print debugging information about variable assignment.
215.It Ar x
216Run shell commands with
217.Fl x
218so the actual commands are printed as they are executed.
219.El
220.It Fl e
221Specify that environment variables override macro assignments within
222makefiles.
223.It Fl f Ar makefile
224Specify a makefile to read instead of the default
225.Ql Pa makefile .
226If
227.Ar makefile
228is
229.Ql Fl ,
230standard input is read.
231Multiple makefiles may be specified, and are read in the order specified.
232.It Fl I Ar directory
233Specify a directory in which to search for makefiles and included makefiles.
234The system makefile directory (or directories, see the
235.Fl m
236option) is automatically included as part of this list.
237.It Fl i
238Ignore non-zero exit of shell commands in the makefile.
239Equivalent to specifying
240.Ql Fl
241before each command line in the makefile.
242.It Fl J Ar private
243This option should
244.Em not
245be specified by the user.
246.Pp
247When the
248.Ar j
249option is in use in a recursive build, this option is passed by a make
250to child makes to allow all the make processes in the build to
251cooperate to avoid overloading the system.
252.It Fl j Ar max_jobs
253Specify the maximum number of jobs that
254.Nm
255may have running at any one time.
256The value is saved in
257.Va .MAKE.JOBS .
258Turns compatibility mode off, unless the
259.Ar B
260flag is also specified.
261When compatibility mode is off, all commands associated with a
262target are executed in a single shell invocation as opposed to the
263traditional one shell invocation per line.
264This can break traditional scripts which change directories on each
265command invocation and then expect to start with a fresh environment
266on the next line.
267It is more efficient to correct the scripts rather than turn backwards
268compatibility on.
269.It Fl k
270Continue processing after errors are encountered, but only on those targets
271that do not depend on the target whose creation caused the error.
272.It Fl m Ar directory
273Specify a directory in which to search for sys.mk and makefiles included
274via the
275.Li \&< Ns Ar file Ns Li \&> Ns -style
276include statement.
277The
278.Fl m
279option can be used multiple times to form a search path.
280This path will override the default system include path: /usr/share/mk.
281Furthermore the system include path will be appended to the search path used
282for
283.Li \*q Ns Ar file Ns Li \*q Ns -style
284include statements (see the
285.Fl I
286option).
287.Pp
288If a file or directory name in the
289.Fl m
290argument (or the
291.Ev MAKESYSPATH
292environment variable) starts with the string
293.Qq \&.../
294then
295.Nm
296will search for the specified file or directory named in the remaining part
297of the argument string.
298The search starts with the current directory of
299the Makefile and then works upward towards the root of the file system.
300If the search is successful, then the resulting directory replaces the
301.Qq \&.../
302specification in the
303.Fl m
304argument.
305If used, this feature allows
306.Nm
307to easily search in the current source tree for customized sys.mk files
308(e.g., by using
309.Qq \&.../mk/sys.mk
310as an argument).
311.It Fl n
312Display the commands that would have been executed, but do not
313actually execute them unless the target depends on the .MAKE special
314source (see below).
315.It Fl N
316Display the commands which would have been executed, but do not
317actually execute any of them; useful for debugging top-level makefiles
318without descending into subdirectories.
319.It Fl q
320Do not execute any commands, but exit 0 if the specified targets are
321up-to-date and 1, otherwise.
322.It Fl r
323Do not use the built-in rules specified in the system makefile.
324.It Fl s
325Do not echo any commands as they are executed.
326Equivalent to specifying
327.Ql Ic @
328before each command line in the makefile.
329.It Fl T Ar tracefile
330When used with the
331.Fl j
332flag,
333append a trace record to
334.Ar tracefile
335for each job started and completed.
336.It Fl t
337Rather than re-building a target as specified in the makefile, create it
338or update its modification time to make it appear up-to-date.
339.It Fl V Ar variable
340Print the value of
341.Ar variable .
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.
346The value printed is extracted from the global context after all
347makefiles have been read.
348By default, the raw variable contents (which may
349include additional unexpanded variable references) are shown.
350If
351.Ar variable
352contains a
353.Ql \&$
354then the value will be recursively expanded to its complete resultant
355text before printing.
356The expanded value will also be printed if
357.Va .MAKE.EXPAND_VARIABLES
358is set to true and
359the
360.Fl dV
361option has not been used to override it.
362Note that loop-local and target-local variables, as well as values
363taken temporarily by global variables during makefile processing, are
364not accessible via this option.
365The
366.Fl dv
367debug mode can be used to see these at the cost of generating
368substantial extraneous output.
369.It Fl v Ar variable
370Like
371.Fl V
372but the variable is always expanded to its complete value.
373.It Fl W
374Treat any warnings during makefile parsing as errors.
375.It Fl w
376Print entering and leaving directory messages, pre and post processing.
377.It Fl X
378Don't export variables passed on the command line to the environment
379individually.
380Variables passed on the command line are still exported
381via the
382.Va MAKEFLAGS
383environment variable.
384This option may be useful on systems which have a small limit on the
385size of command arguments.
386.It Ar variable=value
387Set the value of the variable
388.Ar variable
389to
390.Ar value .
391Normally, all values passed on the command line are also exported to
392sub-makes in the environment.
393The
394.Fl X
395flag disables this behavior.
396Variable assignments should follow options for POSIX compatibility
397but no ordering is enforced.
398.El
399.Pp
400There are seven different types of lines in a makefile: file dependency
401specifications, shell commands, variable assignments, include statements,
402conditional directives, for loops, and comments.
403.Pp
404In general, lines may be continued from one line to the next by ending
405them with a backslash
406.Pq Ql \e .
407The trailing newline character and initial whitespace on the following
408line are compressed into a single space.
409.Sh FILE DEPENDENCY SPECIFICATIONS
410Dependency lines consist of one or more targets, an operator, and zero
411or more sources.
412This creates a relationship where the targets
413.Dq depend
414on the sources
415and are usually created from them.
416The exact relationship between the target and the source is determined
417by the operator that separates them.
418The three operators are as follows:
419.Bl -tag -width flag
420.It Ic \&:
421A target is considered out-of-date if its modification time is less than
422those of any of its sources.
423Sources for a target accumulate over dependency lines when this operator
424is used.
425The target is removed if
426.Nm
427is interrupted.
428.It Ic \&!
429Targets are always re-created, but not until all sources have been
430examined and re-created as necessary.
431Sources for a target accumulate over dependency lines when this operator
432is used.
433The target is removed if
434.Nm
435is interrupted.
436.It Ic \&::
437If no sources are specified, the target is always re-created.
438Otherwise, a target is considered out-of-date if any of its sources has
439been modified more recently than the target.
440Sources for a target do not accumulate over dependency lines when this
441operator is used.
442The target will not be removed if
443.Nm
444is interrupted.
445.El
446.Pp
447Targets and sources may contain the shell wildcard values
448.Ql \&? ,
449.Ql * ,
450.Ql [] ,
451and
452.Ql {} .
453The values
454.Ql \&? ,
455.Ql * ,
456and
457.Ql []
458may only be used as part of the final
459component of the target or source, and must be used to describe existing
460files.
461The value
462.Ql {}
463need not necessarily be used to describe existing files.
464Expansion is in directory order, not alphabetically as done in the shell.
465.Sh SHELL COMMANDS
466Each target may have associated with it one or more lines of shell
467commands, normally
468used to create the target.
469Each of the lines in this script
470.Em must
471be preceded by a tab.
472(For historical reasons, spaces are not accepted.)
473While targets can appear in many dependency lines if desired, by
474default only one of these rules may be followed by a creation
475script.
476If the
477.Ql Ic \&::
478operator is used, however, all rules may include scripts and the
479scripts are executed in the order found.
480.Pp
481Each line is treated as a separate shell command, unless the end of
482line is escaped with a backslash
483.Pq Ql \e
484in which case that line and the next are combined.
485.\" The escaped newline is retained and passed to the shell, which
486.\" normally ignores it.
487.\" However, the tab at the beginning of the following line is removed.
488If the first characters of the command are any combination of
489.Ql Ic @ ,
490.Ql Ic + ,
491or
492.Ql Ic \- ,
493the command is treated specially.
494A
495.Ql Ic @
496causes the command not to be echoed before it is executed.
497A
498.Ql Ic +
499causes the command to be executed even when
500.Fl n
501is given.
502This is similar to the effect of the .MAKE special source,
503except that the effect can be limited to a single line of a script.
504A
505.Ql Ic \-
506in compatibility mode
507causes any non-zero exit status of the command line to be ignored.
