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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.ALWAYS_PASS_JOB_QUEUE
727 whether to pass the descriptors of the job token queue
728 even if the target is not tagged with
732 for backwards compatability with
735 .It Va .MAKE.DEPENDFILE
736 Names the makefile (default
738 from which generated dependencies are read.
739 .It Va .MAKE.EXPAND_VARIABLES
740 A boolean that controls the default behavior of the
743 .It Va .MAKE.EXPORTED
744 The list of variables exported by
750 .It Va .MAKE.JOB.PREFIX
755 then output for each target is prefixed with a token
757 the first part of which can be controlled via
758 .Va .MAKE.JOB.PREFIX .
761 is empty, no token is printed.
764 .Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
765 would produce tokens like
766 .Ql ---make[1234] target ---
767 making it easier to track the degree of parallelism being achieved.
769 The environment variable
771 may contain anything that
775 Anything specified on
777 command line is appended to the
779 variable which is then
780 entered into the environment for all programs which
784 The recursion depth of
786 The initial instance of
788 will be 0, and an incremented value is put into the environment
789 to be seen by the next generation.
790 This allows tests like:
791 .Li .if ${.MAKE.LEVEL} == 0
792 to protect things which should only be evaluated in the initial instance of
794 .It Va .MAKE.MAKEFILE_PREFERENCE
795 The ordered list of makefile names
802 .It Va .MAKE.MAKEFILES
803 The list of makefiles read by
805 which is useful for tracking dependencies.
806 Each makefile is recorded only once, regardless of the number of times read.
808 Processed after reading all makefiles.
809 Can affect the mode that
812 It can contain a number of keywords:
813 .Bl -hang -width ignore-cmd
823 into "meta" mode, where meta files are created for each target
824 to capture the command run, the output generated and if
826 is available, the system calls which are of interest to
828 The captured output can be very useful when diagnosing errors.
829 .It Pa curdirOk= Ar bf
832 will not create .meta files in
834 This can be overridden by setting
836 to a value which represents True.
838 For debugging, it can be useful to inlcude the environment
841 If in "meta" mode, print a clue about the target being built.
842 This is useful if the build is otherwise running silently.
843 The message printed the value of:
844 .Va .MAKE.META.PREFIX .
846 Some makefiles have commands which are simply not stable.
847 This keyword causes them to be ignored for
848 determining whether a target is out of date in "meta" mode.
854 is True, when a .meta file is created, mark the target
857 .It Va .MAKE.META.BAILIWICK
858 In "meta" mode, provides a list of prefixes which
859 match the directories controlled by
861 If a file that was generated outside of
863 but within said bailiwick is missing,
864 the current target is considered out-of-date.
865 .It Va .MAKE.META.CREATED
866 In "meta" mode, this variable contains a list of all the meta files
868 If not empty, it can be used to trigger processing of
869 .Va .MAKE.META.FILES .
870 .It Va .MAKE.META.FILES
871 In "meta" mode, this variable contains a list of all the meta files
872 used (updated or not).
873 This list can be used to process the meta files to extract dependency
875 .It Va .MAKE.META.IGNORE_PATHS
876 Provides a list of path prefixes that should be ignored;
877 because the contents are expected to change over time.
878 The default list includes:
879 .Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
880 .It Va .MAKE.META.PREFIX
881 Defines the message printed for each meta file updated in "meta verbose" mode.
882 The default value is:
883 .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
884 .It Va .MAKEOVERRIDES
885 This variable is used to record the names of variables assigned to
886 on the command line, so that they may be exported as part of
888 This behaviour can be disabled by assigning an empty value to
889 .Ql Va .MAKEOVERRIDES
891 Extra variables can be exported from a makefile
892 by appending their names to
893 .Ql Va .MAKEOVERRIDES .
895 is re-exported whenever
896 .Ql Va .MAKEOVERRIDES
898 .It Va .MAKE.PATH_FILEMON
903 support, this is set to the path of the device node.
