#!/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.
#
# The output will set the following variables:
#   CC                          C Compiler path
#   CXX                         C++ Compiler path
#   PLATFORM_LDFLAGS            Linker flags
#   JAVA_LDFLAGS                Linker flags for RocksDBJava
#   PLATFORM_SHARED_EXT         Extension for shared libraries
#   PLATFORM_SHARED_LDFLAGS     Flags for building shared library
#   PLATFORM_SHARED_CFLAGS      Flags for compiling objects for shared library
#   PLATFORM_CCFLAGS            C compiler flags
#   PLATFORM_CXXFLAGS           C++ compiler flags.  Will contain:
#   PLATFORM_SHARED_VERSIONED   Set to 'true' if platform supports versioned
#                               shared libraries, empty otherwise.
#
# The PLATFORM_CCFLAGS and PLATFORM_CXXFLAGS might include the following:
#
#       -DLEVELDB_PLATFORM_POSIX if cstdatomic is present
#       -DLEVELDB_PLATFORM_NOATOMIC if it is not
#       -DSNAPPY                    if the Snappy library is present
#       -DLZ4                       if the LZ4 library is present
#       -DNUMA                      if the NUMA library is present
#
# Using gflags in rocksdb:
# Our project depends on gflags, which requires users to take some extra steps
# before they can compile the whole repository:
#   1. Install gflags. You may download it from here:
#      https://code.google.com/p/gflags/
#   2. Once install, add the include path/lib path for gflags to CPATH and
#      LIBRARY_PATH respectively. If installed with default mode, the
#      lib and include path will be /usr/local/lib and /usr/local/include
# Mac user can do this by having brew installed and running brew install gflags

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

# we depend on C++11
PLATFORM_CXXFLAGS="-std=c++11"
# we currently depend on POSIX platform
COMMON_FLAGS="-DROCKSDB_PLATFORM_POSIX"

# Default to fbcode gcc on internal fb machines
if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
    FBCODE_BUILD="true"
    # If we're compiling with TSAN we need pic build
    PIC_BUILD=$COMPILE_WITH_TSAN
    source "$PWD/build_tools/fbcode_config.sh"
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

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

if test -z "$TARGET_ARCHITECTURE"; then
    TARGET_ARCHITECTURE=`uname -m`
fi

if test -z "$CLANG_SCAN_BUILD"; then
    CLANG_SCAN_BUILD=scan-build
fi

if test -z "$CLANG_ANALYZER"; then
    CLANG_ANALYZER=$(which clang++ 2> /dev/null)
fi

COMMON_FLAGS="$COMMON_FLAGS ${CFLAGS}"
CROSS_COMPILE=
PLATFORM_CCFLAGS=
PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS ${CXXFLAGS}"
PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS"
PLATFORM_SHARED_EXT="so"
PLATFORM_SHARED_LDFLAGS="-shared -Wl,-soname -Wl,"
PLATFORM_SHARED_CFLAGS="-fPIC"
PLATFORM_SHARED_VERSIONED=false

# generic port files (working on all platform by #ifdef) go directly in /port
GENERIC_PORT_FILES=`cd "$ROCKSDB_ROOT"; find port -name '*.cc' | tr "\n" " "`

# On GCC, we pick libc's memcmp over GCC's memcmp via -fno-builtin-memcmp
case "$TARGET_OS" in
    Darwin)
        PLATFORM=OS_MACOSX
        COMMON_FLAGS="$COMMON_FLAGS -DOS_MACOSX"
        PLATFORM_SHARED_EXT=dylib
        PLATFORM_SHARED_LDFLAGS="-dynamiclib -install_name "
        # PORT_FILES=port/darwin/darwin_specific.cc
        ;;
    IOS)
        PLATFORM=IOS
        COMMON_FLAGS="$COMMON_FLAGS -DOS_MACOSX -DIOS_CROSS_COMPILE -DROCKSDB_LITE"
        PLATFORM_SHARED_EXT=dylib
        PLATFORM_SHARED_LDFLAGS="-dynamiclib -install_name "
        CROSS_COMPILE=true
        ;;
    Linux)
        PLATFORM=OS_LINUX
        COMMON_FLAGS="$COMMON_FLAGS -DOS_LINUX"
        if [ -z "$USE_CLANG" ]; then
            COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp"
        fi
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lrt"
        # PORT_FILES=port/linux/linux_specific.cc
        ;;
    SunOS)
        PLATFORM=OS_SOLARIS
        COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_SOLARIS"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lrt"
        # PORT_FILES=port/sunos/sunos_specific.cc
        ;;
    FreeBSD)
        PLATFORM=OS_FREEBSD
        COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_FREEBSD"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread"
        # PORT_FILES=port/freebsd/freebsd_specific.cc
        ;;
    NetBSD)
        PLATFORM=OS_NETBSD
        COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_NETBSD"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lgcc_s"
        # PORT_FILES=port/netbsd/netbsd_specific.cc
        ;;
    OpenBSD)
        PLATFORM=OS_OPENBSD
        COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_OPENBSD"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -pthread"
        # PORT_FILES=port/openbsd/openbsd_specific.cc
        ;;
    DragonFly)
        PLATFORM=OS_DRAGONFLYBSD
        COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_DRAGONFLYBSD"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread"
        # PORT_FILES=port/dragonfly/dragonfly_specific.cc
        ;;
    OS_ANDROID_CROSSCOMPILE)
        PLATFORM=OS_ANDROID
	COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp -D_REENTRANT -DOS_ANDROID -DLEVELDB_PLATFORM_POSIX"
	PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS "  # All pthread features are in the Android C library
        # PORT_FILES=port/android/android.cc
        CROSS_COMPILE=true
        ;;
    *)
        echo "Unknown platform!" >&2
        exit 1
esac

