Improved variable assignment detection

IDE/Tests/CompileFail001/src/LocalVars.bf

@@ -342,5 +342,79 @@ namespace IDETest
 			int b3 = b; //FAIL
 			int c3 = c; //FAIL
 		}
+
+		Result<int> Read()
+		{
+		    return 0;
+		}
+
+		public void Local8()
+		{
+		    int read;
+		    loop: repeat
+		    {
+		        switch (Read())
+		        {
+		            case .Err: return;
+		            case .Ok(let val): read = val;
+		        }
+		    }
+		    while (read > 0);
+		}
+
+		public void Local9()
+		{
+		    int read;
+		    loop: repeat
+		    {
+		        switch (Read())
+		        {
+		            case .Err: break loop;
+		            case .Ok(let val): read = val;
+		        }
+				int a = read;
+		    }
+		    while (read > 0);
+		}
+
+		public void Local10()
+		{
+		    int read;
+		    loop: repeat
+		    {
+		        switch (Read())
+		        {
+		            case .Err: break;
+		            case .Ok(let val): read = val;
+		        }
+				int a = read; //FAIL
+		    }
+		    while (read > 0); //FAIL
+		}
+
+		public void Local11()
+		{
+			int a = 123;
+
+		    int read;
+		    Loop: repeat
+		    {
+		        break;
+		    }
+		    while (read > 0);
+		}
+
+		public void Local12()
+		{
+			int a = 123;
+
+		    int read;
+		    Loop: repeat
+		    {
+				if (a == 123)
+		        	break;
+		    }
+		    while (read > 0); //FAIL
+		}
 	}
 }

IDEHelper/Compiler/BfExprEvaluator.cpp

@@ -18952,6 +18952,8 @@ void BfExprEvaluator::CheckResultForReading(BfTypedValue& typedValue)
 								undefinedFieldFlags = 0;
 						}
 					}
+					if (deferredLocalAssignData->mLeftBlockUncond)
+						isAssigned = true;
 				}
 
 				if (fieldIdx == -1)

IDEHelper/Compiler/BfModule.cpp

@@ -133,48 +133,61 @@ void BfDeferredLocalAssignData::BreakExtendChain()
 void BfDeferredLocalAssignData::SetIntersection(const BfDeferredLocalAssignData& otherLocalAssignData)
 {	
 	BreakExtendChain();
-
+	
-	for (int i = 0; i < (int)mAssignedLocals.size(); )
+	if (otherLocalAssignData.mLeftBlockUncond)
 	{
-		auto& local = mAssignedLocals[i];
+		// Intersection of self and infinity is self
-
+	}
-		bool wantRemove = true;
+	else if (mLeftBlockUncond)
-		bool foundOtherFields = false;
+	{
-		for (auto& otherLocalAssignData : otherLocalAssignData.mAssignedLocals)
+		// Intersection of infinity and other is other
+		mAssignedLocals = otherLocalAssignData.mAssignedLocals;
+	}
+	else
+	{
+		for (int i = 0; i < (int)mAssignedLocals.size(); )
 		{
-			if (otherLocalAssignData.mLocalVar == local.mLocalVar)
+			auto& local = mAssignedLocals[i];
-			{
-				if ((otherLocalAssignData.mLocalVarField == local.mLocalVarField) || (otherLocalAssignData.mLocalVarField == -1))
-				{
-					if (otherLocalAssignData.mAssignKind == BfLocalVarAssignKind_Conditional)
-						local.mAssignKind = BfLocalVarAssignKind_Conditional;
-					wantRemove = false;
-				}
-				else
-					foundOtherFields = true;
-			}
-		}
 
-		if ((wantRemove) && (foundOtherFields))
+			bool wantRemove = true;
-		{
+			bool foundOtherFields = false;
 			for (auto& otherLocalAssignData : otherLocalAssignData.mAssignedLocals)
 			{
 				if (otherLocalAssignData.mLocalVar == local.mLocalVar)
 				{
-					mAssignedLocals.Add(otherLocalAssignData);
+					if ((otherLocalAssignData.mLocalVarField == local.mLocalVarField) || (otherLocalAssignData.mLocalVarField == -1))
+					{
+						if (otherLocalAssignData.mAssignKind == BfLocalVarAssignKind_Conditional)
+							local.mAssignKind = BfLocalVarAssignKind_Conditional;
+						wantRemove = false;
+					}
+					else
+						foundOtherFields = true;
 				}
 			}
-		}
 
