1BMAKE(1) FreeBSD General Commands Manual
2BMAKE(1)
3[1mNAME[0m
5 [1mbmake [22m‐‐ maintain program dependencies
6[1mSYNOPSIS[0m
8 [1mbmake [22m[[1m‐BeikNnqrstWwX[22m] [[1m‐C [4m[22mdirecto‐
9ry[24m] [[1m‐D [4m[22mvariable[24m] [[1m‐d [4m[22mflags[24m]
10 [[1m‐f [4m[22mmakefile[24m] [[1m‐I [4m[22mdirecto‐
11ry[24m] [[1m‐J [4m[22mprivate[24m] [[1m‐j [4m[22mmax_jobs[24m]
12 [[1m‐m [4m[22mdirectory[24m] [[1m‐T [4m[22mfile[24m]
13[[1m‐V [4m[22mvariable[24m] [[1m‐v [4m[22mvariable[24m]
14 [[4mvariable=value[24m] [[4mtarget[24m [4m...[24m]
15[1mDESCRIPTION[0m
17 [1mbmake [22mis a program designed to simplify the mainte‐
18nance of other pro‐
19 grams. Its input is a list of specifications as to the
20files upon which
21 programs and other files depend. If no [1m‐f [4m[22mmake‐
22file[24m makefile option is
23 given, [1mbmake [22mwill try to open ‘[4mmakefile[24m’ then
24‘[4mMakefile[24m’ in order to find
25 the specifications. If the file ‘[4m.depend[24m’ exists, it
26is read (see
27 mkdep(1)).
28 This manual page is intended as a reference document only.
30For a more
31 thorough description of [1mbmake [22mand makefiles, please
32refer to [4mPMake[24m [4m‐[24m [4mA[0m
33 [4mTutorial[24m.
34 [1mbmake [22mwill prepend the contents of the [4mMAKE‐
36FLAGS[24m environment variable to
37 the command line arguments before parsing them.
38 The options are as follows:
40 [1m‐B [22mTry to be backwards compatible by executing a
42single shell per
43 command and by executing the commands to make the
44sources of a
45 dependency line in sequence.
46 [1m‐C [4m[22mdirectory[0m
48 Change to [4mdirectory[24m before reading the make‐
49files or doing any‐
50 thing else. If multiple [1m‐C [22moptions are spec‐
51ified, each is inter‐
52 preted relative to the previous one: [1m‐C
53[4m[22m/[24m [1m‐C [4m[22metc[24m is equivalent to
54 [1m‐C [4m[22m/etc[24m.
55 [1m‐D [4m[22mvariable[0m
57 Define [4mvariable[24m to be 1, in the global con‐
58text.
59 [1m‐d [4m[22m[‐]flags[0m
61 Turn on debugging, and specify which portions of
62[1mbmake [22mare to
63 print debugging information. Unless the flags are
64preceded by
65 ‘‐’ they are added to the [4mMAKEFLAGS[24m environ‐
66ment variable and will
67 be processed by any child make processes. By de‐
68fault, debugging
69 information is printed to standard error, but this
70can be changed
71 using the [4mF[24m debugging flag. The debugging
72output is always
73 unbuffered; in addition, if debugging is enabled but
74debugging
75 output is not directed to standard output, then the
76standard out‐
77 put is line buffered. [4mFlags[24m is one or more
78of the following:
79 [4mA[24m Print all possible debugging informa‐
81tion; equivalent to
82 specifying all of the debugging flags.
83 [4ma[24m Print debugging information about ar‐
85chive searching and
86 caching.
87 [4mC[24m Print debugging information about
89current working direc‐
90 tory.
91 [4mc[24m Print debugging information about
93conditional evaluation.
94 [4md[24m Print debugging information about di‐
96rectory searching and
97 caching.
98 [4me[24m Print debugging information about
100failed commands and
101 targets.
102 [4mF[24m[[1m+[22m][4mfilename[0m
104 Specify where debugging output is written.
105This must be
106 the last flag, because it consumes the re‐
107mainder of the
108 argument. If the character immediately af‐
109ter the ‘F’
110 flag is ‘+’, then the file will be opened in
111append mode;
112 otherwise the file will be overwritten. If
113the file name
114 is ‘stdout’ or ‘stderr’ then debugging out‐
115put will be
116 written to the standard output or standard
117error output
118 file descriptors respectively (and the ‘+’
119option has no
120 effect). Otherwise, the output will be
121written to the
122 named file. If the file name ends ‘.%d’
123then the ‘%d’ is
124 replaced by the pid.
125 [4mf[24m Print debugging information about
127loop evaluation.
128 [4mg1[24m Print the input graph before making
130anything.
131 [4mg2[24m Print the input graph after making
133everything, or before
134 exiting on error.
135 [4mg3[24m Print the input graph before exiting
137on error.
138 [4mh[24m Print debugging information about
140hash table operations.
141 [4mj[24m Print debugging information about
143running multiple
144 shells.
145 [4mL[24m Turn on lint checks. This will throw
147errors for variable
148 assignments that do not parse correctly, at
149the time of
150 assignment so the file and line number are
151available.
152 [4ml[24m Print commands in Makefiles regard‐
154less of whether or not
155 they are prefixed by ‘@’ or other "quiet"
156flags. Also
157 known as "loud" behavior.
158 [4mM[24m Print debugging information about
160"meta" mode decisions
161 about targets.
162 [4mm[24m Print debugging information about
164making targets, includ‐
165 ing modification dates.
166 [4mn[24m Don’t delete the temporary command
168scripts created when
169 running commands. These temporary scripts
170are created in
171 the directory referred to by the TMPDIR en‐
172vironment vari‐
173 able, or in [4m/tmp[24m if TMPDIR is unset
174or set to the empty
175 string. The temporary scripts are created
176by mkstemp(3),
177 and have names of the form
178[4mmakeXXXXXX[24m. [4mNOTE[24m: This can
179 create many files in TMPDIR or [4m/tmp[24m,
180so use with care.
181 [4mp[24m Print debugging information about
183makefile parsing.
184 [4ms[24m Print debugging information about
186suffix‐transformation
187 rules.
188 [4mt[24m Print debugging information about
190target list mainte‐
191 nance.
192 [4mV[24m Force the [1m‐V [22moption to print
194raw values of variables,
195 overriding the default behavior set via
196 [4m.MAKE.EXPAND_VARIABLES[24m.
197 [4mv[24m Print debugging information about
199variable assignment.
200 [4mx[24m Run shell commands with [1m‐x [22mso
202the actual commands are
203 printed as they are executed.
204 [1m‐e [22mSpecify that environment variables override
206macro assignments
207 within makefiles.
208 [1m‐f [4m[22mmakefile[0m
210 Specify a makefile to read instead of the default
211‘[4mmakefile[24m’. If
212 [4mmakefile[24m is ‘[1m‐[22m’, standard input is
213read. Multiple makefiles may
214 be specified, and are read in the order specified.
215 [1m‐I [4m[22mdirectory[0m
217 Specify a directory in which to search for makefiles
218and included
219 makefiles. The system makefile directory (or direc‐
220tories, see
221 the [1m‐m [22moption) is automatically included as
222part of this list.
223 [1m‐i [22mIgnore non‐zero exit of shell commands in the
225makefile. Equiva‐
226 lent to specifying ‘[1m‐[22m’ before each command
227line in the makefile.
228 [1m‐J [4m[22mprivate[0m
230 This option should [4mnot[24m be specified by the
231user.
232 When the [4mj[24m option is in use in a recursive
234build, this option is
235 passed by a make to child makes to allow all the
236make processes
237 in the build to cooperate to avoid overloading the
238system.
239 [1m‐j [4m[22mmax_jobs[0m
241 Specify the maximum number of jobs that [1mbmake
242[22mmay have running at
243 any one time. The value is saved in
244[4m.MAKE.JOBS[24m. Turns compati‐
245 bility mode off, unless the [4mB[24m flag is also
246specified. When com‐
247 patibility mode is off, all commands associated with
248a target are
249 executed in a single shell invocation as opposed to
250the tradi‐
251 tional one shell invocation per line. This can
252break traditional
253 scripts which change directories on each command in‐
254vocation and
255 then expect to start with a fresh environment on the
256next line.
257 It is more efficient to correct the scripts rather
258than turn
259 backwards compatibility on.
260 [1m‐k [22mContinue processing after errors are encoun‐
262tered, but only on
263 those targets that do not depend on the target whose
264creation
265 caused the error.
266 [1m‐m [4m[22mdirectory[0m
268 Specify a directory in which to search for sys.mk
269and makefiles
270 included via the <[4mfile[24m>‐style include state‐
271ment. The [1m‐m [22moption
272 can be used multiple times to form a search path.
273This path will
274 override the default system include path:
275/usr/share/mk. Fur‐
276 thermore the system include path will be appended to
277the search
278 path used for "[4mfile[24m"‐style include statements
279(see the [1m‐I[0m
280 option).
281 If a file or directory name in the [1m‐m [22margu‐
283ment (or the
284 MAKESYSPATH environment variable) starts with the
285string ".../"
286 then [1mbmake [22mwill search for the specified file
287or directory named
288 in the remaining part of the argument string. The
289search starts
290 with the current directory of the Makefile and then
291works upward
292 towards the root of the file system. If the search
293is success‐
294 ful, then the resulting directory replaces the
295".../" specifica‐
296 tion in the [1m‐m [22margument. If used, this fea‐
297ture allows [1mbmake [22mto
298 easily search in the current source tree for custom‐
299ized sys.mk
300 files (e.g., by using ".../mk/sys.mk" as an argu‐
301ment).
302 [1m‐n [22mDisplay the commands that would have been ex‐
304ecuted, but do not
305 actually execute them unless the target depends on
306the .MAKE spe‐
307 cial source (see below) or the command is prefixed
308with ‘[1m+[22m’.
