1.\" $NetBSD: make.1,v 1.282 2020/06/06 20:28:42 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)make.1 8.4 (Berkeley) 3/19/94 31.\" 32.Dd June 5, 2020 33.Dt BMAKE 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 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 context. 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 j 170Print debugging information about running multiple shells. 171.It Ar l 172Print commands in Makefiles regardless of whether or not they are prefixed by 173.Ql @ 174or other "quiet" flags. 175Also known as "loud" behavior. 176.It Ar M 177Print debugging information about "meta" mode decisions about targets. 178.It Ar m 179Print debugging information about making targets, including modification 180dates. 181.It Ar n 182Don't delete the temporary command scripts created when running commands. 183These temporary scripts are created in the directory 184referred to by the 185.Ev TMPDIR 186environment variable, or in 187.Pa /tmp 188if 189.Ev TMPDIR 190is unset or set to the empty string. 191The temporary scripts are created by 192.Xr mkstemp 3 , 193and have names of the form 194.Pa makeXXXXXX . 195.Em NOTE : 196This can create many files in 197.Ev TMPDIR 198or 199.Pa /tmp , 200so use with care. 201.It Ar p 202Print debugging information about makefile parsing. 203.It Ar s 204Print debugging information about suffix-transformation rules. 205.It Ar t 206Print debugging information about target list maintenance. 207.It Ar V 208Force the 209.Fl V 210option to print raw values of variables, overriding the default behavior 211set via 212.Va .MAKE.EXPAND_VARIABLES . 213.It Ar v 214Print debugging information about variable assignment. 215.It Ar x 216Run shell commands with 217.Fl x 218so the actual commands are printed as they are executed. 219.El 220.It Fl e 221Specify that environment variables override macro assignments within 222makefiles. 223.It Fl f Ar makefile 224Specify a makefile to read instead of the default 225.Ql Pa makefile . 226If 227.Ar makefile 228is 229.Ql Fl , 230standard input is read. 231Multiple makefiles may be specified, and are read in the order specified. 232.It Fl I Ar directory 233Specify a directory in which to search for makefiles and included makefiles. 234The system makefile directory (or directories, see the 235.Fl m 236option) is automatically included as part of this list. 237.It Fl i 238Ignore non-zero exit of shell commands in the makefile. 239Equivalent to specifying 240.Ql Fl 241before each command line in the makefile. 242.It Fl J Ar private 243This option should 244.Em not 245be specified by the user. 246.Pp 247When the 248.Ar j 249option is in use in a recursive build, this option is passed by a make 250to child makes to allow all the make processes in the build to 251cooperate to avoid overloading the system. 252.It Fl j Ar max_jobs 253Specify the maximum number of jobs that 254.Nm 255may have running at any one time. 256The value is saved in 257.Va .MAKE.JOBS . 258Turns compatibility mode off, unless the 259.Ar B 260flag is also specified. 261When compatibility mode is off, all commands associated with a 262target are executed in a single shell invocation as opposed to the 263traditional one shell invocation per line. 264This can break traditional scripts which change directories on each 265command invocation and then expect to start with a fresh environment 266on the next line. 267It is more efficient to correct the scripts rather than turn backwards 268compatibility on. 269.It Fl k 270Continue processing after errors are encountered, but only on those targets 271that do not depend on the target whose creation caused the error. 272.It Fl m Ar directory 273Specify a directory in which to search for sys.mk and makefiles included 274via the 275.Li \&< Ns Ar file Ns Li \&> Ns -style 276include statement. 277The 278.Fl m 279option can be used multiple times to form a search path. 280This path will override the default system include path: /usr/share/mk. 281Furthermore the system include path will be appended to the search path used 282for 283.Li \*q Ns Ar file Ns Li \*q Ns -style 284include statements (see the 285.Fl I 286option). 287.Pp 288If a file or directory name in the 289.Fl m 290argument (or the 291.Ev MAKESYSPATH 292environment variable) starts with the string 293.Qq \&.../ 294then 295.Nm 296will search for the specified file or directory named in the remaining part 297of the argument string. 298The search starts with the current directory of 299the Makefile and then works upward towards the root of the file system. 300If the search is successful, then the resulting directory replaces the 301.Qq \&.../ 302specification in the 303.Fl m 304argument. 305If used, this feature allows 306.Nm 307to easily search in the current source tree for customized sys.mk files 308(e.g., by using 309.Qq \&.../mk/sys.mk 310as an argument). 311.It Fl n 312Display the commands that would have been executed, but do not 313actually execute them unless the target depends on the .MAKE special 314source (see below). 315.It Fl N 316Display the commands which would have been executed, but do not 317actually execute any of them; useful for debugging top-level makefiles 318without descending into subdirectories. 319.It Fl q 320Do not execute any commands, but exit 0 if the specified targets are 321up-to-date and 1, otherwise. 322.It Fl r 323Do not use the built-in rules specified in the system makefile. 324.It Fl s 325Do not echo any commands as they are executed. 326Equivalent to specifying 327.Ql Ic @ 328before each command line in the makefile. 329.It Fl T Ar tracefile 330When used with the 331.Fl j 332flag, 333append a trace record to 334.Ar tracefile 335for each job started and completed. 336.It Fl t 337Rather than re-building a target as specified in the makefile, create it 338or update its modification time to make it appear up-to-date. 339.It Fl V Ar variable 340Print the value of 341.Ar variable . 342Do not build any targets. 343Multiple instances of this option may be specified; 344the variables will be printed one per line, 345with a blank line for each null or undefined variable. 346The value printed is extracted from the global context after all 347makefiles have been read. 348By default, the raw variable contents (which may 349include additional unexpanded variable references) are shown. 350If 351.Ar variable 352contains a 353.Ql \&$ 354then the value will be recursively expanded to its complete resultant 355text before printing. 356The expanded value will also be printed if 357.Va .MAKE.EXPAND_VARIABLES 358is set to true and 359the 360.Fl dV 361option has not been used to override it. 362Note that loop-local and target-local variables, as well as values 363taken temporarily by global variables during makefile processing, are 364not accessible via this option. 365The 366.Fl dv 367debug mode can be used to see these at the cost of generating 368substantial extraneous output. 369.It Fl v Ar variable 370Like 371.Fl V 372but the variable is always expanded to its complete value. 373.It Fl W 374Treat any warnings during makefile parsing as errors. 375.It Fl w 376Print entering and leaving directory messages, pre and post processing. 377.It Fl X 378Don't export variables passed on the command line to the environment 379individually. 380Variables passed on the command line are still exported 381via the 382.Va MAKEFLAGS 383environment variable. 384This option may be useful on systems which have a small limit on the 385size of command arguments. 386.It Ar variable=value 387Set the value of the variable 388.Ar variable 389to 390.Ar value . 391Normally, all values passed on the command line are also exported to 392sub-makes in the environment. 393The 394.Fl X 395flag disables this behavior. 396Variable assignments should follow options for POSIX compatibility 397but no ordering is enforced. 398.El 399.Pp 400There are seven different types of lines in a makefile: file dependency 401specifications, shell commands, variable assignments, include statements, 402conditional directives, for loops, and comments. 403.Pp 404In general, lines may be continued from one line to the next by ending 405them with a backslash 406.Pq Ql \e . 407The trailing newline character and initial whitespace on the following 408line are compressed into a single space. 409.Sh FILE DEPENDENCY SPECIFICATIONS 410Dependency lines consist of one or more targets, an operator, and zero 411or more sources. 412This creates a relationship where the targets 413.Dq depend 414on the sources 415and are usually created from them. 416The exact relationship between the target and the source is determined 417by the operator that separates them. 418The three operators are as follows: 419.Bl -tag -width flag 420.It Ic \&: 421A target is considered out-of-date if its modification time is less than 422those of any of its sources. 