1.\" $NetBSD: make.1,v 1.222 2013/08/11 09:53:49 apb 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 August 11, 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 . 1080.It Cm \&:N Ns Ar pattern 1081This is identical to 1082.Ql Cm \&:M , 1083but selects all words which do not match 1084.Ar pattern . 1085.It Cm \&:O 1086Order every word in variable alphabetically. 1087To sort words in 1088reverse order use the 1089.Ql Cm \&:O:[-1..1] 1090combination of modifiers. 1091.It Cm \&:Ox 1092Randomize words in variable. 1093The results will be different each time you are referring to the 1094modified variable; use the assignment with expansion 1095.Pq Ql Cm \&:= 1096to prevent such behaviour. 1097For example, 1098.Bd -literal -offset indent 1099LIST= uno due tre quattro 1100RANDOM_LIST= ${LIST:Ox} 1101STATIC_RANDOM_LIST:= ${LIST:Ox} 1102 1103all: 1104 @echo "${RANDOM_LIST}" 1105 @echo "${RANDOM_LIST}" 1106 @echo "${STATIC_RANDOM_LIST}" 1107 @echo "${STATIC_RANDOM_LIST}" 1108.Ed 1109may produce output similar to: 1110.Bd -literal -offset indent 1111quattro due tre uno 1112tre due quattro uno 1113due uno quattro tre 1114due uno quattro tre 1115.Ed 1116.It Cm \&:Q 1117Quotes every shell meta-character in the variable, so that it can be passed 1118safely through recursive invocations of 1119.Nm . 1120.It Cm \&:R 1121Replaces each word in the variable with everything but its suffix. 1122.It Cm \&:gmtime 1123The value is a format string for 1124.Xr strftime 3 , 1125using the current 1126.Xr gmtime 3 . 1127.It Cm \&:hash 1128Compute a 32bit hash of the value and encode it as hex digits. 1129.It Cm \&:localtime 1130The value is a format string for 1131.Xr strftime 3 , 1132using the current 1133.Xr localtime 3 . 1134.It Cm \&:tA 1135Attempt to convert variable to an absolute path using 1136.Xr realpath 3 , 1137if that fails, the value is unchanged. 1138.It Cm \&:tl 1139Converts variable to lower-case letters. 1140.It Cm \&:ts Ns Ar c 1141Words in the variable are normally separated by a space on expansion. 1142This modifier sets the separator to the character 1143.Ar c . 1144If 1145.Ar c 1146is omitted, then no separator is used. 1147The common escapes (including octal numeric codes), work as expected. 1148.It Cm \&:tu 1149Converts variable to upper-case letters. 1150.It Cm \&:tW 1151Causes the value to be treated as a single word 1152(possibly containing embedded white space). 1153See also 1154.Ql Cm \&:[*] . 1155.It Cm \&:tw 1156Causes the value to be treated as a sequence of 1157words delimited by white space. 1158See also 1159.Ql Cm \&:[@] . 1160.Sm off 1161.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1162.Sm on 1163Modify the first occurrence of 1164.Ar old_string 1165in the variable's value, replacing it with 1166.Ar new_string . 1167If a 1168.Ql g 1169is appended to the last slash of the pattern, all occurrences 1170in each word are replaced. 1171If a 1172.Ql 1 1173is appended to the last slash of the pattern, only the first word 1174is affected. 1175If a 1176.Ql W 1177is appended to the last slash of the pattern, 1178then the value is treated as a single word 1179(possibly containing embedded white space). 1180If 1181.Ar old_string 1182begins with a caret 1183.Pq Ql ^ , 1184.Ar old_string 1185is anchored at the beginning of each word. 1186If 1187.Ar old_string 1188ends with a dollar sign 1189.Pq Ql \&$ , 1190it is anchored at the end of each word. 1191Inside 1192.Ar new_string , 1193an ampersand 1194.Pq Ql \*[Am] 1195is replaced by 1196.Ar old_string 1197(without any 1198.Ql ^ 1199or 1200.Ql \&$ ) . 1201Any character may be used as a delimiter for the parts of the modifier 1202string. 1203The anchoring, ampersand and delimiter characters may be escaped with a 1204backslash 1205.Pq Ql \e . 1206.Pp 1207Variable expansion occurs in the normal fashion inside both 1208.Ar old_string 1209and 1210.Ar new_string 1211with the single exception that a backslash is used to prevent the expansion 1212of a dollar sign 1213.Pq Ql \&$ , 1214not a preceding dollar sign as is usual. 1215.Sm off 1216.