From: Rob Pike <r@golang.org>
Date: Wed, 5 Nov 2008 18:17:38 +0000 (-0800)
Subject: make sizes and offsets int, not uint64
X-Git-Tag: weekly.2009-11-06~2797
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=554d0aa589c3e90d192ef8904baa154fcb8248ad;p=gostls13.git

make sizes and offsets int, not uint64
add Value.Interface, to extract an empty interface
that can be converted to a regular Go value of the
appropriate type, if known.

R=rsc
DELTA=49  (2 added, 0 deleted, 47 changed)
OCL=18526
CL=18526
---

diff --git a/src/lib/reflect/test.go b/src/lib/reflect/test.go
index 13be64cc08..a260a8aa3c 100644
--- a/src/lib/reflect/test.go
+++ b/src/lib/reflect/test.go
@@ -202,7 +202,7 @@ func main() {
 	var name string;
 	var typ reflect.Type;
 	var tag string;
-	var offset uint64;
+	var offset int;
 
 	// Type strings
 	t = reflect.ParseTypeString("", "int8");
diff --git a/src/lib/reflect/tostring.go b/src/lib/reflect/tostring.go
index 2359b8cd36..4707a8e76f 100644
--- a/src/lib/reflect/tostring.go
+++ b/src/lib/reflect/tostring.go
@@ -39,7 +39,7 @@ func DoubleQuote(s string) string {
 }
 
 type HasFields interface {
-	Field(i int)	(name string, typ Type, tag string, offset uint64);
+	Field(i int)	(name string, typ Type, tag string, offset int);
 	Len()	int;
 }
 
@@ -177,7 +177,7 @@ func ValueToString(val Value) string {
 		v := val.(ArrayValue);
 		str += TypeToString(t, false);
 		str += "{";
-		for i := uint64(0); i < v.Len(); i++ {
+		for i := 0; i < v.Len(); i++ {
 			if i > 0 {
 				str += ", "
 			}
diff --git a/src/lib/reflect/type.go b/src/lib/reflect/type.go
index 09ecbc0675..899b02f155 100644
--- a/src/lib/reflect/type.go
+++ b/src/lib/reflect/type.go
@@ -41,8 +41,9 @@ export const (
 	Uint8Kind;
 )
 
-var ptrsize uint64
-var interfacesize uint64
+// Int is guaranteed large enough to store a size.
+var ptrsize int
+var interfacesize int
 
 var MissingString = "$missing$"	// syntactic name for undefined type names
 var DotDotDotString = "..."
@@ -52,7 +53,7 @@ export type Type interface {
 	Name()	string;
 	String()	string;
 	SetString(string);	// TODO: remove when no longer needed
-	Size()	uint64;
+	Size()	int;
 }
 
 // Fields and methods common to all types
@@ -60,7 +61,7 @@ type Common struct {
 	kind	int;
 	str	string;
 	name	string;
-	size	uint64;
+	size	int;
 }
 
 func (c *Common) Kind() int {
@@ -79,7 +80,7 @@ func (c *Common) SetString(s string) {
 	c.str = s
 }
 
-func (c *Common) Size() uint64 {
+func (c *Common) Size() int {
 	return c.size
 }
 
@@ -89,7 +90,7 @@ type BasicType struct {
 	Common
 }
 
-func NewBasicType(name string, kind int, size uint64) Type {
+func NewBasicType(name string, kind int, size int) Type {
 	return &BasicType{ Common{kind, name, name, size} }
 }
 
@@ -157,7 +158,7 @@ func (t *PtrTypeStruct) Sub() Type {
 
 export type ArrayType interface {
 	Open()	bool;
-	Len()	uint64;
+	Len()	int;
 	Elem()	Type;
 }
 
@@ -165,14 +166,14 @@ type ArrayTypeStruct struct {
 	Common;
 	elem	*StubType;
 	open	bool;	// otherwise fixed size
-	len	uint64;
+	len	int;
 }
 
-func NewArrayTypeStruct(name, typestring string, open bool, len uint64, elem *StubType) *ArrayTypeStruct {
+func NewArrayTypeStruct(name, typestring string, open bool, len int, elem *StubType) *ArrayTypeStruct {
 	return &ArrayTypeStruct{ Common{ArrayKind, typestring, name, 0}, elem, open, len}
 }
 
-func (t *ArrayTypeStruct) Size() uint64 {
+func (t *ArrayTypeStruct) Size() int {
 	if t.open {
 		return ptrsize	// open arrays are pointers to structures
 	}
@@ -183,7 +184,7 @@ func (t *ArrayTypeStruct) Open() bool {
 	return t.open
 }
 
-func (t *ArrayTypeStruct) Len() uint64 {
+func (t *ArrayTypeStruct) Len() int {
 	// what about open array?  TODO
 	return t.len
 }
@@ -209,7 +210,7 @@ func NewMapTypeStruct(name, typestring string, key, elem *StubType) *MapTypeStru
 	return &MapTypeStruct{ Common{MapKind, typestring, name, 0}, key, elem}
 }
 
-func (t *MapTypeStruct) Size() uint64 {
+func (t *MapTypeStruct) Size() int {
 	panic("reflect.type: map.Size(): cannot happen");
 	return 0
 }
@@ -245,7 +246,7 @@ func NewChanTypeStruct(name, typestring string, dir int, elem *StubType) *ChanTy
 	return &ChanTypeStruct{ Common{ChanKind, typestring, name, 0}, elem, dir}
 }
 
