1.\" $NetBSD: make.1,v 1.222 2013/08/11 09:53:49 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 August 11, 2013 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 w 213Print entering and leaving directory messages, pre and post processing. 214.It Ar x 215Run shell commands with 216.Fl x 217so the actual commands are printed as they are executed. 218.El 219.It Fl e 220Specify that environment variables override macro assignments within 221makefiles. 222.It Fl f Ar makefile 223Specify a makefile to read instead of the default 224.Ql Pa makefile . 225If 226.Ar makefile 227is 228.Ql Fl , 229standard input is read. 230Multiple makefiles may be specified, and are read in the order specified. 231.It Fl I Ar directory 232Specify a directory in which to search for makefiles and included makefiles. 233The system makefile directory (or directories, see the 234.Fl m 235option) is automatically included as part of this list. 236.It Fl i 237Ignore non-zero exit of shell commands in the makefile. 238Equivalent to specifying 239.Ql Fl 240before each command line in the makefile. 241.It Fl J Ar private 242This option should 243.Em not 244be specified by the user. 245.Pp 246When the 247.Ar j 248option is in use in a recursive build, this option is passed by a make 249to child makes to allow all the make processes in the build to 250cooperate to avoid overloading the system. 251.It Fl j Ar max_jobs 252Specify the maximum number of jobs that 253.Nm 254may have running at any one time. 255The value is saved in 256.Va .MAKE.JOBS . 257Turns compatibility mode off, unless the 258.Ar B 259flag is also specified. 260When compatibility mode is off, all commands associated with a 261target are executed in a single shell invocation as opposed to the 262traditional one shell invocation per line. 263This can break traditional scripts which change directories on each 264command invocation and then expect to start with a fresh environment 265on the next line. 266It is more efficient to correct the scripts rather than turn backwards 267compatibility on. 268.It Fl k 269Continue processing after errors are encountered, but only on those targets 270that do not depend on the target whose creation caused the error. 271.It Fl m Ar directory 272Specify a directory in which to search for sys.mk and makefiles included 273via the 274.Ao Ar file Ac Ns -style 275include statement. 276The 277.Fl m 278option can be used multiple times to form a search path. 279This path will override the default system include path: /usr/share/mk. 280Furthermore the system include path will be appended to the search path used 281for 282.Qo Ar file Qc Ns -style 283include statements (see the 284.Fl I 285option). 286.Pp 287If a file or directory name in the 288.Fl m 289argument (or the 290.Ev MAKESYSPATH 291environment variable) starts with the string 292.Qq \&.../ 293then 294.Nm 295will search for the specified file or directory named in the remaining part 296of the argument string. 297The search starts with the current directory of 298the Makefile and then works upward towards the root of the filesystem. 299If the search is successful, then the resulting directory replaces the 300.Qq \&.../ 301specification in the 302.Fl m 303argument. 304If used, this feature allows 305.Nm 306to easily search in the current source tree for customized sys.mk files 307(e.g., by using 308.Qq \&.../mk/sys.mk 309as an argument). 310.It Fl n 311Display the commands that would have been executed, but do not 312actually execute them unless the target depends on the .MAKE special 313source (see below). 314.It Fl N 315Display the commands which would have been executed, but do not 316actually execute any of them; useful for debugging top-level makefiles 317without descending into subdirectories. 318.It Fl q 319Do not execute any commands, but exit 0 if the specified targets are 320up-to-date and 1, otherwise. 321.It Fl r 322Do not use the built-in rules specified in the system makefile. 323.It Fl s 324Do not echo any commands as they are executed. 325Equivalent to specifying 326.Ql Ic @ 327before each command line in the makefile. 328.It Fl T Ar tracefile 329When used with the 330.Fl j 331flag, 332append a trace record to 333.Ar tracefile 334for each job started and completed. 335.It Fl t 336Rather than re-building a target as specified in the makefile, create it 337or update its modification time to make it appear up-to-date. 338.It Fl V Ar variable 339Print 340.Nm Ns 's 341idea of the value of 342.Ar variable , 343in the global context. 344Do not build any targets. 345Multiple instances of this option may be specified; 346the variables will be printed one per line, 347with a blank line for each null or undefined variable. 348If 349.Ar variable 350contains a 351.Ql \&$ 352then the value will be expanded before printing. 353.It Fl W 354Treat any warnings during makefile parsing as errors. 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 Ev MAKE 710The name that 711.Nm 712was executed with 713.Pq Va argv[0] . 714For compatibility 715.Nm 716also sets 717.Va .MAKE 718with the same value. 719The preferred variable to use is the environment variable 720.Ev MAKE 721because it is more compatible with other versions of 722.Nm 723and cannot be confused with the special target with the same name. 724.It Va .MAKE.DEPENDFILE 725Names the makefile (default 726.Ql Pa .depend ) 727from which generated dependencies are read. 728.It Va .MAKE.EXPAND_VARIABLES 729A boolean that controls the default behavior of the 730.Fl V 731option. 732.It Va .MAKE.EXPORTED 733The list of variables exported by 734.Nm . 735.It Va .MAKE.JOBS 736The argument to the 737.Fl j 738option. 739.It Va .MAKE.JOB.PREFIX 740If 741.Nm 742is run with 743.Ar j 744then output for each target is prefixed with a token 745.Ql --- target --- 746the first part of which can be controlled via 747.Va .MAKE.JOB.PREFIX . 748If 749.Va .MAKE.JOB.PREFIX 750is empty, no token is printed. 