1.\" $NetBSD: make.1,v 1.229 2014/01/19 10:23:29 apb Exp $ 2.\" 3.\" Copyright (c) 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)make.1 8.4 (Berkeley) 3/19/94 31.\" 32.Dd February 14, 2014 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm bmake 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrstWwX 41.Op Fl C Ar directory 42.Op Fl D Ar variable 43.Op Fl d Ar flags 44.Op Fl f Ar makefile 45.Op Fl I Ar directory 46.Op Fl J Ar private 47.Op Fl j Ar max_jobs 48.Op Fl m Ar directory 49.Op Fl T Ar file 50.Op Fl V Ar variable 51.Op Ar variable=value 52.Op Ar target ... 53.Sh DESCRIPTION 54.Nm 55is a program designed to simplify the maintenance of other programs. 56Its input is a list of specifications as to the files upon which programs 57and other files depend. 58If no 59.Fl f Ar makefile 60makefile option is given, 61.Nm 62will try to open 63.Ql Pa makefile 64then 65.Ql Pa Makefile 66in order to find the specifications. 67If the file 68.Ql Pa .depend 69exists, it is read (see 70.Xr mkdep 1 ) . 71.Pp 72This manual page is intended as a reference document only. 73For a more thorough description of 74.Nm 75and makefiles, please refer to 76.%T "PMake \- A Tutorial" . 77.Pp 78.Nm 79will prepend the contents of the 80.Va MAKEFLAGS 81environment variable to the command line arguments before parsing them. 82.Pp 83The options are as follows: 84.Bl -tag -width Ds 85.It Fl B 86Try to be backwards compatible by executing a single shell per command and 87by executing the commands to make the sources of a dependency line in sequence. 88.It Fl C Ar directory 89Change to 90.Ar directory 91before reading the makefiles or doing anything else. 92If multiple 93.Fl C 94options are specified, each is interpreted relative to the previous one: 95.Fl C Pa / Fl C Pa etc 96is equivalent to 97.Fl C Pa /etc . 98.It Fl D Ar variable 99Define 100.Ar variable 101to be 1, in the global context. 102.It Fl d Ar [-]flags 103Turn on debugging, and specify which portions of 104.Nm 105are to print debugging information. 106Unless the flags are preceded by 107.Ql \- 108they are added to the 109.Va MAKEFLAGS 110environment variable and will be processed by any child make processes. 111By default, debugging information is printed to standard error, 112but this can be changed using the 113.Ar F 114debugging flag. 115The debugging output is always unbuffered; in addition, if debugging 116is enabled but debugging output is not directed to standard output, 117then the standard output is line buffered. 118.Ar Flags 119is one or more of the following: 120.Bl -tag -width Ds 121.It Ar A 122Print all possible debugging information; 123equivalent to specifying all of the debugging flags. 124.It Ar a 125Print debugging information about archive searching and caching. 126.It Ar C 127Print debugging information about current working directory. 128.It Ar c 129Print debugging information about conditional evaluation. 130.It Ar d 131Print debugging information about directory searching and caching. 132.It Ar e 133Print debugging information about failed commands and targets. 134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 135Specify where debugging output is written. 136This must be the last flag, because it consumes the remainder of 137the argument. 138If the character immediately after the 139.Ql F 140flag is 141.Ql \&+ , 142then the file will be opened in append mode; 143otherwise the file will be overwritten. 144If the file name is 145.Ql stdout 146or 147.Ql stderr 148then debugging output will be written to the 149standard output or standard error output file descriptors respectively 150(and the 151.Ql \&+ 152option has no effect). 153Otherwise, the output will be written to the named file. 154If the file name ends 155.Ql .%d 156then the 157.Ql %d 158is replaced by the pid. 159.It Ar f 160Print debugging information about loop evaluation. 161.It Ar "g1" 162Print the input graph before making anything. 163.It Ar "g2" 164Print the input graph after making everything, or before exiting 165on error. 166.It Ar "g3" 167Print the input graph before exiting on error. 168.It Ar j 169Print debugging information about running multiple shells. 170.It Ar l 171Print commands in Makefiles regardless of whether or not they are prefixed by 172.Ql @ 173or other "quiet" flags. 174Also known as "loud" behavior. 175.It Ar M 176Print debugging information about "meta" mode decisions about targets. 177.It Ar m 178Print debugging information about making targets, including modification 179dates. 180.It Ar n 181Don't delete the temporary command scripts created when running commands. 182These temporary scripts are created in the directory 183referred to by the 184.Ev TMPDIR 185environment variable, or in 186.Pa /tmp 187if 188.Ev TMPDIR 189is unset or set to the empty string. 190The temporary scripts are created by 191.Xr mkstemp 3 , 192and have names of the form 193.Pa makeXXXXXX . 194.Em NOTE : 195This can create many files in 196.Ev TMPDIR 197or 198.Pa /tmp , 199so use with care. 200.It Ar p 201Print debugging information about makefile parsing. 202.It Ar s 203Print debugging information about suffix-transformation rules. 204.It Ar t 205Print debugging information about target list maintenance. 206.It Ar V 207Force the 208.Fl V 209option to print raw values of variables. 210.It Ar v 211Print debugging information about variable assignment. 212.It Ar 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 a series of shell commands, normally 445used to create the target. 446Each of the commands in this script 447.Em must 448be preceded by a tab. 449While any target may appear on a dependency line, only one of these 450dependencies may be followed by a creation script, unless the 451.Ql Ic \&:: 452operator is used. 453.Pp 454If the first characters of the command line are any combination of 455.Ql Ic @ , 456.Ql Ic + , 457or 458.Ql Ic \- , 459the command is treated specially. 460A 461.Ql Ic @ 462causes the command not to be echoed before it is executed. 463A 464.Ql Ic + 465causes the command to be executed even when 466.Fl n 467is given. 468This is similar to the effect of the .MAKE special source, 469except that the effect can be limited to a single line of a script. 470A 471.Ql Ic \- 472causes any non-zero exit status of the command line to be ignored. 473.Pp 474When 475.Nm 476is run in jobs mode with 477.Fl j Ar max_jobs , 478the entire script for the target is fed to a 479single instance of the shell. 480.Pp 481In compatibility (non-jobs) mode, each command is run in a separate process. 482If the command contains any shell meta characters 483.Pq Ql #=|^(){};&<>*?[]:$`\e\en 484it will be passed to the shell, otherwise 485.Nm 486will attempt direct execution. 487.Pp 488Since 489.Nm 490will 491.Xr chdir 2 492to 493.Ql Va .OBJDIR 494before executing any targets, each child process 495starts with that as its current working directory. 496.Pp 497Makefiles should be written so that the mode of 498.Nm 499operation does not change their behavior. 