1.\" $NetBSD: make.1,v 1.247 2015/04/10 08:43:32 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 April 9, 2015 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm make 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrstWwX 41.Op Fl C Ar directory 42.Op Fl D Ar variable 43.Op Fl d Ar flags 44.Op Fl f Ar makefile 45.Op Fl I Ar directory 46.Op Fl J Ar private 47.Op Fl j Ar max_jobs 48.Op Fl m Ar directory 49.Op Fl T Ar file 50.Op Fl V Ar variable 51.Op Ar variable=value 52.Op Ar target ... 53.Sh DESCRIPTION 54.Nm 55is a program designed to simplify the maintenance of other programs. 56Its input is a list of specifications as to the files upon which programs 57and other files depend. 58If no 59.Fl f Ar makefile 60makefile option is given, 61.Nm 62will try to open 63.Ql Pa makefile 64then 65.Ql Pa Makefile 66in order to find the specifications. 67If the file 68.Ql Pa .depend 69exists, it is read (see 70.Xr mkdep 1 ) . 71.Pp 72This manual page is intended as a reference document only. 73For a more thorough description of 74.Nm 75and makefiles, please refer to 76.%T "PMake \- A Tutorial" . 77.Pp 78.Nm 79will prepend the contents of the 80.Va MAKEFLAGS 81environment variable to the command line arguments before parsing them. 82.Pp 83The options are as follows: 84.Bl -tag -width Ds 85.It Fl B 86Try to be backwards compatible by executing a single shell per command and 87by executing the commands to make the sources of a dependency line in sequence. 88.It Fl C Ar directory 89Change to 90.Ar directory 91before reading the makefiles or doing anything else. 92If multiple 93.Fl C 94options are specified, each is interpreted relative to the previous one: 95.Fl C Pa / Fl C Pa etc 96is equivalent to 97.Fl C Pa /etc . 98.It Fl D Ar variable 99Define 100.Ar variable 101to be 1, in the global context. 102.It Fl d Ar [-]flags 103Turn on debugging, and specify which portions of 104.Nm 105are to print debugging information. 106Unless the flags are preceded by 107.Ql \- 108they are added to the 109.Va MAKEFLAGS 110environment variable and will be processed by any child make processes. 111By default, debugging information is printed to standard error, 112but this can be changed using the 113.Ar F 114debugging flag. 115The debugging output is always unbuffered; in addition, if debugging 116is enabled but debugging output is not directed to standard output, 117then the standard output is line buffered. 118.Ar Flags 119is one or more of the following: 120.Bl -tag -width Ds 121.It Ar A 122Print all possible debugging information; 123equivalent to specifying all of the debugging flags. 124.It Ar a 125Print debugging information about archive searching and caching. 126.It Ar C 127Print debugging information about current working directory. 128.It Ar c 129Print debugging information about conditional evaluation. 130.It Ar d 131Print debugging information about directory searching and caching. 132.It Ar e 133Print debugging information about failed commands and targets. 134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 135Specify where debugging output is written. 136This must be the last flag, because it consumes the remainder of 137the argument. 138If the character immediately after the 139.Ql F 140flag is 141.Ql \&+ , 142then the file will be opened in append mode; 143otherwise the file will be overwritten. 144If the file name is 145.Ql stdout 146or 147.Ql stderr 148then debugging output will be written to the 149standard output or standard error output file descriptors respectively 150(and the 151.Ql \&+ 152option has no effect). 153Otherwise, the output will be written to the named file. 154If the file name ends 155.Ql .%d 156then the 157.Ql %d 158is replaced by the pid. 159.It Ar f 160Print debugging information about loop evaluation. 161.It Ar "g1" 162Print the input graph before making anything. 163.It Ar "g2" 164Print the input graph after making everything, or before exiting 165on error. 166.It Ar "g3" 167Print the input graph before exiting on error. 168.It Ar j 169Print debugging information about running multiple shells. 170.It Ar l 171Print commands in Makefiles regardless of whether or not they are prefixed by 172.Ql @ 173or other "quiet" flags. 174Also known as "loud" behavior. 175.It Ar M 176Print debugging information about "meta" mode decisions about targets. 177.It Ar m 178Print debugging information about making targets, including modification 179dates. 180.It Ar n 181Don't delete the temporary command scripts created when running commands. 182These temporary scripts are created in the directory 183referred to by the 184.Ev TMPDIR 185environment variable, or in 186.Pa /tmp 187if 188.Ev TMPDIR 189is unset or set to the empty string. 190The temporary scripts are created by 191.Xr mkstemp 3 , 192and have names of the form 193.Pa makeXXXXXX . 194.Em NOTE : 195This can create many files in 196.Ev TMPDIR 197or 198.Pa /tmp , 199so use with care. 200.It Ar p 201Print debugging information about makefile parsing. 202.It Ar s 203Print debugging information about suffix-transformation rules. 204.It Ar t 205Print debugging information about target list maintenance. 206.It Ar V 207Force the 208.Fl V 209option to print raw values of variables. 210.It Ar v 211Print debugging information about variable assignment. 212.It Ar 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 filesystem. 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.ALWAYS_PASS_JOB_QUEUE 769Tells 770.Nm 771whether to pass the descriptors of the job token queue 772even if the target is not tagged with 773.Ic .MAKE 774The default is 775.Ql Pa yes 776for backwards compatability with 777.Fx 9.0 778and earlier. 779.It Va .MAKE.DEPENDFILE 780Names the makefile (default 781.Ql Pa .depend ) 782from which generated dependencies are read. 783.It Va .MAKE.EXPAND_VARIABLES 784A boolean that controls the default behavior of the 785.Fl V 786option. 787.It Va .MAKE.EXPORTED 788The list of variables exported by 789.Nm . 790.It Va .MAKE.JOBS 791The argument to the 792.Fl j 793option. 794.It Va .MAKE.JOB.PREFIX 795If 796.Nm 797is run with 798.Ar j 799then output for each target is prefixed with a token 800.Ql --- target --- 801the first part of which can be controlled via 802.Va .MAKE.JOB.PREFIX . 803If 804.Va .MAKE.JOB.PREFIX 805is empty, no token is printed. 