1.\" $NetBSD: make.1,v 1.230 2014/02/15 18:55:30 sjg Exp $ 2.\" 3.\" Copyright (c) 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 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. 14.\" 3. Neither the name of the University nor the names of its contributors 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 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)make.1 8.4 (Berkeley) 3/19/94 31.\" 32.Dd February 14, 2014 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm make 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrstWwX 41.Op Fl C Ar directory 42.Op Fl D Ar variable 43.Op Fl d Ar flags 44.Op Fl f Ar makefile 45.Op Fl I Ar directory 46.Op Fl J Ar private 47.Op Fl j Ar max_jobs 48.Op Fl m Ar directory 49.Op Fl T Ar file 50.Op Fl V Ar variable 51.Op Ar variable=value 52.Op Ar target ... 53.Sh DESCRIPTION 54.Nm 55is a program designed to simplify the maintenance of other programs. 56Its input is a list of specifications as to the files upon which programs 57and other files depend. 58If no 59.Fl f Ar makefile 60makefile option is given, 61.Nm 62will try to open 63.Ql Pa makefile 64then 65.Ql Pa Makefile 66in order to find the specifications. 67If the file 68.Ql Pa .depend 69exists, it is read (see 70.Xr mkdep 1 ) . 71.Pp 72This manual page is intended as a reference document only. 73For a more thorough description of 74.Nm 75and makefiles, please refer to 76.%T "PMake \- A Tutorial" . 77.Pp 78.Nm 79will prepend the contents of the 80.Va MAKEFLAGS 81environment variable to the command line arguments before parsing them. 82.Pp 83The options are as follows: 84.Bl -tag -width Ds 85.It Fl B 86Try to be backwards compatible by executing a single shell per command and 87by executing the commands to make the sources of a dependency line in sequence. 88.It Fl C Ar directory 89Change to 90.Ar directory 91before reading the makefiles or doing anything else. 92If multiple 93.Fl C 94options are specified, each is interpreted relative to the previous one: 95.Fl C Pa / Fl C Pa etc 96is equivalent to 97.Fl C Pa /etc . 98.It Fl D Ar variable 99Define 100.Ar variable 101to be 1, in the global context. 102.It Fl d Ar [-]flags 103Turn on debugging, and specify which portions of 104.Nm 105are to print debugging information. 106Unless the flags are preceded by 107.Ql \- 108they are added to the 109.Va MAKEFLAGS 110environment variable and will be processed by any child make processes. 111By default, debugging information is printed to standard error, 112but this can be changed using the 113.Ar F 114debugging flag. 115The debugging output is always unbuffered; in addition, if debugging 116is enabled but debugging output is not directed to standard output, 117then the standard output is line buffered. 118.Ar Flags 119is one or more of the following: 120.Bl -tag -width Ds 121.It Ar A 122Print all possible debugging information; 123equivalent to specifying all of the debugging flags. 124.It Ar a 125Print debugging information about archive searching and caching. 126.It Ar C 127Print debugging information about current working directory. 128.It Ar c 129Print debugging information about conditional evaluation. 130.It Ar d 131Print debugging information about directory searching and caching. 132.It Ar e 133Print debugging information about failed commands and targets. 134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 135Specify where debugging output is written. 136This must be the last flag, because it consumes the remainder of 137the argument. 138If the character immediately after the 139.Ql F 140flag is 141.Ql \&+ , 142then the file will be opened in append mode; 143otherwise the file will be overwritten. 144If the file name is 145.Ql stdout 146or 147.Ql stderr 148then debugging output will be written to the 149standard output or standard error output file descriptors respectively 150(and the 151.Ql \&+ 152option has no effect). 153Otherwise, the output will be written to the named file. 154If the file name ends 155.Ql .%d 156then the 157.Ql %d 158is replaced by the pid. 159.It Ar f 160Print debugging information about loop evaluation. 161.It Ar "g1" 162Print the input graph before making anything. 163.It Ar "g2" 164Print the input graph after making everything, or before exiting 165on error. 166.It Ar "g3" 167Print the input graph before exiting on error. 168.It Ar j 169Print debugging information about running multiple shells. 170.It Ar l 171Print commands in Makefiles regardless of whether or not they are prefixed by 172.Ql @ 173or other "quiet" flags. 174Also known as "loud" behavior. 175.It Ar M 176Print debugging information about "meta" mode decisions about targets. 177.It Ar m 178Print debugging information about making targets, including modification 179dates. 180.It Ar n 181Don't delete the temporary command scripts created when running commands. 182These temporary scripts are created in the directory 183referred to by the 184.Ev TMPDIR 185environment variable, or in 186.Pa /tmp 187if 188.Ev TMPDIR 189is unset or set to the empty string. 190The temporary scripts are created by 191.Xr mkstemp 3 , 192and have names of the form 193.Pa makeXXXXXX . 194.Em NOTE : 195This can create many files in 196.Ev TMPDIR 197or 198.Pa /tmp , 199so use with care. 200.It Ar p 201Print debugging information about makefile parsing. 202.It Ar s 203Print debugging information about suffix-transformation rules. 204.It Ar t 205Print debugging information about target list maintenance. 206.It Ar V 207Force the 208.Fl V 209option to print raw values of variables. 210.It Ar v 211Print debugging information about variable assignment. 212.It Ar w 213Print entering and leaving directory messages, pre and post processing. 214.It Ar x 215Run shell commands with 216.Fl x 217so the actual commands are printed as they are executed. 218.El 219.It Fl e 220Specify that environment variables override macro assignments within 221makefiles. 222.It Fl f Ar makefile 223Specify a makefile to read instead of the default 224.Ql Pa makefile . 225If 226.Ar makefile 227is 228.Ql Fl , 229standard input is read. 230Multiple makefiles may be specified, and are read in the order specified. 231.It Fl I Ar directory 232Specify a directory in which to search for makefiles and included makefiles. 233The system makefile directory (or directories, see the 234.Fl m 235option) is automatically included as part of this list. 236.It Fl i 237Ignore non-zero exit of shell commands in the makefile. 238Equivalent to specifying 239.Ql Fl 240before each command line in the makefile. 241.It Fl J Ar private 242This option should 243.Em not 244be specified by the user. 245.Pp 246When the 247.Ar j 248option is in use in a recursive build, this option is passed by a make 249to child makes to allow all the make processes in the build to 250cooperate to avoid overloading the system. 251.It Fl j Ar max_jobs 252Specify the maximum number of jobs that 253.Nm 254may have running at any one time. 255The value is saved in 256.Va .MAKE.JOBS . 257Turns compatibility mode off, unless the 258.Ar B 259flag is also specified. 260When compatibility mode is off, all commands associated with a 261target are executed in a single shell invocation as opposed to the 262traditional one shell invocation per line. 263This can break traditional scripts which change directories on each 264command invocation and then expect to start with a fresh environment 265on the next line. 266It is more efficient to correct the scripts rather than turn backwards 267compatibility on. 268.It Fl k 269Continue processing after errors are encountered, but only on those targets 270that do not depend on the target whose creation caused the error. 271.It Fl m Ar directory 272Specify a directory in which to search for sys.mk and makefiles included 273via the 274.Ao Ar file Ac Ns -style 275include statement. 276The 277.Fl m 278option can be used multiple times to form a search path. 279This path will override the default system include path: /usr/share/mk. 280Furthermore the system include path will be appended to the search path used 281for 282.Qo Ar file Qc Ns -style 283include statements (see the 284.Fl I 285option). 