423Sources for a target accumulate over dependency lines when this operator 424is used. 425The target is removed if 426.Nm 427is interrupted. 428.It Ic \&! 429Targets are always re-created, but not until all sources have been 430examined and re-created as necessary. 431Sources for a target accumulate over dependency lines when this operator 432is used. 433The target is removed if 434.Nm 435is interrupted. 436.It Ic \&:: 437If no sources are specified, the target is always re-created. 438Otherwise, a target is considered out-of-date if any of its sources has 439been modified more recently than the target. 440Sources for a target do not accumulate over dependency lines when this 441operator is used. 442The target will not be removed if 443.Nm 444is interrupted. 445.El 446.Pp 447Targets and sources may contain the shell wildcard values 448.Ql \&? , 449.Ql * , 450.Ql [] , 451and 452.Ql {} . 453The values 454.Ql \&? , 455.Ql * , 456and 457.Ql [] 458may only be used as part of the final 459component of the target or source, and must be used to describe existing 460files. 461The value 462.Ql {} 463need not necessarily be used to describe existing files. 464Expansion is in directory order, not alphabetically as done in the shell. 465.Sh SHELL COMMANDS 466Each target may have associated with it one or more lines of shell 467commands, normally 468used to create the target. 469Each of the lines in this script 470.Em must 471be preceded by a tab. 472(For historical reasons, spaces are not accepted.) 473While targets can appear in many dependency lines if desired, by 474default only one of these rules may be followed by a creation 475script. 476If the 477.Ql Ic \&:: 478operator is used, however, all rules may include scripts and the 479scripts are executed in the order found. 480.Pp 481Each line is treated as a separate shell command, unless the end of 482line is escaped with a backslash 483.Pq Ql \e 484in which case that line and the next are combined. 485.\" The escaped newline is retained and passed to the shell, which 486.\" normally ignores it. 487.\" However, the tab at the beginning of the following line is removed. 488If the first characters of the command are any combination of 489.Ql Ic @ , 490.Ql Ic + , 491or 492.Ql Ic \- , 493the command is treated specially. 494A 495.Ql Ic @ 496causes the command not to be echoed before it is executed. 497A 498.Ql Ic + 499causes the command to be executed even when 500.Fl n 501is given. 502This is similar to the effect of the .MAKE special source, 503except that the effect can be limited to a single line of a script. 504A 505.Ql Ic \- 506in compatibility mode 507causes any non-zero exit status of the command line to be ignored. 508.Pp 509When 510.Nm 511is run in jobs mode with 512.Fl j Ar max_jobs , 513the entire script for the target is fed to a 514single instance of the shell. 515In compatibility (non-jobs) mode, each command is run in a separate process. 516If the command contains any shell meta characters 517.Pq Ql #=|^(){};&<>*?[]:$`\e\en 518it will be passed to the shell; otherwise 519.Nm 520will attempt direct execution. 521If a line starts with 522.Ql Ic \- 523and the shell has ErrCtl enabled then failure of the command line 524will be ignored as in compatibility mode. 525Otherwise 526.Ql Ic \- 527affects the entire job; 528the script will stop at the first command line that fails, 529but the target will not be deemed to have failed. 530.Pp 531Makefiles should be written so that the mode of 532.Nm 533operation does not change their behavior. 534For example, any command which needs to use 535.Dq cd 536or 537.Dq chdir 538without potentially changing the directory for subsequent commands 539should be put in parentheses so it executes in a subshell. 540To force the use of one shell, escape the line breaks so as to make 541the whole script one command. 542For example: 543.Bd -literal -offset indent 544avoid-chdir-side-effects: 545 @echo Building $@ in `pwd` 546 @(cd ${.CURDIR} && ${MAKE} $@) 547 @echo Back in `pwd` 548 549ensure-one-shell-regardless-of-mode: 550 @echo Building $@ in `pwd`; \e 551 (cd ${.CURDIR} && ${MAKE} $@); \e 552 echo Back in `pwd` 553.Ed 554.Pp 555Since 556.Nm 557will 558.Xr chdir 2 559to 560.Ql Va .OBJDIR 561before executing any targets, each child process 562starts with that as its current working directory. 563.Sh VARIABLE ASSIGNMENTS 564Variables in make are much like variables in the shell, and, by tradition, 565consist of all upper-case letters. 566.Ss Variable assignment modifiers 567The five operators that can be used to assign values to variables are as 568follows: 569.Bl -tag -width Ds 570.It Ic \&= 571Assign the value to the variable. 572Any previous value is overridden. 573.It Ic \&+= 574Append the value to the current value of the variable. 575.It Ic \&?= 576Assign the value to the variable if it is not already defined. 577.It Ic \&:= 578Assign with expansion, i.e. expand the value before assigning it 579to the variable. 580Normally, expansion is not done until the variable is referenced. 581.Em NOTE : 582References to undefined variables are 583.Em not 584expanded. 585This can cause problems when variable modifiers are used. 586.It Ic \&!= 587Expand the value and pass it to the shell for execution and assign 588the result to the variable. 589Any newlines in the result are replaced with spaces. 590.El 591.Pp 592Any white-space before the assigned 593.Ar value 594is removed; if the value is being appended, a single space is inserted 595between the previous contents of the variable and the appended value. 596.Pp 597Variables are expanded by surrounding the variable name with either 598curly braces 599.Pq Ql {} 600or parentheses 601.Pq Ql () 602and preceding it with 603a dollar sign 604.Pq Ql \&$ . 605If the variable name contains only a single letter, the surrounding 606braces or parentheses are not required. 607This shorter form is not recommended. 608.Pp 609If the variable name contains a dollar, then the name itself is expanded first. 610This allows almost arbitrary variable names, however names containing dollar, 611braces, parenthesis, or whitespace are really best avoided! 612.Pp 613If the result of expanding a variable contains a dollar sign 614.Pq Ql \&$ 615the string is expanded again. 616.Pp 617Variable substitution occurs at three distinct times, depending on where 618the variable is being used. 619.Bl -enum 620.It 621Variables in dependency lines are expanded as the line is read. 622.It 623Variables in shell commands are expanded when the shell command is 624executed. 625.It 626.Dq .for 627loop index variables are expanded on each loop iteration. 628Note that other variables are not expanded inside loops so 629the following example code: 630.Bd -literal -offset indent 631 632.Dv .for i in 1 2 3 633a+= ${i} 634j= ${i} 635b+= ${j} 636.Dv .endfor 637 638all: 639 @echo ${a} 640 @echo ${b} 641 642.Ed 643will print: 644.Bd -literal -offset indent 6451 2 3 6463 3 3 647 648.Ed 649Because while ${a} contains 650.Dq 1 2 3 651after the loop is executed, ${b} 652contains 653.Dq ${j} ${j} ${j} 654which expands to 655.Dq 3 3 3 656since after the loop completes ${j} contains 657.Dq 3 . 658.El 659.Ss Variable classes 660The four different classes of variables (in order of increasing precedence) 661are: 662.Bl -tag -width Ds 663.It Environment variables 664Variables defined as part of 665.Nm Ns 's 666environment. 667.It Global variables 668Variables defined in the makefile or in included makefiles. 669.It Command line variables 670Variables defined as part of the command line. 671.It Local variables 672Variables that are defined specific to a certain target. 673.El 674.Pp 675Local variables are all built in and their values vary magically from 676target to target. 677It is not currently possible to define new local variables. 678The seven local variables are as follows: 679.Bl -tag -width ".ARCHIVE" -offset indent 680.It Va .ALLSRC 681The list of all sources for this target; also known as 682.Ql Va \&> . 683.It Va .ARCHIVE 684The name of the archive file; also known as 685.Ql Va \&! . 686.It Va .IMPSRC 687In suffix-transformation rules, the name/path of the source from which the 688target is to be transformed (the 689.Dq implied 690source); also known as 691.Ql Va \&< . 692It is not defined in explicit rules. 693.It Va .MEMBER 694The name of the archive member; also known as 695.Ql Va % . 696.It Va .OODATE 697The list of sources for this target that were deemed out-of-date; also 698known as 699.Ql Va \&? . 