2 # scripts/options.awk - library build configuration control
4 # last changed in libpng version 1.5.0 - January 6, 2011
6 # Copyright (c) 1998-2011 Glenn Randers-Pehrson
8 # This code is released under the libpng license.
9 # For conditions of distribution and use, see the disclaimer
10 # and license in png.h
12 # The output of this script is written to the file given by
13 # the variable 'out'. The script is run twice, once with
14 # an intermediate output file, 'options.tmp' then again on
15 # that file to produce the final output:
17 # awk -f scripts/options.awk out=options.tmp scripts/options.dfa 1>&2
18 # awk -f scripts/options.awk out=options.dfn options.tmp 1>&2
20 # Some options may be specified on the command line:
22 # deb=1 Causes debugging to be output
23 # logunsupported=1 Causes all options to be recorded in the output
24 # everything=off Causes all options to be disabled by default
25 # everything=on Causes all options to be enabled by default
27 # If awk fails on your platform, try nawk instead.
29 # These options may also be specified in the original input file (and
30 # are copied to the preprocessed file).
33 out="/dev/null" # intermediate, preprocessed, file
34 pre=-1 # preprocess (first line)
35 err=0 # in-line exit sets this
36 start="PNG_DEFN_MAGIC-" # Arbitrary start
37 end="-PNG_DEFN_END" # Arbitrary end
38 cx= "/@@@*" # Open C comment for output file
39 comment=start cx # Comment start
40 cend="*/" end # Comment end
41 def=start "#define PNG_@@@" # Arbitrary define
42 sup="@@@_SUPPORTED" end # end supported option
43 und=comment "#undef PNG_@@@" # Unsupported option
44 une="@@@_SUPPORTED" cend # end unsupported option
45 error=start "ERROR:" # error message
48 deb=0 # debug - set on command line
49 everything="" # do not override defaults
50 logunsupported=0 # write unsupported options too
53 option[""] = "" # list of all options: default enabled/disabled
54 done[""] = 1 # marks option as having been output
55 requires[""] = "" # requires by option
56 iffs[""] = "" # if by option
57 enabledby[""] = "" # options that enable it by option
58 setting[""] = "" # requires by setting
59 defaults[""] = "" # used for a defaulted value
60 doneset[""] = 1 # marks setting as having been output
61 r[""] = "" # Temporary array
63 # For decorating the output file
67 # The output file must be specified before any input:
69 print "out=output.file must be given on the command line"
74 # The very first line indicates whether we are reading pre-processed
75 # input or not, this must come *first* because 'PREPROCESSED' needs
76 # to be the very first line in the temporary file.
78 if ($0 == "PREPROCESSED") {
83 print "PREPROCESSED" >out
84 # And fall through to continue processing
89 # Sets the given variable to the given value (the syntax is fairly
90 # free form, except for deb (you are expected to understand how to
91 # set the debug variable...)
93 # This happens before the check on 'pre' below skips most of the
94 # rest of the actions, so the variable settings happen during
95 # preprocessing but are recorded in the END action too. This
96 # allows them to be set on the command line too.
97 $0 ~ /^[ ]*everything[ =]*off[ ]*$/{
101 $0 ~ /^[ ]*everything[ =]*on[ ]*$/{
105 $0 ~ /^[ ]*logunsupported[ =]*0[ ]*$/{
109 $0 ~ /^[ ]*logunsupported[ =]*1[ ]*$/{
113 $1 == "deb" && $2 == "=" && NF == 3{
118 # Preprocessing - this just copies the input file with lines
119 # that need preprocessing (just chunk at present) expanded
120 # The bare "pre" instead of "pre != 0" crashes under Sunos awk
121 pre && $1 != "chunk"{
126 # The first characters of the line determine how it is processed,
127 # leading spaces are ignored. In general tokens that are not
128 # keywords are the names of options. An option 'name' is
129 # controlled by the definition of the corresponding macros:
131 # PNG_name_SUPPORTED The option is turned on
133 # PNG_NO_name_SUPPORTED If the first macro is not defined
134 # either of these will turn the option off
136 # If none of these macros are defined the option is turned on, unless
137 # the keyword 'off' is given in a line relating to the option. The
138 # keyword 'on' can also be given, but it will be ignored (since it is
141 # In the syntax below a 'name' is indicated by "NAME", other macro
142 # values are indicated by "MACRO", as with "NAME" the leading "PNG_"
143 # is omitted, but in this case the "NO_" prefix and the "_SUPPORTED"
144 # suffix are never used.
