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30 .\" from: @(#)make.1 8.4 (Berkeley) 3/19/94
37 .Nd maintain program dependencies
55 is a program designed to simplify the maintenance of other programs.
56 Its input is a list of specifications as to the files upon which programs
57 and other files depend.
60 makefile option is given,
66 in order to find the specifications.
69 exists, it is read (see
72 This manual page is intended as a reference document only.
73 For a more thorough description of
75 and makefiles, please refer to
76 .%T "PMake \- A Tutorial" .
79 will prepend the contents of the
81 environment variable to the command line arguments before parsing them.
83 The options are as follows:
86 Try to be backwards compatible by executing a single shell per command and
87 by executing the commands to make the sources of a dependency line in sequence.
91 before reading the makefiles or doing anything else.
94 options are specified, each is interpreted relative to the previous one:
95 .Fl C Pa / Fl C Pa etc
101 to be 1, in the global context.
103 Turn on debugging, and specify which portions of
105 are to print debugging information.
106 Unless the flags are preceded by
108 they are added to the
110 environment variable and will be processed by any child make processes.
111 By default, debugging information is printed to standard error,
112 but this can be changed using the
115 The debugging output is always unbuffered; in addition, if debugging
116 is enabled but debugging output is not directed to standard output,
117 then the standard output is line buffered.
119 is one or more of the following:
122 Print all possible debugging information;
123 equivalent to specifying all of the debugging flags.
125 Print debugging information about archive searching and caching.
127 Print debugging information about current working directory.
129 Print debugging information about conditional evaluation.
131 Print debugging information about directory searching and caching.
133 Print debugging information about failed commands and targets.
134 .It Ar F Ns Oo Sy \&+ Oc Ns Ar filename
135 Specify where debugging output is written.
136 This must be the last flag, because it consumes the remainder of
138 If the character immediately after the
142 then the file will be opened in append mode;
143 otherwise the file will be overwritten.
148 then debugging output will be written to the
149 standard output or standard error output file descriptors respectively
152 option has no effect).
153 Otherwise, the output will be written to the named file.
154 If the file name ends
158 is replaced by the pid.
160 Print debugging information about loop evaluation.
162 Print the input graph before making anything.
164 Print the input graph after making everything, or before exiting
167 Print the input graph before exiting on error.
169 Print debugging information about running multiple shells.
171 Print commands in Makefiles regardless of whether or not they are prefixed by
173 or other "quiet" flags.
174 Also known as "loud" behavior.
176 Print debugging information about "meta" mode decisions about targets.
178 Print debugging information about making targets, including modification
181 Don't delete the temporary command scripts created when running commands.
182 These temporary scripts are created in the directory
185 environment variable, or in
189 is unset or set to the empty string.
190 The temporary scripts are created by
192 and have names of the form
195 This can create many files in
201 Print debugging information about makefile parsing.
203 Print debugging information about suffix-transformation rules.
205 Print debugging information about target list maintenance.
209 option to print raw values of variables.
211 Print debugging information about variable assignment.
213 Print entering and leaving directory messages, pre and post processing.
215 Run shell commands with
217 so the actual commands are printed as they are executed.
220 Specify that environment variables override macro assignments within
223 Specify a makefile to read instead of the default
229 standard input is read.
230 Multiple makefiles may be specified, and are read in the order specified.
231 .It Fl I Ar directory
232 Specify a directory in which to search for makefiles and included makefiles.
233 The system makefile directory (or directories, see the
235 option) is automatically included as part of this list.
237 Ignore non-zero exit of shell commands in the makefile.
238 Equivalent to specifying
240 before each command line in the makefile.
244 be specified by the user.
248 option is in use in a recursive build, this option is passed by a make
249 to child makes to allow all the make processes in the build to
250 cooperate to avoid overloading the system.
252 Specify the maximum number of jobs that
254 may have running at any one time.
255 The value is saved in
257 Turns compatibility mode off, unless the
259 flag is also specified.
260 When compatibility mode is off, all commands associated with a
261 target are executed in a single shell invocation as opposed to the
262 traditional one shell invocation per line.
263 This can break traditional scripts which change directories on each
264 command invocation and then expect to start with a fresh environment
266 It is more efficient to correct the scripts rather than turn backwards
269 Continue processing after errors are encountered, but only on those targets
270 that do not depend on the target whose creation caused the error.
271 .It Fl m Ar directory
272 Specify a directory in which to search for sys.mk and makefiles included
274 .Ao Ar file Ac Ns -style
278 option can be used multiple times to form a search path.
279 This path will override the default system include path: /usr/share/mk.
280 Furthermore the system include path will be appended to the search path used
282 .Qo Ar file Qc Ns -style
283 include statements (see the
287 If a file or directory name in the
291 environment variable) starts with the string
295 will search for the specified file or directory named in the remaining part
296 of the argument string.
297 The search starts with the current directory of
298 the Makefile and then works upward towards the root of the filesystem.
