xref: /dragonfly/contrib/bmake/bmake.cat1 (revision 25a2db75)
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
1304     In compatibility mode, each command is run in a separate process.  If the
1305     command contains any shell meta characters (`#=|^(){};&<>*?[]:$`\\n') it
1306     will be passed to the shell, otherwise bbmmaakkee will attempt direct execu-
1307     tion.
1308
1309SSEEEE AALLSSOO
1310     mkdep(1)
1311
1312HHIISSTTOORRYY
1313     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1314     portability to other platforms.
1315
1316     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1317     is based on Adam De Boor's pmake program which was written for Sprite at
1318     Berkeley.  It was designed to be a parallel distributed make running jobs
1319     on different machines using a daemon called ``customs''.
1320
1321BBUUGGSS
1322     The make syntax is difficult to parse without actually acting of the
1323     data.  For instance finding the end of a variable use should involve
1324     scanning each the modifiers using the correct terminator for each field.
1325     In many places make just counts {} and () in order to find the end of a
1326     variable expansion.
1327
1328MAKE(1)                 NetBSD General Commands Manual                 MAKE(1)
1329
1330     There is no way of escaping a space character in a filename.
1331
1332NNAAMMEE
1333     bbmmaakkee -- maintain program dependencies
1334
1335SSYYNNOOPPSSIISS
1336     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]
1337           [--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]
1338           [--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]
1339           [_t_a_r_g_e_t _._._.]
1340
1341DDEESSCCRRIIPPTTIIOONN
1342     bbmmaakkee is a program designed to simplify the maintenance of other pro-
1343     grams.  Its input is a list of specifications as to the files upon which
1344     programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e makefile option is
1345     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
1346     the specifications.  If the file `_._d_e_p_e_n_d' exists, it is read (see
1347     mkdep(1)).
1348
1349     This manual page is intended as a reference document only.  For a more
1350     thorough description of bbmmaakkee and makefiles, please refer to _P_M_a_k_e _- _A
1351     _T_u_t_o_r_i_a_l.
1352
1353     bbmmaakkee will prepend the contents of the _M_A_K_E_F_L_A_G_S environment variable to
1354     the command line arguments before parsing them.
1355
1356     The options are as follows:
1357
1358     --BB      Try to be backwards compatible by executing a single shell per
1359             command and by executing the commands to make the sources of a
1360             dependency line in sequence.
1361
1362     --CC _d_i_r_e_c_t_o_r_y
1363             Change to _d_i_r_e_c_t_o_r_y before reading the makefiles or doing any-
1364             thing else.  If multiple --CC options are specified, each is inter-
1365             preted relative to the previous one: --CC _/ --CC _e_t_c is equivalent to
1366             --CC _/_e_t_c.
1367
1368     --DD _v_a_r_i_a_b_l_e
1369             Define _v_a_r_i_a_b_l_e to be 1, in the global context.
1370
1371     --dd _[_-_]_f_l_a_g_s
1372             Turn on debugging, and specify which portions of bbmmaakkee are to
1373             print debugging information.  Unless the flags are preceded by
1374             `-' they are added to the _M_A_K_E_F_L_A_G_S environment variable and will
1375             be processed by any child make processes.  By default, debugging
1376             information is printed to standard error, but this can be changed
1377             using the _F debugging flag.  The debugging output is always
1378             unbuffered; in addition, if debugging is enabled but debugging
1379             output is not directed to standard output, then the standard out-
1380             put is line buffered.  _F_l_a_g_s is one or more of the following:
1381
1382             _A       Print all possible debugging information; equivalent to
1383                     specifying all of the debugging flags.
1384
1385             _a       Print debugging information about archive searching and
1386                     caching.
1387
1388             _C       Print debugging information about current working direc-
1389                     tory.
1390
1391             _c       Print debugging information about conditional evaluation.
1392
1393             _d       Print debugging information about directory searching and
1394                     caching.
1395
1396             _e       Print debugging information about failed commands and
1397                     targets.
1398
1399             _F[++]_f_i_l_e_n_a_m_e
1400                     Specify where debugging output is written.  This must be
1401                     the last flag, because it consumes the remainder of the
1402                     argument.  If the character immediately after the `F'
1403                     flag is `+', then the file will be opened in append mode;
1404                     otherwise the file will be overwritten.  If the file name
1405                     is `stdout' or `stderr' then debugging output will be
1406                     written to the standard output or standard error output
1407                     file descriptors respectively (and the `+' option has no
1408                     effect).  Otherwise, the output will be written to the
1409                     named file.  If the file name ends `.%d' then the `%d' is
1410                     replaced by the pid.
1411
1412             _f       Print debugging information about loop evaluation.
1413
1414             _g_1      Print the input graph before making anything.
1415
1416             _g_2      Print the input graph after making everything, or before
1417                     exiting on error.
1418
1419             _g_3      Print the input graph before exiting on error.
1420
1421             _j       Print debugging information about running multiple
1422                     shells.
1423
1424             _l       Print commands in Makefiles regardless of whether or not
1425                     they are prefixed by `@' or other "quiet" flags.  Also
1426                     known as "loud" behavior.
1427
1428             _M       Print debugging information about "meta" mode decisions
1429                     about targets.
1430
1431             _m       Print debugging information about making targets, includ-
1432                     ing modification dates.
1433
1434             _n       Don't delete the temporary command scripts created when
1435                     running commands.  These temporary scripts are created in
1436                     the directory referred to by the TMPDIR environment vari-
1437                     able, or in _/_t_m_p if TMPDIR is unset or set to the empty
1438                     string.  The temporary scripts are created by mkstemp(3),
1439                     and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E: This can
1440                     create many files in TMPDIR or _/_t_m_p, so use with care.
1441
1442             _p       Print debugging information about makefile parsing.
1443
1444             _s       Print debugging information about suffix-transformation
1445                     rules.
1446
1447             _t       Print debugging information about target list mainte-
1448                     nance.
1449
1450             _V       Force the --VV option to print raw values of variables.
1451
1452             _v       Print debugging information about variable assignment.
1453
1454             _x       Run shell commands with --xx so the actual commands are
1455                     printed as they are executed.
