bmake.cat1 revision 246223
1116743SsamMAKE(1)                 NetBSD General Commands Manual                 MAKE(1)
2186904Ssam
3116743SsamNNAAMMEE
4116743Ssam     bbmmaakkee -- maintain program dependencies
5116743Ssam
6116743SsamSSYYNNOOPPSSIISS
7116743Ssam     bbmmaakkee [--BBeeiikkNNnnqqrrssttWWXX] [--CC _d_i_r_e_c_t_o_r_y] [--DD _v_a_r_i_a_b_l_e] [--dd _f_l_a_g_s]
8116743Ssam           [--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]
9116743Ssam           [--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]
10116743Ssam           [_t_a_r_g_e_t _._._.]
11116743Ssam
12116743SsamDDEESSCCRRIIPPTTIIOONN
13116743Ssam     bbmmaakkee is a program designed to simplify the maintenance of other pro-
14116743Ssam     grams.  Its input is a list of specifications as to the files upon which
15116743Ssam     programs and other files depend.  If no --ff _m_a_k_e_f_i_l_e makefile option is
16116743Ssam     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
17116743Ssam     the specifications.  If the file `_._d_e_p_e_n_d' exists, it is read (see
18116743Ssam     mkdep(1)).
19116743Ssam
20116743Ssam     This manual page is intended as a reference document only.  For a more
21116743Ssam     thorough description of bbmmaakkee and makefiles, please refer to _P_M_a_k_e _- _A
22116743Ssam     _T_u_t_o_r_i_a_l.
23116743Ssam
24116743Ssam     bbmmaakkee will prepend the contents of the _M_A_K_E_F_L_A_G_S environment variable to
25116743Ssam     the command line arguments before parsing them.
26116743Ssam
27116743Ssam     The options are as follows:
28116743Ssam
29116743Ssam     --BB      Try to be backwards compatible by executing a single shell per
30116743Ssam             command and by executing the commands to make the sources of a
31116743Ssam             dependency line in sequence.
32116743Ssam
33116743Ssam     --CC _d_i_r_e_c_t_o_r_y
34116743Ssam             Change to _d_i_r_e_c_t_o_r_y before reading the makefiles or doing any-
35116743Ssam             thing else.  If multiple --CC options are specified, each is inter-
36116743Ssam             preted relative to the previous one: --CC _/ --CC _e_t_c is equivalent to
37116743Ssam             --CC _/_e_t_c.
38227327Sadrian
39227327Sadrian     --DD _v_a_r_i_a_b_l_e
40227327Sadrian             Define _v_a_r_i_a_b_l_e to be 1, in the global context.
41227327Sadrian
42227327Sadrian     --dd _[_-_]_f_l_a_g_s
43227327Sadrian             Turn on debugging, and specify which portions of bbmmaakkee are to
44227327Sadrian             print debugging information.  Unless the flags are preceded by
45227327Sadrian             `-' they are added to the _M_A_K_E_F_L_A_G_S environment variable and will
46227327Sadrian             be processed by any child make processes.  By default, debugging
47227327Sadrian             information is printed to standard error, but this can be changed
48116743Ssam             using the _F debugging flag.  The debugging output is always
49116743Ssam             unbuffered; in addition, if debugging is enabled but debugging
50116743Ssam             output is not directed to standard output, then the standard out-
51116743Ssam             put is line buffered.  _F_l_a_g_s is one or more of the following:
52155492Ssam
53138570Ssam             _A       Print all possible debugging information; equivalent to
54116743Ssam                     specifying all of the debugging flags.
55116743Ssam
56116743Ssam             _a       Print debugging information about archive searching and
57138570Ssam                     caching.
58116743Ssam
59138570Ssam             _C       Print debugging information about current working direc-
60116743Ssam                     tory.
61116743Ssam
62116743Ssam             _c       Print debugging information about conditional evaluation.
63116743Ssam
64116743Ssam             _d       Print debugging information about directory searching and
65116743Ssam                     caching.
66116743Ssam
67116743Ssam             _e       Print debugging information about failed commands and
68116743Ssam                     targets.
69116743Ssam
70116743Ssam             _F[++]_f_i_l_e_n_a_m_e
71116743Ssam                     Specify where debugging output is written.  This must be
72116743Ssam                     the last flag, because it consumes the remainder of the
73116743Ssam                     argument.  If the character immediately after the `F'
74116743Ssam                     flag is `+', then the file will be opened in append mode;
75116743Ssam                     otherwise the file will be overwritten.  If the file name
76116743Ssam                     is `stdout' or `stderr' then debugging output will be
77116743Ssam                     written to the standard output or standard error output
78116743Ssam                     file descriptors respectively (and the `+' option has no
79116743Ssam                     effect).  Otherwise, the output will be written to the
80127779Ssam                     named file.  If the file name ends `.%d' then the `%d' is
81127779Ssam                     replaced by the pid.
82170530Ssam
83170530Ssam             _f       Print debugging information about loop evaluation.
84116743Ssam
85116743Ssam             _g_1      Print the input graph before making anything.
86116743Ssam
87116743Ssam             _g_2      Print the input graph after making everything, or before
88116743Ssam                     exiting on error.
89116743Ssam
90138570Ssam             _g_3      Print the input graph before exiting on error.
91116743Ssam
92218689Sadrian             _j       Print debugging information about running multiple
93119147Ssam                     shells.
94127779Ssam
95138570Ssam             _l       Print commands in Makefiles regardless of whether or not
96138570Ssam                     they are prefixed by `@' or other "quiet" flags.  Also
97119147Ssam                     known as "loud" behavior.
98138570Ssam
99138570Ssam             _M       Print debugging information about "meta" mode decisions
100161187Ssam                     about targets.
101138570Ssam
102116743Ssam             _m       Print debugging information about making targets, includ-
103116743Ssam                     ing modification dates.
104116743Ssam
105116743Ssam             _n       Don't delete the temporary command scripts created when
106116743Ssam                     running commands.  These temporary scripts are created in
107116743Ssam                     the directory referred to by the TMPDIR environment vari-
108116743Ssam                     able, or in _/_t_m_p if TMPDIR is unset or set to the empty
109138570Ssam                     string.  The temporary scripts are created by mkstemp(3),
110138570Ssam                     and have names of the form _m_a_k_e_X_X_X_X_X_X.  _N_O_T_E: This can
111138570Ssam                     create many files in TMPDIR or _/_t_m_p, so use with care.
112138570Ssam
113159894Ssam             _p       Print debugging information about makefile parsing.
114159894Ssam
115160992Ssam             _s       Print debugging information about suffix-transformation
116170530Ssam                     rules.
117170530Ssam
118170530Ssam             _t       Print debugging information about target list mainte-
119170530Ssam                     nance.
120170530Ssam
121170530Ssam             _V       Force the --VV option to print raw values of variables.
122186904Ssam
123186904Ssam             _v       Print debugging information about variable assignment.
124186904Ssam
125186904Ssam             _x       Run shell commands with --xx so the actual commands are
126186904Ssam                     printed as they are executed.
127186904Ssam
128188195Ssam     --ee      Specify that environment variables override macro assignments
129188195Ssam             within makefiles.
130188555Ssam
131211299Sadrian     --ff _m_a_k_e_f_i_l_e
132217684Sadrian             Specify a makefile to read instead of the default `_m_a_k_e_f_i_l_e'.  If
133218378Sadrian             _m_a_k_e_f_i_l_e is `--', standard input is read.  Multiple makefiles may
134221965Sadrian             be specified, and are read in the order specified.
135221965Sadrian
136221965Sadrian     --II _d_i_r_e_c_t_o_r_y
137221965Sadrian             Specify a directory in which to search for makefiles and included
138221965Sadrian             makefiles.  The system makefile directory (or directories, see
139218689Sadrian             the --mm option) is automatically included as part of this list.
140218924Sadrian
141221965Sadrian     --ii      Ignore non-zero exit of shell commands in the makefile.  Equiva-
142220772Sadrian             lent to specifying `--' before each command line in the makefile.
