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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 Run shell commands with
215 so the actual commands are printed as they are executed.
218 Specify that environment variables override macro assignments within
221 Specify a makefile to read instead of the default
227 standard input is read.
228 Multiple makefiles may be specified, and are read in the order specified.
229 .It Fl I Ar directory
230 Specify a directory in which to search for makefiles and included makefiles.
231 The system makefile directory (or directories, see the
233 option) is automatically included as part of this list.
235 Ignore non-zero exit of shell commands in the makefile.
236 Equivalent to specifying
238 before each command line in the makefile.
242 be specified by the user.
246 option is in use in a recursive build, this option is passed by a make
247 to child makes to allow all the make processes in the build to
248 cooperate to avoid overloading the system.
250 Specify the maximum number of jobs that
252 may have running at any one time.
253 The value is saved in
255 Turns compatibility mode off, unless the
257 flag is also specified.
258 When compatibility mode is off, all commands associated with a
259 target are executed in a single shell invocation as opposed to the
260 traditional one shell invocation per line.
261 This can break traditional scripts which change directories on each
262 command invocation and then expect to start with a fresh environment
264 It is more efficient to correct the scripts rather than turn backwards
267 Continue processing after errors are encountered, but only on those targets
268 that do not depend on the target whose creation caused the error.
269 .It Fl m Ar directory
270 Specify a directory in which to search for sys.mk and makefiles included
272 .Ao Ar file Ac Ns -style
276 option can be used multiple times to form a search path.
277 This path will override the default system include path: /usr/share/mk.
278 Furthermore the system include path will be appended to the search path used
280 .Qo Ar file Qc Ns -style
281 include statements (see the
285 If a file or directory name in the
289 environment variable) starts with the string
293 will search for the specified file or directory named in the remaining part
294 of the argument string.
295 The search starts with the current directory of
296 the Makefile and then works upward towards the root of the filesystem.
297 If the search is successful, then the resulting directory replaces the
302 If used, this feature allows
304 to easily search in the current source tree for customized sys.mk files
309 Display the commands that would have been executed, but do not
310 actually execute them unless the target depends on the .MAKE special
313 Display the commands which would have been executed, but do not
314 actually execute any of them; useful for debugging top-level makefiles
315 without descending into subdirectories.
317 Do not execute any commands, but exit 0 if the specified targets are
318 up-to-date and 1, otherwise.
320 Do not use the built-in rules specified in the system makefile.
322 Do not echo any commands as they are executed.
323 Equivalent to specifying
325 before each command line in the makefile.
326 .It Fl T Ar tracefile
330 append a trace record to
332 for each job started and completed.
334 Rather than re-building a target as specified in the makefile, create it
335 or update its modification time to make it appear up-to-date.
341 in the global context.
342 Do not build any targets.
343 Multiple instances of this option may be specified;
344 the variables will be printed one per line,
345 with a blank line for each null or undefined variable.
350 then the value will be expanded before printing.
352 Treat any warnings during makefile parsing as errors.
354 Print entering and leaving directory messages, pre and post processing.
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
709 .It Va .INCLUDEDFROMDIR
710 The directory of the file this Makefile was included from.
711 .It Va .INCLUDEDFROMFILE
712 The filename of the file this Makefile was included from.
723 The preferred variable to use is the environment variable
725 because it is more compatible with other versions of
727 and cannot be confused with the special target with the same name.
728 .It Va .MAKE.DEPENDFILE
729 Names the makefile (default
731 from which generated dependencies are read.
732 .It Va .MAKE.EXPAND_VARIABLES
733 A boolean that controls the default behavior of the
736 .It Va .MAKE.EXPORTED
737 The list of variables exported by
743 .It Va .MAKE.JOB.PREFIX
748 then output for each target is prefixed with a token
750 the first part of which can be controlled via
751 .Va .MAKE.JOB.PREFIX .
754 is empty, no token is printed.
