xref: /freebsd/contrib/bmake/bmake.cat1 (revision 6e660824a82f590542932de52f128db584029893)
1MAKE(1)                 NetBSD General Commands Manual                 MAKE(1)
2
3NNAAMMEE
4     bbmmaakkee -- maintain program dependencies
5
6SSYYNNOOPPSSIISS
7     bbmmaakkee [--BBeeiikkNNnnqqrrssttWWXX] [--CC _d_i_r_e_c_t_o_r_y] [--DD _v_a_r_i_a_b_l_e] [--dd _f_l_a_g_s]
8           [--ff _m_a_k_e_f_i_l_e] [--II _d_i_r_e_c_t_o_r_y] [--JJ _p_r_i_v_a_t_e] [--jj _m_a_x___j_o_b_s]
9           [--mm _d_i_r_e_c_t_o_r_y] [--TT _f_i_l_e] [--VV _v_a_r_i_a_b_l_e] [_v_a_r_i_a_b_l_e_=_v_a_l_u_e]
10           [_t_a_r_g_e_t _._._.]
11
12DDEESSCCRRIIPPTTIIOONN
13     bbmmaakkee is a program designed to simplify the maintenance of other pro-
14     grams.  Its input is a list of specifications as to the files upon which
15     programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e makefile option is
16     given, bbmmaakkee will try to open `_m_a_k_e_f_i_l_e' then `_M_a_k_e_f_i_l_e' in order to find
17     the specifications.  If the file `_._d_e_p_e_n_d' exists, it is read (see
18     mkdep(1)).
19
20     This manual page is intended as a reference document only.  For a more
21     thorough description of bbmmaakkee and makefiles, please refer to _P_M_a_k_e _- _A
22     _T_u_t_o_r_i_a_l.
23
24     bbmmaakkee will prepend the contents of the _M_A_K_E_F_L_A_G_S environment variable to
25     the command line arguments before parsing them.
26
27     The options are as follows:
28
29     --BB      Try to be backwards compatible by executing a single shell per
30             command and by executing the commands to make the sources of a
31             dependency line in sequence.
32
33     --CC _d_i_r_e_c_t_o_r_y
34             Change to _d_i_r_e_c_t_o_r_y before reading the makefiles or doing any-
35             thing else.  If multiple --CC options are specified, each is inter-
36             preted relative to the previous one: --CC _/ --CC _e_t_c is equivalent to
37             --CC _/_e_t_c.
38
39     --DD _v_a_r_i_a_b_l_e
40             Define _v_a_r_i_a_b_l_e to be 1, in the global context.
41
42     --dd _[_-_]_f_l_a_g_s
43             Turn on debugging, and specify which portions of bbmmaakkee are to
44             print debugging information.  Unless the flags are preceded by
45             `-' they are added to the _M_A_K_E_F_L_A_G_S environment variable and will
46             be processed by any child make processes.  By default, debugging
47             information is printed to standard error, but this can be changed
48             using the _F debugging flag.  The debugging output is always
49             unbuffered; in addition, if debugging is enabled but debugging
50             output is not directed to standard output, then the standard out-
51             put is line buffered.  _F_l_a_g_s is one or more of the following:
52
53             _A       Print all possible debugging information; equivalent to
54                     specifying all of the debugging flags.
55
56             _a       Print debugging information about archive searching and
57                     caching.
58
59             _C       Print debugging information about current working direc-
60                     tory.
61
62             _c       Print debugging information about conditional evaluation.
63
64             _d       Print debugging information about directory searching and
65                     caching.
66
67             _e       Print debugging information about failed commands and
68                     targets.
69
70             _F[++]_f_i_l_e_n_a_m_e
71                     Specify where debugging output is written.  This must be
72                     the last flag, because it consumes the remainder of the
73                     argument.  If the character immediately after the `F'
74                     flag is `+', then the file will be opened in append mode;
75                     otherwise the file will be overwritten.  If the file name
76                     is `stdout' or `stderr' then debugging output will be
77                     written to the standard output or standard error output
78                     file descriptors respectively (and the `+' option has no
79                     effect).  Otherwise, the output will be written to the
80                     named file.  If the file name ends `.%d' then the `%d' is
81                     replaced by the pid.
82
83             _f       Print debugging information about loop evaluation.
84
85             _g_1      Print the input graph before making anything.
86
87             _g_2      Print the input graph after making everything, or before
88                     exiting on error.
89
90             _g_3      Print the input graph before exiting on error.
91
92             _j       Print debugging information about running multiple
93                     shells.
94
95             _l       Print commands in Makefiles regardless of whether or not
96                     they are prefixed by `@' or other "quiet" flags.  Also
97                     known as "loud" behavior.
98
99             _M       Print debugging information about "meta" mode decisions
100                     about targets.
101
102             _m       Print debugging information about making targets, includ-
103                     ing modification dates.
104
105             _n       Don't delete the temporary command scripts created when
106                     running commands.  These temporary scripts are created in
107                     the directory referred to by the TMPDIR environment vari-
108                     able, or in _/_t_m_p if TMPDIR is unset or set to the empty
109                     string.  The temporary scripts are created by mkstemp(3),
110                     and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E: This can
111                     create many files in TMPDIR or _/_t_m_p, so use with care.
112
113             _p       Print debugging information about makefile parsing.
114
115             _s       Print debugging information about suffix-transformation
116                     rules.
117
118             _t       Print debugging information about target list mainte-
119                     nance.
120
121             _V       Force the --VV option to print raw values of variables.
122
123             _v       Print debugging information about variable assignment.
124
125             _x       Run shell commands with --xx so the actual commands are
126                     printed as they are executed.
127
128     --ee      Specify that environment variables override macro assignments
129             within makefiles.
130
131     --ff _m_a_k_e_f_i_l_e
132             Specify a makefile to read instead of the default `_m_a_k_e_f_i_l_e'.  If
133             _m_a_k_e_f_i_l_e is `--', standard input is read.  Multiple makefiles may
134             be specified, and are read in the order specified.
