1.\" $NetBSD: make.1,v 1.307 2022/03/26 15:39:58 sjg 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 March 24, 2022 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 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 ${j} contains 676.Dq 3 . 677.El 678.Ss Variable classes 679The four different classes of variables (in order of increasing precedence) 680are: 681.Bl -tag -width Ds 682.It Environment variables 683Variables defined as part of 684.Nm Ns 's 685environment. 686.It Global variables 687Variables defined in the makefile or in included makefiles. 688.It Command line variables 689Variables defined as part of the command line. 690.It Local variables 691Variables that are defined specific to a certain target. 692.El 693.Pp 694Local variables can be set on a dependency line, if 695.Va .MAKE.TARGET_LOCAL_VARIABLES 696is not set to 697.Ql false . 698The rest of the line 699(which will already have had global variables expanded) 700is the variable value. 701For example: 702.Bd -literal -offset indent 703COMPILER_WRAPPERS= ccache distcc icecc 704 705${OBJS}: .MAKE.META.CMP_FILTER=${COMPILER_WRAPPERS:S,^,N,} 706.Ed 707.Pp 708Only the targets 709.Ql ${OBJS} 710will be impacted by that filter (in "meta" mode) and 711simply enabling/disabling any of the compiler wrappers will not render all 712of those targets out-of-date. 713.Pp 714.Em NOTE : 715target-local variable assignments behave differently in that; 716.Bl -tag -width Ds -offset indent 717.It Ic \&+= 718Only appends to a previous local assignment 719for the same target and variable. 720.It Ic \&:= 721Is redundant with respect to global variables, 722which have already been expanded. 723.El 724.Pp 725The seven built-in local variables are as follows: 726.Bl -tag -width ".ARCHIVE" -offset indent 727.It Va .ALLSRC 728The list of all sources for this target; also known as 729.Ql Va \&> . 730.It Va .ARCHIVE 731The name of the archive file; also known as 732.Ql Va \&! . 733.It Va .IMPSRC 734In suffix-transformation rules, the name/path of the source from which the 735target is to be transformed (the 736.Dq implied 737source); also known as 738.Ql Va \&< . 739It is not defined in explicit rules. 740.It Va .MEMBER 741The name of the archive member; also known as 742.Ql Va % . 743.It Va .OODATE 744The list of sources for this target that were deemed out-of-date; also 745known as 746.Ql Va \&? . 747.It Va .PREFIX 748The file prefix of the target, containing only the file portion, no suffix 749or preceding directory components; also known as 750.Ql Va * . 751The suffix must be one of the known suffixes declared with 752.Ic .SUFFIXES 753or it will not be recognized. 754.It Va .TARGET 755The name of the target; also known as 756.Ql Va @ . 757For compatibility with other makes this is an alias for 758.Ic .ARCHIVE 759in archive member rules. 760.El 761.Pp 762The shorter forms 763.Ql ( Va > , 764.Ql Va \&! , 765.Ql Va < , 766.Ql Va % , 767.Ql Va \&? , 768.Ql Va * , 769and 770.Ql Va @ ) 771are permitted for backward 772compatibility with historical makefiles and legacy POSIX make and are 773not recommended. 774.Pp 775Variants of these variables with the punctuation followed immediately by 776.Ql D 777or 778.Ql F , 779e.g. 780.Ql Va $(@D) , 781are legacy forms equivalent to using the 782.Ql :H 783and 784.Ql :T 785modifiers. 786These forms are accepted for compatibility with 787.At V 788makefiles and POSIX but are not recommended. 789.Pp 790Four of the local variables may be used in sources on dependency lines 791because they expand to the proper value for each target on the line. 792These variables are 793.Ql Va .TARGET , 794.Ql Va .PREFIX , 795.Ql Va .ARCHIVE , 796and 797.Ql Va .MEMBER . 798.Ss Additional built-in variables 799In addition, 800.Nm 801sets or knows about the following variables: 802.Bl -tag -width .MAKEOVERRIDES 803.It Va \&$ 804A single dollar sign 805.Ql \&$ , 806i.e. 807.Ql \&$$ 808expands to a single dollar 809sign. 810.It Va .ALLTARGETS 811The list of all targets encountered in the Makefile. 812If evaluated during 813Makefile parsing, lists only those targets encountered thus far. 814.It Va .CURDIR 815A path to the directory where 816.Nm 817was executed. 818Refer to the description of 819.Ql Ev PWD 820for more details. 821.It Va .INCLUDEDFROMDIR 822The directory of the file this Makefile was included from. 823.It Va .INCLUDEDFROMFILE 824The filename of the file this Makefile was included from. 825.It Ev MAKE 826The name that 827.Nm 828was executed with 829.Pq Va argv[0] . 830For compatibility 831.Nm 832also sets 833.Va .MAKE 834with the same value. 835The preferred variable to use is the environment variable 836.Ev MAKE 837because it is more compatible with other versions of 838.Nm 839and cannot be confused with the special target with the same name. 840.It Va .MAKE.DEPENDFILE 841Names the makefile (default 842.Ql Pa .depend ) 843from which generated dependencies are read. 844.It Va .MAKE.EXPAND_VARIABLES 845A boolean that controls the default behavior of the 846.Fl V 847option. 848If true, variable values printed with 849.Fl V 850are fully expanded; if false, the raw variable contents (which may 851include additional unexpanded variable references) are shown. 852.It Va .MAKE.EXPORTED 853The list of variables exported by 854.Nm . 855.It Va .MAKE.JOBS 856The argument to the 857.Fl j 858option. 859.It Va .MAKE.JOB.PREFIX 860If 861.Nm 862is run with 863.Ar j 864then output for each target is prefixed with a token 865.Ql --- target --- 866the first part of which can be controlled via 867.Va .MAKE.JOB.PREFIX . 868If 869.Va .MAKE.JOB.PREFIX 870is empty, no token is printed. 871.br 872For example: 873.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 874would produce tokens like 875.Ql ---make[1234] target --- 876making it easier to track the degree of parallelism being achieved. 877.It .MAKE.TARGET_LOCAL_VARIABLES 878If set to 879.Ql false , 880apparent variable assignments in dependency lines are 881treated as normal sources. 882.It Ev MAKEFLAGS 883The environment variable 884.Ql Ev MAKEFLAGS 885may contain anything that 886may be specified on 887.Nm Ns 's 888command line. 889Anything specified on 890.Nm Ns 's 891command line is appended to the 892.Ql Ev MAKEFLAGS 893variable which is then 894entered into the environment for all programs which 895.Nm 896executes. 897.It Va .MAKE.LEVEL 898The recursion depth of 899.Nm . 900The initial instance of 901.Nm 902will be 0, and an incremented value is put into the environment 903to be seen by the next generation. 904This allows tests like: 905.Li .if ${.MAKE.LEVEL} == 0 906to protect things which should only be evaluated in the initial instance of 907.Nm . 908.It Va .MAKE.MAKEFILE_PREFERENCE 909The ordered list of makefile names 910(default 911.Ql Pa makefile , 912.Ql Pa Makefile ) 913that 914.Nm 915will look for. 916.It Va .MAKE.MAKEFILES 917The list of makefiles read by 918.Nm , 919which is useful for tracking dependencies. 