-		if (wantRemove)
+			if ((wantRemove) && (foundOtherFields))
-		{
+			{
-			mAssignedLocals.RemoveAt(i);
+				for (auto& otherLocalAssignData : otherLocalAssignData.mAssignedLocals)
+				{
+					if (otherLocalAssignData.mLocalVar == local.mLocalVar)
+					{
+						mAssignedLocals.Add(otherLocalAssignData);
+					}
+				}
+			}
+
+			if (wantRemove)
+			{
+				mAssignedLocals.RemoveAt(i);
+			}
+			else
+				i++;
 		}
-		else
-			i++;
 	}
 
 	mHadFallthrough = mHadFallthrough && otherLocalAssignData.mHadFallthrough;
+	mLeftBlockUncond = mLeftBlockUncond && otherLocalAssignData.mLeftBlockUncond;	
 }
 
 void BfDeferredLocalAssignData::Validate() const
@@ -191,7 +204,7 @@ void BfDeferredLocalAssignData::SetUnion(const BfDeferredLocalAssignData& otherL
 
 	Validate();
 	otherLocalAssignData.Validate();
-
+	
 	auto otherItr = otherLocalAssignData.mAssignedLocals.begin();
 	while (otherItr != otherLocalAssignData.mAssignedLocals.end())
 	{		
@@ -200,6 +213,7 @@ void BfDeferredLocalAssignData::SetUnion(const BfDeferredLocalAssignData& otherL
 		++otherItr;
 	}
 	mHadFallthrough = mHadFallthrough || otherLocalAssignData.mHadFallthrough;
+	mLeftBlockUncond = mLeftBlockUncond || otherLocalAssignData.mLeftBlockUncond;
 }
 
 BfMethodState::~BfMethodState()
@@ -311,9 +325,36 @@ void BfMethodState::ApplyDeferredLocalAssignData(const BfDeferredLocalAssignData
 {
 	BF_ASSERT(&deferredLocalAssignData != mDeferredLocalAssignData);
 
-	for (auto& assignedLocal : deferredLocalAssignData.mAssignedLocals)
+	if (deferredLocalAssignData.mLeftBlockUncond)
 	{
-		LocalDefined(assignedLocal.mLocalVar, assignedLocal.mLocalVarField, assignedLocal.mAssignKind, true);
+		if (mLeftBlockUncond)
+		{
+			for (int localIdx = 0; localIdx < (int)mLocals.size(); localIdx++)
+			{
+				auto localDef = mLocals[localIdx];
+				if (localDef->mAssignedKind == BfLocalVarAssignKind_None)
+				{
+					bool hadAssignment = false;
+					if (mDeferredLocalAssignData != NULL)
+					{
+						for (auto& entry : mDeferredLocalAssignData->mAssignedLocals)
+							if (entry.mLocalVar == localDef)
+								hadAssignment = true;
+					}
+					if (!hadAssignment)
+					{						
+						LocalDefined(localDef);
+					}
+				}
+			}
+		}
+	}
+	else
+	{
+		for (auto& assignedLocal : deferredLocalAssignData.mAssignedLocals)
+		{
+			LocalDefined(assignedLocal.mLocalVar, assignedLocal.mLocalVarField, assignedLocal.mAssignKind, true);
+		}
 	}
 }
 