286.Pp 287If a file or directory name in the 288.Fl m 289argument (or the 290.Ev MAKESYSPATH 291environment variable) starts with the string 292.Qq \&.../ 293then 294.Nm 295will search for the specified file or directory named in the remaining part 296of the argument string. 297The search starts with the current directory of 298the Makefile and then works upward towards the root of the filesystem. 299If the search is successful, then the resulting directory replaces the 300.Qq \&.../ 301specification in the 302.Fl m 303argument. 304If used, this feature allows 305.Nm 306to easily search in the current source tree for customized sys.mk files 307(e.g., by using 308.Qq \&.../mk/sys.mk 309as an argument). 310.It Fl n 311Display the commands that would have been executed, but do not 312actually execute them unless the target depends on the .MAKE special 313source (see below). 314.It Fl N 315Display the commands which would have been executed, but do not 316actually execute any of them; useful for debugging top-level makefiles 317without descending into subdirectories. 318.It Fl q 319Do not execute any commands, but exit 0 if the specified targets are 320up-to-date and 1, otherwise. 321.It Fl r 322Do not use the built-in rules specified in the system makefile. 323.It Fl s 324Do not echo any commands as they are executed. 325Equivalent to specifying 326.Ql Ic @ 327before each command line in the makefile. 328.It Fl T Ar tracefile 329When used with the 330.Fl j 331flag, 332append a trace record to 333.Ar tracefile 334for each job started and completed. 335.It Fl t 336Rather than re-building a target as specified in the makefile, create it 337or update its modification time to make it appear up-to-date. 338.It Fl V Ar variable 339Print 340.Nm Ns 's 341idea of the value of 342.Ar variable , 343in the global context. 344Do not build any targets. 345Multiple instances of this option may be specified; 346the variables will be printed one per line, 347with a blank line for each null or undefined variable. 348If 349.Ar variable 350contains a 351.Ql \&$ 352then the value will be expanded before printing. 353.It Fl W 354Treat any warnings during makefile parsing as errors. 355.It Fl X 356Don't export variables passed on the command line to the environment 357individually. 358Variables passed on the command line are still exported 359via the 360.Va MAKEFLAGS 361environment variable. 362This option may be useful on systems which have a small limit on the 363size of command arguments. 364.It Ar variable=value 365Set the value of the variable 366.Ar variable 367to 368.Ar value . 369Normally, all values passed on the command line are also exported to 370sub-makes in the environment. 371The 372.Fl X 373flag disables this behavior. 374Variable assignments should follow options for POSIX compatibility 375but no ordering is enforced. 376.El 377.Pp 378There are seven different types of lines in a makefile: file dependency 379specifications, shell commands, variable assignments, include statements, 380conditional directives, for loops, and comments. 381.Pp 382In general, lines may be continued from one line to the next by ending 383them with a backslash 384.Pq Ql \e . 385The trailing newline character and initial whitespace on the following 386line are compressed into a single space. 387.Sh FILE DEPENDENCY SPECIFICATIONS 388Dependency lines consist of one or more targets, an operator, and zero 389or more sources. 390This creates a relationship where the targets 391.Dq depend 392on the sources 393and are usually created from them. 394The exact relationship between the target and the source is determined 395by the operator that separates them. 396The three operators are as follows: 397.Bl -tag -width flag 398.It Ic \&: 399A target is considered out-of-date if its modification time is less than 400those of any of its sources. 401Sources for a target accumulate over dependency lines when this operator 402is used. 403The target is removed if 404.Nm 405is interrupted. 406.It Ic \&! 407Targets are always re-created, but not until all sources have been 408examined and re-created as necessary. 409Sources for a target accumulate over dependency lines when this operator 410is used. 411The target is removed if 412.Nm 413is interrupted. 414.It Ic \&:: 415If no sources are specified, the target is always re-created. 416Otherwise, a target is considered out-of-date if any of its sources has 417been modified more recently than the target. 418Sources for a target do not accumulate over dependency lines when this 419operator is used. 420The target will not be removed if 421.Nm 422is interrupted. 423.El 424.Pp 425Targets and sources may contain the shell wildcard values 426.Ql \&? , 427.Ql * , 428.Ql [] , 429and 430.Ql {} . 431The values 432.Ql \&? , 433.Ql * , 434and 435.Ql [] 436may only be used as part of the final 437component of the target or source, and must be used to describe existing 438files. 439The value 440.Ql {} 441need not necessarily be used to describe existing files. 442Expansion is in directory order, not alphabetically as done in the shell. 443.Sh SHELL COMMANDS 444Each target may have associated with it a series of shell commands, normally 445used to create the target. 446Each of the commands in this script 447.Em must 448be preceded by a tab. 449While any target may appear on a dependency line, only one of these 450dependencies may be followed by a creation script, unless the 451.Ql Ic \&:: 452operator is used. 453.Pp 454If the first characters of the command line are any combination of 455.Ql Ic @ , 456.Ql Ic + , 457or 458.Ql Ic \- , 459the command is treated specially. 460A 461.Ql Ic @ 462causes the command not to be echoed before it is executed. 463A 464.Ql Ic + 465causes the command to be executed even when 466.Fl n 467is given. 468This is similar to the effect of the .MAKE special source, 469except that the effect can be limited to a single line of a script. 470A 471.Ql Ic \- 472causes any non-zero exit status of the command line to be ignored. 473.Pp 474When 475.Nm 476is run in jobs mode with 477.Fl j Ar max_jobs , 478the entire script for the target is fed to a 479single instance of the shell. 480.Pp 481In compatibility (non-jobs) mode, each command is run in a separate process. 482If the command contains any shell meta characters 483.Pq Ql #=|^(){};&<>*?[]:$`\e\en 484it will be passed to the shell, otherwise 485.Nm 486will attempt direct execution. 487.Pp 488Since 489.Nm 490will 491.Xr chdir 2 492to 493.Ql Va .OBJDIR 494before executing any targets, each child process 495starts with that as its current working directory. 496.Pp 497Makefiles should be written so that the mode of 498.Nm 499operation does not change their behavior. 500For example, any command which needs to use 501.Dq cd 502or 503.Dq chdir , 504without side-effect should be put in parenthesis: 505.Bd -literal -offset indent 506 507avoid-chdir-side-effects: 508 @echo Building $@ in `pwd` 509 @(cd ${.CURDIR} && ${.MAKE} $@) 510 @echo Back in `pwd` 511 512ensure-one-shell-regardless-of-mode: 513 @echo Building $@ in `pwd`; \\ 514 (cd ${.CURDIR} && ${.MAKE} $@); \\ 515 echo Back in `pwd` 516.Ed 517.Sh VARIABLE ASSIGNMENTS 518Variables in make are much like variables in the shell, and, by tradition, 519consist of all upper-case letters. 520.Ss Variable assignment modifiers 521The five operators that can be used to assign values to variables are as 522follows: 523.Bl -tag -width Ds 524.It Ic \&= 525Assign the value to the variable. 526Any previous value is overridden. 527.It Ic \&+= 528Append the value to the current value of the variable. 529.It Ic \&?= 530Assign the value to the variable if it is not already defined. 531.It Ic \&:= 532Assign with expansion, i.e. expand the value before assigning it 533to the variable. 534Normally, expansion is not done until the variable is referenced. 535.Em NOTE : 536References to undefined variables are 537.Em not 538expanded. 