1 .\" $NetBSD: make.1,v 1.371 2023/09/10 21:52:36 rillig Exp $
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18 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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30 .\" from: @(#)make.1 8.4 (Berkeley) 3/19/94
37 .Nd maintain program dependencies
52 .Op Ar variable\| Ns Cm \&= Ns Ar value
56 is a program designed to simplify the maintenance of other programs.
57 Its input is a list of specifications as to the files upon which programs
58 and other files depend.
67 in order to find the specifications.
70 exists, it is read, see
73 This manual page is intended as a reference document only.
74 For a more thorough description of
76 and makefiles, please refer to
77 .%T "PMake \- A Tutorial"
81 prepends the contents of the
83 environment variable to the command line arguments before parsing them.
85 The options are as follows:
88 Try to be backwards compatible by executing a single shell per command and
89 by making the sources of a dependency line in sequence.
93 before reading the makefiles or doing anything else.
96 options are specified, each is interpreted relative to the previous one:
97 .Fl C Pa / Fl C Pa etc
103 to be 1, in the global scope.
104 .It Fl d Oo Cm \- Oc Ns Ar flags
105 Turn on debugging, and specify which portions of
107 are to print debugging information.
108 Unless the flags are preceded by
110 they are added to the
112 environment variable and are passed on to any child make processes.
113 By default, debugging information is printed to standard error,
114 but this can be changed using the
117 The debugging output is always unbuffered; in addition, if debugging
118 is enabled but debugging output is not directed to standard output,
119 the standard output is line buffered.
125 Print all possible debugging information;
126 equivalent to specifying all of the debugging flags.
128 Print debugging information about archive searching and caching.
130 Print debugging information about the current working directory.
132 Print debugging information about conditional evaluation.
134 Print debugging information about directory searching and caching.
136 Print debugging information about failed commands and targets.
137 .It Cm F Ns Oo Cm \&+ Oc Ns Ar filename
138 Specify where debugging output is written.
139 This must be the last flag, because it consumes the remainder of
141 If the character immediately after the
145 the file is opened in append mode;
146 otherwise the file is overwritten.
151 debugging output is written to the standard output or standard error output
152 respectively (and the
154 option has no effect).
155 Otherwise, the output is written to the named file.
156 If the file name ends with
160 is replaced by the pid.
162 Print debugging information about loop evaluation.
164 Print the input graph before making anything.
166 Print the input graph after making everything, or before exiting
169 Print the input graph before exiting on error.
171 Print debugging information about hash table operations.
173 Print debugging information about running multiple shells.
176 This throws errors for variable assignments that do not parse correctly,
177 at the time of assignment, so the file and line number are available.
179 Print commands in Makefiles regardless of whether or not they are prefixed by
188 Print debugging information about
190 mode decisions about targets.
192 Print debugging information about making targets, including modification
195 Don't delete the temporary command scripts created when running commands.
196 These temporary scripts are created in the directory
199 environment variable, or in
203 is unset or set to the empty string.
204 The temporary scripts are created by
206 and have names of the form
209 This can create many files in
215 Print debugging information about makefile parsing.
217 Print debugging information about suffix-transformation rules.
219 Print debugging information about target list maintenance.
223 option to print raw values of variables,
224 overriding the default behavior set via
225 .Va .MAKE.EXPAND_VARIABLES .
227 Print debugging information about variable assignment and expansion.
229 Run shell commands with
231 so the actual commands are printed as they are executed.
234 Let environment variables override global variables within makefiles.
236 Specify a makefile to read instead of the default
244 standard input is read.
245 Multiple makefiles may be specified, and are read in the order specified.
246 .It Fl I Ar directory
247 Specify a directory in which to search for makefiles and included makefiles.
248 The system makefile directory (or directories, see the
250 option) is automatically included as part of this list.
252 Ignore non-zero exit of shell commands in the makefile.
253 Equivalent to specifying
255 before each command line in the makefile.
259 be specified by the user.
263 option is in use in a recursive build, this option is passed by a make
264 to child makes to allow all the make processes in the build to
265 cooperate to avoid overloading the system.
267 Specify the maximum number of jobs that
269 may have running at any one time.
272 is a floating point number, or ends with
274 then the value is multiplied by the number of CPUs reported online by
280 Turns compatibility mode off, unless the
282 option is also specified.
283 When compatibility mode is off, all commands associated with a
284 target are executed in a single shell invocation as opposed to the
285 traditional one shell invocation per line.
286 This can break traditional scripts which change directories on each
287 command invocation and then expect to start with a fresh environment
289 It is more efficient to correct the scripts rather than turn backwards
292 A job token pool with
294 tokens is used to control the total number of jobs running.
297 will wait for a token from the pool before running a new job.
299 Continue processing after errors are encountered, but only on those targets
300 that do not depend on the target whose creation caused the error.
301 .It Fl m Ar directory
302 Specify a directory in which to search for
304 and makefiles included via the
305 .Li \&< Ns Ar file Ns Li \&> Ns -style
309 option can be used multiple times to form a search path.
310 This path overrides the default system include path
312 Furthermore, the system include path is appended to the search path used for
313 .Li \*q Ns Ar file Ns Li \*q Ns -style
314 include statements (see the
317 The system include path can be referenced via the read-only variable
320 If a directory name in the
324 environment variable) starts with the string
327 searches for the specified file or directory named in the remaining part
328 of the argument string.
329 The search starts with the current directory
330 and then works upward towards the root of the file system.
331 If the search is successful, the resulting directory replaces the
338 to easily search in the current source tree for customized
340 files (e.g., by using
344 Display the commands that would have been executed, but do not
345 actually execute them unless the target depends on the
347 special source (see below) or the command is prefixed with
350 Display the commands that would have been executed,
351 but do not actually execute any of them;
352 useful for debugging top-level makefiles
353 without descending into subdirectories.
355 Do not execute any commands,
356 instead exit 0 if the specified targets are up to date, and 1 otherwise.
358 Do not use the built-in rules specified in the system makefile.
360 Stop processing if an error is encountered.
361 This is the default behavior and the opposite of
364 Do not echo any commands as they are executed.
365 Equivalent to specifying
367 before each command line in the makefile.
368 .It Fl T Ar tracefile
372 append a trace record to
374 for each job started and completed.
376 Rather than re-building a target as specified in the makefile, create it
377 or update its modification time to make it appear up-to-date.
381 Do not build any targets.
382 Multiple instances of this option may be specified;
383 the variables are printed one per line,
384 with a blank line for each null or undefined variable.
385 The value printed is extracted from the global scope after all
386 makefiles have been read.
388 By default, the raw variable contents (which may
389 include additional unexpanded variable references) are shown.
394 it is not interpreted as a variable name but rather as an expression.
395 Its value is expanded before printing.
396 The value is also expanded before printing if
397 .Va .MAKE.EXPAND_VARIABLES
398 is set to true and the
400 option has not been used to override it.
402 Note that loop-local and target-local variables, as well as values
403 taken temporarily by global variables during makefile processing, are
404 not accessible via this option.
407 debug mode can be used to see these at the cost of generating
408 substantial extraneous output.
412 but all printed variables are always expanded to their complete value.