135
136     --II _d_i_r_e_c_t_o_r_y
137             Specify a directory in which to search for makefiles and included
138             makefiles.  The system makefile directory (or directories, see
139             the --mm option) is automatically included as part of this list.
140
141     --ii      Ignore non-zero exit of shell commands in the makefile.  Equiva-
142             lent to specifying `--' before each command line in the makefile.
143
144     --JJ _p_r_i_v_a_t_e
145             This option should _n_o_t be specified by the user.
146
147             When the _j option is in use in a recursive build, this option is
148             passed by a make to child makes to allow all the make processes
149             in the build to cooperate to avoid overloading the system.
150
151     --jj _m_a_x___j_o_b_s
152             Specify the maximum number of jobs that bbmmaakkee may have running at
153             any one time.  The value is saved in _._M_A_K_E_._J_O_B_S.  Turns compati-
154             bility mode off, unless the _B flag is also specified.  When com-
155             patibility mode is off, all commands associated with a target are
156             executed in a single shell invocation as opposed to the tradi-
157             tional one shell invocation per line.  This can break traditional
158             scripts which change directories on each command invocation and
159             then expect to start with a fresh environment on the next line.
160             It is more efficient to correct the scripts rather than turn
161             backwards compatibility on.
162
163     --kk      Continue processing after errors are encountered, but only on
164             those targets that do not depend on the target whose creation
165             caused the error.
166
167     --mm _d_i_r_e_c_t_o_r_y
168             Specify a directory in which to search for sys.mk and makefiles
169             included via the <_f_i_l_e>-style include statement.  The --mm option
170             can be used multiple times to form a search path.  This path will
171             override the default system include path: /usr/share/mk.  Fur-
172             thermore the system include path will be appended to the search
173             path used for "_f_i_l_e"-style include statements (see the --II
174             option).
175
176             If a file or directory name in the --mm argument (or the
177             MAKESYSPATH environment variable) starts with the string ".../"
178             then bbmmaakkee will search for the specified file or directory named
179             in the remaining part of the argument string.  The search starts
180             with the current directory of the Makefile and then works upward
181             towards the root of the filesystem.  If the search is successful,
182             then the resulting directory replaces the ".../" specification in
183             the --mm argument.  If used, this feature allows bbmmaakkee to easily
184             search in the current source tree for customized sys.mk files
185             (e.g., by using ".../mk/sys.mk" as an argument).
186
187     --nn      Display the commands that would have been executed, but do not
188             actually execute them unless the target depends on the .MAKE spe-
189             cial source (see below).
190
191     --NN      Display the commands which would have been executed, but do not
192             actually execute any of them; useful for debugging top-level
193             makefiles without descending into subdirectories.
194
195     --qq      Do not execute any commands, but exit 0 if the specified targets
196             are up-to-date and 1, otherwise.
197
198     --rr      Do not use the built-in rules specified in the system makefile.
199
200     --ss      Do not echo any commands as they are executed.  Equivalent to
201             specifying `@@' before each command line in the makefile.
202
203     --TT _t_r_a_c_e_f_i_l_e
204             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
205             for each job started and completed.
206
207     --tt      Rather than re-building a target as specified in the makefile,
208             create it or update its modification time to make it appear up-
209             to-date.
210
211     --VV _v_a_r_i_a_b_l_e
212             Print bbmmaakkee's idea of the value of _v_a_r_i_a_b_l_e, in the global con-
213             text.  Do not build any targets.  Multiple instances of this
214             option may be specified; the variables will be printed one per
215             line, with a blank line for each null or undefined variable.  If
216             _v_a_r_i_a_b_l_e contains a `$' then the value will be expanded before
217             printing.
218
219     --WW      Treat any warnings during makefile parsing as errors.
220
221     --XX      Don't export variables passed on the command line to the environ-
222             ment individually.  Variables passed on the command line are
223             still exported via the _M_A_K_E_F_L_A_G_S environment variable.  This
224             option may be useful on systems which have a small limit on the
225             size of command arguments.
226
227     _v_a_r_i_a_b_l_e_=_v_a_l_u_e
228             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
229             values passed on the command line are also exported to sub-makes
230             in the environment.  The --XX flag disables this behavior.  Vari-
231             able assignments should follow options for POSIX compatibility
232             but no ordering is enforced.
233
234     There are seven different types of lines in a makefile: file dependency
235     specifications, shell commands, variable assignments, include statements,
236     conditional directives, for loops, and comments.
237
238     In general, lines may be continued from one line to the next by ending
239     them with a backslash (`\').  The trailing newline character and initial
240     whitespace on the following line are compressed into a single space.
241
242FFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
243     Dependency lines consist of one or more targets, an operator, and zero or
244     more sources.  This creates a relationship where the targets ``depend''
245     on the sources and are usually created from them.  The exact relationship
246     between the target and the source is determined by the operator that sep-
247     arates them.  The three operators are as follows:
248
249     ::     A target is considered out-of-date if its modification time is less
250           than those of any of its sources.  Sources for a target accumulate
251           over dependency lines when this operator is used.  The target is
252           removed if bbmmaakkee is interrupted.
253
254     !!     Targets are always re-created, but not until all sources have been
255           examined and re-created as necessary.  Sources for a target accumu-
256           late over dependency lines when this operator is used.  The target
257           is removed if bbmmaakkee is interrupted.
258
259     ::::    If no sources are specified, the target is always re-created.  Oth-
260           erwise, a target is considered out-of-date if any of its sources
261           has been modified more recently than the target.  Sources for a
262           target do not accumulate over dependency lines when this operator
263           is used.  The target will not be removed if bbmmaakkee is interrupted.
264
265     Targets and sources may contain the shell wildcard values `?', `*', `[]',
266     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
267     final component of the target or source, and must be used to describe
268     existing files.  The value `{}' need not necessarily be used to describe
269     existing files.  Expansion is in directory order, not alphabetically as
270     done in the shell.
271
272SSHHEELLLL CCOOMMMMAANNDDSS
273     Each target may have associated with it a series of shell commands, nor-
274     mally used to create the target.  Each of the commands in this script
275     _m_u_s_t be preceded by a tab.  While any target may appear on a dependency
276     line, only one of these dependencies may be followed by a creation
277     script, unless the `::::' operator is used.
