mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity
libpng/scripts/options.awk
Glenn Randers-Pehrson 862cb20ea6 [devel] Freeze build-time only configuration in the build. 
In all prior versions of libpng most configuration options
    controlled by compiler #defines had to be repeated by the
    application code that used libpng.  This patch changes this
    so that compilation options that can only be changed at build
    time are frozen in the build.  Options that are compiler
    dependent (and those that are system dependent) are evaluated
    each time - pngconf.h holds these.  Options that can be changed
    per-file in the application are in png.h.  Frozen options are
    in the new installed header file pnglconf.h
2010-04-16 22:12:51 -05:00

567 lines
18 KiB
Awk
Raw Blame History

#!/bin/awk -f
# scripts/options.awk - library build configuration control
#
# libpng version 1.5.0beta17 - April 2, 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. Each time the
# output files and whether or not to pre-prrocess must be
# specified:
#
# 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
BEGIN{
out="/dev/null" # intermediate, preprocessed, file
pre=-1 # preprocess
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
deb=0 # debug - set on command line
logunsupported=0 # write unsupported options too
# Precreate arrays
option[""] = "" # list of all options: default on/off/""
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 = ""
}
# 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
}
# option NAME ( (requires|enables|if) NAME* | on | off )*
# Declares an option 'NAME' and describes its default setting (on|off)
# 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'.
$1 == "option" && NF >= 2{
onoff = option[$2] # records default on or default off
key = ""
for (i=3; i<=NF; ++i) {
if ($(i) == "on" || $(i) == "off") {
key = ""
if (onoff != $(i)) {
if (onoff == "")
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 - 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)
option[$2] = onoff
next
}
# Else fall through to the error handler
}
# chunk NAME [requires OPT] [off]
# 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") {
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
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 pnglconf.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
exit 1
}
# For checking purposes names that start with "ok_" or "fail_" are
# not output to pnglconf.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{
if (out == "/dev/null") {
print "out=output.file must be given on the command line"
exit 1
}
if (pre) {
if (pre != 1) {
print "pre=0 or pre=1 must be given on command line"
exit 1
}
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
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) tree[opt] = "" # so unlisted options marked
for (opt in tree) {
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] = "off"
}
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]
# 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 marked "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
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
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
print "#endif" >out
}
print "# ifndef PNG_" i "_SUPPORTED /*!command line*/" >out
print "# ifdef PNG_not_enabled /*!enabled*/" >out
if (option[i] == "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
# pnglconf.h
print "# ifdef PNG_on" >out
if (i ~ /^fail_/)
print error, i, "if" iffs[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, "if" iffs[i], "requires" requires[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
}
Reference in New Issue View Git Blame Copy Permalink