413 The last occurrence of
417 decides whether all variables are expanded or not.
419 Treat any warnings during makefile parsing as errors.
421 Print entering and leaving directory messages, pre and post processing.
423 Don't export variables passed on the command line to the environment
425 Variables passed on the command line are still exported via the
427 environment variable.
428 This option may be useful on systems which have a small limit on the
429 size of command arguments.
430 .It Ar variable\| Ns Cm \&= Ns Ar value
431 Set the value of the variable
435 Normally, all values passed on the command line are also exported to
436 sub-makes in the environment.
439 flag disables this behavior.
440 Variable assignments should follow options for POSIX compatibility
441 but no ordering is enforced.
444 There are several different types of lines in a makefile: dependency
445 specifications, shell commands, variable assignments, include statements,
446 conditional directives, for loops, other directives, and comments.
448 Lines may be continued from one line to the next
449 by ending them with a backslash
451 The trailing newline character and initial whitespace on the following
452 line are compressed into a single space.
453 .Sh FILE DEPENDENCY SPECIFICATIONS
454 Dependency lines consist of one or more targets, an operator, and zero
456 This creates a relationship where the targets
458 on the sources and are customarily created from them.
459 A target is considered out of date if it does not exist,
460 or if its modification time is less than that of any of its sources.
461 An out-of-date target is re-created, but not until all sources
462 have been examined and themselves re-created as needed.
463 Three operators may be used:
466 Many dependency lines may name this target but only one may have
467 attached shell commands.
468 All sources named in all dependency lines are considered together,
469 and if needed the attached shell commands are run to create or
470 re-create the target.
473 is interrupted, the target is removed.
475 The same, but the target is always re-created whether or not it is out
478 Any dependency line may have attached shell commands, but each one
479 is handled independently: its sources are considered and the attached
480 shell commands are run if the target is out of date with respect to
481 (only) those sources.
482 Thus, different groups of the attached shell commands may be run
483 depending on the circumstances.
486 for dependency lines with no sources, the attached shell
487 commands are always run.
490 the target is not removed if
495 All dependency lines mentioning a particular target must use the same
498 Targets and sources may contain the shell wildcard values
509 may only be used as part of the final component of the target or source,
510 and only match existing files.
513 need not necessarily be used to describe existing files.
514 Expansion is in directory order, not alphabetically as done in the shell.
516 Each target may have associated with it one or more lines of shell commands,
517 normally used to create the target.
518 Each of the lines in this script
520 be preceded by a tab.
521 (For historical reasons, spaces are not accepted.)
522 While targets can occur in many dependency lines if desired,
523 by default only one of these rules may be followed by a creation script.
526 operator is used, however, all rules may include scripts,
527 and the respective scripts are executed in the order found.
529 Each line is treated as a separate shell command,
530 unless the end of line is escaped with a backslash
532 in which case that line and the next are combined.
533 If the first characters of the command are any combination of
538 the command is treated specially.
539 .Bl -tag -offset indent -width indent
541 causes the command not to be echoed before it is executed.
543 causes the command to be executed even when
546 This is similar to the effect of the
549 except that the effect can be limited to a single line of a script.
551 in compatibility mode
552 causes any non-zero exit status of the command line to be ignored.
557 is run in jobs mode with
559 the entire script for the target is fed to a single instance of the shell.
560 In compatibility (non-jobs) mode, each command is run in a separate process.
561 If the command contains any shell meta characters
562 .Pq Ql #=|^(){};&<>*?[]:$`\e\en ,
563 it is passed to the shell; otherwise
565 attempts direct execution.
566 If a line starts with
568 and the shell has ErrCtl enabled,
569 failure of the command line is ignored as in compatibility mode.
572 affects the entire job;
573 the script stops at the first command line that fails,
574 but the target is not deemed to have failed.
576 Makefiles should be written so that the mode of
578 operation does not change their behavior.
579 For example, any command which uses
583 without the intention of changing the directory for subsequent commands
584 should be put in parentheses so it executes in a subshell.
585 To force the use of a single shell, escape the line breaks so as to make
586 the whole script one command.
588 .Bd -literal -offset indent
589 avoid-chdir-side-effects:
590 @echo "Building $@ in $$(pwd)"
591 @(cd ${.CURDIR} && ${MAKE} $@)
592 @echo "Back in $$(pwd)"
594 ensure-one-shell-regardless-of-mode:
595 @echo "Building $@ in $$(pwd)"; \e
596 (cd ${.CURDIR} && ${MAKE} $@); \e
597 echo "Back in $$(pwd)"
602 changes the current working directory to
604 before executing any targets,
605 each child process starts with that as its current working directory.
606 .Sh VARIABLE ASSIGNMENTS
607 Variables in make behave much like macros in the C preprocessor.
609 Variable assignments have the form
610 .Sq Ar NAME Ar op Ar value ,
612 .Bl -tag -offset Ds -width Ds
614 is a single-word variable name,
615 consisting, by tradition, of all upper-case letters,
617 is one of the variable assignment operators described below, and
619 is interpreted according to the variable assignment operator.
628 .Ss Variable assignment operators
629 The five operators that assign values to variables are:
632 Assign the value to the variable.
633 Any previous value is overwritten.
635 Append the value to the current value of the variable,
636 separating them by a single space.
638 Assign the value to the variable if it is not already defined.
640 Expand the value, then assign it to the variable.
643 References to undefined variables are
646 This can cause problems when variable modifiers are used.
647 .\" See var-op-expand.mk, the section with LATER and INDIRECT.
649 Expand the value and pass it to the shell for execution,
650 then assign the output from the child's standard output to the variable.
651 Any newlines in the result are replaced with spaces.
653 .Ss Expansion of variables
654 In most contexts where variables are expanded,
656 expands to a single dollar sign.
657 In other contexts (most variable modifiers, string literals in conditions),
659 expands to a single dollar sign.
661 References to variables have the form
662 .Cm \&${ Ns Ar name Ns Oo Ns Cm \&: Ns Ar modifiers Oc Ns Cm \&}
664 .Cm \&$( Ns Ar name Ns Oo Ns Cm \&: Ns Ar modifiers Oc Ns Cm \&) .
665 If the variable name consists of only a single character
666 and the expression contains no modifiers,
667 the surrounding curly braces or parentheses are not required.
668 This shorter form is not recommended.
670 If the variable name contains a dollar, the name itself is expanded first.
671 This allows almost arbitrary variable names, however names containing dollar,
672 braces, parentheses or whitespace are really best avoided.
674 If the result of expanding a nested variable expression contains a dollar sign
676 the result is subject to further expansion.
678 Variable substitution occurs at four distinct times, depending on where
679 the variable is being used.
682 Variables in dependency lines are expanded as the line is read.
684 Variables in conditionals are expanded individually,
685 but only as far as necessary to determine the result of the conditional.
687 Variables in shell commands are expanded when the shell command is
691 loop index variables are expanded on each loop iteration.
