xref: /freebsd/contrib/bmake/bmake.cat1 (revision 792bbaba989533a1fc93823df1720c8c4aaf0442)
1BMAKE(1)                NetBSD General Commands Manual                BMAKE(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 file system.  If the search is success-
182             ful, then the resulting directory replaces the ".../" specifica-
183             tion in the --mm argument.  If used, this feature allows bbmmaakkee to
184             easily search in the current source tree for customized sys.mk
185             files (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 `_@'.  For compati-
442                     bility with other makes this is an alias for ..AARRCCHHIIVVEE in
443                     archive member rules.
444
445     The shorter forms (`_>', `_!', `_<', `_%', `_?', `_*', and `_@') are permitted
446     for backward compatibility with historical makefiles and legacy POSIX
447     make and are not recommended.
448
449     Variants of these variables with the punctuation followed immediately by
450     `D' or `F', e.g.  `_$_(_@_D_)', are legacy forms equivalent to using the `:H'
451     and `:T' modifiers.  These forms are accepted for compatibility with AT&T
452     System V UNIX makefiles and POSIX but are not recommended.
453
454     Four of the local variables may be used in sources on dependency lines
455     because they expand to the proper value for each target on the line.
456     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'.
457
458   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
459     In addition, bbmmaakkee sets or knows about the following variables:
460
461     _$               A single dollar sign `$', i.e.  `$$' expands to a single
462                     dollar sign.
463
464     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
465                     evaluated during Makefile parsing, lists only those tar-
466                     gets encountered thus far.
467
468     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
469                     to the description of `PWD' for more details.
470
471     _._I_N_C_L_U_D_E_D_F_R_O_M_D_I_R
472                     The directory of the file this Makefile was included
473                     from.
474
475     _._I_N_C_L_U_D_E_D_F_R_O_M_F_I_L_E
476                     The filename of the file this Makefile was included from.
477
478     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
479                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
480                     The preferred variable to use is the environment variable
481                     MAKE because it is more compatible with other versions of
482                     bbmmaakkee and cannot be confused with the special target with
483                     the same name.
484
485     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
486                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
487                     ated dependencies are read.
488
489     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
490                     A boolean that controls the default behavior of the --VV
491                     option.
492
493     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
494
495     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
496
497     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
498                     If bbmmaakkee is run with _j then output for each target is
499                     prefixed with a token `--- target ---' the first part of
500                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.  If
501                     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X is empty, no token is printed.
502                     For example:
503                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
504                     would produce tokens like `---make[1234] target ---' mak-
505                     ing it easier to track the degree of parallelism being
506                     achieved.
507
508     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
509                     that may be specified on bbmmaakkee's command line.  Anything
510                     specified on bbmmaakkee's command line is appended to the
511                     `MAKEFLAGS' variable which is then entered into the envi-
512                     ronment for all programs which bbmmaakkee executes.
513
514     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
515                     bbmmaakkee will be 0, and an incremented value is put into the
516                     environment to be seen by the next generation.  This
517                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
518                     things which should only be evaluated in the initial
519                     instance of bbmmaakkee.
520
521     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
522                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
523                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
524
525     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
526                     The list of makefiles read by bbmmaakkee, which is useful for
527                     tracking dependencies.  Each makefile is recorded only
528                     once, regardless of the number of times read.
529
530     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
531                     mode that bbmmaakkee runs in.  It can contain a number of key-
532                     words:
533
534                     _c_o_m_p_a_t               Like --BB, puts bbmmaakkee into "compat"
535                                          mode.
536
537                     _m_e_t_a                 Puts bbmmaakkee into "meta" mode, where
538                                          meta files are created for each tar-
539                                          get to capture the command run, the
540                                          output generated and if filemon(4)
541                                          is available, the system calls which
542                                          are of interest to bbmmaakkee.  The cap-
543                                          tured output can be very useful when
544                                          diagnosing errors.
545
546                     _c_u_r_d_i_r_O_k_= _b_f         Normally bbmmaakkee will not create .meta
547                                          files in `_._C_U_R_D_I_R'.  This can be
548                                          overridden by setting _b_f to a value
549                                          which represents True.
550
551                     _m_i_s_s_i_n_g_-_m_e_t_a_= _b_f     If _b_f is True, then a missing .meta
552                                          file makes the target out-of-date.
553
554                     _m_i_s_s_i_n_g_-_f_i_l_e_m_o_n_= _b_f  If _b_f is True, then missing filemon
555                                          data makes the target out-of-date.
556
557                     _n_o_f_i_l_e_m_o_n            Do not use filemon(4).
558
559                     _e_n_v                  For debugging, it can be useful to
560                                          include the environment in the .meta
561                                          file.