500For example, any command which needs to use 501.Dq cd 502or 503.Dq chdir , 504without side-effect should be put in parenthesis: 505.Bd -literal -offset indent 506 507avoid-chdir-side-effects: 508 @echo Building $@ in `pwd` 509 @(cd ${.CURDIR} && ${.MAKE} $@) 510 @echo Back in `pwd` 511 512ensure-one-shell-regardless-of-mode: 513 @echo Building $@ in `pwd`; \\ 514 (cd ${.CURDIR} && ${.MAKE} $@); \\ 515 echo Back in `pwd` 516.Ed 517.Sh VARIABLE ASSIGNMENTS 518Variables in make are much like variables in the shell, and, by tradition, 519consist of all upper-case letters. 520.Ss Variable assignment modifiers 521The five operators that can be used to assign values to variables are as 522follows: 523.Bl -tag -width Ds 524.It Ic \&= 525Assign the value to the variable. 526Any previous value is overridden. 527.It Ic \&+= 528Append the value to the current value of the variable. 529.It Ic \&?= 530Assign the value to the variable if it is not already defined. 531.It Ic \&:= 532Assign with expansion, i.e. expand the value before assigning it 533to the variable. 534Normally, expansion is not done until the variable is referenced. 535.Em NOTE : 536References to undefined variables are 537.Em not 538expanded. 539This can cause problems when variable modifiers are used. 540.It Ic \&!= 541Expand the value and pass it to the shell for execution and assign 542the result to the variable. 543Any newlines in the result are replaced with spaces. 544.El 545.Pp 546Any white-space before the assigned 547.Ar value 548is removed; if the value is being appended, a single space is inserted 549between the previous contents of the variable and the appended value. 550.Pp 551Variables are expanded by surrounding the variable name with either 552curly braces 553.Pq Ql {} 554or parentheses 555.Pq Ql () 556and preceding it with 557a dollar sign 558.Pq Ql \&$ . 559If the variable name contains only a single letter, the surrounding 560braces or parentheses are not required. 561This shorter form is not recommended. 562.Pp 563If the variable name contains a dollar, then the name itself is expanded first. 564This allows almost arbitrary variable names, however names containing dollar, 565braces, parenthesis, or whitespace are really best avoided! 566.Pp 567If the result of expanding a variable contains a dollar sign 568.Pq Ql \&$ 569the string is expanded again. 570.Pp 571Variable substitution occurs at three distinct times, depending on where 572the variable is being used. 573.Bl -enum 574.It 575Variables in dependency lines are expanded as the line is read. 576.It 577Variables in shell commands are expanded when the shell command is 578executed. 579.It 580.Dq .for 581loop index variables are expanded on each loop iteration. 582Note that other variables are not expanded inside loops so 583the following example code: 584.Bd -literal -offset indent 585 586.Dv .for i in 1 2 3 587a+= ${i} 588j= ${i} 589b+= ${j} 590.Dv .endfor 591 592all: 593 @echo ${a} 594 @echo ${b} 595 596.Ed 597will print: 598.Bd -literal -offset indent 5991 2 3 6003 3 3 601 602.Ed 603Because while ${a} contains 604.Dq 1 2 3 605after the loop is executed, ${b} 606contains 607.Dq ${j} ${j} ${j} 608which expands to 609.Dq 3 3 3 610since after the loop completes ${j} contains 611.Dq 3 . 612.El 613.Ss Variable classes 614The four different classes of variables (in order of increasing precedence) 615are: 616.Bl -tag -width Ds 617.It Environment variables 618Variables defined as part of 619.Nm Ns 's 620environment. 621.It Global variables 622Variables defined in the makefile or in included makefiles. 623.It Command line variables 624Variables defined as part of the command line. 625.It Local variables 626Variables that are defined specific to a certain target. 627The seven local variables are as follows: 628.Bl -tag -width ".ARCHIVE" 629.It Va .ALLSRC 630The list of all sources for this target; also known as 631.Ql Va \&\*[Gt] . 632.It Va .ARCHIVE 633The name of the archive file. 634.It Va .IMPSRC 635In suffix-transformation rules, the name/path of the source from which the 636target is to be transformed (the 637.Dq implied 638source); also known as 639.Ql Va \&\*[Lt] . 640It is not defined in explicit rules. 641.It Va .MEMBER 642The name of the archive member. 643.It Va .OODATE 644The list of sources for this target that were deemed out-of-date; also 645known as 646.Ql Va \&? . 647.It Va .PREFIX 648The file prefix of the target, containing only the file portion, no suffix 649or preceding directory components; also known as 650.Ql Va * . 651.It Va .TARGET 652The name of the target; also known as 653.Ql Va @ . 654.El 655.Pp 656The shorter forms 657.Ql Va @ , 658.Ql Va \&? , 659.Ql Va \&\*[Lt] , 660.Ql Va \&\*[Gt] , 661and 662.Ql Va * 663are permitted for backward 664compatibility with historical makefiles and are not recommended. 665The six variables 666.Ql Va "@F" , 667.Ql Va "@D" , 668.Ql Va "\*[Lt]F" , 669.Ql Va "\*[Lt]D" , 670.Ql Va "*F" , 671and 672.Ql Va "*D" 673are permitted for compatibility with 674.At V 675makefiles and are not recommended. 676.Pp 677Four of the local variables may be used in sources on dependency lines 678because they expand to the proper value for each target on the line. 679These variables are 680.Ql Va .TARGET , 681.Ql Va .PREFIX , 682.Ql Va .ARCHIVE , 683and 684.Ql Va .MEMBER . 685.El 686.Ss Additional built-in variables 687In addition, 688.Nm 689sets or knows about the following variables: 690.Bl -tag -width .MAKEOVERRIDES 691.It Va \&$ 692A single dollar sign 693.Ql \&$ , 694i.e. 695.Ql \&$$ 696expands to a single dollar 697sign. 698.It Va .ALLTARGETS 699The list of all targets encountered in the Makefile. 700If evaluated during 701Makefile parsing, lists only those targets encountered thus far. 702.It Va .CURDIR 703A path to the directory where 704.Nm 705was executed. 706Refer to the description of 707.Ql Ev PWD 708for more details. 709.It Va .INCLUDEDFROMDIR 710The directory of the file this Makefile was included from. 711.It Va .INCLUDEDFROMFILE 712The filename of the file this Makefile was included from. 713.It Ev MAKE 714The name that 715.Nm 716was executed with 717.Pq Va argv[0] . 718For compatibility 719.Nm 720also sets 721.Va .MAKE 722with the same value. 723The preferred variable to use is the environment variable 724.Ev MAKE 725because it is more compatible with other versions of 726.Nm 727and cannot be confused with the special target with the same name. 728.It Va .MAKE.DEPENDFILE 729Names the makefile (default 730.Ql Pa .depend ) 731from which generated dependencies are read. 732.It Va .MAKE.EXPAND_VARIABLES 733A boolean that controls the default behavior of the 734.Fl V 735option. 736.It Va .MAKE.EXPORTED 737The list of variables exported by 738.Nm . 739.It Va .MAKE.JOBS 740The argument to the 741.Fl j 742option. 743.It Va .MAKE.JOB.PREFIX 744If 745.Nm 746is run with 747.Ar j 748then output for each target is prefixed with a token 749.Ql --- target --- 750the first part of which can be controlled via 751.Va .MAKE.JOB.PREFIX . 752If 753.Va .MAKE.JOB.PREFIX 754is empty, no token is printed. 755.br 756For example: 757.