692 Note that other variables are not expanded when composing the body of a loop,
693 so the following example code:
694 .Bd -literal -offset indent
707 .Bd -literal -offset indent
712 After the loop is executed:
713 .Bl -tag -offset indent -width indent
716 .Ql ${:U1} ${:U2} ${:U3} ,
728 .Ql ${:U3} ${:U3} ${:U3}
734 The four different classes of variables (in order of increasing precedence)
737 .It Environment variables
738 Variables defined as part of
742 Variables defined in the makefile or in included makefiles.
743 .It Command line variables
744 Variables defined as part of the command line.
746 Variables that are defined specific to a certain target.
749 Local variables can be set on a dependency line, unless
750 .Va .MAKE.TARGET_LOCAL_VARIABLES
754 (which already has had global variables expanded)
755 is the variable value.
757 .Bd -literal -offset indent
758 COMPILER_WRAPPERS= ccache distcc icecc
760 ${OBJS}: .MAKE.META.CMP_FILTER=${COMPILER_WRAPPERS:S,^,N,}
765 are impacted by that filter (in
768 simply enabling/disabling any of the compiler wrappers does not render all
769 of those targets out-of-date.
772 target-local variable assignments behave differently in that;
773 .Bl -tag -width Ds -offset indent
775 Only appends to a previous local assignment
776 for the same target and variable.
778 Is redundant with respect to global variables,
779 which have already been expanded.
782 The seven built-in local variables are:
783 .Bl -tag -width ".Va .ARCHIVE" -offset indent
785 The list of all sources for this target; also known as
788 The name of the archive file; also known as
791 In suffix-transformation rules, the name/path of the source from which the
792 target is to be transformed (the
794 source); also known as
796 It is not defined in explicit rules.
798 The name of the archive member; also known as
801 The list of sources for this target that were deemed out-of-date; also
805 The name of the target with suffix (if declared in
807 removed; also known as
810 The name of the target; also known as
812 For compatibility with other makes this is an alias for
814 in archive member rules.
828 are permitted for backward
829 compatibility with historical makefiles and legacy POSIX make and are
832 Variants of these variables with the punctuation followed immediately by
838 are legacy forms equivalent to using the
843 These forms are accepted for compatibility with
845 makefiles and POSIX but are not recommended.
847 Four of the local variables may be used in sources on dependency lines
848 because they expand to the proper value for each target on the line.
855 .Ss Additional built-in variables
858 sets or knows about the following variables:
860 .\" NB: This list is sorted case-insensitive, ignoring punctuation.
861 .\" NB: To find all built-in variables in make's source code,
862 .\" NB: search for Var_*, Global_*, SetVarObjdir, GetBooleanExpr,
863 .\" NB: and the implementation of Var_SetWithFlags.
864 .\" NB: Last synced on 2023-01-01.
866 The list of all targets encountered in the makefiles.
867 If evaluated during makefile parsing,
868 lists only those targets encountered thus far.
870 A path to the directory where
873 Refer to the description of
877 Is used in error handling, see
878 .Va MAKE_PRINT_VAR_ON_ERROR .
880 Is used in error handling, see
881 .Va MAKE_PRINT_VAR_ON_ERROR .
882 .It Va .ERROR_META_FILE
883 Is used in error handling in
886 .Va MAKE_PRINT_VAR_ON_ERROR .
888 Is used in error handling, see
889 .Va MAKE_PRINT_VAR_ON_ERROR .
890 .It Va .INCLUDEDFROMDIR
891 The directory of the file this makefile was included from.
892 .It Va .INCLUDEDFROMFILE
893 The filename of the file this makefile was included from.
894 .\" .INCLUDES is intentionally undocumented, as it is obsolete.
895 .\" .LIBS is intentionally undocumented, as it is obsolete.
897 The machine hardware name, see
900 The machine processor architecture name, see
911 The preferred variable to use is the environment variable
913 because it is more compatible with other make variants
914 and cannot be confused with the special target with the same name.
915 .It Va .MAKE.ALWAYS_PASS_JOB_QUEUE
918 whether to pass the descriptors of the job token queue
919 even if the target is not tagged with
923 for backwards compatability with
926 .\" '.MAKE.cmd_filtered' is intentionally undocumented,
927 .\" as it is an internal implementation detail.
928 .It Va .MAKE.DEPENDFILE
929 Names the makefile (default
931 from which generated dependencies are read.
932 .It Va .MAKE.DIE_QUIETLY
935 do not print error information at the end.
936 .It Va .MAKE.EXPAND_VARIABLES
937 A boolean that controls the default behavior of the
940 If true, variable values printed with
942 are fully expanded; if false, the raw variable contents (which may
943 include additional unexpanded variable references) are shown.
944 .It Va .MAKE.EXPORTED
945 The list of variables exported by
948 The top-level makefile that is currently read,
949 as given in the command line.
951 The environment variable
953 may contain anything that
957 Anything specified on
959 command line is appended to the
961 variable, which is then added to the environment for all programs that
965 The numeric group ID of the user running
968 .It Va .MAKE.JOB.PREFIX
973 the output for each target is prefixed with a token
974 .Dl --- Ar target Li ---
975 the first part of which can be controlled via
976 .Va .MAKE.JOB.PREFIX .
979 is empty, no token is printed.
983 .Ql ${.newline}---${.MAKE:T}[${.MAKE.PID}]
984 would produce tokens like
985 .Dl ---make[1234] Ar target Li ---
986 making it easier to track the degree of parallelism being achieved.
992 A read-only boolean that indicates whether the
994 option supports use of
997 The recursion depth of
999 The top-level instance of
1001 has level 0, and each child make has its parent level plus 1.
1002 This allows tests like:
1003 .Li .if ${.MAKE.LEVEL} == 0
1004 to protect things which should only be evaluated in the top-level instance of
1006 .It Va .MAKE.LEVEL.ENV
1007 The name of the environment variable that stores the level of nested calls to
1009 .It Va .MAKE.MAKEFILE_PREFERENCE
1010 The ordered list of makefile names
1017 .It Va .MAKE.MAKEFILES
1018 The list of makefiles read by
1020 which is useful for tracking dependencies.
1021 Each makefile is recorded only once, regardless of the number of times read.
1022 .It Va .MAKE.META.BAILIWICK
1025 mode, provides a list of prefixes which
1026 match the directories controlled by
1028 If a file that was generated outside of
1030 but within said bailiwick is missing,
1031 the current target is considered out-of-date.
1032 .It Va .MAKE.META.CMP_FILTER
1035 mode, it can (very rarely!) be useful to filter command
1036 lines before comparison.
1037 This variable can be set to a set of modifiers that are applied to
1038 each line of the old and new command that differ, if the filtered
1039 commands still differ, the target is considered out-of-date.
1040 .It Va .MAKE.META.CREATED
1043 mode, this variable contains a list of all the meta files
1045 If not empty, it can be used to trigger processing of
1046 .Va .MAKE.META.FILES .
1047 .It Va .MAKE.META.FILES
1050 mode, this variable contains a list of all the meta files
1051 used (updated or not).
1052 This list can be used to process the meta files to extract dependency
1054 .It Va .MAKE.META.IGNORE_FILTER
1055 Provides a list of variable modifiers to apply to each pathname.
1056 Ignore if the expansion is an empty string.
1057 .It Va .MAKE.META.IGNORE_PATHS
1058 Provides a list of path prefixes that should be ignored;
1059 because the contents are expected to change over time.
