1.\" $NetBSD: make.1,v 1.229 2014/01/19 10:23:29 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 February 14, 2014 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm bmake 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrstWwX 41.Op Fl C Ar directory 42.Op Fl D Ar variable 43.Op Fl d Ar flags 44.Op Fl f Ar makefile 45.Op Fl I Ar directory 46.Op Fl J Ar private 47.Op Fl j Ar max_jobs 48.Op Fl m Ar directory 49.Op Fl T Ar file 50.Op Fl V Ar variable 51.Op Ar variable=value 52.Op Ar target ... 53.Sh DESCRIPTION 54.Nm 55is a program designed to simplify the maintenance of other programs. 56Its input is a list of specifications as to the files upon which programs 57and other files depend. 58If no 59.Fl f Ar makefile 60makefile option is given, 61.Nm 62will try to open 63.Ql Pa makefile 64then 65.Ql Pa Makefile 66in order to find the specifications. 67If the file 68.Ql Pa .depend 69exists, it is read (see 70.Xr mkdep 1 ) . 71.Pp 72This manual page is intended as a reference document only. 73For a more thorough description of 74.Nm 75and makefiles, please refer to 76.%T "PMake \- A Tutorial" . 77.Pp 78.Nm 79will prepend the contents of the 80.Va MAKEFLAGS 81environment variable to the command line arguments before parsing them. 82.Pp 83The options are as follows: 84.Bl -tag -width Ds 85.It Fl B 86Try to be backwards compatible by executing a single shell per command and 87by executing the commands to make the sources of a dependency line in sequence. 88.It Fl C Ar directory 89Change to 90.Ar directory 91before reading the makefiles or doing anything else. 92If multiple 93.Fl C 94options are specified, each is interpreted relative to the previous one: 95.Fl C Pa / Fl C Pa etc 96is equivalent to 97.Fl C Pa /etc . 98.It Fl D Ar variable 99Define 100.Ar variable 101to be 1, in the global context. 102.It Fl d Ar [-]flags 103Turn on debugging, and specify which portions of 104.Nm 105are to print debugging information. 106Unless the flags are preceded by 107.Ql \- 108they are added to the 109.Va MAKEFLAGS 110environment variable and will be processed by any child make processes. 111By default, debugging information is printed to standard error, 112but this can be changed using the 113.Ar F 114debugging flag. 115The debugging output is always unbuffered; in addition, if debugging 116is enabled but debugging output is not directed to standard output, 117then the standard output is line buffered. 118.Ar Flags 119is one or more of the following: 120.Bl -tag -width Ds 121.It Ar A 122Print all possible debugging information; 123equivalent to specifying all of the debugging flags. 124.It Ar a 125Print debugging information about archive searching and caching. 126.It Ar C 127Print debugging information about current working directory. 128.It Ar c 129Print debugging information about conditional evaluation. 130.It Ar d 131Print debugging information about directory searching and caching. 132.It Ar e 133Print debugging information about failed commands and targets. 134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 135Specify where debugging output is written. 136This must be the last flag, because it consumes the remainder of 137the argument. 138If the character immediately after the 139.Ql F 140flag is 141.Ql \&+ , 142then the file will be opened in append mode; 143otherwise the file will be overwritten. 144If the file name is 145.Ql stdout 146or 147.Ql stderr 148then debugging output will be written to the 149standard output or standard error output file descriptors respectively 150(and the 151.Ql \&+ 152option has no effect). 153Otherwise, the output will be written to the named file. 154If the file name ends 155.Ql .%d 156then the 157.Ql %d 158is replaced by the pid. 159.It Ar f 160Print debugging information about loop evaluation. 161.It Ar "g1" 162Print the input graph before making anything. 163.It Ar "g2" 164Print the input graph after making everything, or before exiting 165on error. 166.It Ar "g3" 167Print the input graph before exiting on error. 168.It Ar j 169Print debugging information about running multiple shells. 170.It Ar l 171Print commands in Makefiles regardless of whether or not they are prefixed by 172.Ql @ 173or other "quiet" flags. 174Also known as "loud" behavior. 175.It Ar M 176Print debugging information about "meta" mode decisions about targets. 177.It Ar m 178Print debugging information about making targets, including modification 179dates. 180.It Ar n 181Don't delete the temporary command scripts created when running commands. 182These temporary scripts are created in the directory 183referred to by the 184.Ev TMPDIR 185environment variable, or in 186.Pa /tmp 187if 188.Ev TMPDIR 189is unset or set to the empty string. 190The temporary scripts are created by 191.Xr mkstemp 3 , 192and have names of the form 193.Pa makeXXXXXX . 194.Em NOTE : 195This can create many files in 196.Ev TMPDIR 197or 198.Pa /tmp , 199so use with care. 200.It Ar p 201Print debugging information about makefile parsing. 202.It Ar s 203Print debugging information about suffix-transformation rules. 204.It Ar t 205Print debugging information about target list maintenance. 206.It Ar V 207Force the 208.Fl V 209option to print raw values of variables. 210.It Ar v 211Print debugging information about variable assignment. 212.It Ar w 213Print entering and leaving directory messages, pre and post processing. 214.It Ar x 215Run shell commands with 216.Fl x 217so the actual commands are printed as they are executed. 218.El 219.It Fl e 220Specify that environment variables override macro assignments within 221makefiles. 222.It Fl f Ar makefile 223Specify a makefile to read instead of the default 224.Ql Pa makefile . 225If 226.Ar makefile 227is 228.Ql Fl , 229standard input is read. 230Multiple makefiles may be specified, and are read in the order specified. 231.It Fl I Ar directory 232Specify a directory in which to search for makefiles and included makefiles. 233The system makefile directory (or directories, see the 234.Fl m 235option) is automatically included as part of this list. 236.It Fl i 237Ignore non-zero exit of shell commands in the makefile. 238Equivalent to specifying 239.Ql Fl 240before each command line in the makefile. 241.It Fl J Ar private 242This option should 243.Em not 244be specified by the user. 245.Pp 246When the 247.Ar j 248option is in use in a recursive build, this option is passed by a make 249to child makes to allow all the make processes in the build to 250cooperate to avoid overloading the system. 251.It Fl j Ar max_jobs 252Specify the maximum number of jobs that 253.Nm 254may have running at any one time. 255The value is saved in 256.Va .MAKE.JOBS . 257Turns compatibility mode off, unless the 258.Ar B 259flag is also specified. 260When compatibility mode is off, all commands associated with a 261target are executed in a single shell invocation as opposed to the 262traditional one shell invocation per line. 263This can break traditional scripts which change directories on each 264command invocation and then expect to start with a fresh environment 265on the next line. 266It is more efficient to correct the scripts rather than turn backwards 267compatibility on. 268.It Fl k 269Continue processing after errors are encountered, but only on those targets 270that do not depend on the target whose creation caused the error. 