539This can cause problems when variable modifiers are used. 540.It Ic \&!= 541Expand the value and pass it to the shell for execution and assign 542the result to the variable. 543Any newlines in the result are replaced with spaces. 544.El 545.Pp 546Any white-space before the assigned 547.Ar value 548is removed; if the value is being appended, a single space is inserted 549between the previous contents of the variable and the appended value. 550.Pp 551Variables are expanded by surrounding the variable name with either 552curly braces 553.Pq Ql {} 554or parentheses 555.Pq Ql () 556and preceding it with 557a dollar sign 558.Pq Ql \&$ . 559If the variable name contains only a single letter, the surrounding 560braces or parentheses are not required. 561This shorter form is not recommended. 562.Pp 563If the variable name contains a dollar, then the name itself is expanded first. 564This allows almost arbitrary variable names, however names containing dollar, 565braces, parenthesis, or whitespace are really best avoided! 566.Pp 567If the result of expanding a variable contains a dollar sign 568.Pq Ql \&$ 569the string is expanded again. 570.Pp 571Variable substitution occurs at three distinct times, depending on where 572the variable is being used. 573.Bl -enum 574.It 575Variables in dependency lines are expanded as the line is read. 576.It 577Variables in shell commands are expanded when the shell command is 578executed. 579.It 580.Dq .for 581loop index variables are expanded on each loop iteration. 582Note that other variables are not expanded inside loops so 583the following example code: 584.Bd -literal -offset indent 585 586.Dv .for i in 1 2 3 587a+= ${i} 588j= ${i} 589b+= ${j} 590.Dv .endfor 591 592all: 593 @echo ${a} 594 @echo ${b} 595 596.Ed 597will print: 598.Bd -literal -offset indent 5991 2 3 6003 3 3 601 602.Ed 603Because while ${a} contains 604.Dq 1 2 3 605after the loop is executed, ${b} 606contains 607.Dq ${j} ${j} ${j} 608which expands to 609.Dq 3 3 3 610since after the loop completes ${j} contains 611.Dq 3 . 612.El 613.Ss Variable classes 614The four different classes of variables (in order of increasing precedence) 615are: 616.Bl -tag -width Ds 617.It Environment variables 618Variables defined as part of 619.Nm Ns 's 620environment. 621.It Global variables 622Variables defined in the makefile or in included makefiles. 623.It Command line variables 624Variables defined as part of the command line. 625.It Local variables 626Variables that are defined specific to a certain target. 627The seven local variables are as follows: 628.Bl -tag -width ".ARCHIVE" 629.It Va .ALLSRC 630The list of all sources for this target; also known as 631.Ql Va \&\*[Gt] . 632.It Va .ARCHIVE 633The name of the archive file. 634.It Va .IMPSRC 635In suffix-transformation rules, the name/path of the source from which the 636target is to be transformed (the 637.Dq implied 638source); also known as 639.Ql Va \&\*[Lt] . 640It is not defined in explicit rules. 641.It Va .MEMBER 642The name of the archive member. 643.It Va .OODATE 644The list of sources for this target that were deemed out-of-date; also 645known as 646.Ql Va \&? . 647.It Va .PREFIX 648The file prefix of the target, containing only the file portion, no suffix 649or preceding directory components; also known as 650.Ql Va * . 651.It Va .TARGET 652The name of the target; also known as 653.Ql Va @ . 654.El 655.Pp 656The shorter forms 657.Ql Va @ , 658.Ql Va \&? , 659.Ql Va \&\*[Lt] , 660.Ql Va \&\*[Gt] , 661and 662.Ql Va * 663are permitted for backward 664compatibility with historical makefiles and are not recommended. 665The six variables 666.Ql Va "@F" , 667.Ql Va "@D" , 668.Ql Va "\*[Lt]F" , 669.Ql Va "\*[Lt]D" , 670.Ql Va "*F" , 671and 672.Ql Va "*D" 673are permitted for compatibility with 674.At V 675makefiles and are not recommended. 676.Pp 677Four of the local variables may be used in sources on dependency lines 678because they expand to the proper value for each target on the line. 679These variables are 680.Ql Va .TARGET , 681.Ql Va .PREFIX , 682.Ql Va .ARCHIVE , 683and 684.Ql Va .MEMBER . 685.El 686.Ss Additional built-in variables 687In addition, 688.Nm 689sets or knows about the following variables: 690.Bl -tag -width .MAKEOVERRIDES 691.It Va \&$ 692A single dollar sign 693.Ql \&$ , 694i.e. 695.Ql \&$$ 696expands to a single dollar 697sign. 698.It Va .ALLTARGETS 699The list of all targets encountered in the Makefile. 700If evaluated during 701Makefile parsing, lists only those targets encountered thus far. 702.It Va .CURDIR 703A path to the directory where 704.Nm 705was executed. 706Refer to the description of 707.Ql Ev PWD 708for more details. 709.It Va .INCLUDEDFROMDIR 710The directory of the file this Makefile was included from. 711.It Va .INCLUDEDFROMFILE 712The filename of the file this Makefile was included from. 713.It Ev MAKE 714The name that 715.Nm 716was executed with 717.Pq Va argv[0] . 718For compatibility 719.Nm 720also sets 721.Va .MAKE 722with the same value. 723The preferred variable to use is the environment variable 724.Ev MAKE 725because it is more compatible with other versions of 726.Nm 727and cannot be confused with the special target with the same name. 728.It Va .MAKE.ALWAYS_PASS_JOB_QUEUE 729Tells 730.Nm 731whether to pass the descriptors of the job token queue 732even if the target is not tagged with 733.Ic .MAKE 734The default is 735.Ql Pa yes 736for backwards compatability with 737.Fx 9.0 738and earlier. 739.It Va .MAKE.DEPENDFILE 740Names the makefile (default 741.Ql Pa .depend ) 742from which generated dependencies are read. 743.It Va .MAKE.EXPAND_VARIABLES 744A boolean that controls the default behavior of the 745.Fl V 746option. 747.It Va .MAKE.EXPORTED 748The list of variables exported by 749.Nm . 750.It Va .MAKE.JOBS 751The argument to the 752.Fl j 753option. 754.It Va .MAKE.JOB.PREFIX 755If 756.Nm 757is run with 758.Ar j 759then output for each target is prefixed with a token 760.Ql --- target --- 761the first part of which can be controlled via 762.Va .MAKE.JOB.PREFIX . 763If 764.Va .MAKE.JOB.PREFIX 765is empty, no token is printed. 766.br 767For example: 768.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 769would produce tokens like 770.Ql ---make[1234] target --- 771making it easier to track the degree of parallelism being achieved. 772.It Ev MAKEFLAGS 773The environment variable 774.Ql Ev MAKEFLAGS 775may contain anything that 776may be specified on 777.Nm Ns 's 778command line. 779Anything specified on 780.Nm Ns 's 781command line is appended to the 782.Ql Ev MAKEFLAGS 783variable which is then 784entered into the environment for all programs which 785.Nm 786executes. 787.It Va .MAKE.LEVEL 788The recursion depth of 789.Nm . 790The initial instance of 791.Nm 792will be 0, and an incremented value is put into the environment 793to be seen by the next generation. 794This allows tests like: 795.Li .if ${.MAKE.LEVEL} == 0 796to protect things which should only be evaluated in the initial instance of 797.Nm . 798.It Va .MAKE.MAKEFILE_PREFERENCE 799The ordered list of makefile names 800(default 801.Ql Pa makefile , 802.Ql Pa Makefile ) 803that 804.Nm 805will look for. 806.It Va .MAKE.MAKEFILES 807The list of makefiles read by 808.Nm , 809which is useful for tracking dependencies. 810Each makefile is recorded only once, regardless of the number of times read. 811.It Va .MAKE.MODE 812Processed after reading all makefiles. 813Can affect the mode that 814.Nm 815runs in. 816It can contain a number of keywords: 817.Bl -hang -width ignore-cmd 818.It Pa compat 819Like 820.Fl B , 821puts 822.Nm 823into "compat" mode. 824.It Pa meta 825Puts 826.Nm 827into "meta" mode, where meta files are created for each target 828to capture the command run, the output generated and if 829.Xr filemon 4 830is available, the system calls which are of interest to 831.Nm . 832The captured output can be very useful when diagnosing errors. 833.It Pa curdirOk= Ar bf 834Normally 835.Nm 836will not create .meta files in 837.Ql Va .CURDIR . 