562
563                     _v_e_r_b_o_s_e              If in "meta" mode, print a clue
564                                          about the target being built.  This
565                                          is useful if the build is otherwise
566                                          running silently.  The message
567                                          printed the value of:
568                                          _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
569
570                     _i_g_n_o_r_e_-_c_m_d           Some makefiles have commands which
571                                          are simply not stable.  This keyword
572                                          causes them to be ignored for deter-
573                                          mining whether a target is out of
574                                          date in "meta" mode.  See also
575                                          ..NNOOMMEETTAA__CCMMPP.
576
577                     _s_i_l_e_n_t_= _b_f           If _b_f is True, when a .meta file is
578                                          created, mark the target ..SSIILLEENNTT.
579
580     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
581                     In "meta" mode, provides a list of prefixes which match
582                     the directories controlled by bbmmaakkee.  If a file that was
583                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
584                     missing, the current target is considered out-of-date.
585
586     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
587                     In "meta" mode, this variable contains a list of all the
588                     meta files updated.  If not empty, it can be used to
589                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
590
591     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
592                     In "meta" mode, this variable contains a list of all the
593                     meta files used (updated or not).  This list can be used
594                     to process the meta files to extract dependency informa-
595                     tion.
596
597     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_H_S
598                     Provides a list of path prefixes that should be ignored;
599                     because the contents are expected to change over time.
600                     The default list includes: `_/_d_e_v _/_e_t_c _/_p_r_o_c _/_t_m_p _/_v_a_r_/_r_u_n
601                     _/_v_a_r_/_t_m_p'
602
603     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___P_A_T_T_E_R_N_S
604                     Provides a list of patterns to match against pathnames.
605                     Ignore any that match.
606
607     _._M_A_K_E_._M_E_T_A_._I_G_N_O_R_E___F_I_L_T_E_R
608                     Provides a list of variable modifiers to apply to each
609                     pathname.  Ignore if the expansion is an empty string.
610
611     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
612                     Defines the message printed for each meta file updated in
613                     "meta verbose" mode.  The default value is:
614                           Building ${.TARGET:H:tA}/${.TARGET:T}
615
616     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
617                     assigned to on the command line, so that they may be
618                     exported as part of `MAKEFLAGS'.  This behavior can be
619                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
620                     within a makefile.  Extra variables can be exported from
621                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
622                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
623                     modified.
624
625     _._M_A_K_E_._P_A_T_H___F_I_L_E_M_O_N
626                     If bbmmaakkee was built with filemon(4) support, this is set
627                     to the path of the device node.  This allows makefiles to
628                     test for this support.
629
630     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
631
632     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
633
634     _._M_A_K_E_._S_A_V_E___D_O_L_L_A_R_S
635                     value should be a boolean that controls whether `$$' are
636                     preserved when doing `:=' assignments.  The default is
637                     false, for backwards compatibility.  Set to true for com-
638                     patability with other makes.  If set to false, `$$'
639                     becomes `$' per normal evaluation rules.
640
641     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
642                     When bbmmaakkee stops due to an error, it sets `_._E_R_R_O_R___T_A_R_G_E_T'
643                     to the name of the target that failed, `_._E_R_R_O_R___C_M_D' to
644                     the commands of the failed target, and in "meta" mode, it
645                     also sets `_._E_R_R_O_R___C_W_D' to the getcwd(3), and
646                     `_._E_R_R_O_R___M_E_T_A___F_I_L_E' to the path of the meta file (if any)
647                     describing the failed target.  It then prints its name
648                     and the value of `_._C_U_R_D_I_R' as well as the value of any
649                     variables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
650
651     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
652                     its value.  This allows expansions using the ::@@ modifier
653                     to put a newline between iterations of the loop rather
654                     than a space.  For example, the printing of
655                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
656                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
657
658     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
659                     value is determined by trying to chdir(2) to the follow-
660                     ing directories in order and using the first match:
661
662                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
663
664                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
665                          ment or on the command line.)
666
667                     2.   ${MAKEOBJDIR}
668
669                          (Only if `MAKEOBJDIR' is set in the environment or
670                          on the command line.)
671
672                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
673
674                     4.   ${.CURDIR}_/_o_b_j
675
676                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
677
678                     6.   ${.CURDIR}
679
680                     Variable expansion is performed on the value before it's
681                     used, so expressions such as
682                           ${.CURDIR:S,^/usr/src,/var/obj,}
683                     may be used.  This is especially useful with
684                     `MAKEOBJDIR'.
685
686                     `_._O_B_J_D_I_R' may be modified in the makefile via the special
687                     target `..OOBBJJDDIIRR'.  In all cases, bbmmaakkee will chdir(2) to
688                     the specified directory if it exists, and set `_._O_B_J_D_I_R'
689                     and `PWD' to that directory before executing any targets.
