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Annotation of src/usr.bin/make/make.1, Revision 1.218

1.218   ! agc         1: .\"    $NetBSD: make.1,v 1.217 2013/06/25 07:08:10 wiz Exp $
1.15      thorpej     2: .\"
1.16      christos    3: .\" Copyright (c) 1990, 1993
                      4: .\"    The Regents of the University of California.  All rights reserved.
1.1       cgd         5: .\"
                      6: .\" Redistribution and use in source and binary forms, with or without
                      7: .\" modification, are permitted provided that the following conditions
                      8: .\" are met:
                      9: .\" 1. Redistributions of source code must retain the above copyright
                     10: .\"    notice, this list of conditions and the following disclaimer.
                     11: .\" 2. Redistributions in binary form must reproduce the above copyright
                     12: .\"    notice, this list of conditions and the following disclaimer in the
                     13: .\"    documentation and/or other materials provided with the distribution.
1.84      agc        14: .\" 3. Neither the name of the University nor the names of its contributors
1.1       cgd        15: .\"    may be used to endorse or promote products derived from this software
                     16: .\"    without specific prior written permission.
                     17: .\"
                     18: .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     19: .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     20: .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     21: .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     22: .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     23: .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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1.16      christos   30: .\"    from: @(#)make.1        8.4 (Berkeley) 3/19/94
1.1       cgd        31: .\"
1.216     sjg        32: .Dd June 24, 2013
1.1       cgd        33: .Dt MAKE 1
                     34: .Os
                     35: .Sh NAME
                     36: .Nm make
                     37: .Nd maintain program dependencies
                     38: .Sh SYNOPSIS
1.74      wiz        39: .Nm
1.75      thorpej    40: .Op Fl BeikNnqrstWX
1.159     sjg        41: .Op Fl C Ar directory
1.1       cgd        42: .Op Fl D Ar variable
                     43: .Op Fl d Ar flags
                     44: .Op Fl f Ar makefile
                     45: .Op Fl I Ar directory
1.104     wiz        46: .Op Fl J Ar private
                     47: .Op Fl j Ar max_jobs
1.13      christos   48: .Op Fl m Ar directory
1.44      sommerfe   49: .Op Fl T Ar file
1.16      christos   50: .Op Fl V Ar variable
1.1       cgd        51: .Op Ar variable=value
                     52: .Op Ar target ...
                     53: .Sh DESCRIPTION
1.25      lukem      54: .Nm
1.1       cgd        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.
1.128     dsl        58: If no
                     59: .Fl f Ar makefile
                     60: makefile option is given,
                     61: .Nm
                     62: will try to open
1.1       cgd        63: .Ql Pa makefile
1.128     dsl        64: then
1.1       cgd        65: .Ql Pa Makefile
1.128     dsl        66: in order to find the specifications.
1.1       cgd        67: If the file
                     68: .Ql Pa .depend
                     69: exists, it is read (see
1.66      wiz        70: .Xr mkdep 1 ) .
1.1       cgd        71: .Pp
                     72: This manual page is intended as a reference document only.
                     73: For a more thorough description of
1.25      lukem      74: .Nm
1.1       cgd        75: and makefiles, please refer to
1.197     dholland   76: .%T "PMake \- A Tutorial" .
1.1       cgd        77: .Pp
1.128     dsl        78: .Nm
                     79: will prepend the contents of the
                     80: .Va MAKEFLAGS
                     81: environment variable to the command line arguments before parsing them.
                     82: .Pp
1.1       cgd        83: The options are as follows:
                     84: .Bl -tag -width Ds
1.16      christos   85: .It Fl B
1.10      christos   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.
1.159     sjg        88: .It Fl C Ar directory
                     89: Change to
                     90: .Ar directory
                     91: before reading the makefiles or doing anything else.
                     92: If multiple
                     93: .Fl C
                     94: options are specified, each is interpreted relative to the previous one:
                     95: .Fl C Pa / Fl C Pa etc
                     96: is equivalent to
                     97: .Fl C Pa /etc .
1.1       cgd        98: .It Fl D Ar variable
1.8       christos   99: Define
                    100: .Ar variable
1.1       cgd       101: to be 1, in the global context.
1.128     dsl       102: .It Fl d Ar [-]flags
1.1       cgd       103: Turn on debugging, and specify which portions of
1.25      lukem     104: .Nm
1.1       cgd       105: are to print debugging information.
1.128     dsl       106: Unless the flags are preceded by
1.194     sjg       107: .Ql \-
1.128     dsl       108: they are added to the
                    109: .Va MAKEFLAGS
                    110: environment variable and will be processed by any child make processes.
1.141     apb       111: By default, debugging information is printed to standard error,
1.138     apb       112: but this can be changed using the
1.140     wiz       113: .Ar F
1.138     apb       114: debugging flag.
1.139     apb       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.
1.1       cgd       118: .Ar Flags
                    119: is one or more of the following:
                    120: .Bl -tag -width Ds
                    121: .It Ar A
                    122: Print all possible debugging information;
                    123: equivalent to specifying all of the debugging flags.
                    124: .It Ar a
                    125: Print debugging information about archive searching and caching.
1.147     christos  126: .It Ar C
                    127: Print debugging information about current working directory.
1.1       cgd       128: .It Ar c
                    129: Print debugging information about conditional evaluation.
                    130: .It Ar d
                    131: Print debugging information about directory searching and caching.
1.88      jmmv      132: .It Ar e
                    133: Print debugging information about failed commands and targets.
1.138     apb       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
                    137: the argument.
                    138: If the character immediately after the
                    139: .Ql F
                    140: flag is
                    141: .Ql \&+ ,
                    142: then the file will be opened in append mode;
                    143: otherwise the file will be overwritten.
                    144: If the file name is
                    145: .Ql stdout
                    146: or
                    147: .Ql stderr
                    148: then debugging output will be written to the
                    149: standard output or standard error output file descriptors respectively
                    150: (and the
                    151: .Ql \&+
                    152: option has no effect).
                    153: Otherwise, the output will be written to the named file.
                    154: If the file name ends
1.128     dsl       155: .Ql .%d
                    156: then the
                    157: .Ql %d
                    158: is replaced by the pid.
1.87      jmmv      159: .It Ar f
                    160: Print debugging information about loop evaluation.
1.1       cgd       161: .It Ar "g1"
                    162: Print the input graph before making anything.
                    163: .It Ar "g2"
                    164: Print the input graph after making everything, or before exiting
1.93      dsl       165: on error.
1.92      dsl       166: .It Ar "g3"
                    167: Print the input graph before exiting on error.
1.1       cgd       168: .It Ar j
                    169: Print debugging information about running multiple shells.
1.135     sjg       170: .It Ar l
                    171: Print commands in Makefiles regardless of whether or not they are prefixed by
1.137     wiz       172: .Ql @
1.135     sjg       173: or other "quiet" flags.
                    174: Also known as "loud" behavior.
1.180     sjg       175: .It Ar M
                    176: Print debugging information about "meta" mode decisions about targets.
1.1       cgd       177: .It Ar m
                    178: Print debugging information about making targets, including modification
                    179: dates.
1.111     jmc       180: .It Ar n
1.154     apb       181: Don't delete the temporary command scripts created when running commands.
                    182: These temporary scripts are created in the directory
                    183: referred to by the
                    184: .Ev TMPDIR
                    185: environment variable, or in
1.112     wiz       186: .Pa /tmp
1.154     apb       187: if
                    188: .Ev TMPDIR
                    189: is unset or set to the empty string.
                    190: The temporary scripts are created by
                    191: .Xr mkstemp 3 ,
1.112     wiz       192: and have names of the form
1.154     apb       193: .Pa makeXXXXXX .
1.123     wiz       194: .Em NOTE :
1.156     snj       195: This can create many files in
1.154     apb       196: .Ev TMPDIR
                    197: or
                    198: .Pa /tmp ,
1.123     wiz       199: so use with care.
1.119     dsl       200: .It Ar p
                    201: Print debugging information about makefile parsing.
1.1       cgd       202: .It Ar s
                    203: Print debugging information about suffix-transformation rules.
                    204: .It Ar t
                    205: Print debugging information about target list maintenance.
1.205     sjg       206: .It Ar V
                    207: Force the
                    208: .Fl V
1.206     wiz       209: option to print raw values of variables.
1.1       cgd       210: .It Ar v
                    211: Print debugging information about variable assignment.
1.49      sjg       212: .It Ar x
1.57      wiz       213: Run shell commands with
                    214: .Fl x
                    215: so the actual commands are printed as they are executed.
1.1       cgd       216: .El
                    217: .It Fl e
1.68      perry     218: Specify that environment variables override macro assignments within
1.1       cgd       219: makefiles.
                    220: .It Fl f Ar makefile
                    221: Specify a makefile to read instead of the default
1.103     wiz       222: .Ql Pa makefile .
1.1       cgd       223: If
                    224: .Ar makefile
                    225: is
                    226: .Ql Fl ,
                    227: standard input is read.
1.103     wiz       228: Multiple makefiles may be specified, and are read in the order specified.
1.1       cgd       229: .It Fl I Ar directory
                    230: Specify a directory in which to search for makefiles and included makefiles.
1.13      christos  231: The system makefile directory (or directories, see the
                    232: .Fl m
                    233: option) is automatically included as part of this list.
1.1       cgd       234: .It Fl i
                    235: Ignore non-zero exit of shell commands in the makefile.
                    236: Equivalent to specifying
                    237: .Ql Fl
                    238: before each command line in the makefile.
1.44      sommerfe  239: .It Fl J Ar private
                    240: This option should
                    241: .Em not
                    242: be specified by the user.
                    243: .Pp
                    244: When the
                    245: .Ar j
                    246: option is in use in a recursive build, this option is passed by a make
                    247: to child makes to allow all the make processes in the build to
                    248: cooperate to avoid overloading the system.
1.1       cgd       249: .It Fl j Ar max_jobs
                    250: Specify the maximum number of jobs that
1.25      lukem     251: .Nm
1.67      grant     252: may have running at any one time.
1.180     sjg       253: The value is saved in
                    254: .Va .MAKE.JOBS .
1.67      grant     255: Turns compatibility mode off, unless the
1.11      christos  256: .Ar B
                    257: flag is also specified.
1.148     christos  258: When compatibility mode is off, all commands associated with a
                    259: target are executed in a single shell invocation as opposed to the
                    260: traditional one shell invocation per line.
                    261: This can break traditional scripts which change directories on each
                    262: command invocation and then expect to start with a fresh environment
                    263: on the next line.
                    264: It is more efficient to correct the scripts rather than turn backwards
                    265: compatibility on.
1.1       cgd       266: .It Fl k
                    267: Continue processing after errors are encountered, but only on those targets
                    268: that do not depend on the target whose creation caused the error.
1.13      christos  269: .It Fl m Ar directory
                    270: Specify a directory in which to search for sys.mk and makefiles included
1.99      wiz       271: via the
                    272: .Ao Ar file Ac Ns -style
                    273: include statement.
1.98      chuck     274: The
                    275: .Fl m
                    276: option can be used multiple times to form a search path.
1.13      christos  277: This path will override the default system include path: /usr/share/mk.
                    278: Furthermore the system include path will be appended to the search path used
1.99      wiz       279: for
                    280: .Qo Ar file Qc Ns -style
                    281: include statements (see the
1.13      christos  282: .Fl I
                    283: option).
