1#!/bin/awk -f
  2# Check a list of symbols against the master definition
  3# (official) list.  Arguments:
  4#
  5# awk -f checksym.awk official-def list-to-check
  6#
  7# Output is a file in the current directory called 'symbols.new',
  8# the value of the awk variable "of" (which can be changed on the
  9# command line if required.)  stdout holds error messages.  Error
 10# code indicates success or failure.
 11#
 12# NOTE: this is a pure, old fashioned, awk script.  It will
 13# work with any awk
 14
 15BEGIN{
 16   err=0
 17   master=""        # master file
 18   official[1] = "" # defined symbols from master file
 19   symbol[1] = ""   # defined symbols from png.h
 20   removed[1] = ""  # removed symbols from png.h
 21   lasto = 0        # last ordinal value from png.h
 22   mastero = 0      # highest ordinal in master file
 23   symbolo = 0      # highest ordinal in png.h
 24   missing = "error"# log an error on missing symbols
 25   of="symbols.new" # default to a fixed name
 26}
 27
 28# Read existing definitions from the master file (the first
 29# file on the command line.)  This must be a def file and it
 30# has definition lines (others are ignored) of the form:
 31#
 32#   symbol @ordinal
 33#
 34master == "" {
 35   master = FILENAME
 36}
 37FILENAME==master && NF==2 && $2~/^@/ && $1!~/^;/ {
 38   o=0+substr($2,2)
 39   if (o > 0) {
 40      if (official[o] == "") {
 41         official[o] = $1
 42         if (o > mastero) mastero = o
 43         next
 44      } else
 45         print master ": duplicated symbol:", official[o] ":", $0
 46   } else
 47      print master ": bad export line format:", $0
 48   err = 1
 49}
 50FILENAME==master && $1==";missing" && NF==2{
 51   # This allows the master file to control how missing symbols
 52   # are handled; symbols that aren't in either the master or
 53   # the new file.  Valid values are 'ignore', 'warning' and
 54   # 'error'
 55   missing = $2
 56}
 57FILENAME==master {
 58   next
 59}
 60
 61# Read new definitions, these are free form but the lines must
 62# just be symbol definitions.  Lines will be commented out for
 63# 'removed' symbols, introduced in png.h using PNG_REMOVED rather
 64# than PNG_EXPORT.  Use symbols.dfn or pngwin.dfn to generate the
 65# input file.
 66#
 67#  symbol @ordinal   # two fields, exported symbol
 68#  ; symbol @ordinal # three fields, removed symbol
 69#  ; @ordinal        # two fields, the last ordinal
 70NF==2 && $1 == ";" && $2 ~ /^@[1-9][0-9]*$/ { # last ordinal
 71   o=0+substr($2,2)
 72   if (lasto == 0 || lasto == o)
 73      lasto=o
 74   else {
 75      print "png.h: duplicated last ordinal:", lasto, o
 76      err = 1
 77   }
 78   next
 79}
 80NF==3 && $1 == ";" && $3 ~ /^@[1-9][0-9]*$/ { # removed symbol
 81   o=0+substr($3,2)
 82   if (removed[o] == "" || removed[o] == $2) {
 83      removed[o] = $2
 84      if (o > symbolo) symbolo = o
 85   } else {
 86      print "png.h: duplicated removed symbol", o ": '" removed[o] "' != '" $2 "'"
 87      err = 1
 88   }
 89   next
 90}
 91NF==2 && $2 ~ /^@[1-9][0-9]*$/ { # exported symbol
 92   o=0+substr($2,2)
 93   if (symbol[o] == "" || symbol[o] == $1) {
 94      symbol[o] = $1
 95      if (o > symbolo) symbolo = o
 96   } else {
 97      print "png.h: duplicated symbol", o ": '" symbol[o] "' != '" $1 "'"
 98      err = 1
 99   }
100}
101{
102   next # skip all other lines
103}
104
105# At the end check for symbols marked as both duplicated and removed
106END{
107   if (symbolo > lasto) {
108      print "highest symbol ordinal in png.h,", symbolo ", exceeds last ordinal from png.h", lasto
109      err = 1
110   }
111   if (mastero > lasto) {
112      print "highest symbol ordinal in", master ",", mastero ", exceeds last ordinal from png.h", lasto
113      err = 1
114   }
115   unexported=0
116   # Add a standard header to symbols.new:
117   print ";Version INSERT-VERSION-HERE" >of
118   print ";--------------------------------------------------------------" >of
119   print "; LIBPNG symbol list as a Win32 DEF file" >of
120   print "; Contains all the symbols that can be exported from libpng" >of
121   print ";--------------------------------------------------------------" >of
122   print "LIBRARY" >of
123   print "" >of
124   print "EXPORTS" >of
125
126   for (o=1; o<=lasto; ++o) {
127      if (symbol[o] == "" && removed[o] == "") {
128         if (unexported == 0) unexported = o
129         if (official[o] == "") {
130            # missing in export list too, so ok
131            if (o < lasto) continue
132         }
133      }
134      if (unexported != 0) {
135         # Symbols in the .def but not in the new file are errors, but
136         # the 'unexported' symbols aren't in either.  By default this
137         # is an error too (see the setting of 'missing' at the start),
138         # but this can be reset on the command line or by stuff in the
139         # file - see the comments above.
140         if (missing != "ignore") {
141            if (o-1 > unexported)
142               print "png.h:", missing ": missing symbols:", unexported "-" o-1
143            else
144               print "png.h:", missing ": missing symbol:", unexported
145            if (missing != "warning")
146               err = 1
147         }
148         unexported = 0
149      }
150      if (symbol[o] != "" && removed[o] != "") {
151         print "png.h: symbol", o, "both exported as '" symbol[o] "' and removed as '" removed[o] "'"
152         err = 1
153      } else if (symbol[o] != official[o]) {
154         # either the symbol is missing somewhere or it changed
155         err = 1
156         if (symbol[o] == "")
157            print "png.h: symbol", o, "is exported as '" official[o] "' in", master
158         else if (official[o] == "")
159            print "png.h: exported symbol", o, "'" symbol[o] "' not present in", master
160         else
161            print "png.h: exported symbol", o, "'" symbol[o] "' exists as '" official[o] "' in", master
162      }
163
164      # Finally generate symbols.new
165      if (symbol[o] != "")
166         print " " symbol[o], "@" o > of
167   }
168
169   if (err != 0) {
170      print "*** A new list is in", of, "***"
171      exit 1
172   }
173}