1.\" $NetBSD: make.1,v 1.273 2018/05/27 01:14:51 christos 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 December 5, 2018 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 Fl v Ar variable 52.Op Ar variable=value 53.Op Ar target ... 54.Sh DESCRIPTION 55.Nm 56is a program designed to simplify the maintenance of other programs. 57Its input is a list of specifications as to the files upon which programs 58and other files depend. 59If no 60.Fl f Ar makefile 61makefile option is given, 62.Nm 63will try to open 64.Ql Pa makefile 65then 66.Ql Pa Makefile 67in order to find the specifications. 68If the file 69.Ql Pa .depend 70exists, it is read (see 71.Xr mkdep 1 ) . 72.Pp 73This manual page is intended as a reference document only. 74For a more thorough description of 75.Nm 76and makefiles, please refer to 77.%T "PMake \- A Tutorial" . 78.Pp 79.Nm 80will prepend the contents of the 81.Va MAKEFLAGS 82environment variable to the command line arguments before parsing them. 83.Pp 84The options are as follows: 85.Bl -tag -width Ds 86.It Fl B 87Try to be backwards compatible by executing a single shell per command and 88by executing the commands to make the sources of a dependency line in sequence. 89.It Fl C Ar directory 90Change to 91.Ar directory 92before reading the makefiles or doing anything else. 93If multiple 94.Fl C 95options are specified, each is interpreted relative to the previous one: 96.Fl C Pa / Fl C Pa etc 97is equivalent to 98.Fl C Pa /etc . 99.It Fl D Ar variable 100Define 101.Ar variable 102to be 1, in the global context. 103.It Fl d Ar [-]flags 104Turn on debugging, and specify which portions of 105.Nm 106are to print debugging information. 107Unless the flags are preceded by 108.Ql \- 109they are added to the 110.Va MAKEFLAGS 111environment variable and will be processed by any child make processes. 112By default, debugging information is printed to standard error, 113but this can be changed using the 114.Ar F 115debugging flag. 116The debugging output is always unbuffered; in addition, if debugging 117is enabled but debugging output is not directed to standard output, 118then the standard output is line buffered. 119.Ar Flags 120is one or more of the following: 121.Bl -tag -width Ds 122.It Ar A 123Print all possible debugging information; 124equivalent to specifying all of the debugging flags. 125.It Ar a 126Print debugging information about archive searching and caching. 127.It Ar C 128Print debugging information about current working directory. 129.It Ar c 130Print debugging information about conditional evaluation. 131.It Ar d 132Print debugging information about directory searching and caching. 133.It Ar e 134Print debugging information about failed commands and targets. 135.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 136Specify where debugging output is written. 137This must be the last flag, because it consumes the remainder of 138the argument. 139If the character immediately after the 140.Ql F 141flag is 142.Ql \&+ , 143then the file will be opened in append mode; 144otherwise the file will be overwritten. 145If the file name is 146.Ql stdout 147or 148.Ql stderr 149then debugging output will be written to the 150standard output or standard error output file descriptors respectively 151(and the 152.Ql \&+ 153option has no effect). 154Otherwise, the output will be written to the named file. 155If the file name ends 156.Ql .%d 157then the 158.Ql %d 159is replaced by the pid. 160.It Ar f 161Print debugging information about loop evaluation. 162.It Ar "g1" 163Print the input graph before making anything. 164.It Ar "g2" 165Print the input graph after making everything, or before exiting 166on error. 167.It Ar "g3" 168Print the input graph before exiting on error. 169.It Ar j 170Print debugging information about running multiple shells. 171.It Ar l 172Print commands in Makefiles regardless of whether or not they are prefixed by 173.Ql @ 174or other "quiet" flags. 175Also known as "loud" behavior. 176.It Ar M 177Print debugging information about "meta" mode decisions about targets. 178.It Ar m 179Print debugging information about making targets, including modification 180dates. 181.It Ar n 182Don't delete the temporary command scripts created when running commands. 183These temporary scripts are created in the directory 184referred to by the 185.Ev TMPDIR 186environment variable, or in 187.Pa /tmp 188if 189.Ev TMPDIR 190is unset or set to the empty string. 191The temporary scripts are created by 192.Xr mkstemp 3 , 193and have names of the form 194.Pa makeXXXXXX . 195.Em NOTE : 196This can create many files in 197.Ev TMPDIR 198or 199.Pa /tmp , 200so use with care. 201.It Ar p 202Print debugging information about makefile parsing. 203.It Ar s 204Print debugging information about suffix-transformation rules. 205.It Ar t 206Print debugging information about target list maintenance. 207.It Ar V 208Force the 209.Fl V 210option to print raw values of variables, overriding the default behavior 211set via 212.Va .MAKE.EXPAND_VARIABLES . 213.It Ar v 214Print debugging information about variable assignment. 215.It Ar x 216Run shell commands with 217.Fl x 218so the actual commands are printed as they are executed. 219.El 220.It Fl e 221Specify that environment variables override macro assignments within 222makefiles. 223.It Fl f Ar makefile 224Specify a makefile to read instead of the default 225.Ql Pa makefile . 226If 227.Ar makefile 228is 229.Ql Fl , 230standard input is read. 231Multiple makefiles may be specified, and are read in the order specified. 232.It Fl I Ar directory 233Specify a directory in which to search for makefiles and included makefiles. 234The system makefile directory (or directories, see the 235.Fl m 236option) is automatically included as part of this list. 237.It Fl i 238Ignore non-zero exit of shell commands in the makefile. 239Equivalent to specifying 240.Ql Fl 241before each command line in the makefile. 242.It Fl J Ar private 243This option should 244.Em not 245be specified by the user. 246.Pp 247When the 248.Ar j 249option is in use in a recursive build, this option is passed by a make 250to child makes to allow all the make processes in the build to 251cooperate to avoid overloading the system. 252.It Fl j Ar max_jobs 253Specify the maximum number of jobs that 254.Nm 255may have running at any one time. 256The value is saved in 257.Va .MAKE.JOBS . 258Turns compatibility mode off, unless the 259.Ar B 260flag is also specified. 261When compatibility mode is off, all commands associated with a 262target are executed in a single shell invocation as opposed to the 263traditional one shell invocation per line. 264This can break traditional scripts which change directories on each 265command invocation and then expect to start with a fresh environment 266on the next line. 267It is more efficient to correct the scripts rather than turn backwards 268compatibility on. 269.It Fl k 270Continue processing after errors are encountered, but only on those targets 271that do not depend on the target whose creation caused the error. 272.It Fl m Ar directory 273Specify a directory in which to search for sys.mk and makefiles included 274via the 275.Ao Ar file Ac Ns -style 276include statement. 277The 278.Fl m 279option can be used multiple times to form a search path. 280This path will override the default system include path: /usr/share/mk. 281Furthermore the system include path will be appended to the search path used 282for 283.Qo Ar file Qc Ns -style 284include statements (see the 285.Fl I 286option). 287.Pp 288If a file or directory name in the 289.Fl m 290argument (or the 291.Ev MAKESYSPATH 292environment variable) starts with the string 293.Qq \&.../ 294then 295.Nm 296will search for the specified file or directory named in the remaining part 297of the argument string. 298The search starts with the current directory of 299the Makefile and then works upward towards the root of the file system. 300If the search is successful, then the resulting directory replaces the 301.Qq \&.../ 302specification in the 303.Fl m 304argument. 305If used, this feature allows 306.Nm 307to easily search in the current source tree for customized sys.mk files 308(e.g., by using 309.Qq \&.../mk/sys.mk 310as an argument). 311.It Fl n 312Display the commands that would have been executed, but do not 313actually execute them unless the target depends on the .MAKE special 314source (see below). 315.It Fl N 316Display the commands which would have been executed, but do not 317actually execute any of them; useful for debugging top-level makefiles 318without descending into subdirectories. 319.It Fl q 320Do not execute any commands, but exit 0 if the specified targets are 321up-to-date and 1, otherwise. 322.It Fl r 323Do not use the built-in rules specified in the system makefile. 324.It Fl s 325Do not echo any commands as they are executed. 326Equivalent to specifying 327.Ql Ic @ 328before each command line in the makefile. 