| #!/bin/awk -f | 
 | # scripts/options.awk - library build configuration control | 
 | # | 
 | # last changed in libpng version 1.6.11 - June 5, 2014 | 
 | # | 
 | # Copyright (c) 1998-2014 Glenn Randers-Pehrson | 
 | # | 
 | # This code is released under the libpng license. | 
 | # For conditions of distribution and use, see the disclaimer | 
 | # and license in png.h | 
 |  | 
 | # The output of this script is written to the file given by | 
 | # the variable 'out'.  The script is run twice, once with | 
 | # an intermediate output file, 'options.tmp' then again on | 
 | # that file to produce the final output: | 
 | # | 
 | #  awk -f scripts/options.awk out=options.tmp scripts/options.dfa 1>&2 | 
 | #  awk -f scripts/options.awk out=options.dfn options.tmp 1>&2 | 
 | # | 
 | # Some options may be specified on the command line: | 
 | # | 
 | #  deb=1            Causes debugging to be output | 
 | #  logunsupported=1 Causes all options to be recorded in the output | 
 | #  everything=off   Causes all options to be disabled by default | 
 | #  everything=on    Causes all options to be enabled by default | 
 | # | 
 | # If awk fails on your platform, try nawk instead. | 
 | # | 
 | # These options may also be specified in the original input file (and | 
 | # are copied to the preprocessed file). | 
 |  | 
 | BEGIN{ | 
 |    out=""                       # intermediate, preprocessed, file | 
 |    pre=-1                       # preprocess (first line) | 
 |    version="libpng version unknown" # version information | 
 |    version_file=""              # where to find the version | 
 |    err=0                        # in-line exit sets this | 
 |    # The following definitions prevent the C preprocessor noticing the lines | 
 |    # that will be in the final output file.  Some C preprocessors tokenise | 
 |    # the lines, for example by inserting spaces around operators, and all | 
 |    # C preprocessors notice lines that start with '#', most remove comments. | 
 |    # The technique adopted here is to make the final output lines into | 
 |    # C strings (enclosed in double quotes), preceded by PNG_DFN.  As a | 
 |    # consequence the output cannot contain a 'raw' double quote - instead put | 
 |    # @' in, this will be replaced by a single " afterward.  See the parser | 
 |    # script dfn.awk for more capabilities (not required here).  Note that if | 
 |    # you need a " in a 'setting' in pnglibconf.dfa it must also be @'! | 
 |    dq="@'"                      # For a single double quote | 
 |    start=" PNG_DFN \""          # Start stuff to output (can't contain a "!) | 
 |    end="\" "                    # End stuff to output | 
 |    subs="@\" "                  # Substitute start (substitute a C macro) | 
 |    sube=" \"@"                  # Substitute end | 
 |    comment=start "/*"           # Comment start | 
 |    cend="*/" end                # Comment end | 
 |    def=start "#define PNG_"     # Arbitrary define | 
 |    sup="_SUPPORTED" end         # end supported option | 
 |    und=comment "#undef PNG_"    # Unsupported option | 
 |    une="_SUPPORTED" cend        # end unsupported option | 
 |    error=start "ERROR:"         # error message, terminate with 'end' | 
 |  | 
 |    # Variables | 
 |    deb=0                        # debug - set on command line | 
 |    everything=""                # do not override defaults | 
 |    logunsupported=0             # write unsupported options too | 
 |  | 
 |    # Precreate arrays | 
 |    # for each option: | 
 |    option[""] = ""    # list of all options: default enabled/disabled | 
 |    done[""] = 1       # marks option as having been output | 
 |    requires[""] = ""  # requires by option | 
 |    iffs[""] = ""      # if by option | 
 |    enabledby[""] = "" # options that enable it by option | 
 |    sets[""] = ""      # settings set by each option | 
 |    setval[""] = ""    # value to set (indexed: 'option sets[option]') | 
 |    # for each setting: | 
 |    setting[""] = ""   # requires by setting | 
 |    defaults[""] = ""  # used for a defaulted value | 
 |    doneset[""] = 1    # marks setting as having been output | 
 |    r[""] = ""         # Temporary array | 
 |  | 
 |    # For decorating the output file | 
 |    protect = "" | 
 | } | 
 |  | 
 | # The output file must be specified before any input: | 
 | out == "" { | 
 |    print "out=output.file must be given on the command line" | 
 |    err = 1 | 
 |    exit 1 | 
 | } | 
 |  | 
 | # The very first line indicates whether we are reading pre-processed | 
 | # input or not, this must come *first* because 'PREPROCESSED' needs | 