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 758would produce tokens like 759.Ql ---make[1234] target --- 760making it easier to track the degree of parallelism being achieved. 761.It Ev MAKEFLAGS 762The environment variable 763.Ql Ev MAKEFLAGS 764may contain anything that 765may be specified on 766.Nm Ns 's 767command line. 768Anything specified on 769.Nm Ns 's 770command line is appended to the 771.Ql Ev MAKEFLAGS 772variable which is then 773entered into the environment for all programs which 774.Nm 775executes. 776.It Va .MAKE.LEVEL 777The recursion depth of 778.Nm . 779The initial instance of 780.Nm 781will be 0, and an incremented value is put into the environment 782to be seen by the next generation. 783This allows tests like: 784.Li .if ${.MAKE.LEVEL} == 0 785to protect things which should only be evaluated in the initial instance of 786.Nm . 787.It Va .MAKE.MAKEFILE_PREFERENCE 788The ordered list of makefile names 789(default 790.Ql Pa makefile , 791.Ql Pa Makefile ) 792that 793.Nm 794will look for. 795.It Va .MAKE.MAKEFILES 796The list of makefiles read by 797.Nm , 798which is useful for tracking dependencies. 799Each makefile is recorded only once, regardless of the number of times read. 800.It Va .MAKE.MODE 801Processed after reading all makefiles. 802Can affect the mode that 803.Nm 804runs in. 805It can contain a number of keywords: 806.Bl -hang -width ignore-cmd 807.It Pa compat 808Like 809.Fl B , 810puts 811.Nm 812into "compat" mode. 813.It Pa meta 814Puts 815.Nm 816into "meta" mode, where meta files are created for each target 817to capture the command run, the output generated and if 818.Xr filemon 4 819is available, the system calls which are of interest to 820.Nm . 821The captured output can be very useful when diagnosing errors. 822.It Pa curdirOk= Ar bf 823Normally 824.Nm 825will not create .meta files in 826.Ql Va .CURDIR . 827This can be overridden by setting 828.Va bf 829to a value which represents True. 830.It Pa env 831For debugging, it can be useful to inlcude the environment 832in the .meta file. 833.It Pa verbose 834If in "meta" mode, print a clue about the target being built. 835This is useful if the build is otherwise running silently. 836The message printed the value of: 837.Va .MAKE.META.PREFIX . 838.It Pa ignore-cmd 839Some makefiles have commands which are simply not stable. 840This keyword causes them to be ignored for 841determining whether a target is out of date in "meta" mode. 842See also 843.Ic .NOMETA_CMP . 844.It Pa silent= Ar bf 845If 846.Va bf 847is True, when a .meta file is created, mark the target 848.Ic .SILENT . 849.El 850.It Va .MAKE.META.BAILIWICK 851In "meta" mode, provides a list of prefixes which 852match the directories controlled by 853.Nm . 854If a file that was generated outside of 855.Va .OBJDIR 856but within said bailiwick is missing, 857the current target is considered out-of-date. 858.It Va .MAKE.META.CREATED 859In "meta" mode, this variable contains a list of all the meta files 860updated. 861If not empty, it can be used to trigger processing of 862.Va .MAKE.META.FILES . 863.It Va .MAKE.META.FILES 864In "meta" mode, this variable contains a list of all the meta files 865used (updated or not). 866This list can be used to process the meta files to extract dependency 867information. 868.It Va .MAKE.META.IGNORE_PATHS 869Provides a list of path prefixes that should be ignored; 870because the contents are expected to change over time. 871The default list includes: 872.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 873.It Va .MAKE.META.PREFIX 874Defines the message printed for each meta file updated in "meta verbose" mode. 875The default value is: 876.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 877.It Va .MAKEOVERRIDES 878This variable is used to record the names of variables assigned to 879on the command line, so that they may be exported as part of 880.Ql Ev MAKEFLAGS . 881This behaviour can be disabled by assigning an empty value to 882.Ql Va .MAKEOVERRIDES 883within a makefile. 884Extra variables can be exported from a makefile 885by appending their names to 886.Ql Va .MAKEOVERRIDES . 887.Ql Ev MAKEFLAGS 888is re-exported whenever 889.Ql Va .MAKEOVERRIDES 890is modified. 891.It Va .MAKE.PATH_FILEMON 892If 893.Nm 894was built with 895.Xr filemon 4 896support, this is set to the path of the device node. 897This allows makefiles to test for this support. 898.It Va .MAKE.PID 899The process-id of 900.Nm . 901.It Va .MAKE.PPID 902The parent process-id of 903.Nm . 904.It Va .MAKE.BUILT.BY 905The compiler CCVER that built the 906.Dx 907world. 908.It Va MAKE_PRINT_VAR_ON_ERROR 909When 910.Nm 911stops due to an error, it prints its name and the value of 912.Ql Va .CURDIR 913as well as the value of any variables named in 914.Ql Va MAKE_PRINT_VAR_ON_ERROR . 915.It Va .newline 916This variable is simply assigned a newline character as its value. 917This allows expansions using the 918.Cm \&:@ 919modifier to put a newline between 920iterations of the loop rather than a space. 921For example, the printing of 922.Ql Va MAKE_PRINT_VAR_ON_ERROR 923could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 924.It Va .OBJDIR 925A path to the directory where the targets are built. 926Its value is determined by trying to 927.Xr chdir 2 928to the following directories in order and using the first match: 929.Bl -enum 930.It 931.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 932.Pp 933(Only if 934.Ql Ev MAKEOBJDIRPREFIX 935is set in the environment or on the command line.) 936.It 937.Ev ${MAKEOBJDIR} 938.Pp 939(Only if 940.Ql Ev MAKEOBJDIR 941is set in the environment or on the command line.) 942.It 943.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 944.It 945.Ev ${.CURDIR} Ns Pa /obj 946.It 947.Pa /usr/obj/ Ns Ev ${.CURDIR} 948.It 949.Ev ${.CURDIR} 950.El 951.Pp 952Variable expansion is performed on the value before it's used, 953so expressions such as 954.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 955may be used. 956This is especially useful with 957.Ql Ev MAKEOBJDIR . 958.Pp 959.Ql Va .OBJDIR 960may be modified in the makefile as a global variable. 961In all cases, 962.Nm 963will 964.Xr chdir 2 965to 966.Ql Va .OBJDIR 967and set 968.Ql Ev PWD 969to that directory before executing any targets. 970. 971.It Va .PARSEDIR 972A path to the directory of the current 973.Ql Pa Makefile 974being parsed. 975.It Va .PARSEFILE 976The basename of the current 977.Ql Pa Makefile 978being parsed. 979This variable and 980.Ql Va .PARSEDIR 981are both set only while the 982.Ql Pa Makefiles 983are being parsed. 984If you want to retain their current values, assign them to a variable 985using assignment with expansion: 986.Pq Ql Cm \&:= . 987.It Va .PATH 988A variable that represents the list of directories that 989.Nm 990will search for files. 991The search list should be updated using the target 992.Ql Va .PATH 993rather than the variable. 994.It Ev PWD 995Alternate path to the current directory. 996.Nm 997normally sets 998.Ql Va .CURDIR 999to the canonical path given by 1000.Xr getcwd 3 . 