1.\" $NetBSD: make.1,v 1.254 2016/02/20 01:43:28 wiz 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 19, 2016 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 x 213Run shell commands with 214.Fl x 215so the actual commands are printed as they are executed. 216.El 217.It Fl e 218Specify that environment variables override macro assignments within 219makefiles. 220.It Fl f Ar makefile 221Specify a makefile to read instead of the default 222.Ql Pa makefile . 223If 224.Ar makefile 225is 226.Ql Fl , 227standard input is read. 228Multiple makefiles may be specified, and are read in the order specified. 229.It Fl I Ar directory 230Specify a directory in which to search for makefiles and included makefiles. 231The system makefile directory (or directories, see the 232.Fl m 233option) is automatically included as part of this list. 234.It Fl i 235Ignore non-zero exit of shell commands in the makefile. 236Equivalent to specifying 237.Ql Fl 238before each command line in the makefile. 239.It Fl J Ar private 240This option should 241.Em not 242be specified by the user. 243.Pp 244When the 245.Ar j 246option is in use in a recursive build, this option is passed by a make 247to child makes to allow all the make processes in the build to 248cooperate to avoid overloading the system. 249.It Fl j Ar max_jobs 250Specify the maximum number of jobs that 251.Nm 252may have running at any one time. 253The value is saved in 254.Va .MAKE.JOBS . 255Turns compatibility mode off, unless the 256.Ar B 257flag is also specified. 258When compatibility mode is off, all commands associated with a 259target are executed in a single shell invocation as opposed to the 260traditional one shell invocation per line. 261This can break traditional scripts which change directories on each 262command invocation and then expect to start with a fresh environment 263on the next line. 264It is more efficient to correct the scripts rather than turn backwards 265compatibility on. 266.It Fl k 267Continue processing after errors are encountered, but only on those targets 268that do not depend on the target whose creation caused the error. 269.It Fl m Ar directory 270Specify a directory in which to search for sys.mk and makefiles included 271via the 272.Ao Ar file Ac Ns -style 273include statement. 274The 275.Fl m 276option can be used multiple times to form a search path. 277This path will override the default system include path: /usr/share/mk. 278Furthermore the system include path will be appended to the search path used 279for 280.Qo Ar file Qc Ns -style 281include statements (see the 282.Fl I 283option). 284.Pp 285If a file or directory name in the 286.Fl m 287argument (or the 288.Ev MAKESYSPATH 289environment variable) starts with the string 290.Qq \&.../ 291then 292.Nm 293will search for the specified file or directory named in the remaining part 294of the argument string. 295The search starts with the current directory of 296the Makefile and then works upward towards the root of the file system. 297If the search is successful, then the resulting directory replaces the 298.Qq \&.../ 299specification in the 300.Fl m 301argument. 302If used, this feature allows 303.Nm 304to easily search in the current source tree for customized sys.mk files 305(e.g., by using 306.Qq \&.../mk/sys.mk 307as an argument). 308.It Fl n 309Display the commands that would have been executed, but do not 310actually execute them unless the target depends on the .MAKE special 311source (see below). 312.It Fl N 313Display the commands which would have been executed, but do not 314actually execute any of them; useful for debugging top-level makefiles 315without descending into subdirectories. 316.It Fl q 317Do not execute any commands, but exit 0 if the specified targets are 318up-to-date and 1, otherwise. 319.It Fl r 320Do not use the built-in rules specified in the system makefile. 321.It Fl s 322Do not echo any commands as they are executed. 323Equivalent to specifying 324.Ql Ic @ 325before each command line in the makefile. 326.It Fl T Ar tracefile 327When used with the 328.Fl j 329flag, 330append a trace record to 331.Ar tracefile 332for each job started and completed. 333.It Fl t 334Rather than re-building a target as specified in the makefile, create it 335or update its modification time to make it appear up-to-date. 336.It Fl V Ar variable 337Print 338.Nm Ns 's 339idea of the value of 340.Ar variable , 341in the global context. 342Do not build any targets. 343Multiple instances of this option may be specified; 344the variables will be printed one per line, 345with a blank line for each null or undefined variable. 346If 347.Ar variable 348contains a 349.Ql \&$ 350then the value will be expanded before printing. 351.It Fl W 352Treat any warnings during makefile parsing as errors. 353.It Fl w 354Print entering and leaving directory messages, pre and post processing. 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 one or more lines of shell 445commands, normally 446used to create the target. 447Each of the lines in this script 448.Em must 449be preceded by a tab. 450(For historical reasons, spaces are not accepted.) 451While targets can appear in many dependency lines if desired, by 452default only one of these rules may be followed by a creation 453script. 454If the 455.Ql Ic \&:: 456operator is used, however, all rules may include scripts and the 457scripts are executed in the order found. 458.Pp 459Each line is treated as a separate shell command, unless the end of 460line is escaped with a backslash 461.Pq Ql \e 462in which case that line and the next are combined. 463.\" The escaped newline is retained and passed to the shell, which 464.\" normally ignores it. 465.\" However, the tab at the beginning of the following line is removed. 466If the first characters of the command are any combination of 467.Ql Ic @ , 468.Ql Ic + , 469or 470.Ql Ic \- , 471the command is treated specially. 472A 473.Ql Ic @ 474causes the command not to be echoed before it is executed. 475A 476.Ql Ic + 477causes the command to be executed even when 478.Fl n 479is given. 480This is similar to the effect of the .MAKE special source, 481except that the effect can be limited to a single line of a script. 482A 483.Ql Ic \- 484in compatibility mode 485causes any non-zero exit status of the command line to be ignored. 486.Pp 487When 488.Nm 489is run in jobs mode with 490.Fl j Ar max_jobs , 491the entire script for the target is fed to a 492single instance of the shell. 493In compatibility (non-jobs) mode, each command is run in a separate process. 494If the command contains any shell meta characters 495.Pq Ql #=|^(){};&<>*?[]:$`\e\en 496it will be passed to the shell; otherwise 497.Nm 498will attempt direct execution. 499If a line starts with 500.Ql Ic \- 501and the shell has ErrCtl enabled then failure of the command line 502will be ignored as in compatibility mode. 503Otherwise 504.Ql Ic \- 505affects the entire job; 506the script will stop at the first command line that fails, 507but the target will not be deemed to have failed. 508.Pp 509Makefiles should be written so that the mode of 510.Nm 511operation does not change their behavior. 512For example, any command which needs to use 513.Dq cd 514or 515.Dq chdir 516without potentially changing the directory for subsequent commands 517should be put in parentheses so it executes in a subshell. 518To force the use of one shell, escape the line breaks so as to make 519the whole script one command. 