806.br 807For example: 808.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 809would produce tokens like 810.Ql ---make[1234] target --- 811making it easier to track the degree of parallelism being achieved. 812.It Ev MAKEFLAGS 813The environment variable 814.Ql Ev MAKEFLAGS 815may contain anything that 816may be specified on 817.Nm Ns 's 818command line. 819Anything specified on 820.Nm Ns 's 821command line is appended to the 822.Ql Ev MAKEFLAGS 823variable which is then 824entered into the environment for all programs which 825.Nm 826executes. 827.It Va .MAKE.LEVEL 828The recursion depth of 829.Nm . 830The initial instance of 831.Nm 832will be 0, and an incremented value is put into the environment 833to be seen by the next generation. 834This allows tests like: 835.Li .if ${.MAKE.LEVEL} == 0 836to protect things which should only be evaluated in the initial instance of 837.Nm . 838.It Va .MAKE.MAKEFILE_PREFERENCE 839The ordered list of makefile names 840(default 841.Ql Pa makefile , 842.Ql Pa Makefile ) 843that 844.Nm 845will look for. 846.It Va .MAKE.MAKEFILES 847The list of makefiles read by 848.Nm , 849which is useful for tracking dependencies. 850Each makefile is recorded only once, regardless of the number of times read. 851.It Va .MAKE.MODE 852Processed after reading all makefiles. 853Can affect the mode that 854.Nm 855runs in. 856It can contain a number of keywords: 857.Bl -hang -width ignore-cmd 858.It Pa compat 859Like 860.Fl B , 861puts 862.Nm 863into "compat" mode. 864.It Pa meta 865Puts 866.Nm 867into "meta" mode, where meta files are created for each target 868to capture the command run, the output generated and if 869.Xr filemon 4 870is available, the system calls which are of interest to 871.Nm . 872The captured output can be very useful when diagnosing errors. 873.It Pa curdirOk= Ar bf 874Normally 875.Nm 876will not create .meta files in 877.Ql Va .CURDIR . 878This can be overridden by setting 879.Va bf 880to a value which represents True. 881.It Pa env 882For debugging, it can be useful to inlcude the environment 883in the .meta file. 884.It Pa verbose 885If in "meta" mode, print a clue about the target being built. 886This is useful if the build is otherwise running silently. 887The message printed the value of: 888.Va .MAKE.META.PREFIX . 889.It Pa ignore-cmd 890Some makefiles have commands which are simply not stable. 891This keyword causes them to be ignored for 892determining whether a target is out of date in "meta" mode. 893See also 894.Ic .NOMETA_CMP . 895.It Pa silent= Ar bf 896If 897.Va bf 898is True, when a .meta file is created, mark the target 899.Ic .SILENT . 900.El 901.It Va .MAKE.META.BAILIWICK 902In "meta" mode, provides a list of prefixes which 903match the directories controlled by 904.Nm . 905If a file that was generated outside of 906.Va .OBJDIR 907but within said bailiwick is missing, 908the current target is considered out-of-date. 909.It Va .MAKE.META.CREATED 910In "meta" mode, this variable contains a list of all the meta files 911updated. 912If not empty, it can be used to trigger processing of 913.Va .MAKE.META.FILES . 914.It Va .MAKE.META.FILES 915In "meta" mode, this variable contains a list of all the meta files 916used (updated or not). 917This list can be used to process the meta files to extract dependency 918information. 919.It Va .MAKE.META.IGNORE_PATHS 920Provides a list of path prefixes that should be ignored; 921because the contents are expected to change over time. 922The default list includes: 923.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 924.It Va .MAKE.META.PREFIX 925Defines the message printed for each meta file updated in "meta verbose" mode. 926The default value is: 927.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 928.It Va .MAKEOVERRIDES 929This variable is used to record the names of variables assigned to 930on the command line, so that they may be exported as part of 931.Ql Ev MAKEFLAGS . 932This behaviour can be disabled by assigning an empty value to 933.Ql Va .MAKEOVERRIDES 934within a makefile. 935Extra variables can be exported from a makefile 936by appending their names to 937.Ql Va .MAKEOVERRIDES . 938.Ql Ev MAKEFLAGS 939is re-exported whenever 940.Ql Va .MAKEOVERRIDES 941is modified. 942.It Va .MAKE.PATH_FILEMON 943If 944.Nm 945was built with 946.Xr filemon 4 947support, this is set to the path of the device node. 948This allows makefiles to test for this support. 949.It Va .MAKE.PID 950The process-id of 951.Nm . 952.It Va .MAKE.PPID 953The parent process-id of 954.Nm . 955.It Va MAKE_PRINT_VAR_ON_ERROR 956When 957.Nm 958stops due to an error, it prints its name and the value of 959.Ql Va .CURDIR 960as well as the value of any variables named in 961.Ql Va MAKE_PRINT_VAR_ON_ERROR . 962.It Va .newline 963This variable is simply assigned a newline character as its value. 964This allows expansions using the 965.Cm \&:@ 966modifier to put a newline between 967iterations of the loop rather than a space. 968For example, the printing of 969.Ql Va MAKE_PRINT_VAR_ON_ERROR 970could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 971.It Va .OBJDIR 972A path to the directory where the targets are built. 973Its value is determined by trying to 974.Xr chdir 2 975to the following directories in order and using the first match: 976.Bl -enum 977.It 978.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 979.Pp 980(Only if 981.Ql Ev MAKEOBJDIRPREFIX 982is set in the environment or on the command line.) 983.It 984.Ev ${MAKEOBJDIR} 985.Pp 986(Only if 987.Ql Ev MAKEOBJDIR 988is set in the environment or on the command line.) 989.It 990.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 991.It 992.Ev ${.CURDIR} Ns Pa /obj 993.It 994.Pa /usr/obj/ Ns Ev ${.CURDIR} 995.It 996.Ev ${.CURDIR} 997.El 998.Pp 999Variable expansion is performed on the value before it's used, 1000so expressions such as 1001.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1002may be used. 1003This is especially useful with 1004.Ql Ev MAKEOBJDIR . 1005.Pp 1006.Ql Va .OBJDIR 1007may be modified in the makefile as a global variable. 1008In all cases, 1009.Nm 1010will 1011.Xr chdir 2 1012to 1013.Ql Va .OBJDIR 1014and set 1015.Ql Ev PWD 1016to that directory before executing any targets. 1017. 