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1217.Sm on 1218The 1219.Cm \&:C 1220modifier is just like the 1221.Cm \&:S 1222modifier except that the old and new strings, instead of being 1223simple strings, are a regular expression (see 1224.Xr regex 3 ) 1225string 1226.Ar pattern 1227and an 1228.Xr ed 1 Ns \-style 1229string 1230.Ar replacement . 1231Normally, the first occurrence of the pattern 1232.Ar pattern 1233in each word of the value is substituted with 1234.Ar replacement . 1235The 1236.Ql 1 1237modifier causes the substitution to apply to at most one word; the 1238.Ql g 1239modifier causes the substitution to apply to as many instances of the 1240search pattern 1241.Ar pattern 1242as occur in the word or words it is found in; the 1243.Ql W 1244modifier causes the value to be treated as a single word 1245(possibly containing embedded white space). 1246Note that 1247.Ql 1 1248and 1249.Ql g 1250are orthogonal; the former specifies whether multiple words are 1251potentially affected, the latter whether multiple substitutions can 1252potentially occur within each affected word. 1253.It Cm \&:T 1254Replaces each word in the variable with its last component. 1255.It Cm \&:u 1256Remove adjacent duplicate words (like 1257.Xr uniq 1 ) . 1258.Sm off 1259.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1260.Sm on 1261If the variable name (not its value), when parsed as a .if conditional 1262expression, evaluates to true, return as its value the 1263.Ar true_string , 1264otherwise return the 1265.Ar false_string . 1266Since the variable name is used as the expression, \&:\&? must be the 1267first modifier after the variable name itself - which will, of course, 1268usually contain variable expansions. 1269A common error is trying to use expressions like 1270.Dl ${NUMBERS:M42:?match:no} 1271which actually tests defined(NUMBERS), 1272to determine is any words match "42" you need to use something like: 1273.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1274.It Ar :old_string=new_string 1275This is the 1276.At V 1277style variable substitution. 1278It must be the last modifier specified. 1279If 1280.Ar old_string 1281or 1282.Ar new_string 1283do not contain the pattern matching character 1284.Ar % 1285then it is assumed that they are 1286anchored at the end of each word, so only suffixes or entire 1287words may be replaced. 1288Otherwise 1289.Ar % 1290is the substring of 1291.Ar old_string 1292to be replaced in 1293.Ar new_string . 1294.Pp 1295Variable expansion occurs in the normal fashion inside both 1296.Ar old_string 1297and 1298.Ar new_string 1299with the single exception that a backslash is used to prevent the 1300expansion of a dollar sign 1301.Pq Ql \&$ , 1302not a preceding dollar sign as is usual. 1303.Sm off 1304.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1305.Sm on 1306This is the loop expansion mechanism from the OSF Development 1307Environment (ODE) make. 1308Unlike 1309.Cm \&.for 1310loops expansion occurs at the time of 1311reference. 1312Assign 1313.Ar temp 1314to each word in the variable and evaluate 1315.Ar string . 1316The ODE convention is that 1317.Ar temp 1318should start and end with a period. 1319For example. 1320.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1321.Pp 1322However a single character variable is often more readable: 1323.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1324.It Cm \&:U Ns Ar newval 1325If the variable is undefined 1326.Ar newval 1327is the value. 1328If the variable is defined, the existing value is returned. 1329This is another ODE make feature. 1330It is handy for setting per-target CFLAGS for instance: 1331.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1332If a value is only required if the variable is undefined, use: 1333.Dl ${VAR:D:Unewval} 1334.It Cm \&:D Ns Ar newval 1335If the variable is defined 1336.Ar newval 1337is the value. 1338.It Cm \&:L 1339The name of the variable is the value. 1340.It Cm \&:P 1341The path of the node which has the same name as the variable 1342is the value. 