#!/bin/sh
#
#  Shell script to scan the header files and build the DLL export definition
#  files for the Windows port, heavily based on Allegro's ditto.
#
#  It uses misc/scanexp.c as a support for the preprocessing stage and can
#  run in two modes:
#    - without option: generates the export definition files for MSVC,
#      MinGW32 and BCC32
#    - with '--update-symbol-list': generates the reference symbol list
#      misc/dllsyms.lst
#
#  If the reference symbol list misc/dllsyms.lst already exists, the script
#  runs in an incremental way: new symbols (those not listed in
#  misc/dllsyms.lst) are appended at the end of the new symbol list.
#  This mechanism maintains DLL binary compatibility as long as symbols are
#  only added and not removed.


# helper function for removing the temporary files
rm_temp_files() {
   rm -f _ord*.tmp
   rm -f _*syms*.tmp
   rm -f _*def*.tmp
   rm -f _all.def
}


# check that we are in the Adime dir
if [ ! -f include/adime.h ]; then
   echo "*** Error !!! ***"
   echo " you are not in the Adime directory"
   exit 1
fi


# i18n changes the behaviour of sort (under Linux), which we don't want
export LC_ALL=C


# test for the presence of GNU sort
echo "_a" > _ord1.tmp
echo "a" >> _ord1.tmp
sort _ord1.tmp > _ord2.tmp
if { ! cmp -s _ord1.tmp _ord2.tmp; } then
   echo "*** Error !!! ***"
   echo " the first sort utility in the PATH is not GNU sort"
   rm_temp_files
   exit 1
fi


# scan the header files
echo "Scanning for symbols..."
gcc -E -I. -I./include -o _scandef.tmp misc/scanexp.c
sed -n -e "s/^ *_adime_scanex_dll_code  *\(.*\)_dll;/    \\1/p" _scandef.tmp > _scandef1.tmp
sed -n -e "s/^ *_adime_scanex_dll_data  *\(.*\)_dll;/    \\1 DATA/p" _scandef.tmp >> _scandef1.tmp
sort _scandef1.tmp > _scandef2.tmp


# check against the reference symbol list if it exists
if [ -e misc/dllsyms.lst ]; then
   echo "Checking against existing symbol list..."
   # comm works only on sorted files
   sort _scandef2.tmp > _allsyms2.tmp
   sort misc/dllsyms.lst > _dllsyms2.tmp

   # test for missing symbols
   comm -1 -3 _allsyms2.tmp _dllsyms2.tmp > _difsyms2.tmp
   if [ -s _difsyms2.tmp ]; then
      echo " *** Error !!! ***"
      echo "  symbols missing => DLL binary compatibility broken"
      echo "  you need to add the following symbols:"
      cat _difsyms2.tmp
      rm_temp_files
      exit 1
   fi

   # test for new symbols
   comm -2 -3 _allsyms2.tmp _dllsyms2.tmp > _difsyms2.tmp
   if [ -s _difsyms2.tmp ]; then
      echo " "`wc --lines < _difsyms2.tmp`" symbols added:"
      cat _difsyms2.tmp
      cat misc/dllsyms.lst _difsyms2.tmp > _alldef3.tmp
   else
      echo " no symbols added"
      cp misc/dllsyms.lst _alldef3.tmp
   fi
else
   cp _scandef2.tmp _alldef3.tmp
fi


# generate new reference symbol list or the DLL export definition files
if [ "$1" = "--update-symbol-list" ]; then
   echo "Updating symbol list..."
   cp -f _alldef3.tmp misc/dllsyms.lst
else
   echo "; generated by fixdll.sh" > _all.def
   echo "EXPORTS" >> _all.def
   sed -e "p" -e "=" -e "d" _alldef3.tmp > _alldef4.tmp
   sed -e "N" -e "s/\\n/ @/" -e "s/DATA \\(.*\\)/\\1 DATA/" _alldef4.tmp >> _all.def

   echo "Generating..."
   echo " lib/msvc/adime.def"
   cp _all.def lib/msvc/adime.def

   echo " lib/mingw32/adime.def"
   cp _all.def lib/mingw32/adime.def

   echo " lib/bcc32/adime.def"
   sed -e "s/^    \([a-zA-Z0-9_]*\) \([@0-9]*\)\([ A-Z]*\)/    _\1 = \1/" _all.def > lib/bcc32/adime.def

fi

rm_temp_files

echo "Done!"