1.\" $NetBSD: make.1,v 1.296 2021/02/04 21:42:46 rillig 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 20, 2021 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm make 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrSstWwX 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 Fl v Ar variable 52.Op Ar variable=value 53.Op Ar target ... 54.Sh DESCRIPTION 55.Nm 56is a program designed to simplify the maintenance of other programs. 57Its input is a list of specifications as to the files upon which programs 58and other files depend. 59If no 60.Fl f Ar makefile 61makefile option is given, 62.Nm 63will try to open 64.Ql Pa makefile 65then 66.Ql Pa Makefile 67in order to find the specifications. 68If the file 69.Ql Pa .depend 70exists, it is read (see 71.Xr mkdep 1 ) . 72.Pp 73This manual page is intended as a reference document only. 74For a more thorough description of 75.Nm 76and makefiles, please refer to 77.%T "PMake \- A Tutorial" . 78.Pp 79.Nm 80will prepend the contents of the 81.Va MAKEFLAGS 82environment variable to the command line arguments before parsing them. 83.Pp 84The options are as follows: 85.Bl -tag -width Ds 86.It Fl B 87Try to be backwards compatible by executing a single shell per command and 88by executing the commands to make the sources of a dependency line in sequence. 89.It Fl C Ar directory 90Change to 91.Ar directory 92before reading the makefiles or doing anything else. 93If multiple 94.Fl C 95options are specified, each is interpreted relative to the previous one: 96.Fl C Pa / Fl C Pa etc 97is equivalent to 98.Fl C Pa /etc . 99.It Fl D Ar variable 100Define 101.Ar variable 102to be 1, in the global scope. 103.It Fl d Ar [-]flags 104Turn on debugging, and specify which portions of 105.Nm 106are to print debugging information. 107Unless the flags are preceded by 108.Ql \- 109they are added to the 110.Va MAKEFLAGS 111environment variable and will be processed by any child make processes. 112By default, debugging information is printed to standard error, 113but this can be changed using the 114.Ar F 115debugging flag. 116The debugging output is always unbuffered; in addition, if debugging 117is enabled but debugging output is not directed to standard output, 118then the standard output is line buffered. 119.Ar Flags 120is one or more of the following: 121.Bl -tag -width Ds 122.It Ar A 123Print all possible debugging information; 124equivalent to specifying all of the debugging flags. 125.It Ar a 126Print debugging information about archive searching and caching. 127.It Ar C 128Print debugging information about current working directory. 129.It Ar c 130Print debugging information about conditional evaluation. 131.It Ar d 132Print debugging information about directory searching and caching. 133.It Ar e 134Print debugging information about failed commands and targets. 135.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 136Specify where debugging output is written. 137This must be the last flag, because it consumes the remainder of 138the argument. 139If the character immediately after the 140.Ql F 141flag is 142.Ql \&+ , 143then the file will be opened in append mode; 144otherwise the file will be overwritten. 145If the file name is 146.Ql stdout 147or 148.Ql stderr 149then debugging output will be written to the 150standard output or standard error output file descriptors respectively 151(and the 152.Ql \&+ 153option has no effect). 154Otherwise, the output will be written to the named file. 155If the file name ends 156.Ql .%d 157then the 158.Ql %d 159is replaced by the pid. 160.It Ar f 161Print debugging information about loop evaluation. 162.It Ar "g1" 163Print the input graph before making anything. 164.It Ar "g2" 165Print the input graph after making everything, or before exiting 166on error. 167.It Ar "g3" 168Print the input graph before exiting on error. 169.It Ar h 170Print debugging information about hash table operations. 171.It Ar j 172Print debugging information about running multiple shells. 173.It Ar L 174Turn on lint checks. 175This will throw errors for variable assignments that do not parse 176correctly, at the time of assignment so the file and line number 177are available. 178.It Ar l 179Print commands in Makefiles regardless of whether or not they are prefixed by 180.Ql @ 181or other "quiet" flags. 182Also known as "loud" behavior. 183.It Ar M 184Print debugging information about "meta" mode decisions about targets. 185.It Ar m 186Print debugging information about making targets, including modification 187dates. 188.It Ar n 189Don't delete the temporary command scripts created when running commands. 190These temporary scripts are created in the directory 191referred to by the 192.Ev TMPDIR 193environment variable, or in 194.Pa /tmp 195if 196.Ev TMPDIR 197is unset or set to the empty string. 198The temporary scripts are created by 199.Xr mkstemp 3 , 200and have names of the form 201.Pa makeXXXXXX . 202.Em NOTE : 203This can create many files in 204.Ev TMPDIR 205or 206.Pa /tmp , 207so use with care. 208.It Ar p 209Print debugging information about makefile parsing. 210.It Ar s 211Print debugging information about suffix-transformation rules. 212.It Ar t 213Print debugging information about target list maintenance. 214.It Ar V 215Force the 216.Fl V 217option to print raw values of variables, overriding the default behavior 218set via 219.Va .MAKE.EXPAND_VARIABLES . 220.It Ar v 221Print debugging information about variable assignment. 222.It Ar x 223Run shell commands with 224.Fl x 225so the actual commands are printed as they are executed. 226.El 227.It Fl e 228Specify that environment variables override macro assignments within 229makefiles. 230.It Fl f Ar makefile 231Specify a makefile to read instead of the default 232.Ql Pa makefile . 233If 234.Ar makefile 235is 236.Ql Fl , 237standard input is read. 238Multiple makefiles may be specified, and are read in the order specified. 239.It Fl I Ar directory 240Specify a directory in which to search for makefiles and included makefiles. 241The system makefile directory (or directories, see the 242.Fl m 243option) is automatically included as part of this list. 244.It Fl i 245Ignore non-zero exit of shell commands in the makefile. 246Equivalent to specifying 247.Ql Fl 248before each command line in the makefile. 249.It Fl J Ar private 250This option should 251.Em not 252be specified by the user. 253.Pp 254When the 255.Ar j 256option is in use in a recursive build, this option is passed by a make 257to child makes to allow all the make processes in the build to 258cooperate to avoid overloading the system. 259.It Fl j Ar max_jobs 260Specify the maximum number of jobs that 261.Nm 262may have running at any one time. 263The value is saved in 264.Va .MAKE.JOBS . 265Turns compatibility mode off, unless the 266.Ar B 267flag is also specified. 268When compatibility mode is off, all commands associated with a 269target are executed in a single shell invocation as opposed to the 270traditional one shell invocation per line. 271This can break traditional scripts which change directories on each 272command invocation and then expect to start with a fresh environment 273on the next line. 274It is more efficient to correct the scripts rather than turn backwards 275compatibility on. 276.It Fl k 277Continue processing after errors are encountered, but only on those targets 278that do not depend on the target whose creation caused the error. 279.It Fl m Ar directory 280Specify a directory in which to search for sys.mk and makefiles included 281via the 282.Li \&< Ns Ar file Ns Li \&> Ns -style 283include statement. 284The 285.Fl m 286option can be used multiple times to form a search path. 287This path will override the default system include path: /usr/share/mk. 288Furthermore the system include path will be appended to the search path used 289for 290.Li \*q Ns Ar file Ns Li \*q Ns -style 291include statements (see the 292.Fl I 293option). 294.Pp 295If a file or directory name in the 296.Fl m 297argument (or the 298.Ev MAKESYSPATH 299environment variable) starts with the string 300.Qq \&.../ 301then 302.Nm 303will search for the specified file or directory named in the remaining part 304of the argument string. 305The search starts with the current directory of 306the Makefile and then works upward towards the root of the file system. 307If the search is successful, then the resulting directory replaces the 308.Qq \&.../ 309specification in the 310.Fl m 311argument. 312If used, this feature allows 313.Nm 314to easily search in the current source tree for customized sys.mk files 315(e.g., by using 316.Qq \&.../mk/sys.mk 317as an argument). 318.It Fl n 319Display the commands that would have been executed, but do not 320actually execute them unless the target depends on the .MAKE special 321source (see below) or the command is prefixed with 322.Ql Ic + . 323.It Fl N 324Display the commands which would have been executed, but do not 325actually execute any of them; useful for debugging top-level makefiles 326without descending into subdirectories. 327.It Fl q 328Do not execute any commands, but exit 0 if the specified targets are 329up-to-date and 1, otherwise. 