508.Pp
509When
510.Nm
511is run in jobs mode with
512.Fl j Ar max_jobs ,
513the entire script for the target is fed to a
514single instance of the shell.
515In compatibility (non-jobs) mode, each command is run in a separate process.
516If the command contains any shell meta characters
517.Pq Ql #=|^(){};&<>*?[]:$`\e\en
518it will be passed to the shell; otherwise
519.Nm
520will attempt direct execution.
521If a line starts with
522.Ql Ic \-
523and the shell has ErrCtl enabled then failure of the command line
524will be ignored as in compatibility mode.
525Otherwise
526.Ql Ic \-
527affects the entire job;
528the script will stop at the first command line that fails,
529but the target will not be deemed to have failed.
530.Pp
531Makefiles should be written so that the mode of
532.Nm
533operation does not change their behavior.
534For example, any command which needs to use
535.Dq cd
536or
537.Dq chdir
538without potentially changing the directory for subsequent commands
539should be put in parentheses so it executes in a subshell.
540To force the use of one shell, escape the line breaks so as to make
541the whole script one command.
542For example:
543.Bd -literal -offset indent
544avoid-chdir-side-effects:
545	@echo Building $@ in `pwd`
546	@(cd ${.CURDIR} && ${MAKE} $@)
547	@echo Back in `pwd`
548
549ensure-one-shell-regardless-of-mode:
550	@echo Building $@ in `pwd`; \e
551	(cd ${.CURDIR} && ${MAKE} $@); \e
552	echo Back in `pwd`
553.Ed
554.Pp
555Since
556.Nm
557will
558.Xr chdir 2
559to
560.Ql Va .OBJDIR
561before executing any targets, each child process
562starts with that as its current working directory.
563.Sh VARIABLE ASSIGNMENTS
564Variables in make are much like variables in the shell, and, by tradition,
565consist of all upper-case letters.
566.Ss Variable assignment modifiers
567The five operators that can be used to assign values to variables are as
568follows:
569.Bl -tag -width Ds
570.It Ic \&=
571Assign the value to the variable.
572Any previous value is overridden.
573.It Ic \&+=
574Append the value to the current value of the variable.
575.It Ic \&?=
576Assign the value to the variable if it is not already defined.
577.It Ic \&:=
578Assign with expansion, i.e. expand the value before assigning it
579to the variable.
580Normally, expansion is not done until the variable is referenced.
581.Em NOTE :
582References to undefined variables are
583.Em not
584expanded.
585This can cause problems when variable modifiers are used.
586.It Ic \&!=
587Expand the value and pass it to the shell for execution and assign
588the result to the variable.
589Any newlines in the result are replaced with spaces.
590.El
591.Pp
592Any white-space before the assigned
593.Ar value
594is removed; if the value is being appended, a single space is inserted
595between the previous contents of the variable and the appended value.
596.Pp
597Variables are expanded by surrounding the variable name with either
598curly braces
599.Pq Ql {}
600or parentheses
601.Pq Ql ()
602and preceding it with
603a dollar sign
604.Pq Ql \&$ .
605If the variable name contains only a single letter, the surrounding
606braces or parentheses are not required.
607This shorter form is not recommended.
608.Pp
609If the variable name contains a dollar, then the name itself is expanded first.
610This allows almost arbitrary variable names, however names containing dollar,
611braces, parenthesis, or whitespace are really best avoided!
612.Pp
613If the result of expanding a variable contains a dollar sign
614.Pq Ql \&$
615the string is expanded again.
616.Pp
617Variable substitution occurs at three distinct times, depending on where
618the variable is being used.
619.Bl -enum
620.It
621Variables in dependency lines are expanded as the line is read.
622.It
623Variables in shell commands are expanded when the shell command is
624executed.
625.It
626.Dq .for
627loop index variables are expanded on each loop iteration.
628Note that other variables are not expanded inside loops so
629the following example code:
630.Bd -literal -offset indent
631
632.Dv .for i in 1 2 3
633a+=     ${i}
634j=      ${i}
635b+=     ${j}
636.Dv .endfor
637
638all:
639	@echo ${a}
640	@echo ${b}
641
642.Ed
643will print:
644.Bd -literal -offset indent
6451 2 3
6463 3 3
647
648.Ed
649Because while ${a} contains
650.Dq 1 2 3
651after the loop is executed, ${b}
652contains
653.Dq ${j} ${j} ${j}
654which expands to
655.Dq 3 3 3
656since after the loop completes ${j} contains
657.Dq 3 .
658.El
659.Ss Variable classes
660The four different classes of variables (in order of increasing precedence)
661are:
662.Bl -tag -width Ds
663.It Environment variables
664Variables defined as part of
665.Nm Ns 's
666environment.
667.It Global variables
668Variables defined in the makefile or in included makefiles.
669.It Command line variables
670Variables defined as part of the command line.
671.It Local variables
672Variables that are defined specific to a certain target.
673.El
674.Pp
675Local variables are all built in and their values vary magically from
676target to target.
677It is not currently possible to define new local variables.
678The seven local variables are as follows:
679.Bl -tag -width ".ARCHIVE" -offset indent
680.It Va .ALLSRC
681The list of all sources for this target; also known as
682.Ql Va \&> .
683.It Va .ARCHIVE
684The name of the archive file; also known as
685.Ql Va \&! .
686.It Va .IMPSRC
687In suffix-transformation rules, the name/path of the source from which the
688target is to be transformed (the
689.Dq implied
690source); also known as
691.Ql Va \&< .
692It is not defined in explicit rules.
693.It Va .MEMBER
694The name of the archive member; also known as
695.Ql Va % .
696.It Va .OODATE
697The list of sources for this target that were deemed out-of-date; also
698known as
699.Ql Va \&? .
700.It Va .PREFIX
701The file prefix of the target, containing only the file portion, no suffix
702or preceding directory components; also known as
703.Ql Va * .
704The suffix must be one of the known suffixes declared with
705.Ic .SUFFIXES
706or it will not be recognized.
707.It Va .TARGET
708The name of the target; also known as
709.Ql Va @ .
710For compatibility with other makes this is an alias for
711.Ic .ARCHIVE
712in archive member rules.
713.El
714.Pp
715The shorter forms
716.Ql ( Va > ,
717.Ql Va \&! ,
718.Ql Va < ,
719.Ql Va % ,
720.Ql Va \&? ,
721.Ql Va * ,
722and
723.Ql Va @ )
724are permitted for backward
725compatibility with historical makefiles and legacy POSIX make and are
726not recommended.
727.Pp
728Variants of these variables with the punctuation followed immediately by
729.Ql D
730or
731.Ql F ,
732e.g.
733.Ql Va $(@D) ,
734are legacy forms equivalent to using the
735.Ql :H
736and
737.Ql :T
738modifiers.
739These forms are accepted for compatibility with
740.At V
741makefiles and POSIX but are not recommended.
742.Pp
743Four of the local variables may be used in sources on dependency lines
744because they expand to the proper value for each target on the line.
745These variables are
746.Ql Va .TARGET ,
747.Ql Va .PREFIX ,
748.Ql Va .ARCHIVE ,
749and
750.Ql Va .MEMBER .
751.Ss Additional built-in variables
752In addition,
753.Nm
754sets or knows about the following variables:
755.Bl -tag -width .MAKEOVERRIDES
756.It Va \&$
757A single dollar sign
758.Ql \&$ ,
759i.e.
760.Ql \&$$
761expands to a single dollar
762sign.
763.It Va .ALLTARGETS
764The list of all targets encountered in the Makefile.
765If evaluated during
766Makefile parsing, lists only those targets encountered thus far.
767.It Va .CURDIR
768A path to the directory where
769.Nm
770was executed.
771Refer to the description of
772.Ql Ev PWD
773for more details.
774.It Va .INCLUDEDFROMDIR
775The directory of the file this Makefile was included from.
776.It Va .INCLUDEDFROMFILE
777The filename of the file this Makefile was included from.
778.It Ev MAKE
779The name that
780.Nm
781was executed with
782.Pq Va argv[0] .
783For compatibility
784.Nm
785also sets
786.Va .MAKE
787with the same value.
788The preferred variable to use is the environment variable
789.Ev MAKE
790because it is more compatible with other versions of
791.Nm
792and cannot be confused with the special target with the same name.
793.It Va .MAKE.ALWAYS_PASS_JOB_QUEUE
794Tells
795.Nm
796whether to pass the descriptors of the job token queue
797even if the target is not tagged with
798.Ic .MAKE
799The default is
800.Ql Pa yes
801for backwards compatability with
802.Fx 9.0
803and earlier.