1456
1457     --ee      Specify that environment variables override macro assignments
1458             within makefiles.
1459
1460     --ff _m_a_k_e_f_i_l_e
1461             Specify a makefile to read instead of the default `_m_a_k_e_f_i_l_e'.  If
1462             _m_a_k_e_f_i_l_e is `--', standard input is read.  Multiple makefiles may
1463             be specified, and are read in the order specified.
1464
1465     --II _d_i_r_e_c_t_o_r_y
1466             Specify a directory in which to search for makefiles and included
1467             makefiles.  The system makefile directory (or directories, see
1468             the --mm option) is automatically included as part of this list.
1469
1470     --ii      Ignore non-zero exit of shell commands in the makefile.  Equiva-
1471             lent to specifying `--' before each command line in the makefile.
1472
1473     --JJ _p_r_i_v_a_t_e
1474             This option should _n_o_t be specified by the user.
1475
1476             When the _j option is in use in a recursive build, this option is
1477             passed by a make to child makes to allow all the make processes
1478             in the build to cooperate to avoid overloading the system.
1479
1480     --jj _m_a_x___j_o_b_s
1481             Specify the maximum number of jobs that bbmmaakkee may have running at
1482             any one time.  The value is saved in _._M_A_K_E_._J_O_B_S.  Turns compati-
1483             bility mode off, unless the _B flag is also specified.  When com-
1484             patibility mode is off, all commands associated with a target are
1485             executed in a single shell invocation as opposed to the tradi-
1486             tional one shell invocation per line.  This can break traditional
1487             scripts which change directories on each command invocation and
1488             then expect to start with a fresh environment on the next line.
1489             It is more efficient to correct the scripts rather than turn
1490             backwards compatibility on.
1491
1492     --kk      Continue processing after errors are encountered, but only on
1493             those targets that do not depend on the target whose creation
1494             caused the error.
1495
1496     --mm _d_i_r_e_c_t_o_r_y
1497             Specify a directory in which to search for sys.mk and makefiles
1498             included via the <_f_i_l_e>-style include statement.  The --mm option
1499             can be used multiple times to form a search path.  This path will
1500             override the default system include path: /usr/share/mk.  Fur-
1501             thermore the system include path will be appended to the search
1502             path used for "_f_i_l_e"-style include statements (see the --II
1503             option).
1504
1505             If a file or directory name in the --mm argument (or the
1506             MAKESYSPATH environment variable) starts with the string ".../"
1507             then bbmmaakkee will search for the specified file or directory named
1508             in the remaining part of the argument string.  The search starts
1509             with the current directory of the Makefile and then works upward
1510             towards the root of the filesystem.  If the search is successful,
1511             then the resulting directory replaces the ".../" specification in
1512             the --mm argument.  If used, this feature allows bbmmaakkee to easily
1513             search in the current source tree for customized sys.mk files
1514             (e.g., by using ".../mk/sys.mk" as an argument).
1515
1516     --nn      Display the commands that would have been executed, but do not
1517             actually execute them unless the target depends on the .MAKE spe-
1518             cial source (see below).
1519
1520     --NN      Display the commands which would have been executed, but do not
1521             actually execute any of them; useful for debugging top-level
1522             makefiles without descending into subdirectories.
1523
1524     --qq      Do not execute any commands, but exit 0 if the specified targets
1525             are up-to-date and 1, otherwise.
1526
1527     --rr      Do not use the built-in rules specified in the system makefile.
1528
1529     --ss      Do not echo any commands as they are executed.  Equivalent to
1530             specifying `@@' before each command line in the makefile.
1531
1532     --TT _t_r_a_c_e_f_i_l_e
1533             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
1534             for each job started and completed.
1535
1536     --tt      Rather than re-building a target as specified in the makefile,
1537             create it or update its modification time to make it appear up-
1538             to-date.
1539
1540     --VV _v_a_r_i_a_b_l_e
1541             Print bbmmaakkee's idea of the value of _v_a_r_i_a_b_l_e, in the global con-
1542             text.  Do not build any targets.  Multiple instances of this
1543             option may be specified; the variables will be printed one per
1544             line, with a blank line for each null or undefined variable.  If
1545             _v_a_r_i_a_b_l_e contains a `$' then the value will be expanded before
1546             printing.
1547
1548     --WW      Treat any warnings during makefile parsing as errors.
1549
1550     --XX      Don't export variables passed on the command line to the environ-
1551             ment individually.  Variables passed on the command line are
1552             still exported via the _M_A_K_E_F_L_A_G_S environment variable.  This
1553             option may be useful on systems which have a small limit on the
1554             size of command arguments.
1555
1556     _v_a_r_i_a_b_l_e_=_v_a_l_u_e
1557             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
1558             values passed on the command line are also exported to sub-makes
1559             in the environment.  The --XX flag disables this behavior.  Vari-
1560             able assignments should follow options for POSIX compatibility
1561             but no ordering is enforced.
1562
1563     There are seven different types of lines in a makefile: file dependency
1564     specifications, shell commands, variable assignments, include statements,
1565     conditional directives, for loops, and comments.
1566
1567     In general, lines may be continued from one line to the next by ending
1568     them with a backslash (`\').  The trailing newline character and initial
1569     whitespace on the following line are compressed into a single space.
1570
1571FFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
1572     Dependency lines consist of one or more targets, an operator, and zero or
1573     more sources.  This creates a relationship where the targets ``depend''
1574     on the sources and are usually created from them.  The exact relationship
1575     between the target and the source is determined by the operator that sep-
1576     arates them.  The three operators are as follows:
1577
1578     ::     A target is considered out-of-date if its modification time is less
1579           than those of any of its sources.  Sources for a target accumulate
1580           over dependency lines when this operator is used.  The target is
1581           removed if bbmmaakkee is interrupted.
1582
1583     !!     Targets are always re-created, but not until all sources have been
1584           examined and re-created as necessary.  Sources for a target accumu-
1585           late over dependency lines when this operator is used.  The target
1586           is removed if bbmmaakkee is interrupted.