920Each makefile is recorded only once, regardless of the number of times read. 921.It Va .MAKE.MODE 922Processed after reading all makefiles. 923Can affect the mode that 924.Nm 925runs in. 926It can contain a number of keywords: 927.Bl -hang -width missing-filemon=bf. 928.It Pa compat 929Like 930.Fl B , 931puts 932.Nm 933into "compat" mode. 934.It Pa meta 935Puts 936.Nm 937into "meta" mode, where meta files are created for each target 938to capture the command run, the output generated and if 939.Xr filemon 4 940is available, the system calls which are of interest to 941.Nm . 942The captured output can be very useful when diagnosing errors. 943.It Pa curdirOk= Ar bf 944Normally 945.Nm 946will not create .meta files in 947.Ql Va .CURDIR . 948This can be overridden by setting 949.Va bf 950to a value which represents True. 951.It Pa missing-meta= Ar bf 952If 953.Va bf 954is True, then a missing .meta file makes the target out-of-date. 955.It Pa missing-filemon= Ar bf 956If 957.Va bf 958is True, then missing filemon data makes the target out-of-date. 959.It Pa nofilemon 960Do not use 961.Xr filemon 4 . 962.It Pa env 963For debugging, it can be useful to include the environment 964in the .meta file. 965.It Pa verbose 966If in "meta" mode, print a clue about the target being built. 967This is useful if the build is otherwise running silently. 968The message printed the value of: 969.Va .MAKE.META.PREFIX . 970.It Pa ignore-cmd 971Some makefiles have commands which are simply not stable. 972This keyword causes them to be ignored for 973determining whether a target is out of date in "meta" mode. 974See also 975.Ic .NOMETA_CMP . 976.It Pa silent= Ar bf 977If 978.Va bf 979is True, when a .meta file is created, mark the target 980.Ic .SILENT . 981.El 982.It Va .MAKE.META.BAILIWICK 983In "meta" mode, provides a list of prefixes which 984match the directories controlled by 985.Nm . 986If a file that was generated outside of 987.Va .OBJDIR 988but within said bailiwick is missing, 989the current target is considered out-of-date. 990.It Va .MAKE.META.CMP_FILTER 991In "meta" mode, it can (very rarely!) be useful to filter command 992lines before comparison. 993This variable can be set to a set of modifiers that will be applied to 994each line of the old and new command that differ, if the filtered 995commands still differ, the target is considered out-of-date. 996.It Va .MAKE.META.CREATED 997In "meta" mode, this variable contains a list of all the meta files 998updated. 999If not empty, it can be used to trigger processing of 1000.Va .MAKE.META.FILES . 1001.It Va .MAKE.META.FILES 1002In "meta" mode, this variable contains a list of all the meta files 1003used (updated or not). 1004This list can be used to process the meta files to extract dependency 1005information. 1006.It Va .MAKE.META.IGNORE_PATHS 1007Provides a list of path prefixes that should be ignored; 1008because the contents are expected to change over time. 1009The default list includes: 1010.Ql Pa /dev /etc /proc /tmp /var/run /var/tmp 1011.It Va .MAKE.META.IGNORE_PATTERNS 1012Provides a list of patterns to match against pathnames. 1013Ignore any that match. 1014.It Va .MAKE.META.IGNORE_FILTER 1015Provides a list of variable modifiers to apply to each pathname. 1016Ignore if the expansion is an empty string. 1017.It Va .MAKE.META.PREFIX 1018Defines the message printed for each meta file updated in "meta verbose" mode. 1019The default value is: 1020.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 1021.It Va .MAKEOVERRIDES 1022This variable is used to record the names of variables assigned to 1023on the command line, so that they may be exported as part of 1024.Ql Ev MAKEFLAGS . 1025This behavior can be disabled by assigning an empty value to 1026.Ql Va .MAKEOVERRIDES 1027within a makefile. 1028Extra variables can be exported from a makefile 1029by appending their names to 1030.Ql Va .MAKEOVERRIDES . 1031.Ql Ev MAKEFLAGS 1032is re-exported whenever 1033.Ql Va .MAKEOVERRIDES 1034is modified. 1035.It Va .MAKE.PATH_FILEMON 1036If 1037.Nm 1038was built with 1039.Xr filemon 4 1040support, this is set to the path of the device node. 1041This allows makefiles to test for this support. 1042.It Va .MAKE.PID 1043The process-id of 1044.Nm . 1045.It Va .MAKE.PPID 1046The parent process-id of 1047.Nm . 1048.It Va .MAKE.SAVE_DOLLARS 1049value should be a boolean that controls whether 1050.Ql $$ 1051are preserved when doing 1052.Ql := 1053assignments. 1054The default is false, for backwards compatibility. 1055Set to true for compatability with other makes. 1056If set to false, 1057.Ql $$ 1058becomes 1059.Ql $ 1060per normal evaluation rules. 1061.It Va .MAKE.UID 1062The user-id running 1063.Nm . 1064.It Va .MAKE.GID 1065The group-id running 1066.Nm . 1067.It Va MAKE_PRINT_VAR_ON_ERROR 1068When 1069.Nm 1070stops due to an error, it sets 1071.Ql Va .ERROR_TARGET 1072to the name of the target that failed, 1073.Ql Va .ERROR_CMD 1074to the commands of the failed target, 1075and in "meta" mode, it also sets 1076.Ql Va .ERROR_CWD 1077to the 1078.Xr getcwd 3 , 1079and 1080.Ql Va .ERROR_META_FILE 1081to the path of the meta file (if any) describing the failed target. 1082It then prints its name and the value of 1083.Ql Va .CURDIR 1084as well as the value of any variables named in 1085.Ql Va MAKE_PRINT_VAR_ON_ERROR . 1086.It Va .newline 1087This variable is simply assigned a newline character as its value. 1088This allows expansions using the 1089.Cm \&:@ 1090modifier to put a newline between 1091iterations of the loop rather than a space. 1092For example, the printing of 1093.Ql Va MAKE_PRINT_VAR_ON_ERROR 1094could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 1095.It Va .OBJDIR 1096A path to the directory where the targets are built. 1097Its value is determined by trying to 1098.Xr chdir 2 1099to the following directories in order and using the first match: 1100.Bl -enum 1101.It 1102.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 1103.Pp 1104(Only if 1105.Ql Ev MAKEOBJDIRPREFIX 1106is set in the environment or on the command line.) 1107.It 1108.Ev ${MAKEOBJDIR} 1109.Pp 1110(Only if 1111.Ql Ev MAKEOBJDIR 1112is set in the environment or on the command line.) 1113.It 1114.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 1115.It 1116.Ev ${.CURDIR} Ns Pa /obj 1117.It 1118.Pa /usr/obj/ Ns Ev ${.CURDIR} 1119.It 1120.Ev ${.CURDIR} 1121.El 1122.Pp 1123Variable expansion is performed on the value before it's used, 1124so expressions such as 1125.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 1126may be used. 1127This is especially useful with 1128.Ql Ev MAKEOBJDIR . 1129.Pp 1130.Ql Va .OBJDIR 1131may be modified in the makefile via the special target 1132.Ql Ic .OBJDIR . 1133In all cases, 1134.Nm 1135will 1136.Xr chdir 2 1137to the specified directory if it exists, and set 1138.Ql Va .OBJDIR 1139and 1140.Ql Ev PWD 1141to that directory before executing any targets. 