751.br 752For example: 753.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 754would produce tokens like 755.Ql ---make[1234] target --- 756making it easier to track the degree of parallelism being achieved. 757.It Ev MAKEFLAGS 758The environment variable 759.Ql Ev MAKEFLAGS 760may contain anything that 761may be specified on 762.Nm Ns 's 763command line. 764Anything specified on 765.Nm Ns 's 766command line is appended to the 767.Ql Ev MAKEFLAGS 768variable which is then 769entered into the environment for all programs which 770.Nm 771executes. 772.It Va .MAKE.LEVEL 773The recursion depth of 774.Nm . 775The initial instance of 776.Nm 777will be 0, and an incremented value is put into the environment 778to be seen by the next generation. 779This allows tests like: 780.Li .if ${.MAKE.LEVEL} == 0 781to protect things which should only be evaluated in the initial instance of 782.Nm . 783.It Va .MAKE.MAKEFILE_PREFERENCE 784The ordered list of makefile names 785(default 786.Ql Pa makefile , 787.Ql Pa Makefile ) 788that 789.Nm 790will look for. 791.It Va .MAKE.MAKEFILES 792The list of makefiles read by 793.Nm , 794which is useful for tracking dependencies. 795Each makefile is recorded only once, regardless of the number of times read. 796.It Va .MAKE.MODE 797Processed after reading all makefiles. 798Can affect the mode that 799.Nm 800runs in. 801It can contain a number of keywords: 802.Bl -hang -width ignore-cmd 803.It Pa compat 804Like 805.Fl B , 806puts 807.Nm 808into "compat" mode. 809.It Pa meta 810Puts 811.Nm 812into "meta" mode, where meta files are created for each target 813to capture the command run, the output generated and if 814.Xr filemon 4 815is available, the system calls which are of interest to 816.Nm . 817The captured output can be very useful when diagnosing errors. 818.It Pa curdirOk= Ar bf 819Normally 820.Nm 821will not create .meta files in 822.Ql Va .CURDIR . 823This can be overridden by setting 824.Va bf 825to a value which represents True. 826.It Pa env 827For debugging, it can be useful to inlcude the environment 828in the .meta file. 829.It Pa verbose 830If in "meta" mode, print a clue about the target being built. 831This is useful if the build is otherwise running silently. 832The message printed the value of: 833.Va .MAKE.META.PREFIX . 834.It Pa ignore-cmd 835Some makefiles have commands which are simply not stable. 836This keyword causes them to be ignored for 837determining whether a target is out of date in "meta" mode. 838See also 839.Ic .NOMETA_CMP . 840.It Pa silent= Ar bf 841If 842.Va bf 843is True, when a .meta file is created, mark the target 844.Ic .SILENT . 845.El 846.It Va .MAKE.META.BAILIWICK 847In "meta" mode, provides a list of prefixes which 848match the directories controlled by 849.Nm . 850If a file that was generated outside of 851.Va .OBJDIR 852but within said bailiwick is missing, 853the current target is considered out-of-date. 854.It Va .MAKE.META.CREATED 855In "meta" mode, this variable contains a list of all the meta files 856updated. 857If not empty, it can be used to trigger processing of 858.Va .MAKE.META.FILES . 859.It Va .MAKE.META.FILES 860In "meta" mode, this variable contains a list of all the meta files 861used (updated or not). 862This list can be used to process the meta files to extract dependency 863information. 864.It Va .MAKE.META.IGNORE_PATHS 865Provides a list of path prefixes that should be ignored; 866because the contents are expected to change over time. 867The default list includes: 868.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 869.It Va .MAKE.META.PREFIX 870Defines the message printed for each meta file updated in "meta verbose" mode. 871The default value is: 872.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 873.It Va .MAKEOVERRIDES 874This variable is used to record the names of variables assigned to 875on the command line, so that they may be exported as part of 876.Ql Ev MAKEFLAGS . 877This behaviour can be disabled by assigning an empty value to 878.Ql Va .MAKEOVERRIDES 879within a makefile. 880Extra variables can be exported from a makefile 881by appending their names to 882.Ql Va .MAKEOVERRIDES . 883.Ql Ev MAKEFLAGS 884is re-exported whenever 885.Ql Va .MAKEOVERRIDES 886is modified. 887.It Va .MAKE.PATH_FILEMON 888If 889.Nm 890was built with 891.Xr filemon 4 892support, this is set to the path of the device node. 893This allows makefiles to test for this support. 894.It Va .MAKE.PID 895The process-id of 896.Nm . 897.It Va .MAKE.PPID 898The parent process-id of 899.Nm . 900.It Va MAKE_PRINT_VAR_ON_ERROR 901When 902.Nm 903stops due to an error, it prints its name and the value of 904.Ql Va .CURDIR 905as well as the value of any variables named in 906.Ql Va MAKE_PRINT_VAR_ON_ERROR . 907.It Va .newline 908This variable is simply assigned a newline character as its value. 909This allows expansions using the 910.Cm \&:@ 911modifier to put a newline between 912iterations of the loop rather than a space. 913For example, the printing of 914.Ql Va MAKE_PRINT_VAR_ON_ERROR 915could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 916.It Va .OBJDIR 917A path to the directory where the targets are built. 918Its value is determined by trying to 919.Xr chdir 2 920to the following directories in order and using the first match: 921.Bl -enum 922.It 923.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 924.Pp 925(Only if 926.Ql Ev MAKEOBJDIRPREFIX 927is set in the environment or on the command line.) 928.It 929.Ev ${MAKEOBJDIR} 930.Pp 931(Only if 932.Ql Ev MAKEOBJDIR 933is set in the environment or on the command line.) 934.It 935.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 936.It 937.Ev ${.CURDIR} Ns Pa /obj 938.It 939.Pa /usr/obj/ Ns Ev ${.CURDIR} 940.It 941.Ev ${.CURDIR} 942.El 943.Pp 944Variable expansion is performed on the value before it's used, 945so expressions such as 946.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 947may be used. 948This is especially useful with 949.Ql Ev MAKEOBJDIR . 