1587
1588     ::::    If no sources are specified, the target is always re-created.  Oth-
1589           erwise, a target is considered out-of-date if any of its sources
1590           has been modified more recently than the target.  Sources for a
1591           target do not accumulate over dependency lines when this operator
1592           is used.  The target will not be removed if bbmmaakkee is interrupted.
1593
1594     Targets and sources may contain the shell wildcard values `?', `*', `[]',
1595     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
1596     final component of the target or source, and must be used to describe
1597     existing files.  The value `{}' need not necessarily be used to describe
1598     existing files.  Expansion is in directory order, not alphabetically as
1599     done in the shell.
1600
1601SSHHEELLLL CCOOMMMMAANNDDSS
1602     Each target may have associated with it a series of shell commands, nor-
1603     mally used to create the target.  Each of the commands in this script
1604     _m_u_s_t be preceded by a tab.  While any target may appear on a dependency
1605     line, only one of these dependencies may be followed by a creation
1606     script, unless the `::::' operator is used.
1607
1608     If the first characters of the command line are any combination of `@@',
1609     `++', or `--', the command is treated specially.  A `@@' causes the command
1610     not to be echoed before it is executed.  A `++' causes the command to be
1611     executed even when --nn is given.  This is similar to the effect of the
1612     .MAKE special source, except that the effect can be limited to a single
1613     line of a script.  A `--' causes any non-zero exit status of the command
1614     line to be ignored.
1615
1616VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
1617     Variables in make are much like variables in the shell, and, by tradi-
1618     tion, consist of all upper-case letters.
1619
1620   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
1621     The five operators that can be used to assign values to variables are as
1622     follows:
1623
1624     ==       Assign the value to the variable.  Any previous value is overrid-
1625             den.
1626
1627     ++==      Append the value to the current value of the variable.
1628
1629     ??==      Assign the value to the variable if it is not already defined.
1630
1631     ::==      Assign with expansion, i.e. expand the value before assigning it
1632             to the variable.  Normally, expansion is not done until the vari-
1633             able is referenced.  _N_O_T_E: References to undefined variables are
1634             _n_o_t expanded.  This can cause problems when variable modifiers
1635             are used.
1636
1637     !!==      Expand the value and pass it to the shell for execution and
1638             assign the result to the variable.  Any newlines in the result
1639             are replaced with spaces.
1640
1641     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
1642     being appended, a single space is inserted between the previous contents
1643     of the variable and the appended value.
1644
1645     Variables are expanded by surrounding the variable name with either curly
1646     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
1647     (`$').  If the variable name contains only a single letter, the surround-
1648     ing braces or parentheses are not required.  This shorter form is not
1649     recommended.
1650
1651     If the variable name contains a dollar, then the name itself is expanded
1652     first.  This allows almost arbitrary variable names, however names con-
1653     taining dollar, braces, parenthesis, or whitespace are really best
1654     avoided!
1655
1656     If the result of expanding a variable contains a dollar sign (`$') the
1657     string is expanded again.
1658
1659     Variable substitution occurs at three distinct times, depending on where
1660     the variable is being used.
1661
1662     1.   Variables in dependency lines are expanded as the line is read.
1663
1664     2.   Variables in shell commands are expanded when the shell command is
1665          executed.
1666
1667     3.   ``.for'' loop index variables are expanded on each loop iteration.
1668          Note that other variables are not expanded inside loops so the fol-
1669          lowing example code:
1670
1671
1672                .for i in 1 2 3
1673                a+=     ${i}
1674                j=      ${i}
1675                b+=     ${j}
1676                .endfor
1677
1678                all:
1679                        @echo ${a}
1680                        @echo ${b}
1681
1682          will print:
1683
1684                1 2 3
1685                3 3 3
1686
1687          Because while ${a} contains ``1 2 3'' after the loop is executed,
1688          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
1689          after the loop completes ${j} contains ``3''.
1690
1691   VVaarriiaabbllee ccllaasssseess
1692     The four different classes of variables (in order of increasing prece-
1693     dence) are:
1694
1695     Environment variables
1696             Variables defined as part of bbmmaakkee's environment.
1697
1698     Global variables
1699             Variables defined in the makefile or in included makefiles.
1700
1701     Command line variables
1702             Variables defined as part of the command line.
1703
1704     Local variables
1705             Variables that are defined specific to a certain target.  The
1706             seven local variables are as follows:
1707
1708             _._A_L_L_S_R_C   The list of all sources for this target; also known as
1709                       `_>'.
1710
1711             _._A_R_C_H_I_V_E  The name of the archive file.
1712
1713             _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
1714                       source from which the target is to be transformed (the
1715                       ``implied'' source); also known as `_<'.  It is not
1716                       defined in explicit rules.
1717
1718             _._M_E_M_B_E_R   The name of the archive member.
1719
1720             _._O_O_D_A_T_E   The list of sources for this target that were deemed
1721                       out-of-date; also known as `_?'.
1722
1723             _._P_R_E_F_I_X   The file prefix of the target, containing only the file
1724                       portion, no suffix or preceding directory components;
1725                       also known as `_*'.
1726
1727             _._T_A_R_G_E_T   The name of the target; also known as `_@'.
1728
1729             The shorter forms `_@', `_?', `_<', `_>', and `_*' are permitted for
1730             backward compatibility with historical makefiles and are not rec-
1731             ommended.  The six variables `_@_F', `_@_D', `_<_F', `_<_D', `_*_F', and
1732             `_*_D' are permitted for compatibility with AT&T System V UNIX
1733             makefiles and are not recommended.
1734
1735             Four of the local variables may be used in sources on dependency
1736             lines because they expand to the proper value for each target on
1737             the line.  These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E',
1738             and `_._M_E_M_B_E_R'.
1739
1740   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
1741     In addition, bbmmaakkee sets or knows about the following variables:
1742
1743     _$               A single dollar sign `$', i.e.  `$$' expands to a single
1744                     dollar sign.
1745
1746     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
1747                     evaluated during Makefile parsing, lists only those tar-
1748                     gets encountered thus far.
1749
1750     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
1751                     to the description of `PWD' for more details.