329.It Fl T Ar tracefile 330When used with the 331.Fl j 332flag, 333append a trace record to 334.Ar tracefile 335for each job started and completed. 336.It Fl t 337Rather than re-building a target as specified in the makefile, create it 338or update its modification time to make it appear up-to-date. 339.It Fl V Ar variable 340Print the value of 341.Ar variable . 342Do not build any targets. 343Multiple instances of this option may be specified; 344the variables will be printed one per line, 345with a blank line for each null or undefined variable. 346The value printed is extracted from the global context after all 347makefiles have been read. 348By default, the raw variable contents (which may 349include additional unexpanded variable references) are shown. 350If 351.Ar variable 352contains a 353.Ql \&$ 354then the value will be recursively expanded to its complete resultant 355text before printing. 356The expanded value will also be printed if 357.Va .MAKE.EXPAND_VARIABLES 358is set to true and 359the 360.Fl dV 361option has not been used to override it. 362Note that loop-local and target-local variables, as well as values 363taken temporarily by global variables during makefile processing, are 364not accessible via this option. 365The 366.Fl dv 367debug mode can be used to see these at the cost of generating 368substantial extraneous output. 369.It Fl v Ar variable 370Like 371.Fl V 372but the variable is always expanded to its complete value. 373.It Fl W 374Treat any warnings during makefile parsing as errors. 375.It Fl w 376Print entering and leaving directory messages, pre and post processing. 377.It Fl X 378Don't export variables passed on the command line to the environment 379individually. 380Variables passed on the command line are still exported 381via the 382.Va MAKEFLAGS 383environment variable. 384This option may be useful on systems which have a small limit on the 385size of command arguments. 386.It Ar variable=value 387Set the value of the variable 388.Ar variable 389to 390.Ar value . 391Normally, all values passed on the command line are also exported to 392sub-makes in the environment. 393The 394.Fl X 395flag disables this behavior. 396Variable assignments should follow options for POSIX compatibility 397but no ordering is enforced. 398.El 399.Pp 400There are seven different types of lines in a makefile: file dependency 401specifications, shell commands, variable assignments, include statements, 402conditional directives, for loops, and comments. 403.Pp 404In general, lines may be continued from one line to the next by ending 405them with a backslash 406.Pq Ql \e . 407The trailing newline character and initial whitespace on the following 408line are compressed into a single space. 409.Sh FILE DEPENDENCY SPECIFICATIONS 410Dependency lines consist of one or more targets, an operator, and zero 411or more sources. 412This creates a relationship where the targets 413.Dq depend 414on the sources 415and are usually created from them. 416The exact relationship between the target and the source is determined 417by the operator that separates them. 418The three operators are as follows: 419.Bl -tag -width flag 420.It Ic \&: 421A target is considered out-of-date if its modification time is less than 422those of any of its sources. 423Sources for a target accumulate over dependency lines when this operator 424is used. 425The target is removed if 426.Nm 427is interrupted. 428.It Ic \&! 429Targets are always re-created, but not until all sources have been 430examined and re-created as necessary. 431Sources for a target accumulate over dependency lines when this operator 432is used. 433The target is removed if 434.Nm 435is interrupted. 436.It Ic \&:: 437If no sources are specified, the target is always re-created. 438Otherwise, a target is considered out-of-date if any of its sources has 439been modified more recently than the target. 440Sources for a target do not accumulate over dependency lines when this 441operator is used. 442The target will not be removed if 443.Nm 444is interrupted. 445.El 446.Pp 447Targets and sources may contain the shell wildcard values 448.Ql \&? , 449.Ql * , 450.Ql [] , 451and 452.Ql {} . 453The values 454.Ql \&? , 455.Ql * , 456and 457.Ql [] 458may only be used as part of the final 459component of the target or source, and must be used to describe existing 460files. 461The value 462.Ql {} 463need not necessarily be used to describe existing files. 464Expansion is in directory order, not alphabetically as done in the shell. 465.Sh SHELL COMMANDS 466Each target may have associated with it one or more lines of shell 467commands, normally 468used to create the target. 469Each of the lines in this script 470.Em must 471be preceded by a tab. 472(For historical reasons, spaces are not accepted.) 473While targets can appear in many dependency lines if desired, by 474default only one of these rules may be followed by a creation 475script. 476If the 477.Ql Ic \&:: 478operator is used, however, all rules may include scripts and the 479scripts are executed in the order found. 480.Pp 481Each line is treated as a separate shell command, unless the end of 482line is escaped with a backslash 483.Pq Ql \e 484in which case that line and the next are combined. 485.\" The escaped newline is retained and passed to the shell, which 486.\" normally ignores it. 487.\" However, the tab at the beginning of the following line is removed. 488If the first characters of the command are any combination of 489.Ql Ic @ , 490.Ql Ic + , 491or 492.Ql Ic \- , 493the command is treated specially. 494A 495.Ql Ic @ 496causes the command not to be echoed before it is executed. 497A 498.Ql Ic + 499causes the command to be executed even when 500.Fl n 501is given. 502This is similar to the effect of the .MAKE special source, 503except that the effect can be limited to a single line of a script. 504A 505.Ql Ic \- 506in compatibility mode 507causes any non-zero exit status of the command line to be ignored. 508.Pp 509When 510.Nm 511is run in jobs mode with 512.Fl j Ar max_jobs , 513the entire script for the target is fed to a 514single instance of the shell. 515In compatibility (non-jobs) mode, each command is run in a separate process. 516If the command contains any shell meta characters 517.Pq Ql #=|^(){};&<>*?[]:$`\e\en 518it will be passed to the shell; otherwise 519.Nm 520will attempt direct execution. 521If a line starts with 522.Ql Ic \- 523and the shell has ErrCtl enabled then failure of the command line 524will be ignored as in compatibility mode. 525Otherwise 526.Ql Ic \- 527affects the entire job; 528the script will stop at the first command line that fails, 529but the target will not be deemed to have failed. 530.Pp 531Makefiles should be written so that the mode of 532.Nm 533operation does not change their behavior. 534For example, any command which needs to use 535.Dq cd 536or 537.Dq chdir 538without potentially changing the directory for subsequent commands 539should be put in parentheses so it executes in a subshell. 540To force the use of one shell, escape the line breaks so as to make 541the whole script one command. 542For example: 543.Bd -literal -offset indent 544avoid-chdir-side-effects: 545 @echo Building $@ in `pwd` 546 @(cd ${.CURDIR} && ${MAKE} $@) 547 @echo Back in `pwd` 548 549ensure-one-shell-regardless-of-mode: 550 @echo Building $@ in `pwd`; \e 551 (cd ${.CURDIR} && ${MAKE} $@); \e 552 echo Back in `pwd` 553.Ed 554.Pp 555Since 556.Nm 557will 558.Xr chdir 2 559to 560.Ql Va .OBJDIR 561before executing any targets, each child process 562starts with that as its current working directory. 563.Sh VARIABLE ASSIGNMENTS 564Variables in make are much like variables in the shell, and, by tradition, 565consist of all upper-case letters. 566.Ss Variable assignment modifiers 567The five operators that can be used to assign values to variables are as 568follows: 569.Bl -tag -width Ds 570.It Ic \&= 571Assign the value to the variable. 572Any previous value is overridden. 573.It Ic \&+= 574Append the value to the current value of the variable. 575.It Ic \&?= 576Assign the value to the variable if it is not already defined. 577.It Ic \&:= 578Assign with expansion, i.e. expand the value before assigning it 579to the variable. 580Normally, expansion is not done until the variable is referenced. 581.Em NOTE : 582References to undefined variables are 583.Em not 584expanded. 585This can cause problems when variable modifiers are used. 586.It Ic \&!= 587Expand the value and pass it to the shell for execution and assign 588the result to the variable. 589Any newlines in the result are replaced with spaces. 590.El 591.Pp 592Any white-space before the assigned 593.Ar value 594is removed; if the value is being appended, a single space is inserted 595between the previous contents of the variable and the appended value. 596.Pp 597Variables are expanded by surrounding the variable name with either 598curly braces 599.Pq Ql {} 600or parentheses 601.Pq Ql () 602and preceding it with 603a dollar sign 604.Pq Ql \&$ . 