950.Pp 951.Ql Va .OBJDIR 952may be modified in the makefile as a global variable. 953In all cases, 954.Nm 955will 956.Xr chdir 2 957to 958.Ql Va .OBJDIR 959and set 960.Ql Ev PWD 961to that directory before executing any targets. 962. 963.It Va .PARSEDIR 964A path to the directory of the current 965.Ql Pa Makefile 966being parsed. 967.It Va .PARSEFILE 968The basename of the current 969.Ql Pa Makefile 970being parsed. 971This variable and 972.Ql Va .PARSEDIR 973are both set only while the 974.Ql Pa Makefiles 975are being parsed. 976If you want to retain their current values, assign them to a variable 977using assignment with expansion: 978.Pq Ql Cm \&:= . 979.It Va .PATH 980A variable that represents the list of directories that 981.Nm 982will search for files. 983The search list should be updated using the target 984.Ql Va .PATH 985rather than the variable. 986.It Ev PWD 987Alternate path to the current directory. 988.Nm 989normally sets 990.Ql Va .CURDIR 991to the canonical path given by 992.Xr getcwd 3 . 993However, if the environment variable 994.Ql Ev PWD 995is set and gives a path to the current directory, then 996.Nm 997sets 998.Ql Va .CURDIR 999to the value of 1000.Ql Ev PWD 1001instead. 1002This behaviour is disabled if 1003.Ql Ev MAKEOBJDIRPREFIX 1004is set or 1005.Ql Ev MAKEOBJDIR 1006contains a variable transform. 1007.Ql Ev PWD 1008is set to the value of 1009.Ql Va .OBJDIR 1010for all programs which 1011.Nm 1012executes. 1013.It Ev .TARGETS 1014The list of targets explicitly specified on the command line, if any. 1015.It Ev VPATH 1016Colon-separated 1017.Pq Dq \&: 1018lists of directories that 1019.Nm 1020will search for files. 1021The variable is supported for compatibility with old make programs only, 1022use 1023.Ql Va .PATH 1024instead. 1025.El 1026.Ss Variable modifiers 1027Variable expansion may be modified to select or modify each word of the 1028variable (where a 1029.Dq word 1030is white-space delimited sequence of characters). 1031The general format of a variable expansion is as follows: 1032.Pp 1033.Dl ${variable[:modifier[:...]]} 1034.Pp 1035Each modifier begins with a colon, 1036which may be escaped with a backslash 1037.Pq Ql \e . 1038.Pp 1039A set of modifiers can be specified via a variable, as follows: 1040.Pp 1041.Dl modifier_variable=modifier[:...] 1042.Dl ${variable:${modifier_variable}[:...]} 1043.Pp 1044In this case the first modifier in the modifier_variable does not 1045start with a colon, since that must appear in the referencing 1046variable. 1047If any of the modifiers in the modifier_variable contain a dollar sign 1048.Pq Ql $ , 1049these must be doubled to avoid early expansion. 1050.Pp 1051The supported modifiers are: 1052.Bl -tag -width EEE 1053.It Cm \&:E 1054Replaces each word in the variable with its suffix. 1055.It Cm \&:H 1056Replaces each word in the variable with everything but the last component. 1057.It Cm \&:M Ns Ar pattern 1058Select only those words that match 1059.Ar pattern . 1060The standard shell wildcard characters 1061.Pf ( Ql * , 1062.Ql \&? , 1063and 1064.Ql Oo Oc ) 1065may 1066be used. 1067The wildcard characters may be escaped with a backslash 1068.Pq Ql \e . 1069.It Cm \&:N Ns Ar pattern 1070This is identical to 1071.Ql Cm \&:M , 1072but selects all words which do not match 1073.Ar pattern . 1074.It Cm \&:O 1075Order every word in variable alphabetically. 1076To sort words in 1077reverse order use the 1078.Ql Cm \&:O:[-1..1] 1079combination of modifiers. 1080.It Cm \&:Ox 1081Randomize words in variable. 1082The results will be different each time you are referring to the 1083modified variable; use the assignment with expansion 1084.Pq Ql Cm \&:= 1085to prevent such behaviour. 1086For example, 1087.Bd -literal -offset indent 1088LIST= uno due tre quattro 1089RANDOM_LIST= ${LIST:Ox} 1090STATIC_RANDOM_LIST:= ${LIST:Ox} 1091 1092all: 1093 @echo "${RANDOM_LIST}" 1094 @echo "${RANDOM_LIST}" 1095 @echo "${STATIC_RANDOM_LIST}" 1096 @echo "${STATIC_RANDOM_LIST}" 1097.Ed 1098may produce output similar to: 1099.Bd -literal -offset indent 1100quattro due tre uno 1101tre due quattro uno 1102due uno quattro tre 1103due uno quattro tre 1104.Ed 1105.It Cm \&:Q 1106Quotes every shell meta-character in the variable, so that it can be passed 1107safely through recursive invocations of 1108.Nm . 1109.It Cm \&:R 1110Replaces each word in the variable with everything but its suffix. 1111.It Cm \&:gmtime 1112The value is a format string for 1113.Xr strftime 3 , 1114using the current 1115.Xr gmtime 3 . 1116.It Cm \&:hash 1117Compute a 32bit hash of the value and encode it as hex digits. 1118.It Cm \&:localtime 1119The value is a format string for 1120.Xr strftime 3 , 1121using the current 1122.Xr localtime 3 . 1123.It Cm \&:tA 1124Attempt to convert variable to an absolute path using 1125.Xr realpath 3 , 1126if that fails, the value is unchanged. 1127.It Cm \&:tl 1128Converts variable to lower-case letters. 1129.It Cm \&:ts Ns Ar c 1130Words in the variable are normally separated by a space on expansion. 1131This modifier sets the separator to the character 1132.Ar c . 1133If 1134.Ar c 1135is omitted, then no separator is used. 1136The common escapes (including octal numeric codes), work as expected. 1137.It Cm \&:tu 1138Converts variable to upper-case letters. 1139.It Cm \&:tW 1140Causes the value to be treated as a single word 1141(possibly containing embedded white space). 1142See also 1143.Ql Cm \&:[*] . 1144.It Cm \&:tw 1145Causes the value to be treated as a sequence of 1146words delimited by white space. 1147See also 1148.Ql Cm \&:[@] . 1149.Sm off 1150.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1151.Sm on 1152Modify the first occurrence of 1153.Ar old_string 1154in the variable's value, replacing it with 1155.Ar new_string . 1156If a 1157.Ql g 1158is appended to the last slash of the pattern, all occurrences 1159in each word are replaced. 