1343If no such node exists or its path is null, then the 1344name of the variable is used. 1345In order for this modifier to work, the name (node) must at least have 1346appeared on the rhs of a dependency. 1347.Sm off 1348.It Cm \&:\&! Ar cmd Cm \&! 1349.Sm on 1350The output of running 1351.Ar cmd 1352is the value. 1353.It Cm \&:sh 1354If the variable is non-empty it is run as a command and the output 1355becomes the new value. 1356.It Cm \&::= Ns Ar str 1357The variable is assigned the value 1358.Ar str 1359after substitution. 1360This modifier and its variations are useful in 1361obscure situations such as wanting to set a variable when shell commands 1362are being parsed. 1363These assignment modifiers always expand to 1364nothing, so if appearing in a rule line by themselves should be 1365preceded with something to keep 1366.Nm 1367happy. 1368.Pp 1369The 1370.Ql Cm \&:: 1371helps avoid false matches with the 1372.At V 1373style 1374.Cm \&:= 1375modifier and since substitution always occurs the 1376.Cm \&::= 1377form is vaguely appropriate. 1378.It Cm \&::?= Ns Ar str 1379As for 1380.Cm \&::= 1381but only if the variable does not already have a value. 1382.It Cm \&::+= Ns Ar str 1383Append 1384.Ar str 1385to the variable. 1386.It Cm \&::!= Ns Ar cmd 1387Assign the output of 1388.Ar cmd 1389to the variable. 1390.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1391Selects one or more words from the value, 1392or performs other operations related to the way in which the 1393value is divided into words. 1394.Pp 1395Ordinarily, a value is treated as a sequence of words 1396delimited by white space. 1397Some modifiers suppress this behaviour, 1398causing a value to be treated as a single word 1399(possibly containing embedded white space). 1400An empty value, or a value that consists entirely of white-space, 1401is treated as a single word. 1402For the purposes of the 1403.Ql Cm \&:[] 1404modifier, the words are indexed both forwards using positive integers 1405(where index 1 represents the first word), 1406and backwards using negative integers 1407(where index \-1 represents the last word). 1408.Pp 1409The 1410.Ar range 1411is subjected to variable expansion, and the expanded result is 1412then interpreted as follows: 1413.Bl -tag -width index 1414.\" :[n] 1415.It Ar index 1416Selects a single word from the value. 1417.\" :[start..end] 1418.It Ar start Ns Cm \&.. Ns Ar end 1419Selects all words from 1420.Ar start 1421to 1422.Ar end , 1423inclusive. 1424For example, 1425.Ql Cm \&:[2..-1] 1426selects all words from the second word to the last word. 1427If 1428.Ar start 1429is greater than 1430.Ar end , 1431then the words are output in reverse order. 1432For example, 1433.Ql Cm \&:[-1..1] 1434selects all the words from last to first. 1435.\" :[*] 1436.It Cm \&* 1437Causes subsequent modifiers to treat the value as a single word 1438(possibly containing embedded white space). 1439Analogous to the effect of 1440\&"$*\&" 1441in Bourne shell. 1442.\" :[0] 1443.It 0 1444Means the same as 1445.Ql Cm \&:[*] . 1446.\" :[*] 1447.It Cm \&@ 1448Causes subsequent modifiers to treat the value as a sequence of words 1449delimited by white space. 1450Analogous to the effect of 1451\&"$@\&" 1452in Bourne shell. 1453.\" :[#] 1454.It Cm \&# 1455Returns the number of words in the value. 1456.El \" :[range] 1457.El 1458.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1459Makefile inclusion, conditional structures and for loops reminiscent 1460of the C programming language are provided in 1461.Nm . 1462All such structures are identified by a line beginning with a single 1463dot 1464.Pq Ql \&. 1465character. 1466Files are included with either 1467.Cm \&.include Aq Ar file 1468or 1469.Cm \&.include Pf \*q Ar file Ns \*q . 1470Variables between the angle brackets or double quotes are expanded 1471to form the file name. 1472If angle brackets are used, the included makefile is expected to be in 1473the system makefile directory. 1474If double quotes are used, the including makefile's directory and any 1475directories specified using the 1476.Fl I 1477option are searched before the system 1478makefile directory. 