Questions tagged [delegatecall]
The delegatecall tag has no usage guidance.
84
questions
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Using delegatecall for multiple parameters fuction in solidity
Does someone have a exemple of solidity delegatecall for multiple parameters function?
7
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2answers
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Pros and Cons of smart contract upgradable patterns
There have been quite many arguments around how to achieve smart contract updates like Upgradeable smart contracts.
I feel Proxycontract with Delegate-call is currently the most famous one. But aside ...
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No Events After Deploying Another Contract in Remix
I am trying to write an upgradable smart contract in Remix. This involves a Proxy contract, a Logic_0_1_0 contract, and a Logic_0_2_0 contract.
I uploaded Proxy and Logic_0_1_0 only, and the ...
1
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1answer
82 views
Delegatecall return values solidity 5.0
With solidity 5.0+ , the delegatecall function can return a boolean and a bytes representing return value. I want to understand how does one convert the returned bytes to various datatypes. ex
If ...
0
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1answer
20 views
Calling Msg.sender Natively
Caller -> Contract B -> Contract A
Contract A has a msg.sender variable.
I want to use the Caller as Msg.Sender for Contract A through Contract B.
How is this done?
0
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1answer
33 views
How do you pause a Proxy-Logic pattern?
Suppose we have a Proxy contract that forwards to call to a Logic contract by using delegatecall.
If we pause the Proxy, users will still be able to directly interact with the Logic contract. While ...
1
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1answer
54 views
What's the equivalent of Vyper's create_forwarder_to in Solidity?
In Vyper, there's a built-in function called create_forwarder_to, which
Duplicates a contract’s code and deploys it as a new instance, by means of a DELEGATECALL.
If my understanding is correct, ...
1
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0answers
65 views
delegatecall (assembly) didn't change state variable in Remix with Web3 Provider
I am trying to test proxy pattern in Remix, which connected to my private chain with Web3 Provider. By the way, miner is working all the time. After invoking add function of Proxy contract, the state ...
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0answers
42 views
Anything like a static delegatecall from a view function?
let's say there are two contracts A and B, where A calls methods in B. I understand that A can modify and read storage in B with B.call() and B.staticcall(), ie. A can execute B's methods in the ...
0
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1answer
29 views
pass storage through interface to library
Here is what am i doing:
There is a library, accept storage argument as parameter, then do some math and return the result.
And there is a contract to call the function in the library, and an extra ...
1
vote
1answer
65 views
Correct way to make a delegatecall? [duplicate]
I made a delegatecall to the REP contract to approve my contract to spend tokens on behalf of a user and my transaction is failing for some reason here is my code:
(bool b,) = REPAddress.delegatecall(...
0
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1answer
22 views
Unstructured storage proxies. Variables not being overwritten?
When using delegate call I was under the impression that storage slots declared in the proxy will be overwritten by the implementation.
Unstructured storage implementations declare bytes32 variables ...
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1answer
43 views
How to prevent the code of my contract being used in a CALLCODE?
Simple question but I couldn’t find the answer anywhere.
How to know if the code of my contract is used in a CALLCODE or DELEGATECALL by third party sinceaddress(this)returns the address of the caller ...
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0answers
28 views
Delegatecall not changing state
I was trying the code in https://gist.github.com/sogoiii/f0ced0a4e569b5f38d302e7072d78b43 to observe the difference between call and delegatecall.
pragma solidity ^0.4.18;
contract D {
uint public ...
0
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1answer
97 views
Difference in “delegate call via assembly”
I came across a different version of delegate call via assembly and also tried all of them - no different result so far. How does it differ and which is the best version to use?
OpenZepplin version:
...
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36 views
Is it possible to implement upgradable contract with new functions?
I have follows this answer related to Upgradeable smart contracts and Zeppelin's solution.
I have tested those examples, where I was able to update the interface of the functions that are already ...
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0answers
43 views
Subtraces of delegatecall in Parity trace
I'm investigating transactions using Parity trace which provides useful data over a transaction flow. Among this data is the Subtraces field which allows me to understand how many sub-calls each ...
