[libpng16] Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug.

1 files changed, 135 insertions, 0 deletions

diff --git a/scripts/dfn.awk b/scripts/dfn.awk
new file mode 100644
index 000000000..8a5dab6f9
--- /dev/null
+++ b/scripts/dfn.awk
@@ -0,0 +1,135 @@
+#!/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
+}