 | # to be the very first line in the temporary file. | 
 | pre == -1{ | 
 |    if ($0 == "PREPROCESSED") { | 
 |       pre = 0 | 
 |       next | 
 |    } else { | 
 |       pre = 1 | 
 |       print "PREPROCESSED" >out | 
 |       # And fall through to continue processing | 
 |    } | 
 | } | 
 |  | 
 | # While pre-processing if version is set to "search" look for a version string | 
 | # in the following file. | 
 | pre && version == "search" && version_file == ""{ | 
 |    version_file = FILENAME | 
 | } | 
 |  | 
 | pre && version == "search" && version_file != FILENAME{ | 
 |    print "version string not found in", version_file | 
 |    err = 1 | 
 |    exit 1 | 
 | } | 
 |  | 
 | pre && version == "search" && $0 ~ /^ \* libpng version/{ | 
 |    version = substr($0, 4) | 
 |    print "version =", version >out | 
 |    next | 
 | } | 
 |  | 
 | pre && FILENAME == version_file{ | 
 |    next | 
 | } | 
 |  | 
 | # variable=value | 
 | #   Sets the given variable to the given value (the syntax is fairly | 
 | #   free form, except for deb (you are expected to understand how to | 
 | #   set the debug variable...) | 
 | # | 
 | #   This happens before the check on 'pre' below skips most of the | 
 | #   rest of the actions, so the variable settings happen during | 
 | #   preprocessing but are recorded in the END action too.  This | 
 | #   allows them to be set on the command line too. | 
 | $0 ~ /^[ 	]*version[ 	]*=/{ | 
 |    sub(/^[  ]*version[  ]*=[  ]*/, "") | 
 |    version = $0 | 
 |    next | 
 | } | 
 | $0 ~ /^[ 	]*everything[ 	=]*off[ 	]*$/{ | 
 |    everything = "off" | 
 |    next | 
 | } | 
 | $0 ~ /^[ 	]*everything[ 	=]*on[ 	]*$/{ | 
 |    everything = "on" | 
 |    next | 
 | } | 
 | $0 ~ /^[ 	]*logunsupported[ 	=]*0[ 	]*$/{ | 
 |    logunsupported = 0 | 
 |    next | 
 | } | 
 | $0 ~ /^[ 	]*logunsupported[ 	=]*1[ 	]*$/{ | 
 |    logunsupported = 1 | 
 |    next | 
 | } | 
 | $1 == "deb" && $2 == "=" && NF == 3{ | 
 |    deb = $3 | 
 |    next | 
 | } | 
 |  | 
 | # Preprocessing - this just copies the input file with lines | 
 | # that need preprocessing (just chunk at present) expanded | 
 | # The bare "pre" instead of "pre != 0" crashes under Sunos awk | 
 | pre && $1 != "chunk"{ | 
 |    print >out | 
 |    next | 
 | } | 
 |  | 
 | # The first characters of the line determine how it is processed, | 
 | # leading spaces are ignored.  In general tokens that are not | 
 | # keywords are the names of options.  An option 'name' is | 
 | # controlled by the definition of the corresponding macros: | 
 | # | 
 | #   PNG_name_SUPPORTED    The option is turned on | 
 | #   PNG_NO_name | 
 | #   PNG_NO_name_SUPPORTED If the first macro is not defined | 
 | #                         either of these will turn the option off | 
 | # | 
 | # If none of these macros are defined the option is turned on, unless | 
 | # the keyword 'off' is given in a line relating to the option.  The | 
 | # keyword 'on' can also be given, but it will be ignored (since it is | 
 | # the default.) | 
 | # | 
 | # In the syntax below a 'name' is indicated by "NAME", other macro | 
 | # values are indicated by "MACRO", as with "NAME" the leading "PNG_" | 
 | # is omitted, but in this case the "NO_" prefix and the "_SUPPORTED" | 
 | # suffix are never used. | 
 | # | 
 | # Each line is introduced by a keyword - the first non-space characters | 
 | # on the line.  A line starting with a '#' is a comment - it is totally | 
 | # ignored.  Keywords are as follows, a NAME, is simply a macro name | 
 | # without the leading PNG_, PNG_NO_ or the trailing _SUPPORTED. | 
 |  | 
 | $1 ~ /^#/ || $0 ~ /^[ 	]*$/{ | 
 |    next | 
 | } | 
 |  | 
 | # com <comment> | 
 | #   The whole line is placed in the output file as a comment with | 
 | #   the preceding 'com' removed | 
 | $1 == "com"{ | 
 |    if (NF > 1) { | 
 |       # sub(/^[ 	]*com[ 	]*/, "") | 
 |       $1 = "" | 
 |       print comment $0, cend >out | 
 |    } else | 
 |       print start end >out | 
 |    next | 
 | } | 
 |  | 
 | # version | 
 | #   Inserts a version comment | 
 | $1 == "version" && NF == 1{ | 
 |    if (version == "") { | 
 |       print "ERROR: no version string set" | 
 |       err = 1 # prevent END{} running | 
 |       exit 1 | 
 |    } | 
 |  | 
 |    print comment, version, cend >out | 
 |    next | 
 | } | 
 |  | 
 | # file output input protect | 
 | #   Informational: the official name of the input file (without | 
 | #   make generated local directories), the official name of the | 
 | #   output file and, if required, a name to use in a protection | 