1160If a 1161.Ql 1 1162is appended to the last slash of the pattern, only the first word 1163is affected. 1164If a 1165.Ql W 1166is appended to the last slash of the pattern, 1167then the value is treated as a single word 1168(possibly containing embedded white space). 1169If 1170.Ar old_string 1171begins with a caret 1172.Pq Ql ^ , 1173.Ar old_string 1174is anchored at the beginning of each word. 1175If 1176.Ar old_string 1177ends with a dollar sign 1178.Pq Ql \&$ , 1179it is anchored at the end of each word. 1180Inside 1181.Ar new_string , 1182an ampersand 1183.Pq Ql \*[Am] 1184is replaced by 1185.Ar old_string 1186(without any 1187.Ql ^ 1188or 1189.Ql \&$ ) . 1190Any character may be used as a delimiter for the parts of the modifier 1191string. 1192The anchoring, ampersand and delimiter characters may be escaped with a 1193backslash 1194.Pq Ql \e . 1195.Pp 1196Variable expansion occurs in the normal fashion inside both 1197.Ar old_string 1198and 1199.Ar new_string 1200with the single exception that a backslash is used to prevent the expansion 1201of a dollar sign 1202.Pq Ql \&$ , 1203not a preceding dollar sign as is usual. 1204.Sm off 1205.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1206.Sm on 1207The 1208.Cm \&:C 1209modifier is just like the 1210.Cm \&:S 1211modifier except that the old and new strings, instead of being 1212simple strings, are a regular expression (see 1213.Xr regex 3 ) 1214string 1215.Ar pattern 1216and an 1217.Xr ed 1 Ns \-style 1218string 1219.Ar replacement . 1220Normally, the first occurrence of the pattern 1221.Ar pattern 1222in each word of the value is substituted with 1223.Ar replacement . 1224The 1225.Ql 1 1226modifier causes the substitution to apply to at most one word; the 1227.Ql g 1228modifier causes the substitution to apply to as many instances of the 1229search pattern 1230.Ar pattern 1231as occur in the word or words it is found in; the 1232.Ql W 1233modifier causes the value to be treated as a single word 1234(possibly containing embedded white space). 1235Note that 1236.Ql 1 1237and 1238.Ql g 1239are orthogonal; the former specifies whether multiple words are 1240potentially affected, the latter whether multiple substitutions can 1241potentially occur within each affected word. 1242.It Cm \&:T 1243Replaces each word in the variable with its last component. 1244.It Cm \&:u 1245Remove adjacent duplicate words (like 1246.Xr uniq 1 ) . 1247.Sm off 1248.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1249.Sm on 1250If the variable name (not its value), when parsed as a .if conditional 1251expression, evaluates to true, return as its value the 1252.Ar true_string , 1253otherwise return the 1254.Ar false_string . 1255Since the variable name is used as the expression, \&:\&? must be the 1256first modifier after the variable name itself - which will, of course, 1257usually contain variable expansions. 1258A common error is trying to use expressions like 1259.Dl ${NUMBERS:M42:?match:no} 1260which actually tests defined(NUMBERS), 1261to determine is any words match "42" you need to use something like: 1262.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1263.It Ar :old_string=new_string 1264This is the 1265.At V 1266style variable substitution. 1267It must be the last modifier specified. 1268If 1269.Ar old_string 1270or 1271.Ar new_string 1272do not contain the pattern matching character 1273.Ar % 1274then it is assumed that they are 1275anchored at the end of each word, so only suffixes or entire 1276words may be replaced. 1277Otherwise 1278.Ar % 1279is the substring of 1280.Ar old_string 1281to be replaced in 1282.Ar new_string . 1283.Pp 1284Variable expansion occurs in the normal fashion inside both 1285.Ar old_string 1286and 1287.Ar new_string 1288with the single exception that a backslash is used to prevent the 1289expansion of a dollar sign 1290.Pq Ql \&$ , 1291not a preceding dollar sign as is usual. 1292.Sm off 1293.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1294.Sm on 1295This is the loop expansion mechanism from the OSF Development 1296Environment (ODE) make. 1297Unlike 1298.Cm \&.for 1299loops expansion occurs at the time of 1300reference. 1301Assign 1302.Ar temp 1303to each word in the variable and evaluate 1304.Ar string . 1305The ODE convention is that 1306.Ar temp 1307should start and end with a period. 1308For example. 1309.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1310.Pp 1311However a single character variable is often more readable: 1312.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1313.It Cm \&:U Ns Ar newval 1314If the variable is undefined 1315.Ar newval 1316is the value. 1317If the variable is defined, the existing value is returned. 1318This is another ODE make feature. 1319It is handy for setting per-target CFLAGS for instance: 1320.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1321If a value is only required if the variable is undefined, use: 1322.Dl ${VAR:D:Unewval} 1323.It Cm \&:D Ns Ar newval 1324If the variable is defined 1325.Ar newval 1326is the value. 1327.It Cm \&:L 1328The name of the variable is the value. 1329.It Cm \&:P 1330The path of the node which has the same name as the variable 1331is the value. 1332If no such node exists or its path is null, then the 1333name of the variable is used. 1334In order for this modifier to work, the name (node) must at least have 1335appeared on the rhs of a dependency. 1336.Sm off 1337.It Cm \&:\&! Ar cmd Cm \&! 1338.Sm on 1339The output of running 1340.Ar cmd 1341is the value. 1342.It Cm \&:sh 1343If the variable is non-empty it is run as a command and the output 1344becomes the new value. 1345.It Cm \&::= Ns Ar str 1346The variable is assigned the value 1347.Ar str 1348after substitution. 1349This modifier and its variations are useful in 1350obscure situations such as wanting to set a variable when shell commands 1351are being parsed. 1352These assignment modifiers always expand to 1353nothing, so if appearing in a rule line by themselves should be 1354preceded with something to keep 1355.Nm 1356happy. 