xref: /freebsd/contrib/bmake/bmake.cat1 (revision 145992504973bd16cf3518af9ba5ce185fefa82a)
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
287VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
288     Variables in make are much like variables in the shell, and, by tradi-
289     tion, consist of all upper-case letters.
290
291   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
292     The five operators that can be used to assign values to variables are as
293     follows:
294
295     ==       Assign the value to the variable.  Any previous value is overrid-
296             den.
297
298     ++==      Append the value to the current value of the variable.
299
300     ??==      Assign the value to the variable if it is not already defined.
301
302     ::==      Assign with expansion, i.e. expand the value before assigning it
303             to the variable.  Normally, expansion is not done until the vari-
304             able is referenced.  _N_O_T_E: References to undefined variables are
305             _n_o_t expanded.  This can cause problems when variable modifiers
306             are used.
307
308     !!==      Expand the value and pass it to the shell for execution and
309             assign the result to the variable.  Any newlines in the result
310             are replaced with spaces.
311
312     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
313     being appended, a single space is inserted between the previous contents
314     of the variable and the appended value.
315
316     Variables are expanded by surrounding the variable name with either curly
317     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
318     (`$').  If the variable name contains only a single letter, the surround-
319     ing braces or parentheses are not required.  This shorter form is not
320     recommended.
321
322     If the variable name contains a dollar, then the name itself is expanded
323     first.  This allows almost arbitrary variable names, however names con-
324     taining dollar, braces, parenthesis, or whitespace are really best
325     avoided!
326
327     If the result of expanding a variable contains a dollar sign (`$') the
328     string is expanded again.
329
330     Variable substitution occurs at three distinct times, depending on where
331     the variable is being used.
332
333     1.   Variables in dependency lines are expanded as the line is read.
334
335     2.   Variables in shell commands are expanded when the shell command is
336          executed.
337
338     3.   ``.for'' loop index variables are expanded on each loop iteration.
339          Note that other variables are not expanded inside loops so the fol-
340          lowing example code:
341
342
343                .for i in 1 2 3
344                a+=     ${i}
345                j=      ${i}
346                b+=     ${j}
347                .endfor
348
349                all:
350                        @echo ${a}
351                        @echo ${b}
352
353          will print:
354
355                1 2 3
356                3 3 3
357
358          Because while ${a} contains ``1 2 3'' after the loop is executed,
359          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
360          after the loop completes ${j} contains ``3''.
361
362   VVaarriiaabbllee ccllaasssseess
363     The four different classes of variables (in order of increasing prece-
364     dence) are:
365
366     Environment variables
367             Variables defined as part of bbmmaakkee's environment.
368
369     Global variables
370             Variables defined in the makefile or in included makefiles.
371
372     Command line variables
373             Variables defined as part of the command line.
374
375     Local variables
376             Variables that are defined specific to a certain target.  The
377             seven local variables are as follows:
378
379             _._A_L_L_S_R_C   The list of all sources for this target; also known as
380                       `_>'.
381
382             _._A_R_C_H_I_V_E  The name of the archive file.
383
384             _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
385                       source from which the target is to be transformed (the
386                       ``implied'' source); also known as `_<'.  It is not
387                       defined in explicit rules.
388
389             _._M_E_M_B_E_R   The name of the archive member.
390
391             _._O_O_D_A_T_E   The list of sources for this target that were deemed
392                       out-of-date; also known as `_?'.
393
394             _._P_R_E_F_I_X   The file prefix of the target, containing only the file
395                       portion, no suffix or preceding directory components;
396                       also known as `_*'.
397
398             _._T_A_R_G_E_T   The name of the target; also known as `_@'.
399
400             The shorter forms `_@', `_?', `_<', `_>', and `_*' are permitted for
401             backward compatibility with historical makefiles and are not rec-
402             ommended.  The six variables `_@_F', `_@_D', `_<_F', `_<_D', `_*_F', and
403             `_*_D' are permitted for compatibility with AT&T System V UNIX
404             makefiles and are not recommended.
405
406             Four of the local variables may be used in sources on dependency
407             lines because they expand to the proper value for each target on
408             the line.  These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E',
409             and `_._M_E_M_B_E_R'.
410
411   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
412     In addition, bbmmaakkee sets or knows about the following variables:
413
414     _$               A single dollar sign `$', i.e.  `$$' expands to a single
415                     dollar sign.
416
417     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
418                     evaluated during Makefile parsing, lists only those tar-
419                     gets encountered thus far.
420
421     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
422                     to the description of `PWD' for more details.
423
424     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
425                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
426                     The preferred variable to use is the environment variable
427                     MAKE because it is more compatible with other versions of
428                     bbmmaakkee and cannot be confused with the special target with
429                     the same name.
430
431     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
432                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
433                     ated dependencies are read.
434
435     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
436                     A boolean that controls the default behavior of the --VV
437                     option.
438
439     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
440
441     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
442
443     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
444                     If bbmmaakkee is run with _j then output for each target is
445                     prefixed with a token `--- target ---' the first part of
446                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
447                     For example:
448                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
449                     would produce tokens like `---make[1234] target ---' mak-
450                     ing it easier to track the degree of parallelism being
451                     achieved.
452
453     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
454                     that may be specified on bbmmaakkee's command line.  Anything
455                     specified on bbmmaakkee's command line is appended to the
456                     `MAKEFLAGS' variable which is then entered into the envi-
457                     ronment for all programs which bbmmaakkee executes.
458
459     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
460                     bbmmaakkee will be 0, and an incremented value is put into the
461                     environment to be seen by the next generation.  This
462                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
463                     things which should only be evaluated in the initial
464                     instance of bbmmaakkee.
465
466     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
467                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
468                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
469
470     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
471                     The list of makefiles read by bbmmaakkee, which is useful for
472                     tracking dependencies.  Each makefile is recorded only
473                     once, regardless of the number of times read.
474
475     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
476                     mode that bbmmaakkee runs in.  It can contain a number of key-
477                     words:
478
479                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
480
481                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
482                                 are created for each target to capture the
483                                 command run, the output generated and if
484                                 filemon(4) is available, the system calls
485                                 which are of interest to bbmmaakkee.  The captured
486                                 output can be very useful when diagnosing
487                                 errors.
488
489                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
490                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
491                                 ting _b_f to a value which represents True.
492
493                     _e_n_v         For debugging, it can be useful to inlcude
494                                 the environment in the .meta file.
495
496                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
497                                 target being built.  This is useful if the
498                                 build is otherwise running silently.  The
499                                 message printed the value of:
500                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
501
502                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
503                                 not stable.  This keyword causes them to be
504                                 ignored for determining whether a target is
505                                 out of date in "meta" mode.  See also
506                                 ..NNOOMMEETTAA__CCMMPP.
507
508                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
509                                 mark the target ..SSIILLEENNTT.
510
511     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
512                     In "meta" mode, provides a list of prefixes which match
513                     the directories controlled by bbmmaakkee.  If a file that was
514                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
515                     missing, the current target is considered out-of-date.
516
517     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
518                     In "meta" mode, this variable contains a list of all the
519                     meta files updated.  If not empty, it can be used to
520                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
521
522     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
523                     In "meta" mode, this variable contains a list of all the
524                     meta files used (updated or not).  This list can be used
525                     to process the meta files to extract dependency informa-
526                     tion.
527
528     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
529                     Defines the message printed for each meta file updated in
530                     "meta verbose" mode.  The default value is:
531                           Building ${.TARGET:H:tA}/${.TARGET:T}
532
533     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
534                     assigned to on the command line, so that they may be
535                     exported as part of `MAKEFLAGS'.  This behaviour can be
536                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
537                     within a makefile.  Extra variables can be exported from
538                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
539                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
540                     modified.
541
542     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
543
544     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
545
546     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
547                     When bbmmaakkee stops due to an error, it prints its name and
548                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
549                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
550
551     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
552                     its value.  This allows expansions using the ::@@ modifier
553                     to put a newline between iterations of the loop rather
554                     than a space.  For example, the printing of
555                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
556                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
557
558     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
559                     value is determined by trying to chdir(2) to the follow-
560                     ing directories in order and using the first match:
561
562                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
563
564                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
565                          ment or on the command line.)
566
567                     2.   ${MAKEOBJDIR}
568
569                          (Only if `MAKEOBJDIR' is set in the environment or
570                          on the command line.)
571
572                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
573
574                     4.   ${.CURDIR}_/_o_b_j
575
576                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
577
578                     6.   ${.CURDIR}
579
580                     Variable expansion is performed on the value before it's
581                     used, so expressions such as
582                           ${.CURDIR:S,^/usr/src,/var/obj,}
583                     may be used.  This is especially useful with
584                     `MAKEOBJDIR'.
585
586                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
587                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
588                     and set `PWD' to that directory before executing any tar-
589                     gets.
590
591     _._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
592                     parsed.
593
594     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
595                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
596                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
597                     their current values, assign them to a variable using
598                     assignment with expansion: (`::==').
599
600     _._P_A_T_H           A variable that represents the list of directories that
601                     bbmmaakkee will search for files.  The search list should be
602                     updated using the target `_._P_A_T_H' rather than the vari-
603                     able.
604
605     PWD             Alternate path to the current directory.  bbmmaakkee normally
606                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
607                     However, if the environment variable `PWD' is set and
608                     gives a path to the current directory, then bbmmaakkee sets
609                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
610                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
611                     contains a variable transform.  `PWD' is set to the value
612                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
613
614     .TARGETS        The list of targets explicitly specified on the command
615                     line, if any.
616
617     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
618                     will search for files.  The variable is supported for
619                     compatibility with old make programs only, use `_._P_A_T_H'
620                     instead.