 | #   macro for the contents. | 
 | $1 == "file" && NF >= 2{ | 
 |    print comment, $2, cend >out | 
 |    print comment, "Machine generated file: DO NOT EDIT", cend >out | 
 |    if (NF >= 3) | 
 |       print comment, "Derived from:", $3, cend >out | 
 |    protect = $4 | 
 |    if (protect != "") { | 
 |       print start "#ifndef", protect end >out | 
 |       print start "#define", protect end >out | 
 |    } | 
 |    next | 
 | } | 
 |  | 
 | # option NAME ( (requires|enables|if) NAME* | on | off | disabled | | 
 | #                sets SETTING VALUE+ )* | 
 | #      | 
 | #   Declares an option 'NAME' and describes its default setting (disabled) | 
 | #   and its relationship to other options.  The option is disabled | 
 | #   unless *all* the options listed after 'requires' are set and at | 
 | #   least one of the options listed after 'if' is set.  If the | 
 | #   option is set then it turns on all the options listed after 'enables'. | 
 | # | 
 | #   Note that "enables" takes priority over the required/if/disabled/off | 
 | #   setting of the target option. | 
 | # | 
 | #   The definition file may list an option as 'disabled': off by default, | 
 | #   otherwise the option is enabled: on by default.  A later (and it must | 
 | #   be later) entry may turn an option on or off explicitly. | 
 |  | 
 | $1 == "option" && NF >= 2{ | 
 |    opt = $2 | 
 |    sub(/,$/,"",opt) | 
 |    onoff = option[opt]  # records current (and the default is "", enabled) | 
 |    key = "" | 
 |    istart = 3 | 
 |    do { | 
 |       if (istart == 1) {     # continuation line | 
 |          val = getline | 
 |  | 
 |          if (val != 1) { # error reading it | 
 |             if (val == 0) | 
 |                print "option", opt ": ERROR: missing continuation line" | 
 |             else | 
 |                print "option", opt ": ERROR: error reading continuation line" | 
 |  | 
 |             # This is a hard error | 
 |             err = 1 # prevent END{} running | 
 |             exit 1 | 
 |          } | 
 |       } | 
 |  | 
 |       for (i=istart; i<=NF; ++i) { | 
 |          val=$(i) | 
 |          sub(/,$/,"",val) | 
 |          if (val == "on" || val == "off" || val == "disabled" || val =="enabled") { | 
 |             key = "" | 
 |             if (onoff != val) { | 
 |                # on or off can zap disabled or enabled: | 
 |                if (onoff == "" || (onoff == "disabled" || onoff == "enabled") && | 
 |                    (val == "on" || val == "off")) { | 
 |                   # It's easy to mis-spell the option when turning it | 
 |                   # on or off, so warn about it here: | 
 |                   if (onoff == "" && (val == "on" || val == "off")) { | 
 |                      print "option", opt ": ERROR: turning unrecognized option", val | 
 |                      # For the moment error out - it is safer | 
 |                      err = 1 # prevent END{} running | 
 |                      exit 1 | 
 |                   } | 
 |                   onoff = val | 
 |                } else { | 
 |                   # Print a message, otherwise the error | 
 |                   # below is incomprehensible | 
 |                   print "option", opt ": currently", onoff ": attempt to turn", val | 
 |                   break | 
 |                } | 
 |             } | 
 |          } else if (val == "requires" || val == "if" || val == "enables" || val =="sets") { | 
 |             key = val | 
 |          } else if (key == "requires") { | 
 |             requires[opt] = requires[opt] " " val | 
 |          } else if (key == "if") { | 
 |             iffs[opt] = iffs[opt] " " val | 
 |          } else if (key == "enables") { | 
 |             enabledby[val] = enabledby[val] " " opt | 
 |          } else if (key == "sets") { | 
 |             sets[opt] = sets[opt] " " val | 
 |             key = "setval" | 
 |             set = val | 
 |          } else if (key == "setval") { | 
 |             setval[opt " " set] = setval[opt " " set] " " val | 
 |          } else | 
 |             break # bad line format | 
 |       } | 
 |  | 
 |       istart = 1 | 
 |    } while (i > NF && $0 ~ /,$/) | 
 |  | 
 |    if (i > NF) { | 
 |       # Set the option, defaulting to 'enabled' | 
 |       if (onoff == "") onoff = "enabled" | 
 |       option[opt] = onoff | 
 |       next | 
 |    } | 
 |    # Else fall through to the error handler | 
 | } | 
 |  | 
 | # chunk NAME [requires OPT] [enables LIST] [on|off|disabled] | 
 | #   Expands to the 'option' settings appropriate to the reading and | 