1357.Pp 1358The 1359.Ql Cm \&:: 1360helps avoid false matches with the 1361.At V 1362style 1363.Cm \&:= 1364modifier and since substitution always occurs the 1365.Cm \&::= 1366form is vaguely appropriate. 1367.It Cm \&::?= Ns Ar str 1368As for 1369.Cm \&::= 1370but only if the variable does not already have a value. 1371.It Cm \&::+= Ns Ar str 1372Append 1373.Ar str 1374to the variable. 1375.It Cm \&::!= Ns Ar cmd 1376Assign the output of 1377.Ar cmd 1378to the variable. 1379.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1380Selects one or more words from the value, 1381or performs other operations related to the way in which the 1382value is divided into words. 1383.Pp 1384Ordinarily, a value is treated as a sequence of words 1385delimited by white space. 1386Some modifiers suppress this behaviour, 1387causing a value to be treated as a single word 1388(possibly containing embedded white space). 1389An empty value, or a value that consists entirely of white-space, 1390is treated as a single word. 1391For the purposes of the 1392.Ql Cm \&:[] 1393modifier, the words are indexed both forwards using positive integers 1394(where index 1 represents the first word), 1395and backwards using negative integers 1396(where index \-1 represents the last word). 1397.Pp 1398The 1399.Ar range 1400is subjected to variable expansion, and the expanded result is 1401then interpreted as follows: 1402.Bl -tag -width index 1403.\" :[n] 1404.It Ar index 1405Selects a single word from the value. 1406.\" :[start..end] 1407.It Ar start Ns Cm \&.. Ns Ar end 1408Selects all words from 1409.Ar start 1410to 1411.Ar end , 1412inclusive. 1413For example, 1414.Ql Cm \&:[2..-1] 1415selects all words from the second word to the last word. 1416If 1417.Ar start 1418is greater than 1419.Ar end , 1420then the words are output in reverse order. 1421For example, 1422.Ql Cm \&:[-1..1] 1423selects all the words from last to first. 1424.\" :[*] 1425.It Cm \&* 1426Causes subsequent modifiers to treat the value as a single word 1427(possibly containing embedded white space). 1428Analogous to the effect of 1429\&"$*\&" 1430in Bourne shell. 1431.\" :[0] 1432.It 0 1433Means the same as 1434.Ql Cm \&:[*] . 1435.\" :[*] 1436.It Cm \&@ 1437Causes subsequent modifiers to treat the value as a sequence of words 1438delimited by white space. 1439Analogous to the effect of 1440\&"$@\&" 1441in Bourne shell. 1442.\" :[#] 1443.It Cm \&# 1444Returns the number of words in the value. 1445.El \" :[range] 1446.El 1447.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1448Makefile inclusion, conditional structures and for loops reminiscent 1449of the C programming language are provided in 1450.Nm . 1451All such structures are identified by a line beginning with a single 1452dot 1453.Pq Ql \&. 1454character. 1455Files are included with either 1456.Cm \&.include Aq Ar file 1457or 1458.Cm \&.include Pf \*q Ar file Ns \*q . 1459Variables between the angle brackets or double quotes are expanded 1460to form the file name. 1461If angle brackets are used, the included makefile is expected to be in 1462the system makefile directory. 1463If double quotes are used, the including makefile's directory and any 1464directories specified using the 1465.Fl I 1466option are searched before the system 1467makefile directory. 1468For compatibility with other versions of 1469.Nm 1470.Ql include file ... 1471is also accepted. 1472If the include statement is written as 1473.Cm .-include 1474or as 1475.Cm .sinclude 1476then errors locating and/or opening include files are ignored. 1477.Pp 1478Conditional expressions are also preceded by a single dot as the first 1479character of a line. 1480The possible conditionals are as follows: 1481.Bl -tag -width Ds 1482.It Ic .error Ar message 1483The message is printed along with the name of the makefile and line number, 1484then 1485.Nm 1486will exit. 1487.It Ic .export Ar variable ... 1488Export the specified global variable. 1489If no variable list is provided, all globals are exported 1490except for internal variables (those that start with 1491.Ql \&. ) . 1492This is not affected by the 1493.Fl X 1494flag, so should be used with caution. 1495For compatibility with other 1496.Nm 1497programs 1498.Ql export variable=value 1499is also accepted. 1500.Pp 1501Appending a variable name to 1502.Va .MAKE.EXPORTED 1503is equivalent to exporting a variable. 1504.It Ic .export-env Ar variable ... 1505The same as 1506.Ql .export , 1507except that the variable is not appended to 1508.Va .MAKE.EXPORTED . 1509This allows exporting a value to the environment which is different from that 1510used by 1511.Nm 1512internally. 1513.It Ic .info Ar message 1514The message is printed along with the name of the makefile and line number. 1515.It Ic .undef Ar variable 1516Un-define the specified global variable. 1517Only global variables may be un-defined. 1518.It Ic .unexport Ar variable ... 1519The opposite of 1520.Ql .export . 1521The specified global 1522.Va variable 1523will be removed from 1524.Va .MAKE.EXPORTED . 1525If no variable list is provided, all globals are unexported, 1526and 1527.Va .MAKE.EXPORTED 1528deleted. 1529.It Ic .unexport-env 1530Unexport all globals previously exported and 1531clear the environment inherited from the parent. 1532This operation will cause a memory leak of the original environment, 1533so should be used sparingly. 1534Testing for 1535.Va .MAKE.LEVEL 1536being 0, would make sense. 1537Also note that any variables which originated in the parent environment 1538should be explicitly preserved if desired. 1539For example: 1540.Bd -literal -offset indent 1541.Li .if ${.MAKE.LEVEL} == 0 1542PATH := ${PATH} 1543.Li .unexport-env 1544.Li .export PATH 1545.Li .endif 1546.Ed 1547.Pp 1548Would result in an environment containing only 1549.Ql Ev PATH , 1550which is the minimal useful environment. 