700.It Va .PREFIX 701The file prefix of the target, containing only the file portion, no suffix 702or preceding directory components; also known as 703.Ql Va * . 704The suffix must be one of the known suffixes declared with 705.Ic .SUFFIXES 706or it will not be recognized. 707.It Va .TARGET 708The name of the target; also known as 709.Ql Va @ . 710For compatibility with other makes this is an alias for 711.Ic .ARCHIVE 712in archive member rules. 713.El 714.Pp 715The shorter forms 716.Ql ( Va > , 717.Ql Va \&! , 718.Ql Va < , 719.Ql Va % , 720.Ql Va \&? , 721.Ql Va * , 722and 723.Ql Va @ ) 724are permitted for backward 725compatibility with historical makefiles and legacy POSIX make and are 726not recommended. 727.Pp 728Variants of these variables with the punctuation followed immediately by 729.Ql D 730or 731.Ql F , 732e.g. 733.Ql Va $(@D) , 734are legacy forms equivalent to using the 735.Ql :H 736and 737.Ql :T 738modifiers. 739These forms are accepted for compatibility with 740.At V 741makefiles and POSIX but are not recommended. 742.Pp 743Four of the local variables may be used in sources on dependency lines 744because they expand to the proper value for each target on the line. 745These variables are 746.Ql Va .TARGET , 747.Ql Va .PREFIX , 748.Ql Va .ARCHIVE , 749and 750.Ql Va .MEMBER . 751.Ss Additional built-in variables 752In addition, 753.Nm 754sets or knows about the following variables: 755.Bl -tag -width .MAKEOVERRIDES 756.It Va \&$ 757A single dollar sign 758.Ql \&$ , 759i.e. 760.Ql \&$$ 761expands to a single dollar 762sign. 763.It Va .ALLTARGETS 764The list of all targets encountered in the Makefile. 765If evaluated during 766Makefile parsing, lists only those targets encountered thus far. 767.It Va .CURDIR 768A path to the directory where 769.Nm 770was executed. 771Refer to the description of 772.Ql Ev PWD 773for more details. 774.It Va .INCLUDEDFROMDIR 775The directory of the file this Makefile was included from. 776.It Va .INCLUDEDFROMFILE 777The filename of the file this Makefile was included from. 778.It Ev MAKE 779The name that 780.Nm 781was executed with 782.Pq Va argv[0] . 783For compatibility 784.Nm 785also sets 786.Va .MAKE 787with the same value. 788The preferred variable to use is the environment variable 789.Ev MAKE 790because it is more compatible with other versions of 791.Nm 792and cannot be confused with the special target with the same name. 793.It Va .MAKE.DEPENDFILE 794Names the makefile (default 795.Ql Pa .depend ) 796from which generated dependencies are read. 797.It Va .MAKE.EXPAND_VARIABLES 798A boolean that controls the default behavior of the 799.Fl V 800option. 801If true, variable values printed with 802.Fl V 803are fully expanded; if false, the raw variable contents (which may 804include additional unexpanded variable references) are shown. 805.It Va .MAKE.EXPORTED 806The list of variables exported by 807.Nm . 808.It Va .MAKE.JOBS 809The argument to the 810.Fl j 811option. 812.It Va .MAKE.JOB.PREFIX 813If 814.Nm 815is run with 816.Ar j 817then output for each target is prefixed with a token 818.Ql --- target --- 819the first part of which can be controlled via 820.Va .MAKE.JOB.PREFIX . 821If 822.Va .MAKE.JOB.PREFIX 823is empty, no token is printed. 824.br 825For example: 826.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 827would produce tokens like 828.Ql ---make[1234] target --- 829making it easier to track the degree of parallelism being achieved. 830.It Ev MAKEFLAGS 831The environment variable 832.Ql Ev MAKEFLAGS 833may contain anything that 834may be specified on 835.Nm Ns 's 836command line. 837Anything specified on 838.Nm Ns 's 839command line is appended to the 840.Ql Ev MAKEFLAGS 841variable which is then 842entered into the environment for all programs which 843.Nm 844executes. 845.It Va .MAKE.LEVEL 846The recursion depth of 847.Nm . 848The initial instance of 849.Nm 850will be 0, and an incremented value is put into the environment 851to be seen by the next generation. 852This allows tests like: 853.Li .if ${.MAKE.LEVEL} == 0 854to protect things which should only be evaluated in the initial instance of 855.Nm . 856.It Va .MAKE.MAKEFILE_PREFERENCE 857The ordered list of makefile names 858(default 859.Ql Pa makefile , 860.Ql Pa Makefile ) 861that 862.Nm 863will look for. 864.It Va .MAKE.MAKEFILES 865The list of makefiles read by 866.Nm , 867which is useful for tracking dependencies. 868Each makefile is recorded only once, regardless of the number of times read. 869.It Va .MAKE.MODE 870Processed after reading all makefiles. 871Can affect the mode that 872.Nm 873runs in. 874It can contain a number of keywords: 875.Bl -hang -width missing-filemon=bf. 876.It Pa compat 877Like 878.Fl B , 879puts 880.Nm 881into "compat" mode. 882.It Pa meta 883Puts 884.Nm 885into "meta" mode, where meta files are created for each target 886to capture the command run, the output generated and if 887.Xr filemon 4 888is available, the system calls which are of interest to 889.Nm . 890The captured output can be very useful when diagnosing errors. 891.It Pa curdirOk= Ar bf 892Normally 893.Nm 894will not create .meta files in 895.Ql Va .CURDIR . 896This can be overridden by setting 897.Va bf 898to a value which represents True. 899.It Pa missing-meta= Ar bf 900If 901.Va bf 902is True, then a missing .meta file makes the target out-of-date. 903.It Pa missing-filemon= Ar bf 904If 905.Va bf 906is True, then missing filemon data makes the target out-of-date. 907.It Pa nofilemon 908Do not use 909.Xr filemon 4 . 910.It Pa env 911For debugging, it can be useful to include the environment 912in the .meta file. 913.It Pa verbose 914If in "meta" mode, print a clue about the target being built. 915This is useful if the build is otherwise running silently. 916The message printed the value of: 917.Va .MAKE.META.PREFIX . 918.It Pa ignore-cmd 919Some makefiles have commands which are simply not stable. 920This keyword causes them to be ignored for 921determining whether a target is out of date in "meta" mode. 922See also 923.Ic .NOMETA_CMP . 924.It Pa silent= Ar bf 925If 926.Va bf 927is True, when a .meta file is created, mark the target 928.Ic .SILENT . 929.El 930.It Va .MAKE.META.BAILIWICK 931In "meta" mode, provides a list of prefixes which 932match the directories controlled by 933.Nm . 934If a file that was generated outside of 935.Va .OBJDIR 936but within said bailiwick is missing, 937the current target is considered out-of-date. 938.It Va .MAKE.META.CREATED 939In "meta" mode, this variable contains a list of all the meta files 940updated. 941If not empty, it can be used to trigger processing of 942.Va .MAKE.META.FILES . 943.It Va .MAKE.META.FILES 944In "meta" mode, this variable contains a list of all the meta files 945used (updated or not). 946This list can be used to process the meta files to extract dependency 947information. 948.It Va .MAKE.META.IGNORE_PATHS 949Provides a list of path prefixes that should be ignored; 950because the contents are expected to change over time. 951The default list includes: 952.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 953.It Va .MAKE.META.IGNORE_PATTERNS 954Provides a list of patterns to match against pathnames. 955Ignore any that match. 956.It Va .MAKE.META.IGNORE_FILTER 957Provides a list of variable modifiers to apply to each pathname. 958Ignore if the expansion is an empty string. 959.It Va .MAKE.META.PREFIX 960Defines the message printed for each meta file updated in "meta verbose" mode. 961The default value is: 962.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 963.It Va .MAKEOVERRIDES 964This variable is used to record the names of variables assigned to 965on the command line, so that they may be exported as part of 966.Ql Ev MAKEFLAGS . 967This behavior can be disabled by assigning an empty value to 968.Ql Va .MAKEOVERRIDES 969within a makefile. 970Extra variables can be exported from a makefile 971by appending their names to 972.Ql Va .MAKEOVERRIDES . 973.Ql Ev MAKEFLAGS 974is re-exported whenever 975.Ql Va .MAKEOVERRIDES 976is modified. 977.It Va .MAKE.PATH_FILEMON 978If 979.Nm 980was built with 981.Xr filemon 4 982support, this is set to the path of the device node. 983This allows makefiles to test for this support. 984.It Va .MAKE.PID 985The process-id of 986.Nm . 987.It Va .MAKE.PPID 988The parent process-id of 989.Nm . 990.It Va .MAKE.BUILT.BY 991The compiler CCVER that built the 992.Dx 993world. 994.It Va .MAKE.DF.OSREL 995The 996.Dx 997version when the world was built. It is in the "<major>.<minor>" 998format and it used by DPorts. 999.It Va .MAKE.DF.VERSION 1000The value of __DragonFly_version when the 1001.Dx 1002world was built. It is used by DPorts. 