1.98      chuck     284: .Pp
                    285: If a file or directory name in the
                    286: .Fl m
1.99      wiz       287: argument (or the
                    288: .Ev MAKESYSPATH
                    289: environment variable) starts with the string
                    290: .Qq \&.../
                    291: then
                    292: .Nm
                    293: will search for the specified file or directory named in the remaining part
                    294: of the argument string.
                    295: The search starts with the current directory of
1.98      chuck     296: the Makefile and then works upward towards the root of the filesystem.
1.99      wiz       297: If the search is successful, then the resulting directory replaces the
                    298: .Qq \&.../
                    299: specification in the
1.98      chuck     300: .Fl m
1.99      wiz       301: argument.
                    302: If used, this feature allows
1.98      chuck     303: .Nm
                    304: to easily search in the current source tree for customized sys.mk files
1.99      wiz       305: (e.g., by using
                    306: .Qq \&.../mk/sys.mk
                    307: as an argument).
1.1       cgd       308: .It Fl n
1.45      sommerfe  309: Display the commands that would have been executed, but do not
                    310: actually execute them unless the target depends on the .MAKE special
1.64      wiz       311: source (see below).
1.45      sommerfe  312: .It Fl N
                    313: Display the commands which would have been executed, but do not
                    314: actually execute any of them; useful for debugging top-level makefiles
                    315: without descending into subdirectories.
1.1       cgd       316: .It Fl q
                    317: Do not execute any commands, but exit 0 if the specified targets are
                    318: up-to-date and 1, otherwise.
                    319: .It Fl r
                    320: Do not use the built-in rules specified in the system makefile.
                    321: .It Fl s
                    322: Do not echo any commands as they are executed.
                    323: Equivalent to specifying
                    324: .Ql Ic @
                    325: before each command line in the makefile.
1.44      sommerfe  326: .It Fl T Ar tracefile
                    327: When used with the
1.48      wiz       328: .Fl j
1.44      sommerfe  329: flag,
                    330: append a trace record to
                    331: .Ar tracefile
                    332: for each job started and completed.
1.1       cgd       333: .It Fl t
                    334: Rather than re-building a target as specified in the makefile, create it
                    335: or update its modification time to make it appear up-to-date.
1.16      christos  336: .It Fl V Ar variable
                    337: Print
1.74      wiz       338: .Nm Ns 's
1.16      christos  339: idea of the value of
                    340: .Ar variable ,
                    341: in the global context.
                    342: Do not build any targets.
                    343: Multiple instances of this option may be specified;
                    344: the variables will be printed one per line,
                    345: with a blank line for each null or undefined variable.
1.85      sjg       346: If
                    347: .Ar variable
                    348: contains a
                    349: .Ql \&$
                    350: then the value will be expanded before printing.
1.46      christos  351: .It Fl W
                    352: Treat any warnings during makefile parsing as errors.
1.75      thorpej   353: .It Fl X
                    354: Don't export variables passed on the command line to the environment
                    355: individually.
                    356: Variables passed on the command line are still exported
                    357: via the
                    358: .Va MAKEFLAGS
                    359: environment variable.
                    360: This option may be useful on systems which have a small limit on the
                    361: size of command arguments.
1.1       cgd       362: .It Ar variable=value
                    363: Set the value of the variable
                    364: .Ar variable
                    365: to
                    366: .Ar value .
1.75      thorpej   367: Normally, all values passed on the command line are also exported to
                    368: sub-makes in the environment.
                    369: The
                    370: .Fl X
                    371: flag disables this behavior.
1.101     wiz       372: Variable assignments should follow options for POSIX compatibility
1.100     ross      373: but no ordering is enforced.
1.1       cgd       374: .El
                    375: .Pp
1.6       cgd       376: There are seven different types of lines in a makefile: file dependency
1.1       cgd       377: specifications, shell commands, variable assignments, include statements,
1.6       cgd       378: conditional directives, for loops, and comments.
1.1       cgd       379: .Pp
                    380: In general, lines may be continued from one line to the next by ending
                    381: them with a backslash
                    382: .Pq Ql \e .
                    383: The trailing newline character and initial whitespace on the following
                    384: line are compressed into a single space.
                    385: .Sh FILE DEPENDENCY SPECIFICATIONS
                    386: Dependency lines consist of one or more targets, an operator, and zero
                    387: or more sources.
1.137     wiz       388: This creates a relationship where the targets
                    389: .Dq depend
                    390: on the sources
1.1       cgd       391: and are usually created from them.
                    392: The exact relationship between the target and the source is determined
                    393: by the operator that separates them.
                    394: The three operators are as follows:
                    395: .Bl -tag -width flag
                    396: .It Ic \&:
                    397: A target is considered out-of-date if its modification time is less than
                    398: those of any of its sources.
                    399: Sources for a target accumulate over dependency lines when this operator
                    400: is used.
                    401: The target is removed if
1.25      lukem     402: .Nm
1.1       cgd       403: is interrupted.
                    404: .It Ic \&!
                    405: Targets are always re-created, but not until all sources have been
                    406: examined and re-created as necessary.
                    407: Sources for a target accumulate over dependency lines when this operator
                    408: is used.
                    409: The target is removed if
1.25      lukem     410: .Nm
1.1       cgd       411: is interrupted.
                    412: .It Ic \&::
                    413: If no sources are specified, the target is always re-created.
                    414: Otherwise, a target is considered out-of-date if any of its sources has
                    415: been modified more recently than the target.
                    416: Sources for a target do not accumulate over dependency lines when this
                    417: operator is used.
                    418: The target will not be removed if
1.25      lukem     419: .Nm
1.1       cgd       420: is interrupted.
                    421: .El
                    422: .Pp
                    423: Targets and sources may contain the shell wildcard values
1.80      wiz       424: .Ql \&? ,
1.1       cgd       425: .Ql * ,
1.103     wiz       426: .Ql [] ,
1.1       cgd       427: and
                    428: .Ql {} .
                    429: The values
1.80      wiz       430: .Ql \&? ,
1.103     wiz       431: .Ql * ,
1.1       cgd       432: and
                    433: .Ql []
                    434: may only be used as part of the final
                    435: component of the target or source, and must be used to describe existing
                    436: files.
                    437: The value
                    438: .Ql {}
                    439: need not necessarily be used to describe existing files.
                    440: Expansion is in directory order, not alphabetically as done in the shell.
                    441: .Sh SHELL COMMANDS
                    442: Each target may have associated with it a series of shell commands, normally
                    443: used to create the target.
                    444: Each of the commands in this script
                    445: .Em must
                    446: be preceded by a tab.
                    447: While any target may appear on a dependency line, only one of these
                    448: dependencies may be followed by a creation script, unless the
1.91      lukem     449: .Ql Ic \&::
1.1       cgd       450: operator is used.
                    451: .Pp
1.102     sjg       452: If the first characters of the command line are any combination of
                    453: .Ql Ic @ ,
1.103     wiz       454: .Ql Ic + ,
1.102     sjg       455: or
1.1       cgd       456: .Ql Ic \- ,
                    457: the command is treated specially.
                    458: A
                    459: .Ql Ic @
                    460: causes the command not to be echoed before it is executed.
                    461: A
1.102     sjg       462: .Ql Ic +
                    463: causes the command to be executed even when
                    464: .Fl n
                    465: is given.
                    466: This is similar to the effect of the .MAKE special source,
                    467: except that the effect can be limited to a single line of a script.
                    468: A
1.1       cgd       469: .Ql Ic \-
                    470: causes any non-zero exit status of the command line to be ignored.
1.210     sjg       471: .Pp
                    472: When
                    473: .Nm
                    474: is run in jobs mode with
                    475: .Fl j Ar max_jobs ,
                    476: the entire script for the target is fed to a
                    477: single instance of the shell.
                    478: .Pp
                    479: In compatibility (non-jobs) mode, each command is run in a separate process.
                    480: If the command contains any shell meta characters
                    481: .Pq Ql #=|^(){};&<>*?[]:$`\e\en
                    482: it will be passed to the shell, otherwise
                    483: .Nm
                    484: will attempt direct execution.
                    485: .Pp
                    486: Since
                    487: .Nm
                    488: will
                    489: .Xr chdir 2
                    490: to
                    491: .Ql Va .OBJDIR
                    492: before executing any targets, each child process
                    493: starts with that as its current working directory.
                    494: .Pp
                    495: Makefiles should be written so that the mode of
                    496: .Nm
                    497: operation does not change their behavior.
                    498: For example, any command which needs to use
                    499: .Dq cd
                    500: or
                    501: .Dq chdir ,
                    502: without side-effect should be put in parenthesis:
                    503: .Bd -literal -offset indent
                    504:
                    505: avoid-chdir-side-effects:
                    506:        @echo Building $@ in `pwd`
                    507:        @(cd ${.CURDIR} && ${.MAKE} $@)
                    508:        @echo Back in `pwd`
                    509:
                    510: ensure-one-shell-regardless-of-mode:
                    511:        @echo Building $@ in `pwd`; \\
                    512:        (cd ${.CURDIR} && ${.MAKE} $@); \\
                    513:        echo Back in `pwd`
                    514: .Ed
1.1       cgd       515: .Sh VARIABLE ASSIGNMENTS
                    516: Variables in make are much like variables in the shell, and, by tradition,
                    517: consist of all upper-case letters.
1.91      lukem     518: .Ss Variable assignment modifiers
1.1       cgd       519: The five operators that can be used to assign values to variables are as
                    520: follows:
                    521: .Bl -tag -width Ds
                    522: .It Ic \&=
                    523: Assign the value to the variable.
                    524: Any previous value is overridden.
                    525: .It Ic \&+=
                    526: Append the value to the current value of the variable.
                    527: .It Ic \&?=
                    528: Assign the value to the variable if it is not already defined.
                    529: .It Ic \&:=
                    530: Assign with expansion, i.e. expand the value before assigning it
                    531: to the variable.
                    532: Normally, expansion is not done until the variable is referenced.
1.124     sjg       533: .Em NOTE :
                    534: References to undefined variables are
                    535: .Em not
1.125     wiz       536: expanded.
                    537: This can cause problems when variable modifiers are used.
1.1       cgd       538: .It Ic \&!=
                    539: Expand the value and pass it to the shell for execution and assign
                    540: the result to the variable.
                    541: Any newlines in the result are replaced with spaces.
                    542: .El
                    543: .Pp
                    544: Any white-space before the assigned
                    545: .Ar value
                    546: is removed; if the value is being appended, a single space is inserted
                    547: between the previous contents of the variable and the appended value.
                    548: .Pp
                    549: Variables are expanded by surrounding the variable name with either
                    550: curly braces
                    551: .Pq Ql {}
1.7       mycroft   552: or parentheses
1.1       cgd       553: .Pq Ql ()
                    554: and preceding it with
                    555: a dollar sign
                    556: .Pq Ql \&$ .
                    557: If the variable name contains only a single letter, the surrounding
1.7       mycroft   558: braces or parentheses are not required.
1.1       cgd       559: This shorter form is not recommended.
                    560: .Pp
1.149     dsl       561: If the variable name contains a dollar, then the name itself is expanded first.
                    562: This allows almost arbitrary variable names, however names containing dollar,
                    563: braces, parenthesis, or whitespace are really best avoided!
                    564: .Pp
                    565: If the result of expanding a variable contains a dollar sign
                    566: .Pq Ql \&$
                    567: the string is expanded again.