1551Actually 1552.Ql Ev .MAKE.LEVEL 1553will also be pushed into the new environment. 1554.It Ic .warning Ar message 1555The message prefixed by 1556.Ql Pa warning: 1557is printed along with the name of the makefile and line number. 1558.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1559Test the value of an expression. 1560.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1561Test the value of a variable. 1562.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1563Test the value of a variable. 1564.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1565Test the target being built. 1566.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1567Test the target being built. 1568.It Ic .else 1569Reverse the sense of the last conditional. 1570.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1571A combination of 1572.Ql Ic .else 1573followed by 1574.Ql Ic .if . 1575.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1576A combination of 1577.Ql Ic .else 1578followed by 1579.Ql Ic .ifdef . 1580.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1581A combination of 1582.Ql Ic .else 1583followed by 1584.Ql Ic .ifndef . 1585.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1586A combination of 1587.Ql Ic .else 1588followed by 1589.Ql Ic .ifmake . 1590.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1591A combination of 1592.Ql Ic .else 1593followed by 1594.Ql Ic .ifnmake . 1595.It Ic .endif 1596End the body of the conditional. 1597.El 1598.Pp 1599The 1600.Ar operator 1601may be any one of the following: 1602.Bl -tag -width "Cm XX" 1603.It Cm \&|\&| 1604Logical OR. 1605.It Cm \&\*[Am]\*[Am] 1606Logical 1607.Tn AND ; 1608of higher precedence than 1609.Dq \&|\&| . 1610.El 1611.Pp 1612As in C, 1613.Nm 1614will only evaluate a conditional as far as is necessary to determine 1615its value. 1616Parentheses may be used to change the order of evaluation. 1617The boolean operator 1618.Ql Ic \&! 1619may be used to logically negate an entire 1620conditional. 1621It is of higher precedence than 1622.Ql Ic \&\*[Am]\*[Am] . 1623.Pp 1624The value of 1625.Ar expression 1626may be any of the following: 1627.Bl -tag -width defined 1628.It Ic defined 1629Takes a variable name as an argument and evaluates to true if the variable 1630has been defined. 1631.It Ic make 1632Takes a target name as an argument and evaluates to true if the target 1633was specified as part of 1634.Nm Ns 's 1635command line or was declared the default target (either implicitly or 1636explicitly, see 1637.Va .MAIN ) 1638before the line containing the conditional. 1639.It Ic empty 1640Takes a variable, with possible modifiers, and evaluates to true if 1641the expansion of the variable would result in an empty string. 1642.It Ic exists 1643Takes a file name as an argument and evaluates to true if the file exists. 1644The file is searched for on the system search path (see 1645.Va .PATH ) . 1646.It Ic target 1647Takes a target name as an argument and evaluates to true if the target 1648has been defined. 1649.It Ic commands 1650Takes a target name as an argument and evaluates to true if the target 1651has been defined and has commands associated with it. 1652.El 1653.Pp 1654.Ar Expression 1655may also be an arithmetic or string comparison. 1656Variable expansion is 1657performed on both sides of the comparison, after which the integral 1658values are compared. 1659A value is interpreted as hexadecimal if it is 1660preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1661The standard C relational operators are all supported. 1662If after 1663variable expansion, either the left or right hand side of a 1664.Ql Ic == 1665or 1666.Ql Ic "!=" 1667operator is not an integral value, then 1668string comparison is performed between the expanded 1669variables. 1670If no relational operator is given, it is assumed that the expanded 1671variable is being compared against 0 or an empty string in the case 1672of a string comparison. 1673.Pp 1674When 1675.Nm 1676is evaluating one of these conditional expressions, and it encounters 1677a (white-space separated) word it doesn't recognize, either the 1678.Dq make 1679or 1680.Dq defined 1681expression is applied to it, depending on the form of the conditional. 1682If the form is 1683.Ql Ic .ifdef , 1684.Ql Ic .ifndef , 1685or 1686.Ql Ic .if 1687the 1688.Dq defined 1689expression is applied. 1690Similarly, if the form is 1691.Ql Ic .ifmake 1692or 1693.Ql Ic .ifnmake , the 1694.Dq make 1695expression is applied. 1696.Pp 1697If the conditional evaluates to true the parsing of the makefile continues 1698as before. 1699If it evaluates to false, the following lines are skipped. 1700In both cases this continues until a 1701.Ql Ic .else 1702or 1703.Ql Ic .endif 1704is found. 1705.Pp 1706For loops are typically used to apply a set of rules to a list of files. 1707The syntax of a for loop is: 1708.Pp 1709.Bl -tag -compact -width Ds 1710.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1711.It Aq make-rules 1712.It Ic \&.endfor 1713.El 1714.Pp 1715After the for 1716.Ic expression 1717is evaluated, it is split into words. 1718On each iteration of the loop, one word is taken and assigned to each 1719.Ic variable , 1720in order, and these 1721.Ic variables 1722are substituted into the 1723.Ic make-rules 1724inside the body of the for loop. 1725The number of words must come out even; that is, if there are three 1726iteration variables, the number of words provided must be a multiple 1727of three. 1728.Sh COMMENTS 1729Comments begin with a hash 1730.Pq Ql \&# 1731character, anywhere but in a shell 1732command line, and continue to the end of an unescaped new line. 1733.Sh SPECIAL SOURCES (ATTRIBUTES) 1734.Bl -tag -width .IGNOREx 1735.It Ic .EXEC 1736Target is never out of date, but always execute commands anyway. 1737.It Ic .IGNORE 1738Ignore any errors from the commands associated with this target, exactly 1739as if they all were preceded by a dash 1740.Pq Ql \- . 1741.\" .It Ic .INVISIBLE 1742.