520For example: 521.Bd -literal -offset indent 522avoid-chdir-side-effects: 523 @echo Building $@ in `pwd` 524 @(cd ${.CURDIR} && ${MAKE} $@) 525 @echo Back in `pwd` 526 527ensure-one-shell-regardless-of-mode: 528 @echo Building $@ in `pwd`; \e 529 (cd ${.CURDIR} && ${MAKE} $@); \e 530 echo Back in `pwd` 531.Ed 532.Pp 533Since 534.Nm 535will 536.Xr chdir 2 537to 538.Ql Va .OBJDIR 539before executing any targets, each child process 540starts with that as its current working directory. 541.Sh VARIABLE ASSIGNMENTS 542Variables in make are much like variables in the shell, and, by tradition, 543consist of all upper-case letters. 544.Ss Variable assignment modifiers 545The five operators that can be used to assign values to variables are as 546follows: 547.Bl -tag -width Ds 548.It Ic \&= 549Assign the value to the variable. 550Any previous value is overridden. 551.It Ic \&+= 552Append the value to the current value of the variable. 553.It Ic \&?= 554Assign the value to the variable if it is not already defined. 555.It Ic \&:= 556Assign with expansion, i.e. expand the value before assigning it 557to the variable. 558Normally, expansion is not done until the variable is referenced. 559.Em NOTE : 560References to undefined variables are 561.Em not 562expanded. 563This can cause problems when variable modifiers are used. 564.It Ic \&!= 565Expand the value and pass it to the shell for execution and assign 566the result to the variable. 567Any newlines in the result are replaced with spaces. 568.El 569.Pp 570Any white-space before the assigned 571.Ar value 572is removed; if the value is being appended, a single space is inserted 573between the previous contents of the variable and the appended value. 574.Pp 575Variables are expanded by surrounding the variable name with either 576curly braces 577.Pq Ql {} 578or parentheses 579.Pq Ql () 580and preceding it with 581a dollar sign 582.Pq Ql \&$ . 583If the variable name contains only a single letter, the surrounding 584braces or parentheses are not required. 585This shorter form is not recommended. 586.Pp 587If the variable name contains a dollar, then the name itself is expanded first. 588This allows almost arbitrary variable names, however names containing dollar, 589braces, parenthesis, or whitespace are really best avoided! 590.Pp 591If the result of expanding a variable contains a dollar sign 592.Pq Ql \&$ 593the string is expanded again. 594.Pp 595Variable substitution occurs at three distinct times, depending on where 596the variable is being used. 597.Bl -enum 598.It 599Variables in dependency lines are expanded as the line is read. 600.It 601Variables in shell commands are expanded when the shell command is 602executed. 603.It 604.Dq .for 605loop index variables are expanded on each loop iteration. 606Note that other variables are not expanded inside loops so 607the following example code: 608.Bd -literal -offset indent 609 610.Dv .for i in 1 2 3 611a+= ${i} 612j= ${i} 613b+= ${j} 614.Dv .endfor 615 616all: 617 @echo ${a} 618 @echo ${b} 619 620.Ed 621will print: 622.Bd -literal -offset indent 6231 2 3 6243 3 3 625 626.Ed 627Because while ${a} contains 628.Dq 1 2 3 629after the loop is executed, ${b} 630contains 631.Dq ${j} ${j} ${j} 632which expands to 633.Dq 3 3 3 634since after the loop completes ${j} contains 635.Dq 3 . 636.El 637.Ss Variable classes 638The four different classes of variables (in order of increasing precedence) 639are: 640.Bl -tag -width Ds 641.It Environment variables 642Variables defined as part of 643.Nm Ns 's 644environment. 645.It Global variables 646Variables defined in the makefile or in included makefiles. 647.It Command line variables 648Variables defined as part of the command line. 649.It Local variables 650Variables that are defined specific to a certain target. 651.El 652.Pp 653Local variables are all built in and their values vary magically from 654target to target. 655It is not currently possible to define new local variables. 656The seven local variables are as follows: 657.Bl -tag -width ".ARCHIVE" -offset indent 658.It Va .ALLSRC 659The list of all sources for this target; also known as 660.Ql Va \&\*[Gt] . 661.It Va .ARCHIVE 662The name of the archive file; also known as 663.Ql Va \&! . 664.It Va .IMPSRC 665In suffix-transformation rules, the name/path of the source from which the 666target is to be transformed (the 667.Dq implied 668source); also known as 669.Ql Va \&\*[Lt] . 670It is not defined in explicit rules. 671.It Va .MEMBER 672The name of the archive member; also known as 673.Ql Va % . 674.It Va .OODATE 675The list of sources for this target that were deemed out-of-date; also 676known as 677.Ql Va \&? . 678.It Va .PREFIX 679The file prefix of the target, containing only the file portion, no suffix 680or preceding directory components; also known as 681.Ql Va * . 682The suffix must be one of the known suffixes declared with 683.Ic .SUFFIXES 684or it will not be recognized. 685.It Va .TARGET 686The name of the target; also known as 687.Ql Va @ . 688.El 689.Pp 690The shorter forms 691.Ql ( Va \*[Gt] , 692.Ql Va \&! , 693.Ql Va \*[Lt] , 694.Ql Va % , 695.Ql Va \&? , 696.Ql Va * , 697and 698.Ql Va @ ) 699are permitted for backward 700compatibility with historical makefiles and legacy POSIX make and are 701not recommended. 702.Pp 703Variants of these variables with the punctuation followed immediately by 704.Ql D 705or 706.Ql F , 707e.g. 708.Ql Va $(@D) , 709are legacy forms equivalent to using the 710.Ql :H 711and 712.Ql :T 713modifiers. 714These forms are accepted for compatibility with 715.At V 716makefiles and POSIX but are not recommended. 717.Pp 718Four of the local variables may be used in sources on dependency lines 719because they expand to the proper value for each target on the line. 720These variables are 721.Ql Va .TARGET , 722.Ql Va .PREFIX , 723.Ql Va .ARCHIVE , 724and 725.Ql Va .MEMBER . 726.Ss Additional built-in variables 727In addition, 728.Nm 729sets or knows about the following variables: 730.Bl -tag -width .MAKEOVERRIDES 731.It Va \&$ 732A single dollar sign 733.Ql \&$ , 734i.e. 735.Ql \&$$ 736expands to a single dollar 737sign. 738.It Va .ALLTARGETS 739The list of all targets encountered in the Makefile. 740If evaluated during 741Makefile parsing, lists only those targets encountered thus far. 742.It Va .CURDIR 743A path to the directory where 744.Nm 745was executed. 746Refer to the description of 747.Ql Ev PWD 748for more details. 749.It Va .INCLUDEDFROMDIR 750The directory of the file this Makefile was included from. 751.It Va .INCLUDEDFROMFILE 752The filename of the file this Makefile was included from. 753.It Ev MAKE 754The name that 755.Nm 756was executed with 757.Pq Va argv[0] . 758For compatibility 759.Nm 760also sets 761.Va .MAKE 762with the same value. 763The preferred variable to use is the environment variable 764.Ev MAKE 765because it is more compatible with other versions of 766.Nm 767and cannot be confused with the special target with the same name. 768.It Va .MAKE.DEPENDFILE 769Names the makefile (default 770.Ql Pa .depend ) 771from which generated dependencies are read. 772.It Va .MAKE.EXPAND_VARIABLES 773A boolean that controls the default behavior of the 774.Fl V 775option. 776.It Va .MAKE.EXPORTED 777The list of variables exported by 778.Nm . 779.It Va .MAKE.JOBS 780The argument to the 781.Fl j 782option. 783.It Va .MAKE.JOB.PREFIX 784If 785.Nm 786is run with 787.Ar j 788then output for each target is prefixed with a token 789.Ql --- target --- 790the first part of which can be controlled via 791.Va .MAKE.JOB.PREFIX . 