330.It Fl r 331Do not use the built-in rules specified in the system makefile. 332.It Fl S 333Stop processing if an error is encountered. 334This is the default behavior and the opposite of 335.Fl k . 336.It Fl s 337Do not echo any commands as they are executed. 338Equivalent to specifying 339.Ql Ic @ 340before each command line in the makefile. 341.It Fl T Ar tracefile 342When used with the 343.Fl j 344flag, 345append a trace record to 346.Ar tracefile 347for each job started and completed. 348.It Fl t 349Rather than re-building a target as specified in the makefile, create it 350or update its modification time to make it appear up-to-date. 351.It Fl V Ar variable 352Print the value of 353.Ar variable . 354Do not build any targets. 355Multiple instances of this option may be specified; 356the variables will be printed one per line, 357with a blank line for each null or undefined variable. 358The value printed is extracted from the global scope after all 359makefiles have been read. 360By default, the raw variable contents (which may 361include additional unexpanded variable references) are shown. 362If 363.Ar variable 364contains a 365.Ql \&$ 366then the value will be recursively expanded to its complete resultant 367text before printing. 368The expanded value will also be printed if 369.Va .MAKE.EXPAND_VARIABLES 370is set to true and 371the 372.Fl dV 373option has not been used to override it. 374Note that loop-local and target-local variables, as well as values 375taken temporarily by global variables during makefile processing, are 376not accessible via this option. 377The 378.Fl dv 379debug mode can be used to see these at the cost of generating 380substantial extraneous output. 381.It Fl v Ar variable 382Like 383.Fl V 384but the variable is always expanded to its complete value. 385.It Fl W 386Treat any warnings during makefile parsing as errors. 387.It Fl w 388Print entering and leaving directory messages, pre and post processing. 389.It Fl X 390Don't export variables passed on the command line to the environment 391individually. 392Variables passed on the command line are still exported 393via the 394.Va MAKEFLAGS 395environment variable. 396This option may be useful on systems which have a small limit on the 397size of command arguments. 398.It Ar variable=value 399Set the value of the variable 400.Ar variable 401to 402.Ar value . 403Normally, all values passed on the command line are also exported to 404sub-makes in the environment. 405The 406.Fl X 407flag disables this behavior. 408Variable assignments should follow options for POSIX compatibility 409but no ordering is enforced. 410.El 411.Pp 412There are seven different types of lines in a makefile: file dependency 413specifications, shell commands, variable assignments, include statements, 414conditional directives, for loops, and comments. 415.Pp 416In general, lines may be continued from one line to the next by ending 417them with a backslash 418.Pq Ql \e . 419The trailing newline character and initial whitespace on the following 420line are compressed into a single space. 421.Sh FILE DEPENDENCY SPECIFICATIONS 422Dependency lines consist of one or more targets, an operator, and zero 423or more sources. 424This creates a relationship where the targets 425.Dq depend 426on the sources 427and are customarily created from them. 428A target is considered out-of-date if it does not exist, or if its 429modification time is less than that of any of its sources. 430An out-of-date target will be re-created, but not until all sources 431have been examined and themselves re-created as needed. 432Three operators may be used: 433.Bl -tag -width flag 434.It Ic \&: 435Many dependency lines may name this target but only one may have 436attached shell commands. 437All sources named in all dependency lines are considered together, 438and if needed the attached shell commands are run to create or 439re-create the target. 440If 441.Nm 442is interrupted, the target is removed. 443.It Ic \&! 444The same, but the target is always re-created whether or not it is out 445of date. 446.It Ic \&:: 447Any dependency line may have attached shell commands, but each one 448is handled independently: its sources are considered and the attached 449shell commands are run if the target is out of date with respect to 450(only) those sources. 451Thus, different groups of the attached shell commands may be run 452depending on the circumstances. 453Furthermore, unlike 454.Ic \&:, 455for dependency lines with no sources, the attached shell 456commands are always run. 457Also unlike 458.Ic \&:, 459the target will not be removed if 460.Nm 461is interrupted. 462.El 463All dependency lines mentioning a particular target must use the same 464operator. 465.Pp 466Targets and sources may contain the shell wildcard values 467.Ql \&? , 468.Ql * , 469.Ql [] , 470and 471.Ql {} . 472The values 473.Ql \&? , 474.Ql * , 475and 476.Ql [] 477may only be used as part of the final 478component of the target or source, and must be used to describe existing 479files. 480The value 481.Ql {} 482need not necessarily be used to describe existing files. 483Expansion is in directory order, not alphabetically as done in the shell. 484.Sh SHELL COMMANDS 485Each target may have associated with it one or more lines of shell 486commands, normally 487used to create the target. 488Each of the lines in this script 489.Em must 490be preceded by a tab. 491(For historical reasons, spaces are not accepted.) 492While targets can appear in many dependency lines if desired, by 493default only one of these rules may be followed by a creation 494script. 495If the 496.Ql Ic \&:: 497operator is used, however, all rules may include scripts and the 498scripts are executed in the order found. 499.Pp 500Each line is treated as a separate shell command, unless the end of 501line is escaped with a backslash 502.Pq Ql \e 503in which case that line and the next are combined. 504.\" The escaped newline is retained and passed to the shell, which 505.\" normally ignores it. 506.\" However, the tab at the beginning of the following line is removed. 507If the first characters of the command are any combination of 508.Ql Ic @ , 509.Ql Ic + , 510or 511.Ql Ic \- , 512the command is treated specially. 513A 514.Ql Ic @ 515causes the command not to be echoed before it is executed. 516A 517.Ql Ic + 518causes the command to be executed even when 519.Fl n 520is given. 521This is similar to the effect of the .MAKE special source, 522except that the effect can be limited to a single line of a script. 523A 524.Ql Ic \- 525in compatibility mode 526causes any non-zero exit status of the command line to be ignored. 527.Pp 528When 529.Nm 530is run in jobs mode with 531.Fl j Ar max_jobs , 532the entire script for the target is fed to a 533single instance of the shell. 534In compatibility (non-jobs) mode, each command is run in a separate process. 535If the command contains any shell meta characters 536.Pq Ql #=|^(){};&<>*?[]:$`\e\en 537it will be passed to the shell; otherwise 538.Nm 539will attempt direct execution. 540If a line starts with 541.Ql Ic \- 542and the shell has ErrCtl enabled then failure of the command line 543will be ignored as in compatibility mode. 544Otherwise 545.Ql Ic \- 546affects the entire job; 547the script will stop at the first command line that fails, 548but the target will not be deemed to have failed. 549.Pp 550Makefiles should be written so that the mode of 551.Nm 552operation does not change their behavior. 553For example, any command which needs to use 554.Dq cd 555or 556.Dq chdir 557without potentially changing the directory for subsequent commands 558should be put in parentheses so it executes in a subshell. 559To force the use of one shell, escape the line breaks so as to make 560the whole script one command. 561For example: 562.Bd -literal -offset indent 563avoid-chdir-side-effects: 564 @echo Building $@ in `pwd` 565 @(cd ${.CURDIR} && ${MAKE} $@) 566 @echo Back in `pwd` 567 568ensure-one-shell-regardless-of-mode: 569 @echo Building $@ in `pwd`; \e 570 (cd ${.CURDIR} && ${MAKE} $@); \e 571 echo Back in `pwd` 572.Ed 573.Pp 574Since 575.Nm 576will 577.Xr chdir 2 578to 579.Ql Va .OBJDIR 580before executing any targets, each child process 581starts with that as its current working directory. 582.Sh VARIABLE ASSIGNMENTS 583Variables in make are much like variables in the shell, and, by tradition, 584consist of all upper-case letters. 585.Ss Variable assignment modifiers 586The five operators that can be used to assign values to variables are as 587follows: 588.Bl -tag -width Ds 589.It Ic \&= 590Assign the value to the variable. 591Any previous value is overridden. 592.It Ic \&+= 593Append the value to the current value of the variable. 594.It Ic \&?= 595Assign the value to the variable if it is not already defined. 596.It Ic \&:= 597Assign with expansion, i.e. expand the value before assigning it 598to the variable. 599Normally, expansion is not done until the variable is referenced. 600.Em NOTE : 601References to undefined variables are 602.Em not 603expanded. 604This can cause problems when variable modifiers are used. 605.It Ic \&!= 606Expand the value and pass it to the shell for execution and assign 607the result to the variable. 