804.It Va .MAKE.DEPENDFILE
805Names the makefile (default
806.Ql Pa .depend )
807from which generated dependencies are read.
808.It Va .MAKE.EXPAND_VARIABLES
809A boolean that controls the default behavior of the
810.Fl V
811option.
812If true, variable values printed with
813.Fl V
814are fully expanded; if false, the raw variable contents (which may
815include additional unexpanded variable references) are shown.
816.It Va .MAKE.EXPORTED
817The list of variables exported by
818.Nm .
819.It Va .MAKE.JOBS
820The argument to the
821.Fl j
822option.
823.It Va .MAKE.JOB.PREFIX
824If
825.Nm
826is run with
827.Ar j
828then output for each target is prefixed with a token
829.Ql --- target ---
830the first part of which can be controlled via
831.Va .MAKE.JOB.PREFIX .
832If
833.Va .MAKE.JOB.PREFIX
834is empty, no token is printed.
835.br
836For example:
837.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
838would produce tokens like
839.Ql ---make[1234] target ---
840making it easier to track the degree of parallelism being achieved.
841.It Ev MAKEFLAGS
842The environment variable
843.Ql Ev MAKEFLAGS
844may contain anything that
845may be specified on
846.Nm Ns 's
847command line.
848Anything specified on
849.Nm Ns 's
850command line is appended to the
851.Ql Ev MAKEFLAGS
852variable which is then
853entered into the environment for all programs which
854.Nm
855executes.
856.It Va .MAKE.LEVEL
857The recursion depth of
858.Nm .
859The initial instance of
860.Nm
861will be 0, and an incremented value is put into the environment
862to be seen by the next generation.
863This allows tests like:
864.Li .if ${.MAKE.LEVEL} == 0
865to protect things which should only be evaluated in the initial instance of
866.Nm .
867.It Va .MAKE.MAKEFILE_PREFERENCE
868The ordered list of makefile names
869(default
870.Ql Pa makefile ,
871.Ql Pa Makefile )
872that
873.Nm
874will look for.
875.It Va .MAKE.MAKEFILES
876The list of makefiles read by
877.Nm ,
878which is useful for tracking dependencies.
879Each makefile is recorded only once, regardless of the number of times read.
880.It Va .MAKE.MODE
881Processed after reading all makefiles.
882Can affect the mode that
883.Nm
884runs in.
885It can contain a number of keywords:
886.Bl -hang -width missing-filemon=bf.
887.It Pa compat
888Like
889.Fl B ,
890puts
891.Nm
892into "compat" mode.
893.It Pa meta
894Puts
895.Nm
896into "meta" mode, where meta files are created for each target
897to capture the command run, the output generated and if
898.Xr filemon 4
899is available, the system calls which are of interest to
900.Nm .
901The captured output can be very useful when diagnosing errors.
902.It Pa curdirOk= Ar bf
903Normally
904.Nm
905will not create .meta files in
906.Ql Va .CURDIR .
907This can be overridden by setting
908.Va bf
909to a value which represents True.
910.It Pa missing-meta= Ar bf
911If
912.Va bf
913is True, then a missing .meta file makes the target out-of-date.
914.It Pa missing-filemon= Ar bf
915If
916.Va bf
917is True, then missing filemon data makes the target out-of-date.
918.It Pa nofilemon
919Do not use
920.Xr filemon 4 .
921.It Pa env
922For debugging, it can be useful to include the environment
923in the .meta file.
924.It Pa verbose
925If in "meta" mode, print a clue about the target being built.
926This is useful if the build is otherwise running silently.
927The message printed the value of:
928.Va .MAKE.META.PREFIX .
929.It Pa ignore-cmd
930Some makefiles have commands which are simply not stable.
931This keyword causes them to be ignored for
932determining whether a target is out of date in "meta" mode.
933See also
934.Ic .NOMETA_CMP .
935.It Pa silent= Ar bf
936If
937.Va bf
938is True, when a .meta file is created, mark the target
939.Ic .SILENT .
940.El
941.It Va .MAKE.META.BAILIWICK
942In "meta" mode, provides a list of prefixes which
943match the directories controlled by
944.Nm .
945If a file that was generated outside of
946.Va .OBJDIR
947but within said bailiwick is missing,
948the current target is considered out-of-date.
949.It Va .MAKE.META.CREATED
950In "meta" mode, this variable contains a list of all the meta files
951updated.
952If not empty, it can be used to trigger processing of
953.Va .MAKE.META.FILES .
954.It Va .MAKE.META.FILES
955In "meta" mode, this variable contains a list of all the meta files
956used (updated or not).
957This list can be used to process the meta files to extract dependency
958information.
959.It Va .MAKE.META.IGNORE_PATHS
960Provides a list of path prefixes that should be ignored;
961because the contents are expected to change over time.
962The default list includes:
963.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
964.It Va .MAKE.META.IGNORE_PATTERNS
965Provides a list of patterns to match against pathnames.
966Ignore any that match.
967.It Va .MAKE.META.IGNORE_FILTER
968Provides a list of variable modifiers to apply to each pathname.
969Ignore if the expansion is an empty string.
970.It Va .MAKE.META.PREFIX
971Defines the message printed for each meta file updated in "meta verbose" mode.
972The default value is:
973.Dl Building ${.TARGET:H:tA}/${.TARGET:T}
974.It Va .MAKEOVERRIDES
975This variable is used to record the names of variables assigned to
976on the command line, so that they may be exported as part of
977.Ql Ev MAKEFLAGS .
978This behavior can be disabled by assigning an empty value to
979.Ql Va .MAKEOVERRIDES
980within a makefile.
981Extra variables can be exported from a makefile
982by appending their names to
983.Ql Va .MAKEOVERRIDES .
984.Ql Ev MAKEFLAGS
985is re-exported whenever
986.Ql Va .MAKEOVERRIDES
987is modified.
988.It Va .MAKE.PATH_FILEMON
989If
990.Nm
991was built with
992.Xr filemon 4
993support, this is set to the path of the device node.
994This allows makefiles to test for this support.
995.It Va .MAKE.PID
996The process-id of
997.Nm .
998.It Va .MAKE.PPID
999The parent process-id of
1000.Nm .
1001.It Va .MAKE.SAVE_DOLLARS
1002value should be a boolean that controls whether
1003.Ql $$
1004are preserved when doing
1005.Ql :=
1006assignments.
1007The default is false, for backwards compatibility.
1008Set to true for compatability with other makes.
1009If set to false,
1010.Ql $$
1011becomes
1012.Ql $
1013per normal evaluation rules.
1014.It Va MAKE_PRINT_VAR_ON_ERROR
1015When
1016.Nm
1017stops due to an error, it sets
1018.Ql Va .ERROR_TARGET
1019to the name of the target that failed,
1020.Ql Va .ERROR_CMD
1021to the commands of the failed target,
1022and in "meta" mode, it also sets
1023.Ql Va .ERROR_CWD
1024to the
1025.Xr getcwd 3 ,
1026and
1027.Ql Va .ERROR_META_FILE
1028to the path of the meta file (if any) describing the failed target.
1029It then prints its name and the value of
1030.Ql Va .CURDIR
1031as well as the value of any variables named in
1032.Ql Va MAKE_PRINT_VAR_ON_ERROR .
1033.It Va .newline
1034This variable is simply assigned a newline character as its value.
1035This allows expansions using the
1036.Cm \&:@
1037modifier to put a newline between
1038iterations of the loop rather than a space.
1039For example, the printing of
1040.Ql Va MAKE_PRINT_VAR_ON_ERROR
1041could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
1042.It Va .OBJDIR
1043A path to the directory where the targets are built.
1044Its value is determined by trying to
1045.Xr chdir 2
1046to the following directories in order and using the first match:
1047.Bl -enum
1048.It
1049.Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
1050.Pp
1051(Only if
1052.Ql Ev MAKEOBJDIRPREFIX
1053is set in the environment or on the command line.)
1054.It
1055.Ev ${MAKEOBJDIR}
1056.Pp
1057(Only if
1058.Ql Ev MAKEOBJDIR
1059is set in the environment or on the command line.)
1060.It
1061.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
1062.It
1063.Ev ${.CURDIR} Ns Pa /obj
1064.It
1065.Pa /usr/obj/ Ns Ev ${.CURDIR}
1066.It
1067.Ev ${.CURDIR}
1068.El
1069.Pp
1070Variable expansion is performed on the value before it's used,
1071so expressions such as
1072.Dl ${.CURDIR:S,^/usr/src,/var/obj,}
1073may be used.
