#!/bin/sh

OUTPUT=$1
if test -z "$OUTPUT"; then
  echo "usage: $0 <output-filename>" >&2
  exit 1
fi

# Delete existing output, if it exists
rm -f "$OUTPUT"
touch "$OUTPUT"

if test -z "$CXX"; then
    CXX=g++
fi

# Test whether tcmalloc is available
if echo 'int main() {}' | $CXX $CFLAGS -x c++ - -o /dev/null \
  -ltcmalloc 2>/dev/null; then
    TCMALLOC_LDFLAGS=" -ltcmalloc"
fi

# Test whether malloc_extension is available
$CXX $CFLAGS -x c++ - -o /dev/null -ltcmalloc 2>/dev/null  <<EOF
  #include <gperftools/malloc_extension.h>
  int main() {
    MallocExtension::instance()->Initialize();;
    return 0;
  }
EOF
if [ "$?" = 0 ]; then
    TCMALLOC_EXTENSION_FLAGS=" -DTCMALLOC_EXTENSION"
fi

# Test whether Snappy library is installed
# http://code.google.com/p/snappy/
$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <snappy.h>
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lsnappy"
fi

# Test whether gflags library is installed
# http://gflags.github.io/gflags/
# check if the namespace is gflags
$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
  #include <gflags/gflags.h>
  using namespace gflags;
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lgflags"
else
  # check if namespace is google
  $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
    #include <gflags/gflags.h>
    using namespace google;
    int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lgflags"
fi
fi

# Test whether zlib library is installed
$CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <zlib.h>
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lz"
fi

# Test whether bzip library is installed
$CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <bzlib.h>
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lbz2"
fi

# Test whether lz4 library is installed
$CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <lz4.h>
  #include <lz4hc.h>
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -llz4"
fi

# Test whether zstd library is installed
$CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <zstd.h>
  int main() {}
EOF
if [ "$?" = 0 ]; then
    ROCKSDB_LDFLAGS="$ROCKSDB_LDFLAGS -lzstd"
fi



# Test processor nums
PROCESSOR_NUMS=$(cat /proc/cpuinfo | grep processor | wc -l)

echo "ROCKSDB_LDFLAGS=$ROCKSDB_LDFLAGS" >> "$OUTPUT"
echo "TCMALLOC_EXTENSION_FLAGS=$TCMALLOC_EXTENSION_FLAGS" >> "$OUTPUT"
echo "TCMALLOC_LDFLAGS=$TCMALLOC_LDFLAGS" >> "$OUTPUT"
echo "PROCESSOR_NUMS=$PROCESSOR_NUMS" >> "$OUTPUT"