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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 .It Cm \&:N Ns Ar pattern
1081 This is identical to
1083 but selects all words which do not match
1086 Order every word in variable alphabetically.
1088 reverse order use the
1090 combination of modifiers.
1092 Randomize words in variable.
1093 The results will be different each time you are referring to the
1094 modified variable; use the assignment with expansion
1096 to prevent such behaviour.
1098 .Bd -literal -offset indent
1099 LIST= uno due tre quattro
1100 RANDOM_LIST= ${LIST:Ox}
1101 STATIC_RANDOM_LIST:= ${LIST:Ox}
1104 @echo "${RANDOM_LIST}"
1105 @echo "${RANDOM_LIST}"
1106 @echo "${STATIC_RANDOM_LIST}"
1107 @echo "${STATIC_RANDOM_LIST}"
1109 may produce output similar to:
1110 .Bd -literal -offset indent
1117 Quotes every shell meta-character in the variable, so that it can be passed
1118 safely through recursive invocations of
1121 Replaces each word in the variable with everything but its suffix.
1123 The value is a format string for
1128 Compute a 32bit hash of the value and encode it as hex digits.
1130 The value is a format string for
1135 Attempt to convert variable to an absolute path using
1137 if that fails, the value is unchanged.
1139 Converts variable to lower-case letters.
1140 .It Cm \&:ts Ns Ar c
1141 Words in the variable are normally separated by a space on expansion.
1142 This modifier sets the separator to the character
1146 is omitted, then no separator is used.
1147 The common escapes (including octal numeric codes), work as expected.
1149 Converts variable to upper-case letters.
1151 Causes the value to be treated as a single word
1152 (possibly containing embedded white space).
1156 Causes the value to be treated as a sequence of
1157 words delimited by white space.
1161 .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1163 Modify the first occurrence of
1165 in the variable's value, replacing it with
1169 is appended to the last slash of the pattern, all occurrences
1170 in each word are replaced.
1173 is appended to the last slash of the pattern, only the first word
1177 is appended to the last slash of the pattern,
1178 then the value is treated as a single word
1179 (possibly containing embedded white space).
1185 is anchored at the beginning of each word.
1188 ends with a dollar sign
1190 it is anchored at the end of each word.
1201 Any character may be used as a delimiter for the parts of the modifier
1203 The anchoring, ampersand and delimiter characters may be escaped with a
1207 Variable expansion occurs in the normal fashion inside both
1211 with the single exception that a backslash is used to prevent the expansion
1214 not a preceding dollar sign as is usual.
1216 .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1220 modifier is just like the
1222 modifier except that the old and new strings, instead of being
1223 simple strings, are a regular expression (see
1231 Normally, the first occurrence of the pattern
1233 in each word of the value is substituted with
1237 modifier causes the substitution to apply to at most one word; the
1239 modifier causes the substitution to apply to as many instances of the
1242 as occur in the word or words it is found in; the
1244 modifier causes the value to be treated as a single word
1245 (possibly containing embedded white space).
1250 are orthogonal; the former specifies whether multiple words are
1251 potentially affected, the latter whether multiple substitutions can
1252 potentially occur within each affected word.
1254 Replaces each word in the variable with its last component.
1256 Remove adjacent duplicate words (like
1259 .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1261 If the variable name (not its value), when parsed as a .if conditional
1262 expression, evaluates to true, return as its value the
1264 otherwise return the
1266 Since the variable name is used as the expression, \&:\&? must be the
1267 first modifier after the variable name itself - which will, of course,
1268 usually contain variable expansions.
1269 A common error is trying to use expressions like
1270 .Dl ${NUMBERS:M42:?match:no}
1271 which actually tests defined(NUMBERS),
1272 to determine is any words match "42" you need to use something like:
1273 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1274 .It Ar :old_string=new_string
1277 style variable substitution.
1278 It must be the last modifier specified.
1283 do not contain the pattern matching character
1285 then it is assumed that they are
1286 anchored at the end of each word, so only suffixes or entire
1287 words may be replaced.