309 [1m‐N [22mDisplay the commands which would have been
311executed, but do not
312 actually execute any of them; useful for debugging
313top‐level
314 makefiles without descending into subdirectories.
315 [1m‐q [22mDo not execute any commands, but exit 0 if
317the specified targets
318 are up‐to‐date and 1, otherwise.
319 [1m‐r [22mDo not use the built‐in rules specified in
321the system makefile.
322 [1m‐s [22mDo not echo any commands as they are execut‐
324ed. Equivalent to
325 specifying ‘[1m@[22m’ before each command line in
326the makefile.
327 [1m‐T [4m[22mtracefile[0m
329 When used with the [1m‐j [22mflag, append a trace
330record to [4mtracefile[0m
331 for each job started and completed.
332 [1m‐t [22mRather than re‐building a target as specified
334in the makefile,
335 create it or update its modification time to make it
336appear up‐
337 to‐date.
338 [1m‐V [4m[22mvariable[0m
340 Print the value of [4mvariable[24m. Do not build
341any targets. Multiple
342 instances of this option may be specified; the vari‐
343ables will be
344 printed one per line, with a blank line for each
345null or unde‐
346 fined variable. The value printed is extracted from
347the global
348 context after all makefiles have been read. By de‐
349fault, the raw
350 variable contents (which may include additional un‐
351expanded vari‐
352 able references) are shown. If [4mvariable[24m con‐
353tains a ‘$’ then the
354 value will be recursively expanded to its complete
355resultant text
356 before printing. The expanded value will also be
357printed if
358 [4m.MAKE.EXPAND_VARIABLES[24m is set to true and the
359[1m‐dV [22moption has not
360 been used to override it. Note that loop‐local and
361target‐local
362 variables, as well as values taken temporarily by
363global vari‐
364 ables during makefile processing, are not accessible
365via this
366 option. The [1m‐dv [22mdebug mode can be used to
367see these at the cost
368 of generating substantial extraneous output.
369 [1m‐v [4m[22mvariable[0m
371 Like [1m‐V [22mbut the variable is always expanded
372to its complete
373 value.
374 [1m‐W [22mTreat any warnings during makefile parsing as
376errors.
377 [1m‐w [22mPrint entering and leaving directory mes‐
379sages, pre and post pro‐
380 cessing.
381 [1m‐X [22mDon’t export variables passed on the command
383line to the environ‐
384 ment individually. Variables passed on the command
385line are
386 still exported via the [4mMAKEFLAGS[24m environment
387variable. This
388 option may be useful on systems which have a small
389limit on the
390 size of command arguments.
391 [4mvariable=value[0m
393 Set the value of the variable [4mvariable[24m to
394[4mvalue[24m. Normally, all
395 values passed on the command line are also exported
396to sub‐makes
397 in the environment. The [1m‐X [22mflag disables
398this behavior. Vari‐
399 able assignments should follow options for POSIX
400compatibility
401 but no ordering is enforced.
402 There are seven different types of lines in a makefile: file
404dependency
405 specifications, shell commands, variable assignments, in‐
406clude statements,
407 conditional directives, for loops, and comments.
408 In general, lines may be continued from one line to the next
410by ending
411 them with a backslash (‘´). The trailing newline character
412and initial
413 whitespace on the following line are compressed into a sin‐
414gle space.
415[1mFILE DEPENDENCY SPECIFICATIONS[0m
417 Dependency lines consist of one or more targets, an opera‐
418tor, and zero or
419 more sources. This creates a relationship where the targets
420‘‘depend’’
421 on the sources and are customarily created from them. A
422target is con‐
423 sidered out‐of‐date if it does not exist, or if its modifi‐
424cation time is
425 less than that of any of its sources. An out‐of‐date target
426will be re‐
427 created, but not until all sources have been examined and
428themselves re‐
429 created as needed. Three operators may be used:
430 [1m: [22mMany dependency lines may name this target but
432only one may have
433 attached shell commands. All sources named in all de‐
434pendency lines
435 are considered together, and if needed the attached
436shell commands
437 are run to create or re‐create the target. If [1mb‐
438make [22mis inter‐
439 rupted, the target is removed.
440 [1m! [22mThe same, but the target is always re‐created
442whether or not it is
443 out of date.
444 [1m:: [22mAny dependency line may have attached shell
446commands, but each one
447 is handled independently: its sources are considered
448and the
449 attached shell commands are run if the target is out
450of date with
451 respect to (only) those sources. Thus, different
452groups of the
453 attached shell commands may be run depending on the
454circumstances.
455 Furthermore, unlike [1m:, [22mfor dependency lines
456with no sources, the
457 attached shell commands are always run. Also unlike
458[1m:, [22mthe target
459 will not be removed if [1mbmake [22mis interrupted.
460 All dependency lines mentioning a particular target must use
461the same
462 operator.
463 Targets and sources may contain the shell wildcard values
465‘?’, ‘*’, ‘[]’,
466 and ‘{}’. The values ‘?’, ‘*’, and ‘[]’ may only be used as
467part of the
468 final component of the target or source, and must be used to
469describe
470 existing files. The value ‘{}’ need not necessarily be used
471to describe
472 existing files. Expansion is in directory order, not alpha‐
473betically as
474 done in the shell.
475[1mSHELL COMMANDS[0m
477 Each target may have associated with it one or more lines of
478shell com‐
479 mands, normally used to create the target. Each of the
480lines in this
481 script [4mmust[24m be preceded by a tab. (For historical
482reasons, spaces are
483 not accepted.) While targets can appear in many dependency
484lines if
485 desired, by default only one of these rules may be followed
486by a creation
487 script. If the ‘[1m::[22m’ operator is used, however, all
488rules may include
489 scripts and the scripts are executed in the order found.
490 Each line is treated as a separate shell command, unless the
492end of line
493 is escaped with a backslash (‘´) in which case that line and
494the next
495 are combined. If the first characters of the command are
496any combination
497 of ‘[1m@[22m’, ‘[1m+[22m’, or ‘[1m‐[22m’, the command is
498treated specially. A ‘[1m@[22m’ causes the
499 command not to be echoed before it is executed. A
500‘[1m+[22m’ causes the command
501 to be executed even when [1m‐n [22mis given. This is simi‐
502lar to the effect of
503 the .MAKE special source, except that the effect can be lim‐
504ited to a sin‐
505 gle line of a script. A ‘[1m‐[22m’ in compatibility mode
506causes any non‐zero
507 exit status of the command line to be ignored.
508 When [1mbmake [22mis run in jobs mode with [1m‐j
510[4m[22mmax_jobs[24m, the entire script for
511 the target is fed to a single instance of the shell. In
512compatibility
513 (non‐jobs) mode, each command is run in a separate process.
514If the com‐
515 mand contains any shell meta characters
516(‘#=|^(){};&<>*?[]:$‘\n’) it
517 will be passed to the shell; otherwise [1mbmake [22mwill at‐
518tempt direct execu‐
519 tion. If a line starts with ‘[1m‐[22m’ and the shell has
520ErrCtl enabled then
521 failure of the command line will be ignored as in compati‐
522bility mode.
523 Otherwise ‘[1m‐[22m’ affects the entire job; the script will
524stop at the first
525 command line that fails, but the target will not be deemed
526to have
527 failed.
528 Makefiles should be written so that the mode of [1mbmake
530[22moperation does not
531 change their behavior. For example, any command which needs
532to use
533 ‘‘cd’’ or ‘‘chdir’’ without potentially changing the direc‐
534tory for subse‐
535 quent commands should be put in parentheses so it executes
536in a subshell.
537 To force the use of one shell, escape the line breaks so as
538to make the
539 whole script one command. For example:
540 avoid‐chdir‐side‐effects:
542 @echo Building $@ in ‘pwd‘
543 @(cd ${.CURDIR} && ${MAKE} $@)
544 @echo Back in ‘pwd‘
545 ensure‐one‐shell‐regardless‐of‐mode:
547 @echo Building $@ in ‘pwd‘;
548(cd ${.CURDIR} && ${MAKE} $@); echo Back in
549‘pwd‘
550 Since [1mbmake [22mwill chdir(2) to ‘[4m.OBJDIR[24m’ before
552executing any targets, each
553 child process starts with that as its current working direc‐
554tory.
555[1mVARIABLE ASSIGNMENTS[0m
557 Variables in make are much like variables in the shell, and,
558by tradi‐
559 tion, consist of all upper‐case letters.
560 [1mVariable assignment modifiers[0m
562 The five operators that can be used to assign values to
563variables are as
564 follows:
565 [1m= [22mAssign the value to the variable. Any previ‐
567ous value is overrid‐
568 den.
569 [1m+= [22mAppend the value to the current value of the
571variable.
572 [1m?= [22mAssign the value to the variable if it is not
574already defined.
575 [1m:= [22mAssign with expansion, i.e. expand the value
577before assigning it
578 to the variable. Normally, expansion is not done
579until the vari‐
580 able is referenced. [4mNOTE[24m: References to un‐
581defined variables are
582 [4mnot[24m expanded. This can cause problems when
583variable modifiers
584 are used.
585 [1m!= [22mExpand the value and pass it to the shell for
587execution and
588 assign the result to the variable. Any newlines in
589the result
590 are replaced with spaces.
591 Any white‐space before the assigned [4mvalue[24m is removed;
593if the value is
594 being appended, a single space is inserted between the pre‐
595vious contents
596 of the variable and the appended value.
597 Variables are expanded by surrounding the variable name with
599either curly
600 braces (‘{}’) or parentheses (‘()’) and preceding it with a
601dollar sign
602 (‘$’). If the variable name contains only a single letter,
603the surround‐
604 ing braces or parentheses are not required. This shorter
605form is not
606 recommended.