1074This is especially useful with
1075.Ql Ev MAKEOBJDIR .
1076.Pp
1077.Ql Va .OBJDIR
1078may be modified in the makefile via the special target
1079.Ql Ic .OBJDIR .
1080In all cases,
1081.Nm
1082will
1083.Xr chdir 2
1084to the specified directory if it exists, and set
1085.Ql Va .OBJDIR
1086and
1087.Ql Ev PWD
1088to that directory before executing any targets.
1089.
1090.It Va .PARSEDIR
1091A path to the directory of the current
1092.Ql Pa Makefile
1093being parsed.
1094.It Va .PARSEFILE
1095The basename of the current
1096.Ql Pa Makefile
1097being parsed.
1098This variable and
1099.Ql Va .PARSEDIR
1100are both set only while the
1101.Ql Pa Makefiles
1102are being parsed.
1103If you want to retain their current values, assign them to a variable
1104using assignment with expansion:
1105.Pq Ql Cm \&:= .
1106.It Va .PATH
1107A variable that represents the list of directories that
1108.Nm
1109will search for files.
1110The search list should be updated using the target
1111.Ql Va .PATH
1112rather than the variable.
1113.It Ev PWD
1114Alternate path to the current directory.
1115.Nm
1116normally sets
1117.Ql Va .CURDIR
1118to the canonical path given by
1119.Xr getcwd 3 .
1120However, if the environment variable
1121.Ql Ev PWD
1122is set and gives a path to the current directory, then
1123.Nm
1124sets
1125.Ql Va .CURDIR
1126to the value of
1127.Ql Ev PWD
1128instead.
1129This behavior is disabled if
1130.Ql Ev MAKEOBJDIRPREFIX
1131is set or
1132.Ql Ev MAKEOBJDIR
1133contains a variable transform.
1134.Ql Ev PWD
1135is set to the value of
1136.Ql Va .OBJDIR
1137for all programs which
1138.Nm
1139executes.
1140.It Ev .TARGETS
1141The list of targets explicitly specified on the command line, if any.
1142.It Ev VPATH
1143Colon-separated
1144.Pq Dq \&:
1145lists of directories that
1146.Nm
1147will search for files.
1148The variable is supported for compatibility with old make programs only,
1149use
1150.Ql Va .PATH
1151instead.
1152.El
1153.Ss Variable modifiers
1154Variable expansion may be modified to select or modify each word of the
1155variable (where a
1156.Dq word
1157is white-space delimited sequence of characters).
1158The general format of a variable expansion is as follows:
1159.Pp
1160.Dl ${variable[:modifier[:...]]}
1161.Pp
1162Each modifier begins with a colon,
1163which may be escaped with a backslash
1164.Pq Ql \e .
1165.Pp
1166A set of modifiers can be specified via a variable, as follows:
1167.Pp
1168.Dl modifier_variable=modifier[:...]
1169.Dl ${variable:${modifier_variable}[:...]}
1170.Pp
1171In this case the first modifier in the modifier_variable does not
1172start with a colon, since that must appear in the referencing
1173variable.
1174If any of the modifiers in the modifier_variable contain a dollar sign
1175.Pq Ql $ ,
1176these must be doubled to avoid early expansion.
1177.Pp
1178The supported modifiers are:
1179.Bl -tag -width EEE
1180.It Cm \&:E
1181Replaces each word in the variable with its suffix.
1182.It Cm \&:H
1183Replaces each word in the variable with everything but the last component.
1184.It Cm \&:M Ns Ar pattern
1185Select only those words that match
1186.Ar pattern .
1187The standard shell wildcard characters
1188.Pf ( Ql * ,
1189.Ql \&? ,
1190and
1191.Ql Oo Oc )
1192may
1193be used.
1194The wildcard characters may be escaped with a backslash
1195.Pq Ql \e .
1196As a consequence of the way values are split into words, matched,
1197and then joined, a construct like
1198.Dl ${VAR:M*}
1199will normalize the inter-word spacing, removing all leading and
1200trailing space, and converting multiple consecutive spaces
1201to single spaces.
1202.
1203.It Cm \&:N Ns Ar pattern
1204This is identical to
1205.Ql Cm \&:M ,
1206but selects all words which do not match
1207.Ar pattern .
1208.It Cm \&:O
1209Order every word in variable alphabetically.
1210.It Cm \&:Or
1211Order every word in variable in reverse alphabetical order.
1212.It Cm \&:Ox
1213Randomize words in variable.
1214The results will be different each time you are referring to the
1215modified variable; use the assignment with expansion
1216.Pq Ql Cm \&:=
1217to prevent such behavior.
1218For example,
1219.Bd -literal -offset indent
1220LIST=			uno due tre quattro
1221RANDOM_LIST=		${LIST:Ox}
1222STATIC_RANDOM_LIST:=	${LIST:Ox}
1223
1224all:
1225	@echo "${RANDOM_LIST}"
1226	@echo "${RANDOM_LIST}"
1227	@echo "${STATIC_RANDOM_LIST}"
1228	@echo "${STATIC_RANDOM_LIST}"
1229.Ed
1230may produce output similar to:
1231.Bd -literal -offset indent
1232quattro due tre uno
1233tre due quattro uno
1234due uno quattro tre
1235due uno quattro tre
1236.Ed
1237.It Cm \&:Q
1238Quotes every shell meta-character in the variable, so that it can be passed
1239safely to the shell.
1240.It Cm \&:q
1241Quotes every shell meta-character in the variable, and also doubles
1242.Sq $
1243characters so that it can be passed
1244safely through recursive invocations of
1245.Nm .
1246This is equivalent to:
1247.Sq \&:S/\e\&$/&&/g:Q .
1248.It Cm \&:R
1249Replaces each word in the variable with everything but its suffix.
1250.It Cm \&:range[=count]
1251The value is an integer sequence representing the words of the original
1252value, or the supplied
1253.Va count .
1254.It Cm \&:gmtime[=utc]
1255The value is a format string for
1256.Xr strftime 3 ,
1257using
1258.Xr gmtime 3 .
1259If a
1260.Va utc
1261value is not provided or is 0, the current time is used.
1262.It Cm \&:hash
1263Compute a 32-bit hash of the value and encode it as hex digits.
1264.It Cm \&:localtime[=utc]
1265The value is a format string for
1266.Xr strftime 3 ,
1267using
1268.Xr localtime 3 .
1269If a
1270.Va utc
1271value is not provided or is 0, the current time is used.
1272.It Cm \&:tA
1273Attempt to convert variable to an absolute path using
1274.Xr realpath 3 ,
1275if that fails, the value is unchanged.
1276.It Cm \&:tl
1277Converts variable to lower-case letters.
1278.It Cm \&:ts Ns Ar c
1279Words in the variable are normally separated by a space on expansion.
1280This modifier sets the separator to the character
1281.Ar c .
1282If
1283.Ar c
1284is omitted, then no separator is used.
1285The common escapes (including octal numeric codes), work as expected.
1286.It Cm \&:tu
1287Converts variable to upper-case letters.
1288.It Cm \&:tW
1289Causes the value to be treated as a single word
1290(possibly containing embedded white space).
1291See also
1292.Ql Cm \&:[*] .
1293.It Cm \&:tw
1294Causes the value to be treated as a sequence of
1295words delimited by white space.
1296See also
1297.Ql Cm \&:[@] .
1298.Sm off
1299.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1300.Sm on
1301Modify the first occurrence of
1302.Ar old_string
1303in the variable's value, replacing it with
1304.Ar new_string .
1305If a
1306.Ql g
1307is appended to the last slash of the pattern, all occurrences
1308in each word are replaced.
1309If a
1310.Ql 1
1311is appended to the last slash of the pattern, only the first word
1312is affected.
1313If a
1314.Ql W
1315is appended to the last slash of the pattern,
1316then the value is treated as a single word
1317(possibly containing embedded white space).
1318If
1319.Ar old_string
1320begins with a caret
1321.Pq Ql ^ ,
1322.Ar old_string
1323is anchored at the beginning of each word.
1324If
1325.Ar old_string
1326ends with a dollar sign
1327.Pq Ql \&$ ,
1328it is anchored at the end of each word.
1329Inside
1330.Ar new_string ,
1331an ampersand
1332.Pq Ql &
1333is replaced by
1334.Ar old_string
1335(without any
1336.Ql ^
1337or
1338.Ql \&$ ) .