143220782Sadrian
144221965Sadrian     --JJ _p_r_i_v_a_t_e
145221965Sadrian             This option should _n_o_t be specified by the user.
146221965Sadrian
147226798Sadrian             When the _j option is in use in a recursive build, this option is
148226798Sadrian             passed by a make to child makes to allow all the make processes
149226798Sadrian             in the build to cooperate to avoid overloading the system.
150226798Sadrian
151227868Sadrian     --jj _m_a_x___j_o_b_s
152226798Sadrian             Specify the maximum number of jobs that bbmmaakkee may have running at
153226798Sadrian             any one time.  The value is saved in _._M_A_K_E_._J_O_B_S.  Turns compati-
154226798Sadrian             bility mode off, unless the _B flag is also specified.  When com-
155226798Sadrian             patibility mode is off, all commands associated with a target are
156227868Sadrian             executed in a single shell invocation as opposed to the tradi-
157227868Sadrian             tional one shell invocation per line.  This can break traditional
158227868Sadrian             scripts which change directories on each command invocation and
159116743Ssam             then expect to start with a fresh environment on the next line.
160116743Ssam             It is more efficient to correct the scripts rather than turn
161116743Ssam             backwards compatibility on.
162188557Ssam
163116743Ssam     --kk      Continue processing after errors are encountered, but only on
164123044Ssam             those targets that do not depend on the target whose creation
165138570Ssam             caused the error.
166138570Ssam
167138570Ssam     --mm _d_i_r_e_c_t_o_r_y
168138570Ssam             Specify a directory in which to search for sys.mk and makefiles
169138570Ssam             included via the <_f_i_l_e>-style include statement.  The --mm option
170138570Ssam             can be used multiple times to form a search path.  This path will
171138570Ssam             override the default system include path: /usr/share/mk.  Fur-
172138570Ssam             thermore the system include path will be appended to the search
173138570Ssam             path used for "_f_i_l_e"-style include statements (see the --II
174138570Ssam             option).
175123044Ssam
176123044Ssam             If a file or directory name in the --mm argument (or the
177123044Ssam             MAKESYSPATH environment variable) starts with the string ".../"
178224245Sadrian             then bbmmaakkee will search for the specified file or directory named
179123044Ssam             in the remaining part of the argument string.  The search starts
180119783Ssam             with the current directory of the Makefile and then works upward
181119783Ssam             towards the root of the filesystem.  If the search is successful,
182119783Ssam             then the resulting directory replaces the ".../" specification in
183119783Ssam             the --mm argument.  If used, this feature allows bbmmaakkee to easily
184154140Ssam             search in the current source tree for customized sys.mk files
185119783Ssam             (e.g., by using ".../mk/sys.mk" as an argument).
186119783Ssam
187123928Ssam     --nn      Display the commands that would have been executed, but do not
188154140Ssam             actually execute them unless the target depends on the .MAKE spe-
189154140Ssam             cial source (see below).
190170530Ssam
191119783Ssam     --NN      Display the commands which would have been executed, but do not
192119783Ssam             actually execute any of them; useful for debugging top-level
193119783Ssam             makefiles without descending into subdirectories.
194119783Ssam
195154140Ssam     --qq      Do not execute any commands, but exit 0 if the specified targets
196154140Ssam             are up-to-date and 1, otherwise.
197119783Ssam
198170530Ssam     --rr      Do not use the built-in rules specified in the system makefile.
199170530Ssam
200170530Ssam     --ss      Do not echo any commands as they are executed.  Equivalent to
201170530Ssam             specifying `@@' before each command line in the makefile.
202170530Ssam
203119783Ssam     --TT _t_r_a_c_e_f_i_l_e
204170530Ssam             When used with the --jj flag, append a trace record to _t_r_a_c_e_f_i_l_e
205170530Ssam             for each job started and completed.
206170530Ssam
207119783Ssam     --tt      Rather than re-building a target as specified in the makefile,
208119783Ssam             create it or update its modification time to make it appear up-
209154140Ssam             to-date.
210119783Ssam
211119783Ssam     --VV _v_a_r_i_a_b_l_e
212123928Ssam             Print bbmmaakkee's idea of the value of _v_a_r_i_a_b_l_e, in the global con-
213123928Ssam             text.  Do not build any targets.  Multiple instances of this
214170530Ssam             option may be specified; the variables will be printed one per
215119783Ssam             line, with a blank line for each null or undefined variable.  If
216119783Ssam             _v_a_r_i_a_b_l_e contains a `$' then the value will be expanded before
217119783Ssam             printing.
218119783Ssam
219154140Ssam     --WW      Treat any warnings during makefile parsing as errors.
220154140Ssam
221119783Ssam     --XX      Don't export variables passed on the command line to the environ-
222123928Ssam             ment individually.  Variables passed on the command line are
223123928Ssam             still exported via the _M_A_K_E_F_L_A_G_S environment variable.  This
224170530Ssam             option may be useful on systems which have a small limit on the
225170530Ssam             size of command arguments.
226170530Ssam
227170530Ssam     _v_a_r_i_a_b_l_e_=_v_a_l_u_e
228170530Ssam             Set the value of the variable _v_a_r_i_a_b_l_e to _v_a_l_u_e.  Normally, all
229119783Ssam             values passed on the command line are also exported to sub-makes
230224245Sadrian             in the environment.  The --XX flag disables this behavior.  Vari-
231224245Sadrian             able assignments should follow options for POSIX compatibility
232224245Sadrian             but no ordering is enforced.
233224245Sadrian
234224245Sadrian     There are seven different types of lines in a makefile: file dependency
235224245Sadrian     specifications, shell commands, variable assignments, include statements,
236224245Sadrian     conditional directives, for loops, and comments.
237224245Sadrian
238224245Sadrian     In general, lines may be continued from one line to the next by ending
239224245Sadrian     them with a backslash (`\').  The trailing newline character and initial
240224245Sadrian     whitespace on the following line are compressed into a single space.
241224245Sadrian
242224245SadrianFFIILLEE DDEEPPEENNDDEENNCCYY SSPPEECCIIFFIICCAATTIIOONNSS
243224245Sadrian     Dependency lines consist of one or more targets, an operator, and zero or
244224245Sadrian     more sources.  This creates a relationship where the targets ``depend''
245224245Sadrian     on the sources and are usually created from them.  The exact relationship
246224245Sadrian     between the target and the source is determined by the operator that sep-
247224245Sadrian     arates them.  The three operators are as follows:
248224245Sadrian
249224245Sadrian     ::     A target is considered out-of-date if its modification time is less
250224245Sadrian           than those of any of its sources.  Sources for a target accumulate
251224245Sadrian           over dependency lines when this operator is used.  The target is
252224245Sadrian           removed if bbmmaakkee is interrupted.
253224245Sadrian
254224245Sadrian     !!     Targets are always re-created, but not until all sources have been
255224245Sadrian           examined and re-created as necessary.  Sources for a target accumu-
256224245Sadrian           late over dependency lines when this operator is used.  The target
257224245Sadrian           is removed if bbmmaakkee is interrupted.
258224245Sadrian
259224245Sadrian     ::::    If no sources are specified, the target is always re-created.  Oth-
260116743Ssam           erwise, a target is considered out-of-date if any of its sources
261           has been modified more recently than the target.  Sources for a
262           target do not accumulate over dependency lines when this operator
263           is used.  The target will not be removed if bbmmaakkee is interrupted.
264
265     Targets and sources may contain the shell wildcard values `?', `*', `[]',
266     and `{}'.  The values `?', `*', and `[]' may only be used as part of the
267     final component of the target or source, and must be used to describe
268     existing files.  The value `{}' need not necessarily be used to describe
269     existing files.  Expansion is in directory order, not alphabetically as
270     done in the shell.