1479For compatibility with other versions of 1480.Nm 1481.Ql include file ... 1482is also accepted. 1483If the include statement is written as 1484.Cm .-include 1485or as 1486.Cm .sinclude 1487then errors locating and/or opening include files are ignored. 1488.Pp 1489Conditional expressions are also preceded by a single dot as the first 1490character of a line. 1491The possible conditionals are as follows: 1492.Bl -tag -width Ds 1493.It Ic .error Ar message 1494The message is printed along with the name of the makefile and line number, 1495then 1496.Nm 1497will exit. 1498.It Ic .export Ar variable ... 1499Export the specified global variable. 1500If no variable list is provided, all globals are exported 1501except for internal variables (those that start with 1502.Ql \&. ) . 1503This is not affected by the 1504.Fl X 1505flag, so should be used with caution. 1506For compatibility with other 1507.Nm 1508programs 1509.Ql export variable=value 1510is also accepted. 1511.Pp 1512Appending a variable name to 1513.Va .MAKE.EXPORTED 1514is equivalent to exporting a variable. 1515.It Ic .export-env Ar variable ... 1516The same as 1517.Ql .export , 1518except that the variable is not appended to 1519.Va .MAKE.EXPORTED . 1520This allows exporting a value to the environment which is different from that 1521used by 1522.Nm 1523internally. 1524.It Ic .info Ar message 1525The message is printed along with the name of the makefile and line number. 1526.It Ic .undef Ar variable 1527Un-define the specified global variable. 1528Only global variables may be un-defined. 1529.It Ic .unexport Ar variable ... 1530The opposite of 1531.Ql .export . 1532The specified global 1533.Va variable 1534will be removed from 1535.Va .MAKE.EXPORTED . 1536If no variable list is provided, all globals are unexported, 1537and 1538.Va .MAKE.EXPORTED 1539deleted. 1540.It Ic .unexport-env 1541Unexport all globals previously exported and 1542clear the environment inherited from the parent. 1543This operation will cause a memory leak of the original environment, 1544so should be used sparingly. 1545Testing for 1546.Va .MAKE.LEVEL 1547being 0, would make sense. 1548Also note that any variables which originated in the parent environment 1549should be explicitly preserved if desired. 1550For example: 1551.Bd -literal -offset indent 1552.Li .if ${.MAKE.LEVEL} == 0 1553PATH := ${PATH} 1554.Li .unexport-env 1555.Li .export PATH 1556.Li .endif 1557.Pp 1558.Ed 1559Would result in an environment containing only 1560.Ql Ev PATH , 1561which is the minimal useful environment. 1562Actually 1563.Ql Ev .MAKE.LEVEL 1564will also be pushed into the new environment. 1565.It Ic .warning Ar message 1566The message prefixed by 1567.Ql Pa warning: 1568is printed along with the name of the makefile and line number. 1569.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1570Test the value of an expression. 1571.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1572Test the value of a variable. 1573.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1574Test the value of a variable. 1575.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1576Test the target being built. 1577.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1578Test the target being built. 1579.It Ic .else 1580Reverse the sense of the last conditional. 1581.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1582A combination of 1583.Ql Ic .else 1584followed by 1585.Ql Ic .if . 1586.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1587A combination of 1588.Ql Ic .else 1589followed by 1590.Ql Ic .ifdef . 1591.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1592A combination of 1593.Ql Ic .else 1594followed by 1595.Ql Ic .ifndef . 1596.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1597A combination of 1598.Ql Ic .else 1599followed by 1600.Ql Ic .ifmake . 1601.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1602A combination of 1603.Ql Ic .else 1604followed by 1605.Ql Ic .ifnmake . 1606.It Ic .endif 1607End the body of the conditional. 