1339Any character may be used as a delimiter for the parts of the modifier
1340string.
1341The anchoring, ampersand and delimiter characters may be escaped with a
1342backslash
1343.Pq Ql \e .
1344.Pp
1345Variable expansion occurs in the normal fashion inside both
1346.Ar old_string
1347and
1348.Ar new_string
1349with the single exception that a backslash is used to prevent the expansion
1350of a dollar sign
1351.Pq Ql \&$ ,
1352not a preceding dollar sign as is usual.
1353.Sm off
1354.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1355.Sm on
1356The
1357.Cm \&:C
1358modifier is just like the
1359.Cm \&:S
1360modifier except that the old and new strings, instead of being
1361simple strings, are an extended regular expression (see
1362.Xr regex 3 )
1363string
1364.Ar pattern
1365and an
1366.Xr ed 1 Ns \-style
1367string
1368.Ar replacement .
1369Normally, the first occurrence of the pattern
1370.Ar pattern
1371in each word of the value is substituted with
1372.Ar replacement .
1373The
1374.Ql 1
1375modifier causes the substitution to apply to at most one word; the
1376.Ql g
1377modifier causes the substitution to apply to as many instances of the
1378search pattern
1379.Ar pattern
1380as occur in the word or words it is found in; the
1381.Ql W
1382modifier causes the value to be treated as a single word
1383(possibly containing embedded white space).
1384Note that
1385.Ql 1
1386and
1387.Ql g
1388are orthogonal; the former specifies whether multiple words are
1389potentially affected, the latter whether multiple substitutions can
1390potentially occur within each affected word.
1391.Pp
1392As for the
1393.Cm \&:S
1394modifier, the
1395.Ar pattern
1396and
1397.Ar replacement
1398are subjected to variable expansion before being parsed as
1399regular expressions.
1400.It Cm \&:T
1401Replaces each word in the variable with its last component.
1402.It Cm \&:u
1403Remove adjacent duplicate words (like
1404.Xr uniq 1 ) .
1405.Sm off
1406.It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1407.Sm on
1408If the variable name (not its value), when parsed as a .if conditional
1409expression, evaluates to true, return as its value the
1410.Ar true_string ,
1411otherwise return the
1412.Ar false_string .
1413Since the variable name is used as the expression, \&:\&? must be the
1414first modifier after the variable name itself - which will, of course,
1415usually contain variable expansions.
1416A common error is trying to use expressions like
1417.Dl ${NUMBERS:M42:?match:no}
1418which actually tests defined(NUMBERS),
1419to determine is any words match "42" you need to use something like:
1420.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1421.It Ar :old_string=new_string
1422This is the
1423.At V
1424style variable substitution.
1425It must be the last modifier specified.
1426If
1427.Ar old_string
1428or
1429.Ar new_string
1430do not contain the pattern matching character
1431.Ar %
1432then it is assumed that they are
1433anchored at the end of each word, so only suffixes or entire
1434words may be replaced.
1435Otherwise
1436.Ar %
1437is the substring of
1438.Ar old_string
1439to be replaced in
1440.Ar new_string .
1441If only
1442.Ar old_string
1443contains the pattern matching character
1444.Ar % ,
1445and
1446.Ar old_string
1447matches, then the result is the
1448.Ar new_string .
1449If only the
1450.Ar new_string
1451contains the pattern matching character
1452.Ar % ,
1453then it is not treated specially and it is printed as a literal
1454.Ar %
1455on match.
1456If there is more than one pattern matching character
1457.Ar ( % )
1458in either the
1459.Ar new_string
1460or
1461.Ar old_string ,
1462only the first instance is treated specially (as the pattern character);
1463all subsequent instances are treated as regular characters
1464.Pp
1465Variable expansion occurs in the normal fashion inside both
1466.Ar old_string
1467and
1468.Ar new_string
1469with the single exception that a backslash is used to prevent the
1470expansion of a dollar sign
1471.Pq Ql \&$ ,
1472not a preceding dollar sign as is usual.
1473.Sm off
1474.It Cm \&:@ Ar temp Cm @ Ar string Cm @
1475.Sm on
1476This is the loop expansion mechanism from the OSF Development
1477Environment (ODE) make.
1478Unlike
1479.Cm \&.for
1480loops expansion occurs at the time of
1481reference.
1482Assign
1483.Ar temp
1484to each word in the variable and evaluate
1485.Ar string .
1486The ODE convention is that
1487.Ar temp
1488should start and end with a period.
1489For example.
1490.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1491.Pp
1492However a single character variable is often more readable:
1493.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1494.It Cm \&:_[=var]
1495Save the current variable value in
1496.Ql $_
1497or the named
1498.Va var
1499for later reference.
1500Example usage:
1501.Bd -literal -offset indent
1502M_cmpv.units = 1 1000 1000000
1503M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\
1504\\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1505
1506.Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1507
1508.Ed
1509Here
1510.Ql $_
1511is used to save the result of the
1512.Ql :S
1513modifier which is later referenced using the index values from
1514.Ql :range .
1515.It Cm \&:U Ns Ar newval
1516If the variable is undefined
1517.Ar newval
1518is the value.
1519If the variable is defined, the existing value is returned.
1520This is another ODE make feature.
1521It is handy for setting per-target CFLAGS for instance:
1522.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1523If a value is only required if the variable is undefined, use:
1524.Dl ${VAR:D:Unewval}
1525.It Cm \&:D Ns Ar newval
1526If the variable is defined
1527.Ar newval
1528is the value.
1529.It Cm \&:L
1530The name of the variable is the value.
1531.It Cm \&:P
1532The path of the node which has the same name as the variable
1533is the value.
1534If no such node exists or its path is null, then the
1535name of the variable is used.
1536In order for this modifier to work, the name (node) must at least have
1537appeared on the rhs of a dependency.
1538.Sm off
1539.It Cm \&:\&! Ar cmd Cm \&!
1540.Sm on
1541The output of running
1542.Ar cmd
1543is the value.
1544.It Cm \&:sh
1545If the variable is non-empty it is run as a command and the output
1546becomes the new value.
1547.It Cm \&::= Ns Ar str
1548The variable is assigned the value
1549.Ar str
1550after substitution.
1551This modifier and its variations are useful in
1552obscure situations such as wanting to set a variable when shell commands
1553are being parsed.
1554These assignment modifiers always expand to
1555nothing, so if appearing in a rule line by themselves should be
1556preceded with something to keep
1557.Nm
1558happy.
1559.Pp
1560The
1561.Ql Cm \&::
1562helps avoid false matches with the
1563.At V
1564style
1565.Cm \&:=
1566modifier and since substitution always occurs the
1567.Cm \&::=
1568form is vaguely appropriate.
1569.It Cm \&::?= Ns Ar str
1570As for
1571.Cm \&::=
1572but only if the variable does not already have a value.
1573.It Cm \&::+= Ns Ar str
1574Append
1575.Ar str
1576to the variable.
1577.It Cm \&::!= Ns Ar cmd
1578Assign the output of
1579.Ar cmd
1580to the variable.
1581.It Cm \&:\&[ Ns Ar range Ns Cm \&]
1582Selects one or more words from the value,
1583or performs other operations related to the way in which the
1584value is divided into words.
1585.Pp
1586Ordinarily, a value is treated as a sequence of words
1587delimited by white space.
1588Some modifiers suppress this behavior,
1589causing a value to be treated as a single word
1590(possibly containing embedded white space).
1591An empty value, or a value that consists entirely of white-space,
1592is treated as a single word.
1593For the purposes of the
1594.Ql Cm \&:[]
1595modifier, the words are indexed both forwards using positive integers
1596(where index 1 represents the first word),
1597and backwards using negative integers
1598(where index \-1 represents the last word).
1599.Pp
1600The
1601.Ar range
1602is subjected to variable expansion, and the expanded result is
1603then interpreted as follows:
1604.Bl -tag -width index
1605.\" :[n]
1606.It Ar index
1607Selects a single word from the value.
1608.\" :[start..end]
1609.It Ar start Ns Cm \&.. Ns Ar end
1610Selects all words from
1611.Ar start
1612to
1613.Ar end ,
1614inclusive.
1615For example,
1616.Ql Cm \&:[2..-1]
1617selects all words from the second word to the last word.
1618If
1619.Ar start
1620is greater than
1621.Ar end ,
1622then the words are output in reverse order.
1623For example,
1624.Ql Cm \&:[-1..1]
1625selects all the words from last to first.