1003.It Va .MAKE.SAVE_DOLLARS 1004value should be a boolean that controls whether 1005.Ql $$ 1006are preserved when doing 1007.Ql := 1008assignments. 1009The default is false, for backwards compatibility. 1010Set to true for compatibility with other makes. 1011If set to false, 1012.Ql $$ 1013becomes 1014.Ql $ 1015per normal evaluation rules. 1016.It Va MAKE_PRINT_VAR_ON_ERROR 1017When 1018.Nm 1019stops due to an error, it sets 1020.Ql Va .ERROR_TARGET 1021to the name of the target that failed, 1022.Ql Va .ERROR_CMD 1023to the commands of the failed target, 1024and in "meta" mode, it also sets 1025.Ql Va .ERROR_CWD 1026to the 1027.Xr getcwd 3 , 1028and 1029.Ql Va .ERROR_META_FILE 1030to the path of the meta file (if any) describing the failed target. 1031It then prints its name and the value of 1032.Ql Va .CURDIR 1033as well as the value of any variables named in 1034.Ql Va MAKE_PRINT_VAR_ON_ERROR . 1035.It Va .newline 1036This variable is simply assigned a newline character as its value. 1037This allows expansions using the 1038.Cm \&:@ 1039modifier to put a newline between 1040iterations of the loop rather than a space. 1041For example, the printing of 1042.Ql Va MAKE_PRINT_VAR_ON_ERROR 1043could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 1044.It Va .OBJDIR 1045A path to the directory where the targets are built. 1046Its value is determined by trying to 1047.Xr chdir 2 1048to the following directories in order and using the first match: 1049.Bl -enum 1050.It 1051.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 1052.Pp 1053(Only if 1054.Ql Ev MAKEOBJDIRPREFIX 1055is set in the environment or on the command line.) 1056.It 1057.Ev ${MAKEOBJDIR} 1058.Pp 1059(Only if 1060.Ql Ev MAKEOBJDIR 1061is set in the environment or on the command line.) 1062.It 1063.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 1064.It 1065.Ev ${.CURDIR} Ns Pa /obj 1066.It 1067.Pa /usr/obj/ Ns Ev ${.CURDIR} 1068.It 1069.Ev ${.CURDIR} 1070.El 1071.Pp 1072Variable expansion is performed on the value before it's used, 1073so expressions such as 1074.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1075may be used. 1076This is especially useful with 1077.Ql Ev MAKEOBJDIR . 1078.Pp 1079.Ql Va .OBJDIR 1080may be modified in the makefile via the special target 1081.Ql Ic .OBJDIR . 1082In all cases, 1083.Nm 1084will 1085.Xr chdir 2 1086to the specified directory if it exists, and set 1087.Ql Va .OBJDIR 1088and 1089.Ql Ev PWD 1090to that directory before executing any targets. 1091. 1092.It Va .PARSEDIR 1093A path to the directory of the current 1094.Ql Pa Makefile 1095being parsed. 1096.It Va .PARSEFILE 1097The basename of the current 1098.Ql Pa Makefile 1099being parsed. 1100This variable and 1101.Ql Va .PARSEDIR 1102are both set only while the 1103.Ql Pa Makefiles 1104are being parsed. 1105If you want to retain their current values, assign them to a variable 1106using assignment with expansion: 1107.Pq Ql Cm \&:= . 1108.It Va .PATH 1109A variable that represents the list of directories that 1110.Nm 1111will search for files. 1112The search list should be updated using the target 1113.Ql Va .PATH 1114rather than the variable. 1115.It Ev PWD 1116Alternate path to the current directory. 1117.Nm 1118normally sets 1119.Ql Va .CURDIR 1120to the canonical path given by 1121.Xr getcwd 3 . 1122However, if the environment variable 1123.Ql Ev PWD 1124is set and gives a path to the current directory, then 1125.Nm 1126sets 1127.Ql Va .CURDIR 1128to the value of 1129.Ql Ev PWD 1130instead. 1131This behavior is disabled if 1132.Ql Ev MAKEOBJDIRPREFIX 1133is set or 1134.Ql Ev MAKEOBJDIR 1135contains a variable transform. 1136.Ql Ev PWD 1137is set to the value of 1138.Ql Va .OBJDIR 1139for all programs which 1140.Nm 1141executes. 1142.It Ev .TARGETS 1143The list of targets explicitly specified on the command line, if any. 1144.It Ev VPATH 1145Colon-separated 1146.Pq Dq \&: 1147lists of directories that 1148.Nm 1149will search for files. 1150The variable is supported for compatibility with old make programs only, 1151use 1152.Ql Va .PATH 1153instead. 1154.El 1155.Ss Variable modifiers 1156Variable expansion may be modified to select or modify each word of the 1157variable (where a 1158.Dq word 1159is white-space delimited sequence of characters). 1160The general format of a variable expansion is as follows: 1161.Pp 1162.Dl ${variable[:modifier[:...]]} 1163.Pp 1164Each modifier begins with a colon, 1165which may be escaped with a backslash 1166.Pq Ql \e . 1167.Pp 1168A set of modifiers can be specified via a variable, as follows: 1169.Pp 1170.Dl modifier_variable=modifier[:...] 1171.Dl ${variable:${modifier_variable}[:...]} 1172.Pp 1173In this case the first modifier in the modifier_variable does not 1174start with a colon, since that must appear in the referencing 1175variable. 1176If any of the modifiers in the modifier_variable contain a dollar sign 1177.Pq Ql $ , 1178these must be doubled to avoid early expansion. 1179.Pp 1180The supported modifiers are: 1181.Bl -tag -width EEE 1182.It Cm \&:E 1183Replaces each word in the variable with its suffix. 1184.It Cm \&:H 1185Replaces each word in the variable with everything but the last component. 1186.It Cm \&:M Ns Ar pattern 1187Select only those words that match 1188.Ar pattern . 1189The standard shell wildcard characters 1190.Pf ( Ql * , 1191.Ql \&? , 1192and 1193.Ql Oo Oc ) 1194may 1195be used. 1196The wildcard characters may be escaped with a backslash 1197.Pq Ql \e . 1198As a consequence of the way values are split into words, matched, 1199and then joined, a construct like 1200.Dl ${VAR:M*} 1201will normalize the inter-word spacing, removing all leading and 1202trailing space, and converting multiple consecutive spaces 1203to single spaces. 1204. 1205.It Cm \&:N Ns Ar pattern 1206This is identical to 1207.Ql Cm \&:M , 1208but selects all words which do not match 1209.Ar pattern . 1210.It Cm \&:O 1211Order every word in variable alphabetically. 1212.It Cm \&:Or 1213Order every word in variable in reverse alphabetical order. 1214.It Cm \&:Ox 1215Randomize words in variable. 1216The results will be different each time you are referring to the 1217modified variable; use the assignment with expansion 1218.Pq Ql Cm \&:= 1219to prevent such behavior. 1220For example, 1221.Bd -literal -offset indent 1222LIST= uno due tre quattro 1223RANDOM_LIST= ${LIST:Ox} 1224STATIC_RANDOM_LIST:= ${LIST:Ox} 1225 1226all: 1227 @echo "${RANDOM_LIST}" 1228 @echo "${RANDOM_LIST}" 1229 @echo "${STATIC_RANDOM_LIST}" 1230 @echo "${STATIC_RANDOM_LIST}" 1231.Ed 1232may produce output similar to: 1233.Bd -literal -offset indent 1234quattro due tre uno 1235tre due quattro uno 1236due uno quattro tre 1237due uno quattro tre 1238.Ed 1239.It Cm \&:Q 1240Quotes every shell meta-character in the variable, so that it can be passed 1241safely to the shell. 1242.It Cm \&:q 1243Quotes every shell meta-character in the variable, and also doubles 1244.Sq $ 1245characters so that it can be passed 1246safely through recursive invocations of 1247.Nm . 1248This is equivalent to: 1249.Sq \&:S/\e\&$/&&/g:Q . 1250.It Cm \&:R 1251Replaces each word in the variable with everything but its suffix. 1252.It Cm \&:range[=count] 1253The value is an integer sequence representing the words of the original 1254value, or the supplied 1255.Va count . 1256.It Cm \&:gmtime[=utc] 1257The value is a format string for 1258.Xr strftime 3 , 1259using 1260.Xr gmtime 3 . 1261If a 1262.Va utc 1263value is not provided or is 0, the current time is used. 1264.It Cm \&:hash 1265Compute a 32-bit hash of the value and encode it as hex digits. 1266.It Cm \&:localtime[=utc] 1267The value is a format string for 1268.Xr strftime 3 , 1269using 1270.Xr localtime 3 . 1271If a 1272.Va utc 1273value is not provided or is 0, the current time is used. 1274.It Cm \&:tA 1275Attempt to convert variable to an absolute path using 1276.Xr realpath 3 , 1277if that fails, the value is unchanged. 1278.It Cm \&:tl 1279Converts variable to lower-case letters. 1280.It Cm \&:ts Ns Ar c 1281Words in the variable are normally separated by a space on expansion. 1282This modifier sets the separator to the character 1283.Ar c . 1284If 1285.Ar c 1286is omitted, then no separator is used. 1287The common escapes (including octal numeric codes), work as expected. 1288.It Cm \&:tu 1289Converts variable to upper-case letters. 1290.It Cm \&:tW 1291Causes the value to be treated as a single word 1292(possibly containing embedded white space). 1293See also 1294.Ql Cm \&:[*] . 1295.It Cm \&:tw 1296Causes the value to be treated as a sequence of 1297words delimited by white space. 