1142.Pp 1143Except in the case of an explicit 1144.Ql Ic .OBJDIR 1145target, 1146.Nm 1147will check that the specified directory is writable and ignore it if not. 1148This check can be skipped by setting the environment variable 1149.Ql Ev MAKE_OBJDIR_CHECK_WRITABLE 1150to "no". 1151. 1152.It Va .PARSEDIR 1153A path to the directory of the current 1154.Ql Pa Makefile 1155being parsed. 1156.It Va .PARSEFILE 1157The basename of the current 1158.Ql Pa Makefile 1159being parsed. 1160This variable and 1161.Ql Va .PARSEDIR 1162are both set only while the 1163.Ql Pa Makefiles 1164are being parsed. 1165If you want to retain their current values, assign them to a variable 1166using assignment with expansion: 1167.Pq Ql Cm \&:= . 1168.It Va .PATH 1169A variable that represents the list of directories that 1170.Nm 1171will search for files. 1172The search list should be updated using the target 1173.Ql Va .PATH 1174rather than the variable. 1175.It Ev PWD 1176Alternate path to the current directory. 1177.Nm 1178normally sets 1179.Ql Va .CURDIR 1180to the canonical path given by 1181.Xr getcwd 3 . 1182However, if the environment variable 1183.Ql Ev PWD 1184is set and gives a path to the current directory, then 1185.Nm 1186sets 1187.Ql Va .CURDIR 1188to the value of 1189.Ql Ev PWD 1190instead. 1191This behavior is disabled if 1192.Ql Ev MAKEOBJDIRPREFIX 1193is set or 1194.Ql Ev MAKEOBJDIR 1195contains a variable transform. 1196.Ql Ev PWD 1197is set to the value of 1198.Ql Va .OBJDIR 1199for all programs which 1200.Nm 1201executes. 1202.It Ev .SHELL 1203The pathname of the shell used to run target scripts. 1204It is read-only. 1205.It Ev .SUFFIXES 1206The list of known suffixes. 1207It is read-only. 1208.It Ev .TARGETS 1209The list of targets explicitly specified on the command line, if any. 1210.It Ev VPATH 1211Colon-separated 1212.Pq Dq \&: 1213lists of directories that 1214.Nm 1215will search for files. 1216The variable is supported for compatibility with old make programs only, 1217use 1218.Ql Va .PATH 1219instead. 1220.El 1221.Ss Variable modifiers 1222Variable expansion may be modified to select or modify each word of the 1223variable (where a 1224.Dq word 1225is white-space delimited sequence of characters). 1226The general format of a variable expansion is as follows: 1227.Pp 1228.Dl ${variable[:modifier[:...]]} 1229.Pp 1230Each modifier begins with a colon, 1231which may be escaped with a backslash 1232.Pq Ql \e . 1233.Pp 1234A set of modifiers can be specified via a variable, as follows: 1235.Pp 1236.Dl modifier_variable=modifier[:...] 1237.Dl ${variable:${modifier_variable}[:...]} 1238.Pp 1239In this case the first modifier in the modifier_variable does not 1240start with a colon, since that must appear in the referencing 1241variable. 1242If any of the modifiers in the modifier_variable contain a dollar sign 1243.Pq Ql $ , 1244these must be doubled to avoid early expansion. 1245.Pp 1246The supported modifiers are: 1247.Bl -tag -width EEE 1248.It Cm \&:E 1249Replaces each word in the variable with its suffix. 1250.It Cm \&:H 1251Replaces each word in the variable with everything but the last component. 1252.It Cm \&:M Ns Ar pattern 1253Selects only those words that match 1254.Ar pattern . 1255The standard shell wildcard characters 1256.Pf ( Ql * , 1257.Ql \&? , 1258and 1259.Ql Oo Oc ) 1260may 1261be used. 1262The wildcard characters may be escaped with a backslash 1263.Pq Ql \e . 1264As a consequence of the way values are split into words, matched, 1265and then joined, a construct like 1266.Dl ${VAR:M*} 1267will normalize the inter-word spacing, removing all leading and 1268trailing space, and converting multiple consecutive spaces 1269to single spaces. 1270. 1271.It Cm \&:N Ns Ar pattern 1272This is identical to 1273.Ql Cm \&:M , 1274but selects all words which do not match 1275.Ar pattern . 1276.It Cm \&:O 1277Orders every word in variable alphabetically. 1278.It Cm \&:On 1279Orders every word in variable numerically. 1280A number followed by one of 1281.Ql k , 1282.Ql M 1283or 1284.Ql G 1285is multiplied by the appropriate factor (1024 (k), 1048576 (M), or 12861073741824 (G)). 1287Both upper- and lower-case letters are accepted. 1288.It Cm \&:Or 1289Orders every word in variable in reverse alphabetical order. 1290.It Cm \&:Orn 1291Orders every word in variable in reverse numerical order. 1292.It Cm \&:Ox 1293Shuffles the words in variable. 1294The results will be different each time you are referring to the 1295modified variable; use the assignment with expansion 1296.Pq Ql Cm \&:= 1297to prevent such behavior. 1298For example, 1299.Bd -literal -offset indent 1300LIST= uno due tre quattro 1301RANDOM_LIST= ${LIST:Ox} 1302STATIC_RANDOM_LIST:= ${LIST:Ox} 1303 1304all: 1305 @echo "${RANDOM_LIST}" 1306 @echo "${RANDOM_LIST}" 1307 @echo "${STATIC_RANDOM_LIST}" 1308 @echo "${STATIC_RANDOM_LIST}" 1309.Ed 1310may produce output similar to: 1311.Bd -literal -offset indent 1312quattro due tre uno 1313tre due quattro uno 1314due uno quattro tre 1315due uno quattro tre 1316.Ed 1317.It Cm \&:Q 1318Quotes every shell meta-character in the variable, so that it can be passed 1319safely to the shell. 1320.It Cm \&:q 1321Quotes every shell meta-character in the variable, and also doubles 1322.Sq $ 1323characters so that it can be passed 1324safely through recursive invocations of 1325.Nm . 1326This is equivalent to: 1327.Sq \&:S/\e\&$/&&/g:Q . 1328.It Cm \&:R 1329Replaces each word in the variable with everything but its suffix. 1330.It Cm \&:range[=count] 1331The value is an integer sequence representing the words of the original 1332value, or the supplied 1333.Va count . 1334.It Cm \&:gmtime[=utc] 1335The value is a format string for 1336.Xr strftime 3 , 1337using 1338.Xr gmtime 3 . 1339If a 1340.Va utc 1341value is not provided or is 0, the current time is used. 1342.It Cm \&:hash 1343Computes a 32-bit hash of the value and encode it as hex digits. 1344.It Cm \&:localtime[=utc] 1345The value is a format string for 1346.Xr strftime 3 , 1347using 1348.Xr localtime 3 . 1349If a 1350.Va utc 1351value is not provided or is 0, the current time is used. 1352.It Cm \&:tA 1353Attempts to convert variable to an absolute path using 1354.Xr realpath 3 , 1355if that fails, the value is unchanged. 1356.It Cm \&:tl 1357Converts variable to lower-case letters. 1358.It Cm \&:ts Ns Ar c 1359Words in the variable are normally separated by a space on expansion. 1360This modifier sets the separator to the character 1361.Ar c . 1362If 1363.Ar c 1364is omitted, then no separator is used. 1365The common escapes (including octal numeric codes) work as expected. 1366.It Cm \&:tu 1367Converts variable to upper-case letters. 1368.It Cm \&:tW 1369Causes the value to be treated as a single word 1370(possibly containing embedded white space). 1371See also 1372.Ql Cm \&:[*] . 1373.It Cm \&:tw 1374Causes the value to be treated as a sequence of 1375words delimited by white space. 1376See also 1377.Ql Cm \&:[@] . 1378.Sm off 1379.