\" XXX 1743.\" .It Ic .JOIN 1744.\" XXX 1745.It Ic .MADE 1746Mark all sources of this target as being up-to-date. 1747.It Ic .MAKE 1748Execute the commands associated with this target even if the 1749.Fl n 1750or 1751.Fl t 1752options were specified. 1753Normally used to mark recursive 1754.Nm Ns 's . 1755.It Ic .META 1756Create a meta file for the target, even if it is flagged as 1757.Ic .PHONY , 1758.Ic .MAKE , 1759or 1760.Ic .SPECIAL . 1761Usage in conjunction with 1762.Ic .MAKE 1763is the most likely case. 1764In "meta" mode, the target is out-of-date if the meta file is missing. 1765.It Ic .NOMETA 1766Do not create a meta file for the target. 1767Meta files are also not created for 1768.Ic .PHONY , 1769.Ic .MAKE , 1770or 1771.Ic .SPECIAL 1772targets. 1773.It Ic .NOMETA_CMP 1774Ignore differences in commands when deciding if target is out of date. 1775This is useful if the command contains a value which always changes. 1776If the number of commands change, though, the target will still be out of date. 1777The same effect applies to any command line that uses the variable 1778.Va .OODATE , 1779which can be used for that purpose even when not otherwise needed or desired: 1780.Bd -literal -offset indent 1781 1782skip-compare-for-some: 1783 @echo this will be compared 1784 @echo this will not ${.OODATE:M.NOMETA_CMP} 1785 @echo this will also be compared 1786 1787.Ed 1788The 1789.Cm \&:M 1790pattern suppresses any expansion of the unwanted variable. 1791.It Ic .NOPATH 1792Do not search for the target in the directories specified by 1793.Ic .PATH . 1794.It Ic .NOTMAIN 1795Normally 1796.Nm 1797selects the first target it encounters as the default target to be built 1798if no target was specified. 1799This source prevents this target from being selected. 1800.It Ic .OPTIONAL 1801If a target is marked with this attribute and 1802.Nm 1803can't figure out how to create it, it will ignore this fact and assume 1804the file isn't needed or already exists. 1805.It Ic .PHONY 1806The target does not 1807correspond to an actual file; it is always considered to be out of date, 1808and will not be created with the 1809.Fl t 1810option. 1811Suffix-transformation rules are not applied to 1812.Ic .PHONY 1813targets. 1814.It Ic .PRECIOUS 1815When 1816.Nm 1817is interrupted, it normally removes any partially made targets. 1818This source prevents the target from being removed. 1819.It Ic .RECURSIVE 1820Synonym for 1821.Ic .MAKE . 1822.It Ic .SILENT 1823Do not echo any of the commands associated with this target, exactly 1824as if they all were preceded by an at sign 1825.Pq Ql @ . 1826.It Ic .USE 1827Turn the target into 1828.Nm Ns 's 1829version of a macro. 1830When the target is used as a source for another target, the other target 1831acquires the commands, sources, and attributes (except for 1832.Ic .USE ) 1833of the 1834source. 1835If the target already has commands, the 1836.Ic .USE 1837target's commands are appended 1838to them. 1839.It Ic .USEBEFORE 1840Exactly like 1841.Ic .USE , 1842but prepend the 1843.Ic .USEBEFORE 1844target commands to the target. 1845.It Ic .WAIT 1846If 1847.Ic .WAIT 1848appears in a dependency line, the sources that precede it are 1849made before the sources that succeed it in the line. 1850Since the dependents of files are not made until the file itself 1851could be made, this also stops the dependents being built unless they 1852are needed for another branch of the dependency tree. 1853So given: 1854.Bd -literal 1855x: a .WAIT b 1856 echo x 1857a: 1858 echo a 1859b: b1 1860 echo b 1861b1: 1862 echo b1 1863 1864.Ed 1865the output is always 1866.Ql a , 1867.Ql b1 , 1868.Ql b , 1869.Ql x . 1870.br 1871The ordering imposed by 1872.Ic .WAIT 1873is only relevant for parallel makes. 1874.El 1875.Sh SPECIAL TARGETS 1876Special targets may not be included with other targets, i.e. they must be 1877the only target specified. 1878.Bl -tag -width .BEGINx 1879.It Ic .BEGIN 1880Any command lines attached to this target are executed before anything 1881else is done. 1882.It Ic .DEFAULT 1883This is sort of a 1884.Ic .USE 1885rule for any target (that was used only as a 1886source) that 1887.Nm 1888can't figure out any other way to create. 1889Only the shell script is used. 1890The 1891.Ic .IMPSRC 1892variable of a target that inherits 1893.Ic .DEFAULT Ns 's 1894commands is set 1895to the target's own name. 1896.It Ic .END 1897Any command lines attached to this target are executed after everything 1898else is done. 1899.It Ic .ERROR 1900Any command lines attached to this target are executed when another target fails. 1901The 1902.Ic .ERROR_TARGET 1903variable is set to the target that failed. 1904See also 1905.Ic MAKE_PRINT_VAR_ON_ERROR . 1906.It Ic .IGNORE 1907Mark each of the sources with the 1908.Ic .IGNORE 1909attribute. 1910If no sources are specified, this is the equivalent of specifying the 1911.Fl i 1912option. 1913.It Ic .INTERRUPT 1914If 1915.Nm 1916is interrupted, the commands for this target will be executed. 1917.It Ic .MAIN 1918If no target is specified when 1919.Nm 1920is invoked, this target will be built. 1921.It Ic .MAKEFLAGS 1922This target provides a way to specify flags for 1923.Nm 1924when the makefile is used. 1925The flags are as if typed to the shell, though the 1926.Fl f 1927option will have 1928no effect. 1929.\" XXX: NOT YET!!!! 1930.\" .It Ic .NOTPARALLEL 1931.\" The named targets are executed in non parallel mode. 1932.\" If no targets are 1933.\" specified, then all targets are executed in non parallel mode. 1934.It Ic .NOPATH 1935Apply the 1936.Ic .NOPATH 1937attribute to any specified sources. 1938.It Ic .NOTPARALLEL 1939Disable parallel mode. 1940.It Ic .NO_PARALLEL 1941Synonym for 1942.Ic .NOTPARALLEL , 1943for compatibility with other pmake variants. 1944.It Ic .ORDER 1945The named targets are made in sequence. 