1.\" $NetBSD: make.1,v 1.226 2013/11/07 18:50:46 dholland 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 October 25, 2013 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 Ev MAKE 710The name that 711.Nm 712was executed with 713.Pq Va argv[0] . 714For compatibility 715.Nm 716also sets 717.Va .MAKE 718with the same value. 719The preferred variable to use is the environment variable 720.Ev MAKE 721because it is more compatible with other versions of 722.Nm 723and cannot be confused with the special target with the same name. 724.It Va .MAKE.ALWAYS_PASS_JOB_QUEUE 725Tells 726.Nm 727whether to pass the descriptors of the job token queue 728even if the target is not tagged with 729.Ic .MAKE 730The default is 731.Ql Pa yes 732for backwards compatability with 733.Fx 9.0 734and earlier. 735.It Va .MAKE.DEPENDFILE 736Names the makefile (default 737.Ql Pa .depend ) 738from which generated dependencies are read. 739.It Va .MAKE.EXPAND_VARIABLES 740A boolean that controls the default behavior of the 741.Fl V 742option. 743.It Va .MAKE.EXPORTED 744The list of variables exported by 745.Nm . 746.It Va .MAKE.JOBS 747The argument to the 748.Fl j 749option. 750.It Va .MAKE.JOB.PREFIX 751If 752.Nm 753is run with 754.Ar j 755then output for each target is prefixed with a token 756.Ql --- target --- 757the first part of which can be controlled via 758.Va .MAKE.JOB.PREFIX . 759If 760.Va .MAKE.JOB.PREFIX 761is empty, no token is printed. 762.br 763For example: 764.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 765would produce tokens like 766.Ql ---make[1234] target --- 767making it easier to track the degree of parallelism being achieved. 768.It Ev MAKEFLAGS 769The environment variable 770.Ql Ev MAKEFLAGS 771may contain anything that 772may be specified on 773.Nm Ns 's 774command line. 775Anything specified on 776.Nm Ns 's 777command line is appended to the 778.Ql Ev MAKEFLAGS 779variable which is then 780entered into the environment for all programs which 781.Nm 782executes. 783.It Va .MAKE.LEVEL 784The recursion depth of 785.Nm . 786The initial instance of 787.Nm 788will be 0, and an incremented value is put into the environment 789to be seen by the next generation. 790This allows tests like: 791.Li .if ${.MAKE.LEVEL} == 0 792to protect things which should only be evaluated in the initial instance of 793.Nm . 794.It Va .MAKE.MAKEFILE_PREFERENCE 795The ordered list of makefile names 796(default 797.Ql Pa makefile , 798.Ql Pa Makefile ) 799that 800.Nm 801will look for. 802.It Va .MAKE.MAKEFILES 803The list of makefiles read by 804.Nm , 805which is useful for tracking dependencies. 806Each makefile is recorded only once, regardless of the number of times read. 807.It Va .MAKE.MODE 808Processed after reading all makefiles. 809Can affect the mode that 810.Nm 811runs in. 812It can contain a number of keywords: 813.Bl -hang -width ignore-cmd 814.It Pa compat 815Like 816.Fl B , 817puts 818.Nm 819into "compat" mode. 820.It Pa meta 821Puts 822.Nm 823into "meta" mode, where meta files are created for each target 824to capture the command run, the output generated and if 825.Xr filemon 4 826is available, the system calls which are of interest to 827.Nm . 828The captured output can be very useful when diagnosing errors. 829.It Pa curdirOk= Ar bf 830Normally 831.Nm 832will not create .meta files in 833.Ql Va .CURDIR . 834This can be overridden by setting 835.Va bf 836to a value which represents True. 837.It Pa env 838For debugging, it can be useful to inlcude the environment 839in the .meta file. 840.It Pa verbose 841If in "meta" mode, print a clue about the target being built. 842This is useful if the build is otherwise running silently. 843The message printed the value of: 844.Va .MAKE.META.PREFIX . 845.It Pa ignore-cmd 846Some makefiles have commands which are simply not stable. 847This keyword causes them to be ignored for 848determining whether a target is out of date in "meta" mode. 849See also 850.Ic .NOMETA_CMP . 851.It Pa silent= Ar bf 852If 853.Va bf 854is True, when a .meta file is created, mark the target 855.Ic .SILENT . 856.El 857.It Va .MAKE.META.BAILIWICK 858In "meta" mode, provides a list of prefixes which 859match the directories controlled by 860.Nm . 861If a file that was generated outside of 862.Va .OBJDIR 863but within said bailiwick is missing, 864the current target is considered out-of-date. 865.It Va .MAKE.META.CREATED 866In "meta" mode, this variable contains a list of all the meta files 867updated. 868If not empty, it can be used to trigger processing of 869.Va .MAKE.META.FILES . 870.It Va .MAKE.META.FILES 871In "meta" mode, this variable contains a list of all the meta files 872used (updated or not). 873This list can be used to process the meta files to extract dependency 874information. 875.It Va .MAKE.META.IGNORE_PATHS 876Provides a list of path prefixes that should be ignored; 877because the contents are expected to change over time. 878The default list includes: 879.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 880.It Va .MAKE.META.PREFIX 881Defines the message printed for each meta file updated in "meta verbose" mode. 882The default value is: 883.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 884.It Va .MAKEOVERRIDES 885This variable is used to record the names of variables assigned to 886on the command line, so that they may be exported as part of 887.Ql Ev MAKEFLAGS . 