299 If the search is successful, then the resulting directory replaces the
304 If used, this feature allows
306 to easily search in the current source tree for customized sys.mk files
311 Display the commands that would have been executed, but do not
312 actually execute them unless the target depends on the .MAKE special
315 Display the commands which would have been executed, but do not
316 actually execute any of them; useful for debugging top-level makefiles
317 without descending into subdirectories.
319 Do not execute any commands, but exit 0 if the specified targets are
320 up-to-date and 1, otherwise.
322 Do not use the built-in rules specified in the system makefile.
324 Do not echo any commands as they are executed.
325 Equivalent to specifying
327 before each command line in the makefile.
328 .It Fl T Ar tracefile
332 append a trace record to
334 for each job started and completed.
336 Rather than re-building a target as specified in the makefile, create it
337 or update its modification time to make it appear up-to-date.
343 in the global context.
344 Do not build any targets.
345 Multiple instances of this option may be specified;
346 the variables will be printed one per line,
347 with a blank line for each null or undefined variable.
352 then the value will be expanded before printing.
354 Treat any warnings during makefile parsing as errors.
356 Don't export variables passed on the command line to the environment
358 Variables passed on the command line are still exported
361 environment variable.
362 This option may be useful on systems which have a small limit on the
363 size of command arguments.
364 .It Ar variable=value
365 Set the value of the variable
369 Normally, all values passed on the command line are also exported to
370 sub-makes in the environment.
373 flag disables this behavior.
374 Variable assignments should follow options for POSIX compatibility
375 but no ordering is enforced.
378 There are seven different types of lines in a makefile: file dependency
379 specifications, shell commands, variable assignments, include statements,
380 conditional directives, for loops, and comments.
382 In general, lines may be continued from one line to the next by ending
383 them with a backslash
385 The trailing newline character and initial whitespace on the following
386 line are compressed into a single space.
387 .Sh FILE DEPENDENCY SPECIFICATIONS
388 Dependency lines consist of one or more targets, an operator, and zero
390 This creates a relationship where the targets
393 and are usually created from them.
394 The exact relationship between the target and the source is determined
395 by the operator that separates them.
396 The three operators are as follows:
399 A target is considered out-of-date if its modification time is less than
400 those of any of its sources.
401 Sources for a target accumulate over dependency lines when this operator
403 The target is removed if
407 Targets are always re-created, but not until all sources have been
408 examined and re-created as necessary.
409 Sources for a target accumulate over dependency lines when this operator
411 The target is removed if
415 If no sources are specified, the target is always re-created.
416 Otherwise, a target is considered out-of-date if any of its sources has
417 been modified more recently than the target.
418 Sources for a target do not accumulate over dependency lines when this
420 The target will not be removed if
425 Targets and sources may contain the shell wildcard values
436 may only be used as part of the final
437 component of the target or source, and must be used to describe existing
441 need not necessarily be used to describe existing files.
442 Expansion is in directory order, not alphabetically as done in the shell.
444 Each target may have associated with it a series of shell commands, normally
445 used to create the target.
446 Each of the commands in this script
448 be preceded by a tab.
449 While any target may appear on a dependency line, only one of these
450 dependencies may be followed by a creation script, unless the
454 If the first characters of the command line are any combination of
459 the command is treated specially.
462 causes the command not to be echoed before it is executed.
465 causes the command to be executed even when
468 This is similar to the effect of the .MAKE special source,
469 except that the effect can be limited to a single line of a script.
472 causes any non-zero exit status of the command line to be ignored.
476 is run in jobs mode with
478 the entire script for the target is fed to a
479 single instance of the shell.
481 In compatibility (non-jobs) mode, each command is run in a separate process.
482 If the command contains any shell meta characters
483 .Pq Ql #=|^(){};&<>*?[]:$`\e\en
484 it will be passed to the shell, otherwise
486 will attempt direct execution.
494 before executing any targets, each child process
495 starts with that as its current working directory.
497 Makefiles should be written so that the mode of
499 operation does not change their behavior.
500 For example, any command which needs to use
504 without side-effect should be put in parenthesis:
505 .Bd -literal -offset indent
507 avoid-chdir-side-effects:
508 @echo Building $@ in `pwd`
509 @(cd ${.CURDIR} && ${.MAKE} $@)
512 ensure-one-shell-regardless-of-mode:
513 @echo Building $@ in `pwd`; \\
514 (cd ${.CURDIR} && ${.MAKE} $@); \\
517 .Sh VARIABLE ASSIGNMENTS
518 Variables in make are much like variables in the shell, and, by tradition,
519 consist of all upper-case letters.
520 .Ss Variable assignment modifiers
521 The five operators that can be used to assign values to variables are as
525 Assign the value to the variable.
526 Any previous value is overridden.
528 Append the value to the current value of the variable.
530 Assign the value to the variable if it is not already defined.
532 Assign with expansion, i.e. expand the value before assigning it
534 Normally, expansion is not done until the variable is referenced.
536 References to undefined variables are
539 This can cause problems when variable modifiers are used.
541 Expand the value and pass it to the shell for execution and assign
542 the result to the variable.