271.It Fl m Ar directory 272Specify a directory in which to search for sys.mk and makefiles included 273via the 274.Ao Ar file Ac Ns -style 275include statement. 276The 277.Fl m 278option can be used multiple times to form a search path. 279This path will override the default system include path: /usr/share/mk. 280Furthermore the system include path will be appended to the search path used 281for 282.Qo Ar file Qc Ns -style 283include statements (see the 284.Fl I 285option). 286.Pp 287If a file or directory name in the 288.Fl m 289argument (or the 290.Ev MAKESYSPATH 291environment variable) starts with the string 292.Qq \&.../ 293then 294.Nm 295will search for the specified file or directory named in the remaining part 296of the argument string. 297The search starts with the current directory of 298the Makefile and then works upward towards the root of the filesystem. 299If the search is successful, then the resulting directory replaces the 300.Qq \&.../ 301specification in the 302.Fl m 303argument. 304If used, this feature allows 305.Nm 306to easily search in the current source tree for customized sys.mk files 307(e.g., by using 308.Qq \&.../mk/sys.mk 309as an argument). 310.It Fl n 311Display the commands that would have been executed, but do not 312actually execute them unless the target depends on the .MAKE special 313source (see below). 314.It Fl N 315Display the commands which would have been executed, but do not 316actually execute any of them; useful for debugging top-level makefiles 317without descending into subdirectories. 318.It Fl q 319Do not execute any commands, but exit 0 if the specified targets are 320up-to-date and 1, otherwise. 321.It Fl r 322Do not use the built-in rules specified in the system makefile. 323.It Fl s 324Do not echo any commands as they are executed. 325Equivalent to specifying 326.Ql Ic @ 327before each command line in the makefile. 328.It Fl T Ar tracefile 329When used with the 330.Fl j 331flag, 332append a trace record to 333.Ar tracefile 334for each job started and completed. 335.It Fl t 336Rather than re-building a target as specified in the makefile, create it 337or update its modification time to make it appear up-to-date. 338.It Fl V Ar variable 339Print 340.Nm Ns 's 341idea of the value of 342.Ar variable , 343in the global context. 344Do not build any targets. 345Multiple instances of this option may be specified; 346the variables will be printed one per line, 347with a blank line for each null or undefined variable. 348If 349.Ar variable 350contains a 351.Ql \&$ 352then the value will be expanded before printing. 353.It Fl W 354Treat any warnings during makefile parsing as errors. 355.It Fl X 356Don't export variables passed on the command line to the environment 357individually. 358Variables passed on the command line are still exported 359via the 360.Va MAKEFLAGS 361environment variable. 362This option may be useful on systems which have a small limit on the 363size of command arguments. 364.It Ar variable=value 365Set the value of the variable 366.Ar variable 367to 368.Ar value . 369Normally, all values passed on the command line are also exported to 370sub-makes in the environment. 371The 372.Fl X 373flag disables this behavior. 374Variable assignments should follow options for POSIX compatibility 375but no ordering is enforced. 376.El 377.Pp 378There are seven different types of lines in a makefile: file dependency 379specifications, shell commands, variable assignments, include statements, 380conditional directives, for loops, and comments. 381.Pp 382In general, lines may be continued from one line to the next by ending 383them with a backslash 384.Pq Ql \e . 385The trailing newline character and initial whitespace on the following 386line are compressed into a single space. 387.Sh FILE DEPENDENCY SPECIFICATIONS 388Dependency lines consist of one or more targets, an operator, and zero 389or more sources. 390This creates a relationship where the targets 391.Dq depend 392on the sources 393and are usually created from them. 394The exact relationship between the target and the source is determined 395by the operator that separates them. 396The three operators are as follows: 397.Bl -tag -width flag 398.It Ic \&: 399A target is considered out-of-date if its modification time is less than 400those of any of its sources. 401Sources for a target accumulate over dependency lines when this operator 402is used. 403The target is removed if 404.Nm 405is interrupted. 406.It Ic \&! 407Targets are always re-created, but not until all sources have been 408examined and re-created as necessary. 409Sources for a target accumulate over dependency lines when this operator 410is used. 411The target is removed if 412.Nm 413is interrupted. 414.It Ic \&:: 415If no sources are specified, the target is always re-created. 416Otherwise, a target is considered out-of-date if any of its sources has 417been modified more recently than the target. 418Sources for a target do not accumulate over dependency lines when this 419operator is used. 420The target will not be removed if 421.Nm 422is interrupted. 423.El 424.Pp 425Targets and sources may contain the shell wildcard values 426.Ql \&? , 427.Ql * , 428.Ql [] , 429and 430.Ql {} . 431The values 432.Ql \&? , 433.Ql * , 434and 435.Ql [] 436may only be used as part of the final 437component of the target or source, and must be used to describe existing 438files. 439The value 440.Ql {} 441need not necessarily be used to describe existing files. 442Expansion is in directory order, not alphabetically as done in the shell. 443.Sh SHELL COMMANDS 444Each target may have associated with it a series of shell commands, normally 445used to create the target. 446Each of the commands in this script 447.Em must 448be preceded by a tab. 449While any target may appear on a dependency line, only one of these 450dependencies may be followed by a creation script, unless the 451.Ql Ic \&:: 452operator is used. 453.Pp 454If the first characters of the command line are any combination of 455.Ql Ic @ , 456.Ql Ic + , 457or 458.Ql Ic \- , 459the command is treated specially. 460A 461.Ql Ic @ 462causes the command not to be echoed before it is executed. 463A 464.Ql Ic + 465causes the command to be executed even when 466.Fl n 467is given. 468This is similar to the effect of the .MAKE special source, 469except that the effect can be limited to a single line of a script. 470A 471.Ql Ic \- 472causes any non-zero exit status of the command line to be ignored. 473.Pp 474When 475.Nm 476is run in jobs mode with 477.Fl j Ar max_jobs , 478the entire script for the target is fed to a 479single instance of the shell. 480.Pp 481In compatibility (non-jobs) mode, each command is run in a separate process. 482If the command contains any shell meta characters 483.Pq Ql #=|^(){};&<>*?[]:$`\e\en 484it will be passed to the shell, otherwise 485.Nm 486will attempt direct execution. 487.Pp 488Since 489.Nm 490will 491.Xr chdir 2 492to 493.Ql Va .OBJDIR 494before executing any targets, each child process 495starts with that as its current working directory. 496.Pp 497Makefiles should be written so that the mode of 498.Nm 499operation does not change their behavior. 