621
622   VVaarriiaabbllee mmooddiiffiieerrss
623     Variable expansion may be modified to select or modify each word of the
624     variable (where a ``word'' is white-space delimited sequence of charac-
625     ters).  The general format of a variable expansion is as follows:
626
627           ${variable[:modifier[:...]]}
628
629     Each modifier begins with a colon, which may be escaped with a backslash
630     (`\').
631
632     A set of modifiers can be specified via a variable, as follows:
633
634           modifier_variable=modifier[:...]
635           ${variable:${modifier_variable}[:...]}
636
637     In this case the first modifier in the modifier_variable does not start
638     with a colon, since that must appear in the referencing variable.  If any
639     of the modifiers in the modifier_variable contain a dollar sign (`$'),
640     these must be doubled to avoid early expansion.
641
642     The supported modifiers are:
643
644     ::EE   Replaces each word in the variable with its suffix.
645
646     ::HH   Replaces each word in the variable with everything but the last com-
647          ponent.
648
649     ::MM_p_a_t_t_e_r_n
650          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
651          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
652          characters may be escaped with a backslash (`\').
653
654     ::NN_p_a_t_t_e_r_n
655          This is identical to `::MM', but selects all words which do not match
656          _p_a_t_t_e_r_n.
657
658     ::OO   Order every word in variable alphabetically.  To sort words in
659          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
660
661     ::OOxx  Randomize words in variable.  The results will be different each
662          time you are referring to the modified variable; use the assignment
663          with expansion (`::==') to prevent such behaviour.  For example,
664
665                LIST=                   uno due tre quattro
666                RANDOM_LIST=            ${LIST:Ox}
667                STATIC_RANDOM_LIST:=    ${LIST:Ox}
668
669                all:
670                        @echo "${RANDOM_LIST}"
671                        @echo "${RANDOM_LIST}"
672                        @echo "${STATIC_RANDOM_LIST}"
673                        @echo "${STATIC_RANDOM_LIST}"
674          may produce output similar to:
675
676                quattro due tre uno
677                tre due quattro uno
678                due uno quattro tre
679                due uno quattro tre
680
681     ::QQ   Quotes every shell meta-character in the variable, so that it can be
682          passed safely through recursive invocations of bbmmaakkee.
683
684     ::RR   Replaces each word in the variable with everything but its suffix.
685
686     ::ggmmttiimmee
687          The value is a format string for strftime(3), using the current
688          gmtime(3).
689
690     ::hhaasshh
691          Compute a 32bit hash of the value and encode it as hex digits.
692
693     ::llooccaallttiimmee
694          The value is a format string for strftime(3), using the current
695          localtime(3).
696
697     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
698          if that fails, the value is unchanged.
699
700     ::ttll  Converts variable to lower-case letters.
701
702     ::ttss_c
703          Words in the variable are normally separated by a space on expan-
704          sion.  This modifier sets the separator to the character _c.  If _c is
705          omitted, then no separator is used.  The common escapes (including
706          octal numeric codes), work as expected.
707
708     ::ttuu  Converts variable to upper-case letters.
709
710     ::ttWW  Causes the value to be treated as a single word (possibly containing
711          embedded white space).  See also `::[[**]]'.
712
713     ::ttww  Causes the value to be treated as a sequence of words delimited by
714          white space.  See also `::[[@@]]'.
715
716     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
717          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
718          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
719          slash of the pattern, all occurrences in each word are replaced.  If
720          a `1' is appended to the last slash of the pattern, only the first
721          word is affected.  If a `W' is appended to the last slash of the
722          pattern, then the value is treated as a single word (possibly con-
723          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
724          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
725          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
726          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
727          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
728          delimiter for the parts of the modifier string.  The anchoring,
729          ampersand and delimiter characters may be escaped with a backslash
730          (`\').
731
732          Variable expansion occurs in the normal fashion inside both
733          _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
734          is used to prevent the expansion of a dollar sign (`$'), not a pre-
735          ceding dollar sign as is usual.
736
737     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
738          The ::CC modifier is just like the ::SS modifier except that the old and
739          new strings, instead of being simple strings, are a regular expres-
740          sion (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style string
741          _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
742          in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.  The `1'
743          modifier causes the substitution to apply to at most one word; the
744          `g' modifier causes the substitution to apply to as many instances
745          of the search pattern _p_a_t_t_e_r_n as occur in the word or words it is
746          found in; the `W' modifier causes the value to be treated as a sin-
747          gle word (possibly containing embedded white space).  Note that `1'
748          and `g' are orthogonal; the former specifies whether multiple words
749          are potentially affected, the latter whether multiple substitutions
750          can potentially occur within each affected word.
751
752     ::TT   Replaces each word in the variable with its last component.
753
754     ::uu   Remove adjacent duplicate words (like uniq(1)).
755
756     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
757          If the variable name (not its value), when parsed as a .if condi-
758          tional expression, evaluates to true, return as its value the
759          _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
760          name is used as the expression, :? must be the first modifier after
761          the variable name itself - which will, of course, usually contain
762          variable expansions.  A common error is trying to use expressions
763          like
764                ${NUMBERS:M42:?match:no}
765          which actually tests defined(NUMBERS), to determine is any words
766          match "42" you need to use something like:
767                ${"${NUMBERS:M42}" != "":?match:no}.
768
769     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
770          This is the AT&T System V UNIX style variable substitution.  It must
771          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
772          contain the pattern matching character _% then it is assumed that
773          they are anchored at the end of each word, so only suffixes or
774          entire words may be replaced.  Otherwise _% is the substring of
775          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
776
777          Variable expansion occurs in the normal fashion inside both
778          _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
779          is used to prevent the expansion of a dollar sign (`$'), not a pre-
780          ceding dollar sign as is usual.
781
782     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
783          This is the loop expansion mechanism from the OSF Development Envi-
784          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
785          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
786          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
787          period.  For example.
788                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
789
790          However a single character varaiable is often more readable:
791                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
792
793     ::UU_n_e_w_v_a_l
794          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
795          is defined, the existing value is returned.  This is another ODE
796          make feature.  It is handy for setting per-target CFLAGS for
797          instance:
798                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
799          If a value is only required if the variable is undefined, use:
800                ${VAR:D:Unewval}
801
802     ::DD_n_e_w_v_a_l
803          If the variable is defined _n_e_w_v_a_l is the value.
804
805     ::LL   The name of the variable is the value.
806
807     ::PP   The path of the node which has the same name as the variable is the
808          value.  If no such node exists or its path is null, then the name of
809          the variable is used.  In order for this modifier to work, the name
810          (node) must at least have appeared on the rhs of a dependency.
811
812     ::!!_c_m_d!!
813          The output of running _c_m_d is the value.
814
815     ::sshh  If the variable is non-empty it is run as a command and the output
816          becomes the new value.
817
818     ::::==_s_t_r
819          The variable is assigned the value _s_t_r after substitution.  This
820          modifier and its variations are useful in obscure situations such as
821          wanting to set a variable when shell commands are being parsed.
822          These assignment modifiers always expand to nothing, so if appearing
823          in a rule line by themselves should be preceded with something to
824          keep bbmmaakkee happy.
825
826          The `::::' helps avoid false matches with the AT&T System V UNIX style
827          ::== modifier and since substitution always occurs the ::::== form is
828          vaguely appropriate.
829
830     ::::??==_s_t_r
831          As for ::::== but only if the variable does not already have a value.
832
833     ::::++==_s_t_r
834          Append _s_t_r to the variable.
835
836     ::::!!==_c_m_d
837          Assign the output of _c_m_d to the variable.
838
839     ::[[_r_a_n_g_e]]
840          Selects one or more words from the value, or performs other opera-
841          tions related to the way in which the value is divided into words.
842
843          Ordinarily, a value is treated as a sequence of words delimited by
844          white space.  Some modifiers suppress this behaviour, causing a
845          value to be treated as a single word (possibly containing embedded
846          white space).  An empty value, or a value that consists entirely of
847          white-space, is treated as a single word.  For the purposes of the
848          `::[[]]' modifier, the words are indexed both forwards using positive
849          integers (where index 1 represents the first word), and backwards
850          using negative integers (where index -1 represents the last word).
851
852          The _r_a_n_g_e is subjected to variable expansion, and the expanded
853          result is then interpreted as follows:
854
855          _i_n_d_e_x  Selects a single word from the value.
856
857          _s_t_a_r_t...._e_n_d
858                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
859                 `::[[22....--11]]' selects all words from the second word to the last
860                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
861                 put in reverse order.  For example, `::[[--11....11]]' selects all
862                 the words from last to first.
863
864          **      Causes subsequent modifiers to treat the value as a single
865                 word (possibly containing embedded white space).  Analogous
866                 to the effect of "$*" in Bourne shell.
867
868          0      Means the same as `::[[**]]'.
869
870          @@      Causes subsequent modifiers to treat the value as a sequence
871                 of words delimited by white space.  Analogous to the effect
872                 of "$@" in Bourne shell.
873
874          ##      Returns the number of words in the value.
875
876IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
877     Makefile inclusion, conditional structures and for loops  reminiscent of
878     the C programming language are provided in bbmmaakkee.  All such structures
879     are identified by a line beginning with a single dot (`.') character.
880     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
881     ables between the angle brackets or double quotes are expanded to form
882     the file name.  If angle brackets are used, the included makefile is
883     expected to be in the system makefile directory.  If double quotes are
884     used, the including makefile's directory and any directories specified
885     using the --II option are searched before the system makefile directory.
886     For compatibility with other versions of bbmmaakkee `include file ...' is also
887     accepted.  If the include statement is written as ..--iinncclluuddee or as
888     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
889
890     Conditional expressions are also preceded by a single dot as the first
891     character of a line.  The possible conditionals are as follows:
892
893     ..eerrrroorr _m_e_s_s_a_g_e
894             The message is printed along with the name of the makefile and
895             line number, then bbmmaakkee will exit.