278
279     If the first characters of the command line are any combination of `@@',
280     `++', or `--', the command is treated specially.  A `@@' causes the command
281     not to be echoed before it is executed.  A `++' causes the command to be
282     executed even when --nn is given.  This is similar to the effect of the
283     .MAKE special source, except that the effect can be limited to a single
284     line of a script.  A `--' causes any non-zero exit status of the command
285     line to be ignored.
286
287     When bbmmaakkee is run in jobs mode with --jj _m_a_x___j_o_b_s, the entire script for
288     the target is fed to a single instance of the shell.
289
290     In compatibility (non-jobs) mode, each command is run in a separate
291     process.  If the command contains any shell meta characters
292     (`#=|^(){};&<>*?[]:$`\\n') it will be passed to the shell, otherwise
293     bbmmaakkee will attempt direct execution.
294
295     Since bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R' before executing any targets, each
296     child process starts with that as its current working directory.
297
298     Makefiles should be written so that the mode of bbmmaakkee operation does not
299     change their behavior.  For example, any command which needs to use
300     ``cd'' or ``chdir'', without side-effect should be put in parenthesis:
301
302
303           avoid-chdir-side-effects:
304                   @echo Building $@ in `pwd`
305                   @(cd ${.CURDIR} && ${.MAKE} $@)
306                   @echo Back in `pwd`
307
308           ensure-one-shell-regardless-of-mode:
309                   @echo Building $@ in `pwd`; \
310                   (cd ${.CURDIR} && ${.MAKE} $@); \
311                   echo Back in `pwd`
312
313VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
314     Variables in make are much like variables in the shell, and, by tradi-
315     tion, consist of all upper-case letters.
316
317   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
318     The five operators that can be used to assign values to variables are as
319     follows:
320
321     ==       Assign the value to the variable.  Any previous value is overrid-
322             den.
323
324     ++==      Append the value to the current value of the variable.
325
326     ??==      Assign the value to the variable if it is not already defined.
327
328     ::==      Assign with expansion, i.e. expand the value before assigning it
329             to the variable.  Normally, expansion is not done until the vari-
330             able is referenced.  _N_O_T_E: References to undefined variables are
331             _n_o_t expanded.  This can cause problems when variable modifiers
332             are used.
333
334     !!==      Expand the value and pass it to the shell for execution and
335             assign the result to the variable.  Any newlines in the result
336             are replaced with spaces.
337
338     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
339     being appended, a single space is inserted between the previous contents
340     of the variable and the appended value.
341
342     Variables are expanded by surrounding the variable name with either curly
343     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
344     (`$').  If the variable name contains only a single letter, the surround-
345     ing braces or parentheses are not required.  This shorter form is not
346     recommended.
347
348     If the variable name contains a dollar, then the name itself is expanded
349     first.  This allows almost arbitrary variable names, however names con-
350     taining dollar, braces, parenthesis, or whitespace are really best
351     avoided!
352
353     If the result of expanding a variable contains a dollar sign (`$') the
354     string is expanded again.
355
356     Variable substitution occurs at three distinct times, depending on where
357     the variable is being used.
358
359     1.   Variables in dependency lines are expanded as the line is read.
360
361     2.   Variables in shell commands are expanded when the shell command is
362          executed.
363
364     3.   ``.for'' loop index variables are expanded on each loop iteration.
365          Note that other variables are not expanded inside loops so the fol-
366          lowing example code:
367
368
369                .for i in 1 2 3
370                a+=     ${i}
371                j=      ${i}
372                b+=     ${j}
373                .endfor
374
375                all:
376                        @echo ${a}
377                        @echo ${b}
378
379          will print:
380
381                1 2 3
382                3 3 3
383
384          Because while ${a} contains ``1 2 3'' after the loop is executed,
385          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
386          after the loop completes ${j} contains ``3''.
387
388   VVaarriiaabbllee ccllaasssseess
389     The four different classes of variables (in order of increasing prece-
390     dence) are:
391
392     Environment variables
393             Variables defined as part of bbmmaakkee's environment.
394
395     Global variables
396             Variables defined in the makefile or in included makefiles.
397
398     Command line variables
399             Variables defined as part of the command line.
400
401     Local variables
402             Variables that are defined specific to a certain target.  The
403             seven local variables are as follows:
404
405             _._A_L_L_S_R_C   The list of all sources for this target; also known as
406                       `_>'.
407
408             _._A_R_C_H_I_V_E  The name of the archive file.
409
410             _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
411                       source from which the target is to be transformed (the
412                       ``implied'' source); also known as `_<'.  It is not
413                       defined in explicit rules.
414
415             _._M_E_M_B_E_R   The name of the archive member.
416
417             _._O_O_D_A_T_E   The list of sources for this target that were deemed
418                       out-of-date; also known as `_?'.
419
420             _._P_R_E_F_I_X   The file prefix of the target, containing only the file
421                       portion, no suffix or preceding directory components;
422                       also known as `_*'.
423
424             _._T_A_R_G_E_T   The name of the target; also known as `_@'.
425
426             The shorter forms `_@', `_?', `_<', `_>', and `_*' are permitted for
427             backward compatibility with historical makefiles and are not rec-
428             ommended.  The six variables `_@_F', `_@_D', `_<_F', `_<_D', `_*_F', and
429             `_*_D' are permitted for compatibility with AT&T System V UNIX
430             makefiles and are not recommended.
431
432             Four of the local variables may be used in sources on dependency
433             lines because they expand to the proper value for each target on
434             the line.  These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E',
435             and `_._M_E_M_B_E_R'.
436
437   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
438     In addition, bbmmaakkee sets or knows about the following variables:
439
440     _$               A single dollar sign `$', i.e.  `$$' expands to a single
441                     dollar sign.
442
443     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
444                     evaluated during Makefile parsing, lists only those tar-
445                     gets encountered thus far.
446
447     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
448                     to the description of `PWD' for more details.