1295 Variable expansion occurs in the normal fashion inside both
1299 with the single exception that a backslash is used to prevent the
1300 expansion of a dollar sign
1302 not a preceding dollar sign as is usual.
1304 .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1306 This is the loop expansion mechanism from the OSF Development
1307 Environment (ODE) make.
1310 loops expansion occurs at the time of
1314 to each word in the variable and evaluate
1316 The ODE convention is that
1318 should start and end with a period.
1320 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1322 However a single character variable is often more readable:
1323 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1324 .It Cm \&:U Ns Ar newval
1325 If the variable is undefined
1328 If the variable is defined, the existing value is returned.
1329 This is another ODE make feature.
1330 It is handy for setting per-target CFLAGS for instance:
1331 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1332 If a value is only required if the variable is undefined, use:
1333 .Dl ${VAR:D:Unewval}
1334 .It Cm \&:D Ns Ar newval
1335 If the variable is defined
1339 The name of the variable is the value.
1341 The path of the node which has the same name as the variable
1343 If no such node exists or its path is null, then the
1344 name of the variable is used.
1345 In order for this modifier to work, the name (node) must at least have
1346 appeared on the rhs of a dependency.
1348 .It Cm \&:\&! Ar cmd Cm \&!
1350 The output of running
1354 If the variable is non-empty it is run as a command and the output
1355 becomes the new value.
1356 .It Cm \&::= Ns Ar str
1357 The variable is assigned the value
1360 This modifier and its variations are useful in
1361 obscure situations such as wanting to set a variable when shell commands
1363 These assignment modifiers always expand to
1364 nothing, so if appearing in a rule line by themselves should be
1365 preceded with something to keep
1371 helps avoid false matches with the
1375 modifier and since substitution always occurs the
1377 form is vaguely appropriate.
1378 .It Cm \&::?= Ns Ar str
1381 but only if the variable does not already have a value.
1382 .It Cm \&::+= Ns Ar str
1386 .It Cm \&::!= Ns Ar cmd
1387 Assign the output of
1390 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1391 Selects one or more words from the value,
1392 or performs other operations related to the way in which the
1393 value is divided into words.
1395 Ordinarily, a value is treated as a sequence of words
1396 delimited by white space.
1397 Some modifiers suppress this behaviour,
1398 causing a value to be treated as a single word
1399 (possibly containing embedded white space).
1400 An empty value, or a value that consists entirely of white-space,
1401 is treated as a single word.
1402 For the purposes of the
1404 modifier, the words are indexed both forwards using positive integers
1405 (where index 1 represents the first word),
1406 and backwards using negative integers
1407 (where index \-1 represents the last word).
1411 is subjected to variable expansion, and the expanded result is
1412 then interpreted as follows:
1413 .Bl -tag -width index
1416 Selects a single word from the value.
1418 .It Ar start Ns Cm \&.. Ns Ar end
1419 Selects all words from
1426 selects all words from the second word to the last word.
1431 then the words are output in reverse order.
1434 selects all the words from last to first.
1437 Causes subsequent modifiers to treat the value as a single word
1438 (possibly containing embedded white space).
1439 Analogous to the effect of
1448 Causes subsequent modifiers to treat the value as a sequence of words
1449 delimited by white space.
1450 Analogous to the effect of
1455 Returns the number of words in the value.
1458 .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1459 Makefile inclusion, conditional structures and for loops reminiscent
1460 of the C programming language are provided in
1462 All such structures are identified by a line beginning with a single
1466 Files are included with either
1467 .Cm \&.include Aq Ar file
1469 .Cm \&.include Pf \*q Ar file Ns \*q .
1470 Variables between the angle brackets or double quotes are expanded
1471 to form the file name.
1472 If angle brackets are used, the included makefile is expected to be in
1473 the system makefile directory.
1474 If double quotes are used, the including makefile's directory and any
1475 directories specified using the
1477 option are searched before the system
1479 For compatibility with other versions of
1481 .Ql include file ...
1483 If the include statement is written as
1487 then errors locating and/or opening include files are ignored.
1489 Conditional expressions are also preceded by a single dot as the first
1490 character of a line.