690
691     _._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
692                     parsed.
693
694     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
695                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
696                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
697                     their current values, assign them to a variable using
698                     assignment with expansion: (`::==').
699
700     _._P_A_T_H           A variable that represents the list of directories that
701                     bbmmaakkee will search for files.  The search list should be
702                     updated using the target `_._P_A_T_H' rather than the vari-
703                     able.
704
705     PWD             Alternate path to the current directory.  bbmmaakkee normally
706                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
707                     However, if the environment variable `PWD' is set and
708                     gives a path to the current directory, then bbmmaakkee sets
709                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behavior
710                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
711                     contains a variable transform.  `PWD' is set to the value
712                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
713
714     .TARGETS        The list of targets explicitly specified on the command
715                     line, if any.
716
717     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
718                     will search for files.  The variable is supported for
719                     compatibility with old make programs only, use `_._P_A_T_H'
720                     instead.
721
722   VVaarriiaabbllee mmooddiiffiieerrss
723     Variable expansion may be modified to select or modify each word of the
724     variable (where a ``word'' is white-space delimited sequence of charac-
725     ters).  The general format of a variable expansion is as follows:
726
727           ${variable[:modifier[:...]]}
728
729     Each modifier begins with a colon, which may be escaped with a backslash
730     (`\').
731
732     A set of modifiers can be specified via a variable, as follows:
733
734           modifier_variable=modifier[:...]
735           ${variable:${modifier_variable}[:...]}
736
737     In this case the first modifier in the modifier_variable does not start
738     with a colon, since that must appear in the referencing variable.  If any
739     of the modifiers in the modifier_variable contain a dollar sign (`$'),
740     these must be doubled to avoid early expansion.
741
742     The supported modifiers are:
743
744     ::EE   Replaces each word in the variable with its suffix.
745
746     ::HH   Replaces each word in the variable with everything but the last com-
747          ponent.
748
749     ::MM_p_a_t_t_e_r_n
750          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
751          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
752          characters may be escaped with a backslash (`\').  As a consequence
753          of the way values are split into words, matched, and then joined, a
754          construct like
755                ${VAR:M*}
756          will normalize the inter-word spacing, removing all leading and
757          trailing space, and converting multiple consecutive spaces to single
758          spaces.
759
760     ::NN_p_a_t_t_e_r_n
761          This is identical to `::MM', but selects all words which do not match
762          _p_a_t_t_e_r_n.
763
764     ::OO   Order every word in variable alphabetically.  To sort words in
765          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
766
767     ::OOxx  Randomize words in variable.  The results will be different each
768          time you are referring to the modified variable; use the assignment
769          with expansion (`::==') to prevent such behavior.  For example,
770
771                LIST=                   uno due tre quattro
772                RANDOM_LIST=            ${LIST:Ox}
773                STATIC_RANDOM_LIST:=    ${LIST:Ox}
774
775                all:
776                        @echo "${RANDOM_LIST}"
777                        @echo "${RANDOM_LIST}"
778                        @echo "${STATIC_RANDOM_LIST}"
779                        @echo "${STATIC_RANDOM_LIST}"
780          may produce output similar to:
781
782                quattro due tre uno
783                tre due quattro uno
784                due uno quattro tre
785                due uno quattro tre
786
787     ::QQ   Quotes every shell meta-character in the variable, so that it can be
788          passed safely through recursive invocations of bbmmaakkee.
789
790     ::RR   Replaces each word in the variable with everything but its suffix.
791
792     ::ggmmttiimmee
793          The value is a format string for strftime(3), using the current
794          gmtime(3).
795
796     ::hhaasshh
797          Compute a 32-bit hash of the value and encode it as hex digits.
798
799     ::llooccaallttiimmee
800          The value is a format string for strftime(3), using the current
801          localtime(3).
802
803     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
804          if that fails, the value is unchanged.
805
806     ::ttll  Converts variable to lower-case letters.
807
808     ::ttss_c
809          Words in the variable are normally separated by a space on expan-
810          sion.  This modifier sets the separator to the character _c.  If _c is
811          omitted, then no separator is used.  The common escapes (including
812          octal numeric codes), work as expected.
813
814     ::ttuu  Converts variable to upper-case letters.
815
816     ::ttWW  Causes the value to be treated as a single word (possibly containing
817          embedded white space).  See also `::[[**]]'.
818
819     ::ttww  Causes the value to be treated as a sequence of words delimited by
820          white space.  See also `::[[@@]]'.
821
822     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
823          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
824          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
825          slash of the pattern, all occurrences in each word are replaced.  If
826          a `1' is appended to the last slash of the pattern, only the first
827          word is affected.  If a `W' is appended to the last slash of the
828          pattern, then the value is treated as a single word (possibly con-
829          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
830          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
831          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
832          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
833          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
834          delimiter for the parts of the modifier string.  The anchoring,
835          ampersand and delimiter characters may be escaped with a backslash
836          (`\').
