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.DF.OSREL 909The 910.Dx 911version when the world was built. It is in the "<major>.<minor>" 912format and it used by DPorts. 913.It Va .MAKE.DF.VERSION 914The value of __DragonFly_version when the 915.Dx 916world was built. It is used by DPorts. 917.It Va MAKE_PRINT_VAR_ON_ERROR 918When 919.Nm 920stops due to an error, it prints its name and the value of 921.Ql Va .CURDIR 922as well as the value of any variables named in 923.Ql Va MAKE_PRINT_VAR_ON_ERROR . 924.It Va .newline 925This variable is simply assigned a newline character as its value. 926This allows expansions using the 927.Cm \&:@ 928modifier to put a newline between 929iterations of the loop rather than a space. 930For example, the printing of 931.Ql Va MAKE_PRINT_VAR_ON_ERROR 932could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 933.It Va .OBJDIR 934A path to the directory where the targets are built. 935Its value is determined by trying to 936.Xr chdir 2 937to the following directories in order and using the first match: 938.Bl -enum 939.It 940.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 941.Pp 942(Only if 943.Ql Ev MAKEOBJDIRPREFIX 944is set in the environment or on the command line.) 945.It 946.Ev ${MAKEOBJDIR} 947.Pp 948(Only if 949.Ql Ev MAKEOBJDIR 950is set in the environment or on the command line.) 951.It 952.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 953.It 954.Ev ${.CURDIR} Ns Pa /obj 955.It 956.Pa /usr/obj/ Ns Ev ${.CURDIR} 957.It 958.Ev ${.CURDIR} 959.El 960.Pp 961Variable expansion is performed on the value before it's used, 962so expressions such as 963.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 964may be used. 965This is especially useful with 966.Ql Ev MAKEOBJDIR . 967.Pp 968.Ql Va .OBJDIR 969may be modified in the makefile as a global variable. 970In all cases, 971.Nm 972will 973.Xr chdir 2 974to 975.Ql Va .OBJDIR 976and set 977.Ql Ev PWD 978to that directory before executing any targets. 979. 980.It Va .PARSEDIR 981A path to the directory of the current 982.Ql Pa Makefile 983being parsed. 984.It Va .PARSEFILE 985The basename of the current 986.Ql Pa Makefile 987being parsed. 988This variable and 989.Ql Va .PARSEDIR 990are both set only while the 991.Ql Pa Makefiles 992are being parsed. 993If you want to retain their current values, assign them to a variable 994using assignment with expansion: 995.Pq Ql Cm \&:= . 996.It Va .PATH 997A variable that represents the list of directories that 998.Nm 999will search for files. 1000The search list should be updated using the target 1001.Ql Va .PATH 1002rather than the variable. 1003.It Ev PWD 1004Alternate path to the current directory. 1005.Nm 1006normally sets 1007.Ql Va .CURDIR 1008to the canonical path given by 1009.Xr getcwd 3 . 1010However, if the environment variable 1011.Ql Ev PWD 1012is set and gives a path to the current directory, then 1013.Nm 1014sets 1015.Ql Va .CURDIR 1016to the value of 1017.Ql Ev PWD 1018instead. 1019This behaviour is disabled if 1020.Ql Ev MAKEOBJDIRPREFIX 1021is set or 1022.Ql Ev MAKEOBJDIR 1023contains a variable transform. 1024.Ql Ev PWD 1025is set to the value of 1026.Ql Va .OBJDIR 1027for all programs which 1028.Nm 1029executes. 1030.It Ev .TARGETS 1031The list of targets explicitly specified on the command line, if any. 1032.It Ev VPATH 1033Colon-separated 1034.Pq Dq \&: 1035lists of directories that 1036.Nm 1037will search for files. 1038The variable is supported for compatibility with old make programs only, 1039use 1040.Ql Va .PATH 1041instead. 1042.El 1043.Ss Variable modifiers 1044Variable expansion may be modified to select or modify each word of the 1045variable (where a 1046.Dq word 1047is white-space delimited sequence of characters). 1048The general format of a variable expansion is as follows: 1049.Pp 1050.Dl ${variable[:modifier[:...]]} 1051.Pp 1052Each modifier begins with a colon, 1053which may be escaped with a backslash 1054.Pq Ql \e . 1055.Pp 1056A set of modifiers can be specified via a variable, as follows: 1057.Pp 1058.Dl modifier_variable=modifier[:...] 1059.Dl ${variable:${modifier_variable}[:...]} 1060.Pp 1061In this case the first modifier in the modifier_variable does not 1062start with a colon, since that must appear in the referencing 1063variable. 1064If any of the modifiers in the modifier_variable contain a dollar sign 1065.Pq Ql $ , 1066these must be doubled to avoid early expansion. 1067.Pp 1068The supported modifiers are: 1069.Bl -tag -width EEE 1070.It Cm \&:E 1071Replaces each word in the variable with its suffix. 1072.It Cm \&:H 1073Replaces each word in the variable with everything but the last component. 1074.It Cm \&:M Ns Ar pattern 1075Select only those words that match 1076.Ar pattern . 