xref: /freebsd/contrib/bmake/bmake.cat1 (revision 1729d2f741a12a42c61ed5308ee156a0d1cd1918)
1BMAKE(1)                FreeBSD General Commands Manual               BMAKE(1)
2
3NNAAMMEE
4     bbmmaakkee - maintain program dependencies
5
6SSYYNNOOPPSSIISS
7     bbmmaakkee [--BBeeiikkNNnnqqrrSSssttWWwwXX] [--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] [--vv _v_a_r_i_a_b_l_e]
10           [_v_a_r_i_a_b_l_e==_v_a_l_u_e ...] [_t_a_r_g_e_t ...]
11
12DDEESSCCRRIIPPTTIIOONN
13     bbmmaakkee is a program designed to simplify the maintenance of other
14     programs.  Its input is a list of specifications as to the files upon
15     which programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e option is
16     given, bbmmaakkee looks for the makefiles listed in _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
17     (default `_m_a_k_e_f_i_l_e', `_M_a_k_e_f_i_l_e') in order to find the specifications.  If
18     the file `_._d_e_p_e_n_d' exists, it is read, see 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 (from 1993).
23
24     bbmmaakkee prepends the contents of the MAKEFLAGS environment variable to the
25     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 making the sources of a dependency line in
31             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
35             anything else.  If multiple --CC options are specified, each is
36             interpreted relative to the previous one: --CC _/ --CC _e_t_c is
37             equivalent to --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 scope.
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 MAKEFLAGS environment variable and are
46             passed on to any child make processes.  By default, debugging
47             information is printed to standard error, but this can be changed
48             using the FF 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, the standard output is
51             line buffered.  The available _f_l_a_g_s are:
52
53             AA       Print all possible debugging information; equivalent to
54                     specifying all of the debugging flags.
55
56             aa       Print debugging information about archive searching and
57                     caching.
58
59             CC       Print debugging information about the current working
60                     directory.
61
62             cc       Print debugging information about conditional evaluation.
63
64             dd       Print debugging information about directory searching and
65                     caching.
66
67             ee       Print debugging information about failed commands and
68                     targets.
69
70             FF[++]_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 FF flag
74                     is `+', the file is opened in append mode; otherwise the
75                     file is overwritten.  If the file name is `stdout' or
76                     `stderr', debugging output is written to the standard
77                     output or standard error output respectively (and the `+'
78                     option has no effect).  Otherwise, the output is written
79                     to the named file.  If the file name ends with `.%d', the
80                     `%d' is replaced by the pid.
81
82             ff       Print debugging information about loop evaluation.
83
84             gg11      Print the input graph before making anything.
85
86             gg22      Print the input graph after making everything, or before
87                     exiting on error.
88
89             gg33      Print the input graph before exiting on error.
90
91             hh       Print debugging information about hash table operations.
92
93             jj       Print debugging information about running multiple
94                     shells.
95
96             LL       Turn on lint checks.  This throws errors for variable
97                     assignments that do not parse correctly, at the time of
98                     assignment, so the file and line number are available.
99
100             ll       Print commands in Makefiles regardless of whether or not
101                     they are prefixed by `@' or other "quiet" flags.  Also
102                     known as "loud" behavior.
103
104             MM       Print debugging information about "meta" mode decisions
105                     about targets.
106
107             mm       Print debugging information about making targets,
108                     including modification dates.
109
110             nn       Don't delete the temporary command scripts created when
111                     running commands.  These temporary scripts are created in
112                     the directory referred to by the TMPDIR environment
113                     variable, or in _/_t_m_p if TMPDIR is unset or set to the
114                     empty string.  The temporary scripts are created by
115                     mkstemp(3), and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E:
116                     This can create many files in TMPDIR or _/_t_m_p, so use with
117                     care.
118
119             pp       Print debugging information about makefile parsing.
120
121             ss       Print debugging information about suffix-transformation
122                     rules.
123
124             tt       Print debugging information about target list
125                     maintenance.
126
127             VV       Force the --VV option to print raw values of variables,
128                     overriding the default behavior set via
129                     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S.
130
131             vv       Print debugging information about variable assignment and
132                     expansion.
133
134             xx       Run shell commands with --xx so the actual commands are
135                     printed as they are executed.
136
137     --ee      Let environment variables override global variables within
138             makefiles.
139
140     --ff _m_a_k_e_f_i_l_e
141             Specify a makefile to read instead of one of the defaults listed
142             in _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E.  If _m_a_k_e_f_i_l_e is `-', standard input
143             is read.  If _m_a_k_e_f_i_l_e starts with the string `.../', bbmmaakkee
144             searches for the specified path in the rest of the argument in
145             the current directory and its parents.  Multiple makefiles may be
146             specified, and are read in the order specified.
147
148     --II _d_i_r_e_c_t_o_r_y
149             Specify a directory in which to search for makefiles and included
150             makefiles.  The system makefile directory (or directories, see
151             the --mm option) is automatically included as part of this list.
152
153     --ii      Ignore non-zero exit of shell commands in the makefile.
154             Equivalent to specifying `-' before each command line in the
155             makefile.
156
157     --JJ _p_r_i_v_a_t_e
158             This option should _n_o_t be specified by the user.
159
160             When the --jj option is in use in a recursive build, this option is
161             passed by a make to child makes to allow all the make processes
162             in the build to cooperate to avoid overloading the system.
163
164     --jj _m_a_x___j_o_b_s
165             Specify the maximum number of jobs that bbmmaakkee may have running at
166             any one time.  If _m_a_x___j_o_b_s is a floating point number, or ends
167             with `C', then the value is multiplied by the number of CPUs
168             reported online by sysconf(3).  The value of _m_a_x___j_o_b_s is saved in
169             _._M_A_K_E_._J_O_B_S.  Turns compatibility mode off, unless the --BB option
170             is also specified.  When compatibility mode is off, all commands
171             associated with a target are executed in a single shell
172             invocation as opposed to the traditional one shell invocation per
173             line.  This can break traditional scripts which change
174             directories on each command invocation and then expect to start
175             with a fresh environment on the next line.  It is more efficient
176             to correct the scripts rather than turn backwards compatibility
177             on.
178
179             A job token pool with _m_a_x___j_o_b_s tokens is used to control the
180             total number of jobs running.  Each instance of bbmmaakkee will wait
181             for a token from the pool before running a new job.
182
183     --kk      Continue processing after errors are encountered, but only on
184             those targets that do not depend on the target whose creation
185             caused the error.
186
187     --mm _d_i_r_e_c_t_o_r_y
188             Specify a directory in which to search for _s_y_s_._m_k and makefiles
189             included via the <_f_i_l_e>-style include statement.  The --mm option
190             can be used multiple times to form a search path.  This path
191             overrides the default system include path _/_u_s_r_/_s_h_a_r_e_/_m_k.
192             Furthermore, the system include path is appended to the search
193             path used for "_f_i_l_e"-style include statements (see the --II
194             option).  The system include path can be referenced via the read-
195             only variable _._S_Y_S_P_A_T_H.
196
197             If a directory name in the --mm argument (or the MAKESYSPATH
198             environment variable) starts with the string `.../', bbmmaakkee
199             searches for the specified file or directory named in the
200             remaining part of the argument string.  The search starts with
201             the current directory and then works upward towards the root of
202             the file system.  If the search is successful, the resulting
203             directory replaces the `.../' specification in the --mm argument.
204             This feature allows bbmmaakkee to easily search in the current source
205             tree for customized _s_y_s_._m_k files (e.g., by using `.../mk/sys.mk'
206             as an argument).
207
208     --nn      Display the commands that would have been executed, but do not
209             actually execute them unless the target depends on the _._M_A_K_E
210             special source (see below) or the command is prefixed with `++'.
211
212     --NN      Display the commands that would have been executed, but do not
213             actually execute any of them; useful for debugging top-level
214             makefiles without descending into subdirectories.
215
216     --qq      Do not execute any commands, instead exit 0 if the specified
217             targets are up to date, and 1 otherwise.
218
219     --rr      Do not use the built-in rules specified in the system makefile.
220
221     --SS      Stop processing if an error is encountered.  This is the default
222             behavior and the opposite of --kk.
223
224     --ss      Do not echo any commands as they are executed.  Equivalent to
225             specifying `@@' before each command line in the makefile.
226
227     --TT _t_r_a_c_e_f_i_l_e
228             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
229             for each job started and completed.
230
231     --tt      Rather than re-building a target as specified in the makefile,
232             create it or update its modification time to make it appear up-
233             to-date.
234
235     --VV _v_a_r_i_a_b_l_e
236             Print the value of _v_a_r_i_a_b_l_e.  Do not build any targets.  Multiple
237             instances of this option may be specified; the variables are
238             printed one per line, with a blank line for each null or
239             undefined variable.  The value printed is extracted from the
240             global scope after all makefiles have been read.
241
242             By default, the raw variable contents (which may include
243             additional unexpanded variable references) are shown.  If
244             _v_a_r_i_a_b_l_e contains a `$', it is not interpreted as a variable name
245             but rather as an expression.  Its value is expanded before
246             printing.  The value is also expanded before printing if
247             _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S is set to true and the --ddVV option has not
248             been used to override it.
249
250             Note that loop-local and target-local variables, as well as
251             values taken temporarily by global variables during makefile
252             processing, are not accessible via this option.  The --ddvv debug
253             mode can be used to see these at the cost of generating
254             substantial extraneous output.
255
256     --vv _v_a_r_i_a_b_l_e
257             Like --VV, but all printed variables are always expanded to their
258             complete value.  The last occurrence of --VV or --vv decides whether
259             all variables are expanded or not.
260
261     --WW      Treat any warnings during makefile parsing as errors.
