xref: /freebsd/contrib/bmake/bmake.cat1 (revision b740c88bfb6453416926271c089262e7164dace3)
1MAKE(1)                 NetBSD General Commands Manual                 MAKE(1)
2
3NNAAMMEE
4     bbmmaakkee -- maintain program dependencies
5
6SSYYNNOOPPSSIISS
7     bbmmaakkee [--BBeeiikkNNnnqqrrssttWWwwXX] [--CC _d_i_r_e_c_t_o_r_y] [--DD _v_a_r_i_a_b_l_e] [--dd _f_l_a_g_s]
8           [--ff _m_a_k_e_f_i_l_e] [--II _d_i_r_e_c_t_o_r_y] [--JJ _p_r_i_v_a_t_e] [--jj _m_a_x___j_o_b_s]
9           [--mm _d_i_r_e_c_t_o_r_y] [--TT _f_i_l_e] [--VV _v_a_r_i_a_b_l_e] [_v_a_r_i_a_b_l_e_=_v_a_l_u_e]
10           [_t_a_r_g_e_t _._._.]
11
12DDEESSCCRRIIPPTTIIOONN
13     bbmmaakkee is a program designed to simplify the maintenance of other pro-
14     grams.  Its input is a list of specifications as to the files upon which
15     programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e makefile option is
16     given, bbmmaakkee will try to open `_m_a_k_e_f_i_l_e' then `_M_a_k_e_f_i_l_e' in order to find
17     the specifications.  If the file `_._d_e_p_e_n_d' exists, it is read (see
18     mkdep(1)).
19
20     This manual page is intended as a reference document only.  For a more
21     thorough description of bbmmaakkee and makefiles, please refer to _P_M_a_k_e _- _A
22     _T_u_t_o_r_i_a_l.
23
24     bbmmaakkee will prepend the contents of the _M_A_K_E_F_L_A_G_S environment variable to
25     the command line arguments before parsing them.
26
27     The options are as follows:
28
29     --BB      Try to be backwards compatible by executing a single shell per
30             command and by executing the commands to make the sources of a
31             dependency line in sequence.
32
33     --CC _d_i_r_e_c_t_o_r_y
34             Change to _d_i_r_e_c_t_o_r_y before reading the makefiles or doing any-
35             thing else.  If multiple --CC options are specified, each is inter-
36             preted relative to the previous one: --CC _/ --CC _e_t_c is equivalent to
37             --CC _/_e_t_c.
38
39     --DD _v_a_r_i_a_b_l_e
40             Define _v_a_r_i_a_b_l_e to be 1, in the global context.
41
42     --dd _[_-_]_f_l_a_g_s
43             Turn on debugging, and specify which portions of bbmmaakkee are to
44             print debugging information.  Unless the flags are preceded by
45             `-' they are added to the _M_A_K_E_F_L_A_G_S environment variable and will
46             be processed by any child make processes.  By default, debugging
47             information is printed to standard error, but this can be changed
48             using the _F debugging flag.  The debugging output is always
49             unbuffered; in addition, if debugging is enabled but debugging
50             output is not directed to standard output, then the standard out-
51             put is line buffered.  _F_l_a_g_s is one or more of the following:
52
53             _A       Print all possible debugging information; equivalent to
54                     specifying all of the debugging flags.
55
56             _a       Print debugging information about archive searching and
57                     caching.
58
59             _C       Print debugging information about current working direc-
60                     tory.
61
62             _c       Print debugging information about conditional evaluation.
63
64             _d       Print debugging information about directory searching and
65                     caching.
66
67             _e       Print debugging information about failed commands and
68                     targets.
69
70             _F[++]_f_i_l_e_n_a_m_e
71                     Specify where debugging output is written.  This must be
72                     the last flag, because it consumes the remainder of the
73                     argument.  If the character immediately after the `F'
74                     flag is `+', then the file will be opened in append mode;
75                     otherwise the file will be overwritten.  If the file name
76                     is `stdout' or `stderr' then debugging output will be
77                     written to the standard output or standard error output
78                     file descriptors respectively (and the `+' option has no
79                     effect).  Otherwise, the output will be written to the
80                     named file.  If the file name ends `.%d' then the `%d' is
81                     replaced by the pid.
82
83             _f       Print debugging information about loop evaluation.
84
85             _g_1      Print the input graph before making anything.
86
87             _g_2      Print the input graph after making everything, or before
88                     exiting on error.
89
90             _g_3      Print the input graph before exiting on error.
91
92             _j       Print debugging information about running multiple
93                     shells.
94
95             _l       Print commands in Makefiles regardless of whether or not
96                     they are prefixed by `@' or other "quiet" flags.  Also
97                     known as "loud" behavior.
98
99             _M       Print debugging information about "meta" mode decisions
100                     about targets.
101
102             _m       Print debugging information about making targets, includ-
103                     ing modification dates.
104
105             _n       Don't delete the temporary command scripts created when
106                     running commands.  These temporary scripts are created in
107                     the directory referred to by the TMPDIR environment vari-
108                     able, or in _/_t_m_p if TMPDIR is unset or set to the empty
109                     string.  The temporary scripts are created by mkstemp(3),
110                     and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E: This can
111                     create many files in TMPDIR or _/_t_m_p, so use with care.
112
113             _p       Print debugging information about makefile parsing.
114
115             _s       Print debugging information about suffix-transformation
116                     rules.
117
118             _t       Print debugging information about target list mainte-
119                     nance.
120
121             _V       Force the --VV option to print raw values of variables.
122
123             _v       Print debugging information about variable assignment.
124
125             _x       Run shell commands with --xx so the actual commands are
126                     printed as they are executed.
127
128     --ee      Specify that environment variables override macro assignments
129             within makefiles.
130
131     --ff _m_a_k_e_f_i_l_e
132             Specify a makefile to read instead of the default `_m_a_k_e_f_i_l_e'.  If
133             _m_a_k_e_f_i_l_e is `--', standard input is read.  Multiple makefiles may
134             be specified, and are read in the order specified.
135
136     --II _d_i_r_e_c_t_o_r_y
137             Specify a directory in which to search for makefiles and included
138             makefiles.  The system makefile directory (or directories, see
139             the --mm option) is automatically included as part of this list.
140
141     --ii      Ignore non-zero exit of shell commands in the makefile.  Equiva-
142             lent to specifying `--' before each command line in the makefile.