449
450     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
451                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
452                     The preferred variable to use is the environment variable
453                     MAKE because it is more compatible with other versions of
454                     bbmmaakkee and cannot be confused with the special target with
455                     the same name.
456
457     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
458                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
459                     ated dependencies are read.
460
461     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
462                     A boolean that controls the default behavior of the --VV
463                     option.
464
465     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
466
467     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
468
469     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
470                     If bbmmaakkee is run with _j then output for each target is
471                     prefixed with a token `--- target ---' the first part of
472                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
473                     For example:
474                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
475                     would produce tokens like `---make[1234] target ---' mak-
476                     ing it easier to track the degree of parallelism being
477                     achieved.
478
479     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
480                     that may be specified on bbmmaakkee's command line.  Anything
481                     specified on bbmmaakkee's command line is appended to the
482                     `MAKEFLAGS' variable which is then entered into the envi-
483                     ronment for all programs which bbmmaakkee executes.
484
485     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
486                     bbmmaakkee will be 0, and an incremented value is put into the
487                     environment to be seen by the next generation.  This
488                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
489                     things which should only be evaluated in the initial
490                     instance of bbmmaakkee.
491
492     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
493                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
494                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
495
496     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
497                     The list of makefiles read by bbmmaakkee, which is useful for
498                     tracking dependencies.  Each makefile is recorded only
499                     once, regardless of the number of times read.
500
501     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
502                     mode that bbmmaakkee runs in.  It can contain a number of key-
503                     words:
504
505                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
506
507                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
508                                 are created for each target to capture the
509                                 command run, the output generated and if
510                                 filemon(4) is available, the system calls
511                                 which are of interest to bbmmaakkee.  The captured
512                                 output can be very useful when diagnosing
513                                 errors.
514
515                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
516                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
517                                 ting _b_f to a value which represents True.
518
519                     _e_n_v         For debugging, it can be useful to inlcude
520                                 the environment in the .meta file.
521
522                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
523                                 target being built.  This is useful if the
524                                 build is otherwise running silently.  The
525                                 message printed the value of:
526                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
527
528                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
529                                 not stable.  This keyword causes them to be
530                                 ignored for determining whether a target is
531                                 out of date in "meta" mode.  See also
532                                 ..NNOOMMEETTAA__CCMMPP.
533
534                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
535                                 mark the target ..SSIILLEENNTT.
536
537     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
538                     In "meta" mode, provides a list of prefixes which match
539                     the directories controlled by bbmmaakkee.  If a file that was
540                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
541                     missing, the current target is considered out-of-date.
542
543     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
544                     In "meta" mode, this variable contains a list of all the
545                     meta files updated.  If not empty, it can be used to
546                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
547
548     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
549                     In "meta" mode, this variable contains a list of all the
550                     meta files used (updated or not).  This list can be used
551                     to process the meta files to extract dependency informa-
552                     tion.
553
554     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
555                     Defines the message printed for each meta file updated in
556                     "meta verbose" mode.  The default value is:
557                           Building ${.TARGET:H:tA}/${.TARGET:T}
558
559     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
560                     assigned to on the command line, so that they may be
561                     exported as part of `MAKEFLAGS'.  This behaviour can be
562                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
563                     within a makefile.  Extra variables can be exported from
564                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
565                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
566                     modified.
567
568     _._M_A_K_E_._P_A_T_H___F_I_L_E_M_O_N
569                     If bbmmaakkee was built with filemon(4) support, this is set
570                     to the path of the device node.  This allows makefiles to
571                     test for this support.
572
573     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
574
575     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
576
577     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
578                     When bbmmaakkee stops due to an error, it prints its name and
579                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
580                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
581
582     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
583                     its value.  This allows expansions using the ::@@ modifier
584                     to put a newline between iterations of the loop rather
585                     than a space.  For example, the printing of
586                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
587                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
588
589     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
590                     value is determined by trying to chdir(2) to the follow-
591                     ing directories in order and using the first match:
592
593                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
594
595                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
596                          ment or on the command line.)
597
598                     2.   ${MAKEOBJDIR}
599
600                          (Only if `MAKEOBJDIR' is set in the environment or
601                          on the command line.)
602
603                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
604
605                     4.   ${.CURDIR}_/_o_b_j
606
607                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
608
609                     6.   ${.CURDIR}
610
611                     Variable expansion is performed on the value before it's
612                     used, so expressions such as
613                           ${.CURDIR:S,^/usr/src,/var/obj,}
614                     may be used.  This is especially useful with
615                     `MAKEOBJDIR'.
616
617                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
618                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
619                     and set `PWD' to that directory before executing any tar-
620                     gets.
621
622     _._P_A_R_S_E_D_I_R       A path to the directory of the current `_M_a_k_e_f_i_l_e' being
623                     parsed.
624
625     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
626                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
627                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
628                     their current values, assign them to a variable using
629                     assignment with expansion: (`::==').
630
631     _._P_A_T_H           A variable that represents the list of directories that
632                     bbmmaakkee will search for files.  The search list should be
633                     updated using the target `_._P_A_T_H' rather than the vari-
634                     able.
635
636     PWD             Alternate path to the current directory.  bbmmaakkee normally
637                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
638                     However, if the environment variable `PWD' is set and
639                     gives a path to the current directory, then bbmmaakkee sets
640                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
641                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
642                     contains a variable transform.  `PWD' is set to the value
643                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
644
645     .TARGETS        The list of targets explicitly specified on the command
646                     line, if any.
647
648     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
649                     will search for files.  The variable is supported for
650                     compatibility with old make programs only, use `_._P_A_T_H'
651                     instead.
652
653   VVaarriiaabbllee mmooddiiffiieerrss
654     Variable expansion may be modified to select or modify each word of the
655     variable (where a ``word'' is white-space delimited sequence of charac-
656     ters).  The general format of a variable expansion is as follows:
657
658           ${variable[:modifier[:...]]}
659
660     Each modifier begins with a colon, which may be escaped with a backslash
661     (`\').
662
663     A set of modifiers can be specified via a variable, as follows:
664
665           modifier_variable=modifier[:...]