IDEHelper/Compiler/BfModule.h

@@ -378,6 +378,7 @@ public:
 	bool mIsIfCondition;
 	bool mIfMayBeSkipped;
 	bool mLeftBlock;	
+	bool mLeftBlockUncond;
 
 public:
 	BfDeferredLocalAssignData(BfScopeData* scopeData = NULL)
@@ -393,6 +394,7 @@ public:
 		mIsIfCondition = false;
 		mIfMayBeSkipped = false;
 		mLeftBlock = false;
+		mLeftBlockUncond = false;
 	}
 	
 	bool Contains(const BfAssignedLocal& val)
@@ -448,6 +450,7 @@ public:
 	bool mInInitBlock;
 	bool mSupressNextUnreachable;
 	bool mInConstIgnore;
+	bool mIsSharedTempBlock;
 	BfMixinState* mMixinState;
 	BfBlock* mAstBlock;
 	BfAstNode* mCloseNode;
@@ -488,6 +491,7 @@ public:
 		mAllowVariableDeclarations = true;
 		mInInitBlock = false;
 		mInConstIgnore = false;
+		mIsSharedTempBlock = false;
 		mMixinDepth = 0;
 		mScopeDepth = 0;
 		mScopeLocalId = -1;
@@ -1668,7 +1672,7 @@ public:
 	void AddBasicBlock(BfIRBlock bb, bool activate = true);	
 	void VisitEmbeddedStatement(BfAstNode* stmt, BfExprEvaluator* exprEvaluator = NULL, BfEmbeddedStatementFlags flags = BfEmbeddedStatementFlags_None);
 	void VisitCodeBlock(BfBlock* block);
-	void VisitCodeBlock(BfBlock* block, BfIRBlock continueBlock, BfIRBlock breakBlock, BfIRBlock fallthroughBlock, bool defaultBreak, bool* hadReturn = NULL, BfLabelNode* labelNode = NULL, bool closeScope = false);	
+	void VisitCodeBlock(BfBlock* block, BfIRBlock continueBlock, BfIRBlock breakBlock, BfIRBlock fallthroughBlock, bool defaultBreak, bool* hadReturn = NULL, BfLabelNode* labelNode = NULL, bool closeScope = false, BfEmbeddedStatementFlags flags = BfEmbeddedStatementFlags_None);
 	void DoForLess(BfForEachStatement* forEachStmt);
 
 	// Util

IDEHelper/Compiler/BfStmtEvaluator.cpp

@@ -3297,7 +3297,7 @@ void BfModule::VisitEmbeddedStatement(BfAstNode* stmt, BfExprEvaluator* exprEval
 		mCurMethodState->mCurScope->mOuterIsConditional = (flags & BfEmbeddedStatementFlags_IsConditional) != 0;
 		mCurMethodState->mCurScope->mIsDeferredBlock = (flags & BfEmbeddedStatementFlags_IsDeferredBlock) != 0;
 		mCurMethodState->mCurScope->mExprEvaluator = exprEvaluator;		
-		
+
 		//
 		{
 			SetAndRestoreValue<bool> inDeferredBlock(mCurMethodState->mInDeferredBlock, mCurMethodState->mInDeferredBlock || mCurMethodState->mCurScope->mIsDeferredBlock);
@@ -3345,7 +3345,7 @@ void BfModule::VisitEmbeddedStatement(BfAstNode* stmt, BfExprEvaluator* exprEval
 	}
 }
 
-void BfModule::VisitCodeBlock(BfBlock* block, BfIRBlock continueBlock, BfIRBlock breakBlock, BfIRBlock fallthroughBlock, bool defaultBreak, bool* hadReturn, BfLabelNode* labelNode, bool closeScope)
+void BfModule::VisitCodeBlock(BfBlock* block, BfIRBlock continueBlock, BfIRBlock breakBlock, BfIRBlock fallthroughBlock, bool defaultBreak, bool* hadReturn, BfLabelNode* labelNode, bool closeScope, BfEmbeddedStatementFlags flags)
 {
 	BfBreakData breakData;
 	breakData.mIRContinueBlock = continueBlock;
@@ -3355,7 +3355,7 @@ void BfModule::VisitCodeBlock(BfBlock* block, BfIRBlock continueBlock, BfIRBlock
 	breakData.mPrevBreakData = mCurMethodState->mBreakData;
 