143
144     --JJ _p_r_i_v_a_t_e
145             This option should _n_o_t be specified by the user.
146
147             When the _j option is in use in a recursive build, this option is
148             passed by a make to child makes to allow all the make processes
149             in the build to cooperate to avoid overloading the system.
150
151     --jj _m_a_x___j_o_b_s
152             Specify the maximum number of jobs that bbmmaakkee may have running at
153             any one time.  The value is saved in _._M_A_K_E_._J_O_B_S.  Turns compati-
154             bility mode off, unless the _B flag is also specified.  When com-
155             patibility mode is off, all commands associated with a target are
156             executed in a single shell invocation as opposed to the tradi-
157             tional one shell invocation per line.  This can break traditional
158             scripts which change directories on each command invocation and
159             then expect to start with a fresh environment on the next line.
160             It is more efficient to correct the scripts rather than turn
161             backwards compatibility on.
162
163     --kk      Continue processing after errors are encountered, but only on
164             those targets that do not depend on the target whose creation
165             caused the error.
166
167     --mm _d_i_r_e_c_t_o_r_y
168             Specify a directory in which to search for sys.mk and makefiles
169             included via the <_f_i_l_e>-style include statement.  The --mm option
170             can be used multiple times to form a search path.  This path will
171             override the default system include path: /usr/share/mk.  Fur-
172             thermore the system include path will be appended to the search
173             path used for "_f_i_l_e"-style include statements (see the --II
174             option).
175
176             If a file or directory name in the --mm argument (or the
177             MAKESYSPATH environment variable) starts with the string ".../"
178             then bbmmaakkee will search for the specified file or directory named
179             in the remaining part of the argument string.  The search starts
180             with the current directory of the Makefile and then works upward
181             towards the root of the filesystem.  If the search is successful,
182             then the resulting directory replaces the ".../" specification in
183             the --mm argument.  If used, this feature allows bbmmaakkee to easily
184             search in the current source tree for customized sys.mk files
185             (e.g., by using ".../mk/sys.mk" as an argument).
186
187     --nn      Display the commands that would have been executed, but do not
188             actually execute them unless the target depends on the .MAKE spe-
189             cial source (see below).
190
191     --NN      Display the commands which would have been executed, but do not
192             actually execute any of them; useful for debugging top-level
193             makefiles without descending into subdirectories.
194
195     --qq      Do not execute any commands, but exit 0 if the specified targets
196             are up-to-date and 1, otherwise.
197
198     --rr      Do not use the built-in rules specified in the system makefile.
199
200     --ss      Do not echo any commands as they are executed.  Equivalent to
201             specifying `@@' before each command line in the makefile.
202
203     --TT _t_r_a_c_e_f_i_l_e
204             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
205             for each job started and completed.
206
207     --tt      Rather than re-building a target as specified in the makefile,
208             create it or update its modification time to make it appear up-
209             to-date.
210
211     --VV _v_a_r_i_a_b_l_e
212             Print bbmmaakkee's idea of the value of _v_a_r_i_a_b_l_e, in the global con-
213             text.  Do not build any targets.  Multiple instances of this
214             option may be specified; the variables will be printed one per
215             line, with a blank line for each null or undefined variable.  If
216             _v_a_r_i_a_b_l_e contains a `$' then the value will be expanded before
217             printing.
218
219     --WW      Treat any warnings during makefile parsing as errors.
220
221     --ww      Print entering and leaving directory messages, pre and post pro-
222             cessing.
223
224     --XX      Don't export variables passed on the command line to the environ-
225             ment individually.  Variables passed on the command line are
226             still exported via the _M_A_K_E_F_L_A_G_S environment variable.  This
227             option may be useful on systems which have a small limit on the
228             size of command arguments.
229
230     _v_a_r_i_a_b_l_e_=_v_a_l_u_e
231             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
232             values passed on the command line are also exported to sub-makes
233             in the environment.  The --XX flag disables this behavior.  Vari-
234             able assignments should follow options for POSIX compatibility
235             but no ordering is enforced.
236
237     There are seven different types of lines in a makefile: file dependency
238     specifications, shell commands, variable assignments, include statements,
239     conditional directives, for loops, and comments.
240
241     In general, lines may be continued from one line to the next by ending
242     them with a backslash (`\').  The trailing newline character and initial
243     whitespace on the following line are compressed into a single space.
244
245FFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
246     Dependency lines consist of one or more targets, an operator, and zero or
247     more sources.  This creates a relationship where the targets ``depend''
248     on the sources and are usually created from them.  The exact relationship
249     between the target and the source is determined by the operator that sep-
250     arates them.  The three operators are as follows:
251
252     ::     A target is considered out-of-date if its modification time is less
253           than those of any of its sources.  Sources for a target accumulate
254           over dependency lines when this operator is used.  The target is
255           removed if bbmmaakkee is interrupted.
256
257     !!     Targets are always re-created, but not until all sources have been
258           examined and re-created as necessary.  Sources for a target accumu-
259           late over dependency lines when this operator is used.  The target
260           is removed if bbmmaakkee is interrupted.
261
262     ::::    If no sources are specified, the target is always re-created.  Oth-
263           erwise, a target is considered out-of-date if any of its sources
264           has been modified more recently than the target.  Sources for a
265           target do not accumulate over dependency lines when this operator
266           is used.  The target will not be removed if bbmmaakkee is interrupted.
267
268     Targets and sources may contain the shell wildcard values `?', `*', `[]',
269     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
270     final component of the target or source, and must be used to describe
271     existing files.  The value `{}' need not necessarily be used to describe
272     existing files.  Expansion is in directory order, not alphabetically as
273     done in the shell.
274
275SSHHEELLLL CCOOMMMMAANNDDSS
276     Each target may have associated with it one or more lines of shell com-
277     mands, normally used to create the target.  Each of the lines in this
278     script _m_u_s_t be preceded by a tab.  (For historical reasons, spaces are
279     not accepted.)  While targets can appear in many dependency lines if
280     desired, by default only one of these rules may be followed by a creation
281     script.  If the `::::' operator is used, however, all rules may include
282     scripts and the scripts are executed in the order found.
283
284     Each line is treated as a separate shell command, unless the end of line
285     is escaped with a backslash (`\') in which case that line and the next
286     are combined.  If the first characters of the command are any combination
287     of `@@', `++', or `--', the command is treated specially.  A `@@' causes the
288     command not to be echoed before it is executed.  A `++' causes the command
289     to be executed even when --nn is given.  This is similar to the effect of
290     the .MAKE special source, except that the effect can be limited to a sin-
291     gle line of a script.  A `--' in compatibility mode causes any non-zero
292     exit status of the command line to be ignored.