543 Any newlines in the result are replaced with spaces.
546 Any white-space before the assigned
548 is removed; if the value is being appended, a single space is inserted
549 between the previous contents of the variable and the appended value.
551 Variables are expanded by surrounding the variable name with either
556 and preceding it with
559 If the variable name contains only a single letter, the surrounding
560 braces or parentheses are not required.
561 This shorter form is not recommended.
563 If the variable name contains a dollar, then the name itself is expanded first.
564 This allows almost arbitrary variable names, however names containing dollar,
565 braces, parenthesis, or whitespace are really best avoided!
567 If the result of expanding a variable contains a dollar sign
569 the string is expanded again.
571 Variable substitution occurs at three distinct times, depending on where
572 the variable is being used.
575 Variables in dependency lines are expanded as the line is read.
577 Variables in shell commands are expanded when the shell command is
581 loop index variables are expanded on each loop iteration.
582 Note that other variables are not expanded inside loops so
583 the following example code:
584 .Bd -literal -offset indent
598 .Bd -literal -offset indent
603 Because while ${a} contains
605 after the loop is executed, ${b}
610 since after the loop completes ${j} contains
614 The four different classes of variables (in order of increasing precedence)
617 .It Environment variables
618 Variables defined as part of
622 Variables defined in the makefile or in included makefiles.
623 .It Command line variables
624 Variables defined as part of the command line.
626 Variables that are defined specific to a certain target.
627 The seven local variables are as follows:
628 .Bl -tag -width ".ARCHIVE"
630 The list of all sources for this target; also known as
633 The name of the archive file.
635 In suffix-transformation rules, the name/path of the source from which the
636 target is to be transformed (the
638 source); also known as
640 It is not defined in explicit rules.
642 The name of the archive member.
644 The list of sources for this target that were deemed out-of-date; also
648 The file prefix of the target, containing only the file portion, no suffix
649 or preceding directory components; also known as
652 The name of the target; also known as
663 are permitted for backward
664 compatibility with historical makefiles and are not recommended.
673 are permitted for compatibility with
675 makefiles and are not recommended.
677 Four of the local variables may be used in sources on dependency lines
678 because they expand to the proper value for each target on the line.
686 .Ss Additional built-in variables
689 sets or knows about the following variables:
690 .Bl -tag -width .MAKEOVERRIDES
696 expands to a single dollar
699 The list of all targets encountered in the Makefile.
701 Makefile parsing, lists only those targets encountered thus far.
703 A path to the directory where
706 Refer to the description of
719 The preferred variable to use is the environment variable
721 because it is more compatible with other versions of
723 and cannot be confused with the special target with the same name.
724 .It Va .MAKE.DEPENDFILE
725 Names the makefile (default
727 from which generated dependencies are read.
728 .It Va .MAKE.EXPAND_VARIABLES
729 A boolean that controls the default behavior of the
732 .It Va .MAKE.EXPORTED
733 The list of variables exported by
739 .It Va .MAKE.JOB.PREFIX
744 then output for each target is prefixed with a token
746 the first part of which can be controlled via
747 .Va .MAKE.JOB.PREFIX .
750 is empty, no token is printed.
753 .Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
754 would produce tokens like
755 .Ql ---make[1234] target ---
756 making it easier to track the degree of parallelism being achieved.
758 The environment variable
760 may contain anything that
764 Anything specified on
766 command line is appended to the
768 variable which is then
769 entered into the environment for all programs which
773 The recursion depth of
775 The initial instance of
777 will be 0, and an incremented value is put into the environment
778 to be seen by the next generation.
779 This allows tests like:
780 .Li .if ${.MAKE.LEVEL} == 0
781 to protect things which should only be evaluated in the initial instance of
783 .It Va .MAKE.MAKEFILE_PREFERENCE
784 The ordered list of makefile names
791 .It Va .MAKE.MAKEFILES
792 The list of makefiles read by
794 which is useful for tracking dependencies.
795 Each makefile is recorded only once, regardless of the number of times read.
797 Processed after reading all makefiles.
798 Can affect the mode that
801 It can contain a number of keywords:
802 .Bl -hang -width ignore-cmd
812 into "meta" mode, where meta files are created for each target
813 to capture the command run, the output generated and if
815 is available, the system calls which are of interest to
817 The captured output can be very useful when diagnosing errors.
818 .It Pa curdirOk= Ar bf
821 will not create .meta files in
823 This can be overridden by setting
825 to a value which represents True.
827 For debugging, it can be useful to inlcude the environment
830 If in "meta" mode, print a clue about the target being built.
831 This is useful if the build is otherwise running silently.
832 The message printed the value of:
833 .Va .MAKE.META.PREFIX .
835 Some makefiles have commands which are simply not stable.
836 This keyword causes them to be ignored for
837 determining whether a target is out of date in "meta" mode.
