#!/bin/bash
  # Translate the bits making up a GFP mask
  # (c) 2009, Mel Gorman <mel@csn.ul.ie>
  # Licensed under the terms of the GNU GPL License version 2
  SOURCE=
  GFPMASK=none
  
  # Helper function to report failures and exit
  die() {
  	echo ERROR: $@
  	if [ "$TMPFILE" != "" ]; then
  		rm -f $TMPFILE
  	fi
  	exit -1
  }
  
  usage() {
  	echo "usage: gfp-translate [-h] [ --source DIRECTORY ] gfpmask"
  	exit 0
  }

  # Parse command-line arguments

  while [ $# -gt 0 ]; do
  	case $1 in
  		--source)
  			SOURCE=$2
  			shift 2
  			;;
  		-h)
  			usage
  			;;
  		--help)
  			usage
  			;;
  		*)
  			GFPMASK=$1
  			shift
  			;;
  	esac
  done
  
  # Guess the kernel source directory if it's not set. Preference is in order of
  # o current directory
  # o /usr/src/linux
  if [ "$SOURCE" = "" ]; then
  	if [ -r "/usr/src/linux/Makefile" ]; then
  		SOURCE=/usr/src/linux
  	fi
  	if [ -r "`pwd`/Makefile" ]; then
  		SOURCE=`pwd`
  	fi
  fi
  
  # Confirm that a source directory exists
  if [ ! -r "$SOURCE/Makefile" ]; then
  	die "Could not locate kernel source directory or it is invalid"
  fi
  
  # Confirm that a GFP mask has been specified
  if [ "$GFPMASK" = "none" ]; then
  	usage
  fi
  
  # Extract GFP flags from the kernel source
  TMPFILE=`mktemp -t gfptranslate-XXXXXX` || exit 1

  grep -q ___GFP $SOURCE/include/linux/gfp.h
  if [ $? -eq 0 ]; then
  	grep "^#define ___GFP" $SOURCE/include/linux/gfp.h | sed -e 's/u$//' | grep -v GFP_BITS > $TMPFILE
  else
  	grep "^#define __GFP" $SOURCE/include/linux/gfp.h | sed -e 's/(__force gfp_t)//' | sed -e 's/u)/)/' | grep -v GFP_BITS | sed -e 's/)\//) \//' > $TMPFILE
  fi

  
  # Parse the flags
  IFS="
  "
  echo Source: $SOURCE
  echo Parsing: $GFPMASK
  for LINE in `cat $TMPFILE`; do
  	MASK=`echo $LINE | awk '{print $3}'`
  	if [ $(($GFPMASK&$MASK)) -ne 0 ]; then
  		echo $LINE
  	fi
  done
  
  rm -f $TMPFILE
  exit 0