cerc-io/solidity
16
0
Fork 0
mirror of https://github.com/ethereum/solidity synced 2023-10-03 13:03:40 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Update Delegatecall Description in Docs

Browse Source 
The previous description did not include the fact that the storage locations of the two contracts must align up until the storage variable(s) affected in order for the called contract to successfully write to the caller's storage. If they are misaligned, delegatecall will silently fail. This is difficult to debug without underlying knowledge of how delegatecall works, and clarity in the docs would certainly be helpful.
This commit is contained in:
Robbie Ferguson 2018-02-27 21:48:16 +11:00 committed by chriseth
parent 866df15daa
commit 49567b3f4c
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
docs/units-and-global-variables.rst
View File

@ -168,6 +168,13 @@ For more information, see the section on :ref:`address`.
to make safe Ether transfers, always check the return value of ``send``, use ``transfer`` or even better:
Use a pattern where the recipient withdraws the money.
.. note::
If storage variables are accessed via a low-level delegatecall, the storage layout of the two contracts
must align in order for the called contract to correctly access the storage variables of the calling contract by name.
This is of course not the case if storage pointers are passed as function arguments as in the case for
the high-level libraries.
.. note::
The use of ``callcode`` is discouraged and will be removed in the future.