500For example, any command which needs to use 501.Dq cd 502or 503.Dq chdir , 504without side-effect should be put in parenthesis: 505.Bd -literal -offset indent 506 507avoid-chdir-side-effects: 508 @echo Building $@ in `pwd` 509 @(cd ${.CURDIR} && ${.MAKE} $@) 510 @echo Back in `pwd` 511 512ensure-one-shell-regardless-of-mode: 513 @echo Building $@ in `pwd`; \\ 514 (cd ${.CURDIR} && ${.MAKE} $@); \\ 515 echo Back in `pwd` 516.Ed 517.Sh VARIABLE ASSIGNMENTS 518Variables in make are much like variables in the shell, and, by tradition, 519consist of all upper-case letters. 520.Ss Variable assignment modifiers 521The five operators that can be used to assign values to variables are as 522follows: 523.Bl -tag -width Ds 524.It Ic \&= 525Assign the value to the variable. 526Any previous value is overridden. 527.It Ic \&+= 528Append the value to the current value of the variable. 529.It Ic \&?= 530Assign the value to the variable if it is not already defined. 531.It Ic \&:= 532Assign with expansion, i.e. expand the value before assigning it 533to the variable. 534Normally, expansion is not done until the variable is referenced. 535.Em NOTE : 536References to undefined variables are 537.Em not 538expanded. 539This can cause problems when variable modifiers are used. 540.It Ic \&!= 541Expand the value and pass it to the shell for execution and assign 542the result to the variable. 543Any newlines in the result are replaced with spaces. 544.El 545.Pp 546Any white-space before the assigned 547.Ar value 548is removed; if the value is being appended, a single space is inserted 549between the previous contents of the variable and the appended value. 550.Pp 551Variables are expanded by surrounding the variable name with either 552curly braces 553.Pq Ql {} 554or parentheses 555.Pq Ql () 556and preceding it with 557a dollar sign 558.Pq Ql \&$ . 559If the variable name contains only a single letter, the surrounding 560braces or parentheses are not required. 561This shorter form is not recommended. 562.Pp 563If the variable name contains a dollar, then the name itself is expanded first. 564This allows almost arbitrary variable names, however names containing dollar, 565braces, parenthesis, or whitespace are really best avoided! 566.Pp 567If the result of expanding a variable contains a dollar sign 568.Pq Ql \&$ 569the string is expanded again. 570.Pp 571Variable substitution occurs at three distinct times, depending on where 572the variable is being used. 573.Bl -enum 574.It 575Variables in dependency lines are expanded as the line is read. 576.It 577Variables in shell commands are expanded when the shell command is 578executed. 579.It 580.Dq .for 581loop index variables are expanded on each loop iteration. 582Note that other variables are not expanded inside loops so 583the following example code: 584.Bd -literal -offset indent 585 586.Dv .for i in 1 2 3 587a+= ${i} 588j= ${i} 589b+= ${j} 590.Dv .endfor 591 592all: 593 @echo ${a} 594 @echo ${b} 595 596.Ed 597will print: 598.Bd -literal -offset indent 5991 2 3 6003 3 3 601 602.Ed 603Because while ${a} contains 604.Dq 1 2 3 605after the loop is executed, ${b} 606contains 607.Dq ${j} ${j} ${j} 608which expands to 609.Dq 3 3 3 610since after the loop completes ${j} contains 611.Dq 3 . 612.El 613.Ss Variable classes 614The four different classes of variables (in order of increasing precedence) 615are: 616.Bl -tag -width Ds 617.It Environment variables 618Variables defined as part of 619.Nm Ns 's 620environment. 621.It Global variables 622Variables defined in the makefile or in included makefiles. 623.It Command line variables 624Variables defined as part of the command line. 625.It Local variables 626Variables that are defined specific to a certain target. 627The seven local variables are as follows: 628.Bl -tag -width ".ARCHIVE" 629.It Va .ALLSRC 630The list of all sources for this target; also known as 631.Ql Va \&\*[Gt] . 632.It Va .ARCHIVE 633The name of the archive file. 634.It Va .IMPSRC 635In suffix-transformation rules, the name/path of the source from which the 636target is to be transformed (the 637.Dq implied 638source); also known as 639.Ql Va \&\*[Lt] . 640It is not defined in explicit rules. 641.It Va .MEMBER 642The name of the archive member. 643.It Va .OODATE 644The list of sources for this target that were deemed out-of-date; also 645known as 646.Ql Va \&? . 647.It Va .PREFIX 648The file prefix of the target, containing only the file portion, no suffix 649or preceding directory components; also known as 650.Ql Va * . 651.It Va .TARGET 652The name of the target; also known as 653.Ql Va @ . 654.El 655.Pp 656The shorter forms 657.Ql Va @ , 658.Ql Va \&? , 659.Ql Va \&\*[Lt] , 660.Ql Va \&\*[Gt] , 661and 662.Ql Va * 663are permitted for backward 664compatibility with historical makefiles and are not recommended. 665The six variables 666.Ql Va "@F" , 667.Ql Va "@D" , 668.Ql Va "\*[Lt]F" , 669.Ql Va "\*[Lt]D" , 670.Ql Va "*F" , 671and 672.Ql Va "*D" 673are permitted for compatibility with 674.At V 675makefiles and are not recommended. 676.Pp 677Four of the local variables may be used in sources on dependency lines 678because they expand to the proper value for each target on the line. 679These variables are 680.Ql Va .TARGET , 681.Ql Va .PREFIX , 682.Ql Va .ARCHIVE , 683and 684.Ql Va .MEMBER . 685.El 686.Ss Additional built-in variables 687In addition, 688.Nm 689sets or knows about the following variables: 690.Bl -tag -width .MAKEOVERRIDES 691.It Va \&$ 692A single dollar sign 693.Ql \&$ , 694i.e. 695.Ql \&$$ 696expands to a single dollar 697sign. 698.It Va .ALLTARGETS 699The list of all targets encountered in the Makefile. 700If evaluated during 701Makefile parsing, lists only those targets encountered thus far. 702.It Va .CURDIR 703A path to the directory where 704.Nm 705was executed. 706Refer to the description of 707.Ql Ev PWD 708for more details. 709.It Va .INCLUDEDFROMDIR 710The directory of the file this Makefile was included from. 711.It Va .INCLUDEDFROMFILE 712The filename of the file this Makefile was included from. 713.It Ev MAKE 714The name that 715.Nm 716was executed with 717.Pq Va argv[0] . 718For compatibility 719.Nm 720also sets 721.Va .MAKE 722with the same value. 723The preferred variable to use is the environment variable 724.Ev MAKE 725because it is more compatible with other versions of 726.Nm 727and cannot be confused with the special target with the same name. 728.It Va .MAKE.DEPENDFILE 729Names the makefile (default 730.Ql Pa .depend ) 731from which generated dependencies are read. 732.It Va .MAKE.EXPAND_VARIABLES 733A boolean that controls the default behavior of the 734.Fl V 735option. 736.It Va .MAKE.EXPORTED 737The list of variables exported by 738.Nm . 739.It Va .MAKE.JOBS 740The argument to the 741.Fl j 742option. 743.It Va .MAKE.JOB.PREFIX 744If 745.Nm 746is run with 747.Ar j 748then output for each target is prefixed with a token 749.Ql --- target --- 750the first part of which can be controlled via 751.Va .MAKE.JOB.PREFIX . 752If 753.Va .MAKE.JOB.PREFIX 754is empty, no token is printed. 755.br 756For example: 757.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 758would produce tokens like 759.Ql ---make[1234] target --- 760making it easier to track the degree of parallelism being achieved. 761.It Ev MAKEFLAGS 762The environment variable 763.Ql Ev MAKEFLAGS 764may contain anything that 765may be specified on 766.Nm Ns 's 767command line. 768Anything specified on 769.Nm Ns 's 770command line is appended to the 771.Ql Ev MAKEFLAGS 772variable which is then 773entered into the environment for all programs which 774.Nm 775executes. 