1001However, if the environment variable 1002.Ql Ev PWD 1003is set and gives a path to the current directory, then 1004.Nm 1005sets 1006.Ql Va .CURDIR 1007to the value of 1008.Ql Ev PWD 1009instead. 1010This behaviour is disabled if 1011.Ql Ev MAKEOBJDIRPREFIX 1012is set or 1013.Ql Ev MAKEOBJDIR 1014contains a variable transform. 1015.Ql Ev PWD 1016is set to the value of 1017.Ql Va .OBJDIR 1018for all programs which 1019.Nm 1020executes. 1021.It Ev .TARGETS 1022The list of targets explicitly specified on the command line, if any. 1023.It Ev VPATH 1024Colon-separated 1025.Pq Dq \&: 1026lists of directories that 1027.Nm 1028will search for files. 1029The variable is supported for compatibility with old make programs only, 1030use 1031.Ql Va .PATH 1032instead. 1033.El 1034.Ss Variable modifiers 1035Variable expansion may be modified to select or modify each word of the 1036variable (where a 1037.Dq word 1038is white-space delimited sequence of characters). 1039The general format of a variable expansion is as follows: 1040.Pp 1041.Dl ${variable[:modifier[:...]]} 1042.Pp 1043Each modifier begins with a colon, 1044which may be escaped with a backslash 1045.Pq Ql \e . 1046.Pp 1047A set of modifiers can be specified via a variable, as follows: 1048.Pp 1049.Dl modifier_variable=modifier[:...] 1050.Dl ${variable:${modifier_variable}[:...]} 1051.Pp 1052In this case the first modifier in the modifier_variable does not 1053start with a colon, since that must appear in the referencing 1054variable. 1055If any of the modifiers in the modifier_variable contain a dollar sign 1056.Pq Ql $ , 1057these must be doubled to avoid early expansion. 1058.Pp 1059The supported modifiers are: 1060.Bl -tag -width EEE 1061.It Cm \&:E 1062Replaces each word in the variable with its suffix. 1063.It Cm \&:H 1064Replaces each word in the variable with everything but the last component. 1065.It Cm \&:M Ns Ar pattern 1066Select only those words that match 1067.Ar pattern . 1068The standard shell wildcard characters 1069.Pf ( Ql * , 1070.Ql \&? , 1071and 1072.Ql Oo Oc ) 1073may 1074be used. 1075The wildcard characters may be escaped with a backslash 1076.Pq Ql \e . 1077As a consequence of the way values are split into words, matched, 1078and then joined, a construct like 1079.Dl ${VAR:M*} 1080will normalise the inter-word spacing, removing all leading and 1081trailing space, and converting multiple consecutive spaces 1082to single spaces. 1083. 1084.It Cm \&:N Ns Ar pattern 1085This is identical to 1086.Ql Cm \&:M , 1087but selects all words which do not match 1088.Ar pattern . 1089.It Cm \&:O 1090Order every word in variable alphabetically. 1091To sort words in 1092reverse order use the 1093.Ql Cm \&:O:[-1..1] 1094combination of modifiers. 1095.It Cm \&:Ox 1096Randomize words in variable. 1097The results will be different each time you are referring to the 1098modified variable; use the assignment with expansion 1099.Pq Ql Cm \&:= 1100to prevent such behaviour. 1101For example, 1102.Bd -literal -offset indent 1103LIST= uno due tre quattro 1104RANDOM_LIST= ${LIST:Ox} 1105STATIC_RANDOM_LIST:= ${LIST:Ox} 1106 1107all: 1108 @echo "${RANDOM_LIST}" 1109 @echo "${RANDOM_LIST}" 1110 @echo "${STATIC_RANDOM_LIST}" 1111 @echo "${STATIC_RANDOM_LIST}" 1112.Ed 1113may produce output similar to: 1114.Bd -literal -offset indent 1115quattro due tre uno 1116tre due quattro uno 1117due uno quattro tre 1118due uno quattro tre 1119.Ed 1120.It Cm \&:Q 1121Quotes every shell meta-character in the variable, so that it can be passed 1122safely through recursive invocations of 1123.Nm . 1124.It Cm \&:R 1125Replaces each word in the variable with everything but its suffix. 1126.It Cm \&:gmtime 1127The value is a format string for 1128.Xr strftime 3 , 1129using the current 1130.Xr gmtime 3 . 1131.It Cm \&:hash 1132Compute a 32bit hash of the value and encode it as hex digits. 1133.It Cm \&:localtime 1134The value is a format string for 1135.Xr strftime 3 , 1136using the current 1137.Xr localtime 3 . 1138.It Cm \&:tA 1139Attempt to convert variable to an absolute path using 1140.Xr realpath 3 , 1141if that fails, the value is unchanged. 1142.It Cm \&:tl 1143Converts variable to lower-case letters. 1144.It Cm \&:ts Ns Ar c 1145Words in the variable are normally separated by a space on expansion. 1146This modifier sets the separator to the character 1147.Ar c . 1148If 1149.Ar c 1150is omitted, then no separator is used. 1151The common escapes (including octal numeric codes), work as expected. 1152.It Cm \&:tu 1153Converts variable to upper-case letters. 1154.It Cm \&:tW 1155Causes the value to be treated as a single word 1156(possibly containing embedded white space). 1157See also 1158.Ql Cm \&:[*] . 1159.It Cm \&:tw 1160Causes the value to be treated as a sequence of 1161words delimited by white space. 1162See also 1163.Ql Cm \&:[@] . 1164.Sm off 1165.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1166.Sm on 1167Modify the first occurrence of 1168.Ar old_string 1169in the variable's value, replacing it with 1170.Ar new_string . 1171If a 1172.Ql g 1173is appended to the last slash of the pattern, all occurrences 1174in each word are replaced. 1175If a 1176.Ql 1 1177is appended to the last slash of the pattern, only the first word 1178is affected. 1179If a 1180.Ql W 1181is appended to the last slash of the pattern, 1182then the value is treated as a single word 1183(possibly containing embedded white space). 1184If 1185.Ar old_string 1186begins with a caret 1187.Pq Ql ^ , 1188.Ar old_string 1189is anchored at the beginning of each word. 1190If 1191.Ar old_string 1192ends with a dollar sign 1193.Pq Ql \&$ , 1194it is anchored at the end of each word. 1195Inside 1196.Ar new_string , 1197an ampersand 1198.Pq Ql \*[Am] 1199is replaced by 1200.Ar old_string 1201(without any 1202.Ql ^ 1203or 1204.Ql \&$ ) . 1205Any character may be used as a delimiter for the parts of the modifier 1206string. 1207The anchoring, ampersand and delimiter characters may be escaped with a 1208backslash 1209.Pq Ql \e . 1210.Pp 1211Variable expansion occurs in the normal fashion inside both 1212.Ar old_string 1213and 1214.Ar new_string 1215with the single exception that a backslash is used to prevent the expansion 1216of a dollar sign 1217.Pq Ql \&$ , 1218not a preceding dollar sign as is usual. 1219.Sm off 1220.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1221.Sm on 1222The 1223.Cm \&:C 1224modifier is just like the 1225.Cm \&:S 1226modifier except that the old and new strings, instead of being 1227simple strings, are an extended regular expression (see 1228.Xr regex 3 ) 1229string 1230.Ar pattern 1231and an 1232.Xr ed 1 Ns \-style 1233string 1234.Ar replacement . 1235Normally, the first occurrence of the pattern 1236.Ar pattern 1237in each word of the value is substituted with 1238.Ar replacement . 