1298See also 1299.Ql Cm \&:[@] . 1300.Sm off 1301.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1302.Sm on 1303Modify the first occurrence of 1304.Ar old_string 1305in the variable's value, replacing it with 1306.Ar new_string . 1307If a 1308.Ql g 1309is appended to the last slash of the pattern, all occurrences 1310in each word are replaced. 1311If a 1312.Ql 1 1313is appended to the last slash of the pattern, only the first word 1314is affected. 1315If a 1316.Ql W 1317is appended to the last slash of the pattern, 1318then the value is treated as a single word 1319(possibly containing embedded white space). 1320If 1321.Ar old_string 1322begins with a caret 1323.Pq Ql ^ , 1324.Ar old_string 1325is anchored at the beginning of each word. 1326If 1327.Ar old_string 1328ends with a dollar sign 1329.Pq Ql \&$ , 1330it is anchored at the end of each word. 1331Inside 1332.Ar new_string , 1333an ampersand 1334.Pq Ql & 1335is replaced by 1336.Ar old_string 1337(without any 1338.Ql ^ 1339or 1340.Ql \&$ ) . 1341Any character may be used as a delimiter for the parts of the modifier 1342string. 1343The anchoring, ampersand and delimiter characters may be escaped with a 1344backslash 1345.Pq Ql \e . 1346.Pp 1347Variable expansion occurs in the normal fashion inside both 1348.Ar old_string 1349and 1350.Ar new_string 1351with the single exception that a backslash is used to prevent the expansion 1352of a dollar sign 1353.Pq Ql \&$ , 1354not a preceding dollar sign as is usual. 1355.Sm off 1356.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1357.Sm on 1358The 1359.Cm \&:C 1360modifier is just like the 1361.Cm \&:S 1362modifier except that the old and new strings, instead of being 1363simple strings, are an extended regular expression (see 1364.Xr regex 3 ) 1365string 1366.Ar pattern 1367and an 1368.Xr ed 1 Ns \-style 1369string 1370.Ar replacement . 1371Normally, the first occurrence of the pattern 1372.Ar pattern 1373in each word of the value is substituted with 1374.Ar replacement . 1375The 1376.Ql 1 1377modifier causes the substitution to apply to at most one word; the 1378.Ql g 1379modifier causes the substitution to apply to as many instances of the 1380search pattern 1381.Ar pattern 1382as occur in the word or words it is found in; the 1383.Ql W 1384modifier causes the value to be treated as a single word 1385(possibly containing embedded white space). 1386Note that 1387.Ql 1 1388and 1389.Ql g 1390are orthogonal; the former specifies whether multiple words are 1391potentially affected, the latter whether multiple substitutions can 1392potentially occur within each affected word. 1393.Pp 1394As for the 1395.Cm \&:S 1396modifier, the 1397.Ar pattern 1398and 1399.Ar replacement 1400are subjected to variable expansion before being parsed as 1401regular expressions. 1402.It Cm \&:T 1403Replaces each word in the variable with its last component. 1404.It Cm \&:u 1405Remove adjacent duplicate words (like 1406.Xr uniq 1 ) . 1407.Sm off 1408.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1409.Sm on 1410If the variable name (not its value), when parsed as a .if conditional 1411expression, evaluates to true, return as its value the 1412.Ar true_string , 1413otherwise return the 1414.Ar false_string . 1415Since the variable name is used as the expression, \&:\&? must be the 1416first modifier after the variable name itself - which will, of course, 1417usually contain variable expansions. 1418A common error is trying to use expressions like 1419.Dl ${NUMBERS:M42:?match:no} 1420which actually tests defined(NUMBERS), 1421to determine is any words match "42" you need to use something like: 1422.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1423.It Ar :old_string=new_string 1424This is the 1425.At V 1426style variable substitution. 1427It must be the last modifier specified. 1428If 1429.Ar old_string 1430or 1431.Ar new_string 1432do not contain the pattern matching character 1433.Ar % 1434then it is assumed that they are 1435anchored at the end of each word, so only suffixes or entire 1436words may be replaced. 1437Otherwise 1438.Ar % 1439is the substring of 1440.Ar old_string 1441to be replaced in 1442.Ar new_string . 1443If only 1444.Ar old_string 1445contains the pattern matching character 1446.Ar % , 1447and 1448.Ar old_string 1449matches, then the result is the 1450.Ar new_string . 1451If only the 1452.Ar new_string 1453contains the pattern matching character 1454.Ar % , 1455then it is not treated specially and it is printed as a literal 1456.Ar % 1457on match. 1458If there is more than one pattern matching character 1459.Ar ( % ) 1460in either the 1461.Ar new_string 1462or 1463.Ar old_string , 1464only the first instance is treated specially (as the pattern character); 1465all subsequent instances are treated as regular characters 1466.Pp 1467Variable expansion occurs in the normal fashion inside both 1468.Ar old_string 1469and 1470.Ar new_string 1471with the single exception that a backslash is used to prevent the 1472expansion of a dollar sign 1473.Pq Ql \&$ , 1474not a preceding dollar sign as is usual. 1475.Sm off 1476.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1477.Sm on 1478This is the loop expansion mechanism from the OSF Development 1479Environment (ODE) make. 1480Unlike 1481.Cm \&.for 1482loops expansion occurs at the time of 1483reference. 1484Assign 1485.Ar temp 1486to each word in the variable and evaluate 1487.Ar string . 1488The ODE convention is that 1489.Ar temp 1490should start and end with a period. 1491For example. 1492.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1493.Pp 1494However a single character variable is often more readable: 1495.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1496.It Cm \&:_[=var] 1497Save the current variable value in 1498.Ql $_ 1499or the named 1500.Va var 1501for later reference. 1502Example usage: 1503.Bd -literal -offset indent 1504M_cmpv.units = 1 1000 1000000 1505M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\ 1506\\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh 1507 1508.Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}} 1509 1510.Ed 1511Here 1512.Ql $_ 1513is used to save the result of the 1514.Ql :S 1515modifier which is later referenced using the index values from 1516.Ql :range . 1517.It Cm \&:U Ns Ar newval 1518If the variable is undefined 1519.Ar newval 1520is the value. 1521If the variable is defined, the existing value is returned. 1522This is another ODE make feature. 1523It is handy for setting per-target CFLAGS for instance: 1524.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1525If a value is only required if the variable is undefined, use: 1526.Dl ${VAR:D:Unewval} 1527.It Cm \&:D Ns Ar newval 1528If the variable is defined 1529.Ar newval 1530is the value. 1531.It Cm \&:L 1532The name of the variable is the value. 1533.It Cm \&:P 1534The path of the node which has the same name as the variable 1535is the value. 1536If no such node exists or its path is null, then the 1537name of the variable is used. 1538In order for this modifier to work, the name (node) must at least have 1539appeared on the rhs of a dependency. 1540.Sm off 1541.It Cm \&:\&! Ar cmd Cm \&! 1542.Sm on 1543The output of running 1544.Ar cmd 1545is the value. 1546.It Cm \&:sh 1547If the variable is non-empty it is run as a command and the output 1548becomes the new value. 1549.It Cm \&::= Ns Ar str 1550The variable is assigned the value 1551.Ar str 1552after substitution. 1553This modifier and its variations are useful in 1554obscure situations such as wanting to set a variable when shell commands 1555are being parsed. 1556These assignment modifiers always expand to 1557nothing, so if appearing in a rule line by themselves should be 1558preceded with something to keep 1559.Nm 1560happy. 1561.Pp 1562The 1563.Ql Cm \&:: 1564helps avoid false matches with the 1565.At V 1566style 1567.Cm \&:= 1568modifier and since substitution always occurs the 1569.Cm \&::= 1570form is vaguely appropriate. 1571.It Cm \&::?= Ns Ar str 1572As for 1573.Cm \&::= 1574but only if the variable does not already have a value. 1575.It Cm \&::+= Ns Ar str 1576Append 1577.Ar str 1578to the variable. 1579.It Cm \&::!= Ns Ar cmd 1580Assign the output of 1581.Ar cmd 1582to the variable. 1583.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1584Selects one or more words from the value, 1585or performs other operations related to the way in which the 1586value is divided into words. 1587.Pp 1588Ordinarily, a value is treated as a sequence of words 1589delimited by white space. 1590Some modifiers suppress this behavior, 1591causing a value to be treated as a single word 1592(possibly containing embedded white space). 