Segfault in Ruby Extension Code

Question

I'm writing a small Ruby extension in C/C++ that makes boost::dynamic_bitfield available in Ruby. My code does perfectly compile, but when loading the extension and trying to instantiate the class I am getting a segfault.

I haven't been able to properly utilize gdb to find the error or where it is happening. I think I narrowed the problem down to Init_bitfield or bf_new/bf_init.

Full source: http://pastebin.com/qLkMGYqq

static VALUE bf_new(VALUE self, VALUE size)
{
    VALUE argv[1];
    Check_Type(size, T_FIXNUM);
    BitField *bf = BitFieldNew(NUM2INT(size));
    VALUE tdata = Data_Wrap_Struct(self, 0, free, bf);
    argv[0] = size;
    rb_obj_call_init(tdata, 1, argv);
    return tdata;
}

BitField is defined as follows:

typedef struct _bitfield {
        boost::dynamic_bitset<> data;
} BitField;

The code is mainly inspired by this article: http://ruby-doc.org/docs/ProgrammingRuby/html/ext_ruby.html

Answer 1

The solution was to add:

new(bf) BitField();

to BitFieldNew(size); to initialize the struct and boost::dynamic_bitset.