1.\" $NetBSD: make.1,v 1.249 2015/06/05 07:33:40 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 June 4, 2015 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 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.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 inlcude 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 behaviour 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_PRINT_VAR_ON_ERROR 945When 946.Nm 947stops due to an error, it prints its name and the value of 948.Ql Va .CURDIR 949as well as the value of any variables named in 950.Ql Va MAKE_PRINT_VAR_ON_ERROR . 951.It Va .newline 952This variable is simply assigned a newline character as its value. 953This allows expansions using the 954.Cm \&:@ 955modifier to put a newline between 956iterations of the loop rather than a space. 957For example, the printing of 958.Ql Va MAKE_PRINT_VAR_ON_ERROR 959could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 960.It Va .OBJDIR 961A path to the directory where the targets are built. 962Its value is determined by trying to 963.Xr chdir 2 964to the following directories in order and using the first match: 965.Bl -enum 966.It 967.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 968.Pp 969(Only if 970.Ql Ev MAKEOBJDIRPREFIX 971is set in the environment or on the command line.) 972.It 973.Ev ${MAKEOBJDIR} 974.Pp 975(Only if 976.Ql Ev MAKEOBJDIR 977is set in the environment or on the command line.) 978.It 979.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 980.It 981.Ev ${.CURDIR} Ns Pa /obj 982.It 983.Pa /usr/obj/ Ns Ev ${.CURDIR} 984.It 985.Ev ${.CURDIR} 986.El 987.Pp 988Variable expansion is performed on the value before it's used, 989so expressions such as 990.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 991may be used. 992This is especially useful with 993.Ql Ev MAKEOBJDIR . 994.Pp 995.Ql Va .OBJDIR 996may be modified in the makefile via the special target 997.Ql Ic .OBJDIR . 998In all cases, 999.Nm 1000will 1001.Xr chdir 2 1002to the specified directory if it exists, and set 1003.Ql Va .OBJDIR 1004and 1005.Ql Ev PWD 1006to that directory before executing any targets. 1007. 1008.It Va .PARSEDIR 1009A path to the directory of the current 1010.Ql Pa Makefile 1011being parsed. 1012.It Va .PARSEFILE 1013The basename of the current 1014.Ql Pa Makefile 1015being parsed. 1016This variable and 1017.Ql Va .PARSEDIR 1018are both set only while the 1019.Ql Pa Makefiles 1020are being parsed. 1021If you want to retain their current values, assign them to a variable 1022using assignment with expansion: 1023.Pq Ql Cm \&:= . 1024.It Va .PATH 1025A variable that represents the list of directories that 1026.Nm 1027will search for files. 1028The search list should be updated using the target 1029.Ql Va .PATH 1030rather than the variable. 1031.It Ev PWD 1032Alternate path to the current directory. 1033.Nm 1034normally sets 1035.Ql Va .CURDIR 1036to the canonical path given by 1037.Xr getcwd 3 . 1038However, if the environment variable 1039.Ql Ev PWD 1040is set and gives a path to the current directory, then 1041.Nm 1042sets 1043.Ql Va .CURDIR 1044to the value of 1045.Ql Ev PWD 1046instead. 1047This behaviour is disabled if 1048.Ql Ev MAKEOBJDIRPREFIX 1049is set or 1050.Ql Ev MAKEOBJDIR 1051contains a variable transform. 1052.Ql Ev PWD 1053is set to the value of 1054.Ql Va .OBJDIR 1055for all programs which 1056.Nm 1057executes. 1058.It Ev .TARGETS 1059The list of targets explicitly specified on the command line, if any. 1060.It Ev VPATH 1061Colon-separated 1062.Pq Dq \&: 1063lists of directories that 1064.Nm 1065will search for files. 1066The variable is supported for compatibility with old make programs only, 1067use 1068.Ql Va .PATH 1069instead. 1070.El 1071.Ss Variable modifiers 1072Variable expansion may be modified to select or modify each word of the 1073variable (where a 1074.Dq word 1075is white-space delimited sequence of characters). 1076The general format of a variable expansion is as follows: 1077.Pp 1078.Dl ${variable[:modifier[:...]]} 1079.Pp 1080Each modifier begins with a colon, 1081which may be escaped with a backslash 1082.Pq Ql \e . 1083.Pp 1084A set of modifiers can be specified via a variable, as follows: 1085.Pp 1086.Dl modifier_variable=modifier[:...] 1087.Dl ${variable:${modifier_variable}[:...]} 1088.Pp 1089In this case the first modifier in the modifier_variable does not 1090start with a colon, since that must appear in the referencing 1091variable. 1092If any of the modifiers in the modifier_variable contain a dollar sign 1093.Pq Ql $ , 1094these must be doubled to avoid early expansion. 1095.Pp 1096The supported modifiers are: 1097.Bl -tag -width EEE 1098.It Cm \&:E 1099Replaces each word in the variable with its suffix. 1100.It Cm \&:H 1101Replaces each word in the variable with everything but the last component. 1102.It Cm \&:M Ns Ar pattern 1103Select only those words that match 1104.Ar pattern . 1105The standard shell wildcard characters 1106.Pf ( Ql * , 1107.Ql \&? , 1108and 1109.Ql Oo Oc ) 1110may 1111be used. 1112The wildcard characters may be escaped with a backslash 1113.Pq Ql \e . 