1.\" $NetBSD: make.1,v 1.209 2012/10/08 15:09:48 christos 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 October 8, 2012 33.Dt MAKE 1 34.Os 35.Sh NAME 36.Nm make 37.Nd maintain program dependencies 38.Sh SYNOPSIS 39.Nm 40.Op Fl BeikNnqrstWX 41.Op Fl C Ar directory 42.Op Fl D Ar variable 43.Op Fl d Ar flags 44.Op Fl f Ar makefile 45.Op Fl I Ar directory 46.Op Fl J Ar private 47.Op Fl j Ar max_jobs 48.Op Fl m Ar directory 49.Op Fl T Ar file 50.Op Fl V Ar variable 51.Op Ar variable=value 52.Op Ar target ... 53.Sh DESCRIPTION 54.Nm 55is a program designed to simplify the maintenance of other programs. 56Its input is a list of specifications as to the files upon which programs 57and other files depend. 58If no 59.Fl f Ar makefile 60makefile option is given, 61.Nm 62will try to open 63.Ql Pa makefile 64then 65.Ql Pa Makefile 66in order to find the specifications. 67If the file 68.Ql Pa .depend 69exists, it is read (see 70.Xr mkdep 1 ) . 71.Pp 72This manual page is intended as a reference document only. 73For a more thorough description of 74.Nm 75and makefiles, please refer to 76.%T "PMake \- A Tutorial" . 77.Pp 78.Nm 79will prepend the contents of the 80.Va MAKEFLAGS 81environment variable to the command line arguments before parsing them. 82.Pp 83The options are as follows: 84.Bl -tag -width Ds 85.It Fl B 86Try to be backwards compatible by executing a single shell per command and 87by executing the commands to make the sources of a dependency line in sequence. 88.It Fl C Ar directory 89Change to 90.Ar directory 91before reading the makefiles or doing anything else. 92If multiple 93.Fl C 94options are specified, each is interpreted relative to the previous one: 95.Fl C Pa / Fl C Pa etc 96is equivalent to 97.Fl C Pa /etc . 98.It Fl D Ar variable 99Define 100.Ar variable 101to be 1, in the global context. 102.It Fl d Ar [-]flags 103Turn on debugging, and specify which portions of 104.Nm 105are to print debugging information. 106Unless the flags are preceded by 107.Ql \- 108they are added to the 109.Va MAKEFLAGS 110environment variable and will be processed by any child make processes. 111By default, debugging information is printed to standard error, 112but this can be changed using the 113.Ar F 114debugging flag. 115The debugging output is always unbuffered; in addition, if debugging 116is enabled but debugging output is not directed to standard output, 117then the standard output is line buffered. 118.Ar Flags 119is one or more of the following: 120.Bl -tag -width Ds 121.It Ar A 122Print all possible debugging information; 123equivalent to specifying all of the debugging flags. 124.It Ar a 125Print debugging information about archive searching and caching. 126.It Ar C 127Print debugging information about current working directory. 128.It Ar c 129Print debugging information about conditional evaluation. 130.It Ar d 131Print debugging information about directory searching and caching. 132.It Ar e 133Print debugging information about failed commands and targets. 134.It Ar F Ns Oo Sy \&+ Oc Ns Ar filename 135Specify where debugging output is written. 136This must be the last flag, because it consumes the remainder of 137the argument. 138If the character immediately after the 139.Ql F 140flag is 141.Ql \&+ , 142then the file will be opened in append mode; 143otherwise the file will be overwritten. 144If the file name is 145.Ql stdout 146or 147.Ql stderr 148then debugging output will be written to the 149standard output or standard error output file descriptors respectively 150(and the 151.Ql \&+ 152option has no effect). 153Otherwise, the output will be written to the named file. 154If the file name ends 155.Ql .%d 156then the 157.Ql %d 158is replaced by the pid. 159.It Ar f 160Print debugging information about loop evaluation. 161.It Ar "g1" 162Print the input graph before making anything. 163.It Ar "g2" 164Print the input graph after making everything, or before exiting 165on error. 166.It Ar "g3" 167Print the input graph before exiting on error. 168.It Ar j 169Print debugging information about running multiple shells. 170.It Ar l 171Print commands in Makefiles regardless of whether or not they are prefixed by 172.Ql @ 173or other "quiet" flags. 174Also known as "loud" behavior. 175.It Ar M 176Print debugging information about "meta" mode decisions about targets. 177.It Ar m 178Print debugging information about making targets, including modification 179dates. 180.It Ar n 181Don't delete the temporary command scripts created when running commands. 182These temporary scripts are created in the directory 183referred to by the 184.Ev TMPDIR 185environment variable, or in 186.Pa /tmp 187if 188.Ev TMPDIR 189is unset or set to the empty string. 190The temporary scripts are created by 191.Xr mkstemp 3 , 192and have names of the form 193.Pa makeXXXXXX . 194.Em NOTE : 195This can create many files in 196.Ev TMPDIR 197or 198.Pa /tmp , 199so use with care. 200.It Ar p 201Print debugging information about makefile parsing. 202.It Ar s 203Print debugging information about suffix-transformation rules. 204.It Ar t 205Print debugging information about target list maintenance. 206.It Ar V 207Force the 208.Fl V 209option to print raw values of variables. 210.It Ar v 211Print debugging information about variable assignment. 212.It Ar x 213Run shell commands with 214.Fl x 215so the actual commands are printed as they are executed. 216.El 217.It Fl e 218Specify that environment variables override macro assignments within 219makefiles. 220.It Fl f Ar makefile 221Specify a makefile to read instead of the default 222.Ql Pa makefile . 223If 224.Ar makefile 225is 226.Ql Fl , 227standard input is read. 228Multiple makefiles may be specified, and are read in the order specified. 229.It Fl I Ar directory 230Specify a directory in which to search for makefiles and included makefiles. 231The system makefile directory (or directories, see the 232.Fl m 233option) is automatically included as part of this list. 234.It Fl i 235Ignore non-zero exit of shell commands in the makefile. 236Equivalent to specifying 237.Ql Fl 238before each command line in the makefile. 239.It Fl J Ar private 240This option should 241.Em not 242be specified by the user. 243.Pp 244When the 245.Ar j 246option is in use in a recursive build, this option is passed by a make 247to child makes to allow all the make processes in the build to 248cooperate to avoid overloading the system. 249.It Fl j Ar max_jobs 250Specify the maximum number of jobs that 251.Nm 252may have running at any one time. 253The value is saved in 254.Va .MAKE.JOBS . 255Turns compatibility mode off, unless the 256.Ar B 257flag is also specified. 258When compatibility mode is off, all commands associated with a 259target are executed in a single shell invocation as opposed to the 260traditional one shell invocation per line. 261This can break traditional scripts which change directories on each 262command invocation and then expect to start with a fresh environment 263on the next line. 264It is more efficient to correct the scripts rather than turn backwards 265compatibility on. 266.It Fl k 267Continue processing after errors are encountered, but only on those targets 268that do not depend on the target whose creation caused the error. 269.It Fl m Ar directory 270Specify a directory in which to search for sys.mk and makefiles included 271via the 272.Ao Ar file Ac Ns -style 273include statement. 274The 275.Fl m 276option can be used multiple times to form a search path. 277This path will override the default system include path: /usr/share/mk. 278Furthermore the system include path will be appended to the search path used 279for 280.Qo Ar file Qc Ns -style 281include statements (see the 282.Fl I 283option). 