JAVA_LDFLAGS="$PLATFORM_LDFLAGS"

if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
    # Cross-compiling; do not try any compilation tests.
    # Also don't need any compilation tests if compiling on fbcode
    true
else
    # Test whether fallocate is available
    $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
      #include <fcntl.h>
      #include <linux/falloc.h>
      int main() {
	int fd = open("/dev/null", 0);
  fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0, 1024);
      }
EOF
    if [ "$?" = 0 ]; then
        COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_FALLOCATE_PRESENT"
    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
        COMMON_FLAGS="$COMMON_FLAGS -DSNAPPY"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lsnappy"
        JAVA_LDFLAGS="$JAVA_LDFLAGS -lsnappy"
    fi


    # Test whether gflags library is installed
    # http://code.google.com/p/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
        COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=gflags"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
    fi

    # 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
        COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=google"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
    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
        COMMON_FLAGS="$COMMON_FLAGS -DZLIB"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lz"
        JAVA_LDFLAGS="$JAVA_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
        COMMON_FLAGS="$COMMON_FLAGS -DBZIP2"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lbz2"
        JAVA_LDFLAGS="$JAVA_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
        COMMON_FLAGS="$COMMON_FLAGS -DLZ4"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -llz4"
        JAVA_LDFLAGS="$JAVA_LDFLAGS -llz4"
    fi

    # Test whether numa is available
    $CXX $CFLAGS -x c++ - -o /dev/null -lnuma 2>/dev/null  <<EOF
      #include <numa.h>
      #inlcude <numaif.h>
      int main() {}
EOF
    if [ "$?" = 0 ]; then
        COMMON_FLAGS="$COMMON_FLAGS -DNUMA"
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lnuma"
        JAVA_LDFLAGS="$JAVA_LDFLAGS -lnuma"
    fi

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

# TODO(tec): Fix -Wshorten-64-to-32 errors on FreeBSD and enable the warning.
# -Wshorten-64-to-32 breaks compilation on FreeBSD i386
if ! [ "$TARGET_OS" = FreeBSD -a "$TARGET_ARCHITECTURE" = i386 ]; then
  # Test whether -Wshorten-64-to-32 is available
  $CXX $CFLAGS -x c++ - -o /dev/null -Wshorten-64-to-32 2>/dev/null  <<EOF
    int main() {}
EOF
  if [ "$?" = 0 ]; then
    COMMON_FLAGS="$COMMON_FLAGS -Wshorten-64-to-32"
  fi
fi

# shall we use HDFS?

if test "$USE_HDFS"; then
  if test -z "$JAVA_HOME"; then
    echo "JAVA_HOME has to be set for HDFS usage."
    exit 1
  fi
  HDFS_CCFLAGS="$HDFS_CCFLAGS -I$JAVA_HOME/include -I$JAVA_HOME/include/linux -DUSE_HDFS"
  HDFS_LDFLAGS="$HDFS_LDFLAGS -Wl,--no-whole-archive -lhdfs -L$JAVA_HOME/jre/lib/amd64"
  HDFS_LDFLAGS="$HDFS_LDFLAGS -L$JAVA_HOME/jre/lib/amd64/server -L$GLIBC_RUNTIME_PATH/lib"
  HDFS_LDFLAGS="$HDFS_LDFLAGS -ldl -lverify -ljava -ljvm"
  COMMON_FLAGS="$COMMON_FLAGS $HDFS_CCFLAGS"
  PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS $HDFS_LDFLAGS"
  JAVA_LDFLAGS="$JAVA_LDFLAGS $HDFS_LDFLAGS"
fi

if [ "$TARGET_OS" = FreeBSD -a "$TARGET_ARCHITECTURE" = i386 ]; then
  # Intel SSE instructions breaks compilation on FreeBSD i386
  unset USE_SSE
fi

if test "$USE_SSE"; then
  # if Intel SSE instruction set is supported, set USE_SSE=1
  COMMON_FLAGS="$COMMON_FLAGS -msse -msse4.2 "
elif test -z "$PORTABLE"; then
  COMMON_FLAGS="$COMMON_FLAGS -march=native "
fi

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

VALGRIND_VER="$VALGRIND_VER"

ROCKSDB_MAJOR=`build_tools/version.sh major`
ROCKSDB_MINOR=`build_tools/version.sh minor`
ROCKSDB_PATCH=`build_tools/version.sh patch`

echo "CC=$CC" >> "$OUTPUT"
echo "CXX=$CXX" >> "$OUTPUT"
echo "PLATFORM=$PLATFORM" >> "$OUTPUT"
echo "PLATFORM_LDFLAGS=$PLATFORM_LDFLAGS" >> "$OUTPUT"
echo "JAVA_LDFLAGS=$JAVA_LDFLAGS" >> "$OUTPUT"
echo "VALGRIND_VER=$VALGRIND_VER" >> "$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"
echo "EXEC_LDFLAGS=$EXEC_LDFLAGS" >> "$OUTPUT"
echo "JEMALLOC_INCLUDE=$JEMALLOC_INCLUDE" >> "$OUTPUT"
echo "JEMALLOC_LIB=$JEMALLOC_LIB" >> "$OUTPUT"
echo "ROCKSDB_MAJOR=$ROCKSDB_MAJOR" >> "$OUTPUT"
echo "ROCKSDB_MINOR=$ROCKSDB_MINOR" >> "$OUTPUT"
echo "ROCKSDB_PATCH=$ROCKSDB_PATCH" >> "$OUTPUT"
echo "CLANG_SCAN_BUILD=$CLANG_SCAN_BUILD" >> "$OUTPUT"
echo "CLANG_ANALYZER=$CLANG_ANALYZER" >> "$OUTPUT"