1077The standard shell wildcard characters 1078.Pf ( Ql * , 1079.Ql \&? , 1080and 1081.Ql Oo Oc ) 1082may 1083be used. 1084The wildcard characters may be escaped with a backslash 1085.Pq Ql \e . 1086As a consequence of the way values are split into words, matched, 1087and then joined, a construct like 1088.Dl ${VAR:M*} 1089will normalise the inter-word spacing, removing all leading and 1090trailing space, and converting multiple consecutive spaces 1091to single spaces. 1092. 1093.It Cm \&:N Ns Ar pattern 1094This is identical to 1095.Ql Cm \&:M , 1096but selects all words which do not match 1097.Ar pattern . 1098.It Cm \&:O 1099Order every word in variable alphabetically. 1100To sort words in 1101reverse order use the 1102.Ql Cm \&:O:[-1..1] 1103combination of modifiers. 1104.It Cm \&:Ox 1105Randomize words in variable. 1106The results will be different each time you are referring to the 1107modified variable; use the assignment with expansion 1108.Pq Ql Cm \&:= 1109to prevent such behaviour. 1110For example, 1111.Bd -literal -offset indent 1112LIST= uno due tre quattro 1113RANDOM_LIST= ${LIST:Ox} 1114STATIC_RANDOM_LIST:= ${LIST:Ox} 1115 1116all: 1117 @echo "${RANDOM_LIST}" 1118 @echo "${RANDOM_LIST}" 1119 @echo "${STATIC_RANDOM_LIST}" 1120 @echo "${STATIC_RANDOM_LIST}" 1121.Ed 1122may produce output similar to: 1123.Bd -literal -offset indent 1124quattro due tre uno 1125tre due quattro uno 1126due uno quattro tre 1127due uno quattro tre 1128.Ed 1129.It Cm \&:Q 1130Quotes every shell meta-character in the variable, so that it can be passed 1131safely through recursive invocations of 1132.Nm . 1133.It Cm \&:R 1134Replaces each word in the variable with everything but its suffix. 1135.It Cm \&:gmtime 1136The value is a format string for 1137.Xr strftime 3 , 1138using the current 1139.Xr gmtime 3 . 1140.It Cm \&:hash 1141Compute a 32bit hash of the value and encode it as hex digits. 1142.It Cm \&:localtime 1143The value is a format string for 1144.Xr strftime 3 , 1145using the current 1146.Xr localtime 3 . 1147.It Cm \&:tA 1148Attempt to convert variable to an absolute path using 1149.Xr realpath 3 , 1150if that fails, the value is unchanged. 1151.It Cm \&:tl 1152Converts variable to lower-case letters. 1153.It Cm \&:ts Ns Ar c 1154Words in the variable are normally separated by a space on expansion. 1155This modifier sets the separator to the character 1156.Ar c . 1157If 1158.Ar c 1159is omitted, then no separator is used. 1160The common escapes (including octal numeric codes), work as expected. 1161.It Cm \&:tu 1162Converts variable to upper-case letters. 1163.It Cm \&:tW 1164Causes the value to be treated as a single word 1165(possibly containing embedded white space). 1166See also 1167.Ql Cm \&:[*] . 1168.It Cm \&:tw 1169Causes the value to be treated as a sequence of 1170words delimited by white space. 1171See also 1172.Ql Cm \&:[@] . 1173.Sm off 1174.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1175.Sm on 1176Modify the first occurrence of 1177.Ar old_string 1178in the variable's value, replacing it with 1179.Ar new_string . 1180If a 1181.Ql g 1182is appended to the last slash of the pattern, all occurrences 1183in each word are replaced. 1184If a 1185.Ql 1 1186is appended to the last slash of the pattern, only the first word 1187is affected. 1188If a 1189.Ql W 1190is appended to the last slash of the pattern, 1191then the value is treated as a single word 1192(possibly containing embedded white space). 1193If 1194.Ar old_string 1195begins with a caret 1196.Pq Ql ^ , 1197.Ar old_string 1198is anchored at the beginning of each word. 1199If 1200.Ar old_string 1201ends with a dollar sign 1202.Pq Ql \&$ , 1203it is anchored at the end of each word. 1204Inside 1205.Ar new_string , 1206an ampersand 1207.Pq Ql \*[Am] 1208is replaced by 1209.Ar old_string 1210(without any 1211.Ql ^ 1212or 1213.Ql \&$ ) . 1214Any character may be used as a delimiter for the parts of the modifier 1215string. 1216The anchoring, ampersand and delimiter characters may be escaped with a 1217backslash 1218.Pq Ql \e . 1219.Pp 1220Variable expansion occurs in the normal fashion inside both 1221.Ar old_string 1222and 1223.Ar new_string 1224with the single exception that a backslash is used to prevent the expansion 1225of a dollar sign 1226.Pq Ql \&$ , 1227not a preceding dollar sign as is usual. 1228.Sm off 1229.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1230.Sm on 1231The 1232.Cm \&:C 1233modifier is just like the 1234.Cm \&:S 1235modifier except that the old and new strings, instead of being 1236simple strings, are an extended regular expression (see 1237.Xr regex 3 ) 1238string 1239.Ar pattern 1240and an 1241.Xr ed 1 Ns \-style 1242string 1243.Ar replacement . 