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