271
272SSHHEELLLL CCOOMMMMAANNDDSS
273     Each target may have associated with it a series of shell commands, nor-
274     mally used to create the target.  Each of the commands in this script
275     _m_u_s_t be preceded by a tab.  While any target may appear on a dependency
276     line, only one of these dependencies may be followed by a creation
277     script, unless the `::::' operator is used.
278
279     If the first characters of the command line are any combination of `@@',
280     `++', or `--', the command is treated specially.  A `@@' causes the command
281     not to be echoed before it is executed.  A `++' causes the command to be
282     executed even when --nn is given.  This is similar to the effect of the
283     .MAKE special source, except that the effect can be limited to a single
284     line of a script.  A `--' causes any non-zero exit status of the command
285     line to be ignored.
286
287     When bbmmaakkee is run in jobs mode with --jj _m_a_x___j_o_b_s, the entire script for
288     the target is fed to a single instance of the shell.
289
290     In compatibility (non-jobs) mode, each command is run in a separate
291     process.  If the command contains any shell meta characters
292     (`#=|^(){};&<>*?[]:$`\\n') it will be passed to the shell, otherwise
293     bbmmaakkee will attempt direct execution.
294
295     Since bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R' before executing any targets, each
296     child process starts with that as its current working directory.
297
298     Makefiles should be written so that the mode of bbmmaakkee operation does not
299     change their behavior.  For example, any command which needs to use
300     ``cd'' or ``chdir'', without side-effect should be put in parenthesis:
301
302
303           avoid-chdir-side-effects:
304                   @echo Building $@ in `pwd`
305                   @(cd ${.CURDIR} && ${.MAKE} $@)
306                   @echo Back in `pwd`
307
308           ensure-one-shell-regardless-of-mode:
309                   @echo Building $@ in `pwd`; \
310                   (cd ${.CURDIR} && ${.MAKE} $@); \
311                   echo Back in `pwd`
312
313VVAARRIIAABBLLEE AASSSSIIGGNNMMEENNTTSS
314     Variables in make are much like variables in the shell, and, by tradi-
315     tion, consist of all upper-case letters.
316
317   VVaarriiaabbllee aassssiiggnnmmeenntt mmooddiiffiieerrss
318     The five operators that can be used to assign values to variables are as
319     follows:
320
321     ==       Assign the value to the variable.  Any previous value is overrid-
322             den.
323
324     ++==      Append the value to the current value of the variable.
325
326     ??==      Assign the value to the variable if it is not already defined.
327
328     ::==      Assign with expansion, i.e. expand the value before assigning it
329             to the variable.  Normally, expansion is not done until the vari-
330             able is referenced.  _N_O_T_E: References to undefined variables are
331             _n_o_t expanded.  This can cause problems when variable modifiers
332             are used.
333
334     !!==      Expand the value and pass it to the shell for execution and
335             assign the result to the variable.  Any newlines in the result
336             are replaced with spaces.
337
338     Any white-space before the assigned _v_a_l_u_e is removed; if the value is
339     being appended, a single space is inserted between the previous contents
340     of the variable and the appended value.
341
342     Variables are expanded by surrounding the variable name with either curly
343     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
344     (`$').  If the variable name contains only a single letter, the surround-
345     ing braces or parentheses are not required.  This shorter form is not
346     recommended.
347
348     If the variable name contains a dollar, then the name itself is expanded
349     first.  This allows almost arbitrary variable names, however names con-
350     taining dollar, braces, parenthesis, or whitespace are really best
351     avoided!
352
353     If the result of expanding a variable contains a dollar sign (`$') the
354     string is expanded again.
355
356     Variable substitution occurs at three distinct times, depending on where
357     the variable is being used.
358
359     1.   Variables in dependency lines are expanded as the line is read.
360
361     2.   Variables in shell commands are expanded when the shell command is
362          executed.
363
364     3.   ``.for'' loop index variables are expanded on each loop iteration.
365          Note that other variables are not expanded inside loops so the fol-
366          lowing example code:
367
368
369                .for i in 1 2 3
370                a+=     ${i}
371                j=      ${i}
372                b+=     ${j}
373                .endfor
374
375                all:
376                        @echo ${a}
377                        @echo ${b}
378
379          will print:
380
381                1 2 3
382                3 3 3
383
384          Because while ${a} contains ``1 2 3'' after the loop is executed,
385          ${b} contains ``${j} ${j} ${j}'' which expands to ``3 3 3'' since
386          after the loop completes ${j} contains ``3''.
387
388   VVaarriiaabbllee ccllaasssseess
389     The four different classes of variables (in order of increasing prece-
390     dence) are:
391
392     Environment variables
393             Variables defined as part of bbmmaakkee's environment.
394
395     Global variables
396             Variables defined in the makefile or in included makefiles.
397
398     Command line variables
399             Variables defined as part of the command line.
400
401     Local variables
402             Variables that are defined specific to a certain target.  The
403             seven local variables are as follows:
404
405             _._A_L_L_S_R_C   The list of all sources for this target; also known as
406                       `_>'.
407
408             _._A_R_C_H_I_V_E  The name of the archive file.
409
410             _._I_M_P_S_R_C   In suffix-transformation rules, the name/path of the
411                       source from which the target is to be transformed (the
412                       ``implied'' source); also known as `_<'.  It is not
413                       defined in explicit rules.
414
415             _._M_E_M_B_E_R   The name of the archive member.
416
417             _._O_O_D_A_T_E   The list of sources for this target that were deemed
418                       out-of-date; also known as `_?'.
419
420             _._P_R_E_F_I_X   The file prefix of the target, containing only the file
421                       portion, no suffix or preceding directory components;
422                       also known as `_*'.
423
424             _._T_A_R_G_E_T   The name of the target; also known as `_@'.
425
426             The shorter forms `_@', `_?', `_<', `_>', and `_*' are permitted for
427             backward compatibility with historical makefiles and are not rec-
428             ommended.  The six variables `_@_F', `_@_D', `_<_F', `_<_D', `_*_F', and
429             `_*_D' are permitted for compatibility with AT&T System V UNIX
430             makefiles and are not recommended.
431
432             Four of the local variables may be used in sources on dependency
433             lines because they expand to the proper value for each target on
434             the line.  These variables are `_._T_A_R_G_E_T', `_._P_R_E_F_I_X', `_._A_R_C_H_I_V_E',
435             and `_._M_E_M_B_E_R'.
436
437   AAddddiittiioonnaall bbuuiilltt--iinn vvaarriiaabblleess
438     In addition, bbmmaakkee sets or knows about the following variables:
439
440     _$               A single dollar sign `$', i.e.  `$$' expands to a single
441                     dollar sign.
442
443     _._A_L_L_T_A_R_G_E_T_S     The list of all targets encountered in the Makefile.  If
444                     evaluated during Makefile parsing, lists only those tar-
445                     gets encountered thus far.
446
447     _._C_U_R_D_I_R         A path to the directory where bbmmaakkee was executed.  Refer
448                     to the description of `PWD' for more details.
449
450     MAKE            The name that bbmmaakkee was executed with (_a_r_g_v_[_0_]).  For
451                     compatibility bbmmaakkee also sets _._M_A_K_E with the same value.
452                     The preferred variable to use is the environment variable
453                     MAKE because it is more compatible with other versions of
454                     bbmmaakkee and cannot be confused with the special target with
455                     the same name.
456
457     _._M_A_K_E_._D_E_P_E_N_D_F_I_L_E
458                     Names the makefile (default `_._d_e_p_e_n_d') from which gener-
459                     ated dependencies are read.
460
461     _._M_A_K_E_._E_X_P_A_N_D___V_A_R_I_A_B_L_E_S
462                     A boolean that controls the default behavior of the --VV
463                     option.
464
465     _._M_A_K_E_._E_X_P_O_R_T_E_D  The list of variables exported by bbmmaakkee.
466
467     _._M_A_K_E_._J_O_B_S      The argument to the --jj option.
468
469     _._M_A_K_E_._J_O_B_._P_R_E_F_I_X
470                     If bbmmaakkee is run with _j then output for each target is
471                     prefixed with a token `--- target ---' the first part of
472                     which can be controlled via _._M_A_K_E_._J_O_B_._P_R_E_F_I_X.
