ir: do not throw an error on unknown conversions

ir/interpreter.go

@@ -206,7 +206,7 @@ func (p *Program) interpret(instrs []ssa.Instruction, paramKeys []*ssa.Parameter
 			switch typeTo := instr.Type().Underlying().(type) {
 			case *types.Basic:
 				if typeTo.Kind() == types.String {
-					return i, errors.New("todo: init: cannot convert string")
+					return i, nil
 				}
 
 				if _, ok := typeFrom.(*types.Pointer); ok && typeTo.Kind() == types.UnsafePointer {
@@ -217,10 +217,10 @@ func (p *Program) interpret(instrs []ssa.Instruction, paramKeys []*ssa.Parameter
 					} else if typeFrom.Info()&types.IsInteger != 0 && typeTo.Info()&types.IsInteger != 0 {
 						locals[instr] = &ConstValue{Expr: ssa.NewConst(x.(*ConstValue).Expr.Value, typeTo)}
 					} else {
-						return i, errors.New("todo: init: unknown basic-to-basic convert: " + instr.String())
+						return i, nil
 					}
 				} else {
-					return i, errors.New("todo: init: unknown basic convert: " + instr.String())
+					return i, nil
 				}
 			case *types.Pointer:
 				if typeFrom, ok := typeFrom.(*types.Basic); ok && typeFrom.Kind() == types.UnsafePointer {
@@ -229,7 +229,7 @@ func (p *Program) interpret(instrs []ssa.Instruction, paramKeys []*ssa.Parameter
 					panic("expected unsafe pointer conversion")
 				}
 			default:
-				return i, errors.New("todo: init: unknown convert: " + instr.String())
+				return i, nil
 			}
 		case *ssa.DebugRef:
 			// ignore
@@ -384,7 +384,6 @@ func canInterpret(callee *ssa.Function) bool {
 		// above.
 		case *ssa.Alloc:
 		case *ssa.ChangeType:
-		case *ssa.Convert:
 		case *ssa.DebugRef:
 		case *ssa.Extract:
 		case *ssa.FieldAddr:

testdata/init.go

@@ -6,4 +6,26 @@ func init() {
 
 func main() {
 	println("main")
+	println("v1:", v1)
+	println("v2:", v2.x, v2.y)
+	println("v3:", len(v3), cap(v3), v3[0], v3[3])
+	println("v4:", len(v4), v4 == nil)
+	println("v5:", len(v5), v5 == nil)
+	println("v6:", v6)
 }
+
+type (
+	t2 struct {
+		x int
+		y int
+	}
+)
+
+var (
+	v1 = 3
+	v2 = t2{2, 5}
+	v3 = []int{2, 3, 5, 7}
+	v4 map[string]int
+	v5 = map[string]int{}
+	v6 = float64(v1) < 2.6
+)

testdata/init.txt

@@ -1,2 +1,8 @@
 init
 main
+v1: 3
+v2: 2 5
+v3: 4 4 2 7
+v4: 0 true
+v5: 0 false
+v6: false