896
897     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
898             Export the specified global variable.  If no variable list is
899             provided, all globals are exported except for internal variables
900             (those that start with `.').  This is not affected by the --XX
901             flag, so should be used with caution.  For compatibility with
902             other bbmmaakkee programs `export variable=value' is also accepted.
903
904             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
905             exporting a variable.
906
907     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
908             The same as `.export', except that the variable is not appended
909             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
910             ment which is different from that used by bbmmaakkee internally.
911
912     ..iinnffoo _m_e_s_s_a_g_e
913             The message is printed along with the name of the makefile and
914             line number.
915
916     ..uunnddeeff _v_a_r_i_a_b_l_e
917             Un-define the specified global variable.  Only global variables
918             may be un-defined.
919
920     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
921             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
922             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
923             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
924
925     ..uunneexxppoorrtt--eennvv
926             Unexport all globals previously exported and clear the environ-
927             ment inherited from the parent.  This operation will cause a mem-
928             ory leak of the original environment, so should be used spar-
929             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
930             note that any variables which originated in the parent environ-
931             ment should be explicitly preserved if desired.  For example:
932
933                   .if ${.MAKE.LEVEL} == 0
934                   PATH := ${PATH}
935                   .unexport-env
936                   .export PATH
937                   .endif
938
939             Would result in an environment containing only `PATH', which is
940             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
941             be pushed into the new environment.
942
943     ..wwaarrnniinngg _m_e_s_s_a_g_e
944             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
945             of the makefile and line number.
946
947     ..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 _._._.]
948             Test the value of an expression.
949
950     ..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 _._._.]
951             Test the value of a variable.
952
953     ..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 _._._.]
954             Test the value of a variable.
955
956     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
957             Test the target being built.
958
959     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
960             Test the target being built.
961
962     ..eellssee   Reverse the sense of the last conditional.
963
964     ..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 _._._.]
965             A combination of `..eellssee' followed by `..iiff'.
966
967     ..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 _._._.]
968             A combination of `..eellssee' followed by `..iiffddeeff'.
969
970     ..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 _._._.]
971             A combination of `..eellssee' followed by `..iiffnnddeeff'.
972
973     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
974             A combination of `..eellssee' followed by `..iiffmmaakkee'.
975
976     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
977             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
978
979     ..eennddiiff  End the body of the conditional.
980
981     The _o_p_e_r_a_t_o_r may be any one of the following:
982
983     ||||     Logical OR.
984
985     &&&&     Logical AND; of higher precedence than ``||''.
986
987     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
988     determine its value.  Parentheses may be used to change the order of
989     evaluation.  The boolean operator `!!' may be used to logically negate an
990     entire conditional.  It is of higher precedence than `&&&&'.
991
992     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
993
994     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
995              the variable has been defined.
996
997     mmaakkee     Takes a target name as an argument and evaluates to true if the
998              target was specified as part of bbmmaakkee's command line or was
999              declared the default target (either implicitly or explicitly,
1000              see _._M_A_I_N) before the line containing the conditional.
1001
1002     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1003              if the expansion of the variable would result in an empty
1004              string.
1005
1006     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1007              file exists.  The file is searched for on the system search path
1008              (see _._P_A_T_H).
1009
1010     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1011              target has been defined.
1012
1013     ccoommmmaannddss
1014              Takes a target name as an argument and evaluates to true if the
1015              target has been defined and has commands associated with it.
1016
1017     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1018     expansion is performed on both sides of the comparison, after which the
1019     integral values are compared.  A value is interpreted as hexadecimal if
1020     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1021     ported.  The standard C relational operators are all supported.  If after
1022     variable expansion, either the left or right hand side of a `====' or `!!=='
1023     operator is not an integral value, then string comparison is performed
1024     between the expanded variables.  If no relational operator is given, it
1025     is assumed that the expanded variable is being compared against 0 or an
1026     empty string in the case of a string comparison.
1027
1028     When bbmmaakkee is evaluating one of these conditional expressions, and it
1029     encounters a (white-space separated) word it doesn't recognize, either
1030     the ``make'' or ``defined'' expression is applied to it, depending on the
1031     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1032     the ``defined'' expression is applied.  Similarly, if the form is
1033     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1034
1035     If the conditional evaluates to true the parsing of the makefile contin-
1036     ues as before.  If it evaluates to false, the following lines are
1037     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1038     found.
1039
1040     For loops are typically used to apply a set of rules to a list of files.
1041     The syntax of a for loop is:
1042
1043     ..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
1044     <make-rules>
1045     ..eennddffoorr
1046
1047     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1048     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1049     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1050     the body of the for loop.  The number of words must come out even; that
1051     is, if there are three iteration variables, the number of words provided
1052     must be a multiple of three.
1053
1054CCOOMMMMEENNTTSS
1055     Comments begin with a hash (`#') character, anywhere but in a shell com-
1056     mand line, and continue to the end of an unescaped new line.
1057
1058SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1059     ..EEXXEECC     Target is never out of date, but always execute commands any-
1060               way.
1061
1062     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1063               get, exactly as if they all were preceded by a dash (`-').
1064
1065     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1066
1067     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1068               or --tt options were specified.  Normally used to mark recursive
1069               bbmmaakkee's.
1070
1071     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1072               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1073               the most likely case.  In "meta" mode, the target is out-of-
1074               date if the meta file is missing.
1075
1076     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1077               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1078
1079     ..NNOOMMEETTAA__CCMMPP
1080               Ignore differences in commands when deciding if target is out
1081               of date.  This is useful if the command contains a value which
1082               always changes.  If the number of commands change, though, the
1083               target will still be out of date.
1084
1085     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1086               ..PPAATTHH.
1087
1088     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1089               default target to be built if no target was specified.  This
1090               source prevents this target from being selected.
1091
1092     ..OOPPTTIIOONNAALL
1093               If a target is marked with this attribute and bbmmaakkee can't fig-
1094               ure out how to create it, it will ignore this fact and assume
1095               the file isn't needed or already exists.
1096
1097     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1098               considered to be out of date, and will not be created with the
1099               --tt option.  Suffix-transformation rules are not applied to
1100               ..PPHHOONNYY targets.
1101
1102     ..PPRREECCIIOOUUSS
1103               When bbmmaakkee is interrupted, it normally removes any partially
1104               made targets.  This source prevents the target from being
1105               removed.
1106
1107     ..RREECCUURRSSIIVVEE
1108               Synonym for ..MMAAKKEE.
1109
1110     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1111               exactly as if they all were preceded by an at sign (`@').
1112
1113     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1114               get is used as a source for another target, the other target
1115               acquires the commands, sources, and attributes (except for
1116               ..UUSSEE) of the source.  If the target already has commands, the
1117               ..UUSSEE target's commands are appended to them.
1118
1119     ..UUSSEEBBEEFFOORREE
1120               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1121               to the target.
1122
1123     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1124               it are made before the sources that succeed it in the line.
1125               Since the dependents of files are not made until the file
1126               itself could be made, this also stops the dependents being
1127               built unless they are needed for another branch of the depen-
1128               dency tree.  So given:
1129
1130               x: a .WAIT b
1131                       echo x
1132               a:
1133                       echo a
1134               b: b1
1135                       echo b
1136               b1:
1137                       echo b1
1138
1139               the output is always `a', `b1', `b', `x'.
1140               The ordering imposed by ..WWAAIITT is only relevant for parallel
1141               makes.
1142
1143SSPPEECCIIAALL TTAARRGGEETTSS
1144     Special targets may not be included with other targets, i.e. they must be
1145     the only target specified.
1146
1147     ..BBEEGGIINN   Any command lines attached to this target are executed before
1148              anything else is done.
1149
1150     ..DDEEFFAAUULLTT
1151              This is sort of a ..UUSSEE rule for any target (that was used only
1152              as a source) that bbmmaakkee can't figure out any other way to cre-
1153              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1154              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1155              own name.
1156
1157     ..EENNDD     Any command lines attached to this target are executed after
1158              everything else is done.
1159
1160     ..EERRRROORR   Any command lines attached to this target are executed when
1161              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1162              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1163
1164     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1165              sources are specified, this is the equivalent of specifying the
1166              --ii option.
1167
1168     ..IINNTTEERRRRUUPPTT
1169              If bbmmaakkee is interrupted, the commands for this target will be
1170              executed.
1171
1172     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1173              will be built.
1174
1175     ..MMAAKKEEFFLLAAGGSS
1176              This target provides a way to specify flags for bbmmaakkee when the
1177              makefile is used.  The flags are as if typed to the shell,
1178              though the --ff option will have no effect.
1179
1180     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1181
1182     ..NNOOTTPPAARRAALLLLEELL
1183              Disable parallel mode.
1184
1185     ..NNOO__PPAARRAALLLLEELL
1186              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1187              variants.
1188
1189     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1190              add targets to the list of targets to be made.  Since the depen-
1191              dents of a target do not get built until the target itself could
1192              be built, unless `a' is built by another part of the dependency
1193              graph, the following is a dependency loop:
1194
1195              .ORDER: b a
1196              b: a
1197
1198              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1199              makes.
1200
1201     ..PPAATTHH    The sources are directories which are to be searched for files
1202              not found in the current directory.  If no sources are speci-
1203              fied, any previously specified directories are deleted.  If the
1204              source is the special ..DDOOTTLLAASSTT target, then the current working
1205              directory is searched last.
1206
1207     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1208
1209     ..PPRREECCIIOOUUSS
1210              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1211              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1212              every target in the file.
1213
1214     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1215              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1216
1217              _n_a_m_e        This is the minimal specification, used to select
1218                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
1219
1220              _p_a_t_h        Specifies the path to the shell.
1221
1222              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1223
1224              _c_h_e_c_k       The command to turn on error checking.
1225
1226              _i_g_n_o_r_e      The command to disable error checking.