1114As a consequence of the way values are split into words, matched, 1115and then joined, a construct like 1116.Dl ${VAR:M*} 1117will normalise the inter-word spacing, removing all leading and 1118trailing space, and converting multiple consecutive spaces 1119to single spaces. 1120. 1121.It Cm \&:N Ns Ar pattern 1122This is identical to 1123.Ql Cm \&:M , 1124but selects all words which do not match 1125.Ar pattern . 1126.It Cm \&:O 1127Order every word in variable alphabetically. 1128To sort words in 1129reverse order use the 1130.Ql Cm \&:O:[-1..1] 1131combination of modifiers. 1132.It Cm \&:Ox 1133Randomize words in variable. 1134The results will be different each time you are referring to the 1135modified variable; use the assignment with expansion 1136.Pq Ql Cm \&:= 1137to prevent such behaviour. 1138For example, 1139.Bd -literal -offset indent 1140LIST= uno due tre quattro 1141RANDOM_LIST= ${LIST:Ox} 1142STATIC_RANDOM_LIST:= ${LIST:Ox} 1143 1144all: 1145 @echo "${RANDOM_LIST}" 1146 @echo "${RANDOM_LIST}" 1147 @echo "${STATIC_RANDOM_LIST}" 1148 @echo "${STATIC_RANDOM_LIST}" 1149.Ed 1150may produce output similar to: 1151.Bd -literal -offset indent 1152quattro due tre uno 1153tre due quattro uno 1154due uno quattro tre 1155due uno quattro tre 1156.Ed 1157.It Cm \&:Q 1158Quotes every shell meta-character in the variable, so that it can be passed 1159safely through recursive invocations of 1160.Nm . 1161.It Cm \&:R 1162Replaces each word in the variable with everything but its suffix. 1163.It Cm \&:gmtime 1164The value is a format string for 1165.Xr strftime 3 , 1166using the current 1167.Xr gmtime 3 . 1168.It Cm \&:hash 1169Compute a 32bit hash of the value and encode it as hex digits. 1170.It Cm \&:localtime 1171The value is a format string for 1172.Xr strftime 3 , 1173using the current 1174.Xr localtime 3 . 1175.It Cm \&:tA 1176Attempt to convert variable to an absolute path using 1177.Xr realpath 3 , 1178if that fails, the value is unchanged. 1179.It Cm \&:tl 1180Converts variable to lower-case letters. 1181.It Cm \&:ts Ns Ar c 1182Words in the variable are normally separated by a space on expansion. 1183This modifier sets the separator to the character 1184.Ar c . 1185If 1186.Ar c 1187is omitted, then no separator is used. 1188The common escapes (including octal numeric codes), work as expected. 1189.It Cm \&:tu 1190Converts variable to upper-case letters. 1191.It Cm \&:tW 1192Causes the value to be treated as a single word 1193(possibly containing embedded white space). 1194See also 1195.Ql Cm \&:[*] . 1196.It Cm \&:tw 1197Causes the value to be treated as a sequence of 1198words delimited by white space. 1199See also 1200.Ql Cm \&:[@] . 1201.Sm off 1202.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1203.Sm on 1204Modify the first occurrence of 1205.Ar old_string 1206in the variable's value, replacing it with 1207.Ar new_string . 1208If a 1209.Ql g 1210is appended to the last slash of the pattern, all occurrences 1211in each word are replaced. 1212If a 1213.Ql 1 1214is appended to the last slash of the pattern, only the first word 1215is affected. 1216If a 1217.Ql W 1218is appended to the last slash of the pattern, 1219then the value is treated as a single word 1220(possibly containing embedded white space). 1221If 1222.Ar old_string 1223begins with a caret 1224.Pq Ql ^ , 1225.Ar old_string 1226is anchored at the beginning of each word. 1227If 1228.Ar old_string 1229ends with a dollar sign 1230.Pq Ql \&$ , 1231it is anchored at the end of each word. 1232Inside 1233.Ar new_string , 1234an ampersand 1235.Pq Ql \*[Am] 1236is replaced by 1237.Ar old_string 1238(without any 1239.Ql ^ 1240or 1241.Ql \&$ ) . 1242Any character may be used as a delimiter for the parts of the modifier 1243string. 1244The anchoring, ampersand and delimiter characters may be escaped with a 1245backslash 1246.Pq Ql \e . 1247.Pp 1248Variable expansion occurs in the normal fashion inside both 1249.Ar old_string 1250and 1251.Ar new_string 1252with the single exception that a backslash is used to prevent the expansion 1253of a dollar sign 1254.Pq Ql \&$ , 1255not a preceding dollar sign as is usual. 1256.Sm off 1257.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1258.Sm on 1259The 1260.Cm \&:C 1261modifier is just like the 1262.Cm \&:S 1263modifier except that the old and new strings, instead of being 1264simple strings, are an extended regular expression (see 1265.Xr regex 3 ) 1266string 1267.Ar pattern 1268and an 1269.Xr ed 1 Ns \-style 1270string 1271.Ar replacement . 1272Normally, the first occurrence of the pattern 1273.Ar pattern 1274in each word of the value is substituted with 1275.Ar replacement . 1276The 1277.Ql 1 1278modifier causes the substitution to apply to at most one word; the 1279.Ql g 1280modifier causes the substitution to apply to as many instances of the 1281search pattern 1282.Ar pattern 1283as occur in the word or words it is found in; the 1284.Ql W 1285modifier causes the value to be treated as a single word 1286(possibly containing embedded white space). 