xref: /freebsd/contrib/bmake/bmake.cat1 (revision 99429157e8615dc3b7f11afbe3ed92de7476a5db)
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     ::rraannggee[[==ccoouunntt]]
793          The value is an integer sequence representing the words of the orig-
794          inal value, or the supplied _c_o_u_n_t.
795
796     ::ggmmttiimmee[[==uuttcc]]
797          The value is a format string for strftime(3), using gmtime(3).  If a
798          _u_t_c value is not provided or is 0, the current time is used.
799
800     ::hhaasshh
801          Compute a 32-bit hash of the value and encode it as hex digits.
802
803     ::llooccaallttiimmee[[==uuttcc]]
804          The value is a format string for strftime(3), using localtime(3).
805          If a _u_t_c value is not provided or is 0, the current time is used.
806
807     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
808          if that fails, the value is unchanged.
809
810     ::ttll  Converts variable to lower-case letters.
811
812     ::ttss_c
813          Words in the variable are normally separated by a space on expan-
814          sion.  This modifier sets the separator to the character _c.  If _c is
815          omitted, then no separator is used.  The common escapes (including
816          octal numeric codes), work as expected.
817
818     ::ttuu  Converts variable to upper-case letters.
819
820     ::ttWW  Causes the value to be treated as a single word (possibly containing
821          embedded white space).  See also `::[[**]]'.
822
823     ::ttww  Causes the value to be treated as a sequence of words delimited by
824          white space.  See also `::[[@@]]'.
825
826     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
827          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
828          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
829          slash of the pattern, all occurrences in each word are replaced.  If
830          a `1' is appended to the last slash of the pattern, only the first
831          word is affected.  If a `W' is appended to the last slash of the
832          pattern, then the value is treated as a single word (possibly con-
833          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
834          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
835          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
836          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
837          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
838          delimiter for the parts of the modifier string.  The anchoring,
839          ampersand and delimiter characters may be escaped with a backslash
840          (`\').
841
842          Variable expansion occurs in the normal fashion inside both
843          _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
844          is used to prevent the expansion of a dollar sign (`$'), not a pre-
845          ceding dollar sign as is usual.
846
847     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
848          The ::CC modifier is just like the ::SS modifier except that the old and
849          new strings, instead of being simple strings, are an extended regu-
850          lar expression (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style
851          string _r_e_p_l_a_c_e_m_e_n_t.  Normally, the first occurrence of the pattern
852          _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.
853          The `1' modifier causes the substitution to apply to at most one
854          word; the `g' modifier causes the substitution to apply to as many
855          instances of the search pattern _p_a_t_t_e_r_n as occur in the word or
856          words it is found in; the `W' modifier causes the value to be
857          treated as a single word (possibly containing embedded white space).
858          Note that `1' and `g' are orthogonal; the former specifies whether
859          multiple words are potentially affected, the latter whether multiple
860          substitutions can potentially occur within each affected word.
861
862          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
863          variable expansion before being parsed as regular expressions.
864
865     ::TT   Replaces each word in the variable with its last component.
866
867     ::uu   Remove adjacent duplicate words (like uniq(1)).
868
869     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
870          If the variable name (not its value), when parsed as a .if condi-
871          tional expression, evaluates to true, return as its value the
872          _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
873          name is used as the expression, :? must be the first modifier after
874          the variable name itself - which will, of course, usually contain
875          variable expansions.  A common error is trying to use expressions
876          like
877                ${NUMBERS:M42:?match:no}
878          which actually tests defined(NUMBERS), to determine is any words
879          match "42" you need to use something like:
880                ${"${NUMBERS:M42}" != "":?match:no}.
881
882     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
883          This is the AT&T System V UNIX style variable substitution.  It must
884          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
885          contain the pattern matching character _% then it is assumed that
886          they are anchored at the end of each word, so only suffixes or
887          entire words may be replaced.  Otherwise _% is the substring of
888          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
889
890          Variable expansion occurs in the normal fashion inside both
891          _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
892          is used to prevent the expansion of a dollar sign (`$'), not a pre-
893          ceding dollar sign as is usual.
894
895     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
896          This is the loop expansion mechanism from the OSF Development Envi-
897          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
898          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
899          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
900          period.  For example.