0
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1answer
37 views
DelegateCall to internal function doesn't store variable
Why isn't delegate call able to run internal functions?
What is the difference between a self directed delegate call and a contract normally calling one of it's internal function?
contract ...
0
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2answers
115 views
Code Example from “Mastering Ethereum: Building Smart Contracts and DApps” doesn't work
I'm reading the Ethereum book of Gavin Wood right know and the following code example gives an error message when I try to compile it with truffle:
pragma solidity ^0.4.22;
contract calledContract {
...
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0answers
69 views
Proxy contract DELEGATECALL to pass a DYNAMIC array to a function in the target contract
I'm trying to get a Proxy contract to correctly do a delegatecall to a function in another 'target' contract. The problem is, that I need to pass a dynamic array as the parameter to this function.
Q: ...
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0answers
27 views
Replaying the Bad Parity Hack
On a locally hosted instance of Ethererum I am trying to replay and understand the Bad Parity hack. I have a Wallet and a Wallet Library Contract.
Wallet.sol
constructor(address lib) public payable {...
0
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1answer
166 views
Is it possible to send Ether using delegatecall?
I tested this in Remix and it seems that the ether remains in the delegator contract and doesn't get forwarded. Using the code below to test:
contract SomeContract {
address public sender;
...
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0answers
84 views
How would you use a proxy erc20 contract if you cannot preserve msg.sender?
Let's say I use a proxy contract which allows me to make an ERC20 token transfer from my account.
At the moment the only way to do so is to use tx.origin which gets the original EOA address of the ...
0
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1answer
87 views
Delegatecall: Storing values
Using a delegatecall() to call another contract will have that contract run from within your context (e.g. if it calls a contract on its turn as a result, msg.sender will be your address). I am aware ...
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124 views
How to allow delegatecall only from specific contract?
I have a token contract, when transfer is called it calls other contract's transfer with data. Other contract checks msg.sender and allows only the first contract to pass and performs some important ...
0
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1answer
278 views
How to use Role-Based Access Control via Proxy?
I have a PermissionsManager contract that uses OpenZeppelin's Role-Based Access Control (RBAC) template as a base. Currently function modifiers in my app call PermissionsManager directly to check for ...
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vote
1answer
1k views
How does delegatecall work from Solidity 0.5.0 onwards?
I am trying, for learning purposes only, to make a mutable smart contract, but I couldn't find anything useful on stackexchange because everything I found was using pragma solidity ^0.4.x;
So, I have ...
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0answers
85 views
Can anyone give me a working DELEGATECALL example? [duplicate]
I tried many variants of DELEGATECALL, but not one of them gave me the desired result.
When used in assembly: = delegatecall (), I also don't get the result.
I also used different versions of Solidity ...
2
votes
1answer
244 views
Calling fallback function in truffle to delegate a call
I'm playing with the upgradeable contracts via DelegateProxy in Solidity.
This pattern posits that a MutableForwarder contract is deployed once, and all the subsequent calls to the upgradeable ...
0
votes
1answer
136 views
Proxy Contract Not Updating Store Data
I want to setup a proxy contract that my users can interact with. The proxy contract is a store contract with stores the user's age for now. When I call writeData to update my age, I expect it to call ...
1
vote
1answer
162 views
contract kill function
as per ethereum docs
Even if a contract’s code does not contain a call to selfdestruct, it
can still perform that operation using delegatecall or callcode.
is this real?
1.if it is then even if ...
2
votes
1answer
99 views
How does a contract know which library to query or know the library address?
How does a contract know which library to query? For Example in the code below (The code is from solidity docs: https://solidity.readthedocs.io/en/v0.4.24/contracts.html?highlight=library#libraries
...
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Delegatecall Scope - Correct me if I'm wrong
When any contract function is called - delegatecall or otherwise - the EVM loads the requisite pointers & values into that call frame's volatile stack/memory.
Example:
Let's say we have contract ...