1227
1228              _e_c_h_o        The command to turn on echoing of commands executed.
1229
1230              _q_u_i_e_t       The command to turn off echoing of commands exe-
1231                          cuted.
1232
1233              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1234                          mand.  It is typically identical to _q_u_i_e_t.
1235
1236              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1237
1238              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1239                          ing.
1240
1241              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1242                          a single newline character when used outside of any
1243                          quoting characters.
1244              Example:
1245
1246              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1247                      check="set -e" ignore="set +e" \
1248                      echo="set -v" quiet="set +v" filter="set +v" \
1249                      echoFlag=v errFlag=e newline="'\n'"
1250
1251     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1252              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1253              command in the file.
1254
1255     ..SSUUFFFFIIXXEESS
1256              Each source specifies a suffix to bbmmaakkee.  If no sources are
1257              specified, any previously specified suffixes are deleted.  It
1258              allows the creation of suffix-transformation rules.
1259
1260              Example:
1261
1262              .SUFFIXES: .o
1263              .c.o:
1264                      cc -o ${.TARGET} -c ${.IMPSRC}
1265
1266EENNVVIIRROONNMMEENNTT
1267     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1268     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1269     PWD, and TMPDIR.
1270
1271     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1272     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1273     tion of `_._O_B_J_D_I_R' for more details.
1274
1275FFIILLEESS
1276     .depend        list of dependencies
1277     Makefile       list of dependencies
1278     makefile       list of dependencies
1279     sys.mk         system makefile
1280     /usr/share/mk  system makefile directory
1281
1282CCOOMMPPAATTIIBBIILLIITTYY
1283     The basic make syntax is compatible between different versions of make,
1284     however the special variables, variable modifiers and conditionals are
1285     not.
1286
1287     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1288     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1289     rithms used may change again in the future.
1290
1291     The way that .for loop variables are substituted changed after NetBSD 5.0
1292     so that they still appear to be variable expansions.  In particular this
1293     stops them being treated as syntax, and removes some obscure problems
1294     using them in .if statements.
1295
1296     Unlike other bbmmaakkee programs, this implementation by default executes all
1297     commands for a given target using a single shell invocation.  This is
1298     done for both efficiency and to simplify error handling in remote command
1299     invocations.  Typically this is transparent to the user, unless the tar-
1300     get commands change the current working directory using ``cd'' or
1301     ``chdir''.  To be compatible with Makefiles that do this, one can use --BB
1302     to disable this behavior.
1303
1304SSEEEE AALLSSOO
1305     mkdep(1)
1306
1307HHIISSTTOORRYY
1308     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1309MAKE(1)                 NetBSD General Commands Manual                 MAKE(1)
1310
1311     portability to other platforms.
1312
1313NNAAMMEE
1314     bbmmaakkee -- maintain program dependencies
1315
1316SSYYNNOOPPSSIISS
1317     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]
1318           [--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]
1319           [--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]
1320           [_t_a_r_g_e_t _._._.]
1321
1322DDEESSCCRRIIPPTTIIOONN
1323     bbmmaakkee is a program designed to simplify the maintenance of other pro-
1324     grams.  Its input is a list of specifications as to the files upon which
1325     programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e makefile option is
1326     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
1327     the specifications.  If the file `_._d_e_p_e_n_d' exists, it is read (see
1328     mkdep(1)).
1329
1330     This manual page is intended as a reference document only.  For a more
1331     thorough description of bbmmaakkee and makefiles, please refer to _P_M_a_k_e _- _A
1332     _T_u_t_o_r_i_a_l.
1333
1334     bbmmaakkee will prepend the contents of the _M_A_K_E_F_L_A_G_S environment variable to
1335     the command line arguments before parsing them.
1336
1337     The options are as follows:
1338
1339     --BB      Try to be backwards compatible by executing a single shell per
1340             command and by executing the commands to make the sources of a
1341             dependency line in sequence.
1342
1343     --CC _d_i_r_e_c_t_o_r_y
1344             Change to _d_i_r_e_c_t_o_r_y before reading the makefiles or doing any-
1345             thing else.  If multiple --CC options are specified, each is inter-
1346             preted relative to the previous one: --CC _/ --CC _e_t_c is equivalent to
1347             --CC _/_e_t_c.
1348
1349     --DD _v_a_r_i_a_b_l_e
1350             Define _v_a_r_i_a_b_l_e to be 1, in the global context.
1351
1352     --dd _[_-_]_f_l_a_g_s
1353             Turn on debugging, and specify which portions of bbmmaakkee are to
1354             print debugging information.  Unless the flags are preceded by
1355             `-' they are added to the _M_A_K_E_F_L_A_G_S environment variable and will
1356             be processed by any child make processes.  By default, debugging
1357             information is printed to standard error, but this can be changed
1358             using the _F debugging flag.  The debugging output is always
1359             unbuffered; in addition, if debugging is enabled but debugging
1360             output is not directed to standard output, then the standard out-
1361             put is line buffered.  _F_l_a_g_s is one or more of the following:
1362
1363             _A       Print all possible debugging information; equivalent to
1364                     specifying all of the debugging flags.
1365
1366             _a       Print debugging information about archive searching and
1367                     caching.
1368
1369             _C       Print debugging information about current working direc-
1370                     tory.
1371
1372             _c       Print debugging information about conditional evaluation.
1373
1374             _d       Print debugging information about directory searching and
1375                     caching.
1376
1377             _e       Print debugging information about failed commands and
1378                     targets.
1379
1380             _F[++]_f_i_l_e_n_a_m_e
1381                     Specify where debugging output is written.  This must be
1382                     the last flag, because it consumes the remainder of the
1383                     argument.  If the character immediately after the `F'
1384                     flag is `+', then the file will be opened in append mode;
1385                     otherwise the file will be overwritten.  If the file name
1386                     is `stdout' or `stderr' then debugging output will be
1387                     written to the standard output or standard error output
1388                     file descriptors respectively (and the `+' option has no
1389                     effect).  Otherwise, the output will be written to the
1390                     named file.  If the file name ends `.%d' then the `%d' is
1391                     replaced by the pid.
1392
1393             _f       Print debugging information about loop evaluation.
1394
1395             _g_1      Print the input graph before making anything.
1396
1397             _g_2      Print the input graph after making everything, or before
1398                     exiting on error.
1399
1400             _g_3      Print the input graph before exiting on error.
1401
1402             _j       Print debugging information about running multiple
1403                     shells.
1404
1405             _l       Print commands in Makefiles regardless of whether or not
1406                     they are prefixed by `@' or other "quiet" flags.  Also
1407                     known as "loud" behavior.
1408
1409             _M       Print debugging information about "meta" mode decisions
1410                     about targets.
1411
1412             _m       Print debugging information about making targets, includ-
1413                     ing modification dates.
1414
1415             _n       Don't delete the temporary command scripts created when
1416                     running commands.  These temporary scripts are created in
1417                     the directory referred to by the TMPDIR environment vari-
1418                     able, or in _/_t_m_p if TMPDIR is unset or set to the empty
1419                     string.  The temporary scripts are created by mkstemp(3),
1420                     and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E: This can
1421                     create many files in TMPDIR or _/_t_m_p, so use with care.
1422
1423             _p       Print debugging information about makefile parsing.
1424
1425             _s       Print debugging information about suffix-transformation
1426                     rules.
1427
1428             _t       Print debugging information about target list mainte-
1429                     nance.
1430
1431             _V       Force the --VV option to print raw value of variables.
1432
1433             _v       Print debugging information about variable assignment.
1434
1435             _x       Run shell commands with --xx so the actual commands are
1436                     printed as they are executed.
1437
1438     --ee      Specify that environment variables override macro assignments
1439             within makefiles.
1440
1441     --ff _m_a_k_e_f_i_l_e
1442             Specify a makefile to read instead of the default `_m_a_k_e_f_i_l_e'.  If
1443             _m_a_k_e_f_i_l_e is `--', standard input is read.  Multiple makefiles may
1444             be specified, and are read in the order specified.
1445
1446     --II _d_i_r_e_c_t_o_r_y
1447             Specify a directory in which to search for makefiles and included
1448             makefiles.  The system makefile directory (or directories, see
1449             the --mm option) is automatically included as part of this list.
1450
1451     --ii      Ignore non-zero exit of shell commands in the makefile.  Equiva-
1452             lent to specifying `--' before each command line in the makefile.
1453
1454     --JJ _p_r_i_v_a_t_e
1455             This option should _n_o_t be specified by the user.
1456
1457             When the _j option is in use in a recursive build, this option is
1458             passed by a make to child makes to allow all the make processes
1459             in the build to cooperate to avoid overloading the system.
1460
1461     --jj _m_a_x___j_o_b_s
1462             Specify the maximum number of jobs that bbmmaakkee may have running at
1463             any one time.  The value is saved in _._M_A_K_E_._J_O_B_S.  Turns compati-
1464             bility mode off, unless the _B flag is also specified.  When com-
1465             patibility mode is off, all commands associated with a target are
1466             executed in a single shell invocation as opposed to the tradi-
1467             tional one shell invocation per line.  This can break traditional
1468             scripts which change directories on each command invocation and
1469             then expect to start with a fresh environment on the next line.
1470             It is more efficient to correct the scripts rather than turn
1471             backwards compatibility on.
1472
1473     --kk      Continue processing after errors are encountered, but only on
1474             those targets that do not depend on the target whose creation
1475             caused the error.
1476
1477     --mm _d_i_r_e_c_t_o_r_y
1478             Specify a directory in which to search for sys.mk and makefiles
1479             included via the <_f_i_l_e>-style include statement.  The --mm option
1480             can be used multiple times to form a search path.  This path will
1481             override the default system include path: /usr/share/mk.  Fur-
1482             thermore the system include path will be appended to the search
1483             path used for "_f_i_l_e"-style include statements (see the --II
1484             option).