293
294     When bbmmaakkee is run in jobs mode with --jj _m_a_x___j_o_b_s, the entire script for
295     the target is fed to a single instance of the shell.  In compatibility
296     (non-jobs) mode, each command is run in a separate process.  If the com-
297     mand contains any shell meta characters (`#=|^(){};&<>*?[]:$`\\n') it
298     will be passed to the shell; otherwise bbmmaakkee will attempt direct execu-
299     tion.  If a line starts with `--' and the shell has ErrCtl enabled then
300     failure of the command line will be ignored as in compatibility mode.
301     Otherwise `--' affects the entire job; the script will stop at the first
302     command line that fails, but the target will not be deemed to have
303     failed.
304
305     Makefiles should be written so that the mode of bbmmaakkee operation does not
306     change their behavior.  For example, any command which needs to use
307     ``cd'' or ``chdir'' without potentially changing the directory for subse-
308     quent commands should be put in parentheses so it executes in a subshell.
309     To force the use of one shell, escape the line breaks so as to make the
310     whole script one command.  For example:
311
312           avoid-chdir-side-effects:
313                   @echo Building $@ in `pwd`
314                   @(cd ${.CURDIR} && ${MAKE} $@)
315                   @echo Back in `pwd`
316
317           ensure-one-shell-regardless-of-mode:
318                   @echo Building $@ in `pwd`; \
319                   (cd ${.CURDIR} && ${MAKE} $@); \
320                   echo Back in `pwd`
321
322     Since bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R' before executing any targets, each
323     child process starts with that as its current working directory.
324
325VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
326     Variables in make are much like variables in the shell, and, by tradi-
327     tion, consist of all upper-case letters.
328
329   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
330     The five operators that can be used to assign values to variables are as
331     follows:
332
333     ==       Assign the value to the variable.  Any previous value is overrid-
334             den.
335
336     ++==      Append the value to the current value of the variable.
337
338     ??==      Assign the value to the variable if it is not already defined.
339
340     ::==      Assign with expansion, i.e. expand the value before assigning it
341             to the variable.  Normally, expansion is not done until the vari-
342             able is referenced.  _N_O_T_E: References to undefined variables are
343             _n_o_t expanded.  This can cause problems when variable modifiers
344             are used.
345
346     !!==      Expand the value and pass it to the shell for execution and
347             assign the result to the variable.  Any newlines in the result
348             are replaced with spaces.
349
350     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
351     being appended, a single space is inserted between the previous contents
352     of the variable and the appended value.
353
354     Variables are expanded by surrounding the variable name with either curly
355     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
356     (`$').  If the variable name contains only a single letter, the surround-
357     ing braces or parentheses are not required.  This shorter form is not
358     recommended.
359
360     If the variable name contains a dollar, then the name itself is expanded
361     first.  This allows almost arbitrary variable names, however names con-
362     taining dollar, braces, parenthesis, or whitespace are really best
363     avoided!
364
365     If the result of expanding a variable contains a dollar sign (`$') the
366     string is expanded again.
367
368     Variable substitution occurs at three distinct times, depending on where
369     the variable is being used.
370
371     1.   Variables in dependency lines are expanded as the line is read.
372
373     2.   Variables in shell commands are expanded when the shell command is
374          executed.
375
376     3.   ``.for'' loop index variables are expanded on each loop iteration.
377          Note that other variables are not expanded inside loops so the fol-
378          lowing example code:
379
380
381                .for i in 1 2 3
382                a+=     ${i}
383                j=      ${i}
384                b+=     ${j}
385                .endfor
386
387                all:
388                        @echo ${a}
389                        @echo ${b}
390
391          will print:
392
393                1 2 3
394                3 3 3
395
396          Because while ${a} contains ``1 2 3'' after the loop is executed,
397          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
398          after the loop completes ${j} contains ``3''.
399
400   VVaarriiaabbllee ccllaasssseess
401     The four different classes of variables (in order of increasing prece-
402     dence) are:
403
404     Environment variables
405             Variables defined as part of bbmmaakkee's environment.
406
407     Global variables
408             Variables defined in the makefile or in included makefiles.
409
410     Command line variables
411             Variables defined as part of the command line.
412
413     Local variables
414             Variables that are defined specific to a certain target.
415
416     Local variables are all built in and their values vary magically from
417     target to target.  It is not currently possible to define new local vari-
418     ables.  The seven local variables are as follows:
419
420           _._A_L_L_S_R_C   The list of all sources for this target; also known as
421                     `_>'.
422
423           _._A_R_C_H_I_V_E  The name of the archive file; also known as `_!'.
424
425           _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
426                     source from which the target is to be transformed (the
427                     ``implied'' source); also known as `_<'.  It is not
428                     defined in explicit rules.
429
430           _._M_E_M_B_E_R   The name of the archive member; also known as `_%'.
431
432           _._O_O_D_A_T_E   The list of sources for this target that were deemed out-
433                     of-date; also known as `_?'.
434
435           _._P_R_E_F_I_X   The file prefix of the target, containing only the file
436                     portion, no suffix or preceding directory components;
437                     also known as `_*'.  The suffix must be one of the known
438                     suffixes declared with ..SSUUFFFFIIXXEESS or it will not be recog-
439                     nized.
440
441           _._T_A_R_G_E_T   The name of the target; also known as `_@'.
442
443     The shorter forms (`_>', `_!', `_<', `_%', `_?', `_*', and `_@') are permitted
444     for backward compatibility with historical makefiles and legacy POSIX
445     make and are not recommended.
446
447     Variants of these variables with the punctuation followed immediately by
448     `D' or `F', e.g.  `_$_(_@_D_)', are legacy forms equivalent to using the `:H'
449     and `:T' modifiers.  These forms are accepted for compatibility with AT&T
450     System V UNIX makefiles and POSIX but are not recommended.
451
452     Four of the local variables may be used in sources on dependency lines
453     because they expand to the proper value for each target on the line.
454     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'.
455
456   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
457     In addition, bbmmaakkee sets or knows about the following variables:
458
459     _$               A single dollar sign `$', i.e.  `$$' expands to a single
460                     dollar sign.
461
462     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
463                     evaluated during Makefile parsing, lists only those tar-
464                     gets encountered thus far.
465
466     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
467                     to the description of `PWD' for more details.
468
469     _._I_N_C_L_U_D_E_D_F_R_O_M_D_I_R
470                     The directory of the file this Makefile was included
471                     from.