843 is True, when a .meta file is created, mark the target
846 .It Va .MAKE.META.BAILIWICK
847 In "meta" mode, provides a list of prefixes which
848 match the directories controlled by
850 If a file that was generated outside of
852 but within said bailiwick is missing,
853 the current target is considered out-of-date.
854 .It Va .MAKE.META.CREATED
855 In "meta" mode, this variable contains a list of all the meta files
857 If not empty, it can be used to trigger processing of
858 .Va .MAKE.META.FILES .
859 .It Va .MAKE.META.FILES
860 In "meta" mode, this variable contains a list of all the meta files
861 used (updated or not).
862 This list can be used to process the meta files to extract dependency
864 .It Va .MAKE.META.IGNORE_PATHS
865 Provides a list of path prefixes that should be ignored;
866 because the contents are expected to change over time.
867 The default list includes:
868 .Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
869 .It Va .MAKE.META.PREFIX
870 Defines the message printed for each meta file updated in "meta verbose" mode.
871 The default value is:
872 .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
873 .It Va .MAKEOVERRIDES
874 This variable is used to record the names of variables assigned to
875 on the command line, so that they may be exported as part of
877 This behaviour can be disabled by assigning an empty value to
878 .Ql Va .MAKEOVERRIDES
880 Extra variables can be exported from a makefile
881 by appending their names to
882 .Ql Va .MAKEOVERRIDES .
884 is re-exported whenever
885 .Ql Va .MAKEOVERRIDES
887 .It Va .MAKE.PATH_FILEMON
892 support, this is set to the path of the device node.
893 This allows makefiles to test for this support.
898 The parent process-id of
900 .It Va MAKE_PRINT_VAR_ON_ERROR
903 stops due to an error, it prints its name and the value of
905 as well as the value of any variables named in
906 .Ql Va MAKE_PRINT_VAR_ON_ERROR .
908 This variable is simply assigned a newline character as its value.
909 This allows expansions using the
911 modifier to put a newline between
912 iterations of the loop rather than a space.
913 For example, the printing of
914 .Ql Va MAKE_PRINT_VAR_ON_ERROR
915 could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
917 A path to the directory where the targets are built.
918 Its value is determined by trying to
920 to the following directories in order and using the first match:
923 .Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
926 .Ql Ev MAKEOBJDIRPREFIX
927 is set in the environment or on the command line.)
933 is set in the environment or on the command line.)
935 .Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
937 .Ev ${.CURDIR} Ns Pa /obj
939 .Pa /usr/obj/ Ns Ev ${.CURDIR}
944 Variable expansion is performed on the value before it's used,
945 so expressions such as
946 .Dl ${.CURDIR:S,^/usr/src,/var/obj,}
948 This is especially useful with
952 may be modified in the makefile as a global variable.
961 to that directory before executing any targets.
964 A path to the directory of the current
968 The basename of the current
973 are both set only while the
976 If you want to retain their current values, assign them to a variable
977 using assignment with expansion:
980 A variable that represents the list of directories that
982 will search for files.
983 The search list should be updated using the target
985 rather than the variable.
987 Alternate path to the current directory.
991 to the canonical path given by
993 However, if the environment variable
995 is set and gives a path to the current directory, then
1002 This behaviour is disabled if
1003 .Ql Ev MAKEOBJDIRPREFIX
1006 contains a variable transform.
1008 is set to the value of
1010 for all programs which
1014 The list of targets explicitly specified on the command line, if any.
1018 lists of directories that
1020 will search for files.
1021 The variable is supported for compatibility with old make programs only,
1026 .Ss Variable modifiers
1027 Variable expansion may be modified to select or modify each word of the
1030 is white-space delimited sequence of characters).
1031 The general format of a variable expansion is as follows:
1033 .Dl ${variable[:modifier[:...]]}
1035 Each modifier begins with a colon,
1036 which may be escaped with a backslash
1039 A set of modifiers can be specified via a variable, as follows:
1041 .Dl modifier_variable=modifier[:...]
1042 .Dl ${variable:${modifier_variable}[:...]}
1044 In this case the first modifier in the modifier_variable does not
1045 start with a colon, since that must appear in the referencing
1047 If any of the modifiers in the modifier_variable contain a dollar sign
1049 these must be doubled to avoid early expansion.
1051 The supported modifiers are:
1054 Replaces each word in the variable with its suffix.
1056 Replaces each word in the variable with everything but the last component.
1057 .It Cm \&:M Ns Ar pattern
1058 Select only those words that match
1060 The standard shell wildcard characters
1067 The wildcard characters may be escaped with a backslash
1069 .It Cm \&:N Ns Ar pattern
1070 This is identical to
1072 but selects all words which do not match
1075 Order every word in variable alphabetically.
1077 reverse order use the
1079 combination of modifiers.
1081 Randomize words in variable.
1082 The results will be different each time you are referring to the
1083 modified variable; use the assignment with expansion
1085 to prevent such behaviour.