1626If the list is already ordered, then this effectively reverses
1627the list, but it is more efficient to use
1628.Ql Cm \&:Or
1629instead of
1630.Ql Cm \&:O:[-1..1] .
1631.\" :[*]
1632.It Cm \&*
1633Causes subsequent modifiers to treat the value as a single word
1634(possibly containing embedded white space).
1635Analogous to the effect of
1636\&"$*\&"
1637in Bourne shell.
1638.\" :[0]
1639.It 0
1640Means the same as
1641.Ql Cm \&:[*] .
1642.\" :[*]
1643.It Cm \&@
1644Causes subsequent modifiers to treat the value as a sequence of words
1645delimited by white space.
1646Analogous to the effect of
1647\&"$@\&"
1648in Bourne shell.
1649.\" :[#]
1650.It Cm \&#
1651Returns the number of words in the value.
1652.El \" :[range]
1653.El
1654.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1655Makefile inclusion, conditional structures and for loops  reminiscent
1656of the C programming language are provided in
1657.Nm .
1658All such structures are identified by a line beginning with a single
1659dot
1660.Pq Ql \&.
1661character.
1662Files are included with either
1663.Cm \&.include \&< Ns Ar file Ns Cm \&>
1664or
1665.Cm \&.include \&\*q Ns Ar file Ns Cm \&\*q .
1666Variables between the angle brackets or double quotes are expanded
1667to form the file name.
1668If angle brackets are used, the included makefile is expected to be in
1669the system makefile directory.
1670If double quotes are used, the including makefile's directory and any
1671directories specified using the
1672.Fl I
1673option are searched before the system
1674makefile directory.
1675For compatibility with other versions of
1676.Nm
1677.Ql include file ...
1678is also accepted.
1679.Pp
1680If the include statement is written as
1681.Cm .-include
1682or as
1683.Cm .sinclude
1684then errors locating and/or opening include files are ignored.
1685.Pp
1686If the include statement is written as
1687.Cm .dinclude
1688not only are errors locating and/or opening include files ignored,
1689but stale dependencies within the included file will be ignored
1690just like
1691.Va .MAKE.DEPENDFILE .
1692.Pp
1693Conditional expressions are also preceded by a single dot as the first
1694character of a line.
1695The possible conditionals are as follows:
1696.Bl -tag -width Ds
1697.It Ic .error Ar message
1698The message is printed along with the name of the makefile and line number,
1699then
1700.Nm
1701will exit.
1702.It Ic .export Ar variable ...
1703Export the specified global variable.
1704If no variable list is provided, all globals are exported
1705except for internal variables (those that start with
1706.Ql \&. ) .
1707This is not affected by the
1708.Fl X
1709flag, so should be used with caution.
1710For compatibility with other
1711.Nm
1712programs
1713.Ql export variable=value
1714is also accepted.
1715.Pp
1716Appending a variable name to
1717.Va .MAKE.EXPORTED
1718is equivalent to exporting a variable.
1719.It Ic .export-env Ar variable ...
1720The same as
1721.Ql .export ,
1722except that the variable is not appended to
1723.Va .MAKE.EXPORTED .
1724This allows exporting a value to the environment which is different from that
1725used by
1726.Nm
1727internally.
1728.It Ic .export-literal Ar variable ...
1729The same as
1730.Ql .export-env ,
1731except that variables in the value are not expanded.
1732.It Ic .info Ar message
1733The message is printed along with the name of the makefile and line number.
1734.It Ic .undef Ar variable
1735Un-define the specified global variable.
1736Only global variables may be un-defined.
1737.It Ic .unexport Ar variable ...
1738The opposite of
1739.Ql .export .
1740The specified global
1741.Va variable
1742will be removed from
1743.Va .MAKE.EXPORTED .
1744If no variable list is provided, all globals are unexported,
1745and
1746.Va .MAKE.EXPORTED
1747deleted.
1748.It Ic .unexport-env
1749Unexport all globals previously exported and
1750clear the environment inherited from the parent.
1751This operation will cause a memory leak of the original environment,
1752so should be used sparingly.
1753Testing for
1754.Va .MAKE.LEVEL
1755being 0, would make sense.
1756Also note that any variables which originated in the parent environment
1757should be explicitly preserved if desired.
1758For example:
1759.Bd -literal -offset indent
1760.Li .if ${.MAKE.LEVEL} == 0
1761PATH := ${PATH}
1762.Li .unexport-env
1763.Li .export PATH
1764.Li .endif
1765.Pp
1766.Ed
1767Would result in an environment containing only
1768.Ql Ev PATH ,
1769which is the minimal useful environment.
1770Actually
1771.Ql Ev .MAKE.LEVEL
1772will also be pushed into the new environment.
1773.It Ic .warning Ar message
1774The message prefixed by
1775.Ql Pa warning:
1776is printed along with the name of the makefile and line number.
1777.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1778Test the value of an expression.
1779.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1780Test the value of a variable.
1781.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1782Test the value of a variable.
1783.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1784Test the target being built.
1785.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1786Test the target being built.
1787.It Ic .else
1788Reverse the sense of the last conditional.
1789.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1790A combination of
1791.Ql Ic .else
1792followed by
1793.Ql Ic .if .
1794.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1795A combination of
1796.Ql Ic .else
1797followed by
1798.Ql Ic .ifdef .
1799.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1800A combination of
1801.Ql Ic .else
1802followed by
1803.Ql Ic .ifndef .
1804.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1805A combination of
1806.Ql Ic .else
1807followed by
1808.Ql Ic .ifmake .
1809.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1810A combination of
1811.Ql Ic .else
1812followed by
1813.Ql Ic .ifnmake .
1814.It Ic .endif
1815End the body of the conditional.
1816.El
1817.Pp
1818The
1819.Ar operator
1820may be any one of the following:
1821.Bl -tag -width "Cm XX"
1822.It Cm \&|\&|
1823Logical OR.
1824.It Cm \&&&
1825Logical
1826.Tn AND ;
1827of higher precedence than
1828.Dq \&|\&| .
1829.El
1830.Pp
1831As in C,
1832.Nm
1833will only evaluate a conditional as far as is necessary to determine
1834its value.
1835Parentheses may be used to change the order of evaluation.
1836The boolean operator
1837.Ql Ic \&!
1838may be used to logically negate an entire
1839conditional.
1840It is of higher precedence than
1841.Ql Ic \&&& .
1842.Pp
1843The value of
1844.Ar expression
1845may be any of the following:
1846.Bl -tag -width defined
1847.It Ic defined
1848Takes a variable name as an argument and evaluates to true if the variable
1849has been defined.
1850.It Ic make
1851Takes a target name as an argument and evaluates to true if the target
1852was specified as part of
1853.Nm Ns 's
1854command line or was declared the default target (either implicitly or
1855explicitly, see
1856.Va .MAIN )
1857before the line containing the conditional.
1858.It Ic empty
1859Takes a variable, with possible modifiers, and evaluates to true if
1860the expansion of the variable would result in an empty string.
1861.It Ic exists
1862Takes a file name as an argument and evaluates to true if the file exists.
1863The file is searched for on the system search path (see
1864.Va .PATH ) .
1865.It Ic target
1866Takes a target name as an argument and evaluates to true if the target
1867has been defined.
1868.It Ic commands
1869Takes a target name as an argument and evaluates to true if the target
1870has been defined and has commands associated with it.
1871.El
1872.Pp
1873.Ar Expression
1874may also be an arithmetic or string comparison.
1875Variable expansion is
1876performed on both sides of the comparison, after which the integral
1877values are compared.
1878A value is interpreted as hexadecimal if it is
1879preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1880The standard C relational operators are all supported.
1881If after
1882variable expansion, either the left or right hand side of a
1883.Ql Ic ==
1884or
1885.Ql Ic "!="
1886operator is not an integral value, then
1887string comparison is performed between the expanded
1888variables.
1889If no relational operator is given, it is assumed that the expanded
1890variable is being compared against 0 or an empty string in the case
1891of a string comparison.
1892.Pp
1893When
1894.Nm
1895is evaluating one of these conditional expressions, and it encounters
1896a (white-space separated) word it doesn't recognize, either the
1897.Dq make
1898or
1899.Dq defined
1900expression is applied to it, depending on the form of the conditional.
1901If the form is
1902.Ql Ic .ifdef ,
1903.Ql Ic .ifndef ,
1904or
1905.Ql Ic .if
1906the
1907.Dq defined
1908expression is applied.