472
473     _._I_N_C_L_U_D_E_D_F_R_O_M_F_I_L_E
474                     The filename of the file this Makefile was included from.
475
476     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
477                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
478                     The preferred variable to use is the environment variable
479                     MAKE because it is more compatible with other versions of
480                     bbmmaakkee and cannot be confused with the special target with
481                     the same name.
482
483     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
484                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
485                     ated dependencies are read.
486
487     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
488                     A boolean that controls the default behavior of the --VV
489                     option.
490
491     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
492
493     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
494
495     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
496                     If bbmmaakkee is run with _j then output for each target is
497                     prefixed with a token `--- target ---' the first part of
498                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.  If
499                     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X is empty, no token is printed.
500                     For example:
501                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
502                     would produce tokens like `---make[1234] target ---' mak-
503                     ing it easier to track the degree of parallelism being
504                     achieved.
505
506     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
507                     that may be specified on bbmmaakkee's command line.  Anything
508                     specified on bbmmaakkee's command line is appended to the
509                     `MAKEFLAGS' variable which is then entered into the envi-
510                     ronment for all programs which bbmmaakkee executes.
511
512     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
513                     bbmmaakkee will be 0, and an incremented value is put into the
514                     environment to be seen by the next generation.  This
515                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
516                     things which should only be evaluated in the initial
517                     instance of bbmmaakkee.
518
519     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
520                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
521                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
522
523     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
524                     The list of makefiles read by bbmmaakkee, which is useful for
525                     tracking dependencies.  Each makefile is recorded only
526                     once, regardless of the number of times read.
527
528     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
529                     mode that bbmmaakkee runs in.  It can contain a number of key-
530                     words:
531
532                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
533
534                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
535                                 are created for each target to capture the
536                                 command run, the output generated and if
537                                 filemon(4) is available, the system calls
538                                 which are of interest to bbmmaakkee.  The captured
539                                 output can be very useful when diagnosing
540                                 errors.
541
542                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
543                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
544                                 ting _b_f to a value which represents True.
545
546                     _e_n_v         For debugging, it can be useful to inlcude
547                                 the environment in the .meta file.
548
549                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
550                                 target being built.  This is useful if the
551                                 build is otherwise running silently.  The
552                                 message printed the value of:
553                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
554
555                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
556                                 not stable.  This keyword causes them to be
557                                 ignored for determining whether a target is
558                                 out of date in "meta" mode.  See also
559                                 ..NNOOMMEETTAA__CCMMPP.
560
561                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
562                                 mark the target ..SSIILLEENNTT.
563
564     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
565                     In "meta" mode, provides a list of prefixes which match
566                     the directories controlled by bbmmaakkee.  If a file that was
567                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
568                     missing, the current target is considered out-of-date.
569
570     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
571                     In "meta" mode, this variable contains a list of all the
572                     meta files updated.  If not empty, it can be used to
573                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
574
575     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
576                     In "meta" mode, this variable contains a list of all the
577                     meta files used (updated or not).  This list can be used
578                     to process the meta files to extract dependency informa-
579                     tion.
580
581     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_H_S
582                     Provides a list of path prefixes that should be ignored;
583                     because the contents are expected to change over time.
584                     The default list includes: `_/_d_e_v _/_e_t_c _/_p_r_o_c _/_t_m_p _/_v_a_r_/_r_u_n
585                     _/_v_a_r_/_t_m_p'
586
587     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
588                     Defines the message printed for each meta file updated in
589                     "meta verbose" mode.  The default value is:
590                           Building ${.TARGET:H:tA}/${.TARGET:T}
591
592     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
593                     assigned to on the command line, so that they may be
594                     exported as part of `MAKEFLAGS'.  This behaviour can be
595                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
596                     within a makefile.  Extra variables can be exported from
597                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
598                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
599                     modified.
600
601     _._M_A_K_E_._P_A_T_H___F_I_L_E_M_O_N
602                     If bbmmaakkee was built with filemon(4) support, this is set
603                     to the path of the device node.  This allows makefiles to
604                     test for this support.
605
606     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
607
608     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
609
610     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
611                     When bbmmaakkee stops due to an error, it prints its name and
612                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
613                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
614
615     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
616                     its value.  This allows expansions using the ::@@ modifier
617                     to put a newline between iterations of the loop rather
618                     than a space.  For example, the printing of
619                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
620                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
621
622     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
623                     value is determined by trying to chdir(2) to the follow-
624                     ing directories in order and using the first match:
625
626                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
627
628                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
629                          ment or on the command line.)
630
631                     2.   ${MAKEOBJDIR}
632
633                          (Only if `MAKEOBJDIR' is set in the environment or
634                          on the command line.)
635
636                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
637
638                     4.   ${.CURDIR}_/_o_b_j
639
640                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
641
642                     6.   ${.CURDIR}
643
644                     Variable expansion is performed on the value before it's
645                     used, so expressions such as
646                           ${.CURDIR:S,^/usr/src,/var/obj,}
647                     may be used.  This is especially useful with
648                     `MAKEOBJDIR'.
649
650                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
651                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
652                     and set `PWD' to that directory before executing any tar-
653                     gets.
654
655     _._P_A_R_S_E_D_I_R       A path to the directory of the current `_M_a_k_e_f_i_l_e' being
656                     parsed.
657
658     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
659                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
660                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
661                     their current values, assign them to a variable using
662                     assignment with expansion: (`::==').
663
664     _._P_A_T_H           A variable that represents the list of directories that
665                     bbmmaakkee will search for files.  The search list should be
666                     updated using the target `_._P_A_T_H' rather than the vari-
667                     able.
668
669     PWD             Alternate path to the current directory.  bbmmaakkee normally
670                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
671                     However, if the environment variable `PWD' is set and
672                     gives a path to the current directory, then bbmmaakkee sets
673                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
674                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
675                     contains a variable transform.  `PWD' is set to the value
676                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
677
678     .TARGETS        The list of targets explicitly specified on the command
679                     line, if any.
680
681     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
682                     will search for files.  The variable is supported for
683                     compatibility with old make programs only, use `_._P_A_T_H'
684                     instead.
685
686   VVaarriiaabbllee mmooddiiffiieerrss
687     Variable expansion may be modified to select or modify each word of the
688     variable (where a ``word'' is white-space delimited sequence of charac-
689     ters).  The general format of a variable expansion is as follows:
690
691           ${variable[:modifier[:...]]}
692
693     Each modifier begins with a colon, which may be escaped with a backslash
694     (`\').