605If the variable name contains only a single letter, the surrounding 606braces or parentheses are not required. 607This shorter form is not recommended. 608.Pp 609If the variable name contains a dollar, then the name itself is expanded first. 610This allows almost arbitrary variable names, however names containing dollar, 611braces, parenthesis, or whitespace are really best avoided! 612.Pp 613If the result of expanding a variable contains a dollar sign 614.Pq Ql \&$ 615the string is expanded again. 616.Pp 617Variable substitution occurs at three distinct times, depending on where 618the variable is being used. 619.Bl -enum 620.It 621Variables in dependency lines are expanded as the line is read. 622.It 623Variables in shell commands are expanded when the shell command is 624executed. 625.It 626.Dq .for 627loop index variables are expanded on each loop iteration. 628Note that other variables are not expanded inside loops so 629the following example code: 630.Bd -literal -offset indent 631 632.Dv .for i in 1 2 3 633a+= ${i} 634j= ${i} 635b+= ${j} 636.Dv .endfor 637 638all: 639 @echo ${a} 640 @echo ${b} 641 642.Ed 643will print: 644.Bd -literal -offset indent 6451 2 3 6463 3 3 647 648.Ed 649Because while ${a} contains 650.Dq 1 2 3 651after the loop is executed, ${b} 652contains 653.Dq ${j} ${j} ${j} 654which expands to 655.Dq 3 3 3 656since after the loop completes ${j} contains 657.Dq 3 . 658.El 659.Ss Variable classes 660The four different classes of variables (in order of increasing precedence) 661are: 662.Bl -tag -width Ds 663.It Environment variables 664Variables defined as part of 665.Nm Ns 's 666environment. 667.It Global variables 668Variables defined in the makefile or in included makefiles. 669.It Command line variables 670Variables defined as part of the command line. 671.It Local variables 672Variables that are defined specific to a certain target. 673.El 674.Pp 675Local variables are all built in and their values vary magically from 676target to target. 677It is not currently possible to define new local variables. 678The seven local variables are as follows: 679.Bl -tag -width ".ARCHIVE" -offset indent 680.It Va .ALLSRC 681The list of all sources for this target; also known as 682.Ql Va \&> . 683.It Va .ARCHIVE 684The name of the archive file; also known as 685.Ql Va \&! . 686.It Va .IMPSRC 687In suffix-transformation rules, the name/path of the source from which the 688target is to be transformed (the 689.Dq implied 690source); also known as 691.Ql Va \&< . 692It is not defined in explicit rules. 693.It Va .MEMBER 694The name of the archive member; also known as 695.Ql Va % . 696.It Va .OODATE 697The list of sources for this target that were deemed out-of-date; also 698known as 699.Ql Va \&? . 700.It Va .PREFIX 701The file prefix of the target, containing only the file portion, no suffix 702or preceding directory components; also known as 703.Ql Va * . 704The suffix must be one of the known suffixes declared with 705.Ic .SUFFIXES 706or it will not be recognized. 707.It Va .TARGET 708The name of the target; also known as 709.Ql Va @ . 710For compatibility with other makes this is an alias for 711.Ic .ARCHIVE 712in archive member rules. 713.El 714.Pp 715The shorter forms 716.Ql ( Va > , 717.Ql Va \&! , 718.Ql Va < , 719.Ql Va % , 720.Ql Va \&? , 721.Ql Va * , 722and 723.Ql Va @ ) 724are permitted for backward 725compatibility with historical makefiles and legacy POSIX make and are 726not recommended. 727.Pp 728Variants of these variables with the punctuation followed immediately by 729.Ql D 730or 731.Ql F , 732e.g. 733.Ql Va $(@D) , 734are legacy forms equivalent to using the 735.Ql :H 736and 737.Ql :T 738modifiers. 739These forms are accepted for compatibility with 740.At V 741makefiles and POSIX but are not recommended. 742.Pp 743Four of the local variables may be used in sources on dependency lines 744because they expand to the proper value for each target on the line. 745These variables are 746.Ql Va .TARGET , 747.Ql Va .PREFIX , 748.Ql Va .ARCHIVE , 749and 750.Ql Va .MEMBER . 751.Ss Additional built-in variables 752In addition, 753.Nm 754sets or knows about the following variables: 755.Bl -tag -width .MAKEOVERRIDES 756.It Va \&$ 757A single dollar sign 758.Ql \&$ , 759i.e. 760.Ql \&$$ 761expands to a single dollar 762sign. 763.It Va .ALLTARGETS 764The list of all targets encountered in the Makefile. 765If evaluated during 766Makefile parsing, lists only those targets encountered thus far. 767.It Va .CURDIR 768A path to the directory where 769.Nm 770was executed. 771Refer to the description of 772.Ql Ev PWD 773for more details. 774.It Va .INCLUDEDFROMDIR 775The directory of the file this Makefile was included from. 776.It Va .INCLUDEDFROMFILE 777The filename of the file this Makefile was included from. 778.It Ev MAKE 779The name that 780.Nm 781was executed with 782.Pq Va argv[0] . 783For compatibility 784.Nm 785also sets 786.Va .MAKE 787with the same value. 788The preferred variable to use is the environment variable 789.Ev MAKE 790because it is more compatible with other versions of 791.Nm 792and cannot be confused with the special target with the same name. 793.It Va .MAKE.ALWAYS_PASS_JOB_QUEUE 794Tells 795.Nm 796whether to pass the descriptors of the job token queue 797even if the target is not tagged with 798.Ic .MAKE 799The default is 800.Ql Pa yes 801for backwards compatability with 802.Fx 9.0 803and earlier. 804.It Va .MAKE.DEPENDFILE 805Names the makefile (default 806.Ql Pa .depend ) 807from which generated dependencies are read. 808.It Va .MAKE.EXPAND_VARIABLES 809A boolean that controls the default behavior of the 810.Fl V 811option. 812If true, variable values printed with 813.Fl V 814are fully expanded; if false, the raw variable contents (which may 815include additional unexpanded variable references) are shown. 816.It Va .MAKE.EXPORTED 817The list of variables exported by 818.Nm . 819.It Va .MAKE.JOBS 820The argument to the 821.Fl j 822option. 823.It Va .MAKE.JOB.PREFIX 824If 825.Nm 826is run with 827.Ar j 828then output for each target is prefixed with a token 829.Ql --- target --- 830the first part of which can be controlled via 831.Va .MAKE.JOB.PREFIX . 832If 833.Va .MAKE.JOB.PREFIX 834is empty, no token is printed. 835.br 836For example: 837.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 838would produce tokens like 839.Ql ---make[1234] target --- 840making it easier to track the degree of parallelism being achieved. 841.It Ev MAKEFLAGS 842The environment variable 843.Ql Ev MAKEFLAGS 844may contain anything that 845may be specified on 846.Nm Ns 's 847command line. 848Anything specified on 849.Nm Ns 's 850command line is appended to the 851.Ql Ev MAKEFLAGS 852variable which is then 853entered into the environment for all programs which 854.Nm 855executes. 856.It Va .MAKE.LEVEL 857The recursion depth of 858.Nm . 859The initial instance of 860.Nm 861will be 0, and an incremented value is put into the environment 862to be seen by the next generation. 863This allows tests like: 864.Li .if ${.MAKE.LEVEL} == 0 865to protect things which should only be evaluated in the initial instance of 866.Nm . 867.It Va .MAKE.MAKEFILE_PREFERENCE 868The ordered list of makefile names 869(default 870.Ql Pa makefile , 871.Ql Pa Makefile ) 872that 873.Nm 874will look for. 875.It Va .MAKE.MAKEFILES 876The list of makefiles read by 877.Nm , 878which is useful for tracking dependencies. 879Each makefile is recorded only once, regardless of the number of times read. 880.It Va .MAKE.MODE 881Processed after reading all makefiles. 882Can affect the mode that 883.Nm 884runs in. 885It can contain a number of keywords: 886.Bl -hang -width missing-filemon=bf. 887.It Pa compat 888Like 889.Fl B , 890puts 891.Nm 892into "compat" mode. 893.It Pa meta 894Puts 895.Nm 896into "meta" mode, where meta files are created for each target 897to capture the command run, the output generated and if 898.Xr filemon 4 899is available, the system calls which are of interest to 900.Nm . 901The captured output can be very useful when diagnosing errors. 902.It Pa curdirOk= Ar bf 903Normally 904.Nm 905will not create .meta files in 906.Ql Va .CURDIR . 907This can be overridden by setting 908.Va bf 909to a value which represents True. 910.It Pa missing-meta= Ar bf 911If 912.Va bf 913is True, then a missing .meta file makes the target out-of-date. 914.It Pa missing-filemon= Ar bf 915If 916.Va bf 917is True, then missing filemon data makes the target out-of-date. 918.It Pa nofilemon 919Do not use 920.Xr filemon 4 . 921.It Pa env 922For debugging, it can be useful to include the environment 923in the .meta file. 924.It Pa verbose 925If in "meta" mode, print a clue about the target being built. 926This is useful if the build is otherwise running silently. 927The message printed the value of: 928.Va .MAKE.META.PREFIX . 