888This behaviour can be disabled by assigning an empty value to 889.Ql Va .MAKEOVERRIDES 890within a makefile. 891Extra variables can be exported from a makefile 892by appending their names to 893.Ql Va .MAKEOVERRIDES . 894.Ql Ev MAKEFLAGS 895is re-exported whenever 896.Ql Va .MAKEOVERRIDES 897is modified. 898.It Va .MAKE.PATH_FILEMON 899If 900.Nm 901was built with 902.Xr filemon 4 903support, this is set to the path of the device node. 904This allows makefiles to test for this support. 905.It Va .MAKE.PID 906The process-id of 907.Nm . 908.It Va .MAKE.PPID 909The parent process-id of 910.Nm . 911.It Va MAKE_PRINT_VAR_ON_ERROR 912When 913.Nm 914stops due to an error, it prints its name and the value of 915.Ql Va .CURDIR 916as well as the value of any variables named in 917.Ql Va MAKE_PRINT_VAR_ON_ERROR . 918.It Va .newline 919This variable is simply assigned a newline character as its value. 920This allows expansions using the 921.Cm \&:@ 922modifier to put a newline between 923iterations of the loop rather than a space. 924For example, the printing of 925.Ql Va MAKE_PRINT_VAR_ON_ERROR 926could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 927.It Va .OBJDIR 928A path to the directory where the targets are built. 929Its value is determined by trying to 930.Xr chdir 2 931to the following directories in order and using the first match: 932.Bl -enum 933.It 934.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 935.Pp 936(Only if 937.Ql Ev MAKEOBJDIRPREFIX 938is set in the environment or on the command line.) 939.It 940.Ev ${MAKEOBJDIR} 941.Pp 942(Only if 943.Ql Ev MAKEOBJDIR 944is set in the environment or on the command line.) 945.It 946.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 947.It 948.Ev ${.CURDIR} Ns Pa /obj 949.It 950.Pa /usr/obj/ Ns Ev ${.CURDIR} 951.It 952.Ev ${.CURDIR} 953.El 954.Pp 955Variable expansion is performed on the value before it's used, 956so expressions such as 957.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 958may be used. 959This is especially useful with 960.Ql Ev MAKEOBJDIR . 961.Pp 962.Ql Va .OBJDIR 963may be modified in the makefile as a global variable. 964In all cases, 965.Nm 966will 967.Xr chdir 2 968to 969.Ql Va .OBJDIR 970and set 971.Ql Ev PWD 972to that directory before executing any targets. 973. 974.It Va .PARSEDIR 975A path to the directory of the current 976.Ql Pa Makefile 977being parsed. 978.It Va .PARSEFILE 979The basename of the current 980.Ql Pa Makefile 981being parsed. 982This variable and 983.Ql Va .PARSEDIR 984are both set only while the 985.Ql Pa Makefiles 986are being parsed. 987If you want to retain their current values, assign them to a variable 988using assignment with expansion: 989.Pq Ql Cm \&:= . 990.It Va .PATH 991A variable that represents the list of directories that 992.Nm 993will search for files. 994The search list should be updated using the target 995.Ql Va .PATH 996rather than the variable. 997.It Ev PWD 998Alternate path to the current directory. 999.Nm 1000normally sets 1001.Ql Va .CURDIR 1002to the canonical path given by 1003.Xr getcwd 3 . 1004However, if the environment variable 1005.Ql Ev PWD 1006is set and gives a path to the current directory, then 1007.Nm 1008sets 1009.Ql Va .CURDIR 1010to the value of 1011.Ql Ev PWD 1012instead. 1013This behaviour is disabled if 1014.Ql Ev MAKEOBJDIRPREFIX 1015is set or 1016.Ql Ev MAKEOBJDIR 1017contains a variable transform. 1018.Ql Ev PWD 1019is set to the value of 1020.Ql Va .OBJDIR 1021for all programs which 1022.Nm 1023executes. 1024.It Ev .TARGETS 1025The list of targets explicitly specified on the command line, if any. 1026.It Ev VPATH 1027Colon-separated 1028.Pq Dq \&: 1029lists of directories that 1030.Nm 1031will search for files. 1032The variable is supported for compatibility with old make programs only, 1033use 1034.Ql Va .PATH 1035instead. 1036.El 1037.Ss Variable modifiers 1038Variable expansion may be modified to select or modify each word of the 1039variable (where a 1040.Dq word 1041is white-space delimited sequence of characters). 1042The general format of a variable expansion is as follows: 1043.Pp 1044.Dl ${variable[:modifier[:...]]} 1045.Pp 1046Each modifier begins with a colon, 1047which may be escaped with a backslash 1048.Pq Ql \e . 1049.Pp 1050A set of modifiers can be specified via a variable, as follows: 1051.Pp 1052.Dl modifier_variable=modifier[:...] 1053.Dl ${variable:${modifier_variable}[:...]} 1054.Pp 1055In this case the first modifier in the modifier_variable does not 1056start with a colon, since that must appear in the referencing 1057variable. 1058If any of the modifiers in the modifier_variable contain a dollar sign 1059.Pq Ql $ , 1060these must be doubled to avoid early expansion. 1061.Pp 1062The supported modifiers are: 1063.Bl -tag -width EEE 1064.It Cm \&:E 1065Replaces each word in the variable with its suffix. 1066.It Cm \&:H 1067Replaces each word in the variable with everything but the last component. 1068.It Cm \&:M Ns Ar pattern 1069Select only those words that match 1070.Ar pattern . 1071The standard shell wildcard characters 1072.Pf ( Ql * , 1073.Ql \&? , 1074and 1075.Ql Oo Oc ) 1076may 1077be used. 1078The wildcard characters may be escaped with a backslash 1079.Pq Ql \e . 1080As a consequence of the way values are split into words, matched, 1081and then joined, a construct like 1082.Dl ${VAR:M*} 1083will normalise the inter-word spacing, removing all leading and 1084trailing space, and converting multiple consecutive spaces 1085to single spaces. 