prog: fix cheking nonoptional nil pointers in validation

Also update validation code to use arg.Type instead of passing typ recusively.

1 files changed, 43 insertions, 48 deletions

diff --git a/prog/validation.go b/prog/validation.go
index 28c619802..61a12eaab 100644
--- a/prog/validation.go
+++ b/prog/validation.go
@@ -38,8 +38,8 @@ func (c *Call) validate(ctx *validCtx) error {
 	if len(c.Args) != len(c.Meta.Args) {
 		return fmt.Errorf("syscall %v: wrong number of arguments, want %v, got %v", c.Meta.Name, len(c.Meta.Args), len(c.Args))
 	}
-	var checkArg func(arg *Arg, typ sys.Type) error
-	checkArg = func(arg *Arg, typ sys.Type) error {
+	var checkArg func(arg *Arg) error
+	checkArg = func(arg *Arg) error {
 		if arg == nil {
 			return fmt.Errorf("syscall %v: nil arg", c.Meta.Name)
 		}
@@ -53,24 +53,18 @@ func (c *Call) validate(ctx *validCtx) error {
 		if arg.Type == nil {
 			return fmt.Errorf("syscall %v: no type", c.Meta.Name)
 		}
-		if arg.Type.Name() != typ.Name() {
-			return fmt.Errorf("syscall %v: type name mismatch: %v vs %v", c.Meta.Name, arg.Type.Name(), typ.Name())
-		}
-		if arg.Type.FieldName() != typ.FieldName() {
-			return fmt.Errorf("syscall %v: field name mismatch: %v vs %v", c.Meta.Name, arg.Type.FieldName(), typ.FieldName())
-		}
 		if arg.Type.Dir() == sys.DirOut {
 			if (arg.Val != 0 && arg.Val != arg.Type.Default()) || arg.AddrPage != 0 || arg.AddrOffset != 0 {
 				// We generate output len arguments, which makes sense
 				// since it can be a length of a variable-length array
 				// which is not known otherwise.
 				if _, ok := arg.Type.(*sys.LenType); !ok {
-					return fmt.Errorf("syscall %v: output arg '%v' has non default value '%v'", c.Meta.Name, typ.Name(), arg.Val)
+					return fmt.Errorf("syscall %v: output arg '%v' has non default value '%v'", c.Meta.Name, arg.Type.Name(), arg.Val)
 				}
 			}
 			for _, v := range arg.Data {
 				if v != 0 {
-					return fmt.Errorf("syscall %v: output arg '%v' has data", c.Meta.Name, typ.Name())
+					return fmt.Errorf("syscall %v: output arg '%v' has data", c.Meta.Name, arg.Type.Name())
 				}
 			}
 		}
@@ -81,111 +75,112 @@ func (c *Call) validate(ctx *validCtx) error {
 			case ArgReturn:
 			case ArgConst:
 				if arg.Type.Dir() == sys.DirOut && (arg.Val != 0 && arg.Val != arg.Type.Default()) {
-					return fmt.Errorf("syscall %v: out resource arg '%v' has bad const value %v", c.Meta.Name, typ.Name(), arg.Val)
+					return fmt.Errorf("syscall %v: out resource arg '%v' has bad const value %v", c.Meta.Name, arg.Type.Name(), arg.Val)
 				}
 			default:
-				return fmt.Errorf("syscall %v: fd arg '%v' has bad kind %v", c.Meta.Name, typ.Name(), arg.Kind)
+				return fmt.Errorf("syscall %v: fd arg '%v' has bad kind %v", c.Meta.Name, arg.Type.Name(), arg.Kind)
 			}
 		case *sys.StructType, *sys.ArrayType:
 			switch arg.Kind {
 			case ArgGroup:
 			default:
-				return fmt.Errorf("syscall %v: struct/array arg '%v' has bad kind %v", c.Meta.Name, typ.Name(), arg.Kind)
+				return fmt.Errorf("syscall %v: struct/array arg '%v' has bad kind %v", c.Meta.Name, arg.Type.Name(), arg.Kind)
 			}
 		case *sys.UnionType:
 			switch arg.Kind {
 			case ArgUnion:
 			default:
-				return fmt.Errorf("syscall %v: union arg '%v' has bad kind %v", c.Meta.Name, typ.Name(), arg.Kind)
+				return fmt.Errorf("syscall %v: union arg '%v' has bad kind %v", c.Meta.Name, arg.Type.Name(), arg.Kind)
 			}
 		case *sys.ProcType:
 			if arg.Val >= uintptr(typ1.ValuesPerProc) {
-				return fmt.Errorf("syscall %v: per proc arg '%v' has bad value '%v'", c.Meta.Name, typ.Name(), arg.Val)
+				return fmt.Errorf("syscall %v: per proc arg '%v' has bad value '%v'", c.Meta.Name, arg.Type.Name(), arg.Val)
 			}
 		case *sys.BufferType:
 			switch typ1.Kind {
 			case sys.BufferString:
 				if typ1.Length != 0 && len(arg.Data) != int(typ1.Length) {
-					return fmt.Errorf("syscall %v: string arg '%v' has size %v, which should be %v", c.Meta.Name, typ.Name(), len(arg.Data), typ1.Length)
+					return fmt.Errorf("syscall %v: string arg '%v' has size %v, which should be %v", c.Meta.Name, arg.Type.Name(), len(arg.Data), typ1.Length)
 				}
 			}
 		case *sys.CsumType:
 			if arg.Val != 0 {
-				return fmt.Errorf("syscall %v: csum arg '%v' has nonzero value %v", c.Meta.Name, typ.Name(), arg.Val)
+				return fmt.Errorf("syscall %v: csum arg '%v' has nonzero value %v", c.Meta.Name, arg.Type.Name(), arg.Val)
+			}
+		case *sys.PtrType:
+			if arg.Type.Dir() == sys.DirOut {
+				return fmt.Errorf("syscall %v: pointer arg '%v' has output direction", c.Meta.Name, arg.Type.Name())
+			}
+			if arg.Res == nil && !arg.Type.Optional() {
+				return fmt.Errorf("syscall %v: non optional pointer arg '%v' is nil", c.Meta.Name, arg.Type.Name())
 			}
 		}
 		switch arg.Kind {
 		case ArgConst:
 		case ArgResult:
 			if arg.Res == nil {
-				return fmt.Errorf("syscall %v: result arg '%v' has no reference", c.Meta.Name, typ.Name())
+				return fmt.Errorf("syscall %v: result arg '%v' has no reference", c.Meta.Name, arg.Type.Name())
 			}
 			if !ctx.args[arg.Res] {
 				return fmt.Errorf("syscall %v: result arg '%v' references out-of-tree result: %p%+v -> %p%+v",
-					c.Meta.Name, typ.Name(), arg, arg, arg.Res, arg.Res)
+					c.Meta.Name, arg.Type.Name(), arg, arg, arg.Res, arg.Res)
 			}
 			if _, ok := arg.Res.Uses[arg]; !ok {
-				return fmt.Errorf("syscall %v: result arg '%v' has broken link (%+v)", c.Meta.Name, typ.Name(), arg.Res.Uses)
+				return fmt.Errorf("syscall %v: result arg '%v' has broken link (%+v)", c.Meta.Name, arg.Type.Name(), arg.Res.Uses)
 			}
 		case ArgPointer:
-			switch typ1 := typ.(type) {
+			switch arg.Type.(type) {
 			case *sys.VmaType:
 				if arg.Res != nil {
-					return fmt.Errorf("syscall %v: vma arg '%v' has data", c.Meta.Name, typ.Name())
+					return fmt.Errorf("syscall %v: vma arg '%v' has data", c.Meta.Name, arg.Type.Name())
 				}
 				if arg.AddrPagesNum == 0 {
-					return fmt.Errorf("syscall %v: vma arg '%v' has size 0", c.Meta.Name, typ.Name())
+					return fmt.Errorf("syscall %v: vma arg '%v' has size 0", c.Meta.Name, arg.Type.Name())
 				}
 			case *sys.PtrType:
-				if arg.Type.Dir() == sys.DirOut {
-					return fmt.Errorf("syscall %v: pointer arg '%v' has output direction", c.Meta.Name, typ.Name())
-				}
-				if arg.Res == nil && !typ.Optional() {
-					return fmt.Errorf("syscall %v: non optional pointer arg '%v' is nil", c.Meta.Name, typ.Name())
-				}
 				if arg.Res != nil {
-					if err := checkArg(arg.Res, typ1.Type); err != nil {
+					if err := checkArg(arg.Res); err != nil {
 						return err
 					}
 				}
 				if arg.AddrPagesNum != 0 {
-					return fmt.Errorf("syscall %v: pointer arg '%v' has nonzero size", c.Meta.Name, typ.Name())
+					return fmt.Errorf("syscall %v: pointer arg '%v' has nonzero size", c.Meta.Name, arg.Type.Name())
 				}
 			default:
-				return fmt.Errorf("syscall %v: pointer arg '%v' has bad meta type %+v", c.Meta.Name, typ.Name(), typ)
+				return fmt.Errorf("syscall %v: pointer arg '%v' has bad meta type %+v", c.Meta.Name, arg.Type.Name(), arg.Type)
 			}
 		case ArgPageSize:
 		case ArgData:
-			switch typ1 := typ.(type) {
+			switch typ1 := arg.Type.(type) {
 			case *sys.ArrayType:
 				if typ2, ok := typ1.Type.(*sys.IntType); !ok || typ2.Size() != 1 {
-					return fmt.Errorf("syscall %v: data arg '%v' should be an array", c.Meta.Name, typ.Name())
+					return fmt.Errorf("syscall %v: data arg '%v' should be an array", c.Meta.Name, arg.Type.Name())
 				}
 			}
 		case ArgGroup:
-			switch typ1 := typ.(type) {
+			switch typ1 := arg.Type.(type) {
 			case *sys.StructType:
 				if len(arg.Inner) != len(typ1.Fields) {
-					return fmt.Errorf("syscall %v: struct arg '%v' has wrong number of fields: want %v, got %v", c.Meta.Name, typ.Name(), len(typ1.Fields), len(arg.Inner))
+					return fmt.Errorf("syscall %v: struct arg '%v' has wrong number of fields: want %v, got %v", c.Meta.Name, arg.Type.Name(), len(typ1.Fields), len(arg.Inner))
 				}
-				for i, arg1 := range arg.Inner {
-					if err := checkArg(arg1, typ1.Fields[i]); err != nil {
+				for _, arg1 := range arg.Inner {
+					if err := checkArg(arg1); err != nil {
 						return err
 					}
 				}
 			case *sys.ArrayType:
 				for _, arg1 := range arg.Inner {
-					if err := checkArg(arg1, typ1.Type); err != nil {
+					if err := checkArg(arg1); err != nil {
 						return err
 					}
 				}
 			default:
-				return fmt.Errorf("syscall %v: group arg '%v' has bad underlying type %+v", c.Meta.Name, typ.Name(), typ)
+				return fmt.Errorf("syscall %v: group arg '%v' has bad underlying type %+v", c.Meta.Name, arg.Type.Name(), arg.Type)
 			}
 		case ArgUnion:
-			typ1, ok := typ.(*sys.UnionType)
+			typ1, ok := arg.Type.(*sys.UnionType)
 			if !ok {
-				return fmt.Errorf("syscall %v: union arg '%v' has bad type", c.Meta.Name, typ.Name())
+				return fmt.Errorf("syscall %v: union arg '%v' has bad type", c.Meta.Name, arg.Type.Name())
 			}
 			found := false
 			for _, typ2 := range typ1.Options {
@@ -195,22 +190,22 @@ func (c *Call) validate(ctx *validCtx) error {
 				}
 			}
 			if !found {
-				return fmt.Errorf("syscall %v: union arg '%v' has bad option", c.Meta.Name, typ.Name())
+				return fmt.Errorf("syscall %v: union arg '%v' has bad option", c.Meta.Name, arg.Type.Name())
 			}
-			if err := checkArg(arg.Option, arg.OptionType); err != nil {
+			if err := checkArg(arg.Option); err != nil {
 				return err
 			}
 		case ArgReturn:
 		default:
-			return fmt.Errorf("syscall %v: unknown arg '%v' kind", c.Meta.Name, typ.Name())
+			return fmt.Errorf("syscall %v: unknown arg '%v' kind", c.Meta.Name, arg.Type.Name())
 		}
 		return nil
 	}
-	for i, arg := range c.Args {
+	for _, arg := range c.Args {
 		if arg.Kind == ArgReturn {
 			return fmt.Errorf("syscall %v: arg '%v' has wrong return kind", c.Meta.Name, arg.Type.Name())
 		}
-		if err := checkArg(arg, c.Meta.Args[i]); err != nil {
+		if err := checkArg(arg); err != nil {
 			return err
 		}
 	}
@@ -221,7 +216,7 @@ func (c *Call) validate(ctx *validCtx) error {
 		return fmt.Errorf("syscall %v: return value has wrong kind %v", c.Meta.Name, c.Ret.Kind)
 	}
 	if c.Meta.Ret != nil {
-		if err := checkArg(c.Ret, c.Meta.Ret); err != nil {
+		if err := checkArg(c.Ret); err != nil {
 			return err
 		}
 	} else if c.Ret.Type != nil {