1752
1753     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
1754                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
1755                     The preferred variable to use is the environment variable
1756                     MAKE because it is more compatible with other versions of
1757                     bbmmaakkee and cannot be confused with the special target with
1758                     the same name.
1759
1760     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
1761                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
1762                     ated dependencies are read.
1763
1764     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
1765                     A boolean that controls the default behavior of the --VV
1766                     option.
1767
1768     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
1769
1770     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
1771
1772     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
1773                     If bbmmaakkee is run with _j then output for each target is
1774                     prefixed with a token `--- target ---' the first part of
1775                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
1776                     For example:
1777                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
1778                     would produce tokens like `---make[1234] target ---' mak-
1779                     ing it easier to track the degree of parallelism being
1780                     achieved.
1781
1782     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
1783                     that may be specified on bbmmaakkee's command line.  Anything
1784                     specified on bbmmaakkee's command line is appended to the
1785                     `MAKEFLAGS' variable which is then entered into the envi-
1786                     ronment for all programs which bbmmaakkee executes.
1787
1788     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
1789                     bbmmaakkee will be 0, and an incremented value is put into the
1790                     environment to be seen by the next generation.  This
1791                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
1792                     things which should only be evaluated in the initial
1793                     instance of bbmmaakkee.
1794
1795     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
1796                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
1797                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
1798
1799     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
1800                     The list of makefiles read by bbmmaakkee, which is useful for
1801                     tracking dependencies.  Each makefile is recorded only
1802                     once, regardless of the number of times read.
1803
1804     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
1805                     mode that bbmmaakkee runs in.  It can contain a number of key-
1806                     words:
1807
1808                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
1809
1810                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
1811                                 are created for each target to capture the
1812                                 command run, the output generated and if
1813                                 filemon(4) is available, the system calls
1814                                 which are of interest to bbmmaakkee.  The captured
1815                                 output can be very useful when diagnosing
1816                                 errors.
1817
1818                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
1819                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
1820                                 ting _b_f to a value which represents True.
1821
1822                     _e_n_v         For debugging, it can be useful to inlcude
1823                                 the environment in the .meta file.
1824
1825                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
1826                                 target being built.  This is useful if the
1827                                 build is otherwise running silently.  The
1828                                 message printed the value of:
1829                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
1830
1831                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
1832                                 not stable.  This keyword causes them to be
1833                                 ignored for determining whether a target is
1834                                 out of date in "meta" mode.  See also
1835                                 ..NNOOMMEETTAA__CCMMPP.
1836
1837                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
1838                                 mark the target ..SSIILLEENNTT.
1839
1840     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
1841                     In "meta" mode, provides a list of prefixes which match
1842                     the directories controlled by bbmmaakkee.  If a file that was
1843                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
1844                     missing, the current target is considered out-of-date.
1845
1846     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
1847                     In "meta" mode, this variable contains a list of all the
1848                     meta files updated.  If not empty, it can be used to
1849                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
1850
1851     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
1852                     In "meta" mode, this variable contains a list of all the
1853                     meta files used (updated or not).  This list can be used
1854                     to process the meta files to extract dependency informa-
1855                     tion.
1856
1857     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
1858                     Defines the message printed for each meta file updated in
1859                     "meta verbose" mode.  The default value is:
1860                           Building ${.TARGET:H:tA}/${.TARGET:T}
1861
1862     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
1863                     assigned to on the command line, so that they may be
1864                     exported as part of `MAKEFLAGS'.  This behaviour can be
1865                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
1866                     within a makefile.  Extra variables can be exported from
1867                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
1868                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
1869                     modified.
1870
1871     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
1872
1873     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
1874
1875     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
1876                     When bbmmaakkee stops due to an error, it prints its name and
1877                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
1878                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
1879
1880     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
1881                     its value.  This allows expansions using the ::@@ modifier
1882                     to put a newline between iterations of the loop rather
1883                     than a space.  For example, the printing of
1884                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
1885                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
1886
1887     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
1888                     value is determined by trying to chdir(2) to the follow-
1889                     ing directories in order and using the first match:
1890
1891                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
1892
1893                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
1894                          ment or on the command line.)
1895
1896                     2.   ${MAKEOBJDIR}
1897
1898                          (Only if `MAKEOBJDIR' is set in the environment or
1899                          on the command line.)
1900
1901                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
1902
1903                     4.   ${.CURDIR}_/_o_b_j
1904
1905                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
1906
1907                     6.   ${.CURDIR}
1908
1909                     Variable expansion is performed on the value before it's
1910                     used, so expressions such as
1911                           ${.CURDIR:S,^/usr/src,/var/obj,}
1912                     may be used.  This is especially useful with
1913                     `MAKEOBJDIR'.
1914
1915                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
1916                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
1917                     and set `PWD' to that directory before executing any tar-
1918                     gets.
1919
1920     _._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
1921                     parsed.
1922
1923     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
1924                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
1925                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
1926                     their current values, assign them to a variable using
1927                     assignment with expansion: (`::==').
1928
1929     _._P_A_T_H           A variable that represents the list of directories that
1930                     bbmmaakkee will search for files.  The search list should be
1931                     updated using the target `_._P_A_T_H' rather than the vari-
1932                     able.
1933
1934     PWD             Alternate path to the current directory.  bbmmaakkee normally
1935                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
1936                     However, if the environment variable `PWD' is set and
1937                     gives a path to the current directory, then bbmmaakkee sets
1938                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
1939                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
1940                     contains a variable transform.  `PWD' is set to the value
1941                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
1942
1943     .TARGETS        The list of targets explicitly specified on the command
1944                     line, if any.
1945
1946     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
1947                     will search for files.  The variable is supported for
1948                     compatibility with old make programs only, use `_._P_A_T_H'
1949                     instead.
1950
1951   VVaarriiaabbllee mmooddiiffiieerrss
1952     Variable expansion may be modified to select or modify each word of the
1953     variable (where a ``word'' is white-space delimited sequence of charac-
1954     ters).  The general format of a variable expansion is as follows:
1955
1956           ${variable[:modifier[:...]]}
1957
1958     Each modifier begins with a colon, which may be escaped with a backslash
1959     (`\').