1086. 1087.It Cm \&:N Ns Ar pattern 1088This is identical to 1089.Ql Cm \&:M , 1090but selects all words which do not match 1091.Ar pattern . 1092.It Cm \&:O 1093Order every word in variable alphabetically. 1094To sort words in 1095reverse order use the 1096.Ql Cm \&:O:[-1..1] 1097combination of modifiers. 1098.It Cm \&:Ox 1099Randomize words in variable. 1100The results will be different each time you are referring to the 1101modified variable; use the assignment with expansion 1102.Pq Ql Cm \&:= 1103to prevent such behaviour. 1104For example, 1105.Bd -literal -offset indent 1106LIST= uno due tre quattro 1107RANDOM_LIST= ${LIST:Ox} 1108STATIC_RANDOM_LIST:= ${LIST:Ox} 1109 1110all: 1111 @echo "${RANDOM_LIST}" 1112 @echo "${RANDOM_LIST}" 1113 @echo "${STATIC_RANDOM_LIST}" 1114 @echo "${STATIC_RANDOM_LIST}" 1115.Ed 1116may produce output similar to: 1117.Bd -literal -offset indent 1118quattro due tre uno 1119tre due quattro uno 1120due uno quattro tre 1121due uno quattro tre 1122.Ed 1123.It Cm \&:Q 1124Quotes every shell meta-character in the variable, so that it can be passed 1125safely through recursive invocations of 1126.Nm . 1127.It Cm \&:R 1128Replaces each word in the variable with everything but its suffix. 1129.It Cm \&:gmtime 1130The value is a format string for 1131.Xr strftime 3 , 1132using the current 1133.Xr gmtime 3 . 1134.It Cm \&:hash 1135Compute a 32bit hash of the value and encode it as hex digits. 1136.It Cm \&:localtime 1137The value is a format string for 1138.Xr strftime 3 , 1139using the current 1140.Xr localtime 3 . 1141.It Cm \&:tA 1142Attempt to convert variable to an absolute path using 1143.Xr realpath 3 , 1144if that fails, the value is unchanged. 1145.It Cm \&:tl 1146Converts variable to lower-case letters. 1147.It Cm \&:ts Ns Ar c 1148Words in the variable are normally separated by a space on expansion. 1149This modifier sets the separator to the character 1150.Ar c . 1151If 1152.Ar c 1153is omitted, then no separator is used. 1154The common escapes (including octal numeric codes), work as expected. 1155.It Cm \&:tu 1156Converts variable to upper-case letters. 1157.It Cm \&:tW 1158Causes the value to be treated as a single word 1159(possibly containing embedded white space). 1160See also 1161.Ql Cm \&:[*] . 1162.It Cm \&:tw 1163Causes the value to be treated as a sequence of 1164words delimited by white space. 1165See also 1166.Ql Cm \&:[@] . 1167.Sm off 1168.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1169.Sm on 1170Modify the first occurrence of 1171.Ar old_string 1172in the variable's value, replacing it with 1173.Ar new_string . 1174If a 1175.Ql g 1176is appended to the last slash of the pattern, all occurrences 1177in each word are replaced. 1178If a 1179.Ql 1 1180is appended to the last slash of the pattern, only the first word 1181is affected. 1182If a 1183.Ql W 1184is appended to the last slash of the pattern, 1185then the value is treated as a single word 1186(possibly containing embedded white space). 1187If 1188.Ar old_string 1189begins with a caret 1190.Pq Ql ^ , 1191.Ar old_string 1192is anchored at the beginning of each word. 1193If 1194.Ar old_string 1195ends with a dollar sign 1196.Pq Ql \&$ , 1197it is anchored at the end of each word. 1198Inside 1199.Ar new_string , 1200an ampersand 1201.Pq Ql \*[Am] 1202is replaced by 1203.Ar old_string 1204(without any 1205.Ql ^ 1206or 1207.Ql \&$ ) . 1208Any character may be used as a delimiter for the parts of the modifier 1209string. 1210The anchoring, ampersand and delimiter characters may be escaped with a 1211backslash 1212.Pq Ql \e . 1213.Pp 1214Variable expansion occurs in the normal fashion inside both 1215.Ar old_string 1216and 1217.Ar new_string 1218with the single exception that a backslash is used to prevent the expansion 1219of a dollar sign 1220.Pq Ql \&$ , 1221not a preceding dollar sign as is usual. 1222.Sm off 1223.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1224.Sm on 1225The 1226.Cm \&:C 1227modifier is just like the 1228.Cm \&:S 1229modifier except that the old and new strings, instead of being 1230simple strings, are an extended regular expression (see 1231.Xr regex 3 ) 1232string 1233.Ar pattern 1234and an 1235.Xr ed 1 Ns \-style 1236string 1237.Ar replacement . 1238Normally, the first occurrence of the pattern 1239.Ar pattern 1240in each word of the value is substituted with 1241.Ar replacement . 1242The 1243.Ql 1 1244modifier causes the substitution to apply to at most one word; the 1245.Ql g 1246modifier causes the substitution to apply to as many instances of the 1247search pattern 1248.Ar pattern 1249as occur in the word or words it is found in; the 1250.Ql W 1251modifier causes the value to be treated as a single word 1252(possibly containing embedded white space). 1253Note that 1254.Ql 1 1255and 1256.Ql g 1257are orthogonal; the former specifies whether multiple words are 1258potentially affected, the latter whether multiple substitutions can 1259potentially occur within each affected word. 1260.It Cm \&:T 1261Replaces each word in the variable with its last component. 1262.It Cm \&:u 1263Remove adjacent duplicate words (like 1264.Xr uniq 1 ) . 1265.Sm off 1266.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1267.Sm on 1268If the variable name (not its value), when parsed as a .if conditional 1269expression, evaluates to true, return as its value the 1270.Ar true_string , 1271otherwise return the 1272.Ar false_string . 