473                     For example:
474                     .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
475                     would produce tokens like `---make[1234] target ---' mak-
476                     ing it easier to track the degree of parallelism being
477                     achieved.
478
479     MAKEFLAGS       The environment variable `MAKEFLAGS' may contain anything
480                     that may be specified on bbmmaakkee's command line.  Anything
481                     specified on bbmmaakkee's command line is appended to the
482                     `MAKEFLAGS' variable which is then entered into the envi-
483                     ronment for all programs which bbmmaakkee executes.
484
485     _._M_A_K_E_._L_E_V_E_L     The recursion depth of bbmmaakkee.  The initial instance of
486                     bbmmaakkee will be 0, and an incremented value is put into the
487                     environment to be seen by the next generation.  This
488                     allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
489                     things which should only be evaluated in the initial
490                     instance of bbmmaakkee.
491
492     _._M_A_K_E_._M_A_K_E_F_I_L_E___P_R_E_F_E_R_E_N_C_E
493                     The ordered list of makefile names (default `_m_a_k_e_f_i_l_e',
494                     `_M_a_k_e_f_i_l_e') that bbmmaakkee will look for.
495
496     _._M_A_K_E_._M_A_K_E_F_I_L_E_S
497                     The list of makefiles read by bbmmaakkee, which is useful for
498                     tracking dependencies.  Each makefile is recorded only
499                     once, regardless of the number of times read.
500
501     _._M_A_K_E_._M_O_D_E      Processed after reading all makefiles.  Can affect the
502                     mode that bbmmaakkee runs in.  It can contain a number of key-
503                     words:
504
505                     _c_o_m_p_a_t      Like --BB, puts bbmmaakkee into "compat" mode.
506
507                     _m_e_t_a        Puts bbmmaakkee into "meta" mode, where meta files
508                                 are created for each target to capture the
509                                 command run, the output generated and if
510                                 filemon(4) is available, the system calls
511                                 which are of interest to bbmmaakkee.  The captured
512                                 output can be very useful when diagnosing
513                                 errors.
514
515                     _c_u_r_d_i_r_O_k_= _b_f Normally bbmmaakkee will not create .meta files
516                                 in `_._C_U_R_D_I_R'.  This can be overridden by set-
517                                 ting _b_f to a value which represents True.
518
519                     _e_n_v         For debugging, it can be useful to inlcude
520                                 the environment in the .meta file.
521
522                     _v_e_r_b_o_s_e     If in "meta" mode, print a clue about the
523                                 target being built.  This is useful if the
524                                 build is otherwise running silently.  The
525                                 message printed the value of:
526                                 _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X.
527
528                     _i_g_n_o_r_e_-_c_m_d  Some makefiles have commands which are simply
529                                 not stable.  This keyword causes them to be
530                                 ignored for determining whether a target is
531                                 out of date in "meta" mode.  See also
532                                 ..NNOOMMEETTAA__CCMMPP.
533
534                     _s_i_l_e_n_t_= _b_f  If _b_f is True, when a .meta file is created,
535                                 mark the target ..SSIILLEENNTT.
536
537     _._M_A_K_E_._M_E_T_A_._B_A_I_L_I_W_I_C_K
538                     In "meta" mode, provides a list of prefixes which match
539                     the directories controlled by bbmmaakkee.  If a file that was
540                     generated outside of _._O_B_J_D_I_R but within said bailiwick is
541                     missing, the current target is considered out-of-date.
542
543     _._M_A_K_E_._M_E_T_A_._C_R_E_A_T_E_D
544                     In "meta" mode, this variable contains a list of all the
545                     meta files updated.  If not empty, it can be used to
546                     trigger processing of _._M_A_K_E_._M_E_T_A_._F_I_L_E_S.
547
548     _._M_A_K_E_._M_E_T_A_._F_I_L_E_S
549                     In "meta" mode, this variable contains a list of all the
550                     meta files used (updated or not).  This list can be used
551                     to process the meta files to extract dependency informa-
552                     tion.
553
554     _._M_A_K_E_._M_E_T_A_._P_R_E_F_I_X
555                     Defines the message printed for each meta file updated in
556                     "meta verbose" mode.  The default value is:
557                           Building ${.TARGET:H:tA}/${.TARGET:T}
558
559     _._M_A_K_E_O_V_E_R_R_I_D_E_S  This variable is used to record the names of variables
560                     assigned to on the command line, so that they may be
561                     exported as part of `MAKEFLAGS'.  This behaviour can be
562                     disabled by assigning an empty value to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'
563                     within a makefile.  Extra variables can be exported from
564                     a makefile by appending their names to `_._M_A_K_E_O_V_E_R_R_I_D_E_S'.
565                     `MAKEFLAGS' is re-exported whenever `_._M_A_K_E_O_V_E_R_R_I_D_E_S' is
566                     modified.
567
568     _._M_A_K_E_._P_I_D       The process-id of bbmmaakkee.
569
570     _._M_A_K_E_._P_P_I_D      The parent process-id of bbmmaakkee.
571
572     _M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R
573                     When bbmmaakkee stops due to an error, it prints its name and
574                     the value of `_._C_U_R_D_I_R' as well as the value of any vari-
575                     ables named in `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R'.
576
577     _._n_e_w_l_i_n_e        This variable is simply assigned a newline character as
578                     its value.  This allows expansions using the ::@@ modifier
579                     to put a newline between iterations of the loop rather
580                     than a space.  For example, the printing of
581                     `_M_A_K_E___P_R_I_N_T___V_A_R___O_N___E_R_R_O_R' could be done as
582                     ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
583
584     _._O_B_J_D_I_R         A path to the directory where the targets are built.  Its
585                     value is determined by trying to chdir(2) to the follow-
586                     ing directories in order and using the first match:
587
588                     1.   ${MAKEOBJDIRPREFIX}${.CURDIR}
589
590                          (Only if `MAKEOBJDIRPREFIX' is set in the environ-
591                          ment or on the command line.)
592
593                     2.   ${MAKEOBJDIR}
594
595                          (Only if `MAKEOBJDIR' is set in the environment or
596                          on the command line.)
597
598                     3.   ${.CURDIR}_/_o_b_j_.${MACHINE}
599
600                     4.   ${.CURDIR}_/_o_b_j
601
602                     5.   _/_u_s_r_/_o_b_j_/${.CURDIR}
603
604                     6.   ${.CURDIR}
605
606                     Variable expansion is performed on the value before it's
607                     used, so expressions such as
608                           ${.CURDIR:S,^/usr/src,/var/obj,}
609                     may be used.  This is especially useful with
610                     `MAKEOBJDIR'.
611
612                     `_._O_B_J_D_I_R' may be modified in the makefile as a global
613                     variable.  In all cases, bbmmaakkee will chdir(2) to `_._O_B_J_D_I_R'
614                     and set `PWD' to that directory before executing any tar-
615                     gets.
616
617     _._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
618                     parsed.
619
620     _._P_A_R_S_E_F_I_L_E      The basename of the current `_M_a_k_e_f_i_l_e' being parsed.
621                     This variable and `_._P_A_R_S_E_D_I_R' are both set only while the
622                     `_M_a_k_e_f_i_l_e_s' are being parsed.  If you want to retain
623                     their current values, assign them to a variable using
624                     assignment with expansion: (`::==').
625
626     _._P_A_T_H           A variable that represents the list of directories that
627                     bbmmaakkee will search for files.  The search list should be
628                     updated using the target `_._P_A_T_H' rather than the vari-
629                     able.
630
631     PWD             Alternate path to the current directory.  bbmmaakkee normally
632                     sets `_._C_U_R_D_I_R' to the canonical path given by getcwd(3).