262
263     --ww      Print entering and leaving directory messages, pre and post
264             processing.
265
266     --XX      Don't export variables passed on the command line to the
267             environment individually.  Variables passed on the command line
268             are still exported via the MAKEFLAGS environment variable.  This
269             option may be useful on systems which have a small limit on the
270             size of command arguments.
271
272     _v_a_r_i_a_b_l_e==_v_a_l_u_e
273             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
274             values passed on the command line are also exported to sub-makes
275             in the environment.  The --XX flag disables this behavior.
276             Variable assignments should follow options for POSIX
277             compatibility but no ordering is enforced.
278
279     There are several different types of lines in a makefile: dependency
280     specifications, shell commands, variable assignments, include statements,
281     conditional directives, for loops, other directives, and comments.
282
283     Lines may be continued from one line to the next by ending them with a
284     backslash (`\').  The trailing newline character and initial whitespace
285     on the following line are compressed into a single space.
286
287FFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
288     Dependency lines consist of one or more targets, an operator, and zero or
289     more sources.  This creates a relationship where the targets "depend" on
290     the sources and are customarily created from them.  A target is
291     considered out of date if it does not exist, or if its modification time
292     is less than that of any of its sources.  An out-of-date target is re-
293     created, but not until all sources have been examined and themselves re-
294     created as needed.  Three operators may be used:
295
296     ::     Many dependency lines may name this target but only one may have
297           attached shell commands.  All sources named in all dependency lines
298           are considered together, and if needed the attached shell commands
299           are run to create or re-create the target.  If bbmmaakkee is
300           interrupted, the target is removed.
301
302     !!     The same, but the target is always re-created whether or not it is
303           out of date.
304
305     ::::    Any dependency line may have attached shell commands, but each one
306           is handled independently: its sources are considered and the
307           attached shell commands are run if the target is out of date with
308           respect to (only) those sources.  Thus, different groups of the
309           attached shell commands may be run depending on the circumstances.
310           Furthermore, unlike ::, for dependency lines with no sources, the
311           attached shell commands are always run.  Also unlike ::, the target
312           is not removed if bbmmaakkee is interrupted.
313
314     All dependency lines mentioning a particular target must use the same
315     operator.
316
317     Targets and sources may contain the shell wildcard values `?', `*', `[]',
318     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
319     final component of the target or source, and only match existing files.
320     The value `{}' need not necessarily be used to describe existing files.
321     Expansion is in directory order, not alphabetically as done in the shell.
322
323SSHHEELLLL CCOOMMMMAANNDDSS
324     Each target may have associated with it one or more lines of shell
325     commands, normally used to create the target.  Each of the lines in this
326     script _m_u_s_t be preceded by a tab.  (For historical reasons, spaces are
327     not accepted.)  While targets can occur in many dependency lines if
328     desired, by default only one of these rules may be followed by a creation
329     script.  If the `::::' operator is used, however, all rules may include
330     scripts, and the respective scripts are executed in the order found.
331
332     Each line is treated as a separate shell command, unless the end of line
333     is escaped with a backslash `\', in which case that line and the next are
334     combined.  If the first characters of the command are any combination of
335     `@@', `++', or `--', the command is treated specially.
336
337           @@       causes the command not to be echoed before it is executed.
338
339           ++       causes the command to be executed even when --nn is given.
340                   This is similar to the effect of the _._M_A_K_E special source,
341                   except that the effect can be limited to a single line of a
342                   script.
343
344           --       in compatibility mode causes any non-zero exit status of
345                   the command line to be ignored.
346
347                   When bbmmaakkee is run in jobs mode with --jj _m_a_x___j_o_b_s, the entire
348                   script for the target is fed to a single instance of the
349                   shell.  In compatibility (non-jobs) mode, each command is
350                   run in a separate process.  If the command contains any
351                   shell meta characters (`#=|^(){};&<>*?[]:$`\\n'), it is
352                   passed to the shell; otherwise bbmmaakkee attempts direct
353                   execution.  If a line starts with `--' and the shell has
354                   ErrCtl enabled, failure of the command line is ignored as
355                   in compatibility mode.  Otherwise `--' affects the entire
356                   job; the script stops at the first command line that fails,
357                   but the target is not deemed to have failed.
358
359     Makefiles should be written so that the mode of bbmmaakkee operation does not
360     change their behavior.  For example, any command which uses "cd" or
361     "chdir" without the intention of changing the directory for subsequent
362     commands should be put in parentheses so it executes in a subshell.  To
363     force the use of a single shell, escape the line breaks so as to make the
364     whole script one command.  For example:
365
366           avoid-chdir-side-effects:
367                   @echo "Building $@ in $$(pwd)"
368                   @(cd ${.CURDIR} && ${MAKE} $@)
369                   @echo "Back in $$(pwd)"
370
371           ensure-one-shell-regardless-of-mode:
372                   @echo "Building $@ in $$(pwd)"; \
373                   (cd ${.CURDIR} && ${MAKE} $@); \
374                   echo "Back in $$(pwd)"
375
376     Since bbmmaakkee changes the current working directory to `_._O_B_J_D_I_R' before
377     executing any targets, each child process starts with that as its current
378     working directory.
379
380VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
381     Variables in make behave much like macros in the C preprocessor.
382
383     Variable assignments have the form `_N_A_M_E _o_p _v_a_l_u_e', where:
384
385           _N_A_M_E    is a single-word variable name, consisting, by tradition,
386                   of all upper-case letters,
387
388           _o_p      is one of the variable assignment operators described
389                   below, and
390
391           _v_a_l_u_e   is interpreted according to the variable assignment
392                   operator.
393
394     Whitespace around _N_A_M_E, _o_p and _v_a_l_u_e is discarded.
395
396   VVaarriiaabbllee aassssiiggnnmmeenntt ooppeerraattoorrss
397     The five operators that assign values to variables are:
398
399     ==       Assign the value to the variable.  Any previous value is
400             overwritten.
401
402     ++==      Append the value to the current value of the variable, separating
403             them by a single space.
404
405     ??==      Assign the value to the variable if it is not already defined.
406
407     ::==      Expand the value, then assign it to the variable.
408
409             _N_O_T_E: References to undefined variables are _n_o_t expanded.  This
410             can cause problems when variable modifiers are used.
411
412     !!==      Expand the value and pass it to the shell for execution, then
413             assign the output from the child's standard output to the
414             variable.  Any newlines in the result are replaced with spaces.
415
416   EExxppaannssiioonn ooff vvaarriiaabblleess
417     In most contexts where variables are expanded, `$$' expands to a single
418     dollar sign.  In other contexts (most variable modifiers, string literals
419     in conditions), `\$' expands to a single dollar sign.
420
421     References to variables have the form $${{_n_a_m_e[::_m_o_d_i_f_i_e_r_s]}} or
422     $$((_n_a_m_e[::_m_o_d_i_f_i_e_r_s])).  If the variable name consists of only a single
423     character and the expression contains no modifiers, the surrounding curly
424     braces or parentheses are not required.  This shorter form is not
425     recommended.
426
427     If the variable name contains a dollar, the name itself is expanded
428     first.  This allows almost arbitrary variable names, however names
429     containing dollar, braces, parentheses or whitespace are really best
430     avoided.
431
432     If the result of expanding a nested variable expression contains a dollar
433     sign (`$'), the result is subject to further expansion.
434
435     Variable substitution occurs at four distinct times, depending on where
436     the variable is being used.
437
438     1.   Variables in dependency lines are expanded as the line is read.
439
440     2.   Variables in conditionals are expanded individually, but only as far
441          as necessary to determine the result of the conditional.
442
443     3.   Variables in shell commands are expanded when the shell command is
444          executed.
445
446     4.   ..ffoorr loop index variables are expanded on each loop iteration.  Note
447          that other variables are not expanded when composing the body of a
448          loop, so the following example code:
449
450                .for i in 1 2 3
451                a+=     ${i}
452                j=      ${i}
453                b+=     ${j}
454                .endfor
455
456                all:
457                        @echo ${a}
458                        @echo ${b}
459
460          prints:
461
462                1 2 3
463                3 3 3
464
465          After the loop is executed:
466
467                _a       contains `${:U1} ${:U2} ${:U3}', which expands to `1 2
468                        3'.
469
470                _j       contains `${:U3}', which expands to `3'.
471
472                _b       contains `${j} ${j} ${j}', which expands to `${:U3}
473                        ${:U3} ${:U3}' and further to `3 3 3'.
474
475   VVaarriiaabbllee ccllaasssseess
476     The four different classes of variables (in order of increasing
477     precedence) are:
478
479     Environment variables
480             Variables defined as part of bbmmaakkee's environment.
481
482     Global variables
483             Variables defined in the makefile or in included makefiles.
484
485     Command line variables
486             Variables defined as part of the command line.
487
488     Local variables
489             Variables that are defined specific to a certain target.
490
491     Local variables can be set on a dependency line, unless
492     _._M_A_K_E_._T_A_R_G_E_T___L_O_C_A_L___V_A_R_I_A_B_L_E_S is set to `false'.  The rest of the line
493     (which already has had global variables expanded) is the variable value.
494     For example:
495
496           COMPILER_WRAPPERS= ccache distcc icecc
497
498           ${OBJS}: .MAKE.META.CMP_FILTER=${COMPILER_WRAPPERS:S,^,N,}
499
500     Only the targets `${OBJS}' are impacted by that filter (in "meta" mode)
501     and simply enabling/disabling any of the compiler wrappers does not
502     render all of those targets out-of-date.
503
504     _N_O_T_E: target-local variable assignments behave differently in that;
505
506           ++==      Only appends to a previous local assignment for the same
507                   target and variable.
