Gdb Pretty Printer: *(char*){hex_address} equivalent in python -

i have c++ classes in following format (copying important parts):

class my_stringimpl { public: static sample_string* create(const char* str, int len) {     my_stringimpl* sample = static_cast<my_stringimpl*>(malloc(sizeof(my_stringimpl) + len*sizeof(char)));     char* data_ptr = reinterpret_cast<char*>(sample+1);     memset(data_ptr, 0, len);     memcpy(data_ptr, str, len);     return new (sample) my_stringimpl(len); }    private:     int m_length; }; class my_string { public:     my_string(const char* str, int len)         : m_impl(my_stringimpl::create(str, len)) { }     ~my_string() {         delete m_impl;     } private:     my_stringimpl* m_impl; }; 

for my_string class adding pretty printer. added following defs in python script (which including in .gdbinit file) - func defs copied here:

def string_to_char(ptr, length=none):     error_message = ''     if length none:         length = int(0)         error_message = 'null string'     else:         length = int(length)     string = ''.join([chr((ptr + i).dereference()) in xrange(length)])     return string + error_message  class stringprinter(object):     def __init__(self, val):         self.val = val   class stringimplprinter(stringprinter):     def get_length(self):         return self.val['m_length']      def get_data_address(self):         return self.val.address + 1      def to_string(self):         return string_to_char(self.get_data_address(), self.get_length())  class mystringprinter(stringprinter):     def stringimpl_ptr(self):         return self.val['m_impl']      def get_length(self):         if not self.stringimpl_ptr():             return 0         return stringimplprinter(self.stringimpl_ptr().dereference()).get_length()      def to_string(self):         if not self.stringimpl_ptr():             return '(null)'         return stringimplprinter(self.stringimpl_ptr().dereference()).to_string() 

but, on usage getting below error -

python exception <class 'gdb.error'> cannot convert value int.:  

if try change value in 'ptr' int , arthimetic before casting char (like in def above), gives below error:

python exception <type 'exceptions.attributeerror'> 'nonetype' object has no attribute 'cast': 

can tell doing wrong? struck here. :(. in nutshell, trying achieve following c/c++ expr equivalent,

*(char*){hex_address} 

in python. how can it?

it's better post full stack traces or @ least indicate lines throws exception. python provides this...

your string_to_char function can replaced value.string or value.lazy_string, designed use. imagine error coming there; in case ought remove it.

also, printers should implement "hint" methods return "string".