 	SetAndRestoreValue<BfBreakData*> prevBreakData(mCurMethodState->mBreakData, &breakData);
-	Visit(block);
+	VisitEmbeddedStatement(block, NULL, flags);
 
 	if (closeScope)	
 		RestoreScopeState();
@@ -3843,7 +3843,8 @@ void BfModule::DoIfStatement(BfIfStatement* ifStmt, bool includeTrueStmt, bool i
 			ignoredLastBlock = false;
 		VisitEmbeddedStatement(ifStmt->mTrueStatement);
 	}
-	prevDLA.Restore();
+	prevDLA.Restore();	
+
 	if (mCurMethodState->mDeferredLocalAssignData != NULL)
 		mCurMethodState->mDeferredLocalAssignData->mHadBreak |= deferredLocalAssignData.mHadBreak;
 
@@ -3858,7 +3859,10 @@ void BfModule::DoIfStatement(BfIfStatement* ifStmt, bool includeTrueStmt, bool i
 		mBfIRBuilder->CreateBr_NoCollapse(contBB);
 
 	if (mCurMethodState->mLeftBlockUncond)
+	{
+		deferredLocalAssignData.mLeftBlockUncond = true;
 		mCurMethodState->mLeftBlockCond = true;
+	}
 
 	mCurMethodState->mLeftBlockUncond = false;
 	mCurMethodState->SetHadReturn(false);
@@ -3908,7 +3912,10 @@ void BfModule::DoIfStatement(BfIfStatement* ifStmt, bool includeTrueStmt, bool i
 		}
 		falseHadReturn = mCurMethodState->mHadReturn;
 		if (mCurMethodState->mLeftBlockUncond)
+		{
+			falseDeferredLocalAssignData.mLeftBlockUncond = true;
 			mCurMethodState->mLeftBlockCond = true;
+		}
 		mCurMethodState->mLeftBlockUncond = false;
 		mCurMethodState->SetHadReturn(false);
 
@@ -4633,6 +4640,7 @@ void BfModule::Visit(BfSwitchStatement* switchStmt)
 				openedScope = true;
 
 				caseScopeData.mOuterIsConditional = true;
+				caseScopeData.mIsSharedTempBlock = true;
 				mCurMethodState->AddScope(&caseScopeData);
 				NewScopeState();
 				UpdateSrcPos(caseExpr);				
@@ -4915,7 +4923,8 @@ void BfModule::Visit(BfSwitchStatement* switchStmt)
 		{
 			UpdateSrcPos(switchCase->mCodeBlock);			
 
-			VisitCodeBlock(switchCase->mCodeBlock, BfIRBlock(), endBlock, fallthroughBlock, true, &hadReturn, switchStmt->mLabelNode, openedScope);
+			VisitCodeBlock(switchCase->mCodeBlock, BfIRBlock(), endBlock, fallthroughBlock, true, &hadReturn, switchStmt->mLabelNode, openedScope /*, BfEmbeddedStatementFlags_RescopeDLA*/);
+
 			openedScope = false;
 			deferredLocalAssignDataVec[blockIdx].mHadReturn = hadReturn;
 			caseCount++;
@@ -4953,7 +4962,7 @@ void BfModule::Visit(BfSwitchStatement* switchStmt)
 
 		mBfIRBuilder->SetInsertPoint(prevInsertBlock);
 		
-		prevHadFallthrough = mCurMethodState->mDeferredLocalAssignData->mHadFallthrough;
+		prevHadFallthrough = mCurMethodState->mDeferredLocalAssignData->mHadFallthrough;		
 
 		blockIdx++;
 	}
@@ -5053,7 +5062,7 @@ void BfModule::Visit(BfSwitchStatement* switchStmt)
 			mCurMethodState->mDeferredLocalAssignData->mVarIdBarrier = startingLocalVarId;
 