2
votes
3answers
488 views
Scope confusion using delegate call
I am having trouble understanding the scope with delegatecall method. Here are my two contracts:
contract Caller {
uint public testVar = 88;
uint public myVariable = 6;
function ...
2
votes
2answers
402 views
Double delegate call doesn't work
To create an upgradeable contract I have to use multiple proxies. The contract applies to Proxy A, then Proxy A applies to Proxy B. But delegatecall doesn't work in this case.
The simplified code of ...
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1answer
267 views
Use of delegatecall with msg.data
I'm trying to understand below code:
pragma solidity ^0.4.23;
contract Relay {
address public currentVersion;
address public owner;
modifier onlyOwner() {
require(msg.sender == ...
0
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1answer
132 views
Delegatecall require statement does not cause an abortion in any way
This is a sequel to a previous question of mine.
I want to implement a validation function (e.g. for passwords) within a central contract, that could be used by other contracts. It is important to ...
0
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1answer
92 views
What method can I use instead of delegatecall?
I see the warning security/no-low-level-calls: Avoid using low-level function 'delegatecall' when I use delegatecall function in my code.
I understand why it's not a good way, but I still need that ...
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0answers
98 views
delegatecall for Smart Contract versioning
I've a state variable
address public current;
which stores the address of the latest updated contract. This value can be modified with a function.
Then, I've a function of this kind
function ...
1
vote
1answer
663 views
Solidity - selfdestruct
I'm just wondering what would happen if I don't put a selfdestrut() method in my smart contract.
As I read from the Solidity documentation (Self-destruct):
Even if a contract’s code does not ...
0
votes
1answer
96 views
When using Delegatecall or callcode, which Ether balance is used?
Simple question, but I couldn’t find the answer.
When contract A CALLCODE B, B will uses A’s ledger. But which Ether balance will be used if B makes a normal transfer, the balance of A or the balance ...
0
votes
1answer
103 views
What’s the purpose of the delegatecall second target parameter?
Simple question, but I couldn’t figure the answer.
Are there plans/EIP to use the second parameter of DELEGATECALL ? Or am I wrong (in which case the parameter isn’t ignored) ?
In c++ Ethereum evm ...
3
votes
2answers
337 views
Solidity CALL and DELEGATECALL: messages and data format
I have some questions about Solidity CALL and DELEGATECALL. I have already read some related threads (link), but found no answers to my doubts.
1) Is there any difference in performing a CALL to a ...
0
votes
1answer
223 views
Upradeable proxy library throws on any function, how to connect proxy and maincontract
I'm trying to implement a proxy library through the techniques researched by openZeppelin using proxies.
I have 4 contracts
1. Library with logic
2. Library containing the interface for the logic
...
5
votes
1answer
387 views
ERC20 Token tansfer through delegatecall throws
I'm trying to call the transfer() function on an ERC20 token through the use of delegatecall, my proxy contract however returns false from delegatecall.
When I try to call view functions like ...
2
votes
0answers
170 views
delegatecall on library always run out of gas
I'm trying to replicate the Dynamic Library attack of this paper under a recent version of solidity and the EVM.
Streamlining down the code, I've created this very simple contract (which is, in ...
0
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1answer
440 views
deletegateCall to change contract's ownership
I am currently going deep into some Solidity functionalities and I would like to be able to change a contract's A ownership from a contract B, knowing that the caller of contract B is the owner of ...
2
votes
1answer
266 views
Any way to have delegatecall change the delegate contract's storage state?
A delegatecall'ed function executes inside of the delegatecaller contract's own memory & storage context.
But I'm wondering whether the following is in any way possible (i.e. if certain access ...
1
vote
1answer
632 views
Contract call from a contract from a contract?
As I understand it, it is possible for a contract to call another contract by using
othercontractaddress.call(gas_amount).value(eth amount)(tx data).
Or in this case sender -> contract A -> ...
0
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1answer
552 views
Delegatecall to an internal function
Let's say I have a Dispatcher contract that delegates all function calls to an Implementation contract using delegatecall (see for example https://gist.github.com/Arachnid/...