837
838          Variable expansion occurs in the normal fashion inside both
839          _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
840          is used to prevent the expansion of a dollar sign (`$'), not a pre-
841          ceding dollar sign as is usual.
842
843     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
844          The ::CC modifier is just like the ::SS modifier except that the old and
845          new strings, instead of being simple strings, are an extended regu-
846          lar expression (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style
847          string _r_e_p_l_a_c_e_m_e_n_t.  Normally, the first occurrence of the pattern
848          _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.
849          The `1' modifier causes the substitution to apply to at most one
850          word; the `g' modifier causes the substitution to apply to as many
851          instances of the search pattern _p_a_t_t_e_r_n as occur in the word or
852          words it is found in; the `W' modifier causes the value to be
853          treated as a single word (possibly containing embedded white space).
854          Note that `1' and `g' are orthogonal; the former specifies whether
855          multiple words are potentially affected, the latter whether multiple
856          substitutions can potentially occur within each affected word.
857
858          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
859          variable expansion before being parsed as regular expressions.
860
861     ::TT   Replaces each word in the variable with its last component.
862
863     ::uu   Remove adjacent duplicate words (like uniq(1)).
864
865     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
866          If the variable name (not its value), when parsed as a .if condi-
867          tional expression, evaluates to true, return as its value the
868          _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
869          name is used as the expression, :? must be the first modifier after
870          the variable name itself - which will, of course, usually contain
871          variable expansions.  A common error is trying to use expressions
872          like
873                ${NUMBERS:M42:?match:no}
874          which actually tests defined(NUMBERS), to determine is any words
875          match "42" you need to use something like:
876                ${"${NUMBERS:M42}" != "":?match:no}.
877
878     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
879          This is the AT&T System V UNIX style variable substitution.  It must
880          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
881          contain the pattern matching character _% then it is assumed that
882          they are anchored at the end of each word, so only suffixes or
883          entire words may be replaced.  Otherwise _% is the substring of
884          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
885
886          Variable expansion occurs in the normal fashion inside both
887          _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
888          is used to prevent the expansion of a dollar sign (`$'), not a pre-
889          ceding dollar sign as is usual.
890
891     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
892          This is the loop expansion mechanism from the OSF Development Envi-
893          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
894          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
895          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
896          period.  For example.
897                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
898
899          However a single character variable is often more readable:
900                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
901
902     ::UU_n_e_w_v_a_l
903          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
904          is defined, the existing value is returned.  This is another ODE
905          make feature.  It is handy for setting per-target CFLAGS for
906          instance:
907                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
908          If a value is only required if the variable is undefined, use:
909                ${VAR:D:Unewval}
910
911     ::DD_n_e_w_v_a_l
912          If the variable is defined _n_e_w_v_a_l is the value.
913
914     ::LL   The name of the variable is the value.
915
916     ::PP   The path of the node which has the same name as the variable is the
917          value.  If no such node exists or its path is null, then the name of
918          the variable is used.  In order for this modifier to work, the name
919          (node) must at least have appeared on the rhs of a dependency.
920
921     ::!!_c_m_d!!
922          The output of running _c_m_d is the value.
923
924     ::sshh  If the variable is non-empty it is run as a command and the output
925          becomes the new value.
926
927     ::::==_s_t_r
928          The variable is assigned the value _s_t_r after substitution.  This
929          modifier and its variations are useful in obscure situations such as
930          wanting to set a variable when shell commands are being parsed.
931          These assignment modifiers always expand to nothing, so if appearing
932          in a rule line by themselves should be preceded with something to
933          keep bbmmaakkee happy.
934
935          The `::::' helps avoid false matches with the AT&T System V UNIX style
936          ::== modifier and since substitution always occurs the ::::== form is
937          vaguely appropriate.
938
939     ::::??==_s_t_r
940          As for ::::== but only if the variable does not already have a value.
941
942     ::::++==_s_t_r
943          Append _s_t_r to the variable.
944
945     ::::!!==_c_m_d
946          Assign the output of _c_m_d to the variable.
947
948     ::[[_r_a_n_g_e]]
949          Selects one or more words from the value, or performs other opera-
950          tions related to the way in which the value is divided into words.
951
952          Ordinarily, a value is treated as a sequence of words delimited by
953          white space.  Some modifiers suppress this behavior, causing a value
954          to be treated as a single word (possibly containing embedded white
955          space).  An empty value, or a value that consists entirely of white-
956          space, is treated as a single word.  For the purposes of the `::[[]]'
957          modifier, the words are indexed both forwards using positive inte-
958          gers (where index 1 represents the first word), and backwards using
959          negative integers (where index -1 represents the last word).