284.Pp 285If a file or directory name in the 286.Fl m 287argument (or the 288.Ev MAKESYSPATH 289environment variable) starts with the string 290.Qq \&.../ 291then 292.Nm 293will search for the specified file or directory named in the remaining part 294of the argument string. 295The search starts with the current directory of 296the Makefile and then works upward towards the root of the filesystem. 297If the search is successful, then the resulting directory replaces the 298.Qq \&.../ 299specification in the 300.Fl m 301argument. 302If used, this feature allows 303.Nm 304to easily search in the current source tree for customized sys.mk files 305(e.g., by using 306.Qq \&.../mk/sys.mk 307as an argument). 308.It Fl n 309Display the commands that would have been executed, but do not 310actually execute them unless the target depends on the .MAKE special 311source (see below). 312.It Fl N 313Display the commands which would have been executed, but do not 314actually execute any of them; useful for debugging top-level makefiles 315without descending into subdirectories. 316.It Fl q 317Do not execute any commands, but exit 0 if the specified targets are 318up-to-date and 1, otherwise. 319.It Fl r 320Do not use the built-in rules specified in the system makefile. 321.It Fl s 322Do not echo any commands as they are executed. 323Equivalent to specifying 324.Ql Ic @ 325before each command line in the makefile. 326.It Fl T Ar tracefile 327When used with the 328.Fl j 329flag, 330append a trace record to 331.Ar tracefile 332for each job started and completed. 333.It Fl t 334Rather than re-building a target as specified in the makefile, create it 335or update its modification time to make it appear up-to-date. 336.It Fl V Ar variable 337Print 338.Nm Ns 's 339idea of the value of 340.Ar variable , 341in the global context. 342Do not build any targets. 343Multiple instances of this option may be specified; 344the variables will be printed one per line, 345with a blank line for each null or undefined variable. 346If 347.Ar variable 348contains a 349.Ql \&$ 350then the value will be expanded before printing. 351.It Fl W 352Treat any warnings during makefile parsing as errors. 353.It Fl X 354Don't export variables passed on the command line to the environment 355individually. 356Variables passed on the command line are still exported 357via the 358.Va MAKEFLAGS 359environment variable. 360This option may be useful on systems which have a small limit on the 361size of command arguments. 362.It Ar variable=value 363Set the value of the variable 364.Ar variable 365to 366.Ar value . 367Normally, all values passed on the command line are also exported to 368sub-makes in the environment. 369The 370.Fl X 371flag disables this behavior. 372Variable assignments should follow options for POSIX compatibility 373but no ordering is enforced. 374.El 375.Pp 376There are seven different types of lines in a makefile: file dependency 377specifications, shell commands, variable assignments, include statements, 378conditional directives, for loops, and comments. 379.Pp 380In general, lines may be continued from one line to the next by ending 381them with a backslash 382.Pq Ql \e . 383The trailing newline character and initial whitespace on the following 384line are compressed into a single space. 385.Sh FILE DEPENDENCY SPECIFICATIONS 386Dependency lines consist of one or more targets, an operator, and zero 387or more sources. 388This creates a relationship where the targets 389.Dq depend 390on the sources 391and are usually created from them. 392The exact relationship between the target and the source is determined 393by the operator that separates them. 394The three operators are as follows: 395.Bl -tag -width flag 396.It Ic \&: 397A target is considered out-of-date if its modification time is less than 398those of any of its sources. 399Sources for a target accumulate over dependency lines when this operator 400is used. 401The target is removed if 402.Nm 403is interrupted. 404.It Ic \&! 405Targets are always re-created, but not until all sources have been 406examined and re-created as necessary. 407Sources for a target accumulate over dependency lines when this operator 408is used. 409The target is removed if 410.Nm 411is interrupted. 412.It Ic \&:: 413If no sources are specified, the target is always re-created. 414Otherwise, a target is considered out-of-date if any of its sources has 415been modified more recently than the target. 416Sources for a target do not accumulate over dependency lines when this 417operator is used. 418The target will not be removed if 419.Nm 420is interrupted. 421.El 422.Pp 423Targets and sources may contain the shell wildcard values 424.Ql \&? , 425.Ql * , 426.Ql [] , 427and 428.Ql {} . 429The values 430.Ql \&? , 431.Ql * , 432and 433.Ql [] 434may only be used as part of the final 435component of the target or source, and must be used to describe existing 436files. 437The value 438.Ql {} 439need not necessarily be used to describe existing files. 440Expansion is in directory order, not alphabetically as done in the shell. 441.Sh SHELL COMMANDS 442Each target may have associated with it a series of shell commands, normally 443used to create the target. 444Each of the commands in this script 445.Em must 446be preceded by a tab. 447While any target may appear on a dependency line, only one of these 448dependencies may be followed by a creation script, unless the 449.Ql Ic \&:: 450operator is used. 451.Pp 452If the first characters of the command line are any combination of 453.Ql Ic @ , 454.Ql Ic + , 455or 456.Ql Ic \- , 457the command is treated specially. 458A 459.Ql Ic @ 460causes the command not to be echoed before it is executed. 461A 462.Ql Ic + 463causes the command to be executed even when 464.Fl n 465is given. 466This is similar to the effect of the .MAKE special source, 467except that the effect can be limited to a single line of a script. 468A 469.Ql Ic \- 470causes any non-zero exit status of the command line to be ignored. 471.Sh VARIABLE ASSIGNMENTS 472Variables in make are much like variables in the shell, and, by tradition, 473consist of all upper-case letters. 474.Ss Variable assignment modifiers 475The five operators that can be used to assign values to variables are as 476follows: 477.Bl -tag -width Ds 478.It Ic \&= 479Assign the value to the variable. 480Any previous value is overridden. 481.It Ic \&+= 482Append the value to the current value of the variable. 483.It Ic \&?= 484Assign the value to the variable if it is not already defined. 485.It Ic \&:= 486Assign with expansion, i.e. expand the value before assigning it 487to the variable. 488Normally, expansion is not done until the variable is referenced. 489.Em NOTE : 490References to undefined variables are 491.Em not 492expanded. 493This can cause problems when variable modifiers are used. 494.It Ic \&!= 495Expand the value and pass it to the shell for execution and assign 496the result to the variable. 497Any newlines in the result are replaced with spaces. 498.El 499.Pp 500Any white-space before the assigned 501.Ar value 502is removed; if the value is being appended, a single space is inserted 503between the previous contents of the variable and the appended value. 504.Pp 505Variables are expanded by surrounding the variable name with either 506curly braces 507.Pq Ql {} 508or parentheses 509.Pq Ql () 510and preceding it with 511a dollar sign 512.Pq Ql \&$ . 513If the variable name contains only a single letter, the surrounding 514braces or parentheses are not required. 