1244Normally, the first occurrence of the pattern 1245.Ar pattern 1246in each word of the value is substituted with 1247.Ar replacement . 1248The 1249.Ql 1 1250modifier causes the substitution to apply to at most one word; the 1251.Ql g 1252modifier causes the substitution to apply to as many instances of the 1253search pattern 1254.Ar pattern 1255as occur in the word or words it is found in; the 1256.Ql W 1257modifier causes the value to be treated as a single word 1258(possibly containing embedded white space). 1259Note that 1260.Ql 1 1261and 1262.Ql g 1263are orthogonal; the former specifies whether multiple words are 1264potentially affected, the latter whether multiple substitutions can 1265potentially occur within each affected word. 1266.Pp 1267As for the 1268.Cm \&:S 1269modifier, the 1270.Ar pattern 1271and 1272.Ar replacement 1273are subjected to variable expansion before being parsed as 1274regular expressions. 1275.It Cm \&:T 1276Replaces each word in the variable with its last component. 1277.It Cm \&:u 1278Remove adjacent duplicate words (like 1279.Xr uniq 1 ) . 1280.Sm off 1281.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1282.Sm on 1283If the variable name (not its value), when parsed as a .if conditional 1284expression, evaluates to true, return as its value the 1285.Ar true_string , 1286otherwise return the 1287.Ar false_string . 1288Since the variable name is used as the expression, \&:\&? must be the 1289first modifier after the variable name itself - which will, of course, 1290usually contain variable expansions. 1291A common error is trying to use expressions like 1292.Dl ${NUMBERS:M42:?match:no} 1293which actually tests defined(NUMBERS), 1294to determine is any words match "42" you need to use something like: 1295.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1296.It Ar :old_string=new_string 1297This is the 1298.At V 1299style variable substitution. 1300It must be the last modifier specified. 1301If 1302.Ar old_string 1303or 1304.Ar new_string 1305do not contain the pattern matching character 1306.Ar % 1307then it is assumed that they are 1308anchored at the end of each word, so only suffixes or entire 1309words may be replaced. 1310Otherwise 1311.Ar % 1312is the substring of 1313.Ar old_string 1314to be replaced in 1315.Ar new_string . 1316.Pp 1317Variable expansion occurs in the normal fashion inside both 1318.Ar old_string 1319and 1320.Ar new_string 1321with the single exception that a backslash is used to prevent the 1322expansion of a dollar sign 1323.Pq Ql \&$ , 1324not a preceding dollar sign as is usual. 1325.Sm off 1326.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1327.Sm on 1328This is the loop expansion mechanism from the OSF Development 1329Environment (ODE) make. 1330Unlike 1331.Cm \&.for 1332loops expansion occurs at the time of 1333reference. 1334Assign 1335.Ar temp 1336to each word in the variable and evaluate 1337.Ar string . 1338The ODE convention is that 1339.Ar temp 1340should start and end with a period. 1341For example. 1342.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1343.Pp 1344However a single character variable is often more readable: 1345.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1346.It Cm \&:U Ns Ar newval 1347If the variable is undefined 1348.Ar newval 1349is the value. 1350If the variable is defined, the existing value is returned. 1351This is another ODE make feature. 1352It is handy for setting per-target CFLAGS for instance: 1353.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1354If a value is only required if the variable is undefined, use: 1355.Dl ${VAR:D:Unewval} 1356.It Cm \&:D Ns Ar newval 1357If the variable is defined 1358.Ar newval 1359is the value. 1360.It Cm \&:L 1361The name of the variable is the value. 1362.It Cm \&:P 1363The path of the node which has the same name as the variable 1364is the value. 1365If no such node exists or its path is null, then the 1366name of the variable is used. 1367In order for this modifier to work, the name (node) must at least have 1368appeared on the rhs of a dependency. 1369.Sm off 1370.It Cm \&:\&! Ar cmd Cm \&! 1371.Sm on 1372The output of running 1373.Ar cmd 1374is the value. 1375.It Cm \&:sh 1376If the variable is non-empty it is run as a command and the output 1377becomes the new value. 1378.It Cm \&::= Ns Ar str 1379The variable is assigned the value 1380.Ar str 1381after substitution. 1382This modifier and its variations are useful in 1383obscure situations such as wanting to set a variable when shell commands 1384are being parsed. 1385These assignment modifiers always expand to 1386nothing, so if appearing in a rule line by themselves should be 1387preceded with something to keep 1388.Nm 1389happy. 