929.It Pa ignore-cmd 930Some makefiles have commands which are simply not stable. 931This keyword causes them to be ignored for 932determining whether a target is out of date in "meta" mode. 933See also 934.Ic .NOMETA_CMP . 935.It Pa silent= Ar bf 936If 937.Va bf 938is True, when a .meta file is created, mark the target 939.Ic .SILENT . 940.El 941.It Va .MAKE.META.BAILIWICK 942In "meta" mode, provides a list of prefixes which 943match the directories controlled by 944.Nm . 945If a file that was generated outside of 946.Va .OBJDIR 947but within said bailiwick is missing, 948the current target is considered out-of-date. 949.It Va .MAKE.META.CREATED 950In "meta" mode, this variable contains a list of all the meta files 951updated. 952If not empty, it can be used to trigger processing of 953.Va .MAKE.META.FILES . 954.It Va .MAKE.META.FILES 955In "meta" mode, this variable contains a list of all the meta files 956used (updated or not). 957This list can be used to process the meta files to extract dependency 958information. 959.It Va .MAKE.META.IGNORE_PATHS 960Provides a list of path prefixes that should be ignored; 961because the contents are expected to change over time. 962The default list includes: 963.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 964.It Va .MAKE.META.IGNORE_PATTERNS 965Provides a list of patterns to match against pathnames. 966Ignore any that match. 967.It Va .MAKE.META.IGNORE_FILTER 968Provides a list of variable modifiers to apply to each pathname. 969Ignore if the expansion is an empty string. 970.It Va .MAKE.META.PREFIX 971Defines the message printed for each meta file updated in "meta verbose" mode. 972The default value is: 973.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 974.It Va .MAKEOVERRIDES 975This variable is used to record the names of variables assigned to 976on the command line, so that they may be exported as part of 977.Ql Ev MAKEFLAGS . 978This behavior can be disabled by assigning an empty value to 979.Ql Va .MAKEOVERRIDES 980within a makefile. 981Extra variables can be exported from a makefile 982by appending their names to 983.Ql Va .MAKEOVERRIDES . 984.Ql Ev MAKEFLAGS 985is re-exported whenever 986.Ql Va .MAKEOVERRIDES 987is modified. 988.It Va .MAKE.PATH_FILEMON 989If 990.Nm 991was built with 992.Xr filemon 4 993support, this is set to the path of the device node. 994This allows makefiles to test for this support. 995.It Va .MAKE.PID 996The process-id of 997.Nm . 998.It Va .MAKE.PPID 999The parent process-id of 1000.Nm . 1001.It Va .MAKE.SAVE_DOLLARS 1002value should be a boolean that controls whether 1003.Ql $$ 1004are preserved when doing 1005.Ql := 1006assignments. 1007The default is false, for backwards compatibility. 1008Set to true for compatability with other makes. 1009If set to false, 1010.Ql $$ 1011becomes 1012.Ql $ 1013per normal evaluation rules. 1014.It Va MAKE_PRINT_VAR_ON_ERROR 1015When 1016.Nm 1017stops due to an error, it sets 1018.Ql Va .ERROR_TARGET 1019to the name of the target that failed, 1020.Ql Va .ERROR_CMD 1021to the commands of the failed target, 1022and in "meta" mode, it also sets 1023.Ql Va .ERROR_CWD 1024to the 1025.Xr getcwd 3 , 1026and 1027.Ql Va .ERROR_META_FILE 1028to the path of the meta file (if any) describing the failed target. 1029It then prints its name and the value of 1030.Ql Va .CURDIR 1031as well as the value of any variables named in 1032.Ql Va MAKE_PRINT_VAR_ON_ERROR . 1033.It Va .newline 1034This variable is simply assigned a newline character as its value. 1035This allows expansions using the 1036.Cm \&:@ 1037modifier to put a newline between 1038iterations of the loop rather than a space. 1039For example, the printing of 1040.Ql Va MAKE_PRINT_VAR_ON_ERROR 1041could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 1042.It Va .OBJDIR 1043A path to the directory where the targets are built. 1044Its value is determined by trying to 1045.Xr chdir 2 1046to the following directories in order and using the first match: 1047.Bl -enum 1048.It 1049.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 1050.Pp 1051(Only if 1052.Ql Ev MAKEOBJDIRPREFIX 1053is set in the environment or on the command line.) 1054.It 1055.Ev ${MAKEOBJDIR} 1056.Pp 1057(Only if 1058.Ql Ev MAKEOBJDIR 1059is set in the environment or on the command line.) 1060.It 1061.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 1062.It 1063.Ev ${.CURDIR} Ns Pa /obj 1064.It 1065.Pa /usr/obj/ Ns Ev ${.CURDIR} 1066.It 1067.Ev ${.CURDIR} 1068.El 1069.Pp 1070Variable expansion is performed on the value before it's used, 1071so expressions such as 1072.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1073may be used. 1074This is especially useful with 1075.Ql Ev MAKEOBJDIR . 1076.Pp 1077.Ql Va .OBJDIR 1078may be modified in the makefile via the special target 1079.Ql Ic .OBJDIR . 1080In all cases, 1081.Nm 1082will 1083.Xr chdir 2 1084to the specified directory if it exists, and set 1085.Ql Va .OBJDIR 1086and 1087.Ql Ev PWD 1088to that directory before executing any targets. 1089. 1090.It Va .PARSEDIR 1091A path to the directory of the current 1092.Ql Pa Makefile 1093being parsed. 1094.It Va .PARSEFILE 1095The basename of the current 1096.Ql Pa Makefile 1097being parsed. 1098This variable and 1099.Ql Va .PARSEDIR 1100are both set only while the 1101.Ql Pa Makefiles 1102are being parsed. 1103If you want to retain their current values, assign them to a variable 1104using assignment with expansion: 1105.Pq Ql Cm \&:= . 1106.It Va .PATH 1107A variable that represents the list of directories that 1108.Nm 1109will search for files. 1110The search list should be updated using the target 1111.Ql Va .PATH 1112rather than the variable. 1113.It Ev PWD 1114Alternate path to the current directory. 1115.Nm 1116normally sets 1117.Ql Va .CURDIR 1118to the canonical path given by 1119.Xr getcwd 3 . 1120However, if the environment variable 1121.Ql Ev PWD 1122is set and gives a path to the current directory, then 1123.Nm 1124sets 1125.Ql Va .CURDIR 1126to the value of 1127.Ql Ev PWD 1128instead. 1129This behavior is disabled if 1130.Ql Ev MAKEOBJDIRPREFIX 1131is set or 1132.Ql Ev MAKEOBJDIR 1133contains a variable transform. 1134.Ql Ev PWD 1135is set to the value of 1136.Ql Va .OBJDIR 1137for all programs which 1138.Nm 1139executes. 1140.It Ev .TARGETS 1141The list of targets explicitly specified on the command line, if any. 1142.It Ev VPATH 1143Colon-separated 1144.Pq Dq \&: 1145lists of directories that 1146.Nm 1147will search for files. 1148The variable is supported for compatibility with old make programs only, 1149use 1150.Ql Va .PATH 1151instead. 1152.El 1153.Ss Variable modifiers 1154Variable expansion may be modified to select or modify each word of the 1155variable (where a 1156.Dq word 1157is white-space delimited sequence of characters). 1158The general format of a variable expansion is as follows: 1159.Pp 1160.Dl ${variable[:modifier[:...]]} 1161.Pp 1162Each modifier begins with a colon, 1163which may be escaped with a backslash 1164.Pq Ql \e . 1165.Pp 1166A set of modifiers can be specified via a variable, as follows: 1167.Pp 1168.Dl modifier_variable=modifier[:...] 1169.Dl ${variable:${modifier_variable}[:...]} 1170.Pp 1171In this case the first modifier in the modifier_variable does not 1172start with a colon, since that must appear in the referencing 1173variable. 1174If any of the modifiers in the modifier_variable contain a dollar sign 1175.Pq Ql $ , 1176these must be doubled to avoid early expansion. 1177.Pp 1178The supported modifiers are: 1179.Bl -tag -width EEE 1180.It Cm \&:E 1181Replaces each word in the variable with its suffix. 1182.It Cm \&:H 1183Replaces each word in the variable with everything but the last component. 1184.It Cm \&:M Ns Ar pattern 1185Select only those words that match 1186.Ar pattern . 1187The standard shell wildcard characters 1188.Pf ( Ql * , 1189.Ql \&? , 1190and 1191.Ql Oo Oc ) 1192may 1193be used. 1194The wildcard characters may be escaped with a backslash 1195.Pq Ql \e . 1196As a consequence of the way values are split into words, matched, 1197and then joined, a construct like 1198.Dl ${VAR:M*} 1199will normalize the inter-word spacing, removing all leading and 1200trailing space, and converting multiple consecutive spaces 1201to single spaces. 1202. 1203.It Cm \&:N Ns Ar pattern 1204This is identical to 1205.Ql Cm \&:M , 1206but selects all words which do not match 1207.Ar pattern . 1208.It Cm \&:O 1209Order every word in variable alphabetically. 1210To sort words in 1211reverse order use the 1212.Ql Cm \&:O:[-1..1] 1213combination of modifiers. 1214.It Cm \&:Ox 1215Randomize words in variable. 1216The results will be different each time you are referring to the 1217modified variable; use the assignment with expansion 1218.Pq Ql Cm \&:= 1219to prevent such behavior. 