Filter self.actions based on some common parameters.

        :param block_addr:  Only return actions generated in blocks starting at this address.
        :param block_stmt:  Only return actions generated in the nth statement of each block.
        :param insn_addr:   Only return actions generated in the assembly instruction at this address.
        :param read_from:   Only return actions that perform a read from the specified location.
        :param write_to:    Only return actions that perform a write to the specified location.

        Notes:
        If IR optimization is turned on, reads and writes may not occur in the instruction
        they originally came from. Most commonly, If a register is read from twice in the same
        block, the second read will not happen, instead reusing the temp the value is already
        stored in.

        Valid values for read_from and write_to are the string literals 'reg' or 'mem' (matching
        any read or write to registers or memory, respectively), any string (representing a read
        or write to the named register), and any integer (representing a read or write to the
        memory at this address).

def filter_actions(self, block_addr=None, block_stmt=None, insn_addr=None, read_from=None, write_to=None):
        """
        Filter self.actions based on some common parameters.

        :param block_addr:  Only return actions generated in blocks starting at this address.
        :param block_stmt:  Only return actions generated in the nth statement of each block.
        :param insn_addr:   Only return actions generated in the assembly instruction at this address.
        :param read_from:   Only return actions that perform a read from the specified location.
        :param write_to:    Only return actions that perform a write to the specified location.

        Notes:
        If IR optimization is turned on, reads and writes may not occur in the instruction
        they originally came from. Most commonly, If a register is read from twice in the same
        block, the second read will not happen, instead reusing the temp the value is already
        stored in.

        Valid values for read_from and write_to are the string literals 'reg' or 'mem' (matching
        any read or write to registers or memory, respectively), any string (representing a read
        or write to the named register), and any integer (representing a read or write to the
        memory at this address).
        """
        if read_from is not None:
            if write_to is not None:
                raise ValueError("Can't handle read_from and write_to at the same time!")
            if read_from in ('reg', 'mem'):
                read_type = read_from
                read_offset = None
            elif isinstance(read_from, str):
                read_type = 'reg'
                read_offset = self.state.project.arch.registers[read_from][0]
            else:
                read_type = 'mem'
                read_offset = read_from
        if write_to is not None:
            if write_to in ('reg', 'mem'):
                write_type = write_to
                write_offset = None
            elif isinstance(write_to, str):
                write_type = 'reg'
                write_offset = self.state.project.arch.registers[write_to][0]
            else:
                write_type = 'mem'
                write_offset = write_to

        #def addr_of_stmt(bbl_addr, stmt_idx):
        #    if stmt_idx is None:
        #        return None
        #    stmts = self.state.project.factory.block(bbl_addr).vex.statements
        #    if stmt_idx >= len(stmts):
        #        return None
        #    for i in reversed(range(stmt_idx + 1)):
        #        if stmts[i].tag == 'Ist_IMark':
        #            return stmts[i].addr + stmts[i].delta
        #    return None

        def action_reads(action):
            if action.type != read_type:
                return False
            if action.action != 'read':
                return False
            if read_offset is None:
                return True
            addr = action.addr
            if isinstance(addr, SimActionObject):
                addr = addr.ast
            if isinstance(addr, claripy.ast.Base):
                if addr.symbolic:
                    return False
                addr = self.state.solver.eval(addr)
            if addr != read_offset:
                return False
            return True

        def action_writes(action):
            if action.type != write_type:
                return False
            if action.action != 'write':
                return False
            if write_offset is None:
                return True
            addr = action.addr
            if isinstance(addr, SimActionObject):
                addr = addr.ast
            if isinstance(addr, claripy.ast.Base):
                if addr.symbolic:
                    return False
                addr = self.state.solver.eval(addr)
            if addr != write_offset:
                return False
            return True

        return [x for x in reversed(self.actions) if
                    (block_addr is None or x.bbl_addr == block_addr) and
                    (block_stmt is None or x.stmt_idx == block_stmt) and
                    (read_from is None or action_reads(x)) and
                    (write_to is None or action_writes(x)) and
                    (insn_addr is None or (x.sim_procedure is None and x.ins_addr == insn_addr))
                    #(insn_addr is None or (x.sim_procedure is None and addr_of_stmt(x.bbl_addr, x.stmt_idx) == insn_addr))
            ]