757 .Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
758 would produce tokens like
759 .Ql ---make[1234] target ---
760 making it easier to track the degree of parallelism being achieved.
762 The environment variable
764 may contain anything that
768 Anything specified on
770 command line is appended to the
772 variable which is then
773 entered into the environment for all programs which
777 The recursion depth of
779 The initial instance of
781 will be 0, and an incremented value is put into the environment
782 to be seen by the next generation.
783 This allows tests like:
784 .Li .if ${.MAKE.LEVEL} == 0
785 to protect things which should only be evaluated in the initial instance of
787 .It Va .MAKE.MAKEFILE_PREFERENCE
788 The ordered list of makefile names
795 .It Va .MAKE.MAKEFILES
796 The list of makefiles read by
798 which is useful for tracking dependencies.
799 Each makefile is recorded only once, regardless of the number of times read.
801 Processed after reading all makefiles.
802 Can affect the mode that
805 It can contain a number of keywords:
806 .Bl -hang -width ignore-cmd
816 into "meta" mode, where meta files are created for each target
817 to capture the command run, the output generated and if
819 is available, the system calls which are of interest to
821 The captured output can be very useful when diagnosing errors.
822 .It Pa curdirOk= Ar bf
825 will not create .meta files in
827 This can be overridden by setting
829 to a value which represents True.
831 For debugging, it can be useful to inlcude the environment
834 If in "meta" mode, print a clue about the target being built.
835 This is useful if the build is otherwise running silently.
836 The message printed the value of:
837 .Va .MAKE.META.PREFIX .
839 Some makefiles have commands which are simply not stable.
840 This keyword causes them to be ignored for
841 determining whether a target is out of date in "meta" mode.
847 is True, when a .meta file is created, mark the target
850 .It Va .MAKE.META.BAILIWICK
851 In "meta" mode, provides a list of prefixes which
852 match the directories controlled by
854 If a file that was generated outside of
856 but within said bailiwick is missing,
857 the current target is considered out-of-date.
858 .It Va .MAKE.META.CREATED
859 In "meta" mode, this variable contains a list of all the meta files
861 If not empty, it can be used to trigger processing of
862 .Va .MAKE.META.FILES .
863 .It Va .MAKE.META.FILES
864 In "meta" mode, this variable contains a list of all the meta files
865 used (updated or not).
866 This list can be used to process the meta files to extract dependency
868 .It Va .MAKE.META.IGNORE_PATHS
869 Provides a list of path prefixes that should be ignored;
870 because the contents are expected to change over time.
871 The default list includes:
872 .Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
873 .It Va .MAKE.META.PREFIX
874 Defines the message printed for each meta file updated in "meta verbose" mode.
875 The default value is:
876 .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
877 .It Va .MAKEOVERRIDES
878 This variable is used to record the names of variables assigned to
879 on the command line, so that they may be exported as part of
881 This behaviour can be disabled by assigning an empty value to
882 .Ql Va .MAKEOVERRIDES
884 Extra variables can be exported from a makefile
885 by appending their names to
886 .Ql Va .MAKEOVERRIDES .
888 is re-exported whenever
889 .Ql Va .MAKEOVERRIDES
891 .It Va .MAKE.PATH_FILEMON
896 support, this is set to the path of the device node.
897 This allows makefiles to test for this support.
902 The parent process-id of
904 .It Va .MAKE.BUILT.BY
905 The compiler CCVER that built the
908 .It Va .MAKE.DF.OSREL
911 version when the world was built. It is in the "<major>.<minor>"
912 format and it used by DPorts.
913 .It Va .MAKE.DF.VERSION
914 The value of __DragonFly_version when the
916 world was built. It is used by DPorts.
917 .It Va MAKE_PRINT_VAR_ON_ERROR
920 stops due to an error, it prints its name and the value of
922 as well as the value of any variables named in
923 .Ql Va MAKE_PRINT_VAR_ON_ERROR .