1220For example, 1221.Bd -literal -offset indent 1222LIST= uno due tre quattro 1223RANDOM_LIST= ${LIST:Ox} 1224STATIC_RANDOM_LIST:= ${LIST:Ox} 1225 1226all: 1227 @echo "${RANDOM_LIST}" 1228 @echo "${RANDOM_LIST}" 1229 @echo "${STATIC_RANDOM_LIST}" 1230 @echo "${STATIC_RANDOM_LIST}" 1231.Ed 1232may produce output similar to: 1233.Bd -literal -offset indent 1234quattro due tre uno 1235tre due quattro uno 1236due uno quattro tre 1237due uno quattro tre 1238.Ed 1239.It Cm \&:Q 1240Quotes every shell meta-character in the variable, so that it can be passed 1241safely to the shell. 1242.It Cm \&:q 1243Quotes every shell meta-character in the variable, and also doubles 1244.Sq $ 1245characters so that it can be passed 1246safely through recursive invocations of 1247.Nm . 1248This is equivalent to: 1249.Sq \&:S/\e\&$/&&/g:Q . 1250.It Cm \&:R 1251Replaces each word in the variable with everything but its suffix. 1252.It Cm \&:range[=count] 1253The value is an integer sequence representing the words of the original 1254value, or the supplied 1255.Va count . 1256.It Cm \&:gmtime[=utc] 1257The value is a format string for 1258.Xr strftime 3 , 1259using 1260.Xr gmtime 3 . 1261If a 1262.Va utc 1263value is not provided or is 0, the current time is used. 1264.It Cm \&:hash 1265Compute a 32-bit hash of the value and encode it as hex digits. 1266.It Cm \&:localtime[=utc] 1267The value is a format string for 1268.Xr strftime 3 , 1269using 1270.Xr localtime 3 . 1271If a 1272.Va utc 1273value is not provided or is 0, the current time is used. 1274.It Cm \&:tA 1275Attempt to convert variable to an absolute path using 1276.Xr realpath 3 , 1277if that fails, the value is unchanged. 1278.It Cm \&:tl 1279Converts variable to lower-case letters. 1280.It Cm \&:ts Ns Ar c 1281Words in the variable are normally separated by a space on expansion. 1282This modifier sets the separator to the character 1283.Ar c . 1284If 1285.Ar c 1286is omitted, then no separator is used. 1287The common escapes (including octal numeric codes), work as expected. 1288.It Cm \&:tu 1289Converts variable to upper-case letters. 1290.It Cm \&:tW 1291Causes the value to be treated as a single word 1292(possibly containing embedded white space). 1293See also 1294.Ql Cm \&:[*] . 1295.It Cm \&:tw 1296Causes the value to be treated as a sequence of 1297words delimited by white space. 1298See also 1299.Ql Cm \&:[@] . 1300.Sm off 1301.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1302.Sm on 1303Modify the first occurrence of 1304.Ar old_string 1305in the variable's value, replacing it with 1306.Ar new_string . 1307If a 1308.Ql g 1309is appended to the last slash of the pattern, all occurrences 1310in each word are replaced. 1311If a 1312.Ql 1 1313is appended to the last slash of the pattern, only the first word 1314is affected. 1315If a 1316.Ql W 1317is appended to the last slash of the pattern, 1318then the value is treated as a single word 1319(possibly containing embedded white space). 1320If 1321.Ar old_string 1322begins with a caret 1323.Pq Ql ^ , 1324.Ar old_string 1325is anchored at the beginning of each word. 1326If 1327.Ar old_string 1328ends with a dollar sign 1329.Pq Ql \&$ , 1330it is anchored at the end of each word. 1331Inside 1332.Ar new_string , 1333an ampersand 1334.Pq Ql & 1335is replaced by 1336.Ar old_string 1337(without any 1338.Ql ^ 1339or 1340.Ql \&$ ) . 1341Any character may be used as a delimiter for the parts of the modifier 1342string. 1343The anchoring, ampersand and delimiter characters may be escaped with a 1344backslash 1345.Pq Ql \e . 1346.Pp 1347Variable expansion occurs in the normal fashion inside both 1348.Ar old_string 1349and 1350.Ar new_string 1351with the single exception that a backslash is used to prevent the expansion 1352of a dollar sign 1353.Pq Ql \&$ , 1354not a preceding dollar sign as is usual. 1355.Sm off 1356.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1357.Sm on 1358The 1359.Cm \&:C 1360modifier is just like the 1361.Cm \&:S 1362modifier except that the old and new strings, instead of being 1363simple strings, are an extended regular expression (see 1364.Xr regex 3 ) 1365string 1366.Ar pattern 1367and an 1368.Xr ed 1 Ns \-style 1369string 1370.Ar replacement . 1371Normally, the first occurrence of the pattern 1372.Ar pattern 1373in each word of the value is substituted with 1374.Ar replacement . 1375The 1376.Ql 1 1377modifier causes the substitution to apply to at most one word; the 1378.Ql g 1379modifier causes the substitution to apply to as many instances of the 1380search pattern 1381.Ar pattern 1382as occur in the word or words it is found in; the 1383.Ql W 1384modifier causes the value to be treated as a single word 1385(possibly containing embedded white space). 1386Note that 1387.Ql 1 1388and 1389.Ql g 1390are orthogonal; the former specifies whether multiple words are 1391potentially affected, the latter whether multiple substitutions can 1392potentially occur within each affected word. 1393.Pp 1394As for the 1395.Cm \&:S 1396modifier, the 1397.Ar pattern 1398and 1399.Ar replacement 1400are subjected to variable expansion before being parsed as 1401regular expressions. 1402.It Cm \&:T 1403Replaces each word in the variable with its last component. 1404.It Cm \&:u 1405Remove adjacent duplicate words (like 1406.Xr uniq 1 ) . 1407.Sm off 1408.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1409.Sm on 1410If the variable name (not its value), when parsed as a .if conditional 1411expression, evaluates to true, return as its value the 1412.Ar true_string , 1413otherwise return the 1414.Ar false_string . 1415Since the variable name is used as the expression, \&:\&? must be the 1416first modifier after the variable name itself - which will, of course, 1417usually contain variable expansions. 1418A common error is trying to use expressions like 1419.Dl ${NUMBERS:M42:?match:no} 1420which actually tests defined(NUMBERS), 1421to determine is any words match "42" you need to use something like: 1422.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1423.It Ar :old_string=new_string 1424This is the 1425.At V 1426style variable substitution. 1427It must be the last modifier specified. 1428If 1429.Ar old_string 1430or 1431.Ar new_string 1432do not contain the pattern matching character 1433.Ar % 1434then it is assumed that they are 1435anchored at the end of each word, so only suffixes or entire 1436words may be replaced. 1437Otherwise 1438.Ar % 1439is the substring of 1440.Ar old_string 1441to be replaced in 1442.Ar new_string . 1443.Pp 1444Variable expansion occurs in the normal fashion inside both 1445.Ar old_string 1446and 1447.Ar new_string 1448with the single exception that a backslash is used to prevent the 1449expansion of a dollar sign 1450.Pq Ql \&$ , 1451not a preceding dollar sign as is usual. 1452.Sm off 1453.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1454.Sm on 1455This is the loop expansion mechanism from the OSF Development 1456Environment (ODE) make. 1457Unlike 1458.Cm \&.for 1459loops expansion occurs at the time of 1460reference. 1461Assign 1462.Ar temp 1463to each word in the variable and evaluate 1464.Ar string . 1465The ODE convention is that 1466.Ar temp 1467should start and end with a period. 1468For example. 1469.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1470.Pp 1471However a single character variable is often more readable: 1472.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1473.It Cm \&:_[=var] 1474Save the current variable value in 1475.Ql $_ 1476or the named 1477.Va var 1478for later reference. 1479Example usage: 1480.Bd -literal -offset indent 1481M_cmpv.units = 1 1000 1000000 1482M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\ 1483\\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh 1484 1485.Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}} 1486 1487.Ed 1488Here 1489.Ql $_ 1490is used to save the result of the 1491.Ql :S 1492modifier which is later referenced using the index values from 1493.Ql :range . 1494.It Cm \&:U Ns Ar newval 1495If the variable is undefined 1496.Ar newval 1497is the value. 1498If the variable is defined, the existing value is returned. 1499This is another ODE make feature. 1500It is handy for setting per-target CFLAGS for instance: 1501.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1502If a value is only required if the variable is undefined, use: 1503.Dl ${VAR:D:Unewval} 1504.It Cm \&:D Ns Ar newval 1505If the variable is defined 1506.Ar newval 1507is the value. 1508.It Cm \&:L 1509The name of the variable is the value. 1510.It Cm \&:P 1511The path of the node which has the same name as the variable 1512is the value. 1513If no such node exists or its path is null, then the 1514name of the variable is used. 1515In order for this modifier to work, the name (node) must at least have 1516appeared on the rhs of a dependency. 1517.Sm off 1518.It Cm \&:\&! Ar cmd Cm \&! 1519.Sm on 1520The output of running 1521.Ar cmd 1522is the value. 1523.It Cm \&:sh 1524If the variable is non-empty it is run as a command and the output 1525becomes the new value. 1526.It Cm \&::= Ns Ar str 1527The variable is assigned the value 1528.Ar str 1529after substitution. 