1960
1961     A set of modifiers can be specified via a variable, as follows:
1962
1963           modifier_variable=modifier[:...]
1964           ${variable:${modifier_variable}[:...]}
1965
1966     In this case the first modifier in the modifier_variable does not start
1967     with a colon, since that must appear in the referencing variable.  If any
1968     of the modifiers in the modifier_variable contain a dollar sign (`$'),
1969     these must be doubled to avoid early expansion.
1970
1971     The supported modifiers are:
1972
1973     ::EE   Replaces each word in the variable with its suffix.
1974
1975     ::HH   Replaces each word in the variable with everything but the last com-
1976          ponent.
1977
1978     ::MM_p_a_t_t_e_r_n
1979          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
1980          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
1981          characters may be escaped with a backslash (`\').
1982
1983     ::NN_p_a_t_t_e_r_n
1984          This is identical to `::MM', but selects all words which do not match
1985          _p_a_t_t_e_r_n.
1986
1987     ::OO   Order every word in variable alphabetically.  To sort words in
1988          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
1989
1990     ::OOxx  Randomize words in variable.  The results will be different each
1991          time you are referring to the modified variable; use the assignment
1992          with expansion (`::==') to prevent such behaviour.  For example,
1993
1994                LIST=                   uno due tre quattro
1995                RANDOM_LIST=            ${LIST:Ox}
1996                STATIC_RANDOM_LIST:=    ${LIST:Ox}
1997
1998                all:
1999                        @echo "${RANDOM_LIST}"
2000                        @echo "${RANDOM_LIST}"
2001                        @echo "${STATIC_RANDOM_LIST}"
2002                        @echo "${STATIC_RANDOM_LIST}"
2003          may produce output similar to:
2004
2005                quattro due tre uno
2006                tre due quattro uno
2007                due uno quattro tre
2008                due uno quattro tre
2009
2010     ::QQ   Quotes every shell meta-character in the variable, so that it can be
2011          passed safely through recursive invocations of bbmmaakkee.
2012
2013     ::RR   Replaces each word in the variable with everything but its suffix.
2014
2015     ::ggmmttiimmee
2016          The value is a format string for strftime(3), using the current
2017          gmtime(3).
2018
2019     ::hhaasshh
2020          Compute a 32bit hash of the value and encode it as hex digits.
2021
2022     ::llooccaallttiimmee
2023          The value is a format string for strftime(3), using the current
2024          localtime(3).
2025
2026     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
2027          if that fails, the value is unchanged.
2028
2029     ::ttll  Converts variable to lower-case letters.
2030
2031     ::ttss_c
2032          Words in the variable are normally separated by a space on expan-
2033          sion.  This modifier sets the separator to the character _c.  If _c is
2034          omitted, then no separator is used.  The common escapes (including
2035          octal numeric codes), work as expected.
2036
2037     ::ttuu  Converts variable to upper-case letters.
2038
2039     ::ttWW  Causes the value to be treated as a single word (possibly containing
2040          embedded white space).  See also `::[[**]]'.
2041
2042     ::ttww  Causes the value to be treated as a sequence of words delimited by
2043          white space.  See also `::[[@@]]'.
2044
2045     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
2046          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
2047          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
2048          slash of the pattern, all occurrences in each word are replaced.  If
2049          a `1' is appended to the last slash of the pattern, only the first
2050          word is affected.  If a `W' is appended to the last slash of the
2051          pattern, then the value is treated as a single word (possibly con-
2052          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
2053          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
2054          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
2055          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
2056          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
2057          delimiter for the parts of the modifier string.  The anchoring,
2058          ampersand and delimiter characters may be escaped with a backslash
2059          (`\').
2060
2061          Variable expansion occurs in the normal fashion inside both
2062          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
2063          is used to prevent the expansion of a dollar sign (`$'), not a pre-
2064          ceding dollar sign as is usual.
2065
2066     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
2067          The ::CC modifier is just like the ::SS modifier except that the old and
2068          new strings, instead of being simple strings, are a regular expres-
2069          sion (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style string
2070          _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
2071          in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.  The `1'
2072          modifier causes the substitution to apply to at most one word; the
2073          `g' modifier causes the substitution to apply to as many instances
2074          of the search pattern _p_a_t_t_e_r_n as occur in the word or words it is
2075          found in; the `W' modifier causes the value to be treated as a sin-
2076          gle word (possibly containing embedded white space).  Note that `1'
2077          and `g' are orthogonal; the former specifies whether multiple words
2078          are potentially affected, the latter whether multiple substitutions
2079          can potentially occur within each affected word.
2080
2081     ::TT   Replaces each word in the variable with its last component.
2082
2083     ::uu   Remove adjacent duplicate words (like uniq(1)).
2084
2085     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
2086          If the variable name (not its value), when parsed as a .if condi-
2087          tional expression, evaluates to true, return as its value the
2088          _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
2089          name is used as the expression, :? must be the first modifier after
2090          the variable name itself - which will, of course, usually contain
2091          variable expansions.  A common error is trying to use expressions
2092          like
2093                ${NUMBERS:M42:?match:no}
2094          which actually tests defined(NUMBERS), to determine is any words
2095          match "42" you need to use something like:
2096                ${"${NUMBERS:M42}" != "":?match:no}.
2097
2098     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
2099          This is the AT&T System V UNIX style variable substitution.  It must
2100          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
2101          contain the pattern matching character _% then it is assumed that
2102          they are anchored at the end of each word, so only suffixes or
2103          entire words may be replaced.  Otherwise _% is the substring of
2104          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
2105
2106          Variable expansion occurs in the normal fashion inside both
2107          _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
2108          is used to prevent the expansion of a dollar sign (`$'), not a pre-
2109          ceding dollar sign as is usual.
2110
2111     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
2112          This is the loop expansion mechanism from the OSF Development Envi-
2113          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
2114          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
2115          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
2116          period.  For example.