1390.Pp 1391The 1392.Ql Cm \&:: 1393helps avoid false matches with the 1394.At V 1395style 1396.Cm \&:= 1397modifier and since substitution always occurs the 1398.Cm \&::= 1399form is vaguely appropriate. 1400.It Cm \&::?= Ns Ar str 1401As for 1402.Cm \&::= 1403but only if the variable does not already have a value. 1404.It Cm \&::+= Ns Ar str 1405Append 1406.Ar str 1407to the variable. 1408.It Cm \&::!= Ns Ar cmd 1409Assign the output of 1410.Ar cmd 1411to the variable. 1412.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1413Selects one or more words from the value, 1414or performs other operations related to the way in which the 1415value is divided into words. 1416.Pp 1417Ordinarily, a value is treated as a sequence of words 1418delimited by white space. 1419Some modifiers suppress this behaviour, 1420causing a value to be treated as a single word 1421(possibly containing embedded white space). 1422An empty value, or a value that consists entirely of white-space, 1423is treated as a single word. 1424For the purposes of the 1425.Ql Cm \&:[] 1426modifier, the words are indexed both forwards using positive integers 1427(where index 1 represents the first word), 1428and backwards using negative integers 1429(where index \-1 represents the last word). 1430.Pp 1431The 1432.Ar range 1433is subjected to variable expansion, and the expanded result is 1434then interpreted as follows: 1435.Bl -tag -width index 1436.\" :[n] 1437.It Ar index 1438Selects a single word from the value. 1439.\" :[start..end] 1440.It Ar start Ns Cm \&.. Ns Ar end 1441Selects all words from 1442.Ar start 1443to 1444.Ar end , 1445inclusive. 1446For example, 1447.Ql Cm \&:[2..-1] 1448selects all words from the second word to the last word. 1449If 1450.Ar start 1451is greater than 1452.Ar end , 1453then the words are output in reverse order. 1454For example, 1455.Ql Cm \&:[-1..1] 1456selects all the words from last to first. 1457.\" :[*] 1458.It Cm \&* 1459Causes subsequent modifiers to treat the value as a single word 1460(possibly containing embedded white space). 1461Analogous to the effect of 1462\&"$*\&" 1463in Bourne shell. 1464.\" :[0] 1465.It 0 1466Means the same as 1467.Ql Cm \&:[*] . 1468.\" :[*] 1469.It Cm \&@ 1470Causes subsequent modifiers to treat the value as a sequence of words 1471delimited by white space. 1472Analogous to the effect of 1473\&"$@\&" 1474in Bourne shell. 1475.\" :[#] 1476.It Cm \&# 1477Returns the number of words in the value. 1478.El \" :[range] 1479.El 1480.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1481Makefile inclusion, conditional structures and for loops reminiscent 1482of the C programming language are provided in 1483.Nm . 1484All such structures are identified by a line beginning with a single 1485dot 1486.Pq Ql \&. 1487character. 1488Files are included with either 1489.Cm \&.include Aq Ar file 1490or 1491.Cm \&.include Pf \*q Ar file Ns \*q . 1492Variables between the angle brackets or double quotes are expanded 1493to form the file name. 1494If angle brackets are used, the included makefile is expected to be in 1495the system makefile directory. 1496If double quotes are used, the including makefile's directory and any 1497directories specified using the 1498.Fl I 1499option are searched before the system 1500makefile directory. 1501For compatibility with other versions of 1502.Nm 1503.Ql include file ... 1504is also accepted. 1505If the include statement is written as 1506.Cm .-include 1507or as 1508.Cm .sinclude 1509then errors locating and/or opening include files are ignored. 1510.Pp 1511Conditional expressions are also preceded by a single dot as the first 1512character of a line. 1513The possible conditionals are as follows: 1514.Bl -tag -width Ds 1515.It Ic .error Ar message 1516The message is printed along with the name of the makefile and line number, 1517then 1518.Nm 1519will exit. 1520.It Ic .export Ar variable ... 1521Export the specified global variable. 1522If no variable list is provided, all globals are exported 1523except for internal variables (those that start with 1524.Ql \&. ) . 1525This is not affected by the 1526.Fl X 1527flag, so should be used with caution. 1528For compatibility with other 1529.Nm 1530programs 1531.Ql export variable=value 1532is also accepted. 1533.Pp 1534Appending a variable name to 1535.Va .MAKE.EXPORTED 1536is equivalent to exporting a variable. 1537.It Ic .export-env Ar variable ... 1538The same as 1539.Ql .export , 1540except that the variable is not appended to 1541.Va .MAKE.EXPORTED . 1542This allows exporting a value to the environment which is different from that 1543used by 1544.Nm 1545internally. 1546.It Ic .info Ar message 1547The message is printed along with the name of the makefile and line number. 