838This can be overridden by setting 839.Va bf 840to a value which represents True. 841.It Pa env 842For debugging, it can be useful to inlcude the environment 843in the .meta file. 844.It Pa verbose 845If in "meta" mode, print a clue about the target being built. 846This is useful if the build is otherwise running silently. 847The message printed the value of: 848.Va .MAKE.META.PREFIX . 849.It Pa ignore-cmd 850Some makefiles have commands which are simply not stable. 851This keyword causes them to be ignored for 852determining whether a target is out of date in "meta" mode. 853See also 854.Ic .NOMETA_CMP . 855.It Pa silent= Ar bf 856If 857.Va bf 858is True, when a .meta file is created, mark the target 859.Ic .SILENT . 860.El 861.It Va .MAKE.META.BAILIWICK 862In "meta" mode, provides a list of prefixes which 863match the directories controlled by 864.Nm . 865If a file that was generated outside of 866.Va .OBJDIR 867but within said bailiwick is missing, 868the current target is considered out-of-date. 869.It Va .MAKE.META.CREATED 870In "meta" mode, this variable contains a list of all the meta files 871updated. 872If not empty, it can be used to trigger processing of 873.Va .MAKE.META.FILES . 874.It Va .MAKE.META.FILES 875In "meta" mode, this variable contains a list of all the meta files 876used (updated or not). 877This list can be used to process the meta files to extract dependency 878information. 879.It Va .MAKE.META.IGNORE_PATHS 880Provides a list of path prefixes that should be ignored; 881because the contents are expected to change over time. 882The default list includes: 883.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 884.It Va .MAKE.META.PREFIX 885Defines the message printed for each meta file updated in "meta verbose" mode. 886The default value is: 887.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 888.It Va .MAKEOVERRIDES 889This variable is used to record the names of variables assigned to 890on the command line, so that they may be exported as part of 891.Ql Ev MAKEFLAGS . 892This behaviour can be disabled by assigning an empty value to 893.Ql Va .MAKEOVERRIDES 894within a makefile. 895Extra variables can be exported from a makefile 896by appending their names to 897.Ql Va .MAKEOVERRIDES . 898.Ql Ev MAKEFLAGS 899is re-exported whenever 900.Ql Va .MAKEOVERRIDES 901is modified. 902.It Va .MAKE.PATH_FILEMON 903If 904.Nm 905was built with 906.Xr filemon 4 907support, this is set to the path of the device node. 908This allows makefiles to test for this support. 909.It Va .MAKE.PID 910The process-id of 911.Nm . 912.It Va .MAKE.PPID 913The parent process-id of 914.Nm . 915.It Va MAKE_PRINT_VAR_ON_ERROR 916When 917.Nm 918stops due to an error, it prints its name and the value of 919.Ql Va .CURDIR 920as well as the value of any variables named in 921.Ql Va MAKE_PRINT_VAR_ON_ERROR . 922.It Va .newline 923This variable is simply assigned a newline character as its value. 924This allows expansions using the 925.Cm \&:@ 926modifier to put a newline between 927iterations of the loop rather than a space. 928For example, the printing of 929.Ql Va MAKE_PRINT_VAR_ON_ERROR 930could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 931.It Va .OBJDIR 932A path to the directory where the targets are built. 933Its value is determined by trying to 934.Xr chdir 2 935to the following directories in order and using the first match: 936.Bl -enum 937.It 938.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 939.Pp 940(Only if 941.Ql Ev MAKEOBJDIRPREFIX 942is set in the environment or on the command line.) 943.It 944.Ev ${MAKEOBJDIR} 945.Pp 946(Only if 947.Ql Ev MAKEOBJDIR 948is set in the environment or on the command line.) 949.It 950.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 951.It 952.Ev ${.CURDIR} Ns Pa /obj 953.It 954.Pa /usr/obj/ Ns Ev ${.CURDIR} 955.It 956.Ev ${.CURDIR} 957.El 958.Pp 959Variable expansion is performed on the value before it's used, 960so expressions such as 961.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 962may be used. 963This is especially useful with 964.Ql Ev MAKEOBJDIR . 965.Pp 966.Ql Va .OBJDIR 967may be modified in the makefile as a global variable. 968In all cases, 969.Nm 970will 971.Xr chdir 2 972to 973.Ql Va .OBJDIR 974and set 975.Ql Ev PWD 976to that directory before executing any targets. 977. 978.It Va .PARSEDIR 979A path to the directory of the current 980.Ql Pa Makefile 981being parsed. 982.It Va .PARSEFILE 983The basename of the current 984.Ql Pa Makefile 985being parsed. 986This variable and 987.Ql Va .PARSEDIR 988are both set only while the 989.Ql Pa Makefiles 990are being parsed. 991If you want to retain their current values, assign them to a variable 992using assignment with expansion: 993.Pq Ql Cm \&:= . 994.It Va .PATH 995A variable that represents the list of directories that 996.Nm 997will search for files. 998The search list should be updated using the target 999.Ql Va .PATH 1000rather than the variable. 1001.It Ev PWD 1002Alternate path to the current directory. 1003.Nm 1004normally sets 1005.Ql Va .CURDIR 1006to the canonical path given by 1007.Xr getcwd 3 . 1008However, if the environment variable 1009.Ql Ev PWD 1010is set and gives a path to the current directory, then 1011.Nm 1012sets 1013.Ql Va .CURDIR 1014to the value of 1015.Ql Ev PWD 1016instead. 1017This behaviour is disabled if 1018.Ql Ev MAKEOBJDIRPREFIX 1019is set or 1020.Ql Ev MAKEOBJDIR 1021contains a variable transform. 1022.Ql Ev PWD 1023is set to the value of 1024.Ql Va .OBJDIR 1025for all programs which 1026.Nm 1027executes. 1028.It Ev .TARGETS 1029The list of targets explicitly specified on the command line, if any. 1030.It Ev VPATH 1031Colon-separated 1032.Pq Dq \&: 1033lists of directories that 1034.Nm 1035will search for files. 1036The variable is supported for compatibility with old make programs only, 1037use 1038.Ql Va .PATH 1039instead. 1040.El 1041.Ss Variable modifiers 1042Variable expansion may be modified to select or modify each word of the 1043variable (where a 1044.Dq word 1045is white-space delimited sequence of characters). 1046The general format of a variable expansion is as follows: 1047.Pp 1048.Dl ${variable[:modifier[:...]]} 1049.Pp 1050Each modifier begins with a colon, 1051which may be escaped with a backslash 1052.Pq Ql \e . 1053.Pp 1054A set of modifiers can be specified via a variable, as follows: 1055.Pp 1056.Dl modifier_variable=modifier[:...] 1057.Dl ${variable:${modifier_variable}[:...]} 1058.Pp 1059In this case the first modifier in the modifier_variable does not 1060start with a colon, since that must appear in the referencing 1061variable. 1062If any of the modifiers in the modifier_variable contain a dollar sign 1063.Pq Ql $ , 1064these must be doubled to avoid early expansion. 1065.Pp 1066The supported modifiers are: 1067.Bl -tag -width EEE 1068.It Cm \&:E 1069Replaces each word in the variable with its suffix. 1070.It Cm \&:H 1071Replaces each word in the variable with everything but the last component. 1072.It Cm \&:M Ns Ar pattern 1073Select only those words that match 1074.Ar pattern . 1075The standard shell wildcard characters 1076.Pf ( Ql * , 1077.Ql \&? , 1078and 1079.Ql Oo Oc ) 1080may 1081be used. 1082The wildcard characters may be escaped with a backslash 1083.Pq Ql \e . 1084As a consequence of the way values are split into words, matched, 1085and then joined, a construct like 1086.Dl ${VAR:M*} 1087will normalise the inter-word spacing, removing all leading and 1088trailing space, and converting multiple consecutive spaces 1089to single spaces. 1090. 1091.It Cm \&:N Ns Ar pattern 1092This is identical to 1093.Ql Cm \&:M , 1094but selects all words which do not match 1095.Ar pattern . 1096.It Cm \&:O 1097Order every word in variable alphabetically. 1098To sort words in 1099reverse order use the 1100.Ql Cm \&:O:[-1..1] 1101combination of modifiers. 1102.It Cm \&:Ox 1103Randomize words in variable. 1104The results will be different each time you are referring to the 1105modified variable; use the assignment with expansion 1106.Pq Ql Cm \&:= 1107to prevent such behaviour. 