792If 793.Va .MAKE.JOB.PREFIX 794is empty, no token is printed. 795.br 796For example: 797.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 798would produce tokens like 799.Ql ---make[1234] target --- 800making it easier to track the degree of parallelism being achieved. 801.It Ev MAKEFLAGS 802The environment variable 803.Ql Ev MAKEFLAGS 804may contain anything that 805may be specified on 806.Nm Ns 's 807command line. 808Anything specified on 809.Nm Ns 's 810command line is appended to the 811.Ql Ev MAKEFLAGS 812variable which is then 813entered into the environment for all programs which 814.Nm 815executes. 816.It Va .MAKE.LEVEL 817The recursion depth of 818.Nm . 819The initial instance of 820.Nm 821will be 0, and an incremented value is put into the environment 822to be seen by the next generation. 823This allows tests like: 824.Li .if ${.MAKE.LEVEL} == 0 825to protect things which should only be evaluated in the initial instance of 826.Nm . 827.It Va .MAKE.MAKEFILE_PREFERENCE 828The ordered list of makefile names 829(default 830.Ql Pa makefile , 831.Ql Pa Makefile ) 832that 833.Nm 834will look for. 835.It Va .MAKE.MAKEFILES 836The list of makefiles read by 837.Nm , 838which is useful for tracking dependencies. 839Each makefile is recorded only once, regardless of the number of times read. 840.It Va .MAKE.MODE 841Processed after reading all makefiles. 842Can affect the mode that 843.Nm 844runs in. 845It can contain a number of keywords: 846.Bl -hang -width ignore-cmd 847.It Pa compat 848Like 849.Fl B , 850puts 851.Nm 852into "compat" mode. 853.It Pa meta 854Puts 855.Nm 856into "meta" mode, where meta files are created for each target 857to capture the command run, the output generated and if 858.Xr filemon 4 859is available, the system calls which are of interest to 860.Nm . 861The captured output can be very useful when diagnosing errors. 862.It Pa curdirOk= Ar bf 863Normally 864.Nm 865will not create .meta files in 866.Ql Va .CURDIR . 867This can be overridden by setting 868.Va bf 869to a value which represents True. 870.It Pa env 871For debugging, it can be useful to include the environment 872in the .meta file. 873.It Pa verbose 874If in "meta" mode, print a clue about the target being built. 875This is useful if the build is otherwise running silently. 876The message printed the value of: 877.Va .MAKE.META.PREFIX . 878.It Pa ignore-cmd 879Some makefiles have commands which are simply not stable. 880This keyword causes them to be ignored for 881determining whether a target is out of date in "meta" mode. 882See also 883.Ic .NOMETA_CMP . 884.It Pa silent= Ar bf 885If 886.Va bf 887is True, when a .meta file is created, mark the target 888.Ic .SILENT . 889.El 890.It Va .MAKE.META.BAILIWICK 891In "meta" mode, provides a list of prefixes which 892match the directories controlled by 893.Nm . 894If a file that was generated outside of 895.Va .OBJDIR 896but within said bailiwick is missing, 897the current target is considered out-of-date. 898.It Va .MAKE.META.CREATED 899In "meta" mode, this variable contains a list of all the meta files 900updated. 901If not empty, it can be used to trigger processing of 902.Va .MAKE.META.FILES . 903.It Va .MAKE.META.FILES 904In "meta" mode, this variable contains a list of all the meta files 905used (updated or not). 906This list can be used to process the meta files to extract dependency 907information. 908.It Va .MAKE.META.IGNORE_PATHS 909Provides a list of path prefixes that should be ignored; 910because the contents are expected to change over time. 911The default list includes: 912.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 913.It Va .MAKE.META.PREFIX 914Defines the message printed for each meta file updated in "meta verbose" mode. 915The default value is: 916.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 917.It Va .MAKEOVERRIDES 918This variable is used to record the names of variables assigned to 919on the command line, so that they may be exported as part of 920.Ql Ev MAKEFLAGS . 921This behavior can be disabled by assigning an empty value to 922.Ql Va .MAKEOVERRIDES 923within a makefile. 924Extra variables can be exported from a makefile 925by appending their names to 926.Ql Va .MAKEOVERRIDES . 927.Ql Ev MAKEFLAGS 928is re-exported whenever 929.Ql Va .MAKEOVERRIDES 930is modified. 931.It Va .MAKE.PATH_FILEMON 932If 933.Nm 934was built with 935.Xr filemon 4 936support, this is set to the path of the device node. 937This allows makefiles to test for this support. 938.It Va .MAKE.PID 939The process-id of 940.Nm . 941.It Va .MAKE.PPID 942The parent process-id of 943.Nm . 944.It Va .MAKE.SAVE_DOLLARS 945value should be a boolean that controls whether 946.Ql $$ 947are preserved when doing 948.Ql := 949assignments. 950The default is false, for backwards compatibility. 951Set to true for compatability with other makes. 952If set to false, 953.Ql $$ 954becomes 955.Ql $ 956per normal evaluation rules. 957.It Va MAKE_PRINT_VAR_ON_ERROR 958When 959.Nm 960stops due to an error, it prints its name and the value of 961.Ql Va .CURDIR 962as well as the value of any variables named in 963.Ql Va MAKE_PRINT_VAR_ON_ERROR . 964.It Va .newline 965This variable is simply assigned a newline character as its value. 966This allows expansions using the 967.Cm \&:@ 968modifier to put a newline between 969iterations of the loop rather than a space. 970For example, the printing of 971.Ql Va MAKE_PRINT_VAR_ON_ERROR 972could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 973.It Va .OBJDIR 974A path to the directory where the targets are built. 975Its value is determined by trying to 976.Xr chdir 2 977to the following directories in order and using the first match: 978.Bl -enum 979.It 980.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 981.Pp 982(Only if 983.Ql Ev MAKEOBJDIRPREFIX 984is set in the environment or on the command line.) 985.It 986.Ev ${MAKEOBJDIR} 987.Pp 988(Only if 989.Ql Ev MAKEOBJDIR 990is set in the environment or on the command line.) 991.It 992.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 993.It 994.Ev ${.CURDIR} Ns Pa /obj 995.It 996.Pa /usr/obj/ Ns Ev ${.CURDIR} 997.It 998.Ev ${.CURDIR} 999.El 1000.Pp 1001Variable expansion is performed on the value before it's used, 1002so expressions such as 1003.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1004may be used. 1005This is especially useful with 1006.Ql Ev MAKEOBJDIR . 1007.Pp 1008.Ql Va .OBJDIR 1009may be modified in the makefile via the special target 1010.Ql Ic .OBJDIR . 1011In all cases, 1012.Nm 1013will 1014.Xr chdir 2 1015to the specified directory if it exists, and set 1016.Ql Va .OBJDIR 1017and 1018.Ql Ev PWD 1019to that directory before executing any targets. 1020. 1021.It Va .PARSEDIR 1022A path to the directory of the current 1023.Ql Pa Makefile 1024being parsed. 1025.It Va .PARSEFILE 1026The basename of the current 1027.Ql Pa Makefile 1028being parsed. 1029This variable and 1030.Ql Va .PARSEDIR 1031are both set only while the 1032.Ql Pa Makefiles 1033are being parsed. 1034If you want to retain their current values, assign them to a variable 1035using assignment with expansion: 1036.Pq Ql Cm \&:= . 1037.It Va .PATH 1038A variable that represents the list of directories that 1039.Nm 1040will search for files. 1041The search list should be updated using the target 1042.Ql Va .PATH 1043rather than the variable. 1044.It Ev PWD 1045Alternate path to the current directory. 1046.Nm 1047normally sets 1048.Ql Va .CURDIR 1049to the canonical path given by 1050.Xr getcwd 3 . 