1548.It Ic .undef Ar variable 1549Un-define the specified global variable. 1550Only global variables may be un-defined. 1551.It Ic .unexport Ar variable ... 1552The opposite of 1553.Ql .export . 1554The specified global 1555.Va variable 1556will be removed from 1557.Va .MAKE.EXPORTED . 1558If no variable list is provided, all globals are unexported, 1559and 1560.Va .MAKE.EXPORTED 1561deleted. 1562.It Ic .unexport-env 1563Unexport all globals previously exported and 1564clear the environment inherited from the parent. 1565This operation will cause a memory leak of the original environment, 1566so should be used sparingly. 1567Testing for 1568.Va .MAKE.LEVEL 1569being 0, would make sense. 1570Also note that any variables which originated in the parent environment 1571should be explicitly preserved if desired. 1572For example: 1573.Bd -literal -offset indent 1574.Li .if ${.MAKE.LEVEL} == 0 1575PATH := ${PATH} 1576.Li .unexport-env 1577.Li .export PATH 1578.Li .endif 1579.Ed 1580.Pp 1581Would result in an environment containing only 1582.Ql Ev PATH , 1583which is the minimal useful environment. 1584Actually 1585.Ql Ev .MAKE.LEVEL 1586will also be pushed into the new environment. 1587.It Ic .warning Ar message 1588The message prefixed by 1589.Ql Pa warning: 1590is printed along with the name of the makefile and line number. 1591.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1592Test the value of an expression. 1593.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1594Test the value of a variable. 1595.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1596Test the value of a variable. 1597.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1598Test the target being built. 1599.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1600Test the target being built. 1601.It Ic .else 1602Reverse the sense of the last conditional. 1603.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1604A combination of 1605.Ql Ic .else 1606followed by 1607.Ql Ic .if . 1608.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1609A combination of 1610.Ql Ic .else 1611followed by 1612.Ql Ic .ifdef . 1613.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1614A combination of 1615.Ql Ic .else 1616followed by 1617.Ql Ic .ifndef . 1618.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1619A combination of 1620.Ql Ic .else 1621followed by 1622.Ql Ic .ifmake . 1623.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1624A combination of 1625.Ql Ic .else 1626followed by 1627.Ql Ic .ifnmake . 1628.It Ic .endif 1629End the body of the conditional. 1630.El 1631.Pp 1632The 1633.Ar operator 1634may be any one of the following: 1635.Bl -tag -width "Cm XX" 1636.It Cm \&|\&| 1637Logical OR. 1638.It Cm \&\*[Am]\*[Am] 1639Logical 1640.Tn AND ; 1641of higher precedence than 1642.Dq \&|\&| . 1643.El 1644.Pp 1645As in C, 1646.Nm 1647will only evaluate a conditional as far as is necessary to determine 1648its value. 1649Parentheses may be used to change the order of evaluation. 1650The boolean operator 1651.Ql Ic \&! 1652may be used to logically negate an entire 1653conditional. 1654It is of higher precedence than 1655.Ql Ic \&\*[Am]\*[Am] . 1656.Pp 1657The value of 1658.Ar expression 1659may be any of the following: 1660.Bl -tag -width defined 1661.It Ic defined 1662Takes a variable name as an argument and evaluates to true if the variable 1663has been defined. 1664.It Ic make 1665Takes a target name as an argument and evaluates to true if the target 1666was specified as part of 1667.Nm Ns 's 1668command line or was declared the default target (either implicitly or 1669explicitly, see 1670.Va .MAIN ) 1671before the line containing the conditional. 1672.It Ic empty 1673Takes a variable, with possible modifiers, and evaluates to true if 1674the expansion of the variable would result in an empty string. 1675.It Ic exists 1676Takes a file name as an argument and evaluates to true if the file exists. 1677The file is searched for on the system search path (see 1678.Va .PATH ) . 1679.It Ic target 1680Takes a target name as an argument and evaluates to true if the target 1681has been defined. 1682.It Ic commands 1683Takes a target name as an argument and evaluates to true if the target 1684has been defined and has commands associated with it. 1685.El 1686.Pp 1687.Ar Expression 1688may also be an arithmetic or string comparison. 1689Variable expansion is 1690performed on both sides of the comparison, after which the integral 1691values are compared. 1692A value is interpreted as hexadecimal if it is 1693preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1694The standard C relational operators are all supported. 1695If after 1696variable expansion, either the left or right hand side of a 1697.Ql Ic == 1698or 1699.Ql Ic "!