1273Since the variable name is used as the expression, \&:\&? must be the 1274first modifier after the variable name itself - which will, of course, 1275usually contain variable expansions. 1276A common error is trying to use expressions like 1277.Dl ${NUMBERS:M42:?match:no} 1278which actually tests defined(NUMBERS), 1279to determine is any words match "42" you need to use something like: 1280.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1281.It Ar :old_string=new_string 1282This is the 1283.At V 1284style variable substitution. 1285It must be the last modifier specified. 1286If 1287.Ar old_string 1288or 1289.Ar new_string 1290do not contain the pattern matching character 1291.Ar % 1292then it is assumed that they are 1293anchored at the end of each word, so only suffixes or entire 1294words may be replaced. 1295Otherwise 1296.Ar % 1297is the substring of 1298.Ar old_string 1299to be replaced in 1300.Ar new_string . 1301.Pp 1302Variable expansion occurs in the normal fashion inside both 1303.Ar old_string 1304and 1305.Ar new_string 1306with the single exception that a backslash is used to prevent the 1307expansion of a dollar sign 1308.Pq Ql \&$ , 1309not a preceding dollar sign as is usual. 1310.Sm off 1311.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1312.Sm on 1313This is the loop expansion mechanism from the OSF Development 1314Environment (ODE) make. 1315Unlike 1316.Cm \&.for 1317loops expansion occurs at the time of 1318reference. 1319Assign 1320.Ar temp 1321to each word in the variable and evaluate 1322.Ar string . 1323The ODE convention is that 1324.Ar temp 1325should start and end with a period. 1326For example. 1327.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1328.Pp 1329However a single character variable is often more readable: 1330.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1331.It Cm \&:U Ns Ar newval 1332If the variable is undefined 1333.Ar newval 1334is the value. 1335If the variable is defined, the existing value is returned. 1336This is another ODE make feature. 1337It is handy for setting per-target CFLAGS for instance: 1338.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1339If a value is only required if the variable is undefined, use: 1340.Dl ${VAR:D:Unewval} 1341.It Cm \&:D Ns Ar newval 1342If the variable is defined 1343.Ar newval 1344is the value. 1345.It Cm \&:L 1346The name of the variable is the value. 1347.It Cm \&:P 1348The path of the node which has the same name as the variable 1349is the value. 1350If no such node exists or its path is null, then the 1351name of the variable is used. 1352In order for this modifier to work, the name (node) must at least have 1353appeared on the rhs of a dependency. 1354.Sm off 1355.It Cm \&:\&! Ar cmd Cm \&! 1356.Sm on 1357The output of running 1358.Ar cmd 1359is the value. 1360.It Cm \&:sh 1361If the variable is non-empty it is run as a command and the output 1362becomes the new value. 1363.It Cm \&::= Ns Ar str 1364The variable is assigned the value 1365.Ar str 1366after substitution. 1367This modifier and its variations are useful in 1368obscure situations such as wanting to set a variable when shell commands 1369are being parsed. 1370These assignment modifiers always expand to 1371nothing, so if appearing in a rule line by themselves should be 1372preceded with something to keep 1373.Nm 1374happy. 1375.Pp 1376The 1377.Ql Cm \&:: 1378helps avoid false matches with the 1379.At V 1380style 1381.Cm \&:= 1382modifier and since substitution always occurs the 1383.Cm \&::= 1384form is vaguely appropriate. 1385.It Cm \&::?= Ns Ar str 1386As for 1387.Cm \&::= 1388but only if the variable does not already have a value. 1389.It Cm \&::+= Ns Ar str 1390Append 1391.Ar str 1392to the variable. 1393.It Cm \&::!= Ns Ar cmd 1394Assign the output of 1395.Ar cmd 1396to the variable. 1397.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1398Selects one or more words from the value, 1399or performs other operations related to the way in which the 1400value is divided into words. 1401.Pp 1402Ordinarily, a value is treated as a sequence of words 1403delimited by white space. 1404Some modifiers suppress this behaviour, 1405causing a value to be treated as a single word 1406(possibly containing embedded white space). 1407An empty value, or a value that consists entirely of white-space, 1408is treated as a single word. 1409For the purposes of the 1410.Ql Cm \&:[] 1411modifier, the words are indexed both forwards using positive integers 1412(where index 1 represents the first word), 1413and backwards using negative integers 1414(where index \-1 represents the last word). 1415.Pp 1416The 1417.Ar range 1418is subjected to variable expansion, and the expanded result is 1419then interpreted as follows: 1420.Bl -tag -width index 1421.\" :[n] 1422.It Ar index 1423Selects a single word from the value. 1424.\" :[start..end] 1425.It Ar start Ns Cm \&.. Ns Ar end 1426Selects all words from 1427.Ar start 1428to 1429.Ar end , 1430inclusive. 1431For example, 1432.Ql Cm \&:[2..-1] 1433selects all words from the second word to the last word. 1434If 1435.Ar start 1436is greater than 1437.Ar end , 1438then the words are output in reverse order. 1439For example, 1440.Ql Cm \&:[-1..1] 1441selects all the words from last to first. 1442.