925 This variable is simply assigned a newline character as its value.
926 This allows expansions using the
928 modifier to put a newline between
929 iterations of the loop rather than a space.
930 For example, the printing of
931 .Ql Va MAKE_PRINT_VAR_ON_ERROR
932 could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
934 A path to the directory where the targets are built.
935 Its value is determined by trying to
937 to the following directories in order and using the first match:
940 .Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
943 .Ql Ev MAKEOBJDIRPREFIX
944 is set in the environment or on the command line.)
950 is set in the environment or on the command line.)
952 .Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
954 .Ev ${.CURDIR} Ns Pa /obj
956 .Pa /usr/obj/ Ns Ev ${.CURDIR}
961 Variable expansion is performed on the value before it's used,
962 so expressions such as
963 .Dl ${.CURDIR:S,^/usr/src,/var/obj,}
965 This is especially useful with
969 may be modified in the makefile as a global variable.
978 to that directory before executing any targets.
981 A path to the directory of the current
985 The basename of the current
990 are both set only while the
993 If you want to retain their current values, assign them to a variable
994 using assignment with expansion:
997 A variable that represents the list of directories that
999 will search for files.
1000 The search list should be updated using the target
1002 rather than the variable.
1004 Alternate path to the current directory.
1008 to the canonical path given by
1010 However, if the environment variable
1012 is set and gives a path to the current directory, then
1019 This behaviour is disabled if
1020 .Ql Ev MAKEOBJDIRPREFIX
1023 contains a variable transform.
1025 is set to the value of
1027 for all programs which
1031 The list of targets explicitly specified on the command line, if any.
1035 lists of directories that
1037 will search for files.
1038 The variable is supported for compatibility with old make programs only,
1043 .Ss Variable modifiers
1044 Variable expansion may be modified to select or modify each word of the
1047 is white-space delimited sequence of characters).
1048 The general format of a variable expansion is as follows:
1050 .Dl ${variable[:modifier[:...]]}
1052 Each modifier begins with a colon,
1053 which may be escaped with a backslash
1056 A set of modifiers can be specified via a variable, as follows:
1058 .Dl modifier_variable=modifier[:...]
1059 .Dl ${variable:${modifier_variable}[:...]}
1061 In this case the first modifier in the modifier_variable does not
1062 start with a colon, since that must appear in the referencing
1064 If any of the modifiers in the modifier_variable contain a dollar sign
1066 these must be doubled to avoid early expansion.
1068 The supported modifiers are:
1071 Replaces each word in the variable with its suffix.
1073 Replaces each word in the variable with everything but the last component.
1074 .It Cm \&:M Ns Ar pattern
1075 Select only those words that match
1077 The standard shell wildcard characters
1084 The wildcard characters may be escaped with a backslash
1086 As a consequence of the way values are split into words, matched,
1087 and then joined, a construct like
1089 will normalise the inter-word spacing, removing all leading and
1090 trailing space, and converting multiple consecutive spaces
1093 .It Cm \&:N Ns Ar pattern
1094 This is identical to
1096 but selects all words which do not match
1099 Order every word in variable alphabetically.
1101 reverse order use the
1103 combination of modifiers.
1105 Randomize words in variable.
1106 The results will be different each time you are referring to the
1107 modified variable; use the assignment with expansion
1109 to prevent such behaviour.
1111 .Bd -literal -offset indent
1112 LIST= uno due tre quattro
1113 RANDOM_LIST= ${LIST:Ox}
1114 STATIC_RANDOM_LIST:= ${LIST:Ox}
1117 @echo "${RANDOM_LIST}"
1118 @echo "${RANDOM_LIST}"
1119 @echo "${STATIC_RANDOM_LIST}"
1120 @echo "${STATIC_RANDOM_LIST}"
1122 may produce output similar to:
1123 .Bd -literal -offset indent
1130 Quotes every shell meta-character in the variable, so that it can be passed
1131 safely through recursive invocations of
1134 Replaces each word in the variable with everything but its suffix.
1136 The value is a format string for
1141 Compute a 32bit hash of the value and encode it as hex digits.
1143 The value is a format string for
1148 Attempt to convert variable to an absolute path using
1150 if that fails, the value is unchanged.