=" 1700operator is not an integral value, then 1701string comparison is performed between the expanded 1702variables. 1703If no relational operator is given, it is assumed that the expanded 1704variable is being compared against 0 or an empty string in the case 1705of a string comparison. 1706.Pp 1707When 1708.Nm 1709is evaluating one of these conditional expressions, and it encounters 1710a (white-space separated) word it doesn't recognize, either the 1711.Dq make 1712or 1713.Dq defined 1714expression is applied to it, depending on the form of the conditional. 1715If the form is 1716.Ql Ic .ifdef , 1717.Ql Ic .ifndef , 1718or 1719.Ql Ic .if 1720the 1721.Dq defined 1722expression is applied. 1723Similarly, if the form is 1724.Ql Ic .ifmake 1725or 1726.Ql Ic .ifnmake , the 1727.Dq make 1728expression is applied. 1729.Pp 1730If the conditional evaluates to true the parsing of the makefile continues 1731as before. 1732If it evaluates to false, the following lines are skipped. 1733In both cases this continues until a 1734.Ql Ic .else 1735or 1736.Ql Ic .endif 1737is found. 1738.Pp 1739For loops are typically used to apply a set of rules to a list of files. 1740The syntax of a for loop is: 1741.Pp 1742.Bl -tag -compact -width Ds 1743.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1744.It Aq make-rules 1745.It Ic \&.endfor 1746.El 1747.Pp 1748After the for 1749.Ic expression 1750is evaluated, it is split into words. 1751On each iteration of the loop, one word is taken and assigned to each 1752.Ic variable , 1753in order, and these 1754.Ic variables 1755are substituted into the 1756.Ic make-rules 1757inside the body of the for loop. 1758The number of words must come out even; that is, if there are three 1759iteration variables, the number of words provided must be a multiple 1760of three. 1761.Sh COMMENTS 1762Comments begin with a hash 1763.Pq Ql \&# 1764character, anywhere but in a shell 1765command line, and continue to the end of an unescaped new line. 1766.Sh SPECIAL SOURCES (ATTRIBUTES) 1767.Bl -tag -width .IGNOREx 1768.It Ic .EXEC 1769Target is never out of date, but always execute commands anyway. 1770.It Ic .IGNORE 1771Ignore any errors from the commands associated with this target, exactly 1772as if they all were preceded by a dash 1773.Pq Ql \- . 1774.\" .It Ic .INVISIBLE 1775.\" XXX 1776.\" .It Ic .JOIN 1777.\" XXX 1778.It Ic .MADE 1779Mark all sources of this target as being up-to-date. 1780.It Ic .MAKE 1781Execute the commands associated with this target even if the 1782.Fl n 1783or 1784.Fl t 1785options were specified. 1786Normally used to mark recursive 1787.Nm Ns s . 1788.It Ic .META 1789Create a meta file for the target, even if it is flagged as 1790.Ic .PHONY , 1791.Ic .MAKE , 1792or 1793.Ic .SPECIAL . 1794Usage in conjunction with 1795.Ic .MAKE 1796is the most likely case. 1797In "meta" mode, the target is out-of-date if the meta file is missing. 1798.It Ic .NOMETA 1799Do not create a meta file for the target. 1800Meta files are also not created for 1801.Ic .PHONY , 1802.Ic .MAKE , 1803or 1804.Ic .SPECIAL 1805targets. 1806.It Ic .NOMETA_CMP 1807Ignore differences in commands when deciding if target is out of date. 1808This is useful if the command contains a value which always changes. 1809If the number of commands change, though, the target will still be out of date. 1810The same effect applies to any command line that uses the variable 1811.Va .OODATE , 1812which can be used for that purpose even when not otherwise needed or desired: 1813.Bd -literal -offset indent 1814 1815skip-compare-for-some: 1816 @echo this will be compared 1817 @echo this will not ${.OODATE:M.NOMETA_CMP} 1818 @echo this will also be compared 1819 1820.Ed 1821The 1822.Cm \&:M 1823pattern suppresses any expansion of the unwanted variable. 1824.It Ic .NOPATH 1825Do not search for the target in the directories specified by 1826.Ic .PATH . 1827.It Ic .NOTMAIN 1828Normally 1829.Nm 1830selects the first target it encounters as the default target to be built 1831if no target was specified. 1832This source prevents this target from being selected. 1833.It Ic .OPTIONAL 1834If a target is marked with this attribute and 1835.Nm 1836can't figure out how to create it, it will ignore this fact and assume 1837the file isn't needed or already exists. 1838.It Ic .PHONY 1839The target does not 1840correspond to an actual file; it is always considered to be out of date, 1841and will not be created with the 1842.Fl t 1843option. 1844Suffix-transformation rules are not applied to 1845.Ic .PHONY 1846targets. 1847.It Ic .PRECIOUS 1848When 1849.Nm 1850is interrupted, it normally removes any partially made targets. 1851This source prevents the target from being removed. 