1946This ordering does not add targets to the list of targets to be made. 1947Since the dependents of a target do not get built until the target itself 1948could be built, unless 1949.Ql a 1950is built by another part of the dependency graph, 1951the following is a dependency loop: 1952.Bd -literal 1953\&.ORDER: b a 1954b: a 1955.Ed 1956.Pp 1957The ordering imposed by 1958.Ic .ORDER 1959is only relevant for parallel makes. 1960.\" XXX: NOT YET!!!! 1961.\" .It Ic .PARALLEL 1962.\" The named targets are executed in parallel mode. 1963.\" If no targets are 1964.\" specified, then all targets are executed in parallel mode. 1965.It Ic .PATH 1966The sources are directories which are to be searched for files not 1967found in the current directory. 1968If no sources are specified, any previously specified directories are 1969deleted. 1970If the source is the special 1971.Ic .DOTLAST 1972target, then the current working 1973directory is searched last. 1974.It Ic .PATH. Ns Va suffix 1975Like 1976.Ic .PATH 1977but applies only to files with a particular suffix. 1978The suffix must have been previously declared with 1979.Ic .SUFFIXES . 1980.It Ic .PHONY 1981Apply the 1982.Ic .PHONY 1983attribute to any specified sources. 1984.It Ic .PRECIOUS 1985Apply the 1986.Ic .PRECIOUS 1987attribute to any specified sources. 1988If no sources are specified, the 1989.Ic .PRECIOUS 1990attribute is applied to every 1991target in the file. 1992.It Ic .SHELL 1993Sets the shell that 1994.Nm 1995will use to execute commands. 1996The sources are a set of 1997.Ar field=value 1998pairs. 1999.Bl -tag -width hasErrCtls 2000.It Ar name 2001This is the minimal specification, used to select one of the builtin 2002shell specs; 2003.Ar sh , 2004.Ar ksh , 2005and 2006.Ar csh . 2007.It Ar path 2008Specifies the path to the shell. 2009.It Ar hasErrCtl 2010Indicates whether the shell supports exit on error. 2011.It Ar check 2012The command to turn on error checking. 2013.It Ar ignore 2014The command to disable error checking. 2015.It Ar echo 2016The command to turn on echoing of commands executed. 2017.It Ar quiet 2018The command to turn off echoing of commands executed. 2019.It Ar filter 2020The output to filter after issuing the 2021.Ar quiet 2022command. 2023It is typically identical to 2024.Ar quiet . 2025.It Ar errFlag 2026The flag to pass the shell to enable error checking. 2027.It Ar echoFlag 2028The flag to pass the shell to enable command echoing. 2029.It Ar newline 2030The string literal to pass the shell that results in a single newline 2031character when used outside of any quoting characters. 2032.El 2033Example: 2034.Bd -literal 2035\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2036 check="set \-e" ignore="set +e" \e 2037 echo="set \-v" quiet="set +v" filter="set +v" \e 2038 echoFlag=v errFlag=e newline="'\en'" 2039.Ed 2040.It Ic .SILENT 2041Apply the 2042.Ic .SILENT 2043attribute to any specified sources. 2044If no sources are specified, the 2045.Ic .SILENT 2046attribute is applied to every 2047command in the file. 2048.It Ic .STALE 2049This target gets run when a dependency file contains stale entries, having 2050.Va .ALLSRC 2051set to the name of that dependency file. 2052.It Ic .SUFFIXES 2053Each source specifies a suffix to 2054.Nm . 2055If no sources are specified, any previously specified suffixes are deleted. 2056It allows the creation of suffix-transformation rules. 2057.Pp 2058Example: 2059.Bd -literal 2060\&.SUFFIXES: .o 2061\&.c.o: 2062 cc \-o ${.TARGET} \-c ${.IMPSRC} 2063.Ed 2064.El 2065.Sh ENVIRONMENT 2066.Nm 2067uses the following environment variables, if they exist: 2068.Ev MACHINE , 2069.Ev MACHINE_ARCH , 2070.Ev MAKE , 2071.Ev MAKEFLAGS , 2072.Ev MAKEOBJDIR , 2073.Ev MAKEOBJDIRPREFIX , 2074.Ev MAKESYSPATH , 2075.Ev PWD , 2076and 2077.Ev TMPDIR . 2078.Pp 2079.Ev MAKEOBJDIRPREFIX 2080and 2081.Ev MAKEOBJDIR 2082may only be set in the environment or on the command line to 2083.Nm 2084and not as makefile variables; 2085see the description of 2086.Ql Va .OBJDIR 2087for more details. 2088.Sh FILES 2089.Bl -tag -width /usr/share/mk -compact 2090.It .depend 2091list of dependencies 2092.It Makefile 2093list of dependencies 2094.It makefile 2095list of dependencies 2096.It sys.mk 2097system makefile 2098.It /usr/share/mk 2099system makefile directory 2100.El 2101.Sh COMPATIBILITY 2102The basic make syntax is compatible between different versions of make, 2103however the special variables, variable modifiers and conditionals are not. 2104.Pp 2105The way that parallel makes are scheduled changed in 2106NetBSD 4.0 2107so that .ORDER and .WAIT apply recursively to the dependent nodes. 2108The algorithms used may change again in the future. 2109.Pp 2110The way that .for loop variables are substituted changed after 2111NetBSD 5.0 2112so that they still appear to be variable expansions. 2113In particular this stops them being treated as syntax, and removes some 2114obscure problems using them in .if statements. 2115.Sh SEE ALSO 2116.Xr mkdep 1 2117.Sh HISTORY 2118.Nm 2119is derived from NetBSD 2120.Xr make 1 . 2121It uses autoconf to facilitate portability to other platforms. 2122.Pp 2123A 2124make 2125command appeared in 2126.At v7 . 2127This 2128make 2129implementation is based on Adam De Boor's pmake program which was written 2130for Sprite at Berkeley. 2131It was designed to be a parallel distributed make running jobs on different 2132machines using a daemon called 2133.Dq customs . 2134.Pp 2135Historically the target/dependency 2136.Dq FRC 2137has been used to FoRCe rebuilding (since the target/dependency 2138does not exist... unless someone creates an 2139.Dq FRC 2140file). 2141.Sh BUGS 2142The 2143make 2144syntax is difficult to parse without actually acting of the data. 2145For instance finding the end of a variable use should involve scanning each 2146the modifiers using the correct terminator for each field. 2147In many places 2148make 2149just counts {} and () in order to find the end of a variable expansion. 2150.Pp 2151There is no way of escaping a space character in a filename. 2152