1087 .Bd -literal -offset indent
1088 LIST= uno due tre quattro
1089 RANDOM_LIST= ${LIST:Ox}
1090 STATIC_RANDOM_LIST:= ${LIST:Ox}
1093 @echo "${RANDOM_LIST}"
1094 @echo "${RANDOM_LIST}"
1095 @echo "${STATIC_RANDOM_LIST}"
1096 @echo "${STATIC_RANDOM_LIST}"
1098 may produce output similar to:
1099 .Bd -literal -offset indent
1106 Quotes every shell meta-character in the variable, so that it can be passed
1107 safely through recursive invocations of
1110 Replaces each word in the variable with everything but its suffix.
1112 The value is a format string for
1117 Compute a 32bit hash of the value and encode it as hex digits.
1119 The value is a format string for
1124 Attempt to convert variable to an absolute path using
1126 if that fails, the value is unchanged.
1128 Converts variable to lower-case letters.
1129 .It Cm \&:ts Ns Ar c
1130 Words in the variable are normally separated by a space on expansion.
1131 This modifier sets the separator to the character
1135 is omitted, then no separator is used.
1136 The common escapes (including octal numeric codes), work as expected.
1138 Converts variable to upper-case letters.
1140 Causes the value to be treated as a single word
1141 (possibly containing embedded white space).
1145 Causes the value to be treated as a sequence of
1146 words delimited by white space.
1150 .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1152 Modify the first occurrence of
1154 in the variable's value, replacing it with
1158 is appended to the last slash of the pattern, all occurrences
1159 in each word are replaced.
1162 is appended to the last slash of the pattern, only the first word
1166 is appended to the last slash of the pattern,
1167 then the value is treated as a single word
1168 (possibly containing embedded white space).
1174 is anchored at the beginning of each word.
1177 ends with a dollar sign
1179 it is anchored at the end of each word.
1190 Any character may be used as a delimiter for the parts of the modifier
1192 The anchoring, ampersand and delimiter characters may be escaped with a
1196 Variable expansion occurs in the normal fashion inside both
1200 with the single exception that a backslash is used to prevent the expansion
1203 not a preceding dollar sign as is usual.
1205 .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1209 modifier is just like the
1211 modifier except that the old and new strings, instead of being
1212 simple strings, are a regular expression (see
1220 Normally, the first occurrence of the pattern
1222 in each word of the value is substituted with
1226 modifier causes the substitution to apply to at most one word; the
1228 modifier causes the substitution to apply to as many instances of the
1231 as occur in the word or words it is found in; the
1233 modifier causes the value to be treated as a single word
1234 (possibly containing embedded white space).
1239 are orthogonal; the former specifies whether multiple words are
1240 potentially affected, the latter whether multiple substitutions can
1241 potentially occur within each affected word.
1243 Replaces each word in the variable with its last component.
1245 Remove adjacent duplicate words (like
1248 .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1250 If the variable name (not its value), when parsed as a .if conditional
1251 expression, evaluates to true, return as its value the
1253 otherwise return the
1255 Since the variable name is used as the expression, \&:\&? must be the
1256 first modifier after the variable name itself - which will, of course,
1257 usually contain variable expansions.
1258 A common error is trying to use expressions like
1259 .Dl ${NUMBERS:M42:?match:no}
1260 which actually tests defined(NUMBERS),
1261 to determine is any words match "42" you need to use something like:
1262 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1263 .It Ar :old_string=new_string
1266 style variable substitution.
1267 It must be the last modifier specified.
1272 do not contain the pattern matching character
1274 then it is assumed that they are
1275 anchored at the end of each word, so only suffixes or entire
1276 words may be replaced.
1284 Variable expansion occurs in the normal fashion inside both
1288 with the single exception that a backslash is used to prevent the
1289 expansion of a dollar sign
1291 not a preceding dollar sign as is usual.
1293 .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1295 This is the loop expansion mechanism from the OSF Development
1296 Environment (ODE) make.
1299 loops expansion occurs at the time of
1303 to each word in the variable and evaluate
1305 The ODE convention is that
1307 should start and end with a period.
1309 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1311 However a single character variable is often more readable:
1312 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1313 .It Cm \&:U Ns Ar newval
1314 If the variable is undefined
1317 If the variable is defined, the existing value is returned.
1318 This is another ODE make feature.
1319 It is handy for setting per-target CFLAGS for instance:
1320 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1321 If a value is only required if the variable is undefined, use:
1322 .Dl ${VAR:D:Unewval}
1323 .It Cm \&:D Ns Ar newval
1324 If the variable is defined
1328 The name of the variable is the value.
1330 The path of the node which has the same name as the variable
1332 If no such node exists or its path is null, then the
1333 name of the variable is used.
1334 In order for this modifier to work, the name (node) must at least have
1335 appeared on the rhs of a dependency.
1337 .It Cm \&:\&! Ar cmd Cm \&!
1339 The output of running
1343 If the variable is non-empty it is run as a command and the output
1344 becomes the new value.
1345 .It Cm \&::= Ns Ar str
1346 The variable is assigned the value
1349 This modifier and its variations are useful in
1350 obscure situations such as wanting to set a variable when shell commands
1352 These assignment modifiers always expand to
1353 nothing, so if appearing in a rule line by themselves should be
1354 preceded with something to keep
1360 helps avoid false matches with the
1364 modifier and since substitution always occurs the
1366 form is vaguely appropriate.