508
509           ::==      Is redundant with respect to global variables, which have
510                   already been expanded.
511
512     The built-in local variables are:
513
514           _._A_L_L_S_R_C   The list of all sources for this target; also known as
515                     `_>' or `_^'.
516
517           _._A_R_C_H_I_V_E  The name of the archive file; also known as `_!'.
518
519           _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
520                     source from which the target is to be transformed (the
521                     "implied" source); also known as `_<'.  It is not defined
522                     in explicit rules.
523
524           _._M_E_M_B_E_R   The name of the archive member; also known as `_%'.
525
526           _._O_O_D_A_T_E   The list of sources for this target that were deemed out-
527                     of-date; also known as `_?'.
528
529           _._P_R_E_F_I_X   The name of the target with suffix (if declared in
530                     ..SSUUFFFFIIXXEESS) removed; also known as `_*'.
531
532           _._T_A_R_G_E_T   The name of the target; also known as `_@'.  For
533                     compatibility with other makes this is an alias for
534                     _._A_R_C_H_I_V_E in archive member rules.
535
536     The shorter forms (`_>', `_^', `_!', `_<', `_%', `_?', `_*', and `_@') are
537     permitted for backward compatibility with historical makefiles and legacy
538     POSIX make and are not recommended.
539
540     Variants of these variables with the punctuation followed immediately by
541     `D' or `F', e.g. `$(@D)', are legacy forms equivalent to using the `:H'
542     and `:T' modifiers.  These forms are accepted for compatibility with AT&T
543     System V UNIX makefiles and POSIX but are not recommended.
544
545     Four of the local variables may be used in sources on dependency lines
546     because they expand to the proper value for each target on the line.
547     These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E', and `_._M_E_M_B_E_R'.
548
549   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
550     In addition, bbmmaakkee sets or knows about the following variables:
551
552     _._A_L_L_T_A_R_G_E_T_S
553             The list of all targets encountered in the makefiles.  If
554             evaluated during makefile parsing, lists only those targets
555             encountered thus far.
556
557     _._C_U_R_D_I_R
558             A path to the directory where bbmmaakkee was executed.  Refer to the
559             description of `_P_W_D' for more details.
560
561     _._E_R_R_O_R___C_M_D
562             Is used in error handling, see _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R.
563
564     _._E_R_R_O_R___C_W_D
565             Is used in error handling, see _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R.
566
567     _._E_R_R_O_R___E_X_I_T
568             Is used in error handling, see _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R.
569
570     _._E_R_R_O_R___M_E_T_A___F_I_L_E
571             Is used in error handling in "meta" mode, see
572             _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R.
573
574     _._E_R_R_O_R___T_A_R_G_E_T
575             Is used in error handling, see _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R.
576
577     _._I_N_C_L_U_D_E_D_F_R_O_M_D_I_R
578             The directory of the file this makefile was included from.
579
580     _._I_N_C_L_U_D_E_D_F_R_O_M_F_I_L_E
581             The filename of the file this makefile was included from.
582
583     _M_A_C_H_I_N_E
584             The machine hardware name, see uname(1).
585
586     _M_A_C_H_I_N_E___A_R_C_H
587             The machine processor architecture name, see uname(1).
588
589     _M_A_K_E    The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).
590
591     _._M_A_K_E   The same as _M_A_K_E, for compatibility.  The preferred variable to
592             use is the environment variable MAKE because it is more
593             compatible with other make variants and cannot be confused with
594             the special target with the same name.
595
596     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
597             Names the makefile (default `_._d_e_p_e_n_d') from which generated
598             dependencies are read.
599
600     _._M_A_K_E_._D_I_E___Q_U_I_E_T_L_Y
601             If set to `true', do not print error information at the end.
602
603     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
604             A boolean that controls the default behavior of the --VV option.
605             If true, variable values printed with --VV are fully expanded; if
606             false, the raw variable contents (which may include additional
607             unexpanded variable references) are shown.
608
609     _._M_A_K_E_._E_X_P_O_R_T_E_D
610             The list of variables exported by bbmmaakkee.
611
612     _M_A_K_E___V_E_R_S_I_O_N
613             This variable indicates the version of bbmmaakkee.  It is typically
614             the date of last import from NetBSD.  It is useful for checking
615             whether certain features are available.
616
617     _M_A_K_E_F_I_L_E
618             The top-level makefile that is currently read, as given in the
619             command line.
620
621     _._M_A_K_E_F_L_A_G_S
622             The environment variable `MAKEFLAGS' may contain anything that
623             may be specified on bbmmaakkee's command line.  Anything specified on
624             bbmmaakkee's command line is appended to the _._M_A_K_E_F_L_A_G_S variable,
625             which is then added to the environment for all programs that
626             bbmmaakkee executes.
627
628     _._M_A_K_E_._G_I_D
629             The numeric group ID of the user running bbmmaakkee.  It is read-only.
630
631     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
632             If bbmmaakkee is run with --jj, the output for each target is prefixed
633             with a token
634                   --- _t_a_r_g_e_t ---
635             the first part of which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
636             If _._M_A_K_E_._J_O_B_._P_R_E_F_I_X is empty, no token is printed.  For example,
637             setting _._M_A_K_E_._J_O_B_._P_R_E_F_I_X to
638             `${.newline}---${.MAKE:T}[${.MAKE.PID}]' would produce tokens
639             like
640                   ---make[1234] _t_a_r_g_e_t ---
641             making it easier to track the degree of parallelism being
642             achieved.
643
644     _._M_A_K_E_._J_O_B_S
645             The argument to the --jj option.
646
647     _._M_A_K_E_._J_O_B_S_._C
648             A read-only boolean that indicates whether the --jj option supports
649             use of `C'.
650
651     _._M_A_K_E_._L_E_V_E_L
652             The recursion depth of bbmmaakkee.  The top-level instance of bbmmaakkee
653             has level 0, and each child make has its parent level plus 1.
654             This allows tests like: .if ${.MAKE.LEVEL} == 0 to protect things
655             which should only be evaluated in the top-level instance of
656             bbmmaakkee.
657
658     _._M_A_K_E_._L_E_V_E_L_._E_N_V
659             The name of the environment variable that stores the level of
660             nested calls to bbmmaakkee.
661
662     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
663             The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
664             `_M_a_k_e_f_i_l_e') that bbmmaakkee looks for.
665
666     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
667             The list of makefiles read by bbmmaakkee, which is useful for tracking
668             dependencies.  Each makefile is recorded only once, regardless of
669             the number of times read.
670
671     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
672             In "meta" mode, provides a list of prefixes which match the
673             directories controlled by bbmmaakkee.  If a file that was generated
674             outside of _._O_B_J_D_I_R but within said bailiwick is missing, the
675             current target is considered out-of-date.
676
677     _._M_A_K_E_._M_E_T_A_._C_M_P___F_I_L_T_E_R
678             In "meta" mode, it can (very rarely!) be useful to filter command
679             lines before comparison.  This variable can be set to a set of
680             modifiers that are applied to each line of the old and new
681             command that differ, if the filtered commands still differ, the
682             target is considered out-of-date.
683
684     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
685             In "meta" mode, this variable contains a list of all the meta
686             files updated.  If not empty, it can be used to trigger
687             processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
688
689     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
690             In "meta" mode, this variable contains a list of all the meta
691             files used (updated or not).  This list can be used to process
692             the meta files to extract dependency information.
693
694     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___F_I_L_T_E_R
695             Provides a list of variable modifiers to apply to each pathname.
696             Ignore if the expansion is an empty string.
697
698     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_H_S
699             Provides a list of path prefixes that should be ignored; because
700             the contents are expected to change over time.  The default list
701             includes: `_/_d_e_v _/_e_t_c _/_p_r_o_c _/_t_m_p _/_v_a_r_/_r_u_n _/_v_a_r_/_t_m_p'
702
703     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_T_E_R_N_S
704             Provides a list of patterns to match against pathnames.  Ignore
705             any that match.
706
707     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
708             Defines the message printed for each meta file updated in "meta
709             verbose" mode.  The default value is:
710                   Building ${.TARGET:H:tA}/${.TARGET:T}
711
712     _._M_A_K_E_._M_O_D_E
713             Processed after reading all makefiles.  Affects the mode that
714             bbmmaakkee runs in.  It can contain these keywords:
715
716             ccoommppaatt  Like --BB, puts bbmmaakkee into "compat" mode.
717
718             mmeettaa    Puts bbmmaakkee into "meta" mode, where meta files are created
719                     for each target to capture the commands run, the output
720                     generated, and if filemon(4) is available, the system
721                     calls which are of interest to bbmmaakkee.  The captured
722                     output can be useful when diagnosing errors.
723
724                     bbmmaakkee will use the information in the meta file to help
725                     determine if a target is out-of-date when the normal
726                     dependency rules indicate it is not.
727
728                     First, the commands to be executed, will be compared to
729                     those captured previously, if any differ, the target is
730                     out-of-date.
731
732                     This allows for a huge improvement in the reliability and
733                     efficiency of update builds.  It is no longer necessary
734                     for targets to depend on makefiles just in-case they set
735                     a variable that might be relevant.  Mechanisms such as
736                     _._M_A_K_E_._M_E_T_A_._C_M_P___F_I_L_T_E_R and ..NNOOMMEETTAA__CCMMPP, allow limiting or
737                     disabling that comparison on a per target basis.  A
738                     reference to the variable _._O_O_D_A_T_E can be leveraged to
739                     block comparison of certain commands.  For example:
740                     `${.OODATE:M}' will expand to nothing and have no impact
741                     on the target, its side-effect though, will be to prevent
742                     comparison of any command line it appears on.  For
743                     documentation purposes `${.OODATE:MNOMETA_CMP}' is
744                     useful.