633                     However, if the environment variable `PWD' is set and
634                     gives a path to the current directory, then bbmmaakkee sets
635                     `_._C_U_R_D_I_R' to the value of `PWD' instead.  This behaviour
636                     is disabled if `MAKEOBJDIRPREFIX' is set or `MAKEOBJDIR'
637                     contains a variable transform.  `PWD' is set to the value
638                     of `_._O_B_J_D_I_R' for all programs which bbmmaakkee executes.
639
640     .TARGETS        The list of targets explicitly specified on the command
641                     line, if any.
642
643     VPATH           Colon-separated (``:'') lists of directories that bbmmaakkee
644                     will search for files.  The variable is supported for
645                     compatibility with old make programs only, use `_._P_A_T_H'
646                     instead.
647
648   VVaarriiaabbllee mmooddiiffiieerrss
649     Variable expansion may be modified to select or modify each word of the
650     variable (where a ``word'' is white-space delimited sequence of charac-
651     ters).  The general format of a variable expansion is as follows:
652
653           ${variable[:modifier[:...]]}
654
655     Each modifier begins with a colon, which may be escaped with a backslash
656     (`\').
657
658     A set of modifiers can be specified via a variable, as follows:
659
660           modifier_variable=modifier[:...]
661           ${variable:${modifier_variable}[:...]}
662
663     In this case the first modifier in the modifier_variable does not start
664     with a colon, since that must appear in the referencing variable.  If any
665     of the modifiers in the modifier_variable contain a dollar sign (`$'),
666     these must be doubled to avoid early expansion.
667
668     The supported modifiers are:
669
670     ::EE   Replaces each word in the variable with its suffix.
671
672     ::HH   Replaces each word in the variable with everything but the last com-
673          ponent.
674
675     ::MM_p_a_t_t_e_r_n
676          Select only those words that match _p_a_t_t_e_r_n.  The standard shell
677          wildcard characters (`*', `?', and `[]') may be used.  The wildcard
678          characters may be escaped with a backslash (`\').
679
680     ::NN_p_a_t_t_e_r_n
681          This is identical to `::MM', but selects all words which do not match
682          _p_a_t_t_e_r_n.
683
684     ::OO   Order every word in variable alphabetically.  To sort words in
685          reverse order use the `::OO::[[--11....11]]' combination of modifiers.
686
687     ::OOxx  Randomize words in variable.  The results will be different each
688          time you are referring to the modified variable; use the assignment
689          with expansion (`::==') to prevent such behaviour.  For example,
690
691                LIST=                   uno due tre quattro
692                RANDOM_LIST=            ${LIST:Ox}
693                STATIC_RANDOM_LIST:=    ${LIST:Ox}
694
695                all:
696                        @echo "${RANDOM_LIST}"
697                        @echo "${RANDOM_LIST}"
698                        @echo "${STATIC_RANDOM_LIST}"
699                        @echo "${STATIC_RANDOM_LIST}"
700          may produce output similar to:
701
702                quattro due tre uno
703                tre due quattro uno
704                due uno quattro tre
705                due uno quattro tre
706
707     ::QQ   Quotes every shell meta-character in the variable, so that it can be
708          passed safely through recursive invocations of bbmmaakkee.
709
710     ::RR   Replaces each word in the variable with everything but its suffix.
711
712     ::ggmmttiimmee
713          The value is a format string for strftime(3), using the current
714          gmtime(3).
715
716     ::hhaasshh
717          Compute a 32bit hash of the value and encode it as hex digits.
718
719     ::llooccaallttiimmee
720          The value is a format string for strftime(3), using the current
721          localtime(3).
722
723     ::ttAA  Attempt to convert variable to an absolute path using realpath(3),
724          if that fails, the value is unchanged.
725
726     ::ttll  Converts variable to lower-case letters.
727
728     ::ttss_c
729          Words in the variable are normally separated by a space on expan-
730          sion.  This modifier sets the separator to the character _c.  If _c is
731          omitted, then no separator is used.  The common escapes (including
732          octal numeric codes), work as expected.
733
734     ::ttuu  Converts variable to upper-case letters.
735
736     ::ttWW  Causes the value to be treated as a single word (possibly containing
737          embedded white space).  See also `::[[**]]'.
738
739     ::ttww  Causes the value to be treated as a sequence of words delimited by
740          white space.  See also `::[[@@]]'.
741
742     ::SS/_o_l_d___s_t_r_i_n_g/_n_e_w___s_t_r_i_n_g/[11ggWW]
743          Modify the first occurrence of _o_l_d___s_t_r_i_n_g in the variable's value,
744          replacing it with _n_e_w___s_t_r_i_n_g.  If a `g' is appended to the last
745          slash of the pattern, all occurrences in each word are replaced.  If
746          a `1' is appended to the last slash of the pattern, only the first
747          word is affected.  If a `W' is appended to the last slash of the
748          pattern, then the value is treated as a single word (possibly con-
749          taining embedded white space).  If _o_l_d___s_t_r_i_n_g begins with a caret
750          (`^'), _o_l_d___s_t_r_i_n_g is anchored at the beginning of each word.  If
751          _o_l_d___s_t_r_i_n_g ends with a dollar sign (`$'), it is anchored at the end
752          of each word.  Inside _n_e_w___s_t_r_i_n_g, an ampersand (`&') is replaced by
753          _o_l_d___s_t_r_i_n_g (without any `^' or `$').  Any character may be used as a
754          delimiter for the parts of the modifier string.  The anchoring,
755          ampersand and delimiter characters may be escaped with a backslash
756          (`\').
757
758          Variable expansion occurs in the normal fashion inside both
759          _o_l_d___s_t_r_i_n_g and _n_e_w___s_t_r_i_n_g with the single exception that a backslash
760          is used to prevent the expansion of a dollar sign (`$'), not a pre-
761          ceding dollar sign as is usual.
762
763     ::CC/_p_a_t_t_e_r_n/_r_e_p_l_a_c_e_m_e_n_t/[11ggWW]
764          The ::CC modifier is just like the ::SS modifier except that the old and
765          new strings, instead of being simple strings, are a regular expres-
766          sion (see regex(3)) string _p_a_t_t_e_r_n and an ed(1)-style string
767          _r_e_p_l_a_c_e_m_e_n_t.  Normally, the first occurrence of the pattern _p_a_t_t_e_r_n
768          in each word of the value is substituted with _r_e_p_l_a_c_e_m_e_n_t.  The `1'
769          modifier causes the substitution to apply to at most one word; the
770          `g' modifier causes the substitution to apply to as many instances
771          of the search pattern _p_a_t_t_e_r_n as occur in the word or words it is
772          found in; the `W' modifier causes the value to be treated as a sin-
773          gle word (possibly containing embedded white space).  Note that `1'
774          and `g' are orthogonal; the former specifies whether multiple words
775          are potentially affected, the latter whether multiple substitutions
776          can potentially occur within each affected word.
777
778     ::TT   Replaces each word in the variable with its last component.
779
780     ::uu   Remove adjacent duplicate words (like uniq(1)).
781
782     ::??_t_r_u_e___s_t_r_i_n_g::_f_a_l_s_e___s_t_r_i_n_g
783          If the variable name (not its value), when parsed as a .if condi-
784          tional expression, evaluates to true, return as its value the
785          _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
786          name is used as the expression, :? must be the first modifier after
787          the variable name itself - which will, of course, usually contain
788          variable expansions.  A common error is trying to use expressions
789          like
790                ${NUMBERS:M42:?match:no}
791          which actually tests defined(NUMBERS), to determine is any words
792          match "42" you need to use something like:
793                ${"${NUMBERS:M42}" != "":?match:no}.
794
795     _:_o_l_d___s_t_r_i_n_g_=_n_e_w___s_t_r_i_n_g
796          This is the AT&T System V UNIX style variable substitution.  It must
797          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
798          contain the pattern matching character _% then it is assumed that
799          they are anchored at the end of each word, so only suffixes or
800          entire words may be replaced.  Otherwise _% is the substring of
801          _o_l_d___s_t_r_i_n_g to be replaced in _n_e_w___s_t_r_i_n_g.