1108For example, 1109.Bd -literal -offset indent 1110LIST= uno due tre quattro 1111RANDOM_LIST= ${LIST:Ox} 1112STATIC_RANDOM_LIST:= ${LIST:Ox} 1113 1114all: 1115 @echo "${RANDOM_LIST}" 1116 @echo "${RANDOM_LIST}" 1117 @echo "${STATIC_RANDOM_LIST}" 1118 @echo "${STATIC_RANDOM_LIST}" 1119.Ed 1120may produce output similar to: 1121.Bd -literal -offset indent 1122quattro due tre uno 1123tre due quattro uno 1124due uno quattro tre 1125due uno quattro tre 1126.Ed 1127.It Cm \&:Q 1128Quotes every shell meta-character in the variable, so that it can be passed 1129safely through recursive invocations of 1130.Nm . 1131.It Cm \&:R 1132Replaces each word in the variable with everything but its suffix. 1133.It Cm \&:gmtime 1134The value is a format string for 1135.Xr strftime 3 , 1136using the current 1137.Xr gmtime 3 . 1138.It Cm \&:hash 1139Compute a 32bit hash of the value and encode it as hex digits. 1140.It Cm \&:localtime 1141The value is a format string for 1142.Xr strftime 3 , 1143using the current 1144.Xr localtime 3 . 1145.It Cm \&:tA 1146Attempt to convert variable to an absolute path using 1147.Xr realpath 3 , 1148if that fails, the value is unchanged. 1149.It Cm \&:tl 1150Converts variable to lower-case letters. 1151.It Cm \&:ts Ns Ar c 1152Words in the variable are normally separated by a space on expansion. 1153This modifier sets the separator to the character 1154.Ar c . 1155If 1156.Ar c 1157is omitted, then no separator is used. 1158The common escapes (including octal numeric codes), work as expected. 1159.It Cm \&:tu 1160Converts variable to upper-case letters. 1161.It Cm \&:tW 1162Causes the value to be treated as a single word 1163(possibly containing embedded white space). 1164See also 1165.Ql Cm \&:[*] . 1166.It Cm \&:tw 1167Causes the value to be treated as a sequence of 1168words delimited by white space. 1169See also 1170.Ql Cm \&:[@] . 1171.Sm off 1172.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1173.Sm on 1174Modify the first occurrence of 1175.Ar old_string 1176in the variable's value, replacing it with 1177.Ar new_string . 1178If a 1179.Ql g 1180is appended to the last slash of the pattern, all occurrences 1181in each word are replaced. 1182If a 1183.Ql 1 1184is appended to the last slash of the pattern, only the first word 1185is affected. 1186If a 1187.Ql W 1188is appended to the last slash of the pattern, 1189then the value is treated as a single word 1190(possibly containing embedded white space). 1191If 1192.Ar old_string 1193begins with a caret 1194.Pq Ql ^ , 1195.Ar old_string 1196is anchored at the beginning of each word. 1197If 1198.Ar old_string 1199ends with a dollar sign 1200.Pq Ql \&$ , 1201it is anchored at the end of each word. 1202Inside 1203.Ar new_string , 1204an ampersand 1205.Pq Ql \*[Am] 1206is replaced by 1207.Ar old_string 1208(without any 1209.Ql ^ 1210or 1211.Ql \&$ ) . 1212Any character may be used as a delimiter for the parts of the modifier 1213string. 1214The anchoring, ampersand and delimiter characters may be escaped with a 1215backslash 1216.Pq Ql \e . 1217.Pp 1218Variable expansion occurs in the normal fashion inside both 1219.Ar old_string 1220and 1221.Ar new_string 1222with the single exception that a backslash is used to prevent the expansion 1223of a dollar sign 1224.Pq Ql \&$ , 1225not a preceding dollar sign as is usual. 1226.Sm off 1227.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1228.Sm on 1229The 1230.Cm \&:C 1231modifier is just like the 1232.Cm \&:S 1233modifier except that the old and new strings, instead of being 1234simple strings, are an extended regular expression (see 1235.Xr regex 3 ) 1236string 1237.Ar pattern 1238and an 1239.Xr ed 1 Ns \-style 1240string 1241.Ar replacement . 1242Normally, the first occurrence of the pattern 1243.Ar pattern 1244in each word of the value is substituted with 1245.Ar replacement . 1246The 1247.Ql 1 1248modifier causes the substitution to apply to at most one word; the 1249.Ql g 1250modifier causes the substitution to apply to as many instances of the 1251search pattern 1252.Ar pattern 1253as occur in the word or words it is found in; the 1254.Ql W 1255modifier causes the value to be treated as a single word 1256(possibly containing embedded white space). 1257Note that 1258.Ql 1 1259and 1260.Ql g 1261are orthogonal; the former specifies whether multiple words are 1262potentially affected, the latter whether multiple substitutions can 1263potentially occur within each affected word. 1264.Pp 1265As for the 1266.Cm \&:S 1267modifier, the 1268.Ar pattern 1269and 1270.Ar replacement 1271are subjected to variable expansion before being parsed as 1272regular expressions. 1273.It Cm \&:T 1274Replaces each word in the variable with its last component. 1275.It Cm \&:u 1276Remove adjacent duplicate words (like 1277.Xr uniq 1 ) . 1278.Sm off 1279.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1280.Sm on 1281If the variable name (not its value), when parsed as a .if conditional 1282expression, evaluates to true, return as its value the 1283.Ar true_string , 1284otherwise return the 1285.Ar false_string . 1286Since the variable name is used as the expression, \&:\&? must be the 1287first modifier after the variable name itself - which will, of course, 1288usually contain variable expansions. 1289A common error is trying to use expressions like 1290.Dl ${NUMBERS:M42:?match:no} 1291which actually tests defined(NUMBERS), 1292to determine is any words match "42" you need to use something like: 1293.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1294.It Ar :old_string=new_string 1295This is the 1296.At V 1297style variable substitution. 1298It must be the last modifier specified. 1299If 1300.Ar old_string 1301or 1302.Ar new_string 1303do not contain the pattern matching character 1304.Ar % 1305then it is assumed that they are 1306anchored at the end of each word, so only suffixes or entire 1307words may be replaced. 1308Otherwise 1309.Ar % 1310is the substring of 1311.Ar old_string 1312to be replaced in 1313.Ar new_string . 1314.Pp 1315Variable expansion occurs in the normal fashion inside both 1316.Ar old_string 1317and 1318.Ar new_string 1319with the single exception that a backslash is used to prevent the 1320expansion of a dollar sign 1321.Pq Ql \&$ , 1322not a preceding dollar sign as is usual. 1323.Sm off 1324.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1325.Sm on 1326This is the loop expansion mechanism from the OSF Development 1327Environment (ODE) make. 1328Unlike 1329.Cm \&.for 1330loops expansion occurs at the time of 1331reference. 1332Assign 1333.Ar temp 1334to each word in the variable and evaluate 1335.Ar string . 1336The ODE convention is that 1337.Ar temp 1338should start and end with a period. 1339For example. 1340.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1341.Pp 1342However a single character variable is often more readable: 1343.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1344.It Cm \&:U Ns Ar newval 1345If the variable is undefined 1346.Ar newval 1347is the value. 1348If the variable is defined, the existing value is returned. 1349This is another ODE make feature. 1350It is handy for setting per-target CFLAGS for instance: 1351.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1352If a value is only required if the variable is undefined, use: 1353.Dl ${VAR:D:Unewval} 1354.It Cm \&:D Ns Ar newval 1355If the variable is defined 1356.Ar newval 1357is the value. 1358.It Cm \&:L 1359The name of the variable is the value. 1360.It Cm \&:P 1361The path of the node which has the same name as the variable 1362is the value. 1363If no such node exists or its path is null, then the 1364name of the variable is used. 1365In order for this modifier to work, the name (node) must at least have 1366appeared on the rhs of a dependency. 1367.Sm off 1368.It Cm \&:\&! Ar cmd Cm \&! 1369.Sm on 1370The output of running 1371.Ar cmd 1372is the value. 