776.It Va .MAKE.LEVEL 777The recursion depth of 778.Nm . 779The initial instance of 780.Nm 781will be 0, and an incremented value is put into the environment 782to be seen by the next generation. 783This allows tests like: 784.Li .if ${.MAKE.LEVEL} == 0 785to protect things which should only be evaluated in the initial instance of 786.Nm . 787.It Va .MAKE.MAKEFILE_PREFERENCE 788The ordered list of makefile names 789(default 790.Ql Pa makefile , 791.Ql Pa Makefile ) 792that 793.Nm 794will look for. 795.It Va .MAKE.MAKEFILES 796The list of makefiles read by 797.Nm , 798which is useful for tracking dependencies. 799Each makefile is recorded only once, regardless of the number of times read. 800.It Va .MAKE.MODE 801Processed after reading all makefiles. 802Can affect the mode that 803.Nm 804runs in. 805It can contain a number of keywords: 806.Bl -hang -width ignore-cmd 807.It Pa compat 808Like 809.Fl B , 810puts 811.Nm 812into "compat" mode. 813.It Pa meta 814Puts 815.Nm 816into "meta" mode, where meta files are created for each target 817to capture the command run, the output generated and if 818.Xr filemon 4 819is available, the system calls which are of interest to 820.Nm . 821The captured output can be very useful when diagnosing errors. 822.It Pa curdirOk= Ar bf 823Normally 824.Nm 825will not create .meta files in 826.Ql Va .CURDIR . 827This can be overridden by setting 828.Va bf 829to a value which represents True. 830.It Pa env 831For debugging, it can be useful to inlcude the environment 832in the .meta file. 833.It Pa verbose 834If in "meta" mode, print a clue about the target being built. 835This is useful if the build is otherwise running silently. 836The message printed the value of: 837.Va .MAKE.META.PREFIX . 838.It Pa ignore-cmd 839Some makefiles have commands which are simply not stable. 840This keyword causes them to be ignored for 841determining whether a target is out of date in "meta" mode. 842See also 843.Ic .NOMETA_CMP . 844.It Pa silent= Ar bf 845If 846.Va bf 847is True, when a .meta file is created, mark the target 848.Ic .SILENT . 849.El 850.It Va .MAKE.META.BAILIWICK 851In "meta" mode, provides a list of prefixes which 852match the directories controlled by 853.Nm . 854If a file that was generated outside of 855.Va .OBJDIR 856but within said bailiwick is missing, 857the current target is considered out-of-date. 858.It Va .MAKE.META.CREATED 859In "meta" mode, this variable contains a list of all the meta files 860updated. 861If not empty, it can be used to trigger processing of 862.Va .MAKE.META.FILES . 863.It Va .MAKE.META.FILES 864In "meta" mode, this variable contains a list of all the meta files 865used (updated or not). 866This list can be used to process the meta files to extract dependency 867information. 868.It Va .MAKE.META.IGNORE_PATHS 869Provides a list of path prefixes that should be ignored; 870because the contents are expected to change over time. 871The default list includes: 872.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 873.It Va .MAKE.META.PREFIX 874Defines the message printed for each meta file updated in "meta verbose" mode. 875The default value is: 876.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 877.It Va .MAKEOVERRIDES 878This variable is used to record the names of variables assigned to 879on the command line, so that they may be exported as part of 880.Ql Ev MAKEFLAGS . 881This behaviour can be disabled by assigning an empty value to 882.Ql Va .MAKEOVERRIDES 883within a makefile. 884Extra variables can be exported from a makefile 885by appending their names to 886.Ql Va .MAKEOVERRIDES . 887.Ql Ev MAKEFLAGS 888is re-exported whenever 889.Ql Va .MAKEOVERRIDES 890is modified. 891.It Va .MAKE.PATH_FILEMON 892If 893.Nm 894was built with 895.Xr filemon 4 896support, this is set to the path of the device node. 897This allows makefiles to test for this support. 898.It Va .MAKE.PID 899The process-id of 900.Nm . 901.It Va .MAKE.PPID 902The parent process-id of 903.Nm . 904.It Va MAKE_PRINT_VAR_ON_ERROR 905When 906.Nm 907stops due to an error, it prints its name and the value of 908.Ql Va .CURDIR 909as well as the value of any variables named in 910.Ql Va MAKE_PRINT_VAR_ON_ERROR . 911.It Va .newline 912This variable is simply assigned a newline character as its value. 913This allows expansions using the 914.Cm \&:@ 915modifier to put a newline between 916iterations of the loop rather than a space. 917For example, the printing of 918.Ql Va MAKE_PRINT_VAR_ON_ERROR 919could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 920.It Va .OBJDIR 921A path to the directory where the targets are built. 922Its value is determined by trying to 923.Xr chdir 2 924to the following directories in order and using the first match: 925.Bl -enum 926.It 927.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 928.Pp 929(Only if 930.Ql Ev MAKEOBJDIRPREFIX 931is set in the environment or on the command line.) 932.It 933.Ev ${MAKEOBJDIR} 934.Pp 935(Only if 936.Ql Ev MAKEOBJDIR 937is set in the environment or on the command line.) 938.It 939.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 940.It 941.Ev ${.CURDIR} Ns Pa /obj 942.It 943.Pa /usr/obj/ Ns Ev ${.CURDIR} 944.It 945.Ev ${.CURDIR} 946.El 947.Pp 948Variable expansion is performed on the value before it's used, 949so expressions such as 950.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 951may be used. 952This is especially useful with 953.Ql Ev MAKEOBJDIR . 954.Pp 955.Ql Va .OBJDIR 956may be modified in the makefile as a global variable. 957In all cases, 958.Nm 959will 960.Xr chdir 2 961to 962.Ql Va .OBJDIR 963and set 964.Ql Ev PWD 965to that directory before executing any targets. 966. 967.It Va .PARSEDIR 968A path to the directory of the current 969.Ql Pa Makefile 970being parsed. 971.It Va .PARSEFILE 972The basename of the current 973.Ql Pa Makefile 974being parsed. 975This variable and 976.Ql Va .PARSEDIR 977are both set only while the 978.Ql Pa Makefiles 979are being parsed. 980If you want to retain their current values, assign them to a variable 981using assignment with expansion: 982.Pq Ql Cm \&:= . 983.It Va .PATH 984A variable that represents the list of directories that 985.Nm 986will search for files. 987The search list should be updated using the target 988.Ql Va .PATH 989rather than the variable. 990.It Ev PWD 991Alternate path to the current directory. 992.Nm 993normally sets 994.Ql Va .CURDIR 995to the canonical path given by 996.Xr getcwd 3 . 997However, if the environment variable 998.Ql Ev PWD 999is set and gives a path to the current directory, then 1000.Nm 1001sets 1002.Ql Va .CURDIR 1003to the value of 1004.Ql Ev PWD 1005instead. 1006This behaviour is disabled if 1007.Ql Ev MAKEOBJDIRPREFIX 1008is set or 1009.Ql Ev MAKEOBJDIR 1010contains a variable transform. 1011.Ql Ev PWD 1012is set to the value of 1013.Ql Va .OBJDIR 1014for all programs which 1015.Nm 1016executes. 1017.It Ev .TARGETS 1018The list of targets explicitly specified on the command line, if any. 1019.It Ev VPATH 1020Colon-separated 1021.Pq Dq \&: 1022lists of directories that 1023.Nm 1024will search for files. 1025The variable is supported for compatibility with old make programs only, 1026use 1027.Ql Va .PATH 1028instead. 