2117                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
2118
2119          However a single character varaiable is often more readable:
2120                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
2121
2122     ::UU_n_e_w_v_a_l
2123          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
2124          is defined, the existing value is returned.  This is another ODE
2125          make feature.  It is handy for setting per-target CFLAGS for
2126          instance:
2127                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
2128          If a value is only required if the variable is undefined, use:
2129                ${VAR:D:Unewval}
2130
2131     ::DD_n_e_w_v_a_l
2132          If the variable is defined _n_e_w_v_a_l is the value.
2133
2134     ::LL   The name of the variable is the value.
2135
2136     ::PP   The path of the node which has the same name as the variable is the
2137          value.  If no such node exists or its path is null, then the name of
2138          the variable is used.  In order for this modifier to work, the name
2139          (node) must at least have appeared on the rhs of a dependency.
2140
2141     ::!!_c_m_d!!
2142          The output of running _c_m_d is the value.
2143
2144     ::sshh  If the variable is non-empty it is run as a command and the output
2145          becomes the new value.
2146
2147     ::::==_s_t_r
2148          The variable is assigned the value _s_t_r after substitution.  This
2149          modifier and its variations are useful in obscure situations such as
2150          wanting to set a variable when shell commands are being parsed.
2151          These assignment modifiers always expand to nothing, so if appearing
2152          in a rule line by themselves should be preceded with something to
2153          keep bbmmaakkee happy.
2154
2155          The `::::' helps avoid false matches with the AT&T System V UNIX style
2156          ::== modifier and since substitution always occurs the ::::== form is
2157          vaguely appropriate.
2158
2159     ::::??==_s_t_r
2160          As for ::::== but only if the variable does not already have a value.
2161
2162     ::::++==_s_t_r
2163          Append _s_t_r to the variable.
2164
2165     ::::!!==_c_m_d
2166          Assign the output of _c_m_d to the variable.
2167
2168     ::[[_r_a_n_g_e]]
2169          Selects one or more words from the value, or performs other opera-
2170          tions related to the way in which the value is divided into words.
2171
2172          Ordinarily, a value is treated as a sequence of words delimited by
2173          white space.  Some modifiers suppress this behaviour, causing a
2174          value to be treated as a single word (possibly containing embedded
2175          white space).  An empty value, or a value that consists entirely of
2176          white-space, is treated as a single word.  For the purposes of the
2177          `::[[]]' modifier, the words are indexed both forwards using positive
2178          integers (where index 1 represents the first word), and backwards
2179          using negative integers (where index -1 represents the last word).
2180
2181          The _r_a_n_g_e is subjected to variable expansion, and the expanded
2182          result is then interpreted as follows:
2183
2184          _i_n_d_e_x  Selects a single word from the value.
2185
2186          _s_t_a_r_t...._e_n_d
2187                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
2188                 `::[[22....--11]]' selects all words from the second word to the last
2189                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
2190                 put in reverse order.  For example, `::[[--11....11]]' selects all
2191                 the words from last to first.
2192
2193          **      Causes subsequent modifiers to treat the value as a single
2194                 word (possibly containing embedded white space).  Analogous
2195                 to the effect of "$*" in Bourne shell.
2196
2197          0      Means the same as `::[[**]]'.
2198
2199          @@      Causes subsequent modifiers to treat the value as a sequence
2200                 of words delimited by white space.  Analogous to the effect
2201                 of "$@" in Bourne shell.
2202
2203          ##      Returns the number of words in the value.
2204
2205IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
2206     Makefile inclusion, conditional structures and for loops  reminiscent of
2207     the C programming language are provided in bbmmaakkee.  All such structures
2208     are identified by a line beginning with a single dot (`.') character.
2209     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
2210     ables between the angle brackets or double quotes are expanded to form
2211     the file name.  If angle brackets are used, the included makefile is
2212     expected to be in the system makefile directory.  If double quotes are
2213     used, the including makefile's directory and any directories specified
2214     using the --II option are searched before the system makefile directory.
2215     For compatibility with other versions of bbmmaakkee `include file ...' is also
2216     accepted.  If the include statement is written as ..--iinncclluuddee or as
2217     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
2218
2219     Conditional expressions are also preceded by a single dot as the first
2220     character of a line.  The possible conditionals are as follows:
2221
2222     ..eerrrroorr _m_e_s_s_a_g_e
2223             The message is printed along with the name of the makefile and
2224             line number, then bbmmaakkee will exit.
2225
2226     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
2227             Export the specified global variable.  If no variable list is
2228             provided, all globals are exported except for internal variables
2229             (those that start with `.').  This is not affected by the --XX
2230             flag, so should be used with caution.  For compatibility with
2231             other bbmmaakkee programs `export variable=value' is also accepted.
2232
2233             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
2234             exporting a variable.
2235
2236     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
2237             The same as `.export', except that the variable is not appended
2238             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
2239             ment which is different from that used by bbmmaakkee internally.
2240
2241     ..iinnffoo _m_e_s_s_a_g_e
2242             The message is printed along with the name of the makefile and
2243             line number.
2244
2245     ..uunnddeeff _v_a_r_i_a_b_l_e
2246             Un-define the specified global variable.  Only global variables
2247             may be un-defined.
2248
2249     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
2250             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
2251             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
2252             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
2253
2254     ..uunneexxppoorrtt--eennvv
2255             Unexport all globals previously exported and clear the environ-
2256             ment inherited from the parent.  This operation will cause a mem-
2257             ory leak of the original environment, so should be used spar-
2258             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
2259             note that any variables which originated in the parent environ-
2260             ment should be explicitly preserved if desired.  For example:
2261
2262                   .if ${.MAKE.LEVEL} == 0
2263                   PATH := ${PATH}
2264                   .unexport-env
2265                   .export PATH
2266                   .endif
2267
2268             Would result in an environment containing only `PATH', which is
2269             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
2270             be pushed into the new environment.
2271
2272     ..wwaarrnniinngg _m_e_s_s_a_g_e
2273             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
2274             of the makefile and line number.
2275
2276     ..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 _._._.]
2277             Test the value of an expression.
2278
2279     ..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 _._._.]
2280             Test the value of a variable.
2281
2282     ..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 _._._.]
2283             Test the value of a variable.
2284
2285     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2286             Test the target being built.
2287
2288     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2289             Test the target being built.
2290
2291     ..eellssee   Reverse the sense of the last conditional.