146 # Each line is introduced by a keyword - the first non-space characters
147 # on the line. A line starting with a '#' is a comment - it is totally
148 # ignored. Keywords are as follows, a NAME, is simply a macro name
149 # without the leading PNG_, PNG_NO_ or the trailing _SUPPORTED.
151 $1 ~ /^#/ || $0 ~ /^[ ]*$/{
156 # The whole line is placed in the output file as a comment with
157 # the preceding 'com' removed
160 # sub(/^[ ]*com[ ]*/, "")
162 print comment, $0, cend >out
168 # file output input protect
169 # Informational: the official name of the input file (without
170 # make generated local directories), the official name of the
171 # output file and, if required, a name to use in a protection
172 # macro for the contents.
173 $1 == "file" && NF >= 2{
174 print comment, $2, cend >out
175 print comment, "Machine generated file: DO NOT EDIT", cend >out
177 print comment, "Derived from:", $3, cend >out
180 print start "#ifndef", protect end >out
181 print start "#define", protect end >out
186 # option NAME ( (requires|enables|if) NAME* | on | off | disabled )*
187 # Declares an option 'NAME' and describes its default setting (disabled)
188 # and its relationship to other options. The option is disabled
189 # unless *all* the options listed after 'requires' are set and at
190 # least one of the options listed after 'if' is set. If the
191 # option is set then it turns on all the options listed after 'enables'.
193 # Note that "enables" takes priority over the required/if/disabled/off
194 # setting of the target option.
196 # The definition file may list an option as 'disabled': off by default,
197 # otherwise the option is enabled: on by default. A later (and it must
198 # be later) entry may turn an option on or off explicitly.
200 $1 == "option" && NF >= 2{
201 onoff = option[$2] # records current (and the default is "", enabled)
203 for (i=3; i<=NF; ++i) {
204 if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
207 # on or off can zap disabled or enabled:
208 if (onoff == "" || (onoff == "disabled" || onoff == "enabled") && ($(i) == "on" || $(i) == "off")) {
209 # It's easy to mis-spell the option when turning it
210 # on or off, so warn about it here:
211 if (onoff == "" && ($(i) == "on" || $(i) == "off")) {
212 print $2 ": ERROR: turning unrecognized option", $(i)
213 # For the moment error out - it is safer
214 err = 1 # prevent END{} running
219 # Print a message, otherwise the error
220 # below is incomprehensible
221 print $2 ": currently", onoff ": attempt to turn", $(i)
225 } else if ($(i) == "requires" || $(i) == "if" || $(i) == "enables") {
227 } else if (key == "requires") {
228 requires[$2] = requires[$2] " " $(i)
229 } else if (key == "if") {
230 iffs[$2] = iffs[$2] " " $(i)
231 } else if (key == "enables") {
232 enabledby[$(i)] = enabledby[$(i)] " " $2
234 break # bad line format
238 # Set the option, defaulting to 'enabled'
239 if (onoff == "") onoff = "enabled"
243 # Else fall through to the error handler
246 # chunk NAME [requires OPT] [on|off|disabled]
247 # Expands to the 'option' settings appropriate to the reading and
248 # writing of an ancilliary PNG chunk 'NAME':
250 # option READ_NAME requires READ_ANCILLARY_CHUNKS [READ_OPT]
251 # option READ_NAME enables NAME
252 # [option READ_NAME off]
253 # option WRITE_NAME requires WRITE_ANCILLARY_CHUNKS [WRITE_OPT]
254 # option WRITE_NAME enables NAME
255 # [option WRITE_NAME off]
257 pre != 0 && $1 == "chunk" && NF >= 2{
258 # 'chunk' is handled on the first pass by writing appropriate
259 # 'option' lines into the intermediate file.