1852.It Ic .RECURSIVE 1853Synonym for 1854.Ic .MAKE . 1855.It Ic .SILENT 1856Do not echo any of the commands associated with this target, exactly 1857as if they all were preceded by an at sign 1858.Pq Ql @ . 1859.It Ic .USE 1860Turn the target into 1861.Nm Ns 's 1862version of a macro. 1863When the target is used as a source for another target, the other target 1864acquires the commands, sources, and attributes (except for 1865.Ic .USE ) 1866of the 1867source. 1868If the target already has commands, the 1869.Ic .USE 1870target's commands are appended 1871to them. 1872.It Ic .USEBEFORE 1873Exactly like 1874.Ic .USE , 1875but prepend the 1876.Ic .USEBEFORE 1877target commands to the target. 1878.It Ic .WAIT 1879If 1880.Ic .WAIT 1881appears in a dependency line, the sources that precede it are 1882made before the sources that succeed it in the line. 1883Since the dependents of files are not made until the file itself 1884could be made, this also stops the dependents being built unless they 1885are needed for another branch of the dependency tree. 1886So given: 1887.Bd -literal 1888x: a .WAIT b 1889 echo x 1890a: 1891 echo a 1892b: b1 1893 echo b 1894b1: 1895 echo b1 1896 1897.Ed 1898the output is always 1899.Ql a , 1900.Ql b1 , 1901.Ql b , 1902.Ql x . 1903.br 1904The ordering imposed by 1905.Ic .WAIT 1906is only relevant for parallel makes. 1907.El 1908.Sh SPECIAL TARGETS 1909Special targets may not be included with other targets, i.e. they must be 1910the only target specified. 1911.Bl -tag -width .BEGINx 1912.It Ic .BEGIN 1913Any command lines attached to this target are executed before anything 1914else is done. 1915.It Ic .DEFAULT 1916This is sort of a 1917.Ic .USE 1918rule for any target (that was used only as a 1919source) that 1920.Nm 1921can't figure out any other way to create. 1922Only the shell script is used. 1923The 1924.Ic .IMPSRC 1925variable of a target that inherits 1926.Ic .DEFAULT Ns 's 1927commands is set 1928to the target's own name. 1929.It Ic .END 1930Any command lines attached to this target are executed after everything 1931else is done. 1932.It Ic .ERROR 1933Any command lines attached to this target are executed when another target fails. 1934The 1935.Ic .ERROR_TARGET 1936variable is set to the target that failed. 1937See also 1938.Ic MAKE_PRINT_VAR_ON_ERROR . 1939.It Ic .IGNORE 1940Mark each of the sources with the 1941.Ic .IGNORE 1942attribute. 1943If no sources are specified, this is the equivalent of specifying the 1944.Fl i 1945option. 1946.It Ic .INTERRUPT 1947If 1948.Nm 1949is interrupted, the commands for this target will be executed. 1950.It Ic .MAIN 1951If no target is specified when 1952.Nm 1953is invoked, this target will be built. 1954.It Ic .MAKEFLAGS 1955This target provides a way to specify flags for 1956.Nm 1957when the makefile is used. 1958The flags are as if typed to the shell, though the 1959.Fl f 1960option will have 1961no effect. 1962.\" XXX: NOT YET!!!! 1963.\" .It Ic .NOTPARALLEL 1964.\" The named targets are executed in non parallel mode. 1965.\" If no targets are 1966.\" specified, then all targets are executed in non parallel mode. 1967.It Ic .NOPATH 1968Apply the 1969.Ic .NOPATH 1970attribute to any specified sources. 1971.It Ic .NOTPARALLEL 1972Disable parallel mode. 1973.It Ic .NO_PARALLEL 1974Synonym for 1975.Ic .NOTPARALLEL , 1976for compatibility with other pmake variants. 1977.It Ic .ORDER 1978The named targets are made in sequence. 1979This ordering does not add targets to the list of targets to be made. 1980Since the dependents of a target do not get built until the target itself 1981could be built, unless 1982.Ql a 1983is built by another part of the dependency graph, 1984the following is a dependency loop: 1985.Bd -literal 1986\&.ORDER: b a 1987b: a 1988.Ed 1989.Pp 1990The ordering imposed by 1991.Ic .ORDER 1992is only relevant for parallel makes. 1993.\" XXX: NOT YET!!!! 1994.\" .It Ic .PARALLEL 1995.\" The named targets are executed in parallel mode. 1996.\" If no targets are 1997.\" specified, then all targets are executed in parallel mode. 1998.It Ic .PATH 1999The sources are directories which are to be searched for files not 2000found in the current directory. 2001If no sources are specified, any previously specified directories are 2002deleted. 2003If the source is the special 2004.Ic .DOTLAST 2005target, then the current working 2006directory is searched last. 2007.It Ic .PATH. Ns Va suffix 2008Like 2009.Ic .PATH 2010but applies only to files with a particular suffix. 2011The suffix must have been previously declared with 2012.Ic .SUFFIXES . 2013.It Ic .PHONY 2014Apply the 2015.Ic .PHONY 2016attribute to any specified sources. 2017.It Ic .PRECIOUS 2018Apply the 2019.Ic .PRECIOUS 2020attribute to any specified sources. 