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31aee0d0c0
libpng/scripts/options.awk
Glenn Randers-Pehrson 31aee0d0c0 [devel] 
Fixed point APIs are now supported throughout (no missing APIs).
  Internal fixed point arithmetic support exists for all internal floating
    point operations.
  sCAL validates the floating point strings it is passed.
  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
  Two new APIs exist to get the number of passes without turning on the
    PNG_INTERLACE transform and to get the number of rows in the current
    pass.
  A new test program, pngvalid.c, validates the gamma code.
  Errors in the 16 bit gamma correction (overflows) have been corrected.
  cHRM chunk testing is done consistently (previously the floating point
    API bypassed it, because the test really didn't work on FP, now the test
    is performed on the actual values to be stored in the PNG file so it
    works in the FP case too.)
  Most floating point APIs now simply call the fixed point APIs after
    converting the values to the fixed point form used in the PNG file.
  The standard headers no longer include zlib.h, which is currently only
    required for pngstruct.h and can therefore be internal.
  (Patches by John Bowler)
2010-07-29 17:39:14 -05:00

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#!/bin/awk -f
# scripts/options.awk - library build configuration control
#
# last changed in libpng version 1.5.0 - July 29, 2010
#
# Copyright (c) 1998-2010 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="/dev/null" # intermediate, preprocessed, file
pre=-1 # preprocess (first line)
err=0 # in-line exit sets this
start="PNG_DEFN_MAGIC-" # Arbitrary start
end="-PNG_DEFN_END" # Arbitrary end
cx= "/@@@*" # Open C comment for output file
comment=start cx # 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
# Variables
deb=0 # debug - set on command line
everything="" # do not override defaults
logunsupported=0 # write unsupported options too
# Precreate arrays
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
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 == "/dev/null" {
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
}
}
# 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.
$0 ~ /^[ ]*everything[ =]*off[ ]*$/{
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
}
# 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 )*
# 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{
onoff = option[$2] # records current (and the default is "", enabled)
key = ""
for (i=3; i<=NF; ++i) {
if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
key = ""
if (onoff != $(i)) {
# on or off can zap disabled or enabled:
if (onoff == "" || (onoff == "disabled" || onoff == "enabled") && ($(i) == "on" || $(i) == "off")) {
# It's easy to mis-spell the option when turning it
# on or off, so warn about it here:
if (onoff == "" && ($(i) == "on" || $(i) == "off")) {
print $2 ": ERROR: turning unrecognized option", $(i)
# For the moment error out - it is safer
err = 1 # prevent END{} running
exit 1
}
onoff = $(i)
} else {
# Print a message, otherwise the error
# below is incomprehensible
print $2 ": currently", onoff ": attempt to turn", $(i)
break
}
}
} else if ($(i) == "requires" || $(i) == "if" || $(i) == "enables") {
key = $(i)
} else if (key == "requires") {
requires[$2] = requires[$2] " " $(i)
} else if (key == "if") {
iffs[$2] = iffs[$2] " " $(i)
} else if (key == "enables") {
enabledby[$(i)] = enabledby[$(i)] " " $2
} else
break # bad line format
}
if (i > NF) {
# Set the option, defaulting to 'enabled'
if (onoff == "") onoff = "enabled"
option[$2] = onoff
next
}
# Else fall through to the error handler
}
# chunk NAME [requires OPT] [on|off|disabled]
# Expands to the 'option' settings appropriate to the reading and
# writing of an ancilliary PNG chunk 'NAME':
#
# option READ_NAME requires READ_ANCILLARY_CHUNKS [READ_OPT]
# option READ_NAME enables NAME
# [option READ_NAME off]
# option WRITE_NAME requires WRITE_ANCILLARY_CHUNKS [WRITE_OPT]
# option WRITE_NAME enables NAME
# [option WRITE_NAME off]
pre != 0 && $1 == "chunk" && NF >= 2{
# 'chunk' is handled on the first pass by writing appropriate
# 'option' lines into the intermediate file.
onoff = ""
reqread = ""
reqwrite = ""
i = 3 # indicates format error
if (NF > 2) {
# read the keywords/additional OPTS
req = 0
for (i=3; i<=NF; ++i) {
if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
if (onoff != $(i)) {
if (onoff == "")
onoff = $(i)
else
break # on/off conflict
}
} else if ($(i) == "requires")
req = 1
else if (req != 1)
break # bad line: handled below
else {
reqread = reqread " READ_" $(i)
reqwrite = reqwrite " WRITE_" $(i)
}
}
}
if (i > NF) {
# Output new 'option' lines to the intermediate file (out)
print "option READ_" $2, "requires READ_ANCILLARY_CHUNKS" reqread, "enables", $2, onoff >out
print "option WRITE_" $2, "requires WRITE_ANCILLARY_CHUNKS" reqwrite, "enables", $2, 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 unreognized 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 'setting' values first, the algorithm the standard
# tree walk (O(1)) done in an O(2) while/for loop; interations
# settings x depth, outputing the deepest required macros
# first.
print "" >out
print "/* SETTINGS */" >out
print comment, "settings", cend >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) {
for (j=1; j<=nreqs; ++j) if (!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
print "" >out
print "/* setting: ", i >out
print " * requires:" setting[i] >out
print " * default: ", defaults[i], "*/" >out
if (defaults[i] == "") { # no default, only check if defined
print "#ifdef PNG_" i >out
}
for (j=1; j<=nreqs; ++j) {
print "# ifndef PNG_" r[j] >out
print error, i, "requires", r[j] end >out
print "# endif" >out
}
if (defaults[i] != "") { # default handling
print "#ifdef PNG_" i >out
}
print def i, "PNG_" i end >out
if (defaults[i] != "") {
print "#else /*default*/" >out
# And add the default definition for the benefit
# of later settings an options test:
print "# define PNG_" i defaults[i] >out
print def i defaults[i] end >out
}
print "#endif" >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 comment, "end of settings", cend >out
# Now do the options - somewhat more complex. 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' 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
# 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 "#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
nreqs = split(iffs[i], r)
print "#undef PNG_no_if" >out
if (nreqs > 0) {
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
if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off") {
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
}
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 comment, "end of options", cend >out
# Regular end - everything looks ok
if (protect != "") {
print start "#endif", cx, protect, "*/" end >out
}
}
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