515This shorter form is not recommended. 516.Pp 517If the variable name contains a dollar, then the name itself is expanded first. 518This allows almost arbitrary variable names, however names containing dollar, 519braces, parenthesis, or whitespace are really best avoided! 520.Pp 521If the result of expanding a variable contains a dollar sign 522.Pq Ql \&$ 523the string is expanded again. 524.Pp 525Variable substitution occurs at three distinct times, depending on where 526the variable is being used. 527.Bl -enum 528.It 529Variables in dependency lines are expanded as the line is read. 530.It 531Variables in shell commands are expanded when the shell command is 532executed. 533.It 534.Dq .for 535loop index variables are expanded on each loop iteration. 536Note that other variables are not expanded inside loops so 537the following example code: 538.Bd -literal -offset indent 539 540.Dv .for i in 1 2 3 541a+= ${i} 542j= ${i} 543b+= ${j} 544.Dv .endfor 545 546all: 547 @echo ${a} 548 @echo ${b} 549 550.Ed 551will print: 552.Bd -literal -offset indent 5531 2 3 5543 3 3 555 556.Ed 557Because while ${a} contains 558.Dq 1 2 3 559after the loop is executed, ${b} 560contains 561.Dq ${j} ${j} ${j} 562which expands to 563.Dq 3 3 3 564since after the loop completes ${j} contains 565.Dq 3 . 566.El 567.Ss Variable classes 568The four different classes of variables (in order of increasing precedence) 569are: 570.Bl -tag -width Ds 571.It Environment variables 572Variables defined as part of 573.Nm Ns 's 574environment. 575.It Global variables 576Variables defined in the makefile or in included makefiles. 577.It Command line variables 578Variables defined as part of the command line. 579.It Local variables 580Variables that are defined specific to a certain target. 581The seven local variables are as follows: 582.Bl -tag -width ".ARCHIVE" 583.It Va .ALLSRC 584The list of all sources for this target; also known as 585.Ql Va \&\*[Gt] . 586.It Va .ARCHIVE 587The name of the archive file. 588.It Va .IMPSRC 589In suffix-transformation rules, the name/path of the source from which the 590target is to be transformed (the 591.Dq implied 592source); also known as 593.Ql Va \&\*[Lt] . 594It is not defined in explicit rules. 595.It Va .MEMBER 596The name of the archive member. 597.It Va .OODATE 598The list of sources for this target that were deemed out-of-date; also 599known as 600.Ql Va \&? . 601.It Va .PREFIX 602The file prefix of the target, containing only the file portion, no suffix 603or preceding directory components; also known as 604.Ql Va * . 605.It Va .TARGET 606The name of the target; also known as 607.Ql Va @ . 608.El 609.Pp 610The shorter forms 611.Ql Va @ , 612.Ql Va \&? , 613.Ql Va \&\*[Lt] , 614.Ql Va \&\*[Gt] , 615and 616.Ql Va * 617are permitted for backward 618compatibility with historical makefiles and are not recommended. 619The six variables 620.Ql Va "@F" , 621.Ql Va "@D" , 622.Ql Va "\*[Lt]F" , 623.Ql Va "\*[Lt]D" , 624.Ql Va "*F" , 625and 626.Ql Va "*D" 627are permitted for compatibility with 628.At V 629makefiles and are not recommended. 630.Pp 631Four of the local variables may be used in sources on dependency lines 632because they expand to the proper value for each target on the line. 633These variables are 634.Ql Va .TARGET , 635.Ql Va .PREFIX , 636.Ql Va .ARCHIVE , 637and 638.Ql Va .MEMBER . 639.El 640.Ss Additional built-in variables 641In addition, 642.Nm 643sets or knows about the following variables: 644.Bl -tag -width .MAKEOVERRIDES 645.It Va \&$ 646A single dollar sign 647.Ql \&$ , 648i.e. 649.Ql \&$$ 650expands to a single dollar 651sign. 652.It Va .ALLTARGETS 653The list of all targets encountered in the Makefile. 654If evaluated during 655Makefile parsing, lists only those targets encountered thus far. 656.It Va .CURDIR 657A path to the directory where 658.Nm 659was executed. 660Refer to the description of 661.Ql Ev PWD 662for more details. 663.It Ev MAKE 664The name that 665.Nm 666was executed with 667.Pq Va argv[0] . 668For compatibility 669.Nm 670also sets 671.Va .MAKE 672with the same value. 673The preferred variable to use is the environment variable 674.Ev MAKE 675because it is more compatible with other versions of 676.Nm 677and cannot be confused with the special target with the same name. 678.It Va .MAKE.DEPENDFILE 679Names the makefile (default 680.Ql Pa .depend ) 681from which generated dependencies are read. 682.It Va .MAKE.EXPAND_VARIABLES 683A boolean that controls the default behavior of the 684.Fl V 685option. 686.It Va .MAKE.EXPORTED 687The list of variables exported by 688.Nm . 689.It Va .MAKE.JOBS 690The argument to the 691.Fl j 692option. 693.It Va .MAKE.JOB.PREFIX 694If 695.Nm 696is run with 697.Ar j 698then output for each target is prefixed with a token 699.Ql --- target --- 700the first part of which can be controlled via 701.Va .MAKE.JOB.PREFIX . 702.br 703For example: 704.Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}] 705would produce tokens like 706.Ql ---make[1234] target --- 707making it easier to track the degree of parallelism being achieved. 708.It Ev MAKEFLAGS 709The environment variable 710.Ql Ev MAKEFLAGS 711may contain anything that 712may be specified on 713.Nm Ns 's 714command line. 715Anything specified on 716.Nm Ns 's 717command line is appended to the 718.Ql Ev MAKEFLAGS 719variable which is then 720entered into the environment for all programs which 721.Nm 722executes. 723.It Va .MAKE.LEVEL 724The recursion depth of 725.Nm . 726The initial instance of 727.Nm 728will be 0, and an incremented value is put into the environment 729to be seen by the next generation. 730This allows tests like: 731.Li .if ${.MAKE.LEVEL} == 0 732to protect things which should only be evaluated in the initial instance of 733.Nm . 734.It Va .MAKE.MAKEFILE_PREFERENCE 735The ordered list of makefile names 736(default 737.Ql Pa makefile , 738.Ql Pa Makefile ) 739that 740.Nm 741will look for. 742.It Va .MAKE.MAKEFILES 743The list of makefiles read by 744.Nm , 745which is useful for tracking dependencies. 746Each makefile is recorded only once, regardless of the number of times read. 747.It Va .MAKE.MODE 748Processed after reading all makefiles. 749Can affect the mode that 750.Nm 751runs in. 752It can contain a number of keywords: 753.Bl -hang -width ignore-cmd 754.It Pa compat 755Like 756.Fl B , 757puts 758.Nm 759into "compat" mode. 760.It Pa meta 761Puts 762.Nm 763into "meta" mode, where meta files are created for each target 764to capture the command run, the output generated and if 765.Xr filemon 4 766is available, the system calls which are of interest to 767.Nm . 768The captured output can be very useful when diagnosing errors. 769.It Pa curdirOk= Ar bf 770Normally 771.Nm 772will not create .meta files in 773.Ql Va .CURDIR . 774This can be overridden by setting 775.Va bf 776to a value which represents True. 777.It Pa env 778For debugging, it can be useful to inlcude the environment 779in the .meta file. 780.It Pa verbose 781If in "meta" mode, print a clue about the target being built. 782This is useful if the build is otherwise running silently. 783The message printed the value of: 784.Va .MAKE.META.PREFIX . 785.It Pa ignore-cmd 786Some makefiles have commands which are simply not stable. 787This keyword causes them to be ignored for 788determining whether a target is out of date in "meta" mode. 789See also 790.Ic .NOMETA_CMP . 791.It Pa silent= Ar bf 792If 793.Va bf 794is True, when a .meta file is created, mark the target 795.Ic .SILENT . 796.El 797.It Va .MAKE.META.BAILIWICK 798In "meta" mode, provides a list of prefixes which 799match the directories controlled by 800.Nm . 