                    568: .Pp
1.175     christos  569: Variable substitution occurs at three distinct times, depending on where
1.1       cgd       570: the variable is being used.
1.175     christos  571: .Bl -enum
1.176     wiz       572: .It
1.1       cgd       573: Variables in dependency lines are expanded as the line is read.
1.175     christos  574: .It
1.1       cgd       575: Variables in shell commands are expanded when the shell command is
                    576: executed.
1.175     christos  577: .It
                    578: .Dq .for
1.176     wiz       579: loop index variables are expanded on each loop iteration.
                    580: Note that other variables are not expanded inside loops so
1.175     christos  581: the following example code:
                    582: .Bd -literal -offset indent
                    583:
                    584: .Dv .for i in 1 2 3
                    585: a+=     ${i}
                    586: j=      ${i}
                    587: b+=     ${j}
                    588: .Dv .endfor
                    589:
                    590: all:
1.176     wiz       591:        @echo ${a}
1.175     christos  592:        @echo ${b}
                    593:
                    594: .Ed
                    595: will print:
                    596: .Bd -literal -offset indent
                    597: 1 2 3
                    598: 3 3 3
                    599:
                    600: .Ed
                    601: Because while ${a} contains
                    602: .Dq 1 2 3
                    603: after the loop is executed, ${b}
                    604: contains
                    605: .Dq ${j} ${j} ${j}
                    606: which expands to
                    607: .Dq 3 3 3
                    608: since after the loop completes ${j} contains
                    609: .Dq 3 .
                    610: .El
1.91      lukem     611: .Ss Variable classes
1.1       cgd       612: The four different classes of variables (in order of increasing precedence)
                    613: are:
                    614: .Bl -tag -width Ds
                    615: .It Environment variables
                    616: Variables defined as part of
1.74      wiz       617: .Nm Ns 's
1.1       cgd       618: environment.
                    619: .It Global variables
                    620: Variables defined in the makefile or in included makefiles.
                    621: .It Command line variables
                    622: Variables defined as part of the command line.
                    623: .It Local variables
                    624: Variables that are defined specific to a certain target.
                    625: The seven local variables are as follows:
                    626: .Bl -tag -width ".ARCHIVE"
                    627: .It Va .ALLSRC
                    628: The list of all sources for this target; also known as
1.62      ross      629: .Ql Va \&\*[Gt] .
1.1       cgd       630: .It Va .ARCHIVE
                    631: The name of the archive file.
                    632: .It Va .IMPSRC
1.136     cube      633: In suffix-transformation rules, the name/path of the source from which the
1.137     wiz       634: target is to be transformed (the
                    635: .Dq implied
                    636: source); also known as
1.62      ross      637: .Ql Va \&\*[Lt] .
1.136     cube      638: It is not defined in explicit rules.
1.1       cgd       639: .It Va .MEMBER
                    640: The name of the archive member.
                    641: .It Va .OODATE
                    642: The list of sources for this target that were deemed out-of-date; also
                    643: known as
                    644: .Ql Va \&? .
                    645: .It Va .PREFIX
1.177     dholland  646: The file prefix of the target, containing only the file portion, no suffix
1.1       cgd       647: or preceding directory components; also known as
                    648: .Ql Va * .
                    649: .It Va .TARGET
                    650: The name of the target; also known as
                    651: .Ql Va @ .
                    652: .El
                    653: .Pp
                    654: The shorter forms
                    655: .Ql Va @ ,
1.80      wiz       656: .Ql Va \&? ,
1.65      christos  657: .Ql Va \&\*[Lt] ,
                    658: .Ql Va \&\*[Gt] ,
1.1       cgd       659: and
                    660: .Ql Va *
                    661: are permitted for backward
                    662: compatibility with historical makefiles and are not recommended.
                    663: The six variables
                    664: .Ql Va "@F" ,
                    665: .Ql Va "@D" ,
1.62      ross      666: .Ql Va "\*[Lt]F" ,
                    667: .Ql Va "\*[Lt]D" ,
1.66      wiz       668: .Ql Va "*F" ,
1.1       cgd       669: and
                    670: .Ql Va "*D"
1.66      wiz       671: are permitted for compatibility with
1.1       cgd       672: .At V
                    673: makefiles and are not recommended.
                    674: .Pp
                    675: Four of the local variables may be used in sources on dependency lines
                    676: because they expand to the proper value for each target on the line.
                    677: These variables are
                    678: .Ql Va .TARGET ,
                    679: .Ql Va .PREFIX ,
                    680: .Ql Va .ARCHIVE ,
                    681: and
                    682: .Ql Va .MEMBER .
1.59      bgrayson  683: .El
1.145     christos  684: .Ss Additional built-in variables
1.1       cgd       685: In addition,
1.25      lukem     686: .Nm
1.1       cgd       687: sets or knows about the following variables:
1.50      sjg       688: .Bl -tag -width .MAKEOVERRIDES
1.1       cgd       689: .It Va \&$
                    690: A single dollar sign
                    691: .Ql \&$ ,
                    692: i.e.
                    693: .Ql \&$$
                    694: expands to a single dollar
                    695: sign.
1.56      tv        696: .It Va .ALLTARGETS
1.67      grant     697: The list of all targets encountered in the Makefile.
                    698: If evaluated during
1.56      tv        699: Makefile parsing, lists only those targets encountered thus far.
1.1       cgd       700: .It Va .CURDIR
                    701: A path to the directory where
1.25      lukem     702: .Nm
1.1       cgd       703: was executed.
1.117     lukem     704: Refer to the description of
                    705: .Ql Ev PWD
                    706: for more details.
1.78      christos  707: .It Ev MAKE
1.55      tv        708: The name that
                    709: .Nm
1.89      sjg       710: was executed with
                    711: .Pq Va argv[0] .
1.126     reed      712: For compatibility
1.78      christos  713: .Nm
                    714: also sets
                    715: .Va .MAKE
                    716: with the same value.
1.97      lukem     717: The preferred variable to use is the environment variable
1.78      christos  718: .Ev MAKE
                    719: because it is more compatible with other versions of
                    720: .Nm
                    721: and cannot be confused with the special target with the same name.
1.168     sjg       722: .It Va .MAKE.DEPENDFILE
1.169     wiz       723: Names the makefile (default
1.168     sjg       724: .Ql Pa .depend )
                    725: from which generated dependencies are read.
1.205     sjg       726: .It Va .MAKE.EXPAND_VARIABLES
                    727: A boolean that controls the default behavior of the
                    728: .Fl V
                    729: option.
1.134     sjg       730: .It Va .MAKE.EXPORTED
                    731: The list of variables exported by
                    732: .Nm .
1.171     sjg       733: .It Va .MAKE.JOBS
1.172     joerg     734: The argument to the
1.171     sjg       735: .Fl j
                    736: option.
1.132     sjg       737: .It Va .MAKE.JOB.PREFIX
1.137     wiz       738: If
1.132     sjg       739: .Nm
                    740: is run with
                    741: .Ar j
1.137     wiz       742: then output for each target is prefixed with a token
1.132     sjg       743: .Ql --- target ---
                    744: the first part of which can be controlled via
                    745: .Va .MAKE.JOB.PREFIX .
                    746: .br
1.137     wiz       747: For example:
1.132     sjg       748: .Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
                    749: would produce tokens like
                    750: .Ql ---make[1234] target ---
                    751: making it easier to track the degree of parallelism being achieved.
1.1       cgd       752: .It Ev MAKEFLAGS
                    753: The environment variable
                    754: .Ql Ev MAKEFLAGS
                    755: may contain anything that
                    756: may be specified on
1.74      wiz       757: .Nm Ns 's
1.1       cgd       758: command line.
                    759: Anything specified on
1.74      wiz       760: .Nm Ns 's
1.1       cgd       761: command line is appended to the
                    762: .Ql Ev MAKEFLAGS
                    763: variable which is then
                    764: entered into the environment for all programs which
1.25      lukem     765: .Nm
1.1       cgd       766: executes.
1.169     wiz       767: .It Va .MAKE.LEVEL
                    768: The recursion depth of
                    769: .Nm .
                    770: The initial instance of
                    771: .Nm
                    772: will be 0, and an incremented value is put into the environment
                    773: to be seen by the next generation.
                    774: This allows tests like:
                    775: .Li .if ${.MAKE.LEVEL} == 0
                    776: to protect things which should only be evaluated in the initial instance of
                    777: .Nm .
                    778: .It Va .MAKE.MAKEFILE_PREFERENCE
                    779: The ordered list of makefile names
                    780: (default
                    781: .Ql Pa makefile ,
                    782: .Ql Pa Makefile )
                    783: that
                    784: .Nm
                    785: will look for.
                    786: .It Va .MAKE.MAKEFILES
                    787: The list of makefiles read by
                    788: .Nm ,
                    789: which is useful for tracking dependencies.
1.204     sjg       790: Each makefile is recorded only once, regardless of the number of times read.
1.169     wiz       791: .It Va .MAKE.MODE
                    792: Processed after reading all makefiles.
                    793: Can affect the mode that
                    794: .Nm
                    795: runs in.
1.180     sjg       796: It can contain a number of keywords:
                    797: .Bl -hang -width ignore-cmd
                    798: .It Pa compat
1.182     wiz       799: Like
1.184     sjg       800: .Fl B ,
1.182     wiz       801: puts
1.180     sjg       802: .Nm
                    803: into "compat" mode.
                    804: .It Pa meta
                    805: Puts
                    806: .Nm
1.182     wiz       807: into "meta" mode, where meta files are created for each target
1.180     sjg       808: to capture the command run, the output generated and if
                    809: .Xr filemon 4
                    810: is available, the system calls which are of interest to
                    811: .Nm .
                    812: The captured output can be very useful when diagnosing errors.
1.185     sjg       813: .It Pa curdirOk= Ar bf
1.184     sjg       814: Normally
                    815: .Nm
                    816: will not create .meta files in
                    817: .Ql Va .CURDIR .
                    818: This can be overridden by setting
1.188     wiz       819: .Va bf
1.184     sjg       820: to a value which represents True.
1.200     sjg       821: .It Pa env
                    822: For debugging, it can be useful to inlcude the environment
                    823: in the .meta file.
1.180     sjg       824: .It Pa verbose
                    825: If in "meta" mode, print a clue about the target being built.
                    826: This is useful if the build is otherwise running silently.
                    827: The message printed the value of:
                    828: .Va .MAKE.META.PREFIX .
                    829: .It Pa ignore-cmd
                    830: Some makefiles have commands which are simply not stable.
1.182     wiz       831: This keyword causes them to be ignored for
1.180     sjg       832: determining whether a target is out of date in "meta" mode.
                    833: See also
                    834: .Ic .NOMETA_CMP .
1.195     sjg       835: .It Pa silent= Ar bf
                    836: If
                    837: .Va bf
                    838: is True, when a .meta file is created, mark the target
1.200     sjg       839: .Ic .SILENT .
1.180     sjg       840: .El
1.189     sjg       841: .It Va .MAKE.META.BAILIWICK
                    842: In "meta" mode, provides a list of prefixes which
                    843: match the directories controlled by
                    844: .Nm .
                    845: If a file that was generated outside of
                    846: .Va .OBJDIR
                    847: but within said bailiwick is missing,
                    848: the current target is considered out-of-date.