1051However, if the environment variable 1052.Ql Ev PWD 1053is set and gives a path to the current directory, then 1054.Nm 1055sets 1056.Ql Va .CURDIR 1057to the value of 1058.Ql Ev PWD 1059instead. 1060This behavior is disabled if 1061.Ql Ev MAKEOBJDIRPREFIX 1062is set or 1063.Ql Ev MAKEOBJDIR 1064contains a variable transform. 1065.Ql Ev PWD 1066is set to the value of 1067.Ql Va .OBJDIR 1068for all programs which 1069.Nm 1070executes. 1071.It Ev .TARGETS 1072The list of targets explicitly specified on the command line, if any. 1073.It Ev VPATH 1074Colon-separated 1075.Pq Dq \&: 1076lists of directories that 1077.Nm 1078will search for files. 1079The variable is supported for compatibility with old make programs only, 1080use 1081.Ql Va .PATH 1082instead. 1083.El 1084.Ss Variable modifiers 1085Variable expansion may be modified to select or modify each word of the 1086variable (where a 1087.Dq word 1088is white-space delimited sequence of characters). 1089The general format of a variable expansion is as follows: 1090.Pp 1091.Dl ${variable[:modifier[:...]]} 1092.Pp 1093Each modifier begins with a colon, 1094which may be escaped with a backslash 1095.Pq Ql \e . 1096.Pp 1097A set of modifiers can be specified via a variable, as follows: 1098.Pp 1099.Dl modifier_variable=modifier[:...] 1100.Dl ${variable:${modifier_variable}[:...]} 1101.Pp 1102In this case the first modifier in the modifier_variable does not 1103start with a colon, since that must appear in the referencing 1104variable. 1105If any of the modifiers in the modifier_variable contain a dollar sign 1106.Pq Ql $ , 1107these must be doubled to avoid early expansion. 1108.Pp 1109The supported modifiers are: 1110.Bl -tag -width EEE 1111.It Cm \&:E 1112Replaces each word in the variable with its suffix. 1113.It Cm \&:H 1114Replaces each word in the variable with everything but the last component. 1115.It Cm \&:M Ns Ar pattern 1116Select only those words that match 1117.Ar pattern . 1118The standard shell wildcard characters 1119.Pf ( Ql * , 1120.Ql \&? , 1121and 1122.Ql Oo Oc ) 1123may 1124be used. 1125The wildcard characters may be escaped with a backslash 1126.Pq Ql \e . 1127As a consequence of the way values are split into words, matched, 1128and then joined, a construct like 1129.Dl ${VAR:M*} 1130will normalize the inter-word spacing, removing all leading and 1131trailing space, and converting multiple consecutive spaces 1132to single spaces. 1133. 1134.It Cm \&:N Ns Ar pattern 1135This is identical to 1136.Ql Cm \&:M , 1137but selects all words which do not match 1138.Ar pattern . 1139.It Cm \&:O 1140Order every word in variable alphabetically. 1141To sort words in 1142reverse order use the 1143.Ql Cm \&:O:[-1..1] 1144combination of modifiers. 1145.It Cm \&:Ox 1146Randomize words in variable. 1147The results will be different each time you are referring to the 1148modified variable; use the assignment with expansion 1149.Pq Ql Cm \&:= 1150to prevent such behavior. 1151For example, 1152.Bd -literal -offset indent 1153LIST= uno due tre quattro 1154RANDOM_LIST= ${LIST:Ox} 1155STATIC_RANDOM_LIST:= ${LIST:Ox} 1156 1157all: 1158 @echo "${RANDOM_LIST}" 1159 @echo "${RANDOM_LIST}" 1160 @echo "${STATIC_RANDOM_LIST}" 1161 @echo "${STATIC_RANDOM_LIST}" 1162.Ed 1163may produce output similar to: 1164.Bd -literal -offset indent 1165quattro due tre uno 1166tre due quattro uno 1167due uno quattro tre 1168due uno quattro tre 1169.Ed 1170.It Cm \&:Q 1171Quotes every shell meta-character in the variable, so that it can be passed 1172safely through recursive invocations of 1173.Nm . 1174.It Cm \&:R 1175Replaces each word in the variable with everything but its suffix. 1176.It Cm \&:gmtime 1177The value is a format string for 1178.Xr strftime 3 , 1179using the current 1180.Xr gmtime 3 . 1181.It Cm \&:hash 1182Compute a 32-bit hash of the value and encode it as hex digits. 1183.It Cm \&:localtime 1184The value is a format string for 1185.Xr strftime 3 , 1186using the current 1187.Xr localtime 3 . 1188.It Cm \&:tA 1189Attempt to convert variable to an absolute path using 1190.Xr realpath 3 , 1191if that fails, the value is unchanged. 1192.It Cm \&:tl 1193Converts variable to lower-case letters. 1194.It Cm \&:ts Ns Ar c 1195Words in the variable are normally separated by a space on expansion. 1196This modifier sets the separator to the character 1197.Ar c . 1198If 1199.Ar c 1200is omitted, then no separator is used. 1201The common escapes (including octal numeric codes), work as expected. 1202.It Cm \&:tu 1203Converts variable to upper-case letters. 1204.It Cm \&:tW 1205Causes the value to be treated as a single word 1206(possibly containing embedded white space). 1207See also 1208.Ql Cm \&:[*] . 1209.It Cm \&:tw 1210Causes the value to be treated as a sequence of 1211words delimited by white space. 1212See also 1213.Ql Cm \&:[@] . 1214.Sm off 1215.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1216.Sm on 1217Modify the first occurrence of 1218.Ar old_string 1219in the variable's value, replacing it with 1220.Ar new_string . 1221If a 1222.Ql g 1223is appended to the last slash of the pattern, all occurrences 1224in each word are replaced. 1225If a 1226.Ql 1 1227is appended to the last slash of the pattern, only the first word 1228is affected. 1229If a 1230.Ql W 1231is appended to the last slash of the pattern, 1232then the value is treated as a single word 1233(possibly containing embedded white space). 1234If 1235.Ar old_string 1236begins with a caret 1237.Pq Ql ^ , 1238.Ar old_string 1239is anchored at the beginning of each word. 1240If 1241.Ar old_string 1242ends with a dollar sign 1243.Pq Ql \&$ , 1244it is anchored at the end of each word. 1245Inside 1246.Ar new_string , 1247an ampersand 1248.Pq Ql \*[Am] 1249is replaced by 1250.Ar old_string 1251(without any 1252.Ql ^ 1253or 1254.Ql \&$ ) . 1255Any character may be used as a delimiter for the parts of the modifier 1256string. 1257The anchoring, ampersand and delimiter characters may be escaped with a 1258backslash 1259.Pq Ql \e . 1260.Pp 1261Variable expansion occurs in the normal fashion inside both 1262.Ar old_string 1263and 1264.Ar new_string 1265with the single exception that a backslash is used to prevent the expansion 1266of a dollar sign 1267.Pq Ql \&$ , 1268not a preceding dollar sign as is usual. 1269.Sm off 1270.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1271.Sm on 1272The 1273.Cm \&:C 1274modifier is just like the 1275.Cm \&:S 1276modifier except that the old and new strings, instead of being 1277simple strings, are an extended regular expression (see 1278.Xr regex 3 ) 1279string 1280.Ar pattern 1281and an 1282.Xr ed 1 Ns \-style 1283string 1284.Ar replacement . 1285Normally, the first occurrence of the pattern 1286.Ar pattern 1287in each word of the value is substituted with 1288.Ar replacement . 1289The 1290.Ql 1 1291modifier causes the substitution to apply to at most one word; the 1292.Ql g 1293modifier causes the substitution to apply to as many instances of the 1294search pattern 1295.Ar pattern 1296as occur in the word or words it is found in; the 1297.Ql W 1298modifier causes the value to be treated as a single word 1299(possibly containing embedded white space). 1300Note that 1301.Ql 1 1302and 1303.Ql g 1304are orthogonal; the former specifies whether multiple words are 1305potentially affected, the latter whether multiple substitutions can 1306potentially occur within each affected word. 1307.Pp 1308As for the 1309.Cm \&:S 1310modifier, the 1311.Ar pattern 1312and 1313.Ar replacement 1314are subjected to variable expansion before being parsed as 1315regular expressions. 