801If a file that was generated outside of 802.Va .OBJDIR 803but within said bailiwick is missing, 804the current target is considered out-of-date. 805.It Va .MAKE.META.CREATED 806In "meta" mode, this variable contains a list of all the meta files 807updated. 808If not empty, it can be used to trigger processing of 809.Va .MAKE.META.FILES . 810.It Va .MAKE.META.FILES 811In "meta" mode, this variable contains a list of all the meta files 812used (updated or not). 813This list can be used to process the meta files to extract dependency 814information. 815.It Va .MAKE.META.PREFIX 816Defines the message printed for each meta file updated in "meta verbose" mode. 817The default value is: 818.Dl Building ${.TARGET:H:tA}/${.TARGET:T} 819.It Va .MAKEOVERRIDES 820This variable is used to record the names of variables assigned to 821on the command line, so that they may be exported as part of 822.Ql Ev MAKEFLAGS . 823This behaviour can be disabled by assigning an empty value to 824.Ql Va .MAKEOVERRIDES 825within a makefile. 826Extra variables can be exported from a makefile 827by appending their names to 828.Ql Va .MAKEOVERRIDES . 829.Ql Ev MAKEFLAGS 830is re-exported whenever 831.Ql Va .MAKEOVERRIDES 832is modified. 833.It Va .MAKE.PID 834The process-id of 835.Nm . 836.It Va .MAKE.PPID 837The parent process-id of 838.Nm . 839.It Va MAKE_PRINT_VAR_ON_ERROR 840When 841.Nm 842stops due to an error, it prints its name and the value of 843.Ql Va .CURDIR 844as well as the value of any variables named in 845.Ql Va MAKE_PRINT_VAR_ON_ERROR . 846.It Va .newline 847This variable is simply assigned a newline character as its value. 848This allows expansions using the 849.Cm \&:@ 850modifier to put a newline between 851iterations of the loop rather than a space. 852For example, the printing of 853.Ql Va MAKE_PRINT_VAR_ON_ERROR 854could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}. 855.It Va .OBJDIR 856A path to the directory where the targets are built. 857Its value is determined by trying to 858.Xr chdir 2 859to the following directories in order and using the first match: 860.Bl -enum 861.It 862.Ev ${MAKEOBJDIRPREFIX}${.CURDIR} 863.Pp 864(Only if 865.Ql Ev MAKEOBJDIRPREFIX 866is set in the environment or on the command line.) 867.It 868.Ev ${MAKEOBJDIR} 869.Pp 870(Only if 871.Ql Ev MAKEOBJDIR 872is set in the environment or on the command line.) 873.It 874.Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE} 875.It 876.Ev ${.CURDIR} Ns Pa /obj 877.It 878.Pa /usr/obj/ Ns Ev ${.CURDIR} 879.It 880.Ev ${.CURDIR} 881.El 882.Pp 883Variable expansion is performed on the value before it's used, 884so expressions such as 885.Dl ${.CURDIR:S,^/usr/src,/var/obj,} 886may be used. 887This is especially useful with 888.Ql Ev MAKEOBJDIR . 889.Pp 890.Ql Va .OBJDIR 891may be modified in the makefile as a global variable. 892In all cases, 893.Nm 894will 895.Xr chdir 2 896to 897.Ql Va .OBJDIR 898and set 899.Ql Ev PWD 900to that directory before executing any targets. 901. 902.It Va .PARSEDIR 903A path to the directory of the current 904.Ql Pa Makefile 905being parsed. 906.It Va .PARSEFILE 907The basename of the current 908.Ql Pa Makefile 909being parsed. 910This variable and 911.Ql Va .PARSEDIR 912are both set only while the 913.Ql Pa Makefiles 914are being parsed. 915If you want to retain their current values, assign them to a variable 916using assignment with expansion: 917.Pq Ql Cm \&:= . 918.It Va .PATH 919A variable that represents the list of directories that 920.Nm 921will search for files. 922The search list should be updated using the target 923.Ql Va .PATH 924rather than the variable. 925.It Ev PWD 926Alternate path to the current directory. 927.Nm 928normally sets 929.Ql Va .CURDIR 930to the canonical path given by 931.Xr getcwd 3 . 932However, if the environment variable 933.Ql Ev PWD 934is set and gives a path to the current directory, then 935.Nm 936sets 937.Ql Va .CURDIR 938to the value of 939.Ql Ev PWD 940instead. 941This behaviour is disabled if 942.Ql Ev MAKEOBJDIRPREFIX 943is set or 944.Ql Ev MAKEOBJDIR 945contains a variable transform. 946.Ql Ev PWD 947is set to the value of 948.Ql Va .OBJDIR 949for all programs which 950.Nm 951executes. 952.It Ev .TARGETS 953The list of targets explicitly specified on the command line, if any. 954.It Ev VPATH 955Colon-separated 956.Pq Dq \&: 957lists of directories that 958.Nm 959will search for files. 960The variable is supported for compatibility with old make programs only, 961use 962.Ql Va .PATH 963instead. 964.El 965.Ss Variable modifiers 966Variable expansion may be modified to select or modify each word of the 967variable (where a 968.Dq word 969is white-space delimited sequence of characters). 970The general format of a variable expansion is as follows: 971.Pp 972.Dl ${variable[:modifier[:...]]} 973.Pp 974Each modifier begins with a colon, 975which may be escaped with a backslash 976.Pq Ql \e . 977.Pp 978A set of modifiers can be specified via a variable, as follows: 979.Pp 980.Dl modifier_variable=modifier[:...] 981.Dl ${variable:${modifier_variable}[:...]} 982.Pp 983In this case the first modifier in the modifier_variable does not 984start with a colon, since that must appear in the referencing 985variable. 986If any of the modifiers in the modifier_variable contain a dollar sign 987.Pq Ql $ , 988these must be doubled to avoid early expansion. 989.Pp 990The supported modifiers are: 991.Bl -tag -width EEE 992.It Cm \&:E 993Replaces each word in the variable with its suffix. 994.It Cm \&:H 995Replaces each word in the variable with everything but the last component. 996.It Cm \&:M Ns Ar pattern 997Select only those words that match 998.Ar pattern . 999The standard shell wildcard characters 1000.Pf ( Ql * , 1001.Ql \&? , 1002and 1003.Ql Oo Oc ) 1004may 1005be used. 1006The wildcard characters may be escaped with a backslash 1007.Pq Ql \e . 1008.It Cm \&:N Ns Ar pattern 1009This is identical to 1010.Ql Cm \&:M , 1011but selects all words which do not match 1012.Ar pattern . 1013.It Cm \&:O 1014Order every word in variable alphabetically. 1015To sort words in 1016reverse order use the 1017.Ql Cm \&:O:[-1..1] 1018combination of modifiers. 1019.It Cm \&:Ox 1020Randomize words in variable. 1021The results will be different each time you are referring to the 1022modified variable; use the assignment with expansion 1023.Pq Ql Cm \&:= 1024to prevent such behaviour. 1025For example, 1026.Bd -literal -offset indent 1027LIST= uno due tre quattro 1028RANDOM_LIST= ${LIST:Ox} 1029STATIC_RANDOM_LIST:= ${LIST:Ox} 1030 1031all: 1032 @echo "${RANDOM_LIST}" 1033 @echo "${RANDOM_LIST}" 1034 @echo "${STATIC_RANDOM_LIST}" 1035 @echo "${STATIC_RANDOM_LIST}" 1036.Ed 1037may produce output similar to: 1038.Bd -literal -offset indent 1039quattro due tre uno 1040tre due quattro uno 1041due uno quattro tre 1042due uno quattro tre 1043.Ed 1044.It Cm \&:Q 1045Quotes every shell meta-character in the variable, so that it can be passed 1046safely through recursive invocations of 1047.Nm . 1048.It Cm \&:R 1049Replaces each word in the variable with everything but its suffix. 1050.It Cm \&:gmtime 1051The value is a format string for 1052.Xr strftime 3 , 1053using the current 1054.Xr gmtime 3 . 1055.It Cm \&:hash 1056Compute a 32bit hash of the value and encode it as hex digits. 1057.It Cm \&:localtime 1058The value is a format string for 1059.Xr strftime 3 , 1060using the current 1061.Xr localtime 3 . 1062.It Cm \&:tA 1063Attempt to convert variable to an absolute path using 1064.Xr realpath 3 , 1065if that fails, the value is unchanged. 1066.It Cm \&:tl 1067Converts variable to lower-case letters. 