901                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
902
903          However a single character variable is often more readable:
904                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
905
906     ::__[[==vvaarr]]
907          Save the current variable value in `$_' or the named _v_a_r for later
908          reference.  Example usage:
909
910                M_cmpv.units = 1 1000 1000000
911                M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \
912                \* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
913
914                .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
915
916          Here `$_' is used to save the result of the `:S' modifier which is
917          later referenced using the index values from `:range'.
918
919     ::UU_n_e_w_v_a_l
920          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
921          is defined, the existing value is returned.  This is another ODE
922          make feature.  It is handy for setting per-target CFLAGS for
923          instance:
924                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
925          If a value is only required if the variable is undefined, use:
926                ${VAR:D:Unewval}
927
928     ::DD_n_e_w_v_a_l
929          If the variable is defined _n_e_w_v_a_l is the value.
930
931     ::LL   The name of the variable is the value.
932
933     ::PP   The path of the node which has the same name as the variable is the
934          value.  If no such node exists or its path is null, then the name of
935          the variable is used.  In order for this modifier to work, the name
936          (node) must at least have appeared on the rhs of a dependency.
937
938     ::!!_c_m_d!!
939          The output of running _c_m_d is the value.
940
941     ::sshh  If the variable is non-empty it is run as a command and the output
942          becomes the new value.
943
944     ::::==_s_t_r
945          The variable is assigned the value _s_t_r after substitution.  This
946          modifier and its variations are useful in obscure situations such as
947          wanting to set a variable when shell commands are being parsed.
948          These assignment modifiers always expand to nothing, so if appearing
949          in a rule line by themselves should be preceded with something to
950          keep bbmmaakkee happy.
951
952          The `::::' helps avoid false matches with the AT&T System V UNIX style
953          ::== modifier and since substitution always occurs the ::::== form is
954          vaguely appropriate.
955
956     ::::??==_s_t_r
957          As for ::::== but only if the variable does not already have a value.
958
959     ::::++==_s_t_r
960          Append _s_t_r to the variable.
961
962     ::::!!==_c_m_d
963          Assign the output of _c_m_d to the variable.
964
965     ::[[_r_a_n_g_e]]
966          Selects one or more words from the value, or performs other opera-
967          tions related to the way in which the value is divided into words.
968
969          Ordinarily, a value is treated as a sequence of words delimited by
970          white space.  Some modifiers suppress this behavior, causing a value
971          to be treated as a single word (possibly containing embedded white
972          space).  An empty value, or a value that consists entirely of white-
973          space, is treated as a single word.  For the purposes of the `::[[]]'
974          modifier, the words are indexed both forwards using positive inte-
975          gers (where index 1 represents the first word), and backwards using
976          negative integers (where index -1 represents the last word).
977
978          The _r_a_n_g_e is subjected to variable expansion, and the expanded
979          result is then interpreted as follows:
980
981          _i_n_d_e_x  Selects a single word from the value.
982
983          _s_t_a_r_t...._e_n_d
984                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
985                 `::[[22....--11]]' selects all words from the second word to the last
986                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
987                 put in reverse order.  For example, `::[[--11....11]]' selects all
988                 the words from last to first.
989
990          **      Causes subsequent modifiers to treat the value as a single
991                 word (possibly containing embedded white space).  Analogous
992                 to the effect of "$*" in Bourne shell.
993
994          0      Means the same as `::[[**]]'.
995
996          @@      Causes subsequent modifiers to treat the value as a sequence
997                 of words delimited by white space.  Analogous to the effect
998                 of "$@" in Bourne shell.
999
1000          ##      Returns the number of words in the value.
1001
1002IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
1003     Makefile inclusion, conditional structures and for loops  reminiscent of
1004     the C programming language are provided in bbmmaakkee.  All such structures
1005     are identified by a line beginning with a single dot (`.') character.
1006     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
1007     ables between the angle brackets or double quotes are expanded to form
1008     the file name.  If angle brackets are used, the included makefile is
1009     expected to be in the system makefile directory.  If double quotes are
1010     used, the including makefile's directory and any directories specified
1011     using the --II option are searched before the system makefile directory.
1012     For compatibility with other versions of bbmmaakkee `include file ...' is also
1013     accepted.
1014
1015     If the include statement is written as ..--iinncclluuddee or as ..ssiinncclluuddee then
1016     errors locating and/or opening include files are ignored.