1367 .It Cm \&::?= Ns Ar str
1370 but only if the variable does not already have a value.
1371 .It Cm \&::+= Ns Ar str
1375 .It Cm \&::!= Ns Ar cmd
1376 Assign the output of
1379 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1380 Selects one or more words from the value,
1381 or performs other operations related to the way in which the
1382 value is divided into words.
1384 Ordinarily, a value is treated as a sequence of words
1385 delimited by white space.
1386 Some modifiers suppress this behaviour,
1387 causing a value to be treated as a single word
1388 (possibly containing embedded white space).
1389 An empty value, or a value that consists entirely of white-space,
1390 is treated as a single word.
1391 For the purposes of the
1393 modifier, the words are indexed both forwards using positive integers
1394 (where index 1 represents the first word),
1395 and backwards using negative integers
1396 (where index \-1 represents the last word).
1400 is subjected to variable expansion, and the expanded result is
1401 then interpreted as follows:
1402 .Bl -tag -width index
1405 Selects a single word from the value.
1407 .It Ar start Ns Cm \&.. Ns Ar end
1408 Selects all words from
1415 selects all words from the second word to the last word.
1420 then the words are output in reverse order.
1423 selects all the words from last to first.
1426 Causes subsequent modifiers to treat the value as a single word
1427 (possibly containing embedded white space).
1428 Analogous to the effect of
1437 Causes subsequent modifiers to treat the value as a sequence of words
1438 delimited by white space.
1439 Analogous to the effect of
1444 Returns the number of words in the value.
1447 .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1448 Makefile inclusion, conditional structures and for loops reminiscent
1449 of the C programming language are provided in
1451 All such structures are identified by a line beginning with a single
1455 Files are included with either
1456 .Cm \&.include Aq Ar file
1458 .Cm \&.include Pf \*q Ar file Ns \*q .
1459 Variables between the angle brackets or double quotes are expanded
1460 to form the file name.
1461 If angle brackets are used, the included makefile is expected to be in
1462 the system makefile directory.
1463 If double quotes are used, the including makefile's directory and any
1464 directories specified using the
1466 option are searched before the system
1468 For compatibility with other versions of
1470 .Ql include file ...
1472 If the include statement is written as
1476 then errors locating and/or opening include files are ignored.
1478 Conditional expressions are also preceded by a single dot as the first
1479 character of a line.
1480 The possible conditionals are as follows:
1482 .It Ic .error Ar message
1483 The message is printed along with the name of the makefile and line number,
1487 .It Ic .export Ar variable ...
1488 Export the specified global variable.
1489 If no variable list is provided, all globals are exported
1490 except for internal variables (those that start with
1492 This is not affected by the
1494 flag, so should be used with caution.
1495 For compatibility with other
1498 .Ql export variable=value
1501 Appending a variable name to
1503 is equivalent to exporting a variable.
1504 .It Ic .export-env Ar variable ...
1507 except that the variable is not appended to
1508 .Va .MAKE.EXPORTED .
1509 This allows exporting a value to the environment which is different from that
1513 .It Ic .info Ar message
1514 The message is printed along with the name of the makefile and line number.
1515 .It Ic .undef Ar variable
1516 Un-define the specified global variable.
1517 Only global variables may be un-defined.
1518 .It Ic .unexport Ar variable ...
1521 The specified global
1523 will be removed from
1524 .Va .MAKE.EXPORTED .
1525 If no variable list is provided, all globals are unexported,
1529 .It Ic .unexport-env
1530 Unexport all globals previously exported and
1531 clear the environment inherited from the parent.
1532 This operation will cause a memory leak of the original environment,
1533 so should be used sparingly.
1536 being 0, would make sense.
1537 Also note that any variables which originated in the parent environment
1538 should be explicitly preserved if desired.
1540 .Bd -literal -offset indent
1541 .Li .if ${.MAKE.LEVEL} == 0
1548 Would result in an environment containing only
1550 which is the minimal useful environment.
1553 will also be pushed into the new environment.
1554 .It Ic .warning Ar message
1555 The message prefixed by
1557 is printed along with the name of the makefile and line number.
1558 .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1559 Test the value of an expression.
1560 .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1561 Test the value of a variable.
1562 .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1563 Test the value of a variable.
1564 .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1565 Test the target being built.
1566 .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1567 Test the target being built.
1569 Reverse the sense of the last conditional.
1570 .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1575 .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1580 .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1585 .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1590 .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1596 End the body of the conditional.
1601 may be any one of the following:
1602 .Bl -tag -width "Cm XX"
1605 .It Cm \&\*[Am]\*[Am]
1608 of higher precedence than
1614 will only evaluate a conditional as far as is necessary to determine
1616 Parentheses may be used to change the order of evaluation.
1617 The boolean operator
1619 may be used to logically negate an entire
1621 It is of higher precedence than
1622 .Ql Ic \&\*[Am]\*[Am] .