1068.It Cm \&:ts Ns Ar c 1069Words in the variable are normally separated by a space on expansion. 1070This modifier sets the separator to the character 1071.Ar c . 1072If 1073.Ar c 1074is omitted, then no separator is used. 1075The common escapes (including octal numeric codes), work as expected. 1076.It Cm \&:tu 1077Converts variable to upper-case letters. 1078.It Cm \&:tW 1079Causes the value to be treated as a single word 1080(possibly containing embedded white space). 1081See also 1082.Ql Cm \&:[*] . 1083.It Cm \&:tw 1084Causes the value to be treated as a sequence of 1085words delimited by white space. 1086See also 1087.Ql Cm \&:[@] . 1088.Sm off 1089.It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW 1090.Sm on 1091Modify the first occurrence of 1092.Ar old_string 1093in the variable's value, replacing it with 1094.Ar new_string . 1095If a 1096.Ql g 1097is appended to the last slash of the pattern, all occurrences 1098in each word are replaced. 1099If a 1100.Ql 1 1101is appended to the last slash of the pattern, only the first word 1102is affected. 1103If a 1104.Ql W 1105is appended to the last slash of the pattern, 1106then the value is treated as a single word 1107(possibly containing embedded white space). 1108If 1109.Ar old_string 1110begins with a caret 1111.Pq Ql ^ , 1112.Ar old_string 1113is anchored at the beginning of each word. 1114If 1115.Ar old_string 1116ends with a dollar sign 1117.Pq Ql \&$ , 1118it is anchored at the end of each word. 1119Inside 1120.Ar new_string , 1121an ampersand 1122.Pq Ql \*[Am] 1123is replaced by 1124.Ar old_string 1125(without any 1126.Ql ^ 1127or 1128.Ql \&$ ) . 1129Any character may be used as a delimiter for the parts of the modifier 1130string. 1131The anchoring, ampersand and delimiter characters may be escaped with a 1132backslash 1133.Pq Ql \e . 1134.Pp 1135Variable expansion occurs in the normal fashion inside both 1136.Ar old_string 1137and 1138.Ar new_string 1139with the single exception that a backslash is used to prevent the expansion 1140of a dollar sign 1141.Pq Ql \&$ , 1142not a preceding dollar sign as is usual. 1143.Sm off 1144.It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW 1145.Sm on 1146The 1147.Cm \&:C 1148modifier is just like the 1149.Cm \&:S 1150modifier except that the old and new strings, instead of being 1151simple strings, are a regular expression (see 1152.Xr regex 3 ) 1153string 1154.Ar pattern 1155and an 1156.Xr ed 1 Ns \-style 1157string 1158.Ar replacement . 1159Normally, the first occurrence of the pattern 1160.Ar pattern 1161in each word of the value is substituted with 1162.Ar replacement . 1163The 1164.Ql 1 1165modifier causes the substitution to apply to at most one word; the 1166.Ql g 1167modifier causes the substitution to apply to as many instances of the 1168search pattern 1169.Ar pattern 1170as occur in the word or words it is found in; the 1171.Ql W 1172modifier causes the value to be treated as a single word 1173(possibly containing embedded white space). 1174Note that 1175.Ql 1 1176and 1177.Ql g 1178are orthogonal; the former specifies whether multiple words are 1179potentially affected, the latter whether multiple substitutions can 1180potentially occur within each affected word. 1181.It Cm \&:T 1182Replaces each word in the variable with its last component. 1183.It Cm \&:u 1184Remove adjacent duplicate words (like 1185.Xr uniq 1 ) . 1186.Sm off 1187.It Cm \&:\&? Ar true_string Cm \&: Ar false_string 1188.Sm on 1189If the variable name (not its value), when parsed as a .if conditional 1190expression, evaluates to true, return as its value the 1191.Ar true_string , 1192otherwise return the 1193.Ar false_string . 1194Since the variable name is used as the expression, \&:\&? must be the 1195first modifier after the variable name itself - which will, of course, 1196usually contain variable expansions. 1197A common error is trying to use expressions like 1198.Dl ${NUMBERS:M42:?match:no} 1199which actually tests defined(NUMBERS), 1200to determine is any words match "42" you need to use something like: 1201.Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} . 1202.It Ar :old_string=new_string 1203This is the 1204.At V 1205style variable substitution. 1206It must be the last modifier specified. 1207If 1208.Ar old_string 1209or 1210.Ar new_string 1211do not contain the pattern matching character 1212.Ar % 1213then it is assumed that they are 1214anchored at the end of each word, so only suffixes or entire 1215words may be replaced. 1216Otherwise 1217.Ar % 1218is the substring of 1219.Ar old_string 1220to be replaced in 1221.Ar new_string . 1222.Pp 1223Variable expansion occurs in the normal fashion inside both 1224.Ar old_string 1225and 1226.Ar new_string 1227with the single exception that a backslash is used to prevent the 1228expansion of a dollar sign 1229.Pq Ql \&$ , 1230not a preceding dollar sign as is usual. 1231.Sm off 1232.It Cm \&:@ Ar temp Cm @ Ar string Cm @ 1233.Sm on 1234This is the loop expansion mechanism from the OSF Development 1235Environment (ODE) make. 1236Unlike 1237.Cm \&.for 1238loops expansion occurs at the time of 1239reference. 1240Assign 1241.Ar temp 1242to each word in the variable and evaluate 1243.Ar string . 1244The ODE convention is that 1245.Ar temp 1246should start and end with a period. 1247For example. 1248.Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@} 1249.Pp 1250However a single character varaiable is often more readable: 1251.Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@} 1252.It Cm \&:U Ns Ar newval 1253If the variable is undefined 1254.Ar newval 1255is the value. 1256If the variable is defined, the existing value is returned. 1257This is another ODE make feature. 1258It is handy for setting per-target CFLAGS for instance: 1259.Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}} 1260If a value is only required if the variable is undefined, use: 1261.Dl ${VAR:D:Unewval} 1262.It Cm \&:D Ns Ar newval 1263If the variable is defined 1264.Ar newval 1265is the value. 1266.It Cm \&:L 1267The name of the variable is the value. 1268.It Cm \&:P 1269The path of the node which has the same name as the variable 1270is the value. 1271If no such node exists or its path is null, then the 1272name of the variable is used. 1273In order for this modifier to work, the name (node) must at least have 1274appeared on the rhs of a dependency. 1275.Sm off 1276.It Cm \&:\&! Ar cmd Cm \&! 1277.Sm on 1278The output of running 1279.Ar cmd 1280is the value. 1281.It Cm \&:sh 1282If the variable is non-empty it is run as a command and the output 1283becomes the new value. 1284.It Cm \&::= Ns Ar str 1285The variable is assigned the value 1286.Ar str 1287after substitution. 1288This modifier and its variations are useful in 1289obscure situations such as wanting to set a variable when shell commands 1290are being parsed. 1291These assignment modifiers always expand to 1292nothing, so if appearing in a rule line by themselves should be 1293preceded with something to keep 1294.Nm 1295happy. 1296.Pp 1297The 1298.Ql Cm \&:: 1299helps avoid false matches with the 1300.At V 1301style 1302.Cm \&:= 1303modifier and since substitution always occurs the 1304.Cm \&::= 1305form is vaguely appropriate. 1306.It Cm \&::?= Ns Ar str 1307As for 1308.Cm \&::= 1309but only if the variable does not already have a value. 1310.It Cm \&::+= Ns Ar str 1311Append 1312.Ar str 1313to the variable. 1314.It Cm \&::!= Ns Ar cmd 1315Assign the output of 1316.Ar cmd 1317to the variable. 1318.It Cm \&:\&[ Ns Ar range Ns Cm \&] 1319Selects one or more words from the value, 1320or performs other operations related to the way in which the 1321value is divided into words. 