1017
1018     If the include statement is written as ..ddiinncclluuddee not only are errors
1019     locating and/or opening include files ignored, but stale dependencies
1020     within the included file will be ignored just like _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E.
1021
1022     Conditional expressions are also preceded by a single dot as the first
1023     character of a line.  The possible conditionals are as follows:
1024
1025     ..eerrrroorr _m_e_s_s_a_g_e
1026             The message is printed along with the name of the makefile and
1027             line number, then bbmmaakkee will exit.
1028
1029     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
1030             Export the specified global variable.  If no variable list is
1031             provided, all globals are exported except for internal variables
1032             (those that start with `.').  This is not affected by the --XX
1033             flag, so should be used with caution.  For compatibility with
1034             other bbmmaakkee programs `export variable=value' is also accepted.
1035
1036             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
1037             exporting a variable.
1038
1039     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
1040             The same as `.export', except that the variable is not appended
1041             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
1042             ment which is different from that used by bbmmaakkee internally.
1043
1044     ..eexxppoorrtt--lliitteerraall _v_a_r_i_a_b_l_e _._._.
1045             The same as `.export-env', except that variables in the value are
1046             not expanded.
1047
1048     ..iinnffoo _m_e_s_s_a_g_e
1049             The message is printed along with the name of the makefile and
1050             line number.
1051
1052     ..uunnddeeff _v_a_r_i_a_b_l_e
1053             Un-define the specified global variable.  Only global variables
1054             may be un-defined.
1055
1056     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
1057             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
1058             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
1059             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
1060
1061     ..uunneexxppoorrtt--eennvv
1062             Unexport all globals previously exported and clear the environ-
1063             ment inherited from the parent.  This operation will cause a mem-
1064             ory leak of the original environment, so should be used spar-
1065             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
1066             note that any variables which originated in the parent environ-
1067             ment should be explicitly preserved if desired.  For example:
1068
1069                   .if ${.MAKE.LEVEL} == 0
1070                   PATH := ${PATH}
1071                   .unexport-env
1072                   .export PATH
1073                   .endif
1074
1075             Would result in an environment containing only `PATH', which is
1076             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
1077             be pushed into the new environment.
1078
1079     ..wwaarrnniinngg _m_e_s_s_a_g_e
1080             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
1081             of the makefile and line number.
1082
1083     ..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 _._._.]
1084             Test the value of an expression.
1085
1086     ..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 _._._.]
1087             Test the value of a variable.
1088
1089     ..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 _._._.]
1090             Test the value of a variable.
1091
1092     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1093             Test the target being built.
1094
1095     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1096             Test the target being built.
1097
1098     ..eellssee   Reverse the sense of the last conditional.
1099
1100     ..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 _._._.]
1101             A combination of `..eellssee' followed by `..iiff'.
1102
1103     ..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 _._._.]
1104             A combination of `..eellssee' followed by `..iiffddeeff'.
1105
1106     ..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 _._._.]
1107             A combination of `..eellssee' followed by `..iiffnnddeeff'.
1108
1109     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1110             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1111
1112     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1113             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1114
1115     ..eennddiiff  End the body of the conditional.
1116
1117     The _o_p_e_r_a_t_o_r may be any one of the following:
1118
1119     ||||     Logical OR.
1120
1121     &&&&     Logical AND; of higher precedence than ``||''.
1122
1123     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
1124     determine its value.  Parentheses may be used to change the order of
1125     evaluation.  The boolean operator `!!' may be used to logically negate an
1126     entire conditional.  It is of higher precedence than `&&&&'.
1127
1128     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
1129
1130     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
1131              the variable has been defined.
1132
1133     mmaakkee     Takes a target name as an argument and evaluates to true if the
1134              target was specified as part of bbmmaakkee's command line or was
1135              declared the default target (either implicitly or explicitly,
1136              see _._M_A_I_N) before the line containing the conditional.
1137
1138     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1139              if the expansion of the variable would result in an empty
1140              string.
1141
1142     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1143              file exists.  The file is searched for on the system search path
1144              (see _._P_A_T_H).
1145
1146     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1147              target has been defined.
1148
1149     ccoommmmaannddss
1150              Takes a target name as an argument and evaluates to true if the
1151              target has been defined and has commands associated with it.