 | #   writing of an ancillary PNG chunk 'NAME': | 
 | # | 
 | #   option READ_NAME requires READ_ANCILLARY_CHUNKS [READ_OPT] | 
 | #   option READ_NAME enables NAME LIST | 
 | #   [option READ_NAME off] | 
 | #   option WRITE_NAME requires WRITE_ANCILLARY_CHUNKS [WRITE_OPT] | 
 | #   option WRITE_NAME enables NAME LIST | 
 | #   [option WRITE_NAME off] | 
 |  | 
 | pre != 0 && $1 == "chunk" && NF >= 2{ | 
 |    # 'chunk' is handled on the first pass by writing appropriate | 
 |    # 'option' lines into the intermediate file. | 
 |    opt = $2 | 
 |    sub(/,$/,"",opt) | 
 |    onoff = "" | 
 |    reqread = "" | 
 |    reqwrite = "" | 
 |    enables = "" | 
 |    req = 0 | 
 |    istart = 3 | 
 |    do { | 
 |       if (istart == 1) {     # continuation line | 
 |          val = getline | 
 |  | 
 |          if (val != 1) { # error reading it | 
 |             if (val == 0) | 
 |                print "chunk", opt ": ERROR: missing continuation line" | 
 |             else | 
 |                print "chunk", opt ": ERROR: error reading continuation line" | 
 |  | 
 |             # This is a hard error | 
 |             err = 1 # prevent END{} running | 
 |             exit 1 | 
 |          } | 
 |       } | 
 |  | 
 |       # read the keywords/additional OPTS | 
 |       for (i=istart; i<=NF; ++i) { | 
 |          val = $(i) | 
 |          sub(/,$/,"",val) | 
 |          if (val == "on" || val == "off" || val == "disabled") { | 
 |             if (onoff != val) { | 
 |                if (onoff == "") | 
 |                   onoff = val | 
 |                else | 
 |                   break # on/off conflict | 
 |             } | 
 |             req = 0 | 
 |          } else if (val == "requires") | 
 |             req = 1 | 
 |          else if (val == "enables") | 
 |             req = 2 | 
 |          else if (req == 1){ | 
 |             reqread = reqread " READ_" val | 
 |             reqwrite = reqwrite " WRITE_" val | 
 |          } else if (req == 2) | 
 |             enables = enables " " val | 
 |          else | 
 |             break # bad line: handled below | 
 |       } | 
 |  | 
 |       istart = 1 | 
 |    } while (i > NF && $0 ~ /,$/) | 
 |  | 
 |    if (i > NF) { | 
 |       # Output new 'option' lines to the intermediate file (out) | 
 |       print "option READ_" opt, "requires READ_ANCILLARY_CHUNKS" reqread, "enables", opt enables , onoff >out | 
 |       print "option WRITE_" opt, "requires WRITE_ANCILLARY_CHUNKS" reqwrite, "enables", opt enables, onoff >out | 
 |       next | 
 |    } | 
 |    # Else hit the error handler below - bad line format! | 
 | } | 
 |  | 
 | # setting MACRO ( requires MACRO* )* [ default VALUE ] | 
 | #   Behaves in a similar way to 'option' without looking for NO_ or | 
 | #   _SUPPORTED; the macro is enabled if it is defined so long as all | 
 | #   the 'requires' macros are also defined.  The definitions may be | 
 | #   empty, an error will be issued if the 'requires' macros are | 
 | #   *not* defined.  If given the 'default' value is used if the | 
 | #   macro is not defined.  The default value will be re-tokenised. | 
 | #   (BTW: this is somewhat restrictive, it mainly exists for the | 
 | #   support of non-standard configurations and numeric parameters, | 
 | #   see the uses in scripts/options.dat | 
 |  | 
 | $1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){ | 
 |    reqs = "" | 
 |    deflt = "" | 
 |    isdef = 0 | 
 |    key = "" | 
 |    for (i=3; i<=NF; ++i) | 
 |       if ($(i) == "requires" || $(i) == "default") { | 
 |          key = $(i) | 
 |          if (key == "default") isdef = 1 | 
 |       } else if (key == "requires") | 
 |          reqs = reqs " " $(i) | 
 |       else if (key == "default") | 
 |          deflt = deflt " " $(i) | 
 |       else | 
 |          break # Format error, handled below | 
 |  | 
 |    setting[$2] = reqs | 
 |    # NOTE: this overwrites a previous value silently | 
 |    if (isdef && deflt == "") | 
 |       deflt = " " # as a flag to force output | 
 |    defaults[$2] = deflt | 
 |    next | 
 | } | 
 |  | 
 | # The order of the dependency lines (option, chunk, setting) is irrelevant | 
 | # - the 'enables', 'requires' and 'if' settings will be used to determine | 
 | # the correct order in the output and the final values in pnglibconf.h are | 
 | # not order dependent.  'requires' and 'if' entries take precedence over | 
 | # 'enables' from other options; if an option requires another option it | 
 | # won't be set regardless of any options that enable it unless the other | 
 | # option is also enabled. | 
 | # | 