1239The 1240.Ql 1 1241modifier causes the substitution to apply to at most one word; the 1242.Ql g 1243modifier causes the substitution to apply to as many instances of the 1244search pattern 1245.Ar pattern 1246as occur in the word or words it is found in; the 1247.Ql W 1248modifier causes the value to be treated as a single word 1249(possibly containing embedded white space). 1250Note that 1251.Ql 1 1252and 1253.Ql g 1254are orthogonal; the former specifies whether multiple words are 1255potentially affected, the latter whether multiple substitutions can 1256potentially occur within each affected word. 1257.Pp 1258As for the 1259.Cm \&:S 1260modifier, the 1261.Ar pattern 1262and 1263.Ar replacement 1264are subjected to variable expansion before being parsed as 1265regular expressions. 1266.It Cm \&:T 1267Replaces each word in the variable with its last component. 1268.It Cm \&:u 1269Remove adjacent duplicate words (like 1270.Xr uniq 1 ) . 1271.Sm off 1272.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1273.Sm on 1274If the variable name (not its value), when parsed as a .if conditional 1275expression, evaluates to true, return as its value the 1276.Ar true_string , 1277otherwise return the 1278.Ar false_string . 1279Since the variable name is used as the expression, \&:\&? must be the 1280first modifier after the variable name itself - which will, of course, 1281usually contain variable expansions. 1282A common error is trying to use expressions like 1283.Dl ${NUMBERS:M42:?match:no} 1284which actually tests defined(NUMBERS), 1285to determine is any words match "42" you need to use something like: 1286.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1287.It Ar :old_string=new_string 1288This is the 1289.At V 1290style variable substitution. 1291It must be the last modifier specified. 1292If 1293.Ar old_string 1294or 1295.Ar new_string 1296do not contain the pattern matching character 1297.Ar % 1298then it is assumed that they are 1299anchored at the end of each word, so only suffixes or entire 1300words may be replaced. 1301Otherwise 1302.Ar % 1303is the substring of 1304.Ar old_string 1305to be replaced in 1306.Ar new_string . 1307.Pp 1308Variable expansion occurs in the normal fashion inside both 1309.Ar old_string 1310and 1311.Ar new_string 1312with the single exception that a backslash is used to prevent the 1313expansion of a dollar sign 1314.Pq Ql \&$ , 1315not a preceding dollar sign as is usual. 1316.Sm off 1317.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1318.Sm on 1319This is the loop expansion mechanism from the OSF Development 1320Environment (ODE) make. 1321Unlike 1322.Cm \&.for 1323loops expansion occurs at the time of 1324reference. 1325Assign 1326.Ar temp 1327to each word in the variable and evaluate 1328.Ar string . 1329The ODE convention is that 1330.Ar temp 1331should start and end with a period. 1332For example. 1333.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1334.Pp 1335However a single character variable is often more readable: 1336.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1337.It Cm \&:U Ns Ar newval 1338If the variable is undefined 1339.Ar newval 1340is the value. 1341If the variable is defined, the existing value is returned. 1342This is another ODE make feature. 1343It is handy for setting per-target CFLAGS for instance: 1344.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1345If a value is only required if the variable is undefined, use: 1346.Dl ${VAR:D:Unewval} 1347.It Cm \&:D Ns Ar newval 1348If the variable is defined 1349.Ar newval 1350is the value. 1351.It Cm \&:L 1352The name of the variable is the value. 1353.It Cm \&:P 1354The path of the node which has the same name as the variable 1355is the value. 1356If no such node exists or its path is null, then the 1357name of the variable is used. 1358In order for this modifier to work, the name (node) must at least have 1359appeared on the rhs of a dependency. 1360.Sm off 1361.It Cm \&:\&! Ar cmd Cm \&! 1362.Sm on 1363The output of running 1364.Ar cmd 1365is the value. 1366.It Cm \&:sh 1367If the variable is non-empty it is run as a command and the output 1368becomes the new value. 1369.It Cm \&::= Ns Ar str 1370The variable is assigned the value 1371.Ar str 1372after substitution. 1373This modifier and its variations are useful in 1374obscure situations such as wanting to set a variable when shell commands 1375are being parsed. 1376These assignment modifiers always expand to 1377nothing, so if appearing in a rule line by themselves should be 1378preceded with something to keep 1379.Nm 1380happy. 1381.Pp 1382The 1383.Ql Cm \&:: 1384helps avoid false matches with the 1385.At V 1386style 1387.Cm \&:= 1388modifier and since substitution always occurs the 1389.Cm \&::= 1390form is vaguely appropriate. 1391.It Cm \&::?= Ns Ar str 1392As for 1393.Cm \&::= 1394but only if the variable does not already have a value. 1395.It Cm \&::+= Ns Ar str 1396Append 1397.Ar str 1398to the variable. 1399.It Cm \&::!= Ns Ar cmd 1400Assign the output of 1401.Ar cmd 1402to the variable. 1403.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1404Selects one or more words from the value, 1405or performs other operations related to the way in which the 1406value is divided into words. 1407.Pp 1408Ordinarily, a value is treated as a sequence of words 1409delimited by white space. 1410Some modifiers suppress this behaviour, 1411causing a value to be treated as a single word 1412(possibly containing embedded white space). 1413An empty value, or a value that consists entirely of white-space, 1414is treated as a single word. 1415For the purposes of the 1416.Ql Cm \&:[] 1417modifier, the words are indexed both forwards using positive integers 1418(where index 1 represents the first word), 1419and backwards using negative integers 1420(where index \-1 represents the last word). 1421.Pp 1422The 1423.Ar range 1424is subjected to variable expansion, and the expanded result is 1425then interpreted as follows: 1426.Bl -tag -width index 1427.\" :[n] 1428.It Ar index 1429Selects a single word from the value. 1430.\" :[start..end] 1431.It Ar start Ns Cm \&.. Ns Ar end 1432Selects all words from 1433.Ar start 1434to 1435.Ar end , 1436inclusive. 1437For example, 1438.Ql Cm \&:[2..-1] 1439selects all words from the second word to the last word. 1440If 1441.Ar start 1442is greater than 1443.Ar end , 1444then the words are output in reverse order. 1445For example, 1446.Ql Cm \&:[-1..1] 1447selects all the words from last to first. 1448.\" :[*] 1449.It Cm \&* 1450Causes subsequent modifiers to treat the value as a single word 1451(possibly containing embedded white space). 1452Analogous to the effect of 1453\&"$*\&" 1454in Bourne shell. 1455.\" :[0] 1456.It 0 1457Means the same as 1458.Ql Cm \&:[*] . 1459.\" :[*] 1460.It Cm \&@ 1461Causes subsequent modifiers to treat the value as a sequence of words 1462delimited by white space. 1463Analogous to the effect of 1464\&"$@\&" 1465in Bourne shell. 1466.\" :[#] 1467.It Cm \&# 1468Returns the number of words in the value. 1469.El \" :[range] 1470.El 1471.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1472Makefile inclusion, conditional structures and for loops reminiscent 1473of the C programming language are provided in 1474.Nm . 