802
803          Variable expansion occurs in the normal fashion inside both
804          _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
805          is used to prevent the expansion of a dollar sign (`$'), not a pre-
806          ceding dollar sign as is usual.
807
808     ::@@_t_e_m_p@@_s_t_r_i_n_g@@
809          This is the loop expansion mechanism from the OSF Development Envi-
810          ronment (ODE) make.  Unlike ..ffoorr loops expansion occurs at the time
811          of reference.  Assign _t_e_m_p to each word in the variable and evaluate
812          _s_t_r_i_n_g.  The ODE convention is that _t_e_m_p should start and end with a
813          period.  For example.
814                ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
815
816          However a single character varaiable is often more readable:
817                ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
818
819     ::UU_n_e_w_v_a_l
820          If the variable is undefined _n_e_w_v_a_l is the value.  If the variable
821          is defined, the existing value is returned.  This is another ODE
822          make feature.  It is handy for setting per-target CFLAGS for
823          instance:
824                ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
825          If a value is only required if the variable is undefined, use:
826                ${VAR:D:Unewval}
827
828     ::DD_n_e_w_v_a_l
829          If the variable is defined _n_e_w_v_a_l is the value.
830
831     ::LL   The name of the variable is the value.
832
833     ::PP   The path of the node which has the same name as the variable is the
834          value.  If no such node exists or its path is null, then the name of
835          the variable is used.  In order for this modifier to work, the name
836          (node) must at least have appeared on the rhs of a dependency.
837
838     ::!!_c_m_d!!
839          The output of running _c_m_d is the value.
840
841     ::sshh  If the variable is non-empty it is run as a command and the output
842          becomes the new value.
843
844     ::::==_s_t_r
845          The variable is assigned the value _s_t_r after substitution.  This
846          modifier and its variations are useful in obscure situations such as
847          wanting to set a variable when shell commands are being parsed.
848          These assignment modifiers always expand to nothing, so if appearing
849          in a rule line by themselves should be preceded with something to
850          keep bbmmaakkee happy.
851
852          The `::::' helps avoid false matches with the AT&T System V UNIX style
853          ::== modifier and since substitution always occurs the ::::== form is
854          vaguely appropriate.
855
856     ::::??==_s_t_r
857          As for ::::== but only if the variable does not already have a value.
858
859     ::::++==_s_t_r
860          Append _s_t_r to the variable.
861
862     ::::!!==_c_m_d
863          Assign the output of _c_m_d to the variable.
864
865     ::[[_r_a_n_g_e]]
866          Selects one or more words from the value, or performs other opera-
867          tions related to the way in which the value is divided into words.
868
869          Ordinarily, a value is treated as a sequence of words delimited by
870          white space.  Some modifiers suppress this behaviour, causing a
871          value to be treated as a single word (possibly containing embedded
872          white space).  An empty value, or a value that consists entirely of
873          white-space, is treated as a single word.  For the purposes of the
874          `::[[]]' modifier, the words are indexed both forwards using positive
875          integers (where index 1 represents the first word), and backwards
876          using negative integers (where index -1 represents the last word).
877
878          The _r_a_n_g_e is subjected to variable expansion, and the expanded
879          result is then interpreted as follows:
880
881          _i_n_d_e_x  Selects a single word from the value.
882
883          _s_t_a_r_t...._e_n_d
884                 Selects all words from _s_t_a_r_t to _e_n_d, inclusive.  For example,
885                 `::[[22....--11]]' selects all words from the second word to the last
886                 word.  If _s_t_a_r_t is greater than _e_n_d, then the words are out-
887                 put in reverse order.  For example, `::[[--11....11]]' selects all
888                 the words from last to first.
889
890          **      Causes subsequent modifiers to treat the value as a single
891                 word (possibly containing embedded white space).  Analogous
892                 to the effect of "$*" in Bourne shell.
893
894          0      Means the same as `::[[**]]'.
895
896          @@      Causes subsequent modifiers to treat the value as a sequence
897                 of words delimited by white space.  Analogous to the effect
898                 of "$@" in Bourne shell.
899
900          ##      Returns the number of words in the value.
901
902IINNCCLLUUDDEE SSTTAATTEEMMEENNTTSS,, CCOONNDDIITTIIOONNAALLSS AANNDD FFOORR LLOOOOPPSS
903     Makefile inclusion, conditional structures and for loops  reminiscent of
904     the C programming language are provided in bbmmaakkee.  All such structures
905     are identified by a line beginning with a single dot (`.') character.
906     Files are included with either ..iinncclluuddee <_f_i_l_e> or ..iinncclluuddee "_f_i_l_e".  Vari-
907     ables between the angle brackets or double quotes are expanded to form
908     the file name.  If angle brackets are used, the included makefile is
909     expected to be in the system makefile directory.  If double quotes are
910     used, the including makefile's directory and any directories specified
911     using the --II option are searched before the system makefile directory.
912     For compatibility with other versions of bbmmaakkee `include file ...' is also
913     accepted.  If the include statement is written as ..--iinncclluuddee or as
914     ..ssiinncclluuddee then errors locating and/or opening include files are ignored.
915
916     Conditional expressions are also preceded by a single dot as the first
917     character of a line.  The possible conditionals are as follows:
918
919     ..eerrrroorr _m_e_s_s_a_g_e
920             The message is printed along with the name of the makefile and
921             line number, then bbmmaakkee will exit.
922
923     ..eexxppoorrtt _v_a_r_i_a_b_l_e _._._.
924             Export the specified global variable.  If no variable list is
925             provided, all globals are exported except for internal variables
926             (those that start with `.').  This is not affected by the --XX
927             flag, so should be used with caution.  For compatibility with
928             other bbmmaakkee programs `export variable=value' is also accepted.
929
930             Appending a variable name to _._M_A_K_E_._E_X_P_O_R_T_E_D is equivalent to
931             exporting a variable.
932
933     ..eexxppoorrtt--eennvv _v_a_r_i_a_b_l_e _._._.
934             The same as `.export', except that the variable is not appended
935             to _._M_A_K_E_._E_X_P_O_R_T_E_D.  This allows exporting a value to the environ-
936             ment which is different from that used by bbmmaakkee internally.
937
938     ..iinnffoo _m_e_s_s_a_g_e
939             The message is printed along with the name of the makefile and
940             line number.
941
942     ..uunnddeeff _v_a_r_i_a_b_l_e
943             Un-define the specified global variable.  Only global variables
944             may be un-defined.
945
946     ..uunneexxppoorrtt _v_a_r_i_a_b_l_e _._._.
947             The opposite of `.export'.  The specified global _v_a_r_i_a_b_l_e will be
948             removed from _._M_A_K_E_._E_X_P_O_R_T_E_D.  If no variable list is provided,
949             all globals are unexported, and _._M_A_K_E_._E_X_P_O_R_T_E_D deleted.
950
951     ..uunneexxppoorrtt--eennvv
952             Unexport all globals previously exported and clear the environ-
953             ment inherited from the parent.  This operation will cause a mem-
954             ory leak of the original environment, so should be used spar-
955             ingly.  Testing for _._M_A_K_E_._L_E_V_E_L being 0, would make sense.  Also
956             note that any variables which originated in the parent environ-
957             ment should be explicitly preserved if desired.  For example:
958
959                   .if ${.MAKE.LEVEL} == 0
960                   PATH := ${PATH}
961                   .unexport-env
962                   .export PATH
963                   .endif
964
965             Would result in an environment containing only `PATH', which is
966             the minimal useful environment.  Actually `.MAKE.LEVEL' will also
967             be pushed into the new environment.
968
969     ..wwaarrnniinngg _m_e_s_s_a_g_e
970             The message prefixed by `_w_a_r_n_i_n_g_:' is printed along with the name
971             of the makefile and line number.
972
973     ..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 _._._.]
974             Test the value of an expression.
975
976     ..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 _._._.]
977             Test the value of a variable.
978
979     ..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 _._._.]