 | # Similarly 'enables' trumps a NO_ definition in CFLAGS or pngusr.h | 
 | # | 
 | # For simplicity cycles in the definitions are regarded as errors, | 
 | # even if they are not ambiguous. | 
 | # A given NAME can be specified in as many 'option' lines as required, the | 
 | # definitions are additive. | 
 |  | 
 | # For backwards compatibility equivalent macros may be listed thus: | 
 | # | 
 | # = [NO_]NAME MACRO | 
 | #   Makes -DMACRO equivalent to -DPNG_NO_NAME or -DPNG_NAME_SUPPORTED | 
 | #   as appropriate. | 
 | # | 
 | # The definition is injected into the C compiler input when encountered | 
 | # in the second pass (so all these definitions appear *after* the @ | 
 | # lines!) | 
 | # | 
 | # 'NAME' is as above, but 'MACRO' is the full text of the equivalent | 
 | # old, deprecated, macro. | 
 |  | 
 | $1 == "=" && NF == 3{ | 
 |    print "#ifdef PNG_" $3 >out | 
 |    if ($2 ~ /^NO_/) | 
 |       print "#   define PNG_" $2 >out | 
 |    else | 
 |       print "#   define PNG_" $2 "_SUPPORTED" >out | 
 |    print "#endif" >out | 
 |    next | 
 | } | 
 |  | 
 | # Lines may be injected into the C compiler input by preceding them | 
 | # with an "@" character.  The line is copied with just the leading | 
 | # @ removed. | 
 |  | 
 | $1 ~ /^@/{ | 
 |    # sub(/^[ 	]*@/, "") | 
 |    $1 = substr($1, 2) | 
 |    print >out | 
 |    next | 
 | } | 
 |  | 
 | # Check for unrecognized lines, because of the preprocessing chunk | 
 | # format errors will be detected on the first pass independent of | 
 | # any other format errors. | 
 | { | 
 |    print "options.awk: bad line (" NR "):", $0 | 
 |    err = 1 # prevent END{} running | 
 |    exit 1 | 
 | } | 
 |  | 
 | # For checking purposes names that start with "ok_" or "fail_" are | 
 | # not output to pnglibconf.h and must be either enabled or disabled | 
 | # respectively for the build to succeed.  This allows interdependencies | 
 | # between options of the form "at least one of" or "at most one of" | 
 | # to be checked.  For example: | 
 | # | 
 | # option FLOATING_POINT enables ok_math | 
 | # option FIXED_POINT enables ok_math | 
 | #   This ensures that at least one of FLOATING_POINT and FIXED_POINT | 
 | #   must be set for the build to succeed. | 
 | # | 
 | # option fail_math requires FLOATING_POINT FIXED_POINT | 
 | #   This means the build will fail if *both* FLOATING_POINT and | 
 | #   FIXED_POINT are set (this is an example; in fact both are allowed.) | 
 | # | 
 | # If all these options were given the build would require exactly one | 
 | # of the names to be enabled. | 
 |  | 
 | END{ | 
 |    # END{} gets run on an exit (a traditional awk feature) | 
 |    if (err) exit 1 | 
 |  | 
 |    if (pre) { | 
 |       # Record the final value of the variables | 
 |       print "deb =", deb >out | 
 |       if (everything != "") { | 
 |          print "everything =", everything >out | 
 |       } | 
 |       print "logunsupported =", logunsupported >out | 
 |       exit 0 | 
 |    } | 
 |  | 
 |    # Do the options first (allowing options to set settings).  The dependency | 
 |    # tree is thus: | 
 |    # | 
 |    #   name     >     name | 
 |    #   name requires  name | 
 |    #   name if        name | 
 |    #   name enabledby name | 
 |    # | 
 |    # First build a list 'tree' by option of all the things on which | 
 |    # it depends. | 
 |    print "" >out | 
 |    print "/* OPTIONS */" >out | 
 |    print comment, "options", cend >out | 
 |    for (opt in enabledby) tree[opt] = 1  # may not be explicit options | 
 |    for (opt in option) if (opt != "") { | 
 |       o = option[opt] | 
 |       # option should always be one of the following values | 
 |       if (o != "on" && o != "off" && o != "disabled" && o != "enabled") { | 
 |          print "internal option error (" o ")" | 
 |          exit 1 | 
 |       } | 
 |       tree[opt] = ""   # so unlisted options marked | 
 |    } | 
 |    for (opt in tree) if (opt != "") { | 
 |       if (tree[opt] == 1) { | 
 |          tree[opt] = "" | 
 |          if (option[opt] != "") { | 
 |             print "internal error (1)" | 
 |             exit 1 | 
 |          } | 
 |          # Macros only listed in 'enables' remain off unless | 
 |          # one of the enabling macros is on. | 
 |          option[opt] = "disabled" | 
 |       } | 
 |  | 
 |       split("", list) # clear 'list' | 
 |       # Now add every requires, iffs or enabledby entry to 'list' | 
 |       # so that we can add a unique list of requirements to tree[i] | 
 |       split(requires[opt] iffs[opt] enabledby[opt], r) | 
 |       for (i in r) list[r[i]] = 1 | 