\" :[*] 1443.It Cm \&* 1444Causes subsequent modifiers to treat the value as a single word 1445(possibly containing embedded white space). 1446Analogous to the effect of 1447\&"$*\&" 1448in Bourne shell. 1449.\" :[0] 1450.It 0 1451Means the same as 1452.Ql Cm \&:[*] . 1453.\" :[*] 1454.It Cm \&@ 1455Causes subsequent modifiers to treat the value as a sequence of words 1456delimited by white space. 1457Analogous to the effect of 1458\&"$@\&" 1459in Bourne shell. 1460.\" :[#] 1461.It Cm \&# 1462Returns the number of words in the value. 1463.El \" :[range] 1464.El 1465.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1466Makefile inclusion, conditional structures and for loops reminiscent 1467of the C programming language are provided in 1468.Nm . 1469All such structures are identified by a line beginning with a single 1470dot 1471.Pq Ql \&. 1472character. 1473Files are included with either 1474.Cm \&.include Aq Ar file 1475or 1476.Cm \&.include Pf \*q Ar file Ns \*q . 1477Variables between the angle brackets or double quotes are expanded 1478to form the file name. 1479If angle brackets are used, the included makefile is expected to be in 1480the system makefile directory. 1481If double quotes are used, the including makefile's directory and any 1482directories specified using the 1483.Fl I 1484option are searched before the system 1485makefile directory. 1486For compatibility with other versions of 1487.Nm 1488.Ql include file ... 1489is also accepted. 1490If the include statement is written as 1491.Cm .-include 1492or as 1493.Cm .sinclude 1494then errors locating and/or opening include files are ignored. 1495.Pp 1496Conditional expressions are also preceded by a single dot as the first 1497character of a line. 1498The possible conditionals are as follows: 1499.Bl -tag -width Ds 1500.It Ic .error Ar message 1501The message is printed along with the name of the makefile and line number, 1502then 1503.Nm 1504will exit. 1505.It Ic .export Ar variable ... 1506Export the specified global variable. 1507If no variable list is provided, all globals are exported 1508except for internal variables (those that start with 1509.Ql \&. ) . 1510This is not affected by the 1511.Fl X 1512flag, so should be used with caution. 1513For compatibility with other 1514.Nm 1515programs 1516.Ql export variable=value 1517is also accepted. 1518.Pp 1519Appending a variable name to 1520.Va .MAKE.EXPORTED 1521is equivalent to exporting a variable. 1522.It Ic .export-env Ar variable ... 1523The same as 1524.Ql .export , 1525except that the variable is not appended to 1526.Va .MAKE.EXPORTED . 1527This allows exporting a value to the environment which is different from that 1528used by 1529.Nm 1530internally. 1531.It Ic .info Ar message 1532The message is printed along with the name of the makefile and line number. 1533.It Ic .undef Ar variable 1534Un-define the specified global variable. 1535Only global variables may be un-defined. 1536.It Ic .unexport Ar variable ... 1537The opposite of 1538.Ql .export . 1539The specified global 1540.Va variable 1541will be removed from 1542.Va .MAKE.EXPORTED . 1543If no variable list is provided, all globals are unexported, 1544and 1545.Va .MAKE.EXPORTED 1546deleted. 1547.It Ic .unexport-env 1548Unexport all globals previously exported and 1549clear the environment inherited from the parent. 1550This operation will cause a memory leak of the original environment, 1551so should be used sparingly. 1552Testing for 1553.Va .MAKE.LEVEL 1554being 0, would make sense. 1555Also note that any variables which originated in the parent environment 1556should be explicitly preserved if desired. 1557For example: 1558.Bd -literal -offset indent 1559.Li .if ${.MAKE.LEVEL} == 0 1560PATH := ${PATH} 1561.Li .unexport-env 1562.Li .export PATH 1563.Li .endif 1564.Pp 1565.Ed 1566Would result in an environment containing only 1567.Ql Ev PATH , 1568which is the minimal useful environment. 1569Actually 1570.Ql Ev .MAKE.LEVEL 1571will also be pushed into the new environment. 1572.It Ic .warning Ar message 1573The message prefixed by 1574.Ql Pa warning: 1575is printed along with the name of the makefile and line number. 1576.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1577Test the value of an expression. 1578.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1579Test the value of a variable. 1580.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1581Test the value of a variable. 1582.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1583Test the target being built. 1584.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1585Test the target being built. 1586.It Ic .else 1587Reverse the sense of the last conditional. 1588.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1589A combination of 1590.Ql Ic .else 1591followed by 1592.Ql Ic .if . 1593.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1594A combination of 1595.Ql Ic .else 1596followed by 1597.Ql Ic .ifdef . 1598.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1599A combination of 1600.Ql Ic .else 1601followed by 1602.Ql Ic .ifndef . 1603.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1604A combination of 1605.Ql Ic .else 1606followed by 1607.Ql Ic .ifmake . 1608.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1609A combination of 1610.Ql Ic .else 1611followed by 1612.Ql Ic .ifnmake . 1613.It Ic .endif 1614End the body of the conditional. 