1287Note that 1288.Ql 1 1289and 1290.Ql g 1291are orthogonal; the former specifies whether multiple words are 1292potentially affected, the latter whether multiple substitutions can 1293potentially occur within each affected word. 1294.Pp 1295As for the 1296.Cm \&:S 1297modifier, the 1298.Ar pattern 1299and 1300.Ar replacement 1301are subjected to variable expansion before being parsed as 1302regular expressions. 1303.It Cm \&:T 1304Replaces each word in the variable with its last component. 1305.It Cm \&:u 1306Remove adjacent duplicate words (like 1307.Xr uniq 1 ) . 1308.Sm off 1309.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1310.Sm on 1311If the variable name (not its value), when parsed as a .if conditional 1312expression, evaluates to true, return as its value the 1313.Ar true_string , 1314otherwise return the 1315.Ar false_string . 1316Since the variable name is used as the expression, \&:\&? must be the 1317first modifier after the variable name itself - which will, of course, 1318usually contain variable expansions. 1319A common error is trying to use expressions like 1320.Dl ${NUMBERS:M42:?match:no} 1321which actually tests defined(NUMBERS), 1322to determine is any words match "42" you need to use something like: 1323.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1324.It Ar :old_string=new_string 1325This is the 1326.At V 1327style variable substitution. 1328It must be the last modifier specified. 1329If 1330.Ar old_string 1331or 1332.Ar new_string 1333do not contain the pattern matching character 1334.Ar % 1335then it is assumed that they are 1336anchored at the end of each word, so only suffixes or entire 1337words may be replaced. 1338Otherwise 1339.Ar % 1340is the substring of 1341.Ar old_string 1342to be replaced in 1343.Ar new_string . 1344.Pp 1345Variable expansion occurs in the normal fashion inside both 1346.Ar old_string 1347and 1348.Ar new_string 1349with the single exception that a backslash is used to prevent the 1350expansion of a dollar sign 1351.Pq Ql \&$ , 1352not a preceding dollar sign as is usual. 1353.Sm off 1354.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1355.Sm on 1356This is the loop expansion mechanism from the OSF Development 1357Environment (ODE) make. 1358Unlike 1359.Cm \&.for 1360loops expansion occurs at the time of 1361reference. 1362Assign 1363.Ar temp 1364to each word in the variable and evaluate 1365.Ar string . 1366The ODE convention is that 1367.Ar temp 1368should start and end with a period. 1369For example. 1370.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1371.Pp 1372However a single character variable is often more readable: 1373.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1374.It Cm \&:U Ns Ar newval 1375If the variable is undefined 1376.Ar newval 1377is the value. 1378If the variable is defined, the existing value is returned. 1379This is another ODE make feature. 1380It is handy for setting per-target CFLAGS for instance: 1381.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1382If a value is only required if the variable is undefined, use: 1383.Dl ${VAR:D:Unewval} 1384.It Cm \&:D Ns Ar newval 1385If the variable is defined 1386.Ar newval 1387is the value. 1388.It Cm \&:L 1389The name of the variable is the value. 1390.It Cm \&:P 1391The path of the node which has the same name as the variable 1392is the value. 1393If no such node exists or its path is null, then the 1394name of the variable is used. 1395In order for this modifier to work, the name (node) must at least have 1396appeared on the rhs of a dependency. 1397.Sm off 1398.It Cm \&:\&! Ar cmd Cm \&! 1399.Sm on 1400The output of running 1401.Ar cmd 1402is the value. 1403.It Cm \&:sh 1404If the variable is non-empty it is run as a command and the output 1405becomes the new value. 1406.It Cm \&::= Ns Ar str 1407The variable is assigned the value 1408.Ar str 1409after substitution. 1410This modifier and its variations are useful in 1411obscure situations such as wanting to set a variable when shell commands 1412are being parsed. 1413These assignment modifiers always expand to 1414nothing, so if appearing in a rule line by themselves should be 1415preceded with something to keep 1416.Nm 1417happy. 1418.Pp 1419The 1420.Ql Cm \&:: 1421helps avoid false matches with the 1422.At V 1423style 1424.Cm \&:= 1425modifier and since substitution always occurs the 1426.Cm \&::= 1427form is vaguely appropriate. 1428.It Cm \&::?= Ns Ar str 1429As for 1430.Cm \&::= 1431but only if the variable does not already have a value. 1432.It Cm \&::+= Ns Ar str 1433Append 1434.Ar str 1435to the variable. 1436.It Cm \&::!= Ns Ar cmd 1437Assign the output of 1438.Ar cmd 1439to the variable. 1440.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1441Selects one or more words from the value, 1442or performs other operations related to the way in which the 1443value is divided into words. 