1593An empty value, or a value that consists entirely of white-space, 1594is treated as a single word. 1595For the purposes of the 1596.Ql Cm \&:[] 1597modifier, the words are indexed both forwards using positive integers 1598(where index 1 represents the first word), 1599and backwards using negative integers 1600(where index \-1 represents the last word). 1601.Pp 1602The 1603.Ar range 1604is subjected to variable expansion, and the expanded result is 1605then interpreted as follows: 1606.Bl -tag -width index 1607.\" :[n] 1608.It Ar index 1609Selects a single word from the value. 1610.\" :[start..end] 1611.It Ar start Ns Cm \&.. Ns Ar end 1612Selects all words from 1613.Ar start 1614to 1615.Ar end , 1616inclusive. 1617For example, 1618.Ql Cm \&:[2..-1] 1619selects all words from the second word to the last word. 1620If 1621.Ar start 1622is greater than 1623.Ar end , 1624then the words are output in reverse order. 1625For example, 1626.Ql Cm \&:[-1..1] 1627selects all the words from last to first. 1628If the list is already ordered, then this effectively reverses 1629the list, but it is more efficient to use 1630.Ql Cm \&:Or 1631instead of 1632.Ql Cm \&:O:[-1..1] . 1633.\" :[*] 1634.It Cm \&* 1635Causes subsequent modifiers to treat the value as a single word 1636(possibly containing embedded white space). 1637Analogous to the effect of 1638\&"$*\&" 1639in Bourne shell. 1640.\" :[0] 1641.It 0 1642Means the same as 1643.Ql Cm \&:[*] . 1644.\" :[*] 1645.It Cm \&@ 1646Causes subsequent modifiers to treat the value as a sequence of words 1647delimited by white space. 1648Analogous to the effect of 1649\&"$@\&" 1650in Bourne shell. 1651.\" :[#] 1652.It Cm \&# 1653Returns the number of words in the value. 1654.El \" :[range] 1655.El 1656.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1657Makefile inclusion, conditional structures and for loops reminiscent 1658of the C programming language are provided in 1659.Nm . 1660All such structures are identified by a line beginning with a single 1661dot 1662.Pq Ql \&. 1663character. 1664Files are included with either 1665.Cm \&.include \&< Ns Ar file Ns Cm \&> 1666or 1667.Cm \&.include \&\*q Ns Ar file Ns Cm \&\*q . 1668Variables between the angle brackets or double quotes are expanded 1669to form the file name. 1670If angle brackets are used, the included makefile is expected to be in 1671the system makefile directory. 1672If double quotes are used, the including makefile's directory and any 1673directories specified using the 1674.Fl I 1675option are searched before the system 1676makefile directory. 1677For compatibility with other versions of 1678.Nm 1679.Ql include file ... 1680is also accepted. 1681.Pp 1682If the include statement is written as 1683.Cm .-include 1684or as 1685.Cm .sinclude 1686then errors locating and/or opening include files are ignored. 1687.Pp 1688If the include statement is written as 1689.Cm .dinclude 1690not only are errors locating and/or opening include files ignored, 1691but stale dependencies within the included file will be ignored 1692just like 1693.Va .MAKE.DEPENDFILE . 1694.Pp 1695Conditional expressions are also preceded by a single dot as the first 1696character of a line. 1697The possible conditionals are as follows: 1698.Bl -tag -width Ds 1699.It Ic .error Ar message 1700The message is printed along with the name of the makefile and line number, 1701then 1702.Nm 1703will exit. 1704.It Ic .export Ar variable ... 1705Export the specified global variable. 1706If no variable list is provided, all globals are exported 1707except for internal variables (those that start with 1708.Ql \&. ) . 1709This is not affected by the 1710.Fl X 1711flag, so should be used with caution. 1712For compatibility with other 1713.Nm 1714programs 1715.Ql export variable=value 1716is also accepted. 1717.Pp 1718Appending a variable name to 1719.Va .MAKE.EXPORTED 1720is equivalent to exporting a variable. 1721.It Ic .export-env Ar variable ... 1722The same as 1723.Ql .export , 1724except that the variable is not appended to 1725.Va .MAKE.EXPORTED . 1726This allows exporting a value to the environment which is different from that 1727used by 1728.Nm 1729internally. 1730.It Ic .export-literal Ar variable ... 1731The same as 1732.Ql .export-env , 1733except that variables in the value are not expanded. 1734.It Ic .info Ar message 1735The message is printed along with the name of the makefile and line number. 1736.It Ic .undef Ar variable 1737Un-define the specified global variable. 1738Only global variables may be un-defined. 1739.It Ic .unexport Ar variable ... 1740The opposite of 1741.Ql .export . 1742The specified global 1743.Va variable 1744will be removed from 1745.Va .MAKE.EXPORTED . 1746If no variable list is provided, all globals are unexported, 1747and 1748.Va .MAKE.EXPORTED 1749deleted. 1750.It Ic .unexport-env 1751Unexport all globals previously exported and 1752clear the environment inherited from the parent. 1753This operation will cause a memory leak of the original environment, 1754so should be used sparingly. 1755Testing for 1756.Va .MAKE.LEVEL 1757being 0, would make sense. 1758Also note that any variables which originated in the parent environment 1759should be explicitly preserved if desired. 1760For example: 1761.Bd -literal -offset indent 1762.Li .if ${.MAKE.LEVEL} == 0 1763PATH := ${PATH} 1764.Li .unexport-env 1765.Li .export PATH 1766.Li .endif 1767.Ed 1768.Pp 1769Would result in an environment containing only 1770.Ql Ev PATH , 1771which is the minimal useful environment. 1772Actually 1773.Ql Ev .MAKE.LEVEL 1774will also be pushed into the new environment. 1775.It Ic .warning Ar message 1776The message prefixed by 1777.Ql Pa warning: 1778is printed along with the name of the makefile and line number. 1779.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1780Test the value of an expression. 1781.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1782Test the value of a variable. 1783.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1784Test the value of a variable. 1785.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1786Test the target being built. 1787.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1788Test the target being built. 1789.It Ic .else 1790Reverse the sense of the last conditional. 1791.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1792A combination of 1793.Ql Ic .else 1794followed by 1795.Ql Ic .if . 1796.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1797A combination of 1798.Ql Ic .else 1799followed by 1800.Ql Ic .ifdef . 1801.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1802A combination of 1803.Ql Ic .else 1804followed by 1805.Ql Ic .ifndef . 1806.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1807A combination of 1808.Ql Ic .else 1809followed by 1810.Ql Ic .ifmake . 1811.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1812A combination of 1813.Ql Ic .else 1814followed by 1815.Ql Ic .ifnmake . 1816.It Ic .endif 1817End the body of the conditional. 1818.El 1819.Pp 1820The 1821.Ar operator 1822may be any one of the following: 1823.Bl -tag -width "Cm XX" 1824.It Cm \&|\&| 1825Logical OR. 1826.It Cm \&&& 1827Logical 1828.Tn AND ; 1829of higher precedence than 1830.Dq \&|\&| . 1831.El 1832.Pp 1833As in C, 1834.Nm 1835will only evaluate a conditional as far as is necessary to determine 1836its value. 1837Parentheses may be used to change the order of evaluation. 1838The boolean operator 1839.Ql Ic \&! 1840may be used to logically negate an entire 1841conditional. 1842It is of higher precedence than 1843.Ql Ic \&&& . 1844.Pp 1845The value of 1846.Ar expression 1847may be any of the following: 1848.Bl -tag -width defined 1849.It Ic defined 1850Takes a variable name as an argument and evaluates to true if the variable 1851has been defined. 1852.It Ic make 1853Takes a target name as an argument and evaluates to true if the target 1854was specified as part of 1855.Nm Ns 's 1856command line or was declared the default target (either implicitly or 1857explicitly, see 1858.Va .MAIN ) 1859before the line containing the conditional. 1860.It Ic empty 1861Takes a variable, with possible modifiers, and evaluates to true if 1862the expansion of the variable would result in an empty string. 1863.It Ic exists 1864Takes a file name as an argument and evaluates to true if the file exists. 1865The file is searched for on the system search path (see 1866.Va .PATH ) . 1867.It Ic target 1868Takes a target name as an argument and evaluates to true if the target 1869has been defined. 