This release contains several new features and bugfixes and also an important security fix: The ecrecover function can be forced to return invalid data, which can be used to bypass authentication in very special circumstances.


  • C API (jsonCompiler): Export the license method.
  • Code Generator: Optimise the fallback function, by removing a useless jump.
  • Inline Assembly: Show useful error message if trying to access calldata variables.
  • Inline Assembly: Support variable declaration without initial value (defaults to 0).
  • Metadata: Only include files which were used to compile the given contract.
  • Type Checker: Disallow value transfers to contracts without a payable fallback function.
  • Type Checker: Include types in explicit conversion error message.
  • Type Checker: Raise proper error for arrays too large for ABI encoding.
  • Type checker: Warn if using this in a constructor.
  • Type checker: Warn when existing symbols, including builtins, are overwritten.


  • Code Generator: Properly clear return memory area for ecrecover.
  • Type Checker: Fix crash for some assignment to non-lvalue.
  • Type Checker: Fix invalid “specify storage keyword” warning for reference members of structs.
  • Type Checker: Mark modifiers as internal.
  • Type Checker: Re-allow multiple mentions of the same modifier per function.

A big thank you to all contributors who helped make this release possible!

Download the new version of Solidity here.