1444.Pp 1445Ordinarily, a value is treated as a sequence of words 1446delimited by white space. 1447Some modifiers suppress this behaviour, 1448causing a value to be treated as a single word 1449(possibly containing embedded white space). 1450An empty value, or a value that consists entirely of white-space, 1451is treated as a single word. 1452For the purposes of the 1453.Ql Cm \&:[] 1454modifier, the words are indexed both forwards using positive integers 1455(where index 1 represents the first word), 1456and backwards using negative integers 1457(where index \-1 represents the last word). 1458.Pp 1459The 1460.Ar range 1461is subjected to variable expansion, and the expanded result is 1462then interpreted as follows: 1463.Bl -tag -width index 1464.\" :[n] 1465.It Ar index 1466Selects a single word from the value. 1467.\" :[start..end] 1468.It Ar start Ns Cm \&.. Ns Ar end 1469Selects all words from 1470.Ar start 1471to 1472.Ar end , 1473inclusive. 1474For example, 1475.Ql Cm \&:[2..-1] 1476selects all words from the second word to the last word. 1477If 1478.Ar start 1479is greater than 1480.Ar end , 1481then the words are output in reverse order. 1482For example, 1483.Ql Cm \&:[-1..1] 1484selects all the words from last to first. 1485.\" :[*] 1486.It Cm \&* 1487Causes subsequent modifiers to treat the value as a single word 1488(possibly containing embedded white space). 1489Analogous to the effect of 1490\&"$*\&" 1491in Bourne shell. 1492.\" :[0] 1493.It 0 1494Means the same as 1495.Ql Cm \&:[*] . 1496.\" :[*] 1497.It Cm \&@ 1498Causes subsequent modifiers to treat the value as a sequence of words 1499delimited by white space. 1500Analogous to the effect of 1501\&"$@\&" 1502in Bourne shell. 1503.\" :[#] 1504.It Cm \&# 1505Returns the number of words in the value. 1506.El \" :[range] 1507.El 1508.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1509Makefile inclusion, conditional structures and for loops reminiscent 1510of the C programming language are provided in 1511.Nm . 1512All such structures are identified by a line beginning with a single 1513dot 1514.Pq Ql \&. 1515character. 1516Files are included with either 1517.Cm \&.include Aq Ar file 1518or 1519.Cm \&.include Pf \*q Ar file Ns \*q . 1520Variables between the angle brackets or double quotes are expanded 1521to form the file name. 1522If angle brackets are used, the included makefile is expected to be in 1523the system makefile directory. 1524If double quotes are used, the including makefile's directory and any 1525directories specified using the 1526.Fl I 1527option are searched before the system 1528makefile directory. 1529For compatibility with other versions of 1530.Nm 1531.Ql include file ... 1532is also accepted. 1533If the include statement is written as 1534.Cm .-include 1535or as 1536.Cm .sinclude 1537then errors locating and/or opening include files are ignored. 1538.Pp 1539Conditional expressions are also preceded by a single dot as the first 1540character of a line. 1541The possible conditionals are as follows: 1542.Bl -tag -width Ds 1543.It Ic .error Ar message 1544The message is printed along with the name of the makefile and line number, 1545then 1546.Nm 1547will exit. 1548.It Ic .export Ar variable ... 1549Export the specified global variable. 1550If no variable list is provided, all globals are exported 1551except for internal variables (those that start with 1552.Ql \&. ) . 1553This is not affected by the 1554.Fl X 1555flag, so should be used with caution. 1556For compatibility with other 1557.Nm 1558programs 1559.Ql export variable=value 1560is also accepted. 1561.Pp 1562Appending a variable name to 1563.Va .MAKE.EXPORTED 1564is equivalent to exporting a variable. 1565.It Ic .export-env Ar variable ... 1566The same as 1567.Ql .export , 1568except that the variable is not appended to 1569.Va .MAKE.EXPORTED . 1570This allows exporting a value to the environment which is different from that 1571used by 1572.Nm 1573internally. 1574.It Ic .info Ar message 1575The message is printed along with the name of the makefile and line number. 1576.It Ic .undef Ar variable 1577Un-define the specified global variable. 1578Only global variables may be un-defined. 1579.It Ic .unexport Ar variable ... 1580The opposite of 1581.Ql .export . 1582The specified global 1583.Va variable 1584will be removed from 1585.Va .MAKE.EXPORTED . 1586If no variable list is provided, all globals are unexported, 1587and 1588.Va .MAKE.EXPORTED 1589deleted. 1590.It Ic .unexport-env 1591Unexport all globals previously exported and 1592clear the environment inherited from the parent. 1593This operation will cause a memory leak of the original environment, 1594so should be used sparingly. 1595Testing for 1596.Va .MAKE.LEVEL 1597being 0, would make sense. 1598Also note that any variables which originated in the parent environment 1599should be explicitly preserved if desired. 1600For example: 1601.Bd -literal -offset indent 1602.Li .if ${.MAKE.LEVEL} == 0 1603PATH := ${PATH} 1604.Li .unexport-env 1605.Li .export PATH 1606.Li .endif 1607.Pp 1608.Ed 1609Would result in an environment containing only 1610.Ql Ev PATH , 1611which is the minimal useful environment. 