960
961          The _r_a_n_g_e is subjected to variable expansion, and the expanded
962          result is then interpreted as follows:
963
964          _i_n_d_e_x  Selects a single word from the value.
965
966          _s_t_a_r_t...._e_n_d
967                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
968                 `::[[22....--11]]' selects all words from the second word to the last
969                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
970                 put in reverse order.  For example, `::[[--11....11]]' selects all
971                 the words from last to first.
972
973          **      Causes subsequent modifiers to treat the value as a single
974                 word (possibly containing embedded white space).  Analogous
975                 to the effect of "$*" in Bourne shell.
976
977          0      Means the same as `::[[**]]'.
978
979          @@      Causes subsequent modifiers to treat the value as a sequence
980                 of words delimited by white space.  Analogous to the effect
981                 of "$@" in Bourne shell.
982
983          ##      Returns the number of words in the value.
984
985IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
986     Makefile inclusion, conditional structures and for loops  reminiscent of
987     the C programming language are provided in bbmmaakkee.  All such structures
988     are identified by a line beginning with a single dot (`.') character.
989     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
990     ables between the angle brackets or double quotes are expanded to form
991     the file name.  If angle brackets are used, the included makefile is
992     expected to be in the system makefile directory.  If double quotes are
993     used, the including makefile's directory and any directories specified
994     using the --II option are searched before the system makefile directory.
995     For compatibility with other versions of bbmmaakkee `include file ...' is also
996     accepted.
997
998     If the include statement is written as ..--iinncclluuddee or as ..ssiinncclluuddee then
999     errors locating and/or opening include files are ignored.
1000
1001     If the include statement is written as ..ddiinncclluuddee not only are errors
1002     locating and/or opening include files ignored, but stale dependencies
1003     within the included file will be ignored just like _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E.
1004
1005     Conditional expressions are also preceded by a single dot as the first
1006     character of a line.  The possible conditionals are as follows:
1007
1008     ..eerrrroorr _m_e_s_s_a_g_e
1009             The message is printed along with the name of the makefile and
1010             line number, then bbmmaakkee will exit.
1011
1012     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
1013             Export the specified global variable.  If no variable list is
1014             provided, all globals are exported except for internal variables
1015             (those that start with `.').  This is not affected by the --XX
1016             flag, so should be used with caution.  For compatibility with
1017             other bbmmaakkee programs `export variable=value' is also accepted.
1018
1019             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
1020             exporting a variable.
1021
1022     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
1023             The same as `.export', except that the variable is not appended
1024             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
1025             ment which is different from that used by bbmmaakkee internally.
1026
1027     ..eexxppoorrtt--lliitteerraall _v_a_r_i_a_b_l_e _._._.
1028             The same as `.export-env', except that variables in the value are
1029             not expanded.
1030
1031     ..iinnffoo _m_e_s_s_a_g_e
1032             The message is printed along with the name of the makefile and
1033             line number.
1034
1035     ..uunnddeeff _v_a_r_i_a_b_l_e
1036             Un-define the specified global variable.  Only global variables
1037             may be un-defined.
1038
1039     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
1040             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
1041             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
1042             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
1043
1044     ..uunneexxppoorrtt--eennvv
1045             Unexport all globals previously exported and clear the environ-
1046             ment inherited from the parent.  This operation will cause a mem-
1047             ory leak of the original environment, so should be used spar-
1048             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
1049             note that any variables which originated in the parent environ-
1050             ment should be explicitly preserved if desired.  For example:
1051
1052                   .if ${.MAKE.LEVEL} == 0
1053                   PATH := ${PATH}
1054                   .unexport-env
1055                   .export PATH
1056                   .endif
1057
1058             Would result in an environment containing only `PATH', which is
1059             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
1060             be pushed into the new environment.
1061
1062     ..wwaarrnniinngg _m_e_s_s_a_g_e
1063             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
1064             of the makefile and line number.
1065
1066     ..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 _._._.]
1067             Test the value of an expression.
1068
1069     ..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 _._._.]
1070             Test the value of a variable.
1071
1072     ..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 _._._.]
1073             Test the value of a variable.
1074
1075     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1076             Test the target being built.
1077
1078     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1079             Test the target being built.
1080
1081     ..eellssee   Reverse the sense of the last conditional.
1082
1083     ..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 _._._.]
1084             A combination of `..eellssee' followed by `..iiff'.
1085
1086     ..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 _._._.]
1087             A combination of `..eellssee' followed by `..iiffddeeff'.
1088
1089     ..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 _._._.]
1090             A combination of `..eellssee' followed by `..iiffnnddeeff'.
1091
1092     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1093             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1094
1095     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1096             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1097
1098     ..eennddiiff  End the body of the conditional.