666           ${variable:${modifier_variable}[:...]}
667
668     In this case the first modifier in the modifier_variable does not start
669     with a colon, since that must appear in the referencing variable.  If any
670     of the modifiers in the modifier_variable contain a dollar sign (`$'),
671     these must be doubled to avoid early expansion.
672
673     The supported modifiers are:
674
675     ::EE   Replaces each word in the variable with its suffix.
676
677     ::HH   Replaces each word in the variable with everything but the last com-
678          ponent.
679
680     ::MM_p_a_t_t_e_r_n
681          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
682          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
683          characters may be escaped with a backslash (`\').
684
685     ::NN_p_a_t_t_e_r_n
686          This is identical to `::MM', but selects all words which do not match
687          _p_a_t_t_e_r_n.
688
689     ::OO   Order every word in variable alphabetically.  To sort words in
690          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
691
692     ::OOxx  Randomize words in variable.  The results will be different each
693          time you are referring to the modified variable; use the assignment
694          with expansion (`::==') to prevent such behaviour.  For example,
695
696                LIST=                   uno due tre quattro
697                RANDOM_LIST=            ${LIST:Ox}
698                STATIC_RANDOM_LIST:=    ${LIST:Ox}
699
700                all:
701                        @echo "${RANDOM_LIST}"
702                        @echo "${RANDOM_LIST}"
703                        @echo "${STATIC_RANDOM_LIST}"
704                        @echo "${STATIC_RANDOM_LIST}"
705          may produce output similar to:
706
707                quattro due tre uno
708                tre due quattro uno
709                due uno quattro tre
710                due uno quattro tre
711
712     ::QQ   Quotes every shell meta-character in the variable, so that it can be
713          passed safely through recursive invocations of bbmmaakkee.
714
715     ::RR   Replaces each word in the variable with everything but its suffix.
716
717     ::ggmmttiimmee
718          The value is a format string for strftime(3), using the current
719          gmtime(3).
720
721     ::hhaasshh
722          Compute a 32bit hash of the value and encode it as hex digits.
723
724     ::llooccaallttiimmee
725          The value is a format string for strftime(3), using the current
726          localtime(3).
727
728     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
729          if that fails, the value is unchanged.
730
731     ::ttll  Converts variable to lower-case letters.
732
733     ::ttss_c
734          Words in the variable are normally separated by a space on expan-
735          sion.  This modifier sets the separator to the character _c.  If _c is
736          omitted, then no separator is used.  The common escapes (including
737          octal numeric codes), work as expected.
738
739     ::ttuu  Converts variable to upper-case letters.
740
741     ::ttWW  Causes the value to be treated as a single word (possibly containing
742          embedded white space).  See also `::[[**]]'.
743
744     ::ttww  Causes the value to be treated as a sequence of words delimited by
745          white space.  See also `::[[@@]]'.
746
747     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
748          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
749          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
750          slash of the pattern, all occurrences in each word are replaced.  If
751          a `1' is appended to the last slash of the pattern, only the first
752          word is affected.  If a `W' is appended to the last slash of the
753          pattern, then the value is treated as a single word (possibly con-
754          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
755          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
756          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
757          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
758          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
759          delimiter for the parts of the modifier string.  The anchoring,
760          ampersand and delimiter characters may be escaped with a backslash
761          (`\').
762
763          Variable expansion occurs in the normal fashion inside both
764          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
765          is used to prevent the expansion of a dollar sign (`$'), not a pre-
766          ceding dollar sign as is usual.
767
768     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
769          The ::CC modifier is just like the ::SS modifier except that the old and
770          new strings, instead of being simple strings, are a regular expres-
771          sion (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style string
772          _r_e_p_l_a_c_e_m_e_n_t.  Normally, the first occurrence of the pattern _p_a_t_t_e_r_n
773          in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.  The `1'
774          modifier causes the substitution to apply to at most one word; the
775          `g' modifier causes the substitution to apply to as many instances
776          of the search pattern _p_a_t_t_e_r_n as occur in the word or words it is
777          found in; the `W' modifier causes the value to be treated as a sin-
778          gle word (possibly containing embedded white space).  Note that `1'
779          and `g' are orthogonal; the former specifies whether multiple words
780          are potentially affected, the latter whether multiple substitutions
781          can potentially occur within each affected word.
782
783     ::TT   Replaces each word in the variable with its last component.
784
785     ::uu   Remove adjacent duplicate words (like uniq(1)).
786
787     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
788          If the variable name (not its value), when parsed as a .if condi-
789          tional expression, evaluates to true, return as its value the
790          _t_r_u_e___s_t_r_i_n_g, otherwise return the _f_a_l_s_e___s_t_r_i_n_g.  Since the variable
791          name is used as the expression, :? must be the first modifier after
792          the variable name itself - which will, of course, usually contain
793          variable expansions.  A common error is trying to use expressions
794          like
795                ${NUMBERS:M42:?match:no}
796          which actually tests defined(NUMBERS), to determine is any words
797          match "42" you need to use something like:
798                ${"${NUMBERS:M42}" != "":?match:no}.
799
800     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
801          This is the AT&T System V UNIX style variable substitution.  It must
802          be the last modifier specified.  If _o_l_d___s_t_r_i_n_g or _n_e_w___s_t_r_i_n_g do not
803          contain the pattern matching character _% then it is assumed that
804          they are anchored at the end of each word, so only suffixes or
805          entire words may be replaced.  Otherwise _% is the substring of
806          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
807
808          Variable expansion occurs in the normal fashion inside both
809          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
810          is used to prevent the expansion of a dollar sign (`$'), not a pre-
811          ceding dollar sign as is usual.
812
813     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
814          This is the loop expansion mechanism from the OSF Development Envi-
815          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
816          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
817          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
818          period.  For example.
819                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
820
821          However a single character varaiable is often more readable:
822                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
823
824     ::UU_n_e_w_v_a_l
825          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
826          is defined, the existing value is returned.  This is another ODE
827          make feature.  It is handy for setting per-target CFLAGS for
828          instance:
829                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
830          If a value is only required if the variable is undefined, use:
831                ${VAR:D:Unewval}
832
833     ::DD_n_e_w_v_a_l
834          If the variable is defined _n_e_w_v_a_l is the value.
835
836     ::LL   The name of the variable is the value.