1612Actually 1613.Ql Ev .MAKE.LEVEL 1614will also be pushed into the new environment. 1615.It Ic .warning Ar message 1616The message prefixed by 1617.Ql Pa warning: 1618is printed along with the name of the makefile and line number. 1619.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1620Test the value of an expression. 1621.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1622Test the value of a variable. 1623.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1624Test the value of a variable. 1625.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1626Test the target being built. 1627.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1628Test the target being built. 1629.It Ic .else 1630Reverse the sense of the last conditional. 1631.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1632A combination of 1633.Ql Ic .else 1634followed by 1635.Ql Ic .if . 1636.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1637A combination of 1638.Ql Ic .else 1639followed by 1640.Ql Ic .ifdef . 1641.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1642A combination of 1643.Ql Ic .else 1644followed by 1645.Ql Ic .ifndef . 1646.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1647A combination of 1648.Ql Ic .else 1649followed by 1650.Ql Ic .ifmake . 1651.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1652A combination of 1653.Ql Ic .else 1654followed by 1655.Ql Ic .ifnmake . 1656.It Ic .endif 1657End the body of the conditional. 1658.El 1659.Pp 1660The 1661.Ar operator 1662may be any one of the following: 1663.Bl -tag -width "Cm XX" 1664.It Cm \&|\&| 1665Logical OR. 1666.It Cm \&\*[Am]\*[Am] 1667Logical 1668.Tn AND ; 1669of higher precedence than 1670.Dq \&|\&| . 1671.El 1672.Pp 1673As in C, 1674.Nm 1675will only evaluate a conditional as far as is necessary to determine 1676its value. 1677Parentheses may be used to change the order of evaluation. 1678The boolean operator 1679.Ql Ic \&! 1680may be used to logically negate an entire 1681conditional. 1682It is of higher precedence than 1683.Ql Ic \&\*[Am]\*[Am] . 1684.Pp 1685The value of 1686.Ar expression 1687may be any of the following: 1688.Bl -tag -width defined 1689.It Ic defined 1690Takes a variable name as an argument and evaluates to true if the variable 1691has been defined. 1692.It Ic make 1693Takes a target name as an argument and evaluates to true if the target 1694was specified as part of 1695.Nm Ns 's 1696command line or was declared the default target (either implicitly or 1697explicitly, see 1698.Va .MAIN ) 1699before the line containing the conditional. 1700.It Ic empty 1701Takes a variable, with possible modifiers, and evaluates to true if 1702the expansion of the variable would result in an empty string. 1703.It Ic exists 1704Takes a file name as an argument and evaluates to true if the file exists. 1705The file is searched for on the system search path (see 1706.Va .PATH ) . 1707.It Ic target 1708Takes a target name as an argument and evaluates to true if the target 1709has been defined. 1710.It Ic commands 1711Takes a target name as an argument and evaluates to true if the target 1712has been defined and has commands associated with it. 1713.El 1714.Pp 1715.Ar Expression 1716may also be an arithmetic or string comparison. 1717Variable expansion is 1718performed on both sides of the comparison, after which the integral 1719values are compared. 1720A value is interpreted as hexadecimal if it is 1721preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1722The standard C relational operators are all supported. 1723If after 1724variable expansion, either the left or right hand side of a 1725.Ql Ic == 1726or 1727.Ql Ic "!=" 1728operator is not an integral value, then 1729string comparison is performed between the expanded 1730variables. 1731If no relational operator is given, it is assumed that the expanded 1732variable is being compared against 0 or an empty string in the case 1733of a string comparison. 1734.Pp 1735When 1736.Nm 1737is evaluating one of these conditional expressions, and it encounters 1738a (white-space separated) word it doesn't recognize, either the 1739.Dq make 1740or 1741.Dq defined 1742expression is applied to it, depending on the form of the conditional. 1743If the form is 1744.Ql Ic .ifdef , 1745.Ql Ic .ifndef , 1746or 1747.Ql Ic .if 1748the 1749.Dq defined 1750expression is applied. 1751Similarly, if the form is 1752.Ql Ic .ifmake 1753or 1754.Ql Ic .ifnmake , the 1755.Dq make 1756expression is applied. 1757.Pp 1758If the conditional evaluates to true the parsing of the makefile continues 1759as before. 1760If it evaluates to false, the following lines are skipped. 1761In both cases this continues until a 1762.Ql Ic .else 1763or 1764.Ql Ic .endif 1765is found. 1766.Pp 1767For loops are typically used to apply a set of rules to a list of files. 1768The syntax of a for loop is: 1769.Pp 1770.Bl -tag -compact -width Ds 1771.