 |       for (i in list) tree[opt] = tree[opt] " " i | 
 |    } | 
 |  | 
 |    # print the tree for extreme debugging | 
 |    if (deb > 2) for (i in tree) if (i != "") print i, "depends-on" tree[i] | 
 |  | 
 |    # Ok, now check all options marked explicitly 'on' or 'off': | 
 |    # | 
 |    # If an option[opt] is 'on' then turn on all requires[opt] | 
 |    # If an option[opt] is 'off' then turn off all enabledby[opt] | 
 |    # | 
 |    # Error out if we have to turn 'on' to an 'off' option or vice versa. | 
 |    npending = 0 | 
 |    for (opt in option) if (opt != "") { | 
 |       if (option[opt] == "on" || option[opt] == "off") { | 
 |          pending[++npending] = opt | 
 |       } | 
 |    } | 
 |  | 
 |    err = 0 # set on error | 
 |    while (npending > 0) { | 
 |       opt = pending[npending--] | 
 |       if (option[opt] == "on") { | 
 |          nreqs = split(requires[opt], r) | 
 |          for (j=1; j<=nreqs; ++j) { | 
 |             if (option[r[j]] == "off") { | 
 |                print "option", opt, "turned on, but requirement", r[j], "is turned off" | 
 |                err = 1 | 
 |             } else if (option[r[j]] != "on") { | 
 |                option[r[j]] = "on" | 
 |                pending[++npending] = r[j] | 
 |             } | 
 |          } | 
 |       } else { | 
 |          if (option[opt] != "off") { | 
 |             print "internal error (2)" | 
 |             exit 1 | 
 |          } | 
 |          nreqs = split(enabledby[opt], r) | 
 |          for (j=1; j<=nreqs; ++j) { | 
 |             if (option[r[j]] == "on") { | 
 |                print "option", opt, "turned off, but enabled by", r[j], "which is turned on" | 
 |                err = 1 | 
 |             } else if (option[r[j]] != "off") { | 
 |                option[r[j]] = "off" | 
 |                pending[++npending] = r[j] | 
 |             } | 
 |          } | 
 |       } | 
 |    } | 
 |    if (err) exit 1 | 
 |  | 
 |    # Sort options: | 
 |    print "PNG_DFN_START_SORT 2" >out | 
 |  | 
 |    # option[i] is now the complete list of all the tokens we may | 
 |    # need to output, go through it as above, depth first. | 
 |    finished = 0 | 
 |    while (!finished) { | 
 |       finished = 1 | 
 |       movement = 0 # done nothing | 
 |       for (i in option) if (!done[i]) { | 
 |          nreqs = split(tree[i], r) | 
 |          if (nreqs > 0) { | 
 |             for (j=1; j<=nreqs; ++j) if (!done[r[j]]) { | 
 |                break | 
 |             } | 
 |             if (j<=nreqs) { | 
 |                finished = 0 | 
 |                continue  # next option | 
 |             } | 
 |          } | 
 |  | 
 |          # All the requirements have been processed, output | 
 |          # this option.  An option is _SUPPORTED if: | 
 |          # | 
 |          # all 'requires' are _SUPPORTED AND | 
 |          # at least one of the 'if' options are _SUPPORTED AND | 
 |          # EITHER: | 
 |          #   The name is _SUPPORTED (on the command line) | 
 |          # OR: | 
 |          #   an 'enabledby' is _SUPPORTED | 
 |          # OR: | 
 |          #   NO_name is not defined AND | 
 |          #   the option is not disabled; an option is disabled if: | 
 |          #    option == off | 
 |          #    option == disabled && everything != on | 
 |          #    option == "" && everything == off | 
 |          if (deb) print "option", i | 
 |          print "" >out | 
 |          print "/* option:", i, option[i] >out | 
 |          print " *   requires:  " requires[i] >out | 
 |          print " *   if:        " iffs[i] >out | 
 |          print " *   enabled-by:" enabledby[i] >out | 
 |          print " *   sets:      " sets[i], "*/" >out | 
 |          print "#undef PNG_on" >out | 
 |          print "#define PNG_on 1" >out | 
 |  | 
 |          # requires | 
 |          nreqs = split(requires[i], r) | 
 |          for (j=1; j<=nreqs; ++j) { | 
 |             print "#ifndef PNG_" r[j] "_SUPPORTED" >out | 
 |             print "#   undef PNG_on /*!" r[j] "*/" >out | 
 |             # This error appears in the final output if something | 
 |             # was switched 'on' but the processing above to force | 
 |             # the requires did not work | 
 |             if (option[i] == "on") { | 
 |                print error, i, "requires", r[j] end >out | 
 |             } | 
 |             print "#endif" >out | 
 |          } | 
 |  | 
 |          # if | 
 |          have_ifs = 0 | 
 |          nreqs = split(iffs[i], r) | 
 |          print "#undef PNG_no_if" >out | 
 |          if (nreqs > 0) { | 
 |             have_ifs = 1 | 