1.180     sjg       849: .It Va .MAKE.META.CREATED
                    850: In "meta" mode, this variable contains a list of all the meta files
                    851: updated.
                    852: If not empty, it can be used to trigger processing of
                    853: .Va .MAKE.META.FILES .
                    854: .It Va .MAKE.META.FILES
                    855: In "meta" mode, this variable contains a list of all the meta files
                    856: used (updated or not).
1.182     wiz       857: This list can be used to process the meta files to extract dependency
1.180     sjg       858: information.
1.216     sjg       859: .It Va .MAKE.META.IGNORE_PATHS
                    860: Provides a list of path prefixes that should be ignored;
                    861: because the contents are expected to change over time.
                    862: The default list includes:
                    863: .Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
1.180     sjg       864: .It Va .MAKE.META.PREFIX
                    865: Defines the message printed for each meta file updated in "meta verbose" mode.
                    866: The default value is:
                    867: .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
1.50      sjg       868: .It Va .MAKEOVERRIDES
1.57      wiz       869: This variable is used to record the names of variables assigned to
                    870: on the command line, so that they may be exported as part of
1.50      sjg       871: .Ql Ev MAKEFLAGS .
1.57      wiz       872: This behaviour can be disabled by assigning an empty value to
1.50      sjg       873: .Ql Va .MAKEOVERRIDES
1.67      grant     874: within a makefile.
                    875: Extra variables can be exported from a makefile
1.57      wiz       876: by appending their names to
1.51      sjg       877: .Ql Va .MAKEOVERRIDES .
                    878: .Ql Ev MAKEFLAGS
1.57      wiz       879: is re-exported whenever
1.51      sjg       880: .Ql Va .MAKEOVERRIDES
                    881: is modified.
1.212     sjg       882: .It Va .MAKE.PATH_FILEMON
                    883: If
                    884: .Nm
1.217     wiz       885: was built with
1.212     sjg       886: .Xr filemon 4
                    887: support, this is set to the path of the device node.
                    888: This allows makefiles to test for this support.
1.169     wiz       889: .It Va .MAKE.PID
                    890: The process-id of
                    891: .Nm .
                    892: .It Va .MAKE.PPID
                    893: The parent process-id of
                    894: .Nm .
1.55      tv        895: .It Va MAKE_PRINT_VAR_ON_ERROR
1.57      wiz       896: When
1.55      tv        897: .Nm
                    898: stops due to an error, it prints its name and the value of
                    899: .Ql Va .CURDIR
1.57      wiz       900: as well as the value of any variables named in
1.55      tv        901: .Ql Va MAKE_PRINT_VAR_ON_ERROR .
                    902: .It Va .newline
                    903: This variable is simply assigned a newline character as its value.
1.91      lukem     904: This allows expansions using the
                    905: .Cm \&:@
                    906: modifier to put a newline between
1.67      grant     907: iterations of the loop rather than a space.
                    908: For example, the printing of
1.55      tv        909: .Ql Va MAKE_PRINT_VAR_ON_ERROR
                    910: could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
                    911: .It Va .OBJDIR
                    912: A path to the directory where the targets are built.
1.117     lukem     913: Its value is determined by trying to
                    914: .Xr chdir 2
                    915: to the following directories in order and using the first match:
                    916: .Bl -enum
                    917: .It
1.118     wiz       918: .Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
                    919: .Pp
1.117     lukem     920: (Only if
                    921: .Ql Ev MAKEOBJDIRPREFIX
                    922: is set in the environment or on the command line.)
                    923: .It
1.118     wiz       924: .Ev ${MAKEOBJDIR}
                    925: .Pp
1.117     lukem     926: (Only if
                    927: .Ql Ev MAKEOBJDIR
                    928: is set in the environment or on the command line.)
                    929: .It
                    930: .Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
                    931: .It
                    932: .Ev ${.CURDIR} Ns Pa /obj
                    933: .It
                    934: .Pa /usr/obj/ Ns Ev ${.CURDIR}
                    935: .It
                    936: .Ev ${.CURDIR}
                    937: .El
                    938: .Pp
                    939: Variable expansion is performed on the value before it's used,
                    940: so expressions such as
1.173     sjg       941: .Dl ${.CURDIR:S,^/usr/src,/var/obj,}
1.117     lukem     942: may be used.
1.173     sjg       943: This is especially useful with
                    944: .Ql Ev MAKEOBJDIR .
1.117     lukem     945: .Pp
                    946: .Ql Va .OBJDIR
                    947: may be modified in the makefile as a global variable.
1.137     wiz       948: In all cases,
1.117     lukem     949: .Nm
                    950: will
                    951: .Xr chdir 2
                    952: to
                    953: .Ql Va .OBJDIR
                    954: and set
                    955: .Ql Ev PWD
                    956: to that directory before executing any targets.
                    957: .
1.55      tv        958: .It Va .PARSEDIR
                    959: A path to the directory of the current
                    960: .Ql Pa Makefile
                    961: being parsed.
                    962: .It Va .PARSEFILE
                    963: The basename of the current
                    964: .Ql Pa Makefile
                    965: being parsed.
                    966: This variable and
                    967: .Ql Va .PARSEDIR
                    968: are both set only while the
                    969: .Ql Pa Makefiles
                    970: are being parsed.
1.196     christos  971: If you want to retain their current values, assign them to a variable
                    972: using assignment with expansion:
                    973: .Pq Ql Cm \&:= .
1.69      sjg       974: .It Va .PATH
1.82      wiz       975: A variable that represents the list of directories that
1.69      sjg       976: .Nm
1.70      wiz       977: will search for files.
                    978: The search list should be updated using the target
1.69      sjg       979: .Ql Va .PATH
                    980: rather than the variable.
1.16      christos  981: .It Ev PWD
                    982: Alternate path to the current directory.
1.25      lukem     983: .Nm
1.16      christos  984: normally sets
                    985: .Ql Va .CURDIR
                    986: to the canonical path given by
1.48      wiz       987: .Xr getcwd 3 .
1.16      christos  988: However, if the environment variable
                    989: .Ql Ev PWD
                    990: is set and gives a path to the current directory, then
1.25      lukem     991: .Nm
1.16      christos  992: sets
                    993: .Ql Va .CURDIR
                    994: to the value of
                    995: .Ql Ev PWD
1.67      grant     996: instead.
                    997: This behaviour is disabled if
1.40      sjg       998: .Ql Ev MAKEOBJDIRPREFIX
1.117     lukem     999: is set or
                   1000: .Ql Ev MAKEOBJDIR
                   1001: contains a variable transform.
1.16      christos 1002: .Ql Ev PWD
                   1003: is set to the value of
                   1004: .Ql Va .OBJDIR
                   1005: for all programs which
1.25      lukem    1006: .Nm
1.16      christos 1007: executes.
1.179     dholland 1008: .It Ev .TARGETS
                   1009: The list of targets explicitly specified on the command line, if any.
1.145     christos 1010: .It Ev VPATH
1.146     wiz      1011: Colon-separated
                   1012: .Pq Dq \&:
                   1013: lists of directories that
                   1014: .Nm
                   1015: will search for files.
1.145     christos 1016: The variable is supported for compatibility with old make programs only,
                   1017: use
                   1018: .Ql Va .PATH
                   1019: instead.
1.1       cgd      1020: .El
1.91      lukem    1021: .Ss Variable modifiers
1.1       cgd      1022: Variable expansion may be modified to select or modify each word of the
1.137     wiz      1023: variable (where a
                   1024: .Dq word
                   1025: is white-space delimited sequence of characters).
1.1       cgd      1026: The general format of a variable expansion is as follows:
                   1027: .Pp
1.120     sjg      1028: .Dl ${variable[:modifier[:...]]}
1.1       cgd      1029: .Pp
1.97      lukem    1030: Each modifier begins with a colon,
                   1031: which may be escaped with a backslash
1.1       cgd      1032: .Pq Ql \e .
1.120     sjg      1033: .Pp
                   1034: A set of modifiers can be specified via a variable, as follows:
                   1035: .Pp
                   1036: .Dl modifier_variable=modifier[:...]
                   1037: .Dl ${variable:${modifier_variable}[:...]}
                   1038: .Pp
                   1039: In this case the first modifier in the modifier_variable does not
                   1040: start with a colon, since that must appear in the referencing
                   1041: variable.
                   1042: If any of the modifiers in the modifier_variable contain a dollar sign
                   1043: .Pq Ql $ ,
                   1044: these must be doubled to avoid early expansion.
                   1045: .Pp
1.97      lukem    1046: The supported modifiers are:
1.61      ross     1047: .Bl -tag -width EEE
1.91      lukem    1048: .It Cm \&:E
1.1       cgd      1049: Replaces each word in the variable with its suffix.
1.91      lukem    1050: .It Cm \&:H
1.1       cgd      1051: Replaces each word in the variable with everything but the last component.
1.91      lukem    1052: .It Cm \&:M Ns Ar pattern
1.72      uebayasi 1053: Select only those words that match
                   1054: .Ar pattern .
1.1       cgd      1055: The standard shell wildcard characters
                   1056: .Pf ( Ql * ,
1.80      wiz      1057: .Ql \&? ,
1.1       cgd      1058: and
1.172     joerg    1059: .Ql Oo Oc )
1.1       cgd      1060: may
                   1061: be used.
                   1062: The wildcard characters may be escaped with a backslash
                   1063: .Pq Ql \e .
1.91      lukem    1064: .It Cm \&:N Ns Ar pattern
1.1       cgd      1065: This is identical to
1.91      lukem    1066: .Ql Cm \&:M ,
1.1       cgd      1067: but selects all words which do not match
1.72      uebayasi 1068: .Ar pattern .
1.91      lukem    1069: .It Cm \&:O
1.109     wiz      1070: Order every word in variable alphabetically.
                   1071: To sort words in
                   1072: reverse order use the
1.108     sjg      1073: .Ql Cm \&:O:[-1..1]
                   1074: combination of modifiers.
                   1075: .It Cm \&:Ox
1.109     wiz      1076: Randomize words in variable.
                   1077: The results will be different each time you are referring to the
                   1078: modified variable; use the assignment with expansion
1.108     sjg      1079: .Pq Ql Cm \&:=
1.109     wiz      1080: to prevent such behaviour.
                   1081: For example,
1.108     sjg      1082: .Bd -literal -offset indent
                   1083: LIST=                  uno due tre quattro
                   1084: RANDOM_LIST=           ${LIST:Ox}
                   1085: STATIC_RANDOM_LIST:=   ${LIST:Ox}
                   1086:
                   1087: all:
                   1088:        @echo "${RANDOM_LIST}"
                   1089:        @echo "${RANDOM_LIST}"
                   1090:        @echo "${STATIC_RANDOM_LIST}"
                   1091:        @echo "${STATIC_RANDOM_LIST}"
                   1092: .Ed
1.109     wiz      1093: may produce output similar to:
1.108     sjg      1094: .Bd -literal -offset indent
                   1095: quattro due tre uno
                   1096: tre due quattro uno
                   1097: due uno quattro tre
                   1098: due uno quattro tre
                   1099: .Ed
1.91      lukem    1100: .It Cm \&:Q
1.17      christos 1101: Quotes every shell meta-character in the variable, so that it can be passed
                   1102: safely through recursive invocations of
1.74      wiz      1103: .Nm .
1.91      lukem    1104: .It Cm \&:R
1.1       cgd      1105: Replaces each word in the variable with everything but its suffix.
