Fix warnings in unreachable code

oscar64/Declaration.cpp

@@ -898,11 +898,19 @@ Expression* Expression::ConstantFold(Errors * errors, LinkerSection * dataSectio
 		{
 			int64	ival = 0, ileft = mLeft->mDecValue->mInteger, iright = mRight->mDecValue->mInteger;
 
-			bool	signop =
+			Declaration* dtype = TheSignedIntTypeDeclaration;
-				(mLeft->mDecValue->mBase->mSize < 2 || (mLeft->mDecValue->mBase->mFlags & DTF_SIGNED)) &&
+			if (mLeft->mDecValue->mBase->mSize > mRight->mDecValue->mBase->mSize)
-				(mRight->mDecValue->mBase->mSize < 2 || (mRight->mDecValue->mBase->mFlags & DTF_SIGNED));
+				dtype = mLeft->mDecValue->mBase;
+			else if (mLeft->mDecValue->mBase->mSize < mRight->mDecValue->mBase->mSize)
+				dtype = mRight->mDecValue->mBase;
+			else if (mLeft->mDecValue->mBase->mSize > 1)
+			{
+				if ((mLeft->mDecValue->mBase->mFlags & DTF_SIGNED) && !(mRight->mDecValue->mBase->mFlags & DTF_SIGNED))
+					dtype = mRight->mDecValue->mBase;
+				else
+					dtype = mLeft->mDecValue->mBase;
+			}
 
-			bool	promote = true;
 			switch (mToken)
 			{
 			case TK_ADD:
@@ -916,27 +924,25 @@ Expression* Expression::ConstantFold(Errors * errors, LinkerSection * dataSectio
 				break;
 			case TK_DIV:
 				if (iright == 0)
-					errors->Error(mLocation, EERR_INVALID_VALUE, "Constant division by zero");
+					return this;
-				else if (signop)
+				else if (dtype->mFlags & DTF_SIGNED)
 					ival = ileft / iright;
 				else
 					ival = (uint64)ileft / (uint64)iright;
 				break;
 			case TK_MOD:
 				if (iright == 0)
-					errors->Error(mLocation, EERR_INVALID_VALUE, "Constant division by zero");
+					return this;
-				else if (signop)
+				else if (dtype->mFlags & DTF_SIGNED)
 					ival = ileft % iright;
 				else
 					ival = (uint64)ileft % (uint64)iright;
 				break;
 			case TK_LEFT_SHIFT:
 				ival = ileft << iright;
-				promote = false;
 				break;
 			case TK_RIGHT_SHIFT:
 				ival = ileft >> iright;
-				promote = false;
 				break;
 			case TK_BINARY_AND:
 				ival = ileft & iright;
@@ -953,29 +959,14 @@ Expression* Expression::ConstantFold(Errors * errors, LinkerSection * dataSectio
 
 			Expression* ex = new Expression(mLocation, EX_CONSTANT);
 			Declaration* dec = new Declaration(mLocation, DT_CONST_INTEGER);
-			if (promote)
+			dec->mBase = dtype;
-			{
+			dec->mInteger = signextend(ival, dec->mBase);
-				if (mLeft->mDecValue->mBase->mSize <= 2 && mRight->mDecValue->mBase->mSize <= 2)
-					dec->mBase = ival < 32768 ? TheSignedIntTypeDeclaration : TheUnsignedIntTypeDeclaration;
-				else
-					dec->mBase = ival < 2147483648 ? TheSignedLongTypeDeclaration : TheUnsignedLongTypeDeclaration;
-			}
-			else
-			{
-				if (mLeft->mDecValue->mBase->mSize < 2)
-					dec->mBase = TheSignedIntTypeDeclaration;
-				else
-					dec->mBase = mLeft->mDecValue->mBase;
-			}
-
-			dec->mInteger = ival;
 			ex->mDecValue = dec;
 			ex->mDecType = dec->mBase;
 			return ex;
 		}
 		else if ((mLeft->mDecValue->mType == DT_CONST_INTEGER || mLeft->mDecValue->mType == DT_CONST_FLOAT) && (mRight->mDecValue->mType == DT_CONST_INTEGER || mRight->mDecValue->mType == DT_CONST_FLOAT))
 		{
-
 			double	dval;
 			double	dleft = mLeft->mDecValue->mType == DT_CONST_INTEGER ? mLeft->mDecValue->mInteger : mLeft->mDecValue->mNumber;
 			double	dright = mRight->mDecValue->mType == DT_CONST_INTEGER ? mRight->mDecValue->mInteger : mRight->mDecValue->mNumber;

oscar64/Errors.cpp

@@ -4,11 +4,18 @@
 #include <stdlib.h>
 
 Errors::Errors(void)
-	: mErrorCount(0)
+	: mErrorCount(0), mMinLevel(EINFO_GENERIC)
 {
 
 }
 
+ErrorID	Errors::SetMinLevel(ErrorID id)
+{
+	ErrorID	pid = mMinLevel;
+	mMinLevel = id;
+	return pid;
+}
+
 void Errors::Error(const Location& loc, ErrorID eid, const char* msg, const Ident* info1, const Ident* info2)
 {
 	if (!info1)
@@ -21,6 +28,8 @@ void Errors::Error(const Location& loc, ErrorID eid, const char* msg, const Iden
 
 
 void Errors::Error(const Location& loc, ErrorID eid, const char* msg, const char* info1, const char * info2) 
+{
+	if (eid >= mMinLevel)
 	{
 		const char* level = "info";
 		if (eid >= EERR_GENERIC)
@@ -58,5 +67,6 @@ void Errors::Error(const Location& loc, ErrorID eid, const char* msg, const char
 		if (mErrorCount > 10 || eid >= EFATAL_GENERIC)
 			exit(20);
 	}
+}
 