1485
1486             If a file or directory name in the --mm argument (or the
1487             MAKESYSPATH environment variable) starts with the string ".../"
1488             then bbmmaakkee will search for the specified file or directory named
1489             in the remaining part of the argument string.  The search starts
1490             with the current directory of the Makefile and then works upward
1491             towards the root of the filesystem.  If the search is successful,
1492             then the resulting directory replaces the ".../" specification in
1493             the --mm argument.  If used, this feature allows bbmmaakkee to easily
1494             search in the current source tree for customized sys.mk files
1495             (e.g., by using ".../mk/sys.mk" as an argument).
1496
1497     --nn      Display the commands that would have been executed, but do not
1498             actually execute them unless the target depends on the .MAKE spe-
1499             cial source (see below).
1500
1501     --NN      Display the commands which would have been executed, but do not
1502             actually execute any of them; useful for debugging top-level
1503             makefiles without descending into subdirectories.
1504
1505     --qq      Do not execute any commands, but exit 0 if the specified targets
1506             are up-to-date and 1, otherwise.
1507
1508     --rr      Do not use the built-in rules specified in the system makefile.
1509
1510     --ss      Do not echo any commands as they are executed.  Equivalent to
1511             specifying `@@' before each command line in the makefile.
1512
1513     --TT _t_r_a_c_e_f_i_l_e
1514             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
1515             for each job started and completed.
1516
1517     --tt      Rather than re-building a target as specified in the makefile,
1518             create it or update its modification time to make it appear up-
1519             to-date.
1520
1521     --VV _v_a_r_i_a_b_l_e
1522             Print bbmmaakkee's idea of the value of _v_a_r_i_a_b_l_e, in the global con-
1523             text.  Do not build any targets.  Multiple instances of this
1524             option may be specified; the variables will be printed one per
1525             line, with a blank line for each null or undefined variable.  If
1526             _v_a_r_i_a_b_l_e contains a `$' then the value will be expanded before
1527             printing.
1528
1529     --WW      Treat any warnings during makefile parsing as errors.
1530
1531     --XX      Don't export variables passed on the command line to the environ-
1532             ment individually.  Variables passed on the command line are
1533             still exported via the _M_A_K_E_F_L_A_G_S environment variable.  This
1534             option may be useful on systems which have a small limit on the
1535             size of command arguments.
1536
1537     _v_a_r_i_a_b_l_e_=_v_a_l_u_e
1538             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
1539             values passed on the command line are also exported to sub-makes
1540             in the environment.  The --XX flag disables this behavior.  Vari-
1541             able assignments should follow options for POSIX compatibility
1542             but no ordering is enforced.
1543
1544     There are seven different types of lines in a makefile: file dependency
1545     specifications, shell commands, variable assignments, include statements,
1546     conditional directives, for loops, and comments.
1547
1548     In general, lines may be continued from one line to the next by ending
1549     them with a backslash (`\').  The trailing newline character and initial
1550     whitespace on the following line are compressed into a single space.
1551
1552FFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
1553     Dependency lines consist of one or more targets, an operator, and zero or
1554     more sources.  This creates a relationship where the targets ``depend''
1555     on the sources and are usually created from them.  The exact relationship
1556     between the target and the source is determined by the operator that sep-
1557     arates them.  The three operators are as follows:
1558
1559     ::     A target is considered out-of-date if its modification time is less
1560           than those of any of its sources.  Sources for a target accumulate
1561           over dependency lines when this operator is used.  The target is
1562           removed if bbmmaakkee is interrupted.
1563
1564     !!     Targets are always re-created, but not until all sources have been
1565           examined and re-created as necessary.  Sources for a target accumu-
1566           late over dependency lines when this operator is used.  The target
1567           is removed if bbmmaakkee is interrupted.
1568
1569     ::::    If no sources are specified, the target is always re-created.  Oth-
1570           erwise, a target is considered out-of-date if any of its sources
1571           has been modified more recently than the target.  Sources for a
1572           target do not accumulate over dependency lines when this operator
1573           is used.  The target will not be removed if bbmmaakkee is interrupted.
1574
1575     Targets and sources may contain the shell wildcard values `?', `*', `[]',
1576     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
1577     final component of the target or source, and must be used to describe
1578     existing files.  The value `{}' need not necessarily be used to describe
1579     existing files.  Expansion is in directory order, not alphabetically as
1580     done in the shell.
1581
1582SSHHEELLLL CCOOMMMMAANNDDSS
1583     Each target may have associated with it a series of shell commands, nor-
1584     mally used to create the target.  Each of the commands in this script
1585     _m_u_s_t be preceded by a tab.  While any target may appear on a dependency
1586     line, only one of these dependencies may be followed by a creation
1587     script, unless the `::::' operator is used.
1588
1589     If the first characters of the command line are any combination of `@@',
1590     `++', or `--', the command is treated specially.  A `@@' causes the command
1591     not to be echoed before it is executed.  A `++' causes the command to be
1592     executed even when --nn is given.  This is similar to the effect of the
1593     .MAKE special source, except that the effect can be limited to a single
1594     line of a script.  A `--' causes any non-zero exit status of the command
1595     line to be ignored.
1596
1597VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
1598     Variables in make are much like variables in the shell, and, by tradi-
1599     tion, consist of all upper-case letters.
1600
1601   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
1602     The five operators that can be used to assign values to variables are as
1603     follows:
1604
1605     ==       Assign the value to the variable.  Any previous value is overrid-
1606             den.
1607
1608     ++==      Append the value to the current value of the variable.
1609
1610     ??==      Assign the value to the variable if it is not already defined.
1611
1612     ::==      Assign with expansion, i.e. expand the value before assigning it
1613             to the variable.  Normally, expansion is not done until the vari-
1614             able is referenced.  _N_O_T_E: References to undefined variables are
1615             _n_o_t expanded.  This can cause problems when variable modifiers
1616             are used.
1617
1618     !!==      Expand the value and pass it to the shell for execution and
1619             assign the result to the variable.  Any newlines in the result
1620             are replaced with spaces.
1621
1622     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
1623     being appended, a single space is inserted between the previous contents
1624     of the variable and the appended value.
1625
1626     Variables are expanded by surrounding the variable name with either curly
1627     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
1628     (`$').  If the variable name contains only a single letter, the surround-
1629     ing braces or parentheses are not required.  This shorter form is not
1630     recommended.
1631
1632     If the variable name contains a dollar, then the name itself is expanded
1633     first.  This allows almost arbitrary variable names, however names con-
1634     taining dollar, braces, parenthesis, or whitespace are really best
1635     avoided!
1636
1637     If the result of expanding a variable contains a dollar sign (`$') the
1638     string is expanded again.
1639
1640     Variable substitution occurs at three distinct times, depending on where
1641     the variable is being used.
1642
1643     1.   Variables in dependency lines are expanded as the line is read.
1644
1645     2.   Variables in shell commands are expanded when the shell command is
1646          executed.
1647
1648     3.   ``.for'' loop index variables are expanded on each loop iteration.
1649          Note that other variables are not expanded inside loops so the fol-
1650          lowing example code:
1651
1652
1653                .for i in 1 2 3
1654                a+=     ${i}
1655                j=      ${i}
1656                b+=     ${j}
1657                .endfor
1658
1659                all:
1660                        @echo ${a}
1661                        @echo ${b}
1662
1663          will print:
1664
1665                1 2 3
1666                3 3 3
1667
1668          Because while ${a} contains ``1 2 3'' after the loop is executed,
1669          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
1670          after the loop completes ${j} contains ``3''.
1671
1672   VVaarriiaabbllee ccllaasssseess
1673     The four different classes of variables (in order of increasing prece-
1674     dence) are:
1675
1676     Environment variables
1677             Variables defined as part of bbmmaakkee's environment.
1678
1679     Global variables
1680             Variables defined in the makefile or in included makefiles.
1681
1682     Command line variables
1683             Variables defined as part of the command line.
1684
1685     Local variables
1686             Variables that are defined specific to a certain target.  The
1687             seven local variables are as follows:
1688
1689             _._A_L_L_S_R_C   The list of all sources for this target; also known as
1690                       `_>'.
1691
1692             _._A_R_C_H_I_V_E  The name of the archive file.
1693
1694             _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
1695                       source from which the target is to be transformed (the
1696                       ``implied'' source); also known as `_<'.  It is not
1697                       defined in explicit rules.
1698
1699             _._M_E_M_B_E_R   The name of the archive member.
1700
1701             _._O_O_D_A_T_E   The list of sources for this target that were deemed
1702                       out-of-date; also known as `_?'.
1703
1704             _._P_R_E_F_I_X   The file prefix of the target, containing only the file
1705                       portion, no suffix or preceding directory components;
1706                       also known as `_*'.
1707
1708             _._T_A_R_G_E_T   The name of the target; also known as `_@'.
1709
1710             The shorter forms `_@', `_?', `_<', `_>', and `_*' are permitted for
1711             backward compatibility with historical makefiles and are not rec-
1712             ommended.  The six variables `_@_F', `_@_D', `_<_F', `_<_D', `_*_F', and
1713             `_*_D' are permitted for compatibility with AT&T System V UNIX
1714             makefiles and are not recommended.
1715
1716             Four of the local variables may be used in sources on dependency
1717             lines because they expand to the proper value for each target on
1718             the line.  These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E',
1719             and `_._M_E_M_B_E_R'.
1720
1721   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
1722     In addition, bbmmaakkee sets or knows about the following variables:
1723
1724     _$               A single dollar sign `$', i.e.  `$$' expands to a single
1725                     dollar sign.
1726
1727     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
1728                     evaluated during Makefile parsing, lists only those tar-
1729                     gets encountered thus far.
1730
1731     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
1732                     to the description of `PWD' for more details.