 |             print "/* if" iffs[i], "*/" >out | 
 |             print "#define PNG_no_if 1" >out | 
 |             for (j=1; j<=nreqs; ++j) { | 
 |                print "#ifdef PNG_" r[j] "_SUPPORTED" >out | 
 |                print "#   undef PNG_no_if /*" r[j] "*/" >out | 
 |                print "#endif" >out | 
 |             } | 
 |             print "#ifdef PNG_no_if /*missing if*/" >out | 
 |             print "#   undef PNG_on" >out | 
 |             # There is no checking above for this, because we | 
 |             # don't know which 'if' to choose, so whine about | 
 |             # it here: | 
 |             if (option[i] == "on") { | 
 |                print error, i, "needs one of:", iffs[i] end >out | 
 |             } | 
 |             print "#endif" >out | 
 |          } | 
 |  | 
 |          print "#ifdef PNG_on /*requires, if*/" >out | 
 |          # enables | 
 |          print "#   undef PNG_not_enabled" >out | 
 |          print "#   define PNG_not_enabled 1" >out | 
 |          print "   /* enabled by" enabledby[i], "*/" >out | 
 |          nreqs = split(enabledby[i], r) | 
 |          for (j=1; j<=nreqs; ++j) { | 
 |             print "#ifdef PNG_" r[j] "_SUPPORTED" >out | 
 |             print "#   undef PNG_not_enabled /*" r[j] "*/" >out | 
 |             # Oops, probably not intended (should be factored | 
 |             # out by the checks above). | 
 |             if (option[i] == "off") { | 
 |                print error, i, "enabled by:", r[j] end >out | 
 |             } | 
 |             print "#endif" >out | 
 |          } | 
 |  | 
 |          print "#   ifndef PNG_" i "_SUPPORTED /*!command line*/" >out | 
 |          print "#    ifdef PNG_not_enabled /*!enabled*/" >out | 
 |          # 'have_ifs' here means that everything = "off" still allows an 'if' on | 
 |          # an otherwise enabled option to turn it on; otherwise the 'if' | 
 |          # handling is effectively disabled by 'everything = off' | 
 |          if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off" && !have_ifs) { | 
 |             print "#      undef PNG_on /*default off*/" >out | 
 |          } else { | 
 |             print "#      ifdef PNG_NO_" i >out | 
 |             print "#       undef PNG_on /*turned off*/" >out | 
 |             print "#      endif" >out | 
 |             print "#      ifdef PNG_NO_" i "_SUPPORTED" >out | 
 |             print "#       undef PNG_on /*turned off*/" >out | 
 |             print "#      endif" >out | 
 |          } | 
 |          print "#    endif /*!enabled*/" >out | 
 |          print "#    ifdef PNG_on" >out | 
 |          # The _SUPPORTED macro must be defined so that dependent | 
 |          # options output later work. | 
 |          print "#      define PNG_" i "_SUPPORTED" >out | 
 |          print "#    endif" >out | 
 |          print "#   endif /*!command line*/" >out | 
 |          # If PNG_on is still set the option should be defined in | 
 |          # pnglibconf.h | 
 |          print "#   ifdef PNG_on" >out | 
 |          if (i ~ /^fail_/) { | 
 |             print error, i, "is on: enabled by:" iffs[i] enabledby[i] ", requires" requires[i] end >out | 
 |          } else if (i !~ /^ok_/) { | 
 |             print def i sup >out | 
 |             # Supported option, set required settings | 
 |             nreqs = split(sets[i], r) | 
 |             for (j=1; j<=nreqs; ++j) { | 
 |                print "#    ifdef PNG_set_" r[j] >out | 
 |                # Some other option has already set a value: | 
 |                print error, i, "sets", r[j] ": duplicate setting" end >out | 
 |                print error, "   previous value: " end "PNG_set_" r[j] >out | 
 |                print "#    else" >out | 
 |                # Else set the default: note that this won't accept arbitrary | 
 |                # values, the setval string must be acceptable to all the C | 
 |                # compilers we use.  That means it must be VERY simple; a number, | 
 |                # a name or a string. | 
 |                print "#     define PNG_set_" r[j], setval[i " " r[j]] >out | 
 |                print "#    endif" >out | 
 |             } | 
 |          } | 
 |          print "#   endif /* definition */" >out | 
 |          print "#endif /*requires, if*/" >out | 
 |          if (logunsupported || i ~ /^ok_/) { | 
 |             print "#ifndef  PNG_on" >out | 
 |             if (logunsupported) { | 
 |                print und i une >out | 
 |             } | 
 |             if (i ~ /^ok_/) { | 
