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tjade273/generic_proxy.sol

Forked from holiman/generic_proxy.sol
Created June 20, 2016 20:14
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  1. @holiman holiman created this gist Jun 15, 2016.
    58 changes: 58 additions & 0 deletions generic_proxy.sol
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,58 @@

    contract complex{
    address add;
    uint aa;
    uint bb;

    function thrower()
    {
    throw;
    }
    function toggle() returns(uint){
    if (aa > 0) aa=0;
    else aa =1;
    if (bb > 0) bb=0;
    else bb = 1;
    return 0x1337;
    }
    }

    contract proxy{
    address add;
    uint aa;
    uint bb;

    function proxy(address a){
    add = a;
    }
    function (){
    assembly{

    //gas needs to be uint:ed
    let g := and(gas,0xEFFFFFFF)
    let o_code := mload(0x40) //Memory end
    //Address also needs to be masked
    //Also, important, storage location must be correct
    // sload(0) is dependant on the order of declaration above
    let addr := and(sload(0),0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF) //Dest address
    //Get call data (method sig & params)
    calldatacopy(o_code, 0, calldatasize)
    //callcode(
    let retval := call(g
    , addr //address
    , 0 //value
    , o_code //mem in
    , calldatasize //mem_insz
    , o_code //reuse mem
    , 32) //We expect no return data

    // Check return value
    // 0 == it threw, so we do aswell by jumping to
    // bad destination (02)
    jumpi(0x02,iszero(retval))

    // return(p,s) : end execution, return data mem[p..(p+s))
    return(o_code,32)
    }
    }
    }