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1380.Sm on 1381Modifies the first occurrence of 1382.Ar old_string 1383in each word of the variable's value, replacing it with 1384.Ar new_string . 1385If a 1386.Ql g 1387is appended to the last delimiter of the pattern, all occurrences 1388in each word are replaced. 1389If a 1390.Ql 1 1391is appended to the last delimiter of the pattern, only the first occurrence 1392is affected. 1393If a 1394.Ql W 1395is appended to the last delimiter of the pattern, 1396then the value is treated as a single word 1397(possibly containing embedded white space). 1398If 1399.Ar old_string 1400begins with a caret 1401.Pq Ql ^ , 1402.Ar old_string 1403is anchored at the beginning of each word. 1404If 1405.Ar old_string 1406ends with a dollar sign 1407.Pq Ql \&$ , 1408it is anchored at the end of each word. 1409Inside 1410.Ar new_string , 1411an ampersand 1412.Pq Ql & 1413is replaced by 1414.Ar old_string 1415(without any 1416.Ql ^ 1417or 1418.Ql \&$ ) . 1419Any character may be used as a delimiter for the parts of the modifier 1420string. 1421The anchoring, ampersand and delimiter characters may be escaped with a 1422backslash 1423.Pq Ql \e . 1424.Pp 1425Variable expansion occurs in the normal fashion inside both 1426.Ar old_string 1427and 1428.Ar new_string 1429with the single exception that a backslash is used to prevent the expansion 1430of a dollar sign 1431.Pq Ql \&$ , 1432not a preceding dollar sign as is usual. 1433.Sm off 1434.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1435.Sm on 1436The 1437.Cm \&:C 1438modifier is just like the 1439.Cm \&:S 1440modifier except that the old and new strings, instead of being 1441simple strings, are an extended regular expression (see 1442.Xr regex 3 ) 1443string 1444.Ar pattern 1445and an 1446.Xr ed 1 Ns \-style 1447string 1448.Ar replacement . 1449Normally, the first occurrence of the pattern 1450.Ar pattern 1451in each word of the value is substituted with 1452.Ar replacement . 1453The 1454.Ql 1 1455modifier causes the substitution to apply to at most one word; the 1456.Ql g 1457modifier causes the substitution to apply to as many instances of the 1458search pattern 1459.Ar pattern 1460as occur in the word or words it is found in; the 1461.Ql W 1462modifier causes the value to be treated as a single word 1463(possibly containing embedded white space). 1464.Pp 1465As for the 1466.Cm \&:S 1467modifier, the 1468.Ar pattern 1469and 1470.Ar replacement 1471are subjected to variable expansion before being parsed as 1472regular expressions. 1473.It Cm \&:T 1474Replaces each word in the variable with its last path component. 1475.It Cm \&:u 1476Removes adjacent duplicate words (like 1477.Xr uniq 1 ) . 1478.Sm off 1479.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1480.Sm on 1481If the variable name (not its value), when parsed as a .if conditional 1482expression, evaluates to true, return as its value the 1483.Ar true_string , 1484otherwise return the 1485.Ar false_string . 1486Since the variable name is used as the expression, \&:\&? must be the 1487first modifier after the variable name itself - which will, of course, 1488usually contain variable expansions. 1489A common error is trying to use expressions like 1490.Dl ${NUMBERS:M42:?match:no} 1491which actually tests defined(NUMBERS), 1492to determine if any words match "42" you need to use something like: 1493.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1494.It Ar :old_string=new_string 1495This is the 1496.At V 1497style variable substitution. 1498It must be the last modifier specified. 1499If 1500.Ar old_string 1501or 1502.Ar new_string 1503do not contain the pattern matching character 1504.Ar % 1505then it is assumed that they are 1506anchored at the end of each word, so only suffixes or entire 1507words may be replaced. 1508Otherwise 1509.Ar % 1510is the substring of 1511.Ar old_string 1512to be replaced in 1513.Ar new_string . 1514If only 1515.Ar old_string 1516contains the pattern matching character 1517.Ar % , 1518and 1519.Ar old_string 1520matches, then the result is the 1521.Ar new_string . 1522If only the 1523.Ar new_string 1524contains the pattern matching character 1525.Ar % , 1526then it is not treated specially and it is printed as a literal 1527.Ar % 1528on match. 1529If there is more than one pattern matching character 1530.Ar ( % ) 1531in either the 1532.Ar new_string 1533or 1534.Ar old_string , 1535only the first instance is treated specially (as the pattern character); 1536all subsequent instances are treated as regular characters. 1537.Pp 1538Variable expansion occurs in the normal fashion inside both 1539.Ar old_string 1540and 1541.Ar new_string 1542with the single exception that a backslash is used to prevent the 1543expansion of a dollar sign 1544.Pq Ql \&$ , 1545not a preceding dollar sign as is usual. 1546.Sm off 1547.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1548.Sm on 1549This is the loop expansion mechanism from the OSF Development 1550Environment (ODE) make. 1551Unlike 1552.Cm \&.for 1553loops, expansion occurs at the time of reference. 1554Assigns 1555.Ar temp 1556to each word in the variable and evaluates 1557.Ar string . 1558The ODE convention is that 1559.Ar temp 1560should start and end with a period. 1561For example. 1562.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1563.Pp 1564However a single character variable is often more readable: 1565.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1566.It Cm \&:_[=var] 1567Saves the current variable value in 1568.Ql $_ 1569or the named 1570.Va var 1571for later reference. 1572Example usage: 1573.Bd -literal -offset indent 1574M_cmpv.units = 1 1000 1000000 1575M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\ 1576\\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh 1577 1578.Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}} 1579 1580.Ed 1581Here 1582.Ql $_ 1583is used to save the result of the 1584.Ql :S 1585modifier which is later referenced using the index values from 1586.Ql :range . 1587.It Cm \&:U Ns Ar newval 1588If the variable is undefined, 1589.Ar newval 1590is the value. 1591If the variable is defined, the existing value is returned. 1592This is another ODE make feature. 1593It is handy for setting per-target CFLAGS for instance: 1594.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1595If a value is only required if the variable is undefined, use: 1596.Dl ${VAR:D:Unewval} 1597.It Cm \&:D Ns Ar newval 1598If the variable is defined, 1599.Ar newval 1600is the value. 1601.It Cm \&:L 1602The name of the variable is the value. 1603.It Cm \&:P 1604The path of the node which has the same name as the variable 1605is the value. 1606If no such node exists or its path is null, then the 1607name of the variable is used. 1608In order for this modifier to work, the name (node) must at least have 1609appeared on the rhs of a dependency. 1610.Sm off 1611.It Cm \&:\&! Ar cmd Cm \&! 1612.Sm on 1613The output of running 1614.Ar cmd 1615is the value. 