1099
1100     The _o_p_e_r_a_t_o_r may be any one of the following:
1101
1102     ||||     Logical OR.
1103
1104     &&&&     Logical AND; of higher precedence than ``||''.
1105
1106     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
1107     determine its value.  Parentheses may be used to change the order of
1108     evaluation.  The boolean operator `!!' may be used to logically negate an
1109     entire conditional.  It is of higher precedence than `&&&&'.
1110
1111     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
1112
1113     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
1114              the variable has been defined.
1115
1116     mmaakkee     Takes a target name as an argument and evaluates to true if the
1117              target was specified as part of bbmmaakkee's command line or was
1118              declared the default target (either implicitly or explicitly,
1119              see _._M_A_I_N) before the line containing the conditional.
1120
1121     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1122              if the expansion of the variable would result in an empty
1123              string.
1124
1125     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1126              file exists.  The file is searched for on the system search path
1127              (see _._P_A_T_H).
1128
1129     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1130              target has been defined.
1131
1132     ccoommmmaannddss
1133              Takes a target name as an argument and evaluates to true if the
1134              target has been defined and has commands associated with it.
1135
1136     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1137     expansion is performed on both sides of the comparison, after which the
1138     integral values are compared.  A value is interpreted as hexadecimal if
1139     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1140     ported.  The standard C relational operators are all supported.  If after
1141     variable expansion, either the left or right hand side of a `====' or `!!=='
1142     operator is not an integral value, then string comparison is performed
1143     between the expanded variables.  If no relational operator is given, it
1144     is assumed that the expanded variable is being compared against 0 or an
1145     empty string in the case of a string comparison.
1146
1147     When bbmmaakkee is evaluating one of these conditional expressions, and it
1148     encounters a (white-space separated) word it doesn't recognize, either
1149     the ``make'' or ``defined'' expression is applied to it, depending on the
1150     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1151     the ``defined'' expression is applied.  Similarly, if the form is
1152     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1153
1154     If the conditional evaluates to true the parsing of the makefile contin-
1155     ues as before.  If it evaluates to false, the following lines are
1156     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1157     found.
1158
1159     For loops are typically used to apply a set of rules to a list of files.
1160     The syntax of a for loop is:
1161
1162     ..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
1163     <make-rules>
1164     ..eennddffoorr
1165
1166     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1167     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1168     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1169     the body of the for loop.  The number of words must come out even; that
1170     is, if there are three iteration variables, the number of words provided
1171     must be a multiple of three.
1172
1173CCOOMMMMEENNTTSS
1174     Comments begin with a hash (`#') character, anywhere but in a shell com-
1175     mand line, and continue to the end of an unescaped new line.
1176
1177SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1178     ..EEXXEECC     Target is never out of date, but always execute commands any-
1179               way.
1180
1181     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1182               get, exactly as if they all were preceded by a dash (`-').
1183
1184     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1185
1186     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1187               or --tt options were specified.  Normally used to mark recursive
1188               bbmmaakkees.
1189
1190     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1191               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1192               the most likely case.  In "meta" mode, the target is out-of-
1193               date if the meta file is missing.
1194
1195     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1196               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1197
1198     ..NNOOMMEETTAA__CCMMPP
1199               Ignore differences in commands when deciding if target is out
1200               of date.  This is useful if the command contains a value which
1201               always changes.  If the number of commands change, though, the
1202               target will still be out of date.  The same effect applies to
1203               any command line that uses the variable _._O_O_D_A_T_E, which can be
1204               used for that purpose even when not otherwise needed or
1205               desired:
1206
1207
1208                     skip-compare-for-some:
1209                             @echo this will be compared
1210                             @echo this will not ${.OODATE:M.NOMETA_CMP}
1211                             @echo this will also be compared
1212
1213               The ::MM pattern suppresses any expansion of the unwanted vari-
1214               able.
1215
1216     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1217               ..PPAATTHH.
1218
1219     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1220               default target to be built if no target was specified.  This
1221               source prevents this target from being selected.
1222
1223     ..OOPPTTIIOONNAALL
1224               If a target is marked with this attribute and bbmmaakkee can't fig-
1225               ure out how to create it, it will ignore this fact and assume
1226               the file isn't needed or already exists.
1227
1228     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1229               considered to be out of date, and will not be created with the
1230               --tt option.  Suffix-transformation rules are not applied to
1231               ..PPHHOONNYY targets.
1232
1233     ..PPRREECCIIOOUUSS
1234               When bbmmaakkee is interrupted, it normally removes any partially
1235               made targets.  This source prevents the target from being
1236               removed.
1237
1238     ..RREECCUURRSSIIVVEE
1239               Synonym for ..MMAAKKEE.
1240
1241     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1242               exactly as if they all were preceded by an at sign (`@').