607 If the variable name contains a dollar, then the name itself
609is expanded
610 first. This allows almost arbitrary variable names, however
611names con‐
612 taining dollar, braces, parentheses, or whitespace are real‐
613ly best
614 avoided!
615 If the result of expanding a variable contains a dollar sign
617(‘$’) the
618 string is expanded again.
619 Variable substitution occurs at three distinct times, de‐
621pending on where
622 the variable is being used.
623 1. Variables in dependency lines are expanded as the line
625is read.
626 2. Variables in shell commands are expanded when the shell
628command is
629 executed.
630 3. ‘‘.for’’ loop index variables are expanded on each loop
632iteration.
633 Note that other variables are not expanded inside loops
634so the fol‐
635 lowing example code:
636 .for i in 1 2 3
639 a+= ${i}
640 j= ${i}
641 b+= ${j}
642 .endfor
643 all:
645 @echo ${a}
646 @echo ${b}
647 will print:
649 1 2 3
651 3 3 3
652 Because while ${a} contains ‘‘1 2 3’’ after the loop is
654executed,
655 ${b} contains ‘‘${j} ${j} ${j}’’ which expands to ‘‘3 3
6563’’ since
657 after the loop completes ${j} contains ‘‘3’’.
658 [1mVariable classes[0m
660 The four different classes of variables (in order of in‐
661creasing prece‐
662 dence) are:
663 Environment variables
665 Variables defined as part of [1mbmake[22m’s environ‐
666ment.
667 Global variables
669 Variables defined in the makefile or in included
670makefiles.
671 Command line variables
673 Variables defined as part of the command line.
674 Local variables
676 Variables that are defined specific to a certain
677target.
678 Local variables are all built in and their values vary magi‐
680cally from
681 target to target. It is not currently possible to define
682new local vari‐
683 ables. The seven local variables are as follows:
684 [4m.ALLSRC[24m The list of all sources for this tar‐
686get; also known as
687 ‘[4m>[24m’.
688 [4m.ARCHIVE[24m The name of the archive file; also
690known as ‘[4m![24m’.
691 [4m.IMPSRC[24m In suffix‐transformation rules, the
693name/path of the
694 source from which the target is to be trans‐
695formed (the
696 ‘‘implied’’ source); also known as
697‘[4m<[24m’. It is not
698 defined in explicit rules.
699 [4m.MEMBER[24m The name of the archive member; also
701known as ‘[4m%[24m’.
702 [4m.OODATE[24m The list of sources for this target
704that were deemed out‐
705 of‐date; also known as ‘[4m?[24m’.
706 [4m.PREFIX[24m The file prefix of the target, con‐
708taining only the file
709 portion, no suffix or preceding directory
710components;
711 also known as ‘[4m*[24m’. The suffix must
712be one of the known
713 suffixes declared with [1m.SUFFIXES [22mor
714it will not be recog‐
715 nized.
716 [4m.TARGET[24m The name of the target; also known as
718‘[4m@[24m’. For compati‐
719 bility with other makes this is an alias for
720[1m.ARCHIVE [22min
721 archive member rules.
722 The shorter forms (‘[4m>[24m’, ‘[4m![24m’, ‘[4m<[24m’,
724‘[4m%[24m’, ‘[4m?[24m’, ‘[4m*[24m’, and ‘[4m@[24m’) are permitted
725 for backward compatibility with historical makefiles and
726legacy POSIX
727 make and are not recommended.
728 Variants of these variables with the punctuation followed
730immediately by
731 ‘D’ or ‘F’, e.g. ‘[4m$(@D)[24m’, are legacy forms equiva‐
732lent to using the ‘:H’
733 and ‘:T’ modifiers. These forms are accepted for compati‐
734bility with AT&T
735 System V UNIX makefiles and POSIX but are not recommended.
736 Four of the local variables may be used in sources on depen‐
738dency lines
739 because they expand to the proper value for each target on
740the line.
741 These variables are ‘[4m.TARGET[24m’, ‘[4m.PREFIX[24m’,
742‘[4m.ARCHIVE[24m’, and ‘[4m.MEMBER[24m’.
743 [1mAdditional built‐in variables[0m
745 In addition, [1mbmake [22msets or knows about the following
746variables:
747 [4m$[24m A single dollar sign ‘$’, i.e. ‘$$’
749expands to a single
750 dollar sign.
751 [4m.ALLTARGETS[24m The list of all targets encountered
753in the Makefile. If
754 evaluated during Makefile parsing, lists on‐
755ly those tar‐
756 gets encountered thus far.
757 [4m.CURDIR[24m A path to the directory where [1mb‐
759make [22mwas executed. Refer
760 to the description of ‘PWD’ for more de‐
761tails.
762 [4m.INCLUDEDFROMDIR[0m
764 The directory of the file this Makefile was
765included
766 from.
767 [4m.INCLUDEDFROMFILE[0m
769 The filename of the file this Makefile was
770included from.
771 MAKE The name that [1mbmake [22mwas executed with
773([4margv[0][24m). For
774 compatibility [1mbmake [22malso sets
775[4m.MAKE[24m with the same value.
776 The preferred variable to use is the envi‐
777ronment variable
778 MAKE because it is more compatible with oth‐
779er versions of
780 [1mbmake [22mand cannot be confused with the
781special target with
782 the same name.
783 [4m.MAKE.DEPENDFILE[0m
785 Names the makefile (default ‘[4m.de‐
786pend[24m’) from which gener‐
787 ated dependencies are read.
788 [4m.MAKE.EXPAND_VARIABLES[0m
790 A boolean that controls the default behavior
791of the [1m‐V[0m
792 option. If true, variable values printed
793with [1m‐V [22mare
794 fully expanded; if false, the raw variable
795contents
796 (which may include additional unexpanded
797variable refer‐
798 ences) are shown.
799 [4m.MAKE.EXPORTED[24m The list of variables exported by
801[1mbmake[22m.
802 [4m.MAKE.JOBS[24m The argument to the [1m‐j [22moption.
804 [4m.MAKE.JOB.PREFIX[0m
806 If [1mbmake [22mis run with [4mj[24m then
807output for each target is
808 prefixed with a token ‘‐‐‐ target ‐‐‐’ the
809first part of
810 which can be controlled via
811[4m.MAKE.JOB.PREFIX[24m. If
812 [4m.MAKE.JOB.PREFIX[24m is empty, no token
813is printed.
814 For example:
815 .MAKE.JOB.PREFIX=${.new‐
816line}‐‐‐${.MAKE:T}[${.MAKE.PID}]
817 would produce tokens like ‘‐‐‐make[1234]
818target ‐‐‐’ mak‐
819 ing it easier to track the degree of paral‐
820lelism being
821 achieved.
822 MAKEFLAGS The environment variable ‘MAKEFLAGS’ may
824contain anything
825 that may be specified on [1mbmake[22m’s com‐
826mand line. Anything
827 specified on [1mbmake[22m’s command line is
828appended to the
829 ‘MAKEFLAGS’ variable which is then entered
830into the envi‐
831 ronment for all programs which [1mbmake
832[22mexecutes.
833 [4m.MAKE.LEVEL[24m The recursion depth of [1mbmake[22m.
835The initial instance of
836 [1mbmake [22mwill be 0, and an incremented
837value is put into the
838 environment to be seen by the next genera‐
839tion. This
840 allows tests like: .if ${.MAKE.LEVEL} == 0
841to protect
842 things which should only be evaluated in the
843initial
844 instance of [1mbmake[22m.
845 [4m.MAKE.MAKEFILE_PREFERENCE[0m
847 The ordered list of makefile names (default
848‘[4mmakefile[24m’,
849 ‘[4mMakefile[24m’) that [1mbmake [22mwill
850look for.
851 [4m.MAKE.MAKEFILES[0m
853 The list of makefiles read by [1mbmake[22m,
854which is useful for
855 tracking dependencies. Each makefile is
856recorded only
857 once, regardless of the number of times
858read.
859 [4m.MAKE.MODE[24m Processed after reading all make‐
861files. Can affect the
862 mode that [1mbmake [22mruns in. It can con‐
863tain a number of key‐
864 words:
865 [4mcompat[24m Like [1m‐B[22m,
867puts [1mbmake [22minto "compat"
868 mode.
869 [4mmeta[24m Puts [1mbmake
871[22minto "meta" mode, where
872 meta files are created
873for each tar‐
874 get to capture the com‐
875mand run, the
876 output generated and if
877filemon(4)
878 is available, the sys‐
879tem calls which
880 are of interest to
881[1mbmake[22m. The cap‐
882 tured output can be
883very useful when
884 diagnosing errors.
885 [4mcurdirOk=[24m [4mbf[24m Normally
887[1mbmake [22mwill not create .meta
888 files in ‘[4m.CUR‐
889DIR[24m’. This can be
890 overridden by setting
891[4mbf[24m to a value
892 which represents True.
893 [4mmissing‐meta=[24m [4mbf[24m If
895[4mbf[24m is True, then a missing .meta
896 file makes the target
897out‐of‐date.
898 [4mmissing‐filemon=[24m [4mbf[24m If
900[4mbf[24m is True, then missing filemon
901 data makes the target
902out‐of‐date.
903 [4mnofilemon[24m Do not use file‐
905mon(4).
906 [4menv[24m For debugging,
908it can be useful to
909 include the environment
910in the .meta
911 file.
912 [4mverbose[24m If in "meta"
914mode, print a clue
915 about the target being
916built. This
917 is useful if the build
918is otherwise
919 running silently. The
920message
921 printed the value of:
922 [4m.MAKE.META.PRE‐
923FIX[24m.
924 [4mignore‐cmd[24m Some makefiles
926have commands which
927 are simply not stable.
928This keyword
929 causes them to be ig‐
930nored for deter‐
931 mining whether a target
932is out of
933 date in "meta" mode.
934See also
935 [1m.NOMETA_CMP[22m.