1909Similarly, if the form is
1910.Ql Ic .ifmake
1911or
1912.Ql Ic .ifnmake ,
1913the
1914.Dq make
1915expression is applied.
1916.Pp
1917If the conditional evaluates to true the parsing of the makefile continues
1918as before.
1919If it evaluates to false, the following lines are skipped.
1920In both cases this continues until a
1921.Ql Ic .else
1922or
1923.Ql Ic .endif
1924is found.
1925.Pp
1926For loops are typically used to apply a set of rules to a list of files.
1927The syntax of a for loop is:
1928.Pp
1929.Bl -tag -compact -width Ds
1930.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1931.It Aq make-rules
1932.It Ic \&.endfor
1933.El
1934.Pp
1935After the for
1936.Ic expression
1937is evaluated, it is split into words.
1938On each iteration of the loop, one word is taken and assigned to each
1939.Ic variable ,
1940in order, and these
1941.Ic variables
1942are substituted into the
1943.Ic make-rules
1944inside the body of the for loop.
1945The number of words must come out even; that is, if there are three
1946iteration variables, the number of words provided must be a multiple
1947of three.
1948.Sh COMMENTS
1949Comments begin with a hash
1950.Pq Ql \&#
1951character, anywhere but in a shell
1952command line, and continue to the end of an unescaped new line.
1953.Sh SPECIAL SOURCES (ATTRIBUTES)
1954.Bl -tag -width .IGNOREx
1955.It Ic .EXEC
1956Target is never out of date, but always execute commands anyway.
1957.It Ic .IGNORE
1958Ignore any errors from the commands associated with this target, exactly
1959as if they all were preceded by a dash
1960.Pq Ql \- .
1961.\" .It Ic .INVISIBLE
1962.\" XXX
1963.\" .It Ic .JOIN
1964.\" XXX
1965.It Ic .MADE
1966Mark all sources of this target as being up-to-date.
1967.It Ic .MAKE
1968Execute the commands associated with this target even if the
1969.Fl n
1970or
1971.Fl t
1972options were specified.
1973Normally used to mark recursive
1974.Nm Ns s .
1975.It Ic .META
1976Create a meta file for the target, even if it is flagged as
1977.Ic .PHONY ,
1978.Ic .MAKE ,
1979or
1980.Ic .SPECIAL .
1981Usage in conjunction with
1982.Ic .MAKE
1983is the most likely case.
1984In "meta" mode, the target is out-of-date if the meta file is missing.
1985.It Ic .NOMETA
1986Do not create a meta file for the target.
1987Meta files are also not created for
1988.Ic .PHONY ,
1989.Ic .MAKE ,
1990or
1991.Ic .SPECIAL
1992targets.
1993.It Ic .NOMETA_CMP
1994Ignore differences in commands when deciding if target is out of date.
1995This is useful if the command contains a value which always changes.
1996If the number of commands change, though, the target will still be out of date.
1997The same effect applies to any command line that uses the variable
1998.Va .OODATE ,
1999which can be used for that purpose even when not otherwise needed or desired:
2000.Bd -literal -offset indent
2001
2002skip-compare-for-some:
2003	@echo this will be compared
2004	@echo this will not ${.OODATE:M.NOMETA_CMP}
2005	@echo this will also be compared
2006
2007.Ed
2008The
2009.Cm \&:M
2010pattern suppresses any expansion of the unwanted variable.
2011.It Ic .NOPATH
2012Do not search for the target in the directories specified by
2013.Ic .PATH .
2014.It Ic .NOTMAIN
2015Normally
2016.Nm
2017selects the first target it encounters as the default target to be built
2018if no target was specified.
2019This source prevents this target from being selected.
2020.It Ic .OPTIONAL
2021If a target is marked with this attribute and
2022.Nm
2023can't figure out how to create it, it will ignore this fact and assume
2024the file isn't needed or already exists.
2025.It Ic .PHONY
2026The target does not
2027correspond to an actual file; it is always considered to be out of date,
2028and will not be created with the
2029.Fl t
2030option.
2031Suffix-transformation rules are not applied to
2032.Ic .PHONY
2033targets.
2034.It Ic .PRECIOUS
2035When
2036.Nm
2037is interrupted, it normally removes any partially made targets.
2038This source prevents the target from being removed.
2039.It Ic .RECURSIVE
2040Synonym for
2041.Ic .MAKE .
2042.It Ic .SILENT
2043Do not echo any of the commands associated with this target, exactly
2044as if they all were preceded by an at sign
2045.Pq Ql @ .
2046.It Ic .USE
2047Turn the target into
2048.Nm Ns 's
2049version of a macro.
2050When the target is used as a source for another target, the other target
2051acquires the commands, sources, and attributes (except for
2052.Ic .USE )
2053of the
2054source.
2055If the target already has commands, the
2056.Ic .USE
2057target's commands are appended
2058to them.
2059.It Ic .USEBEFORE
2060Exactly like
2061.Ic .USE ,
2062but prepend the
2063.Ic .USEBEFORE
2064target commands to the target.
2065.It Ic .WAIT
2066If
2067.Ic .WAIT
2068appears in a dependency line, the sources that precede it are
2069made before the sources that succeed it in the line.
2070Since the dependents of files are not made until the file itself
2071could be made, this also stops the dependents being built unless they
2072are needed for another branch of the dependency tree.
2073So given:
2074.Bd -literal
2075x: a .WAIT b
2076	echo x
2077a:
2078	echo a
2079b: b1
2080	echo b
2081b1:
2082	echo b1
2083
2084.Ed
2085the output is always
2086.Ql a ,
2087.Ql b1 ,
2088.Ql b ,
2089.Ql x .
2090.br
2091The ordering imposed by
2092.Ic .WAIT
2093is only relevant for parallel makes.
2094.El
2095.Sh SPECIAL TARGETS
2096Special targets may not be included with other targets, i.e. they must be
2097the only target specified.
2098.Bl -tag -width .BEGINx
2099.It Ic .BEGIN
2100Any command lines attached to this target are executed before anything
2101else is done.
2102.It Ic .DEFAULT
2103This is sort of a
2104.Ic .USE
2105rule for any target (that was used only as a
2106source) that
2107.Nm
2108can't figure out any other way to create.
2109Only the shell script is used.
2110The
2111.Ic .IMPSRC
2112variable of a target that inherits
2113.Ic .DEFAULT Ns 's
2114commands is set
2115to the target's own name.
2116.It Ic .DELETE_ON_ERROR
2117If this target is present in the makefile, it globally causes make to
2118delete targets whose commands fail.
2119(By default, only targets whose commands are interrupted during
2120execution are deleted.
2121This is the historical behavior.)
2122This setting can be used to help prevent half-finished or malformed
2123targets from being left around and corrupting future rebuilds.
2124.It Ic .END
2125Any command lines attached to this target are executed after everything
2126else is done.
2127.It Ic .ERROR
2128Any command lines attached to this target are executed when another target fails.
2129The
2130.Ic .ERROR_TARGET
2131variable is set to the target that failed.
2132See also
2133.Ic MAKE_PRINT_VAR_ON_ERROR .
2134.It Ic .IGNORE
2135Mark each of the sources with the
2136.Ic .IGNORE
2137attribute.
2138If no sources are specified, this is the equivalent of specifying the
2139.Fl i
2140option.
2141.It Ic .INTERRUPT
2142If
2143.Nm
2144is interrupted, the commands for this target will be executed.
2145.It Ic .MAIN
2146If no target is specified when
2147.Nm
2148is invoked, this target will be built.
2149.It Ic .MAKEFLAGS
2150This target provides a way to specify flags for
2151.Nm
2152when the makefile is used.
2153The flags are as if typed to the shell, though the
2154.Fl f
2155option will have
2156no effect.
2157.\" XXX: NOT YET!!!!
2158.\" .It Ic .NOTPARALLEL
2159.\" The named targets are executed in non parallel mode.
2160.\" If no targets are
2161.\" specified, then all targets are executed in non parallel mode.
2162.It Ic .NOPATH
2163Apply the
2164.Ic .NOPATH
2165attribute to any specified sources.
2166.It Ic .NOTPARALLEL
2167Disable parallel mode.
2168.It Ic .NO_PARALLEL
2169Synonym for
2170.Ic .NOTPARALLEL ,
2171for compatibility with other pmake variants.
2172.It Ic .OBJDIR
2173The source is a new value for
2174.Ql Va .OBJDIR .
2175If it exists,
2176.Nm
2177will
2178.Xr chdir 2
2179to it and update the value of
2180.Ql Va .OBJDIR .
