ICE during Natspec generation when emitting an event from a foreign contract or interface

[Amxx]

I moves the OZ contract repo to 0.8.21 to benefit from the new language features, but I'm getting the following error:

Internal exception in StandardCompiler::compile: /solidity/libsolidity/interface/Natspec.cpp(85): Throw in function static Json::Value solidity::frontend::Natspec::userDocumentation(const solidity::frontend::ContractDefinition&)
Dynamic exception type: boost::wrapexcept<solidity::langutil::InternalCompilerError>
std::exception::what: Solidity assertion failed
[solidity::util::tag_comment*] = Solidity assertion failed

Environment

• Compiler version: 0.8.21
• Target EVM version (as per compiler settings): shanghai
• Framework/IDE (e.g. Truffle or Remix): hardhat
• EVM execution environment / backend / blockchain client: hardhat node
• Operating system: linux

Steps to Reproduce

Minimal example:

// SPDX-License-Identifier: MIT
pragma solidity 0.8.21;

interface I {
    event E();
}

library L {
    function f() internal {
        emit I.E();
    }
}

contract C {
    function g() public {
        L.f();
    }
}

[Amxx]

This is the assert that fails:

solAssert(
	*eventOrigin == _contractDef ||
	(!eventOrigin->isLibrary() && _contractDef.derivesFrom(*eventOrigin)) ||
	(eventOrigin->isLibrary() && !_contractDef.derivesFrom(*eventOrigin))
);

In my case the event is declared in an interface and used (emited) by a library. Please don't tell me that is not supported ...

[blitz-1306]

This happends when using WASM and linux-native compilers.

[blitz-1306]

@Amxx It is not only libraries. I get the same error with even more minimalistic example:

// SPDX-License-Identifier: MIT
pragma solidity 0.8.21;

contract X {
    event E();
}

contract C {
    function g() public {
        emit X.E();
    }
}

Results:

Internal exception in StandardCompiler::compile: /solidity/libsolidity/interface/Natspec.cpp(89): Throw in function static Json::Value solidity::frontend::Natspec::userDocumentation(const ContractDefinition &)
Dynamic exception type: boost::wrapexcept<solidity::langutil::InternalCompilerError>
std::exception::what: Solidity assertion failed
[solidity::util::tag_comment*] = Solidity assertion failed

It seems to happen when event is referenced with qualifier.

[nikola-matic]

This is the assert that fails:

solAssert(
	*eventOrigin == _contractDef ||
	(!eventOrigin->isLibrary() && _contractDef.derivesFrom(*eventOrigin)) ||
	(eventOrigin->isLibrary() && !_contractDef.derivesFrom(*eventOrigin))
);

In my case the event is declared in an interface and used (emited) by a library. Please don't tell me that is not supported ...

Heya, so obviously, the compiler throwing an ICE is generally going to be considered a bug - however, the snippets that both you and @blitz-1306 posted do compile without throwing an ICE. Also, looking at the ICE, it's thrown in Natspec, and I can reproduce it by requesting user docs, i.e. solc --userdoc test.sol, so it's more of a Natspec bug than an event bug by the looks of it.

In any case, fix is on the way.

edit: same issue is present when requesting --devdoc, due to the same failing assertion.

[pcaversaccio]

You claim that compilation works fine but I'm having a hard time making a contract compile (without userdoc or devdoc), however; let's take the following contract (Test.sol):

// SPDX-License-Identifier: MIT
pragma solidity 0.8.21;

contract X {
    event E();
}

contract C {
    function g() public {
        emit X.E();
    }
}

Now invoking something like solc --asm .\Test.sol (not requesting userdoc nor devdoc), will still throw:

Internal compiler error:
C:\Users\circleci\project\libsolidity\interface\Natspec.cpp(89): Throw in function class Json::Value __cdecl solidity::frontend::Natspec::userDocumentation(const class solidity::frontend::ContractDefinition &)
Dynamic exception type: struct boost::wrapexcept<struct solidity::langutil::InternalCompilerError>
std::exception::what: Solidity assertion failed
[struct solidity::util::tag_comment * __ptr64] = Solidity assertion failed

Can you elaborate on what am doing wrong? The version I used is the Windows one 0.8.21+commit.d9974bed.Windows.msvc but I get the similar behaviour on Ubuntu & Debian.

[pcaversaccio]

Cross-posting the answer by @nikola-matic here for clarity:

In that case nothing - essentially, any steps that require userdoc or devdoc (asm, metadata, etc.) will indeed fail - I was just commenting in case you just read the issue and didn't try to compile anything. I guess you'll have to wait for the 0.8.22 release like most everyone else :)