936 [4msilent=[24m [4mbf[24m If
938[4mbf[24m is True, when a .meta file is
939 created, mark the tar‐
940get [1m.SILENT[22m.
941 [4m.MAKE.META.BAILIWICK[0m
943 In "meta" mode, provides a list of prefixes
944which match
945 the directories controlled by [1mbmake[22m.
946If a file that was
947 generated outside of [4m.OBJDIR[24m but
948within said bailiwick is
949 missing, the current target is considered
950out‐of‐date.
951 [4m.MAKE.META.CREATED[0m
953 In "meta" mode, this variable contains a
954list of all the
955 meta files updated. If not empty, it can be
956used to
957 trigger processing of
958[4m.MAKE.META.FILES[24m.
959 [4m.MAKE.META.FILES[0m
961 In "meta" mode, this variable contains a
962list of all the
963 meta files used (updated or not). This list
964can be used
965 to process the meta files to extract depen‐
966dency informa‐
967 tion.
968 [4m.MAKE.META.IGNORE_PATHS[0m
970 Provides a list of path prefixes that should
971be ignored;
972 because the contents are expected to change
973over time.
974 The default list includes: ‘[4m/dev[24m
975[4m/etc[24m [4m/proc[24m [4m/tmp[24m [4m/var/run[0m
976 [4m/var/tmp[24m’
977 [4m.MAKE.META.IGNORE_PATTERNS[0m
979 Provides a list of patterns to match against
980pathnames.
981 Ignore any that match.
982 [4m.MAKE.META.IGNORE_FILTER[0m
984 Provides a list of variable modifiers to ap‐
985ply to each
986 pathname. Ignore if the expansion is an
987empty string.
988 [4m.MAKE.META.PREFIX[0m
990 Defines the message printed for each meta
991file updated in
992 "meta verbose" mode. The default value is:
993 Building ${.TARGET:H:tA}/${.TARGET:T}
994 [4m.MAKEOVERRIDES[24m This variable is used to record the
996names of variables
997 assigned to on the command line, so that
998they may be
999 exported as part of ‘MAKEFLAGS’. This be‐
1000havior can be
1001 disabled by assigning an empty value to
1002‘[4m.MAKEOVERRIDES[24m’
1003 within a makefile. Extra variables can be
1004exported from
1005 a makefile by appending their names to
1006‘[4m.MAKEOVERRIDES[24m’.
1007 ‘MAKEFLAGS’ is re‐exported whenever
1008‘[4m.MAKEOVERRIDES[24m’ is
1009 modified.
1010 [4m.MAKE.PATH_FILEMON[0m
1012 If [1mbmake [22mwas built with filemon(4)
1013support, this is set
1014 to the path of the device node. This allows
1015makefiles to
1016 test for this support.
1017 [4m.MAKE.PID[24m The process‐id of [1mbmake[22m.
1019 [4m.MAKE.PPID[24m The parent process‐id of [1mb‐
1021make[22m.
1022 [4m.MAKE.SAVE_DOLLARS[0m
1024 value should be a boolean that controls
1025whether ‘$$’ are
1026 preserved when doing ‘:=’ assignments. The
1027default is
1028 false, for backwards compatibility. Set to
1029true for com‐
1030 patability with other makes. If set to
1031false, ‘$$’
1032 becomes ‘$’ per normal evaluation rules.
1033 [4mMAKE_PRINT_VAR_ON_ERROR[0m
1035 When [1mbmake [22mstops due to an error, it
1036sets ‘[4m.ERROR_TARGET[24m’
1037 to the name of the target that failed,
1038‘[4m.ERROR_CMD[24m’ to
1039 the commands of the failed target, and in
1040"meta" mode, it
1041 also sets ‘[4m.ERROR_CWD[24m’ to the
1042getcwd(3), and
1043 ‘[4m.ERROR_META_FILE[24m’ to the path of the
1044meta file (if any)
1045 describing the failed target. It then
1046prints its name
1047 and the value of ‘[4m.CURDIR[24m’ as well as
1048the value of any
1049 variables named in ‘[4mMAKE_PRINT_VAR_ON_ER‐
1050ROR[24m’.
1051 [4m.newline[24m This variable is simply assigned a
1053newline character as
1054 its value. This allows expansions using the
1055[1m:@ [22mmodifier
1056 to put a newline between iterations of the
1057loop rather
1058 than a space. For example, the printing of
1059 ‘[4mMAKE_PRINT_VAR_ON_ERROR[24m’ could be
1060done as
1061 ${MAKE_PRINT_VAR_ON_ER‐
1062ROR:@v@$v=’${$v}’${.newline}@}.
1063 [4m.OBJDIR[24m A path to the directory where the
1065targets are built. Its
1066 value is determined by trying to chdir(2) to
1067the follow‐
1068 ing directories in order and using the first
1069match:
1070 1. ${MAKEOBJDIRPREFIX}${.CURDIR}
1072 (Only if ‘MAKEOBJDIRPREFIX’ is set in
1074the environ‐
1075 ment or on the command line.)
1076 2. ${MAKEOBJDIR}
1078 (Only if ‘MAKEOBJDIR’ is set in the en‐
1080vironment or
1081 on the command line.)
1082 3. ${.CURDIR}[4m/obj.[24m${MACHINE}
1084 4. ${.CURDIR}[4m/obj[0m
1086 5. [4m/usr/obj/[24m${.CURDIR}
1088 6. ${.CURDIR}
1090 Variable expansion is performed on the value
1092before it’s
1093 used, so expressions such as
1094 ${.CURDIR:S,^/usr/src,/var/obj,}
1095 may be used. This is especially useful with
1096 ‘MAKEOBJDIR’.
1097 ‘[4m.OBJDIR[24m’ may be modified in the
1099makefile via the special
1100 target ‘[1m.OBJDIR[22m’. In all cases,
1101[1mbmake [22mwill chdir(2) to
1102 the specified directory if it exists, and
1103set ‘[4m.OBJDIR[24m’
1104 and ‘PWD’ to that directory before executing
1105any targets.
1106 [4m.PARSEDIR[24m A path to the directory of the cur‐
1108rent ‘[4mMakefile[24m’ being
1109 parsed.
1110 [4m.PARSEFILE[24m The basename of the current ‘[4mMake‐
1112file[24m’ being parsed.
1113 This variable and ‘[4m.PARSEDIR[24m’ are
1114both set only while the
1115 ‘[4mMakefiles[24m’ are being parsed. If you
1116want to retain
1117 their current values, assign them to a vari‐
1118able using
1119 assignment with expansion: (‘[1m:=[22m’).
1120 [4m.PATH[24m A variable that represents the list
1122of directories that
1123 [1mbmake [22mwill search for files. The
1124search list should be
1125 updated using the target ‘[4m.PATH[24m’
1126rather than the vari‐
1127 able.
1128 PWD Alternate path to the current directory.
1130[1mbmake [22mnormally
1131 sets ‘[4m.CURDIR[24m’ to the canonical path
1132given by getcwd(3).
1133 However, if the environment variable ‘PWD’
1134is set and
1135 gives a path to the current directory, then
1136[1mbmake [22msets
1137 ‘[4m.CURDIR[24m’ to the value of ‘PWD’ in‐
1138stead. This behavior
1139 is disabled if ‘MAKEOBJDIRPREFIX’ is set or
1140‘MAKEOBJDIR’
1141 contains a variable transform. ‘PWD’ is set
1142to the value
1143 of ‘[4m.OBJDIR[24m’ for all programs which
1144[1mbmake [22mexecutes.
1145 .SHELL The pathname of the shell used to run target
1147scripts. It
1148 is read‐only.
1149 .TARGETS The list of targets explicitly specified on
1151the command
1152 line, if any.
1153 VPATH Colon‐separated (‘‘:’’) lists of directories
1155that [1mbmake[0m
1156 will search for files. The variable is sup‐
1157ported for
1158 compatibility with old make programs only,
1159use ‘[4m.PATH[24m’
1160 instead.
1161 [1mVariable modifiers[0m
1163 Variable expansion may be modified to select or modify each
1164word of the
1165 variable (where a ‘‘word’’ is white‐space delimited sequence
1166of charac‐
1167 ters). The general format of a variable expansion is as
1168follows:
1169 ${variable[:modifier[:...]]}
1171 Each modifier begins with a colon, which may be escaped with
1173a backslash
1174 (‘´).
1175 A set of modifiers can be specified via a variable, as fol‐
1177lows:
1178 modifier_variable=modifier[:...]
1180 ${variable:${modifier_variable}[:...]}
1181 In this case the first modifier in the modifier_variable
1183does not start
1184 with a colon, since that must appear in the referencing
1185variable. If any
1186 of the modifiers in the modifier_variable contain a dollar
1187sign (‘$’),
1188 these must be doubled to avoid early expansion.
1189 The supported modifiers are:
1191 [1m:E [22mReplaces each word in the variable with its suf‐
1193fix.
1194 [1m:H [22mReplaces each word in the variable with every‐
1196thing but the last com‐
1197 ponent.
1198 [1m:M[4m[22mpattern[0m
1200 Selects only those words that match [4mpattern[24m.
1201The standard shell
1202 wildcard characters (‘*’, ‘?’, and ‘[]’) may be used.
1203The wildcard
1204 characters may be escaped with a backslash (‘´). As a
1205consequence
1206 of the way values are split into words, matched, and
1207then joined, a
1208 construct like
1209 ${VAR:M*}
1210 will normalize the inter‐word spacing, removing all
1211leading and
1212 trailing space, and converting multiple consecutive
1213spaces to single
1214 spaces.
1215 [1m:N[4m[22mpattern[0m
1217 This is identical to ‘[1m:M[22m’, but selects all words
1218which do not match
1219 [4mpattern[24m.
1220 [1m:O [22mOrders every word in variable alphabetically.