837
838     ::PP   The path of the node which has the same name as the variable is the
839          value.  If no such node exists or its path is null, then the name of
840          the variable is used.  In order for this modifier to work, the name
841          (node) must at least have appeared on the rhs of a dependency.
842
843     ::!!_c_m_d!!
844          The output of running _c_m_d is the value.
845
846     ::sshh  If the variable is non-empty it is run as a command and the output
847          becomes the new value.
848
849     ::::==_s_t_r
850          The variable is assigned the value _s_t_r after substitution.  This
851          modifier and its variations are useful in obscure situations such as
852          wanting to set a variable when shell commands are being parsed.
853          These assignment modifiers always expand to nothing, so if appearing
854          in a rule line by themselves should be preceded with something to
855          keep bbmmaakkee happy.
856
857          The `::::' helps avoid false matches with the AT&T System V UNIX style
858          ::== modifier and since substitution always occurs the ::::== form is
859          vaguely appropriate.
860
861     ::::??==_s_t_r
862          As for ::::== but only if the variable does not already have a value.
863
864     ::::++==_s_t_r
865          Append _s_t_r to the variable.
866
867     ::::!!==_c_m_d
868          Assign the output of _c_m_d to the variable.
869
870     ::[[_r_a_n_g_e]]
871          Selects one or more words from the value, or performs other opera-
872          tions related to the way in which the value is divided into words.
873
874          Ordinarily, a value is treated as a sequence of words delimited by
875          white space.  Some modifiers suppress this behaviour, causing a
876          value to be treated as a single word (possibly containing embedded
877          white space).  An empty value, or a value that consists entirely of
878          white-space, is treated as a single word.  For the purposes of the
879          `::[[]]' modifier, the words are indexed both forwards using positive
880          integers (where index 1 represents the first word), and backwards
881          using negative integers (where index -1 represents the last word).
882
883          The _r_a_n_g_e is subjected to variable expansion, and the expanded
884          result is then interpreted as follows:
885
886          _i_n_d_e_x  Selects a single word from the value.
887
888          _s_t_a_r_t...._e_n_d
889                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
890                 `::[[22....--11]]' selects all words from the second word to the last
891                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
892                 put in reverse order.  For example, `::[[--11....11]]' selects all
893                 the words from last to first.
894
895          **      Causes subsequent modifiers to treat the value as a single
896                 word (possibly containing embedded white space).  Analogous
897                 to the effect of "$*" in Bourne shell.
898
899          0      Means the same as `::[[**]]'.
900
901          @@      Causes subsequent modifiers to treat the value as a sequence
902                 of words delimited by white space.  Analogous to the effect
903                 of "$@" in Bourne shell.
904
905          ##      Returns the number of words in the value.
906
907IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
908     Makefile inclusion, conditional structures and for loops  reminiscent of
909     the C programming language are provided in bbmmaakkee.  All such structures
910     are identified by a line beginning with a single dot (`.') character.
911     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
912     ables between the angle brackets or double quotes are expanded to form
913     the file name.  If angle brackets are used, the included makefile is
914     expected to be in the system makefile directory.  If double quotes are
915     used, the including makefile's directory and any directories specified
916     using the --II option are searched before the system makefile directory.
917     For compatibility with other versions of bbmmaakkee `include file ...' is also
918     accepted.  If the include statement is written as ..--iinncclluuddee or as
919     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
920
921     Conditional expressions are also preceded by a single dot as the first
922     character of a line.  The possible conditionals are as follows:
923
924     ..eerrrroorr _m_e_s_s_a_g_e
925             The message is printed along with the name of the makefile and
926             line number, then bbmmaakkee will exit.
927
928     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
929             Export the specified global variable.  If no variable list is
930             provided, all globals are exported except for internal variables
931             (those that start with `.').  This is not affected by the --XX
932             flag, so should be used with caution.  For compatibility with
933             other bbmmaakkee programs `export variable=value' is also accepted.
934
935             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
936             exporting a variable.
937
938     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
939             The same as `.export', except that the variable is not appended
940             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
941             ment which is different from that used by bbmmaakkee internally.
942
943     ..iinnffoo _m_e_s_s_a_g_e
944             The message is printed along with the name of the makefile and
945             line number.
946
947     ..uunnddeeff _v_a_r_i_a_b_l_e
948             Un-define the specified global variable.  Only global variables
949             may be un-defined.
950
951     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
952             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
953             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
954             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
955
956     ..uunneexxppoorrtt--eennvv
957             Unexport all globals previously exported and clear the environ-
958             ment inherited from the parent.  This operation will cause a mem-
959             ory leak of the original environment, so should be used spar-
960             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
961             note that any variables which originated in the parent environ-
962             ment should be explicitly preserved if desired.  For example:
963
964                   .if ${.MAKE.LEVEL} == 0
965                   PATH := ${PATH}
966                   .unexport-env
967                   .export PATH
968                   .endif
969
970             Would result in an environment containing only `PATH', which is
971             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
972             be pushed into the new environment.
973
974     ..wwaarrnniinngg _m_e_s_s_a_g_e
975             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
976             of the makefile and line number.
977
978     ..iiff [!]_e_x_p_r_e_s_s_i_o_n [_o_p_e_r_a_t_o_r _e_x_p_r_e_s_s_i_o_n _._._.]
979             Test the value of an expression.
980
981     ..iiffddeeff [!]_v_a_r_i_a_b_l_e [_o_p_e_r_a_t_o_r _v_a_r_i_a_b_l_e _._._.]
982             Test the value of a variable.
983
984     ..iiffnnddeeff [!]_v_a_r_i_a_b_l_e [_o_p_e_r_a_t_o_r _v_a_r_i_a_b_l_e _._._.]
985             Test the value of a variable.
986
987     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
988             Test the target being built.
989
990     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
991             Test the target being built.
992
993     ..eellssee   Reverse the sense of the last conditional.