1615.El 1616.Pp 1617The 1618.Ar operator 1619may be any one of the following: 1620.Bl -tag -width "Cm XX" 1621.It Cm \&|\&| 1622Logical OR. 1623.It Cm \&\*[Am]\*[Am] 1624Logical 1625.Tn AND ; 1626of higher precedence than 1627.Dq \&|\&| . 1628.El 1629.Pp 1630As in C, 1631.Nm 1632will only evaluate a conditional as far as is necessary to determine 1633its value. 1634Parentheses may be used to change the order of evaluation. 1635The boolean operator 1636.Ql Ic \&! 1637may be used to logically negate an entire 1638conditional. 1639It is of higher precedence than 1640.Ql Ic \&\*[Am]\*[Am] . 1641.Pp 1642The value of 1643.Ar expression 1644may be any of the following: 1645.Bl -tag -width defined 1646.It Ic defined 1647Takes a variable name as an argument and evaluates to true if the variable 1648has been defined. 1649.It Ic make 1650Takes a target name as an argument and evaluates to true if the target 1651was specified as part of 1652.Nm Ns 's 1653command line or was declared the default target (either implicitly or 1654explicitly, see 1655.Va .MAIN ) 1656before the line containing the conditional. 1657.It Ic empty 1658Takes a variable, with possible modifiers, and evaluates to true if 1659the expansion of the variable would result in an empty string. 1660.It Ic exists 1661Takes a file name as an argument and evaluates to true if the file exists. 1662The file is searched for on the system search path (see 1663.Va .PATH ) . 1664.It Ic target 1665Takes a target name as an argument and evaluates to true if the target 1666has been defined. 1667.It Ic commands 1668Takes a target name as an argument and evaluates to true if the target 1669has been defined and has commands associated with it. 1670.El 1671.Pp 1672.Ar Expression 1673may also be an arithmetic or string comparison. 1674Variable expansion is 1675performed on both sides of the comparison, after which the integral 1676values are compared. 1677A value is interpreted as hexadecimal if it is 1678preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1679The standard C relational operators are all supported. 1680If after 1681variable expansion, either the left or right hand side of a 1682.Ql Ic == 1683or 1684.Ql Ic "!=" 1685operator is not an integral value, then 1686string comparison is performed between the expanded 1687variables. 1688If no relational operator is given, it is assumed that the expanded 1689variable is being compared against 0 or an empty string in the case 1690of a string comparison. 1691.Pp 1692When 1693.Nm 1694is evaluating one of these conditional expressions, and it encounters 1695a (white-space separated) word it doesn't recognize, either the 1696.Dq make 1697or 1698.Dq defined 1699expression is applied to it, depending on the form of the conditional. 1700If the form is 1701.Ql Ic .ifdef , 1702.Ql Ic .ifndef , 1703or 1704.Ql Ic .if 1705the 1706.Dq defined 1707expression is applied. 1708Similarly, if the form is 1709.Ql Ic .ifmake 1710or 1711.Ql Ic .ifnmake , the 1712.Dq make 1713expression is applied. 1714.Pp 1715If the conditional evaluates to true the parsing of the makefile continues 1716as before. 1717If it evaluates to false, the following lines are skipped. 1718In both cases this continues until a 1719.Ql Ic .else 1720or 1721.Ql Ic .endif 1722is found. 1723.Pp 1724For loops are typically used to apply a set of rules to a list of files. 1725The syntax of a for loop is: 1726.Pp 1727.Bl -tag -compact -width Ds 1728.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1729.It Aq make-rules 1730.It Ic \&.endfor 1731.El 1732.Pp 1733After the for 1734.Ic expression 1735is evaluated, it is split into words. 1736On each iteration of the loop, one word is taken and assigned to each 1737.Ic variable , 1738in order, and these 1739.Ic variables 1740are substituted into the 1741.Ic make-rules 1742inside the body of the for loop. 1743The number of words must come out even; that is, if there are three 1744iteration variables, the number of words provided must be a multiple 1745of three. 1746.Sh COMMENTS 1747Comments begin with a hash 1748.Pq Ql \&# 1749character, anywhere but in a shell 1750command line, and continue to the end of an unescaped new line. 1751.Sh SPECIAL SOURCES (ATTRIBUTES) 1752.Bl -tag -width .IGNOREx 1753.It Ic .EXEC 1754Target is never out of date, but always execute commands anyway. 1755.It Ic .IGNORE 1756Ignore any errors from the commands associated with this target, exactly 1757as if they all were preceded by a dash 1758.Pq Ql \- . 1759.\" .It Ic .INVISIBLE 1760.\" XXX 1761.\" .It Ic .JOIN 1762.\" XXX 1763.It Ic .MADE 1764Mark all sources of this target as being up-to-date. 1765.It Ic .MAKE 1766Execute the commands associated with this target even if the 1767.Fl n 1768or 1769.Fl t 1770options were specified. 1771Normally used to mark recursive 1772.Nm Ns s . 1773.It Ic .META 1774Create a meta file for the target, even if it is flagged as 1775.Ic .PHONY , 1776.Ic .MAKE , 1777or 1778.Ic .SPECIAL . 1779Usage in conjunction with 1780.Ic .MAKE 1781is the most likely case. 1782In "meta" mode, the target is out-of-date if the meta file is missing. 1783.It Ic .NOMETA 1784Do not create a meta file for the target. 1785Meta files are also not created for 1786.Ic .PHONY , 1787.Ic .MAKE , 1788or 1789.Ic .SPECIAL 1790targets. 1791.It Ic .NOMETA_CMP 1792Ignore differences in commands when deciding if target is out of date. 1793This is useful if the command contains a value which always changes. 