608Any newlines in the result are replaced with spaces. 609.El 610.Pp 611Any white-space before the assigned 612.Ar value 613is removed; if the value is being appended, a single space is inserted 614between the previous contents of the variable and the appended value. 615.Pp 616Variables are expanded by surrounding the variable name with either 617curly braces 618.Pq Ql {} 619or parentheses 620.Pq Ql () 621and preceding it with 622a dollar sign 623.Pq Ql \&$ . 624If the variable name contains only a single letter, the surrounding 625braces or parentheses are not required. 626This shorter form is not recommended. 627.Pp 628If the variable name contains a dollar, then the name itself is expanded first. 629This allows almost arbitrary variable names, however names containing dollar, 630braces, parentheses, or whitespace are really best avoided! 631.Pp 632If the result of expanding a variable contains a dollar sign 633.Pq Ql \&$ 634the string is expanded again. 635.Pp 636Variable substitution occurs at three distinct times, depending on where 637the variable is being used. 638.Bl -enum 639.It 640Variables in dependency lines are expanded as the line is read. 641.It 642Variables in shell commands are expanded when the shell command is 643executed. 644.It 645.Dq .for 646loop index variables are expanded on each loop iteration. 647Note that other variables are not expanded inside loops so 648the following example code: 649.Bd -literal -offset indent 650 651.Dv .for i in 1 2 3 652a+= ${i} 653j= ${i} 654b+= ${j} 655.Dv .endfor 656 657all: 658 @echo ${a} 659 @echo ${b} 660 661.Ed 662will print: 663.Bd -literal -offset indent 6641 2 3 6653 3 3 666 667.Ed 668Because while ${a} contains 669.Dq 1 2 3 670after the loop is executed, ${b} 671contains 672.Dq ${j} ${j} ${j} 673which expands to 674.Dq 3 3 3 675since after the loop completes ${j} contains 676.Dq 3 . 677.El 678.Ss Variable classes 679The four different classes of variables (in order of increasing precedence) 680are: 681.Bl -tag -width Ds 682.It Environment variables 683Variables defined as part of 684.Nm Ns 's 685environment. 686.It Global variables 687Variables defined in the makefile or in included makefiles. 688.It Command line variables 689Variables defined as part of the command line. 690.It Local variables 691Variables that are defined specific to a certain target. 692.El 693.Pp 694Local variables are all built in and their values vary magically from 695target to target. 696It is not currently possible to define new local variables. 697The seven local variables are as follows: 698.Bl -tag -width ".ARCHIVE" -offset indent 699.It Va .ALLSRC 700The list of all sources for this target; also known as 701.Ql Va \&> . 702.It Va .ARCHIVE 703The name of the archive file; also known as 704.Ql Va \&! . 705.It Va .IMPSRC 706In suffix-transformation rules, the name/path of the source from which the 707target is to be transformed (the 708.Dq implied 709source); also known as 710.Ql Va \&< . 711It is not defined in explicit rules. 712.It Va .MEMBER 713The name of the archive member; also known as 714.Ql Va % . 715.It Va .OODATE 716The list of sources for this target that were deemed out-of-date; also 717known as 718.Ql Va \&? . 719.It Va .PREFIX 720The file prefix of the target, containing only the file portion, no suffix 721or preceding directory components; also known as 722.Ql Va * . 723The suffix must be one of the known suffixes declared with 724.Ic .SUFFIXES 725or it will not be recognized. 726.It Va .TARGET 727The name of the target; also known as 728.Ql Va @ . 729For compatibility with other makes this is an alias for 730.Ic .ARCHIVE 731in archive member rules. 732.El 733.Pp 734The shorter forms 735.Ql ( Va > , 736.Ql Va \&! , 737.Ql Va < , 738.Ql Va % , 739.Ql Va \&? , 740.Ql Va * , 741and 742.Ql Va @ ) 743are permitted for backward 744compatibility with historical makefiles and legacy POSIX make and are 745not recommended. 746.Pp 747Variants of these variables with the punctuation followed immediately by 748.Ql D 749or 750.Ql F , 751e.g. 752.Ql Va $(@D) , 753are legacy forms equivalent to using the 754.Ql :H 755and 756.Ql :T 757modifiers. 758These forms are accepted for compatibility with 759.At V 760makefiles and POSIX but are not recommended. 761.Pp 762Four of the local variables may be used in sources on dependency lines 763because they expand to the proper value for each target on the line. 764These variables are 765.Ql Va .TARGET , 766.Ql Va .PREFIX , 767.Ql Va .ARCHIVE , 768and 769.Ql Va .MEMBER . 770.Ss Additional built-in variables 771In addition, 772.Nm 773sets or knows about the following variables: 774.Bl -tag -width .MAKEOVERRIDES 775.It Va \&$ 776A single dollar sign 777.Ql \&$ , 778i.e. 779.Ql \&$$ 780expands to a single dollar 781sign. 782.It Va .ALLTARGETS 783The list of all targets encountered in the Makefile. 784If evaluated during 785Makefile parsing, lists only those targets encountered thus far. 786.It Va .CURDIR 787A path to the directory where 788.Nm 789was executed. 790Refer to the description of 791.Ql Ev PWD 792for more details. 793.It Va .INCLUDEDFROMDIR 794The directory of the file this Makefile was included from. 795.It Va .INCLUDEDFROMFILE 796The filename of the file this Makefile was included from. 797.It Ev MAKE 798The name that 799.Nm 800was executed with 801.Pq Va argv[0] . 802For compatibility 803.Nm 804also sets 805.Va .MAKE 806with the same value. 807The preferred variable to use is the environment variable 808.Ev MAKE 809because it is more compatible with other versions of 810.Nm 811and cannot be confused with the special target with the same name. 812.It Va .MAKE.DEPENDFILE 813Names the makefile (default 814.Ql Pa .depend ) 815from which generated dependencies are read. 816.It Va .MAKE.EXPAND_VARIABLES 817A boolean that controls the default behavior of the 818.Fl V 819option. 820If true, variable values printed with 821.Fl V 822are fully expanded; if false, the raw variable contents (which may 823include additional unexpanded variable references) are shown. 824.It Va .MAKE.EXPORTED 825The list of variables exported by 826.Nm . 827.It Va .MAKE.JOBS 828The argument to the 829.Fl j 830option. 831.It Va .MAKE.JOB.PREFIX 832If 833.Nm 834is run with 835.Ar j 836then output for each target is prefixed with a token 837.Ql --- target --- 838the first part of which can be controlled via 839.Va .MAKE.JOB.PREFIX . 840If 841.Va .MAKE.JOB.PREFIX 842is empty, no token is printed. 843.br 844For example: 845.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 846would produce tokens like 847.Ql ---make[1234] target --- 848making it easier to track the degree of parallelism being achieved. 849.It Ev MAKEFLAGS 850The environment variable 851.Ql Ev MAKEFLAGS 852may contain anything that 853may be specified on 854.Nm Ns 's 855command line. 856Anything specified on 857.Nm Ns 's 858command line is appended to the 859.Ql Ev MAKEFLAGS 860variable which is then 861entered into the environment for all programs which 862.Nm 863executes. 864.It Va .MAKE.LEVEL 865The recursion depth of 866.Nm . 867The initial instance of 868.Nm 869will be 0, and an incremented value is put into the environment 870to be seen by the next generation. 871This allows tests like: 872.Li .if ${.MAKE.LEVEL} == 0 873to protect things which should only be evaluated in the initial instance of 874.Nm . 875.It Va .MAKE.MAKEFILE_PREFERENCE 876The ordered list of makefile names 877(default 878.Ql Pa makefile , 879.Ql Pa Makefile ) 880that 881.Nm 882will look for. 883.It Va .MAKE.MAKEFILES 884The list of makefiles read by 885.Nm , 886which is useful for tracking dependencies. 887Each makefile is recorded only once, regardless of the number of times read. 888.It Va .MAKE.MODE 889Processed after reading all makefiles. 890Can affect the mode that 891.Nm 892runs in. 893It can contain a number of keywords: 894.Bl -hang -width missing-filemon=bf. 895.It Pa compat 896Like 897.Fl B , 898puts 899.Nm 900into "compat" mode. 901.It Pa meta 902Puts 903.Nm 904into "meta" mode, where meta files are created for each target 905to capture the command run, the output generated and if 906.Xr filemon 4 907is available, the system calls which are of interest to 908.Nm . 909The captured output can be very useful when diagnosing errors. 910.It Pa curdirOk= Ar bf 911Normally 912.Nm 913will not create .meta files in 914.Ql Va .CURDIR . 915This can be overridden by setting 916.Va bf 917to a value which represents True. 918.It Pa missing-meta= Ar bf 919If 920.Va bf 921is True, then a missing .meta file makes the target out-of-date. 922.It Pa missing-filemon= Ar bf 923If 924.Va bf 925is True, then missing filemon data makes the target out-of-date. 926.It Pa nofilemon 927Do not use 928.Xr filemon 4 . 929.It Pa env 930For debugging, it can be useful to include the environment 931in the .meta file. 932.It Pa verbose 933If in "meta" mode, print a clue about the target being built. 934This is useful if the build is otherwise running silently. 935The message printed the value of: 936.Va .MAKE.META.PREFIX . 937.It Pa ignore-cmd 938Some makefiles have commands which are simply not stable. 939This keyword causes them to be ignored for 940determining whether a target is out of date in "meta" mode. 941See also 942.Ic .NOMETA_CMP . 