2292
2293     ..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 _._._.]
2294             A combination of `..eellssee' followed by `..iiff'.
2295
2296     ..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 _._._.]
2297             A combination of `..eellssee' followed by `..iiffddeeff'.
2298
2299     ..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 _._._.]
2300             A combination of `..eellssee' followed by `..iiffnnddeeff'.
2301
2302     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2303             A combination of `..eellssee' followed by `..iiffmmaakkee'.
2304
2305     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
2306             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
2307
2308     ..eennddiiff  End the body of the conditional.
2309
2310     The _o_p_e_r_a_t_o_r may be any one of the following:
2311
2312     ||||     Logical OR.
2313
2314     &&&&     Logical AND; of higher precedence than ``||''.
2315
2316     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
2317     determine its value.  Parentheses may be used to change the order of
2318     evaluation.  The boolean operator `!!' may be used to logically negate an
2319     entire conditional.  It is of higher precedence than `&&&&'.
2320
2321     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
2322
2323     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
2324              the variable has been defined.
2325
2326     mmaakkee     Takes a target name as an argument and evaluates to true if the
2327              target was specified as part of bbmmaakkee's command line or was
2328              declared the default target (either implicitly or explicitly,
2329              see _._M_A_I_N) before the line containing the conditional.
2330
2331     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
2332              if the expansion of the variable would result in an empty
2333              string.
2334
2335     eexxiissttss   Takes a file name as an argument and evaluates to true if the
2336              file exists.  The file is searched for on the system search path
2337              (see _._P_A_T_H).
2338
2339     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
2340              target has been defined.
2341
2342     ccoommmmaannddss
2343              Takes a target name as an argument and evaluates to true if the
2344              target has been defined and has commands associated with it.
2345
2346     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
2347     expansion is performed on both sides of the comparison, after which the
2348     integral values are compared.  A value is interpreted as hexadecimal if
2349     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
2350     ported.  The standard C relational operators are all supported.  If after
2351     variable expansion, either the left or right hand side of a `====' or `!!=='
2352     operator is not an integral value, then string comparison is performed
2353     between the expanded variables.  If no relational operator is given, it
2354     is assumed that the expanded variable is being compared against 0 or an
2355     empty string in the case of a string comparison.
2356
2357     When bbmmaakkee is evaluating one of these conditional expressions, and it
2358     encounters a (white-space separated) word it doesn't recognize, either
2359     the ``make'' or ``defined'' expression is applied to it, depending on the
2360     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
2361     the ``defined'' expression is applied.  Similarly, if the form is
2362     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
2363
2364     If the conditional evaluates to true the parsing of the makefile contin-
2365     ues as before.  If it evaluates to false, the following lines are
2366     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
2367     found.
2368
2369     For loops are typically used to apply a set of rules to a list of files.
2370     The syntax of a for loop is:
2371
2372     ..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
2373     <make-rules>
2374     ..eennddffoorr
2375
2376     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
2377     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
2378     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
2379     the body of the for loop.  The number of words must come out even; that
2380     is, if there are three iteration variables, the number of words provided
2381     must be a multiple of three.
2382
2383CCOOMMMMEENNTTSS
2384     Comments begin with a hash (`#') character, anywhere but in a shell com-
2385     mand line, and continue to the end of an unescaped new line.
2386
2387SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
2388     ..EEXXEECC     Target is never out of date, but always execute commands any-
2389               way.
2390
2391     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
2392               get, exactly as if they all were preceded by a dash (`-').
2393
2394     ..MMAADDEE     Mark all sources of this target as being up-to-date.
2395
2396     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
2397               or --tt options were specified.  Normally used to mark recursive
2398               bbmmaakkee's.
2399
2400     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
2401               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
2402               the most likely case.  In "meta" mode, the target is out-of-
2403               date if the meta file is missing.
2404
2405     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
2406               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
2407
2408     ..NNOOMMEETTAA__CCMMPP
2409               Ignore differences in commands when deciding if target is out
2410               of date.  This is useful if the command contains a value which
2411               always changes.  If the number of commands change, though, the
2412               target will still be out of date.
2413
2414     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
2415               ..PPAATTHH.
2416
2417     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
2418               default target to be built if no target was specified.  This
2419               source prevents this target from being selected.
2420
2421     ..OOPPTTIIOONNAALL
2422               If a target is marked with this attribute and bbmmaakkee can't fig-
2423               ure out how to create it, it will ignore this fact and assume
2424               the file isn't needed or already exists.
2425
2426     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
2427               considered to be out of date, and will not be created with the
2428               --tt option.  Suffix-transformation rules are not applied to
2429               ..PPHHOONNYY targets.
2430
2431     ..PPRREECCIIOOUUSS
2432               When bbmmaakkee is interrupted, it normally removes any partially
2433               made targets.  This source prevents the target from being
2434               removed.
2435
2436     ..RREECCUURRSSIIVVEE
2437               Synonym for ..MMAAKKEE.
2438
2439     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
2440               exactly as if they all were preceded by an at sign (`@').
2441
2442     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
2443               get is used as a source for another target, the other target
2444               acquires the commands, sources, and attributes (except for
2445               ..UUSSEE) of the source.  If the target already has commands, the
2446               ..UUSSEE target's commands are appended to them.
2447
2448     ..UUSSEEBBEEFFOORREE
2449               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
2450               to the target.
2451
2452     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
2453               it are made before the sources that succeed it in the line.
2454               Since the dependents of files are not made until the file
2455               itself could be made, this also stops the dependents being
2456               built unless they are needed for another branch of the depen-
2457               dency tree.  So given:
2458
2459               x: a .WAIT b
2460                       echo x
2461               a:
2462                       echo a
2463               b: b1
2464                       echo b
2465               b1:
2466                       echo b1
2467
2468               the output is always `a', `b1', `b', `x'.
2469               The ordering imposed by ..WWAAIITT is only relevant for parallel
2470               makes.
2471
2472SSPPEECCIIAALL TTAARRGGEETTSS
2473     Special targets may not be included with other targets, i.e. they must be
2474     the only target specified.