1152 Converts variable to lower-case letters.
1153 .It Cm \&:ts Ns Ar c
1154 Words in the variable are normally separated by a space on expansion.
1155 This modifier sets the separator to the character
1159 is omitted, then no separator is used.
1160 The common escapes (including octal numeric codes), work as expected.
1162 Converts variable to upper-case letters.
1164 Causes the value to be treated as a single word
1165 (possibly containing embedded white space).
1169 Causes the value to be treated as a sequence of
1170 words delimited by white space.
1174 .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1176 Modify the first occurrence of
1178 in the variable's value, replacing it with
1182 is appended to the last slash of the pattern, all occurrences
1183 in each word are replaced.
1186 is appended to the last slash of the pattern, only the first word
1190 is appended to the last slash of the pattern,
1191 then the value is treated as a single word
1192 (possibly containing embedded white space).
1198 is anchored at the beginning of each word.
1201 ends with a dollar sign
1203 it is anchored at the end of each word.
1214 Any character may be used as a delimiter for the parts of the modifier
1216 The anchoring, ampersand and delimiter characters may be escaped with a
1220 Variable expansion occurs in the normal fashion inside both
1224 with the single exception that a backslash is used to prevent the expansion
1227 not a preceding dollar sign as is usual.
1229 .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1233 modifier is just like the
1235 modifier except that the old and new strings, instead of being
1236 simple strings, are an extended regular expression (see
1244 Normally, the first occurrence of the pattern
1246 in each word of the value is substituted with
1250 modifier causes the substitution to apply to at most one word; the
1252 modifier causes the substitution to apply to as many instances of the
1255 as occur in the word or words it is found in; the
1257 modifier causes the value to be treated as a single word
1258 (possibly containing embedded white space).
1263 are orthogonal; the former specifies whether multiple words are
1264 potentially affected, the latter whether multiple substitutions can
1265 potentially occur within each affected word.
1273 are subjected to variable expansion before being parsed as
1274 regular expressions.
1276 Replaces each word in the variable with its last component.
1278 Remove adjacent duplicate words (like
1281 .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1283 If the variable name (not its value), when parsed as a .if conditional
1284 expression, evaluates to true, return as its value the
1286 otherwise return the
1288 Since the variable name is used as the expression, \&:\&? must be the
1289 first modifier after the variable name itself - which will, of course,
1290 usually contain variable expansions.
1291 A common error is trying to use expressions like
1292 .Dl ${NUMBERS:M42:?match:no}
1293 which actually tests defined(NUMBERS),
1294 to determine is any words match "42" you need to use something like:
1295 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1296 .It Ar :old_string=new_string
1299 style variable substitution.
1300 It must be the last modifier specified.
1305 do not contain the pattern matching character
1307 then it is assumed that they are
1308 anchored at the end of each word, so only suffixes or entire
1309 words may be replaced.
1317 Variable expansion occurs in the normal fashion inside both
1321 with the single exception that a backslash is used to prevent the
1322 expansion of a dollar sign
1324 not a preceding dollar sign as is usual.
1326 .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1328 This is the loop expansion mechanism from the OSF Development
1329 Environment (ODE) make.
1332 loops expansion occurs at the time of
1336 to each word in the variable and evaluate
1338 The ODE convention is that
1340 should start and end with a period.
1342 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1344 However a single character variable is often more readable:
1345 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1346 .It Cm \&:U Ns Ar newval
1347 If the variable is undefined
1350 If the variable is defined, the existing value is returned.
1351 This is another ODE make feature.
1352 It is handy for setting per-target CFLAGS for instance:
1353 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1354 If a value is only required if the variable is undefined, use:
1355 .Dl ${VAR:D:Unewval}
1356 .It Cm \&:D Ns Ar newval
1357 If the variable is defined
1361 The name of the variable is the value.
1363 The path of the node which has the same name as the variable
1365 If no such node exists or its path is null, then the
1366 name of the variable is used.