943.It Pa silent= Ar bf 944If 945.Va bf 946is True, when a .meta file is created, mark the target 947.Ic .SILENT . 948.El 949.It Va .MAKE.META.BAILIWICK 950In "meta" mode, provides a list of prefixes which 951match the directories controlled by 952.Nm . 953If a file that was generated outside of 954.Va .OBJDIR 955but within said bailiwick is missing, 956the current target is considered out-of-date. 957.It Va .MAKE.META.CREATED 958In "meta" mode, this variable contains a list of all the meta files 959updated. 960If not empty, it can be used to trigger processing of 961.Va .MAKE.META.FILES . 962.It Va .MAKE.META.FILES 963In "meta" mode, this variable contains a list of all the meta files 964used (updated or not). 965This list can be used to process the meta files to extract dependency 966information. 967.It Va .MAKE.META.IGNORE_PATHS 968Provides a list of path prefixes that should be ignored; 969because the contents are expected to change over time. 970The default list includes: 971.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 972.It Va .MAKE.META.IGNORE_PATTERNS 973Provides a list of patterns to match against pathnames. 974Ignore any that match. 975.It Va .MAKE.META.IGNORE_FILTER 976Provides a list of variable modifiers to apply to each pathname. 977Ignore if the expansion is an empty string. 978.It Va .MAKE.META.PREFIX 979Defines the message printed for each meta file updated in "meta verbose" mode. 980The default value is: 981.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 982.It Va .MAKEOVERRIDES 983This variable is used to record the names of variables assigned to 984on the command line, so that they may be exported as part of 985.Ql Ev MAKEFLAGS . 986This behavior can be disabled by assigning an empty value to 987.Ql Va .MAKEOVERRIDES 988within a makefile. 989Extra variables can be exported from a makefile 990by appending their names to 991.Ql Va .MAKEOVERRIDES . 992.Ql Ev MAKEFLAGS 993is re-exported whenever 994.Ql Va .MAKEOVERRIDES 995is modified. 996.It Va .MAKE.PATH_FILEMON 997If 998.Nm 999was built with 1000.Xr filemon 4 1001support, this is set to the path of the device node. 1002This allows makefiles to test for this support. 1003.It Va .MAKE.PID 1004The process-id of 1005.Nm . 1006.It Va .MAKE.PPID 1007The parent process-id of 1008.Nm . 1009.It Va .MAKE.BUILT.BY 1010The compiler CCVER that built the 1011.Dx 1012world. 1013.It Va .MAKE.DF.OSREL 1014The 1015.Dx 1016version when the world was built. It is in the "<major>.<minor>" 1017format and it used by DPorts. 1018.It Va .MAKE.DF.VERSION 1019The value of __DragonFly_version when the 1020.Dx 1021world was built. It is used by DPorts. 1022.It Va .MAKE.SAVE_DOLLARS 1023value should be a boolean that controls whether 1024.Ql $$ 1025are preserved when doing 1026.Ql := 1027assignments. 1028The default is false, for backwards compatibility. 1029Set to true for compatibility with other makes. 1030If set to false, 1031.Ql $$ 1032becomes 1033.Ql $ 1034per normal evaluation rules. 1035.It Va .MAKE.UID 1036The user-id running 1037.Nm . 1038.It Va .MAKE.GID 1039The group-id running 1040.Nm . 1041.It Va MAKE_PRINT_VAR_ON_ERROR 1042When 1043.Nm 1044stops due to an error, it sets 1045.Ql Va .ERROR_TARGET 1046to the name of the target that failed, 1047.Ql Va .ERROR_CMD 1048to the commands of the failed target, 1049and in "meta" mode, it also sets 1050.Ql Va .ERROR_CWD 1051to the 1052.Xr getcwd 3 , 1053and 1054.Ql Va .ERROR_META_FILE 1055to the path of the meta file (if any) describing the failed target. 1056It then prints its name and the value of 1057.Ql Va .CURDIR 1058as well as the value of any variables named in 1059.Ql Va MAKE_PRINT_VAR_ON_ERROR . 1060.It Va .newline 1061This variable is simply assigned a newline character as its value. 1062This allows expansions using the 1063.Cm \&:@ 1064modifier to put a newline between 1065iterations of the loop rather than a space. 1066For example, the printing of 1067.Ql Va MAKE_PRINT_VAR_ON_ERROR 1068could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 1069.It Va .OBJDIR 1070A path to the directory where the targets are built. 1071Its value is determined by trying to 1072.Xr chdir 2 1073to the following directories in order and using the first match: 1074.Bl -enum 1075.It 1076.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 1077.Pp 1078(Only if 1079.Ql Ev MAKEOBJDIRPREFIX 1080is set in the environment or on the command line.) 1081.It 1082.Ev ${MAKEOBJDIR} 1083.Pp 1084(Only if 1085.Ql Ev MAKEOBJDIR 1086is set in the environment or on the command line.) 1087.It 1088.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 1089.It 1090.Ev ${.CURDIR} Ns Pa /obj 1091.It 1092.Pa /usr/obj/ Ns Ev ${.CURDIR} 1093.It 1094.Ev ${.CURDIR} 1095.El 1096.Pp 1097Variable expansion is performed on the value before it's used, 1098so expressions such as 1099.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1100may be used. 1101This is especially useful with 1102.Ql Ev MAKEOBJDIR . 1103.Pp 1104.Ql Va .OBJDIR 1105may be modified in the makefile via the special target 1106.Ql Ic .OBJDIR . 1107In all cases, 1108.Nm 1109will 1110.Xr chdir 2 1111to the specified directory if it exists, and set 1112.Ql Va .OBJDIR 1113and 1114.Ql Ev PWD 1115to that directory before executing any targets. 1116.Pp 1117Except in the case of an explicit 1118.Ql Ic .OBJDIR 1119target, 1120.Nm 1121will check that the specified directory is writable and ignore it if not. 1122This check can be skipped by setting the environment variable 1123.Ql Ev MAKE_OBJDIR_CHECK_WRITABLE 1124to "no". 1125. 1126.It Va .PARSEDIR 1127A path to the directory of the current 1128.Ql Pa Makefile 1129being parsed. 1130.It Va .PARSEFILE 1131The basename of the current 1132.Ql Pa Makefile 1133being parsed. 1134This variable and 1135.Ql Va .PARSEDIR 1136are both set only while the 1137.Ql Pa Makefiles 1138are being parsed. 1139If you want to retain their current values, assign them to a variable 1140using assignment with expansion: 1141.Pq Ql Cm \&:= . 1142.It Va .PATH 1143A variable that represents the list of directories that 1144.Nm 1145will search for files. 1146The search list should be updated using the target 1147.Ql Va .PATH 1148rather than the variable. 1149.It Ev PWD 1150Alternate path to the current directory. 1151.Nm 1152normally sets 1153.Ql Va .CURDIR 1154to the canonical path given by 1155.Xr getcwd 3 . 1156However, if the environment variable 1157.Ql Ev PWD 1158is set and gives a path to the current directory, then 1159.Nm 1160sets 1161.Ql Va .CURDIR 1162to the value of 1163.Ql Ev PWD 1164instead. 1165This behavior is disabled if 1166.Ql Ev MAKEOBJDIRPREFIX 1167is set or 1168.Ql Ev MAKEOBJDIR 1169contains a variable transform. 1170.Ql Ev PWD 1171is set to the value of 1172.Ql Va .OBJDIR 1173for all programs which 1174.Nm 1175executes. 1176.It Ev .SHELL 1177The pathname of the shell used to run target scripts. 1178It is read-only. 1179.It Ev .TARGETS 1180The list of targets explicitly specified on the command line, if any. 1181.It Ev VPATH 1182Colon-separated 1183.Pq Dq \&: 1184lists of directories that 1185.Nm 1186will search for files. 1187The variable is supported for compatibility with old make programs only, 1188use 1189.Ql Va .PATH 1190instead. 1191.El 1192.Ss Variable modifiers 1193Variable expansion may be modified to select or modify each word of the 1194variable (where a 1195.Dq word 1196is white-space delimited sequence of characters). 1197The general format of a variable expansion is as follows: 1198.Pp 1199.Dl ${variable[:modifier[:...]]} 1200.Pp 1201Each modifier begins with a colon, 1202which may be escaped with a backslash 1203.Pq Ql \e . 1204.Pp 1205A set of modifiers can be specified via a variable, as follows: 1206.Pp 1207.Dl modifier_variable=modifier[:...] 1208.Dl ${variable:${modifier_variable}[:...]} 1209.Pp 1210In this case the first modifier in the modifier_variable does not 1211start with a colon, since that must appear in the referencing 1212variable. 1213If any of the modifiers in the modifier_variable contain a dollar sign 1214.Pq Ql $ , 1215these must be doubled to avoid early expansion. 1216.Pp 1217The supported modifiers are: 1218.Bl -tag -width EEE 1219.It Cm \&:E 1220Replaces each word in the variable with its suffix. 1221.It Cm \&:H 1222Replaces each word in the variable with everything but the last component. 1223.It Cm \&:M Ns Ar pattern 1224Selects only those words that match 1225.Ar pattern . 1226The standard shell wildcard characters 1227.Pf ( Ql * , 1228.Ql \&? , 1229and 1230.Ql Oo Oc ) 1231may 1232be used. 1233The wildcard characters may be escaped with a backslash 1234.Pq Ql \e . 1235As a consequence of the way values are split into words, matched, 1236and then joined, a construct like 1237.Dl ${VAR:M*} 1238will normalize the inter-word spacing, removing all leading and 1239trailing space, and converting multiple consecutive spaces 1240to single spaces. 1241. 1242.It Cm \&:N Ns Ar pattern 1243This is identical to 1244.Ql Cm \&:M , 1245but selects all words which do not match 1246.Ar pattern . 1247.It Cm \&:O 1248Orders every word in variable alphabetically. 1249.It Cm \&:Or 1250Orders every word in variable in reverse alphabetical order. 