1870.It Ic commands 1871Takes a target name as an argument and evaluates to true if the target 1872has been defined and has commands associated with it. 1873.El 1874.Pp 1875.Ar Expression 1876may also be an arithmetic or string comparison. 1877Variable expansion is 1878performed on both sides of the comparison, after which the integral 1879values are compared. 1880A value is interpreted as hexadecimal if it is 1881preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1882The standard C relational operators are all supported. 1883If after 1884variable expansion, either the left or right hand side of a 1885.Ql Ic == 1886or 1887.Ql Ic "!=" 1888operator is not an integral value, then 1889string comparison is performed between the expanded 1890variables. 1891If no relational operator is given, it is assumed that the expanded 1892variable is being compared against 0 or an empty string in the case 1893of a string comparison. 1894.Pp 1895When 1896.Nm 1897is evaluating one of these conditional expressions, and it encounters 1898a (white-space separated) word it doesn't recognize, either the 1899.Dq make 1900or 1901.Dq defined 1902expression is applied to it, depending on the form of the conditional. 1903If the form is 1904.Ql Ic .ifdef , 1905.Ql Ic .ifndef , 1906or 1907.Ql Ic .if 1908the 1909.Dq defined 1910expression is applied. 1911Similarly, if the form is 1912.Ql Ic .ifmake 1913or 1914.Ql Ic .ifnmake , 1915the 1916.Dq make 1917expression is applied. 1918.Pp 1919If the conditional evaluates to true the parsing of the makefile continues 1920as before. 1921If it evaluates to false, the following lines are skipped. 1922In both cases this continues until a 1923.Ql Ic .else 1924or 1925.Ql Ic .endif 1926is found. 1927.Pp 1928For loops are typically used to apply a set of rules to a list of files. 1929The syntax of a for loop is: 1930.Pp 1931.Bl -tag -compact -width Ds 1932.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1933.It Aq make-rules 1934.It Ic \&.endfor 1935.El 1936.Pp 1937After the for 1938.Ic expression 1939is evaluated, it is split into words. 1940On each iteration of the loop, one word is taken and assigned to each 1941.Ic variable , 1942in order, and these 1943.Ic variables 1944are substituted into the 1945.Ic make-rules 1946inside the body of the for loop. 1947The number of words must come out even; that is, if there are three 1948iteration variables, the number of words provided must be a multiple 1949of three. 1950.Sh COMMENTS 1951Comments begin with a hash 1952.Pq Ql \&# 1953character, anywhere but in a shell 1954command line, and continue to the end of an unescaped new line. 1955.Sh SPECIAL SOURCES (ATTRIBUTES) 1956.Bl -tag -width .IGNOREx 1957.It Ic .EXEC 1958Target is never out of date, but always execute commands anyway. 1959.It Ic .IGNORE 1960Ignore any errors from the commands associated with this target, exactly 1961as if they all were preceded by a dash 1962.Pq Ql \- . 1963.\" .It Ic .INVISIBLE 1964.\" XXX 1965.\" .It Ic .JOIN 1966.\" XXX 1967.It Ic .MADE 1968Mark all sources of this target as being up-to-date. 1969.It Ic .MAKE 1970Execute the commands associated with this target even if the 1971.Fl n 1972or 1973.Fl t 1974options were specified. 1975Normally used to mark recursive 1976.Nm Ns s . 1977.It Ic .META 1978Create a meta file for the target, even if it is flagged as 1979.Ic .PHONY , 1980.Ic .MAKE , 1981or 1982.Ic .SPECIAL . 1983Usage in conjunction with 1984.Ic .MAKE 1985is the most likely case. 1986In "meta" mode, the target is out-of-date if the meta file is missing. 1987.It Ic .NOMETA 1988Do not create a meta file for the target. 1989Meta files are also not created for 1990.Ic .PHONY , 1991.Ic .MAKE , 1992or 1993.Ic .SPECIAL 1994targets. 1995.It Ic .NOMETA_CMP 1996Ignore differences in commands when deciding if target is out of date. 1997This is useful if the command contains a value which always changes. 1998If the number of commands change, though, the target will still be out of date. 1999The same effect applies to any command line that uses the variable 2000.Va .OODATE , 2001which can be used for that purpose even when not otherwise needed or desired: 2002.Bd -literal -offset indent 2003 2004skip-compare-for-some: 2005 @echo this will be compared 2006 @echo this will not ${.OODATE:M.NOMETA_CMP} 2007 @echo this will also be compared 2008 2009.Ed 2010The 2011.Cm \&:M 2012pattern suppresses any expansion of the unwanted variable. 2013.It Ic .NOPATH 2014Do not search for the target in the directories specified by 2015.Ic .PATH . 2016.It Ic .NOTMAIN 2017Normally 2018.Nm 2019selects the first target it encounters as the default target to be built 2020if no target was specified. 2021This source prevents this target from being selected. 2022.It Ic .OPTIONAL 2023If a target is marked with this attribute and 2024.Nm 2025can't figure out how to create it, it will ignore this fact and assume 2026the file isn't needed or already exists. 2027.It Ic .PHONY 2028The target does not 2029correspond to an actual file; it is always considered to be out of date, 2030and will not be created with the 2031.Fl t 2032option. 2033Suffix-transformation rules are not applied to 2034.Ic .PHONY 2035targets. 2036.It Ic .PRECIOUS 2037When 2038.Nm 2039is interrupted, it normally removes any partially made targets. 2040This source prevents the target from being removed. 2041.It Ic .RECURSIVE 2042Synonym for 2043.Ic .MAKE . 2044.It Ic .SILENT 2045Do not echo any of the commands associated with this target, exactly 2046as if they all were preceded by an at sign 2047.Pq Ql @ . 2048.It Ic .USE 2049Turn the target into 2050.Nm Ns 's 2051version of a macro. 2052When the target is used as a source for another target, the other target 2053acquires the commands, sources, and attributes (except for 2054.Ic .USE ) 2055of the 2056source. 2057If the target already has commands, the 2058.Ic .USE 2059target's commands are appended 2060to them. 2061.It Ic .USEBEFORE 2062Exactly like 2063.Ic .USE , 2064but prepend the 2065.Ic .USEBEFORE 2066target commands to the target. 2067.It Ic .WAIT 2068If 2069.Ic .WAIT 2070appears in a dependency line, the sources that precede it are 2071made before the sources that succeed it in the line. 2072Since the dependents of files are not made until the file itself 2073could be made, this also stops the dependents being built unless they 2074are needed for another branch of the dependency tree. 2075So given: 2076.Bd -literal 2077x: a .WAIT b 2078 echo x 2079a: 2080 echo a 2081b: b1 2082 echo b 2083b1: 2084 echo b1 2085 2086.Ed 2087the output is always 2088.Ql a , 2089.Ql b1 , 2090.Ql b , 2091.Ql x . 2092.br 2093The ordering imposed by 2094.Ic .WAIT 2095is only relevant for parallel makes. 2096.El 2097.Sh SPECIAL TARGETS 2098Special targets may not be included with other targets, i.e. they must be 2099the only target specified. 2100.Bl -tag -width .BEGINx 2101.It Ic .BEGIN 2102Any command lines attached to this target are executed before anything 2103else is done. 2104.It Ic .DEFAULT 2105This is sort of a 2106.Ic .USE 2107rule for any target (that was used only as a 2108source) that 2109.Nm 2110can't figure out any other way to create. 2111Only the shell script is used. 2112The 2113.Ic .IMPSRC 2114variable of a target that inherits 2115.Ic .DEFAULT Ns 's 2116commands is set 2117to the target's own name. 2118.It Ic .DELETE_ON_ERROR 2119If this target is present in the makefile, it globally causes make to 2120delete targets whose commands fail. 2121(By default, only targets whose commands are interrupted during 2122execution are deleted. 2123This is the historical behavior.) 2124This setting can be used to help prevent half-finished or malformed 2125targets from being left around and corrupting future rebuilds. 2126.It Ic .END 2127Any command lines attached to this target are executed after everything 2128else is done. 2129.It Ic .ERROR 2130Any command lines attached to this target are executed when another target fails. 2131The 2132.Ic .ERROR_TARGET 2133variable is set to the target that failed. 2134See also 2135.Ic MAKE_PRINT_VAR_ON_ERROR . 2136.It Ic .IGNORE 2137Mark each of the sources with the 2138.Ic .IGNORE 2139attribute. 2140If no sources are specified, this is the equivalent of specifying the 2141.Fl i 2142option. 2143.It Ic .INTERRUPT 2144If 2145.Nm 2146is interrupted, the commands for this target will be executed. 2147.It Ic .MAIN 2148If no target is specified when 2149.Nm 2150is invoked, this target will be built. 2151.It Ic .MAKEFLAGS 2152This target provides a way to specify flags for 2153.Nm 2154when the makefile is used. 2155The flags are as if typed to the shell, though the 2156.Fl f 2157option will have 2158no effect. 2159.\" XXX: NOT YET!!!! 2160.\" .It Ic .NOTPARALLEL 2161.