1322.Pp 1323Ordinarily, a value is treated as a sequence of words 1324delimited by white space. 1325Some modifiers suppress this behaviour, 1326causing a value to be treated as a single word 1327(possibly containing embedded white space). 1328An empty value, or a value that consists entirely of white-space, 1329is treated as a single word. 1330For the purposes of the 1331.Ql Cm \&:[] 1332modifier, the words are indexed both forwards using positive integers 1333(where index 1 represents the first word), 1334and backwards using negative integers 1335(where index \-1 represents the last word). 1336.Pp 1337The 1338.Ar range 1339is subjected to variable expansion, and the expanded result is 1340then interpreted as follows: 1341.Bl -tag -width index 1342.\" :[n] 1343.It Ar index 1344Selects a single word from the value. 1345.\" :[start..end] 1346.It Ar start Ns Cm \&.. Ns Ar end 1347Selects all words from 1348.Ar start 1349to 1350.Ar end , 1351inclusive. 1352For example, 1353.Ql Cm \&:[2..-1] 1354selects all words from the second word to the last word. 1355If 1356.Ar start 1357is greater than 1358.Ar end , 1359then the words are output in reverse order. 1360For example, 1361.Ql Cm \&:[-1..1] 1362selects all the words from last to first. 1363.\" :[*] 1364.It Cm \&* 1365Causes subsequent modifiers to treat the value as a single word 1366(possibly containing embedded white space). 1367Analogous to the effect of 1368\&"$*\&" 1369in Bourne shell. 1370.\" :[0] 1371.It 0 1372Means the same as 1373.Ql Cm \&:[*] . 1374.\" :[*] 1375.It Cm \&@ 1376Causes subsequent modifiers to treat the value as a sequence of words 1377delimited by white space. 1378Analogous to the effect of 1379\&"$@\&" 1380in Bourne shell. 1381.\" :[#] 1382.It Cm \&# 1383Returns the number of words in the value. 1384.El \" :[range] 1385.El 1386.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS 1387Makefile inclusion, conditional structures and for loops reminiscent 1388of the C programming language are provided in 1389.Nm . 1390All such structures are identified by a line beginning with a single 1391dot 1392.Pq Ql \&. 1393character. 1394Files are included with either 1395.Cm \&.include Aq Ar file 1396or 1397.Cm \&.include Pf \*q Ar file Ns \*q . 1398Variables between the angle brackets or double quotes are expanded 1399to form the file name. 1400If angle brackets are used, the included makefile is expected to be in 1401the system makefile directory. 1402If double quotes are used, the including makefile's directory and any 1403directories specified using the 1404.Fl I 1405option are searched before the system 1406makefile directory. 1407For compatibility with other versions of 1408.Nm 1409.Ql include file ... 1410is also accepted. 1411If the include statement is written as 1412.Cm .-include 1413or as 1414.Cm .sinclude 1415then errors locating and/or opening include files are ignored. 1416.Pp 1417Conditional expressions are also preceded by a single dot as the first 1418character of a line. 1419The possible conditionals are as follows: 1420.Bl -tag -width Ds 1421.It Ic .error Ar message 1422The message is printed along with the name of the makefile and line number, 1423then 1424.Nm 1425will exit. 1426.It Ic .export Ar variable ... 1427Export the specified global variable. 1428If no variable list is provided, all globals are exported 1429except for internal variables (those that start with 1430.Ql \&. ) . 1431This is not affected by the 1432.Fl X 1433flag, so should be used with caution. 1434For compatibility with other 1435.Nm 1436programs 1437.Ql export variable=value 1438is also accepted. 1439.Pp 1440Appending a variable name to 1441.Va .MAKE.EXPORTED 1442is equivalent to exporting a variable. 1443.It Ic .export-env Ar variable ... 1444The same as 1445.Ql .export , 1446except that the variable is not appended to 1447.Va .MAKE.EXPORTED . 1448This allows exporting a value to the environment which is different from that 1449used by 1450.Nm 1451internally. 1452.It Ic .info Ar message 1453The message is printed along with the name of the makefile and line number. 1454.It Ic .undef Ar variable 1455Un-define the specified global variable. 1456Only global variables may be un-defined. 1457.It Ic .unexport Ar variable ... 1458The opposite of 1459.Ql .export . 1460The specified global 1461.Va variable 1462will be removed from 1463.Va .MAKE.EXPORTED . 1464If no variable list is provided, all globals are unexported, 1465and 1466.Va .MAKE.EXPORTED 1467deleted. 1468.It Ic .unexport-env 1469Unexport all globals previously exported and 1470clear the environment inherited from the parent. 1471This operation will cause a memory leak of the original environment, 1472so should be used sparingly. 1473Testing for 1474.Va .MAKE.LEVEL 1475being 0, would make sense. 1476Also note that any variables which originated in the parent environment 1477should be explicitly preserved if desired. 1478For example: 1479.Bd -literal -offset indent 1480.Li .if ${.MAKE.LEVEL} == 0 1481PATH := ${PATH} 1482.Li .unexport-env 1483.Li .export PATH 1484.Li .endif 1485.Pp 1486.Ed 1487Would result in an environment containing only 1488.Ql Ev PATH , 1489which is the minimal useful environment. 1490Actually 1491.Ql Ev .MAKE.LEVEL 1492will also be pushed into the new environment. 1493.It Ic .warning Ar message 1494The message prefixed by 1495.Ql Pa warning: 1496is printed along with the name of the makefile and line number. 1497.It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ... 1498Test the value of an expression. 1499.It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1500Test the value of a variable. 1501.It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1502Test the value of a variable. 1503.It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1504Test the target being built. 1505.It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ... 1506Test the target being built. 1507.It Ic .else 1508Reverse the sense of the last conditional. 1509.It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ... 1510A combination of 1511.Ql Ic .else 1512followed by 1513.Ql Ic .if . 1514.It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1515A combination of 1516.Ql Ic .else 1517followed by 1518.Ql Ic .ifdef . 1519.It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ... 1520A combination of 1521.Ql Ic .else 1522followed by 1523.Ql Ic .ifndef . 1524.It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1525A combination of 1526.Ql Ic .else 1527followed by 1528.Ql Ic .ifmake . 1529.It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ... 1530A combination of 1531.Ql Ic .else 1532followed by 1533.Ql Ic .ifnmake . 1534.It Ic .endif 1535End the body of the conditional. 1536.El 1537.Pp 1538The 1539.Ar operator 1540may be any one of the following: 1541.Bl -tag -width "Cm XX" 1542.It Cm \&|\&| 1543Logical OR. 1544.It Cm \&\*[Am]\*[Am] 1545Logical 1546.Tn AND ; 1547of higher precedence than 1548.Dq \&|\&| . 1549.El 1550.Pp 1551As in C, 1552.Nm 1553will only evaluate a conditional as far as is necessary to determine 1554its value. 1555Parentheses may be used to change the order of evaluation. 1556The boolean operator 1557.Ql Ic \&! 1558may be used to logically negate an entire 1559conditional. 1560It is of higher precedence than 1561.Ql Ic \&\*[Am]\*[Am] . 1562.Pp 1563The value of 1564.Ar expression 1565may be any of the following: 1566.Bl -tag -width defined 1567.It Ic defined 1568Takes a variable name as an argument and evaluates to true if the variable 1569has been defined. 