1530This modifier and its variations are useful in 1531obscure situations such as wanting to set a variable when shell commands 1532are being parsed. 1533These assignment modifiers always expand to 1534nothing, so if appearing in a rule line by themselves should be 1535preceded with something to keep 1536.Nm 1537happy. 1538.Pp 1539The 1540.Ql Cm \&:: 1541helps avoid false matches with the 1542.At V 1543style 1544.Cm \&:= 1545modifier and since substitution always occurs the 1546.Cm \&::= 1547form is vaguely appropriate. 1548.It Cm \&::?= Ns Ar str 1549As for 1550.Cm \&::= 1551but only if the variable does not already have a value. 1552.It Cm \&::+= Ns Ar str 1553Append 1554.Ar str 1555to the variable. 1556.It Cm \&::!= Ns Ar cmd 1557Assign the output of 1558.Ar cmd 1559to the variable. 1560.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1561Selects one or more words from the value, 1562or performs other operations related to the way in which the 1563value is divided into words. 1564.Pp 1565Ordinarily, a value is treated as a sequence of words 1566delimited by white space. 1567Some modifiers suppress this behavior, 1568causing a value to be treated as a single word 1569(possibly containing embedded white space). 1570An empty value, or a value that consists entirely of white-space, 1571is treated as a single word. 1572For the purposes of the 1573.Ql Cm \&:[] 1574modifier, the words are indexed both forwards using positive integers 1575(where index 1 represents the first word), 1576and backwards using negative integers 1577(where index \-1 represents the last word). 1578.Pp 1579The 1580.Ar range 1581is subjected to variable expansion, and the expanded result is 1582then interpreted as follows: 1583.Bl -tag -width index 1584.\" :[n] 1585.It Ar index 1586Selects a single word from the value. 1587.\" :[start..end] 1588.It Ar start Ns Cm \&.. Ns Ar end 1589Selects all words from 1590.Ar start 1591to 1592.Ar end , 1593inclusive. 1594For example, 1595.Ql Cm \&:[2..-1] 1596selects all words from the second word to the last word. 1597If 1598.Ar start 1599is greater than 1600.Ar end , 1601then the words are output in reverse order. 1602For example, 1603.Ql Cm \&:[-1..1] 1604selects all the words from last to first. 1605.\" :[*] 1606.It Cm \&* 1607Causes subsequent modifiers to treat the value as a single word 1608(possibly containing embedded white space). 1609Analogous to the effect of 1610\&"$*\&" 1611in Bourne shell. 1612.\" :[0] 1613.It 0 1614Means the same as 1615.Ql Cm \&:[*] . 1616.\" :[*] 1617.It Cm \&@ 1618Causes subsequent modifiers to treat the value as a sequence of words 1619delimited by white space. 1620Analogous to the effect of 1621\&"$@\&" 1622in Bourne shell. 1623.\" :[#] 1624.It Cm \&# 1625Returns the number of words in the value. 1626.El \" :[range] 1627.El 1628.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1629Makefile inclusion, conditional structures and for loops reminiscent 1630of the C programming language are provided in 1631.Nm . 1632All such structures are identified by a line beginning with a single 1633dot 1634.Pq Ql \&. 1635character. 1636Files are included with either 1637.Cm \&.include Aq Ar file 1638or 1639.Cm \&.include Pf \*q Ar file Ns \*q . 1640Variables between the angle brackets or double quotes are expanded 1641to form the file name. 1642If angle brackets are used, the included makefile is expected to be in 1643the system makefile directory. 1644If double quotes are used, the including makefile's directory and any 1645directories specified using the 1646.Fl I 1647option are searched before the system 1648makefile directory. 1649For compatibility with other versions of 1650.Nm 1651.Ql include file ... 1652is also accepted. 1653.Pp 1654If the include statement is written as 1655.Cm .-include 1656or as 1657.Cm .sinclude 1658then errors locating and/or opening include files are ignored. 1659.Pp 1660If the include statement is written as 1661.Cm .dinclude 1662not only are errors locating and/or opening include files ignored, 1663but stale dependencies within the included file will be ignored 1664just like 1665.Va .MAKE.DEPENDFILE . 1666.Pp 1667Conditional expressions are also preceded by a single dot as the first 1668character of a line. 1669The possible conditionals are as follows: 1670.Bl -tag -width Ds 1671.It Ic .error Ar message 1672The message is printed along with the name of the makefile and line number, 1673then 1674.Nm 1675will exit. 1676.It Ic .export Ar variable ... 1677Export the specified global variable. 1678If no variable list is provided, all globals are exported 1679except for internal variables (those that start with 1680.Ql \&. ) . 1681This is not affected by the 1682.Fl X 1683flag, so should be used with caution. 1684For compatibility with other 1685.Nm 1686programs 1687.Ql export variable=value 1688is also accepted. 1689.Pp 1690Appending a variable name to 1691.Va .MAKE.EXPORTED 1692is equivalent to exporting a variable. 1693.It Ic .export-env Ar variable ... 1694The same as 1695.Ql .export , 1696except that the variable is not appended to 1697.Va .MAKE.EXPORTED . 1698This allows exporting a value to the environment which is different from that 1699used by 1700.Nm 1701internally. 1702.It Ic .export-literal Ar variable ... 1703The same as 1704.Ql .export-env , 1705except that variables in the value are not expanded. 1706.It Ic .info Ar message 1707The message is printed along with the name of the makefile and line number. 1708.It Ic .undef Ar variable 1709Un-define the specified global variable. 1710Only global variables may be un-defined. 1711.It Ic .unexport Ar variable ... 1712The opposite of 1713.Ql .export . 1714The specified global 1715.Va variable 1716will be removed from 1717.Va .MAKE.EXPORTED . 1718If no variable list is provided, all globals are unexported, 1719and 1720.Va .MAKE.EXPORTED 1721deleted. 1722.It Ic .unexport-env 1723Unexport all globals previously exported and 1724clear the environment inherited from the parent. 1725This operation will cause a memory leak of the original environment, 1726so should be used sparingly. 1727Testing for 1728.Va .MAKE.LEVEL 1729being 0, would make sense. 1730Also note that any variables which originated in the parent environment 1731should be explicitly preserved if desired. 1732For example: 1733.Bd -literal -offset indent 1734.Li .if ${.MAKE.LEVEL} == 0 1735PATH := ${PATH} 1736.Li .unexport-env 1737.Li .export PATH 1738.Li .endif 1739.Pp 1740.Ed 1741Would result in an environment containing only 1742.Ql Ev PATH , 1743which is the minimal useful environment. 1744Actually 1745.Ql Ev .MAKE.LEVEL 1746will also be pushed into the new environment. 1747.It Ic .warning Ar message 1748The message prefixed by 1749.Ql Pa warning: 1750is printed along with the name of the makefile and line number. 1751.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1752Test the value of an expression. 1753.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1754Test the value of a variable. 1755.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1756Test the value of a variable. 1757.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1758Test the target being built. 1759.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1760Test the target being built. 1761.It Ic .else 1762Reverse the sense of the last conditional. 1763.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1764A combination of 1765.Ql Ic .else 1766followed by 1767.Ql Ic .if . 1768.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1769A combination of 1770.Ql Ic .else 1771followed by 1772.Ql Ic .ifdef . 1773.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1774A combination of 1775.Ql Ic .else 1776followed by 1777.Ql Ic .ifndef . 1778.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1779A combination of 1780.Ql Ic .else 1781followed by 1782.Ql Ic .ifmake . 1783.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1784A combination of 1785.Ql Ic .else 1786followed by 1787.Ql Ic .ifnmake . 1788.It Ic .endif 1789End the body of the conditional. 1790.El 1791.Pp 1792The 1793.Ar operator 1794may be any one of the following: 1795.Bl -tag -width "Cm XX" 1796.It Cm \&|\&| 1797Logical OR. 1798.It Cm \&&& 1799Logical 1800.Tn AND ; 1801of higher precedence than 1802.Dq \&|\&| . 1803.El 1804.Pp 1805As in C, 1806.Nm 1807will only evaluate a conditional as far as is necessary to determine 1808its value. 1809Parentheses may be used to change the order of evaluation. 1810The boolean operator 1811.Ql Ic \&! 1812may be used to logically negate an entire 1813conditional. 1814It is of higher precedence than 1815.Ql Ic \&&& . 1816.Pp 1817The value of 1818.Ar expression 1819may be any of the following: 1820.Bl -tag -width defined 1821.It Ic defined 1822Takes a variable name as an argument and evaluates to true if the variable 1823has been defined. 