\" The named targets are executed in non parallel mode. 2162.\" If no targets are 2163.\" specified, then all targets are executed in non parallel mode. 2164.It Ic .NOPATH 2165Apply the 2166.Ic .NOPATH 2167attribute to any specified sources. 2168.It Ic .NOTPARALLEL 2169Disable parallel mode. 2170.It Ic .NO_PARALLEL 2171Synonym for 2172.Ic .NOTPARALLEL , 2173for compatibility with other pmake variants. 2174.It Ic .OBJDIR 2175The source is a new value for 2176.Ql Va .OBJDIR . 2177If it exists, 2178.Nm 2179will 2180.Xr chdir 2 2181to it and update the value of 2182.Ql Va .OBJDIR . 2183.It Ic .ORDER 2184The named targets are made in sequence. 2185This ordering does not add targets to the list of targets to be made. 2186Since the dependents of a target do not get built until the target itself 2187could be built, unless 2188.Ql a 2189is built by another part of the dependency graph, 2190the following is a dependency loop: 2191.Bd -literal 2192\&.ORDER: b a 2193b: a 2194.Ed 2195.Pp 2196The ordering imposed by 2197.Ic .ORDER 2198is only relevant for parallel makes. 2199.\" XXX: NOT YET!!!! 2200.\" .It Ic .PARALLEL 2201.\" The named targets are executed in parallel mode. 2202.\" If no targets are 2203.\" specified, then all targets are executed in parallel mode. 2204.It Ic .PATH 2205The sources are directories which are to be searched for files not 2206found in the current directory. 2207If no sources are specified, any previously specified directories are 2208deleted. 2209If the source is the special 2210.Ic .DOTLAST 2211target, then the current working 2212directory is searched last. 2213.It Ic .PATH. Ns Va suffix 2214Like 2215.Ic .PATH 2216but applies only to files with a particular suffix. 2217The suffix must have been previously declared with 2218.Ic .SUFFIXES . 2219.It Ic .PHONY 2220Apply the 2221.Ic .PHONY 2222attribute to any specified sources. 2223.It Ic .PRECIOUS 2224Apply the 2225.Ic .PRECIOUS 2226attribute to any specified sources. 2227If no sources are specified, the 2228.Ic .PRECIOUS 2229attribute is applied to every 2230target in the file. 2231.It Ic .SHELL 2232Sets the shell that 2233.Nm 2234will use to execute commands. 2235The sources are a set of 2236.Ar field=value 2237pairs. 2238.Bl -tag -width hasErrCtls 2239.It Ar name 2240This is the minimal specification, used to select one of the built-in 2241shell specs; 2242.Ar sh , 2243.Ar ksh , 2244and 2245.Ar csh . 2246.It Ar path 2247Specifies the path to the shell. 2248.It Ar hasErrCtl 2249Indicates whether the shell supports exit on error. 2250.It Ar check 2251The command to turn on error checking. 2252.It Ar ignore 2253The command to disable error checking. 2254.It Ar echo 2255The command to turn on echoing of commands executed. 2256.It Ar quiet 2257The command to turn off echoing of commands executed. 2258.It Ar filter 2259The output to filter after issuing the 2260.Ar quiet 2261command. 2262It is typically identical to 2263.Ar quiet . 2264.It Ar errFlag 2265The flag to pass the shell to enable error checking. 2266.It Ar echoFlag 2267The flag to pass the shell to enable command echoing. 2268.It Ar newline 2269The string literal to pass the shell that results in a single newline 2270character when used outside of any quoting characters. 2271.El 2272Example: 2273.Bd -literal 2274\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2275 check="set \-e" ignore="set +e" \e 2276 echo="set \-v" quiet="set +v" filter="set +v" \e 2277 echoFlag=v errFlag=e newline="'\en'" 2278.Ed 2279.It Ic .SILENT 2280Apply the 2281.Ic .SILENT 2282attribute to any specified sources. 2283If no sources are specified, the 2284.Ic .SILENT 2285attribute is applied to every 2286command in the file. 2287.It Ic .STALE 2288This target gets run when a dependency file contains stale entries, having 2289.Va .ALLSRC 2290set to the name of that dependency file. 2291.It Ic .SUFFIXES 2292Each source specifies a suffix to 2293.Nm . 2294If no sources are specified, any previously specified suffixes are deleted. 2295It allows the creation of suffix-transformation rules. 2296.Pp 2297Example: 2298.Bd -literal 2299\&.SUFFIXES: .o 2300\&.c.o: 2301 cc \-o ${.TARGET} \-c ${.IMPSRC} 2302.Ed 2303.El 2304.Sh ENVIRONMENT 2305.Nm 2306uses the following environment variables, if they exist: 2307.Ev MACHINE , 2308.Ev MACHINE_ARCH , 2309.Ev MAKE , 2310.Ev MAKEFLAGS , 2311.Ev MAKEOBJDIR , 2312.Ev MAKEOBJDIRPREFIX , 2313.Ev MAKESYSPATH , 2314.Ev PWD , 2315and 2316.Ev TMPDIR . 2317.Pp 2318.Ev MAKEOBJDIRPREFIX 2319and 2320.Ev MAKEOBJDIR 2321may only be set in the environment or on the command line to 2322.Nm 2323and not as makefile variables; 2324see the description of 2325.Ql Va .OBJDIR 2326for more details. 2327.Sh FILES 2328.Bl -tag -width /usr/share/mk -compact 2329.It .depend 2330list of dependencies 2331.It Makefile 2332list of dependencies 2333.It makefile 2334list of dependencies 2335.It sys.mk 2336system makefile 2337.It /usr/share/mk 2338system makefile directory 2339.El 2340.Sh COMPATIBILITY 2341The basic make syntax is compatible between different versions of make; 2342however the special variables, variable modifiers and conditionals are not. 2343.Ss Older versions 2344An incomplete list of changes in older versions of 2345.Nm : 2346.Pp 2347The way that .for loop variables are substituted changed after 2348NetBSD 5.0 2349so that they still appear to be variable expansions. 2350In particular this stops them being treated as syntax, and removes some 2351obscure problems using them in .if statements. 2352.Pp 2353The way that parallel makes are scheduled changed in 2354NetBSD 4.0 2355so that .ORDER and .WAIT apply recursively to the dependent nodes. 2356The algorithms used may change again in the future. 2357.Ss Other make dialects 2358Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2359support most of the features of 2360.Nm 2361as described in this manual. 2362Most notably: 2363.Bl -bullet -offset indent 2364.It 2365The 2366.Ic .WAIT 2367and 2368.Ic .ORDER 2369declarations and most functionality pertaining to parallelization. 2370(GNU make supports parallelization but lacks these features needed to 2371control it effectively.) 2372.It 2373Directives, including for loops and conditionals and most of the 2374forms of include files. 2375(GNU make has its own incompatible and less powerful syntax for 2376conditionals.) 2377.It 2378All built-in variables that begin with a dot. 2379.It 2380Most of the special sources and targets that begin with a dot, 2381with the notable exception of 2382.Ic .PHONY , 2383.Ic .PRECIOUS , 2384and 2385.Ic .SUFFIXES . 2386.It 2387Variable modifiers, except for the 2388.Dl :old=new 2389string substitution, which does not portably support globbing with 2390.Ql % 2391and historically only works on declared suffixes. 2392.It 2393The 2394.Ic $> 2395variable even in its short form; most makes support this functionality 2396but its name varies. 2397.El 2398.Pp 2399Some features are somewhat more portable, such as assignment with 2400.Ic += , 2401.Ic ?= , 2402and 2403.Ic != . 2404The 2405.Ic .PATH 2406functionality is based on an older feature 2407.Ic VPATH 2408found in GNU make and many versions of SVR4 make; however, 2409historically its behavior is too ill-defined (and too buggy) to rely 2410upon. 2411.Pp 2412The 2413.Ic $@ 2414and 2415.Ic $< 2416variables are more or less universally portable, as is the 2417.Ic $(MAKE) 2418variable. 2419Basic use of suffix rules (for files only in the current directory, 2420not trying to chain transformations together, etc.) is also reasonably 2421portable. 2422.Sh SEE ALSO 2423.Xr mkdep 1 2424.Sh HISTORY 2425.Nm 2426is derived from NetBSD 2427.Xr make 1 . 2428It uses autoconf to facilitate portability to other platforms. 2429.Pp 2430A 2431make 2432command appeared in 2433.At v7 . 2434This 2435make 2436implementation is based on Adam De Boor's pmake program which was written 2437for Sprite at Berkeley. 2438It was designed to be a parallel distributed make running jobs on different 2439machines using a daemon called 2440.Dq customs . 2441.Pp 2442Historically the target/dependency 2443.Dq FRC 2444has been used to FoRCe rebuilding (since the target/dependency 2445does not exist... unless someone creates an 2446.Dq FRC 2447file). 2448.Sh BUGS 2449The 2450make 2451syntax is difficult to parse without actually acting on the data. 2452For instance, finding the end of a variable's use should involve scanning 2453each of the modifiers, using the correct terminator for each field. 2454In many places 2455make 2456just counts {} and () in order to find the end of a variable expansion. 2457.Pp 2458There is no way of escaping a space character in a filename. 2459