1475All such structures are identified by a line beginning with a single 1476dot 1477.Pq Ql \&. 1478character. 1479Files are included with either 1480.Cm \&.include Aq Ar file 1481or 1482.Cm \&.include Pf \*q Ar file Ns \*q . 1483Variables between the angle brackets or double quotes are expanded 1484to form the file name. 1485If angle brackets are used, the included makefile is expected to be in 1486the system makefile directory. 1487If double quotes are used, the including makefile's directory and any 1488directories specified using the 1489.Fl I 1490option are searched before the system 1491makefile directory. 1492For compatibility with other versions of 1493.Nm 1494.Ql include file ... 1495is also accepted. 1496If the include statement is written as 1497.Cm .-include 1498or as 1499.Cm .sinclude 1500then errors locating and/or opening include files are ignored. 1501.Pp 1502Conditional expressions are also preceded by a single dot as the first 1503character of a line. 1504The possible conditionals are as follows: 1505.Bl -tag -width Ds 1506.It Ic .error Ar message 1507The message is printed along with the name of the makefile and line number, 1508then 1509.Nm 1510will exit. 1511.It Ic .export Ar variable ... 1512Export the specified global variable. 1513If no variable list is provided, all globals are exported 1514except for internal variables (those that start with 1515.Ql \&. ) . 1516This is not affected by the 1517.Fl X 1518flag, so should be used with caution. 1519For compatibility with other 1520.Nm 1521programs 1522.Ql export variable=value 1523is also accepted. 1524.Pp 1525Appending a variable name to 1526.Va .MAKE.EXPORTED 1527is equivalent to exporting a variable. 1528.It Ic .export-env Ar variable ... 1529The same as 1530.Ql .export , 1531except that the variable is not appended to 1532.Va .MAKE.EXPORTED . 1533This allows exporting a value to the environment which is different from that 1534used by 1535.Nm 1536internally. 1537.It Ic .info Ar message 1538The message is printed along with the name of the makefile and line number. 1539.It Ic .undef Ar variable 1540Un-define the specified global variable. 1541Only global variables may be un-defined. 1542.It Ic .unexport Ar variable ... 1543The opposite of 1544.Ql .export . 1545The specified global 1546.Va variable 1547will be removed from 1548.Va .MAKE.EXPORTED . 1549If no variable list is provided, all globals are unexported, 1550and 1551.Va .MAKE.EXPORTED 1552deleted. 1553.It Ic .unexport-env 1554Unexport all globals previously exported and 1555clear the environment inherited from the parent. 1556This operation will cause a memory leak of the original environment, 1557so should be used sparingly. 1558Testing for 1559.Va .MAKE.LEVEL 1560being 0, would make sense. 1561Also note that any variables which originated in the parent environment 1562should be explicitly preserved if desired. 1563For example: 1564.Bd -literal -offset indent 1565.Li .if ${.MAKE.LEVEL} == 0 1566PATH := ${PATH} 1567.Li .unexport-env 1568.Li .export PATH 1569.Li .endif 1570.Ed 1571.Pp 1572Would result in an environment containing only 1573.Ql Ev PATH , 1574which is the minimal useful environment. 1575Actually 1576.Ql Ev .MAKE.LEVEL 1577will also be pushed into the new environment. 1578.It Ic .warning Ar message 1579The message prefixed by 1580.Ql Pa warning: 1581is printed along with the name of the makefile and line number. 1582.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1583Test the value of an expression. 1584.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1585Test the value of a variable. 1586.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1587Test the value of a variable. 1588.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1589Test the target being built. 1590.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1591Test the target being built. 1592.It Ic .else 1593Reverse the sense of the last conditional. 1594.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1595A combination of 1596.Ql Ic .else 1597followed by 1598.Ql Ic .if . 1599.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1600A combination of 1601.Ql Ic .else 1602followed by 1603.Ql Ic .ifdef . 1604.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1605A combination of 1606.Ql Ic .else 1607followed by 1608.Ql Ic .ifndef . 1609.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1610A combination of 1611.Ql Ic .else 1612followed by 1613.Ql Ic .ifmake . 1614.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1615A combination of 1616.Ql Ic .else 1617followed by 1618.Ql Ic .ifnmake . 1619.It Ic .endif 1620End the body of the conditional. 1621.El 1622.Pp 1623The 1624.Ar operator 1625may be any one of the following: 1626.Bl -tag -width "Cm XX" 1627.It Cm \&|\&| 1628Logical OR. 1629.It Cm \&\*[Am]\*[Am] 1630Logical 1631.Tn AND ; 1632of higher precedence than 1633.Dq \&|\&| . 1634.El 1635.Pp 1636As in C, 1637.Nm 1638will only evaluate a conditional as far as is necessary to determine 1639its value. 1640Parentheses may be used to change the order of evaluation. 1641The boolean operator 1642.Ql Ic \&! 1643may be used to logically negate an entire 1644conditional. 1645It is of higher precedence than 1646.Ql Ic \&\*[Am]\*[Am] . 1647.Pp 1648The value of 1649.Ar expression 1650may be any of the following: 1651.Bl -tag -width defined 1652.It Ic defined 1653Takes a variable name as an argument and evaluates to true if the variable 1654has been defined. 1655.It Ic make 1656Takes a target name as an argument and evaluates to true if the target 1657was specified as part of 1658.Nm Ns 's 1659command line or was declared the default target (either implicitly or 1660explicitly, see 1661.Va .MAIN ) 1662before the line containing the conditional. 1663.It Ic empty 1664Takes a variable, with possible modifiers, and evaluates to true if 1665the expansion of the variable would result in an empty string. 1666.It Ic exists 1667Takes a file name as an argument and evaluates to true if the file exists. 1668The file is searched for on the system search path (see 1669.Va .PATH ) . 1670.It Ic target 1671Takes a target name as an argument and evaluates to true if the target 1672has been defined. 1673.It Ic commands 1674Takes a target name as an argument and evaluates to true if the target 1675has been defined and has commands associated with it. 1676.El 1677.Pp 1678.Ar Expression 1679may also be an arithmetic or string comparison. 1680Variable expansion is 1681performed on both sides of the comparison, after which the integral 1682values are compared. 1683A value is interpreted as hexadecimal if it is 1684preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1685The standard C relational operators are all supported. 1686If after 1687variable expansion, either the left or right hand side of a 1688.Ql Ic == 1689or 1690.Ql Ic "!=" 1691operator is not an integral value, then 1692string comparison is performed between the expanded 1693variables. 