1251.It Cm \&:Ox 1252Shuffles the words in variable. 1253The results will be different each time you are referring to the 1254modified variable; use the assignment with expansion 1255.Pq Ql Cm \&:= 1256to prevent such behavior. 1257For example, 1258.Bd -literal -offset indent 1259LIST= uno due tre quattro 1260RANDOM_LIST= ${LIST:Ox} 1261STATIC_RANDOM_LIST:= ${LIST:Ox} 1262 1263all: 1264 @echo "${RANDOM_LIST}" 1265 @echo "${RANDOM_LIST}" 1266 @echo "${STATIC_RANDOM_LIST}" 1267 @echo "${STATIC_RANDOM_LIST}" 1268.Ed 1269may produce output similar to: 1270.Bd -literal -offset indent 1271quattro due tre uno 1272tre due quattro uno 1273due uno quattro tre 1274due uno quattro tre 1275.Ed 1276.It Cm \&:Q 1277Quotes every shell meta-character in the variable, so that it can be passed 1278safely to the shell. 1279.It Cm \&:q 1280Quotes every shell meta-character in the variable, and also doubles 1281.Sq $ 1282characters so that it can be passed 1283safely through recursive invocations of 1284.Nm . 1285This is equivalent to: 1286.Sq \&:S/\e\&$/&&/g:Q . 1287.It Cm \&:R 1288Replaces each word in the variable with everything but its suffix. 1289.It Cm \&:range[=count] 1290The value is an integer sequence representing the words of the original 1291value, or the supplied 1292.Va count . 1293.It Cm \&:gmtime[=utc] 1294The value is a format string for 1295.Xr strftime 3 , 1296using 1297.Xr gmtime 3 . 1298If a 1299.Va utc 1300value is not provided or is 0, the current time is used. 1301.It Cm \&:hash 1302Computes a 32-bit hash of the value and encode it as hex digits. 1303.It Cm \&:localtime[=utc] 1304The value is a format string for 1305.Xr strftime 3 , 1306using 1307.Xr localtime 3 . 1308If a 1309.Va utc 1310value is not provided or is 0, the current time is used. 1311.It Cm \&:tA 1312Attempts to convert variable to an absolute path using 1313.Xr realpath 3 , 1314if that fails, the value is unchanged. 1315.It Cm \&:tl 1316Converts variable to lower-case letters. 1317.It Cm \&:ts Ns Ar c 1318Words in the variable are normally separated by a space on expansion. 1319This modifier sets the separator to the character 1320.Ar c . 1321If 1322.Ar c 1323is omitted, then no separator is used. 1324The common escapes (including octal numeric codes) work as expected. 1325.It Cm \&:tu 1326Converts variable to upper-case letters. 1327.It Cm \&:tW 1328Causes the value to be treated as a single word 1329(possibly containing embedded white space). 1330See also 1331.Ql Cm \&:[*] . 1332.It Cm \&:tw 1333Causes the value to be treated as a sequence of 1334words delimited by white space. 1335See also 1336.Ql Cm \&:[@] . 1337.Sm off 1338.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1339.Sm on 1340Modifies the first occurrence of 1341.Ar old_string 1342in each word of the variable's value, replacing it with 1343.Ar new_string . 1344If a 1345.Ql g 1346is appended to the last delimiter of the pattern, all occurrences 1347in each word are replaced. 1348If a 1349.Ql 1 1350is appended to the last delimiter of the pattern, only the first occurrence 1351is affected. 1352If a 1353.Ql W 1354is appended to the last delimiter of the pattern, 1355then the value is treated as a single word 1356(possibly containing embedded white space). 1357If 1358.Ar old_string 1359begins with a caret 1360.Pq Ql ^ , 1361.Ar old_string 1362is anchored at the beginning of each word. 1363If 1364.Ar old_string 1365ends with a dollar sign 1366.Pq Ql \&$ , 1367it is anchored at the end of each word. 1368Inside 1369.Ar new_string , 1370an ampersand 1371.Pq Ql & 1372is replaced by 1373.Ar old_string 1374(without any 1375.Ql ^ 1376or 1377.Ql \&$ ) . 1378Any character may be used as a delimiter for the parts of the modifier 1379string. 1380The anchoring, ampersand and delimiter characters may be escaped with a 1381backslash 1382.Pq Ql \e . 1383.Pp 1384Variable expansion occurs in the normal fashion inside both 1385.Ar old_string 1386and 1387.Ar new_string 1388with the single exception that a backslash is used to prevent the expansion 1389of a dollar sign 1390.Pq Ql \&$ , 1391not a preceding dollar sign as is usual. 1392.Sm off 1393.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1394.Sm on 1395The 1396.Cm \&:C 1397modifier is just like the 1398.Cm \&:S 1399modifier except that the old and new strings, instead of being 1400simple strings, are an extended regular expression (see 1401.Xr regex 3 ) 1402string 1403.Ar pattern 1404and an 1405.Xr ed 1 Ns \-style 1406string 1407.Ar replacement . 1408Normally, the first occurrence of the pattern 1409.Ar pattern 1410in each word of the value is substituted with 1411.Ar replacement . 1412The 1413.Ql 1 1414modifier causes the substitution to apply to at most one word; the 1415.Ql g 1416modifier causes the substitution to apply to as many instances of the 1417search pattern 1418.Ar pattern 1419as occur in the word or words it is found in; the 1420.Ql W 1421modifier causes the value to be treated as a single word 1422(possibly containing embedded white space). 1423.Pp 1424As for the 1425.Cm \&:S 1426modifier, the 1427.Ar pattern 1428and 1429.Ar replacement 1430are subjected to variable expansion before being parsed as 1431regular expressions. 1432.It Cm \&:T 1433Replaces each word in the variable with its last path component. 1434.It Cm \&:u 1435Removes adjacent duplicate words (like 1436.Xr uniq 1 ) . 1437.Sm off 1438.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1439.Sm on 1440If the variable name (not its value), when parsed as a .if conditional 1441expression, evaluates to true, return as its value the 1442.Ar true_string , 1443otherwise return the 1444.Ar false_string . 1445Since the variable name is used as the expression, \&:\&? must be the 1446first modifier after the variable name itself - which will, of course, 1447usually contain variable expansions. 1448A common error is trying to use expressions like 1449.Dl ${NUMBERS:M42:?match:no} 1450which actually tests defined(NUMBERS), 1451to determine if any words match "42" you need to use something like: 1452.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1453.It Ar :old_string=new_string 1454This is the 1455.At V 1456style variable substitution. 1457It must be the last modifier specified. 1458If 1459.Ar old_string 1460or 1461.Ar new_string 1462do not contain the pattern matching character 1463.Ar % 1464then it is assumed that they are 1465anchored at the end of each word, so only suffixes or entire 1466words may be replaced. 1467Otherwise 1468.Ar % 1469is the substring of 1470.Ar old_string 1471to be replaced in 1472.Ar new_string . 1473If only 1474.Ar old_string 1475contains the pattern matching character 1476.Ar % , 1477and 1478.Ar old_string 1479matches, then the result is the 1480.Ar new_string . 1481If only the 1482.Ar new_string 1483contains the pattern matching character 1484.Ar % , 1485then it is not treated specially and it is printed as a literal 1486.Ar % 1487on match. 1488If there is more than one pattern matching character 1489.Ar ( % ) 1490in either the 1491.Ar new_string 1492or 1493.Ar old_string , 1494only the first instance is treated specially (as the pattern character); 1495all subsequent instances are treated as regular characters. 1496.Pp 1497Variable expansion occurs in the normal fashion inside both 1498.Ar old_string 1499and 1500.Ar new_string 1501with the single exception that a backslash is used to prevent the 1502expansion of a dollar sign 1503.Pq Ql \&$ , 1504not a preceding dollar sign as is usual. 1505.Sm off 1506.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1507.Sm on 1508This is the loop expansion mechanism from the OSF Development 1509Environment (ODE) make. 1510Unlike 1511.Cm \&.for 1512loops, expansion occurs at the time of reference. 1513Assigns 1514.Ar temp 1515to each word in the variable and evaluates 1516.Ar string . 1517The ODE convention is that 1518.Ar temp 1519should start and end with a period. 1520For example. 1521.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1522.Pp 1523However a single character variable is often more readable: 1524.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1525.It Cm \&:_[=var] 1526Saves the current variable value in 1527.Ql $_ 1528or the named 1529.Va var 1530for later reference. 1531Example usage: 1532.Bd -literal -offset indent 1533M_cmpv.units = 1 1000 1000000 1534M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\ 1535\\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh 1536 1537.Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}} 1538 1539.Ed 1540Here 1541.Ql $_ 1542is used to save the result of the 1543.Ql :S 1544modifier which is later referenced using the index values from 1545.Ql :range . 1546.It Cm \&:U Ns Ar newval 1547If the variable is undefined, 1548.Ar newval 1549is the value. 1550If the variable is defined, the existing value is returned. 1551This is another ODE make feature. 1552It is handy for setting per-target CFLAGS for instance: 1553.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1554If a value is only required if the variable is undefined, use: 1555.Dl ${VAR:D:Unewval} 1556.It Cm \&:D Ns Ar newval 1557If the variable is defined, 1558.Ar newval 1559is the value. 1560.It Cm \&:L 1561The name of the variable is the value. 