1626 may be any of the following:
1627 .Bl -tag -width defined
1629 Takes a variable name as an argument and evaluates to true if the variable
1632 Takes a target name as an argument and evaluates to true if the target
1633 was specified as part of
1635 command line or was declared the default target (either implicitly or
1638 before the line containing the conditional.
1640 Takes a variable, with possible modifiers, and evaluates to true if
1641 the expansion of the variable would result in an empty string.
1643 Takes a file name as an argument and evaluates to true if the file exists.
1644 The file is searched for on the system search path (see
1647 Takes a target name as an argument and evaluates to true if the target
1650 Takes a target name as an argument and evaluates to true if the target
1651 has been defined and has commands associated with it.
1655 may also be an arithmetic or string comparison.
1656 Variable expansion is
1657 performed on both sides of the comparison, after which the integral
1658 values are compared.
1659 A value is interpreted as hexadecimal if it is
1660 preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1661 The standard C relational operators are all supported.
1663 variable expansion, either the left or right hand side of a
1667 operator is not an integral value, then
1668 string comparison is performed between the expanded
1670 If no relational operator is given, it is assumed that the expanded
1671 variable is being compared against 0 or an empty string in the case
1672 of a string comparison.
1676 is evaluating one of these conditional expressions, and it encounters
1677 a (white-space separated) word it doesn't recognize, either the
1681 expression is applied to it, depending on the form of the conditional.
1689 expression is applied.
1690 Similarly, if the form is
1693 .Ql Ic .ifnmake , the
1695 expression is applied.
1697 If the conditional evaluates to true the parsing of the makefile continues
1699 If it evaluates to false, the following lines are skipped.
1700 In both cases this continues until a
1706 For loops are typically used to apply a set of rules to a list of files.
1707 The syntax of a for loop is:
1709 .Bl -tag -compact -width Ds
1710 .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1717 is evaluated, it is split into words.
1718 On each iteration of the loop, one word is taken and assigned to each
1722 are substituted into the
1724 inside the body of the for loop.
1725 The number of words must come out even; that is, if there are three
1726 iteration variables, the number of words provided must be a multiple
1729 Comments begin with a hash
1731 character, anywhere but in a shell
1732 command line, and continue to the end of an unescaped new line.
1733 .Sh SPECIAL SOURCES (ATTRIBUTES)
1734 .Bl -tag -width .IGNOREx
1736 Target is never out of date, but always execute commands anyway.
1738 Ignore any errors from the commands associated with this target, exactly
1739 as if they all were preceded by a dash
1741 .\" .It Ic .INVISIBLE
1746 Mark all sources of this target as being up-to-date.
1748 Execute the commands associated with this target even if the
1752 options were specified.
1753 Normally used to mark recursive
1756 Create a meta file for the target, even if it is flagged as
1761 Usage in conjunction with
1763 is the most likely case.
1764 In "meta" mode, the target is out-of-date if the meta file is missing.
1766 Do not create a meta file for the target.
1767 Meta files are also not created for
1774 Ignore differences in commands when deciding if target is out of date.
1775 This is useful if the command contains a value which always changes.
1776 If the number of commands change, though, the target will still be out of date.
1777 The same effect applies to any command line that uses the variable
1779 which can be used for that purpose even when not otherwise needed or desired:
1780 .Bd -literal -offset indent
1782 skip-compare-for-some:
1783 @echo this will be compared
1784 @echo this will not ${.OODATE:M.NOMETA_CMP}
1785 @echo this will also be compared
1790 pattern suppresses any expansion of the unwanted variable.
1792 Do not search for the target in the directories specified by
1797 selects the first target it encounters as the default target to be built
1798 if no target was specified.
1799 This source prevents this target from being selected.
1801 If a target is marked with this attribute and
1803 can't figure out how to create it, it will ignore this fact and assume
1804 the file isn't needed or already exists.
1807 correspond to an actual file; it is always considered to be out of date,
1808 and will not be created with the
1811 Suffix-transformation rules are not applied to
1817 is interrupted, it normally removes any partially made targets.
1818 This source prevents the target from being removed.
1823 Do not echo any of the commands associated with this target, exactly
1824 as if they all were preceded by an at sign
1827 Turn the target into
1830 When the target is used as a source for another target, the other target
1831 acquires the commands, sources, and attributes (except for
1835 If the target already has commands, the
1837 target's commands are appended
1844 target commands to the target.
1848 appears in a dependency line, the sources that precede it are
1849 made before the sources that succeed it in the line.
1850 Since the dependents of files are not made until the file itself
1851 could be made, this also stops the dependents being built unless they
1852 are needed for another branch of the dependency tree.
1865 the output is always
1871 The ordering imposed by
1873 is only relevant for parallel makes.
1876 Special targets may not be included with other targets, i.e. they must be
1877 the only target specified.