1694If no relational operator is given, it is assumed that the expanded 1695variable is being compared against 0 or an empty string in the case 1696of a string comparison. 1697.Pp 1698When 1699.Nm 1700is evaluating one of these conditional expressions, and it encounters 1701a (white-space separated) word it doesn't recognize, either the 1702.Dq make 1703or 1704.Dq defined 1705expression is applied to it, depending on the form of the conditional. 1706If the form is 1707.Ql Ic .ifdef , 1708.Ql Ic .ifndef , 1709or 1710.Ql Ic .if 1711the 1712.Dq defined 1713expression is applied. 1714Similarly, if the form is 1715.Ql Ic .ifmake 1716or 1717.Ql Ic .ifnmake , the 1718.Dq make 1719expression is applied. 1720.Pp 1721If the conditional evaluates to true the parsing of the makefile continues 1722as before. 1723If it evaluates to false, the following lines are skipped. 1724In both cases this continues until a 1725.Ql Ic .else 1726or 1727.Ql Ic .endif 1728is found. 1729.Pp 1730For loops are typically used to apply a set of rules to a list of files. 1731The syntax of a for loop is: 1732.Pp 1733.Bl -tag -compact -width Ds 1734.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1735.It Aq make-rules 1736.It Ic \&.endfor 1737.El 1738.Pp 1739After the for 1740.Ic expression 1741is evaluated, it is split into words. 1742On each iteration of the loop, one word is taken and assigned to each 1743.Ic variable , 1744in order, and these 1745.Ic variables 1746are substituted into the 1747.Ic make-rules 1748inside the body of the for loop. 1749The number of words must come out even; that is, if there are three 1750iteration variables, the number of words provided must be a multiple 1751of three. 1752.Sh COMMENTS 1753Comments begin with a hash 1754.Pq Ql \&# 1755character, anywhere but in a shell 1756command line, and continue to the end of an unescaped new line. 1757.Sh SPECIAL SOURCES (ATTRIBUTES) 1758.Bl -tag -width .IGNOREx 1759.It Ic .EXEC 1760Target is never out of date, but always execute commands anyway. 1761.It Ic .IGNORE 1762Ignore any errors from the commands associated with this target, exactly 1763as if they all were preceded by a dash 1764.Pq Ql \- . 1765.\" .It Ic .INVISIBLE 1766.\" XXX 1767.\" .It Ic .JOIN 1768.\" XXX 1769.It Ic .MADE 1770Mark all sources of this target as being up-to-date. 1771.It Ic .MAKE 1772Execute the commands associated with this target even if the 1773.Fl n 1774or 1775.Fl t 1776options were specified. 1777Normally used to mark recursive 1778.Nm Ns s . 1779.It Ic .META 1780Create a meta file for the target, even if it is flagged as 1781.Ic .PHONY , 1782.Ic .MAKE , 1783or 1784.Ic .SPECIAL . 1785Usage in conjunction with 1786.Ic .MAKE 1787is the most likely case. 1788In "meta" mode, the target is out-of-date if the meta file is missing. 1789.It Ic .NOMETA 1790Do not create a meta file for the target. 1791Meta files are also not created for 1792.Ic .PHONY , 1793.Ic .MAKE , 1794or 1795.Ic .SPECIAL 1796targets. 1797.It Ic .NOMETA_CMP 1798Ignore differences in commands when deciding if target is out of date. 1799This is useful if the command contains a value which always changes. 1800If the number of commands change, though, the target will still be out of date. 1801The same effect applies to any command line that uses the variable 1802.Va .OODATE , 1803which can be used for that purpose even when not otherwise needed or desired: 1804.Bd -literal -offset indent 1805 1806skip-compare-for-some: 1807 @echo this will be compared 1808 @echo this will not ${.OODATE:M.NOMETA_CMP} 1809 @echo this will also be compared 1810 1811.Ed 1812The 1813.Cm \&:M 1814pattern suppresses any expansion of the unwanted variable. 1815.It Ic .NOPATH 1816Do not search for the target in the directories specified by 1817.Ic .PATH . 1818.It Ic .NOTMAIN 1819Normally 1820.Nm 1821selects the first target it encounters as the default target to be built 1822if no target was specified. 1823This source prevents this target from being selected. 1824.It Ic .OPTIONAL 1825If a target is marked with this attribute and 1826.Nm 1827can't figure out how to create it, it will ignore this fact and assume 1828the file isn't needed or already exists. 1829.It Ic .PHONY 1830The target does not 1831correspond to an actual file; it is always considered to be out of date, 1832and will not be created with the 1833.Fl t 1834option. 1835Suffix-transformation rules are not applied to 1836.Ic .PHONY 1837targets. 1838.It Ic .PRECIOUS 1839When 1840.Nm 1841is interrupted, it normally removes any partially made targets. 1842This source prevents the target from being removed. 1843.It Ic .RECURSIVE 1844Synonym for 1845.Ic .MAKE . 1846.It Ic .SILENT 1847Do not echo any of the commands associated with this target, exactly 1848as if they all were preceded by an at sign 1849.Pq Ql @ . 1850.It Ic .USE 1851Turn the target into 1852.Nm Ns 's 1853version of a macro. 1854When the target is used as a source for another target, the other target 1855acquires the commands, sources, and attributes (except for 1856.Ic .USE ) 1857of the 1858source. 1859If the target already has commands, the 1860.Ic .USE 1861target's commands are appended 1862to them. 1863.It Ic .USEBEFORE 1864Exactly like 1865.Ic .USE , 1866but prepend the 1867.Ic .USEBEFORE 1868target commands to the target. 1869.It Ic .WAIT 1870If 1871.Ic .WAIT 1872appears in a dependency line, the sources that precede it are 1873made before the sources that succeed it in the line. 1874Since the dependents of files are not made until the file itself 1875could be made, this also stops the dependents being built unless they 1876are needed for another branch of the dependency tree. 1877So given: 1878.Bd -literal 1879x: a .WAIT b 1880 echo x 1881a: 1882 echo a 1883b: b1 1884 echo b 1885b1: 1886 echo b1 1887 1888.Ed 1889the output is always 1890.Ql a , 1891.Ql b1 , 1892.Ql b , 1893.Ql x . 1894.br 1895The ordering imposed by 1896.Ic .WAIT 1897is only relevant for parallel makes. 1898.El 1899.Sh SPECIAL TARGETS 1900Special targets may not be included with other targets, i.e. they must be 1901the only target specified. 1902.Bl -tag -width .BEGINx 1903.It Ic .BEGIN 1904Any command lines attached to this target are executed before anything 1905else is done. 1906.It Ic .DEFAULT 1907This is sort of a 1908.Ic .USE 1909rule for any target (that was used only as a 1910source) that 1911.Nm 1912can't figure out any other way to create. 1913Only the shell script is used. 1914The 1915.Ic .IMPSRC 1916variable of a target that inherits 1917.Ic .DEFAULT Ns 's 1918commands is set 1919to the target's own name. 1920.It Ic .END 1921Any command lines attached to this target are executed after everything 1922else is done. 1923.It Ic .ERROR 1924Any command lines attached to this target are executed when another target fails. 1925The 1926.Ic .ERROR_TARGET 1927variable is set to the target that failed. 1928See also 1929.Ic MAKE_PRINT_VAR_ON_ERROR . 1930.It Ic .IGNORE 1931Mark each of the sources with the 1932.Ic .IGNORE 1933attribute. 1934If no sources are specified, this is the equivalent of specifying the 1935.Fl i 1936option. 