980             Test the value of a variable.
981
982     ..iiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
983             Test the target being built.
984
985     ..iiffnnmmaakkee [!] _t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
986             Test the target being built.
987
988     ..eellssee   Reverse the sense of the last conditional.
989
990     ..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 _._._.]
991             A combination of `..eellssee' followed by `..iiff'.
992
993     ..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 _._._.]
994             A combination of `..eellssee' followed by `..iiffddeeff'.
995
996     ..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 _._._.]
997             A combination of `..eellssee' followed by `..iiffnnddeeff'.
998
999     ..eelliiffmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1000             A combination of `..eellssee' followed by `..iiffmmaakkee'.
1001
1002     ..eelliiffnnmmaakkee [!]_t_a_r_g_e_t [_o_p_e_r_a_t_o_r _t_a_r_g_e_t _._._.]
1003             A combination of `..eellssee' followed by `..iiffnnmmaakkee'.
1004
1005     ..eennddiiff  End the body of the conditional.
1006
1007     The _o_p_e_r_a_t_o_r may be any one of the following:
1008
1009     ||||     Logical OR.
1010
1011     &&&&     Logical AND; of higher precedence than ``||''.
1012
1013     As in C, bbmmaakkee will only evaluate a conditional as far as is necessary to
1014     determine its value.  Parentheses may be used to change the order of
1015     evaluation.  The boolean operator `!!' may be used to logically negate an
1016     entire conditional.  It is of higher precedence than `&&&&'.
1017
1018     The value of _e_x_p_r_e_s_s_i_o_n may be any of the following:
1019
1020     ddeeffiinneedd  Takes a variable name as an argument and evaluates to true if
1021              the variable has been defined.
1022
1023     mmaakkee     Takes a target name as an argument and evaluates to true if the
1024              target was specified as part of bbmmaakkee's command line or was
1025              declared the default target (either implicitly or explicitly,
1026              see _._M_A_I_N) before the line containing the conditional.
1027
1028     eemmppttyy    Takes a variable, with possible modifiers, and evaluates to true
1029              if the expansion of the variable would result in an empty
1030              string.
1031
1032     eexxiissttss   Takes a file name as an argument and evaluates to true if the
1033              file exists.  The file is searched for on the system search path
1034              (see _._P_A_T_H).
1035
1036     ttaarrggeett   Takes a target name as an argument and evaluates to true if the
1037              target has been defined.
1038
1039     ccoommmmaannddss
1040              Takes a target name as an argument and evaluates to true if the
1041              target has been defined and has commands associated with it.
1042
1043     _E_x_p_r_e_s_s_i_o_n may also be an arithmetic or string comparison.  Variable
1044     expansion is performed on both sides of the comparison, after which the
1045     integral values are compared.  A value is interpreted as hexadecimal if
1046     it is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
1047     ported.  The standard C relational operators are all supported.  If after
1048     variable expansion, either the left or right hand side of a `====' or `!!=='
1049     operator is not an integral value, then string comparison is performed
1050     between the expanded variables.  If no relational operator is given, it
1051     is assumed that the expanded variable is being compared against 0 or an
1052     empty string in the case of a string comparison.
1053
1054     When bbmmaakkee is evaluating one of these conditional expressions, and it
1055     encounters a (white-space separated) word it doesn't recognize, either
1056     the ``make'' or ``defined'' expression is applied to it, depending on the
1057     form of the conditional.  If the form is `..iiffddeeff', `..iiffnnddeeff', or `..iiff'
1058     the ``defined'' expression is applied.  Similarly, if the form is
1059     `..iiffmmaakkee' or `..iiffnnmmaakkee, tthhee' ``make'' expression is applied.
1060
1061     If the conditional evaluates to true the parsing of the makefile contin-
1062     ues as before.  If it evaluates to false, the following lines are
1063     skipped.  In both cases this continues until a `..eellssee' or `..eennddiiff' is
1064     found.
1065
1066     For loops are typically used to apply a set of rules to a list of files.
1067     The syntax of a for loop is:
1068
1069     ..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
1070     <make-rules>
1071     ..eennddffoorr
1072
1073     After the for eexxpprreessssiioonn is evaluated, it is split into words.  On each
1074     iteration of the loop, one word is taken and assigned to each vvaarriiaabbllee,
1075     in order, and these vvaarriiaabblleess are substituted into the mmaakkee--rruulleess inside
1076     the body of the for loop.  The number of words must come out even; that
1077     is, if there are three iteration variables, the number of words provided
1078     must be a multiple of three.
1079
1080CCOOMMMMEENNTTSS
1081     Comments begin with a hash (`#') character, anywhere but in a shell com-
1082     mand line, and continue to the end of an unescaped new line.
1083
1084SSPPEECCIIAALL SSOOUURRCCEESS ((AATTTTRRIIBBUUTTEESS))
1085     ..EEXXEECC     Target is never out of date, but always execute commands any-
1086               way.
1087
1088     ..IIGGNNOORREE   Ignore any errors from the commands associated with this tar-
1089               get, exactly as if they all were preceded by a dash (`-').
1090
1091     ..MMAADDEE     Mark all sources of this target as being up-to-date.
1092
1093     ..MMAAKKEE     Execute the commands associated with this target even if the --nn
1094               or --tt options were specified.  Normally used to mark recursive
1095               bbmmaakkee's.
1096
1097     ..MMEETTAA     Create a meta file for the target, even if it is flagged as
1098               ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL.  Usage in conjunction with ..MMAAKKEE is
1099               the most likely case.  In "meta" mode, the target is out-of-
1100               date if the meta file is missing.
1101
1102     ..NNOOMMEETTAA   Do not create a meta file for the target.  Meta files are also
1103               not created for ..PPHHOONNYY, ..MMAAKKEE, or ..SSPPEECCIIAALL targets.
1104
1105     ..NNOOMMEETTAA__CCMMPP
1106               Ignore differences in commands when deciding if target is out
1107               of date.  This is useful if the command contains a value which
1108               always changes.  If the number of commands change, though, the
1109               target will still be out of date.
1110
1111     ..NNOOPPAATTHH   Do not search for the target in the directories specified by
1112               ..PPAATTHH.
1113
1114     ..NNOOTTMMAAIINN  Normally bbmmaakkee selects the first target it encounters as the
1115               default target to be built if no target was specified.  This
1116               source prevents this target from being selected.
1117
1118     ..OOPPTTIIOONNAALL
1119               If a target is marked with this attribute and bbmmaakkee can't fig-
1120               ure out how to create it, it will ignore this fact and assume
1121               the file isn't needed or already exists.
1122
1123     ..PPHHOONNYY    The target does not correspond to an actual file; it is always
1124               considered to be out of date, and will not be created with the
1125               --tt option.  Suffix-transformation rules are not applied to
1126               ..PPHHOONNYY targets.
1127
1128     ..PPRREECCIIOOUUSS
1129               When bbmmaakkee is interrupted, it normally removes any partially
1130               made targets.  This source prevents the target from being
1131               removed.
1132
1133     ..RREECCUURRSSIIVVEE
1134               Synonym for ..MMAAKKEE.
1135
1136     ..SSIILLEENNTT   Do not echo any of the commands associated with this target,
1137               exactly as if they all were preceded by an at sign (`@').
1138
1139     ..UUSSEE      Turn the target into bbmmaakkee's version of a macro.  When the tar-
1140               get is used as a source for another target, the other target
1141               acquires the commands, sources, and attributes (except for
1142               ..UUSSEE) of the source.  If the target already has commands, the
1143               ..UUSSEE target's commands are appended to them.
1144
1145     ..UUSSEEBBEEFFOORREE
1146               Exactly like ..UUSSEE, but prepend the ..UUSSEEBBEEFFOORREE target commands
1147               to the target.
1148
1149     ..WWAAIITT     If ..WWAAIITT appears in a dependency line, the sources that precede
1150               it are made before the sources that succeed it in the line.