1608.El 1609.Pp 1610The 1611.Ar operator 1612may be any one of the following: 1613.Bl -tag -width "Cm XX" 1614.It Cm \&|\&| 1615Logical OR. 1616.It Cm \&\*[Am]\*[Am] 1617Logical 1618.Tn AND ; 1619of higher precedence than 1620.Dq \&|\&| . 1621.El 1622.Pp 1623As in C, 1624.Nm 1625will only evaluate a conditional as far as is necessary to determine 1626its value. 1627Parentheses may be used to change the order of evaluation. 1628The boolean operator 1629.Ql Ic \&! 1630may be used to logically negate an entire 1631conditional. 1632It is of higher precedence than 1633.Ql Ic \&\*[Am]\*[Am] . 1634.Pp 1635The value of 1636.Ar expression 1637may be any of the following: 1638.Bl -tag -width defined 1639.It Ic defined 1640Takes a variable name as an argument and evaluates to true if the variable 1641has been defined. 1642.It Ic make 1643Takes a target name as an argument and evaluates to true if the target 1644was specified as part of 1645.Nm Ns 's 1646command line or was declared the default target (either implicitly or 1647explicitly, see 1648.Va .MAIN ) 1649before the line containing the conditional. 1650.It Ic empty 1651Takes a variable, with possible modifiers, and evaluates to true if 1652the expansion of the variable would result in an empty string. 1653.It Ic exists 1654Takes a file name as an argument and evaluates to true if the file exists. 1655The file is searched for on the system search path (see 1656.Va .PATH ) . 1657.It Ic target 1658Takes a target name as an argument and evaluates to true if the target 1659has been defined. 1660.It Ic commands 1661Takes a target name as an argument and evaluates to true if the target 1662has been defined and has commands associated with it. 1663.El 1664.Pp 1665.Ar Expression 1666may also be an arithmetic or string comparison. 1667Variable expansion is 1668performed on both sides of the comparison, after which the integral 1669values are compared. 1670A value is interpreted as hexadecimal if it is 1671preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1672The standard C relational operators are all supported. 1673If after 1674variable expansion, either the left or right hand side of a 1675.Ql Ic == 1676or 1677.Ql Ic "!=" 1678operator is not an integral value, then 1679string comparison is performed between the expanded 1680variables. 1681If no relational operator is given, it is assumed that the expanded 1682variable is being compared against 0 or an empty string in the case 1683of a string comparison. 1684.Pp 1685When 1686.Nm 1687is evaluating one of these conditional expressions, and it encounters 1688a (white-space separated) word it doesn't recognize, either the 1689.Dq make 1690or 1691.Dq defined 1692expression is applied to it, depending on the form of the conditional. 1693If the form is 1694.Ql Ic .ifdef , 1695.Ql Ic .ifndef , 1696or 1697.Ql Ic .if 1698the 1699.Dq defined 1700expression is applied. 1701Similarly, if the form is 1702.Ql Ic .ifmake 1703or 1704.Ql Ic .ifnmake , the 1705.Dq make 1706expression is applied. 1707.Pp 1708If the conditional evaluates to true the parsing of the makefile continues 1709as before. 1710If it evaluates to false, the following lines are skipped. 1711In both cases this continues until a 1712.Ql Ic .else 1713or 1714.Ql Ic .endif 1715is found. 1716.Pp 1717For loops are typically used to apply a set of rules to a list of files. 1718The syntax of a for loop is: 1719.Pp 1720.Bl -tag -compact -width Ds 1721.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1722.It Aq make-rules 1723.It Ic \&.endfor 1724.El 1725.Pp 1726After the for 1727.Ic expression 1728is evaluated, it is split into words. 1729On each iteration of the loop, one word is taken and assigned to each 1730.Ic variable , 1731in order, and these 1732.Ic variables 1733are substituted into the 1734.Ic make-rules 1735inside the body of the for loop. 1736The number of words must come out even; that is, if there are three 1737iteration variables, the number of words provided must be a multiple 1738of three. 