1316.It Cm \&:T 1317Replaces each word in the variable with its last component. 1318.It Cm \&:u 1319Remove adjacent duplicate words (like 1320.Xr uniq 1 ) . 1321.Sm off 1322.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1323.Sm on 1324If the variable name (not its value), when parsed as a .if conditional 1325expression, evaluates to true, return as its value the 1326.Ar true_string , 1327otherwise return the 1328.Ar false_string . 1329Since the variable name is used as the expression, \&:\&? must be the 1330first modifier after the variable name itself - which will, of course, 1331usually contain variable expansions. 1332A common error is trying to use expressions like 1333.Dl ${NUMBERS:M42:?match:no} 1334which actually tests defined(NUMBERS), 1335to determine is any words match "42" you need to use something like: 1336.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1337.It Ar :old_string=new_string 1338This is the 1339.At V 1340style variable substitution. 1341It must be the last modifier specified. 1342If 1343.Ar old_string 1344or 1345.Ar new_string 1346do not contain the pattern matching character 1347.Ar % 1348then it is assumed that they are 1349anchored at the end of each word, so only suffixes or entire 1350words may be replaced. 1351Otherwise 1352.Ar % 1353is the substring of 1354.Ar old_string 1355to be replaced in 1356.Ar new_string . 1357.Pp 1358Variable expansion occurs in the normal fashion inside both 1359.Ar old_string 1360and 1361.Ar new_string 1362with the single exception that a backslash is used to prevent the 1363expansion of a dollar sign 1364.Pq Ql \&$ , 1365not a preceding dollar sign as is usual. 1366.Sm off 1367.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1368.Sm on 1369This is the loop expansion mechanism from the OSF Development 1370Environment (ODE) make. 1371Unlike 1372.Cm \&.for 1373loops expansion occurs at the time of 1374reference. 1375Assign 1376.Ar temp 1377to each word in the variable and evaluate 1378.Ar string . 1379The ODE convention is that 1380.Ar temp 1381should start and end with a period. 1382For example. 1383.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1384.Pp 1385However a single character variable is often more readable: 1386.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1387.It Cm \&:U Ns Ar newval 1388If the variable is undefined 1389.Ar newval 1390is the value. 1391If the variable is defined, the existing value is returned. 1392This is another ODE make feature. 1393It is handy for setting per-target CFLAGS for instance: 1394.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1395If a value is only required if the variable is undefined, use: 1396.Dl ${VAR:D:Unewval} 1397.It Cm \&:D Ns Ar newval 1398If the variable is defined 1399.Ar newval 1400is the value. 1401.It Cm \&:L 1402The name of the variable is the value. 1403.It Cm \&:P 1404The path of the node which has the same name as the variable 1405is the value. 1406If no such node exists or its path is null, then the 1407name of the variable is used. 1408In order for this modifier to work, the name (node) must at least have 1409appeared on the rhs of a dependency. 1410.Sm off 1411.It Cm \&:\&! Ar cmd Cm \&! 1412.Sm on 1413The output of running 1414.Ar cmd 1415is the value. 1416.It Cm \&:sh 1417If the variable is non-empty it is run as a command and the output 1418becomes the new value. 1419.It Cm \&::= Ns Ar str 1420The variable is assigned the value 1421.Ar str 1422after substitution. 1423This modifier and its variations are useful in 1424obscure situations such as wanting to set a variable when shell commands 1425are being parsed. 1426These assignment modifiers always expand to 1427nothing, so if appearing in a rule line by themselves should be 1428preceded with something to keep 1429.Nm 1430happy. 1431.Pp 1432The 1433.Ql Cm \&:: 1434helps avoid false matches with the 1435.At V 1436style 1437.Cm \&:= 1438modifier and since substitution always occurs the 1439.Cm \&::= 1440form is vaguely appropriate. 1441.It Cm \&::?= Ns Ar str 1442As for 1443.Cm \&::= 1444but only if the variable does not already have a value. 1445.It Cm \&::+= Ns Ar str 1446Append 1447.Ar str 1448to the variable. 1449.It Cm \&::!= Ns Ar cmd 1450Assign the output of 1451.Ar cmd 1452to the variable. 1453.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1454Selects one or more words from the value, 1455or performs other operations related to the way in which the 1456value is divided into words. 1457.Pp 1458Ordinarily, a value is treated as a sequence of words 1459delimited by white space. 1460Some modifiers suppress this behavior, 1461causing a value to be treated as a single word 1462(possibly containing embedded white space). 1463An empty value, or a value that consists entirely of white-space, 1464is treated as a single word. 1465For the purposes of the 1466.Ql Cm \&:[] 1467modifier, the words are indexed both forwards using positive integers 1468(where index 1 represents the first word), 1469and backwards using negative integers 1470(where index \-1 represents the last word). 1471.Pp 1472The 1473.Ar range 1474is subjected to variable expansion, and the expanded result is 1475then interpreted as follows: 1476.Bl -tag -width index 1477.\" :[n] 1478.It Ar index 1479Selects a single word from the value. 1480.\" :[start..end] 1481.It Ar start Ns Cm \&.. Ns Ar end 1482Selects all words from 1483.Ar start 1484to 1485.Ar end , 1486inclusive. 1487For example, 1488.Ql Cm \&:[2..-1] 1489selects all words from the second word to the last word. 1490If 1491.Ar start 1492is greater than 1493.Ar end , 1494then the words are output in reverse order. 1495For example, 1496.Ql Cm \&:[-1..1] 1497selects all the words from last to first. 1498.\" :[*] 1499.It Cm \&* 1500Causes subsequent modifiers to treat the value as a single word 1501(possibly containing embedded white space). 1502Analogous to the effect of 1503\&"$*\&" 1504in Bourne shell. 1505.\" :[0] 1506.It 0 1507Means the same as 1508.Ql Cm \&:[*] . 1509.\" :[*] 1510.It Cm \&@ 1511Causes subsequent modifiers to treat the value as a sequence of words 1512delimited by white space. 1513Analogous to the effect of 1514\&"$@\&" 1515in Bourne shell. 1516.\" :[#] 1517.It Cm \&# 1518Returns the number of words in the value. 1519.El \" :[range] 1520.El 1521.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1522Makefile inclusion, conditional structures and for loops reminiscent 1523of the C programming language are provided in 1524.Nm . 1525All such structures are identified by a line beginning with a single 1526dot 1527.Pq Ql \&. 1528character. 1529Files are included with either 1530.Cm \&.include Aq Ar file 1531or 1532.Cm \&.include Pf \*q Ar file Ns \*q . 1533Variables between the angle brackets or double quotes are expanded 1534to form the file name. 1535If angle brackets are used, the included makefile is expected to be in 1536the system makefile directory. 1537If double quotes are used, the including makefile's directory and any 1538directories specified using the 1539.Fl I 1540option are searched before the system 1541makefile directory. 1542For compatibility with other versions of 1543.Nm 1544.Ql include file ... 1545is also accepted. 1546.Pp 1547If the include statement is written as 1548.Cm .-include 1549or as 1550.Cm .sinclude 1551then errors locating and/or opening include files are ignored. 