1937.It Ic .INTERRUPT 1938If 1939.Nm 1940is interrupted, the commands for this target will be executed. 1941.It Ic .MAIN 1942If no target is specified when 1943.Nm 1944is invoked, this target will be built. 1945.It Ic .MAKEFLAGS 1946This target provides a way to specify flags for 1947.Nm 1948when the makefile is used. 1949The flags are as if typed to the shell, though the 1950.Fl f 1951option will have 1952no effect. 1953.\" XXX: NOT YET!!!! 1954.\" .It Ic .NOTPARALLEL 1955.\" The named targets are executed in non parallel mode. 1956.\" If no targets are 1957.\" specified, then all targets are executed in non parallel mode. 1958.It Ic .NOPATH 1959Apply the 1960.Ic .NOPATH 1961attribute to any specified sources. 1962.It Ic .NOTPARALLEL 1963Disable parallel mode. 1964.It Ic .NO_PARALLEL 1965Synonym for 1966.Ic .NOTPARALLEL , 1967for compatibility with other pmake variants. 1968.It Ic .ORDER 1969The named targets are made in sequence. 1970This ordering does not add targets to the list of targets to be made. 1971Since the dependents of a target do not get built until the target itself 1972could be built, unless 1973.Ql a 1974is built by another part of the dependency graph, 1975the following is a dependency loop: 1976.Bd -literal 1977\&.ORDER: b a 1978b: a 1979.Ed 1980.Pp 1981The ordering imposed by 1982.Ic .ORDER 1983is only relevant for parallel makes. 1984.\" XXX: NOT YET!!!! 1985.\" .It Ic .PARALLEL 1986.\" The named targets are executed in parallel mode. 1987.\" If no targets are 1988.\" specified, then all targets are executed in parallel mode. 1989.It Ic .PATH 1990The sources are directories which are to be searched for files not 1991found in the current directory. 1992If no sources are specified, any previously specified directories are 1993deleted. 1994If the source is the special 1995.Ic .DOTLAST 1996target, then the current working 1997directory is searched last. 1998.It Ic .PATH. Ns Va suffix 1999Like 2000.Ic .PATH 2001but applies only to files with a particular suffix. 2002The suffix must have been previously declared with 2003.Ic .SUFFIXES . 2004.It Ic .PHONY 2005Apply the 2006.Ic .PHONY 2007attribute to any specified sources. 2008.It Ic .PRECIOUS 2009Apply the 2010.Ic .PRECIOUS 2011attribute to any specified sources. 2012If no sources are specified, the 2013.Ic .PRECIOUS 2014attribute is applied to every 2015target in the file. 2016.It Ic .SHELL 2017Sets the shell that 2018.Nm 2019will use to execute commands. 2020The sources are a set of 2021.Ar field=value 2022pairs. 2023.Bl -tag -width hasErrCtls 2024.It Ar name 2025This is the minimal specification, used to select one of the builtin 2026shell specs; 2027.Ar sh , 2028.Ar ksh , 2029and 2030.Ar csh . 2031.It Ar path 2032Specifies the path to the shell. 2033.It Ar hasErrCtl 2034Indicates whether the shell supports exit on error. 2035.It Ar check 2036The command to turn on error checking. 2037.It Ar ignore 2038The command to disable error checking. 2039.It Ar echo 2040The command to turn on echoing of commands executed. 2041.It Ar quiet 2042The command to turn off echoing of commands executed. 2043.It Ar filter 2044The output to filter after issuing the 2045.Ar quiet 2046command. 2047It is typically identical to 2048.Ar quiet . 2049.It Ar errFlag 2050The flag to pass the shell to enable error checking. 2051.It Ar echoFlag 2052The flag to pass the shell to enable command echoing. 2053.It Ar newline 2054The string literal to pass the shell that results in a single newline 2055character when used outside of any quoting characters. 2056.El 2057Example: 2058.Bd -literal 2059\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2060 check="set \-e" ignore="set +e" \e 2061 echo="set \-v" quiet="set +v" filter="set +v" \e 2062 echoFlag=v errFlag=e newline="'\en'" 2063.Ed 2064.It Ic .SILENT 2065Apply the 2066.Ic .SILENT 2067attribute to any specified sources. 2068If no sources are specified, the 2069.Ic .SILENT 2070attribute is applied to every 2071command in the file. 2072.It Ic .STALE 2073This target gets run when a dependency file contains stale entries, having 2074.Va .ALLSRC 2075set to the name of that dependency file. 2076.It Ic .SUFFIXES 2077Each source specifies a suffix to 2078.Nm . 2079If no sources are specified, any previously specified suffixes are deleted. 2080It allows the creation of suffix-transformation rules. 2081.Pp 2082Example: 2083.Bd -literal 2084\&.SUFFIXES: .o 2085\&.c.o: 2086 cc \-o ${.TARGET} \-c ${.IMPSRC} 2087.Ed 2088.El 2089.Sh ENVIRONMENT 2090.Nm 2091uses the following environment variables, if they exist: 2092.Ev MACHINE , 2093.Ev MACHINE_ARCH , 2094.Ev MAKE , 2095.Ev MAKEFLAGS , 2096.Ev MAKEOBJDIR , 2097.Ev MAKEOBJDIRPREFIX , 2098.Ev MAKESYSPATH , 2099.Ev PWD , 2100and 2101.Ev TMPDIR . 2102.Pp 2103.Ev MAKEOBJDIRPREFIX 2104and 2105.Ev MAKEOBJDIR 2106may only be set in the environment or on the command line to 2107.Nm 2108and not as makefile variables; 2109see the description of 2110.Ql Va .OBJDIR 2111for more details. 2112.Sh FILES 2113.Bl -tag -width /usr/share/mk -compact 2114.It .depend 2115list of dependencies 2116.It Makefile 2117list of dependencies 2118.It makefile 2119list of dependencies 2120.It sys.mk 2121system makefile 2122.It /usr/share/mk 2123system makefile directory 2124.El 2125.Sh COMPATIBILITY 2126The basic make syntax is compatible between different versions of make, 2127however the special variables, variable modifiers and conditionals are not. 2128.Pp 2129The way that parallel makes are scheduled changed in 2130NetBSD 4.0 2131so that .ORDER and .WAIT apply recursively to the dependent nodes. 2132The algorithms used may change again in the future. 2133.Pp 2134The way that .for loop variables are substituted changed after 2135NetBSD 5.0 2136so that they still appear to be variable expansions. 2137In particular this stops them being treated as syntax, and removes some 2138obscure problems using them in .if statements. 2139.Sh SEE ALSO 2140.Xr mkdep 1 2141.Sh HISTORY 2142.Nm 2143is derived from NetBSD 2144.Xr make 1 . 2145It uses autoconf to facilitate portability to other platforms. 2146.Pp 2147A 2148make 2149command appeared in 2150.At v7 . 2151This 2152make 2153implementation is based on Adam De Boor's pmake program which was written 2154for Sprite at Berkeley. 2155It was designed to be a parallel distributed make running jobs on different 2156machines using a daemon called 2157.Dq customs . 2158.Pp 2159Historically the target/dependency 2160.Dq FRC 2161has been used to FoRCe rebuilding (since the target/dependency 2162does not exist... unless someone creates an 2163.Dq FRC 2164file). 2165.Sh BUGS 2166The 2167make 2168syntax is difficult to parse without actually acting of the data. 2169For instance finding the end of a variable use should involve scanning each 2170the modifiers using the correct terminator for each field. 2171In many places 2172make 2173just counts {} and () in order to find the end of a variable expansion. 2174.Pp 2175There is no way of escaping a space character in a filename. 2176