994
995     ..eelliiff [!] _e_x_p_r_e_s_s_i_o_n [_o_p_e_r_a_t_o_r _e_x_p_r_e_s_s_i_o_n _._._.]
996             A combination of `..eellssee' followed by `..iiff'.
997
998     ..eelliiffddeeff [!]_v_a_r_i_a_b_l_e [_o_p_e_r_a_t_o_r _v_a_r_i_a_b_l_e _._._.]
999             A combination of `..eellssee' followed by `..iiffddeeff'.
1000
1001     ..eelliiffnnddeeff [!]_v_a_r_i_a_b_l_e [_o_p_e_r_a_t_o_r _v_a_r_i_a_b_l_e _._._.]
1002             A combination of `..eellssee' followed by `..iiffnnddeeff'.
1003
1004     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1005             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1006
1007     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1008             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1009
1010     ..eennddiiff  End the body of the conditional.
1011
1012     The _o_p_e_r_a_t_o_r may be any one of the following:
1013
1014     ||||     Logical OR.
1015
1016     &&&&     Logical AND; of higher precedence than ``||''.
1017
1018     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
1019     determine its value.  Parentheses may be used to change the order of
1020     evaluation.  The boolean operator `!!' may be used to logically negate an
1021     entire conditional.  It is of higher precedence than `&&&&'.
1022
1023     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
1024
1025     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
1026              the variable has been defined.
1027
1028     mmaakkee     Takes a target name as an argument and evaluates to true if the
1029              target was specified as part of bbmmaakkee's command line or was
1030              declared the default target (either implicitly or explicitly,
1031              see _._M_A_I_N) before the line containing the conditional.
1032
1033     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1034              if the expansion of the variable would result in an empty
1035              string.
1036
1037     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1038              file exists.  The file is searched for on the system search path
1039              (see _._P_A_T_H).
1040
1041     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1042              target has been defined.
1043
1044     ccoommmmaannddss
1045              Takes a target name as an argument and evaluates to true if the
1046              target has been defined and has commands associated with it.
1047
1048     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1049     expansion is performed on both sides of the comparison, after which the
1050     integral values are compared.  A value is interpreted as hexadecimal if
1051     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1052     ported.  The standard C relational operators are all supported.  If after
1053     variable expansion, either the left or right hand side of a `====' or `!!=='
1054     operator is not an integral value, then string comparison is performed
1055     between the expanded variables.  If no relational operator is given, it
1056     is assumed that the expanded variable is being compared against 0 or an
1057     empty string in the case of a string comparison.
1058
1059     When bbmmaakkee is evaluating one of these conditional expressions, and it
1060     encounters a (white-space separated) word it doesn't recognize, either
1061     the ``make'' or ``defined'' expression is applied to it, depending on the
1062     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1063     the ``defined'' expression is applied.  Similarly, if the form is
1064     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1065
1066     If the conditional evaluates to true the parsing of the makefile contin-
1067     ues as before.  If it evaluates to false, the following lines are
1068     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1069     found.
1070
1071     For loops are typically used to apply a set of rules to a list of files.
1072     The syntax of a for loop is:
1073
1074     ..ffoorr _v_a_r_i_a_b_l_e [_v_a_r_i_a_b_l_e _._._.] iinn _e_x_p_r_e_s_s_i_o_n
1075     <make-rules>
1076     ..eennddffoorr
1077
1078     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1079     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1080     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1081     the body of the for loop.  The number of words must come out even; that
1082     is, if there are three iteration variables, the number of words provided
1083     must be a multiple of three.
1084
1085CCOOMMMMEENNTTSS
1086     Comments begin with a hash (`#') character, anywhere but in a shell com-
1087     mand line, and continue to the end of an unescaped new line.
1088
1089SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1090     ..EEXXEECC     Target is never out of date, but always execute commands any-
1091               way.
1092
1093     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1094               get, exactly as if they all were preceded by a dash (`-').
1095
1096     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1097
1098     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1099               or --tt options were specified.  Normally used to mark recursive
1100               bbmmaakkee's.
1101
1102     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1103               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1104               the most likely case.  In "meta" mode, the target is out-of-
1105               date if the meta file is missing.
1106
1107     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1108               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1109
1110     ..NNOOMMEETTAA__CCMMPP
1111               Ignore differences in commands when deciding if target is out
1112               of date.  This is useful if the command contains a value which
1113               always changes.  If the number of commands change, though, the
1114               target will still be out of date.  The same effect applies to
1115               any command line that uses the variable _._O_O_D_A_T_E, which can be
1116               used for that purpose even when not otherwise needed or
1117               desired:
1118
1119
1120                     skip-compare-for-some:
1121                             @echo this will be compared
1122                             @echo this will not ${.OODATE:M.NOMETA_CMP}
1123                             @echo this will also be compared
1124
1125               The ::MM pattern suppresses any expansion of the unwanted vari-
1126               able.
1127
1128     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1129               ..PPAATTHH.
1130
1131     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1132               default target to be built if no target was specified.  This
1133               source prevents this target from being selected.
1134
1135     ..OOPPTTIIOONNAALL
1136               If a target is marked with this attribute and bbmmaakkee can't fig-
1137               ure out how to create it, it will ignore this fact and assume
1138               the file isn't needed or already exists.
1139
1140     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1141               considered to be out of date, and will not be created with the
1142               --tt option.  Suffix-transformation rules are not applied to
1143               ..PPHHOONNYY targets.
1144
1145     ..PPRREECCIIOOUUSS
1146               When bbmmaakkee is interrupted, it normally removes any partially
1147               made targets.  This source prevents the target from being
1148               removed.
1149
1150     ..RREECCUURRSSIIVVEE
1151               Synonym for ..MMAAKKEE.
1152
1153     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1154               exactly as if they all were preceded by an at sign (`@').
1155
1156     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1157               get is used as a source for another target, the other target
1158               acquires the commands, sources, and attributes (except for
1159               ..UUSSEE) of the source.  If the target already has commands, the
1160               ..UUSSEE target's commands are appended to them.
1161
1162     ..UUSSEEBBEEFFOORREE
1163               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1164               to the target.
