This check from build_tools/build_platform_detect won't define LEVELDB_CSTDATOMIC_PRESENT because doesn't exist for gcc 4.7. Maybe it did for older gcc versions, but I don't track modern gcc/g++ enough to understand it. I think the check might need to use "include " instead.

# If -std=c++0x works, use <cstdatomic>.  Otherwise use port_posix.h.
$CXX $CFLAGS -std=c++0x -x c++ - -o /dev/null 2>/dev/null  <<EOF
  #include <cstdatomic>
  int main() {}

EOF
if [ "$?" = 0 ]; then
COMMON_FLAGS="$COMMON_FLAGS -DLEVELDB_PLATFORM_POSIX -DLEVELDB_CSTDATOMIC_PRESENT"
PLATFORM_CXXFLAGS="-std=c++0x"
else
COMMON_FLAGS="$COMMON_FLAGS -DLEVELDB_PLATFORM_POSIX"
fi