forward revert message from low level solidity call












1















I'm working on a proxy contract that will perform calls as follows:



bool success;
bytes memory returndata;
(success, returndata) = _to.call.value(_value)(_data);
require(success);


this works great, except that, if the call reverts with an error message, this function will simply reverts, hiding the reason string.



How can I retrieve the reason string (I assume in the returndata) and use if to revert properly










share|improve this question



























    1















    I'm working on a proxy contract that will perform calls as follows:



    bool success;
    bytes memory returndata;
    (success, returndata) = _to.call.value(_value)(_data);
    require(success);


    this works great, except that, if the call reverts with an error message, this function will simply reverts, hiding the reason string.



    How can I retrieve the reason string (I assume in the returndata) and use if to revert properly










    share|improve this question

























      1












      1








      1


      2






      I'm working on a proxy contract that will perform calls as follows:



      bool success;
      bytes memory returndata;
      (success, returndata) = _to.call.value(_value)(_data);
      require(success);


      this works great, except that, if the call reverts with an error message, this function will simply reverts, hiding the reason string.



      How can I retrieve the reason string (I assume in the returndata) and use if to revert properly










      share|improve this question














      I'm working on a proxy contract that will perform calls as follows:



      bool success;
      bytes memory returndata;
      (success, returndata) = _to.call.value(_value)(_data);
      require(success);


      this works great, except that, if the call reverts with an error message, this function will simply reverts, hiding the reason string.



      How can I retrieve the reason string (I assume in the returndata) and use if to revert properly







      solidity revert-opcode proxy-contracts






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Apr 1 at 14:02









      AmxxAmxx

      1185




      1185






















          1 Answer
          1






          active

          oldest

          votes


















          3














          It is simpler than you think:



          require(success, string (returndata));


          See documentation for details. You may also forward raw bytes, but you will need to use assembly.






          share|improve this answer
























          • I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

            – Amxx
            Apr 1 at 14:52












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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          3














          It is simpler than you think:



          require(success, string (returndata));


          See documentation for details. You may also forward raw bytes, but you will need to use assembly.






          share|improve this answer
























          • I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

            – Amxx
            Apr 1 at 14:52
















          3














          It is simpler than you think:



          require(success, string (returndata));


          See documentation for details. You may also forward raw bytes, but you will need to use assembly.






          share|improve this answer
























          • I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

            – Amxx
            Apr 1 at 14:52














          3












          3








          3







          It is simpler than you think:



          require(success, string (returndata));


          See documentation for details. You may also forward raw bytes, but you will need to use assembly.






          share|improve this answer













          It is simpler than you think:



          require(success, string (returndata));


          See documentation for details. You may also forward raw bytes, but you will need to use assembly.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Apr 1 at 14:31









          Mikhail VladimirovMikhail Vladimirov

          1,351316




          1,351316













          • I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

            – Amxx
            Apr 1 at 14:52



















          • I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

            – Amxx
            Apr 1 at 14:52

















          I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

          – Amxx
          Apr 1 at 14:52





          I tryed require(success, returndata); and started looking into assembly when it failled to compile ... thanks for proving how stupid I am :P

          – Amxx
          Apr 1 at 14:52


















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