904 This allows makefiles to test for this support.
909 The parent process-id of
911 .It Va MAKE_PRINT_VAR_ON_ERROR
914 stops due to an error, it prints its name and the value of
916 as well as the value of any variables named in
917 .Ql Va MAKE_PRINT_VAR_ON_ERROR .
919 This variable is simply assigned a newline character as its value.
920 This allows expansions using the
922 modifier to put a newline between
923 iterations of the loop rather than a space.
924 For example, the printing of
925 .Ql Va MAKE_PRINT_VAR_ON_ERROR
926 could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
928 A path to the directory where the targets are built.
929 Its value is determined by trying to
931 to the following directories in order and using the first match:
934 .Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
937 .Ql Ev MAKEOBJDIRPREFIX
938 is set in the environment or on the command line.)
944 is set in the environment or on the command line.)
946 .Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
948 .Ev ${.CURDIR} Ns Pa /obj
950 .Pa /usr/obj/ Ns Ev ${.CURDIR}
955 Variable expansion is performed on the value before it's used,
956 so expressions such as
957 .Dl ${.CURDIR:S,^/usr/src,/var/obj,}
959 This is especially useful with
963 may be modified in the makefile as a global variable.
972 to that directory before executing any targets.
975 A path to the directory of the current
979 The basename of the current
984 are both set only while the
987 If you want to retain their current values, assign them to a variable
988 using assignment with expansion:
991 A variable that represents the list of directories that
993 will search for files.
994 The search list should be updated using the target
996 rather than the variable.
998 Alternate path to the current directory.
1002 to the canonical path given by
1004 However, if the environment variable
1006 is set and gives a path to the current directory, then
1013 This behaviour is disabled if
1014 .Ql Ev MAKEOBJDIRPREFIX
1017 contains a variable transform.
1019 is set to the value of
1021 for all programs which
1025 The list of targets explicitly specified on the command line, if any.
1029 lists of directories that
1031 will search for files.
1032 The variable is supported for compatibility with old make programs only,
1037 .Ss Variable modifiers
1038 Variable expansion may be modified to select or modify each word of the
1041 is white-space delimited sequence of characters).
1042 The general format of a variable expansion is as follows:
1044 .Dl ${variable[:modifier[:...]]}
1046 Each modifier begins with a colon,
1047 which may be escaped with a backslash
1050 A set of modifiers can be specified via a variable, as follows:
1052 .Dl modifier_variable=modifier[:...]
1053 .Dl ${variable:${modifier_variable}[:...]}
1055 In this case the first modifier in the modifier_variable does not
1056 start with a colon, since that must appear in the referencing
1058 If any of the modifiers in the modifier_variable contain a dollar sign
1060 these must be doubled to avoid early expansion.
1062 The supported modifiers are:
1065 Replaces each word in the variable with its suffix.
1067 Replaces each word in the variable with everything but the last component.
1068 .It Cm \&:M Ns Ar pattern
1069 Select only those words that match
1071 The standard shell wildcard characters
1078 The wildcard characters may be escaped with a backslash
1080 As a consequence of the way values are split into words, matched,
1081 and then joined, a construct like
1083 will normalise the inter-word spacing, removing all leading and
1084 trailing space, and converting multiple consecutive spaces
1087 .It Cm \&:N Ns Ar pattern
1088 This is identical to
1090 but selects all words which do not match
1093 Order every word in variable alphabetically.
1095 reverse order use the
1097 combination of modifiers.
1099 Randomize words in variable.
1100 The results will be different each time you are referring to the
1101 modified variable; use the assignment with expansion
1103 to prevent such behaviour.