1.187     sjg      1106: .It Cm \&:gmtime
1.188     wiz      1107: The value is a format string for
1.187     sjg      1108: .Xr strftime 3 ,
1.188     wiz      1109: using the current
1.187     sjg      1110: .Xr gmtime 3 .
1.186     joerg    1111: .It Cm \&:hash
                   1112: Compute a 32bit hash of the value and encode it as hex digits.
1.187     sjg      1113: .It Cm \&:localtime
1.188     wiz      1114: The value is a format string for
1.187     sjg      1115: .Xr strftime 3 ,
1.188     wiz      1116: using the current
1.187     sjg      1117: .Xr localtime 3 .
1.170     sjg      1118: .It Cm \&:tA
                   1119: Attempt to convert variable to an absolute path using
                   1120: .Xr realpath 3 ,
                   1121: if that fails, the value is unchanged.
1.91      lukem    1122: .It Cm \&:tl
1.60      pk       1123: Converts variable to lower-case letters.
1.91      lukem    1124: .It Cm \&:ts Ns Ar c
1.81      sjg      1125: Words in the variable are normally separated by a space on expansion.
                   1126: This modifier sets the separator to the character
                   1127: .Ar c .
                   1128: If
                   1129: .Ar c
                   1130: is omitted, then no separator is used.
1.170     sjg      1131: The common escapes (including octal numeric codes), work as expected.
1.91      lukem    1132: .It Cm \&:tu
1.82      wiz      1133: Converts variable to upper-case letters.
1.91      lukem    1134: .It Cm \&:tW
1.89      sjg      1135: Causes the value to be treated as a single word
                   1136: (possibly containing embedded white space).
                   1137: See also
1.91      lukem    1138: .Ql Cm \&:[*] .
                   1139: .It Cm \&:tw
1.89      sjg      1140: Causes the value to be treated as a sequence of
                   1141: words delimited by white space.
                   1142: See also
1.91      lukem    1143: .Ql Cm \&:[@] .
1.1       cgd      1144: .Sm off
1.164     joerg    1145: .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1.1       cgd      1146: .Sm on
                   1147: Modify the first occurrence of
1.17      christos 1148: .Ar old_string
                   1149: in the variable's value, replacing it with
                   1150: .Ar new_string .
1.1       cgd      1151: If a
                   1152: .Ql g
                   1153: is appended to the last slash of the pattern, all occurrences
                   1154: in each word are replaced.
1.17      christos 1155: If a
                   1156: .Ql 1
                   1157: is appended to the last slash of the pattern, only the first word
                   1158: is affected.
1.89      sjg      1159: If a
                   1160: .Ql W
                   1161: is appended to the last slash of the pattern,
                   1162: then the value is treated as a single word
                   1163: (possibly containing embedded white space).
1.1       cgd      1164: If
1.17      christos 1165: .Ar old_string
                   1166: begins with a caret
1.1       cgd      1167: .Pq Ql ^ ,
1.17      christos 1168: .Ar old_string
1.1       cgd      1169: is anchored at the beginning of each word.
                   1170: If
1.17      christos 1171: .Ar old_string
1.1       cgd      1172: ends with a dollar sign
                   1173: .Pq Ql \&$ ,
                   1174: it is anchored at the end of each word.
                   1175: Inside
                   1176: .Ar new_string ,
                   1177: an ampersand
1.62      ross     1178: .Pq Ql \*[Am]
1.1       cgd      1179: is replaced by
1.17      christos 1180: .Ar old_string
                   1181: (without any
                   1182: .Ql ^
                   1183: or
                   1184: .Ql \&$ ) .
1.1       cgd      1185: Any character may be used as a delimiter for the parts of the modifier
                   1186: string.
                   1187: The anchoring, ampersand and delimiter characters may be escaped with a
                   1188: backslash
                   1189: .Pq Ql \e .
                   1190: .Pp
                   1191: Variable expansion occurs in the normal fashion inside both
                   1192: .Ar old_string
                   1193: and
                   1194: .Ar new_string
                   1195: with the single exception that a backslash is used to prevent the expansion
                   1196: of a dollar sign
1.17      christos 1197: .Pq Ql \&$ ,
1.1       cgd      1198: not a preceding dollar sign as is usual.
1.17      christos 1199: .Sm off
1.164     joerg    1200: .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1.17      christos 1201: .Sm on
                   1202: The
1.91      lukem    1203: .Cm \&:C
1.17      christos 1204: modifier is just like the
1.91      lukem    1205: .Cm \&:S
1.37      msaitoh  1206: modifier except that the old and new strings, instead of being
1.17      christos 1207: simple strings, are a regular expression (see
                   1208: .Xr regex 3 )
1.72      uebayasi 1209: string
                   1210: .Ar pattern
1.17      christos 1211: and an
                   1212: .Xr ed 1 Ns \-style
1.72      uebayasi 1213: string
                   1214: .Ar replacement .
                   1215: Normally, the first occurrence of the pattern
                   1216: .Ar pattern
                   1217: in each word of the value is substituted with
                   1218: .Ar replacement .
1.67      grant    1219: The
1.17      christos 1220: .Ql 1
                   1221: modifier causes the substitution to apply to at most one word; the
                   1222: .Ql g
                   1223: modifier causes the substitution to apply to as many instances of the
1.72      uebayasi 1224: search pattern
                   1225: .Ar pattern
1.89      sjg      1226: as occur in the word or words it is found in; the
                   1227: .Ql W
                   1228: modifier causes the value to be treated as a single word
                   1229: (possibly containing embedded white space).
1.67      grant    1230: Note that
1.17      christos 1231: .Ql 1
                   1232: and
                   1233: .Ql g
                   1234: are orthogonal; the former specifies whether multiple words are
                   1235: potentially affected, the latter whether multiple substitutions can
                   1236: potentially occur within each affected word.
1.91      lukem    1237: .It Cm \&:T
1.1       cgd      1238: Replaces each word in the variable with its last component.
1.91      lukem    1239: .It Cm \&:u
1.43      christos 1240: Remove adjacent duplicate words (like
1.57      wiz      1241: .Xr uniq 1 ) .
1.91      lukem    1242: .Sm off
                   1243: .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
                   1244: .Sm on
1.152     dsl      1245: If the variable name (not its value), when parsed as a .if conditional
                   1246: expression, evaluates to true, return as its value the
1.57      wiz      1247: .Ar true_string ,
1.27      christos 1248: otherwise return the
1.57      wiz      1249: .Ar false_string .
1.152     dsl      1250: Since the variable name is used as the expression, \&:\&? must be the
                   1251: first modifier after the variable name itself - which will, of course,
                   1252: usually contain variable expansions.
1.162     dsl      1253: A common error is trying to use expressions like
                   1254: .Dl ${NUMBERS:M42:?match:no}
                   1255: which actually tests defined(NUMBERS),
                   1256: to determine is any words match "42" you need to use something like:
1.183     sjg      1257: .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1.91      lukem    1258: .It Ar :old_string=new_string
1.1       cgd      1259: This is the
                   1260: .At V
                   1261: style variable substitution.
                   1262: It must be the last modifier specified.
1.16      christos 1263: If
1.6       cgd      1264: .Ar old_string
                   1265: or
                   1266: .Ar new_string
                   1267: do not contain the pattern matching character
                   1268: .Ar %
1.16      christos 1269: then it is assumed that they are
1.6       cgd      1270: anchored at the end of each word, so only suffixes or entire
1.67      grant    1271: words may be replaced.
                   1272: Otherwise
1.6       cgd      1273: .Ar %
1.16      christos 1274: is the substring of
                   1275: .Ar old_string
1.6       cgd      1276: to be replaced in
1.64      wiz      1277: .Ar new_string .
1.95      jmc      1278: .Pp
                   1279: Variable expansion occurs in the normal fashion inside both
                   1280: .Ar old_string
                   1281: and
                   1282: .Ar new_string
1.96      wiz      1283: with the single exception that a backslash is used to prevent the
                   1284: expansion of a dollar sign
                   1285: .Pq Ql \&$ ,
                   1286: not a preceding dollar sign as is usual.
1.91      lukem    1287: .Sm off
1.164     joerg    1288: .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1.91      lukem    1289: .Sm on
1.40      sjg      1290: This is the loop expansion mechanism from the OSF Development
1.67      grant    1291: Environment (ODE) make.
                   1292: Unlike
1.48      wiz      1293: .Cm \&.for
1.40      sjg      1294: loops expansion occurs at the time of
1.67      grant    1295: reference.
                   1296: Assign
1.40      sjg      1297: .Ar temp
                   1298: to each word in the variable and evaluate
                   1299: .Ar string .
1.48      wiz      1300: The ODE convention is that
1.40      sjg      1301: .Ar temp
1.67      grant    1302: should start and end with a period.
                   1303: For example.
1.40      sjg      1304: .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1.198     sjg      1305: .Pp
1.218   ! agc      1306: However a single character variable is often more readable:
1.198     sjg      1307: .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1.91      lukem    1308: .It Cm \&:U Ns Ar newval
1.40      sjg      1309: If the variable is undefined
                   1310: .Ar newval
1.63      lukem    1311: is the value.
                   1312: If the variable is defined, the existing value is returned.
1.67      grant    1313: This is another ODE make feature.
                   1314: It is handy for setting per-target CFLAGS for instance:
1.40      sjg      1315: .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1.63      lukem    1316: If a value is only required if the variable is undefined, use:
                   1317: .Dl ${VAR:D:Unewval}
1.91      lukem    1318: .It Cm \&:D Ns Ar newval
1.40      sjg      1319: If the variable is defined
                   1320: .Ar newval
                   1321: is the value.
1.91      lukem    1322: .It Cm \&:L
1.40      sjg      1323: The name of the variable is the value.
1.91      lukem    1324: .It Cm \&:P
1.40      sjg      1325: The path of the node which has the same name as the variable
1.67      grant    1326: is the value.
                   1327: If no such node exists or its path is null, then the
1.40      sjg      1328: name of the variable is used.
1.217     wiz      1329: In order for this modifier to work, the name (node) must at least have
1.199     sjg      1330: appeared on the rhs of a dependency.
1.91      lukem    1331: .Sm off
                   1332: .It Cm \&:\&! Ar cmd Cm \&!
                   1333: .Sm on
1.40      sjg      1334: The output of running
                   1335: .Ar cmd
                   1336: is the value.
1.91      lukem    1337: .It Cm \&:sh
1.40      sjg      1338: If the variable is non-empty it is run as a command and the output
                   1339: becomes the new value.
1.91      lukem    1340: .It Cm \&::= Ns Ar str
1.48      wiz      1341: The variable is assigned the value
1.41      sjg      1342: .Ar str
1.67      grant    1343: after substitution.
                   1344: This modifier and its variations are useful in
1.149     dsl      1345: obscure situations such as wanting to set a variable when shell commands
                   1346: are being parsed.
1.67      grant    1347: These assignment modifiers always expand to
1.41      sjg      1348: nothing, so if appearing in a rule line by themselves should be
1.48      wiz      1349: preceded with something to keep
1.41      sjg      1350: .Nm
1.67      grant    1351: happy.
1.149     dsl      1352: .Pp
1.91      lukem    1353: The
                   1354: .Ql Cm \&::
1.42      sjg      1355: helps avoid false matches with the
                   1356: .At V
1.48      wiz      1357: style
1.91      lukem    1358: .Cm \&:=
1.48      wiz      1359: modifier and since substitution always occurs the
1.91      lukem    1360: .Cm \&::=
1.42      sjg      1361: form is vaguely appropriate.