1733
1734     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
1735                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
1736                     The preferred variable to use is the environment variable
1737                     MAKE because it is more compatible with other versions of
1738                     bbmmaakkee and cannot be confused with the special target with
1739                     the same name.
1740
1741     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
1742                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
1743                     ated dependencies are read.
1744
1745     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
1746                     A boolean that controls the default behavior of the --VV
1747                     option.
1748
1749     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
1750
1751     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
1752
1753     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
1754                     If bbmmaakkee is run with _j then output for each target is
1755                     prefixed with a token `--- target ---' the first part of
1756                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
1757                     For example:
1758                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
1759                     would produce tokens like `---make[1234] target ---' mak-
1760                     ing it easier to track the degree of parallelism being
1761                     achieved.
1762
1763     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
1764                     that may be specified on bbmmaakkee's command line.  Anything
1765                     specified on bbmmaakkee's command line is appended to the
1766                     `MAKEFLAGS' variable which is then entered into the envi-
1767                     ronment for all programs which bbmmaakkee executes.
1768
1769     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
1770                     bbmmaakkee will be 0, and an incremented value is put into the
1771                     environment to be seen by the next generation.  This
1772                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
1773                     things which should only be evaluated in the initial
1774                     instance of bbmmaakkee.
1775
1776     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
1777                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
1778                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
1779
1780     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
1781                     The list of makefiles read by bbmmaakkee, which is useful for
1782                     tracking dependencies.  Each makefile is recorded only
1783                     once, regardless of the number of times read.
1784
1785     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
1786                     mode that bbmmaakkee runs in.  It can contain a number of key-
1787                     words:
1788
1789                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
1790
1791                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
1792                                 are created for each target to capture the
1793                                 command run, the output generated and if
1794                                 filemon(4) is available, the system calls
1795                                 which are of interest to bbmmaakkee.  The captured
1796                                 output can be very useful when diagnosing
1797                                 errors.
1798
1799                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
1800                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
1801                                 ting _b_f to a value which represents True.
1802
1803                     _e_n_v         For debugging, it can be useful to inlcude
1804                                 the environment in the .meta file.
1805
1806                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
1807                                 target being built.  This is useful if the
1808                                 build is otherwise running silently.  The
1809                                 message printed the value of:
1810                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
1811
1812                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
1813                                 not stable.  This keyword causes them to be
1814                                 ignored for determining whether a target is
1815                                 out of date in "meta" mode.  See also
1816                                 ..NNOOMMEETTAA__CCMMPP.
1817
1818                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
1819                                 mark the target ..SSIILLEENNTT.
1820
1821     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
1822                     In "meta" mode, provides a list of prefixes which match
1823                     the directories controlled by bbmmaakkee.  If a file that was
1824                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
1825                     missing, the current target is considered out-of-date.
1826
1827     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
1828                     In "meta" mode, this variable contains a list of all the
1829                     meta files updated.  If not empty, it can be used to
1830                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
1831
1832     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
1833                     In "meta" mode, this variable contains a list of all the
1834                     meta files used (updated or not).  This list can be used
1835                     to process the meta files to extract dependency informa-
1836                     tion.
1837
1838     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
1839                     Defines the message printed for each meta file updated in
1840                     "meta verbose" mode.  The default value is:
1841                           Building ${.TARGET:H:tA}/${.TARGET:T}
1842
1843     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
1844                     assigned to on the command line, so that they may be
1845                     exported as part of `MAKEFLAGS'.  This behaviour can be
1846                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
1847                     within a makefile.  Extra variables can be exported from
1848                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
1849                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
1850                     modified.
1851
1852     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
1853
1854     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
1855
1856     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
1857                     When bbmmaakkee stops due to an error, it prints its name and
1858                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
1859                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
1860
1861     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
1862                     its value.  This allows expansions using the ::@@ modifier
1863                     to put a newline between iterations of the loop rather
1864                     than a space.  For example, the printing of
1865                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
1866                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
1867
1868     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
1869                     value is determined by trying to chdir(2) to the follow-
1870                     ing directories in order and using the first match:
1871
1872                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
1873
1874                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
1875                          ment or on the command line.)
1876
1877                     2.   ${MAKEOBJDIR}
1878
1879                          (Only if `MAKEOBJDIR' is set in the environment or
1880                          on the command line.)
1881
1882                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
1883
1884                     4.   ${.CURDIR}_/_o_b_j
1885
1886                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
1887
1888                     6.   ${.CURDIR}
1889
1890                     Variable expansion is performed on the value before it's
1891                     used, so expressions such as
1892                           ${.CURDIR:S,^/usr/src,/var/obj,}
1893                     may be used.  This is especially useful with
1894                     `MAKEOBJDIR'.
1895
1896                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
1897                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
1898                     and set `PWD' to that directory before executing any tar-
1899                     gets.
1900
1901     _._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
1902                     parsed.
1903
1904     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
1905                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
1906                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
1907                     their current values, assign them to a variable using
1908                     assignment with expansion: (`::==').
1909
1910     _._P_A_T_H           A variable that represents the list of directories that
1911                     bbmmaakkee will search for files.  The search list should be
1912                     updated using the target `_._P_A_T_H' rather than the vari-
1913                     able.
1914
1915     PWD             Alternate path to the current directory.  bbmmaakkee normally
1916                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
1917                     However, if the environment variable `PWD' is set and
1918                     gives a path to the current directory, then bbmmaakkee sets
1919                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
1920                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
1921                     contains a variable transform.  `PWD' is set to the value
1922                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
1923
1924     .TARGETS        The list of targets explicitly specified on the command
1925                     line, if any.
1926
1927     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
1928                     will search for files.  The variable is supported for
1929                     compatibility with old make programs only, use `_._P_A_T_H'
1930                     instead.
1931
1932   VVaarriiaabbllee mmooddiiffiieerrss
1933     Variable expansion may be modified to select or modify each word of the
1934     variable (where a ``word'' is white-space delimited sequence of charac-
1935     ters).  The general format of a variable expansion is as follows:
1936
1937           ${variable[:modifier[:...]]}
1938
1939     Each modifier begins with a colon, which may be escaped with a backslash
1940     (`\').
1941
1942     A set of modifiers can be specified via a variable, as follows:
1943
1944           modifier_variable=modifier[:...]
1945           ${variable:${modifier_variable}[:...]}
1946
1947     In this case the first modifier in the modifier_variable does not start
1948     with a colon, since that must appear in the referencing variable.  If any
1949     of the modifiers in the modifier_variable contain a dollar sign (`$'),
1950     these must be doubled to avoid early expansion.
1951
1952     The supported modifiers are:
1953
1954     ::EE   Replaces each word in the variable with its suffix.
1955
1956     ::HH   Replaces each word in the variable with everything but the last com-
1957          ponent.
1958
1959     ::MM_p_a_t_t_e_r_n
1960          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
1961          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
1962          characters may be escaped with a backslash (`\').
1963
1964     ::NN_p_a_t_t_e_r_n
1965          This is identical to `::MM', but selects all words which do not match
1966          _p_a_t_t_e_r_n.
1967
1968     ::OO   Order every word in variable alphabetically.  To sort words in
1969          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
1970
1971     ::OOxx  Randomize words in variable.  The results will be different each
1972          time you are referring to the modified variable; use the assignment
1973          with expansion (`::==') to prevent such behaviour.  For example,
1974
1975                LIST=                   uno due tre quattro
1976                RANDOM_LIST=            ${LIST:Ox}
1977                STATIC_RANDOM_LIST:=    ${LIST:Ox}
1978
1979                all:
1980                        @echo "${RANDOM_LIST}"
1981                        @echo "${RANDOM_LIST}"
1982                        @echo "${STATIC_RANDOM_LIST}"
1983                        @echo "${STATIC_RANDOM_LIST}"
1984          may produce output similar to:
1985
1986                quattro due tre uno
1987                tre due quattro uno
1988                due uno quattro tre
1989                due uno quattro tre
1990
1991     ::QQ   Quotes every shell meta-character in the variable, so that it can be
1992          passed safely through recursive invocations of bbmmaakkee.
1993
1994     ::RR   Replaces each word in the variable with everything but its suffix.
1995
1996     ::ggmmttiimmee
1997          The value is a format string for strftime(3), using the current
1998          gmtime(3).
1999
2000     ::hhaasshh
2001          Compute a 32bit hash of the value and encode it as hex digits.
2002
2003     ::llooccaallttiimmee
2004          The value is a format string for strftime(3), using the current
2005          localtime(3).
2006
2007     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
2008          if that fails, the value is unchanged.
2009
2010     ::ttll  Converts variable to lower-case letters.
2011
2012     ::ttss_c
2013          Words in the variable are normally separated by a space on expan-
2014          sion.  This modifier sets the separator to the character _c.  If _c is
2015          omitted, then no separator is used.  The common escapes (including
2016          octal numeric codes), work as expected.
2017
2018     ::ttuu  Converts variable to upper-case letters.
2019
2020     ::ttWW  Causes the value to be treated as a single word (possibly containing
2021          embedded white space).  See also `::[[**]]'.
2022
2023     ::ttww  Causes the value to be treated as a sequence of words delimited by
2024          white space.  See also `::[[@@]]'.
2025
2026     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
2027          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
2028          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
2029          slash of the pattern, all occurrences in each word are replaced.  If
2030          a `1' is appended to the last slash of the pattern, only the first
2031          word is affected.  If a `W' is appended to the last slash of the
2032          pattern, then the value is treated as a single word (possibly con-
2033          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
2034          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
2035          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
2036          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
2037          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
2038          delimiter for the parts of the modifier string.  The anchoring,
2039          ampersand and delimiter characters may be escaped with a backslash
2040          (`\').
2041
2042          Variable expansion occurs in the normal fashion inside both
2043          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
2044          is used to prevent the expansion of a dollar sign (`$'), not a pre-
2045          ceding dollar sign as is usual.