1029.El 1030.Ss Variable modifiers 1031Variable expansion may be modified to select or modify each word of the 1032variable (where a 1033.Dq word 1034is white-space delimited sequence of characters). 1035The general format of a variable expansion is as follows: 1036.Pp 1037.Dl ${variable[:modifier[:...]]} 1038.Pp 1039Each modifier begins with a colon, 1040which may be escaped with a backslash 1041.Pq Ql \e . 1042.Pp 1043A set of modifiers can be specified via a variable, as follows: 1044.Pp 1045.Dl modifier_variable=modifier[:...] 1046.Dl ${variable:${modifier_variable}[:...]} 1047.Pp 1048In this case the first modifier in the modifier_variable does not 1049start with a colon, since that must appear in the referencing 1050variable. 1051If any of the modifiers in the modifier_variable contain a dollar sign 1052.Pq Ql $ , 1053these must be doubled to avoid early expansion. 1054.Pp 1055The supported modifiers are: 1056.Bl -tag -width EEE 1057.It Cm \&:E 1058Replaces each word in the variable with its suffix. 1059.It Cm \&:H 1060Replaces each word in the variable with everything but the last component. 1061.It Cm \&:M Ns Ar pattern 1062Select only those words that match 1063.Ar pattern . 1064The standard shell wildcard characters 1065.Pf ( Ql * , 1066.Ql \&? , 1067and 1068.Ql Oo Oc ) 1069may 1070be used. 1071The wildcard characters may be escaped with a backslash 1072.Pq Ql \e . 1073As a consequence of the way values are split into words, matched, 1074and then joined, a construct like 1075.Dl ${VAR:M*} 1076will normalise the inter-word spacing, removing all leading and 1077trailing space, and converting multiple consecutive spaces 1078to single spaces. 1079. 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 an extended 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.Pp 1254As for the 1255.Cm \&:S 1256modifier, the 1257.Ar pattern 1258and 1259.Ar replacement 1260are subjected to variable expansion before being parsed as 1261regular expressions. 1262.It Cm \&:T 1263Replaces each word in the variable with its last component. 1264.It Cm \&:u 1265Remove adjacent duplicate words (like 1266.Xr uniq 1 ) . 1267.Sm off 1268.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1269.Sm on 1270If the variable name (not its value), when parsed as a .if conditional 1271expression, evaluates to true, return as its value the 1272.Ar true_string , 1273otherwise return the 1274.Ar false_string . 1275Since the variable name is used as the expression, \&:\&? must be the 1276first modifier after the variable name itself - which will, of course, 1277usually contain variable expansions. 1278A common error is trying to use expressions like 1279.Dl ${NUMBERS:M42:?match:no} 1280which actually tests defined(NUMBERS), 1281to determine is any words match "42" you need to use something like: 1282.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1283.It Ar :old_string=new_string 1284This is the 1285.At V 1286style variable substitution. 1287It must be the last modifier specified. 1288If 1289.Ar old_string 1290or 1291.Ar new_string 1292do not contain the pattern matching character 1293.Ar % 1294then it is assumed that they are 1295anchored at the end of each word, so only suffixes or entire 1296words may be replaced. 1297Otherwise 1298.Ar % 1299is the substring of 1300.Ar old_string 1301to be replaced in 1302.Ar new_string . 1303.Pp 1304Variable expansion occurs in the normal fashion inside both 1305.Ar old_string 1306and 1307.Ar new_string 1308with the single exception that a backslash is used to prevent the 1309expansion of a dollar sign 1310.Pq Ql \&$ , 1311not a preceding dollar sign as is usual. 1312.Sm off 1313.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1314.Sm on 1315This is the loop expansion mechanism from the OSF Development 1316Environment (ODE) make. 1317Unlike 1318.Cm \&.for 1319loops expansion occurs at the time of 1320reference. 1321Assign 1322.Ar temp 1323to each word in the variable and evaluate 1324.Ar string . 1325The ODE convention is that 1326.Ar temp 1327should start and end with a period. 1328For example. 1329.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1330.Pp 1331However a single character variable is often more readable: 1332.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1333.It Cm \&:U Ns Ar newval 1334If the variable is undefined 1335.Ar newval 1336is the value. 1337If the variable is defined, the existing value is returned. 1338This is another ODE make feature. 1339It is handy for setting per-target CFLAGS for instance: 1340.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1341If a value is only required if the variable is undefined, use: 1342.Dl ${VAR:D:Unewval} 1343.It Cm \&:D Ns Ar newval 1344If the variable is defined 1345.Ar newval 1346is the value. 1347.It Cm \&:L 1348The name of the variable is the value. 1349.It Cm \&:P 1350The path of the node which has the same name as the variable 1351is the value. 1352If no such node exists or its path is null, then the 1353name of the variable is used. 1354In order for this modifier to work, the name (node) must at least have 1355appeared on the rhs of a dependency. 1356.Sm off 1357.It Cm \&:\&! Ar cmd Cm \&! 1358.Sm on 1359The output of running 1360.Ar cmd 1361is the value. 1362.It Cm \&:sh 1363If the variable is non-empty it is run as a command and the output 1364becomes the new value. 1365.It Cm \&::= Ns Ar str 1366The variable is assigned the value 1367.Ar str 1368after substitution. 1369This modifier and its variations are useful in 1370obscure situations such as wanting to set a variable when shell commands 1371are being parsed. 1372These assignment modifiers always expand to 1373nothing, so if appearing in a rule line by themselves should be 1374preceded with something to keep 1375.Nm 1376happy. 1377.Pp 1378The 1379.Ql Cm \&:: 1380helps avoid false matches with the 1381.At V 1382style 1383.Cm \&:= 1384modifier and since substitution always occurs the 1385.Cm \&::= 1386form is vaguely appropriate. 1387.It Cm \&::?= Ns Ar str 1388As for 1389.Cm \&::= 1390but only if the variable does not already have a value. 1391.It Cm \&::+= Ns Ar str 1392Append 1393.Ar str 1394to the variable. 1395.It Cm \&::!= Ns Ar cmd 1396Assign the output of 1397.Ar cmd 1398to the variable. 1399.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1400Selects one or more words from the value, 1401or performs other operations related to the way in which the 1402value is divided into words. 1403.Pp 1404Ordinarily, a value is treated as a sequence of words 1405delimited by white space. 1406Some modifiers suppress this behaviour, 1407causing a value to be treated as a single word 1408(possibly containing embedded white space). 1409An empty value, or a value that consists entirely of white-space, 1410is treated as a single word. 1411For the purposes of the 1412.Ql Cm \&:[] 1413modifier, the words are indexed both forwards using positive integers 1414(where index 1 represents the first word), 1415and backwards using negative integers 1416(where index \-1 represents the last word). 1417.Pp 1418The 1419.Ar range 1420is subjected to variable expansion, and the expanded result is 1421then interpreted as follows: 1422.Bl -tag -width index 1423.\" :[n] 1424.It Ar index 1425Selects a single word from the value. 1426.\" :[start..end] 1427.It Ar start Ns Cm \&.. Ns Ar end 1428Selects all words from 1429.Ar start 1430to 1431.Ar end , 1432inclusive. 