1105 .Bd -literal -offset indent
1106 LIST= uno due tre quattro
1107 RANDOM_LIST= ${LIST:Ox}
1108 STATIC_RANDOM_LIST:= ${LIST:Ox}
1111 @echo "${RANDOM_LIST}"
1112 @echo "${RANDOM_LIST}"
1113 @echo "${STATIC_RANDOM_LIST}"
1114 @echo "${STATIC_RANDOM_LIST}"
1116 may produce output similar to:
1117 .Bd -literal -offset indent
1124 Quotes every shell meta-character in the variable, so that it can be passed
1125 safely through recursive invocations of
1128 Replaces each word in the variable with everything but its suffix.
1130 The value is a format string for
1135 Compute a 32bit hash of the value and encode it as hex digits.
1137 The value is a format string for
1142 Attempt to convert variable to an absolute path using
1144 if that fails, the value is unchanged.
1146 Converts variable to lower-case letters.
1147 .It Cm \&:ts Ns Ar c
1148 Words in the variable are normally separated by a space on expansion.
1149 This modifier sets the separator to the character
1153 is omitted, then no separator is used.
1154 The common escapes (including octal numeric codes), work as expected.
1156 Converts variable to upper-case letters.
1158 Causes the value to be treated as a single word
1159 (possibly containing embedded white space).
1163 Causes the value to be treated as a sequence of
1164 words delimited by white space.
1168 .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1170 Modify the first occurrence of
1172 in the variable's value, replacing it with
1176 is appended to the last slash of the pattern, all occurrences
1177 in each word are replaced.
1180 is appended to the last slash of the pattern, only the first word
1184 is appended to the last slash of the pattern,
1185 then the value is treated as a single word
1186 (possibly containing embedded white space).
1192 is anchored at the beginning of each word.
1195 ends with a dollar sign
1197 it is anchored at the end of each word.
1208 Any character may be used as a delimiter for the parts of the modifier
1210 The anchoring, ampersand and delimiter characters may be escaped with a
1214 Variable expansion occurs in the normal fashion inside both
1218 with the single exception that a backslash is used to prevent the expansion
1221 not a preceding dollar sign as is usual.
1223 .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1227 modifier is just like the
1229 modifier except that the old and new strings, instead of being
1230 simple strings, are an extended regular expression (see
1238 Normally, the first occurrence of the pattern
1240 in each word of the value is substituted with
1244 modifier causes the substitution to apply to at most one word; the
1246 modifier causes the substitution to apply to as many instances of the
1249 as occur in the word or words it is found in; the
1251 modifier causes the value to be treated as a single word
1252 (possibly containing embedded white space).
1257 are orthogonal; the former specifies whether multiple words are
1258 potentially affected, the latter whether multiple substitutions can
1259 potentially occur within each affected word.
1261 Replaces each word in the variable with its last component.
1263 Remove adjacent duplicate words (like
1266 .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1268 If the variable name (not its value), when parsed as a .if conditional
1269 expression, evaluates to true, return as its value the
1271 otherwise return the
1273 Since the variable name is used as the expression, \&:\&? must be the
1274 first modifier after the variable name itself - which will, of course,
1275 usually contain variable expansions.
1276 A common error is trying to use expressions like
1277 .Dl ${NUMBERS:M42:?match:no}
1278 which actually tests defined(NUMBERS),
1279 to determine is any words match "42" you need to use something like:
1280 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1281 .It Ar :old_string=new_string
1284 style variable substitution.
1285 It must be the last modifier specified.
1290 do not contain the pattern matching character
1292 then it is assumed that they are
1293 anchored at the end of each word, so only suffixes or entire
1294 words may be replaced.
1302 Variable expansion occurs in the normal fashion inside both
1306 with the single exception that a backslash is used to prevent the
1307 expansion of a dollar sign
1309 not a preceding dollar sign as is usual.
1311 .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1313 This is the loop expansion mechanism from the OSF Development
1314 Environment (ODE) make.
1317 loops expansion occurs at the time of
1321 to each word in the variable and evaluate
1323 The ODE convention is that
1325 should start and end with a period.