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1772.It Aq make-rules 1773.It Ic \&.endfor 1774.El 1775.Pp 1776After the for 1777.Ic expression 1778is evaluated, it is split into words. 1779On each iteration of the loop, one word is taken and assigned to each 1780.Ic variable , 1781in order, and these 1782.Ic variables 1783are substituted into the 1784.Ic make-rules 1785inside the body of the for loop. 1786The number of words must come out even; that is, if there are three 1787iteration variables, the number of words provided must be a multiple 1788of three. 1789.Sh COMMENTS 1790Comments begin with a hash 1791.Pq Ql \&# 1792character, anywhere but in a shell 1793command line, and continue to the end of an unescaped new line. 1794.Sh SPECIAL SOURCES (ATTRIBUTES) 1795.Bl -tag -width .IGNOREx 1796.It Ic .EXEC 1797Target is never out of date, but always execute commands anyway. 1798.It Ic .IGNORE 1799Ignore any errors from the commands associated with this target, exactly 1800as if they all were preceded by a dash 1801.Pq Ql \- . 1802.\" .It Ic .INVISIBLE 1803.\" XXX 1804.\" .It Ic .JOIN 1805.\" XXX 1806.It Ic .MADE 1807Mark all sources of this target as being up-to-date. 1808.It Ic .MAKE 1809Execute the commands associated with this target even if the 1810.Fl n 1811or 1812.Fl t 1813options were specified. 1814Normally used to mark recursive 1815.Nm Ns s . 1816.It Ic .META 1817Create a meta file for the target, even if it is flagged as 1818.Ic .PHONY , 1819.Ic .MAKE , 1820or 1821.Ic .SPECIAL . 1822Usage in conjunction with 1823.Ic .MAKE 1824is the most likely case. 1825In "meta" mode, the target is out-of-date if the meta file is missing. 1826.It Ic .NOMETA 1827Do not create a meta file for the target. 1828Meta files are also not created for 1829.Ic .PHONY , 1830.Ic .MAKE , 1831or 1832.Ic .SPECIAL 1833targets. 1834.It Ic .NOMETA_CMP 1835Ignore differences in commands when deciding if target is out of date. 1836This is useful if the command contains a value which always changes. 1837If the number of commands change, though, the target will still be out of date. 1838The same effect applies to any command line that uses the variable 1839.Va .OODATE , 1840which can be used for that purpose even when not otherwise needed or desired: 1841.Bd -literal -offset indent 1842 1843skip-compare-for-some: 1844 @echo this will be compared 1845 @echo this will not ${.OODATE:M.NOMETA_CMP} 1846 @echo this will also be compared 1847 1848.Ed 1849The 1850.Cm \&:M 1851pattern suppresses any expansion of the unwanted variable. 1852.It Ic .NOPATH 1853Do not search for the target in the directories specified by 1854.Ic .PATH . 1855.It Ic .NOTMAIN 1856Normally 1857.Nm 1858selects the first target it encounters as the default target to be built 1859if no target was specified. 1860This source prevents this target from being selected. 1861.It Ic .OPTIONAL 1862If a target is marked with this attribute and 1863.Nm 1864can't figure out how to create it, it will ignore this fact and assume 1865the file isn't needed or already exists. 1866.It Ic .PHONY 1867The target does not 1868correspond to an actual file; it is always considered to be out of date, 1869and will not be created with the 1870.Fl t 1871option. 1872Suffix-transformation rules are not applied to 1873.Ic .PHONY 1874targets. 1875.It Ic .PRECIOUS 1876When 1877.Nm 1878is interrupted, it normally removes any partially made targets. 1879This source prevents the target from being removed. 1880.It Ic .RECURSIVE 1881Synonym for 1882.Ic .MAKE . 1883.It Ic .SILENT 1884Do not echo any of the commands associated with this target, exactly 1885as if they all were preceded by an at sign 1886.Pq Ql @ . 1887.It Ic .USE 1888Turn the target into 1889.Nm Ns 's 1890version of a macro. 1891When the target is used as a source for another target, the other target 1892acquires the commands, sources, and attributes (except for 1893.Ic .USE ) 1894of the 1895source. 1896If the target already has commands, the 1897.Ic .USE 1898target's commands are appended 1899to them. 1900.It Ic .USEBEFORE 1901Exactly like 1902.Ic .USE , 1903but prepend the 1904.Ic .USEBEFORE 1905target commands to the target. 1906.It Ic .WAIT 1907If 1908.Ic .WAIT 1909appears in a dependency line, the sources that precede it are 1910made before the sources that succeed it in the line. 1911Since the dependents of files are not made until the file itself 1912could be made, this also stops the dependents being built unless they 1913are needed for another branch of the dependency tree. 1914So given: 1915.Bd -literal 1916x: a .WAIT b 1917 echo x 1918a: 1919 echo a 1920b: b1 1921 echo b 1922b1: 1923 echo b1 1924 1925.Ed 1926the output is always 1927.Ql a , 1928.Ql b1 , 1929.Ql b , 1930.Ql x . 1931.br 1932The ordering imposed by 1933.Ic .WAIT 1934is only relevant for parallel makes. 1935.El 1936.Sh SPECIAL TARGETS 1937Special targets may not be included with other targets, i.e. they must be 1938the only target specified. 