1060 The default list includes:
1061 .Sq Pa /dev /etc /proc /tmp /var/run /var/tmp
1062 .It Va .MAKE.META.IGNORE_PATTERNS
1063 Provides a list of patterns to match against pathnames.
1064 Ignore any that match.
1065 .It Va .MAKE.META.PREFIX
1066 Defines the message printed for each meta file updated in
1069 The default value is:
1070 .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
1072 Processed after reading all makefiles.
1073 Affects the mode that
1076 It can contain these keywords:
1077 .Bl -tag -width indent
1091 mode, where meta files are created for each target
1092 to capture the command run, the output generated, and if
1094 is available, the system calls which are of interest to
1096 The captured output can be useful when diagnosing errors.
1097 .It Cm curdirOk= Ns Ar bf
1104 This can be overridden by setting
1106 to a value which represents true.
1107 .It Cm missing-meta= Ns Ar bf
1112 file makes the target out-of-date.
1113 .It Cm missing-filemon= Ns Ar bf
1116 is true, missing filemon data makes the target out-of-date.
1121 For debugging, it can be useful to include the environment
1128 mode, print a clue about the target being built.
1129 This is useful if the build is otherwise running silently.
1130 The message printed is the expanded value of
1131 .Va .MAKE.META.PREFIX .
1133 Some makefiles have commands which are simply not stable.
1134 This keyword causes them to be ignored for
1135 determining whether a target is out of date in
1140 .It Cm silent= Ns Ar bf
1143 is true, when a .meta file is created, mark the target
1145 .It Cm randomize-targets
1146 In both compat and parallel mode, do not make the targets in the usual order,
1147 but instead randomize their order.
1148 This mode can be used to detect undeclared dependencies between files.
1151 Used to create files in a separate directory, see
1153 .It Va MAKE_OBJDIR_CHECK_WRITABLE
1154 Used to force a separate directory for the created files,
1155 even if that directory is not writable, see
1157 .It Va MAKEOBJDIRPREFIX
1158 Used to create files in a separate directory, see
1161 The name of the operating system, see
1164 .It Va .MAKEOVERRIDES
1165 This variable is used to record the names of variables assigned to
1166 on the command line, so that they may be exported as part of
1168 This behavior can be disabled by assigning an empty value to
1169 .Sq Va .MAKEOVERRIDES
1171 Extra variables can be exported from a makefile
1172 by appending their names to
1173 .Sq Va .MAKEOVERRIDES .
1175 is re-exported whenever
1176 .Sq Va .MAKEOVERRIDES
1178 .It Va .MAKE.PATH_FILEMON
1183 support, this is set to the path of the device node.
1184 This allows makefiles to test for this support.
1190 The parent process ID of
1193 .It Va MAKE_PRINT_VAR_ON_ERROR
1196 stops due to an error, it sets
1197 .Sq Va .ERROR_TARGET
1198 to the name of the target that failed,
1200 to the commands of the failed target,
1208 .Sq Va .ERROR_META_FILE
1209 to the path of the meta file (if any) describing the failed target.
1210 It then prints its name and the value of
1212 as well as the value of any variables named in
1213 .Sq Va MAKE_PRINT_VAR_ON_ERROR .
1214 .It Va .MAKE.SAVE_DOLLARS
1217 are preserved when doing
1220 The default is false, for backwards compatibility.
1221 Set to true for compatability with other makes.
1226 per normal evaluation rules.
1227 .It Va .MAKE.TARGET_LOCAL_VARIABLES
1230 apparent variable assignments in dependency lines are
1231 treated as normal sources.
1233 The numeric ID of the user running
1236 .\" 'MAKE_VERSION' is intentionally undocumented
1237 .\" since it is only defined in the bmake distribution,
1238 .\" but not in NetBSD's native make.
1239 .\" '.meta.%d.lcwd' is intentionally undocumented
1240 .\" since it is an internal implementation detail.
1241 .\" '.meta.%d.ldir' is intentionally undocumented
1242 .\" since it is an internal implementation detail.
1243 .\" 'MFLAGS' is intentionally undocumented
1244 .\" since it is obsolete.
1246 This variable is simply assigned a newline character as its value.
1248 This allows expansions using the
1250 modifier to put a newline between
1251 iterations of the loop rather than a space.
1252 For example, in case of an error,
1254 prints the variable names and their values using:
1255 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1257 A path to the directory where the targets are built.
1258 Its value is determined by trying to
1260 to the following directories in order and using the first match:
1263 .Cm ${MAKEOBJDIRPREFIX} Ns Cm ${.CURDIR}
1266 .Sq Ev MAKEOBJDIRPREFIX
1267 is set in the environment or on the command line.)
1273 is set in the environment or on the command line.)
1275 .Cm ${.CURDIR} Ns Pa /obj. Ns Cm ${MACHINE}
1277 .Cm ${.CURDIR} Ns Pa /obj
1279 .Pa /usr/obj/ Ns Cm ${.CURDIR}
1284 Variable expansion is performed on the value before it is used,
1285 so expressions such as
1286 .Cm ${.CURDIR:S,^/usr/src,/var/obj,}
1288 This is especially useful with
1292 may be modified in the makefile via the special target
1296 changes to the specified directory if it exists, and sets
1300 to that directory before executing any targets.
1302 Except in the case of an explicit
1306 checks that the specified directory is writable and ignores it if not.
1307 This check can be skipped by setting the environment variable
1308 .Sq Ev MAKE_OBJDIR_CHECK_WRITABLE
1312 The directory name of the current makefile being parsed.
1314 The basename of the current makefile being parsed.
1317 are both set only while the makefiles are being parsed.
1318 To retain their current values,
1319 assign them to a variable using assignment with expansion
1322 The space-separated list of directories that
1325 To update this search list, use the special target
1327 rather than modifying the variable directly.
1329 Is set in POSIX mode, see the special
1332 .\" XXX: There is no make variable named 'PWD',
1333 .\" XXX: make only reads and writes the environment variable 'PWD'.
1335 Alternate path to the current directory.
1339 to the canonical path given by
1341 However, if the environment variable
1343 is set and gives a path to the current directory,
1350 This behavior is disabled if
1351 .Sq Ev MAKEOBJDIRPREFIX
1354 contains a variable transform.
1356 is set to the value of
1358 for all programs which
1362 The pathname of the shell used to run target scripts.
1365 The list of known suffixes.
1368 The space-separated list of directories that
1370 searches for makefiles, referred to as the system include path.
1371 To update this search list, use the special target
1373 rather than modifying the variable which is read-only.