2021If no sources are specified, the 2022.Ic .PRECIOUS 2023attribute is applied to every 2024target in the file. 2025.It Ic .SHELL 2026Sets the shell that 2027.Nm 2028will use to execute commands. 2029The sources are a set of 2030.Ar field=value 2031pairs. 2032.Bl -tag -width hasErrCtls 2033.It Ar name 2034This is the minimal specification, used to select one of the builtin 2035shell specs; 2036.Ar sh , 2037.Ar ksh , 2038and 2039.Ar csh . 2040.It Ar path 2041Specifies the path to the shell. 2042.It Ar hasErrCtl 2043Indicates whether the shell supports exit on error. 2044.It Ar check 2045The command to turn on error checking. 2046.It Ar ignore 2047The command to disable error checking. 2048.It Ar echo 2049The command to turn on echoing of commands executed. 2050.It Ar quiet 2051The command to turn off echoing of commands executed. 2052.It Ar filter 2053The output to filter after issuing the 2054.Ar quiet 2055command. 2056It is typically identical to 2057.Ar quiet . 2058.It Ar errFlag 2059The flag to pass the shell to enable error checking. 2060.It Ar echoFlag 2061The flag to pass the shell to enable command echoing. 2062.It Ar newline 2063The string literal to pass the shell that results in a single newline 2064character when used outside of any quoting characters. 2065.El 2066Example: 2067.Bd -literal 2068\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2069 check="set \-e" ignore="set +e" \e 2070 echo="set \-v" quiet="set +v" filter="set +v" \e 2071 echoFlag=v errFlag=e newline="'\en'" 2072.Ed 2073.It Ic .SILENT 2074Apply the 2075.Ic .SILENT 2076attribute to any specified sources. 2077If no sources are specified, the 2078.Ic .SILENT 2079attribute is applied to every 2080command in the file. 2081.It Ic .STALE 2082This target gets run when a dependency file contains stale entries, having 2083.Va .ALLSRC 2084set to the name of that dependency file. 2085.It Ic .SUFFIXES 2086Each source specifies a suffix to 2087.Nm . 2088If no sources are specified, any previously specified suffixes are deleted. 2089It allows the creation of suffix-transformation rules. 2090.Pp 2091Example: 2092.Bd -literal 2093\&.SUFFIXES: .o 2094\&.c.o: 2095 cc \-o ${.TARGET} \-c ${.IMPSRC} 2096.Ed 2097.El 2098.Sh ENVIRONMENT 2099.Nm 2100uses the following environment variables, if they exist: 2101.Ev MACHINE , 2102.Ev MACHINE_ARCH , 2103.Ev MAKE , 2104.Ev MAKEFLAGS , 2105.Ev MAKEOBJDIR , 2106.Ev MAKEOBJDIRPREFIX , 2107.Ev MAKESYSPATH , 2108.Ev PWD , 2109and 2110.Ev TMPDIR . 2111.Pp 2112.Ev MAKEOBJDIRPREFIX 2113and 2114.Ev MAKEOBJDIR 2115may only be set in the environment or on the command line to 2116.Nm 2117and not as makefile variables; 2118see the description of 2119.Ql Va .OBJDIR 2120for more details. 2121.Sh FILES 2122.Bl -tag -width /usr/share/mk -compact 2123.It .depend 2124list of dependencies 2125.It Makefile 2126list of dependencies 2127.It makefile 2128list of dependencies 2129.It sys.mk 2130system makefile 2131.It /usr/share/mk 2132system makefile directory 2133.El 2134.Sh COMPATIBILITY 2135The basic make syntax is compatible between different versions of make, 2136however the special variables, variable modifiers and conditionals are not. 2137.Pp 2138The way that parallel makes are scheduled changed in 2139NetBSD 4.0 2140so that .ORDER and .WAIT apply recursively to the dependent nodes. 2141The algorithms used may change again in the future. 2142.Pp 2143The way that .for loop variables are substituted changed after 2144NetBSD 5.0 2145so that they still appear to be variable expansions. 2146In particular this stops them being treated as syntax, and removes some 2147obscure problems using them in .if statements. 2148.Sh SEE ALSO 2149.Xr mkdep 1 2150.Sh HISTORY 2151.Nm 2152is derived from NetBSD 2153.Xr make 1 . 2154It uses autoconf to facilitate portability to other platforms. 2155.Pp 2156A 2157make 2158command appeared in 2159.At v7 . 2160This 2161make 2162implementation is based on Adam De Boor's pmake program which was written 2163for Sprite at Berkeley. 2164It was designed to be a parallel distributed make running jobs on different 2165machines using a daemon called 2166.Dq customs . 2167.Pp 2168Historically the target/dependency 2169.Dq FRC 2170has been used to FoRCe rebuilding (since the target/dependency 2171does not exist... unless someone creates an 2172.Dq FRC 2173file). 2174.Sh BUGS 2175The 2176make 2177syntax is difficult to parse without actually acting of the data. 2178For instance finding the end of a variable use should involve scanning each 2179the modifiers using the correct terminator for each field. 2180In many places 2181make 2182just counts {} and () in order to find the end of a variable expansion. 2183.Pp 2184There is no way of escaping a space character in a filename. 2185