1939.Bl -tag -width .BEGINx 1940.It Ic .BEGIN 1941Any command lines attached to this target are executed before anything 1942else is done. 1943.It Ic .DEFAULT 1944This is sort of a 1945.Ic .USE 1946rule for any target (that was used only as a 1947source) that 1948.Nm 1949can't figure out any other way to create. 1950Only the shell script is used. 1951The 1952.Ic .IMPSRC 1953variable of a target that inherits 1954.Ic .DEFAULT Ns 's 1955commands is set 1956to the target's own name. 1957.It Ic .END 1958Any command lines attached to this target are executed after everything 1959else is done. 1960.It Ic .ERROR 1961Any command lines attached to this target are executed when another target fails. 1962The 1963.Ic .ERROR_TARGET 1964variable is set to the target that failed. 1965See also 1966.Ic MAKE_PRINT_VAR_ON_ERROR . 1967.It Ic .IGNORE 1968Mark each of the sources with the 1969.Ic .IGNORE 1970attribute. 1971If no sources are specified, this is the equivalent of specifying the 1972.Fl i 1973option. 1974.It Ic .INTERRUPT 1975If 1976.Nm 1977is interrupted, the commands for this target will be executed. 1978.It Ic .MAIN 1979If no target is specified when 1980.Nm 1981is invoked, this target will be built. 1982.It Ic .MAKEFLAGS 1983This target provides a way to specify flags for 1984.Nm 1985when the makefile is used. 1986The flags are as if typed to the shell, though the 1987.Fl f 1988option will have 1989no effect. 1990.\" XXX: NOT YET!!!! 1991.\" .It Ic .NOTPARALLEL 1992.\" The named targets are executed in non parallel mode. 1993.\" If no targets are 1994.\" specified, then all targets are executed in non parallel mode. 1995.It Ic .NOPATH 1996Apply the 1997.Ic .NOPATH 1998attribute to any specified sources. 1999.It Ic .NOTPARALLEL 2000Disable parallel mode. 2001.It Ic .NO_PARALLEL 2002Synonym for 2003.Ic .NOTPARALLEL , 2004for compatibility with other pmake variants. 2005.It Ic .OBJDIR 2006The source is a new value for 2007.Ql Va .OBJDIR . 2008If it exists, 2009.Nm 2010will 2011.Xr chdir 2 2012to it and update the value of 2013.Ql Va .OBJDIR . 2014.It Ic .ORDER 2015The named targets are made in sequence. 2016This ordering does not add targets to the list of targets to be made. 2017Since the dependents of a target do not get built until the target itself 2018could be built, unless 2019.Ql a 2020is built by another part of the dependency graph, 2021the following is a dependency loop: 2022.Bd -literal 2023\&.ORDER: b a 2024b: a 2025.Ed 2026.Pp 2027The ordering imposed by 2028.Ic .ORDER 2029is only relevant for parallel makes. 2030.\" XXX: NOT YET!!!! 2031.\" .It Ic .PARALLEL 2032.\" The named targets are executed in parallel mode. 2033.\" If no targets are 2034.\" specified, then all targets are executed in parallel mode. 2035.It Ic .PATH 2036The sources are directories which are to be searched for files not 2037found in the current directory. 2038If no sources are specified, any previously specified directories are 2039deleted. 2040If the source is the special 2041.Ic .DOTLAST 2042target, then the current working 2043directory is searched last. 2044.It Ic .PATH. Ns Va suffix 2045Like 2046.Ic .PATH 2047but applies only to files with a particular suffix. 2048The suffix must have been previously declared with 2049.Ic .SUFFIXES . 2050.It Ic .PHONY 2051Apply the 2052.Ic .PHONY 2053attribute to any specified sources. 2054.It Ic .PRECIOUS 2055Apply the 2056.Ic .PRECIOUS 2057attribute to any specified sources. 2058If no sources are specified, the 2059.Ic .PRECIOUS 2060attribute is applied to every 2061target in the file. 2062.It Ic .SHELL 2063Sets the shell that 2064.Nm 2065will use to execute commands. 2066The sources are a set of 2067.Ar field=value 2068pairs. 2069.Bl -tag -width hasErrCtls 2070.It Ar name 2071This is the minimal specification, used to select one of the builtin 2072shell specs; 2073.Ar sh , 2074.Ar ksh , 2075and 2076.Ar csh . 2077.It Ar path 2078Specifies the path to the shell. 2079.It Ar hasErrCtl 2080Indicates whether the shell supports exit on error. 2081.It Ar check 2082The command to turn on error checking. 2083.It Ar ignore 2084The command to disable error checking. 2085.It Ar echo 2086The command to turn on echoing of commands executed. 2087.It Ar quiet 2088The command to turn off echoing of commands executed. 2089.It Ar filter 2090The output to filter after issuing the 2091.Ar quiet 2092command. 2093It is typically identical to 2094.Ar quiet . 2095.It Ar errFlag 2096The flag to pass the shell to enable error checking. 2097.It Ar echoFlag 2098The flag to pass the shell to enable command echoing. 2099.It Ar newline 2100The string literal to pass the shell that results in a single newline 2101character when used outside of any quoting characters. 2102.El 2103Example: 2104.Bd -literal 2105\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2106 check="set \-e" ignore="set +e" \e 2107 echo="set \-v" quiet="set +v" filter="set +v" \e 2108 echoFlag=v errFlag=e newline="'\en'" 2109.Ed 2110.It Ic .SILENT 2111Apply the 2112.Ic .SILENT 2113attribute to any specified sources. 