2046
2047     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
2048          The ::CC modifier is just like the ::SS modifier except that the old and
2049          new strings, instead of being simple strings, are a regular expres-
2050          sion (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style string
2051          _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
2052          in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.  The `1'
2053          modifier causes the substitution to apply to at most one word; the
2054          `g' modifier causes the substitution to apply to as many instances
2055          of the search pattern _p_a_t_t_e_r_n as occur in the word or words it is
2056          found in; the `W' modifier causes the value to be treated as a sin-
2057          gle word (possibly containing embedded white space).  Note that `1'
2058          and `g' are orthogonal; the former specifies whether multiple words
2059          are potentially affected, the latter whether multiple substitutions
2060          can potentially occur within each affected word.
2061
2062     ::TT   Replaces each word in the variable with its last component.
2063
2064     ::uu   Remove adjacent duplicate words (like uniq(1)).
2065
2066     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
2067          If the variable name (not its value), when parsed as a .if condi-
2068          tional expression, evaluates to true, return as its value the
2069          _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
2070          name is used as the expression, :? must be the first modifier after
2071          the variable name itself - which will, of course, usually contain
2072          variable expansions.  A common error is trying to use expressions
2073          like
2074                ${NUMBERS:M42:?match:no}
2075          which actually tests defined(NUMBERS), to determine is any words
2076          match "42" you need to use something like:
2077                ${"${NUMBERS:M42}" != "":?match:no}.
2078
2079     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
2080          This is the AT&T System V UNIX style variable substitution.  It must
2081          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
2082          contain the pattern matching character _% then it is assumed that
2083          they are anchored at the end of each word, so only suffixes or
2084          entire words may be replaced.  Otherwise _% is the substring of
2085          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
2086
2087          Variable expansion occurs in the normal fashion inside both
2088          _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
2089          is used to prevent the expansion of a dollar sign (`$'), not a pre-
2090          ceding dollar sign as is usual.
2091
2092     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
2093          This is the loop expansion mechanism from the OSF Development Envi-
2094          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
2095          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
2096          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
2097          period.  For example.
2098                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
2099
2100          However a single character varaiable is often more readable:
2101                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
2102
2103     ::UU_n_e_w_v_a_l
2104          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
2105          is defined, the existing value is returned.  This is another ODE
2106          make feature.  It is handy for setting per-target CFLAGS for
2107          instance:
2108                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
2109          If a value is only required if the variable is undefined, use:
2110                ${VAR:D:Unewval}
2111
2112     ::DD_n_e_w_v_a_l
2113          If the variable is defined _n_e_w_v_a_l is the value.
2114
2115     ::LL   The name of the variable is the value.
2116
2117     ::PP   The path of the node which has the same name as the variable is the
2118          value.  If no such node exists or its path is null, then the name of
2119          the variable is used.  In order for this modifier to work, the name
2120          (node) must at least have appeared on the rhs of a dependency.
2121
2122     ::!!_c_m_d!!
2123          The output of running _c_m_d is the value.
2124
2125     ::sshh  If the variable is non-empty it is run as a command and the output
2126          becomes the new value.
2127
2128     ::::==_s_t_r
2129          The variable is assigned the value _s_t_r after substitution.  This
2130          modifier and its variations are useful in obscure situations such as
2131          wanting to set a variable when shell commands are being parsed.
2132          These assignment modifiers always expand to nothing, so if appearing
2133          in a rule line by themselves should be preceded with something to
2134          keep bbmmaakkee happy.
2135
2136          The `::::' helps avoid false matches with the AT&T System V UNIX style
2137          ::== modifier and since substitution always occurs the ::::== form is
2138          vaguely appropriate.
2139
2140     ::::??==_s_t_r
2141          As for ::::== but only if the variable does not already have a value.
2142
2143     ::::++==_s_t_r
2144          Append _s_t_r to the variable.
2145
2146     ::::!!==_c_m_d
2147          Assign the output of _c_m_d to the variable.
2148
2149     ::[[_r_a_n_g_e]]
2150          Selects one or more words from the value, or performs other opera-
2151          tions related to the way in which the value is divided into words.
2152
2153          Ordinarily, a value is treated as a sequence of words delimited by
2154          white space.  Some modifiers suppress this behaviour, causing a
2155          value to be treated as a single word (possibly containing embedded
2156          white space).  An empty value, or a value that consists entirely of
2157          white-space, is treated as a single word.  For the purposes of the
2158          `::[[]]' modifier, the words are indexed both forwards using positive
2159          integers (where index 1 represents the first word), and backwards
2160          using negative integers (where index -1 represents the last word).
2161
2162          The _r_a_n_g_e is subjected to variable expansion, and the expanded
2163          result is then interpreted as follows:
2164
2165          _i_n_d_e_x  Selects a single word from the value.
2166
2167          _s_t_a_r_t...._e_n_d
2168                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
2169                 `::[[22....--11]]' selects all words from the second word to the last
2170                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
2171                 put in reverse order.  For example, `::[[--11....11]]' selects all
2172                 the words from last to first.
2173
2174          **      Causes subsequent modifiers to treat the value as a single
2175                 word (possibly containing embedded white space).  Analogous
2176                 to the effect of "$*" in Bourne shell.
2177
2178          0      Means the same as `::[[**]]'.
2179
2180          @@      Causes subsequent modifiers to treat the value as a sequence
2181                 of words delimited by white space.  Analogous to the effect
2182                 of "$@" in Bourne shell.
2183
2184          ##      Returns the number of words in the value.
2185
2186IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
2187     Makefile inclusion, conditional structures and for loops  reminiscent of
2188     the C programming language are provided in bbmmaakkee.  All such structures
2189     are identified by a line beginning with a single dot (`.') character.
2190     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
2191     ables between the angle brackets or double quotes are expanded to form
2192     the file name.  If angle brackets are used, the included makefile is
2193     expected to be in the system makefile directory.  If double quotes are
2194     used, the including makefile's directory and any directories specified
2195     using the --II option are searched before the system makefile directory.
2196     For compatibility with other versions of bbmmaakkee `include file ...' is also
2197     accepted.  If the include statement is written as ..--iinncclluuddee or as
2198     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
2199
2200     Conditional expressions are also preceded by a single dot as the first
2201     character of a line.  The possible conditionals are as follows:
2202
2203     ..eerrrroorr _m_e_s_s_a_g_e
2204             The message is printed along with the name of the makefile and
2205             line number, then bbmmaakkee will exit.
2206
2207     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
2208             Export the specified global variable.  If no variable list is
2209             provided, all globals are exported except for internal variables
2210             (those that start with `.').  This is not affected by the --XX
2211             flag, so should be used with caution.  For compatibility with
2212             other bbmmaakkee programs `export variable=value' is also accepted.
2213
2214             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
2215             exporting a variable.
2216
2217     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
2218             The same as `.export', except that the variable is not appended
2219             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
2220             ment which is different from that used by bbmmaakkee internally.
2221
2222     ..iinnffoo _m_e_s_s_a_g_e
2223             The message is printed along with the name of the makefile and
2224             line number.
2225
2226     ..uunnddeeff _v_a_r_i_a_b_l_e
2227             Un-define the specified global variable.  Only global variables
2228             may be un-defined.
2229
2230     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
2231             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
2232             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
2233             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
2234
2235     ..uunneexxppoorrtt--eennvv
2236             Unexport all globals previously exported and clear the environ-
2237             ment inherited from the parent.  This operation will cause a mem-
2238             ory leak of the original environment, so should be used spar-
2239             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
2240             note that any variables which originated in the parent environ-
2241             ment should be explicitly preserved if desired.  For example:
2242
2243                   .if ${.MAKE.LEVEL} == 0
2244                   PATH := ${PATH}
2245                   .unexport-env
2246                   .export PATH
2247                   .endif
2248
2249             Would result in an environment containing only `PATH', which is
2250             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
2251             be pushed into the new environment.
2252
2253     ..wwaarrnniinngg _m_e_s_s_a_g_e
2254             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
2255             of the makefile and line number.
2256
2257     ..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 _._._.]
2258             Test the value of an expression.
2259
2260     ..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 _._._.]
2261             Test the value of a variable.
2262
2263     ..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 _._._.]
2264             Test the value of a variable.
2265
2266     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2267             Test the target being built.
2268
2269     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2270             Test the target being built.
2271
2272     ..eellssee   Reverse the sense of the last conditional.
2273
2274     ..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 _._._.]
2275             A combination of `..eellssee' followed by `..iiff'.
2276
2277     ..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 _._._.]
2278             A combination of `..eellssee' followed by `..iiffddeeff'.
2279
2280     ..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 _._._.]
2281             A combination of `..eellssee' followed by `..iiffnnddeeff'.
2282
2283     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2284             A combination of `..eellssee' followed by `..iiffmmaakkee'.
2285
2286     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2287             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
2288
2289     ..eennddiiff  End the body of the conditional.
2290
2291     The _o_p_e_r_a_t_o_r may be any one of the following:
2292
2293     ||||     Logical OR.
2294
2295     &&&&     Logical AND; of higher precedence than ``||''.
2296
2297     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
2298     determine its value.  Parentheses may be used to change the order of
2299     evaluation.  The boolean operator `!!' may be used to logically negate an
2300     entire conditional.  It is of higher precedence than `&&&&'.
2301
2302     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
2303
2304     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
2305              the variable has been defined.
2306
2307     mmaakkee     Takes a target name as an argument and evaluates to true if the
2308              target was specified as part of bbmmaakkee's command line or was
2309              declared the default target (either implicitly or explicitly,
2310              see _._M_A_I_N) before the line containing the conditional.
2311
2312     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
2313              if the expansion of the variable would result in an empty
2314              string.