1433For example, 1434.Ql Cm \&:[2..-1] 1435selects all words from the second word to the last word. 1436If 1437.Ar start 1438is greater than 1439.Ar end , 1440then the words are output in reverse order. 1441For example, 1442.Ql Cm \&:[-1..1] 1443selects all the words from last to first. 1444.\" :[*] 1445.It Cm \&* 1446Causes subsequent modifiers to treat the value as a single word 1447(possibly containing embedded white space). 1448Analogous to the effect of 1449\&"$*\&" 1450in Bourne shell. 1451.\" :[0] 1452.It 0 1453Means the same as 1454.Ql Cm \&:[*] . 1455.\" :[*] 1456.It Cm \&@ 1457Causes subsequent modifiers to treat the value as a sequence of words 1458delimited by white space. 1459Analogous to the effect of 1460\&"$@\&" 1461in Bourne shell. 1462.\" :[#] 1463.It Cm \&# 1464Returns the number of words in the value. 1465.El \" :[range] 1466.El 1467.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1468Makefile inclusion, conditional structures and for loops reminiscent 1469of the C programming language are provided in 1470.Nm . 1471All such structures are identified by a line beginning with a single 1472dot 1473.Pq Ql \&. 1474character. 1475Files are included with either 1476.Cm \&.include Aq Ar file 1477or 1478.Cm \&.include Pf \*q Ar file Ns \*q . 1479Variables between the angle brackets or double quotes are expanded 1480to form the file name. 1481If angle brackets are used, the included makefile is expected to be in 1482the system makefile directory. 1483If double quotes are used, the including makefile's directory and any 1484directories specified using the 1485.Fl I 1486option are searched before the system 1487makefile directory. 1488For compatibility with other versions of 1489.Nm 1490.Ql include file ... 1491is also accepted. 1492If the include statement is written as 1493.Cm .-include 1494or as 1495.Cm .sinclude 1496then errors locating and/or opening include files are ignored. 1497.Pp 1498Conditional expressions are also preceded by a single dot as the first 1499character of a line. 1500The possible conditionals are as follows: 1501.Bl -tag -width Ds 1502.It Ic .error Ar message 1503The message is printed along with the name of the makefile and line number, 1504then 1505.Nm 1506will exit. 1507.It Ic .export Ar variable ... 1508Export the specified global variable. 1509If no variable list is provided, all globals are exported 1510except for internal variables (those that start with 1511.Ql \&. ) . 1512This is not affected by the 1513.Fl X 1514flag, so should be used with caution. 1515For compatibility with other 1516.Nm 1517programs 1518.Ql export variable=value 1519is also accepted. 1520.Pp 1521Appending a variable name to 1522.Va .MAKE.EXPORTED 1523is equivalent to exporting a variable. 1524.It Ic .export-env Ar variable ... 1525The same as 1526.Ql .export , 1527except that the variable is not appended to 1528.Va .MAKE.EXPORTED . 1529This allows exporting a value to the environment which is different from that 1530used by 1531.Nm 1532internally. 1533.It Ic .info Ar message 1534The message is printed along with the name of the makefile and line number. 1535.It Ic .undef Ar variable 1536Un-define the specified global variable. 1537Only global variables may be un-defined. 1538.It Ic .unexport Ar variable ... 1539The opposite of 1540.Ql .export . 1541The specified global 1542.Va variable 1543will be removed from 1544.Va .MAKE.EXPORTED . 1545If no variable list is provided, all globals are unexported, 1546and 1547.Va .MAKE.EXPORTED 1548deleted. 1549.It Ic .unexport-env 1550Unexport all globals previously exported and 1551clear the environment inherited from the parent. 1552This operation will cause a memory leak of the original environment, 1553so should be used sparingly. 1554Testing for 1555.Va .MAKE.LEVEL 1556being 0, would make sense. 1557Also note that any variables which originated in the parent environment 1558should be explicitly preserved if desired. 1559For example: 1560.Bd -literal -offset indent 1561.Li .if ${.MAKE.LEVEL} == 0 1562PATH := ${PATH} 1563.Li .unexport-env 1564.Li .export PATH 1565.Li .endif 1566.Pp 1567.Ed 1568Would result in an environment containing only 1569.Ql Ev PATH , 1570which is the minimal useful environment. 1571Actually 1572.Ql Ev .MAKE.LEVEL 1573will also be pushed into the new environment. 1574.It Ic .warning Ar message 1575The message prefixed by 1576.Ql Pa warning: 1577is printed along with the name of the makefile and line number. 1578.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1579Test the value of an expression. 1580.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1581Test the value of a variable. 1582.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1583Test the value of a variable. 1584.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1585Test the target being built. 1586.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1587Test the target being built. 1588.It Ic .else 1589Reverse the sense of the last conditional. 1590.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1591A combination of 1592.Ql Ic .else 1593followed by 1594.Ql Ic .if . 1595.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1596A combination of 1597.Ql Ic .else 1598followed by 1599.Ql Ic .ifdef . 1600.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1601A combination of 1602.Ql Ic .else 1603followed by 1604.Ql Ic .ifndef . 1605.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1606A combination of 1607.Ql Ic .else 1608followed by 1609.Ql Ic .ifmake . 1610.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1611A combination of 1612.Ql Ic .else 1613followed by 1614.Ql Ic .ifnmake . 1615.It Ic .endif 1616End the body of the conditional. 1617.El 1618.Pp 1619The 1620.Ar operator 1621may be any one of the following: 1622.Bl -tag -width "Cm XX" 1623.It Cm \&|\&| 1624Logical OR. 1625.It Cm \&\*[Am]\*[Am] 1626Logical 1627.Tn AND ; 1628of higher precedence than 1629.Dq \&|\&| . 1630.El 1631.Pp 1632As in C, 1633.Nm 1634will only evaluate a conditional as far as is necessary to determine 1635its value. 1636Parentheses may be used to change the order of evaluation. 1637The boolean operator 1638.Ql Ic \&! 1639may be used to logically negate an entire 1640conditional. 1641It is of higher precedence than 1642.Ql Ic \&\*[Am]\*[Am] . 1643.Pp 1644The value of 1645.Ar expression 1646may be any of the following: 1647.Bl -tag -width defined 1648.It Ic defined 1649Takes a variable name as an argument and evaluates to true if the variable 1650has been defined. 1651.It Ic make 1652Takes a target name as an argument and evaluates to true if the target 1653was specified as part of 1654.Nm Ns 's 1655command line or was declared the default target (either implicitly or 1656explicitly, see 1657.Va .MAIN ) 1658before the line containing the conditional. 1659.It Ic empty 1660Takes a variable, with possible modifiers, and evaluates to true if 1661the expansion of the variable would result in an empty string. 1662.It Ic exists 1663Takes a file name as an argument and evaluates to true if the file exists. 1664The file is searched for on the system search path (see 1665.Va .PATH ) . 1666.It Ic target 1667Takes a target name as an argument and evaluates to true if the target 1668has been defined. 1669.It Ic commands 1670Takes a target name as an argument and evaluates to true if the target 1671has been defined and has commands associated with it. 1672.El 1673.Pp 1674.Ar Expression 1675may also be an arithmetic or string comparison. 