745
746                     If necessary, bbmmaakkee will then use the information
747                     captured by filemon(4), to check the modification time of
748                     any file used in generating the target, if any is newer,
749                     the target is out-of-date.
750
751                     Such deep inspection can easily lead to cases where a
752                     target is _a_l_w_a_y_s considered out-of-date, which is why
753                     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___F_I_L_T_E_R, _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_H_S and
754                     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_T_E_R_N_S, are provided to limit that
755                     inspection when necessary.
756
757             ccuurrddiirrOOkk==_b_f
758                     By default, bbmmaakkee does not create _._m_e_t_a files in
759                     `_._C_U_R_D_I_R'.  This can be overridden by setting _b_f to a
760                     value which represents true.
761
762             mmiissssiinngg--mmeettaa==_b_f
763                     If _b_f is true, a missing _._m_e_t_a file makes the target out-
764                     of-date.
765
766             mmiissssiinngg--ffiilleemmoonn==_b_f
767                     If _b_f is true, missing filemon data makes the target out-
768                     of-date.
769
770             nnooffiilleemmoonn
771                     Do not use filemon(4).
772
773             eennvv     For debugging, it can be useful to include the
774                     environment in the _._m_e_t_a file.
775
776             vveerrbboossee
777                     If in "meta" mode, print a clue about the target being
778                     built.  This is useful if the build is otherwise running
779                     silently.  The message printed is the expanded value of
780                     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
781
782             iiggnnoorree--ccmmdd
783                     Some makefiles have commands which are simply not stable.
784                     This keyword causes them to be ignored for determining
785                     whether a target is out of date in "meta" mode.  See also
786                     ..NNOOMMEETTAA__CCMMPP.
787
788             ssiilleenntt==_b_f
789                     If _b_f is true, when a .meta file is created, mark the
790                     target ..SSIILLEENNTT.
791
792             rraannddoommiizzee--ttaarrggeettss
793                     In both compat and parallel mode, do not make the targets
794                     in the usual order, but instead randomize their order.
795                     This mode can be used to detect undeclared dependencies
796                     between files.
797
798     _M_A_K_E_O_B_J_D_I_R
799             Used to create files in a separate directory, see _._O_B_J_D_I_R.
800
801     _M_A_K_E___O_B_J_D_I_R___C_H_E_C_K___W_R_I_T_A_B_L_E
802             When true, bbmmaakkee will check that _._O_B_J_D_I_R is writable, and issue a
803             warning if not.
804
805     _M_A_K_E___D_E_B_U_G___O_B_J_D_I_R___C_H_E_C_K___W_R_I_T_A_B_L_E
806             When true and bbmmaakkee is warning about an unwritable _._O_B_J_D_I_R,
807             report the variables listed in _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R to help
808             debug.
809
810     _M_A_K_E_O_B_J_D_I_R_P_R_E_F_I_X
811             Used to create files in a separate directory, see _._O_B_J_D_I_R.  It
812             should be an absolute path.
813
814     _._M_A_K_E_._O_S
815             The name of the operating system, see uname(1).  It is read-only.
816
817     _._M_A_K_E_O_V_E_R_R_I_D_E_S
818             This variable is used to record the names of variables assigned
819             to on the command line, so that they may be exported as part of
820             `MAKEFLAGS'.  This behavior can be disabled by assigning an empty
821             value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S' within a makefile.  Extra variables can
822             be exported from a makefile by appending their names to
823             `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.  `MAKEFLAGS' is re-exported whenever
824             `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is modified.
825
826     _._M_A_K_E_._P_A_T_H___F_I_L_E_M_O_N
827             If bbmmaakkee was built with filemon(4) support, this is set to the
828             path of the device node.  This allows makefiles to test for this
829             support.
830
831     _._M_A_K_E_._P_I_D
832             The process ID of bbmmaakkee.  It is read-only.
833
834     _._M_A_K_E_._P_P_I_D
835             The parent process ID of bbmmaakkee.  It is read-only.
836
837     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
838             When bbmmaakkee stops due to an error, it sets `_._E_R_R_O_R___T_A_R_G_E_T' to the
839             name of the target that failed, `_._E_R_R_O_R___E_X_I_T' to the exit status
840             of the failed target, `_._E_R_R_O_R___C_M_D' to the commands of the failed
841             target, and in "meta" mode, it also sets `_._E_R_R_O_R___C_W_D' to the
842             getcwd(3), and `_._E_R_R_O_R___M_E_T_A___F_I_L_E' to the path of the meta file
843             (if any) describing the failed target.  It then prints its name
844             and the value of `_._C_U_R_D_I_R' as well as the value of any variables
845             named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
846
847     _._M_A_K_E_._S_A_V_E___D_O_L_L_A_R_S
848             If true, `$$' are preserved when doing `:=' assignments.  The
849             default is false, for backwards compatibility.  Set to true for
850             compatability with other makes.  If set to false, `$$' becomes
851             `$' per normal evaluation rules.
852
853     _._M_A_K_E_._T_A_R_G_E_T___L_O_C_A_L___V_A_R_I_A_B_L_E_S
854             If set to `false', apparent variable assignments in dependency
855             lines are treated as normal sources.
856
857     _._M_A_K_E_._U_I_D
858             The numeric ID of the user running bbmmaakkee.  It is read-only.
859
860     _._n_e_w_l_i_n_e
861             This variable is simply assigned a newline character as its
862             value.  It is read-only.  This allows expansions using the ::@@
863             modifier to put a newline between iterations of the loop rather
864             than a space.  For example, in case of an error, bbmmaakkee prints the
865             variable names and their values using:
866                   ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
867
868     _._O_B_J_D_I_R
869             A path to the directory where the targets are built.  Its value
870             is determined by trying to chdir(2) to the following directories
871             in order and using the first match:
872
873             1.   $${{MMAAKKEEOOBBJJDDIIRRPPRREEFFIIXX}}$${{..CCUURRDDIIRR}}
874
875                  (Only if `MAKEOBJDIRPREFIX' is set in the environment or on
876                  the command line.)
877
878             2.   $${{MMAAKKEEOOBBJJDDIIRR}}
879
880                  (Only if `MAKEOBJDIR' is set in the environment or on the
881                  command line.)
882
883             3.   $${{..CCUURRDDIIRR}}_/_o_b_j_.$${{MMAACCHHIINNEE}}
884
885             4.   $${{..CCUURRDDIIRR}}_/_o_b_j
886
887             5.   _/_u_s_r_/_o_b_j_/$${{..CCUURRDDIIRR}}
888
889             6.   $${{..CCUURRDDIIRR}}
890
891             Variable expansion is performed on the value before it is used,
892             so expressions such as $${{..CCUURRDDIIRR::SS,,^^//uussrr//ssrrcc,,//vvaarr//oobbjj,,}} may be
893             used.  This is especially useful with `MAKEOBJDIR'.
894
895             `_._O_B_J_D_I_R' may be modified in the makefile via the special target
896             `..OOBBJJDDIIRR'.  In all cases, bbmmaakkee changes to the specified
897             directory if it exists, and sets `_._O_B_J_D_I_R' and `_P_W_D' to that
898             directory before executing any targets.
899
900             Except in the case of an explicit `..OOBBJJDDIIRR' target, bbmmaakkee checks
901             that the specified directory is writable and ignores it if not.
902             This check can be skipped by setting the environment variable
903             `MAKE_OBJDIR_CHECK_WRITABLE' to "no".
904
905     _._P_A_R_S_E_D_I_R
906             The directory name of the current makefile being parsed.
907
908     _._P_A_R_S_E_F_I_L_E
909             The basename of the current makefile being parsed.  This variable
910             and `_._P_A_R_S_E_D_I_R' are both set only while the makefiles are being
911             parsed.  To retain their current values, assign them to a
912             variable using assignment with expansion `::=='.
913
914     _._P_A_T_H   The space-separated list of directories that bbmmaakkee searches for
915             files.  To update this search list, use the special target
916             `..PPAATTHH' rather than modifying the variable directly.
917
918     _%_P_O_S_I_X  Is set in POSIX mode, see the special `_._P_O_S_I_X' target.
919
920     _P_W_D     Alternate path to the current directory.  bbmmaakkee normally sets
921             `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).  However, if
922             the environment variable `PWD' is set and gives a path to the
923             current directory, bbmmaakkee sets `_._C_U_R_D_I_R' to the value of `PWD'
924             instead.  This behavior is disabled if `MAKEOBJDIRPREFIX' is set
925             or `MAKEOBJDIR' contains a variable transform.  `_P_W_D' is set to
926             the value of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
927
928     _._S_H_E_L_L  The pathname of the shell used to run target scripts.  It is
929             read-only.
930
931     _._S_U_F_F_I_X_E_S
932             The list of known suffixes.  It is read-only.
933
934     _._S_Y_S_P_A_T_H
935             The space-separated list of directories that bbmmaakkee searches for
936             makefiles, referred to as the system include path.  To update
937             this search list, use the special target `..SSYYSSPPAATTHH' rather than
938             modifying the variable which is read-only.
939
940     _._T_A_R_G_E_T_S
941             The list of targets explicitly specified on the command line, if
942             any.
943
944     _V_P_A_T_H   The colon-separated (":") list of directories that bbmmaakkee searches
945             for files.  This variable is supported for compatibility with old
946             make programs only, use `_._P_A_T_H' instead.
947
948   VVaarriiaabbllee mmooddiiffiieerrss
949     The general format of a variable expansion is:
950
951           $${{_v_a_r_i_a_b_l_e[::_m_o_d_i_f_i_e_r[::...]]}}
952
953     Each modifier begins with a colon.  To escape a colon, precede it with a
954     backslash `\'.