1570.It Ic make 1571Takes a target name as an argument and evaluates to true if the target 1572was specified as part of 1573.Nm Ns 's 1574command line or was declared the default target (either implicitly or 1575explicitly, see 1576.Va .MAIN ) 1577before the line containing the conditional. 1578.It Ic empty 1579Takes a variable, with possible modifiers, and evaluates to true if 1580the expansion of the variable would result in an empty string. 1581.It Ic exists 1582Takes a file name as an argument and evaluates to true if the file exists. 1583The file is searched for on the system search path (see 1584.Va .PATH ) . 1585.It Ic target 1586Takes a target name as an argument and evaluates to true if the target 1587has been defined. 1588.It Ic commands 1589Takes a target name as an argument and evaluates to true if the target 1590has been defined and has commands associated with it. 1591.El 1592.Pp 1593.Ar Expression 1594may also be an arithmetic or string comparison. 1595Variable expansion is 1596performed on both sides of the comparison, after which the integral 1597values are compared. 1598A value is interpreted as hexadecimal if it is 1599preceded by 0x, otherwise it is decimal; octal numbers are not supported. 1600The standard C relational operators are all supported. 1601If after 1602variable expansion, either the left or right hand side of a 1603.Ql Ic == 1604or 1605.Ql Ic "!=" 1606operator is not an integral value, then 1607string comparison is performed between the expanded 1608variables. 1609If no relational operator is given, it is assumed that the expanded 1610variable is being compared against 0 or an empty string in the case 1611of a string comparison. 1612.Pp 1613When 1614.Nm 1615is evaluating one of these conditional expressions, and it encounters 1616a (white-space separated) word it doesn't recognize, either the 1617.Dq make 1618or 1619.Dq defined 1620expression is applied to it, depending on the form of the conditional. 1621If the form is 1622.Ql Ic .ifdef , 1623.Ql Ic .ifndef , 1624or 1625.Ql Ic .if 1626the 1627.Dq defined 1628expression is applied. 1629Similarly, if the form is 1630.Ql Ic .ifmake 1631or 1632.Ql Ic .ifnmake , the 1633.Dq make 1634expression is applied. 1635.Pp 1636If the conditional evaluates to true the parsing of the makefile continues 1637as before. 1638If it evaluates to false, the following lines are skipped. 1639In both cases this continues until a 1640.Ql Ic .else 1641or 1642.Ql Ic .endif 1643is found. 1644.Pp 1645For loops are typically used to apply a set of rules to a list of files. 1646The syntax of a for loop is: 1647.Pp 1648.Bl -tag -compact -width Ds 1649.It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression 1650.It Aq make-rules 1651.It Ic \&.endfor 1652.El 1653.Pp 1654After the for 1655.Ic expression 1656is evaluated, it is split into words. 1657On each iteration of the loop, one word is taken and assigned to each 1658.Ic variable , 1659in order, and these 1660.Ic variables 1661are substituted into the 1662.Ic make-rules 1663inside the body of the for loop. 1664The number of words must come out even; that is, if there are three 1665iteration variables, the number of words provided must be a multiple 1666of three. 1667.Sh COMMENTS 1668Comments begin with a hash 1669.Pq Ql \&# 1670character, anywhere but in a shell 1671command line, and continue to the end of an unescaped new line. 1672.Sh SPECIAL SOURCES (ATTRIBUTES) 1673.Bl -tag -width .IGNOREx 1674.It Ic .EXEC 1675Target is never out of date, but always execute commands anyway. 1676.It Ic .IGNORE 1677Ignore any errors from the commands associated with this target, exactly 1678as if they all were preceded by a dash 1679.Pq Ql \- . 1680.\" .It Ic .INVISIBLE 1681.\" XXX 1682.\" .It Ic .JOIN 1683.\" XXX 1684.It Ic .MADE 1685Mark all sources of this target as being up-to-date. 1686.It Ic .MAKE 1687Execute the commands associated with this target even if the 1688.Fl n 1689or 1690.Fl t 1691options were specified. 1692Normally used to mark recursive 1693.Nm Ns 's . 1694.It Ic .META 1695Create a meta file for the target, even if it is flagged as 1696.Ic .PHONY , 1697.Ic .MAKE , 1698or 1699.Ic .SPECIAL . 1700Usage in conjunction with 1701.Ic .MAKE 1702is the most likely case. 1703In "meta" mode, the target is out-of-date if the meta file is missing. 1704.It Ic .NOMETA 1705Do not create a meta file for the target. 1706Meta files are also not created for 1707.Ic .PHONY , 1708.Ic .MAKE , 1709or 1710.Ic .SPECIAL 1711targets. 1712.It Ic .NOMETA_CMP 1713Ignore differences in commands when deciding if target is out of date. 1714This is useful if the command contains a value which always changes. 1715If the number of commands change, though, the target will still be out of date. 1716.It Ic .NOPATH 1717Do not search for the target in the directories specified by 1718.Ic .PATH . 1719.It Ic .NOTMAIN 1720Normally 1721.Nm 1722selects the first target it encounters as the default target to be built 1723if no target was specified. 1724This source prevents this target from being selected. 1725.It Ic .OPTIONAL 1726If a target is marked with this attribute and 1727.Nm 1728can't figure out how to create it, it will ignore this fact and assume 1729the file isn't needed or already exists. 1730.It Ic .PHONY 1731The target does not 1732correspond to an actual file; it is always considered to be out of date, 1733and will not be created with the 1734.Fl t 1735option. 1736Suffix-transformation rules are not applied to 1737.Ic .PHONY 1738targets. 1739.It Ic .PRECIOUS 1740When 1741.Nm 1742is interrupted, it normally removes any partially made targets. 1743This source prevents the target from being removed. 1744.It Ic .RECURSIVE 1745Synonym for 1746.Ic .MAKE . 1747.It Ic .SILENT 1748Do not echo any of the commands associated with this target, exactly 1749as if they all were preceded by an at sign 1750.Pq Ql @ . 1751.It Ic .USE 1752Turn the target into 1753.Nm Ns 's 1754version of a macro. 1755When the target is used as a source for another target, the other target 1756acquires the commands, sources, and attributes (except for 1757.Ic .USE ) 1758of the 1759source. 1760If the target already has commands, the 1761.Ic .USE 1762target's commands are appended 1763to them. 1764.It Ic .USEBEFORE 1765Exactly like 1766.Ic .USE , 1767but prepend the 1768.Ic .USEBEFORE 1769target commands to the target. 1770.It Ic .WAIT 1771If 1772.Ic .WAIT 1773appears in a dependency line, the sources that precede it are 1774made before the sources that succeed it in the line. 1775Since the dependents of files are not made until the file itself 1776could be made, this also stops the dependents being built unless they 1777are needed for another branch of the dependency tree. 1778So given: 1779.Bd -literal 1780x: a .WAIT b 1781 echo x 1782a: 1783 echo a 1784b: b1 1785 echo b 1786b1: 1787 echo b1 1788 1789.Ed 1790the output is always 1791.Ql a , 1792.Ql b1 , 1793.Ql b , 1794.Ql x . 1795.br 1796The ordering imposed by 1797.Ic .WAIT 1798is only relevant for parallel makes. 1799.El 1800.Sh SPECIAL TARGETS 1801Special targets may not be included with other targets, i.e. they must be 1802the only target specified. 1803.Bl -tag -width .BEGINx 1804.It Ic .BEGIN 1805Any command lines attached to this target are executed before anything 1806else is done. 1807.It Ic .DEFAULT 1808This is sort of a 1809.Ic .USE 1810rule for any target (that was used only as a 1811source) that 1812.Nm 1813can't figure out any other way to create. 1814Only the shell script is used. 1815The 1816.Ic .IMPSRC 1817variable of a target that inherits 1818.Ic .DEFAULT Ns 's 1819commands is set 1820to the target's own name. 1821.It Ic .END 1822Any command lines attached to this target are executed after everything 1823else is done. 1824.It Ic .ERROR 1825Any command lines attached to this target are executed when another target fails. 