1739.Sh COMMENTS 1740Comments begin with a hash 1741.Pq Ql \&# 1742character, anywhere but in a shell 1743command line, and continue to the end of an unescaped new line. 1744.Sh SPECIAL SOURCES (ATTRIBUTES) 1745.Bl -tag -width .IGNOREx 1746.It Ic .EXEC 1747Target is never out of date, but always execute commands anyway. 1748.It Ic .IGNORE 1749Ignore any errors from the commands associated with this target, exactly 1750as if they all were preceded by a dash 1751.Pq Ql \- . 1752.\" .It Ic .INVISIBLE 1753.\" XXX 1754.\" .It Ic .JOIN 1755.\" XXX 1756.It Ic .MADE 1757Mark all sources of this target as being up-to-date. 1758.It Ic .MAKE 1759Execute the commands associated with this target even if the 1760.Fl n 1761or 1762.Fl t 1763options were specified. 1764Normally used to mark recursive 1765.Nm Ns 's . 1766.It Ic .META 1767Create a meta file for the target, even if it is flagged as 1768.Ic .PHONY , 1769.Ic .MAKE , 1770or 1771.Ic .SPECIAL . 1772Usage in conjunction with 1773.Ic .MAKE 1774is the most likely case. 1775In "meta" mode, the target is out-of-date if the meta file is missing. 1776.It Ic .NOMETA 1777Do not create a meta file for the target. 1778Meta files are also not created for 1779.Ic .PHONY , 1780.Ic .MAKE , 1781or 1782.Ic .SPECIAL 1783targets. 1784.It Ic .NOMETA_CMP 1785Ignore differences in commands when deciding if target is out of date. 1786This is useful if the command contains a value which always changes. 1787If the number of commands change, though, the target will still be out of date. 1788The same effect applies to any command line that uses the variable 1789.Va .OODATE , 1790which can be used for that purpose even when not otherwise needed or desired: 1791.Bd -literal -offset indent 1792 1793skip-compare-for-some: 1794 @echo this will be compared 1795 @echo this will not ${.OODATE:M.NOMETA_CMP} 1796 @echo this will also be compared 1797 1798.Ed 1799The 1800.Cm \&:M 1801pattern suppresses any expansion of the unwanted variable. 1802.It Ic .NOPATH 1803Do not search for the target in the directories specified by 1804.Ic .PATH . 1805.It Ic .NOTMAIN 1806Normally 1807.Nm 1808selects the first target it encounters as the default target to be built 1809if no target was specified. 1810This source prevents this target from being selected. 1811.It Ic .OPTIONAL 1812If a target is marked with this attribute and 1813.Nm 1814can't figure out how to create it, it will ignore this fact and assume 1815the file isn't needed or already exists. 1816.It Ic .PHONY 1817The target does not 1818correspond to an actual file; it is always considered to be out of date, 1819and will not be created with the 1820.Fl t 1821option. 1822Suffix-transformation rules are not applied to 1823.Ic .PHONY 1824targets. 1825.It Ic .PRECIOUS 1826When 1827.Nm 1828is interrupted, it normally removes any partially made targets. 1829This source prevents the target from being removed. 1830.It Ic .RECURSIVE 1831Synonym for 1832.Ic .MAKE . 1833.It Ic .SILENT 1834Do not echo any of the commands associated with this target, exactly 1835as if they all were preceded by an at sign 1836.Pq Ql @ . 1837.It Ic .USE 1838Turn the target into 1839.Nm Ns 's 1840version of a macro. 1841When the target is used as a source for another target, the other target 1842acquires the commands, sources, and attributes (except for 1843.Ic .USE ) 1844of the 1845source. 1846If the target already has commands, the 1847.Ic .USE 1848target's commands are appended 1849to them. 1850.It Ic .USEBEFORE 1851Exactly like 1852.Ic .USE , 1853but prepend the 1854.Ic .USEBEFORE 1855target commands to the target. 1856.It Ic .WAIT 1857If 1858.Ic .WAIT 1859appears in a dependency line, the sources that precede it are 1860made before the sources that succeed it in the line. 1861Since the dependents of files are not made until the file itself 1862could be made, this also stops the dependents being built unless they 1863are needed for another branch of the dependency tree. 1864So given: 1865.Bd -literal 1866x: a .WAIT b 1867 echo x 1868a: 1869 echo a 1870b: b1 1871 echo b 1872b1: 1873 echo b1 1874 1875.Ed 1876the output is always 1877.Ql a , 1878.Ql b1 , 1879.Ql b , 1880.Ql x . 