1018.It Va .PARSEDIR 1019A path to the directory of the current 1020.Ql Pa Makefile 1021being parsed. 1022.It Va .PARSEFILE 1023The basename of the current 1024.Ql Pa Makefile 1025being parsed. 1026This variable and 1027.Ql Va .PARSEDIR 1028are both set only while the 1029.Ql Pa Makefiles 1030are being parsed. 1031If you want to retain their current values, assign them to a variable 1032using assignment with expansion: 1033.Pq Ql Cm \&:= . 1034.It Va .PATH 1035A variable that represents the list of directories that 1036.Nm 1037will search for files. 1038The search list should be updated using the target 1039.Ql Va .PATH 1040rather than the variable. 1041.It Ev PWD 1042Alternate path to the current directory. 1043.Nm 1044normally sets 1045.Ql Va .CURDIR 1046to the canonical path given by 1047.Xr getcwd 3 . 1048However, if the environment variable 1049.Ql Ev PWD 1050is set and gives a path to the current directory, then 1051.Nm 1052sets 1053.Ql Va .CURDIR 1054to the value of 1055.Ql Ev PWD 1056instead. 1057This behaviour is disabled if 1058.Ql Ev MAKEOBJDIRPREFIX 1059is set or 1060.Ql Ev MAKEOBJDIR 1061contains a variable transform. 1062.Ql Ev PWD 1063is set to the value of 1064.Ql Va .OBJDIR 1065for all programs which 1066.Nm 1067executes. 1068.It Ev .TARGETS 1069The list of targets explicitly specified on the command line, if any. 1070.It Ev VPATH 1071Colon-separated 1072.Pq Dq \&: 1073lists of directories that 1074.Nm 1075will search for files. 1076The variable is supported for compatibility with old make programs only, 1077use 1078.Ql Va .PATH 1079instead. 1080.El 1081.Ss Variable modifiers 1082Variable expansion may be modified to select or modify each word of the 1083variable (where a 1084.Dq word 1085is white-space delimited sequence of characters). 1086The general format of a variable expansion is as follows: 1087.Pp 1088.Dl ${variable[:modifier[:...]]} 1089.Pp 1090Each modifier begins with a colon, 1091which may be escaped with a backslash 1092.Pq Ql \e . 1093.Pp 1094A set of modifiers can be specified via a variable, as follows: 1095.Pp 1096.Dl modifier_variable=modifier[:...] 1097.Dl ${variable:${modifier_variable}[:...]} 1098.Pp 1099In this case the first modifier in the modifier_variable does not 1100start with a colon, since that must appear in the referencing 1101variable. 1102If any of the modifiers in the modifier_variable contain a dollar sign 1103.Pq Ql $ , 1104these must be doubled to avoid early expansion. 1105.Pp 1106The supported modifiers are: 1107.Bl -tag -width EEE 1108.It Cm \&:E 1109Replaces each word in the variable with its suffix. 1110.It Cm \&:H 1111Replaces each word in the variable with everything but the last component. 1112.It Cm \&:M Ns Ar pattern 1113Select only those words that match 1114.Ar pattern . 1115The standard shell wildcard characters 1116.Pf ( Ql * , 1117.Ql \&? , 1118and 1119.Ql Oo Oc ) 1120may 1121be used. 1122The wildcard characters may be escaped with a backslash 1123.Pq Ql \e . 1124As a consequence of the way values are split into words, matched, 1125and then joined, a construct like 1126.Dl ${VAR:M*} 1127will normalise the inter-word spacing, removing all leading and 1128trailing space, and converting multiple consecutive spaces 1129to single spaces. 1130. 1131.It Cm \&:N Ns Ar pattern 1132This is identical to 1133.Ql Cm \&:M , 1134but selects all words which do not match 1135.Ar pattern . 1136.It Cm \&:O 1137Order every word in variable alphabetically. 1138To sort words in 1139reverse order use the 1140.Ql Cm \&:O:[-1..1] 1141combination of modifiers. 1142.It Cm \&:Ox 1143Randomize words in variable. 1144The results will be different each time you are referring to the 1145modified variable; use the assignment with expansion 1146.Pq Ql Cm \&:= 1147to prevent such behaviour. 1148For example, 1149.Bd -literal -offset indent 1150LIST= uno due tre quattro 1151RANDOM_LIST= ${LIST:Ox} 1152STATIC_RANDOM_LIST:= ${LIST:Ox} 1153 1154all: 1155 @echo "${RANDOM_LIST}" 1156 @echo "${RANDOM_LIST}" 1157 @echo "${STATIC_RANDOM_LIST}" 1158 @echo "${STATIC_RANDOM_LIST}" 1159.Ed 1160may produce output similar to: 1161.Bd -literal -offset indent 1162quattro due tre uno 1163tre due quattro uno 1164due uno quattro tre 1165due uno quattro tre 1166.Ed 1167.It Cm \&:Q 1168Quotes every shell meta-character in the variable, so that it can be passed 1169safely through recursive invocations of 1170.Nm . 1171.It Cm \&:R 1172Replaces each word in the variable with everything but its suffix. 1173.It Cm \&:gmtime 1174The value is a format string for 1175.Xr strftime 3 , 1176using the current 1177.Xr gmtime 3 . 1178.It Cm \&:hash 1179Compute a 32bit hash of the value and encode it as hex digits. 1180.It Cm \&:localtime 1181The value is a format string for 1182.Xr strftime 3 , 1183using the current 1184.Xr localtime 3 . 1185.It Cm \&:tA 1186Attempt to convert variable to an absolute path using 1187.Xr realpath 3 , 1188if that fails, the value is unchanged. 1189.It Cm \&:tl 1190Converts variable to lower-case letters. 1191.It Cm \&:ts Ns Ar c 1192Words in the variable are normally separated by a space on expansion. 1193This modifier sets the separator to the character 1194.Ar c . 1195If 1196.Ar c 1197is omitted, then no separator is used. 1198The common escapes (including octal numeric codes), work as expected. 1199.It Cm \&:tu 1200Converts variable to upper-case letters. 1201.It Cm \&:tW 1202Causes the value to be treated as a single word 1203(possibly containing embedded white space). 1204See also 1205.Ql Cm \&:[*] . 1206.It Cm \&:tw 1207Causes the value to be treated as a sequence of 1208words delimited by white space. 1209See also 1210.Ql Cm \&:[@] . 1211.Sm off 1212.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1213.Sm on 1214Modify the first occurrence of 1215.Ar old_string 1216in the variable's value, replacing it with 1217.Ar new_string . 1218If a 1219.Ql g 1220is appended to the last slash of the pattern, all occurrences 1221in each word are replaced. 1222If a 1223.Ql 1 1224is appended to the last slash of the pattern, only the first word 1225is affected. 1226If a 1227.Ql W 1228is appended to the last slash of the pattern, 1229then the value is treated as a single word 1230(possibly containing embedded white space). 