1794If the number of commands change, though, the target will still be out of date. 1795The same effect applies to any command line that uses the variable 1796.Va .OODATE , 1797which can be used for that purpose even when not otherwise needed or desired: 1798.Bd -literal -offset indent 1799 1800skip-compare-for-some: 1801 @echo this will be compared 1802 @echo this will not ${.OODATE:M.NOMETA_CMP} 1803 @echo this will also be compared 1804 1805.Ed 1806The 1807.Cm \&:M 1808pattern suppresses any expansion of the unwanted variable. 1809.It Ic .NOPATH 1810Do not search for the target in the directories specified by 1811.Ic .PATH . 1812.It Ic .NOTMAIN 1813Normally 1814.Nm 1815selects the first target it encounters as the default target to be built 1816if no target was specified. 1817This source prevents this target from being selected. 1818.It Ic .OPTIONAL 1819If a target is marked with this attribute and 1820.Nm 1821can't figure out how to create it, it will ignore this fact and assume 1822the file isn't needed or already exists. 1823.It Ic .PHONY 1824The target does not 1825correspond to an actual file; it is always considered to be out of date, 1826and will not be created with the 1827.Fl t 1828option. 1829Suffix-transformation rules are not applied to 1830.Ic .PHONY 1831targets. 1832.It Ic .PRECIOUS 1833When 1834.Nm 1835is interrupted, it normally removes any partially made targets. 1836This source prevents the target from being removed. 1837.It Ic .RECURSIVE 1838Synonym for 1839.Ic .MAKE . 1840.It Ic .SILENT 1841Do not echo any of the commands associated with this target, exactly 1842as if they all were preceded by an at sign 1843.Pq Ql @ . 1844.It Ic .USE 1845Turn the target into 1846.Nm Ns 's 1847version of a macro. 1848When the target is used as a source for another target, the other target 1849acquires the commands, sources, and attributes (except for 1850.Ic .USE ) 1851of the 1852source. 1853If the target already has commands, the 1854.Ic .USE 1855target's commands are appended 1856to them. 1857.It Ic .USEBEFORE 1858Exactly like 1859.Ic .USE , 1860but prepend the 1861.Ic .USEBEFORE 1862target commands to the target. 1863.It Ic .WAIT 1864If 1865.Ic .WAIT 1866appears in a dependency line, the sources that precede it are 1867made before the sources that succeed it in the line. 1868Since the dependents of files are not made until the file itself 1869could be made, this also stops the dependents being built unless they 1870are needed for another branch of the dependency tree. 1871So given: 1872.Bd -literal 1873x: a .WAIT b 1874 echo x 1875a: 1876 echo a 1877b: b1 1878 echo b 1879b1: 1880 echo b1 1881 1882.Ed 1883the output is always 1884.Ql a , 1885.Ql b1 , 1886.Ql b , 1887.Ql x . 1888.br 1889The ordering imposed by 1890.Ic .WAIT 1891is only relevant for parallel makes. 1892.El 1893.Sh SPECIAL TARGETS 1894Special targets may not be included with other targets, i.e. they must be 1895the only target specified. 1896.Bl -tag -width .BEGINx 1897.It Ic .BEGIN 1898Any command lines attached to this target are executed before anything 1899else is done. 1900.It Ic .DEFAULT 1901This is sort of a 1902.Ic .USE 1903rule for any target (that was used only as a 1904source) that 1905.Nm 1906can't figure out any other way to create. 1907Only the shell script is used. 1908The 1909.Ic .IMPSRC 1910variable of a target that inherits 1911.Ic .DEFAULT Ns 's 1912commands is set 1913to the target's own name. 1914.It Ic .END 1915Any command lines attached to this target are executed after everything 1916else is done. 1917.It Ic .ERROR 1918Any command lines attached to this target are executed when another target fails. 1919The 1920.Ic .ERROR_TARGET 1921variable is set to the target that failed. 1922See also 1923.Ic MAKE_PRINT_VAR_ON_ERROR . 1924.It Ic .IGNORE 1925Mark each of the sources with the 1926.Ic .IGNORE 1927attribute. 1928If no sources are specified, this is the equivalent of specifying the 1929.Fl i 1930option. 1931.It Ic .INTERRUPT 1932If 1933.Nm 1934is interrupted, the commands for this target will be executed. 1935.It Ic .MAIN 1936If no target is specified when 1937.Nm 1938is invoked, this target will be built. 1939.It Ic .MAKEFLAGS 1940This target provides a way to specify flags for 1941.Nm 1942when the makefile is used. 1943The flags are as if typed to the shell, though the 1944.Fl f 1945option will have 1946no effect. 1947.\" XXX: NOT YET!!!! 1948.\" .It Ic .NOTPARALLEL 1949.\" The named targets are executed in non parallel mode. 1950.\" If no targets are 1951.\" specified, then all targets are executed in non parallel mode. 1952.It Ic .NOPATH 1953Apply the 1954.Ic .NOPATH 1955attribute to any specified sources. 1956.It Ic .NOTPARALLEL 1957Disable parallel mode. 1958.It Ic .NO_PARALLEL 1959Synonym for 1960.Ic .NOTPARALLEL , 1961for compatibility with other pmake variants. 1962.It Ic .ORDER 1963The named targets are made in sequence. 1964This ordering does not add targets to the list of targets to be made. 1965Since the dependents of a target do not get built until the target itself 1966could be built, unless 1967.Ql a 1968is built by another part of the dependency graph, 1969the following is a dependency loop: 1970.Bd -literal 1971\&.ORDER: b a 1972b: a 1973.Ed 1974.Pp 1975The ordering imposed by 1976.Ic .ORDER 1977is only relevant for parallel makes. 1978.\" XXX: NOT YET!!!! 1979.\" .It Ic .PARALLEL 1980.\" The named targets are executed in parallel mode. 1981.