2315
2316     eexxiissttss   Takes a file name as an argument and evaluates to true if the
2317              file exists.  The file is searched for on the system search path
2318              (see _._P_A_T_H).
2319
2320     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
2321              target has been defined.
2322
2323     ccoommmmaannddss
2324              Takes a target name as an argument and evaluates to true if the
2325              target has been defined and has commands associated with it.
2326
2327     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
2328     expansion is performed on both sides of the comparison, after which the
2329     integral values are compared.  A value is interpreted as hexadecimal if
2330     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
2331     ported.  The standard C relational operators are all supported.  If after
2332     variable expansion, either the left or right hand side of a `====' or `!!=='
2333     operator is not an integral value, then string comparison is performed
2334     between the expanded variables.  If no relational operator is given, it
2335     is assumed that the expanded variable is being compared against 0 or an
2336     empty string in the case of a string comparison.
2337
2338     When bbmmaakkee is evaluating one of these conditional expressions, and it
2339     encounters a (white-space separated) word it doesn't recognize, either
2340     the ``make'' or ``defined'' expression is applied to it, depending on the
2341     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
2342     the ``defined'' expression is applied.  Similarly, if the form is
2343     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
2344
2345     If the conditional evaluates to true the parsing of the makefile contin-
2346     ues as before.  If it evaluates to false, the following lines are
2347     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
2348     found.
2349
2350     For loops are typically used to apply a set of rules to a list of files.
2351     The syntax of a for loop is:
2352
2353     ..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
2354     <make-rules>
2355     ..eennddffoorr
2356
2357     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
2358     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
2359     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
2360     the body of the for loop.  The number of words must come out even; that
2361     is, if there are three iteration variables, the number of words provided
2362     must be a multiple of three.
2363
2364CCOOMMMMEENNTTSS
2365     Comments begin with a hash (`#') character, anywhere but in a shell com-
2366     mand line, and continue to the end of an unescaped new line.
2367
2368SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
2369     ..EEXXEECC     Target is never out of date, but always execute commands any-
2370               way.
2371
2372     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
2373               get, exactly as if they all were preceded by a dash (`-').
2374
2375     ..MMAADDEE     Mark all sources of this target as being up-to-date.
2376
2377     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
2378               or --tt options were specified.  Normally used to mark recursive
2379               bbmmaakkee's.
2380
2381     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
2382               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
2383               the most likely case.  In "meta" mode, the target is out-of-
2384               date if the meta file is missing.
2385
2386     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
2387               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
2388
2389     ..NNOOMMEETTAA__CCMMPP
2390               Ignore differences in commands when deciding if target is out
2391               of date.  This is useful if the command contains a value which
2392               always changes.  If the number of commands change, though, the
2393               target will still be out of date.
2394
2395     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
2396               ..PPAATTHH.
2397
2398     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
2399               default target to be built if no target was specified.  This
2400               source prevents this target from being selected.
2401
2402     ..OOPPTTIIOONNAALL
2403               If a target is marked with this attribute and bbmmaakkee can't fig-
2404               ure out how to create it, it will ignore this fact and assume
2405               the file isn't needed or already exists.
2406
2407     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
2408               considered to be out of date, and will not be created with the
2409               --tt option.  Suffix-transformation rules are not applied to
2410               ..PPHHOONNYY targets.
2411
2412     ..PPRREECCIIOOUUSS
2413               When bbmmaakkee is interrupted, it normally removes any partially
2414               made targets.  This source prevents the target from being
2415               removed.
2416
2417     ..RREECCUURRSSIIVVEE
2418               Synonym for ..MMAAKKEE.
2419
2420     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
2421               exactly as if they all were preceded by an at sign (`@').
2422
2423     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
2424               get is used as a source for another target, the other target
2425               acquires the commands, sources, and attributes (except for
2426               ..UUSSEE) of the source.  If the target already has commands, the
2427               ..UUSSEE target's commands are appended to them.
2428
2429     ..UUSSEEBBEEFFOORREE
2430               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
2431               to the target.
2432
2433     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
2434               it are made before the sources that succeed it in the line.
2435               Since the dependents of files are not made until the file
2436               itself could be made, this also stops the dependents being
2437               built unless they are needed for another branch of the depen-
2438               dency tree.  So given:
2439
2440               x: a .WAIT b
2441                       echo x
2442               a:
2443                       echo a
2444               b: b1
2445                       echo b
2446               b1:
2447                       echo b1
2448
2449               the output is always `a', `b1', `b', `x'.
2450               The ordering imposed by ..WWAAIITT is only relevant for parallel
2451               makes.
2452
2453SSPPEECCIIAALL TTAARRGGEETTSS
2454     Special targets may not be included with other targets, i.e. they must be
2455     the only target specified.
2456
2457     ..BBEEGGIINN   Any command lines attached to this target are executed before
2458              anything else is done.
2459
2460     ..DDEEFFAAUULLTT
2461              This is sort of a ..UUSSEE rule for any target (that was used only
2462              as a source) that bbmmaakkee can't figure out any other way to cre-
2463              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
2464              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
2465              own name.
2466
2467     ..EENNDD     Any command lines attached to this target are executed after
2468              everything else is done.
2469
2470     ..EERRRROORR   Any command lines attached to this target are executed when
2471              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
2472              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
2473
2474     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
2475              sources are specified, this is the equivalent of specifying the
2476              --ii option.
2477
2478     ..IINNTTEERRRRUUPPTT
2479              If bbmmaakkee is interrupted, the commands for this target will be
2480              executed.
2481
2482     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
2483              will be built.
2484
2485     ..MMAAKKEEFFLLAAGGSS
2486              This target provides a way to specify flags for bbmmaakkee when the
2487              makefile is used.  The flags are as if typed to the shell,
2488              though the --ff option will have no effect.
2489
2490     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
2491
2492     ..NNOOTTPPAARRAALLLLEELL
2493              Disable parallel mode.
2494
2495     ..NNOO__PPAARRAALLLLEELL
2496              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
2497              variants.
2498
2499     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
2500              add targets to the list of targets to be made.  Since the depen-
2501              dents of a target do not get built until the target itself could
2502              be built, unless `a' is built by another part of the dependency
2503              graph, the following is a dependency loop:
2504
2505              .ORDER: b a
2506              b: a
2507
2508              The ordering imposed by ..OORRDDEERR is only relevant for parallel
2509              makes.
2510
2511     ..PPAATTHH    The sources are directories which are to be searched for files
2512              not found in the current directory.  If no sources are speci-
2513              fied, any previously specified directories are deleted.  If the
2514              source is the special ..DDOOTTLLAASSTT target, then the current working
2515              directory is searched last.
2516
2517     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
2518
2519     ..PPRREECCIIOOUUSS
2520              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
2521              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
2522              every target in the file.
2523
2524     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
2525              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
2526
2527              _n_a_m_e        This is the minimal specification, used to select
2528                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
2529
2530              _p_a_t_h        Specifies the path to the shell.
2531
2532              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
2533
2534              _c_h_e_c_k       The command to turn on error checking.
2535
2536              _i_g_n_o_r_e      The command to disable error checking.
2537
2538              _e_c_h_o        The command to turn on echoing of commands executed.
2539
2540              _q_u_i_e_t       The command to turn off echoing of commands exe-
2541                          cuted.
2542
2543              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
2544                          mand.  It is typically identical to _q_u_i_e_t.
2545
2546              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
2547
2548              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
2549                          ing.
2550
2551              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
2552                          a single newline character when used outside of any
2553                          quoting characters.
2554              Example:
2555
2556              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
2557                      check="set -e" ignore="set +e" \
2558                      echo="set -v" quiet="set +v" filter="set +v" \
2559                      echoFlag=v errFlag=e newline="'\n'"
2560
2561     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
2562              sources are specified, the ..SSIILLEENNTT attribute is applied to every
2563              command in the file.
2564
2565     ..SSUUFFFFIIXXEESS
2566              Each source specifies a suffix to bbmmaakkee.  If no sources are
2567              specified, any previously specified suffixes are deleted.  It
2568              allows the creation of suffix-transformation rules.
2569
2570              Example:
2571
2572              .SUFFIXES: .o
2573              .c.o:
2574                      cc -o ${.TARGET} -c ${.IMPSRC}
2575
2576EENNVVIIRROONNMMEENNTT
2577     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
2578     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
2579     PWD, and TMPDIR.
2580
2581     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
2582     the command line to bbmmaakkee and not as makefile variables; see the descrip-
2583     tion of `_._O_B_J_D_I_R' for more details.
2584
2585FFIILLEESS
2586     .depend        list of dependencies
2587     Makefile       list of dependencies
2588     makefile       list of dependencies
2589     sys.mk         system makefile
2590     /usr/share/mk  system makefile directory
2591
2592CCOOMMPPAATTIIBBIILLIITTYY
2593     The basic make syntax is compatible between different versions of make,
2594     however the special variables, variable modifiers and conditionals are
2595     not.
2596
2597     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
2598     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
2599     rithms used may change again in the future.
2600
2601     The way that .for loop variables are substituted changed after NetBSD 5.0
2602     so that they still appear to be variable expansions.  In particular this
2603     stops them being treated as syntax, and removes some obscure problems
2604     using them in .if statements.
2605
2606     Unlike other bbmmaakkee programs, this implementation by default executes all
2607     commands for a given target using a single shell invocation.  This is
2608     done for both efficiency and to simplify error handling in remote command
2609     invocations.  Typically this is transparent to the user, unless the tar-
2610     get commands change the current working directory using ``cd'' or
2611     ``chdir''.  To be compatible with Makefiles that do this, one can use --BB
2612     to disable this behavior.
2613
2614SSEEEE AALLSSOO
2615     mkdep(1)
2616
2617HHIISSTTOORRYY
2618     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
2619     portability to other platforms.
2620
2621NetBSD 5.1                      August 30, 2012                     NetBSD 5.1
2622