1491 The possible conditionals are as follows:
1493 .It Ic .error Ar message
1494 The message is printed along with the name of the makefile and line number,
1498 .It Ic .export Ar variable ...
1499 Export the specified global variable.
1500 If no variable list is provided, all globals are exported
1501 except for internal variables (those that start with
1503 This is not affected by the
1505 flag, so should be used with caution.
1506 For compatibility with other
1509 .Ql export variable=value
1512 Appending a variable name to
1514 is equivalent to exporting a variable.
1515 .It Ic .export-env Ar variable ...
1518 except that the variable is not appended to
1519 .Va .MAKE.EXPORTED .
1520 This allows exporting a value to the environment which is different from that
1524 .It Ic .info Ar message
1525 The message is printed along with the name of the makefile and line number.
1526 .It Ic .undef Ar variable
1527 Un-define the specified global variable.
1528 Only global variables may be un-defined.
1529 .It Ic .unexport Ar variable ...
1532 The specified global
1534 will be removed from
1535 .Va .MAKE.EXPORTED .
1536 If no variable list is provided, all globals are unexported,
1540 .It Ic .unexport-env
1541 Unexport all globals previously exported and
1542 clear the environment inherited from the parent.
1543 This operation will cause a memory leak of the original environment,
1544 so should be used sparingly.
1547 being 0, would make sense.
1548 Also note that any variables which originated in the parent environment
1549 should be explicitly preserved if desired.
1551 .Bd -literal -offset indent
1552 .Li .if ${.MAKE.LEVEL} == 0
1559 Would result in an environment containing only
1561 which is the minimal useful environment.
1564 will also be pushed into the new environment.
1565 .It Ic .warning Ar message
1566 The message prefixed by
1568 is printed along with the name of the makefile and line number.
1569 .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1570 Test the value of an expression.
1571 .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1572 Test the value of a variable.
1573 .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1574 Test the value of a variable.
1575 .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1576 Test the target being built.
1577 .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1578 Test the target being built.
1580 Reverse the sense of the last conditional.
1581 .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1586 .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1591 .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1596 .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1601 .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1607 End the body of the conditional.
1612 may be any one of the following:
1613 .Bl -tag -width "Cm XX"
1616 .It Cm \&\*[Am]\*[Am]
1619 of higher precedence than
1625 will only evaluate a conditional as far as is necessary to determine
1627 Parentheses may be used to change the order of evaluation.
1628 The boolean operator
1630 may be used to logically negate an entire
1632 It is of higher precedence than
1633 .Ql Ic \&\*[Am]\*[Am] .
1637 may be any of the following:
1638 .Bl -tag -width defined
1640 Takes a variable name as an argument and evaluates to true if the variable
1643 Takes a target name as an argument and evaluates to true if the target
1644 was specified as part of
1646 command line or was declared the default target (either implicitly or
1649 before the line containing the conditional.
1651 Takes a variable, with possible modifiers, and evaluates to true if
1652 the expansion of the variable would result in an empty string.
1654 Takes a file name as an argument and evaluates to true if the file exists.
1655 The file is searched for on the system search path (see
1658 Takes a target name as an argument and evaluates to true if the target
1661 Takes a target name as an argument and evaluates to true if the target
1662 has been defined and has commands associated with it.
1666 may also be an arithmetic or string comparison.
1667 Variable expansion is
1668 performed on both sides of the comparison, after which the integral
1669 values are compared.
1670 A value is interpreted as hexadecimal if it is
1671 preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1672 The standard C relational operators are all supported.
1674 variable expansion, either the left or right hand side of a
1678 operator is not an integral value, then
1679 string comparison is performed between the expanded
1681 If no relational operator is given, it is assumed that the expanded
1682 variable is being compared against 0 or an empty string in the case
1683 of a string comparison.
1687 is evaluating one of these conditional expressions, and it encounters
1688 a (white-space separated) word it doesn't recognize, either the
1692 expression is applied to it, depending on the form of the conditional.
1700 expression is applied.
1701 Similarly, if the form is
1704 .Ql Ic .ifnmake , the
1706 expression is applied.
