mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
64 lines
1.5 KiB
Python
64 lines
1.5 KiB
Python
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import sys
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from z3 import Solver, Int, unsat
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"""
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Tests that the conditions inside RedundantStoreEliminator::knownUnrelated
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only return "unrelated" incorrectly if one of the operation reverts
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due to large memory access.
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"""
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n_bits = 256
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solver = Solver()
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solver.set("timeout", 60000)
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def restrict(x):
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solver.add(x >= 0)
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solver.add(x < 2**n_bits)
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def restrictedInt(x):
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var = Int(x)
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restrict(var)
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return var
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start1 = restrictedInt('start1')
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length1 = restrictedInt('length1')
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start2 = restrictedInt('start2')
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length2 = restrictedInt('length2')
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k = Int('k')
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diff = Int('diff')
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solver.add(diff == start2 - start1 + k * 2**n_bits)
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restrict(diff)
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# diff is the result of sub(start2, start1) in EVM
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# These are the conditions in the code.
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solver.add(diff >= length1)
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solver.add(diff <= 2**(n_bits-1))
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# We check that the two conditions are conflicting:
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# - overlap
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# - start1 is small
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# Overlap:
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# x is a potential point where the memory operations
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# overlap.
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# Note that we do not use wrapping arithmetic
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# here, because it is not done in the EVM either.
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# For example calldatacopy(2**256 - 2, 0, 10)
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# (copy 10 bytes from calldata position zero to memory
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# position 2**256 - 2) would not write to memory position
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# zero either.
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x = Int('x')
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solver.add(start1 <= x)
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solver.add(x < start1 + length1)
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solver.add(start2 <= x)
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solver.add(x < start2 + length2)
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# start1 is "small":
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solver.add(start1 < 2**(n_bits-1))
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if solver.check() != unsat:
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print("Expected unsat but got something else")
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sys.exit(1)
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