 

oscar64/Errors.h

@@ -45,6 +45,7 @@ enum ErrorID
 	EWARN_INSUFFICIENT_MEMORY,
 	EWARN_FUNCTION_NOT_INLINED,
 	EWARN_INVALID_VOID_POINTER_ARITHMETIC,
+	EWARN_DIVISION_BY_ZERO,
 
 	EERR_GENERIC = 3000,
 	EERR_FILE_NOT_FOUND,
@@ -129,7 +130,11 @@ class Errors
 public:
 	Errors(void);
 
+	ErrorID	SetMinLevel(ErrorID id);
+
 	int		mErrorCount;
+	ErrorID	mMinLevel;
+
 
 	void Error(const Location& loc, ErrorID eid, const char* msg, const Ident* info1, const Ident* info2 = nullptr);
 	void Error(const Location& loc, ErrorID eid, const char* msg, const char* info1 = nullptr, const char* info2 = nullptr);

oscar64/GlobalOptimizer.cpp

@@ -243,6 +243,19 @@ bool GlobalOptimizer::ReplaceParamConst(Expression* exp, Declaration* param)
 	bool	changed = false;
 	if (exp)
 	{
+		if (ReplaceParamConst(exp->mLeft, param))
+			changed = true;
+		if (ReplaceParamConst(exp->mRight, param))
+			changed = true;
+
+		if (changed)
+		{
+			if (exp->mLeft)
+				exp->mLeft = exp->mLeft->ConstantFold(mErrors, nullptr);
+			if (exp->mRight)
+				exp->mRight = exp->mRight->ConstantFold(mErrors, nullptr);
+		}
+
 		if (exp->mType == EX_VARIABLE && exp->mDecValue == param)
 		{
 			exp->mType = EX_CONSTANT;
@@ -251,10 +264,6 @@ bool GlobalOptimizer::ReplaceParamConst(Expression* exp, Declaration* param)
 			changed = true;
 		}
 
-		if (ReplaceParamConst(exp->mLeft, param))
-			changed = true;
-		if (ReplaceParamConst(exp->mRight, param))
-			changed = true;
 	}
 	return changed;
 }
@@ -382,6 +391,7 @@ bool GlobalOptimizer::Optimize(void)
 						{
 							if (ReplaceParamConst(func->mValue, pdec))
 							{
+								func->mValue = func->mValue->ConstantFold(mErrors, nullptr);
 #if DUMP_OPTS
 								printf("Const parameter %s\n", pdec->mIdent ? pdec->mIdent->mString : "_");
 #endif

oscar64/InterCodeGenerator.cpp

@@ -3181,9 +3181,13 @@ InterCodeGenerator::ExValue InterCodeGenerator::TranslateExpression(Declaration*
 					break;
 				case TK_DIV:
 					ins->mOperator = signedOP ? IA_DIVS : IA_DIVU;
+					if (exp->mRight->mType == EX_CONSTANT && exp->mRight->mDecValue->mType == DT_CONST_INTEGER && exp->mRight->mDecValue->mInteger == 0)
+						mErrors->Error(exp->mLocation, EWARN_DIVISION_BY_ZERO, "Constant division by zero");
 					break;
 				case TK_MOD:
 					ins->mOperator = signedOP ? IA_MODS : IA_MODU;
+					if (exp->mRight->mType == EX_CONSTANT && exp->mRight->mDecValue->mType == DT_CONST_INTEGER && exp->mRight->mDecValue->mInteger == 0)
+						mErrors->Error(exp->mLocation, EWARN_DIVISION_BY_ZERO, "Constant division by zero");
 					break;
 				case TK_LEFT_SHIFT:
 					ins->mOperator = IA_SHL;
@@ -5349,19 +5353,36 @@ InterCodeGenerator::ExValue InterCodeGenerator::TranslateExpression(Declaration*
 			TranslateLogic(procType, proc, block, tblock, fblock, exp->mLeft, destack, gotos, inlineMapper);
 
 			DestructStack* itdestack = destack;
+			ErrorID	eid;
+			
+			bool	alwaysTrue = false, alwaysFalse = false;
+			if (exp->mLeft->mType == EX_CONSTANT && exp->mLeft->mDecValue->mType == DT_CONST_INTEGER)
+			{
+				alwaysTrue = exp->mLeft->mDecValue->mInteger != 0;
+				alwaysFalse = exp->mLeft->mDecValue->mInteger == 0;
+			}
+			
+			if (alwaysFalse)
+				eid = mErrors->SetMinLevel(EERR_GENERIC);
 			vr = TranslateExpression(procType, proc, tblock, exp->mRight->mLeft, destack, gotos, breakBlock, continueBlock, inlineMapper);
 			UnwindDestructStack(procType, proc, tblock, destack, itdestack, inlineMapper);
 			destack = itdestack;
+			if (alwaysFalse)
+				mErrors->SetMinLevel(eid);
 
 			tblock->Append(jins0);
 			tblock->Close(eblock, nullptr);
 
 			if (exp->mRight->mRight)
 			{
+				if (alwaysTrue)
+					eid = mErrors->SetMinLevel(EERR_GENERIC);
 				DestructStack* ifdestack = destack;
 				vr = TranslateExpression(procType, proc, fblock, exp->mRight->mRight, destack, gotos, breakBlock, continueBlock, inlineMapper);
 				UnwindDestructStack(procType, proc, fblock, destack, ifdestack, inlineMapper);
 				destack = ifdestack;
+				if (alwaysTrue)
+					mErrors->SetMinLevel(eid);
 			}
 			fblock->Append(jins1);
 			fblock->Close(eblock, nullptr);