1708 If the conditional evaluates to true the parsing of the makefile continues
1710 If it evaluates to false, the following lines are skipped.
1711 In both cases this continues until a
1717 For loops are typically used to apply a set of rules to a list of files.
1718 The syntax of a for loop is:
1720 .Bl -tag -compact -width Ds
1721 .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1728 is evaluated, it is split into words.
1729 On each iteration of the loop, one word is taken and assigned to each
1733 are substituted into the
1735 inside the body of the for loop.
1736 The number of words must come out even; that is, if there are three
1737 iteration variables, the number of words provided must be a multiple
1740 Comments begin with a hash
1742 character, anywhere but in a shell
1743 command line, and continue to the end of an unescaped new line.
1744 .Sh SPECIAL SOURCES (ATTRIBUTES)
1745 .Bl -tag -width .IGNOREx
1747 Target is never out of date, but always execute commands anyway.
1749 Ignore any errors from the commands associated with this target, exactly
1750 as if they all were preceded by a dash
1752 .\" .It Ic .INVISIBLE
1757 Mark all sources of this target as being up-to-date.
1759 Execute the commands associated with this target even if the
1763 options were specified.
1764 Normally used to mark recursive
1767 Create a meta file for the target, even if it is flagged as
1772 Usage in conjunction with
1774 is the most likely case.
1775 In "meta" mode, the target is out-of-date if the meta file is missing.
1777 Do not create a meta file for the target.
1778 Meta files are also not created for
1785 Ignore differences in commands when deciding if target is out of date.
1786 This is useful if the command contains a value which always changes.
1787 If the number of commands change, though, the target will still be out of date.
1788 The same effect applies to any command line that uses the variable
1790 which can be used for that purpose even when not otherwise needed or desired:
1791 .Bd -literal -offset indent
1793 skip-compare-for-some:
1794 @echo this will be compared
1795 @echo this will not ${.OODATE:M.NOMETA_CMP}
1796 @echo this will also be compared
1801 pattern suppresses any expansion of the unwanted variable.
1803 Do not search for the target in the directories specified by
1808 selects the first target it encounters as the default target to be built
1809 if no target was specified.
1810 This source prevents this target from being selected.
1812 If a target is marked with this attribute and
1814 can't figure out how to create it, it will ignore this fact and assume
1815 the file isn't needed or already exists.
1818 correspond to an actual file; it is always considered to be out of date,
1819 and will not be created with the
1822 Suffix-transformation rules are not applied to
1828 is interrupted, it normally removes any partially made targets.
1829 This source prevents the target from being removed.
1834 Do not echo any of the commands associated with this target, exactly
1835 as if they all were preceded by an at sign
1838 Turn the target into
1841 When the target is used as a source for another target, the other target
1842 acquires the commands, sources, and attributes (except for
1846 If the target already has commands, the
1848 target's commands are appended
1855 target commands to the target.
1859 appears in a dependency line, the sources that precede it are
1860 made before the sources that succeed it in the line.
1861 Since the dependents of files are not made until the file itself
1862 could be made, this also stops the dependents being built unless they
1863 are needed for another branch of the dependency tree.
1876 the output is always
1882 The ordering imposed by
1884 is only relevant for parallel makes.
1887 Special targets may not be included with other targets, i.e. they must be
1888 the only target specified.
1889 .Bl -tag -width .BEGINx
1891 Any command lines attached to this target are executed before anything
1896 rule for any target (that was used only as a
1899 can't figure out any other way to create.
1900 Only the shell script is used.
1903 variable of a target that inherits
1906 to the target's own name.
1908 Any command lines attached to this target are executed after everything
1911 Any command lines attached to this target are executed when another target fails.
1914 variable is set to the target that failed.
1916 .Ic MAKE_PRINT_VAR_ON_ERROR .
1918 Mark each of the sources with the
1921 If no sources are specified, this is the equivalent of specifying the
1927 is interrupted, the commands for this target will be executed.
1929 If no target is specified when
1931 is invoked, this target will be built.
1933 This target provides a way to specify flags for
1935 when the makefile is used.
1936 The flags are as if typed to the shell, though the
1940 .\" XXX: NOT YET!!!!
