blob: 346b9db7d59c53d8907492ce3b0771d79dac52e2 [file] [log] [blame]
#!/bin/awk -f
# scripts/dfn.awk - process a .dfn file
#
# last changed in libpng version 1.5.19 - August 21, 2014
#
# Copyright (c) 2013-2014 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', which should be set on the command line.
# Error messages are printed to stdout and if any are printed
# the script will exit with error code 1.
BEGIN{
out="/dev/null" # as a flag
out_count=0 # count of output lines
err=0 # set if an error occurred
sort=0 # sort the output
array[""]=""
}
# The output file must be specified before any input:
NR==1 && out == "/dev/null" {
print "out=output.file must be given on the command line"
# but continue without setting the error code; this allows the
# script to be checked easily
}
# Output can be sorted; two lines are recognized
$1 == "PNG_DFN_START_SORT"{
sort=0+$2
next
}
$1 ~ /^PNG_DFN_END_SORT/{
# Do a very simple, slow, sort; notice that blank lines won't be
# output by this
for (entry in array) {
while (array[entry] != "") {
key = entry
value = array[key]
array[key] = ""
for (alt in array) {
if (array[alt] != "" && alt < key) {
array[key] = value
value = array[alt]
key = alt
array[alt] = ""
}
}
print value >out
}
}
sort=0
next
}
/^[^"]*PNG_DFN *".*"[^"]*$/{
# A definition line, apparently correctly formatted; extract the
# definition then replace any doubled "" that remain with a single
# double quote. Notice that the original doubled double quotes
# may have been split by tokenization
#
# Sometimes GCC splits the PNG_DFN lines; we know this has happened
# if the quotes aren't closed and must read another line. In this
# case it is essential to reject lines that start with '#' because those
# are introduced #line directives.
orig=$0
line=$0
lineno=FNR
if (lineno == "") lineno=NR
if (sub(/^[^"]*PNG_DFN *"/,"",line) != 1) {
print "line", lineno ": processing failed:"
print orig
err=1
next
} else {
++out_count
}
# Now examine quotes within the value:
#
# @" - delete this and any following spaces
# "@ - delete this and any preceding spaces
# @' - replace this by a double quote
#
# This allows macro substitution by the C compiler thus:
#
# #define first_name John
# #define last_name Smith
#
# PNG_DFN"#define name @'@" first_name "@ @" last_name "@@'"
#
# Might get C preprocessed to:
#
# PNG_DFN "#define foo @'@" John "@ @" Smith "@@'"
#
# Which this script reduces to:
#
# #define name "John Smith"
#
while (1) {
# While there is an @" remove it and the next "@
if (line ~ /@"/) {
if (line ~ /@".*"@/) {
# Do this special case first to avoid swallowing extra spaces
# before or after the @ stuff:
if (!sub(/@" *"@/, "", line)) {
# Ok, do it in pieces - there has to be a non-space between the
# two. NOTE: really weird things happen if a leading @" is
# lost - the code will error out below (I believe).
if (!sub(/@" */, "", line) || !sub(/ *"@/, "", line)) {
print "line", lineno, ": internal error:", orig
exit 1
}
}
}
# There is no matching "@. Assume a split line
else while (1) {
if (getline nextline) {
# If the line starts with '#' it is a preprocesor line directive
# from cc -E; skip it:
if (nextline !~ /^#/) {
line = line " " nextline
break
}
} else {
# This is end-of-input - probably a missing "@ on the first line:
print "line", lineno ": unbalanced @\" ... \"@ pair"
err=1
next
}
}
# Keep going until all the @" have gone
continue
}
# Attempt to remove a trailing " (not preceded by '@') - if this can
# be done, stop now; if not assume a split line again
if (sub(/"[^"]*$/, "", line))
break
# Read another line
while (1) {
if (getline nextline) {
if (nextline !~ /^#/) {
line = line " " nextline
# Go back to stripping @" "@ pairs
break
}
} else {
print "line", lineno ": unterminated PNG_DFN string"
err=1
next
}
}
}
# Put any needed double quotes in (at the end, because these would otherwise
# interfere with the processing above.)
gsub(/@'/,"\"", line)
# Remove any trailing spaces (not really required, but for
# editorial consistency
sub(/ *$/, "", line)
# Remove trailing CR
sub(/ $/, "", line)
if (sort) {
if (split(line, parts) < sort) {
print "line", lineno ": missing sort field:", line
err=1
} else
array[parts[sort]] = line
}
else
print line >out
next
}
/PNG_DFN/{
print "line", NR, "incorrectly formatted PNG_DFN line:"
print $0
err = 1
}
END{
if (out_count > 0 || err > 0)
exit err
print "no definition lines found"
exit 1
}