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53c07f5909
libpng/scripts/options.awk
Glenn Randers-Pehrson 53c07f5909 [devel] Imported from libpng-1.5.0beta25.tar
2010-06-25 20:06:28 -05:00

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#!/bin/awk -f
# scripts/options.awk - library build configuration control
#
# last changed in libpng version 1.5.0 - June 18, 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
#
# 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
}
}
# Preprocessing - this just copies the input file with lines
# that need preprocessing (just chunk at present) expanded
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[ ]*/, "")
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
}
# 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...)
$0 ~ /^[ ]*everything[ =]*off[ ]*$/{
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
}
# 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 && $1 == "chunk" && NF >= 2{
# 'chunk' is handled on the first pass by writing appropriate
# 'option' lines into the intermediate file.
onoff = ""
reqread = ""
reqwrite = ""
i = 3 # indicates format error
if (NF > 2) {
# read the keywords/additional OPTS
req = 0
for (i=3; i<=NF; ++i) {
if ($(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(/^[ ]*@/, "")
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 variables
print "deb =", deb
if (everything != "")
print "everything =", everything
print "logunsupported =", logunsupported
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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