1375 The list of targets explicitly specified on the command line, if any.
1379 list of directories that
1382 This variable is supported for compatibility with old make programs only, use
1386 .Ss Variable modifiers
1387 The general format of a variable expansion is:
1390 .D1 Ic \&${ Ar variable\| Oo Ic \&: Ar modifier\| Oo Ic \&: No ... Oc Oc Ic \&}
1393 Each modifier begins with a colon.
1394 To escape a colon, precede it with a backslash
1397 A list of indirect modifiers can be specified via a variable, as follows:
1399 .Bd -literal -offset indent
1400 .Ar modifier_variable\^ Li \&= Ar modifier Ns Oo Ic \&: Ns No ... Oc
1403 .Ic \&${ Ar variable Ic \&:${ Ar modifier_variable Ic \&} Oo Ic \&: No ... Oc Ic \&}
1407 In this case, the first modifier in the
1408 .Ar modifier_variable
1409 does not start with a colon,
1410 since that colon already occurs in the referencing variable.
1411 If any of the modifiers in the
1412 .Ar modifier_variable
1413 contains a dollar sign
1415 these must be doubled to avoid early expansion.
1417 Some modifiers interpret the expression value as a single string,
1418 others treat the expression value as a whitespace-separated list of words.
1419 When splitting a string into words,
1420 whitespace can be escaped using double quotes, single quotes and backslashes,
1422 The quotes and backslashes are retained in the words.
1424 The supported modifiers are:
1427 Replaces each word with its suffix.
1429 Replaces each word with its dirname.
1430 .It Cm \&:M\| Ns Ar pattern
1431 Selects only those words that match
1433 The standard shell wildcard characters
1440 The wildcard characters may be escaped with a backslash
1442 As a consequence of the way values are split into words, matched,
1443 and then joined, the construct
1445 removes all leading and trailing whitespace
1446 and normalizes the inter-word spacing to a single space.
1447 .It Cm \&:N\| Ns Ar pattern
1448 This is the opposite of
1450 selecting all words which do
1455 Orders the words lexicographically.
1457 Orders the words numerically.
1458 A number followed by one of
1463 is multiplied by the appropriate factor, which is 1024 for
1469 Both upper- and lower-case letters are accepted.
1471 Orders the words in reverse lexicographical order.
1473 Orders the words in reverse numerical order.
1476 The results are different each time you are referring to the
1477 modified variable; use the assignment with expansion
1479 to prevent such behavior.
1481 .Bd -literal -offset indent
1482 LIST= uno due tre quattro
1483 RANDOM_LIST= ${LIST:Ox}
1484 STATIC_RANDOM_LIST:= ${LIST:Ox}
1487 @echo "${RANDOM_LIST}"
1488 @echo "${RANDOM_LIST}"
1489 @echo "${STATIC_RANDOM_LIST}"
1490 @echo "${STATIC_RANDOM_LIST}"
1492 may produce output similar to:
1493 .Bd -literal -offset indent
1500 Quotes every shell meta-character in the value, so that it can be passed
1501 safely to the shell.
1503 Quotes every shell meta-character in the value, and also doubles
1505 characters so that it can be passed
1506 safely through recursive invocations of
1508 This is equivalent to
1509 .Sq Cm \&:S/\e\&$/&&/g:Q .
1511 Replaces each word with everything but its suffix.
1512 .It Cm \&:range Ns Oo Cm = Ns Ar count Oc
1513 The value is an integer sequence representing the words of the original
1514 value, or the supplied
1516 .It Cm \&:gmtime Ns Oo Cm = Ns Ar timestamp Oc
1517 The value is interpreted as a format string for
1521 producing the formatted timestamp.
1524 format should only be used with
1525 .Sq Cm \&:localtime .
1528 value is not provided or is 0, the current time is used.
1530 Computes a 32-bit hash of the value and encodes it as 8 hex digits.
1531 .It Cm \&:localtime Ns Oo Cm = Ns Ar timestamp Oc
1532 The value is interpreted as a format string for
1536 producing the formatted timestamp.
1539 value is not provided or is 0, the current time is used.
1540 .It Cm \&:mtime Ns Oo Cm = Ns Ar timestamp Oc
1543 with each word as pathname;
1558 failure will cause an error.
1560 Attempts to convert the value to an absolute path using
1562 If that fails, the value is unchanged.
1564 Converts the value to lower-case letters.
1565 .It Cm \&:ts Ns Ar c
1566 When joining the words after a modifier that treats the value as words,
1567 the words are normally separated by a space.
1568 This modifier changes the separator to the character
1572 is omitted, no separator is used.
1573 The common escapes (including octal numeric codes) work as expected.
1575 Converts the value to upper-case letters.
1577 Causes subsequent modifiers to treat the value as a single word
1578 (possibly containing embedded whitespace).
1582 Causes the value to be treated as a list of words.
1586 .It Cm \&:S\| No \&/ Ar old_string\| No \&/ Ar new_string\| No \&/ Op Cm 1gW
1588 Modifies the first occurrence of
1590 in each word of the value, replacing it with
1594 is appended to the last delimiter of the pattern,
1595 all occurrences in each word are replaced.
1598 is appended to the last delimiter of the pattern,
1599 only the first occurrence is affected.
1602 is appended to the last delimiter of the pattern,
1603 the value is treated as a single word.
1609 is anchored at the beginning of each word.
1612 ends with a dollar sign
1614 it is anchored at the end of each word.
1621 (without the anchoring
1625 Any character may be used as the delimiter for the parts of the modifier
1627 The anchoring, ampersand and delimiter characters can be escaped with a
1635 may contain nested expressions.
1636 To prevent a dollar sign from starting a nested expression,
1637 escape it with a backslash.
1639 .It Cm \&:C\| No \&/ Ar pattern\| No \&/ Ar replacement\| No \&/ Op Cm 1gW
1643 modifier works like the
1645 modifier except that the old and new strings, instead of being
1646 simple strings, are an extended regular expression
1653 Normally, the first occurrence of the pattern
1655 in each word of the value is substituted with
1659 modifier causes the substitution to apply to at most one word; the
1661 modifier causes the substitution to apply to as many instances of the
1664 as occur in the word or words it is found in; the
1666 modifier causes the value to be treated as a single word
1667 (possibly containing embedded whitespace).
1675 are subjected to variable expansion before being parsed as
1676 regular expressions.
1678 Replaces each word with its last path component (basename).
1680 Removes adjacent duplicate words (like
1683 .It Cm \&:\&?\| Ar true_string\| Cm \&: Ar false_string
1685 If the variable name (not its value), when parsed as a
1687 conditional expression, evaluates to true, return as its value the
1689 otherwise return the
1691 Since the variable name is used as the expression,
1692 \&:\&? must be the first modifier after the variable name
1693 .No itself Ns \^\(em\^ Ns
1694 which, of course, usually contains variable expansions.
1695 A common error is trying to use expressions like
1696 .Dl ${NUMBERS:M42:?match:no}
1697 which actually tests defined(NUMBERS).
1698 To determine if any words match
1700 you need to use something like:
1701 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1702 .It Cm :\| Ns Ar old_string\| Ns Cm = Ns Ar new_string
1706 It can only be the last modifier specified,
1713 is treated as a regular character, not as the end of the modifier.
1717 does not contain the pattern matching character
1719 and the word ends with
1722 that suffix is replaced with
1725 Otherwise, the first
1729 matches a possibly empty substring of arbitrary characters,
1730 and if the whole pattern is found in the word,
1731 the matching part is replaced with
1733 and the first occurrence of
1737 (if any) is replaced with the substring matched by the
1744 may contain nested expressions.
