[devel] Improved the options.awk script; added an "everything off" option.
diff --git a/scripts/options.awk b/scripts/options.awk
index 4896798..898a1ae 100755
--- a/scripts/options.awk
+++ b/scripts/options.awk
@@ -1,7 +1,7 @@
#!/bin/awk -f
# scripts/options.awk - library build configuration control
#
-# last changed in libpng version 1.5.0 - April 27, 2010
+# last changed in libpng version 1.5.0 - April 28, 2010
#
# Copyright (c) 1998-2010 Glenn Randers-Pehrson
#
@@ -12,16 +12,25 @@
# 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. Each time the
-# output files and whether or not to pre-prrocess must be
-# specified:
+# that file to produce the final output:
#
-# awk -f scripts/options.awk pre=1 out=options.tmp scripts/options.dat 1>&2
-# awk -f scripts/options.awk pre=0 out=options.dfn options.tmp 1>&2
+# 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
+ 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
@@ -32,11 +41,14 @@
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 on/off/""
+ option[""] = "" # list of all options: default enabled/disabled
done[""] = 1 # marks option as having been output
requires[""] = "" # requires by option
iffs[""] = "" # if by option
@@ -50,6 +62,27 @@
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"{
@@ -116,23 +149,66 @@
next
}
-# option NAME ( (requires|enables|if) NAME* | on | off )*
-# Declares an option 'NAME' and describes its default setting (on|off)
+# 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 default on or default off
+ onoff = option[$2] # records current (and the default is "", enabled)
key = ""
for (i=3; i<=NF; ++i) {
- if ($(i) == "on" || $(i) == "off") {
+ if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
key = ""
if (onoff != $(i)) {
- if (onoff == "")
+ # on or off can zap disabled or enabled:
+ if (onoff == "" ||
+ (onoff == "disabled" || onoff == "enabled") &&
+ ($(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 {
+ } else {
# Print a message, otherwise the error
# below is incomprehensible
print $2 ": currently", onoff ": attempt to turn", $(i)
@@ -152,17 +228,15 @@
}
if (i > NF) {
- # Set the option - this may explicitly set it to "", that's good
- # becaue we need to ensure it exists and we can't rely on some
- # actually quite sensible awk implementation not optimising the
- # read above away (gawk doesn't)
+ # Set the option, defaulting to 'enabled'
+ if (onoff == "") onoff = "enabled"
option[$2] = onoff
next
}
# Else fall through to the error handler
}
-# chunk NAME [requires OPT] [off]
+# chunk NAME [requires OPT] [on|off|disabled]
# Expands to the 'option' settings appropriate to the reading and
# writing of an ancilliary PNG chunk 'NAME':
#
@@ -184,7 +258,7 @@
# read the keywords/additional OPTS
req = 0
for (i=3; i<=NF; ++i) {
- if ($(i) == "on" || $(i) == "off") {
+ if ($(i) == "on" || $(i) == "off" || $(i) == "disabled") {
if (onoff != $(i)) {
if (onoff == "")
onoff = $(i)
@@ -243,6 +317,7 @@
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
@@ -302,6 +377,7 @@
# any other format errors.
{
print "options.awk: bad line (" NR "):", $0
+ err = 1 # prevent END{} running
exit 1
}
@@ -324,15 +400,15 @@
# of the names to be enabled.
END{
- if (out == "/dev/null") {
- print "out=output.file must be given on the command line"
- exit 1
- }
+ # END{} gets run on an exit (a traditional awk feature)
+ if (err) exit 1
+
if (pre) {
- if (pre != 1) {
- print "pre=0 or pre=1 must be given on command line"
- exit 1
- }
+ # Record the variables
+ print "deb =", deb
+ if (everything != "")
+ print "everything =", everything
+ print "logunsupported =", logunsupported
exit 0
}
@@ -377,6 +453,9 @@
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
@@ -408,8 +487,16 @@
print "/* OPTIONS */" >out
print comment, "options", cend >out
for (opt in enabledby) tree[opt] = 1 # may not be explicit options
- for (opt in option) tree[opt] = "" # so unlisted options marked
- for (opt in tree) {
+ 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] != "") {
@@ -418,7 +505,7 @@
}
# Macros only listed in 'enables' remain off unless
# one of the enabling macros is on.
- option[opt] = "off"
+ option[opt] = "disabled"
}
split("", list) # clear 'list'
@@ -432,6 +519,51 @@
# 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
@@ -460,7 +592,10 @@
# an 'enabledby' is _SUPPORTED
# OR:
# NO_name is not defined AND
- # the option is not marked "off"
+ # 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
@@ -475,6 +610,11 @@
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
}
@@ -491,6 +631,11 @@
}
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
}
@@ -503,12 +648,18 @@
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") {
+ 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
@@ -529,7 +680,7 @@
# pnglibconf.h
print "# ifdef PNG_on" >out
if (i ~ /^fail_/)
- print error, i, "if" iffs[i], "requires" requires[i] end >out
+ 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
@@ -539,7 +690,7 @@
if (logunsupported)
print und i une >out
if (i ~ /^ok_/)
- print error, i, "if" iffs[i], "requires" requires[i] end >out
+ print error, i, "not enabled: requires:" requires[i] ", enabled by:" iffs[i] enabledby[i] end >out
print "#endif" >out
}