1231If 1232.Ar old_string 1233begins with a caret 1234.Pq Ql ^ , 1235.Ar old_string 1236is anchored at the beginning of each word. 1237If 1238.Ar old_string 1239ends with a dollar sign 1240.Pq Ql \&$ , 1241it is anchored at the end of each word. 1242Inside 1243.Ar new_string , 1244an ampersand 1245.Pq Ql \*[Am] 1246is replaced by 1247.Ar old_string 1248(without any 1249.Ql ^ 1250or 1251.Ql \&$ ) . 1252Any character may be used as a delimiter for the parts of the modifier 1253string. 1254The anchoring, ampersand and delimiter characters may be escaped with a 1255backslash 1256.Pq Ql \e . 1257.Pp 1258Variable expansion occurs in the normal fashion inside both 1259.Ar old_string 1260and 1261.Ar new_string 1262with the single exception that a backslash is used to prevent the expansion 1263of a dollar sign 1264.Pq Ql \&$ , 1265not a preceding dollar sign as is usual. 1266.Sm off 1267.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1268.Sm on 1269The 1270.Cm \&:C 1271modifier is just like the 1272.Cm \&:S 1273modifier except that the old and new strings, instead of being 1274simple strings, are an extended regular expression (see 1275.Xr regex 3 ) 1276string 1277.Ar pattern 1278and an 1279.Xr ed 1 Ns \-style 1280string 1281.Ar replacement . 1282Normally, the first occurrence of the pattern 1283.Ar pattern 1284in each word of the value is substituted with 1285.Ar replacement . 1286The 1287.Ql 1 1288modifier causes the substitution to apply to at most one word; the 1289.Ql g 1290modifier causes the substitution to apply to as many instances of the 1291search pattern 1292.Ar pattern 1293as occur in the word or words it is found in; the 1294.Ql W 1295modifier causes the value to be treated as a single word 1296(possibly containing embedded white space). 1297Note that 1298.Ql 1 1299and 1300.Ql g 1301are orthogonal; the former specifies whether multiple words are 1302potentially affected, the latter whether multiple substitutions can 1303potentially occur within each affected word. 1304.Pp 1305As for the 1306.Cm \&:S 1307modifier, the 1308.Ar pattern 1309and 1310.Ar replacement 1311are subjected to variable expansion before being parsed as 1312regular expressions. 1313.It Cm \&:T 1314Replaces each word in the variable with its last component. 1315.It Cm \&:u 1316Remove adjacent duplicate words (like 1317.Xr uniq 1 ) . 1318.Sm off 1319.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1320.Sm on 1321If the variable name (not its value), when parsed as a .if conditional 1322expression, evaluates to true, return as its value the 1323.Ar true_string , 1324otherwise return the 1325.Ar false_string . 1326Since the variable name is used as the expression, \&:\&? must be the 1327first modifier after the variable name itself - which will, of course, 1328usually contain variable expansions. 1329A common error is trying to use expressions like 1330.Dl ${NUMBERS:M42:?match:no} 1331which actually tests defined(NUMBERS), 1332to determine is any words match "42" you need to use something like: 1333.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1334.It Ar :old_string=new_string 1335This is the 1336.At V 1337style variable substitution. 1338It must be the last modifier specified. 1339If 1340.Ar old_string 1341or 1342.Ar new_string 1343do not contain the pattern matching character 1344.Ar % 1345then it is assumed that they are 1346anchored at the end of each word, so only suffixes or entire 1347words may be replaced. 1348Otherwise 1349.Ar % 1350is the substring of 1351.Ar old_string 1352to be replaced in 1353.Ar new_string . 1354.Pp 1355Variable expansion occurs in the normal fashion inside both 1356.Ar old_string 1357and 1358.Ar new_string 1359with the single exception that a backslash is used to prevent the 1360expansion of a dollar sign 1361.Pq Ql \&$ , 1362not a preceding dollar sign as is usual. 1363.Sm off 1364.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1365.Sm on 1366This is the loop expansion mechanism from the OSF Development 1367Environment (ODE) make. 1368Unlike 1369.Cm \&.for 1370loops expansion occurs at the time of 1371reference. 1372Assign 1373.Ar temp 1374to each word in the variable and evaluate 1375.Ar string . 1376The ODE convention is that 1377.Ar temp 1378should start and end with a period. 1379For example. 1380.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1381.Pp 1382However a single character variable is often more readable: 1383.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1384.It Cm \&:U Ns Ar newval 1385If the variable is undefined 1386.Ar newval 1387is the value. 1388If the variable is defined, the existing value is returned. 1389This is another ODE make feature. 1390It is handy for setting per-target CFLAGS for instance: 1391.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1392If a value is only required if the variable is undefined, use: 1393.Dl ${VAR:D:Unewval} 1394.It Cm \&:D Ns Ar newval 1395If the variable is defined 1396.Ar newval 1397is the value. 1398.It Cm \&:L 1399The name of the variable is the value. 1400.It Cm \&:P 1401The path of the node which has the same name as the variable 1402is the value. 1403If no such node exists or its path is null, then the 1404name of the variable is used. 1405In order for this modifier to work, the name (node) must at least have 1406appeared on the rhs of a dependency. 1407.Sm off 1408.It Cm \&:\&! Ar cmd Cm \&! 1409.Sm on 1410The output of running 1411.Ar cmd 1412is the value. 1413.It Cm \&:sh 1414If the variable is non-empty it is run as a command and the output 1415becomes the new value. 1416.It Cm \&::= Ns Ar str 1417The variable is assigned the value 1418.Ar str 1419after substitution. 1420This modifier and its variations are useful in 1421obscure situations such as wanting to set a variable when shell commands 1422are being parsed. 1423These assignment modifiers always expand to 1424nothing, so if appearing in a rule line by themselves should be 1425preceded with something to keep 1426.Nm 1427happy. 1428.Pp 1429The 1430.Ql Cm \&:: 1431helps avoid false matches with the 1432.At V 1433style 1434.Cm \&:= 1435modifier and since substitution always occurs the 1436.Cm \&::= 1437form is vaguely appropriate. 1438.It Cm \&::?= Ns Ar str 1439As for 1440.Cm \&::= 1441but only if the variable does not already have a value. 1442.It Cm \&::+= Ns Ar str 1443Append 1444.Ar str 1445to the variable. 