#!/bin/awk -f

# Check a list of symbols against the master definition

# (official) list.  Arguments:

#

# awk -f checksym.awk official-def list-to-check

#

# Output is a file in the current directory called 'symbols.new',

# the value of the awk variable "of" (which can be changed on the

# command line if required.)  stdout holds error messages.  Error

# code indicates success or failure.

#

# NOTE: this is a pure, old fashioned, awk script.  It will

# work with any awk

BEGIN{

   err=0

   master=""        # master file

   official[1] = "" # defined symbols from master file

   symbol[1] = ""   # defined symbols from png.h

   removed[1] = ""  # removed symbols from png.h

   lasto = 0        # last ordinal value from png.h

   mastero = 0      # highest ordinal in master file

   symbolo = 0      # highest ordinal in png.h

   missing = "error"# log an error on missing symbols

   of="symbols.new" # default to a fixed name

}

# Read existing definitions from the master file (the first

# file on the command line.)  This must be a def file and it

# has definition lines (others are ignored) of the form:

#

#   symbol @ordinal

#

master == "" {

   master = FILENAME

}

FILENAME==master && NF==2 && $2~/^@/ && $1!~/^;/ {

   o=0+substr($2,2)

   if (o > 0) {

      if (official[o] == "") {

         official[o] = $1

         if (o > mastero) mastero = o

         next

      } else

         print master ": duplicated symbol:", official[o] ":", $0

   } else

      print master ": bad export line format:", $0

   err = 1

}

FILENAME==master && $1==";missing" && NF==2{

   # This allows the master file to control how missing symbols

   # are handled; symbols that aren't in either the master or

   # the new file.  Valid values are 'ignore', 'warning' and

   # 'error'

   missing = $2

}

FILENAME==master {

   next

}

# Read new definitions, these are free form but the lines must

# just be symbol definitions.  Lines will be commented out for

# 'removed' symbols, introduced in png.h using PNG_REMOVED rather

# than PNG_EXPORT.  Use symbols.dfn or pngwin.dfn to generate the

# input file.

#

#  symbol @ordinal   # two fields, exported symbol

#  ; symbol @ordinal # three fields, removed symbol

#  ; @ordinal        # two fields, the last ordinal

NF==2 && $1 == ";" && $2 ~ /^@[1-9][0-9]*$/ { # last ordinal

   o=0+substr($2,2)

   if (lasto == 0 || lasto == o)

      lasto=o

   else {

      print "png.h: duplicated last ordinal:", lasto, o

      err = 1

   }

   next

}

NF==3 && $1 == ";" && $3 ~ /^@[1-9][0-9]*$/ { # removed symbol

   o=0+substr($3,2)

   if (removed[o] == "" || removed[o] == $2) {

      removed[o] = $2

      if (o > symbolo) symbolo = o

   } else {

      print "png.h: duplicated removed symbol", o ": '" removed[o] "' != '" $2 "'"

      err = 1

   }

   next

}

NF==2 && $2 ~ /^@[1-9][0-9]*$/ { # exported symbol

   o=0+substr($2,2)

   if (symbol[o] == "" || symbol[o] == $1) {

      symbol[o] = $1

      if (o > symbolo) symbolo = o

   } else {

      print "png.h: duplicated symbol", o ": '" symbol[o] "' != '" $1 "'"

      err = 1

   }

}

{

   next # skip all other lines

}

# At the end check for symbols marked as both duplicated and removed

END{

   if (symbolo > lasto) {

      print "highest symbol ordinal in png.h,", symbolo ", exceeds last ordinal from png.h", lasto

      err = 1

   }

   if (mastero > lasto) {

      print "highest symbol ordinal in", master ",", mastero ", exceeds last ordinal from png.h", lasto

      err = 1

   }

   unexported=0

   # Add a standard header to symbols.new:

   print ";Version INSERT-VERSION-HERE" >of

   print ";--------------------------------------------------------------" >of

   print "; LIBPNG symbol list as a Win32 DEF file" >of

   print "; Contains all the symbols that can be exported from libpng" >of

   print ";--------------------------------------------------------------" >of

   print "LIBRARY" >of

   print "" >of

   print "EXPORTS" >of

   for (o=1; o<=lasto; ++o) {

      if (symbol[o] == "" && removed[o] == "") {

         if (unexported == 0) unexported = o

         if (official[o] == "") {

            # missing in export list too, so ok

            if (o < lasto) continue

         }

      }

      if (unexported != 0) {

         # Symbols in the .def but not in the new file are errors, but

         # the 'unexported' symbols aren't in either.  By default this

         # is an error too (see the setting of 'missing' at the start),

         # but this can be reset on the command line or by stuff in the

         # file - see the comments above.

         if (missing != "ignore") {

            if (o-1 > unexported)

               print "png.h:", missing ": missing symbols:", unexported "-" o-1

            else

               print "png.h:", missing ": missing symbol:", unexported

            if (missing != "warning")

               err = 1

         }

         unexported = 0

      }

      if (symbol[o] != "" && removed[o] != "") {

         print "png.h: symbol", o, "both exported as '" symbol[o] "' and removed as '" removed[o] "'"

         err = 1

      } else if (symbol[o] != official[o]) {

         # either the symbol is missing somewhere or it changed

         err = 1

         if (symbol[o] == "")

            print "png.h: symbol", o, "is exported as '" official[o] "' in", master

         else if (official[o] == "")

            print "png.h: exported symbol", o, "'" symbol[o] "' not present in", master

         else

            print "png.h: exported symbol", o, "'" symbol[o] "' exists as '" official[o] "' in", master

      }

      # Finally generate symbols.new

      if (symbol[o] != "")

         print " " symbol[o], "@" o > of

   }

   if (err != 0) {

      print "*** A new list is in", of, "***"

      exit 1

   }

}