1881.br 1882The ordering imposed by 1883.Ic .WAIT 1884is only relevant for parallel makes. 1885.El 1886.Sh SPECIAL TARGETS 1887Special targets may not be included with other targets, i.e. they must be 1888the only target specified. 1889.Bl -tag -width .BEGINx 1890.It Ic .BEGIN 1891Any command lines attached to this target are executed before anything 1892else is done. 1893.It Ic .DEFAULT 1894This is sort of a 1895.Ic .USE 1896rule for any target (that was used only as a 1897source) that 1898.Nm 1899can't figure out any other way to create. 1900Only the shell script is used. 1901The 1902.Ic .IMPSRC 1903variable of a target that inherits 1904.Ic .DEFAULT Ns 's 1905commands is set 1906to the target's own name. 1907.It Ic .END 1908Any command lines attached to this target are executed after everything 1909else is done. 1910.It Ic .ERROR 1911Any command lines attached to this target are executed when another target fails. 1912The 1913.Ic .ERROR_TARGET 1914variable is set to the target that failed. 1915See also 1916.Ic MAKE_PRINT_VAR_ON_ERROR . 1917.It Ic .IGNORE 1918Mark each of the sources with the 1919.Ic .IGNORE 1920attribute. 1921If no sources are specified, this is the equivalent of specifying the 1922.Fl i 1923option. 1924.It Ic .INTERRUPT 1925If 1926.Nm 1927is interrupted, the commands for this target will be executed. 1928.It Ic .MAIN 1929If no target is specified when 1930.Nm 1931is invoked, this target will be built. 1932.It Ic .MAKEFLAGS 1933This target provides a way to specify flags for 1934.Nm 1935when the makefile is used. 1936The flags are as if typed to the shell, though the 1937.Fl f 1938option will have 1939no effect. 1940.\" XXX: NOT YET!!!! 1941.\" .It Ic .NOTPARALLEL 1942.\" The named targets are executed in non parallel mode. 1943.\" If no targets are 1944.\" specified, then all targets are executed in non parallel mode. 1945.It Ic .NOPATH 1946Apply the 1947.Ic .NOPATH 1948attribute to any specified sources. 1949.It Ic .NOTPARALLEL 1950Disable parallel mode. 1951.It Ic .NO_PARALLEL 1952Synonym for 1953.Ic .NOTPARALLEL , 1954for compatibility with other pmake variants. 1955.It Ic .ORDER 1956The named targets are made in sequence. 1957This ordering does not add targets to the list of targets to be made. 1958Since the dependents of a target do not get built until the target itself 1959could be built, unless 1960.Ql a 1961is built by another part of the dependency graph, 1962the following is a dependency loop: 1963.Bd -literal 1964\&.ORDER: b a 1965b: a 1966.Ed 1967.Pp 1968The ordering imposed by 1969.Ic .ORDER 1970is only relevant for parallel makes. 1971.\" XXX: NOT YET!!!! 1972.\" .It Ic .PARALLEL 1973.\" The named targets are executed in parallel mode. 1974.\" If no targets are 1975.\" specified, then all targets are executed in parallel mode. 1976.It Ic .PATH 1977The sources are directories which are to be searched for files not 1978found in the current directory. 1979If no sources are specified, any previously specified directories are 1980deleted. 1981If the source is the special 1982.Ic .DOTLAST 1983target, then the current working 1984directory is searched last. 1985.It Ic .PATH. Ns Va suffix 1986Like 1987.Ic .PATH 1988but applies only to files with a particular suffix. 1989The suffix must have been previously declared with 1990.Ic .SUFFIXES . 1991.It Ic .PHONY 1992Apply the 1993.Ic .PHONY 1994attribute to any specified sources. 1995.It Ic .PRECIOUS 1996Apply the 1997.Ic .PRECIOUS 1998attribute to any specified sources. 1999If no sources are specified, the 2000.Ic .PRECIOUS 2001attribute is applied to every 2002target in the file. 2003.It Ic .SHELL 2004Sets the shell that 2005.Nm 2006will use to execute commands. 2007The sources are a set of 2008.Ar field=value 2009pairs. 2010.Bl -tag -width hasErrCtls 2011.It Ar name 2012This is the minimal specification, used to select one of the builtin 2013shell specs; 2014.Ar sh , 2015.Ar ksh , 2016and 2017.Ar csh . 2018.It Ar path 2019Specifies the path to the shell. 2020.It Ar hasErrCtl 2021Indicates whether the shell supports exit on error. 