1446.It Cm \&::!= Ns Ar cmd 1447Assign the output of 1448.Ar cmd 1449to the variable. 1450.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1451Selects one or more words from the value, 1452or performs other operations related to the way in which the 1453value is divided into words. 1454.Pp 1455Ordinarily, a value is treated as a sequence of words 1456delimited by white space. 1457Some modifiers suppress this behaviour, 1458causing a value to be treated as a single word 1459(possibly containing embedded white space). 1460An empty value, or a value that consists entirely of white-space, 1461is treated as a single word. 1462For the purposes of the 1463.Ql Cm \&:[] 1464modifier, the words are indexed both forwards using positive integers 1465(where index 1 represents the first word), 1466and backwards using negative integers 1467(where index \-1 represents the last word). 1468.Pp 1469The 1470.Ar range 1471is subjected to variable expansion, and the expanded result is 1472then interpreted as follows: 1473.Bl -tag -width index 1474.\" :[n] 1475.It Ar index 1476Selects a single word from the value. 1477.\" :[start..end] 1478.It Ar start Ns Cm \&.. Ns Ar end 1479Selects all words from 1480.Ar start 1481to 1482.Ar end , 1483inclusive. 1484For example, 1485.Ql Cm \&:[2..-1] 1486selects all words from the second word to the last word. 1487If 1488.Ar start 1489is greater than 1490.Ar end , 1491then the words are output in reverse order. 1492For example, 1493.Ql Cm \&:[-1..1] 1494selects all the words from last to first. 1495.\" :[*] 1496.It Cm \&* 1497Causes subsequent modifiers to treat the value as a single word 1498(possibly containing embedded white space). 1499Analogous to the effect of 1500\&"$*\&" 1501in Bourne shell. 1502.\" :[0] 1503.It 0 1504Means the same as 1505.Ql Cm \&:[*] . 1506.\" :[*] 1507.It Cm \&@ 1508Causes subsequent modifiers to treat the value as a sequence of words 1509delimited by white space. 1510Analogous to the effect of 1511\&"$@\&" 1512in Bourne shell. 1513.\" :[#] 1514.It Cm \&# 1515Returns the number of words in the value. 1516.El \" :[range] 1517.El 1518.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1519Makefile inclusion, conditional structures and for loops reminiscent 1520of the C programming language are provided in 1521.Nm . 1522All such structures are identified by a line beginning with a single 1523dot 1524.Pq Ql \&. 1525character. 1526Files are included with either 1527.Cm \&.include Aq Ar file 1528or 1529.Cm \&.include Pf \*q Ar file Ns \*q . 1530Variables between the angle brackets or double quotes are expanded 1531to form the file name. 1532If angle brackets are used, the included makefile is expected to be in 1533the system makefile directory. 1534If double quotes are used, the including makefile's directory and any 1535directories specified using the 1536.Fl I 1537option are searched before the system 1538makefile directory. 1539For compatibility with other versions of 1540.Nm 1541.Ql include file ... 1542is also accepted. 1543If the include statement is written as 1544.Cm .-include 1545or as 1546.Cm .sinclude 1547then errors locating and/or opening include files are ignored. 1548.Pp 1549Conditional expressions are also preceded by a single dot as the first 1550character of a line. 1551The possible conditionals are as follows: 1552.Bl -tag -width Ds 1553.It Ic .error Ar message 1554The message is printed along with the name of the makefile and line number, 1555then 1556.Nm 1557will exit. 1558.It Ic .export Ar variable ... 1559Export the specified global variable. 1560If no variable list is provided, all globals are exported 1561except for internal variables (those that start with 1562.Ql \&. ) . 1563This is not affected by the 1564.Fl X 1565flag, so should be used with caution. 1566For compatibility with other 1567.Nm 1568programs 1569.Ql export variable=value 1570is also accepted. 1571.Pp 1572Appending a variable name to 1573.Va .MAKE.EXPORTED 1574is equivalent to exporting a variable. 1575.It Ic .export-env Ar variable ... 1576The same as 1577.Ql .export , 1578except that the variable is not appended to 1579.Va .MAKE.EXPORTED . 1580This allows exporting a value to the environment which is different from that 1581used by 1582.Nm 1583internally. 1584.It Ic .info Ar message 1585The message is printed along with the name of the makefile and line number. 1586.It Ic .undef Ar variable 1587Un-define the specified global variable. 1588Only global variables may be un-defined. 1589.It Ic .unexport Ar variable ... 1590The opposite of 1591.Ql .export . 1592The specified global 1593.Va variable 1594will be removed from 1595.Va .MAKE.EXPORTED . 1596If no variable list is provided, all globals are unexported, 1597and 1598.Va .MAKE.EXPORTED 1599deleted. 1600.It Ic .unexport-env 1601Unexport all globals previously exported and 1602clear the environment inherited from the parent. 1603This operation will cause a memory leak of the original environment, 1604so should be used sparingly. 1605Testing for 1606.Va .MAKE.LEVEL 1607being 0, would make sense. 1608Also note that any variables which originated in the parent environment 1609should be explicitly preserved if desired. 1610For example: 1611.Bd -literal -offset indent 1612.Li .if ${.MAKE.LEVEL} == 0 1613PATH := ${PATH} 1614.Li .unexport-env 1615.Li .export PATH 1616.Li .endif 1617.Pp 1618.Ed 1619Would result in an environment containing only 1620.Ql Ev PATH , 1621which is the minimal useful environment. 1622Actually 1623.Ql Ev .MAKE.LEVEL 1624will also be pushed into the new environment. 1625.It Ic .warning Ar message 1626The message prefixed by 1627.Ql Pa warning: 1628is printed along with the name of the makefile and line number. 1629.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1630Test the value of an expression. 1631.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1632Test the value of a variable. 1633.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1634Test the value of a variable. 1635.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1636Test the target being built. 1637.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1638Test the target being built. 1639.It Ic .else 1640Reverse the sense of the last conditional. 1641.