1367 In order for this modifier to work, the name (node) must at least have
1368 appeared on the rhs of a dependency.
1370 .It Cm \&:\&! Ar cmd Cm \&!
1372 The output of running
1376 If the variable is non-empty it is run as a command and the output
1377 becomes the new value.
1378 .It Cm \&::= Ns Ar str
1379 The variable is assigned the value
1382 This modifier and its variations are useful in
1383 obscure situations such as wanting to set a variable when shell commands
1385 These assignment modifiers always expand to
1386 nothing, so if appearing in a rule line by themselves should be
1387 preceded with something to keep
1393 helps avoid false matches with the
1397 modifier and since substitution always occurs the
1399 form is vaguely appropriate.
1400 .It Cm \&::?= Ns Ar str
1403 but only if the variable does not already have a value.
1404 .It Cm \&::+= Ns Ar str
1408 .It Cm \&::!= Ns Ar cmd
1409 Assign the output of
1412 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1413 Selects one or more words from the value,
1414 or performs other operations related to the way in which the
1415 value is divided into words.
1417 Ordinarily, a value is treated as a sequence of words
1418 delimited by white space.
1419 Some modifiers suppress this behaviour,
1420 causing a value to be treated as a single word
1421 (possibly containing embedded white space).
1422 An empty value, or a value that consists entirely of white-space,
1423 is treated as a single word.
1424 For the purposes of the
1426 modifier, the words are indexed both forwards using positive integers
1427 (where index 1 represents the first word),
1428 and backwards using negative integers
1429 (where index \-1 represents the last word).
1433 is subjected to variable expansion, and the expanded result is
1434 then interpreted as follows:
1435 .Bl -tag -width index
1438 Selects a single word from the value.
1440 .It Ar start Ns Cm \&.. Ns Ar end
1441 Selects all words from
1448 selects all words from the second word to the last word.
1453 then the words are output in reverse order.
1456 selects all the words from last to first.
1459 Causes subsequent modifiers to treat the value as a single word
1460 (possibly containing embedded white space).
1461 Analogous to the effect of
1470 Causes subsequent modifiers to treat the value as a sequence of words
1471 delimited by white space.
1472 Analogous to the effect of
1477 Returns the number of words in the value.
1480 .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1481 Makefile inclusion, conditional structures and for loops reminiscent
1482 of the C programming language are provided in
1484 All such structures are identified by a line beginning with a single
1488 Files are included with either
1489 .Cm \&.include Aq Ar file
1491 .Cm \&.include Pf \*q Ar file Ns \*q .
1492 Variables between the angle brackets or double quotes are expanded
1493 to form the file name.
1494 If angle brackets are used, the included makefile is expected to be in
1495 the system makefile directory.
1496 If double quotes are used, the including makefile's directory and any
1497 directories specified using the
1499 option are searched before the system
1501 For compatibility with other versions of
1503 .Ql include file ...
1505 If the include statement is written as
1509 then errors locating and/or opening include files are ignored.
1511 Conditional expressions are also preceded by a single dot as the first
1512 character of a line.
1513 The possible conditionals are as follows:
1515 .It Ic .error Ar message
1516 The message is printed along with the name of the makefile and line number,
1520 .It Ic .export Ar variable ...
1521 Export the specified global variable.
1522 If no variable list is provided, all globals are exported
1523 except for internal variables (those that start with
1525 This is not affected by the
1527 flag, so should be used with caution.
1528 For compatibility with other
1531 .Ql export variable=value
1534 Appending a variable name to
1536 is equivalent to exporting a variable.
1537 .It Ic .export-env Ar variable ...
1540 except that the variable is not appended to
1541 .Va .MAKE.EXPORTED .