1222 [1m:Or [22mOrders every word in variable in reverse alpha‐
1224betical order.
1225 [1m:Ox [22mShuffles the words in variable. The results
1227will be different each
1228 time you are referring to the modified variable; use
1229the assignment
1230 with expansion (‘[1m:=[22m’) to prevent such behavior.
1231For example,
1232 LIST= uno due tre quattro
1234 RANDOM_LIST= ${LIST:Ox}
1235 STATIC_RANDOM_LIST:= ${LIST:Ox}
1236 all:
1238 @echo "${RANDOM_LIST}"
1239 @echo "${RANDOM_LIST}"
1240 @echo "${STATIC_RANDOM_LIST}"
1241 @echo "${STATIC_RANDOM_LIST}"
1242 may produce output similar to:
1243 quattro due tre uno
1245 tre due quattro uno
1246 due uno quattro tre
1247 due uno quattro tre
1248 [1m:Q [22mQuotes every shell meta‐character in the vari‐
1250able, so that it can be
1251 passed safely to the shell.
1252 [1m:q [22mQuotes every shell meta‐character in the vari‐
1254able, and also doubles
1255 ‘$’ characters so that it can be passed safely through
1256recursive
1257 invocations of [1mbmake[22m. This is equivalent to:
1258‘:S/&&/g:Q’.
1259 [1m:R [22mReplaces each word in the variable with every‐
1261thing but its suffix.
1262 [1m:range[=count][0m
1264 The value is an integer sequence representing the words
1265of the orig‐
1266 inal value, or the supplied [4mcount[24m.
1267 [1m:gmtime[=utc][0m
1269 The value is a format string for strftime(3), using gm‐
1270time(3). If a
1271 [4mutc[24m value is not provided or is 0, the current
1272time is used.
1273 [1m:hash[0m
1275 Computes a 32‐bit hash of the value and encode it as
1276hex digits.
1277 [1m:localtime[=utc][0m
1279 The value is a format string for strftime(3), using lo‐
1280caltime(3).
1281 If a [4mutc[24m value is not provided or is 0, the cur‐
1282rent time is used.
1283 [1m:tA [22mAttempts to convert variable to an absolute path
1285using realpath(3),
1286 if that fails, the value is unchanged.
1287 [1m:tl [22mConverts variable to lower‐case letters.
1289 [1m:ts[4m[22mc[0m
1291 Words in the variable are normally separated by a space
1292on expan‐
1293 sion. This modifier sets the separator to the charac‐
1294ter [4mc[24m. If [4mc[24m is
1295 omitted, then no separator is used. The common escapes
1296(including
1297 octal numeric codes) work as expected.
1298 [1m:tu [22mConverts variable to upper‐case letters.
1300 [1m:tW [22mCauses the value to be treated as a single word
1302(possibly containing
1303 embedded white space). See also ‘[1m:[*][22m’.
1304 [1m:tw [22mCauses the value to be treated as a sequence of
1306words delimited by
1307 white space. See also ‘[1m:[@][22m’.
1308 [1m:S[22m/[4mold_string[24m/[4mnew_string[24m/[[1m1gW[22m]
1310 Modifies the first occurrence of [4mold_string[24m in
1311each word of the
1312 variable’s value, replacing it with [4mnew_string[24m.
1313If a ‘g’ is
1314 appended to the last delimiter of the pattern, all oc‐
1315currences in
1316 each word are replaced. If a ‘1’ is appended to the
1317last delimiter
1318 of the pattern, only the first occurrence is affected.
1319If a ‘W’ is
1320 appended to the last delimiter of the pattern, then the
1321value is
1322 treated as a single word (possibly containing embedded
1323white space).
1324 If [4mold_string[24m begins with a caret (‘^’),
1325[4mold_string[24m is anchored at
1326 the beginning of each word. If [4mold_string[24m ends
1327with a dollar sign
1328 (‘$’), it is anchored at the end of each word. Inside
1329[4mnew_string[24m,
1330 an ampersand (‘&’) is replaced by [4mold_string[24m
1331(without any ‘^’ or
1332 ‘$’). Any character may be used as a delimiter for the
1333parts of the
1334 modifier string. The anchoring, ampersand and delim‐
1335iter characters
1336 may be escaped with a backslash (‘´).
1337 Variable expansion occurs in the normal fashion inside
1339both
1340 [4mold_string[24m and [4mnew_string[24m with the single
1341exception that a backslash
1342 is used to prevent the expansion of a dollar sign
1343(‘$’), not a pre‐
1344 ceding dollar sign as is usual.
1345 [1m:C[22m/[4mpattern[24m/[4mreplacement[24m/[[1m1gW[22m]
1347 The [1m:C [22mmodifier is just like the [1m:S [22mmodi‐
1348fier except that the old and
1349 new strings, instead of being simple strings, are an
1350extended regu‐
1351 lar expression (see regex(3)) string [4mpattern[24m and
1352an ed(1)‐style
1353 string [4mreplacement[24m. Normally, the first occur‐
1354rence of the pattern
1355 [4mpattern[24m in each word of the value is substituted
1356with [4mreplacement[24m.
1357 The ‘1’ modifier causes the substitution to apply to at
1358most one
1359 word; the ‘g’ modifier causes the substitution to apply
1360to as many
1361 instances of the search pattern [4mpattern[24m as occur
1362in the word or
1363 words it is found in; the ‘W’ modifier causes the value
1364to be
1365 treated as a single word (possibly containing embedded
1366white space).
1367 As for the [1m:S [22mmodifier, the [4mpattern[24m and
1369[4mreplacement[24m are subjected to
1370 variable expansion before being parsed as regular ex‐
1371pressions.
1372 [1m:T [22mReplaces each word in the variable with its last
1374path component.
1375 [1m:u [22mRemoves adjacent duplicate words (like uniq(1)).
1377 [1m:?[4m[22mtrue_string[24m[1m:[4m[22mfalse_string[0m
1379 If the variable name (not its value), when parsed as a
1380.if condi‐
1381 tional expression, evaluates to true, return as its
1382value the
1383 [4mtrue_string[24m, otherwise return the
1384[4mfalse_string[24m. Since the variable
1385 name is used as the expression, :? must be the first
1386modifier after
1387 the variable name itself ‐ which will, of course, usu‐
1388ally contain
1389 variable expansions. A common error is trying to use
1390expressions
1391 like
1392 ${NUMBERS:M42:?match:no}
1393 which actually tests defined(NUMBERS), to determine if
1394any words
1395 match "42" you need to use something like:
1396 ${"${NUMBERS:M42}" != "":?match:no}.
1397 [4m:old_string=new_string[0m
1399 This is the AT&T System V UNIX style variable substitu‐
1400tion. It must
1401 be the last modifier specified. If [4mold_string[24m
1402or [4mnew_string[24m do not
1403 contain the pattern matching character [4m%[24m then it
1404is assumed that
1405 they are anchored at the end of each word, so only suf‐
1406fixes or
1407 entire words may be replaced. Otherwise [4m%[24m is
1408the substring of
1409 [4mold_string[24m to be replaced in [4mnew_string[24m.
1410If only [4mold_string[24m con‐
1411 tains the pattern matching character [4m%[24m, and
1412[4mold_string[24m matches, then
1413 the result is the [4mnew_string[24m. If only the
1414[4mnew_string[24m contains the
1415 pattern matching character [4m%[24m, then it is not
1416treated specially and
1417 it is printed as a literal [4m%[24m on match. If there
1418is more than one
1419 pattern matching character ([4m%[24m) in either the
1420[4mnew_string[24m or
1421 [4mold_string[24m, only the first instance is treated
1422specially (as the
1423 pattern character); all subsequent instances are treat‐
1424ed as regular
1425 characters.
1426 Variable expansion occurs in the normal fashion inside
1428both
1429 [4mold_string[24m and [4mnew_string[24m with the single
1430exception that a backslash
1431 is used to prevent the expansion of a dollar sign
1432(‘$’), not a pre‐
1433 ceding dollar sign as is usual.
1434 [1m:@[4m[22mtemp[24m[1m@[4m[22mstring[24m[1m@[0m
1436 This is the loop expansion mechanism from the OSF De‐
1437velopment Envi‐
1438 ronment (ODE) make. Unlike [1m.for [22mloops, expan‐
1439sion occurs at the time
1440 of reference. Assigns [4mtemp[24m to each word in the
1441variable and evalu‐
1442 ates [4mstring[24m. The ODE convention is that
1443[4mtemp[24m should start and end
1444 with a period. For example.
1445 ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1446 However a single character variable is often more read‐
1448able:
1449 ${MAKE_PRINT_VAR_ON_ERROR:@v@$v=’${$v}’${.new‐
1450line}@}
1451 [1m:_[=var][0m
1453 Saves the current variable value in ‘$_’ or the named
1454[4mvar[24m for later
1455 reference. Example usage:
1456 M_cmpv.units = 1 1000 1000000
1458 M_cmpv = S,., ,g:_:range:@i@+ $${_:[‐$$i]}
1459$${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1460 .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1462 Here ‘$_’ is used to save the result of the ‘:S’ modi‐
1464fier which is
1465 later referenced using the index values from ‘:range’.
1466 [1m:U[4m[22mnewval[0m
1468 If the variable is undefined, [4mnewval[24m is the val‐
1469ue. If the variable
1470 is defined, the existing value is returned. This is
1471another ODE
1472 make feature. It is handy for setting per‐target
1473CFLAGS for
1474 instance:
1475 ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1476 If a value is only required if the variable is unde‐
1477fined, use:
1478 ${VAR:D:Unewval}
1479 [1m:D[4m[22mnewval[0m
1481 If the variable is defined, [4mnewval[24m is the value.
1482 [1m:L [22mThe name of the variable is the value.