1.91      lukem    1362: .It Cm \&::?= Ns Ar str
1.41      sjg      1363: As for
1.91      lukem    1364: .Cm \&::=
1.41      sjg      1365: but only if the variable does not already have a value.
1.91      lukem    1366: .It Cm \&::+= Ns Ar str
1.48      wiz      1367: Append
1.41      sjg      1368: .Ar str
                   1369: to the variable.
1.91      lukem    1370: .It Cm \&::!= Ns Ar cmd
1.48      wiz      1371: Assign the output of
1.41      sjg      1372: .Ar cmd
                   1373: to the variable.
1.91      lukem    1374: .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1.89      sjg      1375: Selects one or more words from the value,
                   1376: or performs other operations related to the way in which the
                   1377: value is divided into words.
                   1378: .Pp
                   1379: Ordinarily, a value is treated as a sequence of words
                   1380: delimited by white space.
                   1381: Some modifiers suppress this behaviour,
                   1382: causing a value to be treated as a single word
                   1383: (possibly containing embedded white space).
                   1384: An empty value, or a value that consists entirely of white-space,
                   1385: is treated as a single word.
                   1386: For the purposes of the
1.91      lukem    1387: .Ql Cm \&:[]
1.89      sjg      1388: modifier, the words are indexed both forwards using positive integers
                   1389: (where index 1 represents the first word),
                   1390: and backwards using negative integers
1.194     sjg      1391: (where index \-1 represents the last word).
1.89      sjg      1392: .Pp
                   1393: The
                   1394: .Ar range
                   1395: is subjected to variable expansion, and the expanded result is
                   1396: then interpreted as follows:
                   1397: .Bl -tag -width index
1.90      jdolecek 1398: .\" :[n]
1.89      sjg      1399: .It Ar index
                   1400: Selects a single word from the value.
1.90      jdolecek 1401: .\" :[start..end]
1.89      sjg      1402: .It Ar start Ns Cm \&.. Ns Ar end
                   1403: Selects all words from
                   1404: .Ar start
                   1405: to
                   1406: .Ar end ,
                   1407: inclusive.
                   1408: For example,
1.91      lukem    1409: .Ql Cm \&:[2..-1]
1.89      sjg      1410: selects all words from the second word to the last word.
                   1411: If
                   1412: .Ar start
                   1413: is greater than
                   1414: .Ar end ,
1.91      lukem    1415: then the words are output in reverse order.
                   1416: For example,
                   1417: .Ql Cm \&:[-1..1]
1.89      sjg      1418: selects all the words from last to first.
1.90      jdolecek 1419: .\" :[*]
1.89      sjg      1420: .It Cm \&*
                   1421: Causes subsequent modifiers to treat the value as a single word
1.109     wiz      1422: (possibly containing embedded white space).
                   1423: Analogous to the effect of
1.94      wiz      1424: \&"$*\&"
1.89      sjg      1425: in Bourne shell.
1.90      jdolecek 1426: .\" :[0]
1.89      sjg      1427: .It 0
                   1428: Means the same as
1.91      lukem    1429: .Ql Cm \&:[*] .
1.90      jdolecek 1430: .\" :[*]
1.89      sjg      1431: .It Cm \&@
                   1432: Causes subsequent modifiers to treat the value as a sequence of words
1.109     wiz      1433: delimited by white space.
                   1434: Analogous to the effect of
1.94      wiz      1435: \&"$@\&"
1.89      sjg      1436: in Bourne shell.
1.90      jdolecek 1437: .\" :[#]
1.89      sjg      1438: .It Cm \&#
                   1439: Returns the number of words in the value.
                   1440: .El \" :[range]
1.6       cgd      1441: .El
                   1442: .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1.16      christos 1443: Makefile inclusion, conditional structures and for loops  reminiscent
1.6       cgd      1444: of the C programming language are provided in
1.74      wiz      1445: .Nm .
1.1       cgd      1446: All such structures are identified by a line beginning with a single
                   1447: dot
                   1448: .Pq Ql \&.
                   1449: character.
                   1450: Files are included with either
1.29      ross     1451: .Cm \&.include Aq Ar file
1.1       cgd      1452: or
1.29      ross     1453: .Cm \&.include Pf \*q Ar file Ns \*q .
1.1       cgd      1454: Variables between the angle brackets or double quotes are expanded
                   1455: to form the file name.
                   1456: If angle brackets are used, the included makefile is expected to be in
                   1457: the system makefile directory.
                   1458: If double quotes are used, the including makefile's directory and any
                   1459: directories specified using the
                   1460: .Fl I
                   1461: option are searched before the system
                   1462: makefile directory.
1.28      christos 1463: For compatibility with other versions of
                   1464: .Nm
                   1465: .Ql include file ...
1.67      grant    1466: is also accepted.
                   1467: If the include statement is written as
1.29      ross     1468: .Cm .-include
                   1469: or as
                   1470: .Cm .sinclude
1.28      christos 1471: then errors locating and/or opening include files are ignored.
1.1       cgd      1472: .Pp
                   1473: Conditional expressions are also preceded by a single dot as the first
1.5       jtc      1474: character of a line.
1.1       cgd      1475: The possible conditionals are as follows:
                   1476: .Bl -tag -width Ds
1.168     sjg      1477: .It Ic .error Ar message
                   1478: The message is printed along with the name of the makefile and line number,
                   1479: then
                   1480: .Nm
                   1481: will exit.
1.165     sjg      1482: .It Ic .export Ar variable ...
1.133     sjg      1483: Export the specified global variable.
1.165     sjg      1484: If no variable list is provided, all globals are exported
1.133     sjg      1485: except for internal variables (those that start with
1.157     wiz      1486: .Ql \&. ) .
1.133     sjg      1487: This is not affected by the
                   1488: .Fl X
                   1489: flag, so should be used with caution.
1.201     christos 1490: For compatibility with other
                   1491: .Nm
                   1492: programs
                   1493: .Ql export variable=value
                   1494: is also accepted.
1.165     sjg      1495: .Pp
1.133     sjg      1496: Appending a variable name to
                   1497: .Va .MAKE.EXPORTED
                   1498: is equivalent to exporting a variable.
1.173     sjg      1499: .It Ic .export-env Ar variable ...
1.176     wiz      1500: The same as
1.173     sjg      1501: .Ql .export ,
1.176     wiz      1502: except that the variable is not appended to
1.173     sjg      1503: .Va .MAKE.EXPORTED .
1.176     wiz      1504: This allows exporting a value to the environment which is different from that
                   1505: used by
1.173     sjg      1506: .Nm
                   1507: internally.
1.168     sjg      1508: .It Ic .info Ar message
                   1509: The message is printed along with the name of the makefile and line number.
1.169     wiz      1510: .It Ic .undef Ar variable
                   1511: Un-define the specified global variable.
                   1512: Only global variables may be un-defined.
1.165     sjg      1513: .It Ic .unexport Ar variable ...
                   1514: The opposite of
                   1515: .Ql .export .
                   1516: The specified global
1.166     wiz      1517: .Va variable
                   1518: will be removed from
1.165     sjg      1519: .Va .MAKE.EXPORTED .
                   1520: If no variable list is provided, all globals are unexported,
                   1521: and
1.166     wiz      1522: .Va .MAKE.EXPORTED
1.165     sjg      1523: deleted.
                   1524: .It Ic .unexport-env
                   1525: Unexport all globals previously exported and
                   1526: clear the environment inherited from the parent.
1.166     wiz      1527: This operation will cause a memory leak of the original environment,
                   1528: so should be used sparingly.
                   1529: Testing for
1.165     sjg      1530: .Va .MAKE.LEVEL
                   1531: being 0, would make sense.
1.166     wiz      1532: Also note that any variables which originated in the parent environment
1.165     sjg      1533: should be explicitly preserved if desired.
                   1534: For example:
                   1535: .Bd -literal -offset indent
                   1536: .Li .if ${.MAKE.LEVEL} == 0
                   1537: PATH := ${PATH}
                   1538: .Li .unexport-env
                   1539: .Li .export PATH
                   1540: .Li .endif
                   1541: .Pp
                   1542: .Ed
1.166     wiz      1543: Would result in an environment containing only
1.165     sjg      1544: .Ql Ev PATH ,
                   1545: which is the minimal useful environment.
                   1546: Actually
1.166     wiz      1547: .Ql Ev .MAKE.LEVEL
1.165     sjg      1548: will also be pushed into the new environment.
1.168     sjg      1549: .It Ic .warning Ar message
                   1550: The message prefixed by
                   1551: .Ql Pa warning:
                   1552: is printed along with the name of the makefile and line number.
1.164     joerg    1553: .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1.1       cgd      1554: Test the value of an expression.
1.164     joerg    1555: .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1.7       mycroft  1556: Test the value of a variable.
1.164     joerg    1557: .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1.7       mycroft  1558: Test the value of a variable.
1.164     joerg    1559: .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1.7       mycroft  1560: Test the target being built.
1.164     joerg    1561: .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1.1       cgd      1562: Test the target being built.
                   1563: .It Ic .else
                   1564: Reverse the sense of the last conditional.
1.164     joerg    1565: .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1.1       cgd      1566: A combination of
                   1567: .Ql Ic .else
                   1568: followed by
                   1569: .Ql Ic .if .
1.164     joerg    1570: .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1.1       cgd      1571: A combination of
                   1572: .Ql Ic .else
                   1573: followed by
                   1574: .Ql Ic .ifdef .
1.164     joerg    1575: .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1.1       cgd      1576: A combination of
                   1577: .Ql Ic .else
                   1578: followed by
                   1579: .Ql Ic .ifndef .
1.164     joerg    1580: .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1.1       cgd      1581: A combination of
                   1582: .Ql Ic .else
                   1583: followed by
                   1584: .Ql Ic .ifmake .
1.164     joerg    1585: .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1.1       cgd      1586: A combination of
                   1587: .Ql Ic .else
                   1588: followed by
                   1589: .Ql Ic .ifnmake .
                   1590: .It Ic .endif
                   1591: End the body of the conditional.
                   1592: .El
                   1593: .Pp
                   1594: The
                   1595: .Ar operator
                   1596: may be any one of the following:
                   1597: .Bl -tag -width "Cm XX"
                   1598: .It Cm \&|\&|
1.64      wiz      1599: Logical OR.
1.62      ross     1600: .It Cm \&\*[Am]\*[Am]
1.1       cgd      1601: Logical
                   1602: .Tn AND ;
                   1603: of higher precedence than
1.26      hubertf  1604: .Dq \&|\&| .
1.1       cgd      1605: .El
                   1606: .Pp
                   1607: As in C,
1.25      lukem    1608: .Nm
1.1       cgd      1609: will only evaluate a conditional as far as is necessary to determine
                   1610: its value.
1.16      christos 1611: Parentheses may be used to change the order of evaluation.
1.1       cgd      1612: The boolean operator
                   1613: .Ql Ic \&!
                   1614: may be used to logically negate an entire
                   1615: conditional.
1.5       jtc      1616: It is of higher precedence than
1.62      ross     1617: .Ql Ic \&\*[Am]\*[Am] .
