setup GovLateQuorum and add 3 rules for deadlines

certora/specs/GovernorPreventLateQuorum.spec

@@ -0,0 +1,115 @@
+//////////////////////////////////////////////////////////////////////////////
+///////////////////// Governor.sol base definitions //////////////////////////
+//////////////////////////////////////////////////////////////////////////////
+
+using ERC721VotesHarness as erc20votes
+
+methods {
+    proposalSnapshot(uint256) returns uint256 envfree // matches proposalVoteStart
+    proposalDeadline(uint256) returns uint256 envfree // matches proposalVoteEnd
+    hashProposal(address[],uint256[],bytes[],bytes32) returns uint256 envfree
+    isExecuted(uint256) returns bool envfree
+    isCanceled(uint256) returns bool envfree
+    execute(address[], uint256[], bytes[], bytes32) returns uint256
+    hasVoted(uint256, address) returns bool
+    castVote(uint256, uint8) returns uint256
+    updateQuorumNumerator(uint256)
+    queue(address[], uint256[], bytes[], bytes32) returns uint256
+    quorumNumerator() returns uint256 envfree
+    quorumDenominator() returns uint256 envfree
+    votingPeriod() returns uint256 envfree
+    lateQuorumVoteExtension() returns uint64 envfree
+
+    // harness
+    getExtendedDeadlineIsUnset(uint256) returns bool envfree
+    getExtendedDeadline(uint256) returns uint64 envfree
+    quorumReached(uint256) returns bool envfree
+    latestCastVoteCall() returns uint256 envfree // more robust check than f.selector == _castVote(...).selector
+
+    // function summarization
+    proposalThreshold() returns uint256 envfree
+
+    getVotes(address, uint256) returns uint256 => DISPATCHER(true)
+
+    getPastTotalSupply(uint256 t) returns uint256      => PER_CALLEE_CONSTANT
+    getPastVotes(address a, uint256 t) returns uint256 => PER_CALLEE_CONSTANT
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//////////////////////////////// Definitions /////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////
+
+// create definition for extended
+definition deadlineCanBeExtended(uint256 id) returns bool = 
+    getExtendedDeadlineIsUnset(id) &&
+    getExtendedDeadline(id) == 0 && 
+    !quorumReached(id);
+
+definition deadlineHasBeenExtended(uint256 id) returns bool = 
+    !getExtendedDeadlineIsUnset(id) &&
+    getExtendedDeadline(id) > 0 &&
+    quorumReached(id);
+
+
+
+// RULE deadline can only be extended once
+    // 1. if deadline changes then we have state transition from deadlineCanBeExtended to deadlineHasBeenExtended
+rule deadlineChangeEffects(method f) filtered {f -> !f.isView /* bottleneck, restrict for faster testing && f.selector != propose(address[], uint256[], bytes[], string).selector*/ } {
+    env e; calldataarg args; uint256 id;
+
+    require (latestCastVoteCall() < e.block.number);
+    require (quorumNumerator() <= quorumDenominator());
+    require deadlineCanBeExtended(id);
+    require (proposalDeadline(id) < e.block.number 
+    && proposalDeadline(id) >= proposalSnapshot(id) + votingPeriod() 
+    && proposalSnapshot(id) > e.block.number); 
+    
+    uint256 deadlineBefore = proposalDeadline(id);
+    f(e, args);
+    uint256 deadlineAfter = proposalDeadline(id);
+    
+    assert(deadlineAfter > deadlineBefore => latestCastVoteCall() == e.block.number && deadlineHasBeenExtended(id));
+}
+
+    // 2. cant unextend
+rule deadlineCantBeUnextended(method f) filtered {f -> !f.isView /* && f.selector != propose(address[], uint256[], bytes[], string).selector*/ } {
+    env e; calldataarg args; uint256 id;
+    require(deadlineHasBeenExtended(id));
+    f(e, args);
+    assert(deadlineHasBeenExtended(id));
+}
+
+    // 3. extended => can't change deadline
+        //@note if deadline changed, then it wasnt extended and castvote was called
+rule canExtendDeadlineOnce(method f) filtered {f -> !f.isView /* && f.selector != propose(address[], uint256[], bytes[], string).selector*/ } {
+    env e; calldataarg args;
+    uint256 id;
+    require(deadlineHasBeenExtended(id)); // stays true
+    require (proposalDeadline(id) < e.block.number 
+    && proposalDeadline(id) >= proposalSnapshot(id) + votingPeriod() 
+    && proposalSnapshot(id) > e.block.number); 
+    uint256 deadlineBefore = proposalDeadline(id);
+    f(e, args);
+    uint256 deadlineAfter = proposalDeadline(id);
+    assert(deadlineBefore == deadlineAfter, "deadline can not be extended twice");
+}
+
+
+// RULE deadline can only extended if quorum reached w/ <= timeOfExtension left to vote
+// 3 rules
+    // 1. voting increases total votes
+    // 2. number of votes > quorum => quorum reached
+    // 3. deadline can only extended if quorum reached w/ <= timeOfExtension left to vote
+rule deadlineCanOnlyBeExtenededIfQuorumReached() {
+    env e; method f; calldataarg args;
+    uint256 id;
+    require(getExtendedDeadlineIsUnset(id));
+    f(e, args);
+    assert(false);
+}
+
+// RULE extendedDeadline is used iff quorum is reached w/ <= extensionTime left to vote
+
+// RULE extendedDeadlineField is set iff quroum is reached 
+
+// RULE if the deadline/extendedDeadline has not been reached, you can still vote (base)