955
956     A list of indirect modifiers can be specified via a variable, as follows:
957
958           _m_o_d_i_f_i_e_r___v_a_r_i_a_b_l_e = _m_o_d_i_f_i_e_r[::...]
959
960           $${{_v_a_r_i_a_b_l_e::$${{_m_o_d_i_f_i_e_r___v_a_r_i_a_b_l_e}}[::...]}}
961
962     In this case, the first modifier in the _m_o_d_i_f_i_e_r___v_a_r_i_a_b_l_e does not start
963     with a colon, since that colon already occurs in the referencing
964     variable.  If any of the modifiers in the _m_o_d_i_f_i_e_r___v_a_r_i_a_b_l_e contains a
965     dollar sign (`$'), these must be doubled to avoid early expansion.
966
967     Some modifiers interpret the expression value as a single string, others
968     treat the expression value as a whitespace-separated list of words.  When
969     splitting a string into words, whitespace can be escaped using double
970     quotes, single quotes and backslashes, like in the shell.  The quotes and
971     backslashes are retained in the words.
972
973     The supported modifiers are:
974
975     ::EE   Replaces each word with its suffix.
976
977     ::HH   Replaces each word with its dirname.
978
979     ::MM_p_a_t_t_e_r_n
980          Selects only those words that match _p_a_t_t_e_r_n.  The standard shell
981          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
982          characters may be escaped with a backslash (`\').  As a consequence
983          of the way values are split into words, matched, and then joined,
984          the construct `${VAR:M*}' removes all leading and trailing
985          whitespace and normalizes the inter-word spacing to a single space.
986
987     ::NN_p_a_t_t_e_r_n
988          This is the opposite of `::MM', selecting all words which do _n_o_t match
989          _p_a_t_t_e_r_n.
990
991     ::OO   Orders the words lexicographically.
992
993     ::OOnn  Orders the words numerically.  A number followed by one of `k', `M'
994          or `G' is multiplied by the appropriate factor, which is 1024 for
995          `k', 1048576 for `M', or 1073741824 for `G'.  Both upper- and lower-
996          case letters are accepted.
997
998     ::OOrr  Orders the words in reverse lexicographical order.
999
1000     ::OOrrnn
1001          Orders the words in reverse numerical order.
1002
1003     ::OOxx  Shuffles the words.  The results are different each time you are
1004          referring to the modified variable; use the assignment with
1005          expansion `::==' to prevent such behavior.  For example,
1006
1007                LIST=                   uno due tre quattro
1008                RANDOM_LIST=            ${LIST:Ox}
1009                STATIC_RANDOM_LIST:=    ${LIST:Ox}
1010
1011                all:
1012                        @echo "${RANDOM_LIST}"
1013                        @echo "${RANDOM_LIST}"
1014                        @echo "${STATIC_RANDOM_LIST}"
1015                        @echo "${STATIC_RANDOM_LIST}"
1016          may produce output similar to:
1017
1018                quattro due tre uno
1019                tre due quattro uno
1020                due uno quattro tre
1021                due uno quattro tre
1022
1023     ::QQ   Quotes every shell meta-character in the value, so that it can be
1024          passed safely to the shell.
1025
1026     ::qq   Quotes every shell meta-character in the value, and also doubles `$'
1027          characters so that it can be passed safely through recursive
1028          invocations of bbmmaakkee.  This is equivalent to `::SS//\\$$//&&&&//gg::QQ'.
1029
1030     ::RR   Replaces each word with everything but its suffix.
1031
1032     ::rraannggee[==_c_o_u_n_t]
1033          The value is an integer sequence representing the words of the
1034          original value, or the supplied _c_o_u_n_t.
1035
1036     ::ggmmttiimmee[==_t_i_m_e_s_t_a_m_p]
1037          The value is interpreted as a format string for strftime(3), using
1038          gmtime(3), producing the formatted timestamp.  Note: the `%s' format
1039          should only be used with `::llooccaallttiimmee'.  If a _t_i_m_e_s_t_a_m_p value is not
1040          provided or is 0, the current time is used.
1041
1042     ::hhaasshh
1043          Computes a 32-bit hash of the value and encodes it as 8 hex digits.
1044
1045     ::llooccaallttiimmee[==_t_i_m_e_s_t_a_m_p]
1046          The value is interpreted as a format string for strftime(3), using
1047          localtime(3), producing the formatted timestamp.  If a _t_i_m_e_s_t_a_m_p
1048          value is not provided or is 0, the current time is used.
1049
1050     ::mmttiimmee[==_t_i_m_e_s_t_a_m_p]
1051          Call stat(2) with each word as pathname; use `st_mtime' as the new
1052          value.  If stat(2) fails; use _t_i_m_e_s_t_a_m_p or current time.  If
1053          _t_i_m_e_s_t_a_m_p is set to `error', then stat(2) failure will cause an
1054          error.
1055
1056     ::ttAA  Attempts to convert the value to an absolute path using realpath(3).
1057          If that fails, the value is unchanged.
1058
1059     ::ttll  Converts the value to lower-case letters.
1060
1061     ::ttss_c
1062          When joining the words after a modifier that treats the value as
1063          words, the words are normally separated by a space.  This modifier
1064          changes the separator to the character _c.  If _c is omitted, no
1065          separator is used.  The common escapes (including octal numeric
1066          codes) work as expected.
1067
1068     ::tttt  Converts the first character of each word to upper-case, and the
1069          rest to lower-case letters.
1070
1071     ::ttuu  Converts the value to upper-case letters.
1072
1073     ::ttWW  Causes subsequent modifiers to treat the value as a single word
1074          (possibly containing embedded whitespace).  See also `::[[**]]'.
1075
1076     ::ttww  Causes the value to be treated as a list of words.  See also `::[[@@]]'.
1077
1078     ::SS/[^^]_o_l_d___s_t_r_i_n_g[$$]/_n_e_w___s_t_r_i_n_g/[11ggWW]
1079          Modifies the first occurrence of _o_l_d___s_t_r_i_n_g in each word of the
1080          value, replacing it with _n_e_w___s_t_r_i_n_g.
1081
1082          If _o_l_d___s_t_r_i_n_g is preceded by a caret (`^'), _o_l_d___s_t_r_i_n_g is anchored
1083          at the beginning of each word.  If _o_l_d___s_t_r_i_n_g is followed by a
1084          dollar sign (`$'), it is anchored at the end of each word.  Inside
1085          _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by _o_l_d___s_t_r_i_n_g.  Both
1086          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g may contain nested expressions.
1087
1088          Further options:
1089
1090          11       Only the word of the first occurrence is affected.
1091
1092          gg       All occurrences in each affected word are replaced.
1093
1094          WW       The expression value is treated as a single word.
1095
1096          Any character may be used as the delimiter for the parts of the
1097          modifier string.  The anchoring, ampersand, dollar and delimiter
1098          characters can be escaped with a backslash (`\').
1099
1100     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
1101          Modifies the first occurrence of the extended regular expression
1102          _p_a_t_t_e_r_n (see regex(3)) in each word of the value, replacing it with
1103          an ed(1)-style _r_e_p_l_a_c_e_m_e_n_t.
1104
1105          Both _p_a_t_t_e_r_n and _r_e_p_l_a_c_e_m_e_n_t may contain nested expressions.
1106
1107          Further options:
1108
1109          11       Only the word of the first occurrence is affected.
1110
1111          gg       All occurrences in each affected word are replaced.
1112
1113          WW       The expression value is treated as a single word.
1114
1115          Any character may be used as the delimiter for the parts of the
1116          modifier string.  The anchoring, ampersand, dollar and delimiter
1117          characters can be escaped with a backslash (`\').
1118
1119     ::TT   Replaces each word with its last path component (basename).
1120
1121     ::uu   Removes adjacent duplicate words (like uniq(1)).
1122
1123     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
1124          If the variable name (not its value), when parsed as a ..iiff
1125          conditional expression, evaluates to true, return as its value the
1126          _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
1127          name is used as the expression, :? must be the first modifier after
1128          the variable name itself--which, of course, usually contains
1129          variable expansions.  A common error is trying to use expressions
1130          like
1131                ${NUMBERS:M42:?match:no}
1132          which actually tests defined(NUMBERS).  To determine if any words
1133          match "42", you need to use something like:
1134                ${"${NUMBERS:M42}" != "":?match:no}.
1135
1136     ::_o_l_d___s_t_r_i_n_g==_n_e_w___s_t_r_i_n_g
1137          This is the AT&T System V UNIX style substitution.  It can only be
1138          the last modifier specified, as a `:' in either _o_l_d___s_t_r_i_n_g or
1139          _n_e_w___s_t_r_i_n_g is treated as a regular character, not as the end of the
1140          modifier.
1141
1142          If _o_l_d___s_t_r_i_n_g does not contain the pattern matching character `%',
1143          and the word ends with _o_l_d___s_t_r_i_n_g or equals it, that suffix is
1144          replaced with _n_e_w___s_t_r_i_n_g.
1145
1146          Otherwise, the first `%' in _o_l_d___s_t_r_i_n_g matches a possibly empty
1147          substring of arbitrary characters, and if the whole pattern is found
1148          in the word, the matching part is replaced with _n_e_w___s_t_r_i_n_g, and the
1149          first occurrence of `%' in _n_e_w___s_t_r_i_n_g (if any) is replaced with the
1150          substring matched by the `%'.
1151
1152          Both _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g may contain nested expressions.  To
1153          prevent a dollar sign from starting a nested expression, escape it
1154          with a backslash.