2181.It Ic .ORDER
2182The named targets are made in sequence.
2183This ordering does not add targets to the list of targets to be made.
2184Since the dependents of a target do not get built until the target itself
2185could be built, unless
2186.Ql a
2187is built by another part of the dependency graph,
2188the following is a dependency loop:
2189.Bd -literal
2190\&.ORDER: b a
2191b: a
2192.Ed
2193.Pp
2194The ordering imposed by
2195.Ic .ORDER
2196is only relevant for parallel makes.
2197.\" XXX: NOT YET!!!!
2198.\" .It Ic .PARALLEL
2199.\" The named targets are executed in parallel mode.
2200.\" If no targets are
2201.\" specified, then all targets are executed in parallel mode.
2202.It Ic .PATH
2203The sources are directories which are to be searched for files not
2204found in the current directory.
2205If no sources are specified, any previously specified directories are
2206deleted.
2207If the source is the special
2208.Ic .DOTLAST
2209target, then the current working
2210directory is searched last.
2211.It Ic .PATH. Ns Va suffix
2212Like
2213.Ic .PATH
2214but applies only to files with a particular suffix.
2215The suffix must have been previously declared with
2216.Ic .SUFFIXES .
2217.It Ic .PHONY
2218Apply the
2219.Ic .PHONY
2220attribute to any specified sources.
2221.It Ic .PRECIOUS
2222Apply the
2223.Ic .PRECIOUS
2224attribute to any specified sources.
2225If no sources are specified, the
2226.Ic .PRECIOUS
2227attribute is applied to every
2228target in the file.
2229.It Ic .SHELL
2230Sets the shell that
2231.Nm
2232will use to execute commands.
2233The sources are a set of
2234.Ar field=value
2235pairs.
2236.Bl -tag -width hasErrCtls
2237.It Ar name
2238This is the minimal specification, used to select one of the built-in
2239shell specs;
2240.Ar sh ,
2241.Ar ksh ,
2242and
2243.Ar csh .
2244.It Ar path
2245Specifies the path to the shell.
2246.It Ar hasErrCtl
2247Indicates whether the shell supports exit on error.
2248.It Ar check
2249The command to turn on error checking.
2250.It Ar ignore
2251The command to disable error checking.
2252.It Ar echo
2253The command to turn on echoing of commands executed.
2254.It Ar quiet
2255The command to turn off echoing of commands executed.
2256.It Ar filter
2257The output to filter after issuing the
2258.Ar quiet
2259command.
2260It is typically identical to
2261.Ar quiet .
2262.It Ar errFlag
2263The flag to pass the shell to enable error checking.
2264.It Ar echoFlag
2265The flag to pass the shell to enable command echoing.
2266.It Ar newline
2267The string literal to pass the shell that results in a single newline
2268character when used outside of any quoting characters.
2269.El
2270Example:
2271.Bd -literal
2272\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2273	check="set \-e" ignore="set +e" \e
2274	echo="set \-v" quiet="set +v" filter="set +v" \e
2275	echoFlag=v errFlag=e newline="'\en'"
2276.Ed
2277.It Ic .SILENT
2278Apply the
2279.Ic .SILENT
2280attribute to any specified sources.
2281If no sources are specified, the
2282.Ic .SILENT
2283attribute is applied to every
2284command in the file.
2285.It Ic .STALE
2286This target gets run when a dependency file contains stale entries, having
2287.Va .ALLSRC
2288set to the name of that dependency file.
2289.It Ic .SUFFIXES
2290Each source specifies a suffix to
2291.Nm .
2292If no sources are specified, any previously specified suffixes are deleted.
2293It allows the creation of suffix-transformation rules.
2294.Pp
2295Example:
2296.Bd -literal
2297\&.SUFFIXES: .o
2298\&.c.o:
2299	cc \-o ${.TARGET} \-c ${.IMPSRC}
2300.Ed
2301.El
2302.Sh ENVIRONMENT
2303.Nm
2304uses the following environment variables, if they exist:
2305.Ev MACHINE ,
2306.Ev MACHINE_ARCH ,
2307.Ev MAKE ,
2308.Ev MAKEFLAGS ,
2309.Ev MAKEOBJDIR ,
2310.Ev MAKEOBJDIRPREFIX ,
2311.Ev MAKESYSPATH ,
2312.Ev PWD ,
2313and
2314.Ev TMPDIR .
2315.Pp
2316.Ev MAKEOBJDIRPREFIX
2317and
2318.Ev MAKEOBJDIR
2319may only be set in the environment or on the command line to
2320.Nm
2321and not as makefile variables;
2322see the description of
2323.Ql Va .OBJDIR
2324for more details.
2325.Sh FILES
2326.Bl -tag -width /usr/share/mk -compact
2327.It .depend
2328list of dependencies
2329.It Makefile
2330list of dependencies
2331.It makefile
2332list of dependencies
2333.It sys.mk
2334system makefile
2335.It /usr/share/mk
2336system makefile directory
2337.El
2338.Sh COMPATIBILITY
2339The basic make syntax is compatible between different versions of make;
2340however the special variables, variable modifiers and conditionals are not.
2341.Ss Older versions
2342An incomplete list of changes in older versions of
2343.Nm :
2344.Pp
2345The way that .for loop variables are substituted changed after
2346.Nx 5.0
2347so that they still appear to be variable expansions.
2348In particular this stops them being treated as syntax, and removes some
2349obscure problems using them in .if statements.
2350.Pp
2351The way that parallel makes are scheduled changed in
2352.Nx 4.0
2353so that .ORDER and .WAIT apply recursively to the dependent nodes.
2354The algorithms used may change again in the future.
2355.Ss Other make dialects
2356Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not
2357support most of the features of
2358.Nm
2359as described in this manual.
2360Most notably:
2361.Bl -bullet -offset indent
2362.It
2363The
2364.Ic .WAIT
2365and
2366.Ic .ORDER
2367declarations and most functionality pertaining to parallelization.
2368(GNU make supports parallelization but lacks these features needed to
2369control it effectively.)
2370.It
2371Directives, including for loops and conditionals and most of the
2372forms of include files.
2373(GNU make has its own incompatible and less powerful syntax for
2374conditionals.)
2375.It
2376All built-in variables that begin with a dot.
2377.It
2378Most of the special sources and targets that begin with a dot,
2379with the notable exception of
2380.Ic .PHONY ,
2381.Ic .PRECIOUS ,
2382and
2383.Ic .SUFFIXES .
2384.It
2385Variable modifiers, except for the
2386.Dl :old=new
2387string substitution, which does not portably support globbing with
2388.Ql %
2389and historically only works on declared suffixes.
2390.It
2391The
2392.Ic $>
2393variable even in its short form; most makes support this functionality
2394but its name varies.
2395.El
2396.Pp
2397Some features are somewhat more portable, such as assignment with
2398.Ic += ,
2399.Ic ?= ,
2400and
2401.Ic != .
2402The
2403.Ic .PATH
2404functionality is based on an older feature
2405.Ic VPATH
2406found in GNU make and many versions of SVR4 make; however,
2407historically its behavior is too ill-defined (and too buggy) to rely
2408upon.
2409.Pp
2410The
2411.Ic $@
2412and
2413.Ic $<
2414variables are more or less universally portable, as is the
2415.Ic $(MAKE)
2416variable.
2417Basic use of suffix rules (for files only in the current directory,
2418not trying to chain transformations together, etc.) is also reasonably
2419portable.
2420.Sh SEE ALSO
2421.Xr mkdep 1 ,
2422.Xr style.Makefile 5
2423.Sh HISTORY
2424A
2425.Nm
2426command appeared in
2427.At v7 .
2428This
2429.Nm
2430implementation is based on Adam De Boor's pmake program which was written
2431for Sprite at Berkeley.
2432It was designed to be a parallel distributed make running jobs on different
2433machines using a daemon called
2434.Dq customs .
2435.Pp
2436Historically the target/dependency
2437.Dq FRC
2438has been used to FoRCe rebuilding (since the target/dependency
2439does not exist... unless someone creates an
2440.Dq FRC
2441file).
2442.Sh BUGS
2443The
2444.Nm
2445syntax is difficult to parse without actually acting on the data.
2446For instance, finding the end of a variable's use should involve scanning
2447each of the modifiers, using the correct terminator for each field.
2448In many places
2449.Nm
2450just counts {} and () in order to find the end of a variable expansion.
2451.Pp
2452There is no way of escaping a space character in a filename.
2453