1152
1153     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1154     expansion is performed on both sides of the comparison, after which the
1155     integral values are compared.  A value is interpreted as hexadecimal if
1156     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1157     ported.  The standard C relational operators are all supported.  If after
1158     variable expansion, either the left or right hand side of a `====' or `!!=='
1159     operator is not an integral value, then string comparison is performed
1160     between the expanded variables.  If no relational operator is given, it
1161     is assumed that the expanded variable is being compared against 0 or an
1162     empty string in the case of a string comparison.
1163
1164     When bbmmaakkee is evaluating one of these conditional expressions, and it
1165     encounters a (white-space separated) word it doesn't recognize, either
1166     the ``make'' or ``defined'' expression is applied to it, depending on the
1167     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1168     the ``defined'' expression is applied.  Similarly, if the form is
1169     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1170
1171     If the conditional evaluates to true the parsing of the makefile contin-
1172     ues as before.  If it evaluates to false, the following lines are
1173     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1174     found.
1175
1176     For loops are typically used to apply a set of rules to a list of files.
1177     The syntax of a for loop is:
1178
1179     ..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
1180     <make-rules>
1181     ..eennddffoorr
1182
1183     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1184     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1185     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1186     the body of the for loop.  The number of words must come out even; that
1187     is, if there are three iteration variables, the number of words provided
1188     must be a multiple of three.
1189
1190CCOOMMMMEENNTTSS
1191     Comments begin with a hash (`#') character, anywhere but in a shell com-
1192     mand line, and continue to the end of an unescaped new line.
1193
1194SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1195     ..EEXXEECC     Target is never out of date, but always execute commands any-
1196               way.
1197
1198     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1199               get, exactly as if they all were preceded by a dash (`-').
1200
1201     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1202
1203     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1204               or --tt options were specified.  Normally used to mark recursive
1205               bbmmaakkees.
1206
1207     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1208               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1209               the most likely case.  In "meta" mode, the target is out-of-
1210               date if the meta file is missing.
1211
1212     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1213               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1214
1215     ..NNOOMMEETTAA__CCMMPP
1216               Ignore differences in commands when deciding if target is out
1217               of date.  This is useful if the command contains a value which
1218               always changes.  If the number of commands change, though, the
1219               target will still be out of date.  The same effect applies to
1220               any command line that uses the variable _._O_O_D_A_T_E, which can be
1221               used for that purpose even when not otherwise needed or
1222               desired:
1223
1224
1225                     skip-compare-for-some:
1226                             @echo this will be compared
1227                             @echo this will not ${.OODATE:M.NOMETA_CMP}
1228                             @echo this will also be compared
1229
1230               The ::MM pattern suppresses any expansion of the unwanted vari-
1231               able.
1232
1233     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1234               ..PPAATTHH.
1235
1236     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1237               default target to be built if no target was specified.  This
1238               source prevents this target from being selected.
1239
1240     ..OOPPTTIIOONNAALL
1241               If a target is marked with this attribute and bbmmaakkee can't fig-
1242               ure out how to create it, it will ignore this fact and assume
1243               the file isn't needed or already exists.
1244
1245     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1246               considered to be out of date, and will not be created with the
1247               --tt option.  Suffix-transformation rules are not applied to
1248               ..PPHHOONNYY targets.
1249
1250     ..PPRREECCIIOOUUSS
1251               When bbmmaakkee is interrupted, it normally removes any partially
1252               made targets.  This source prevents the target from being
1253               removed.
1254
1255     ..RREECCUURRSSIIVVEE
1256               Synonym for ..MMAAKKEE.
1257
1258     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1259               exactly as if they all were preceded by an at sign (`@').
1260
1261     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1262               get is used as a source for another target, the other target
1263               acquires the commands, sources, and attributes (except for
1264               ..UUSSEE) of the source.  If the target already has commands, the
1265               ..UUSSEE target's commands are appended to them.
1266
1267     ..UUSSEEBBEEFFOORREE
1268               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1269               to the target.
1270
1271     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1272               it are made before the sources that succeed it in the line.
1273               Since the dependents of files are not made until the file
1274               itself could be made, this also stops the dependents being
1275               built unless they are needed for another branch of the depen-
1276               dency tree.  So given:
1277
1278               x: a .WAIT b
1279                       echo x
1280               a:
1281                       echo a
1282               b: b1
1283                       echo b
1284               b1:
1285                       echo b1
1286
1287               the output is always `a', `b1', `b', `x'.