263 i = 3 # indicates format error
265 # read the keywords/additional OPTS
267 for (i=3; i<=NF; ++i) {
268 if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
273 break # on/off conflict
275 } else if ($(i) == "requires")
278 break # bad line: handled below
280 reqread = reqread " READ_" $(i)
281 reqwrite = reqwrite " WRITE_" $(i)
287 # Output new 'option' lines to the intermediate file (out)
288 print "option READ_" $2, "requires READ_ANCILLARY_CHUNKS" reqread, "enables", $2, onoff >out
289 print "option WRITE_" $2, "requires WRITE_ANCILLARY_CHUNKS" reqwrite, "enables", $2, onoff >out
292 # Else hit the error handler below - bad line format!
295 # setting MACRO ( requires MACRO* )* [ default VALUE ]
296 # Behaves in a similar way to 'option' without looking for NO_ or
297 # _SUPPORTED; the macro is enabled if it is defined so long as all
298 # the 'requires' macros are also defined. The definitions may be
299 # empty, an error will be issued if the 'requires' macros are
300 # *not* defined. If given the 'default' value is used if the
301 # macro is not defined. The default value will be re-tokenised.
302 # (BTW: this is somewhat restrictive, it mainly exists for the
303 # support of non-standard configurations and numeric parameters,
304 # see the uses in scripts/options.dat
306 $1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){
311 for (i=3; i<=NF; ++i)
312 if ($(i) == "requires" || $(i) == "default") {
314 if (key == "default") isdef = 1
315 } else if (key == "requires")
317 else if (key == "default")
318 deflt = deflt " " $(i)
320 break # Format error, handled below
323 # NOTE: this overwrites a previous value silently
324 if (isdef && deflt == "")
325 deflt = " " # as a flag to force output
330 # The order of the dependency lines (option, chunk, setting) is irrelevant
331 # - the 'enables', 'requires' and 'if' settings will be used to determine
332 # the correct order in the output and the final values in pnglibconf.h are
333 # not order dependent. 'requires' and 'if' entries take precedence over
334 # 'enables' from other options; if an option requires another option it
335 # won't be set regardless of any options that enable it unless the other
336 # option is also enabled.
338 # Similarly 'enables' trumps a NO_ definition in CFLAGS or pngusr.h
340 # For simplicity cycles in the definitions are regarded as errors,
341 # even if they are not ambiguous.
342 # A given NAME can be specified in as many 'option' lines as required, the
343 # definitions are additive.
345 # For backwards compatibility equivalent macros may be listed thus:
348 # Makes -DMACRO equivalent to -DPNG_NO_NAME or -DPNG_NAME_SUPPORTED
351 # The definition is injected into the C compiler input when encountered
352 # in the second pass (so all these definitions appear *after* the @
355 # 'NAME' is as above, but 'MACRO' is the full text of the equivalent
356 # old, deprecated, macro.
358 $1 == "=" && NF == 3{
359 print "#ifdef PNG_" $3 >out
361 print "# define PNG_" $2 >out
363 print "# define PNG_" $2 "_SUPPORTED" >out
368 # Lines may be injected into the C compiler input by preceding them
369 # with an "@" character. The line is copied with just the leading
379 # Check for unreognized lines, because of the preprocessing chunk
380 # format errors will be detected on the first pass independent of
381 # any other format errors.
383 print "options.awk: bad line (" NR "):", $0
384 err = 1 # prevent END{} running
388 # For checking purposes names that start with "ok_" or "fail_" are
389 # not output to pnglibconf.h and must be either enabled or disabled
390 # respectively for the build to succeed. This allows interdependencies
391 # between options of the form "at least one of" or "at most one of"
392 # to be checked. For example:
394 # option FLOATING_POINT enables ok_math
395 # option FIXED_POINT enables ok_math
396 # This ensures that at least one of FLOATING_POINT and FIXED_POINT
397 # must be set for the build to succeed.
399 # option fail_math requires FLOATING_POINT FIXED_POINT
400 # This means the build will fail if *both* FLOATING_POINT and
401 # FIXED_POINT are set (this is an example; in fact both are allowed.)
403 # If all these options were given the build would require exactly one
404 # of the names to be enabled.
