Use automatic allocation and std::move for RPN bytes (#1336)

src/asm/rpn.cpp

@@ -29,7 +29,7 @@ static void initExpression(Expression &expr) {
 	expr.reason.clear();
 	expr.isKnown = true;
 	expr.isSymbol = false;
-	expr.rpn = nullptr;
+	expr.rpn.clear();
 	expr.rpnPatchSize = 0;
 }
 
@@ -42,21 +42,14 @@ static void makeUnknown(Expression &expr, Ts... parts) {
 }
 
 static uint8_t *reserveSpace(Expression &expr, uint32_t size) {
-	if (!expr.rpn) {
-		expr.rpn = new (std::nothrow) std::vector<uint8_t>();
-		if (!expr.rpn)
-			fatalerror("Failed to allocate RPN expression: %s\n", strerror(errno));
-	}
+	size_t curSize = expr.rpn.size();
 
-	size_t curSize = expr.rpn->size();
-
-	expr.rpn->resize(curSize + size);
-	return &(*expr.rpn)[curSize];
+	expr.rpn.resize(curSize + size);
+	return &expr.rpn[curSize];
 }
 
 // Free the RPN expression
 void rpn_Free(Expression &expr) {
-	delete expr.rpn;
 	initExpression(expr);
 }
 
@@ -220,8 +213,7 @@ void rpn_StartOfSectionType(Expression &expr, SectionType type) {
 	*ptr++ = type;
 }
 
-void rpn_CheckHRAM(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_CheckHRAM(Expression &expr) {
 	expr.isSymbol = false;
 
 	if (!expr.isKnown) {
@@ -235,9 +227,7 @@ void rpn_CheckHRAM(Expression &expr, const Expression &src) {
 	}
 }
 
-void rpn_CheckRST(Expression &expr, const Expression &src) {
-	expr = src;
-
+void rpn_CheckRST(Expression &expr) {
 	if (expr.isKnown) {
 		// A valid RST address must be masked with 0x38
 		if (expr.val & ~0x38)
@@ -251,7 +241,7 @@ void rpn_CheckRST(Expression &expr, const Expression &src) {
 }
 
 // Checks that an RPN expression's value fits within N bits (signed or unsigned)
-void rpn_CheckNBit(Expression const &expr, uint8_t n) {
+void rpn_CheckNBit(const Expression &expr, uint8_t n) {
 	assert(n != 0);                     // That doesn't make sense
 	assert(n < CHAR_BIT * sizeof(int)); // Otherwise `1 << n` is UB
 
@@ -273,8 +263,8 @@ int32_t Expression::getConstVal() const {
 	return val;
 }
 
-void rpn_LOGNOT(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_LOGNOT(Expression &expr, Expression &&src) {
+	expr = std::move(src);
 	expr.isSymbol = false;
 
 	if (expr.isKnown) {
@@ -288,7 +278,7 @@ void rpn_LOGNOT(Expression &expr, const Expression &src) {
 Symbol const *Expression::symbolOf() const {
 	if (!isSymbol)
 		return nullptr;
-	return sym_FindScopedSymbol((char const *)&(*rpn)[1]);
+	return sym_FindScopedSymbol((char const *)&rpn[1]);
 }
 
 bool Expression::isDiffConstant(Symbol const *sym) const {
@@ -343,7 +333,7 @@ static int32_t tryConstMask(Expression const &lhs, Expression const &rhs) {
 	return (symbolOfs + sect.alignOfs) & ~unknownBits;
 }
 
-void rpn_BinaryOp(RPNCommand op, Expression &expr, const Expression &src1, const Expression &src2) {
+void rpn_BinaryOp(RPNCommand op, Expression &expr, Expression &&src1, const Expression &src2) {
 	initExpression(expr);
 	expr.isSymbol = false;
 	int32_t constMaskVal;
@@ -515,7 +505,7 @@ void rpn_BinaryOp(RPNCommand op, Expression &expr, const Expression &src1, const
 			    (uint8_t)(lval >> 24),
 			};
 			expr.rpnPatchSize = sizeof(bytes);
-			expr.rpn = nullptr;
+			expr.rpn.clear();
 			memcpy(reserveSpace(expr, sizeof(bytes)), bytes, sizeof(bytes));
 
 			// Use the other expression's un-const reason
@@ -523,7 +513,7 @@ void rpn_BinaryOp(RPNCommand op, Expression &expr, const Expression &src1, const
 		} else {
 			// Otherwise just reuse its RPN buffer
 			expr.rpnPatchSize = src1.rpnPatchSize;
-			expr.rpn = src1.rpn;
+			std::swap(expr.rpn, src1.rpn);
 			expr.reason = src1.reason;
 		}
 
@@ -546,8 +536,8 @@ void rpn_BinaryOp(RPNCommand op, Expression &expr, const Expression &src1, const
 			len = sizeof(bytes);
 			patchSize = sizeof(bytes);
 		} else {
-			ptr = src2.rpn->data(); // Pointer to the right RPN
-			len = src2.rpn->size(); // Size of the right RPN
+			ptr = src2.rpn.data(); // Pointer to the right RPN
+			len = src2.rpn.size(); // Size of the right RPN
 			patchSize = src2.rpnPatchSize;
 		}
 		// Copy the right RPN and append the operator
@@ -558,13 +548,12 @@ void rpn_BinaryOp(RPNCommand op, Expression &expr, const Expression &src1, const
 			memcpy(buf, ptr, len);
 		buf[len] = op;
 
-		delete src2.rpn; // If there was none, this is `delete nullptr`
 		expr.rpnPatchSize += patchSize + 1;
 	}
 }
 
-void rpn_HIGH(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_HIGH(Expression &expr, Expression &&src) {
+	expr = std::move(src);
 	expr.isSymbol = false;
 
 	if (expr.isKnown) {
@@ -576,8 +565,8 @@ void rpn_HIGH(Expression &expr, const Expression &src) {
 	}
 }
 
-void rpn_LOW(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_LOW(Expression &expr, Expression &&src) {
+	expr = std::move(src);
 	expr.isSymbol = false;
 
 	if (expr.isKnown) {
@@ -597,8 +586,8 @@ void rpn_ISCONST(Expression &expr, const Expression &src) {
 	expr.isSymbol = false;
 }
 
-void rpn_NEG(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_NEG(Expression &expr, Expression &&src) {
+	expr = std::move(src);
 	expr.isSymbol = false;
 
 	if (expr.isKnown) {
@@ -609,8 +598,8 @@ void rpn_NEG(Expression &expr, const Expression &src) {
 	}
 }
 
-void rpn_NOT(Expression &expr, const Expression &src) {
-	expr = src;
+void rpn_NOT(Expression &expr, Expression &&src) {
+	expr = std::move(src);
 	expr.isSymbol = false;
 
 	if (expr.isKnown) {