 			bool hadReturn = false;
-			VisitCodeBlock(switchCase->mCodeBlock, BfIRBlock(), endBlock, BfIRBlock(), true, &hadReturn, switchStmt->mLabelNode);		
+			VisitCodeBlock(switchCase->mCodeBlock, BfIRBlock(), endBlock, BfIRBlock(), true, &hadReturn, switchStmt->mLabelNode);
 			deferredLocalAssignDataVec[blockIdx].mHadReturn = hadReturn;
 			caseCount++;
 			if (!hadReturn)
@@ -5381,18 +5390,7 @@ void BfModule::Visit(BfBreakStatement* breakStmt)
 			checkScope = checkScope->mPrevScope;
 		}
 	}
-
+	
-	auto checkLocalAssignData = mCurMethodState->mDeferredLocalAssignData;
-	while (checkLocalAssignData != NULL)
-	{
-		if ((checkLocalAssignData->mScopeData != NULL) && (checkLocalAssignData->mScopeData->mScopeDepth >= breakData->mScope->mScopeDepth))
-		{
-			checkLocalAssignData->mLeftBlock = true;
-			checkLocalAssignData->mHadBreak = true;
-		}
-		checkLocalAssignData = checkLocalAssignData->mChainedAssignData;
-	}
-
 	if (HasDeferredScopeCalls(breakData->mScope))
 	{		
 		EmitDeferredScopeCalls(true, breakData->mScope, breakData->mIRBreakBlock);
@@ -5403,16 +5401,41 @@ void BfModule::Visit(BfBreakStatement* breakStmt)
 	}
 	mCurMethodState->mLeftBlockUncond = true;	
 
+	bool isCond = false;
+	int uncondScopeDepth = 0;
+	if (mCurMethodState->mCurScope != NULL)
+		uncondScopeDepth = mCurMethodState->mCurScope->mScopeDepth + 1;
+
 	BfIRValue earliestValueScopeStart;	
 	auto checkScope = mCurMethodState->mCurScope;
 	while (checkScope != NULL)
-	{		
+	{	
+		if (!isCond)
+			uncondScopeDepth = checkScope->mScopeDepth;
+		if ((checkScope->mOuterIsConditional) && (!checkScope->mIsSharedTempBlock))
+			isCond = true;
+
 		if (checkScope->mValueScopeStart)
 			earliestValueScopeStart = checkScope->mValueScopeStart;
 		if (checkScope == breakData->mScope)
 			break;
+		
 		checkScope = checkScope->mPrevScope;
 	}
+
+	auto checkLocalAssignData = mCurMethodState->mDeferredLocalAssignData;
+	while (checkLocalAssignData != NULL)
+	{
+		if ((checkLocalAssignData->mScopeData != NULL) && (checkLocalAssignData->mScopeData->mScopeDepth >= breakData->mScope->mScopeDepth))
+		{
+			if (checkLocalAssignData->mScopeData->mScopeDepth >= uncondScopeDepth)
+				checkLocalAssignData->mLeftBlockUncond = true;
+			checkLocalAssignData->mLeftBlock = true;
+			checkLocalAssignData->mHadBreak = true;
+		}
+		checkLocalAssignData = checkLocalAssignData->mChainedAssignData;
+	}
+
 	MarkScopeLeft(breakData->mScope);
 	ValueScopeEnd(earliestValueScopeStart);	
 
@@ -5734,11 +5757,18 @@ void BfModule::Visit(BfRepeatStatement* repeatStmt)
 
 	mBfIRBuilder->CreateBr(bodyBB);
 	mBfIRBuilder->SetInsertPoint(bodyBB);	
-	scopeData.mIsLoop = true;
+	scopeData.mIsLoop = true;	
-	VisitEmbeddedStatement(repeatStmt->mEmbeddedStatement);	
+
+	BfDeferredLocalAssignData deferredLocalAssignData(mCurMethodState->mCurScope);
+	deferredLocalAssignData.ExtendFrom(mCurMethodState->mDeferredLocalAssignData, false);
+	deferredLocalAssignData.mVarIdBarrier = mCurMethodState->GetRootMethodState()->mCurLocalVarId;
+	SetAndRestoreValue<BfDeferredLocalAssignData*> prevDLA(mCurMethodState->mDeferredLocalAssignData, &deferredLocalAssignData);
+
+	VisitEmbeddedStatement(repeatStmt->mEmbeddedStatement);
+
 	if (!mCurMethodState->mLeftBlockUncond)
 		mBfIRBuilder->CreateBr(condBB);
-	mCurMethodState->SetHadReturn(false);
+	mCurMethodState->SetHadReturn(false);	
 	mCurMethodState->mLeftBlockUncond = false;
 	mCurMethodState->mLeftBlockCond = false;