1676Variable expansion is 1677performed on both sides of the comparison, after which the integral 1678values are compared. 1679A value is interpreted as hexadecimal if it is 1680preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1681The standard C relational operators are all supported. 1682If after 1683variable expansion, either the left or right hand side of a 1684.Ql Ic == 1685or 1686.Ql Ic "!=" 1687operator is not an integral value, then 1688string comparison is performed between the expanded 1689variables. 1690If no relational operator is given, it is assumed that the expanded 1691variable is being compared against 0 or an empty string in the case 1692of a string comparison. 1693.Pp 1694When 1695.Nm 1696is evaluating one of these conditional expressions, and it encounters 1697a (white-space separated) word it doesn't recognize, either the 1698.Dq make 1699or 1700.Dq defined 1701expression is applied to it, depending on the form of the conditional. 1702If the form is 1703.Ql Ic .ifdef , 1704.Ql Ic .ifndef , 1705or 1706.Ql Ic .if 1707the 1708.Dq defined 1709expression is applied. 1710Similarly, if the form is 1711.Ql Ic .ifmake 1712or 1713.Ql Ic .ifnmake , the 1714.Dq make 1715expression is applied. 1716.Pp 1717If the conditional evaluates to true the parsing of the makefile continues 1718as before. 1719If it evaluates to false, the following lines are skipped. 1720In both cases this continues until a 1721.Ql Ic .else 1722or 1723.Ql Ic .endif 1724is found. 1725.Pp 1726For loops are typically used to apply a set of rules to a list of files. 1727The syntax of a for loop is: 1728.Pp 1729.Bl -tag -compact -width Ds 1730.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1731.It Aq make-rules 1732.It Ic \&.endfor 1733.El 1734.Pp 1735After the for 1736.Ic expression 1737is evaluated, it is split into words. 1738On each iteration of the loop, one word is taken and assigned to each 1739.Ic variable , 1740in order, and these 1741.Ic variables 1742are substituted into the 1743.Ic make-rules 1744inside the body of the for loop. 1745The number of words must come out even; that is, if there are three 1746iteration variables, the number of words provided must be a multiple 1747of three. 1748.Sh COMMENTS 1749Comments begin with a hash 1750.Pq Ql \&# 1751character, anywhere but in a shell 1752command line, and continue to the end of an unescaped new line. 1753.Sh SPECIAL SOURCES (ATTRIBUTES) 1754.Bl -tag -width .IGNOREx 1755.It Ic .EXEC 1756Target is never out of date, but always execute commands anyway. 1757.It Ic .IGNORE 1758Ignore any errors from the commands associated with this target, exactly 1759as if they all were preceded by a dash 1760.Pq Ql \- . 1761.\" .It Ic .INVISIBLE 1762.\" XXX 1763.\" .It Ic .JOIN 1764.\" XXX 1765.It Ic .MADE 1766Mark all sources of this target as being up-to-date. 1767.It Ic .MAKE 1768Execute the commands associated with this target even if the 1769.Fl n 1770or 1771.Fl t 1772options were specified. 1773Normally used to mark recursive 1774.Nm Ns s . 1775.It Ic .META 1776Create a meta file for the target, even if it is flagged as 1777.Ic .PHONY , 1778.Ic .MAKE , 1779or 1780.Ic .SPECIAL . 1781Usage in conjunction with 1782.Ic .MAKE 1783is the most likely case. 1784In "meta" mode, the target is out-of-date if the meta file is missing. 1785.It Ic .NOMETA 1786Do not create a meta file for the target. 1787Meta files are also not created for 1788.Ic .PHONY , 1789.Ic .MAKE , 1790or 1791.Ic .SPECIAL 1792targets. 1793.It Ic .NOMETA_CMP 1794Ignore differences in commands when deciding if target is out of date. 1795This is useful if the command contains a value which always changes. 1796If the number of commands change, though, the target will still be out of date. 1797The same effect applies to any command line that uses the variable 1798.Va .OODATE , 1799which can be used for that purpose even when not otherwise needed or desired: 1800.Bd -literal -offset indent 1801 1802skip-compare-for-some: 1803 @echo this will be compared 1804 @echo this will not ${.OODATE:M.NOMETA_CMP} 1805 @echo this will also be compared 1806 1807.Ed 1808The 1809.Cm \&:M 1810pattern suppresses any expansion of the unwanted variable. 1811.It Ic .NOPATH 1812Do not search for the target in the directories specified by 1813.Ic .PATH . 1814.It Ic .NOTMAIN 1815Normally 1816.Nm 1817selects the first target it encounters as the default target to be built 1818if no target was specified. 1819This source prevents this target from being selected. 1820.It Ic .OPTIONAL 1821If a target is marked with this attribute and 1822.Nm 1823can't figure out how to create it, it will ignore this fact and assume 1824the file isn't needed or already exists. 1825.It Ic .PHONY 1826The target does not 1827correspond to an actual file; it is always considered to be out of date, 1828and will not be created with the 1829.Fl t 1830option. 1831Suffix-transformation rules are not applied to 1832.Ic .PHONY 1833targets. 1834.It Ic .PRECIOUS 1835When 1836.Nm 1837is interrupted, it normally removes any partially made targets. 1838This source prevents the target from being removed. 1839.It Ic .RECURSIVE 1840Synonym for 1841.Ic .MAKE . 1842.It Ic .SILENT 1843Do not echo any of the commands associated with this target, exactly 1844as if they all were preceded by an at sign 1845.Pq Ql @ . 1846.It Ic .USE 1847Turn the target into 1848.Nm Ns 's 1849version of a macro. 1850When the target is used as a source for another target, the other target 1851acquires the commands, sources, and attributes (except for 1852.Ic .USE ) 1853of the 1854source. 1855If the target already has commands, the 1856.Ic .USE 1857target's commands are appended 1858to them. 1859.It Ic .USEBEFORE 1860Exactly like 1861.Ic .USE , 1862but prepend the 1863.Ic .USEBEFORE 1864target commands to the target. 1865.It Ic .WAIT 1866If 1867.Ic .WAIT 1868appears in a dependency line, the sources that precede it are 1869made before the sources that succeed it in the line. 1870Since the dependents of files are not made until the file itself 1871could be made, this also stops the dependents being built unless they 1872are needed for another branch of the dependency tree. 1873So given: 1874.Bd -literal 1875x: a .WAIT b 1876 echo x 1877a: 1878 echo a 1879b: b1 1880 echo b 1881b1: 1882 echo b1 1883 1884.Ed 1885the output is always 1886.Ql a , 1887.Ql b1 , 1888.Ql b , 1889.Ql x . 1890.br 1891The ordering imposed by 1892.Ic .WAIT 1893is only relevant for parallel makes. 1894.El 1895.Sh SPECIAL TARGETS 1896Special targets may not be included with other targets, i.e. they must be 1897the only target specified. 1898.Bl -tag -width .BEGINx 1899.It Ic .BEGIN 1900Any command lines attached to this target are executed before anything 1901else is done. 1902.It Ic .DEFAULT 1903This is sort of a 1904.Ic .USE 1905rule for any target (that was used only as a 1906source) that 1907.Nm 1908can't figure out any other way to create. 1909Only the shell script is used. 1910The 1911.Ic .IMPSRC 1912variable of a target that inherits 1913.Ic .DEFAULT Ns 's 1914commands is set 1915to the target's own name. 1916.It Ic .END 1917Any command lines attached to this target are executed after everything 1918else is done. 1919.It Ic .ERROR 1920Any command lines attached to this target are executed when another target fails. 