1373.It Cm \&:sh 1374If the variable is non-empty it is run as a command and the output 1375becomes the new value. 1376.It Cm \&::= Ns Ar str 1377The variable is assigned the value 1378.Ar str 1379after substitution. 1380This modifier and its variations are useful in 1381obscure situations such as wanting to set a variable when shell commands 1382are being parsed. 1383These assignment modifiers always expand to 1384nothing, so if appearing in a rule line by themselves should be 1385preceded with something to keep 1386.Nm 1387happy. 1388.Pp 1389The 1390.Ql Cm \&:: 1391helps avoid false matches with the 1392.At V 1393style 1394.Cm \&:= 1395modifier and since substitution always occurs the 1396.Cm \&::= 1397form is vaguely appropriate. 1398.It Cm \&::?= Ns Ar str 1399As for 1400.Cm \&::= 1401but only if the variable does not already have a value. 1402.It Cm \&::+= Ns Ar str 1403Append 1404.Ar str 1405to the variable. 1406.It Cm \&::!= Ns Ar cmd 1407Assign the output of 1408.Ar cmd 1409to the variable. 1410.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1411Selects one or more words from the value, 1412or performs other operations related to the way in which the 1413value is divided into words. 1414.Pp 1415Ordinarily, a value is treated as a sequence of words 1416delimited by white space. 1417Some modifiers suppress this behaviour, 1418causing a value to be treated as a single word 1419(possibly containing embedded white space). 1420An empty value, or a value that consists entirely of white-space, 1421is treated as a single word. 1422For the purposes of the 1423.Ql Cm \&:[] 1424modifier, the words are indexed both forwards using positive integers 1425(where index 1 represents the first word), 1426and backwards using negative integers 1427(where index \-1 represents the last word). 1428.Pp 1429The 1430.Ar range 1431is subjected to variable expansion, and the expanded result is 1432then interpreted as follows: 1433.Bl -tag -width index 1434.\" :[n] 1435.It Ar index 1436Selects a single word from the value. 1437.\" :[start..end] 1438.It Ar start Ns Cm \&.. Ns Ar end 1439Selects all words from 1440.Ar start 1441to 1442.Ar end , 1443inclusive. 1444For example, 1445.Ql Cm \&:[2..-1] 1446selects all words from the second word to the last word. 1447If 1448.Ar start 1449is greater than 1450.Ar end , 1451then the words are output in reverse order. 1452For example, 1453.Ql Cm \&:[-1..1] 1454selects all the words from last to first. 1455.\" :[*] 1456.It Cm \&* 1457Causes subsequent modifiers to treat the value as a single word 1458(possibly containing embedded white space). 1459Analogous to the effect of 1460\&"$*\&" 1461in Bourne shell. 1462.\" :[0] 1463.It 0 1464Means the same as 1465.Ql Cm \&:[*] . 1466.\" :[*] 1467.It Cm \&@ 1468Causes subsequent modifiers to treat the value as a sequence of words 1469delimited by white space. 1470Analogous to the effect of 1471\&"$@\&" 1472in Bourne shell. 1473.\" :[#] 1474.It Cm \&# 1475Returns the number of words in the value. 1476.El \" :[range] 1477.El 1478.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1479Makefile inclusion, conditional structures and for loops reminiscent 1480of the C programming language are provided in 1481.Nm . 1482All such structures are identified by a line beginning with a single 1483dot 1484.Pq Ql \&. 1485character. 1486Files are included with either 1487.Cm \&.include Aq Ar file 1488or 1489.Cm \&.include Pf \*q Ar file Ns \*q . 1490Variables between the angle brackets or double quotes are expanded 1491to form the file name. 1492If angle brackets are used, the included makefile is expected to be in 1493the system makefile directory. 1494If double quotes are used, the including makefile's directory and any 1495directories specified using the 1496.Fl I 1497option are searched before the system 1498makefile directory. 1499For compatibility with other versions of 1500.Nm 1501.Ql include file ... 1502is also accepted. 1503If the include statement is written as 1504.Cm .-include 1505or as 1506.Cm .sinclude 1507then errors locating and/or opening include files are ignored. 1508.Pp 1509Conditional expressions are also preceded by a single dot as the first 1510character of a line. 1511The possible conditionals are as follows: 1512.Bl -tag -width Ds 1513.It Ic .error Ar message 1514The message is printed along with the name of the makefile and line number, 1515then 1516.Nm 1517will exit. 1518.It Ic .export Ar variable ... 1519Export the specified global variable. 1520If no variable list is provided, all globals are exported 1521except for internal variables (those that start with 1522.Ql \&. ) . 1523This is not affected by the 1524.Fl X 1525flag, so should be used with caution. 1526For compatibility with other 1527.Nm 1528programs 1529.Ql export variable=value 1530is also accepted. 1531.Pp 1532Appending a variable name to 1533.Va .MAKE.EXPORTED 1534is equivalent to exporting a variable. 1535.It Ic .export-env Ar variable ... 1536The same as 1537.Ql .export , 1538except that the variable is not appended to 1539.Va .MAKE.EXPORTED . 1540This allows exporting a value to the environment which is different from that 1541used by 1542.Nm 1543internally. 1544.It Ic .info Ar message 1545The message is printed along with the name of the makefile and line number. 1546.It Ic .undef Ar variable 1547Un-define the specified global variable. 1548Only global variables may be un-defined. 1549.It Ic .unexport Ar variable ... 1550The opposite of 1551.Ql .export . 1552The specified global 1553.Va variable 1554will be removed from 1555.Va .MAKE.EXPORTED . 1556If no variable list is provided, all globals are unexported, 1557and 1558.Va .MAKE.EXPORTED 1559deleted. 1560.It Ic .unexport-env 1561Unexport all globals previously exported and 1562clear the environment inherited from the parent. 1563This operation will cause a memory leak of the original environment, 1564so should be used sparingly. 1565Testing for 1566.Va .MAKE.LEVEL 1567being 0, would make sense. 1568Also note that any variables which originated in the parent environment 1569should be explicitly preserved if desired. 1570For example: 1571.Bd -literal -offset indent 1572.Li .if ${.MAKE.LEVEL} == 0 1573PATH := ${PATH} 1574.Li .unexport-env 1575.Li .export PATH 1576.Li .endif 1577.Pp 1578.Ed 1579Would result in an environment containing only 1580.Ql Ev PATH , 1581which is the minimal useful environment. 1582Actually 1583.Ql Ev .MAKE.LEVEL 1584will also be pushed into the new environment. 1585.It Ic .warning Ar message 1586The message prefixed by 1587.Ql Pa warning: 1588is printed along with the name of the makefile and line number. 1589.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1590Test the value of an expression. 1591.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1592Test the value of a variable. 1593.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1594Test the value of a variable. 1595.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1596Test the target being built. 1597.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1598Test the target being built. 1599.It Ic .else 1600Reverse the sense of the last conditional. 1601.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1602A combination of 1603.Ql Ic .else 1604followed by 1605.Ql Ic .if . 1606.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1607A combination of 1608.Ql Ic .else 1609followed by 1610.Ql Ic .ifdef . 1611.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1612A combination of 1613.Ql Ic .else 1614followed by 1615.Ql Ic .ifndef . 1616.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1617A combination of 1618.Ql Ic .else 1619followed by 1620.Ql Ic .ifmake . 1621.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1622A combination of 1623.Ql Ic .else 1624followed by 1625.Ql Ic .ifnmake . 1626.It Ic .endif 1627End the body of the conditional. 1628.El 1629.Pp 1630The 1631.Ar operator 1632may be any one of the following: 1633.Bl -tag -width "Cm XX" 1634.It Cm \&|\&| 1635Logical OR. 1636.It Cm \&\*[Am]\*[Am] 1637Logical 1638.Tn AND ; 1639of higher precedence than 1640.Dq \&|\&| . 