1824.It Ic make 1825Takes a target name as an argument and evaluates to true if the target 1826was specified as part of 1827.Nm Ns 's 1828command line or was declared the default target (either implicitly or 1829explicitly, see 1830.Va .MAIN ) 1831before the line containing the conditional. 1832.It Ic empty 1833Takes a variable, with possible modifiers, and evaluates to true if 1834the expansion of the variable would result in an empty string. 1835.It Ic exists 1836Takes a file name as an argument and evaluates to true if the file exists. 1837The file is searched for on the system search path (see 1838.Va .PATH ) . 1839.It Ic target 1840Takes a target name as an argument and evaluates to true if the target 1841has been defined. 1842.It Ic commands 1843Takes a target name as an argument and evaluates to true if the target 1844has been defined and has commands associated with it. 1845.El 1846.Pp 1847.Ar Expression 1848may also be an arithmetic or string comparison. 1849Variable expansion is 1850performed on both sides of the comparison, after which the integral 1851values are compared. 1852A value is interpreted as hexadecimal if it is 1853preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1854The standard C relational operators are all supported. 1855If after 1856variable expansion, either the left or right hand side of a 1857.Ql Ic == 1858or 1859.Ql Ic "!=" 1860operator is not an integral value, then 1861string comparison is performed between the expanded 1862variables. 1863If no relational operator is given, it is assumed that the expanded 1864variable is being compared against 0 or an empty string in the case 1865of a string comparison. 1866.Pp 1867When 1868.Nm 1869is evaluating one of these conditional expressions, and it encounters 1870a (white-space separated) word it doesn't recognize, either the 1871.Dq make 1872or 1873.Dq defined 1874expression is applied to it, depending on the form of the conditional. 1875If the form is 1876.Ql Ic .ifdef , 1877.Ql Ic .ifndef , 1878or 1879.Ql Ic .if 1880the 1881.Dq defined 1882expression is applied. 1883Similarly, if the form is 1884.Ql Ic .ifmake 1885or 1886.Ql Ic .ifnmake , 1887the 1888.Dq make 1889expression is applied. 1890.Pp 1891If the conditional evaluates to true the parsing of the makefile continues 1892as before. 1893If it evaluates to false, the following lines are skipped. 1894In both cases this continues until a 1895.Ql Ic .else 1896or 1897.Ql Ic .endif 1898is found. 1899.Pp 1900For loops are typically used to apply a set of rules to a list of files. 1901The syntax of a for loop is: 1902.Pp 1903.Bl -tag -compact -width Ds 1904.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1905.It Aq make-rules 1906.It Ic \&.endfor 1907.El 1908.Pp 1909After the for 1910.Ic expression 1911is evaluated, it is split into words. 1912On each iteration of the loop, one word is taken and assigned to each 1913.Ic variable , 1914in order, and these 1915.Ic variables 1916are substituted into the 1917.Ic make-rules 1918inside the body of the for loop. 1919The number of words must come out even; that is, if there are three 1920iteration variables, the number of words provided must be a multiple 1921of three. 1922.Sh COMMENTS 1923Comments begin with a hash 1924.Pq Ql \&# 1925character, anywhere but in a shell 1926command line, and continue to the end of an unescaped new line. 1927.Sh SPECIAL SOURCES (ATTRIBUTES) 1928.Bl -tag -width .IGNOREx 1929.It Ic .EXEC 1930Target is never out of date, but always execute commands anyway. 1931.It Ic .IGNORE 1932Ignore any errors from the commands associated with this target, exactly 1933as if they all were preceded by a dash 1934.Pq Ql \- . 1935.\" .It Ic .INVISIBLE 1936.\" XXX 1937.\" .It Ic .JOIN 1938.\" XXX 1939.It Ic .MADE 1940Mark all sources of this target as being up-to-date. 1941.It Ic .MAKE 1942Execute the commands associated with this target even if the 1943.Fl n 1944or 1945.Fl t 1946options were specified. 1947Normally used to mark recursive 1948.Nm Ns s . 1949.It Ic .META 1950Create a meta file for the target, even if it is flagged as 1951.Ic .PHONY , 1952.Ic .MAKE , 1953or 1954.Ic .SPECIAL . 1955Usage in conjunction with 1956.Ic .MAKE 1957is the most likely case. 1958In "meta" mode, the target is out-of-date if the meta file is missing. 1959.It Ic .NOMETA 1960Do not create a meta file for the target. 1961Meta files are also not created for 1962.Ic .PHONY , 1963.Ic .MAKE , 1964or 1965.Ic .SPECIAL 1966targets. 1967.It Ic .NOMETA_CMP 1968Ignore differences in commands when deciding if target is out of date. 1969This is useful if the command contains a value which always changes. 1970If the number of commands change, though, the target will still be out of date. 1971The same effect applies to any command line that uses the variable 1972.Va .OODATE , 1973which can be used for that purpose even when not otherwise needed or desired: 1974.Bd -literal -offset indent 1975 1976skip-compare-for-some: 1977 @echo this will be compared 1978 @echo this will not ${.OODATE:M.NOMETA_CMP} 1979 @echo this will also be compared 1980 1981.Ed 1982The 1983.Cm \&:M 1984pattern suppresses any expansion of the unwanted variable. 1985.It Ic .NOPATH 1986Do not search for the target in the directories specified by 1987.Ic .PATH . 1988.It Ic .NOTMAIN 1989Normally 1990.Nm 1991selects the first target it encounters as the default target to be built 1992if no target was specified. 1993This source prevents this target from being selected. 1994.It Ic .OPTIONAL 1995If a target is marked with this attribute and 1996.Nm 1997can't figure out how to create it, it will ignore this fact and assume 1998the file isn't needed or already exists. 1999.It Ic .PHONY 2000The target does not 2001correspond to an actual file; it is always considered to be out of date, 2002and will not be created with the 2003.Fl t 2004option. 2005Suffix-transformation rules are not applied to 2006.Ic .PHONY 2007targets. 2008.It Ic .PRECIOUS 2009When 2010.Nm 2011is interrupted, it normally removes any partially made targets. 2012This source prevents the target from being removed. 2013.It Ic .RECURSIVE 2014Synonym for 2015.Ic .MAKE . 2016.It Ic .SILENT 2017Do not echo any of the commands associated with this target, exactly 2018as if they all were preceded by an at sign 2019.Pq Ql @ . 2020.It Ic .USE 2021Turn the target into 2022.Nm Ns 's 2023version of a macro. 2024When the target is used as a source for another target, the other target 2025acquires the commands, sources, and attributes (except for 2026.Ic .USE ) 2027of the 2028source. 2029If the target already has commands, the 2030.Ic .USE 2031target's commands are appended 2032to them. 2033.It Ic .USEBEFORE 2034Exactly like 2035.Ic .USE , 2036but prepend the 2037.Ic .USEBEFORE 2038target commands to the target. 2039.It Ic .WAIT 2040If 2041.Ic .WAIT 2042appears in a dependency line, the sources that precede it are 2043made before the sources that succeed it in the line. 2044Since the dependents of files are not made until the file itself 2045could be made, this also stops the dependents being built unless they 2046are needed for another branch of the dependency tree. 2047So given: 2048.Bd -literal 2049x: a .WAIT b 2050 echo x 2051a: 2052 echo a 2053b: b1 2054 echo b 2055b1: 2056 echo b1 2057 2058.Ed 2059the output is always 2060.Ql a , 2061.Ql b1 , 2062.Ql b , 2063.Ql x . 2064.br 2065The ordering imposed by 2066.Ic .WAIT 2067is only relevant for parallel makes. 2068.El 2069.Sh SPECIAL TARGETS 2070Special targets may not be included with other targets, i.e. they must be 2071the only target specified. 2072.Bl -tag -width .BEGINx 2073.It Ic .BEGIN 2074Any command lines attached to this target are executed before anything 2075else is done. 2076.It Ic .DEFAULT 2077This is sort of a 2078.Ic .USE 2079rule for any target (that was used only as a 2080source) that 2081.Nm 2082can't figure out any other way to create. 2083Only the shell script is used. 2084The 2085.Ic .IMPSRC 2086variable of a target that inherits 2087.Ic .DEFAULT Ns 's 2088commands is set 2089to the target's own name. 2090.It Ic .DELETE_ON_ERROR 2091If this target is present in the makefile, it globally causes make to 2092delete targets whose commands fail. 2093(By default, only targets whose commands are interrupted during 2094execution are deleted. 2095This is the historical behavior.) 2096This setting can be used to help prevent half-finished or malformed 2097targets from being left around and corrupting future rebuilds. 2098.It Ic .END 2099Any command lines attached to this target are executed after everything 2100else is done. 2101.It Ic .ERROR 2102Any command lines attached to this target are executed when another target fails. 2103The 2104.Ic .ERROR_TARGET 2105variable is set to the target that failed. 2106See also 2107.Ic MAKE_PRINT_VAR_ON_ERROR . 2108.It Ic .IGNORE 2109Mark each of the sources with the 2110.Ic .IGNORE 2111attribute. 2112If no sources are specified, this is the equivalent of specifying the 2113.Fl i 2114option. 2115.It Ic .INTERRUPT 2116If 2117.Nm 2118is interrupted, the commands for this target will be executed. 