1616.It Cm \&:sh 1617If the variable is non-empty it is run as a command and the output 1618becomes the new value. 1619.It Cm \&::= Ns Ar str 1620The variable is assigned the value 1621.Ar str 1622after substitution. 1623This modifier and its variations are useful in 1624obscure situations such as wanting to set a variable when shell commands 1625are being parsed. 1626These assignment modifiers always expand to 1627nothing, so if appearing in a rule line by themselves should be 1628preceded with something to keep 1629.Nm 1630happy. 1631.Pp 1632The 1633.Ql Cm \&:: 1634helps avoid false matches with the 1635.At V 1636style 1637.Cm \&:= 1638modifier and since substitution always occurs the 1639.Cm \&::= 1640form is vaguely appropriate. 1641.It Cm \&::?= Ns Ar str 1642As for 1643.Cm \&::= 1644but only if the variable does not already have a value. 1645.It Cm \&::+= Ns Ar str 1646Append 1647.Ar str 1648to the variable. 1649.It Cm \&::!= Ns Ar cmd 1650Assign the output of 1651.Ar cmd 1652to the variable. 1653.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1654Selects one or more words from the value, 1655or performs other operations related to the way in which the 1656value is divided into words. 1657.Pp 1658Ordinarily, a value is treated as a sequence of words 1659delimited by white space. 1660Some modifiers suppress this behavior, 1661causing a value to be treated as a single word 1662(possibly containing embedded white space). 1663An empty value, or a value that consists entirely of white-space, 1664is treated as a single word. 1665For the purposes of the 1666.Ql Cm \&:[] 1667modifier, the words are indexed both forwards using positive integers 1668(where index 1 represents the first word), 1669and backwards using negative integers 1670(where index \-1 represents the last word). 1671.Pp 1672The 1673.Ar range 1674is subjected to variable expansion, and the expanded result is 1675then interpreted as follows: 1676.Bl -tag -width index 1677.\" :[n] 1678.It Ar index 1679Selects a single word from the value. 1680.\" :[start..end] 1681.It Ar start Ns Cm \&.. Ns Ar end 1682Selects all words from 1683.Ar start 1684to 1685.Ar end , 1686inclusive. 1687For example, 1688.Ql Cm \&:[2..-1] 1689selects all words from the second word to the last word. 1690If 1691.Ar start 1692is greater than 1693.Ar end , 1694then the words are output in reverse order. 1695For example, 1696.Ql Cm \&:[-1..1] 1697selects all the words from last to first. 1698If the list is already ordered, then this effectively reverses 1699the list, but it is more efficient to use 1700.Ql Cm \&:Or 1701instead of 1702.Ql Cm \&:O:[-1..1] . 1703.\" :[*] 1704.It Cm \&* 1705Causes subsequent modifiers to treat the value as a single word 1706(possibly containing embedded white space). 1707Analogous to the effect of 1708\&"$*\&" 1709in Bourne shell. 1710.\" :[0] 1711.It 0 1712Means the same as 1713.Ql Cm \&:[*] . 1714.\" :[*] 1715.It Cm \&@ 1716Causes subsequent modifiers to treat the value as a sequence of words 1717delimited by white space. 1718Analogous to the effect of 1719\&"$@\&" 1720in Bourne shell. 1721.\" :[#] 1722.It Cm \&# 1723Returns the number of words in the value. 1724.El \" :[range] 1725.El 1726.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1727Makefile inclusion, conditional structures and for loops reminiscent 1728of the C programming language are provided in 1729.Nm . 1730All such structures are identified by a line beginning with a single 1731dot 1732.Pq Ql \&. 1733character. 1734Files are included with either 1735.Cm \&.include \&< Ns Ar file Ns Cm \&> 1736or 1737.Cm \&.include \&\*q Ns Ar file Ns Cm \&\*q . 1738Variables between the angle brackets or double quotes are expanded 1739to form the file name. 1740If angle brackets are used, the included makefile is expected to be in 1741the system makefile directory. 1742If double quotes are used, the including makefile's directory and any 1743directories specified using the 1744.Fl I 1745option are searched before the system 1746makefile directory. 1747For compatibility with other versions of 1748.Nm 1749.Ql include file ... 1750is also accepted. 1751.Pp 1752If the include statement is written as 1753.Cm .-include 1754or as 1755.Cm .sinclude 1756then errors locating and/or opening include files are ignored. 1757.Pp 1758If the include statement is written as 1759.Cm .dinclude 1760not only are errors locating and/or opening include files ignored, 1761but stale dependencies within the included file will be ignored 1762just like 1763.Va .MAKE.DEPENDFILE . 1764.Pp 1765Conditional expressions are also preceded by a single dot as the first 1766character of a line. 1767The possible conditionals are as follows: 1768.Bl -tag -width Ds 1769.It Ic .error Ar message 1770The message is printed along with the name of the makefile and line number, 1771then 1772.Nm 1773will exit immediately. 1774.It Ic .export Ar variable ... 1775Export the specified global variable. 1776If no variable list is provided, all globals are exported 1777except for internal variables (those that start with 1778.Ql \&. ) . 1779This is not affected by the 1780.Fl X 1781flag, so should be used with caution. 1782For compatibility with other 1783.Nm 1784programs 1785.Ql export variable=value 1786is also accepted. 1787.Pp 1788Appending a variable name to 1789.Va .MAKE.EXPORTED 1790is equivalent to exporting a variable. 1791.It Ic .export-env Ar variable ... 1792The same as 1793.Ql .export , 1794except that the variable is not appended to 1795.Va .MAKE.EXPORTED . 1796This allows exporting a value to the environment which is different from that 1797used by 1798.Nm 1799internally. 1800.It Ic .export-literal Ar variable ... 1801The same as 1802.Ql .export-env , 1803except that variables in the value are not expanded. 1804.It Ic .info Ar message 1805The message is printed along with the name of the makefile and line number. 1806.It Ic .undef Ar variable ... 1807Un-define the specified global variables. 1808Only global variables can be un-defined. 1809.It Ic .unexport Ar variable ... 1810The opposite of 1811.Ql .export . 1812The specified global 1813.Va variable 1814will be removed from 1815.Va .MAKE.EXPORTED . 1816If no variable list is provided, all globals are unexported, 1817and 1818.Va .MAKE.EXPORTED 1819deleted. 1820.It Ic .unexport-env 1821Unexport all globals previously exported and 1822clear the environment inherited from the parent. 1823This operation will cause a memory leak of the original environment, 1824so should be used sparingly. 1825Testing for 1826.Va .MAKE.LEVEL 1827being 0, would make sense. 1828Also note that any variables which originated in the parent environment 1829should be explicitly preserved if desired. 1830For example: 1831.Bd -literal -offset indent 1832.Li .if ${.MAKE.LEVEL} == 0 1833PATH := ${PATH} 1834.Li .unexport-env 1835.Li .export PATH 1836.Li .endif 1837.Pp 1838.Ed 1839Would result in an environment containing only 1840.Ql Ev PATH , 1841which is the minimal useful environment. 