1552.Pp 1553If the include statement is written as 1554.Cm .dinclude 1555not only are errors locating and/or opening include files ignored, 1556but stale dependencies within the included file will be ignored 1557just like 1558.Va .MAKE.DEPENDFILE . 1559.Pp 1560Conditional expressions are also preceded by a single dot as the first 1561character of a line. 1562The possible conditionals are as follows: 1563.Bl -tag -width Ds 1564.It Ic .error Ar message 1565The message is printed along with the name of the makefile and line number, 1566then 1567.Nm 1568will exit. 1569.It Ic .export Ar variable ... 1570Export the specified global variable. 1571If no variable list is provided, all globals are exported 1572except for internal variables (those that start with 1573.Ql \&. ) . 1574This is not affected by the 1575.Fl X 1576flag, so should be used with caution. 1577For compatibility with other 1578.Nm 1579programs 1580.Ql export variable=value 1581is also accepted. 1582.Pp 1583Appending a variable name to 1584.Va .MAKE.EXPORTED 1585is equivalent to exporting a variable. 1586.It Ic .export-env Ar variable ... 1587The same as 1588.Ql .export , 1589except that the variable is not appended to 1590.Va .MAKE.EXPORTED . 1591This allows exporting a value to the environment which is different from that 1592used by 1593.Nm 1594internally. 1595.It Ic .export-literal Ar variable ... 1596The same as 1597.Ql .export-env , 1598except that variables in the value are not expanded. 1599.It Ic .info Ar message 1600The message is printed along with the name of the makefile and line number. 1601.It Ic .undef Ar variable 1602Un-define the specified global variable. 1603Only global variables may be un-defined. 1604.It Ic .unexport Ar variable ... 1605The opposite of 1606.Ql .export . 1607The specified global 1608.Va variable 1609will be removed from 1610.Va .MAKE.EXPORTED . 1611If no variable list is provided, all globals are unexported, 1612and 1613.Va .MAKE.EXPORTED 1614deleted. 1615.It Ic .unexport-env 1616Unexport all globals previously exported and 1617clear the environment inherited from the parent. 1618This operation will cause a memory leak of the original environment, 1619so should be used sparingly. 1620Testing for 1621.Va .MAKE.LEVEL 1622being 0, would make sense. 1623Also note that any variables which originated in the parent environment 1624should be explicitly preserved if desired. 1625For example: 1626.Bd -literal -offset indent 1627.Li .if ${.MAKE.LEVEL} == 0 1628PATH := ${PATH} 1629.Li .unexport-env 1630.Li .export PATH 1631.Li .endif 1632.Pp 1633.Ed 1634Would result in an environment containing only 1635.Ql Ev PATH , 1636which is the minimal useful environment. 1637Actually 1638.Ql Ev .MAKE.LEVEL 1639will also be pushed into the new environment. 1640.It Ic .warning Ar message 1641The message prefixed by 1642.Ql Pa warning: 1643is printed along with the name of the makefile and line number. 1644.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1645Test the value of an expression. 1646.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1647Test the value of a variable. 1648.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1649Test the value of a variable. 1650.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1651Test the target being built. 1652.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1653Test the target being built. 1654.It Ic .else 1655Reverse the sense of the last conditional. 1656.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1657A combination of 1658.Ql Ic .else 1659followed by 1660.Ql Ic .if . 1661.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1662A combination of 1663.Ql Ic .else 1664followed by 1665.Ql Ic .ifdef . 1666.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1667A combination of 1668.Ql Ic .else 1669followed by 1670.Ql Ic .ifndef . 1671.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1672A combination of 1673.Ql Ic .else 1674followed by 1675.Ql Ic .ifmake . 1676.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1677A combination of 1678.Ql Ic .else 1679followed by 1680.Ql Ic .ifnmake . 1681.It Ic .endif 1682End the body of the conditional. 1683.El 1684.Pp 1685The 1686.Ar operator 1687may be any one of the following: 1688.Bl -tag -width "Cm XX" 1689.It Cm \&|\&| 1690Logical OR. 1691.It Cm \&\*[Am]\*[Am] 1692Logical 1693.Tn AND ; 1694of higher precedence than 1695.Dq \&|\&| . 1696.El 1697.Pp 1698As in C, 1699.Nm 1700will only evaluate a conditional as far as is necessary to determine 1701its value. 1702Parentheses may be used to change the order of evaluation. 1703The boolean operator 1704.Ql Ic \&! 1705may be used to logically negate an entire 1706conditional. 1707It is of higher precedence than 1708.Ql Ic \&\*[Am]\*[Am] . 1709.Pp 1710The value of 1711.Ar expression 1712may be any of the following: 1713.Bl -tag -width defined 1714.It Ic defined 1715Takes a variable name as an argument and evaluates to true if the variable 1716has been defined. 1717.It Ic make 1718Takes a target name as an argument and evaluates to true if the target 1719was specified as part of 1720.Nm Ns 's 1721command line or was declared the default target (either implicitly or 1722explicitly, see 1723.Va .MAIN ) 1724before the line containing the conditional. 1725.It Ic empty 1726Takes a variable, with possible modifiers, and evaluates to true if 1727the expansion of the variable would result in an empty string. 1728.It Ic exists 1729Takes a file name as an argument and evaluates to true if the file exists. 1730The file is searched for on the system search path (see 1731.Va .PATH ) . 1732.It Ic target 1733Takes a target name as an argument and evaluates to true if the target 1734has been defined. 1735.It Ic commands 1736Takes a target name as an argument and evaluates to true if the target 1737has been defined and has commands associated with it. 1738.El 1739.Pp 1740.Ar Expression 1741may also be an arithmetic or string comparison. 1742Variable expansion is 1743performed on both sides of the comparison, after which the integral 1744values are compared. 1745A value is interpreted as hexadecimal if it is 1746preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1747The standard C relational operators are all supported. 1748If after 1749variable expansion, either the left or right hand side of a 1750.Ql Ic == 1751or 1752.Ql Ic "!=" 1753operator is not an integral value, then 1754string comparison is performed between the expanded 1755variables. 1756If no relational operator is given, it is assumed that the expanded 1757variable is being compared against 0 or an empty string in the case 1758of a string comparison. 1759.Pp 1760When 1761.Nm 1762is evaluating one of these conditional expressions, and it encounters 1763a (white-space separated) word it doesn't recognize, either the 1764.Dq make 1765or 1766.Dq defined 1767expression is applied to it, depending on the form of the conditional. 1768If the form is 1769.Ql Ic .ifdef , 1770.Ql Ic .ifndef , 1771or 1772.Ql Ic .if 1773the 1774.Dq defined 1775expression is applied. 1776Similarly, if the form is 1777.Ql Ic .ifmake 1778or 1779.Ql Ic .ifnmake , the 1780.Dq make 1781expression is applied. 1782.Pp 1783If the conditional evaluates to true the parsing of the makefile continues 1784as before. 1785If it evaluates to false, the following lines are skipped. 1786In both cases this continues until a 1787.Ql Ic .else 1788or 1789.Ql Ic .endif 1790is found. 1791.Pp 1792For loops are typically used to apply a set of rules to a list of files. 1793The syntax of a for loop is: 1794.Pp 1795.Bl -tag -compact -width Ds 1796.