2119.It Ic .MAIN 2120If no target is specified when 2121.Nm 2122is invoked, this target will be built. 2123.It Ic .MAKEFLAGS 2124This target provides a way to specify flags for 2125.Nm 2126when the makefile is used. 2127The flags are as if typed to the shell, though the 2128.Fl f 2129option will have 2130no effect. 2131.\" XXX: NOT YET!!!! 2132.\" .It Ic .NOTPARALLEL 2133.\" The named targets are executed in non parallel mode. 2134.\" If no targets are 2135.\" specified, then all targets are executed in non parallel mode. 2136.It Ic .NOPATH 2137Apply the 2138.Ic .NOPATH 2139attribute to any specified sources. 2140.It Ic .NOTPARALLEL 2141Disable parallel mode. 2142.It Ic .NO_PARALLEL 2143Synonym for 2144.Ic .NOTPARALLEL , 2145for compatibility with other pmake variants. 2146.It Ic .OBJDIR 2147The source is a new value for 2148.Ql Va .OBJDIR . 2149If it exists, 2150.Nm 2151will 2152.Xr chdir 2 2153to it and update the value of 2154.Ql Va .OBJDIR . 2155.It Ic .ORDER 2156The named targets are made in sequence. 2157This ordering does not add targets to the list of targets to be made. 2158Since the dependents of a target do not get built until the target itself 2159could be built, unless 2160.Ql a 2161is built by another part of the dependency graph, 2162the following is a dependency loop: 2163.Bd -literal 2164\&.ORDER: b a 2165b: a 2166.Ed 2167.Pp 2168The ordering imposed by 2169.Ic .ORDER 2170is only relevant for parallel makes. 2171.\" XXX: NOT YET!!!! 2172.\" .It Ic .PARALLEL 2173.\" The named targets are executed in parallel mode. 2174.\" If no targets are 2175.\" specified, then all targets are executed in parallel mode. 2176.It Ic .PATH 2177The sources are directories which are to be searched for files not 2178found in the current directory. 2179If no sources are specified, any previously specified directories are 2180deleted. 2181If the source is the special 2182.Ic .DOTLAST 2183target, then the current working 2184directory is searched last. 2185.It Ic .PATH. Ns Va suffix 2186Like 2187.Ic .PATH 2188but applies only to files with a particular suffix. 2189The suffix must have been previously declared with 2190.Ic .SUFFIXES . 2191.It Ic .PHONY 2192Apply the 2193.Ic .PHONY 2194attribute to any specified sources. 2195.It Ic .PRECIOUS 2196Apply the 2197.Ic .PRECIOUS 2198attribute to any specified sources. 2199If no sources are specified, the 2200.Ic .PRECIOUS 2201attribute is applied to every 2202target in the file. 2203.It Ic .SHELL 2204Sets the shell that 2205.Nm 2206will use to execute commands. 2207The sources are a set of 2208.Ar field=value 2209pairs. 2210.Bl -tag -width hasErrCtls 2211.It Ar name 2212This is the minimal specification, used to select one of the built-in 2213shell specs; 2214.Ar sh , 2215.Ar ksh , 2216and 2217.Ar csh . 2218.It Ar path 2219Specifies the path to the shell. 2220.It Ar hasErrCtl 2221Indicates whether the shell supports exit on error. 2222.It Ar check 2223The command to turn on error checking. 2224.It Ar ignore 2225The command to disable error checking. 2226.It Ar echo 2227The command to turn on echoing of commands executed. 2228.It Ar quiet 2229The command to turn off echoing of commands executed. 2230.It Ar filter 2231The output to filter after issuing the 2232.Ar quiet 2233command. 2234It is typically identical to 2235.Ar quiet . 2236.It Ar errFlag 2237The flag to pass the shell to enable error checking. 2238.It Ar echoFlag 2239The flag to pass the shell to enable command echoing. 2240.It Ar newline 2241The string literal to pass the shell that results in a single newline 2242character when used outside of any quoting characters. 2243.El 2244Example: 2245.Bd -literal 2246\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2247 check="set \-e" ignore="set +e" \e 2248 echo="set \-v" quiet="set +v" filter="set +v" \e 2249 echoFlag=v errFlag=e newline="'\en'" 2250.Ed 2251.It Ic .SILENT 2252Apply the 2253.Ic .SILENT 2254attribute to any specified sources. 2255If no sources are specified, the 2256.Ic .SILENT 2257attribute is applied to every 2258command in the file. 2259.It Ic .STALE 2260This target gets run when a dependency file contains stale entries, having 2261.Va .ALLSRC 2262set to the name of that dependency file. 2263.It Ic .SUFFIXES 2264Each source specifies a suffix to 2265.Nm . 2266If no sources are specified, any previously specified suffixes are deleted. 2267It allows the creation of suffix-transformation rules. 2268.Pp 2269Example: 2270.Bd -literal 2271\&.SUFFIXES: .o 2272\&.c.o: 2273 cc \-o ${.TARGET} \-c ${.IMPSRC} 2274.Ed 2275.El 2276.Sh ENVIRONMENT 2277.Nm 2278uses the following environment variables, if they exist: 2279.Ev MACHINE , 2280.Ev MACHINE_ARCH , 2281.Ev MAKE , 2282.Ev MAKEFLAGS , 2283.Ev MAKEOBJDIR , 2284.Ev MAKEOBJDIRPREFIX , 2285.Ev MAKESYSPATH , 2286.Ev PWD , 2287and 2288.Ev TMPDIR . 2289.Pp 2290.Ev MAKEOBJDIRPREFIX 2291and 2292.Ev MAKEOBJDIR 2293may only be set in the environment or on the command line to 2294.Nm 2295and not as makefile variables; 2296see the description of 2297.Ql Va .OBJDIR 2298for more details. 2299.Sh FILES 2300.Bl -tag -width /usr/share/mk -compact 2301.It .depend 2302list of dependencies 2303.It Makefile 2304list of dependencies 2305.It makefile 2306list of dependencies 2307.It sys.mk 2308system makefile 2309.It /usr/share/mk 2310system makefile directory 2311.El 2312.Sh COMPATIBILITY 2313The basic make syntax is compatible between different versions of make; 2314however the special variables, variable modifiers and conditionals are not. 2315.Ss Older versions 2316An incomplete list of changes in older versions of 2317.Nm : 2318.Pp 2319The way that .for loop variables are substituted changed after 2320.Nx 5.0 2321so that they still appear to be variable expansions. 2322In particular this stops them being treated as syntax, and removes some 2323obscure problems using them in .if statements. 2324.Pp 2325The way that parallel makes are scheduled changed in 2326.Nx 4.0 2327so that .ORDER and .WAIT apply recursively to the dependent nodes. 2328The algorithms used may change again in the future. 2329.Ss Other make dialects 2330Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2331support most of the features of 2332.Nm 2333as described in this manual. 2334Most notably: 2335.Bl -bullet -offset indent 2336.It 2337The 2338.Ic .WAIT 2339and 2340.Ic .ORDER 2341declarations and most functionality pertaining to parallelization. 2342(GNU make supports parallelization but lacks these features needed to 2343control it effectively.) 2344.It 2345Directives, including for loops and conditionals and most of the 2346forms of include files. 2347(GNU make has its own incompatible and less powerful syntax for 2348conditionals.) 2349.It 2350All built-in variables that begin with a dot. 2351.It 2352Most of the special sources and targets that begin with a dot, 2353with the notable exception of 2354.Ic .PHONY , 2355.Ic .PRECIOUS , 2356and 2357.Ic .SUFFIXES . 2358.It 2359Variable modifiers, except for the 2360.Dl :old=new 2361string substitution, which does not portably support globbing with 2362.Ql % 2363and historically only works on declared suffixes. 2364.It 2365The 2366.Ic $> 2367variable even in its short form; most makes support this functionality 2368but its name varies. 2369.El 2370.Pp 2371Some features are somewhat more portable, such as assignment with 2372.Ic += , 2373.Ic ?= , 2374and 2375.Ic != . 2376The 2377.Ic .PATH 2378functionality is based on an older feature 2379.Ic VPATH 2380found in GNU make and many versions of SVR4 make; however, 2381historically its behavior is too ill-defined (and too buggy) to rely 2382upon. 2383.Pp 2384The 2385.Ic $@ 2386and 2387.Ic $< 2388variables are more or less universally portable, as is the 2389.Ic $(MAKE) 2390variable. 2391Basic use of suffix rules (for files only in the current directory, 2392not trying to chain transformations together, etc.) is also reasonably 2393portable. 2394.Sh SEE ALSO 2395.Xr mkdep 1 , 2396.Xr style.Makefile 5 2397.Sh HISTORY 2398A 2399.Nm 2400command appeared in 2401.At v7 . 2402This 2403.Nm 2404implementation is based on Adam De Boor's pmake program which was written 2405for Sprite at Berkeley. 2406It was designed to be a parallel distributed make running jobs on different 2407machines using a daemon called 2408.Dq customs . 2409.Pp 2410Historically the target/dependency 2411.Dq FRC 2412has been used to FoRCe rebuilding (since the target/dependency 2413does not exist... unless someone creates an 2414.Dq FRC 2415file). 2416.Sh BUGS 2417The 2418.Nm 2419syntax is difficult to parse without actually acting of the data. 2420For instance finding the end of a variable use should involve scanning each 2421the modifiers using the correct terminator for each field. 2422In many places 2423.Nm 2424just counts {} and () in order to find the end of a variable expansion. 2425.Pp 2426There is no way of escaping a space character in a filename. 2427