1327 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1329 However a single character variable is often more readable:
1330 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1331 .It Cm \&:U Ns Ar newval
1332 If the variable is undefined
1335 If the variable is defined, the existing value is returned.
1336 This is another ODE make feature.
1337 It is handy for setting per-target CFLAGS for instance:
1338 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1339 If a value is only required if the variable is undefined, use:
1340 .Dl ${VAR:D:Unewval}
1341 .It Cm \&:D Ns Ar newval
1342 If the variable is defined
1346 The name of the variable is the value.
1348 The path of the node which has the same name as the variable
1350 If no such node exists or its path is null, then the
1351 name of the variable is used.
1352 In order for this modifier to work, the name (node) must at least have
1353 appeared on the rhs of a dependency.
1355 .It Cm \&:\&! Ar cmd Cm \&!
1357 The output of running
1361 If the variable is non-empty it is run as a command and the output
1362 becomes the new value.
1363 .It Cm \&::= Ns Ar str
1364 The variable is assigned the value
1367 This modifier and its variations are useful in
1368 obscure situations such as wanting to set a variable when shell commands
1370 These assignment modifiers always expand to
1371 nothing, so if appearing in a rule line by themselves should be
1372 preceded with something to keep
1378 helps avoid false matches with the
1382 modifier and since substitution always occurs the
1384 form is vaguely appropriate.
1385 .It Cm \&::?= Ns Ar str
1388 but only if the variable does not already have a value.
1389 .It Cm \&::+= Ns Ar str
1393 .It Cm \&::!= Ns Ar cmd
1394 Assign the output of
1397 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1398 Selects one or more words from the value,
1399 or performs other operations related to the way in which the
1400 value is divided into words.
1402 Ordinarily, a value is treated as a sequence of words
1403 delimited by white space.
1404 Some modifiers suppress this behaviour,
1405 causing a value to be treated as a single word
1406 (possibly containing embedded white space).
1407 An empty value, or a value that consists entirely of white-space,
1408 is treated as a single word.
1409 For the purposes of the
1411 modifier, the words are indexed both forwards using positive integers
1412 (where index 1 represents the first word),
1413 and backwards using negative integers
1414 (where index \-1 represents the last word).
1418 is subjected to variable expansion, and the expanded result is
1419 then interpreted as follows:
1420 .Bl -tag -width index
1423 Selects a single word from the value.
1425 .It Ar start Ns Cm \&.. Ns Ar end
1426 Selects all words from
1433 selects all words from the second word to the last word.
1438 then the words are output in reverse order.
1441 selects all the words from last to first.
1444 Causes subsequent modifiers to treat the value as a single word
1445 (possibly containing embedded white space).
1446 Analogous to the effect of
1455 Causes subsequent modifiers to treat the value as a sequence of words
1456 delimited by white space.
1457 Analogous to the effect of
1462 Returns the number of words in the value.
1465 .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1466 Makefile inclusion, conditional structures and for loops reminiscent
1467 of the C programming language are provided in
1469 All such structures are identified by a line beginning with a single
1473 Files are included with either
1474 .Cm \&.include Aq Ar file
1476 .Cm \&.include Pf \*q Ar file Ns \*q .
1477 Variables between the angle brackets or double quotes are expanded
1478 to form the file name.
1479 If angle brackets are used, the included makefile is expected to be in
1480 the system makefile directory.
1481 If double quotes are used, the including makefile's directory and any
1482 directories specified using the
1484 option are searched before the system
1486 For compatibility with other versions of
1488 .Ql include file ...
1490 If the include statement is written as
1494 then errors locating and/or opening include files are ignored.
1496 Conditional expressions are also preceded by a single dot as the first
1497 character of a line.
1498 The possible conditionals are as follows:
1500 .It Ic .error Ar message
1501 The message is printed along with the name of the makefile and line number,
1505 .It Ic .export Ar variable ...
1506 Export the specified global variable.
1507 If no variable list is provided, all globals are exported
1508 except for internal variables (those that start with
1510 This is not affected by the
1512 flag, so should be used with caution.
1513 For compatibility with other
1516 .Ql export variable=value
1519 Appending a variable name to
1521 is equivalent to exporting a variable.