1641.El 1642.Pp 1643As in C, 1644.Nm 1645will only evaluate a conditional as far as is necessary to determine 1646its value. 1647Parentheses may be used to change the order of evaluation. 1648The boolean operator 1649.Ql Ic \&! 1650may be used to logically negate an entire 1651conditional. 1652It is of higher precedence than 1653.Ql Ic \&\*[Am]\*[Am] . 1654.Pp 1655The value of 1656.Ar expression 1657may be any of the following: 1658.Bl -tag -width defined 1659.It Ic defined 1660Takes a variable name as an argument and evaluates to true if the variable 1661has been defined. 1662.It Ic make 1663Takes a target name as an argument and evaluates to true if the target 1664was specified as part of 1665.Nm Ns 's 1666command line or was declared the default target (either implicitly or 1667explicitly, see 1668.Va .MAIN ) 1669before the line containing the conditional. 1670.It Ic empty 1671Takes a variable, with possible modifiers, and evaluates to true if 1672the expansion of the variable would result in an empty string. 1673.It Ic exists 1674Takes a file name as an argument and evaluates to true if the file exists. 1675The file is searched for on the system search path (see 1676.Va .PATH ) . 1677.It Ic target 1678Takes a target name as an argument and evaluates to true if the target 1679has been defined. 1680.It Ic commands 1681Takes a target name as an argument and evaluates to true if the target 1682has been defined and has commands associated with it. 1683.El 1684.Pp 1685.Ar Expression 1686may also be an arithmetic or string comparison. 1687Variable expansion is 1688performed on both sides of the comparison, after which the integral 1689values are compared. 1690A value is interpreted as hexadecimal if it is 1691preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1692The standard C relational operators are all supported. 1693If after 1694variable expansion, either the left or right hand side of a 1695.Ql Ic == 1696or 1697.Ql Ic "!=" 1698operator is not an integral value, then 1699string comparison is performed between the expanded 1700variables. 1701If no relational operator is given, it is assumed that the expanded 1702variable is being compared against 0 or an empty string in the case 1703of a string comparison. 1704.Pp 1705When 1706.Nm 1707is evaluating one of these conditional expressions, and it encounters 1708a (white-space separated) word it doesn't recognize, either the 1709.Dq make 1710or 1711.Dq defined 1712expression is applied to it, depending on the form of the conditional. 1713If the form is 1714.Ql Ic .ifdef , 1715.Ql Ic .ifndef , 1716or 1717.Ql Ic .if 1718the 1719.Dq defined 1720expression is applied. 1721Similarly, if the form is 1722.Ql Ic .ifmake 1723or 1724.Ql Ic .ifnmake , the 1725.Dq make 1726expression is applied. 1727.Pp 1728If the conditional evaluates to true the parsing of the makefile continues 1729as before. 1730If it evaluates to false, the following lines are skipped. 1731In both cases this continues until a 1732.Ql Ic .else 1733or 1734.Ql Ic .endif 1735is found. 1736.Pp 1737For loops are typically used to apply a set of rules to a list of files. 1738The syntax of a for loop is: 1739.Pp 1740.Bl -tag -compact -width Ds 1741.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1742.It Aq make-rules 1743.It Ic \&.endfor 1744.El 1745.Pp 1746After the for 1747.Ic expression 1748is evaluated, it is split into words. 1749On each iteration of the loop, one word is taken and assigned to each 1750.Ic variable , 1751in order, and these 1752.Ic variables 1753are substituted into the 1754.Ic make-rules 1755inside the body of the for loop. 1756The number of words must come out even; that is, if there are three 1757iteration variables, the number of words provided must be a multiple 1758of three. 1759.Sh COMMENTS 1760Comments begin with a hash 1761.Pq Ql \&# 1762character, anywhere but in a shell 1763command line, and continue to the end of an unescaped new line. 1764.Sh SPECIAL SOURCES (ATTRIBUTES) 1765.Bl -tag -width .IGNOREx 1766.It Ic .EXEC 1767Target is never out of date, but always execute commands anyway. 1768.It Ic .IGNORE 1769Ignore any errors from the commands associated with this target, exactly 1770as if they all were preceded by a dash 1771.Pq Ql \- . 1772.\" .It Ic .INVISIBLE 1773.\" XXX 1774.\" .It Ic .JOIN 1775.\" XXX 1776.It Ic .MADE 1777Mark all sources of this target as being up-to-date. 1778.It Ic .MAKE 1779Execute the commands associated with this target even if the 1780.Fl n 1781or 1782.Fl t 1783options were specified. 1784Normally used to mark recursive 1785.Nm Ns s . 1786.It Ic .META 1787Create a meta file for the target, even if it is flagged as 1788.Ic .PHONY , 1789.Ic .MAKE , 1790or 1791.Ic .SPECIAL . 1792Usage in conjunction with 1793.Ic .MAKE 1794is the most likely case. 1795In "meta" mode, the target is out-of-date if the meta file is missing. 1796.It Ic .NOMETA 1797Do not create a meta file for the target. 1798Meta files are also not created for 1799.Ic .PHONY , 1800.Ic .MAKE , 1801or 1802.Ic .SPECIAL 1803targets. 1804.It Ic .NOMETA_CMP 1805Ignore differences in commands when deciding if target is out of date. 1806This is useful if the command contains a value which always changes. 1807If the number of commands change, though, the target will still be out of date. 1808The same effect applies to any command line that uses the variable 1809.Va .OODATE , 1810which can be used for that purpose even when not otherwise needed or desired: 1811.Bd -literal -offset indent 1812 1813skip-compare-for-some: 1814 @echo this will be compared 1815 @echo this will not ${.OODATE:M.NOMETA_CMP} 1816 @echo this will also be compared 1817 1818.Ed 1819The 1820.Cm \&:M 1821pattern suppresses any expansion of the unwanted variable. 1822.It Ic .NOPATH 1823Do not search for the target in the directories specified by 1824.Ic .PATH . 1825.It Ic .NOTMAIN 1826Normally 1827.Nm 1828selects the first target it encounters as the default target to be built 1829if no target was specified. 1830This source prevents this target from being selected. 1831.It Ic .OPTIONAL 1832If a target is marked with this attribute and 1833.Nm 1834can't figure out how to create it, it will ignore this fact and assume 1835the file isn't needed or already exists. 1836.It Ic .PHONY 1837The target does not 1838correspond to an actual file; it is always considered to be out of date, 1839and will not be created with the 1840.Fl t 1841option. 1842Suffix-transformation rules are not applied to 1843.Ic .PHONY 1844targets. 1845.It Ic .PRECIOUS 1846When 1847.Nm 1848is interrupted, it normally removes any partially made targets. 1849This source prevents the target from being removed. 1850.It Ic .RECURSIVE 1851Synonym for 1852.Ic .MAKE . 1853.It Ic .SILENT 1854Do not echo any of the commands associated with this target, exactly 1855as if they all were preceded by an at sign 1856.Pq Ql @ . 1857.It Ic .USE 1858Turn the target into 1859.Nm Ns 's 1860version of a macro. 1861When the target is used as a source for another target, the other target 1862acquires the commands, sources, and attributes (except for 1863.Ic .USE ) 1864of the 1865source. 1866If the target already has commands, the 1867.Ic .USE 1868target's commands are appended 1869to them. 1870.It Ic .USEBEFORE 1871Exactly like 1872.Ic .USE , 1873but prepend the 1874.Ic .USEBEFORE 1875target commands to the target. 1876.It Ic .WAIT 1877If 1878.Ic .WAIT 1879appears in a dependency line, the sources that precede it are 1880made before the sources that succeed it in the line. 1881Since the dependents of files are not made until the file itself 1882could be made, this also stops the dependents being built unless they 1883are needed for another branch of the dependency tree. 1884So given: 1885.Bd -literal 1886x: a .WAIT b 1887 echo x 1888a: 1889 echo a 1890b: b1 1891 echo b 1892b1: 1893 echo b1 1894 1895.Ed 1896the output is always 1897.Ql a , 1898.Ql b1 , 1899.Ql b , 1900.Ql x . 1901.br 1902The ordering imposed by 1903.Ic .WAIT 1904is only relevant for parallel makes. 