2114If no sources are specified, the 2115.Ic .SILENT 2116attribute is applied to every 2117command in the file. 2118.It Ic .STALE 2119This target gets run when a dependency file contains stale entries, having 2120.Va .ALLSRC 2121set to the name of that dependency file. 2122.It Ic .SUFFIXES 2123Each source specifies a suffix to 2124.Nm . 2125If no sources are specified, any previously specified suffixes are deleted. 2126It allows the creation of suffix-transformation rules. 2127.Pp 2128Example: 2129.Bd -literal 2130\&.SUFFIXES: .o 2131\&.c.o: 2132 cc \-o ${.TARGET} \-c ${.IMPSRC} 2133.Ed 2134.El 2135.Sh ENVIRONMENT 2136.Nm 2137uses the following environment variables, if they exist: 2138.Ev MACHINE , 2139.Ev MACHINE_ARCH , 2140.Ev MAKE , 2141.Ev MAKEFLAGS , 2142.Ev MAKEOBJDIR , 2143.Ev MAKEOBJDIRPREFIX , 2144.Ev MAKESYSPATH , 2145.Ev PWD , 2146and 2147.Ev TMPDIR . 2148.Pp 2149.Ev MAKEOBJDIRPREFIX 2150and 2151.Ev MAKEOBJDIR 2152may only be set in the environment or on the command line to 2153.Nm 2154and not as makefile variables; 2155see the description of 2156.Ql Va .OBJDIR 2157for more details. 2158.Sh FILES 2159.Bl -tag -width /usr/share/mk -compact 2160.It .depend 2161list of dependencies 2162.It Makefile 2163list of dependencies 2164.It makefile 2165list of dependencies 2166.It sys.mk 2167system makefile 2168.It /usr/share/mk 2169system makefile directory 2170.El 2171.Sh COMPATIBILITY 2172The basic make syntax is compatible between different versions of make; 2173however the special variables, variable modifiers and conditionals are not. 2174.Ss Older versions 2175An incomplete list of changes in older versions of 2176.Nm : 2177.Pp 2178The way that .for loop variables are substituted changed after 2179NetBSD 5.0 2180so that they still appear to be variable expansions. 2181In particular this stops them being treated as syntax, and removes some 2182obscure problems using them in .if statements. 2183.Pp 2184The way that parallel makes are scheduled changed in 2185NetBSD 4.0 2186so that .ORDER and .WAIT apply recursively to the dependent nodes. 2187The algorithms used may change again in the future. 2188.Ss Other make dialects 2189Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2190support most of the features of 2191.Nm 2192as described in this manual. 2193Most notably: 2194.Bl -bullet -offset indent 2195.It 2196The 2197.Ic .WAIT 2198and 2199.Ic .ORDER 2200declarations and most functionality pertaining to parallelization. 2201(GNU make supports parallelization but lacks these features needed to 2202control it effectively.) 2203.It 2204Directives, including for loops and conditionals and most of the 2205forms of include files. 2206(GNU make has its own incompatible and less powerful syntax for 2207conditionals.) 2208.It 2209All built-in variables that begin with a dot. 2210.It 2211Most of the special sources and targets that begin with a dot, 2212with the notable exception of 2213.Ic .PHONY , 2214.Ic .PRECIOUS , 2215and 2216.Ic .SUFFIXES . 2217.It 2218Variable modifiers, except for the 2219.Dl :old=new 2220string substitution, which does not portably support globbing with 2221.Ql % 2222and historically only works on declared suffixes. 2223.It 2224The 2225.Ic $> 2226variable even in its short form; most makes support this functionality 2227but its name varies. 2228.El 2229.Pp 2230Some features are somewhat more portable, such as assignment with 2231.Ic += , 2232.Ic ?= , 2233and 2234.Ic != . 2235The 2236.Ic .PATH 2237functionality is based on an older feature 2238.Ic VPATH 2239found in GNU make and many versions of SVR4 make; however, 2240historically its behavior is too ill-defined (and too buggy) to rely 2241upon. 2242.Pp 2243The 2244.Ic $@ 2245and 2246.Ic $< 2247variables are more or less universally portable, as is the 2248.Ic $(MAKE) 2249variable. 2250Basic use of suffix rules (for files only in the current directory, 2251not trying to chain transformations together, etc.) is also reasonably 2252portable. 2253.Sh SEE ALSO 2254.Xr mkdep 1 2255.Sh HISTORY 2256.Nm 2257is derived from NetBSD 2258.Xr make 1 . 2259It uses autoconf to facilitate portability to other platforms. 2260.Pp 2261A 2262make 2263command appeared in 2264.At v7 . 2265This 2266make 2267implementation is based on Adam De Boor's pmake program which was written 2268for Sprite at Berkeley. 2269It was designed to be a parallel distributed make running jobs on different 2270machines using a daemon called 2271.Dq customs . 2272.Pp 2273Historically the target/dependency 2274.Dq FRC 2275has been used to FoRCe rebuilding (since the target/dependency 2276does not exist... unless someone creates an 2277.Dq FRC 2278file). 2279.Sh BUGS 2280The 2281make 2282syntax is difficult to parse without actually acting of the data. 2283For instance finding the end of a variable use should involve scanning each 2284the modifiers using the correct terminator for each field. 2285In many places 2286make 2287just counts {} and () in order to find the end of a variable expansion. 2288.Pp 2289There is no way of escaping a space character in a filename. 2290