695
696     A set of modifiers can be specified via a variable, as follows:
697
698           modifier_variable=modifier[:...]
699           ${variable:${modifier_variable}[:...]}
700
701     In this case the first modifier in the modifier_variable does not start
702     with a colon, since that must appear in the referencing variable.  If any
703     of the modifiers in the modifier_variable contain a dollar sign (`$'),
704     these must be doubled to avoid early expansion.
705
706     The supported modifiers are:
707
708     ::EE   Replaces each word in the variable with its suffix.
709
710     ::HH   Replaces each word in the variable with everything but the last com-
711          ponent.
712
713     ::MM_p_a_t_t_e_r_n
714          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
715          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
716          characters may be escaped with a backslash (`\').  As a consequence
717          of the way values are split into words, matched, and then joined, a
718          construct like
719                ${VAR:M*}
720          will normalise the inter-word spacing, removing all leading and
721          trailing space, and converting multiple consecutive spaces to single
722          spaces.
723
724     ::NN_p_a_t_t_e_r_n
725          This is identical to `::MM', but selects all words which do not match
726          _p_a_t_t_e_r_n.
727
728     ::OO   Order every word in variable alphabetically.  To sort words in
729          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
730
731     ::OOxx  Randomize words in variable.  The results will be different each
732          time you are referring to the modified variable; use the assignment
733          with expansion (`::==') to prevent such behaviour.  For example,
734
735                LIST=                   uno due tre quattro
736                RANDOM_LIST=            ${LIST:Ox}
737                STATIC_RANDOM_LIST:=    ${LIST:Ox}
738
739                all:
740                        @echo "${RANDOM_LIST}"
741                        @echo "${RANDOM_LIST}"
742                        @echo "${STATIC_RANDOM_LIST}"
743                        @echo "${STATIC_RANDOM_LIST}"
744          may produce output similar to:
745
746                quattro due tre uno
747                tre due quattro uno
748                due uno quattro tre
749                due uno quattro tre
750
751     ::QQ   Quotes every shell meta-character in the variable, so that it can be
752          passed safely through recursive invocations of bbmmaakkee.
753
754     ::RR   Replaces each word in the variable with everything but its suffix.
755
756     ::ggmmttiimmee
757          The value is a format string for strftime(3), using the current
758          gmtime(3).
759
760     ::hhaasshh
761          Compute a 32bit hash of the value and encode it as hex digits.
762
763     ::llooccaallttiimmee
764          The value is a format string for strftime(3), using the current
765          localtime(3).
766
767     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
768          if that fails, the value is unchanged.
769
770     ::ttll  Converts variable to lower-case letters.
771
772     ::ttss_c
773          Words in the variable are normally separated by a space on expan-
774          sion.  This modifier sets the separator to the character _c.  If _c is
775          omitted, then no separator is used.  The common escapes (including
776          octal numeric codes), work as expected.
777
778     ::ttuu  Converts variable to upper-case letters.
779
780     ::ttWW  Causes the value to be treated as a single word (possibly containing
781          embedded white space).  See also `::[[**]]'.
782
783     ::ttww  Causes the value to be treated as a sequence of words delimited by
784          white space.  See also `::[[@@]]'.
785
786     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
787          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
788          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
789          slash of the pattern, all occurrences in each word are replaced.  If
790          a `1' is appended to the last slash of the pattern, only the first
791          word is affected.  If a `W' is appended to the last slash of the
792          pattern, then the value is treated as a single word (possibly con-
793          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
794          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
795          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
796          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
797          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
798          delimiter for the parts of the modifier string.  The anchoring,
799          ampersand and delimiter characters may be escaped with a backslash
800          (`\').
801
802          Variable expansion occurs in the normal fashion inside both
803          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
804          is used to prevent the expansion of a dollar sign (`$'), not a pre-
805          ceding dollar sign as is usual.
806
807     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
808          The ::CC modifier is just like the ::SS modifier except that the old and
809          new strings, instead of being simple strings, are an extended regu-
810          lar expression (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style
811          string _r_e_p_l_a_c_e_m_e_n_t.  Normally, the first occurrence of the pattern
812          _p_a_t_t_e_r_n in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.
813          The `1' modifier causes the substitution to apply to at most one
814          word; the `g' modifier causes the substitution to apply to as many
815          instances of the search pattern _p_a_t_t_e_r_n as occur in the word or
816          words it is found in; the `W' modifier causes the value to be
817          treated as a single word (possibly containing embedded white space).
818          Note that `1' and `g' are orthogonal; the former specifies whether
819          multiple words are potentially affected, the latter whether multiple
820          substitutions can potentially occur within each affected word.
821
822          As for the ::SS modifier, the _p_a_t_t_e_r_n and _r_e_p_l_a_c_e_m_e_n_t are subjected to
823          variable expansion before being parsed as regular expressions.
824
825     ::TT   Replaces each word in the variable with its last component.
826
827     ::uu   Remove adjacent duplicate words (like uniq(1)).
828
829     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
830          If the variable name (not its value), when parsed as a .if condi-
831          tional expression, evaluates to true, return as its value the
832          _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
833          name is used as the expression, :? must be the first modifier after
834          the variable name itself - which will, of course, usually contain
835          variable expansions.  A common error is trying to use expressions
836          like
837                ${NUMBERS:M42:?match:no}
838          which actually tests defined(NUMBERS), to determine is any words
839          match "42" you need to use something like:
840                ${"${NUMBERS:M42}" != "":?match:no}.
841
842     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
843          This is the AT&T System V UNIX style variable substitution.  It must
844          be the last modifier specified.  If _o_l_d___s_t_r_i_n_g or _n_e_w___s_t_r_i_n_g do not
845          contain the pattern matching character _% then it is assumed that
846          they are anchored at the end of each word, so only suffixes or
847          entire words may be replaced.  Otherwise _% is the substring of
848          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
849
850          Variable expansion occurs in the normal fashion inside both
851          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
852          is used to prevent the expansion of a dollar sign (`$'), not a pre-
853          ceding dollar sign as is usual.
854
855     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
856          This is the loop expansion mechanism from the OSF Development Envi-
857          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
858          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
859          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
860          period.  For example.
861                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
862
863          However a single character variable is often more readable:
864                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
865
866     ::UU_n_e_w_v_a_l
867          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
868          is defined, the existing value is returned.  This is another ODE
869          make feature.  It is handy for setting per-target CFLAGS for
870          instance:
871                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
872          If a value is only required if the variable is undefined, use:
873                ${VAR:D:Unewval}
874
875     ::DD_n_e_w_v_a_l
876          If the variable is defined _n_e_w_v_a_l is the value.
877
878     ::LL   The name of the variable is the value.