2022.It Ar check 2023The command to turn on error checking. 2024.It Ar ignore 2025The command to disable error checking. 2026.It Ar echo 2027The command to turn on echoing of commands executed. 2028.It Ar quiet 2029The command to turn off echoing of commands executed. 2030.It Ar filter 2031The output to filter after issuing the 2032.Ar quiet 2033command. 2034It is typically identical to 2035.Ar quiet . 2036.It Ar errFlag 2037The flag to pass the shell to enable error checking. 2038.It Ar echoFlag 2039The flag to pass the shell to enable command echoing. 2040.It Ar newline 2041The string literal to pass the shell that results in a single newline 2042character when used outside of any quoting characters. 2043.El 2044Example: 2045.Bd -literal 2046\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2047 check="set \-e" ignore="set +e" \e 2048 echo="set \-v" quiet="set +v" filter="set +v" \e 2049 echoFlag=v errFlag=e newline="'\en'" 2050.Ed 2051.It Ic .SILENT 2052Apply the 2053.Ic .SILENT 2054attribute to any specified sources. 2055If no sources are specified, the 2056.Ic .SILENT 2057attribute is applied to every 2058command in the file. 2059.It Ic .STALE 2060This target gets run when a dependency file contains stale entries, having 2061.Va .ALLSRC 2062set to the name of that dependency file. 2063.It Ic .SUFFIXES 2064Each source specifies a suffix to 2065.Nm . 2066If no sources are specified, any previously specified suffixes are deleted. 2067It allows the creation of suffix-transformation rules. 2068.Pp 2069Example: 2070.Bd -literal 2071\&.SUFFIXES: .o 2072\&.c.o: 2073 cc \-o ${.TARGET} \-c ${.IMPSRC} 2074.Ed 2075.El 2076.Sh ENVIRONMENT 2077.Nm 2078uses the following environment variables, if they exist: 2079.Ev MACHINE , 2080.Ev MACHINE_ARCH , 2081.Ev MAKE , 2082.Ev MAKEFLAGS , 2083.Ev MAKEOBJDIR , 2084.Ev MAKEOBJDIRPREFIX , 2085.Ev MAKESYSPATH , 2086.Ev PWD , 2087and 2088.Ev TMPDIR . 2089.Pp 2090.Ev MAKEOBJDIRPREFIX 2091and 2092.Ev MAKEOBJDIR 2093may only be set in the environment or on the command line to 2094.Nm 2095and not as makefile variables; 2096see the description of 2097.Ql Va .OBJDIR 2098for more details. 2099.Sh FILES 2100.Bl -tag -width /usr/share/mk -compact 2101.It .depend 2102list of dependencies 2103.It Makefile 2104list of dependencies 2105.It makefile 2106list of dependencies 2107.It sys.mk 2108system makefile 2109.It /usr/share/mk 2110system makefile directory 2111.El 2112.Sh COMPATIBILITY 2113The basic make syntax is compatible between different versions of make, 2114however the special variables, variable modifiers and conditionals are not. 2115.Pp 2116The way that parallel makes are scheduled changed in 2117.Nx 4.0 2118so that .ORDER and .WAIT apply recursively to the dependent nodes. 2119The algorithms used may change again in the future. 2120.Pp 2121The way that .for loop variables are substituted changed after 2122.Nx 5.0 2123so that they still appear to be variable expansions. 2124In particular this stops them being treated as syntax, and removes some 2125obscure problems using them in .if statements. 2126.Sh SEE ALSO 2127.Xr mkdep 1 2128.Sh HISTORY 2129A 2130.Nm 2131command appeared in 2132.At v7 . 2133This 2134.Nm 2135implementation is based on Adam De Boor's pmake program which was written 2136for Sprite at Berkeley. 2137It was designed to be a parallel distributed make running jobs on different 2138machines using a daemon called 2139.Dq customs . 2140.Pp 2141Historically the target/dependency 2142.Dq FRC 2143has been used to FoRCe rebuilding (since the target/dependency 2144does not exist... unless someone creates an 2145.Dq FRC 2146file). 2147.Sh BUGS 2148The 2149.Nm 2150syntax is difficult to parse without actually acting of the data. 2151For instance finding the end of a variable use should involve scanning each 2152the modifiers using the correct terminator for each field. 2153In many places 2154.Nm 2155just counts {} and () in order to find the end of a variable expansion. 2156.Pp 2157There is no way of escaping a space character in a filename. 2158