feat: add disable short-circuiting option to compiler (#847)

* feat: add disable short-circuiting option to compiler

* fix: nil config && unit test

---------

Co-authored-by: Anton Medvedev <anton@medv.io>

Author: lvliangxiong

compiler/compiler.go

@@ -448,6 +448,14 @@ func (c *compiler) BinaryNode(node *ast.BinaryNode) {
 		c.emit(OpNot)
 
 	case "or", "||":
+		if c.config != nil && c.config.DisableSC {
+			c.compile(node.Left)
+			c.derefInNeeded(node.Left)
+			c.compile(node.Right)
+			c.derefInNeeded(node.Right)
+			c.emit(OpOr)
+			break
+		}
 		c.compile(node.Left)
 		c.derefInNeeded(node.Left)
 		end := c.emit(OpJumpIfTrue, placeholder)
@@ -457,6 +465,14 @@ func (c *compiler) BinaryNode(node *ast.BinaryNode) {
 		c.patchJump(end)
 
 	case "and", "&&":
+		if c.config != nil && c.config.DisableSC {
+			c.compile(node.Left)
+			c.derefInNeeded(node.Left)
+			c.compile(node.Right)
+			c.derefInNeeded(node.Right)
+			c.emit(OpAnd)
+			break
+		}
 		c.compile(node.Left)
 		c.derefInNeeded(node.Left)
 		end := c.emit(OpJumpIfFalse, placeholder)

conf/config.go

@@ -35,6 +35,7 @@ type Config struct {
 	Builtins  FunctionsTable
 	Disabled  map[string]bool // disabled builtins
 	NtCache   nature.Cache
+	DisableSC bool
 }
 
 // CreateNew creates new config with default values.
@@ -46,6 +47,7 @@ func CreateNew() *Config {
 		Functions: make(map[string]*builtin.Function),
 		Builtins:  make(map[string]*builtin.Function),
 		Disabled:  make(map[string]bool),
+		DisableSC: false,
 	}
 	for _, f := range builtin.Builtins {
 		c.Builtins[f.Name] = f

expr.go

@@ -126,6 +126,13 @@ func Optimize(b bool) Option {
 	}
 }
 
+// DisableShortCircuit turns short circuit off.
+func DisableShortCircuit() Option {
+	return func(c *conf.Config) {
+		c.DisableSC = true
+	}
+}
+
 // Patch adds visitor to list of visitors what will be applied before compiling AST to bytecode.
 func Patch(visitor ast.Visitor) Option {
 	return func(c *conf.Config) {

expr_test.go

@@ -2883,3 +2883,55 @@ func TestIssue807(t *testing.T) {
 		t.Fatalf("expected 'in' operator to return false for unexported field")
 	}
 }
+
+func ExampleDisableShortCircuit() {
+	OR := func(a, b bool) bool {
+		return a || b
+	}
+
+	env := map[string]any{
+		"foo": func() bool {
+			fmt.Println("foo")
+			return false
+		},
+		"bar": func() bool {
+			fmt.Println("bar")
+			return false
+		},
+		"OR": OR,
+	}
+
+	program, _ := expr.Compile("true || foo() or bar()", expr.Env(env), expr.Operator("or", "OR"), expr.Operator("||", "OR"))
+	got, _ := expr.Run(program, env)
+	fmt.Println(got)
+
+	// Output:
+	// foo
+	// bar
+	// true
+}
+
+func TestDisableShortCircuit(t *testing.T) {
+	count := 0
+	exprStr := "foo() or bar()"
+	env := map[string]any{
+		"foo": func() bool {
+			count++
+			return true
+		},
+		"bar": func() bool {
+			count++
+			return true
+		},
+	}
+
+	program, _ := expr.Compile(exprStr, expr.DisableShortCircuit())
+	got, _ := expr.Run(program, env)
+	assert.Equal(t, 2, count)
+	assert.True(t, got.(bool))
+
+	program, _ = expr.Compile(exprStr)
+	got, _ = expr.Run(program, env)
+	assert.Equal(t, 3, count)
+	assert.True(t, got.(bool))
+}

vm/opcodes.go

@@ -84,5 +84,7 @@ const (
 	OpProfileStart
 	OpProfileEnd
 	OpBegin
+	OpAnd
+	OpOr
 	OpEnd // This opcode must be at the end of this list.
 )

vm/program.go

@@ -375,6 +375,12 @@ func (program *Program) DisassembleWriter(w io.Writer) {
 		case OpBegin:
 			code("OpBegin")
 
+		case OpAnd:
+			code("OpAnd")
+
+		case OpOr:
+			code("OpOr")
+
 		case OpEnd:
 			code("OpEnd")
 

vm/vm.go

@@ -601,6 +601,16 @@ func (vm *VM) Run(program *Program, env any) (_ any, err error) {
 				Len:   array.Len(),
 			})
 
+		case OpAnd:
+			a := vm.pop()
+			b := vm.pop()
+			vm.push(a.(bool) && b.(bool))
+
+		case OpOr:
+			a := vm.pop()
+			b := vm.pop()
+			vm.push(a.(bool) || b.(bool))
+
 		case OpEnd:
 			vm.Scopes = vm.Scopes[:len(vm.Scopes)-1]