879
880     ::PP   The path of the node which has the same name as the variable is the
881          value.  If no such node exists or its path is null, then the name of
882          the variable is used.  In order for this modifier to work, the name
883          (node) must at least have appeared on the rhs of a dependency.
884
885     ::!!_c_m_d!!
886          The output of running _c_m_d is the value.
887
888     ::sshh  If the variable is non-empty it is run as a command and the output
889          becomes the new value.
890
891     ::::==_s_t_r
892          The variable is assigned the value _s_t_r after substitution.  This
893          modifier and its variations are useful in obscure situations such as
894          wanting to set a variable when shell commands are being parsed.
895          These assignment modifiers always expand to nothing, so if appearing
896          in a rule line by themselves should be preceded with something to
897          keep bbmmaakkee happy.
898
899          The `::::' helps avoid false matches with the AT&T System V UNIX style
900          ::== modifier and since substitution always occurs the ::::== form is
901          vaguely appropriate.
902
903     ::::??==_s_t_r
904          As for ::::== but only if the variable does not already have a value.
905
906     ::::++==_s_t_r
907          Append _s_t_r to the variable.
908
909     ::::!!==_c_m_d
910          Assign the output of _c_m_d to the variable.
911
912     ::[[_r_a_n_g_e]]
913          Selects one or more words from the value, or performs other opera-
914          tions related to the way in which the value is divided into words.
915
916          Ordinarily, a value is treated as a sequence of words delimited by
917          white space.  Some modifiers suppress this behaviour, causing a
918          value to be treated as a single word (possibly containing embedded
919          white space).  An empty value, or a value that consists entirely of
920          white-space, is treated as a single word.  For the purposes of the
921          `::[[]]' modifier, the words are indexed both forwards using positive
922          integers (where index 1 represents the first word), and backwards
923          using negative integers (where index -1 represents the last word).
924
925          The _r_a_n_g_e is subjected to variable expansion, and the expanded
926          result is then interpreted as follows:
927
928          _i_n_d_e_x  Selects a single word from the value.
929
930          _s_t_a_r_t...._e_n_d
931                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
932                 `::[[22....--11]]' selects all words from the second word to the last
933                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
934                 put in reverse order.  For example, `::[[--11....11]]' selects all
935                 the words from last to first.
936
937          **      Causes subsequent modifiers to treat the value as a single
938                 word (possibly containing embedded white space).  Analogous
939                 to the effect of "$*" in Bourne shell.
940
941          0      Means the same as `::[[**]]'.
942
943          @@      Causes subsequent modifiers to treat the value as a sequence
944                 of words delimited by white space.  Analogous to the effect
945                 of "$@" in Bourne shell.
946
947          ##      Returns the number of words in the value.
948
949IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
950     Makefile inclusion, conditional structures and for loops  reminiscent of
951     the C programming language are provided in bbmmaakkee.  All such structures
952     are identified by a line beginning with a single dot (`.') character.
953     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
954     ables between the angle brackets or double quotes are expanded to form
955     the file name.  If angle brackets are used, the included makefile is
956     expected to be in the system makefile directory.  If double quotes are
957     used, the including makefile's directory and any directories specified
958     using the --II option are searched before the system makefile directory.
959     For compatibility with other versions of bbmmaakkee `include file ...' is also
960     accepted.  If the include statement is written as ..--iinncclluuddee or as
961     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
962
963     Conditional expressions are also preceded by a single dot as the first
964     character of a line.  The possible conditionals are as follows:
965
966     ..eerrrroorr _m_e_s_s_a_g_e
967             The message is printed along with the name of the makefile and
968             line number, then bbmmaakkee will exit.
969
970     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
971             Export the specified global variable.  If no variable list is
972             provided, all globals are exported except for internal variables
973             (those that start with `.').  This is not affected by the --XX
974             flag, so should be used with caution.  For compatibility with
975             other bbmmaakkee programs `export variable=value' is also accepted.
976
977             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
978             exporting a variable.
979
980     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
981             The same as `.export', except that the variable is not appended
982             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
983             ment which is different from that used by bbmmaakkee internally.
984
985     ..iinnffoo _m_e_s_s_a_g_e
986             The message is printed along with the name of the makefile and
987             line number.
988
989     ..uunnddeeff _v_a_r_i_a_b_l_e
990             Un-define the specified global variable.  Only global variables
991             may be un-defined.
992
993     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
994             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
995             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
996             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
997
998     ..uunneexxppoorrtt--eennvv
999             Unexport all globals previously exported and clear the environ-
1000             ment inherited from the parent.  This operation will cause a mem-
1001             ory leak of the original environment, so should be used spar-
1002             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
1003             note that any variables which originated in the parent environ-
1004             ment should be explicitly preserved if desired.  For example:
1005
1006                   .if ${.MAKE.LEVEL} == 0
1007                   PATH := ${PATH}
1008                   .unexport-env
1009                   .export PATH
1010                   .endif
1011
1012             Would result in an environment containing only `PATH', which is
1013             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
1014             be pushed into the new environment.
1015
1016     ..wwaarrnniinngg _m_e_s_s_a_g_e
1017             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
1018             of the makefile and line number.
1019
1020     ..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 _._._.]
1021             Test the value of an expression.
1022
1023     ..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 _._._.]
1024             Test the value of a variable.
1025
1026     ..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 _._._.]
1027             Test the value of a variable.
1028
1029     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1030             Test the target being built.
1031
1032     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1033             Test the target being built.
1034
1035     ..eellssee   Reverse the sense of the last conditional.
1036
1037     ..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 _._._.]
1038             A combination of `..eellssee' followed by `..iiff'.
1039
1040     ..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 _._._.]
1041             A combination of `..eellssee' followed by `..iiffddeeff'.
1042
1043     ..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 _._._.]
1044             A combination of `..eellssee' followed by `..iiffnnddeeff'.
1045
1046     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1047             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1048
1049     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1050             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1051
1052     ..eennddiiff  End the body of the conditional.
1053
1054     The _o_p_e_r_a_t_o_r may be any one of the following:
1055
1056     ||||     Logical OR.
1057
1058     &&&&     Logical AND; of higher precedence than ``||''.
1059
1060     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
1061     determine its value.  Parentheses may be used to change the order of
1062     evaluation.  The boolean operator `!!' may be used to logically negate an
1063     entire conditional.  It is of higher precedence than `&&&&'.