1.1       cgd      1618: .Pp
                   1619: The value of
                   1620: .Ar expression
                   1621: may be any of the following:
1.61      ross     1622: .Bl -tag -width defined
1.1       cgd      1623: .It Ic defined
                   1624: Takes a variable name as an argument and evaluates to true if the variable
                   1625: has been defined.
                   1626: .It Ic make
                   1627: Takes a target name as an argument and evaluates to true if the target
                   1628: was specified as part of
1.74      wiz      1629: .Nm Ns 's
1.1       cgd      1630: command line or was declared the default target (either implicitly or
                   1631: explicitly, see
                   1632: .Va .MAIN )
                   1633: before the line containing the conditional.
                   1634: .It Ic empty
1.5       jtc      1635: Takes a variable, with possible modifiers, and evaluates to true if
1.1       cgd      1636: the expansion of the variable would result in an empty string.
                   1637: .It Ic exists
                   1638: Takes a file name as an argument and evaluates to true if the file exists.
                   1639: The file is searched for on the system search path (see
                   1640: .Va .PATH ) .
                   1641: .It Ic target
                   1642: Takes a target name as an argument and evaluates to true if the target
                   1643: has been defined.
1.47      christos 1644: .It Ic commands
                   1645: Takes a target name as an argument and evaluates to true if the target
                   1646: has been defined and has commands associated with it.
1.1       cgd      1647: .El
                   1648: .Pp
                   1649: .Ar Expression
1.67      grant    1650: may also be an arithmetic or string comparison.
                   1651: Variable expansion is
1.6       cgd      1652: performed on both sides of the comparison, after which the integral
1.67      grant    1653: values are compared.
                   1654: A value is interpreted as hexadecimal if it is
1.6       cgd      1655: preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1.67      grant    1656: The standard C relational operators are all supported.
                   1657: If after
1.6       cgd      1658: variable expansion, either the left or right hand side of a
1.1       cgd      1659: .Ql Ic ==
                   1660: or
                   1661: .Ql Ic "!="
1.6       cgd      1662: operator is not an integral value, then
                   1663: string comparison is performed between the expanded
                   1664: variables.
1.1       cgd      1665: If no relational operator is given, it is assumed that the expanded
1.102     sjg      1666: variable is being compared against 0 or an empty string in the case
                   1667: of a string comparison.
1.1       cgd      1668: .Pp
                   1669: When
1.25      lukem    1670: .Nm
1.150     dsl      1671: is evaluating one of these conditional expressions, and it encounters
                   1672: a (white-space separated) word it doesn't recognize, either the
1.137     wiz      1673: .Dq make
                   1674: or
                   1675: .Dq defined
1.1       cgd      1676: expression is applied to it, depending on the form of the conditional.
                   1677: If the form is
1.150     dsl      1678: .Ql Ic .ifdef ,
                   1679: .Ql Ic .ifndef ,
1.1       cgd      1680: or
1.150     dsl      1681: .Ql Ic .if
1.137     wiz      1682: the
                   1683: .Dq defined
                   1684: expression is applied.
1.1       cgd      1685: Similarly, if the form is
                   1686: .Ql Ic .ifmake
                   1687: or
1.137     wiz      1688: .Ql Ic .ifnmake , the
                   1689: .Dq make
1.1       cgd      1690: expression is applied.
                   1691: .Pp
                   1692: If the conditional evaluates to true the parsing of the makefile continues
                   1693: as before.
                   1694: If it evaluates to false, the following lines are skipped.
                   1695: In both cases this continues until a
                   1696: .Ql Ic .else
                   1697: or
                   1698: .Ql Ic .endif
                   1699: is found.
1.16      christos 1700: .Pp
1.6       cgd      1701: For loops are typically used to apply a set of rules to a list of files.
                   1702: The syntax of a for loop is:
1.59      bgrayson 1703: .Pp
                   1704: .Bl -tag -compact -width Ds
1.164     joerg    1705: .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1.80      wiz      1706: .It Aq make-rules
                   1707: .It Ic \&.endfor
1.6       cgd      1708: .El
1.59      bgrayson 1709: .Pp
1.6       cgd      1710: After the for
1.16      christos 1711: .Ic expression
1.67      grant    1712: is evaluated, it is split into words.
                   1713: On each iteration of the loop, one word is taken and assigned to each
1.39      christos 1714: .Ic variable ,
                   1715: in order, and these
                   1716: .Ic variables
                   1717: are substituted into the
1.16      christos 1718: .Ic make-rules
1.6       cgd      1719: inside the body of the for loop.
1.39      christos 1720: The number of words must come out even; that is, if there are three
                   1721: iteration variables, the number of words provided must be a multiple
                   1722: of three.
1.1       cgd      1723: .Sh COMMENTS
                   1724: Comments begin with a hash
                   1725: .Pq Ql \&#
                   1726: character, anywhere but in a shell
1.114     wiz      1727: command line, and continue to the end of an unescaped new line.
1.97      lukem    1728: .Sh SPECIAL SOURCES (ATTRIBUTES)
1.61      ross     1729: .Bl -tag -width .IGNOREx
1.97      lukem    1730: .It Ic .EXEC
                   1731: Target is never out of date, but always execute commands anyway.
1.1       cgd      1732: .It Ic .IGNORE
                   1733: Ignore any errors from the commands associated with this target, exactly
                   1734: as if they all were preceded by a dash
                   1735: .Pq Ql \- .
1.97      lukem    1736: .\" .It Ic .INVISIBLE
                   1737: .\" XXX
                   1738: .\" .It Ic .JOIN
                   1739: .\" XXX
1.18      christos 1740: .It Ic .MADE
1.48      wiz      1741: Mark all sources of this target as being up-to-date.
1.1       cgd      1742: .It Ic .MAKE
                   1743: Execute the commands associated with this target even if the
                   1744: .Fl n
                   1745: or
                   1746: .Fl t
                   1747: options were specified.
                   1748: Normally used to mark recursive
1.74      wiz      1749: .Nm Ns 's .
1.180     sjg      1750: .It Ic .META
                   1751: Create a meta file for the target, even if it is flagged as
                   1752: .Ic .PHONY ,
1.182     wiz      1753: .Ic .MAKE ,
1.180     sjg      1754: or
                   1755: .Ic .SPECIAL .
                   1756: Usage in conjunction with
                   1757: .Ic .MAKE
                   1758: is the most likely case.
1.194     sjg      1759: In "meta" mode, the target is out-of-date if the meta file is missing.
1.180     sjg      1760: .It Ic .NOMETA
                   1761: Do not create a meta file for the target.
                   1762: Meta files are also not created for
                   1763: .Ic .PHONY ,
1.182     wiz      1764: .Ic .MAKE ,
1.180     sjg      1765: or
                   1766: .Ic .SPECIAL
                   1767: targets.
                   1768: .It Ic .NOMETA_CMP
                   1769: Ignore differences in commands when deciding if target is out of date.
                   1770: This is useful if the command contains a value which always changes.
1.182     wiz      1771: If the number of commands change, though, the target will still be out of date.
1.213     sjg      1772: The same effect applies to any command line that uses the variable
                   1773: .Va .OODATE ,
                   1774: which can be used for that purpose even when not otherwise needed or desired:
                   1775: .Bd -literal -offset indent
                   1776:
                   1777: skip-compare-for-some:
                   1778:        @echo this will be compared
                   1779:        @echo this will not ${.OODATE:M.NOMETA_CMP}
                   1780:        @echo this will also be compared
                   1781:
                   1782: .Ed
                   1783: The
                   1784: .Cm \&:M
                   1785: pattern suppresses any expansion of the unwanted variable.
1.97      lukem    1786: .It Ic .NOPATH
                   1787: Do not search for the target in the directories specified by
                   1788: .Ic .PATH .
1.1       cgd      1789: .It Ic .NOTMAIN
                   1790: Normally
1.25      lukem    1791: .Nm
1.1       cgd      1792: selects the first target it encounters as the default target to be built
                   1793: if no target was specified.
                   1794: This source prevents this target from being selected.
                   1795: .It Ic .OPTIONAL
                   1796: If a target is marked with this attribute and
1.25      lukem    1797: .Nm
1.1       cgd      1798: can't figure out how to create it, it will ignore this fact and assume
                   1799: the file isn't needed or already exists.
1.97      lukem    1800: .It Ic .PHONY
                   1801: The target does not
                   1802: correspond to an actual file; it is always considered to be out of date,
                   1803: and will not be created with the
                   1804: .Fl t
                   1805: option.
1.179     dholland 1806: Suffix-transformation rules are not applied to
                   1807: .Ic .PHONY
                   1808: targets.
1.1       cgd      1809: .It Ic .PRECIOUS
                   1810: When
1.25      lukem    1811: .Nm
1.131     rillig   1812: is interrupted, it normally removes any partially made targets.
1.1       cgd      1813: This source prevents the target from being removed.
1.97      lukem    1814: .It Ic .RECURSIVE
                   1815: Synonym for
                   1816: .Ic .MAKE .
1.1       cgd      1817: .It Ic .SILENT
                   1818: Do not echo any of the commands associated with this target, exactly
                   1819: as if they all were preceded by an at sign
                   1820: .Pq Ql @ .
                   1821: .It Ic .USE
                   1822: Turn the target into
1.74      wiz      1823: .Nm Ns 's
1.1       cgd      1824: version of a macro.
                   1825: When the target is used as a source for another target, the other target
                   1826: acquires the commands, sources, and attributes (except for
                   1827: .Ic .USE )
                   1828: of the
                   1829: source.
                   1830: If the target already has commands, the
                   1831: .Ic .USE
                   1832: target's commands are appended
                   1833: to them.
1.52      christos 1834: .It Ic .USEBEFORE
                   1835: Exactly like
                   1836: .Ic .USE ,
1.57      wiz      1837: but prepend the
1.52      christos 1838: .Ic .USEBEFORE
                   1839: target commands to the target.
1.12      christos 1840: .It Ic .WAIT
1.71      mjl      1841: If
1.12      christos 1842: .Ic .WAIT
1.71      mjl      1843: appears in a dependency line, the sources that precede it are
1.67      grant    1844: made before the sources that succeed it in the line.
1.128     dsl      1845: Since the dependents of files are not made until the file itself
                   1846: could be made, this also stops the dependents being built unless they
                   1847: are needed for another branch of the dependency tree.
                   1848: So given:
                   1849: .Bd -literal
                   1850: x: a .WAIT b
                   1851:        echo x
                   1852: a:
                   1853:        echo a
                   1854: b: b1
                   1855:        echo b
                   1856: b1:
                   1857:        echo b1
                   1858:
                   1859: .Ed
                   1860: the output is always
1.151     dholland 1861: .Ql a ,
1.128     dsl      1862: .Ql b1 ,
                   1863: .Ql b ,
                   1864: .Ql x .
                   1865: .br
1.122     apb      1866: The ordering imposed by
                   1867: .Ic .WAIT
1.128     dsl      1868: is only relevant for parallel makes.
1.1       cgd      1869: .El
1.57      wiz      1870: .Sh SPECIAL TARGETS
1.1       cgd      1871: Special targets may not be included with other targets, i.e. they must be
                   1872: the only target specified.
1.61      ross     1873: .Bl -tag -width .BEGINx
1.1       cgd      1874: .It Ic .BEGIN
                   1875: Any command lines attached to this target are executed before anything
                   1876: else is done.