1921The 1922.Ic .ERROR_TARGET 1923variable is set to the target that failed. 1924See also 1925.Ic MAKE_PRINT_VAR_ON_ERROR . 1926.It Ic .IGNORE 1927Mark each of the sources with the 1928.Ic .IGNORE 1929attribute. 1930If no sources are specified, this is the equivalent of specifying the 1931.Fl i 1932option. 1933.It Ic .INTERRUPT 1934If 1935.Nm 1936is interrupted, the commands for this target will be executed. 1937.It Ic .MAIN 1938If no target is specified when 1939.Nm 1940is invoked, this target will be built. 1941.It Ic .MAKEFLAGS 1942This target provides a way to specify flags for 1943.Nm 1944when the makefile is used. 1945The flags are as if typed to the shell, though the 1946.Fl f 1947option will have 1948no effect. 1949.\" XXX: NOT YET!!!! 1950.\" .It Ic .NOTPARALLEL 1951.\" The named targets are executed in non parallel mode. 1952.\" If no targets are 1953.\" specified, then all targets are executed in non parallel mode. 1954.It Ic .NOPATH 1955Apply the 1956.Ic .NOPATH 1957attribute to any specified sources. 1958.It Ic .NOTPARALLEL 1959Disable parallel mode. 1960.It Ic .NO_PARALLEL 1961Synonym for 1962.Ic .NOTPARALLEL , 1963for compatibility with other pmake variants. 1964.It Ic .ORDER 1965The named targets are made in sequence. 1966This ordering does not add targets to the list of targets to be made. 1967Since the dependents of a target do not get built until the target itself 1968could be built, unless 1969.Ql a 1970is built by another part of the dependency graph, 1971the following is a dependency loop: 1972.Bd -literal 1973\&.ORDER: b a 1974b: a 1975.Ed 1976.Pp 1977The ordering imposed by 1978.Ic .ORDER 1979is only relevant for parallel makes. 1980.\" XXX: NOT YET!!!! 1981.\" .It Ic .PARALLEL 1982.\" The named targets are executed in parallel mode. 1983.\" If no targets are 1984.\" specified, then all targets are executed in parallel mode. 1985.It Ic .PATH 1986The sources are directories which are to be searched for files not 1987found in the current directory. 1988If no sources are specified, any previously specified directories are 1989deleted. 1990If the source is the special 1991.Ic .DOTLAST 1992target, then the current working 1993directory is searched last. 1994.It Ic .PATH. Ns Va suffix 1995Like 1996.Ic .PATH 1997but applies only to files with a particular suffix. 1998The suffix must have been previously declared with 1999.Ic .SUFFIXES . 2000.It Ic .PHONY 2001Apply the 2002.Ic .PHONY 2003attribute to any specified sources. 2004.It Ic .PRECIOUS 2005Apply the 2006.Ic .PRECIOUS 2007attribute to any specified sources. 2008If no sources are specified, the 2009.Ic .PRECIOUS 2010attribute is applied to every 2011target in the file. 2012.It Ic .SHELL 2013Sets the shell that 2014.Nm 2015will use to execute commands. 2016The sources are a set of 2017.Ar field=value 2018pairs. 2019.Bl -tag -width hasErrCtls 2020.It Ar name 2021This is the minimal specification, used to select one of the builtin 2022shell specs; 2023.Ar sh , 2024.Ar ksh , 2025and 2026.Ar csh . 2027.It Ar path 2028Specifies the path to the shell. 2029.It Ar hasErrCtl 2030Indicates whether the shell supports exit on error. 2031.It Ar check 2032The command to turn on error checking. 2033.It Ar ignore 2034The command to disable error checking. 2035.It Ar echo 2036The command to turn on echoing of commands executed. 2037.It Ar quiet 2038The command to turn off echoing of commands executed. 2039.It Ar filter 2040The output to filter after issuing the 2041.Ar quiet 2042command. 2043It is typically identical to 2044.Ar quiet . 2045.It Ar errFlag 2046The flag to pass the shell to enable error checking. 2047.It Ar echoFlag 2048The flag to pass the shell to enable command echoing. 2049.It Ar newline 2050The string literal to pass the shell that results in a single newline 2051character when used outside of any quoting characters. 2052.El 2053Example: 2054.Bd -literal 2055\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2056 check="set \-e" ignore="set +e" \e 2057 echo="set \-v" quiet="set +v" filter="set +v" \e 2058 echoFlag=v errFlag=e newline="'\en'" 2059.Ed 2060.It Ic .SILENT 2061Apply the 2062.Ic .SILENT 2063attribute to any specified sources. 2064If no sources are specified, the 2065.Ic .SILENT 2066attribute is applied to every 2067command in the file. 2068.It Ic .STALE 2069This target gets run when a dependency file contains stale entries, having 2070.Va .ALLSRC 2071set to the name of that dependency file. 2072.It Ic .SUFFIXES 2073Each source specifies a suffix to 2074.Nm . 2075If no sources are specified, any previously specified suffixes are deleted. 2076It allows the creation of suffix-transformation rules. 2077.Pp 2078Example: 2079.Bd -literal 2080\&.SUFFIXES: .o 2081\&.c.o: 2082 cc \-o ${.TARGET} \-c ${.IMPSRC} 2083.Ed 2084.El 2085.Sh ENVIRONMENT 2086.Nm 2087uses the following environment variables, if they exist: 2088.Ev MACHINE , 2089.Ev MACHINE_ARCH , 2090.Ev MAKE , 2091.Ev MAKEFLAGS , 2092.Ev MAKEOBJDIR , 2093.Ev MAKEOBJDIRPREFIX , 2094.Ev MAKESYSPATH , 2095.Ev PWD , 2096and 2097.Ev TMPDIR . 2098.Pp 2099.Ev MAKEOBJDIRPREFIX 2100and 2101.Ev MAKEOBJDIR 2102may only be set in the environment or on the command line to 2103.Nm 2104and not as makefile variables; 2105see the description of 2106.Ql Va .OBJDIR 2107for more details. 2108.Sh FILES 2109.Bl -tag -width /usr/share/mk -compact 2110.It .depend 2111list of dependencies 2112.It Makefile 2113list of dependencies 2114.It makefile 2115list of dependencies 2116.It sys.mk 2117system makefile 2118.It /usr/share/mk 2119system makefile directory 2120.El 2121.Sh COMPATIBILITY 2122The basic make syntax is compatible between different versions of make, 2123however the special variables, variable modifiers and conditionals are not. 2124.Pp 2125The way that parallel makes are scheduled changed in 2126NetBSD 4.0 2127so that .ORDER and .WAIT apply recursively to the dependent nodes. 2128The algorithms used may change again in the future. 2129.Pp 2130The way that .for loop variables are substituted changed after 2131NetBSD 5.0 2132so that they still appear to be variable expansions. 2133In particular this stops them being treated as syntax, and removes some 2134obscure problems using them in .if statements. 2135.Sh SEE ALSO 2136.Xr mkdep 1 2137.Sh HISTORY 2138.Nm 2139is derived from NetBSD 2140.Xr make 1 . 2141It uses autoconf to facilitate portability to other platforms. 2142.Pp 2143A 2144make 2145command appeared in 2146.At v7 . 2147This 2148make 2149implementation is based on Adam De Boor's pmake program which was written 2150for Sprite at Berkeley. 2151It was designed to be a parallel distributed make running jobs on different 2152machines using a daemon called 2153.Dq customs . 2154.Pp 2155Historically the target/dependency 2156.Dq FRC 2157has been used to FoRCe rebuilding (since the target/dependency 2158does not exist... unless someone creates an 2159.Dq FRC 2160file). 2161.Sh BUGS 2162The 2163make 2164syntax is difficult to parse without actually acting of the data. 2165For instance finding the end of a variable use should involve scanning each 2166the modifiers using the correct terminator for each field. 2167In many places 2168make 2169just counts {} and () in order to find the end of a variable expansion. 2170.Pp 2171There is no way of escaping a space character in a filename. 2172