1542 This allows exporting a value to the environment which is different from that
1546 .It Ic .info Ar message
1547 The message is printed along with the name of the makefile and line number.
1548 .It Ic .undef Ar variable
1549 Un-define the specified global variable.
1550 Only global variables may be un-defined.
1551 .It Ic .unexport Ar variable ...
1554 The specified global
1556 will be removed from
1557 .Va .MAKE.EXPORTED .
1558 If no variable list is provided, all globals are unexported,
1562 .It Ic .unexport-env
1563 Unexport all globals previously exported and
1564 clear the environment inherited from the parent.
1565 This operation will cause a memory leak of the original environment,
1566 so should be used sparingly.
1569 being 0, would make sense.
1570 Also note that any variables which originated in the parent environment
1571 should be explicitly preserved if desired.
1573 .Bd -literal -offset indent
1574 .Li .if ${.MAKE.LEVEL} == 0
1581 Would result in an environment containing only
1583 which is the minimal useful environment.
1586 will also be pushed into the new environment.
1587 .It Ic .warning Ar message
1588 The message prefixed by
1590 is printed along with the name of the makefile and line number.
1591 .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1592 Test the value of an expression.
1593 .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1594 Test the value of a variable.
1595 .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1596 Test the value of a variable.
1597 .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1598 Test the target being built.
1599 .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1600 Test the target being built.
1602 Reverse the sense of the last conditional.
1603 .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1608 .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1613 .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1618 .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1623 .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1629 End the body of the conditional.
1634 may be any one of the following:
1635 .Bl -tag -width "Cm XX"
1638 .It Cm \&\*[Am]\*[Am]
1641 of higher precedence than
1647 will only evaluate a conditional as far as is necessary to determine
1649 Parentheses may be used to change the order of evaluation.
1650 The boolean operator
1652 may be used to logically negate an entire
1654 It is of higher precedence than
1655 .Ql Ic \&\*[Am]\*[Am] .
1659 may be any of the following:
1660 .Bl -tag -width defined
1662 Takes a variable name as an argument and evaluates to true if the variable
1665 Takes a target name as an argument and evaluates to true if the target
1666 was specified as part of
1668 command line or was declared the default target (either implicitly or
1671 before the line containing the conditional.
1673 Takes a variable, with possible modifiers, and evaluates to true if
1674 the expansion of the variable would result in an empty string.
1676 Takes a file name as an argument and evaluates to true if the file exists.
1677 The file is searched for on the system search path (see
1680 Takes a target name as an argument and evaluates to true if the target
1683 Takes a target name as an argument and evaluates to true if the target
1684 has been defined and has commands associated with it.
1688 may also be an arithmetic or string comparison.
1689 Variable expansion is
1690 performed on both sides of the comparison, after which the integral
1691 values are compared.
1692 A value is interpreted as hexadecimal if it is
1693 preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1694 The standard C relational operators are all supported.
1696 variable expansion, either the left or right hand side of a
1700 operator is not an integral value, then
1701 string comparison is performed between the expanded
1703 If no relational operator is given, it is assumed that the expanded
1704 variable is being compared against 0 or an empty string in the case
1705 of a string comparison.
1709 is evaluating one of these conditional expressions, and it encounters
1710 a (white-space separated) word it doesn't recognize, either the
1714 expression is applied to it, depending on the form of the conditional.
1722 expression is applied.
1723 Similarly, if the form is
1726 .Ql Ic .ifnmake , the
1728 expression is applied.
1730 If the conditional evaluates to true the parsing of the makefile continues
1732 If it evaluates to false, the following lines are skipped.
1733 In both cases this continues until a
1739 For loops are typically used to apply a set of rules to a list of files.
1740 The syntax of a for loop is:
1742 .Bl -tag -compact -width Ds
1743 .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1750 is evaluated, it is split into words.
1751 On each iteration of the loop, one word is taken and assigned to each
1755 are substituted into the
1757 inside the body of the for loop.