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1642A combination of 1643.Ql Ic .else 1644followed by 1645.Ql Ic .if . 1646.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1647A combination of 1648.Ql Ic .else 1649followed by 1650.Ql Ic .ifdef . 1651.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1652A combination of 1653.Ql Ic .else 1654followed by 1655.Ql Ic .ifndef . 1656.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1657A combination of 1658.Ql Ic .else 1659followed by 1660.Ql Ic .ifmake . 1661.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1662A combination of 1663.Ql Ic .else 1664followed by 1665.Ql Ic .ifnmake . 1666.It Ic .endif 1667End the body of the conditional. 1668.El 1669.Pp 1670The 1671.Ar operator 1672may be any one of the following: 1673.Bl -tag -width "Cm XX" 1674.It Cm \&|\&| 1675Logical OR. 1676.It Cm \&\*[Am]\*[Am] 1677Logical 1678.Tn AND ; 1679of higher precedence than 1680.Dq \&|\&| . 1681.El 1682.Pp 1683As in C, 1684.Nm 1685will only evaluate a conditional as far as is necessary to determine 1686its value. 1687Parentheses may be used to change the order of evaluation. 1688The boolean operator 1689.Ql Ic \&! 1690may be used to logically negate an entire 1691conditional. 1692It is of higher precedence than 1693.Ql Ic \&\*[Am]\*[Am] . 1694.Pp 1695The value of 1696.Ar expression 1697may be any of the following: 1698.Bl -tag -width defined 1699.It Ic defined 1700Takes a variable name as an argument and evaluates to true if the variable 1701has been defined. 1702.It Ic make 1703Takes a target name as an argument and evaluates to true if the target 1704was specified as part of 1705.Nm Ns 's 1706command line or was declared the default target (either implicitly or 1707explicitly, see 1708.Va .MAIN ) 1709before the line containing the conditional. 1710.It Ic empty 1711Takes a variable, with possible modifiers, and evaluates to true if 1712the expansion of the variable would result in an empty string. 1713.It Ic exists 1714Takes a file name as an argument and evaluates to true if the file exists. 1715The file is searched for on the system search path (see 1716.Va .PATH ) . 1717.It Ic target 1718Takes a target name as an argument and evaluates to true if the target 1719has been defined. 1720.It Ic commands 1721Takes a target name as an argument and evaluates to true if the target 1722has been defined and has commands associated with it. 1723.El 1724.Pp 1725.Ar Expression 1726may also be an arithmetic or string comparison. 1727Variable expansion is 1728performed on both sides of the comparison, after which the integral 1729values are compared. 1730A value is interpreted as hexadecimal if it is 1731preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1732The standard C relational operators are all supported. 1733If after 1734variable expansion, either the left or right hand side of a 1735.Ql Ic == 1736or 1737.Ql Ic "!=" 1738operator is not an integral value, then 1739string comparison is performed between the expanded 1740variables. 1741If no relational operator is given, it is assumed that the expanded 1742variable is being compared against 0 or an empty string in the case 1743of a string comparison. 1744.Pp 1745When 1746.Nm 1747is evaluating one of these conditional expressions, and it encounters 1748a (white-space separated) word it doesn't recognize, either the 1749.Dq make 1750or 1751.Dq defined 1752expression is applied to it, depending on the form of the conditional. 1753If the form is 1754.Ql Ic .ifdef , 1755.Ql Ic .ifndef , 1756or 1757.Ql Ic .if 1758the 1759.Dq defined 1760expression is applied. 1761Similarly, if the form is 1762.Ql Ic .ifmake 1763or 1764.Ql Ic .ifnmake , the 1765.Dq make 1766expression is applied. 1767.Pp 1768If the conditional evaluates to true the parsing of the makefile continues 1769as before. 1770If it evaluates to false, the following lines are skipped. 1771In both cases this continues until a 1772.Ql Ic .else 1773or 1774.Ql Ic .endif 1775is found. 1776.Pp 1777For loops are typically used to apply a set of rules to a list of files. 1778The syntax of a for loop is: 1779.Pp 1780.Bl -tag -compact -width Ds 1781.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1782.It Aq make-rules 1783.It Ic \&.endfor 1784.El 1785.Pp 1786After the for 1787.Ic expression 1788is evaluated, it is split into words. 1789On each iteration of the loop, one word is taken and assigned to each 1790.Ic variable , 1791in order, and these 1792.Ic variables 1793are substituted into the 1794.Ic make-rules 1795inside the body of the for loop. 1796The number of words must come out even; that is, if there are three 1797iteration variables, the number of words provided must be a multiple 1798of three. 1799.Sh COMMENTS 1800Comments begin with a hash 1801.Pq Ql \&# 1802character, anywhere but in a shell 1803command line, and continue to the end of an unescaped new line. 1804.Sh SPECIAL SOURCES (ATTRIBUTES) 1805.Bl -tag -width .IGNOREx 1806.It Ic .EXEC 1807Target is never out of date, but always execute commands anyway. 1808.It Ic .IGNORE 1809Ignore any errors from the commands associated with this target, exactly 1810as if they all were preceded by a dash 1811.Pq Ql \- . 1812.\" .It Ic .INVISIBLE 1813.\" XXX 1814.\" .It Ic .JOIN 1815.\" XXX 1816.It Ic .MADE 1817Mark all sources of this target as being up-to-date. 1818.It Ic .MAKE 1819Execute the commands associated with this target even if the 1820.Fl n 1821or 1822.Fl t 1823options were specified. 1824Normally used to mark recursive 1825.Nm Ns s . 1826.It Ic .META 1827Create a meta file for the target, even if it is flagged as 1828.Ic .PHONY , 1829.Ic .MAKE , 1830or 1831.Ic .SPECIAL . 1832Usage in conjunction with 1833.Ic .MAKE 1834is the most likely case. 1835In "meta" mode, the target is out-of-date if the meta file is missing. 1836.It Ic .NOMETA 1837Do not create a meta file for the target. 1838Meta files are also not created for 1839.Ic .PHONY , 1840.Ic .MAKE , 1841or 1842.Ic .SPECIAL 1843targets. 1844.It Ic .NOMETA_CMP 1845Ignore differences in commands when deciding if target is out of date. 1846This is useful if the command contains a value which always changes. 