compiler: refactor BinaryExpr handling

Reuse code between if conditions and expression context.

pkg/compiler/codegen.go

@@ -561,8 +561,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		lElseEnd := c.newLabel()
 
 		if n.Cond != nil {
-			ast.Walk(c, n.Cond)
+			c.emitBoolExpr(n.Cond, true, false, lElse)
-			emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOTL, lElse)
 		}
 
 		c.setLabel(lIf)
@@ -689,50 +688,8 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		return nil
 
 	case *ast.BinaryExpr:
-		// The AST package will try to resolve all basic literals for us.
+		c.emitBinaryExpr(n, false, false, 0)
-		// If the typeinfo.Value is not nil we know that the expr is resolved
+		return nil
-		// and needs no further action. e.g. x := 2 + 2 + 2 will be resolved to 6.
-		// NOTE: Constants will also be automatically resolved be the AST parser.
-		// example:
-		// const x = 10
-		// x + 2 will results into 12
-		tinfo := c.typeAndValueOf(n)
-		if tinfo.Value != nil {
-			c.emitLoadConst(tinfo)
-			return nil
-		}
-
-		if arg := c.getCompareWithNilArg(n); arg != nil {
-			ast.Walk(c, arg)
-			emit.Opcode(c.prog.BinWriter, opcode.ISNULL)
-			if n.Op == token.NEQ {
-				emit.Opcode(c.prog.BinWriter, opcode.NOT)
-			}
-			return nil
-		}
-
-		switch n.Op {
-		case token.LAND, token.LOR:
-			end := c.newLabel()
-			ast.Walk(c, n.X)
-			if n.Op == token.LAND {
-				emit.Instruction(c.prog.BinWriter, opcode.JMPIF, []byte{2 + 1 + 5})
-				emit.Opcode(c.prog.BinWriter, opcode.PUSHF)
-			} else {
-				emit.Instruction(c.prog.BinWriter, opcode.JMPIFNOT, []byte{2 + 1 + 5})
-				emit.Opcode(c.prog.BinWriter, opcode.PUSHT)
-			}
-			emit.Jmp(c.prog.BinWriter, opcode.JMPL, end)
-			ast.Walk(c, n.Y)
-			c.setLabel(end)
-			return nil
-
-		default:
-			ast.Walk(c, n.X)
-			ast.Walk(c, n.Y)
-			c.emitToken(n.Op, c.typeOf(n.X))
-			return nil
-		}
 
 	case *ast.CallExpr:
 		var (
@@ -1122,6 +1079,84 @@ func (c *codegen) getCompareWithNilArg(n *ast.BinaryExpr) ast.Expr {
 	return nil
 }
 
+func (c *codegen) emitJumpOnCondition(cond bool, jmpLabel uint16) {
+	if cond {
+		emit.Jmp(c.prog.BinWriter, opcode.JMPIFL, jmpLabel)
+	} else {
+		emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOTL, jmpLabel)
+	}
+}
+
+func (c *codegen) emitBoolExpr(n ast.Expr, needJump bool, cond bool, jmpLabel uint16) {
+	if be, ok := n.(*ast.BinaryExpr); ok {
+		c.emitBinaryExpr(be, needJump, cond, jmpLabel)
+	} else {
+		ast.Walk(c, n)
+		if needJump {
+			c.emitJumpOnCondition(cond, jmpLabel)
+		}
+	}
+}
+
+func (c *codegen) emitBinaryExpr(n *ast.BinaryExpr, needJump bool, cond bool, jmpLabel uint16) {
+	// The AST package will try to resolve all basic literals for us.
+	// If the typeinfo.Value is not nil we know that the expr is resolved
+	// and needs no further action. e.g. x := 2 + 2 + 2 will be resolved to 6.
+	// NOTE: Constants will also be automatically resolved be the AST parser.
+	// example:
+	// const x = 10
+	// x + 2 will results into 12
+	tinfo := c.typeAndValueOf(n)
+	if tinfo.Value != nil {
+		c.emitLoadConst(tinfo)
+		if needJump && isBool(tinfo.Type) {
+			c.emitJumpOnCondition(cond, jmpLabel)
+		}
+		return
+	} else if arg := c.getCompareWithNilArg(n); arg != nil {
+		ast.Walk(c, arg)
+		emit.Opcode(c.prog.BinWriter, opcode.ISNULL)
+		if needJump {
+			c.emitJumpOnCondition(cond == (n.Op == token.EQL), jmpLabel)
+		} else if n.Op == token.NEQ {
+			emit.Opcode(c.prog.BinWriter, opcode.NOT)
+		}
+		return
+	}
+
+	switch n.Op {
+	case token.LAND, token.LOR:
+		end := c.newLabel()
+
+		// true || .. == true, false && .. == false
+		condShort := n.Op == token.LOR
+		if needJump {
+			l := end
+			if cond == condShort {
+				l = jmpLabel
+			}
+			c.emitBoolExpr(n.X, true, condShort, l)
+			c.emitBoolExpr(n.Y, true, cond, jmpLabel)
+		} else {
+			push := c.newLabel()
+			c.emitBoolExpr(n.X, true, condShort, push)
+			c.emitBoolExpr(n.Y, false, false, 0)
+			emit.Jmp(c.prog.BinWriter, opcode.JMPL, end)
+			c.setLabel(push)
+			emit.Bool(c.prog.BinWriter, condShort)
+		}
+		c.setLabel(end)
+
+	default:
+		ast.Walk(c, n.X)
+		ast.Walk(c, n.Y)
+		c.emitToken(n.Op, c.typeOf(n.X))
+		if needJump {
+			c.emitJumpOnCondition(cond, jmpLabel)
+		}
+	}
+}
+
 func (c *codegen) pushStackLabel(name string, size int) {
 	c.labelList = append(c.labelList, labelWithStackSize{
 		name: name,

pkg/compiler/types.go

@@ -31,6 +31,10 @@ func isByte(typ types.Type) bool {
 	return isBasicTypeOfKind(typ, types.Uint8, types.Int8)
 }
 
+func isBool(typ types.Type) bool {
+	return isBasicTypeOfKind(typ, types.Bool, types.UntypedBool)
+}
+
 func isNumber(typ types.Type) bool {
 	t, ok := typ.Underlying().(*types.Basic)
 	return ok && t.Info()&types.IsNumeric != 0