1562.It Cm \&:P 1563The path of the node which has the same name as the variable 1564is the value. 1565If no such node exists or its path is null, then the 1566name of the variable is used. 1567In order for this modifier to work, the name (node) must at least have 1568appeared on the rhs of a dependency. 1569.Sm off 1570.It Cm \&:\&! Ar cmd Cm \&! 1571.Sm on 1572The output of running 1573.Ar cmd 1574is the value. 1575.It Cm \&:sh 1576If the variable is non-empty it is run as a command and the output 1577becomes the new value. 1578.It Cm \&::= Ns Ar str 1579The variable is assigned the value 1580.Ar str 1581after substitution. 1582This modifier and its variations are useful in 1583obscure situations such as wanting to set a variable when shell commands 1584are being parsed. 1585These assignment modifiers always expand to 1586nothing, so if appearing in a rule line by themselves should be 1587preceded with something to keep 1588.Nm 1589happy. 1590.Pp 1591The 1592.Ql Cm \&:: 1593helps avoid false matches with the 1594.At V 1595style 1596.Cm \&:= 1597modifier and since substitution always occurs the 1598.Cm \&::= 1599form is vaguely appropriate. 1600.It Cm \&::?= Ns Ar str 1601As for 1602.Cm \&::= 1603but only if the variable does not already have a value. 1604.It Cm \&::+= Ns Ar str 1605Append 1606.Ar str 1607to the variable. 1608.It Cm \&::!= Ns Ar cmd 1609Assign the output of 1610.Ar cmd 1611to the variable. 1612.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1613Selects one or more words from the value, 1614or performs other operations related to the way in which the 1615value is divided into words. 1616.Pp 1617Ordinarily, a value is treated as a sequence of words 1618delimited by white space. 1619Some modifiers suppress this behavior, 1620causing a value to be treated as a single word 1621(possibly containing embedded white space). 1622An empty value, or a value that consists entirely of white-space, 1623is treated as a single word. 1624For the purposes of the 1625.Ql Cm \&:[] 1626modifier, the words are indexed both forwards using positive integers 1627(where index 1 represents the first word), 1628and backwards using negative integers 1629(where index \-1 represents the last word). 1630.Pp 1631The 1632.Ar range 1633is subjected to variable expansion, and the expanded result is 1634then interpreted as follows: 1635.Bl -tag -width index 1636.\" :[n] 1637.It Ar index 1638Selects a single word from the value. 1639.\" :[start..end] 1640.It Ar start Ns Cm \&.. Ns Ar end 1641Selects all words from 1642.Ar start 1643to 1644.Ar end , 1645inclusive. 1646For example, 1647.Ql Cm \&:[2..-1] 1648selects all words from the second word to the last word. 1649If 1650.Ar start 1651is greater than 1652.Ar end , 1653then the words are output in reverse order. 1654For example, 1655.Ql Cm \&:[-1..1] 1656selects all the words from last to first. 1657If the list is already ordered, then this effectively reverses 1658the list, but it is more efficient to use 1659.Ql Cm \&:Or 1660instead of 1661.Ql Cm \&:O:[-1..1] . 1662.\" :[*] 1663.It Cm \&* 1664Causes subsequent modifiers to treat the value as a single word 1665(possibly containing embedded white space). 1666Analogous to the effect of 1667\&"$*\&" 1668in Bourne shell. 1669.\" :[0] 1670.It 0 1671Means the same as 1672.Ql Cm \&:[*] . 1673.\" :[*] 1674.It Cm \&@ 1675Causes subsequent modifiers to treat the value as a sequence of words 1676delimited by white space. 1677Analogous to the effect of 1678\&"$@\&" 1679in Bourne shell. 1680.\" :[#] 1681.It Cm \&# 1682Returns the number of words in the value. 1683.El \" :[range] 1684.El 1685.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1686Makefile inclusion, conditional structures and for loops reminiscent 1687of the C programming language are provided in 1688.Nm . 1689All such structures are identified by a line beginning with a single 1690dot 1691.Pq Ql \&. 1692character. 1693Files are included with either 1694.Cm \&.include \&< Ns Ar file Ns Cm \&> 1695or 1696.Cm \&.include \&\*q Ns Ar file Ns Cm \&\*q . 1697Variables between the angle brackets or double quotes are expanded 1698to form the file name. 1699If angle brackets are used, the included makefile is expected to be in 1700the system makefile directory. 1701If double quotes are used, the including makefile's directory and any 1702directories specified using the 1703.Fl I 1704option are searched before the system 1705makefile directory. 1706For compatibility with other versions of 1707.Nm 1708.Ql include file ... 1709is also accepted. 1710.Pp 1711If the include statement is written as 1712.Cm .-include 1713or as 1714.Cm .sinclude 1715then errors locating and/or opening include files are ignored. 1716.Pp 1717If the include statement is written as 1718.Cm .dinclude 1719not only are errors locating and/or opening include files ignored, 1720but stale dependencies within the included file will be ignored 1721just like 1722.Va .MAKE.DEPENDFILE . 1723.Pp 1724Conditional expressions are also preceded by a single dot as the first 1725character of a line. 1726The possible conditionals are as follows: 1727.Bl -tag -width Ds 1728.It Ic .error Ar message 1729The message is printed along with the name of the makefile and line number, 1730then 1731.Nm 1732will exit immediately. 1733.It Ic .export Ar variable ... 1734Export the specified global variable. 1735If no variable list is provided, all globals are exported 1736except for internal variables (those that start with 1737.Ql \&. ) . 1738This is not affected by the 1739.Fl X 1740flag, so should be used with caution. 1741For compatibility with other 1742.Nm 1743programs 1744.Ql export variable=value 1745is also accepted. 1746.Pp 1747Appending a variable name to 1748.Va .MAKE.EXPORTED 1749is equivalent to exporting a variable. 1750.It Ic .export-env Ar variable ... 1751The same as 1752.Ql .export , 1753except that the variable is not appended to 1754.Va .MAKE.EXPORTED . 1755This allows exporting a value to the environment which is different from that 1756used by 1757.Nm 1758internally. 1759.It Ic .export-literal Ar variable ... 1760The same as 1761.Ql .export-env , 1762except that variables in the value are not expanded. 1763.It Ic .info Ar message 1764The message is printed along with the name of the makefile and line number. 1765.It Ic .undef Ar variable ... 1766Un-define the specified global variables. 1767Only global variables can be un-defined. 1768.It Ic .unexport Ar variable ... 1769The opposite of 1770.Ql .export . 1771The specified global 1772.Va variable 1773will be removed from 1774.Va .MAKE.EXPORTED . 1775If no variable list is provided, all globals are unexported, 1776and 1777.Va .MAKE.EXPORTED 1778deleted. 1779.It Ic .unexport-env 1780Unexport all globals previously exported and 1781clear the environment inherited from the parent. 1782This operation will cause a memory leak of the original environment, 1783so should be used sparingly. 1784Testing for 1785.Va .MAKE.LEVEL 1786being 0, would make sense. 1787Also note that any variables which originated in the parent environment 1788should be explicitly preserved if desired. 1789For example: 1790.Bd -literal -offset indent 1791.Li .if ${.MAKE.LEVEL} == 0 1792PATH := ${PATH} 1793.Li .unexport-env 1794.Li .export PATH 1795.Li .endif 1796.Ed 1797.Pp 1798Would result in an environment containing only 1799.Ql Ev PATH , 1800which is the minimal useful environment. 1801Actually 1802.Ql Ev .MAKE.LEVEL 1803will also be pushed into the new environment. 1804.It Ic .warning Ar message 1805The message prefixed by 1806.Ql Pa warning: 1807is printed along with the name of the makefile and line number. 1808.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1809Test the value of an expression. 1810.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1811Test the value of a variable. 1812.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1813Test the value of a variable. 1814.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1815Test the target being built. 1816.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1817Test the target being built. 1818.It Ic .else 1819Reverse the sense of the last conditional. 1820.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1821A combination of 1822.Ql Ic .else 1823followed by 1824.Ql Ic .if . 1825.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1826A combination of 1827.Ql Ic .else 1828followed by 1829.Ql Ic .ifdef . 1830.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1831A combination of 1832.Ql Ic .else 1833followed by 1834.Ql Ic .ifndef . 1835.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1836A combination of 1837.Ql Ic .else 1838followed by 1839.Ql Ic .ifmake . 1840.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1841A combination of 1842.Ql Ic .else 1843followed by 1844.Ql Ic .ifnmake . 1845.It Ic .endif 1846End the body of the conditional. 1847.El 1848.Pp 1849The 1850.Ar operator 1851may be any one of the following: 1852.Bl -tag -width "Cm XX" 1853.It Cm \&|\&| 1854Logical OR. 1855.It Cm \&&& 1856Logical 1857.Tn AND ; 1858of higher precedence than 1859.Dq \&|\&| . 1860.El 1861.Pp 1862As in C, 1863.Nm 1864will only evaluate a conditional as far as is necessary to determine 1865its value. 