1842Actually 1843.Ql Ev .MAKE.LEVEL 1844will also be pushed into the new environment. 1845.It Ic .warning Ar message 1846The message prefixed by 1847.Ql Pa warning: 1848is printed along with the name of the makefile and line number. 1849.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1850Test the value of an expression. 1851.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1852Test the value of a variable. 1853.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1854Test the value of a variable. 1855.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1856Test the target being built. 1857.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1858Test the target being built. 1859.It Ic .else 1860Reverse the sense of the last conditional. 1861.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1862A combination of 1863.Ql Ic .else 1864followed by 1865.Ql Ic .if . 1866.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1867A combination of 1868.Ql Ic .else 1869followed by 1870.Ql Ic .ifdef . 1871.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1872A combination of 1873.Ql Ic .else 1874followed by 1875.Ql Ic .ifndef . 1876.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1877A combination of 1878.Ql Ic .else 1879followed by 1880.Ql Ic .ifmake . 1881.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1882A combination of 1883.Ql Ic .else 1884followed by 1885.Ql Ic .ifnmake . 1886.It Ic .endif 1887End the body of the conditional. 1888.El 1889.Pp 1890The 1891.Ar operator 1892may be any one of the following: 1893.Bl -tag -width "Cm XX" 1894.It Cm \&|\&| 1895Logical OR. 1896.It Cm \&&& 1897Logical 1898.Tn AND ; 1899of higher precedence than 1900.Dq \&|\&| . 1901.El 1902.Pp 1903As in C, 1904.Nm 1905will only evaluate a conditional as far as is necessary to determine 1906its value. 1907Parentheses may be used to change the order of evaluation. 1908The boolean operator 1909.Ql Ic \&! 1910may be used to logically negate an entire 1911conditional. 1912It is of higher precedence than 1913.Ql Ic \&&& . 1914.Pp 1915The value of 1916.Ar expression 1917may be any of the following: 1918.Bl -tag -width defined 1919.It Ic defined 1920Takes a variable name as an argument and evaluates to true if the variable 1921has been defined. 1922.It Ic make 1923Takes a target name as an argument and evaluates to true if the target 1924was specified as part of 1925.Nm Ns 's 1926command line or was declared the default target (either implicitly or 1927explicitly, see 1928.Va .MAIN ) 1929before the line containing the conditional. 1930.It Ic empty 1931Takes a variable, with possible modifiers, and evaluates to true if 1932the expansion of the variable would result in an empty string. 1933.It Ic exists 1934Takes a file name as an argument and evaluates to true if the file exists. 1935The file is searched for on the system search path (see 1936.Va .PATH ) . 1937.It Ic target 1938Takes a target name as an argument and evaluates to true if the target 1939has been defined. 1940.It Ic commands 1941Takes a target name as an argument and evaluates to true if the target 1942has been defined and has commands associated with it. 1943.El 1944.Pp 1945.Ar Expression 1946may also be an arithmetic or string comparison. 1947Variable expansion is 1948performed on both sides of the comparison, after which the numerical 1949values are compared. 1950A value is interpreted as hexadecimal if it is 1951preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1952The standard C relational operators are all supported. 1953If after 1954variable expansion, either the left or right hand side of a 1955.Ql Ic == 1956or 1957.Ql Ic "!=" 1958operator is not a numerical value, then 1959string comparison is performed between the expanded 1960variables. 1961If no relational operator is given, it is assumed that the expanded 1962variable is being compared against 0, or an empty string in the case 1963of a string comparison. 1964.Pp 1965When 1966.Nm 1967is evaluating one of these conditional expressions, and it encounters 1968a (white-space separated) word it doesn't recognize, either the 1969.Dq make 1970or 1971.Dq defined 1972expression is applied to it, depending on the form of the conditional. 1973If the form is 1974.Ql Ic .ifdef , 1975.Ql Ic .ifndef , 1976or 1977.Ql Ic .if 1978the 1979.Dq defined 1980expression is applied. 1981Similarly, if the form is 1982.Ql Ic .ifmake 1983or 1984.Ql Ic .ifnmake , 1985the 1986.Dq make 1987expression is applied. 1988.Pp 1989If the conditional evaluates to true the parsing of the makefile continues 1990as before. 1991If it evaluates to false, the following lines are skipped. 1992In both cases this continues until a 1993.Ql Ic .else 1994or 1995.Ql Ic .endif 1996is found. 1997.Pp 1998For loops are typically used to apply a set of rules to a list of files. 1999The syntax of a for loop is: 2000.Pp 2001.Bl -tag -compact -width Ds 2002.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 2003.It Aq make-lines 2004.It Ic \&.endfor 2005.El 2006.Pp 2007After the for 2008.Ic expression 2009is evaluated, it is split into words. 2010On each iteration of the loop, one word is taken and assigned to each 2011.Ic variable , 2012in order, and these 2013.Ic variables 2014are substituted into the 2015.Ic make-lines 2016inside the body of the for loop. 2017The number of words must come out even; that is, if there are three 2018iteration variables, the number of words provided must be a multiple 2019of three. 2020.Sh COMMENTS 2021Comments begin with a hash 2022.Pq Ql \&# 2023character, anywhere but in a shell 2024command line, and continue to the end of an unescaped new line. 2025.Sh SPECIAL SOURCES (ATTRIBUTES) 2026.Bl -tag -width .IGNOREx 2027.It Ic .EXEC 2028Target is never out of date, but always execute commands anyway. 2029.It Ic .IGNORE 2030Ignore any errors from the commands associated with this target, exactly 2031as if they all were preceded by a dash 2032.Pq Ql \- . 2033.\" .It Ic .INVISIBLE 2034.\" XXX 2035.\" .It Ic .JOIN 2036.\" XXX 2037.It Ic .MADE 2038Mark all sources of this target as being up-to-date. 2039.It Ic .MAKE 2040Execute the commands associated with this target even if the 2041.Fl n 2042or 2043.Fl t 2044options were specified. 2045Normally used to mark recursive 2046.Nm Ns s . 2047.It Ic .META 2048Create a meta file for the target, even if it is flagged as 2049.Ic .PHONY , 2050.Ic .MAKE , 2051or 2052.Ic .SPECIAL . 2053Usage in conjunction with 2054.Ic .MAKE 2055is the most likely case. 2056In "meta" mode, the target is out-of-date if the meta file is missing. 2057.It Ic .NOMETA 2058Do not create a meta file for the target. 2059Meta files are also not created for 2060.Ic .PHONY , 2061.Ic .MAKE , 2062or 2063.Ic .SPECIAL 2064targets. 2065.It Ic .NOMETA_CMP 2066Ignore differences in commands when deciding if target is out of date. 2067This is useful if the command contains a value which always changes. 