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Merge pull request #12116 from ethereum/cleanupInlineAsm

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[DOCS] Add inline assembly section to cleanup.
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chriseth 2021-10-11 14:25:49 +02:00 committed by GitHub
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docs/internals/variable_cleanup.rst
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@ -14,7 +14,12 @@ hashes or sent as the data of a message call. Similarly, before
storing a value in the storage, the remaining bits need to be cleaned storing a value in the storage, the remaining bits need to be cleaned
because otherwise the garbled value can be observed. because otherwise the garbled value can be observed.
On the other hand, we do not clean the bits if the immediately Note that access via inline assembly is not considered such an operation:
If you use inline assembly to access Solidity variables
shorter than 256 bits, the compiler does not guarantee that
the value is properly cleaned up.
Moreover, we do not clean the bits if the immediately
following operation is not affected. For instance, since any non-zero following operation is not affected. For instance, since any non-zero
value is considered ``true`` by ``JUMPI`` instruction, we do not clean value is considered ``true`` by ``JUMPI`` instruction, we do not clean
the boolean values before they are used as the condition for the boolean values before they are used as the condition for