#!/bin/sh

# javac-xlint can be run as a PREFIX to a javac line (javac-xlint is not a
# replacement for javac), like so:
#
#   javac-xlint [-p regexp] javac [javac-options] file...
#
# javac-xlint makes 3 changes to the invocation of javac that it prefixes:
#  1. It supplies the -Xlint option.
#  2. It suppresses certain warning messages.  (See note below.)
#  3. It returns non-zero status if any other warnings (or errors) exist.
#     Ordinarily, javac returns non-zero status only if errors exist.
#
# The suppressed warnings are of two sorts.
#  1. Any warning in a file that matches the regexp provided with -p
#     (mnemonic: "prune").
#  2. Specific warnings disabled on a per-line basis by a source code
#     comment.  The javac warning category is given in square brackets,
#     such as "warning: [unchecked]" or "warning: [deprecation]".  A
#     comment of the form "// CATEGORY" disables warnings of that category
#     on that line.  Other warnings (of different categories) on that line
#     are retained.

# Regarding the warning message suppression feature of this script:  As of
# Java 5 update 6 (JDK 5.0u6), javac has a way to suppress warnings:
# @SuppressWarnings("unchecked").  This is more portable and standard than
# this script.  However:
#  * it does not permit suppression per-line, only per declaration.
#    (A way to get per-line suppression is to put the offending statement
#    in a variable declaration, and then annotate the declaration.)
#  * it does not permit suppression based on directory/package (I think)
#  * it does not give a non-zero return status if non-suppressed warnings exist.

# Regarding the warnings-as-errors feature of this script:  As of Java 6,
# the -Werror flag has the same effect.


# This script uses the separate) javac-xlint-prune script.
# As an alternative to this script, pipe javac output into javac-xlint-prune:
#   JAVA-COMMAND-LINE 2>&1 | javac-xlint-prune
# (That's all that this script does.)

# Design note:
# Here are two possible ways a wrapper script around javac could work
# (this script does the latter).
#  1. Drop-in replacement for javac:  "javac-xlint args..."
#     An advantage is that it looks more like javac, and may be somewhat
#     easier to remember/use.
#  2. Prefix to javac line, like so:  "javac-xlint javac args..."
#     An advantage is that we can continue to respect user settings of
#     javac (to "javac -g", "javac-1.5.0", etc.), rather than
#     overriding them.  Note that even so, this script doesn't
#     currently permit using (say) jikes: prune-xlint is hard-coded
#     for "javac" output.

# DEBUG_JAVAC_XLINT=1

if [ ! -z $DEBUG_JAVAC_XLINT ]; then
  echo "all javac-xlint args: $*"
  echo "javac-xlint arg 1: $1"
fi

if [ "$1" = "-p" ]; then
  if [ ! -z $DEBUG_JAVAC_XLINT ]; then
    echo "found p option"
  fi
  PRUNE_XLINT_ARGS=$2
  shift
  shift
  if [ ! -z $DEBUG_JAVAC_XLINT ]; then
    echo "all remaining javac-xlint args: $*"
  fi
fi

## Older option processing code.
## A problem with this is that it does not halt the script, nor is its error
## message (e.g., "illegal option -- d") comprehensible.
## I could do my own such processing, however, using the getopts return value.
# # Parse arguments.
# while getopts "p:" Option
# do
#   case $Option in
#     p )
# #      echo "found p!"
#       PRUNE_XLINT_ARGS=$OPTARG
#   esac
# done
# shift $(($OPTIND - 1))

# Separate the first argument (the Java compiler) from all the others.
SUPPLIED_JAVAC=$1
shift

## This does not work because the given javac may be a command name rather
## than a fully-qualified pathname.  However, I would like to find a way to
## warn in the common case that the javac argument is omitted.
# if [ ! -x ${SUPPLIED_JAVAC} ]; then
#   echo "Supplied Java compiler is not executable: ${SUPPLIED_JAVAC}"
#   exit 1
# fi

# Put filenames in a file in order to avoid errors due to overly long
# command lines.
FILES_FILE=/tmp/javac-xlint-files-$$
echo $* > $FILES_FILE

# Fixup the filename for cygwin
JAVA_FILES_FILE=$FILES_FILE
if [ "$OSTYPE" = "cygwin" ]; then
    JAVA_FILES_FILE=`cygpath -w $JAVA_FILES_FILE`
fi

if [ ! -z $DEBUG_JAVAC_XLINT ]; then
  echo ${SUPPLIED_JAVAC} -Xlint @$JAVA_FILES_FILE PIPED-INTO `dirname ${0}`/javac-xlint-prune -p "${PRUNE_XLINT_ARGS}"
fi
if [ ! -z "${PRUNE_XLINT_ARGS}" ]; then
  ${SUPPLIED_JAVAC} -Xlint @$JAVA_FILES_FILE 2>&1 | `dirname ${0}`/javac-xlint-prune -p "${PRUNE_XLINT_ARGS}"
else
  ${SUPPLIED_JAVAC} -Xlint @$JAVA_FILES_FILE 2>&1 | `dirname ${0}`/javac-xlint-prune
fi

STATUS=$?
if [ -z $DEBUG_JAVAC_XLINT ]; then
  rm -f $FILES_FILE
fi
exit $STATUS