88 lines
3.1 KiB
Python
88 lines
3.1 KiB
Python
#! /usr/bin/env python
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# ______________________________________________________________________
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# Module imports
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from __future__ import absolute_import
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from .byte_flow import Instr, BytecodeFlowBuilder, demo_flow_builder
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from .opcode_util import build_basic_blocks, itercodeobjs
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# ______________________________________________________________________
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# Class definition(s)
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class AddressFlowBuilder(BytecodeFlowBuilder):
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'''
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Builds on top of the BytecodeFlowBuilder with two important differences:
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* Child nodes are represented by bytecode indices.
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* All operations (other than purely stack manipulation operations)
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are retained in the block list (as opposed to being nested).
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The resulting data structure describes a directed acyclic graph
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(DAG) in a similar fashion to BytecodeFlowBuilder:
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* `flow_dag` ``:=`` ``{`` `blocks` ``*`` ``}``
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* `blocks` ``:=`` `block_index` ``:`` ``[`` `bytecode_tuple` ``*`` ``]``
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* `bytecode_tuple` ``:=`` ``(`` `opcode_index` ``,`` `opcode` ``,``
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`opname` ``,`` `arg` ``,`` ``[`` `opcode_index` ``*`` ``]`` ``)``
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'''
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def _visit_op(self, i, op, arg, opname, pops, pushes, appends):
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assert pops is not None, ('%s not well defined in opcode_util.'
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'OPCODE_MAP' % opname)
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if pops:
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if pops < 0:
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pops = arg - pops - 1
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assert pops <= len(self.stack), ("Stack underflow at instruction "
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"%d (%s)!" % (i, opname))
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stk_args = [stk_arg[0] for stk_arg in self.stack[-pops:]]
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del self.stack[-pops:]
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else:
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stk_args = []
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ret_val = Instr(i, op, opname, arg, stk_args)
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if pushes:
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self.stack.append(ret_val)
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self.block.append(ret_val)
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return ret_val
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def op_IMPORT_FROM (self, i, op, arg):
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# References top of stack without popping, so we can't use the
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# generic machinery.
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opname = self.opmap[op][0]
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ret_val = Instr(i, op, opname, arg, [self.stack[-1][0]])
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self.stack.append(ret_val)
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self.block.append(ret_val)
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return ret_val
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def op_JUMP_IF_FALSE (self, i, op, arg):
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ret_val = Instr(i, op, self.opnames[op], arg, [self.stack[-1][0]])
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self.block.append(ret_val)
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return ret_val
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op_JUMP_IF_TRUE = op_JUMP_IF_FALSE
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def op_LIST_APPEND (self, i, op, arg):
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'''This method is used for both LIST_APPEND, and SET_ADD
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opcodes.'''
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elem = self.stack.pop()
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container = self.stack[-arg]
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ret_val = Instr(i, op, self.opnames[op], arg, [container[0], elem[0]])
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self.block.append(ret_val)
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return ret_val
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op_SET_ADD = op_LIST_APPEND
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# ______________________________________________________________________
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# Main (self-test) routine
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def main(*args):
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return demo_flow_builder(AddressFlowBuilder, *args)
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# ______________________________________________________________________
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if __name__ == "__main__":
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import sys
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main(*sys.argv[1:])
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# ______________________________________________________________________
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# End of addr_flow.py
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