1151               Since the dependents of files are not made until the file
1152               itself could be made, this also stops the dependents being
1153               built unless they are needed for another branch of the depen-
1154               dency tree.  So given:
1155
1156               x: a .WAIT b
1157                       echo x
1158               a:
1159                       echo a
1160               b: b1
1161                       echo b
1162               b1:
1163                       echo b1
1164
1165               the output is always `a', `b1', `b', `x'.
1166               The ordering imposed by ..WWAAIITT is only relevant for parallel
1167               makes.
1168
1169SSPPEECCIIAALL TTAARRGGEETTSS
1170     Special targets may not be included with other targets, i.e. they must be
1171     the only target specified.
1172
1173     ..BBEEGGIINN   Any command lines attached to this target are executed before
1174              anything else is done.
1175
1176     ..DDEEFFAAUULLTT
1177              This is sort of a ..UUSSEE rule for any target (that was used only
1178              as a source) that bbmmaakkee can't figure out any other way to cre-
1179              ate.  Only the shell script is used.  The ..IIMMPPSSRRCC variable of a
1180              target that inherits ..DDEEFFAAUULLTT's commands is set to the target's
1181              own name.
1182
1183     ..EENNDD     Any command lines attached to this target are executed after
1184              everything else is done.
1185
1186     ..EERRRROORR   Any command lines attached to this target are executed when
1187              another target fails.  The ..EERRRROORR__TTAARRGGEETT variable is set to the
1188              target that failed.  See also MMAAKKEE__PPRRIINNTT__VVAARR__OONN__EERRRROORR.
1189
1190     ..IIGGNNOORREE  Mark each of the sources with the ..IIGGNNOORREE attribute.  If no
1191              sources are specified, this is the equivalent of specifying the
1192              --ii option.
1193
1194     ..IINNTTEERRRRUUPPTT
1195              If bbmmaakkee is interrupted, the commands for this target will be
1196              executed.
1197
1198     ..MMAAIINN    If no target is specified when bbmmaakkee is invoked, this target
1199              will be built.
1200
1201     ..MMAAKKEEFFLLAAGGSS
1202              This target provides a way to specify flags for bbmmaakkee when the
1203              makefile is used.  The flags are as if typed to the shell,
1204              though the --ff option will have no effect.
1205
1206     ..NNOOPPAATTHH  Apply the ..NNOOPPAATTHH attribute to any specified sources.
1207
1208     ..NNOOTTPPAARRAALLLLEELL
1209              Disable parallel mode.
1210
1211     ..NNOO__PPAARRAALLLLEELL
1212              Synonym for ..NNOOTTPPAARRAALLLLEELL, for compatibility with other pmake
1213              variants.
1214
1215     ..OORRDDEERR   The named targets are made in sequence.  This ordering does not
1216              add targets to the list of targets to be made.  Since the depen-
1217              dents of a target do not get built until the target itself could
1218              be built, unless `a' is built by another part of the dependency
1219              graph, the following is a dependency loop:
1220
1221              .ORDER: b a
1222              b: a
1223
1224              The ordering imposed by ..OORRDDEERR is only relevant for parallel
1225              makes.
1226
1227     ..PPAATTHH    The sources are directories which are to be searched for files
1228              not found in the current directory.  If no sources are speci-
1229              fied, any previously specified directories are deleted.  If the
1230              source is the special ..DDOOTTLLAASSTT target, then the current working
1231              directory is searched last.
1232
1233     ..PPHHOONNYY   Apply the ..PPHHOONNYY attribute to any specified sources.
1234
1235     ..PPRREECCIIOOUUSS
1236              Apply the ..PPRREECCIIOOUUSS attribute to any specified sources.  If no
1237              sources are specified, the ..PPRREECCIIOOUUSS attribute is applied to
1238              every target in the file.
1239
1240     ..SSHHEELLLL   Sets the shell that bbmmaakkee will use to execute commands.  The
1241              sources are a set of _f_i_e_l_d_=_v_a_l_u_e pairs.
1242
1243              _n_a_m_e        This is the minimal specification, used to select
1244                          one of the builtin shell specs; _s_h, _k_s_h, and _c_s_h.
1245
1246              _p_a_t_h        Specifies the path to the shell.
1247
1248              _h_a_s_E_r_r_C_t_l   Indicates whether the shell supports exit on error.
1249
1250              _c_h_e_c_k       The command to turn on error checking.
1251
1252              _i_g_n_o_r_e      The command to disable error checking.
1253
1254              _e_c_h_o        The command to turn on echoing of commands executed.
1255
1256              _q_u_i_e_t       The command to turn off echoing of commands exe-
1257                          cuted.
1258
1259              _f_i_l_t_e_r      The output to filter after issuing the _q_u_i_e_t com-
1260                          mand.  It is typically identical to _q_u_i_e_t.
1261
1262              _e_r_r_F_l_a_g     The flag to pass the shell to enable error checking.
1263
1264              _e_c_h_o_F_l_a_g    The flag to pass the shell to enable command echo-
1265                          ing.
1266
1267              _n_e_w_l_i_n_e     The string literal to pass the shell that results in
1268                          a single newline character when used outside of any
1269                          quoting characters.
1270              Example:
1271
1272              .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1273                      check="set -e" ignore="set +e" \
1274                      echo="set -v" quiet="set +v" filter="set +v" \
1275                      echoFlag=v errFlag=e newline="'\n'"
1276
1277     ..SSIILLEENNTT  Apply the ..SSIILLEENNTT attribute to any specified sources.  If no
1278              sources are specified, the ..SSIILLEENNTT attribute is applied to every
1279              command in the file.
1280
1281     ..SSUUFFFFIIXXEESS
1282              Each source specifies a suffix to bbmmaakkee.  If no sources are
1283              specified, any previously specified suffixes are deleted.  It
1284              allows the creation of suffix-transformation rules.
1285
1286              Example:
1287
1288              .SUFFIXES: .o
1289              .c.o:
1290                      cc -o ${.TARGET} -c ${.IMPSRC}
1291
1292EENNVVIIRROONNMMEENNTT
1293     bbmmaakkee uses the following environment variables, if they exist: MACHINE,
1294     MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1295     PWD, and TMPDIR.
1296
1297     MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1298     the command line to bbmmaakkee and not as makefile variables; see the descrip-
1299     tion of `_._O_B_J_D_I_R' for more details.
1300
1301FFIILLEESS
1302     .depend        list of dependencies
1303     Makefile       list of dependencies
1304     makefile       list of dependencies
1305     sys.mk         system makefile
1306     /usr/share/mk  system makefile directory
1307
1308CCOOMMPPAATTIIBBIILLIITTYY
1309     The basic make syntax is compatible between different versions of make,
1310     however the special variables, variable modifiers and conditionals are
1311     not.
1312
1313     The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1314     .ORDER and .WAIT apply recursively to the dependent nodes.  The algo-
1315     rithms used may change again in the future.
1316
1317     The way that .for loop variables are substituted changed after NetBSD 5.0
1318     so that they still appear to be variable expansions.  In particular this
1319     stops them being treated as syntax, and removes some obscure problems
1320     using them in .if statements.
1321
1322SSEEEE AALLSSOO
1323     mkdep(1)
1324
1325HHIISSTTOORRYY
1326     bbmmaakkee is derived from NetBSD make(1).  It uses autoconf to facilitate
1327     portability to other platforms.
1328
1329     A make command appeared in Version 7 AT&T UNIX.  This make implementation
1330     is based on Adam De Boor's pmake program which was written for Sprite at
1331     Berkeley.  It was designed to be a parallel distributed make running jobs
1332     on different machines using a daemon called ``customs''.
1333
1334BBUUGGSS
1335     The make syntax is difficult to parse without actually acting of the
1336     data.  For instance finding the end of a variable use should involve
1337     scanning each the modifiers using the correct terminator for each field.
1338     In many places make just counts {} and () in order to find the end of a
1339     variable expansion.
1340
1341     There is no way of escaping a space character in a filename.
1342
1343NetBSD 5.1                     January 23, 2013                     NetBSD 5.1
1344