1155
1156     ::@@_v_a_r_n_a_m_e@@_s_t_r_i_n_g@@
1157          This is the loop expansion mechanism from the OSF Development
1158          Environment (ODE) make.  Unlike ..ffoorr loops, expansion occurs at the
1159          time of reference.  For each word in the value, assign the word to
1160          the variable named _v_a_r_n_a_m_e and evaluate _s_t_r_i_n_g.  The ODE convention
1161          is that _v_a_r_n_a_m_e should start and end with a period, for example:
1162                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1163
1164          However, a single-letter variable is often more readable:
1165                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1166
1167     ::__[==_v_a_r]
1168          Saves the current variable value in `$_' or the named _v_a_r for later
1169          reference.  Example usage:
1170
1171                M_cmpv.units = 1 1000 1000000
1172                M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \
1173                \* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1174
1175                .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1176
1177          Here `$_' is used to save the result of the `:S' modifier which is
1178          later referenced using the index values from `:range'.
1179
1180     ::UU_n_e_w_v_a_l
1181          If the variable is undefined, the optional _n_e_w_v_a_l (which may be
1182          empty) is the value.  If the variable is defined, the existing value
1183          is returned.  This is another ODE make feature.  It is handy for
1184          setting per-target CFLAGS for instance:
1185                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1186          If a value is only required if the variable is undefined, use:
1187                ${VAR:D:Unewval}
1188
1189     ::DD_n_e_w_v_a_l
1190          If the variable is defined, _n_e_w_v_a_l (which may be empty) is the
1191          value.
1192
1193     ::LL   The name of the variable is the value.
1194
1195     ::PP   The path of the node which has the same name as the variable is the
1196          value.  If no such node exists or its path is null, the name of the
1197          variable is used.  In order for this modifier to work, the name
1198          (node) must at least have appeared on the right-hand side of a
1199          dependency.
1200
1201     ::!!_c_m_d!!
1202          The output of running _c_m_d is the value.
1203
1204     ::sshh  The value is run as a command, and the output becomes the new value.
1205
1206     ::sshh11
1207          The value is run as a command, for the first reference only, and the
1208          output is cached for subsequent references.  This modifier is useful
1209          when the result is not expected to change.
1210
1211     ::::==_s_t_r
1212          The variable is assigned the value _s_t_r after substitution.  This
1213          modifier and its variations are useful in obscure situations such as
1214          wanting to set a variable at a point where a target's shell commands
1215          are being parsed.  These assignment modifiers always expand to
1216          nothing.
1217
1218          The `::::' helps avoid false matches with the AT&T System V UNIX style
1219          `:=' modifier and since substitution always occurs, the `::=' form
1220          is vaguely appropriate.
1221
1222     ::::??==_s_t_r
1223          As for ::::== but only if the variable does not already have a value.
1224
1225     ::::++==_s_t_r
1226          Append _s_t_r to the variable.
1227
1228     ::::!!==_c_m_d
1229          Assign the output of _c_m_d to the variable.
1230
1231     ::[[_r_a_n_g_e]]
1232          Selects one or more words from the value, or performs other
1233          operations related to the way in which the value is split into
1234          words.
1235
1236          An empty value, or a value that consists entirely of white-space, is
1237          treated as a single word.  For the purposes of the `::[[]]' modifier,
1238          the words are indexed both forwards using positive integers (where
1239          index 1 represents the first word), and backwards using negative
1240          integers (where index -1 represents the last word).
1241
1242          The _r_a_n_g_e is subjected to variable expansion, and the expanded
1243          result is then interpreted as follows:
1244
1245          _i_n_d_e_x  Selects a single word from the value.
1246
1247          _s_t_a_r_t...._e_n_d
1248                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
1249                 `::[[22....--11]]' selects all words from the second word to the last
1250                 word.  If _s_t_a_r_t is greater than _e_n_d, the words are output in
1251                 reverse order.  For example, `::[[--11....11]]' selects all the words
1252                 from last to first.  If the list is already ordered, this
1253                 effectively reverses the list, but it is more efficient to
1254                 use `::OOrr' instead of `::OO::[[--11....11]]'.
1255
1256          **      Causes subsequent modifiers to treat the value as a single
1257                 word (possibly containing embedded whitespace).  Analogous to
1258                 the effect of $* in Bourne shell.
1259
1260          0      Means the same as `::[[**]]'.
1261
1262          @@      Causes subsequent modifiers to treat the value as a sequence
1263                 of words delimited by whitespace.  Analogous to the effect of
1264                 $@ in Bourne shell.
1265
1266          ##      Returns the number of words in the value.
1267
1268DDIIRREECCTTIIVVEESS
1269     bbmmaakkee offers directives for including makefiles, conditionals and for
1270     loops.  All these directives are identified by a line beginning with a
1271     single dot (`.') character, followed by the keyword of the directive,
1272     such as iinncclluuddee or iiff.
1273
1274   FFiillee iinncclluussiioonn
1275     Files are included with either ..iinncclluuddee <<_f_i_l_e>> or ..iinncclluuddee ""_f_i_l_e"".
1276     Variables between the angle brackets or double quotes are expanded to
1277     form the file name.  If angle brackets are used, the included makefile is
1278     expected to be in the system makefile directory.  If double quotes are
1279     used, the including makefile's directory and any directories specified
1280     using the --II option are searched before the system makefile directory.
1281
1282     For compatibility with other make variants, `iinncclluuddee _f_i_l_e ...' (without
1283     leading dot) is also accepted.
1284
1285     If the include statement is written as ..--iinncclluuddee or as ..ssiinncclluuddee, errors
1286     locating and/or opening include files are ignored.
1287
1288     If the include statement is written as ..ddiinncclluuddee, not only are errors
1289     locating and/or opening include files ignored, but stale dependencies
1290     within the included file are ignored just like in _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E.
1291
1292   EExxppoorrttiinngg vvaarriiaabblleess
1293     The directives for exporting and unexporting variables are:
1294
1295     ..eexxppoorrtt _v_a_r_i_a_b_l_e ...
1296             Export the specified global variable.
1297
1298             For compatibility with other make programs, eexxppoorrtt _v_a_r_i_a_b_l_e==_v_a_l_u_e
1299             (without leading dot) is also accepted.
1300
1301             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
1302             exporting a variable.
1303
1304     ..eexxppoorrtt--aallll
1305             Export all globals except for internal variables (those that
1306             start with `.').  This is not affected by the --XX flag, so should
1307             be used with caution.
1308
1309     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e ...
1310             The same as `.export', except that the variable is not appended
1311             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the
1312             environment which is different from that used by bbmmaakkee
1313             internally.
1314
1315     ..eexxppoorrtt--lliitteerraall _v_a_r_i_a_b_l_e ...
1316             The same as `.export-env', except that variables in the value are
1317             not expanded.
1318
1319     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e ...
1320             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e is
1321             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
1322             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
1323
1324     ..uunneexxppoorrtt--eennvv
1325             Unexport all globals previously exported and clear the
1326             environment inherited from the parent.  This operation causes a
1327             memory leak of the original environment, so should be used
1328             sparingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0 would make sense.
1329             Also note that any variables which originated in the parent
1330             environment should be explicitly preserved if desired.  For
1331             example:
1332
1333                   .if ${.MAKE.LEVEL} == 0
1334                   PATH := ${PATH}
1335                   .unexport-env
1336                   .export PATH
1337                   .endif
1338
1339             Would result in an environment containing only `PATH', which is
1340             the minimal useful environment.  Actually `_._M_A_K_E_._L_E_V_E_L' is also
1341             pushed into the new environment.
1342
1343   MMeessssaaggeess
1344     The directives for printing messages to the output are:
1345
1346     ..iinnffoo _m_e_s_s_a_g_e
1347             The message is printed along with the name of the makefile and
1348             line number.
1349
1350     ..wwaarrnniinngg _m_e_s_s_a_g_e
1351             The message prefixed by `warning:' is printed along with the name
1352             of the makefile and line number.
1353
1354     ..eerrrroorr _m_e_s_s_a_g_e
1355             The message is printed along with the name of the makefile and
1356             line number, bbmmaakkee exits immediately.
1357
1358   CCoonnddiittiioonnaallss
1359     The directives for conditionals are:
1360
1361     ..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 ...]
1362             Test the value of an expression.
1363
1364     ..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 ...]
1365             Test whether a variable is defined.
1366
1367     ..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 ...]
1368             Test whether a variable is not defined.
1369
1370     ..iiffmmaakkee [!!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t ...]
1371             Test the target being requested.
1372
1373     ..iiffnnmmaakkee [!!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t ...]
1374             Test the target being requested.
1375
1376     ..eellssee   Reverse the sense of the last conditional.
1377
1378     ..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 ...]
1379             A combination of `..eellssee' followed by `..iiff'.
1380
1381     ..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 ...]
1382             A combination of `..eellssee' followed by `..iiffddeeff'.
1383
1384     ..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 ...]
1385             A combination of `..eellssee' followed by `..iiffnnddeeff'.
1386
1387     ..eelliiffmmaakkee [!!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t ...]
1388             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1389
1390     ..eelliiffnnmmaakkee [!!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t ...]
1391             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1392
1393     ..eennddiiff  End the body of the conditional.
1394
1395     The _o_p_e_r_a_t_o_r may be any one of the following:
1396
1397     ||||      Logical OR.
1398
1399     &&&&      Logical AND; of higher precedence than `||||'.
1400
1401     bbmmaakkee only evaluates a conditional as far as is necessary to determine
1402     its value.  Parentheses can be used to override the operator precedence.
1403     The boolean operator `!!' may be used to logically negate an expression,
1404     typically a function call.  It is of higher precedence than `&&&&'.