2068If the number of commands change, though, the target will still be out of date. 2069The same effect applies to any command line that uses the variable 2070.Va .OODATE , 2071which can be used for that purpose even when not otherwise needed or desired: 2072.Bd -literal -offset indent 2073 2074skip-compare-for-some: 2075 @echo this will be compared 2076 @echo this will not ${.OODATE:M.NOMETA_CMP} 2077 @echo this will also be compared 2078 2079.Ed 2080The 2081.Cm \&:M 2082pattern suppresses any expansion of the unwanted variable. 2083.It Ic .NOPATH 2084Do not search for the target in the directories specified by 2085.Ic .PATH . 2086.It Ic .NOTMAIN 2087Normally 2088.Nm 2089selects the first target it encounters as the default target to be built 2090if no target was specified. 2091This source prevents this target from being selected. 2092.It Ic .OPTIONAL 2093If a target is marked with this attribute and 2094.Nm 2095can't figure out how to create it, it will ignore this fact and assume 2096the file isn't needed or already exists. 2097.It Ic .PHONY 2098The target does not 2099correspond to an actual file; it is always considered to be out of date, 2100and will not be created with the 2101.Fl t 2102option. 2103Suffix-transformation rules are not applied to 2104.Ic .PHONY 2105targets. 2106.It Ic .PRECIOUS 2107When 2108.Nm 2109is interrupted, it normally removes any partially made targets. 2110This source prevents the target from being removed. 2111.It Ic .RECURSIVE 2112Synonym for 2113.Ic .MAKE . 2114.It Ic .SILENT 2115Do not echo any of the commands associated with this target, exactly 2116as if they all were preceded by an at sign 2117.Pq Ql @ . 2118.It Ic .USE 2119Turn the target into 2120.Nm Ns 's 2121version of a macro. 2122When the target is used as a source for another target, the other target 2123acquires the commands, sources, and attributes (except for 2124.Ic .USE ) 2125of the 2126source. 2127If the target already has commands, the 2128.Ic .USE 2129target's commands are appended 2130to them. 2131.It Ic .USEBEFORE 2132Exactly like 2133.Ic .USE , 2134but prepend the 2135.Ic .USEBEFORE 2136target commands to the target. 2137.It Ic .WAIT 2138If 2139.Ic .WAIT 2140appears in a dependency line, the sources that precede it are 2141made before the sources that succeed it in the line. 2142Since the dependents of files are not made until the file itself 2143could be made, this also stops the dependents being built unless they 2144are needed for another branch of the dependency tree. 2145So given: 2146.Bd -literal 2147x: a .WAIT b 2148 echo x 2149a: 2150 echo a 2151b: b1 2152 echo b 2153b1: 2154 echo b1 2155 2156.Ed 2157the output is always 2158.Ql a , 2159.Ql b1 , 2160.Ql b , 2161.Ql x . 2162.br 2163The ordering imposed by 2164.Ic .WAIT 2165is only relevant for parallel makes. 2166.El 2167.Sh SPECIAL TARGETS 2168Special targets may not be included with other targets, i.e. they must be 2169the only target specified. 2170.Bl -tag -width .BEGINx 2171.It Ic .BEGIN 2172Any command lines attached to this target are executed before anything 2173else is done. 2174.It Ic .DEFAULT 2175This is sort of a 2176.Ic .USE 2177rule for any target (that was used only as a 2178source) that 2179.Nm 2180can't figure out any other way to create. 2181Only the shell script is used. 2182The 2183.Ic .IMPSRC 2184variable of a target that inherits 2185.Ic .DEFAULT Ns 's 2186commands is set 2187to the target's own name. 2188.It Ic .DELETE_ON_ERROR 2189If this target is present in the makefile, it globally causes make to 2190delete targets whose commands fail. 2191(By default, only targets whose commands are interrupted during 2192execution are deleted. 2193This is the historical behavior.) 2194This setting can be used to help prevent half-finished or malformed 2195targets from being left around and corrupting future rebuilds. 2196.It Ic .END 2197Any command lines attached to this target are executed after everything 2198else is done. 2199.It Ic .ERROR 2200Any command lines attached to this target are executed when another target fails. 2201The 2202.Ic .ERROR_TARGET 2203variable is set to the target that failed. 2204See also 2205.Ic MAKE_PRINT_VAR_ON_ERROR . 2206.It Ic .IGNORE 2207Mark each of the sources with the 2208.Ic .IGNORE 2209attribute. 2210If no sources are specified, this is the equivalent of specifying the 2211.Fl i 2212option. 2213.It Ic .INTERRUPT 2214If 2215.Nm 2216is interrupted, the commands for this target will be executed. 2217.It Ic .MAIN 2218If no target is specified when 2219.Nm 2220is invoked, this target will be built. 2221.It Ic .MAKEFLAGS 2222This target provides a way to specify flags for 2223.Nm 2224when the makefile is used. 2225The flags are as if typed to the shell, though the 2226.Fl f 2227option will have 2228no effect. 2229.\" XXX: NOT YET!!!! 2230.\" .It Ic .NOTPARALLEL 2231.\" The named targets are executed in non parallel mode. 2232.\" If no targets are 2233.\" specified, then all targets are executed in non parallel mode. 2234.It Ic .NOPATH 2235Apply the 2236.Ic .NOPATH 2237attribute to any specified sources. 2238.It Ic .NOTPARALLEL 2239Disable parallel mode. 2240.It Ic .NO_PARALLEL 2241Synonym for 2242.Ic .NOTPARALLEL , 2243for compatibility with other pmake variants. 2244.It Ic .OBJDIR 2245The source is a new value for 2246.Ql Va .OBJDIR . 2247If it exists, 2248.Nm 2249will 2250.Xr chdir 2 2251to it and update the value of 2252.Ql Va .OBJDIR . 2253.It Ic .ORDER 2254The named targets are made in sequence. 2255This ordering does not add targets to the list of targets to be made. 2256Since the dependents of a target do not get built until the target itself 2257could be built, unless 2258.Ql a 2259is built by another part of the dependency graph, 2260the following is a dependency loop: 2261.Bd -literal 2262\&.ORDER: b a 2263b: a 2264.Ed 2265.Pp 2266The ordering imposed by 2267.Ic .ORDER 2268is only relevant for parallel makes. 2269.\" XXX: NOT YET!!!! 2270.\" .It Ic .PARALLEL 2271.\" The named targets are executed in parallel mode. 2272.\" If no targets are 2273.\" specified, then all targets are executed in parallel mode. 2274.It Ic .PATH 2275The sources are directories which are to be searched for files not 2276found in the current directory. 2277If no sources are specified, any previously specified directories are 2278deleted. 2279If the source is the special 2280.Ic .DOTLAST 2281target, then the current working 2282directory is searched last. 2283.It Ic .PATH. Ns Va suffix 2284Like 2285.Ic .PATH 2286but applies only to files with a particular suffix. 2287The suffix must have been previously declared with 2288.Ic .SUFFIXES . 2289.It Ic .PHONY 2290Apply the 2291.Ic .PHONY 2292attribute to any specified sources. 2293.It Ic .POSIX 2294This should be the first non-comment line in a Makefile. 2295It results in the variable 2296.Va %POSIX 2297being defined with the value 2298.Ql 1003.2 . 2299The first time 2300.Ic .POSIX 2301is encountered, the makefile 2302.Ql posix.mk 2303will be included if possible, 2304to provide POSIX compatible default rules. 