1826The 1827.Ic .ERROR_TARGET 1828variable is set to the target that failed. 1829See also 1830.Ic MAKE_PRINT_VAR_ON_ERROR . 1831.It Ic .IGNORE 1832Mark each of the sources with the 1833.Ic .IGNORE 1834attribute. 1835If no sources are specified, this is the equivalent of specifying the 1836.Fl i 1837option. 1838.It Ic .INTERRUPT 1839If 1840.Nm 1841is interrupted, the commands for this target will be executed. 1842.It Ic .MAIN 1843If no target is specified when 1844.Nm 1845is invoked, this target will be built. 1846.It Ic .MAKEFLAGS 1847This target provides a way to specify flags for 1848.Nm 1849when the makefile is used. 1850The flags are as if typed to the shell, though the 1851.Fl f 1852option will have 1853no effect. 1854.\" XXX: NOT YET!!!! 1855.\" .It Ic .NOTPARALLEL 1856.\" The named targets are executed in non parallel mode. 1857.\" If no targets are 1858.\" specified, then all targets are executed in non parallel mode. 1859.It Ic .NOPATH 1860Apply the 1861.Ic .NOPATH 1862attribute to any specified sources. 1863.It Ic .NOTPARALLEL 1864Disable parallel mode. 1865.It Ic .NO_PARALLEL 1866Synonym for 1867.Ic .NOTPARALLEL , 1868for compatibility with other pmake variants. 1869.It Ic .ORDER 1870The named targets are made in sequence. 1871This ordering does not add targets to the list of targets to be made. 1872Since the dependents of a target do not get built until the target itself 1873could be built, unless 1874.Ql a 1875is built by another part of the dependency graph, 1876the following is a dependency loop: 1877.Bd -literal 1878\&.ORDER: b a 1879b: a 1880.Ed 1881.Pp 1882The ordering imposed by 1883.Ic .ORDER 1884is only relevant for parallel makes. 1885.\" XXX: NOT YET!!!! 1886.\" .It Ic .PARALLEL 1887.\" The named targets are executed in parallel mode. 1888.\" If no targets are 1889.\" specified, then all targets are executed in parallel mode. 1890.It Ic .PATH 1891The sources are directories which are to be searched for files not 1892found in the current directory. 1893If no sources are specified, any previously specified directories are 1894deleted. 1895If the source is the special 1896.Ic .DOTLAST 1897target, then the current working 1898directory is searched last. 1899.It Ic .PHONY 1900Apply the 1901.Ic .PHONY 1902attribute to any specified sources. 1903.It Ic .PRECIOUS 1904Apply the 1905.Ic .PRECIOUS 1906attribute to any specified sources. 1907If no sources are specified, the 1908.Ic .PRECIOUS 1909attribute is applied to every 1910target in the file. 1911.It Ic .SHELL 1912Sets the shell that 1913.Nm 1914will use to execute commands. 1915The sources are a set of 1916.Ar field=value 1917pairs. 1918.Bl -tag -width hasErrCtls 1919.It Ar name 1920This is the minimal specification, used to select one of the builtin 1921shell specs; 1922.Ar sh , 1923.Ar ksh , 1924and 1925.Ar csh . 1926.It Ar path 1927Specifies the path to the shell. 1928.It Ar hasErrCtl 1929Indicates whether the shell supports exit on error. 1930.It Ar check 1931The command to turn on error checking. 1932.It Ar ignore 1933The command to disable error checking. 1934.It Ar echo 1935The command to turn on echoing of commands executed. 1936.It Ar quiet 1937The command to turn off echoing of commands executed. 1938.It Ar filter 1939The output to filter after issuing the 1940.Ar quiet 1941command. 1942It is typically identical to 1943.Ar quiet . 1944.It Ar errFlag 1945The flag to pass the shell to enable error checking. 1946.It Ar echoFlag 1947The flag to pass the shell to enable command echoing. 1948.It Ar newline 1949The string literal to pass the shell that results in a single newline 1950character when used outside of any quoting characters. 1951.El 1952Example: 1953.Bd -literal 1954\&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e 1955 check="set \-e" ignore="set +e" \e 1956 echo="set \-v" quiet="set +v" filter="set +v" \e 1957 echoFlag=v errFlag=e newline="'\en'" 1958.Ed 1959.It Ic .SILENT 1960Apply the 1961.Ic .SILENT 1962attribute to any specified sources. 1963If no sources are specified, the 1964.Ic .SILENT 1965attribute is applied to every 1966command in the file. 1967.It Ic .SUFFIXES 1968Each source specifies a suffix to 1969.Nm . 1970If no sources are specified, any previously specified suffixes are deleted. 1971It allows the creation of suffix-transformation rules. 1972.Pp 1973Example: 1974.Bd -literal 1975\&.SUFFIXES: .o 1976\&.c.o: 1977 cc \-o ${.TARGET} \-c ${.IMPSRC} 1978.Ed 1979.El 1980.Sh ENVIRONMENT 1981.Nm 1982uses the following environment variables, if they exist: 1983.Ev MACHINE , 1984.Ev MACHINE_ARCH , 1985.Ev MAKE , 1986.Ev MAKEFLAGS , 1987.Ev MAKEOBJDIR , 1988.Ev MAKEOBJDIRPREFIX , 1989.Ev MAKESYSPATH , 1990.Ev PWD , 1991and 1992.Ev TMPDIR . 1993.Pp 1994.Ev MAKEOBJDIRPREFIX 1995and 1996.Ev MAKEOBJDIR 1997may only be set in the environment or on the command line to 1998.Nm 1999and not as makefile variables; 2000see the description of 2001.Ql Va .OBJDIR 2002for more details. 2003.Sh FILES 2004.Bl -tag -width /usr/share/mk -compact 2005.It .depend 2006list of dependencies 2007.It Makefile 2008list of dependencies 2009.It makefile 2010list of dependencies 2011.It sys.mk 2012system makefile 2013.It /usr/share/mk 2014system makefile directory 2015.El 2016.Sh COMPATIBILITY 2017The basic make syntax is compatible between different versions of make, 2018however the special variables, variable modifiers and conditionals are not. 2019.Pp 2020The way that parallel makes are scheduled changed in 2021NetBSD 4.0 2022so that .ORDER and .WAIT apply recursively to the dependent nodes. 2023The algorithms used may change again in the future. 2024.Pp 2025The way that .for loop variables are substituted changed after 2026NetBSD 5.0 2027so that they still appear to be variable expansions. 2028In particular this stops them being treated as syntax, and removes some 2029obscure problems using them in .if statements. 2030.Pp 2031Unlike other 2032.Nm 2033programs, this implementation by default executes all commands for a given 2034target using a single shell invocation. 2035This is done for both efficiency and to simplify error handling in remote 2036command invocations. 2037Typically this is transparent to the user, unless the target commands change 2038the current working directory using 2039.Dq cd 2040or 2041.Dq chdir . 2042To be compatible with Makefiles that do this, one can use 2043.Fl B 2044to disable this behavior. 2045.Pp 2046In compatibility mode, each command is run in a separate process. 2047If the command contains any shell meta characters 2048.Pq Ql #=|^(){};&<>*?[]:$`\e\en 2049it will be passed to the shell, otherwise 2050.Nm 2051will attempt direct execution. 2052.Sh SEE ALSO 2053.Xr mkdep 1 2054.Sh HISTORY 2055make 2056is derived from NetBSD 2057.Xr make 1 . 2058It uses autoconf to facilitate portability to other platforms. 2059.Pp 2060A 2061make 2062command appeared in 2063.At v7 . 2064This 2065make 2066implementation is based on Adam De Boor's pmake program which was written 2067for Sprite at Berkeley. 2068It was designed to be a parallel distributed make running jobs on different 2069machines using a daemon called 2070.Dq customs . 2071.Sh BUGS 2072The 2073make 2074syntax is difficult to parse without actually acting of the data. 2075For instance finding the end of a variable use should involve scanning each 2076the modifiers using the correct terminator for each field. 2077In many places 2078make 2079just counts {} and () in order to find the end of a variable expansion. 2080.Pp 2081There is no way of escaping a space character in a filename. 2082