2475
2476     ..BBEEGGIINN   Any command lines attached to this target are executed before
2477              anything else is done.
2478
2479     ..DDEEFFAAUULLTT
2480              This is sort of a ..UUSSEE rule for any target (that was used only
2481              as a source) that bbmmaakkee can't figure out any other way to cre-
2482              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
2483              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
2484              own name.
2485
2486     ..EENNDD     Any command lines attached to this target are executed after
2487              everything else is done.
2488
2489     ..EERRRROORR   Any command lines attached to this target are executed when
2490              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
2491              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
2492
2493     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
2494              sources are specified, this is the equivalent of specifying the
2495              --ii option.
2496
2497     ..IINNTTEERRRRUUPPTT
2498              If bbmmaakkee is interrupted, the commands for this target will be
2499              executed.
2500
2501     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
2502              will be built.
2503
2504     ..MMAAKKEEFFLLAAGGSS
2505              This target provides a way to specify flags for bbmmaakkee when the
2506              makefile is used.  The flags are as if typed to the shell,
2507              though the --ff option will have no effect.
2508
2509     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
2510
2511     ..NNOOTTPPAARRAALLLLEELL
2512              Disable parallel mode.
2513
2514     ..NNOO__PPAARRAALLLLEELL
2515              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
2516              variants.
2517
2518     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
2519              add targets to the list of targets to be made.  Since the depen-
2520              dents of a target do not get built until the target itself could
2521              be built, unless `a' is built by another part of the dependency
2522              graph, the following is a dependency loop:
2523
2524              .ORDER: b a
2525              b: a
2526
2527              The ordering imposed by ..OORRDDEERR is only relevant for parallel
2528              makes.
2529
2530     ..PPAATTHH    The sources are directories which are to be searched for files
2531              not found in the current directory.  If no sources are speci-
2532              fied, any previously specified directories are deleted.  If the
2533              source is the special ..DDOOTTLLAASSTT target, then the current working
2534              directory is searched last.
2535
2536     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
2537
2538     ..PPRREECCIIOOUUSS
2539              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
2540              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
2541              every target in the file.
2542
2543     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
2544              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
2545
2546              _n_a_m_e        This is the minimal specification, used to select
2547                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
2548
2549              _p_a_t_h        Specifies the path to the shell.
2550
2551              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
2552
2553              _c_h_e_c_k       The command to turn on error checking.
2554
2555              _i_g_n_o_r_e      The command to disable error checking.
2556
2557              _e_c_h_o        The command to turn on echoing of commands executed.
2558
2559              _q_u_i_e_t       The command to turn off echoing of commands exe-
2560                          cuted.
2561
2562              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
2563                          mand.  It is typically identical to _q_u_i_e_t.
2564
2565              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
2566
2567              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
2568                          ing.
2569
2570              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
2571                          a single newline character when used outside of any
2572                          quoting characters.
2573              Example:
2574
2575              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
2576                      check="set -e" ignore="set +e" \
2577                      echo="set -v" quiet="set +v" filter="set +v" \
2578                      echoFlag=v errFlag=e newline="'\n'"
2579
2580     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
2581              sources are specified, the ..SSIILLEENNTT attribute is applied to every
2582              command in the file.
2583
2584     ..SSUUFFFFIIXXEESS
2585              Each source specifies a suffix to bbmmaakkee.  If no sources are
2586              specified, any previously specified suffixes are deleted.  It
2587              allows the creation of suffix-transformation rules.
2588
2589              Example:
2590
2591              .SUFFIXES: .o
2592              .c.o:
2593                      cc -o ${.TARGET} -c ${.IMPSRC}
2594
2595EENNVVIIRROONNMMEENNTT
2596     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
2597     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
2598     PWD, and TMPDIR.
2599
2600     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
2601     the command line to bbmmaakkee and not as makefile variables; see the descrip-
2602     tion of `_._O_B_J_D_I_R' for more details.
2603
2604FFIILLEESS
2605     .depend        list of dependencies
2606     Makefile       list of dependencies
2607     makefile       list of dependencies
2608     sys.mk         system makefile
2609     /usr/share/mk  system makefile directory
2610
2611CCOOMMPPAATTIIBBIILLIITTYY
2612     The basic make syntax is compatible between different versions of make,
2613     however the special variables, variable modifiers and conditionals are
2614     not.
2615
2616     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
2617     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
2618     rithms used may change again in the future.
2619
2620     The way that .for loop variables are substituted changed after NetBSD 5.0
2621     so that they still appear to be variable expansions.  In particular this
2622     stops them being treated as syntax, and removes some obscure problems
2623     using them in .if statements.
2624
2625     Unlike other bbmmaakkee programs, this implementation by default executes all
2626     commands for a given target using a single shell invocation.  This is
2627     done for both efficiency and to simplify error handling in remote command
2628     invocations.  Typically this is transparent to the user, unless the tar-
2629     get commands change the current working directory using ``cd'' or
2630     ``chdir''.  To be compatible with Makefiles that do this, one can use --BB
2631     to disable this behavior.
2632
2633     In compatibility mode, each command is run in a separate process.  If the
2634     command contains any shell meta characters (`#=|^(){};&<>*?[]:$`\\n') it
2635     will be passed to the shell, otherwise bbmmaakkee will attempt direct execu-
2636     tion.
2637
2638SSEEEE AALLSSOO
2639     mkdep(1)
2640
2641HHIISSTTOORRYY
2642     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
2643     portability to other platforms.
2644
2645     A make command appeared in Version 7 AT&T UNIX.  This make implementation
2646     is based on Adam De Boor's pmake program which was written for Sprite at
2647     Berkeley.  It was designed to be a parallel distributed make running jobs
2648     on different machines using a daemon called ``customs''.
2649
2650BBUUGGSS
2651     The make syntax is difficult to parse without actually acting of the
2652     data.  For instance finding the end of a variable use should involve
2653     scanning each the modifiers using the correct terminator for each field.
2654     In many places make just counts {} and () in order to find the end of a
2655     variable expansion.
2656
2657     There is no way of escaping a space character in a filename.
2658
2659NetBSD 5.1                      October 8, 2012                     NetBSD 5.1
2660