1243
1244     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1245               get is used as a source for another target, the other target
1246               acquires the commands, sources, and attributes (except for
1247               ..UUSSEE) of the source.  If the target already has commands, the
1248               ..UUSSEE target's commands are appended to them.
1249
1250     ..UUSSEEBBEEFFOORREE
1251               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1252               to the target.
1253
1254     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1255               it are made before the sources that succeed it in the line.
1256               Since the dependents of files are not made until the file
1257               itself could be made, this also stops the dependents being
1258               built unless they are needed for another branch of the depen-
1259               dency tree.  So given:
1260
1261               x: a .WAIT b
1262                       echo x
1263               a:
1264                       echo a
1265               b: b1
1266                       echo b
1267               b1:
1268                       echo b1
1269
1270               the output is always `a', `b1', `b', `x'.
1271               The ordering imposed by ..WWAAIITT is only relevant for parallel
1272               makes.
1273
1274SSPPEECCIIAALL TTAARRGGEETTSS
1275     Special targets may not be included with other targets, i.e. they must be
1276     the only target specified.
1277
1278     ..BBEEGGIINN   Any command lines attached to this target are executed before
1279              anything else is done.
1280
1281     ..DDEEFFAAUULLTT
1282              This is sort of a ..UUSSEE rule for any target (that was used only
1283              as a source) that bbmmaakkee can't figure out any other way to cre-
1284              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1285              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1286              own name.
1287
1288     ..DDEELLEETTEE__OONN__EERRRROORR
1289              If this target is present in the makefile, it globally causes
1290              make to delete targets whose commands fail.  (By default, only
1291              targets whose commands are interrupted during execution are
1292              deleted.  This is the historical behavior.)  This setting can be
1293              used to help prevent half-finished or malformed targets from
1294              being left around and corrupting future rebuilds.
1295
1296     ..EENNDD     Any command lines attached to this target are executed after
1297              everything else is done.
1298
1299     ..EERRRROORR   Any command lines attached to this target are executed when
1300              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1301              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1302
1303     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1304              sources are specified, this is the equivalent of specifying the
1305              --ii option.
1306
1307     ..IINNTTEERRRRUUPPTT
1308              If bbmmaakkee is interrupted, the commands for this target will be
1309              executed.
1310
1311     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1312              will be built.
1313
1314     ..MMAAKKEEFFLLAAGGSS
1315              This target provides a way to specify flags for bbmmaakkee when the
1316              makefile is used.  The flags are as if typed to the shell,
1317              though the --ff option will have no effect.
1318
1319     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1320
1321     ..NNOOTTPPAARRAALLLLEELL
1322              Disable parallel mode.
1323
1324     ..NNOO__PPAARRAALLLLEELL
1325              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1326              variants.
1327
1328     ..OOBBJJDDIIRR  The source is a new value for `_._O_B_J_D_I_R'.  If it exists, bbmmaakkee
1329              will chdir(2) to it and update the value of `_._O_B_J_D_I_R'.
1330
1331     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1332              add targets to the list of targets to be made.  Since the depen-
1333              dents of a target do not get built until the target itself could
1334              be built, unless `a' is built by another part of the dependency
1335              graph, the following is a dependency loop:
1336
1337              .ORDER: b a
1338              b: a
1339
1340              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1341              makes.
1342
1343     ..PPAATTHH    The sources are directories which are to be searched for files
1344              not found in the current directory.  If no sources are speci-
1345              fied, any previously specified directories are deleted.  If the
1346              source is the special ..DDOOTTLLAASSTT target, then the current working
1347              directory is searched last.
1348
1349     ..PPAATTHH.._s_u_f_f_i_x
1350              Like ..PPAATTHH but applies only to files with a particular suffix.
1351              The suffix must have been previously declared with ..SSUUFFFFIIXXEESS.
1352
1353     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1354
1355     ..PPRREECCIIOOUUSS
1356              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1357              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1358              every target in the file.
1359
1360     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1361              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1362
1363              _n_a_m_e        This is the minimal specification, used to select
1364                          one of the built-in shell specs; _s_h, _k_s_h, and _c_s_h.
1365
1366              _p_a_t_h        Specifies the path to the shell.
1367
1368              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1369
1370              _c_h_e_c_k       The command to turn on error checking.
1371
1372              _i_g_n_o_r_e      The command to disable error checking.
1373
1374              _e_c_h_o        The command to turn on echoing of commands executed.
1375
1376              _q_u_i_e_t       The command to turn off echoing of commands exe-
1377                          cuted.
1378
1379              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1380                          mand.  It is typically identical to _q_u_i_e_t.
1381
1382              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1383
1384              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1385                          ing.