1165
1166     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1167               it are made before the sources that succeed it in the line.
1168               Since the dependents of files are not made until the file
1169               itself could be made, this also stops the dependents being
1170               built unless they are needed for another branch of the depen-
1171               dency tree.  So given:
1172
1173               x: a .WAIT b
1174                       echo x
1175               a:
1176                       echo a
1177               b: b1
1178                       echo b
1179               b1:
1180                       echo b1
1181
1182               the output is always `a', `b1', `b', `x'.
1183               The ordering imposed by ..WWAAIITT is only relevant for parallel
1184               makes.
1185
1186SSPPEECCIIAALL TTAARRGGEETTSS
1187     Special targets may not be included with other targets, i.e. they must be
1188     the only target specified.
1189
1190     ..BBEEGGIINN   Any command lines attached to this target are executed before
1191              anything else is done.
1192
1193     ..DDEEFFAAUULLTT
1194              This is sort of a ..UUSSEE rule for any target (that was used only
1195              as a source) that bbmmaakkee can't figure out any other way to cre-
1196              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1197              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1198              own name.
1199
1200     ..EENNDD     Any command lines attached to this target are executed after
1201              everything else is done.
1202
1203     ..EERRRROORR   Any command lines attached to this target are executed when
1204              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1205              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1206
1207     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1208              sources are specified, this is the equivalent of specifying the
1209              --ii option.
1210
1211     ..IINNTTEERRRRUUPPTT
1212              If bbmmaakkee is interrupted, the commands for this target will be
1213              executed.
1214
1215     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1216              will be built.
1217
1218     ..MMAAKKEEFFLLAAGGSS
1219              This target provides a way to specify flags for bbmmaakkee when the
1220              makefile is used.  The flags are as if typed to the shell,
1221              though the --ff option will have no effect.
1222
1223     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1224
1225     ..NNOOTTPPAARRAALLLLEELL
1226              Disable parallel mode.
1227
1228     ..NNOO__PPAARRAALLLLEELL
1229              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1230              variants.
1231
1232     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1233              add targets to the list of targets to be made.  Since the depen-
1234              dents of a target do not get built until the target itself could
1235              be built, unless `a' is built by another part of the dependency
1236              graph, the following is a dependency loop:
1237
1238              .ORDER: b a
1239              b: a
1240
1241              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1242              makes.
1243
1244     ..PPAATTHH    The sources are directories which are to be searched for files
1245              not found in the current directory.  If no sources are speci-
1246              fied, any previously specified directories are deleted.  If the
1247              source is the special ..DDOOTTLLAASSTT target, then the current working
1248              directory is searched last.
1249
1250     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1251
1252     ..PPRREECCIIOOUUSS
1253              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1254              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1255              every target in the file.
1256
1257     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1258              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1259
1260              _n_a_m_e        This is the minimal specification, used to select
1261                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
1262
1263              _p_a_t_h        Specifies the path to the shell.
1264
1265              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1266
1267              _c_h_e_c_k       The command to turn on error checking.
1268
1269              _i_g_n_o_r_e      The command to disable error checking.
1270
1271              _e_c_h_o        The command to turn on echoing of commands executed.
1272
1273              _q_u_i_e_t       The command to turn off echoing of commands exe-
1274                          cuted.
1275
1276              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1277                          mand.  It is typically identical to _q_u_i_e_t.
1278
1279              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1280
1281              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1282                          ing.
1283
1284              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1285                          a single newline character when used outside of any
1286                          quoting characters.
1287              Example:
1288
1289              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1290                      check="set -e" ignore="set +e" \
1291                      echo="set -v" quiet="set +v" filter="set +v" \
1292                      echoFlag=v errFlag=e newline="'\n'"
1293
1294     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1295              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1296              command in the file.
1297
1298     ..SSTTAALLEE   This target gets run when a dependency file contains stale
1299              entries, having _._A_L_L_S_R_C set to the name of that dependency file.
1300
1301     ..SSUUFFFFIIXXEESS
1302              Each source specifies a suffix to bbmmaakkee.  If no sources are
1303              specified, any previously specified suffixes are deleted.  It
1304              allows the creation of suffix-transformation rules.
1305
1306              Example:
1307
1308              .SUFFIXES: .o
1309              .c.o:
1310                      cc -o ${.TARGET} -c ${.IMPSRC}
1311
1312EENNVVIIRROONNMMEENNTT
1313     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1314     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1315     PWD, and TMPDIR.
1316
1317     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1318     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1319     tion of `_._O_B_J_D_I_R' for more details.
1320
1321FFIILLEESS
1322     .depend        list of dependencies
1323     Makefile       list of dependencies
1324     makefile       list of dependencies
1325     sys.mk         system makefile
1326     /usr/share/mk  system makefile directory
1327
1328CCOOMMPPAATTIIBBIILLIITTYY
1329     The basic make syntax is compatible between different versions of make,
1330     however the special variables, variable modifiers and conditionals are
1331     not.
1332
1333     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1334     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1335     rithms used may change again in the future.
1336
1337     The way that .for loop variables are substituted changed after NetBSD 5.0
1338     so that they still appear to be variable expansions.  In particular this
1339     stops them being treated as syntax, and removes some obscure problems
1340     using them in .if statements.
1341
1342SSEEEE AALLSSOO
1343     mkdep(1)
1344
1345HHIISSTTOORRYY
1346     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1347     portability to other platforms.
1348
1349     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1350     is based on Adam De Boor's pmake program which was written for Sprite at
1351     Berkeley.  It was designed to be a parallel distributed make running jobs
1352     on different machines using a daemon called ``customs''.
1353
1354BBUUGGSS
1355     The make syntax is difficult to parse without actually acting of the
1356     data.  For instance finding the end of a variable use should involve
1357     scanning each the modifiers using the correct terminator for each field.
1358     In many places make just counts {} and () in order to find the end of a
1359     variable expansion.
1360
1361     There is no way of escaping a space character in a filename.
1362
1363NetBSD 5.1                      March 30, 2013                      NetBSD 5.1
1364