1522 .It Ic .export-env Ar variable ...
1525 except that the variable is not appended to
1526 .Va .MAKE.EXPORTED .
1527 This allows exporting a value to the environment which is different from that
1531 .It Ic .info Ar message
1532 The message is printed along with the name of the makefile and line number.
1533 .It Ic .undef Ar variable
1534 Un-define the specified global variable.
1535 Only global variables may be un-defined.
1536 .It Ic .unexport Ar variable ...
1539 The specified global
1541 will be removed from
1542 .Va .MAKE.EXPORTED .
1543 If no variable list is provided, all globals are unexported,
1547 .It Ic .unexport-env
1548 Unexport all globals previously exported and
1549 clear the environment inherited from the parent.
1550 This operation will cause a memory leak of the original environment,
1551 so should be used sparingly.
1554 being 0, would make sense.
1555 Also note that any variables which originated in the parent environment
1556 should be explicitly preserved if desired.
1558 .Bd -literal -offset indent
1559 .Li .if ${.MAKE.LEVEL} == 0
1566 Would result in an environment containing only
1568 which is the minimal useful environment.
1571 will also be pushed into the new environment.
1572 .It Ic .warning Ar message
1573 The message prefixed by
1575 is printed along with the name of the makefile and line number.
1576 .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1577 Test the value of an expression.
1578 .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1579 Test the value of a variable.
1580 .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1581 Test the value of a variable.
1582 .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1583 Test the target being built.
1584 .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1585 Test the target being built.
1587 Reverse the sense of the last conditional.
1588 .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1593 .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1598 .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1603 .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1608 .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1614 End the body of the conditional.
1619 may be any one of the following:
1620 .Bl -tag -width "Cm XX"
1623 .It Cm \&\*[Am]\*[Am]
1626 of higher precedence than
1632 will only evaluate a conditional as far as is necessary to determine
1634 Parentheses may be used to change the order of evaluation.
1635 The boolean operator
1637 may be used to logically negate an entire
1639 It is of higher precedence than
1640 .Ql Ic \&\*[Am]\*[Am] .
1644 may be any of the following:
1645 .Bl -tag -width defined
1647 Takes a variable name as an argument and evaluates to true if the variable
1650 Takes a target name as an argument and evaluates to true if the target
1651 was specified as part of
1653 command line or was declared the default target (either implicitly or
1656 before the line containing the conditional.
1658 Takes a variable, with possible modifiers, and evaluates to true if
1659 the expansion of the variable would result in an empty string.
1661 Takes a file name as an argument and evaluates to true if the file exists.
1662 The file is searched for on the system search path (see
1665 Takes a target name as an argument and evaluates to true if the target
1668 Takes a target name as an argument and evaluates to true if the target
1669 has been defined and has commands associated with it.
1673 may also be an arithmetic or string comparison.
1674 Variable expansion is
1675 performed on both sides of the comparison, after which the integral
1676 values are compared.
1677 A value is interpreted as hexadecimal if it is
1678 preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1679 The standard C relational operators are all supported.
1681 variable expansion, either the left or right hand side of a
1685 operator is not an integral value, then
1686 string comparison is performed between the expanded
1688 If no relational operator is given, it is assumed that the expanded
1689 variable is being compared against 0 or an empty string in the case
1690 of a string comparison.
1694 is evaluating one of these conditional expressions, and it encounters
1695 a (white-space separated) word it doesn't recognize, either the
1699 expression is applied to it, depending on the form of the conditional.
1707 expression is applied.
1708 Similarly, if the form is
1711 .Ql Ic .ifnmake , the
1713 expression is applied.
1715 If the conditional evaluates to true the parsing of the makefile continues
1717 If it evaluates to false, the following lines are skipped.
1718 In both cases this continues until a
1724 For loops are typically used to apply a set of rules to a list of files.
1725 The syntax of a for loop is:
1727 .Bl -tag -compact -width Ds
1728 .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1735 is evaluated, it is split into words.