1745 To prevent a dollar sign from starting a nested expression,
1746 escape it with a backslash.
1748 .It Cm \&:@ Ar varname\| Cm @ Ar string\| Cm @
1750 This is the loop expansion mechanism from the OSF Development
1751 Environment (ODE) make.
1754 loops, expansion occurs at the time of reference.
1755 For each word in the value, assign the word to the variable named
1759 The ODE convention is that
1761 should start and end with a period, for example:
1762 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1764 However, a single-letter variable is often more readable:
1765 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1766 .It Cm \&:_ Ns Oo Cm = Ns Ar var Oc
1767 Saves the current variable value in
1771 for later reference.
1773 .Bd -literal -offset indent
1774 M_cmpv.units = 1 1000 1000000
1775 M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\
1776 \\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1778 .Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1783 is used to save the result of the
1785 modifier which is later referenced using the index values from
1787 .It Cm \&:U\| Ns Ar newval
1788 If the variable is undefined,
1791 If the variable is defined, the existing value is returned.
1792 This is another ODE make feature.
1793 It is handy for setting per-target CFLAGS for instance:
1794 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1795 If a value is only required if the variable is undefined, use:
1796 .Dl ${VAR:D:Unewval}
1797 .It Cm \&:D\| Ns Ar newval
1798 If the variable is defined,
1802 The name of the variable is the value.
1804 The path of the node which has the same name as the variable is the value.
1805 If no such node exists or its path is null, the name of the variable is used.
1806 In order for this modifier to work, the name (node) must at least have
1807 appeared on the right-hand side of a dependency.
1809 .It Cm \&:\&! Ar cmd\| Cm \&!
1811 The output of running
1815 The value is run as a command, and the output becomes the new value.
1816 .It Cm \&::= Ns Ar str
1817 The variable is assigned the value
1820 This modifier and its variations are useful in obscure situations
1821 such as wanting to set a variable
1822 at a point where a target's shell commands are being parsed.
1823 These assignment modifiers always expand to nothing.
1827 helps avoid false matches with the
1831 modifier and since substitution always occurs, the
1833 form is vaguely appropriate.
1834 .It Cm \&::?= Ns Ar str
1837 but only if the variable does not already have a value.
1838 .It Cm \&::+= Ns Ar str
1842 .It Cm \&::!= Ns Ar cmd
1843 Assign the output of
1846 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1847 Selects one or more words from the value,
1848 or performs other operations related to the way in which the
1849 value is split into words.
1851 An empty value, or a value that consists entirely of white-space,
1852 is treated as a single word.
1853 For the purposes of the
1855 modifier, the words are indexed both forwards using positive integers
1856 (where index 1 represents the first word),
1857 and backwards using negative integers
1858 (where index \-1 represents the last word).
1862 is subjected to variable expansion, and the expanded result is
1863 then interpreted as follows:
1864 .Bl -tag -width index
1867 Selects a single word from the value.
1869 .It Ar start Ns Cm \&.. Ns Ar end
1870 Selects all words from
1877 selects all words from the second word to the last word.
1882 the words are output in reverse order.
1885 selects all the words from last to first.
1886 If the list is already ordered,
1887 this effectively reverses the list,
1888 but it is more efficient to use
1891 .Sq Cm \&:O:[-1..1] .
1894 Causes subsequent modifiers to treat the value as a single word
1895 (possibly containing embedded whitespace).
1896 Analogous to the effect of
1905 Causes subsequent modifiers to treat the value as a sequence of words
1906 delimited by whitespace.
1907 Analogous to the effect of
1912 Returns the number of words in the value.
1917 offers directives for including makefiles, conditionals and for loops.
1918 All these directives are identified by a line beginning with a single dot
1920 character, followed by the keyword of the directive, such as
1925 Files are included with either
1926 .Cm \&.include \&< Ns Ar file Ns Cm \&>
1928 .Cm \&.include \&\*q Ns Ar file Ns Cm \&\*q .
1929 Variables between the angle brackets or double quotes are expanded
1930 to form the file name.
1931 If angle brackets are used, the included makefile is expected to be in
1932 the system makefile directory.
1933 If double quotes are used, the including makefile's directory and any
1934 directories specified using the
1936 option are searched before the system makefile directory.
1938 For compatibility with other make variants,
1939 .Sq Cm include Ar file No ...
1940 (without leading dot)
1943 If the include statement is written as
1947 errors locating and/or opening include files are ignored.
1949 If the include statement is written as
1951 not only are errors locating and/or opening include files ignored,
1952 but stale dependencies within the included file are ignored just like in
1953 .Va .MAKE.DEPENDFILE .
1954 .Ss Exporting variables
1955 The directives for exporting and unexporting variables are:
1957 .It Ic .export Ar variable No ...
1958 Export the specified global variable.
1959 If no variable list is provided, all globals are exported
1960 except for internal variables (those that start with
1962 This is not affected by the
1964 flag, so should be used with caution.
1965 For compatibility with other make programs,
1966 .Cm export Ar variable\| Ns Cm \&= Ns Ar value
1967 (without leading dot) is also accepted.
1969 Appending a variable name to
1971 is equivalent to exporting a variable.
1972 .It Ic .export-env Ar variable No ...
1975 except that the variable is not appended to
1976 .Va .MAKE.EXPORTED .
1977 This allows exporting a value to the environment which is different from that
1981 .It Ic .export-literal Ar variable No ...
1984 except that variables in the value are not expanded.
1985 .It Ic .unexport Ar variable No ...
1988 The specified global
1991 .Va .MAKE.EXPORTED .
1992 If no variable list is provided, all globals are unexported,
1996 .It Ic .unexport-env
1997 Unexport all globals previously exported and
1998 clear the environment inherited from the parent.
1999 This operation causes a memory leak of the original environment,
2000 so should be used sparingly.
2003 being 0 would make sense.
2004 Also note that any variables which originated in the parent environment
2005 should be explicitly preserved if desired.
2007 .Bd -literal -offset indent
2008 .Li .if ${.MAKE.LEVEL} == 0
2015 Would result in an environment containing only
2017 which is the minimal useful environment.
2018 .\" TODO: Check the below sentence, environment variables don't start with '.'.
2021 is also pushed into the new environment.
2024 The directives for printing messages to the output are:
2026 .It Ic .info Ar message
2027 The message is printed along with the name of the makefile and line number.
2028 .It Ic .warning Ar message
2029 The message prefixed by
2031 is printed along with the name of the makefile and line number.
2032 .It Ic .error Ar message
2033 The message is printed along with the name of the makefile and line number,
2038 The directives for conditionals are:
2039 .ds maybenot Oo Ic \&! Oc Ns
2041 .It Ic .if \*[maybenot] Ar expression Op Ar operator expression No ...
2042 Test the value of an expression.
2043 .It Ic .ifdef \*[maybenot] Ar variable Op Ar operator variable No ...
2044 Test whether a variable is defined.
2045 .It Ic .ifndef \*[maybenot] Ar variable Op Ar operator variable No ...
2046 Test whether a variable is not defined.
2047 .It Ic .ifmake \*[maybenot] Ar target Op Ar operator target No ...