1064
1065     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
1066
1067     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
1068              the variable has been defined.
1069
1070     mmaakkee     Takes a target name as an argument and evaluates to true if the
1071              target was specified as part of bbmmaakkee's command line or was
1072              declared the default target (either implicitly or explicitly,
1073              see _._M_A_I_N) before the line containing the conditional.
1074
1075     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1076              if the expansion of the variable would result in an empty
1077              string.
1078
1079     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1080              file exists.  The file is searched for on the system search path
1081              (see _._P_A_T_H).
1082
1083     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1084              target has been defined.
1085
1086     ccoommmmaannddss
1087              Takes a target name as an argument and evaluates to true if the
1088              target has been defined and has commands associated with it.
1089
1090     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1091     expansion is performed on both sides of the comparison, after which the
1092     integral values are compared.  A value is interpreted as hexadecimal if
1093     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1094     ported.  The standard C relational operators are all supported.  If after
1095     variable expansion, either the left or right hand side of a `====' or `!!=='
1096     operator is not an integral value, then string comparison is performed
1097     between the expanded variables.  If no relational operator is given, it
1098     is assumed that the expanded variable is being compared against 0 or an
1099     empty string in the case of a string comparison.
1100
1101     When bbmmaakkee is evaluating one of these conditional expressions, and it
1102     encounters a (white-space separated) word it doesn't recognize, either
1103     the ``make'' or ``defined'' expression is applied to it, depending on the
1104     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1105     the ``defined'' expression is applied.  Similarly, if the form is
1106     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1107
1108     If the conditional evaluates to true the parsing of the makefile contin-
1109     ues as before.  If it evaluates to false, the following lines are
1110     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1111     found.
1112
1113     For loops are typically used to apply a set of rules to a list of files.
1114     The syntax of a for loop is:
1115
1116     ..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
1117     <make-rules>
1118     ..eennddffoorr
1119
1120     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1121     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1122     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1123     the body of the for loop.  The number of words must come out even; that
1124     is, if there are three iteration variables, the number of words provided
1125     must be a multiple of three.
1126
1127CCOOMMMMEENNTTSS
1128     Comments begin with a hash (`#') character, anywhere but in a shell com-
1129     mand line, and continue to the end of an unescaped new line.
1130
1131SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1132     ..EEXXEECC     Target is never out of date, but always execute commands any-
1133               way.
1134
1135     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1136               get, exactly as if they all were preceded by a dash (`-').
1137
1138     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1139
1140     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1141               or --tt options were specified.  Normally used to mark recursive
1142               bbmmaakkees.
1143
1144     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1145               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1146               the most likely case.  In "meta" mode, the target is out-of-
1147               date if the meta file is missing.
1148
1149     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1150               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1151
1152     ..NNOOMMEETTAA__CCMMPP
1153               Ignore differences in commands when deciding if target is out
1154               of date.  This is useful if the command contains a value which
1155               always changes.  If the number of commands change, though, the
1156               target will still be out of date.  The same effect applies to
1157               any command line that uses the variable _._O_O_D_A_T_E, which can be
1158               used for that purpose even when not otherwise needed or
1159               desired:
1160
1161
1162                     skip-compare-for-some:
1163                             @echo this will be compared
1164                             @echo this will not ${.OODATE:M.NOMETA_CMP}
1165                             @echo this will also be compared
1166
1167               The ::MM pattern suppresses any expansion of the unwanted vari-
1168               able.
1169
1170     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1171               ..PPAATTHH.
1172
1173     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1174               default target to be built if no target was specified.  This
1175               source prevents this target from being selected.
1176
1177     ..OOPPTTIIOONNAALL
1178               If a target is marked with this attribute and bbmmaakkee can't fig-
1179               ure out how to create it, it will ignore this fact and assume
1180               the file isn't needed or already exists.
1181
1182     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1183               considered to be out of date, and will not be created with the
1184               --tt option.  Suffix-transformation rules are not applied to
1185               ..PPHHOONNYY targets.
1186
1187     ..PPRREECCIIOOUUSS
1188               When bbmmaakkee is interrupted, it normally removes any partially
1189               made targets.  This source prevents the target from being
1190               removed.
1191
1192     ..RREECCUURRSSIIVVEE
1193               Synonym for ..MMAAKKEE.
1194
1195     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1196               exactly as if they all were preceded by an at sign (`@').
1197
1198     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1199               get is used as a source for another target, the other target
1200               acquires the commands, sources, and attributes (except for
1201               ..UUSSEE) of the source.  If the target already has commands, the
1202               ..UUSSEE target's commands are appended to them.
1203
1204     ..UUSSEEBBEEFFOORREE
1205               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1206               to the target.
1207
1208     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1209               it are made before the sources that succeed it in the line.
1210               Since the dependents of files are not made until the file
1211               itself could be made, this also stops the dependents being
1212               built unless they are needed for another branch of the depen-
1213               dency tree.  So given:
1214
1215               x: a .WAIT b
1216                       echo x
1217               a:
1218                       echo a
1219               b: b1
1220                       echo b
1221               b1:
1222                       echo b1
1223
1224               the output is always `a', `b1', `b', `x'.
1225               The ordering imposed by ..WWAAIITT is only relevant for parallel
1226               makes.
1227
1228SSPPEECCIIAALL TTAARRGGEETTSS
1229     Special targets may not be included with other targets, i.e. they must be
1230     the only target specified.
1231
1232     ..BBEEGGIINN   Any command lines attached to this target are executed before
1233              anything else is done.
1234
1235     ..DDEEFFAAUULLTT
1236              This is sort of a ..UUSSEE rule for any target (that was used only
1237              as a source) that bbmmaakkee can't figure out any other way to cre-
1238              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1239              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1240              own name.
1241
1242     ..EENNDD     Any command lines attached to this target are executed after
1243              everything else is done.
1244
1245     ..EERRRROORR   Any command lines attached to this target are executed when
1246              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1247              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1248
1249     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1250              sources are specified, this is the equivalent of specifying the
1251              --ii option.
1252
1253     ..IINNTTEERRRRUUPPTT
1254              If bbmmaakkee is interrupted, the commands for this target will be
1255              executed.
1256
1257     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1258              will be built.
1259
1260     ..MMAAKKEEFFLLAAGGSS
1261              This target provides a way to specify flags for bbmmaakkee when the
1262              makefile is used.  The flags are as if typed to the shell,
1263              though the --ff option will have no effect.