                   1877: .It Ic .DEFAULT
                   1878: This is sort of a
                   1879: .Ic .USE
                   1880: rule for any target (that was used only as a
                   1881: source) that
1.25      lukem    1882: .Nm
1.1       cgd      1883: can't figure out any other way to create.
                   1884: Only the shell script is used.
                   1885: The
                   1886: .Ic .IMPSRC
                   1887: variable of a target that inherits
                   1888: .Ic .DEFAULT Ns 's
                   1889: commands is set
                   1890: to the target's own name.
                   1891: .It Ic .END
                   1892: Any command lines attached to this target are executed after everything
                   1893: else is done.
1.168     sjg      1894: .It Ic .ERROR
                   1895: Any command lines attached to this target are executed when another target fails.
                   1896: The
                   1897: .Ic .ERROR_TARGET
                   1898: variable is set to the target that failed.
1.169     wiz      1899: See also
1.168     sjg      1900: .Ic MAKE_PRINT_VAR_ON_ERROR .
1.1       cgd      1901: .It Ic .IGNORE
                   1902: Mark each of the sources with the
                   1903: .Ic .IGNORE
                   1904: attribute.
                   1905: If no sources are specified, this is the equivalent of specifying the
                   1906: .Fl i
                   1907: option.
                   1908: .It Ic .INTERRUPT
                   1909: If
1.25      lukem    1910: .Nm
1.1       cgd      1911: is interrupted, the commands for this target will be executed.
                   1912: .It Ic .MAIN
                   1913: If no target is specified when
1.25      lukem    1914: .Nm
1.1       cgd      1915: is invoked, this target will be built.
                   1916: .It Ic .MAKEFLAGS
                   1917: This target provides a way to specify flags for
1.25      lukem    1918: .Nm
1.1       cgd      1919: when the makefile is used.
                   1920: The flags are as if typed to the shell, though the
                   1921: .Fl f
                   1922: option will have
                   1923: no effect.
1.12      christos 1924: .\" XXX: NOT YET!!!!
                   1925: .\" .It Ic .NOTPARALLEL
1.70      wiz      1926: .\" The named targets are executed in non parallel mode.
                   1927: .\" If no targets are
1.12      christos 1928: .\" specified, then all targets are executed in non parallel mode.
1.20      gwr      1929: .It Ic .NOPATH
                   1930: Apply the
                   1931: .Ic .NOPATH
1.67      grant    1932: attribute to any specified sources.
1.12      christos 1933: .It Ic .NOTPARALLEL
                   1934: Disable parallel mode.
                   1935: .It Ic .NO_PARALLEL
1.97      lukem    1936: Synonym for
                   1937: .Ic .NOTPARALLEL ,
                   1938: for compatibility with other pmake variants.
1.12      christos 1939: .It Ic .ORDER
                   1940: The named targets are made in sequence.
1.128     dsl      1941: This ordering does not add targets to the list of targets to be made.
                   1942: Since the dependents of a target do not get built until the target itself
                   1943: could be built, unless
                   1944: .Ql a
1.129     wiz      1945: is built by another part of the dependency graph,
1.128     dsl      1946: the following is a dependency loop:
                   1947: .Bd -literal
1.192     cheusov  1948: \&.ORDER: b a
1.128     dsl      1949: b: a
                   1950: .Ed
1.129     wiz      1951: .Pp
1.122     apb      1952: The ordering imposed by
                   1953: .Ic .ORDER
1.128     dsl      1954: is only relevant for parallel makes.
1.12      christos 1955: .\" XXX: NOT YET!!!!
                   1956: .\" .It Ic .PARALLEL
1.70      wiz      1957: .\" The named targets are executed in parallel mode.
                   1958: .\" If no targets are
1.12      christos 1959: .\" specified, then all targets are executed in parallel mode.
1.1       cgd      1960: .It Ic .PATH
                   1961: The sources are directories which are to be searched for files not
                   1962: found in the current directory.
                   1963: If no sources are specified, any previously specified directories are
                   1964: deleted.
1.34      thorpej  1965: If the source is the special
                   1966: .Ic .DOTLAST
                   1967: target, then the current working
1.33      thorpej  1968: directory is searched last.
1.14      christos 1969: .It Ic .PHONY
                   1970: Apply the
                   1971: .Ic .PHONY
1.67      grant    1972: attribute to any specified sources.
1.1       cgd      1973: .It Ic .PRECIOUS
                   1974: Apply the
                   1975: .Ic .PRECIOUS
                   1976: attribute to any specified sources.
                   1977: If no sources are specified, the
                   1978: .Ic .PRECIOUS
                   1979: attribute is applied to every
                   1980: target in the file.
1.83      sjg      1981: .It Ic .SHELL
1.86      wiz      1982: Sets the shell that
1.83      sjg      1983: .Nm
1.86      wiz      1984: will use to execute commands.
                   1985: The sources are a set of
1.83      sjg      1986: .Ar field=value
1.86      wiz      1987: pairs.
1.83      sjg      1988: .Bl -tag -width hasErrCtls
                   1989: .It Ar name
                   1990: This is the minimal specification, used to select one of the builtin
                   1991: shell specs;
                   1992: .Ar sh ,
                   1993: .Ar ksh ,
                   1994: and
                   1995: .Ar csh .
                   1996: .It Ar path
                   1997: Specifies the path to the shell.
                   1998: .It Ar hasErrCtl
                   1999: Indicates whether the shell supports exit on error.
                   2000: .It Ar check
                   2001: The command to turn on error checking.
                   2002: .It Ar ignore
                   2003: The command to disable error checking.
                   2004: .It Ar echo
                   2005: The command to turn on echoing of commands executed.
                   2006: .It Ar quiet
                   2007: The command to turn off echoing of commands executed.
                   2008: .It Ar filter
                   2009: The output to filter after issuing the
                   2010: .Ar quiet
1.86      wiz      2011: command.
                   2012: It is typically identical to
1.83      sjg      2013: .Ar quiet .
                   2014: .It Ar errFlag
                   2015: The flag to pass the shell to enable error checking.
                   2016: .It Ar echoFlag
                   2017: The flag to pass the shell to enable command echoing.
1.127     rillig   2018: .It Ar newline
                   2019: The string literal to pass the shell that results in a single newline
                   2020: character when used outside of any quoting characters.
1.83      sjg      2021: .El
                   2022: Example:
                   2023: .Bd -literal
1.167     joerg    2024: \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
1.194     sjg      2025:        check="set \-e" ignore="set +e" \e
                   2026:        echo="set \-v" quiet="set +v" filter="set +v" \e
1.167     joerg    2027:        echoFlag=v errFlag=e newline="'\en'"
1.83      sjg      2028: .Ed
1.1       cgd      2029: .It Ic .SILENT
                   2030: Apply the
                   2031: .Ic .SILENT
                   2032: attribute to any specified sources.
                   2033: If no sources are specified, the
                   2034: .Ic .SILENT
                   2035: attribute is applied to every
                   2036: command in the file.
1.211     christos 2037: .It Ic .STALE
                   2038: This target gets run when a dependency file contains stale entries, having
                   2039: .Va .ALLSRC
                   2040: set to the name of that dependency file.
1.1       cgd      2041: .It Ic .SUFFIXES
                   2042: Each source specifies a suffix to
1.74      wiz      2043: .Nm .
1.71      mjl      2044: If no sources are specified, any previously specified suffixes are deleted.
1.136     cube     2045: It allows the creation of suffix-transformation rules.
                   2046: .Pp
                   2047: Example:
                   2048: .Bd -literal
                   2049: \&.SUFFIXES: .o
                   2050: \&.c.o:
1.194     sjg      2051:        cc \-o ${.TARGET} \-c ${.IMPSRC}
1.136     cube     2052: .Ed
1.31      ross     2053: .El
1.1       cgd      2054: .Sh ENVIRONMENT
1.25      lukem    2055: .Nm
1.73      perry    2056: uses the following environment variables, if they exist:
1.16      christos 2057: .Ev MACHINE ,
1.26      hubertf  2058: .Ev MACHINE_ARCH ,
1.1       cgd      2059: .Ev MAKE ,
1.16      christos 2060: .Ev MAKEFLAGS ,
                   2061: .Ev MAKEOBJDIR ,
1.38      sjg      2062: .Ev MAKEOBJDIRPREFIX ,
1.76      jrf      2063: .Ev MAKESYSPATH ,
1.154     apb      2064: .Ev PWD ,
1.1       cgd      2065: and
1.154     apb      2066: .Ev TMPDIR .
1.57      wiz      2067: .Pp
1.38      sjg      2068: .Ev MAKEOBJDIRPREFIX
1.117     lukem    2069: and
1.38      sjg      2070: .Ev MAKEOBJDIR
1.117     lukem    2071: may only be set in the environment or on the command line to
1.38      sjg      2072: .Nm
1.117     lukem    2073: and not as makefile variables;
                   2074: see the description of
                   2075: .Ql Va .OBJDIR
                   2076: for more details.
1.1       cgd      2077: .Sh FILES
                   2078: .Bl -tag -width /usr/share/mk -compact
                   2079: .It .depend
                   2080: list of dependencies
                   2081: .It Makefile
                   2082: list of dependencies
                   2083: .It makefile
                   2084: list of dependencies
                   2085: .It sys.mk
                   2086: system makefile
                   2087: .It /usr/share/mk
                   2088: system makefile directory
                   2089: .El
1.128     dsl      2090: .Sh COMPATIBILITY
                   2091: The basic make syntax is compatible between different versions of make,
                   2092: however the special variables, variable modifiers and conditionals are not.
                   2093: .Pp
1.129     wiz      2094: The way that parallel makes are scheduled changed in
1.130     wiz      2095: .Nx 4.0
1.193     wiz      2096: so that .ORDER and .WAIT apply recursively to the dependent nodes.
1.128     dsl      2097: The algorithms used may change again in the future.
1.152     dsl      2098: .Pp
                   2099: The way that .for loop variables are substituted changed after
                   2100: .Nx 5.0
                   2101: so that they still appear to be variable expansions.
                   2102: In particular this stops them being treated as syntax, and removes some
                   2103: obscure problems using them in .if statements.
1.153     wiz      2104: .Sh SEE ALSO
                   2105: .Xr mkdep 1
                   2106: .Sh HISTORY
                   2107: A
                   2108: .Nm
                   2109: command appeared in
                   2110: .At v7 .
1.190     christos 2111: This
                   2112: .Nm
                   2113: implementation is based on Adam De Boor's pmake program which was written
1.209     christos 2114: for Sprite at Berkeley.
1.190     christos 2115: It was designed to be a parallel distributed make running jobs on different
1.191     wiz      2116: machines using a daemon called
1.190     christos 2117: .Dq customs .
1.214     christos 2118: .Pp
                   2119: Historically the target/dependency
                   2120: .Dq FRC
1.215     christos 2121: has been used to FoRCe rebuilding (since the target/dependency
1.217     wiz      2122: does not exist... unless someone creates an
1.214     christos 2123: .Dq FRC
1.215     christos 2124: file).
1.152     dsl      2125: .Sh BUGS
                   2126: The
                   2127: .Nm
                   2128: syntax is difficult to parse without actually acting of the data.
                   2129: For instance finding the end of a variable use should involve scanning each
                   2130: the modifiers using the correct terminator for each field.
                   2131: In many places
                   2132: .Nm
                   2133: just counts {} and () in order to find the end of a variable expansion.
                   2134: .Pp
1.153     wiz      2135: There is no way of escaping a space character in a filename.

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