1878 .Bl -tag -width .BEGINx
1880 Any command lines attached to this target are executed before anything
1885 rule for any target (that was used only as a
1888 can't figure out any other way to create.
1889 Only the shell script is used.
1892 variable of a target that inherits
1895 to the target's own name.
1897 Any command lines attached to this target are executed after everything
1900 Any command lines attached to this target are executed when another target fails.
1903 variable is set to the target that failed.
1905 .Ic MAKE_PRINT_VAR_ON_ERROR .
1907 Mark each of the sources with the
1910 If no sources are specified, this is the equivalent of specifying the
1916 is interrupted, the commands for this target will be executed.
1918 If no target is specified when
1920 is invoked, this target will be built.
1922 This target provides a way to specify flags for
1924 when the makefile is used.
1925 The flags are as if typed to the shell, though the
1929 .\" XXX: NOT YET!!!!
1930 .\" .It Ic .NOTPARALLEL
1931 .\" The named targets are executed in non parallel mode.
1932 .\" If no targets are
1933 .\" specified, then all targets are executed in non parallel mode.
1937 attribute to any specified sources.
1939 Disable parallel mode.
1943 for compatibility with other pmake variants.
1945 The named targets are made in sequence.
1946 This ordering does not add targets to the list of targets to be made.
1947 Since the dependents of a target do not get built until the target itself
1948 could be built, unless
1950 is built by another part of the dependency graph,
1951 the following is a dependency loop:
1957 The ordering imposed by
1959 is only relevant for parallel makes.
1960 .\" XXX: NOT YET!!!!
1961 .\" .It Ic .PARALLEL
1962 .\" The named targets are executed in parallel mode.
1963 .\" If no targets are
1964 .\" specified, then all targets are executed in parallel mode.
1966 The sources are directories which are to be searched for files not
1967 found in the current directory.
1968 If no sources are specified, any previously specified directories are
1970 If the source is the special
1972 target, then the current working
1973 directory is searched last.
1974 .It Ic .PATH. Ns Va suffix
1977 but applies only to files with a particular suffix.
1978 The suffix must have been previously declared with
1983 attribute to any specified sources.
1987 attribute to any specified sources.
1988 If no sources are specified, the
1990 attribute is applied to every
1995 will use to execute commands.
1996 The sources are a set of
1999 .Bl -tag -width hasErrCtls
2001 This is the minimal specification, used to select one of the builtin
2008 Specifies the path to the shell.
2010 Indicates whether the shell supports exit on error.
2012 The command to turn on error checking.
2014 The command to disable error checking.
2016 The command to turn on echoing of commands executed.
2018 The command to turn off echoing of commands executed.
2020 The output to filter after issuing the
2023 It is typically identical to
2026 The flag to pass the shell to enable error checking.
2028 The flag to pass the shell to enable command echoing.
2030 The string literal to pass the shell that results in a single newline
2031 character when used outside of any quoting characters.
2035 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2036 check="set \-e" ignore="set +e" \e
2037 echo="set \-v" quiet="set +v" filter="set +v" \e
2038 echoFlag=v errFlag=e newline="'\en'"
2043 attribute to any specified sources.
2044 If no sources are specified, the
2046 attribute is applied to every
2047 command in the file.
2049 This target gets run when a dependency file contains stale entries, having
2051 set to the name of that dependency file.
2053 Each source specifies a suffix to
2055 If no sources are specified, any previously specified suffixes are deleted.
2056 It allows the creation of suffix-transformation rules.
2062 cc \-o ${.TARGET} \-c ${.IMPSRC}
2067 uses the following environment variables, if they exist:
2073 .Ev MAKEOBJDIRPREFIX ,
2079 .Ev MAKEOBJDIRPREFIX
2082 may only be set in the environment or on the command line to
2084 and not as makefile variables;
2085 see the description of
2089 .Bl -tag -width /usr/share/mk -compact
2091 list of dependencies
2093 list of dependencies
2095 list of dependencies
2099 system makefile directory
2102 The basic make syntax is compatible between different versions of make,
2103 however the special variables, variable modifiers and conditionals are not.
2105 The way that parallel makes are scheduled changed in
2107 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2108 The algorithms used may change again in the future.
2110 The way that .for loop variables are substituted changed after
2112 so that they still appear to be variable expansions.
2113 In particular this stops them being treated as syntax, and removes some
2114 obscure problems using them in .if statements.
2119 is derived from NetBSD
2121 It uses autoconf to facilitate portability to other platforms.
2129 implementation is based on Adam De Boor's pmake program which was written
2130 for Sprite at Berkeley.
2131 It was designed to be a parallel distributed make running jobs on different
2132 machines using a daemon called
2135 Historically the target/dependency
2137 has been used to FoRCe rebuilding (since the target/dependency
2138 does not exist... unless someone creates an
2144 syntax is difficult to parse without actually acting of the data.
2145 For instance finding the end of a variable use should involve scanning each
2146 the modifiers using the correct terminator for each field.
2149 just counts {} and () in order to find the end of a variable expansion.
2151 There is no way of escaping a space character in a filename.