1736 On each iteration of the loop, one word is taken and assigned to each
1740 are substituted into the
1742 inside the body of the for loop.
1743 The number of words must come out even; that is, if there are three
1744 iteration variables, the number of words provided must be a multiple
1747 Comments begin with a hash
1749 character, anywhere but in a shell
1750 command line, and continue to the end of an unescaped new line.
1751 .Sh SPECIAL SOURCES (ATTRIBUTES)
1752 .Bl -tag -width .IGNOREx
1754 Target is never out of date, but always execute commands anyway.
1756 Ignore any errors from the commands associated with this target, exactly
1757 as if they all were preceded by a dash
1759 .\" .It Ic .INVISIBLE
1764 Mark all sources of this target as being up-to-date.
1766 Execute the commands associated with this target even if the
1770 options were specified.
1771 Normally used to mark recursive
1774 Create a meta file for the target, even if it is flagged as
1779 Usage in conjunction with
1781 is the most likely case.
1782 In "meta" mode, the target is out-of-date if the meta file is missing.
1784 Do not create a meta file for the target.
1785 Meta files are also not created for
1792 Ignore differences in commands when deciding if target is out of date.
1793 This is useful if the command contains a value which always changes.
1794 If the number of commands change, though, the target will still be out of date.
1795 The same effect applies to any command line that uses the variable
1797 which can be used for that purpose even when not otherwise needed or desired:
1798 .Bd -literal -offset indent
1800 skip-compare-for-some:
1801 @echo this will be compared
1802 @echo this will not ${.OODATE:M.NOMETA_CMP}
1803 @echo this will also be compared
1808 pattern suppresses any expansion of the unwanted variable.
1810 Do not search for the target in the directories specified by
1815 selects the first target it encounters as the default target to be built
1816 if no target was specified.
1817 This source prevents this target from being selected.
1819 If a target is marked with this attribute and
1821 can't figure out how to create it, it will ignore this fact and assume
1822 the file isn't needed or already exists.
1825 correspond to an actual file; it is always considered to be out of date,
1826 and will not be created with the
1829 Suffix-transformation rules are not applied to
1835 is interrupted, it normally removes any partially made targets.
1836 This source prevents the target from being removed.
1841 Do not echo any of the commands associated with this target, exactly
1842 as if they all were preceded by an at sign
1845 Turn the target into
1848 When the target is used as a source for another target, the other target
1849 acquires the commands, sources, and attributes (except for
1853 If the target already has commands, the
1855 target's commands are appended
1862 target commands to the target.
1866 appears in a dependency line, the sources that precede it are
1867 made before the sources that succeed it in the line.
1868 Since the dependents of files are not made until the file itself
1869 could be made, this also stops the dependents being built unless they
1870 are needed for another branch of the dependency tree.
1883 the output is always
1889 The ordering imposed by
1891 is only relevant for parallel makes.
1894 Special targets may not be included with other targets, i.e. they must be
1895 the only target specified.
1896 .Bl -tag -width .BEGINx
1898 Any command lines attached to this target are executed before anything
1903 rule for any target (that was used only as a
1906 can't figure out any other way to create.
1907 Only the shell script is used.
1910 variable of a target that inherits
1913 to the target's own name.
1915 Any command lines attached to this target are executed after everything
1918 Any command lines attached to this target are executed when another target fails.
1921 variable is set to the target that failed.
1923 .Ic MAKE_PRINT_VAR_ON_ERROR .
1925 Mark each of the sources with the
1928 If no sources are specified, this is the equivalent of specifying the
1934 is interrupted, the commands for this target will be executed.
1936 If no target is specified when
1938 is invoked, this target will be built.
1940 This target provides a way to specify flags for
1942 when the makefile is used.
1943 The flags are as if typed to the shell, though the
1947 .\" XXX: NOT YET!!!!
1948 .\" .It Ic .NOTPARALLEL
1949 .\" The named targets are executed in non parallel mode.
1950 .\" If no targets are
1951 .\" specified, then all targets are executed in non parallel mode.