1758 The number of words must come out even; that is, if there are three
1759 iteration variables, the number of words provided must be a multiple
1762 Comments begin with a hash
1764 character, anywhere but in a shell
1765 command line, and continue to the end of an unescaped new line.
1766 .Sh SPECIAL SOURCES (ATTRIBUTES)
1767 .Bl -tag -width .IGNOREx
1769 Target is never out of date, but always execute commands anyway.
1771 Ignore any errors from the commands associated with this target, exactly
1772 as if they all were preceded by a dash
1774 .\" .It Ic .INVISIBLE
1779 Mark all sources of this target as being up-to-date.
1781 Execute the commands associated with this target even if the
1785 options were specified.
1786 Normally used to mark recursive
1789 Create a meta file for the target, even if it is flagged as
1794 Usage in conjunction with
1796 is the most likely case.
1797 In "meta" mode, the target is out-of-date if the meta file is missing.
1799 Do not create a meta file for the target.
1800 Meta files are also not created for
1807 Ignore differences in commands when deciding if target is out of date.
1808 This is useful if the command contains a value which always changes.
1809 If the number of commands change, though, the target will still be out of date.
1810 The same effect applies to any command line that uses the variable
1812 which can be used for that purpose even when not otherwise needed or desired:
1813 .Bd -literal -offset indent
1815 skip-compare-for-some:
1816 @echo this will be compared
1817 @echo this will not ${.OODATE:M.NOMETA_CMP}
1818 @echo this will also be compared
1823 pattern suppresses any expansion of the unwanted variable.
1825 Do not search for the target in the directories specified by
1830 selects the first target it encounters as the default target to be built
1831 if no target was specified.
1832 This source prevents this target from being selected.
1834 If a target is marked with this attribute and
1836 can't figure out how to create it, it will ignore this fact and assume
1837 the file isn't needed or already exists.
1840 correspond to an actual file; it is always considered to be out of date,
1841 and will not be created with the
1844 Suffix-transformation rules are not applied to
1850 is interrupted, it normally removes any partially made targets.
1851 This source prevents the target from being removed.
1856 Do not echo any of the commands associated with this target, exactly
1857 as if they all were preceded by an at sign
1860 Turn the target into
1863 When the target is used as a source for another target, the other target
1864 acquires the commands, sources, and attributes (except for
1868 If the target already has commands, the
1870 target's commands are appended
1877 target commands to the target.
1881 appears in a dependency line, the sources that precede it are
1882 made before the sources that succeed it in the line.
1883 Since the dependents of files are not made until the file itself
1884 could be made, this also stops the dependents being built unless they
1885 are needed for another branch of the dependency tree.
1898 the output is always
1904 The ordering imposed by
1906 is only relevant for parallel makes.
1909 Special targets may not be included with other targets, i.e. they must be
1910 the only target specified.
1911 .Bl -tag -width .BEGINx
1913 Any command lines attached to this target are executed before anything
1918 rule for any target (that was used only as a
1921 can't figure out any other way to create.
1922 Only the shell script is used.
1925 variable of a target that inherits
1928 to the target's own name.
1930 Any command lines attached to this target are executed after everything
1933 Any command lines attached to this target are executed when another target fails.
1936 variable is set to the target that failed.
1938 .Ic MAKE_PRINT_VAR_ON_ERROR .
1940 Mark each of the sources with the
1943 If no sources are specified, this is the equivalent of specifying the
1949 is interrupted, the commands for this target will be executed.
1951 If no target is specified when
1953 is invoked, this target will be built.
1955 This target provides a way to specify flags for
1957 when the makefile is used.
1958 The flags are as if typed to the shell, though the
1962 .\" XXX: NOT YET!!!!
1963 .\" .It Ic .NOTPARALLEL
1964 .\" The named targets are executed in non parallel mode.
1965 .\" If no targets are
1966 .\" specified, then all targets are executed in non parallel mode.
1970 attribute to any specified sources.
1972 Disable parallel mode.
1976 for compatibility with other pmake variants.