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1797.It Aq make-rules 1798.It Ic \&.endfor 1799.El 1800.Pp 1801After the for 1802.Ic expression 1803is evaluated, it is split into words. 1804On each iteration of the loop, one word is taken and assigned to each 1805.Ic variable , 1806in order, and these 1807.Ic variables 1808are substituted into the 1809.Ic make-rules 1810inside the body of the for loop. 1811The number of words must come out even; that is, if there are three 1812iteration variables, the number of words provided must be a multiple 1813of three. 1814.Sh COMMENTS 1815Comments begin with a hash 1816.Pq Ql \&# 1817character, anywhere but in a shell 1818command line, and continue to the end of an unescaped new line. 1819.Sh SPECIAL SOURCES (ATTRIBUTES) 1820.Bl -tag -width .IGNOREx 1821.It Ic .EXEC 1822Target is never out of date, but always execute commands anyway. 1823.It Ic .IGNORE 1824Ignore any errors from the commands associated with this target, exactly 1825as if they all were preceded by a dash 1826.Pq Ql \- . 1827.\" .It Ic .INVISIBLE 1828.\" XXX 1829.\" .It Ic .JOIN 1830.\" XXX 1831.It Ic .MADE 1832Mark all sources of this target as being up-to-date. 1833.It Ic .MAKE 1834Execute the commands associated with this target even if the 1835.Fl n 1836or 1837.Fl t 1838options were specified. 1839Normally used to mark recursive 1840.Nm Ns s . 1841.It Ic .META 1842Create a meta file for the target, even if it is flagged as 1843.Ic .PHONY , 1844.Ic .MAKE , 1845or 1846.Ic .SPECIAL . 1847Usage in conjunction with 1848.Ic .MAKE 1849is the most likely case. 1850In "meta" mode, the target is out-of-date if the meta file is missing. 1851.It Ic .NOMETA 1852Do not create a meta file for the target. 1853Meta files are also not created for 1854.Ic .PHONY , 1855.Ic .MAKE , 1856or 1857.Ic .SPECIAL 1858targets. 1859.It Ic .NOMETA_CMP 1860Ignore differences in commands when deciding if target is out of date. 1861This is useful if the command contains a value which always changes. 1862If the number of commands change, though, the target will still be out of date. 1863The same effect applies to any command line that uses the variable 1864.Va .OODATE , 1865which can be used for that purpose even when not otherwise needed or desired: 1866.Bd -literal -offset indent 1867 1868skip-compare-for-some: 1869 @echo this will be compared 1870 @echo this will not ${.OODATE:M.NOMETA_CMP} 1871 @echo this will also be compared 1872 1873.Ed 1874The 1875.Cm \&:M 1876pattern suppresses any expansion of the unwanted variable. 1877.It Ic .NOPATH 1878Do not search for the target in the directories specified by 1879.Ic .PATH . 1880.It Ic .NOTMAIN 1881Normally 1882.Nm 1883selects the first target it encounters as the default target to be built 1884if no target was specified. 1885This source prevents this target from being selected. 1886.It Ic .OPTIONAL 1887If a target is marked with this attribute and 1888.Nm 1889can't figure out how to create it, it will ignore this fact and assume 1890the file isn't needed or already exists. 1891.It Ic .PHONY 1892The target does not 1893correspond to an actual file; it is always considered to be out of date, 1894and will not be created with the 1895.Fl t 1896option. 1897Suffix-transformation rules are not applied to 1898.Ic .PHONY 1899targets. 1900.It Ic .PRECIOUS 1901When 1902.Nm 1903is interrupted, it normally removes any partially made targets. 1904This source prevents the target from being removed. 1905.It Ic .RECURSIVE 1906Synonym for 1907.Ic .MAKE . 1908.It Ic .SILENT 1909Do not echo any of the commands associated with this target, exactly 1910as if they all were preceded by an at sign 1911.Pq Ql @ . 1912.It Ic .USE 1913Turn the target into 1914.Nm Ns 's 1915version of a macro. 1916When the target is used as a source for another target, the other target 1917acquires the commands, sources, and attributes (except for 1918.Ic .USE ) 1919of the 1920source. 1921If the target already has commands, the 1922.Ic .USE 1923target's commands are appended 1924to them. 1925.It Ic .USEBEFORE 1926Exactly like 1927.Ic .USE , 1928but prepend the 1929.Ic .USEBEFORE 1930target commands to the target. 1931.It Ic .WAIT 1932If 1933.Ic .WAIT 1934appears in a dependency line, the sources that precede it are 1935made before the sources that succeed it in the line. 1936Since the dependents of files are not made until the file itself 1937could be made, this also stops the dependents being built unless they 1938are needed for another branch of the dependency tree. 1939So given: 1940.Bd -literal 1941x: a .WAIT b 1942 echo x 1943a: 1944 echo a 1945b: b1 1946 echo b 1947b1: 1948 echo b1 1949 1950.Ed 1951the output is always 1952.Ql a , 1953.Ql b1 , 1954.Ql b , 1955.Ql x . 1956.br 1957The ordering imposed by 1958.Ic .WAIT 1959is only relevant for parallel makes. 1960.El 1961.Sh SPECIAL TARGETS 1962Special targets may not be included with other targets, i.e. they must be 1963the only target specified. 1964.Bl -tag -width .BEGINx 1965.It Ic .BEGIN 1966Any command lines attached to this target are executed before anything 1967else is done. 1968.It Ic .DEFAULT 1969This is sort of a 1970.Ic .USE 1971rule for any target (that was used only as a 1972source) that 1973.Nm 1974can't figure out any other way to create. 1975Only the shell script is used. 1976The 1977.Ic .IMPSRC 1978variable of a target that inherits 1979.Ic .DEFAULT Ns 's 1980commands is set 1981to the target's own name. 1982.It Ic .END 1983Any command lines attached to this target are executed after everything 1984else is done. 1985.It Ic .ERROR 1986Any command lines attached to this target are executed when another target fails. 1987The 1988.Ic .ERROR_TARGET 1989variable is set to the target that failed. 1990See also 1991.Ic MAKE_PRINT_VAR_ON_ERROR . 1992.It Ic .IGNORE 1993Mark each of the sources with the 1994.Ic .IGNORE 1995attribute. 1996If no sources are specified, this is the equivalent of specifying the 1997.Fl i 1998option. 1999.It Ic .INTERRUPT 2000If 2001.Nm 2002is interrupted, the commands for this target will be executed. 2003.It Ic .MAIN 2004If no target is specified when 2005.Nm 2006is invoked, this target will be built. 2007.It Ic .MAKEFLAGS 2008This target provides a way to specify flags for 2009.Nm 2010when the makefile is used. 2011The flags are as if typed to the shell, though the 2012.Fl f 2013option will have 2014no effect. 2015.\" XXX: NOT YET!!!! 2016.\" .It Ic .NOTPARALLEL 2017.\" The named targets are executed in non parallel mode. 2018.\" If no targets are 2019.\" specified, then all targets are executed in non parallel mode. 2020.It Ic .NOPATH 2021Apply the 2022.Ic .NOPATH 2023attribute to any specified sources. 2024.It Ic .NOTPARALLEL 2025Disable parallel mode. 2026.It Ic .NO_PARALLEL 2027Synonym for 2028.Ic .NOTPARALLEL , 2029for compatibility with other pmake variants. 2030.It Ic .OBJDIR 2031The source is a new value for 2032.Ql Va .OBJDIR . 2033If it exists, 2034.Nm 2035will 2036.Xr chdir 2 2037to it and update the value of 2038.Ql Va .OBJDIR . 2039.It Ic .ORDER 2040The named targets are made in sequence. 2041This ordering does not add targets to the list of targets to be made. 2042Since the dependents of a target do not get built until the target itself 2043could be built, unless 2044.Ql a 2045is built by another part of the dependency graph, 2046the following is a dependency loop: 2047.Bd -literal 2048\&.ORDER: b a 2049b: a 2050.Ed 2051.Pp 2052The ordering imposed by 2053.Ic .ORDER 2054is only relevant for parallel makes. 2055.\" XXX: NOT YET!!!! 2056.\" .It Ic .PARALLEL 2057.