#!/bin/sh
#
# Detects OS we're compiling on and outputs a file specified by the first
# argument, which in turn gets read while processing Makefile.
#
# Updated for LevelDB 1.23: port layer is now header-only (port_stdcxx.h),
# platform env files must be selected (env_posix.cc vs env_windows.cc).

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

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

if test -z "$CC"; then
    CC=cc
fi

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

if test -z "$TMPDIR"; then
    TMPDIR=/tmp
fi

# Detect OS
if test -z "$TARGET_OS"; then
    TARGET_OS=`uname -s`
fi

COMMON_FLAGS=
CROSS_COMPILE=
PLATFORM_CCFLAGS=
PLATFORM_CXXFLAGS=
PLATFORM_LDFLAGS=
PLATFORM_LIBS=
PLATFORM_SHARED_EXT="so"
PLATFORM_SHARED_LDFLAGS="-shared -Wl,-soname -Wl,"
PLATFORM_SHARED_CFLAGS="-fPIC"
PLATFORM_SHARED_VERSIONED=true

# LevelDB 1.23 requires C++11
PLATFORM_CXXFLAGS="-std=c++11"

MEMCMP_FLAG=
if [ "$CXX" = "g++" ]; then
    MEMCMP_FLAG="-fno-builtin-memcmp"
fi

# Which env_*.cc to exclude from the build
PRUNE_ENV_FILE="env_windows.cc"

case "$TARGET_OS" in
    Darwin)
        PLATFORM=OS_MACOSX
        COMMON_FLAGS="$MEMCMP_FLAG -DOS_MACOSX -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_SHARED_EXT=dylib
        [ -z "$INSTALL_PATH" ] && INSTALL_PATH=`pwd`
        PLATFORM_SHARED_LDFLAGS="-dynamiclib -install_name $INSTALL_PATH/"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    Linux)
        PLATFORM=OS_LINUX
        COMMON_FLAGS="$MEMCMP_FLAG -pthread -DOS_LINUX -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LDFLAGS="-pthread"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    SunOS)
        PLATFORM=OS_SOLARIS
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_SOLARIS -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LIBS="-lpthread -lrt"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    FreeBSD)
        PLATFORM=OS_FREEBSD
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_FREEBSD -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LIBS="-lpthread"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    GNU/kFreeBSD)
        PLATFORM=OS_KFREEBSD
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_KFREEBSD -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LIBS="-lpthread"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    NetBSD)
        PLATFORM=OS_NETBSD
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_NETBSD -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LIBS="-lpthread -lgcc_s"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    OpenBSD)
        PLATFORM=OS_OPENBSD
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_OPENBSD -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LDFLAGS="-pthread"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    DragonFly)
        PLATFORM=OS_DRAGONFLYBSD
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_DRAGONFLYBSD -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LIBS="-lpthread"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    OS_ANDROID_CROSSCOMPILE)
        PLATFORM=OS_ANDROID
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_ANDROID -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LDFLAGS=""
        PRUNE_ENV_FILE="env_windows.cc"
        CROSS_COMPILE=true
        ;;
    HP-UX)
        PLATFORM=OS_HPUX
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_HPUX -DLEVELDB_PLATFORM_POSIX"
        PLATFORM_LDFLAGS="-pthread"
        PLATFORM_SHARED_LDFLAGS="-shared -Wl,+h -Wl,"
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    IOS)
        PLATFORM=IOS
        COMMON_FLAGS="$MEMCMP_FLAG -DOS_MACOSX -DLEVELDB_PLATFORM_POSIX"
        [ -z "$INSTALL_PATH" ] && INSTALL_PATH=`pwd`
        PLATFORM_SHARED_EXT=
        PLATFORM_SHARED_LDFLAGS=
        PLATFORM_SHARED_CFLAGS=
        PLATFORM_SHARED_VERSIONED=
        PRUNE_ENV_FILE="env_windows.cc"
        ;;
    OS_WINDOWS_CROSSCOMPILE | NATIVE_WINDOWS | MINGW* | MSYS*)
        PLATFORM=OS_WINDOWS
        COMMON_FLAGS="$MEMCMP_FLAG -D_REENTRANT -DOS_WINDOWS -DLEVELDB_PLATFORM_WINDOWS -DWINVER=0x0500 -D__USE_MINGW_ANSI_STDIO=1"
        PLATFORM_LIBS="-lshlwapi"
        PRUNE_ENV_FILE="env_posix.cc"
        CROSS_COMPILE=true
        ;;
    *)
        echo "Unknown platform!" >&2
        exit 1
esac

# We want to make a list of all cc files within util, db, table, and helpers
# except for the test and benchmark files and the wrong platform env file.
DIRS="$PREFIX/db $PREFIX/util $PREFIX/table"

set -f # temporarily disable globbing so that our patterns aren't expanded
PRUNE_TEST="-name *test*.cc -prune"
PRUNE_BENCH="-name *_bench.cc -prune"
PRUNE_TOOL="-name leveldbutil.cc -prune"
PRUNE_ENV="-name $PRUNE_ENV_FILE -prune"
PORTABLE_FILES=`find $DIRS $PRUNE_TEST -o $PRUNE_BENCH -o $PRUNE_TOOL -o $PRUNE_ENV -o -name '*.cc' -print | sort | sed "s,^$PREFIX/,," | tr "\n" " "`

set +f # re-enable globbing

# LevelDB 1.23: port layer is header-only (port_stdcxx.h), no port .cc file needed
echo "SOURCES=$PORTABLE_FILES" >> $OUTPUT
echo "MEMENV_SOURCES=helpers/memenv/memenv.cc" >> $OUTPUT

if [ "$CROSS_COMPILE" = "true" ]; then
    # Cross-compiling; do not try any compilation tests.
    true
else
    CXXOUTPUT="${TMPDIR}/leveldb_build_detect_platform-cxx.$$"

    # Test whether tcmalloc is available
    $CXX $CXXFLAGS -x c++ - -o $CXXOUTPUT -ltcmalloc 2>/dev/null  <<EOF
      int main() {}
EOF
    if [ "$?" = 0 ]; then
        PLATFORM_LIBS="$PLATFORM_LIBS -ltcmalloc"
    fi

    rm -f $CXXOUTPUT 2>/dev/null
fi

PLATFORM_CCFLAGS="$PLATFORM_CCFLAGS $COMMON_FLAGS"
PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"

echo "CC=$CC" >> $OUTPUT
echo "CXX=$CXX" >> $OUTPUT
echo "PLATFORM=$PLATFORM" >> $OUTPUT
echo "PLATFORM_LDFLAGS=$PLATFORM_LDFLAGS" >> $OUTPUT
echo "PLATFORM_LIBS=$PLATFORM_LIBS" >> $OUTPUT
echo "PLATFORM_CCFLAGS=$PLATFORM_CCFLAGS" >> $OUTPUT
echo "PLATFORM_CXXFLAGS=$PLATFORM_CXXFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_CFLAGS=$PLATFORM_SHARED_CFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_EXT=$PLATFORM_SHARED_EXT" >> $OUTPUT
echo "PLATFORM_SHARED_LDFLAGS=$PLATFORM_SHARED_LDFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_VERSIONED=$PLATFORM_SHARED_VERSIONED" >> $OUTPUT