2048 Test the target being requested.
2049 .It Ic .ifnmake \*[maybenot] Ar target Op Ar operator target No ...
2050 Test the target being requested.
2052 Reverse the sense of the last conditional.
2053 .It Ic .elif \*[maybenot] Ar expression Op Ar operator expression No ...
2058 .It Ic .elifdef \*[maybenot] Ar variable Op Ar operator variable No ...
2063 .It Ic .elifndef \*[maybenot] Ar variable Op Ar operator variable No ...
2068 .It Ic .elifmake \*[maybenot] Ar target Op Ar operator target No ...
2073 .It Ic .elifnmake \*[maybenot] Ar target Op Ar operator target No ...
2079 End the body of the conditional.
2084 may be any one of the following:
2089 Logical AND; of higher precedence than
2094 only evaluates a conditional as far as is necessary to determine its value.
2095 Parentheses can be used to override the operator precedence.
2096 The boolean operator
2098 may be used to logically negate an expression, typically a function call.
2099 It is of higher precedence than
2104 may be any of the following function call expressions:
2107 .It Ic defined Li \&( Ar varname Li \&)
2109 Evaluates to true if the variable
2113 .It Ic make Li \&( Ar target Li \&)
2115 Evaluates to true if the target was specified as part of
2117 command line or was declared the default target (either implicitly or
2120 before the line containing the conditional.
2122 .It Ic empty Li \&( Ar varname Oo Li : Ar modifiers Oc Li \&)
2124 Evaluates to true if the expansion of the variable,
2125 after applying the modifiers, results in an empty string.
2127 .It Ic exists Li \&( Ar pathname Li \&)
2129 Evaluates to true if the given pathname exists.
2130 If relative, the pathname is searched for on the system search path (see
2133 .It Ic target Li \&( Ar target Li \&)
2135 Evaluates to true if the target has been defined.
2137 .It Ic commands Li \&( Ar target Li \&)
2139 Evaluates to true if the target has been defined
2140 and has commands associated with it.
2144 may also be an arithmetic or string comparison.
2145 Variable expansion is performed on both sides of the comparison.
2146 If both sides are numeric and neither is enclosed in quotes,
2147 the comparison is done numerically, otherwise lexicographically.
2148 A string is interpreted as a hexadecimal integer if it is preceded by
2150 otherwise it is interpreted as a decimal floating-point number;
2151 octal numbers are not supported.
2153 All comparisons may use the operators
2157 Numeric comparisons may also use the operators
2164 If the comparison has neither a comparison operator nor a right side,
2165 the expression evaluates to true if it is nonempty
2166 and its numeric value (if any) is not zero.
2170 is evaluating one of these conditional expressions, and it encounters
2171 a (whitespace-separated) word it doesn't recognize, either the
2175 function is applied to it, depending on the form of the conditional.
2183 function is applied.
2184 Similarly, if the form is
2190 function is applied.
2192 If the conditional evaluates to true,
2193 parsing of the makefile continues as before.
2194 If it evaluates to false, the following lines until the corresponding
2202 For loops are typically used to apply a set of rules to a list of files.
2203 The syntax of a for loop is:
2205 .Bl -tag -compact -width Ds
2206 .It Ic \&.for Ar variable Oo Ar variable No ... Oc Ic in Ar expression
2207 .It Aq Ar make-lines
2213 is expanded and then split into words.
2214 On each iteration of the loop, one word is taken and assigned to each
2218 are substituted into the
2220 inside the body of the for loop.
2221 The number of words must come out even; that is, if there are three
2222 iteration variables, the number of words provided must be a multiple
2227 is encountered within a
2229 loop, it causes early termination of the loop, otherwise a parse error.
2230 .\" TODO: Describe limitations with defined/empty.
2231 .Ss Other directives
2233 .It Ic .undef Ar variable No ...
2234 Un-define the specified global variables.
2235 Only global variables can be un-defined.
2238 Comments begin with a hash
2240 character, anywhere but in a shell
2241 command line, and continue to the end of an unescaped new line.
2242 .Sh SPECIAL SOURCES (ATTRIBUTES)
2243 .Bl -tag -width .IGNOREx
2245 Target is never out of date, but always execute commands anyway.
2247 Ignore any errors from the commands associated with this target, exactly
2248 as if they all were preceded by a dash
2250 .\" .It Ic .INVISIBLE
2255 Mark all sources of this target as being up to date.
2257 Execute the commands associated with this target even if the
2261 options were specified.
2262 Normally used to mark recursive
2265 Create a meta file for the target, even if it is flagged as
2270 Usage in conjunction with
2272 is the most likely case.
2275 mode, the target is out-of-date if the meta file is missing.
2277 Do not create a meta file for the target.
2278 Meta files are also not created for
2285 Ignore differences in commands when deciding if target is out of date.
2286 This is useful if the command contains a value which always changes.
2287 If the number of commands change, though,
2288 the target is still considered out of date.
2289 The same effect applies to any command line that uses the variable
2291 which can be used for that purpose even when not otherwise needed or desired:
2292 .Bd -literal -offset indent
2294 skip-compare-for-some:
2295 @echo this is compared
2296 @echo this is not ${.OODATE:M.NOMETA_CMP}
2297 @echo this is also compared
2302 pattern suppresses any expansion of the unwanted variable.
2304 Do not search for the target in the directories specified by
2309 selects the first target it encounters as the default target to be built
2310 if no target was specified.
2311 This source prevents this target from being selected.
2313 If a target is marked with this attribute and
2315 can't figure out how to create it, it ignores this fact and assumes
2316 the file isn't needed or already exists.
2318 The target does not correspond to an actual file;
2319 it is always considered to be out of date,
2320 and is not created with the
2323 Suffix-transformation rules are not applied to
2329 is interrupted, it normally removes any partially made targets.
2330 This source prevents the target from being removed.
2335 Do not echo any of the commands associated with this target, exactly
2336 as if they all were preceded by an at sign
2339 Turn the target into
2342 When the target is used as a source for another target, the other target
2343 acquires the commands, sources, and attributes (except for
2347 If the target already has commands, the
2349 target's commands are appended
2354 but instead of appending, prepend the
2356 target commands to the target.
2360 appears in a dependency line, the sources that precede it are
2361 made before the sources that succeed it in the line.
2362 Since the dependents of files are not made until the file itself
2363 could be made, this also stops the dependents being built unless they
2364 are needed for another branch of the dependency tree.
2377 the output is always
2383 The ordering imposed by
2385 is only relevant for parallel makes.
2388 Special targets may not be included with other targets, i.e. they must be
2389 the only target specified.
2390 .Bl -tag -width .BEGINx
2392 Any command lines attached to this target are executed before anything
2397 rule for any target (that was used only as a source) that
2399 can't figure out any other way to create.
2400 Only the shell script is used.
2403 variable of a target that inherits
2405 commands is set to the target's own name.
2406 .It Ic .DELETE_ON_ERROR
2407 If this target is present in the makefile, it globally causes make to
2408 delete targets whose commands fail.
2409 (By default, only targets whose commands are interrupted during
2410 execution are deleted.