1941 .\" .It Ic .NOTPARALLEL
1942 .\" The named targets are executed in non parallel mode.
1943 .\" If no targets are
1944 .\" specified, then all targets are executed in non parallel mode.
1948 attribute to any specified sources.
1950 Disable parallel mode.
1954 for compatibility with other pmake variants.
1956 The named targets are made in sequence.
1957 This ordering does not add targets to the list of targets to be made.
1958 Since the dependents of a target do not get built until the target itself
1959 could be built, unless
1961 is built by another part of the dependency graph,
1962 the following is a dependency loop:
1968 The ordering imposed by
1970 is only relevant for parallel makes.
1971 .\" XXX: NOT YET!!!!
1972 .\" .It Ic .PARALLEL
1973 .\" The named targets are executed in parallel mode.
1974 .\" If no targets are
1975 .\" specified, then all targets are executed in parallel mode.
1977 The sources are directories which are to be searched for files not
1978 found in the current directory.
1979 If no sources are specified, any previously specified directories are
1981 If the source is the special
1983 target, then the current working
1984 directory is searched last.
1985 .It Ic .PATH. Ns Va suffix
1988 but applies only to files with a particular suffix.
1989 The suffix must have been previously declared with
1994 attribute to any specified sources.
1998 attribute to any specified sources.
1999 If no sources are specified, the
2001 attribute is applied to every
2006 will use to execute commands.
2007 The sources are a set of
2010 .Bl -tag -width hasErrCtls
2012 This is the minimal specification, used to select one of the builtin
2019 Specifies the path to the shell.
2021 Indicates whether the shell supports exit on error.
2023 The command to turn on error checking.
2025 The command to disable error checking.
2027 The command to turn on echoing of commands executed.
2029 The command to turn off echoing of commands executed.
2031 The output to filter after issuing the
2034 It is typically identical to
2037 The flag to pass the shell to enable error checking.
2039 The flag to pass the shell to enable command echoing.
2041 The string literal to pass the shell that results in a single newline
2042 character when used outside of any quoting characters.
2046 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2047 check="set \-e" ignore="set +e" \e
2048 echo="set \-v" quiet="set +v" filter="set +v" \e
2049 echoFlag=v errFlag=e newline="'\en'"
2054 attribute to any specified sources.
2055 If no sources are specified, the
2057 attribute is applied to every
2058 command in the file.
2060 This target gets run when a dependency file contains stale entries, having
2062 set to the name of that dependency file.
2064 Each source specifies a suffix to
2066 If no sources are specified, any previously specified suffixes are deleted.
2067 It allows the creation of suffix-transformation rules.
2073 cc \-o ${.TARGET} \-c ${.IMPSRC}
2078 uses the following environment variables, if they exist:
2084 .Ev MAKEOBJDIRPREFIX ,
2090 .Ev MAKEOBJDIRPREFIX
2093 may only be set in the environment or on the command line to
2095 and not as makefile variables;
2096 see the description of
2100 .Bl -tag -width /usr/share/mk -compact
2102 list of dependencies
2104 list of dependencies
2106 list of dependencies
2110 system makefile directory
2113 The basic make syntax is compatible between different versions of make,
2114 however the special variables, variable modifiers and conditionals are not.
2116 The way that parallel makes are scheduled changed in
2118 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2119 The algorithms used may change again in the future.
2121 The way that .for loop variables are substituted changed after
2123 so that they still appear to be variable expansions.
2124 In particular this stops them being treated as syntax, and removes some
2125 obscure problems using them in .if statements.
2135 implementation is based on Adam De Boor's pmake program which was written
2136 for Sprite at Berkeley.
2137 It was designed to be a parallel distributed make running jobs on different
2138 machines using a daemon called
2141 Historically the target/dependency
2143 has been used to FoRCe rebuilding (since the target/dependency
2144 does not exist... unless someone creates an
2150 syntax is difficult to parse without actually acting of the data.
2151 For instance finding the end of a variable use should involve scanning each
2152 the modifiers using the correct terminator for each field.
2155 just counts {} and () in order to find the end of a variable expansion.
2157 There is no way of escaping a space character in a filename.