2305If 2306.Nm 2307is run with the 2308.Fl r 2309flag, then only 2310.Ql posix.mk 2311will contribute to the default rules. 2312.It Ic .PRECIOUS 2313Apply the 2314.Ic .PRECIOUS 2315attribute to any specified sources. 2316If no sources are specified, the 2317.Ic .PRECIOUS 2318attribute is applied to every 2319target in the file. 2320.It Ic .SHELL 2321Sets the shell that 2322.Nm 2323will use to execute commands. 2324The sources are a set of 2325.Ar field=value 2326pairs. 2327.Bl -tag -width hasErrCtls 2328.It Ar name 2329This is the minimal specification, used to select one of the built-in 2330shell specs; 2331.Ar sh , 2332.Ar ksh , 2333and 2334.Ar csh . 2335.It Ar path 2336Specifies the path to the shell. 2337.It Ar hasErrCtl 2338Indicates whether the shell supports exit on error. 2339.It Ar check 2340The command to turn on error checking. 2341.It Ar ignore 2342The command to disable error checking. 2343.It Ar echo 2344The command to turn on echoing of commands executed. 2345.It Ar quiet 2346The command to turn off echoing of commands executed. 2347.It Ar filter 2348The output to filter after issuing the 2349.Ar quiet 2350command. 2351It is typically identical to 2352.Ar quiet . 2353.It Ar errFlag 2354The flag to pass the shell to enable error checking. 2355.It Ar echoFlag 2356The flag to pass the shell to enable command echoing. 2357.It Ar newline 2358The string literal to pass the shell that results in a single newline 2359character when used outside of any quoting characters. 2360.El 2361Example: 2362.Bd -literal 2363\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 2364 check="set \-e" ignore="set +e" \e 2365 echo="set \-v" quiet="set +v" filter="set +v" \e 2366 echoFlag=v errFlag=e newline="'\en'" 2367.Ed 2368.It Ic .SILENT 2369Apply the 2370.Ic .SILENT 2371attribute to any specified sources. 2372If no sources are specified, the 2373.Ic .SILENT 2374attribute is applied to every 2375command in the file. 2376.It Ic .STALE 2377This target gets run when a dependency file contains stale entries, having 2378.Va .ALLSRC 2379set to the name of that dependency file. 2380.It Ic .SUFFIXES 2381Each source specifies a suffix to 2382.Nm . 2383If no sources are specified, any previously specified suffixes are deleted. 2384It allows the creation of suffix-transformation rules. 2385.Pp 2386Example: 2387.Bd -literal 2388\&.SUFFIXES: .o 2389\&.c.o: 2390 cc \-o ${.TARGET} \-c ${.IMPSRC} 2391.Ed 2392.El 2393.Sh ENVIRONMENT 2394.Nm 2395uses the following environment variables, if they exist: 2396.Ev MACHINE , 2397.Ev MACHINE_ARCH , 2398.Ev MAKE , 2399.Ev MAKEFLAGS , 2400.Ev MAKEOBJDIR , 2401.Ev MAKEOBJDIRPREFIX , 2402.Ev MAKESYSPATH , 2403.Ev PWD , 2404and 2405.Ev TMPDIR . 2406.Pp 2407.Ev MAKEOBJDIRPREFIX 2408and 2409.Ev MAKEOBJDIR 2410may only be set in the environment or on the command line to 2411.Nm 2412and not as makefile variables; 2413see the description of 2414.Ql Va .OBJDIR 2415for more details. 2416.Sh FILES 2417.Bl -tag -width /usr/share/mk -compact 2418.It .depend 2419list of dependencies 2420.It Makefile 2421list of dependencies 2422.It makefile 2423list of dependencies 2424.It sys.mk 2425system makefile 2426.It /usr/share/mk 2427system makefile directory 2428.El 2429.Sh COMPATIBILITY 2430The basic make syntax is compatible between different versions of make; 2431however the special variables, variable modifiers and conditionals are not. 2432.Ss Older versions 2433An incomplete list of changes in older versions of 2434.Nm : 2435.Pp 2436The way that .for loop variables are substituted changed after 2437NetBSD 5.0 2438so that they still appear to be variable expansions. 2439In particular this stops them being treated as syntax, and removes some 2440obscure problems using them in .if statements. 2441.Pp 2442The way that parallel makes are scheduled changed in 2443NetBSD 4.0 2444so that .ORDER and .WAIT apply recursively to the dependent nodes. 2445The algorithms used may change again in the future. 2446.Ss Other make dialects 2447Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not 2448support most of the features of 2449.Nm 2450as described in this manual. 2451Most notably: 2452.Bl -bullet -offset indent 2453.It 2454The 2455.Ic .WAIT 2456and 2457.Ic .ORDER 2458declarations and most functionality pertaining to parallelization. 2459(GNU make supports parallelization but lacks these features needed to 2460control it effectively.) 2461.It 2462Directives, including for loops and conditionals and most of the 2463forms of include files. 2464(GNU make has its own incompatible and less powerful syntax for 2465conditionals.) 2466.It 2467All built-in variables that begin with a dot. 2468.It 2469Most of the special sources and targets that begin with a dot, 2470with the notable exception of 2471.Ic .PHONY , 2472.Ic .PRECIOUS , 2473and 2474.Ic .SUFFIXES . 2475.It 2476Variable modifiers, except for the 2477.Dl :old=new 2478string substitution, which does not portably support globbing with 2479.Ql % 2480and historically only works on declared suffixes. 2481.It 2482The 2483.Ic $> 2484variable even in its short form; most makes support this functionality 2485but its name varies. 2486.El 2487.Pp 2488Some features are somewhat more portable, such as assignment with 2489.Ic += , 2490.Ic ?= , 2491and 2492.Ic != . 2493The 2494.Ic .PATH 2495functionality is based on an older feature 2496.Ic VPATH 2497found in GNU make and many versions of SVR4 make; however, 2498historically its behavior is too ill-defined (and too buggy) to rely 2499upon. 2500.Pp 2501The 2502.Ic $@ 2503and 2504.Ic $< 2505variables are more or less universally portable, as is the 2506.Ic $(MAKE) 2507variable. 2508Basic use of suffix rules (for files only in the current directory, 2509not trying to chain transformations together, etc.) is also reasonably 2510portable. 2511.Sh SEE ALSO 2512.Xr mkdep 1 2513.Sh HISTORY 2514.Nm 2515is derived from NetBSD 2516.Xr make 1 . 2517It uses autoconf to facilitate portability to other platforms. 2518.Pp 2519A 2520make 2521command appeared in 2522.At v7 . 2523This 2524make 2525implementation is based on Adam De Boor's pmake program which was written 2526for Sprite at Berkeley. 2527It was designed to be a parallel distributed make running jobs on different 2528machines using a daemon called 2529.Dq customs . 2530.Pp 2531Historically the target/dependency 2532.Dq FRC 2533has been used to FoRCe rebuilding (since the target/dependency 2534does not exist... unless someone creates an 2535.Dq FRC 2536file). 2537.Sh BUGS 2538The 2539make 2540syntax is difficult to parse without actually acting on the data. 2541For instance, finding the end of a variable's use should involve scanning 2542each of the modifiers, using the correct terminator for each field. 2543In many places 2544make 2545just counts {} and () in order to find the end of a variable expansion. 2546.Pp 2547There is no way of escaping a space character in a filename. 2548