1405
1406     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following function call
1407     expressions:
1408
1409     ddeeffiinneedd(_v_a_r_n_a_m_e)
1410             Evaluates to true if the variable _v_a_r_n_a_m_e has been defined.
1411
1412     mmaakkee(_t_a_r_g_e_t)
1413             Evaluates to true if the target was specified as part of bbmmaakkee's
1414             command line or was declared the default target (either
1415             implicitly or explicitly, see _._M_A_I_N) before the line containing
1416             the conditional.
1417
1418     eemmppttyy(_v_a_r_n_a_m_e[:_m_o_d_i_f_i_e_r_s])
1419             Evaluates to true if the expansion of the variable, after
1420             applying the modifiers, results in an empty string.
1421
1422     eexxiissttss(_p_a_t_h_n_a_m_e)
1423             Evaluates to true if the given pathname exists.  If relative, the
1424             pathname is searched for on the system search path (see _._P_A_T_H).
1425
1426     ttaarrggeett(_t_a_r_g_e_t)
1427             Evaluates to true if the target has been defined.
1428
1429     ccoommmmaannddss(_t_a_r_g_e_t)
1430             Evaluates to true if the target has been defined and has commands
1431             associated with it.
1432
1433     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1434     expansion is performed on both sides of the comparison.  If both sides
1435     are numeric and neither is enclosed in quotes, the comparison is done
1436     numerically, otherwise lexicographically.  A string is interpreted as a
1437     hexadecimal integer if it is preceded by 0x, otherwise it is interpreted
1438     as a decimal floating-point number; octal numbers are not supported.
1439
1440     All comparisons may use the operators `====' and `!!=='.  Numeric comparisons
1441     may also use the operators `<<', `<<==', `>>' and `>>=='.
1442
1443     If the comparison has neither a comparison operator nor a right side, the
1444     expression evaluates to true if it is nonempty and its numeric value (if
1445     any) is not zero.
1446
1447     When bbmmaakkee is evaluating one of these conditional expressions, and it
1448     encounters a (whitespace-separated) word it doesn't recognize, either the
1449     "make" or "defined" function is applied to it, depending on the form of
1450     the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff' or `..iiff', the
1451     "defined" function is applied.  Similarly, if the form is `..iiffmmaakkee' or
1452     `..iiffnnmmaakkee', the "make" function is applied.
1453
1454     If the conditional evaluates to true, parsing of the makefile continues
1455     as before.  If it evaluates to false, the following lines until the
1456     corresponding `..eelliiff' variant, `..eellssee' or `..eennddiiff' are skipped.
1457
1458   FFoorr llooooppss
1459     For loops are typically used to apply a set of rules to a list of files.
1460     The syntax of a for loop is:
1461
1462     ..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
1463     <_m_a_k_e_-_l_i_n_e_s>
1464     ..eennddffoorr
1465
1466     The _e_x_p_r_e_s_s_i_o_n is expanded and then split into words.  On each iteration
1467     of the loop, one word is taken and assigned to each _v_a_r_i_a_b_l_e, in order,
1468     and these _v_a_r_i_a_b_l_e_s are substituted into the _m_a_k_e_-_l_i_n_e_s inside the body
1469     of the for loop.  The number of words must come out even; that is, if
1470     there are three iteration variables, the number of words provided must be
1471     a multiple of three.
1472
1473     If `..bbrreeaakk' is encountered within a ..ffoorr loop, it causes early
1474     termination of the loop, otherwise a parse error.
1475
1476   OOtthheerr ddiirreeccttiivveess
1477     ..uunnddeeff _v_a_r_i_a_b_l_e ...
1478             Un-define the specified global variables.  Only global variables
1479             can be un-defined.
1480
1481CCOOMMMMEENNTTSS
1482     Comments begin with a hash (`#') character, anywhere but in a shell
1483     command line, and continue to the end of an unescaped new line.
1484
1485SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1486     ..EEXXEECC     Target is never out of date, but always execute commands
1487               anyway.
1488
1489     ..IIGGNNOORREE   Ignore any errors from the commands associated with this
1490               target, exactly as if they all were preceded by a dash (`-').
1491
1492     ..MMAADDEE     Mark all sources of this target as being up to date.
1493
1494     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1495               or --tt options were specified.  Normally used to mark recursive
1496               bbmmaakkees.
1497
1498     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1499               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1500               the most likely case.  In "meta" mode, the target is out-of-
1501               date if the meta file is missing.
1502
1503     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1504               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1505
1506     ..NNOOMMEETTAA__CCMMPP
1507               Ignore differences in commands when deciding if target is out
1508               of date.  This is useful if the command contains a value which
1509               always changes.  If the number of commands change, though, the
1510               target is still considered out of date.  The same effect
1511               applies to any command line that uses the variable _._O_O_D_A_T_E,
1512               which can be used for that purpose even when not otherwise
1513               needed or desired:
1514
1515
1516                     skip-compare-for-some:
1517                             @echo this is compared
1518                             @echo this is not ${.OODATE:M.NOMETA_CMP}
1519                             @echo this is also compared
1520
1521               The ::MM pattern suppresses any expansion of the unwanted
1522               variable.
1523
1524     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1525               _._P_A_T_H.
1526
1527     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1528               default target to be built if no target was specified.  This
1529               source prevents this target from being selected.
1530
1531     ..OOPPTTIIOONNAALL
1532               If a target is marked with this attribute and bbmmaakkee can't
1533               figure out how to create it, it ignores this fact and assumes
1534               the file isn't needed or already exists.
1535
1536     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1537               considered to be out of date, and is not created with the --tt
1538               option.  Suffix-transformation rules are not applied to ..PPHHOONNYY
1539               targets.
1540
1541     ..PPRREECCIIOOUUSS
1542               When bbmmaakkee is interrupted, it normally removes any partially
1543               made targets.  This source prevents the target from being
1544               removed.
1545
1546     ..RREECCUURRSSIIVVEE
1547               Synonym for ..MMAAKKEE.
1548
1549     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1550               exactly as if they all were preceded by an at sign (`@').
1551
1552     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the
1553               target is used as a source for another target, the other target
1554               acquires the commands, sources, and attributes (except for
1555               ..UUSSEE) of the source.  If the target already has commands, the
1556               ..UUSSEE target's commands are appended to them.
1557
1558     ..UUSSEEBBEEFFOORREE
1559               Like ..UUSSEE, but instead of appending, prepend the ..UUSSEEBBEEFFOORREE
1560               target commands to the target.
1561
1562     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1563               it are made before the sources that succeed it in the line.
1564               Since the dependents of files are not made until the file
1565               itself could be made, this also stops the dependents being
1566               built unless they are needed for another branch of the
1567               dependency tree.  So given:
1568
1569               x: a .WAIT b
1570                       echo x
1571               a:
1572                       echo a
1573               b: b1
1574                       echo b
1575               b1:
1576                       echo b1
1577
1578               the output is always `a', `b1', `b', `x'.
1579
1580               The ordering imposed by ..WWAAIITT is only relevant for parallel
1581               makes.
1582
1583SSPPEECCIIAALL TTAARRGGEETTSS
1584     Special targets may not be included with other targets, i.e. they must be
1585     the only target specified.
1586
1587     ..BBEEGGIINN   Any command lines attached to this target are executed before
1588              anything else is done.
1589
1590     ..DDEEFFAAUULLTT
1591              This is sort of a ..UUSSEE rule for any target (that was used only
1592              as a source) that bbmmaakkee can't figure out any other way to
1593              create.  Only the shell script is used.  The _._I_M_P_S_R_C variable of
1594              a target that inherits ..DDEEFFAAUULLTT's commands is set to the
1595              target's own name.
1596
1597     ..DDEELLEETTEE__OONN__EERRRROORR
1598              If this target is present in the makefile, it globally causes
1599              make to delete targets whose commands fail.  (By default, only
1600              targets whose commands are interrupted during execution are
1601              deleted.  This is the historical behavior.)  This setting can be
1602              used to help prevent half-finished or malformed targets from
1603              being left around and corrupting future rebuilds.
1604
1605     ..EENNDD     Any command lines attached to this target are executed after
1606              everything else is done successfully.
1607
1608     ..EERRRROORR   Any command lines attached to this target are executed when
1609              another target fails.  See _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R for the
1610              variables that will be set.
1611
1612     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1613              sources are specified, this is the equivalent of specifying the
1614              --ii option.
1615
1616     ..IINNTTEERRRRUUPPTT
1617              If bbmmaakkee is interrupted, the commands for this target are
1618              executed.
1619
1620     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target is
1621              built.
1622
1623     ..MMAAKKEEFFLLAAGGSS
1624              This target provides a way to specify flags for bbmmaakkee at the
1625              time when the makefiles are read.  The flags are as if typed to
1626              the shell, though the --ff option has no effect.
1627
1628     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1629
1630     ..NNOOTTPPAARRAALLLLEELL
1631              Disable parallel mode.
1632
1633     ..NNOO__PPAARRAALLLLEELL
1634              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1635              variants.
1636
1637     ..NNOORREEAADDOONNLLYY
1638              clear the read-only attribute from the global variables
1639              specified as sources.
1640
1641     ..OOBBJJDDIIRR  The source is a new value for `_._O_B_J_D_I_R'.  If it exists, bbmmaakkee
1642              changes the current working directory to it and updates the
1643              value of `_._O_B_J_D_I_R'.
1644
1645     ..OORRDDEERR   In parallel mode, the named targets are made in sequence.  This
1646              ordering does not add targets to the list of targets to be made.
1647
1648              Since the dependents of a target do not get built until the
1649              target itself could be built, unless `a' is built by another
1650              part of the dependency graph, the following is a dependency
1651              loop:
1652
1653              .ORDER: b a
1654              b: a
1655
1656     ..PPAATTHH    The sources are directories which are to be searched for files
1657              not found in the current directory.  If no sources are
1658              specified, any previously specified directories are removed from
1659              the search path.  If the source is the special ..DDOOTTLLAASSTT target,
1660              the current working directory is searched last.