\" The named targets are executed in parallel mode. 2058.\" If no targets are 2059.\" specified, then all targets are executed in parallel mode. 2060.It Ic .PATH 2061The sources are directories which are to be searched for files not 2062found in the current directory. 2063If no sources are specified, any previously specified directories are 2064deleted. 2065If the source is the special 2066.Ic .DOTLAST 2067target, then the current working 2068directory is searched last. 2069.It Ic .PATH. Ns Va suffix 2070Like 2071.Ic .PATH 2072but applies only to files with a particular suffix. 2073The suffix must have been previously declared with 2074.Ic .SUFFIXES . 2075.It Ic .PHONY 2076Apply the 2077.Ic .PHONY 2078attribute to any specified sources. 2079.It Ic .PRECIOUS 2080Apply the 2081.Ic .PRECIOUS 2082attribute to any specified sources. 2083If no sources are specified, the 2084.Ic .PRECIOUS 2085attribute is applied to every 2086target in the file. 2087.It Ic .SHELL 2088Sets the shell that 2089.Nm 2090will use to execute commands. 2091The sources are a set of 2092.Ar field=value 2093pairs. 2094.Bl -tag -width hasErrCtls 2095.It Ar name 2096This is the minimal specification, used to select one of the built-in 2097shell specs; 2098.Ar sh , 2099.Ar ksh , 2100and 2101.Ar csh . 2102.It Ar path 2103Specifies the path to the shell. 2104.It Ar hasErrCtl 2105Indicates whether the shell supports exit on error. 2106.It Ar check 2107The command to turn on error checking. 2108.It Ar ignore 2109The command to disable error checking. 2110.It Ar echo 2111The command to turn on echoing of commands executed. 2112.It Ar quiet 2113The command to turn off echoing of commands executed. 2114.It Ar filter 2115The output to filter after issuing the 2116.Ar quiet 2117command. 2118It is typically identical to 2119.Ar quiet . 2120.It Ar errFlag 2121The flag to pass the shell to enable error checking. 2122.It Ar echoFlag 2123The flag to pass the shell to enable command echoing. 2124.It Ar newline 2125The string literal to pass the shell that results in a single newline 2126character when used outside of any quoting characters. 2127.El 2128Example: 2129.Bd -literal 2130\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2131 check="set \-e" ignore="set +e" \e 2132 echo="set \-v" quiet="set +v" filter="set +v" \e 2133 echoFlag=v errFlag=e newline="'\en'" 2134.Ed 2135.It Ic .SILENT 2136Apply the 2137.Ic .SILENT 2138attribute to any specified sources. 2139If no sources are specified, the 2140.Ic .SILENT 2141attribute is applied to every 2142command in the file. 2143.It Ic .STALE 2144This target gets run when a dependency file contains stale entries, having 2145.Va .ALLSRC 2146set to the name of that dependency file. 2147.It Ic .SUFFIXES 2148Each source specifies a suffix to 2149.Nm . 2150If no sources are specified, any previously specified suffixes are deleted. 2151It allows the creation of suffix-transformation rules. 2152.Pp 2153Example: 2154.Bd -literal 2155\&.SUFFIXES: .o 2156\&.c.o: 2157 cc \-o ${.TARGET} \-c ${.IMPSRC} 2158.Ed 2159.El 2160.Sh ENVIRONMENT 2161.Nm 2162uses the following environment variables, if they exist: 2163.Ev MACHINE , 2164.Ev MACHINE_ARCH , 2165.Ev MAKE , 2166.Ev MAKEFLAGS , 2167.Ev MAKEOBJDIR , 2168.Ev MAKEOBJDIRPREFIX , 2169.Ev MAKESYSPATH , 2170.Ev PWD , 2171and 2172.Ev TMPDIR . 2173.Pp 2174.Ev MAKEOBJDIRPREFIX 2175and 2176.Ev MAKEOBJDIR 2177may only be set in the environment or on the command line to 2178.Nm 2179and not as makefile variables; 2180see the description of 2181.Ql Va .OBJDIR 2182for more details. 2183.Sh FILES 2184.Bl -tag -width /usr/share/mk -compact 2185.It .depend 2186list of dependencies 2187.It Makefile 2188list of dependencies 2189.It makefile 2190list of dependencies 2191.It sys.mk 2192system makefile 2193.It /usr/share/mk 2194system makefile directory 2195.El 2196.Sh COMPATIBILITY 2197The basic make syntax is compatible between different versions of make; 2198however the special variables, variable modifiers and conditionals are not. 2199.Ss Older versions 2200An incomplete list of changes in older versions of 2201.Nm : 2202.Pp 2203The way that .for loop variables are substituted changed after 2204NetBSD 5.0 2205so that they still appear to be variable expansions. 2206In particular this stops them being treated as syntax, and removes some 2207obscure problems using them in .if statements. 2208.Pp 2209The way that parallel makes are scheduled changed in 2210NetBSD 4.0 2211so that .ORDER and .WAIT apply recursively to the dependent nodes. 2212The algorithms used may change again in the future. 2213.Ss Other make dialects 2214Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2215support most of the features of 2216.Nm 2217as described in this manual. 2218Most notably: 2219.Bl -bullet -offset indent 2220.It 2221The 2222.Ic .WAIT 2223and 2224.Ic .ORDER 2225declarations and most functionality pertaining to parallelization. 2226(GNU make supports parallelization but lacks these features needed to 2227control it effectively.) 2228.It 2229Directives, including for loops and conditionals and most of the 2230forms of include files. 2231(GNU make has its own incompatible and less powerful syntax for 2232conditionals.) 2233.It 2234All built-in variables that begin with a dot. 2235.It 2236Most of the special sources and targets that begin with a dot, 2237with the notable exception of 2238.Ic .PHONY , 2239.Ic .PRECIOUS , 2240and 2241.Ic .SUFFIXES . 2242.It 2243Variable modifiers, except for the 2244.Dl :old=new 2245string substitution, which does not portably support globbing with 2246.Ql % 2247and historically only works on declared suffixes. 2248.It 2249The 2250.Ic $> 2251variable even in its short form; most makes support this functionality 2252but its name varies. 2253.El 2254.Pp 2255Some features are somewhat more portable, such as assignment with 2256.Ic += , 2257.Ic ?= , 2258and 2259.Ic != . 2260The 2261.Ic .PATH 2262functionality is based on an older feature 2263.Ic VPATH 2264found in GNU make and many versions of SVR4 make; however, 2265historically its behavior is too ill-defined (and too buggy) to rely 2266upon. 2267.Pp 2268The 2269.Ic $@ 2270and 2271.Ic $< 2272variables are more or less universally portable, as is the 2273.Ic $(MAKE) 2274variable. 2275Basic use of suffix rules (for files only in the current directory, 2276not trying to chain transformations together, etc.) is also reasonably 2277portable. 2278.Sh SEE ALSO 2279.Xr mkdep 1 2280.Sh HISTORY 2281.Nm 2282is derived from NetBSD 2283.Xr make 1 . 2284It uses autoconf to facilitate portability to other platforms. 2285.Pp 2286A 2287make 2288command appeared in 2289.At v7 . 2290This 2291make 2292implementation is based on Adam De Boor's pmake program which was written 2293for Sprite at Berkeley. 2294It was designed to be a parallel distributed make running jobs on different 2295machines using a daemon called 2296.Dq customs . 2297.Pp 2298Historically the target/dependency 2299.Dq FRC 2300has been used to FoRCe rebuilding (since the target/dependency 2301does not exist... unless someone creates an 2302.Dq FRC 2303file). 2304.Sh BUGS 2305The 2306make 2307syntax is difficult to parse without actually acting of the data. 2308For instance finding the end of a variable use should involve scanning each 2309the modifiers using the correct terminator for each field. 2310In many places 2311make 2312just counts {} and () in order to find the end of a variable expansion. 2313.Pp 2314There is no way of escaping a space character in a filename. 2315