407 # END{} gets run on an exit (a traditional awk feature)
411 # Record the final value of the variables
412 print "deb =", deb >out
413 if (everything != "") {
414 print "everything =", everything >out
416 print "logunsupported =", logunsupported >out
420 # Do the 'setting' values first, the algorithm the standard
421 # tree walk (O(1)) done in an O(2) while/for loop; interations
422 # settings x depth, outputing the deepest required macros
425 print "/* SETTINGS */" >out
426 print comment, "settings", cend >out
430 movement = 0 # done nothing
431 for (i in setting) if (!doneset[i]) {
432 nreqs = split(setting[i], r)
434 for (j=1; j<=nreqs; ++j) if (!doneset[r[j]]) {
439 continue # try a different setting
443 # All the requirements have been processed, output
445 if (deb) print "setting", i
447 print "/* setting: ", i >out
448 print " * requires:" setting[i] >out
449 print " * default: ", defaults[i], "*/" >out
450 if (defaults[i] == "") { # no default, only check if defined
451 print "#ifdef PNG_" i >out
453 for (j=1; j<=nreqs; ++j) {
454 print "# ifndef PNG_" r[j] >out
455 print error, i, "requires", r[j] end >out
458 if (defaults[i] != "") { # default handling
459 print "#ifdef PNG_" i >out
461 print def i, "PNG_" i end >out
462 if (defaults[i] != "") {
463 print "#else /*default*/" >out
464 # And add the default definition for the benefit
465 # of later settings an options test:
466 print "# define PNG_" i defaults[i] >out
467 print def i defaults[i] end >out
475 if (!finished && !movement) {
476 print "setting: loop or missing setting in 'requires', cannot process:"
477 for (i in setting) if (!doneset[i]) {
478 print " setting", i, "requires" setting[i]
483 print comment, "end of settings", cend >out
485 # Now do the options - somewhat more complex. The dependency
491 # name enabledby name
493 # First build a list 'tree' by option of all the things on which
496 print "/* OPTIONS */" >out
497 print comment, "options", cend >out
498 for (opt in enabledby) tree[opt] = 1 # may not be explicit options
499 for (opt in option) if (opt != "") {
501 # option should always be one of the following values
502 if (o != "on" && o != "off" && o != "disabled" && o != "enabled") {
503 print "internal option error (" o ")"
506 tree[opt] = "" # so unlisted options marked
508 for (opt in tree) if (opt != "") {
509 if (tree[opt] == 1) {
511 if (option[opt] != "") {
512 print "internal error (1)"
515 # Macros only listed in 'enables' remain off unless
516 # one of the enabling macros is on.
517 option[opt] = "disabled"
520 split("", list) # clear 'list'
521 # Now add every requires, iffs or enabledby entry to 'list'
522 # so that we can add a unique list of requirements to tree[i]
523 split(requires[opt] iffs[opt] enabledby[opt], r)
524 for (i in r) list[r[i]] = 1
525 for (i in list) tree[opt] = tree[opt] " " i
528 # print the tree for extreme debugging
529 if (deb > 2) for (i in tree) if (i != "") print i, "depends-on" tree[i]
531 # Ok, now check all options marked explicitly 'on' or 'off':
533 # If an option[opt] is 'on' then turn on all requires[opt]
534 # If an option[opt] is 'off' then turn off all enabledby[opt]
536 # Error out if we have to turn 'on' an 'off' option or vice versa.
538 for (opt in option) if (opt != "") {
539 if (option[opt] == "on" || option[opt] == "off") {
540 pending[++npending] = opt
544 err = 0 # set on error
545 while (npending > 0) {
546 opt = pending[npending--]
547 if (option[opt] == "on") {
548 nreqs = split(requires[opt], r)
549 for (j=1; j<=nreqs; ++j) {
550 if (option[r[j]] == "off") {
551 print "option", opt, "turned on, but requirement", r[j], "is turned off"
553 } else if (option[r[j]] != "on") {
555 pending[++npending] = r[j]
559 if (option[opt] != "off") {
560 print "internal error (2)"
563 nreqs = split(enabledby[opt], r)
564 for (j=1; j<=nreqs; ++j) {
565 if (option[r[j]] == "on") {
566 print "option", opt, "turned off, but enabled by", r[j], "which is turned on"
568 } else if (option[r[j]] != "off") {
570 pending[++npending] = r[j]
577 # option[i] is now the complete list of all the tokens we may
578 # need to output, go through it as above, depth first.