1484 [1m:P [22mThe path of the node which has the same name as
1486the variable is the
1487 value. If no such node exists or its path is null,
1488then the name of
1489 the variable is used. In order for this modifier to
1490work, the name
1491 (node) must at least have appeared on the rhs of a de‐
1492pendency.
1493 [1m:![4m[22mcmd[24m[1m![0m
1495 The output of running [4mcmd[24m is the value.
1496 [1m:sh [22mIf the variable is non‐empty it is run as a com‐
1498mand and the output
1499 becomes the new value.
1500 [1m::=[4m[22mstr[0m
1502 The variable is assigned the value [4mstr[24m after
1503substitution. This
1504 modifier and its variations are useful in obscure situ‐
1505ations such as
1506 wanting to set a variable when shell commands are being
1507parsed.
1508 These assignment modifiers always expand to nothing, so
1509if appearing
1510 in a rule line by themselves should be preceded with
1511something to
1512 keep [1mbmake [22mhappy.
1513 The ‘[1m::[22m’ helps avoid false matches with the AT&T
1515System V UNIX style
1516 [1m:= [22mmodifier and since substitution always occurs
1517the [1m::= [22mform is
1518 vaguely appropriate.
1519 [1m::?=[4m[22mstr[0m
1521 As for [1m::= [22mbut only if the variable does not al‐
1522ready have a value.
1523 [1m::+=[4m[22mstr[0m
1525 Append [4mstr[24m to the variable.
1526 [1m::!=[4m[22mcmd[0m
1528 Assign the output of [4mcmd[24m to the variable.
1529 [1m:[[4m[22mrange[24m[1m][0m
1531 Selects one or more words from the value, or performs
1532other opera‐
1533 tions related to the way in which the value is divided
1534into words.
1535 Ordinarily, a value is treated as a sequence of words
1537delimited by
1538 white space. Some modifiers suppress this behavior,
1539causing a value
1540 to be treated as a single word (possibly containing em‐
1541bedded white
1542 space). An empty value, or a value that consists en‐
1543tirely of white‐
1544 space, is treated as a single word. For the purposes
1545of the ‘[1m:[][22m’
1546 modifier, the words are indexed both forwards using
1547positive inte‐
1548 gers (where index 1 represents the first word), and
1549backwards using
1550 negative integers (where index ‐1 represents the last
1551word).
1552 The [4mrange[24m is subjected to variable expansion,
1554and the expanded
1555 result is then interpreted as follows:
1556 [4mindex[24m Selects a single word from the value.
1558 [4mstart[24m[1m..[4m[22mend[0m
1560 Selects all words from [4mstart[24m to
1561[4mend[24m, inclusive. For example,
1562 ‘[1m:[2..‐1][22m’ selects all words from the
1563second word to the last
1564 word. If [4mstart[24m is greater than
1565[4mend[24m, then the words are out‐
1566 put in reverse order. For example,
1567‘[1m:[‐1..1][22m’ selects all
1568 the words from last to first. If the list is
1569already
1570 ordered, then this effectively reverses the
1571list, but it is
1572 more efficient to use ‘[1m:Or[22m’ instead of
1573‘[1m:O:[‐1..1][22m’.
1574 [1m* [22mCauses subsequent modifiers to treat the
1576value as a single
1577 word (possibly containing embedded white space).
1578Analogous
1579 to the effect of "$*" in Bourne shell.
1580 0 Means the same as ‘[1m:[*][22m’.
1582 [1m@ [22mCauses subsequent modifiers to treat the
1584value as a sequence
1585 of words delimited by white space. Analogous to
1586the effect
1587 of "$@" in Bourne shell.
1588 [1m# [22mReturns the number of words in the value.
1590[1mINCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS[0m
1592 Makefile inclusion, conditional structures and for loops
1593reminiscent of
1594 the C programming language are provided in [1mbmake[22m.
1595All such structures
1596 are identified by a line beginning with a single dot (‘.’)
1597character.
1598 Files are included with either [1m.include
1599<[4m[22mfile[24m[1m> [22mor [1m.include "[4m[22mfile[24m[1m"[22m.
1600Vari‐
1601 ables between the angle brackets or double quotes are ex‐
1602panded to form
1603 the file name. If angle brackets are used, the included
1604makefile is
1605 expected to be in the system makefile directory. If double
1606quotes are
1607 used, the including makefile’s directory and any directories
1608specified
1609 using the [1m‐I [22moption are searched before the system
1610makefile directory.
1611 For compatibility with other versions of [1mbmake [22m‘in‐
1612clude file ...’ is also
1613 accepted.
1614 If the include statement is written as [1m.‐include [22mor
1616as [1m.sinclude [22mthen
1617 errors locating and/or opening include files are ignored.
1618 If the include statement is written as [1m.dinclude [22mnot
1620only are errors
1621 locating and/or opening include files ignored, but stale de‐
1622pendencies
1623 within the included file will be ignored just like
1624[4m.MAKE.DEPENDFILE[24m.
1625 Conditional expressions are also preceded by a single dot as
1627the first
1628 character of a line. The possible conditionals are as fol‐
1629lows:
1630 [1m.error [4m[22mmessage[0m
1632 The message is printed along with the name of the
1633makefile and
1634 line number, then [1mbmake [22mwill exit immediate‐
1635ly.
1636 [1m.export [4m[22mvariable[24m [4m...[0m
1638 Export the specified global variable. If no vari‐
1639able list is
1640 provided, all globals are exported except for inter‐
1641nal variables
1642 (those that start with ‘.’). This is not affected
1643by the [1m‐X[0m
1644 flag, so should be used with caution. For compati‐
1645bility with
1646 other [1mbmake [22mprograms ‘export variable=value’
1647is also accepted.
1648 Appending a variable name to [4m.MAKE.EXPORTED[24m
1650is equivalent to
1651 exporting a variable.
1652 [1m.export‐env [4m[22mvariable[24m [4m...[0m
1654 The same as ‘.export’, except that the variable is
1655not appended
1656 to [4m.MAKE.EXPORTED[24m. This allows exporting a
1657value to the environ‐
1658 ment which is different from that used by [1mbmake
1659[22minternally.
1660 [1m.export‐literal [4m[22mvariable[24m [4m...[0m
1662 The same as ‘.export‐env’, except that variables in
1663the value are
1664 not expanded.
1665 [1m.info [4m[22mmessage[0m
1667 The message is printed along with the name of the
1668makefile and
1669 line number.
1670 [1m.undef [4m[22mvariable[0m
1672 Un‐define the specified global variable. Only glob‐
1673al variables
1674 may be un‐defined.
1675 [1m.unexport [4m[22mvariable[24m [4m...[0m
1677 The opposite of ‘.export’. The specified global
1678[4mvariable[24m will be
1679 removed from [4m.MAKE.EXPORTED[24m. If no variable
1680list is provided,
1681 all globals are unexported, and [4m.MAKE.EXPORT‐
1682ED[24m deleted.
1683 [1m.unexport‐env[0m
1685 Unexport all globals previously exported and clear
1686the environ‐
1687 ment inherited from the parent. This operation will
1688cause a mem‐
1689 ory leak of the original environment, so should be
1690used spar‐
1691 ingly. Testing for [4m.MAKE.LEVEL[24m being 0,
1692would make sense. Also
1693 note that any variables which originated in the par‐
1694ent environ‐
1695 ment should be explicitly preserved if desired. For
1696example:
1697 .if ${.MAKE.LEVEL} == 0
1699 PATH := ${PATH}
1700 .unexport‐env
1701 .export PATH
1702 .endif
1703 Would result in an environment containing only
1705‘PATH’, which is
1706 the minimal useful environment. Actually
1707‘.MAKE.LEVEL’ will also
1708 be pushed into the new environment.
1709 [1m.warning [4m[22mmessage[0m
1711 The message prefixed by ‘[4mwarning:[24m’ is printed
1712along with the name
1713 of the makefile and line number.
1714 [1m.if [22m[!][4mexpression[24m [[4moperator[24m [4mexpres‐
1716sion[24m [4m...[24m]
1717 Test the value of an expression.
1718 [1m.ifdef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1720able[24m [4m...[24m]
1721 Test the value of a variable.
1722 [1m.ifndef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1724able[24m [4m...[24m]
1725 Test the value of a variable.
1726 [1m.ifmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1728get[24m [4m...[24m]
1729 Test the target being built.
1730 [1m.ifnmake [22m[!] [4mtarget[24m [[4moperator[24m [4mtar‐
1732get[24m [4m...[24m]
1733 Test the target being built.
1734 [1m.else [22mReverse the sense of the last conditional.
1736 [1m.elif [22m[!] [4mexpression[24m [[4moperator[24m [4mex‐
1738pression[24m [4m...[24m]
1739 A combination of ‘[1m.else[22m’ followed by
1740‘[1m.if[22m’.
1741 [1m.elifdef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1743able[24m [4m...[24m]
1744 A combination of ‘[1m.else[22m’ followed by
1745‘[1m.ifdef[22m’.
1746 [1m.elifndef [22m[!][4mvariable[24m [[4moperator[24m
1748[4mvariable[24m [4m...[24m]
1749 A combination of ‘[1m.else[22m’ followed by
1750‘[1m.ifndef[22m’.
1751 [1m.elifmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1753get[24m [4m...[24m]
1754 A combination of ‘[1m.else[22m’ followed by ‘[1m.if‐
1755make[22m’.
1756 [1m.elifnmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1758get[24m [4m...[24m]
1759 A combination of ‘[1m.else[22m’ followed by
1760‘[1m.ifnmake[22m’.
1761 [1m.endif [22mEnd the body of the conditional.
1763 The [4moperator[24m may be any one of the following:
1765 [1m|| [22mLogical OR.
1767 [1m&& [22mLogical AND; of higher precedence than ‘‘||’’.
