#!/bin/awk -f # scripts/dfn.awk - process a .dfn file # # last changed in libpng version 1.5.14 - February 4, 2013 # # Copyright (c) 2013-2013 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 occured 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=$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 formated, 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 orig=$0 if (gsub(/^[^"]*PNG_DFN *"/,"") != 1 || gsub(/"[^"]*$/, "") != 1) { print "line", NR, "processing failed:" print orig print $0 err=1 } else { ++out_count } # Now examine quotes within the value: # # @" - delete this and any following spaces # "@ - delete this and any original spaces # @' - replace this by a double quote # # This allows macro substitution by the C compiler thus: # # #define first_name John # #define last_name Smith # # PNG_DFN"#define name @'@" first_name "@ @" last_name "@@'" # # Might get C preprocessed to: # # PNG_DFN "#define foo @'@" John "@ @" Smith "@@'" # # Which this script reduces to: # # #define name "John Smith" # while (sub(/@" */, "")) { if (!sub(/ *"@/, "")) { print "unbalanced @\" ... \"@ pair" err=1 break } } # Put any needed double quotes in gsub(/@'/,"\"") # Remove any trailing spaces (not really required, but for # editorial consistency sub(/ *$/, "") if (sort) array[$(sort)] = $0 else print $0 >out next } /PNG_DFN/{ print "line", NR, "incorrectly formated PNG_DFN line:" print $0 err = 1 } END{ if (out_count > 0 || err > 0) exit err print "no definition lines found" exit 1 }