 |                print error, i, "not enabled: requires:" requires[i] ", enabled by:" iffs[i] enabledby[i] end >out | 
 |             } | 
 |             print "#endif" >out | 
 |          } | 
 |  | 
 |          done[i] = 1 | 
 |          ++movement | 
 |       } | 
 |  | 
 |       if (!finished && !movement) { | 
 |          print "option: loop or missing option in dependency tree, cannot process:" | 
 |          for (i in option) if (!done[i]) { | 
 |             print "  option", i, "depends on" tree[i], "needs:" | 
 |             nreqs = split(tree[i], r) | 
 |             if (nreqs > 0) for (j=1; j<=nreqs; ++j) if (!done[r[j]]) { | 
 |                print "   " r[j] | 
 |             } | 
 |          } | 
 |          exit 1 | 
 |       } | 
 |    } | 
 |    print "PNG_DFN_END_SORT" >out | 
 |    print comment, "end of options", cend >out | 
 |  | 
 |    # Do the 'setting' values second, the algorithm the standard | 
 |    # tree walk (O(1)) done in an O(2) while/for loop; iterations | 
 |    # settings x depth, outputting the deepest required macros | 
 |    # first. | 
 |    print "" >out | 
 |    print "/* SETTINGS */" >out | 
 |    print comment, "settings", cend >out | 
 |    # Sort (in dfn.awk) on field 2, the setting name | 
 |    print "PNG_DFN_START_SORT 2" >out | 
 |    finished = 0 | 
 |    while (!finished) { | 
 |       finished = 1 | 
 |       movement = 0 # done nothing | 
 |       for (i in setting) if (!doneset[i]) { | 
 |          nreqs = split(setting[i], r) | 
 |          if (nreqs > 0) { | 
 |             # By default assume the requires values are options, but if there | 
 |             # is no option with that name check for a setting | 
 |             for (j=1; j<=nreqs; ++j) if (option[r[j]] == "" && !doneset[r[j]]) { | 
 |                break | 
 |             } | 
 |             if (j<=nreqs) { | 
 |                finished = 0 | 
 |                continue # try a different setting | 
 |             } | 
 |          } | 
 |  | 
 |          # All the requirements have been processed, output | 
 |          # this setting. | 
 |          if (deb) print "setting", i | 
 |          deflt = defaults[i] | 
 |          # Remove any spurious trailing spaces | 
 |          sub(/ *$/,"",deflt) | 
 |          # A leading @ means leave it unquoted so the preprocessor | 
 |          # can substitute the build time value | 
 |          if (deflt ~ /^ @/) | 
 |             deflt = " " subs substr(deflt, 3) sube | 
 |          print "" >out | 
 |          print "/* setting: ", i >out | 
 |          print " *   requires:" setting[i] >out | 
 |          print " *   default: ", defaults[i] deflt, "*/" >out | 
 |          for (j=1; j<=nreqs; ++j) { | 
 |             if (option[r[j]] != "") | 
 |                print "#ifndef PNG_" r[j] "_SUPPORTED" >out | 
 |             else | 
 |                print "#ifndef PNG_" r[j] >out | 
 |             print error, i, "requires", r[j] end >out | 
 |             print "# endif" >out | 
 |          } | 
 |          # The precedence is: | 
 |          # | 
 |          #  1) External definition; trumps: | 
 |          #  2) Option 'sets' value; trumps: | 
 |          #  3) Setting 'default' | 
 |          # | 
 |          print "#ifdef PNG_" i >out | 
 |          # PNG_<i> is defined, so substitute the value: | 
 |          print def i, subs "PNG_" i sube end >out | 
 |          print "#else /* use default */" >out | 
 |          print "# ifdef PNG_set_" i >out | 
 |          # Value from an option 'sets' argument | 
 |          print def i, subs "PNG_set_" i sube end >out | 
 |          # This is so that subsequent tests on the setting work: | 
 |          print "#  define PNG_" i, "1" >out | 
 |          if (defaults[i] != "") { | 
 |             print "# else /*default*/" >out | 
 |             print def i deflt end >out | 
 |             print "#  define PNG_" i, "1" >out | 
 |          } | 
 |          print "# endif /* defaults */" >out | 
 |          print "#endif /* setting", i, "*/" >out | 
 |  | 
 |          doneset[i] = 1 | 
 |          ++movement | 
 |       } | 
 |  | 
 |       if (!finished && !movement) { | 
 |          print "setting: loop or missing setting in 'requires', cannot process:" | 
 |          for (i in setting) if (!doneset[i]) { | 
 |             print "  setting", i, "requires" setting[i] | 
 |          } | 
 |          exit 1 | 
 |       } | 
 |    } | 
 |    print "PNG_DFN_END_SORT" >out | 
 |    print comment, "end of settings", cend >out | 
 |  | 
 |    # Regular end - everything looks ok | 
 |    if (protect != "") { | 
 |       print start "#endif", "/*", protect, "*/" end >out | 
 |    } | 
 | } |