1866Parentheses may be used to change the order of evaluation. 1867The boolean operator 1868.Ql Ic \&! 1869may be used to logically negate an entire 1870conditional. 1871It is of higher precedence than 1872.Ql Ic \&&& . 1873.Pp 1874The value of 1875.Ar expression 1876may be any of the following: 1877.Bl -tag -width defined 1878.It Ic defined 1879Takes a variable name as an argument and evaluates to true if the variable 1880has been defined. 1881.It Ic make 1882Takes a target name as an argument and evaluates to true if the target 1883was specified as part of 1884.Nm Ns 's 1885command line or was declared the default target (either implicitly or 1886explicitly, see 1887.Va .MAIN ) 1888before the line containing the conditional. 1889.It Ic empty 1890Takes a variable, with possible modifiers, and evaluates to true if 1891the expansion of the variable would result in an empty string. 1892.It Ic exists 1893Takes a file name as an argument and evaluates to true if the file exists. 1894The file is searched for on the system search path (see 1895.Va .PATH ) . 1896.It Ic target 1897Takes a target name as an argument and evaluates to true if the target 1898has been defined. 1899.It Ic commands 1900Takes a target name as an argument and evaluates to true if the target 1901has been defined and has commands associated with it. 1902.El 1903.Pp 1904.Ar Expression 1905may also be an arithmetic or string comparison. 1906Variable expansion is 1907performed on both sides of the comparison, after which the numerical 1908values are compared. 1909A value is interpreted as hexadecimal if it is 1910preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1911The standard C relational operators are all supported. 1912If after 1913variable expansion, either the left or right hand side of a 1914.Ql Ic == 1915or 1916.Ql Ic "!=" 1917operator is not a numerical value, then 1918string comparison is performed between the expanded 1919variables. 1920If no relational operator is given, it is assumed that the expanded 1921variable is being compared against 0, or an empty string in the case 1922of a string comparison. 1923.Pp 1924When 1925.Nm 1926is evaluating one of these conditional expressions, and it encounters 1927a (white-space separated) word it doesn't recognize, either the 1928.Dq make 1929or 1930.Dq defined 1931expression is applied to it, depending on the form of the conditional. 1932If the form is 1933.Ql Ic .ifdef , 1934.Ql Ic .ifndef , 1935or 1936.Ql Ic .if 1937the 1938.Dq defined 1939expression is applied. 1940Similarly, if the form is 1941.Ql Ic .ifmake 1942or 1943.Ql Ic .ifnmake , 1944the 1945.Dq make 1946expression is applied. 1947.Pp 1948If the conditional evaluates to true the parsing of the makefile continues 1949as before. 1950If it evaluates to false, the following lines are skipped. 1951In both cases this continues until a 1952.Ql Ic .else 1953or 1954.Ql Ic .endif 1955is found. 1956.Pp 1957For loops are typically used to apply a set of rules to a list of files. 1958The syntax of a for loop is: 1959.Pp 1960.Bl -tag -compact -width Ds 1961.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1962.It Aq make-lines 1963.It Ic \&.endfor 1964.El 1965.Pp 1966After the for 1967.Ic expression 1968is evaluated, it is split into words. 1969On each iteration of the loop, one word is taken and assigned to each 1970.Ic variable , 1971in order, and these 1972.Ic variables 1973are substituted into the 1974.Ic make-lines 1975inside the body of the for loop. 1976The number of words must come out even; that is, if there are three 1977iteration variables, the number of words provided must be a multiple 1978of three. 1979.Sh COMMENTS 1980Comments begin with a hash 1981.Pq Ql \&# 1982character, anywhere but in a shell 1983command line, and continue to the end of an unescaped new line. 1984.Sh SPECIAL SOURCES (ATTRIBUTES) 1985.Bl -tag -width .IGNOREx 1986.It Ic .EXEC 1987Target is never out of date, but always execute commands anyway. 1988.It Ic .IGNORE 1989Ignore any errors from the commands associated with this target, exactly 1990as if they all were preceded by a dash 1991.Pq Ql \- . 1992.\" .It Ic .INVISIBLE 1993.\" XXX 1994.\" .It Ic .JOIN 1995.\" XXX 1996.It Ic .MADE 1997Mark all sources of this target as being up-to-date. 1998.It Ic .MAKE 1999Execute the commands associated with this target even if the 2000.Fl n 2001or 2002.Fl t 2003options were specified. 2004Normally used to mark recursive 2005.Nm Ns s . 2006.It Ic .META 2007Create a meta file for the target, even if it is flagged as 2008.Ic .PHONY , 2009.Ic .MAKE , 2010or 2011.Ic .SPECIAL . 2012Usage in conjunction with 2013.Ic .MAKE 2014is the most likely case. 2015In "meta" mode, the target is out-of-date if the meta file is missing. 2016.It Ic .NOMETA 2017Do not create a meta file for the target. 2018Meta files are also not created for 2019.Ic .PHONY , 2020.Ic .MAKE , 2021or 2022.Ic .SPECIAL 2023targets. 2024.It Ic .NOMETA_CMP 2025Ignore differences in commands when deciding if target is out of date. 2026This is useful if the command contains a value which always changes. 2027If the number of commands change, though, the target will still be out of date. 2028The same effect applies to any command line that uses the variable 2029.Va .OODATE , 2030which can be used for that purpose even when not otherwise needed or desired: 2031.Bd -literal -offset indent 2032 2033skip-compare-for-some: 2034 @echo this will be compared 2035 @echo this will not ${.OODATE:M.NOMETA_CMP} 2036 @echo this will also be compared 2037 2038.Ed 2039The 2040.Cm \&:M 2041pattern suppresses any expansion of the unwanted variable. 2042.It Ic .NOPATH 2043Do not search for the target in the directories specified by 2044.Ic .PATH . 2045.It Ic .NOTMAIN 2046Normally 2047.Nm 2048selects the first target it encounters as the default target to be built 2049if no target was specified. 2050This source prevents this target from being selected. 2051.It Ic .OPTIONAL 2052If a target is marked with this attribute and 2053.Nm 2054can't figure out how to create it, it will ignore this fact and assume 2055the file isn't needed or already exists. 2056.It Ic .PHONY 2057The target does not 2058correspond to an actual file; it is always considered to be out of date, 2059and will not be created with the 2060.Fl t 2061option. 2062Suffix-transformation rules are not applied to 2063.Ic .PHONY 2064targets. 2065.It Ic .PRECIOUS 2066When 2067.Nm 2068is interrupted, it normally removes any partially made targets. 2069This source prevents the target from being removed. 2070.It Ic .RECURSIVE 2071Synonym for 2072.Ic .MAKE . 2073.It Ic .SILENT 2074Do not echo any of the commands associated with this target, exactly 2075as if they all were preceded by an at sign 2076.Pq Ql @ . 2077.It Ic .USE 2078Turn the target into 2079.Nm Ns 's 2080version of a macro. 2081When the target is used as a source for another target, the other target 2082acquires the commands, sources, and attributes (except for 2083.Ic .USE ) 2084of the 2085source. 2086If the target already has commands, the 2087.Ic .USE 2088target's commands are appended 2089to them. 2090.It Ic .USEBEFORE 2091Exactly like 2092.Ic .USE , 2093but prepend the 2094.Ic .USEBEFORE 2095target commands to the target. 2096.It Ic .WAIT 2097If 2098.Ic .WAIT 2099appears in a dependency line, the sources that precede it are 2100made before the sources that succeed it in the line. 2101Since the dependents of files are not made until the file itself 2102could be made, this also stops the dependents being built unless they 2103are needed for another branch of the dependency tree. 2104So given: 2105.Bd -literal 2106x: a .WAIT b 2107 echo x 2108a: 2109 echo a 2110b: b1 2111 echo b 2112b1: 2113 echo b1 2114 2115.Ed 2116the output is always 2117.Ql a , 2118.Ql b1 , 2119.Ql b , 2120.Ql x . 2121.br 2122The ordering imposed by 2123.Ic .WAIT 2124is only relevant for parallel makes. 2125.El 2126.Sh SPECIAL TARGETS 2127Special targets may not be included with other targets, i.e. they must be 2128the only target specified. 2129.Bl -tag -width .BEGINx 2130.It Ic .BEGIN 2131Any command lines attached to this target are executed before anything 2132else is done. 2133.It Ic .DEFAULT 2134This is sort of a 2135.Ic .USE 2136rule for any target (that was used only as a 2137source) that 2138.Nm 2139can't figure out any other way to create. 2140Only the shell script is used. 2141The 2142.Ic .IMPSRC 2143variable of a target that inherits 2144.Ic .DEFAULT Ns 's 2145commands is set 2146to the target's own name. 2147.It Ic .DELETE_ON_ERROR 2148If this target is present in the makefile, it globally causes make to 2149delete targets whose commands fail. 2150(By default, only targets whose commands are interrupted during 2151execution are deleted. 2152This is the historical behavior.) 2153This setting can be used to help prevent half-finished or malformed 2154targets from being left around and corrupting future rebuilds. 2155.It Ic .END 2156Any command lines attached to this target are executed after everything 2157else is done. 2158.It Ic .ERROR 2159Any command lines attached to this target are executed when another target fails. 2160The 2161.Ic .ERROR_TARGET 2162variable is set to the target that failed. 