1661
1662     ..PPAATTHH.._s_u_f_f_i_x
1663              Like ..PPAATTHH but applies only to files with a particular suffix.
1664              The suffix must have been previously declared with ..SSUUFFFFIIXXEESS.
1665
1666     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1667
1668     ..PPOOSSIIXX   If this is the first non-comment line in the main makefile, the
1669              variable _%_P_O_S_I_X is set to the value `1003.2' and the makefile
1670              `<posix.mk>' is included if it exists, to provide POSIX-
1671              compatible default rules.  If bbmmaakkee is run with the --rr flag,
1672              only `posix.mk' contributes to the default rules.  In POSIX-
1673              compatible mode, the AT&T System V UNIX style substitution
1674              modifier is checked first rather than as a fallback.
1675
1676     ..PPRREECCIIOOUUSS
1677              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1678              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1679              every target in the file.
1680
1681     ..RREEAADDOONNLLYY
1682              set the read-only attribute on the global variables specified as
1683              sources.
1684
1685     ..SSHHEELLLL   Sets the shell that bbmmaakkee uses to execute commands.  The sources
1686              are a set of _f_i_e_l_d==_v_a_l_u_e pairs.
1687
1688              name        This is the minimal specification, used to select
1689                          one of the built-in shell specs; sh, ksh, and csh.
1690
1691              path        Specifies the absolute path to the shell.
1692
1693              hasErrCtl   Indicates whether the shell supports exit on error.
1694
1695              check       The command to turn on error checking.
1696
1697              ignore      The command to disable error checking.
1698
1699              echo        The command to turn on echoing of commands executed.
1700
1701              quiet       The command to turn off echoing of commands
1702                          executed.
1703
1704              filter      The output to filter after issuing the quiet
1705                          command.  It is typically identical to quiet.
1706
1707              errFlag     The flag to pass the shell to enable error checking.
1708
1709              echoFlag    The flag to pass the shell to enable command
1710                          echoing.
1711
1712              newline     The string literal to pass the shell that results in
1713                          a single newline character when used outside of any
1714                          quoting characters.
1715              Example:
1716
1717              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1718                      check="set -e" ignore="set +e" \
1719                      echo="set -v" quiet="set +v" filter="set +v" \
1720                      echoFlag=v errFlag=e newline="'\n'"
1721
1722     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1723              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1724              command in the file.
1725
1726     ..SSTTAALLEE   This target gets run when a dependency file contains stale
1727              entries, having _._A_L_L_S_R_C set to the name of that dependency file.
1728
1729     ..SSUUFFFFIIXXEESS
1730              Each source specifies a suffix to bbmmaakkee.  If no sources are
1731              specified, any previously specified suffixes are deleted.  It
1732              allows the creation of suffix-transformation rules.
1733
1734              Example:
1735
1736              .SUFFIXES: .c .o
1737              .c.o:
1738                      cc -o ${.TARGET} -c ${.IMPSRC}
1739
1740     ..SSYYSSPPAATTHH
1741              The sources are directories which are to be added to the system
1742              include path which bbmmaakkee searches for makefiles.  If no sources
1743              are specified, any previously specified directories are removed
1744              from the system include path.
1745
1746EENNVVIIRROONNMMEENNTT
1747     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1748     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1749     MAKE_STACK_TRACE, PWD, and TMPDIR.
1750
1751     MAKEOBJDIRPREFIX and MAKEOBJDIR should be set in the environment or on
1752     the command line to bbmmaakkee and not as makefile variables; see the
1753     description of `_._O_B_J_D_I_R' for more details.  It is possible to set these
1754     via makefile variables but unless done very early and the `..OOBBJJDDIIRR'
1755     target is used to reset `_._O_B_J_D_I_R', there may be unexpected side effects.
1756
1757     If the MAKE_STACK_TRACE environment variable is set to "yes", any stack
1758     traces include the call chain of the parent processes.
1759
1760FFIILLEESS
1761     .depend        list of dependencies
1762     makefile       first default makefile if no makefile is specified on the
1763                    command line
1764     Makefile       second default makefile if no makefile is specified on the
1765                    command line
1766     sys.mk         system makefile
1767     /usr/share/mk  system makefile directory
1768
1769DDIIAAGGNNOOSSTTIICCSS
1770     Invalid internal option "-J" in "_d_i_r_e_c_t_o_r_y"
1771             The internal --JJ option coordinates the main bbmmaakkee process with
1772             the sub-make processes to limit the number of jobs that run in
1773             parallel.  The option is passed to all child processes via the
1774             MAKEFLAGS environment variable.  To become valid, this option
1775             requires that the target running the sub-make is marked with the
1776             .MAKE special source, or that one of the target's commands
1777             directly contains the word "make" or one of the expressions
1778             "${MAKE}", "${.MAKE}", "$(MAKE)", "$(.MAKE)".  If that's not the
1779             case, make issues the above warning and falls back to compat
1780             mode.
1781
1782             To see the chain of sub-makes that leads to the invalid option,
1783             set the MAKE_STACK_TRACE environment variable to "yes".
1784
1785             To run the sub-make in parallel mode, even in dry-run mode (see
1786             the --nn option), add the .MAKE pseudo source to the target.  This
1787             is appropriate when the sub-make runs the same target in a
1788             subdirectory.
1789
1790             To run the sub-make in parallel mode but not in dry-mode, add a
1791             "${:D make}" marker to one of the target's commands.  This marker
1792             expands to an empty string and thus does not affect the executed
1793             commands.
1794
1795             To run the sub-make in compat mode, add the --BB option to its
1796             invocation.  This is appropriate when the sub-make is only used
1797             to print a variable's value using the --vv or --VV options.
1798
1799             To make the sub-make independent from the parent make, unset the
1800             MAKEFLAGS environment variable in the target's commands.
1801
1802CCOOMMPPAATTIIBBIILLIITTYY
1803     The basic make syntax is compatible between different make variants;
1804     however the special variables, variable modifiers and conditionals are
1805     not.
1806
1807   OOllddeerr vveerrssiioonnss
1808     An incomplete list of changes in older versions of bbmmaakkee:
1809
1810     The way that .for loop variables are substituted changed after NetBSD 5.0
1811     so that they still appear to be variable expansions.  In particular this
1812     stops them being treated as syntax, and removes some obscure problems
1813     using them in .if statements.
1814
1815     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1816     .ORDER and .WAIT apply recursively to the dependent nodes.  The
1817     algorithms used may change again in the future.
1818
1819   OOtthheerr mmaakkee ddiiaalleeccttss
1820     Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not
1821     support most of the features of bbmmaakkee as described in this manual.  Most
1822     notably:
1823
1824           ++oo   The ..WWAAIITT and ..OORRDDEERR declarations and most functionality
1825               pertaining to parallelization.  (GNU make supports
1826               parallelization but lacks the features needed to control it
1827               effectively.)
1828
1829           ++oo   Directives, including for loops and conditionals and most of
1830               the forms of include files.  (GNU make has its own incompatible
1831               and less powerful syntax for conditionals.)
1832
1833           ++oo   All built-in variables that begin with a dot.
1834
1835           ++oo   Most of the special sources and targets that begin with a dot,
1836               with the notable exception of ..PPHHOONNYY, ..PPRREECCIIOOUUSS, and ..SSUUFFFFIIXXEESS.
1837
1838           ++oo   Variable modifiers, except for the `:old=new' string
1839               substitution, which does not portably support globbing with `%'
1840               and historically only works on declared suffixes.
1841
1842           ++oo   The $$>> variable even in its short form; most makes support this
1843               functionality but its name varies.
1844
1845     Some features are somewhat more portable, such as assignment with ++==, ??==,
1846     and !!==.  The _._P_A_T_H functionality is based on an older feature VVPPAATTHH found
1847     in GNU make and many versions of SVR4 make; however, historically its
1848     behavior is too ill-defined (and too buggy) to rely upon.
1849
1850     The $$@@ and $$<< variables are more or less universally portable, as is the
1851     $$((MMAAKKEE)) variable.  Basic use of suffix rules (for files only in the
1852     current directory, not trying to chain transformations together, etc.) is
1853     also reasonably portable.
1854
1855SSEEEE AALLSSOO
1856     mkdep(1)
1857
1858HHIISSTTOORRYY
1859     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1860     portability to other platforms.
1861
1862     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1863     is based on Adam de Boor's pmake program, which was written for Sprite at
1864     Berkeley.  It was designed to be a parallel distributed make running jobs
1865     on different machines using a daemon called "customs".
1866
1867     Historically the target/dependency FFRRCC has been used to FoRCe rebuilding
1868     (since the target/dependency does not exist ... unless someone creates an
1869     _F_R_C file).
1870
1871BBUUGGSS
1872     The bbmmaakkee syntax is difficult to parse.  For instance, finding the end of
1873     a variable's use should involve scanning each of the modifiers, using the
1874     correct terminator for each field.  In many places bbmmaakkee just counts {}
1875     and () in order to find the end of a variable expansion.
1876
1877     There is no way of escaping a space character in a filename.
1878
1879     In jobs mode, when a target fails; bbmmaakkee will put an error token into the
1880     job token pool.  This will cause all other instances of bbmmaakkee using that
1881     token pool to abort the build and exit with error code 6.  Sometimes the
1882     attempt to suppress a cascade of unnecessary errors, can result in a
1883     seemingly unexplained `*** Error code 6'
1884
1885FreeBSD 14.3-RELEASE-p9           May 8, 2026          FreeBSD 14.3-RELEASE-p9
1886