582 movement = 0 # done nothing
583 for (i in option) if (!done[i]) {
584 nreqs = split(tree[i], r)
586 for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
591 continue # next option
595 # All the requirements have been processed, output
596 # this option. An option is _SUPPORTED if:
598 # all 'requires' are _SUPPORTED AND
599 # at least one of the 'if' options are _SUPPORTED AND
601 # The name is _SUPPORTED (on the command line)
603 # an 'enabledby' is _SUPPORTED
605 # NO_name is not defined AND
606 # the option is not disabled; an option is disabled if:
608 # option == disabled && everything != on
609 # option == "" && everything == off
610 if (deb) print "option", i
612 print "/* option:", i, option[i] >out
613 print " * requires: " requires[i] >out
614 print " * if: " iffs[i] >out
615 print " * enabled-by:" enabledby[i], "*/" >out
616 print "#undef PNG_on" >out
617 print "#define PNG_on 1" >out
620 nreqs = split(requires[i], r)
621 for (j=1; j<=nreqs; ++j) {
622 print "#ifndef PNG_" r[j] "_SUPPORTED" >out
623 print "# undef PNG_on /*!" r[j] "*/" >out
624 # this error appears in the final output if something
625 # was switched 'on' but the processing above to force
626 # the requires did not work
627 if (option[i] == "on") {
628 print error, i, "requires", r[j] end >out
634 nreqs = split(iffs[i], r)
635 print "#undef PNG_no_if" >out
637 print "/* if" iffs[i], "*/" >out
638 print "#define PNG_no_if 1" >out
639 for (j=1; j<=nreqs; ++j) {
640 print "#ifdef PNG_" r[j] "_SUPPORTED" >out
641 print "# undef PNG_no_if /*" r[j] "*/" >out
644 print "#ifdef PNG_no_if /*missing if*/" >out
645 print "# undef PNG_on" >out
646 # There is no checking above for this, because we
647 # don't know which 'if' to choose, so whine about
649 if (option[i] == "on") {
650 print error, i, "needs one of:", iffs[i] end >out
655 print "#ifdef PNG_on /*requires, if*/" >out
657 print "# undef PNG_not_enabled" >out
658 print "# define PNG_not_enabled 1" >out
659 print " /* enabled by" enabledby[i], "*/" >out
660 nreqs = split(enabledby[i], r)
661 for (j=1; j<=nreqs; ++j) {
662 print "#ifdef PNG_" r[j] "_SUPPORTED" >out
663 print "# undef PNG_not_enabled /*" r[j] "*/" >out
664 # Oops, probably not intended (should be factored
665 # out by the checks above).
666 if (option[i] == "off") {
667 print error, i, "enabled by:", r[j] end >out
672 print "# ifndef PNG_" i "_SUPPORTED /*!command line*/" >out
673 print "# ifdef PNG_not_enabled /*!enabled*/" >out
674 if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off") {
675 print "# undef PNG_on /*default off*/" >out
677 print "# ifdef PNG_NO_" i >out
678 print "# undef PNG_on /*turned off*/" >out
680 print "# ifdef PNG_NO_" i "_SUPPORTED" >out
681 print "# undef PNG_on /*turned off*/" >out
684 print "# endif /*!enabled*/" >out
685 print "# ifdef PNG_on" >out
686 # The _SUPPORTED macro must be defined so that dependent
687 # options output later work.
688 print "# define PNG_" i "_SUPPORTED" >out
690 print "# endif /*!command line*/" >out
691 # If PNG_on is still set the option should be defined in
693 print "# ifdef PNG_on" >out
695 print error, i, "is on: enabled by:" iffs[i] enabledby[i] ", requires" requires[i] end >out
696 } else if (i !~ /^ok_/) {
699 print "# endif /* definition */" >out
700 print "#endif /*requires, if*/" >out
701 if (logunsupported || i ~ /^ok_/) {
702 print "#ifndef PNG_on" >out
703 if (logunsupported) {
707 print error, i, "not enabled: requires:" requires[i] ", enabled by:" iffs[i] enabledby[i] end >out
716 if (!finished && !movement) {
717 print "option: loop or missing option in dependency tree, cannot process:"
718 for (i in option) if (!done[i]) {
719 print " option", i, "depends on" tree[i], "needs:"
720 nreqs = split(tree[i], r)
721 if (nreqs > 0) for (j=1; j<=nreqs; ++j) if (!done[r[j]]) {
728 print comment, "end of options", cend >out
730 # Regular end - everything looks ok
732 print start "#endif", cx, protect, "*/" end >out