1955 attribute to any specified sources.
1957 Disable parallel mode.
1961 for compatibility with other pmake variants.
1963 The named targets are made in sequence.
1964 This ordering does not add targets to the list of targets to be made.
1965 Since the dependents of a target do not get built until the target itself
1966 could be built, unless
1968 is built by another part of the dependency graph,
1969 the following is a dependency loop:
1975 The ordering imposed by
1977 is only relevant for parallel makes.
1978 .\" XXX: NOT YET!!!!
1979 .\" .It Ic .PARALLEL
1980 .\" The named targets are executed in parallel mode.
1981 .\" If no targets are
1982 .\" specified, then all targets are executed in parallel mode.
1984 The sources are directories which are to be searched for files not
1985 found in the current directory.
1986 If no sources are specified, any previously specified directories are
1988 If the source is the special
1990 target, then the current working
1991 directory is searched last.
1992 .It Ic .PATH. Ns Va suffix
1995 but applies only to files with a particular suffix.
1996 The suffix must have been previously declared with
2001 attribute to any specified sources.
2005 attribute to any specified sources.
2006 If no sources are specified, the
2008 attribute is applied to every
2013 will use to execute commands.
2014 The sources are a set of
2017 .Bl -tag -width hasErrCtls
2019 This is the minimal specification, used to select one of the builtin
2026 Specifies the path to the shell.
2028 Indicates whether the shell supports exit on error.
2030 The command to turn on error checking.
2032 The command to disable error checking.
2034 The command to turn on echoing of commands executed.
2036 The command to turn off echoing of commands executed.
2038 The output to filter after issuing the
2041 It is typically identical to
2044 The flag to pass the shell to enable error checking.
2046 The flag to pass the shell to enable command echoing.
2048 The string literal to pass the shell that results in a single newline
2049 character when used outside of any quoting characters.
2053 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2054 check="set \-e" ignore="set +e" \e
2055 echo="set \-v" quiet="set +v" filter="set +v" \e
2056 echoFlag=v errFlag=e newline="'\en'"
2061 attribute to any specified sources.
2062 If no sources are specified, the
2064 attribute is applied to every
2065 command in the file.
2067 This target gets run when a dependency file contains stale entries, having
2069 set to the name of that dependency file.
2071 Each source specifies a suffix to
2073 If no sources are specified, any previously specified suffixes are deleted.
2074 It allows the creation of suffix-transformation rules.
2080 cc \-o ${.TARGET} \-c ${.IMPSRC}
2085 uses the following environment variables, if they exist:
2091 .Ev MAKEOBJDIRPREFIX ,
2097 .Ev MAKEOBJDIRPREFIX
2100 may only be set in the environment or on the command line to
2102 and not as makefile variables;
2103 see the description of
2107 .Bl -tag -width /usr/share/mk -compact
2109 list of dependencies
2111 list of dependencies
2113 list of dependencies
2117 system makefile directory
2120 The basic make syntax is compatible between different versions of make,
2121 however the special variables, variable modifiers and conditionals are not.
2123 The way that parallel makes are scheduled changed in
2125 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2126 The algorithms used may change again in the future.
2128 The way that .for loop variables are substituted changed after
2130 so that they still appear to be variable expansions.
2131 In particular this stops them being treated as syntax, and removes some
2132 obscure problems using them in .if statements.
2142 implementation is based on Adam De Boor's pmake program which was written
2143 for Sprite at Berkeley.
2144 It was designed to be a parallel distributed make running jobs on different
2145 machines using a daemon called
2148 Historically the target/dependency
2150 has been used to FoRCe rebuilding (since the target/dependency
2151 does not exist... unless someone creates an
2157 syntax is difficult to parse without actually acting of the data.
2158 For instance finding the end of a variable use should involve scanning each
2159 the modifiers using the correct terminator for each field.
2162 just counts {} and () in order to find the end of a variable expansion.
2164 There is no way of escaping a space character in a filename.