1769 As in C, [1mbmake [22mwill only evaluate a conditional as
1771far as is necessary to
1772 determine its value. Parentheses may be used to change the
1773order of
1774 evaluation. The boolean operator ‘[1m![22m’ may be used to
1775logically negate an
1776 entire conditional. It is of higher precedence than
1777‘[1m&&[22m’.
1778 The value of [4mexpression[24m may be any of the following:
1780 [1mdefined [22mTakes a variable name as an argument and
1782evaluates to true if
1783 the variable has been defined.
1784 [1mmake [22mTakes a target name as an argument and eval‐
1786uates to true if the
1787 target was specified as part of [1mbmake[22m’s com‐
1788mand line or was
1789 declared the default target (either implicitly or
1790explicitly,
1791 see [4m.MAIN[24m) before the line containing the
1792conditional.
1793 [1mempty [22mTakes a variable, with possible modifiers,
1795and evaluates to true
1796 if the expansion of the variable would result in an
1797empty
1798 string.
1799 [1mexists [22mTakes a file name as an argument and evalu‐
1801ates to true if the
1802 file exists. The file is searched for on the sys‐
1803tem search path
1804 (see [4m.PATH[24m).
1805 [1mtarget [22mTakes a target name as an argument and eval‐
1807uates to true if the
1808 target has been defined.
1809 [1mcommands[0m
1811 Takes a target name as an argument and evaluates to
1812true if the
1813 target has been defined and has commands associated
1814with it.
1815 [4mExpression[24m may also be an arithmetic or string com‐
1817parison. Variable
1818 expansion is performed on both sides of the comparison, af‐
1819ter which the
1820 integral values are compared. A value is interpreted as
1821hexadecimal if
1822 it is preceded by 0x, otherwise it is decimal; octal numbers
1823are not sup‐
1824 ported. The standard C relational operators are all sup‐
1825ported. If after
1826 variable expansion, either the left or right hand side of a
1827‘[1m==[22m’ or ‘[1m!=[22m’
1828 operator is not an integral value, then string comparison is
1829performed
1830 between the expanded variables. If no relational operator
1831is given, it
1832 is assumed that the expanded variable is being compared
1833against 0, or an
1834 empty string in the case of a string comparison.
1835 When [1mbmake [22mis evaluating one of these conditional ex‐
1837pressions, and it
1838 encounters a (white‐space separated) word it doesn’t recog‐
1839nize, either
1840 the ‘‘make’’ or ‘‘defined’’ expression is applied to it, de‐
1841pending on the
1842 form of the conditional. If the form is ‘[1m.ifdef[22m’,
1843‘[1m.ifndef[22m’, or ‘[1m.if[22m’
1844 the ‘‘defined’’ expression is applied. Similarly, if the
1845form is
1846 ‘[1m.ifmake[22m’ or ‘[1m.ifnmake[22m’, the ‘‘make’’ expres‐
1847sion is applied.
1848 If the conditional evaluates to true the parsing of the
1850makefile contin‐
1851 ues as before. If it evaluates to false, the following
1852lines are
1853 skipped. In both cases this continues until a
1854‘[1m.else[22m’ or ‘[1m.endif[22m’ is
1855 found.
1856 For loops are typically used to apply a set of rules to a
1858list of files.
1859 The syntax of a for loop is:
1860 [1m.for [4m[22mvariable[24m [[4mvariable[24m [4m...[24m]
1862[1min [4m[22mexpression[0m
1863 <make‐lines>
1864 [1m.endfor[0m
1865 After the for [1mexpression [22mis evaluated, it is split
1867into words. On each
1868 iteration of the loop, one word is taken and assigned to
1869each [1mvariable[22m,
1870 in order, and these [1mvariables [22mare substituted into
1871the [1mmake‐lines [22minside
1872 the body of the for loop. The number of words must come out
1873even; that
1874 is, if there are three iteration variables, the number of
1875words provided
1876 must be a multiple of three.
1877[1mCOMMENTS[0m
1879 Comments begin with a hash (‘#’) character, anywhere but in
1880a shell com‐
1881 mand line, and continue to the end of an unescaped new line.
1882[1mSPECIAL SOURCES (ATTRIBUTES)[0m
1884 [1m.EXEC [22mTarget is never out of date, but always ex‐
1885ecute commands any‐
1886 way.
1887 [1m.IGNORE [22mIgnore any errors from the commands associ‐
1889ated with this tar‐
1890 get, exactly as if they all were preceded by a
1891dash (‘‐’).
1892 [1m.MADE [22mMark all sources of this target as being
1894up‐to‐date.
1895 [1m.MAKE [22mExecute the commands associated with this
1897target even if the [1m‐n[0m
1898 or [1m‐t [22moptions were specified. Normally
1899used to mark recursive
1900 [1mbmake[22ms.
1901 [1m.META [22mCreate a meta file for the target, even if
1903it is flagged as
1904 [1m.PHONY[22m, [1m.MAKE[22m, or [1m.SPECIAL[22m.
1905Usage in conjunction with [1m.MAKE [22mis
1906 the most likely case. In "meta" mode, the target
1907is out‐of‐
1908 date if the meta file is missing.
1909 [1m.NOMETA [22mDo not create a meta file for the target.
1911Meta files are also
1912 not created for [1m.PHONY[22m, [1m.MAKE[22m, or
1913[1m.SPECIAL [22mtargets.
1914 [1m.NOMETA_CMP[0m
1916 Ignore differences in commands when deciding if
1917target is out
1918 of date. This is useful if the command contains a
1919value which
1920 always changes. If the number of commands change,
1921though, the
1922 target will still be out of date. The same effect
1923applies to
1924 any command line that uses the variable [4m.OO‐
1925DATE[24m, which can be
1926 used for that purpose even when not otherwise
1927needed or
1928 desired:
1929 skip‐compare‐for‐some:
1932 @echo this will be compared
1933 @echo this will not ${.OO‐
1934DATE:M.NOMETA_CMP}
1935 @echo this will also be compared
1936 The [1m:M [22mpattern suppresses any expansion of
1938the unwanted vari‐
1939 able.
1940 [1m.NOPATH [22mDo not search for the target in the direc‐
1942tories specified by
1943 [1m.PATH[22m.
1944 [1m.NOTMAIN [22mNormally [1mbmake [22mselects the first
1946target it encounters as the
1947 default target to be built if no target was speci‐
1948fied. This
1949 source prevents this target from being selected.
1950 [1m.OPTIONAL[0m
1952 If a target is marked with this attribute and
1953[1mbmake [22mcan’t fig‐
1954 ure out how to create it, it will ignore this fact
1955and assume
1956 the file isn’t needed or already exists.
1957 [1m.PHONY [22mThe target does not correspond to an actual
1959file; it is always
1960 considered to be out of date, and will not be cre‐
1961ated with the
1962 [1m‐t [22moption. Suffix‐transformation rules are
1963not applied to
1964 [1m.PHONY [22mtargets.
1965 [1m.PRECIOUS[0m
1967 When [1mbmake [22mis interrupted, it normally re‐
1968moves any partially
1969 made targets. This source prevents the target
1970from being
1971 removed.
1972 [1m.RECURSIVE[0m
1974 Synonym for [1m.MAKE[22m.
1975 [1m.SILENT [22mDo not echo any of the commands associated
1977with this target,
1978 exactly as if they all were preceded by an at sign
1979(‘@’).
1980 [1m.USE [22mTurn the target into [1mbmake[22m’s version
1982of a macro. When the tar‐
1983 get is used as a source for another target, the
1984other target
1985 acquires the commands, sources, and attributes
1986(except for
1987 [1m.USE[22m) of the source. If the target already
1988has commands, the
1989 [1m.USE [22mtarget’s commands are appended to
1990them.
1991 [1m.USEBEFORE[0m
1993 Exactly like [1m.USE[22m, but prepend the [1m.USE‐
1994BEFORE [22mtarget commands
1995 to the target.
1996 [1m.WAIT [22mIf [1m.WAIT [22mappears in a dependency
1998line, the sources that precede
1999 it are made before the sources that succeed it in
2000the line.
2001 Since the dependents of files are not made until
2002the file
2003 itself could be made, this also stops the depen‐
2004dents being
2005 built unless they are needed for another branch of
2006the depen‐
2007 dency tree. So given:
2008 x: a .WAIT b
2010 echo x
2011 a:
2012 echo a
2013 b: b1
2014 echo b
2015 b1:
2016 echo b1
2017 the output is always ‘a’, ‘b1’, ‘b’, ‘x’.
2019 The ordering imposed by [1m.WAIT [22mis only rele‐
2020vant for parallel
2021 makes.
2022[1mSPECIAL TARGETS[0m
2024 Special targets may not be included with other targets, i.e.
2025they must be
2026 the only target specified.
2027 [1m.BEGIN [22mAny command lines attached to this target
2029are executed before
2030 anything else is done.
2031 [1m.DEFAULT[0m
2033 This is sort of a [1m.USE [22mrule for any target
2034(that was used only
2035 as a source) that [1mbmake [22mcan’t figure out any
2036other way to cre‐
2037 ate. Only the shell script is used. The [1m.IMP‐
2038SRC [22mvariable of a
2039 target that inherits [1m.DEFAULT[22m’s commands is
2040set to the target’s
2041 own name.
2042 [1m.DELETE_ON_ERROR[0m
2044 If this target is present in the makefile, it glob‐
2045ally causes
2046 make to delete targets whose commands fail. (By
2047default, only
2048 targets whose commands are interrupted during exe‐
2049cution are
2050 deleted. This is the historical behavior.) This
2051setting can be
2052 used to help prevent half‐finished or malformed
2053targets from
2054 being left around and corrupting future rebuilds.
2055 [1m.END [22mAny command lines attached to this target
2057are executed after
2058 everything else is done.
2059 [1m.ERROR [22mAny command lines attached to this target
2061are executed when
2062 another target fails. The [1m.ERROR_TARGET
2063[22mvariable is set to the
2064 target that failed. See also
2065[1mMAKE_PRINT_VAR_ON_ERROR[22m.