1847If the number of commands change, though, the target will still be out of date. 1848The same effect applies to any command line that uses the variable 1849.Va .OODATE , 1850which can be used for that purpose even when not otherwise needed or desired: 1851.Bd -literal -offset indent 1852 1853skip-compare-for-some: 1854 @echo this will be compared 1855 @echo this will not ${.OODATE:M.NOMETA_CMP} 1856 @echo this will also be compared 1857 1858.Ed 1859The 1860.Cm \&:M 1861pattern suppresses any expansion of the unwanted variable. 1862.It Ic .NOPATH 1863Do not search for the target in the directories specified by 1864.Ic .PATH . 1865.It Ic .NOTMAIN 1866Normally 1867.Nm 1868selects the first target it encounters as the default target to be built 1869if no target was specified. 1870This source prevents this target from being selected. 1871.It Ic .OPTIONAL 1872If a target is marked with this attribute and 1873.Nm 1874can't figure out how to create it, it will ignore this fact and assume 1875the file isn't needed or already exists. 1876.It Ic .PHONY 1877The target does not 1878correspond to an actual file; it is always considered to be out of date, 1879and will not be created with the 1880.Fl t 1881option. 1882Suffix-transformation rules are not applied to 1883.Ic .PHONY 1884targets. 1885.It Ic .PRECIOUS 1886When 1887.Nm 1888is interrupted, it normally removes any partially made targets. 1889This source prevents the target from being removed. 1890.It Ic .RECURSIVE 1891Synonym for 1892.Ic .MAKE . 1893.It Ic .SILENT 1894Do not echo any of the commands associated with this target, exactly 1895as if they all were preceded by an at sign 1896.Pq Ql @ . 1897.It Ic .USE 1898Turn the target into 1899.Nm Ns 's 1900version of a macro. 1901When the target is used as a source for another target, the other target 1902acquires the commands, sources, and attributes (except for 1903.Ic .USE ) 1904of the 1905source. 1906If the target already has commands, the 1907.Ic .USE 1908target's commands are appended 1909to them. 1910.It Ic .USEBEFORE 1911Exactly like 1912.Ic .USE , 1913but prepend the 1914.Ic .USEBEFORE 1915target commands to the target. 1916.It Ic .WAIT 1917If 1918.Ic .WAIT 1919appears in a dependency line, the sources that precede it are 1920made before the sources that succeed it in the line. 1921Since the dependents of files are not made until the file itself 1922could be made, this also stops the dependents being built unless they 1923are needed for another branch of the dependency tree. 1924So given: 1925.Bd -literal 1926x: a .WAIT b 1927 echo x 1928a: 1929 echo a 1930b: b1 1931 echo b 1932b1: 1933 echo b1 1934 1935.Ed 1936the output is always 1937.Ql a , 1938.Ql b1 , 1939.Ql b , 1940.Ql x . 1941.br 1942The ordering imposed by 1943.Ic .WAIT 1944is only relevant for parallel makes. 1945.El 1946.Sh SPECIAL TARGETS 1947Special targets may not be included with other targets, i.e. they must be 1948the only target specified. 1949.Bl -tag -width .BEGINx 1950.It Ic .BEGIN 1951Any command lines attached to this target are executed before anything 1952else is done. 1953.It Ic .DEFAULT 1954This is sort of a 1955.Ic .USE 1956rule for any target (that was used only as a 1957source) that 1958.Nm 1959can't figure out any other way to create. 1960Only the shell script is used. 1961The 1962.Ic .IMPSRC 1963variable of a target that inherits 1964.Ic .DEFAULT Ns 's 1965commands is set 1966to the target's own name. 1967.It Ic .END 1968Any command lines attached to this target are executed after everything 1969else is done. 1970.It Ic .ERROR 1971Any command lines attached to this target are executed when another target fails. 1972The 1973.Ic .ERROR_TARGET 1974variable is set to the target that failed. 1975See also 1976.Ic MAKE_PRINT_VAR_ON_ERROR . 1977.It Ic .IGNORE 1978Mark each of the sources with the 1979.Ic .IGNORE 1980attribute. 1981If no sources are specified, this is the equivalent of specifying the 1982.Fl i 1983option. 1984.It Ic .INTERRUPT 1985If 1986.Nm 1987is interrupted, the commands for this target will be executed. 1988.It Ic .MAIN 1989If no target is specified when 1990.Nm 1991is invoked, this target will be built. 1992.It Ic .MAKEFLAGS 1993This target provides a way to specify flags for 1994.Nm 1995when the makefile is used. 1996The flags are as if typed to the shell, though the 1997.Fl f 1998option will have 1999no effect. 2000.\" XXX: NOT YET!!!! 2001.\" .It Ic .NOTPARALLEL 2002.\" The named targets are executed in non parallel mode. 2003.\" If no targets are 2004.\" specified, then all targets are executed in non parallel mode. 2005.It Ic .NOPATH 2006Apply the 2007.Ic .NOPATH 2008attribute to any specified sources. 2009.It Ic .NOTPARALLEL 2010Disable parallel mode. 2011.It Ic .NO_PARALLEL 2012Synonym for 2013.Ic .NOTPARALLEL , 2014for compatibility with other pmake variants. 2015.It Ic .ORDER 2016The named targets are made in sequence. 2017This ordering does not add targets to the list of targets to be made. 2018Since the dependents of a target do not get built until the target itself 2019could be built, unless 2020.Ql a 2021is built by another part of the dependency graph, 2022the following is a dependency loop: 2023.Bd -literal 2024\&.ORDER: b a 2025b: a 2026.Ed 2027.Pp 2028The ordering imposed by 2029.Ic .ORDER 2030is only relevant for parallel makes. 2031.\" XXX: NOT YET!!!! 2032.\" .It Ic .PARALLEL 2033.\" The named targets are executed in parallel mode. 2034.\" If no targets are 2035.\" specified, then all targets are executed in parallel mode. 2036.It Ic .PATH 2037The sources are directories which are to be searched for files not 2038found in the current directory. 2039If no sources are specified, any previously specified directories are 2040deleted. 2041If the source is the special 2042.Ic .DOTLAST 2043target, then the current working 2044directory is searched last. 2045.It Ic .PATH. Ns Va suffix 2046Like 2047.Ic .PATH 2048but applies only to files with a particular suffix. 2049The suffix must have been previously declared with 2050.Ic .SUFFIXES . 2051.It Ic .PHONY 2052Apply the 2053.Ic .PHONY 2054attribute to any specified sources. 2055.It Ic .PRECIOUS 2056Apply the 2057.Ic .PRECIOUS 2058attribute to any specified sources. 2059If no sources are specified, the 2060.Ic .PRECIOUS 2061attribute is applied to every 2062target in the file. 2063.It Ic .SHELL 2064Sets the shell that 2065.Nm 2066will use to execute commands. 2067The sources are a set of 2068.Ar field=value 2069pairs. 