1264
1265     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1266
1267     ..NNOOTTPPAARRAALLLLEELL
1268              Disable parallel mode.
1269
1270     ..NNOO__PPAARRAALLLLEELL
1271              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1272              variants.
1273
1274     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1275              add targets to the list of targets to be made.  Since the depen-
1276              dents of a target do not get built until the target itself could
1277              be built, unless `a' is built by another part of the dependency
1278              graph, the following is a dependency loop:
1279
1280              .ORDER: b a
1281              b: a
1282
1283              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1284              makes.
1285
1286     ..PPAATTHH    The sources are directories which are to be searched for files
1287              not found in the current directory.  If no sources are speci-
1288              fied, any previously specified directories are deleted.  If the
1289              source is the special ..DDOOTTLLAASSTT target, then the current working
1290              directory is searched last.
1291
1292     ..PPAATTHH.._s_u_f_f_i_x
1293              Like ..PPAATTHH but applies only to files with a particular suffix.
1294              The suffix must have been previously declared with ..SSUUFFFFIIXXEESS.
1295
1296     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1297
1298     ..PPRREECCIIOOUUSS
1299              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1300              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1301              every target in the file.
1302
1303     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1304              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1305
1306              _n_a_m_e        This is the minimal specification, used to select
1307                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
1308
1309              _p_a_t_h        Specifies the path to the shell.
1310
1311              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1312
1313              _c_h_e_c_k       The command to turn on error checking.
1314
1315              _i_g_n_o_r_e      The command to disable error checking.
1316
1317              _e_c_h_o        The command to turn on echoing of commands executed.
1318
1319              _q_u_i_e_t       The command to turn off echoing of commands exe-
1320                          cuted.
1321
1322              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1323                          mand.  It is typically identical to _q_u_i_e_t.
1324
1325              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1326
1327              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1328                          ing.
1329
1330              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1331                          a single newline character when used outside of any
1332                          quoting characters.
1333              Example:
1334
1335              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1336                      check="set -e" ignore="set +e" \
1337                      echo="set -v" quiet="set +v" filter="set +v" \
1338                      echoFlag=v errFlag=e newline="'\n'"
1339
1340     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1341              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1342              command in the file.
1343
1344     ..SSTTAALLEE   This target gets run when a dependency file contains stale
1345              entries, having _._A_L_L_S_R_C set to the name of that dependency file.
1346
1347     ..SSUUFFFFIIXXEESS
1348              Each source specifies a suffix to bbmmaakkee.  If no sources are
1349              specified, any previously specified suffixes are deleted.  It
1350              allows the creation of suffix-transformation rules.
1351
1352              Example:
1353
1354              .SUFFIXES: .o
1355              .c.o:
1356                      cc -o ${.TARGET} -c ${.IMPSRC}
1357
1358EENNVVIIRROONNMMEENNTT
1359     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1360     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1361     PWD, and TMPDIR.
1362
1363     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1364     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1365     tion of `_._O_B_J_D_I_R' for more details.
1366
1367FFIILLEESS
1368     .depend        list of dependencies
1369     Makefile       list of dependencies
1370     makefile       list of dependencies
1371     sys.mk         system makefile
1372     /usr/share/mk  system makefile directory
1373
1374CCOOMMPPAATTIIBBIILLIITTYY
1375     The basic make syntax is compatible between different versions of make;
1376     however the special variables, variable modifiers and conditionals are
1377     not.
1378
1379   OOllddeerr vveerrssiioonnss
1380     An incomplete list of changes in older versions of bbmmaakkee:
1381
1382     The way that .for loop variables are substituted changed after NetBSD 5.0
1383     so that they still appear to be variable expansions.  In particular this
1384     stops them being treated as syntax, and removes some obscure problems
1385     using them in .if statements.
1386
1387     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1388     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1389     rithms used may change again in the future.
1390
1391   OOtthheerr mmaakkee ddiiaalleeccttss
1392     Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not sup-
1393     port most of the features of bbmmaakkee as described in this manual.  Most
1394     notably:
1395
1396           ++oo   The ..WWAAIITT and ..OORRDDEERR declarations and most functionality per-
1397               taining to parallelization.  (GNU make supports parallelization
1398               but lacks these features needed to control it effectively.)
1399
1400           ++oo   Directives, including for loops and conditionals and most of
1401               the forms of include files.  (GNU make has its own incompatible
1402               and less powerful syntax for conditionals.)
1403
1404           ++oo   All built-in variables that begin with a dot.
1405
1406           ++oo   Most of the special sources and targets that begin with a dot,
1407               with the notable exception of ..PPHHOONNYY, ..PPRREECCIIOOUUSS, and ..SSUUFFFFIIXXEESS.
1408
1409           ++oo   Variable modifiers, except for the
1410                     :old=new
1411               string substitution, which does not portably support globbing
1412               with `%' and historically only works on declared suffixes.
1413
1414           ++oo   The $$>> variable even in its short form; most makes support this
1415               functionality but its name varies.
1416
1417     Some features are somewhat more portable, such as assignment with ++==, ??==,
1418     and !!==.  The ..PPAATTHH functionality is based on an older feature VVPPAATTHH found
1419     in GNU make and many versions of SVR4 make; however, historically its
1420     behavior is too ill-defined (and too buggy) to rely upon.
1421
1422     The $$@@ and $$<< variables are more or less universally portable, as is the
1423     $$((MMAAKKEE)) variable.  Basic use of suffix rules (for files only in the cur-
1424     rent directory, not trying to chain transformations together, etc.) is
1425     also reasonably portable.
1426
1427SSEEEE AALLSSOO
1428     mkdep(1)
1429
1430HHIISSTTOORRYY
1431     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1432     portability to other platforms.
1433
1434     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1435     is based on Adam De Boor's pmake program which was written for Sprite at
1436     Berkeley.  It was designed to be a parallel distributed make running jobs
1437     on different machines using a daemon called ``customs''.
1438
1439     Historically the target/dependency ``FRC'' has been used to FoRCe
1440     rebuilding (since the target/dependency does not exist... unless someone
1441     creates an ``FRC'' file).
1442
1443BBUUGGSS
1444     The make syntax is difficult to parse without actually acting of the
1445     data.  For instance finding the end of a variable use should involve
1446     scanning each the modifiers using the correct terminator for each field.
1447     In many places make just counts {} and () in order to find the end of a
1448     variable expansion.
1449
1450     There is no way of escaping a space character in a filename.
1451
1452NetBSD 5.1                       April 9, 2015                      NetBSD 5.1
1453