#! /bin/sh
# Fix struct exception in /usr/include/math.h.
#
# We expect several systems which did not need fixincludes in the past
# to need to fix just math.h.  So we created a separate fixinc.mathh
# script to fix just that problem.
# See README-fixinc for more information.

# Directory containing the original header files.
# (This was named INCLUDES, but that conflicts with a name in Makefile.in.)
INPUT=${2-${INPUT-/usr/include}}

# Directory in which to store the results.
LIB=${1?"fixincludes: output directory not specified"}

# Define PWDCMD as a command to use to get the working dir
# in the form that we want.
PWDCMD=pwd
case "`pwd`" in
//*)
	# On an Apollo, discard everything before `/usr'.
	PWDCMD="eval pwd | sed -e 's,.*/usr/,/usr/,'"
	;;
esac

# Original directory.
ORIGDIR=`${PWDCMD}`

# Make sure it exists.
if [ ! -d $LIB ]; then
  mkdir $LIB || exit 1
fi

# Make LIB absolute only if needed to avoid problems with the amd.
case $LIB in
/*)
	;;
*)
	cd $LIB; LIB=`${PWDCMD}`
	;;
esac

# Fail if no arg to specify a directory for the output.
if [ x$1 = x ]
then echo fixincludes: no output directory specified
exit 1
fi

echo Building fixed headers in ${LIB}

# Determine whether this system has symbolic links.
if ln -s X $LIB/ShouldNotExist 2>/dev/null; then
  rm -f $LIB/ShouldNotExist
  LINKS=true
elif ln -s X /tmp/ShouldNotExist 2>/dev/null; then
  rm -f /tmp/ShouldNotExist
  LINKS=true
else
  LINKS=false
fi

cd ${INPUT}

# Some math.h files define struct exception, which conflicts with
# the class exception defined in the C++ file std/stdexcept.h.  We
# redefine it to __math_exception.  This is not a great fix, but I
# haven't been able to think of anything better.
file=math.h
if [ -r $file ] && [ ! -r ${LIB}/$file ]; then
  cp $file ${LIB}/$file >/dev/null 2>&1 || echo "Can't copy $file"
  chmod +w ${LIB}/$file 2>/dev/null
  chmod a+r ${LIB}/$file 2>/dev/null
fi

if [ -r ${LIB}/$file ]; then
  echo Fixing $file, exception
  sed -e '/struct exception/i\
#ifdef __cplusplus\
#define exception __math_exception\
#endif\
'\
      -e '/struct exception/a\
#ifdef __cplusplus\
#undef exception\
#endif\
' ${LIB}/$file > ${LIB}/${file}.sed
  rm -f ${LIB}/$file; mv ${LIB}/${file}.sed ${LIB}/$file
  if egrep 'matherr()' ${LIB}/$file >/dev/null 2>&1; then
    sed -e '/matherr/i\
#ifdef __cplusplus\
#define exception __math_exception\
#endif\
'\
        -e '/matherr/a\
#ifdef __cplusplus\
#undef exception\
#endif\
' ${LIB}/$file > ${LIB}/${file}.sed
    rm -f ${LIB}/$file; mv ${LIB}/${file}.sed ${LIB}/$file
  fi
  if cmp $file ${LIB}/$file >/dev/null 2>&1; then
    rm -f ${LIB}/$file
  else
    # Find any include directives that use "file".
    for include in `egrep '^[       ]*#[    ]*include[      ]*"[^/]' ${LIB}/$file | sed -e 's/^[    ]*#[    ]*include[      ]*"\([^"]*\)".*$/\1/'`; do
      dir=`echo $file | sed -e s'|/[^/]*$||'`
      required="$required ${INPUT} $dir/$include ${LIB}/$dir/$include"
    done
  fi
fi
exit 0