1288               The ordering imposed by ..WWAAIITT is only relevant for parallel
1289               makes.
1290
1291SSPPEECCIIAALL TTAARRGGEETTSS
1292     Special targets may not be included with other targets, i.e. they must be
1293     the only target specified.
1294
1295     ..BBEEGGIINN   Any command lines attached to this target are executed before
1296              anything else is done.
1297
1298     ..DDEEFFAAUULLTT
1299              This is sort of a ..UUSSEE rule for any target (that was used only
1300              as a source) that bbmmaakkee can't figure out any other way to cre-
1301              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1302              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1303              own name.
1304
1305     ..DDEELLEETTEE__OONN__EERRRROORR
1306              If this target is present in the makefile, it globally causes
1307              make to delete targets whose commands fail.  (By default, only
1308              targets whose commands are interrupted during execution are
1309              deleted.  This is the historical behavior.)  This setting can be
1310              used to help prevent half-finished or malformed targets from
1311              being left around and corrupting future rebuilds.
1312
1313     ..EENNDD     Any command lines attached to this target are executed after
1314              everything else is done.
1315
1316     ..EERRRROORR   Any command lines attached to this target are executed when
1317              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1318              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1319
1320     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1321              sources are specified, this is the equivalent of specifying the
1322              --ii option.
1323
1324     ..IINNTTEERRRRUUPPTT
1325              If bbmmaakkee is interrupted, the commands for this target will be
1326              executed.
1327
1328     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1329              will be built.
1330
1331     ..MMAAKKEEFFLLAAGGSS
1332              This target provides a way to specify flags for bbmmaakkee when the
1333              makefile is used.  The flags are as if typed to the shell,
1334              though the --ff option will have no effect.
1335
1336     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1337
1338     ..NNOOTTPPAARRAALLLLEELL
1339              Disable parallel mode.
1340
1341     ..NNOO__PPAARRAALLLLEELL
1342              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1343              variants.
1344
1345     ..OOBBJJDDIIRR  The source is a new value for `_._O_B_J_D_I_R'.  If it exists, bbmmaakkee
1346              will chdir(2) to it and update the value of `_._O_B_J_D_I_R'.
1347
1348     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1349              add targets to the list of targets to be made.  Since the depen-
1350              dents of a target do not get built until the target itself could
1351              be built, unless `a' is built by another part of the dependency
1352              graph, the following is a dependency loop:
1353
1354              .ORDER: b a
1355              b: a
1356
1357              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1358              makes.
1359
1360     ..PPAATTHH    The sources are directories which are to be searched for files
1361              not found in the current directory.  If no sources are speci-
1362              fied, any previously specified directories are deleted.  If the
1363              source is the special ..DDOOTTLLAASSTT target, then the current working
1364              directory is searched last.
1365
1366     ..PPAATTHH.._s_u_f_f_i_x
1367              Like ..PPAATTHH but applies only to files with a particular suffix.
1368              The suffix must have been previously declared with ..SSUUFFFFIIXXEESS.
1369
1370     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1371
1372     ..PPRREECCIIOOUUSS
1373              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1374              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1375              every target in the file.
1376
1377     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1378              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1379
1380              _n_a_m_e        This is the minimal specification, used to select
1381                          one of the built-in shell specs; _s_h, _k_s_h, and _c_s_h.
1382
1383              _p_a_t_h        Specifies the path to the shell.
1384
1385              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1386
1387              _c_h_e_c_k       The command to turn on error checking.
1388
1389              _i_g_n_o_r_e      The command to disable error checking.
1390
1391              _e_c_h_o        The command to turn on echoing of commands executed.
1392
1393              _q_u_i_e_t       The command to turn off echoing of commands exe-
1394                          cuted.
1395
1396              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1397                          mand.  It is typically identical to _q_u_i_e_t.
1398
1399              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1400
1401              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1402                          ing.
1403
1404              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1405                          a single newline character when used outside of any
1406                          quoting characters.
1407              Example:
1408
1409              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1410                      check="set -e" ignore="set +e" \
1411                      echo="set -v" quiet="set +v" filter="set +v" \
1412                      echoFlag=v errFlag=e newline="'\n'"
1413
1414     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1415              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1416              command in the file.
1417
1418     ..SSTTAALLEE   This target gets run when a dependency file contains stale
1419              entries, having _._A_L_L_S_R_C set to the name of that dependency file.