1905.El 1906.Sh SPECIAL TARGETS 1907Special targets may not be included with other targets, i.e. they must be 1908the only target specified. 1909.Bl -tag -width .BEGINx 1910.It Ic .BEGIN 1911Any command lines attached to this target are executed before anything 1912else is done. 1913.It Ic .DEFAULT 1914This is sort of a 1915.Ic .USE 1916rule for any target (that was used only as a 1917source) that 1918.Nm 1919can't figure out any other way to create. 1920Only the shell script is used. 1921The 1922.Ic .IMPSRC 1923variable of a target that inherits 1924.Ic .DEFAULT Ns 's 1925commands is set 1926to the target's own name. 1927.It Ic .END 1928Any command lines attached to this target are executed after everything 1929else is done. 1930.It Ic .ERROR 1931Any command lines attached to this target are executed when another target fails. 1932The 1933.Ic .ERROR_TARGET 1934variable is set to the target that failed. 1935See also 1936.Ic MAKE_PRINT_VAR_ON_ERROR . 1937.It Ic .IGNORE 1938Mark each of the sources with the 1939.Ic .IGNORE 1940attribute. 1941If no sources are specified, this is the equivalent of specifying the 1942.Fl i 1943option. 1944.It Ic .INTERRUPT 1945If 1946.Nm 1947is interrupted, the commands for this target will be executed. 1948.It Ic .MAIN 1949If no target is specified when 1950.Nm 1951is invoked, this target will be built. 1952.It Ic .MAKEFLAGS 1953This target provides a way to specify flags for 1954.Nm 1955when the makefile is used. 1956The flags are as if typed to the shell, though the 1957.Fl f 1958option will have 1959no effect. 1960.\" XXX: NOT YET!!!! 1961.\" .It Ic .NOTPARALLEL 1962.\" The named targets are executed in non parallel mode. 1963.\" If no targets are 1964.\" specified, then all targets are executed in non parallel mode. 1965.It Ic .NOPATH 1966Apply the 1967.Ic .NOPATH 1968attribute to any specified sources. 1969.It Ic .NOTPARALLEL 1970Disable parallel mode. 1971.It Ic .NO_PARALLEL 1972Synonym for 1973.Ic .NOTPARALLEL , 1974for compatibility with other pmake variants. 1975.It Ic .ORDER 1976The named targets are made in sequence. 1977This ordering does not add targets to the list of targets to be made. 1978Since the dependents of a target do not get built until the target itself 1979could be built, unless 1980.Ql a 1981is built by another part of the dependency graph, 1982the following is a dependency loop: 1983.Bd -literal 1984\&.ORDER: b a 1985b: a 1986.Ed 1987.Pp 1988The ordering imposed by 1989.Ic .ORDER 1990is only relevant for parallel makes. 1991.\" XXX: NOT YET!!!! 1992.\" .It Ic .PARALLEL 1993.\" The named targets are executed in parallel mode. 1994.\" If no targets are 1995.\" specified, then all targets are executed in parallel mode. 1996.It Ic .PATH 1997The sources are directories which are to be searched for files not 1998found in the current directory. 1999If no sources are specified, any previously specified directories are 2000deleted. 2001If the source is the special 2002.Ic .DOTLAST 2003target, then the current working 2004directory is searched last. 2005.It Ic .PATH. Ns Va suffix 2006Like 2007.Ic .PATH 2008but applies only to files with a particular suffix. 2009The suffix must have been previously declared with 2010.Ic .SUFFIXES . 2011.It Ic .PHONY 2012Apply the 2013.Ic .PHONY 2014attribute to any specified sources. 2015.It Ic .PRECIOUS 2016Apply the 2017.Ic .PRECIOUS 2018attribute to any specified sources. 2019If no sources are specified, the 2020.Ic .PRECIOUS 2021attribute is applied to every 2022target in the file. 2023.It Ic .SHELL 2024Sets the shell that 2025.Nm 2026will use to execute commands. 2027The sources are a set of 2028.Ar field=value 2029pairs. 2030.Bl -tag -width hasErrCtls 2031.It Ar name 2032This is the minimal specification, used to select one of the builtin 2033shell specs; 2034.Ar sh , 2035.Ar ksh , 2036and 2037.Ar csh . 2038.It Ar path 2039Specifies the path to the shell. 2040.It Ar hasErrCtl 2041Indicates whether the shell supports exit on error. 2042.It Ar check 2043The command to turn on error checking. 2044.It Ar ignore 2045The command to disable error checking. 2046.It Ar echo 2047The command to turn on echoing of commands executed. 2048.It Ar quiet 2049The command to turn off echoing of commands executed. 2050.It Ar filter 2051The output to filter after issuing the 2052.Ar quiet 2053command. 2054It is typically identical to 2055.Ar quiet . 2056.It Ar errFlag 2057The flag to pass the shell to enable error checking. 2058.It Ar echoFlag 2059The flag to pass the shell to enable command echoing. 2060.It Ar newline 2061The string literal to pass the shell that results in a single newline 2062character when used outside of any quoting characters. 2063.El 2064Example: 2065.Bd -literal 2066\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2067 check="set \-e" ignore="set +e" \e 2068 echo="set \-v" quiet="set +v" filter="set +v" \e 2069 echoFlag=v errFlag=e newline="'\en'" 2070.Ed 2071.It Ic .SILENT 2072Apply the 2073.Ic .SILENT 2074attribute to any specified sources. 2075If no sources are specified, the 2076.Ic .SILENT 2077attribute is applied to every 2078command in the file. 2079.It Ic .STALE 2080This target gets run when a dependency file contains stale entries, having 2081.Va .ALLSRC 2082set to the name of that dependency file. 2083.It Ic .SUFFIXES 2084Each source specifies a suffix to 2085.Nm . 2086If no sources are specified, any previously specified suffixes are deleted. 2087It allows the creation of suffix-transformation rules. 2088.Pp 2089Example: 2090.Bd -literal 2091\&.SUFFIXES: .o 2092\&.c.o: 2093 cc \-o ${.TARGET} \-c ${.IMPSRC} 2094.Ed 2095.El 2096.Sh ENVIRONMENT 2097.Nm 2098uses the following environment variables, if they exist: 2099.Ev MACHINE , 2100.Ev MACHINE_ARCH , 2101.Ev MAKE , 2102.Ev MAKEFLAGS , 2103.Ev MAKEOBJDIR , 2104.Ev MAKEOBJDIRPREFIX , 2105.Ev MAKESYSPATH , 2106.Ev PWD , 2107and 2108.Ev TMPDIR . 2109.Pp 2110.Ev MAKEOBJDIRPREFIX 2111and 2112.Ev MAKEOBJDIR 2113may only be set in the environment or on the command line to 2114.Nm 2115and not as makefile variables; 2116see the description of 2117.Ql Va .OBJDIR 2118for more details. 2119.Sh FILES 2120.Bl -tag -width /usr/share/mk -compact 2121.It .depend 2122list of dependencies 2123.It Makefile 2124list of dependencies 2125.It makefile 2126list of dependencies 2127.It sys.mk 2128system makefile 2129.It /usr/share/mk 2130system makefile directory 2131.El 2132.Sh COMPATIBILITY 2133The basic make syntax is compatible between different versions of make, 2134however the special variables, variable modifiers and conditionals are not. 2135.Pp 2136The way that parallel makes are scheduled changed in 2137.Nx 4.0 2138so that .ORDER and .WAIT apply recursively to the dependent nodes. 2139The algorithms used may change again in the future. 2140.Pp 2141The way that .for loop variables are substituted changed after 2142.Nx 5.0 2143so that they still appear to be variable expansions. 2144In particular this stops them being treated as syntax, and removes some 2145obscure problems using them in .if statements. 2146.Sh SEE ALSO 2147.Xr mkdep 1 2148.Sh HISTORY 2149A 2150.Nm 2151command appeared in 2152.At v7 . 2153This 2154.Nm 2155implementation is based on Adam De Boor's pmake program which was written 2156for Sprite at Berkeley. 2157It was designed to be a parallel distributed make running jobs on different 2158machines using a daemon called 2159.Dq customs . 2160.Pp 2161Historically the target/dependency 2162.Dq FRC 2163has been used to FoRCe rebuilding (since the target/dependency 2164does not exist... unless someone creates an 2165.Dq FRC 2166file). 2167.Sh BUGS 2168The 2169.Nm 2170syntax is difficult to parse without actually acting of the data. 2171For instance finding the end of a variable use should involve scanning each 2172the modifiers using the correct terminator for each field. 2173In many places 2174.Nm 2175just counts {} and () in order to find the end of a variable expansion. 2176.Pp 2177There is no way of escaping a space character in a filename. 2178