2066 [1m.IGNORE [22mMark each of the sources with the [1m.IGNORE
2068[22mattribute. If no
2069 sources are specified, this is the equivalent of
2070specifying the
2071 [1m‐i [22moption.
2072 [1m.INTERRUPT[0m
2074 If [1mbmake [22mis interrupted, the commands for
2075this target will be
2076 executed.
2077 [1m.MAIN [22mIf no target is specified when [1mbmake
2079[22mis invoked, this target
2080 will be built.
2081 [1m.MAKEFLAGS[0m
2083 This target provides a way to specify flags for
2084[1mbmake [22mwhen the
2085 makefile is used. The flags are as if typed to the
2086shell,
2087 though the [1m‐f [22moption will have no effect.
2088 [1m.NOPATH [22mApply the [1m.NOPATH [22mattribute to any
2090specified sources.
2091 [1m.NOTPARALLEL[0m
2093 Disable parallel mode.
2094 [1m.NO_PARALLEL[0m
2096 Synonym for [1m.NOTPARALLEL[22m, for compatibility
2097with other pmake
2098 variants.
2099 [1m.OBJDIR [22mThe source is a new value for ‘[4m.OB‐
2101JDIR[24m’. If it exists, [1mbmake[0m
2102 will chdir(2) to it and update the value of
2103‘[4m.OBJDIR[24m’.
2104 [1m.ORDER [22mThe named targets are made in sequence.
2106This ordering does not
2107 add targets to the list of targets to be made.
2108Since the depen‐
2109 dents of a target do not get built until the target
2110itself could
2111 be built, unless ‘a’ is built by another part of
2112the dependency
2113 graph, the following is a dependency loop:
2114 .ORDER: b a
2116 b: a
2117 The ordering imposed by [1m.ORDER [22mis only rele‐
2119vant for parallel
2120 makes.
2121 [1m.PATH [22mThe sources are directories which are to be
2123searched for files
2124 not found in the current directory. If no sources
2125are speci‐
2126 fied, any previously specified directories are
2127deleted. If the
2128 source is the special [1m.DOTLAST [22mtarget, then
2129the current working
2130 directory is searched last.
2131 [1m.PATH.[4m[22msuffix[0m
2133 Like [1m.PATH [22mbut applies only to files with a
2134particular suffix.
2135 The suffix must have been previously declared with
2136[1m.SUFFIXES[22m.
2137 [1m.PHONY [22mApply the [1m.PHONY [22mattribute to any
2139specified sources.
2140 [1m.PRECIOUS[0m
2142 Apply the [1m.PRECIOUS [22mattribute to any speci‐
2143fied sources. If no
2144 sources are specified, the [1m.PRECIOUS [22mat‐
2145tribute is applied to
2146 every target in the file.
2147 [1m.SHELL [22mSets the shell that [1mbmake [22mwill use to
2149execute commands. The
2150 sources are a set of [4mfield=value[24m pairs.
2151 [4mname[24m This is the minimal specifica‐
2153tion, used to select
2154 one of the built‐in shell specs;
2155[4msh[24m, [4mksh[24m, and [4mcsh[24m.
2156 [4mpath[24m Specifies the path to the shell.
2158 [4mhasErrCtl[24m Indicates whether the shell sup‐
2160ports exit on error.
2161 [4mcheck[24m The command to turn on error
2163checking.
2164 [4mignore[24m The command to disable error
2166checking.
2167 [4mecho[24m The command to turn on echoing
2169of commands executed.
2170 [4mquiet[24m The command to turn off echoing
2172of commands exe‐
2173 cuted.
2174 [4mfilter[24m The output to filter after issu‐
2176ing the [4mquiet[24m com‐
2177 mand. It is typically identical to
2178[4mquiet[24m.
2179 [4merrFlag[24m The flag to pass the shell to
2181enable error checking.
2182 [4mechoFlag[24m The flag to pass the shell to
2184enable command echo‐
2185 ing.
2186 [4mnewline[24m The string literal to pass the
2188shell that results in
2189 a single newline character when used
2190outside of any
2191 quoting characters.
2192 Example:
2193 .SHELL: name=ksh path=/bin/ksh hasErrCtl=true
2195check="set ‐e" ignore="set +e" echo="set
2196‐v" quiet="set +v" filter="set +v"
2197echoFlag=v errFlag=e newline="’0"
2198 [1m.SILENT [22mApply the [1m.SILENT [22mattribute to any
2200specified sources. If no
2201 sources are specified, the [1m.SILENT [22mattribute
2202is applied to every
2203 command in the file.
2204 [1m.STALE [22mThis target gets run when a dependency file
2206contains stale
2207 entries, having [4m.ALLSRC[24m set to the name of
2208that dependency file.
2209 [1m.SUFFIXES[0m
2211 Each source specifies a suffix to [1mbmake[22m. If
2212no sources are
2213 specified, any previously specified suffixes are
2214deleted. It
2215 allows the creation of suffix‐transformation rules.
2216 Example:
2218 .SUFFIXES: .o
2220 .c.o:
2221 cc ‐o ${.TARGET} ‐c ${.IMPSRC}
2222[1mENVIRONMENT[0m
2224 [1mbmake [22muses the following environment variables, if
2225they exist: MACHINE,
2226 MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX,
2227MAKESYSPATH,
2228 PWD, and TMPDIR.
2229 MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the envi‐
2231ronment or on
2232 the command line to [1mbmake [22mand not as makefile vari‐
2233ables; see the descrip‐
2234 tion of ‘[4m.OBJDIR[24m’ for more details.
2235[1mFILES[0m
2237 .depend list of dependencies
2238 Makefile list of dependencies
2239 makefile list of dependencies
2240 sys.mk system makefile
2241 /usr/share/mk system makefile directory
2242[1mCOMPATIBILITY[0m
2244 The basic make syntax is compatible between different ver‐
2245sions of make;
2246 however the special variables, variable modifiers and condi‐
2247tionals are
2248 not.
2249 [1mOlder versions[0m
2251 An incomplete list of changes in older versions of [1mb‐
2252make[22m:
2253 The way that .for loop variables are substituted changed af‐
2255ter NetBSD 5.0
2256 so that they still appear to be variable expansions. In
2257particular this
2258 stops them being treated as syntax, and removes some obscure
2259problems
2260 using them in .if statements.
2261 The way that parallel makes are scheduled changed in NetBSD
22634.0 so that
2264 .ORDER and .WAIT apply recursively to the dependent nodes.
2265The algo‐
2266 rithms used may change again in the future.
2267 [1mOther make dialects[0m
2269 Other make dialects (GNU make, SVR4 make, POSIX make, etc.)
2270do not sup‐
2271 port most of the features of [1mbmake [22mas described in
2272this manual. Most
2273 notably:
2274 [1m+o [22mThe [1m.WAIT [22mand [1m.ORDER [22mdeclara‐
2276tions and most functionality per‐
2277 taining to parallelization. (GNU make supports
2278parallelization
2279 but lacks these features needed to control it ef‐
2280fectively.)
2281 [1m+o [22mDirectives, including for loops and condi‐
2283tionals and most of
2284 the forms of include files. (GNU make has its own
2285incompatible
2286 and less powerful syntax for conditionals.)
2287 [1m+o [22mAll built‐in variables that begin with a
2289dot.
2290 [1m+o [22mMost of the special sources and targets
2292that begin with a dot,
2293 with the notable exception of [1m.PHONY[22m,
2294[1m.PRECIOUS[22m, and [1m.SUFFIXES[22m.
2295 [1m+o [22mVariable modifiers, except for the
2297 :old=new
2298 string substitution, which does not portably sup‐
2299port globbing
2300 with ‘%’ and historically only works on declared
2301suffixes.
2302 [1m+o [22mThe [1m$> [22mvariable even in its short
2304form; most makes support this
2305 functionality but its name varies.
2306 Some features are somewhat more portable, such as assignment
2308with [1m+=[22m, [1m?=[22m,
2309 and [1m!=[22m. The [1m.PATH [22mfunctionality is based on
2310an older feature [1mVPATH [22mfound
2311 in GNU make and many versions of SVR4 make; however, histor‐
2312ically its
2313 behavior is too ill‐defined (and too buggy) to rely upon.
2314 The [1m$@ [22mand [1m$< [22mvariables are more or less uni‐
2316versally portable, as is the
2317 [1m$(MAKE) [22mvariable. Basic use of suffix rules (for
2318files only in the cur‐
2319 rent directory, not trying to chain transformations togeth‐
2320er, etc.) is
2321 also reasonably portable.
2322[1mSEE ALSO[0m
2324 mkdep(1)
2325[1mHISTORY[0m
2327 [1mbmake [22mis derived from NetBSD make(1). It uses auto‐
2328conf to facilitate
2329 portability to other platforms.
2330 A make command appeared in Version 7 AT&T UNIX. This make
2332implementation
2333 is based on Adam De Boor’s pmake program which was written
2334for Sprite at
2335 Berkeley. It was designed to be a parallel distributed make
2336running jobs
2337 on different machines using a daemon called ‘‘customs’’.
2338 Historically the target/dependency ‘‘FRC’’ has been used to
2340FoRCe
2341 rebuilding (since the target/dependency does not exist...
2342unless someone
2343 creates an ‘‘FRC’’ file).
2344[1mBUGS[0m
2346 The make syntax is difficult to parse without actually act‐
2347ing on the
2348 data. For instance, finding the end of a variable’s use
2349should involve
2350 scanning each of the modifiers, using the correct terminator
2351for each
2352 field. In many places make just counts {} and () in order
2353to find the
2354 end of a variable expansion.
2355 There is no way of escaping a space character in a filename.
2357FreeBSD 11.3 August 28, 2020
2359FreeBSD 11.3
2360