1420
1421     ..SSUUFFFFIIXXEESS
1422              Each source specifies a suffix to bbmmaakkee.  If no sources are
1423              specified, any previously specified suffixes are deleted.  It
1424              allows the creation of suffix-transformation rules.
1425
1426              Example:
1427
1428              .SUFFIXES: .o
1429              .c.o:
1430                      cc -o ${.TARGET} -c ${.IMPSRC}
1431
1432EENNVVIIRROONNMMEENNTT
1433     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1434     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1435     PWD, and TMPDIR.
1436
1437     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1438     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1439     tion of `_._O_B_J_D_I_R' for more details.
1440
1441FFIILLEESS
1442     .depend        list of dependencies
1443     Makefile       list of dependencies
1444     makefile       list of dependencies
1445     sys.mk         system makefile
1446     /usr/share/mk  system makefile directory
1447
1448CCOOMMPPAATTIIBBIILLIITTYY
1449     The basic make syntax is compatible between different versions of make;
1450     however the special variables, variable modifiers and conditionals are
1451     not.
1452
1453   OOllddeerr vveerrssiioonnss
1454     An incomplete list of changes in older versions of bbmmaakkee:
1455
1456     The way that .for loop variables are substituted changed after NetBSD 5.0
1457     so that they still appear to be variable expansions.  In particular this
1458     stops them being treated as syntax, and removes some obscure problems
1459     using them in .if statements.
1460
1461     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1462     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1463     rithms used may change again in the future.
1464
1465   OOtthheerr mmaakkee ddiiaalleeccttss
1466     Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not sup-
1467     port most of the features of bbmmaakkee as described in this manual.  Most
1468     notably:
1469
1470           ++oo   The ..WWAAIITT and ..OORRDDEERR declarations and most functionality per-
1471               taining to parallelization.  (GNU make supports parallelization
1472               but lacks these features needed to control it effectively.)
1473
1474           ++oo   Directives, including for loops and conditionals and most of
1475               the forms of include files.  (GNU make has its own incompatible
1476               and less powerful syntax for conditionals.)
1477
1478           ++oo   All built-in variables that begin with a dot.
1479
1480           ++oo   Most of the special sources and targets that begin with a dot,
1481               with the notable exception of ..PPHHOONNYY, ..PPRREECCIIOOUUSS, and ..SSUUFFFFIIXXEESS.
1482
1483           ++oo   Variable modifiers, except for the
1484                     :old=new
1485               string substitution, which does not portably support globbing
1486               with `%' and historically only works on declared suffixes.
1487
1488           ++oo   The $$>> variable even in its short form; most makes support this
1489               functionality but its name varies.
1490
1491     Some features are somewhat more portable, such as assignment with ++==, ??==,
1492     and !!==.  The ..PPAATTHH functionality is based on an older feature VVPPAATTHH found
1493     in GNU make and many versions of SVR4 make; however, historically its
1494     behavior is too ill-defined (and too buggy) to rely upon.
1495
1496     The $$@@ and $$<< variables are more or less universally portable, as is the
1497     $$((MMAAKKEE)) variable.  Basic use of suffix rules (for files only in the cur-
1498     rent directory, not trying to chain transformations together, etc.) is
1499     also reasonably portable.
1500
1501SSEEEE AALLSSOO
1502     mkdep(1)
1503
1504HHIISSTTOORRYY
1505     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1506     portability to other platforms.
1507
1508     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1509     is based on Adam De Boor's pmake program which was written for Sprite at
1510     Berkeley.  It was designed to be a parallel distributed make running jobs
1511     on different machines using a daemon called ``customs''.
1512
1513     Historically the target/dependency ``FRC'' has been used to FoRCe
1514     rebuilding (since the target/dependency does not exist... unless someone
1515     creates an ``FRC'' file).
1516
1517BBUUGGSS
1518     The make syntax is difficult to parse without actually acting of the
1519     data.  For instance finding the end of a variable use should involve
1520     scanning each the modifiers using the correct terminator for each field.
1521     In many places make just counts {} and () in order to find the end of a
1522     variable expansion.
1523
1524     There is no way of escaping a space character in a filename.
1525
1526NetBSD 7.1_RC1                 February 1, 2017                 NetBSD 7.1_RC1
1527