2163See also 2164.Ic MAKE_PRINT_VAR_ON_ERROR . 2165.It Ic .IGNORE 2166Mark each of the sources with the 2167.Ic .IGNORE 2168attribute. 2169If no sources are specified, this is the equivalent of specifying the 2170.Fl i 2171option. 2172.It Ic .INTERRUPT 2173If 2174.Nm 2175is interrupted, the commands for this target will be executed. 2176.It Ic .MAIN 2177If no target is specified when 2178.Nm 2179is invoked, this target will be built. 2180.It Ic .MAKEFLAGS 2181This target provides a way to specify flags for 2182.Nm 2183when the makefile is used. 2184The flags are as if typed to the shell, though the 2185.Fl f 2186option will have 2187no effect. 2188.\" XXX: NOT YET!!!! 2189.\" .It Ic .NOTPARALLEL 2190.\" The named targets are executed in non parallel mode. 2191.\" If no targets are 2192.\" specified, then all targets are executed in non parallel mode. 2193.It Ic .NOPATH 2194Apply the 2195.Ic .NOPATH 2196attribute to any specified sources. 2197.It Ic .NOTPARALLEL 2198Disable parallel mode. 2199.It Ic .NO_PARALLEL 2200Synonym for 2201.Ic .NOTPARALLEL , 2202for compatibility with other pmake variants. 2203.It Ic .OBJDIR 2204The source is a new value for 2205.Ql Va .OBJDIR . 2206If it exists, 2207.Nm 2208will 2209.Xr chdir 2 2210to it and update the value of 2211.Ql Va .OBJDIR . 2212.It Ic .ORDER 2213The named targets are made in sequence. 2214This ordering does not add targets to the list of targets to be made. 2215Since the dependents of a target do not get built until the target itself 2216could be built, unless 2217.Ql a 2218is built by another part of the dependency graph, 2219the following is a dependency loop: 2220.Bd -literal 2221\&.ORDER: b a 2222b: a 2223.Ed 2224.Pp 2225The ordering imposed by 2226.Ic .ORDER 2227is only relevant for parallel makes. 2228.\" XXX: NOT YET!!!! 2229.\" .It Ic .PARALLEL 2230.\" The named targets are executed in parallel mode. 2231.\" If no targets are 2232.\" specified, then all targets are executed in parallel mode. 2233.It Ic .PATH 2234The sources are directories which are to be searched for files not 2235found in the current directory. 2236If no sources are specified, any previously specified directories are 2237deleted. 2238If the source is the special 2239.Ic .DOTLAST 2240target, then the current working 2241directory is searched last. 2242.It Ic .PATH. Ns Va suffix 2243Like 2244.Ic .PATH 2245but applies only to files with a particular suffix. 2246The suffix must have been previously declared with 2247.Ic .SUFFIXES . 2248.It Ic .PHONY 2249Apply the 2250.Ic .PHONY 2251attribute to any specified sources. 2252.It Ic .PRECIOUS 2253Apply the 2254.Ic .PRECIOUS 2255attribute to any specified sources. 2256If no sources are specified, the 2257.Ic .PRECIOUS 2258attribute is applied to every 2259target in the file. 2260.It Ic .SHELL 2261Sets the shell that 2262.Nm 2263will use to execute commands. 2264The sources are a set of 2265.Ar field=value 2266pairs. 2267.Bl -tag -width hasErrCtls 2268.It Ar name 2269This is the minimal specification, used to select one of the built-in 2270shell specs; 2271.Ar sh , 2272.Ar ksh , 2273and 2274.Ar csh . 2275.It Ar path 2276Specifies the path to the shell. 2277.It Ar hasErrCtl 2278Indicates whether the shell supports exit on error. 2279.It Ar check 2280The command to turn on error checking. 2281.It Ar ignore 2282The command to disable error checking. 2283.It Ar echo 2284The command to turn on echoing of commands executed. 2285.It Ar quiet 2286The command to turn off echoing of commands executed. 2287.It Ar filter 2288The output to filter after issuing the 2289.Ar quiet 2290command. 2291It is typically identical to 2292.Ar quiet . 2293.It Ar errFlag 2294The flag to pass the shell to enable error checking. 2295.It Ar echoFlag 2296The flag to pass the shell to enable command echoing. 2297.It Ar newline 2298The string literal to pass the shell that results in a single newline 2299character when used outside of any quoting characters. 2300.El 2301Example: 2302.Bd -literal 2303\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2304 check="set \-e" ignore="set +e" \e 2305 echo="set \-v" quiet="set +v" filter="set +v" \e 2306 echoFlag=v errFlag=e newline="'\en'" 2307.Ed 2308.It Ic .SILENT 2309Apply the 2310.Ic .SILENT 2311attribute to any specified sources. 2312If no sources are specified, the 2313.Ic .SILENT 2314attribute is applied to every 2315command in the file. 2316.It Ic .STALE 2317This target gets run when a dependency file contains stale entries, having 2318.Va .ALLSRC 2319set to the name of that dependency file. 2320.It Ic .SUFFIXES 2321Each source specifies a suffix to 2322.Nm . 2323If no sources are specified, any previously specified suffixes are deleted. 2324It allows the creation of suffix-transformation rules. 2325.Pp 2326Example: 2327.Bd -literal 2328\&.SUFFIXES: .o 2329\&.c.o: 2330 cc \-o ${.TARGET} \-c ${.IMPSRC} 2331.Ed 2332.El 2333.Sh ENVIRONMENT 2334.Nm 2335uses the following environment variables, if they exist: 2336.Ev MACHINE , 2337.Ev MACHINE_ARCH , 2338.Ev MAKE , 2339.Ev MAKEFLAGS , 2340.Ev MAKEOBJDIR , 2341.Ev MAKEOBJDIRPREFIX , 2342.Ev MAKESYSPATH , 2343.Ev PWD , 2344and 2345.Ev TMPDIR . 2346.Pp 2347.Ev MAKEOBJDIRPREFIX 2348and 2349.Ev MAKEOBJDIR 2350may only be set in the environment or on the command line to 2351.Nm 2352and not as makefile variables; 2353see the description of 2354.Ql Va .OBJDIR 2355for more details. 2356.Sh FILES 2357.Bl -tag -width /usr/share/mk -compact 2358.It .depend 2359list of dependencies 2360.It Makefile 2361list of dependencies 2362.It makefile 2363list of dependencies 2364.It sys.mk 2365system makefile 2366.It /usr/share/mk 2367system makefile directory 2368.El 2369.Sh COMPATIBILITY 2370The basic make syntax is compatible between different versions of make; 2371however the special variables, variable modifiers and conditionals are not. 2372.Ss Older versions 2373An incomplete list of changes in older versions of 2374.Nm : 2375.Pp 2376The way that .for loop variables are substituted changed after 2377.Nx 5.0 2378so that they still appear to be variable expansions. 2379In particular this stops them being treated as syntax, and removes some 2380obscure problems using them in .if statements. 2381.Pp 2382The way that parallel makes are scheduled changed in 2383.Nx 4.0 2384so that .ORDER and .WAIT apply recursively to the dependent nodes. 2385The algorithms used may change again in the future. 2386.Ss Other make dialects 2387Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2388support most of the features of 2389.Nm 2390as described in this manual. 2391Most notably: 2392.Bl -bullet -offset indent 2393.It 2394The 2395.Ic .WAIT 2396and 2397.Ic .ORDER 2398declarations and most functionality pertaining to parallelization. 2399(GNU make supports parallelization but lacks these features needed to 2400control it effectively.) 2401.It 2402Directives, including for loops and conditionals and most of the 2403forms of include files. 2404(GNU make has its own incompatible and less powerful syntax for 2405conditionals.) 2406.It 2407All built-in variables that begin with a dot. 2408.It 2409Most of the special sources and targets that begin with a dot, 2410with the notable exception of 2411.Ic .PHONY , 2412.Ic .PRECIOUS , 2413and 2414.Ic .SUFFIXES . 2415.It 2416Variable modifiers, except for the 2417.Dl :old=new 2418string substitution, which does not portably support globbing with 2419.Ql % 2420and historically only works on declared suffixes. 2421.It 2422The 2423.Ic $> 2424variable even in its short form; most makes support this functionality 2425but its name varies. 2426.El 2427.Pp 2428Some features are somewhat more portable, such as assignment with 2429.Ic += , 2430.Ic ?= , 2431and 2432.Ic != . 2433The 2434.Ic .PATH 2435functionality is based on an older feature 2436.Ic VPATH 2437found in GNU make and many versions of SVR4 make; however, 2438historically its behavior is too ill-defined (and too buggy) to rely 2439upon. 2440.Pp 2441The 2442.Ic $@ 2443and 2444.Ic $< 2445variables are more or less universally portable, as is the 2446.Ic $(MAKE) 2447variable. 2448Basic use of suffix rules (for files only in the current directory, 2449not trying to chain transformations together, etc.) is also reasonably 2450portable. 2451.Sh SEE ALSO 2452.Xr mkdep 1 2453.Sh HISTORY 2454A 2455.Nm 2456command appeared in 2457.At v7 . 2458This 2459.Nm 2460implementation is based on Adam De Boor's pmake program which was written 2461for Sprite at Berkeley. 2462It was designed to be a parallel distributed make running jobs on different 2463machines using a daemon called 2464.Dq customs . 2465.Pp 2466Historically the target/dependency 2467.Dq FRC 2468has been used to FoRCe rebuilding (since the target/dependency 2469does not exist... unless someone creates an 2470.Dq FRC 2471file). 2472.Sh BUGS 2473The 2474.Nm 2475syntax is difficult to parse without actually acting on the data. 2476For instance, finding the end of a variable's use should involve scanning 2477each of the modifiers, using the correct terminator for each field. 2478In many places 2479.Nm 2480just counts {} and () in order to find the end of a variable expansion. 2481.Pp 2482There is no way of escaping a space character in a filename. 2483