1978 The named targets are made in sequence.
1979 This ordering does not add targets to the list of targets to be made.
1980 Since the dependents of a target do not get built until the target itself
1981 could be built, unless
1983 is built by another part of the dependency graph,
1984 the following is a dependency loop:
1990 The ordering imposed by
1992 is only relevant for parallel makes.
1993 .\" XXX: NOT YET!!!!
1994 .\" .It Ic .PARALLEL
1995 .\" The named targets are executed in parallel mode.
1996 .\" If no targets are
1997 .\" specified, then all targets are executed in parallel mode.
1999 The sources are directories which are to be searched for files not
2000 found in the current directory.
2001 If no sources are specified, any previously specified directories are
2003 If the source is the special
2005 target, then the current working
2006 directory is searched last.
2007 .It Ic .PATH. Ns Va suffix
2010 but applies only to files with a particular suffix.
2011 The suffix must have been previously declared with
2016 attribute to any specified sources.
2020 attribute to any specified sources.
2021 If no sources are specified, the
2023 attribute is applied to every
2028 will use to execute commands.
2029 The sources are a set of
2032 .Bl -tag -width hasErrCtls
2034 This is the minimal specification, used to select one of the builtin
2041 Specifies the path to the shell.
2043 Indicates whether the shell supports exit on error.
2045 The command to turn on error checking.
2047 The command to disable error checking.
2049 The command to turn on echoing of commands executed.
2051 The command to turn off echoing of commands executed.
2053 The output to filter after issuing the
2056 It is typically identical to
2059 The flag to pass the shell to enable error checking.
2061 The flag to pass the shell to enable command echoing.
2063 The string literal to pass the shell that results in a single newline
2064 character when used outside of any quoting characters.
2068 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2069 check="set \-e" ignore="set +e" \e
2070 echo="set \-v" quiet="set +v" filter="set +v" \e
2071 echoFlag=v errFlag=e newline="'\en'"
2076 attribute to any specified sources.
2077 If no sources are specified, the
2079 attribute is applied to every
2080 command in the file.
2082 This target gets run when a dependency file contains stale entries, having
2084 set to the name of that dependency file.
2086 Each source specifies a suffix to
2088 If no sources are specified, any previously specified suffixes are deleted.
2089 It allows the creation of suffix-transformation rules.
2095 cc \-o ${.TARGET} \-c ${.IMPSRC}
2100 uses the following environment variables, if they exist:
2106 .Ev MAKEOBJDIRPREFIX ,
2112 .Ev MAKEOBJDIRPREFIX
2115 may only be set in the environment or on the command line to
2117 and not as makefile variables;
2118 see the description of
2122 .Bl -tag -width /usr/share/mk -compact
2124 list of dependencies
2126 list of dependencies
2128 list of dependencies
2132 system makefile directory
2135 The basic make syntax is compatible between different versions of make,
2136 however the special variables, variable modifiers and conditionals are not.
2138 The way that parallel makes are scheduled changed in
2140 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2141 The algorithms used may change again in the future.
2143 The way that .for loop variables are substituted changed after
2145 so that they still appear to be variable expansions.
2146 In particular this stops them being treated as syntax, and removes some
2147 obscure problems using them in .if statements.
2152 is derived from NetBSD
2154 It uses autoconf to facilitate portability to other platforms.
2162 implementation is based on Adam De Boor's pmake program which was written
2163 for Sprite at Berkeley.
2164 It was designed to be a parallel distributed make running jobs on different
2165 machines using a daemon called
2168 Historically the target/dependency
2170 has been used to FoRCe rebuilding (since the target/dependency
2171 does not exist... unless someone creates an
2177 syntax is difficult to parse without actually acting of the data.
2178 For instance finding the end of a variable use should involve scanning each
2179 the modifiers using the correct terminator for each field.
2182 just counts {} and () in order to find the end of a variable expansion.
2184 There is no way of escaping a space character in a filename.