2070.Bl -tag -width hasErrCtls 2071.It Ar name 2072This is the minimal specification, used to select one of the builtin 2073shell specs; 2074.Ar sh , 2075.Ar ksh , 2076and 2077.Ar csh . 2078.It Ar path 2079Specifies the path to the shell. 2080.It Ar hasErrCtl 2081Indicates whether the shell supports exit on error. 2082.It Ar check 2083The command to turn on error checking. 2084.It Ar ignore 2085The command to disable error checking. 2086.It Ar echo 2087The command to turn on echoing of commands executed. 2088.It Ar quiet 2089The command to turn off echoing of commands executed. 2090.It Ar filter 2091The output to filter after issuing the 2092.Ar quiet 2093command. 2094It is typically identical to 2095.Ar quiet . 2096.It Ar errFlag 2097The flag to pass the shell to enable error checking. 2098.It Ar echoFlag 2099The flag to pass the shell to enable command echoing. 2100.It Ar newline 2101The string literal to pass the shell that results in a single newline 2102character when used outside of any quoting characters. 2103.El 2104Example: 2105.Bd -literal 2106\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2107 check="set \-e" ignore="set +e" \e 2108 echo="set \-v" quiet="set +v" filter="set +v" \e 2109 echoFlag=v errFlag=e newline="'\en'" 2110.Ed 2111.It Ic .SILENT 2112Apply the 2113.Ic .SILENT 2114attribute to any specified sources. 2115If no sources are specified, the 2116.Ic .SILENT 2117attribute is applied to every 2118command in the file. 2119.It Ic .STALE 2120This target gets run when a dependency file contains stale entries, having 2121.Va .ALLSRC 2122set to the name of that dependency file. 2123.It Ic .SUFFIXES 2124Each source specifies a suffix to 2125.Nm . 2126If no sources are specified, any previously specified suffixes are deleted. 2127It allows the creation of suffix-transformation rules. 2128.Pp 2129Example: 2130.Bd -literal 2131\&.SUFFIXES: .o 2132\&.c.o: 2133 cc \-o ${.TARGET} \-c ${.IMPSRC} 2134.Ed 2135.El 2136.Sh ENVIRONMENT 2137.Nm 2138uses the following environment variables, if they exist: 2139.Ev MACHINE , 2140.Ev MACHINE_ARCH , 2141.Ev MAKE , 2142.Ev MAKEFLAGS , 2143.Ev MAKEOBJDIR , 2144.Ev MAKEOBJDIRPREFIX , 2145.Ev MAKESYSPATH , 2146.Ev PWD , 2147and 2148.Ev TMPDIR . 2149.Pp 2150.Ev MAKEOBJDIRPREFIX 2151and 2152.Ev MAKEOBJDIR 2153may only be set in the environment or on the command line to 2154.Nm 2155and not as makefile variables; 2156see the description of 2157.Ql Va .OBJDIR 2158for more details. 2159.Sh FILES 2160.Bl -tag -width /usr/share/mk -compact 2161.It .depend 2162list of dependencies 2163.It Makefile 2164list of dependencies 2165.It makefile 2166list of dependencies 2167.It sys.mk 2168system makefile 2169.It /usr/share/mk 2170system makefile directory 2171.El 2172.Sh COMPATIBILITY 2173The basic make syntax is compatible between different versions of make; 2174however the special variables, variable modifiers and conditionals are not. 2175.Ss Older versions 2176An incomplete list of changes in older versions of 2177.Nm : 2178.Pp 2179The way that .for loop variables are substituted changed after 2180.Nx 5.0 2181so that they still appear to be variable expansions. 2182In particular this stops them being treated as syntax, and removes some 2183obscure problems using them in .if statements. 2184.Pp 2185The way that parallel makes are scheduled changed in 2186.Nx 4.0 2187so that .ORDER and .WAIT apply recursively to the dependent nodes. 2188The algorithms used may change again in the future. 2189.Ss Other make dialects 2190Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2191support most of the features of 2192.Nm 2193as described in this manual. 2194Most notably: 2195.Bl -bullet -offset indent 2196.It 2197The 2198.Ic .WAIT 2199and 2200.Ic .ORDER 2201declarations and most functionality pertaining to parallelization. 2202(GNU make supports parallelization but lacks these features needed to 2203control it effectively.) 2204.It 2205Directives, including for loops and conditionals and most of the 2206forms of include files. 2207(GNU make has its own incompatible and less powerful syntax for 2208conditionals.) 2209.It 2210All built-in variables that begin with a dot. 2211.It 2212Most of the special sources and targets that begin with a dot, 2213with the notable exception of 2214.Ic .PHONY , 2215.Ic .PRECIOUS , 2216and 2217.Ic .SUFFIXES . 2218.It 2219Variable modifiers, except for the 2220.Dl :old=new 2221string substitution, which does not portably support globbing with 2222.Ql % 2223and historically only works on declared suffixes. 2224.It 2225The 2226.Ic $> 2227variable even in its short form; most makes support this functionality 2228but its name varies. 2229.El 2230.Pp 2231Some features are somewhat more portable, such as assignment with 2232.Ic += , 2233.Ic ?= , 2234and 2235.Ic != . 2236The 2237.Ic .PATH 2238functionality is based on an older feature 2239.Ic VPATH 2240found in GNU make and many versions of SVR4 make; however, 2241historically its behavior is too ill-defined (and too buggy) to rely 2242upon. 2243.Pp 2244The 2245.Ic $@ 2246and 2247.Ic $< 2248variables are more or less universally portable, as is the 2249.Ic $(MAKE) 2250variable. 2251Basic use of suffix rules (for files only in the current directory, 2252not trying to chain transformations together, etc.) is also reasonably 2253portable. 2254.Sh SEE ALSO 2255.Xr mkdep 1 2256.Sh HISTORY 2257A 2258.Nm 2259command appeared in 2260.At v7 . 2261This 2262.Nm 2263implementation is based on Adam De Boor's pmake program which was written 2264for Sprite at Berkeley. 2265It was designed to be a parallel distributed make running jobs on different 2266machines using a daemon called 2267.Dq customs . 2268.Pp 2269Historically the target/dependency 2270.Dq FRC 2271has been used to FoRCe rebuilding (since the target/dependency 2272does not exist... unless someone creates an 2273.Dq FRC 2274file). 2275.Sh BUGS 2276The 2277.Nm 2278syntax is difficult to parse without actually acting of the data. 2279For instance finding the end of a variable use should involve scanning each 2280the modifiers using the correct terminator for each field. 2281In many places 2282.Nm 2283just counts {} and () in order to find the end of a variable expansion. 2284.Pp 2285There is no way of escaping a space character in a filename. 2286