2411 This is the historical behavior.)
2412 This setting can be used to help prevent half-finished or malformed
2413 targets from being left around and corrupting future rebuilds.
2415 Any command lines attached to this target are executed after everything
2416 else is done successfully.
2418 Any command lines attached to this target are executed when another target fails.
2421 variable is set to the target that failed.
2423 .Va MAKE_PRINT_VAR_ON_ERROR .
2425 Mark each of the sources with the
2428 If no sources are specified, this is the equivalent of specifying the
2434 is interrupted, the commands for this target are executed.
2436 If no target is specified when
2438 is invoked, this target is built.
2440 This target provides a way to specify flags for
2442 at the time when the makefiles are read.
2443 The flags are as if typed to the shell, though the
2447 .\" XXX: NOT YET!!!!
2448 .\" .It Ic .NOTPARALLEL
2449 .\" The named targets are executed in non parallel mode.
2450 .\" If no targets are
2451 .\" specified, all targets are executed in non parallel mode.
2455 attribute to any specified sources.
2457 Disable parallel mode.
2461 for compatibility with other pmake variants.
2463 clear the read-only attribute from the global variables specified as sources.
2465 The source is a new value for
2469 changes the current working directory to it and updates the value of
2472 In parallel mode, the named targets are made in sequence.
2473 This ordering does not add targets to the list of targets to be made.
2475 Since the dependents of a target do not get built until the target itself
2476 could be built, unless
2478 is built by another part of the dependency graph,
2479 the following is a dependency loop:
2485 .\" XXX: NOT YET!!!!
2486 .\" .It Ic .PARALLEL
2487 .\" The named targets are executed in parallel mode.
2488 .\" If no targets are
2489 .\" specified, all targets are executed in parallel mode.
2491 The sources are directories which are to be searched for files not
2492 found in the current directory.
2493 If no sources are specified,
2494 any previously specified directories are removed from the search path.
2495 If the source is the special
2497 target, the current working directory is searched last.
2498 .It Ic .PATH. Ns Ar suffix
2501 but applies only to files with a particular suffix.
2502 The suffix must have been previously declared with
2507 attribute to any specified sources.
2509 If this is the first non-comment line in the main makefile,
2516 is included if it exists,
2517 to provide POSIX-compatible default rules.
2524 contributes to the default rules.
2528 attribute to any specified sources.
2529 If no sources are specified, the
2531 attribute is applied to every target in the file.
2533 set the read-only attribute on the global variables specified as sources.
2537 uses to execute commands in jobs mode.
2538 The sources are a set of
2539 .Ar field\| Ns Cm \&= Ns Ar value
2541 .Bl -tag -width ".Li hasErrCtls"
2543 This is the minimal specification, used to select one of the built-in
2550 Specifies the absolute path to the shell.
2552 Indicates whether the shell supports exit on error.
2554 The command to turn on error checking.
2556 The command to disable error checking.
2558 The command to turn on echoing of commands executed.
2560 The command to turn off echoing of commands executed.
2562 The output to filter after issuing the
2565 It is typically identical to
2568 The flag to pass the shell to enable error checking.
2570 The flag to pass the shell to enable command echoing.
2572 The string literal to pass the shell that results in a single newline
2573 character when used outside of any quoting characters.
2577 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2578 check="set \-e" ignore="set +e" \e
2579 echo="set \-v" quiet="set +v" filter="set +v" \e
2580 echoFlag=v errFlag=e newline="'\en'"
2585 attribute to any specified sources.
2586 If no sources are specified, the
2588 attribute is applied to every
2589 command in the file.
2591 This target gets run when a dependency file contains stale entries, having
2593 set to the name of that dependency file.
2595 Each source specifies a suffix to
2597 If no sources are specified, any previously specified suffixes are deleted.
2598 It allows the creation of suffix-transformation rules.
2604 cc \-o ${.TARGET} \-c ${.IMPSRC}
2607 The sources are directories which are to be added to the system
2610 searches for makefiles.
2611 If no sources are specified,
2612 any previously specified directories are removed from the system
2617 uses the following environment variables, if they exist:
2623 .Ev MAKEOBJDIRPREFIX ,
2629 .Ev MAKEOBJDIRPREFIX
2632 may only be set in the environment or on the command line to
2634 and not as makefile variables;
2635 see the description of
2639 .Bl -tag -width /usr/share/mk -compact
2641 list of dependencies
2643 first default makefile if no makefile is specified on the command line
2645 second default makefile if no makefile is specified on the command line
2649 system makefile directory
2652 The basic make syntax is compatible between different make variants;
2653 however the special variables, variable modifiers and conditionals are not.
2655 An incomplete list of changes in older versions of
2658 The way that .for loop variables are substituted changed after
2660 so that they still appear to be variable expansions.
2661 In particular this stops them being treated as syntax, and removes some
2662 obscure problems using them in .if statements.
2664 The way that parallel makes are scheduled changed in
2666 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2667 The algorithms used may change again in the future.
2668 .Ss Other make dialects
2669 Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not
2670 support most of the features of
2672 as described in this manual.
2674 .Bl -bullet -offset indent
2680 declarations and most functionality pertaining to parallelization.
2681 (GNU make supports parallelization but lacks the features needed to
2682 control it effectively.)
2684 Directives, including for loops and conditionals and most of the
2685 forms of include files.
2686 (GNU make has its own incompatible and less powerful syntax for
2688 .\" The "less powerful" above means that GNU make does not have the
2689 .\" make(target), target(target) and commands(target) functions.
2691 All built-in variables that begin with a dot.
2693 Most of the special sources and targets that begin with a dot,
2694 with the notable exception of
2700 Variable modifiers, except for the
2702 string substitution, which does not portably support globbing with
2704 and historically only works on declared suffixes.
2708 variable even in its short form; most makes support this functionality
2709 but its name varies.
2712 Some features are somewhat more portable, such as assignment with
2719 functionality is based on an older feature
2721 found in GNU make and many versions of SVR4 make; however,
2722 historically its behavior is too ill-defined (and too buggy) to rely
2729 variables are more or less universally portable, as is the
2732 Basic use of suffix rules (for files only in the current directory,
2733 not trying to chain transformations together, etc.) is also reasonably
2737 .Xr style.Makefile 5
2745 implementation is based on Adam de Boor's pmake program,
2746 which was written for Sprite at Berkeley.
2747 It was designed to be a parallel distributed make running jobs on different
2748 machines using a daemon called
2751 Historically the target/dependency
2753 has been used to FoRCe rebuilding (since the target/dependency
2754 does not exist ... unless someone creates an
2760 syntax is difficult to parse.
2761 For instance, finding the end of a variable's use should involve scanning
2762 each of the modifiers, using the correct terminator for each field.
2765 just counts {} and () in order to find the end of a variable expansion.
2767 There is no way of escaping a space character in a filename.
2769 In jobs mode, when a target fails;
2771 will put an error token into the job token pool.
2772 This will cause all other instances of
2774 using that token pool to abort the build and exit with error code 6.
2775 Sometimes the attempt to suppress a cascade of unnecessary errors,
2776 can result in a seemingly unexplained
2777 .Ql *** Error code 6