mirror of
https://github.com/idapython/src
synced 2026-06-08 14:47:00 +00:00
Arnaud Diederen
80 lines
2.2 KiB
Python
80 lines
2.2 KiB
Python
#
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# Hex-Rays Decompiler project
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# Copyright (c) 2007-2019 by Hex-Rays, support@hex-rays.com
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# ALL RIGHTS RESERVED.
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#
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# Sample plugin for Hex-Rays Decompiler.
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# It installs a custom block optimization rule:
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#
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# goto L1 => goto L2
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# ...
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# L1:
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# goto L2
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#
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# In other words we fix a goto target if it points to a chain of gotos.
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# This improves the decompiler output in some cases.
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#
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# This is a rewrite in Python of the vds11 example that comes with hexrays sdk.
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#
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import ida_bytes
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import ida_range
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import ida_kernwin
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import ida_hexrays
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import ida_typeinf
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class goto_optimizer_t(ida_hexrays.optblock_t):
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def func(self, blk):
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if self.handle_goto_chain(blk):
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return 1
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return 0
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def handle_goto_chain(self, blk):
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mgoto = blk.tail
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if not mgoto or mgoto.opcode != ida_hexrays.m_goto:
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return False
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visited = []
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t0 = mgoto.l.b
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i = t0
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mba = blk.mba
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# follow the goto chain
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while True:
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if i in visited:
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return False
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visited.append(i)
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b = mba.get_mblock(i)
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m2 = ida_hexrays.getf_reginsn(b.head)
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if not m2 or m2.opcode != ida_hexrays.m_goto:
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break
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i = m2.l.b
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if i == t0:
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return False # not a chain
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# all ok, found a goto chain
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mgoto.l.b = i # jump directly to the end of the chain
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# fix the successor/predecessor lists
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blk.succset[0] = i
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mba.get_mblock(i).predset.add(blk.serial)
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mba.get_mblock(t0).predset._del(blk.serial)
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# since we changed the control flow graph, invalidate the use/def chains.
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# stricly speaking it is not really necessary in our plugin because
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# we did not move around any microcode operands.
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mba.mark_chains_dirty()
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# it is a good idea to verify microcode after each change
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# however, it may be time consuming, so comment it out eventually
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mba.verify(True);
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return True
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if ida_hexrays.init_hexrays_plugin():
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optimizer = goto_optimizer_t()
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optimizer.install()
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else:
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print('vds11: Hex-rays is not available.')
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