1386
1387              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1388                          a single newline character when used outside of any
1389                          quoting characters.
1390              Example:
1391
1392              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1393                      check="set -e" ignore="set +e" \
1394                      echo="set -v" quiet="set +v" filter="set +v" \
1395                      echoFlag=v errFlag=e newline="'\n'"
1396
1397     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1398              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1399              command in the file.
1400
1401     ..SSTTAALLEE   This target gets run when a dependency file contains stale
1402              entries, having _._A_L_L_S_R_C set to the name of that dependency file.
1403
1404     ..SSUUFFFFIIXXEESS
1405              Each source specifies a suffix to bbmmaakkee.  If no sources are
1406              specified, any previously specified suffixes are deleted.  It
1407              allows the creation of suffix-transformation rules.
1408
1409              Example:
1410
1411              .SUFFIXES: .o
1412              .c.o:
1413                      cc -o ${.TARGET} -c ${.IMPSRC}
1414
1415EENNVVIIRROONNMMEENNTT
1416     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1417     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1418     PWD, and TMPDIR.
1419
1420     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1421     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1422     tion of `_._O_B_J_D_I_R' for more details.
1423
1424FFIILLEESS
1425     .depend        list of dependencies
1426     Makefile       list of dependencies
1427     makefile       list of dependencies
1428     sys.mk         system makefile
1429     /usr/share/mk  system makefile directory
1430
1431CCOOMMPPAATTIIBBIILLIITTYY
1432     The basic make syntax is compatible between different versions of make;
1433     however the special variables, variable modifiers and conditionals are
1434     not.
1435
1436   OOllddeerr vveerrssiioonnss
1437     An incomplete list of changes in older versions of bbmmaakkee:
1438
1439     The way that .for loop variables are substituted changed after NetBSD 5.0
1440     so that they still appear to be variable expansions.  In particular this
1441     stops them being treated as syntax, and removes some obscure problems
1442     using them in .if statements.
1443
1444     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1445     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1446     rithms used may change again in the future.
1447
1448   OOtthheerr mmaakkee ddiiaalleeccttss
1449     Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not sup-
1450     port most of the features of bbmmaakkee as described in this manual.  Most
1451     notably:
1452
1453           ++oo   The ..WWAAIITT and ..OORRDDEERR declarations and most functionality per-
1454               taining to parallelization.  (GNU make supports parallelization
1455               but lacks these features needed to control it effectively.)
1456
1457           ++oo   Directives, including for loops and conditionals and most of
1458               the forms of include files.  (GNU make has its own incompatible
1459               and less powerful syntax for conditionals.)
1460
1461           ++oo   All built-in variables that begin with a dot.
1462
1463           ++oo   Most of the special sources and targets that begin with a dot,
1464               with the notable exception of ..PPHHOONNYY, ..PPRREECCIIOOUUSS, and ..SSUUFFFFIIXXEESS.
1465
1466           ++oo   Variable modifiers, except for the
1467                     :old=new
1468               string substitution, which does not portably support globbing
1469               with `%' and historically only works on declared suffixes.
1470
1471           ++oo   The $$>> variable even in its short form; most makes support this
1472               functionality but its name varies.
1473
1474     Some features are somewhat more portable, such as assignment with ++==, ??==,
1475     and !!==.  The ..PPAATTHH functionality is based on an older feature VVPPAATTHH found
1476     in GNU make and many versions of SVR4 make; however, historically its
1477     behavior is too ill-defined (and too buggy) to rely upon.
1478
1479     The $$@@ and $$<< variables are more or less universally portable, as is the
1480     $$((MMAAKKEE)) variable.  Basic use of suffix rules (for files only in the cur-
1481     rent directory, not trying to chain transformations together, etc.) is
1482     also reasonably portable.
1483
1484SSEEEE AALLSSOO
1485     mkdep(1)
1486
1487HHIISSTTOORRYY
1488     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1489     portability to other platforms.
1490
1491     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1492     is based on Adam De Boor's pmake program which was written for Sprite at
1493     Berkeley.  It was designed to be a parallel distributed make running jobs
1494     on different machines using a daemon called ``customs''.
1495
1496     Historically the target/dependency ``FRC'' has been used to FoRCe
1497     rebuilding (since the target/dependency does not exist... unless someone
1498     creates an ``FRC'' file).
1499
1500BBUUGGSS
1501     The make syntax is difficult to parse without actually acting of the
1502     data.  For instance finding the end of a variable use should involve
1503     scanning each the modifiers using the correct terminator for each field.
1504     In many places make just counts {} and () in order to find the end of a
1505     variable expansion.
1506
1507     There is no way of escaping a space character in a filename.
1508
1509NetBSD 5.1                      August 26, 2016                     NetBSD 5.1
1510