\" If no targets are 1982.\" specified, then all targets are executed in parallel mode. 1983.It Ic .PATH 1984The sources are directories which are to be searched for files not 1985found in the current directory. 1986If no sources are specified, any previously specified directories are 1987deleted. 1988If the source is the special 1989.Ic .DOTLAST 1990target, then the current working 1991directory is searched last. 1992.It Ic .PATH. Ns Va suffix 1993Like 1994.Ic .PATH 1995but applies only to files with a particular suffix. 1996The suffix must have been previously declared with 1997.Ic .SUFFIXES . 1998.It Ic .PHONY 1999Apply the 2000.Ic .PHONY 2001attribute to any specified sources. 2002.It Ic .PRECIOUS 2003Apply the 2004.Ic .PRECIOUS 2005attribute to any specified sources. 2006If no sources are specified, the 2007.Ic .PRECIOUS 2008attribute is applied to every 2009target in the file. 2010.It Ic .SHELL 2011Sets the shell that 2012.Nm 2013will use to execute commands. 2014The sources are a set of 2015.Ar field=value 2016pairs. 2017.Bl -tag -width hasErrCtls 2018.It Ar name 2019This is the minimal specification, used to select one of the builtin 2020shell specs; 2021.Ar sh , 2022.Ar ksh , 2023and 2024.Ar csh . 2025.It Ar path 2026Specifies the path to the shell. 2027.It Ar hasErrCtl 2028Indicates whether the shell supports exit on error. 2029.It Ar check 2030The command to turn on error checking. 2031.It Ar ignore 2032The command to disable error checking. 2033.It Ar echo 2034The command to turn on echoing of commands executed. 2035.It Ar quiet 2036The command to turn off echoing of commands executed. 2037.It Ar filter 2038The output to filter after issuing the 2039.Ar quiet 2040command. 2041It is typically identical to 2042.Ar quiet . 2043.It Ar errFlag 2044The flag to pass the shell to enable error checking. 2045.It Ar echoFlag 2046The flag to pass the shell to enable command echoing. 2047.It Ar newline 2048The string literal to pass the shell that results in a single newline 2049character when used outside of any quoting characters. 2050.El 2051Example: 2052.Bd -literal 2053\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2054 check="set \-e" ignore="set +e" \e 2055 echo="set \-v" quiet="set +v" filter="set +v" \e 2056 echoFlag=v errFlag=e newline="'\en'" 2057.Ed 2058.It Ic .SILENT 2059Apply the 2060.Ic .SILENT 2061attribute to any specified sources. 2062If no sources are specified, the 2063.Ic .SILENT 2064attribute is applied to every 2065command in the file. 2066.It Ic .STALE 2067This target gets run when a dependency file contains stale entries, having 2068.Va .ALLSRC 2069set to the name of that dependency file. 2070.It Ic .SUFFIXES 2071Each source specifies a suffix to 2072.Nm . 2073If no sources are specified, any previously specified suffixes are deleted. 2074It allows the creation of suffix-transformation rules. 2075.Pp 2076Example: 2077.Bd -literal 2078\&.SUFFIXES: .o 2079\&.c.o: 2080 cc \-o ${.TARGET} \-c ${.IMPSRC} 2081.Ed 2082.El 2083.Sh ENVIRONMENT 2084.Nm 2085uses the following environment variables, if they exist: 2086.Ev MACHINE , 2087.Ev MACHINE_ARCH , 2088.Ev MAKE , 2089.Ev MAKEFLAGS , 2090.Ev MAKEOBJDIR , 2091.Ev MAKEOBJDIRPREFIX , 2092.Ev MAKESYSPATH , 2093.Ev PWD , 2094and 2095.Ev TMPDIR . 2096.Pp 2097.Ev MAKEOBJDIRPREFIX 2098and 2099.Ev MAKEOBJDIR 2100may only be set in the environment or on the command line to 2101.Nm 2102and not as makefile variables; 2103see the description of 2104.Ql Va .OBJDIR 2105for more details. 2106.Sh FILES 2107.Bl -tag -width /usr/share/mk -compact 2108.It .depend 2109list of dependencies 2110.It Makefile 2111list of dependencies 2112.It makefile 2113list of dependencies 2114.It sys.mk 2115system makefile 2116.It /usr/share/mk 2117system makefile directory 2118.El 2119.Sh COMPATIBILITY 2120The basic make syntax is compatible between different versions of make, 2121however the special variables, variable modifiers and conditionals are not. 2122.Pp 2123The way that parallel makes are scheduled changed in 2124.Nx 4.0 2125so that .ORDER and .WAIT apply recursively to the dependent nodes. 2126The algorithms used may change again in the future. 2127.Pp 2128The way that .for loop variables are substituted changed after 2129.Nx 5.0 2130so that they still appear to be variable expansions. 2131In particular this stops them being treated as syntax, and removes some 2132obscure problems using them in .if statements. 2133.Sh SEE ALSO 2134.Xr mkdep 1 2135.Sh HISTORY 2136A 2137.Nm 2138command appeared in 2139.At v7 . 2140This 2141.Nm 2142implementation is based on Adam De Boor's pmake program which was written 2143for Sprite at Berkeley. 2144It was designed to be a parallel distributed make running jobs on different 2145machines using a daemon called 2146.Dq customs . 2147.Pp 2148Historically the target/dependency 2149.Dq FRC 2150has been used to FoRCe rebuilding (since the target/dependency 2151does not exist... unless someone creates an 2152.Dq FRC 2153file). 2154.Sh BUGS 2155The 2156.Nm 2157syntax is difficult to parse without actually acting of the data. 2158For instance finding the end of a variable use should involve scanning each 2159the modifiers using the correct terminator for each field. 2160In many places 2161.Nm 2162just counts {} and () in order to find the end of a variable expansion. 2163.Pp 2164There is no way of escaping a space character in a filename. 2165