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Clarify the reason for the memory-unsafe assembly example being unsafe

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aathan 2022-03-29 13:48:49 -07:00 committed by Kamil Śliwak
parent 803585d2e6
commit 9e2b26e046
1 changed files with 4 additions and 2 deletions
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6
docs/assembly.rst
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@ -313,7 +313,8 @@ Furthermore, if the assembly block assigns to Solidity variables in memory, you
the Solidity variables only access these memory ranges.
Since this is mainly about the optimizer, these restrictions still need to be followed, even if the assembly block
reverts or terminates. As an example, the following assembly snippet is not memory safe:
reverts or terminates. As an example, the following assembly snippet is not memory safe, because the value of
``returndatasize()`` may exceed the 64 byte scratch space:
.. code-block:: solidity
@ -322,7 +323,8 @@ reverts or terminates. As an example, the following assembly snippet is not memo
revert(0, returndatasize())
}
But the following is:
On the other hand, the following code *is* memory safe, because memory beyond the location pointed to by the
free memory pointer can safely be used as temporary scratch space:
.. code-block:: solidity