-func (t *ChanTypeStruct) Size() uint64 {
+func (t *ChanTypeStruct) Size() int {
 	panic("reflect.type: chan.Size(): cannot happen");
 	return 0
 }
@@ -261,7 +262,7 @@ func (t *ChanTypeStruct) Elem() Type {
 // -- Struct
 
 export type StructType interface {
-	Field(int)	(name string, typ Type, tag string, offset uint64);
+	Field(int)	(name string, typ Type, tag string, offset int);
 	Len()	int;
 }
 
@@ -269,8 +270,8 @@ type Field struct {
 	name	string;
 	typ	*StubType;
 	tag	string;
-	size	uint64;
-	offset	uint64;
+	size	int;
+	offset	int;
 }
 
 type StructTypeStruct struct {
@@ -283,11 +284,11 @@ func NewStructTypeStruct(name, typestring string, field *[]Field) *StructTypeStr
 }
 
 // TODO: not portable; depends on 6g
-func (t *StructTypeStruct) Size() uint64 {
+func (t *StructTypeStruct) Size() int {
 	if t.size > 0 {
 		return t.size
 	}
-	size := uint64(0);
+	size := 0;
 	for i := 0; i < len(t.field); i++ {
 		elemsize := t.field[i].typ.Get().Size();
 		// pad until at (elemsize mod 8) boundary
@@ -301,12 +302,13 @@ func (t *StructTypeStruct) Size() uint64 {
 		t.field[i].offset = size;
 		size += elemsize;
 	}
-	size = (size + 7) & ((1<<64 - 1) & ^7);
+	structalignmask := 7;	// TODO: knows that size fits in int32 (also can't use const here)
+	size = (size + structalignmask) & ^(structalignmask);
 	t.size = size;
 	return size;
 }
 
-func (t *StructTypeStruct) Field(i int) (name string, typ Type, tag string, offset uint64) {
+func (t *StructTypeStruct) Field(i int) (name string, typ Type, tag string, offset int) {
 	if t.field[i].offset == 0 {
 		t.Size();	// will compute offsets
 	}
@@ -320,7 +322,7 @@ func (t *StructTypeStruct) Len() int {
 // -- Interface
 
 export type InterfaceType interface {
-	Field(int)	(name string, typ Type, tag string, offset uint64);
+	Field(int)	(name string, typ Type, tag string, offset int);
 	Len()	int;
 }
 
@@ -333,7 +335,7 @@ func NewInterfaceTypeStruct(name, typestring string, field *[]Field) *InterfaceT
 	return &InterfaceTypeStruct{ Common{InterfaceKind, typestring, name, interfacesize}, field }
 }
 
-func (t *InterfaceTypeStruct) Field(i int) (name string, typ Type, tag string, offset uint64) {
+func (t *InterfaceTypeStruct) Field(i int) (name string, typ Type, tag string, offset int) {
 	return t.field[i].name, t.field[i].typ.Get(), "", 0
 }
 
@@ -358,7 +360,7 @@ func NewFuncTypeStruct(name, typestring string, in, out *StructTypeStruct) *Func
 	return &FuncTypeStruct{ Common{FuncKind, typestring, name, 0}, in, out }
 }
 
-func (t *FuncTypeStruct) Size() uint64 {
+func (t *FuncTypeStruct) Size() int {
 	panic("reflect.type: func.Size(): cannot happen");
 	return 0
 }
@@ -622,7 +624,7 @@ func (p *Parser) Next() {
 func (p *Parser) Type(name string) *StubType
 
 func (p *Parser) Array(name string, tokstart int) *StubType {
-	size := uint64(0);
+	size := 0;
 	open := true;
 	if p.token != "]" {
 		if len(p.token) == 0 || !isdigit(p.token[0]) {
@@ -631,7 +633,7 @@ func (p *Parser) Array(name string, tokstart int) *StubType {
 		// write our own (trivial and simpleminded) atoi to avoid dependency
 		size = 0;
 		for i := 0; i < len(p.token); i++ {
-			size = size * 10 + uint64(p.token[i]) - '0'
+			size = size * 10 + int(p.token[i]) - '0'
 		}
 		p.Next();
 		open = false;
diff --git a/src/lib/reflect/value.go b/src/lib/reflect/value.go
index 527f1ff005..c7089b1580 100644
--- a/src/lib/reflect/value.go
+++ b/src/lib/reflect/value.go
@@ -39,7 +39,7 @@ export type Empty interface {}	// TODO(r): Delete when no longer needed?
 export type Value interface {
 	Kind()	int;
 	Type()	Type;
-	Unreflect()	Empty;
+	Interface()	Empty;
 }
 
 // Common fields and functionality for all values
@@ -58,7 +58,7 @@ func (c *Common) Type() Type {
 	return c.typ
 }
 
-func (c *Common) Unreflect() Empty {
+func (c *Common) Interface() Empty {
 	return sys.unreflect(*AddrToPtrAddr(c.addr), c.typ.String());
 }
 
@@ -517,14 +517,14 @@ export type ArrayValue interface {
 	Kind()	int;
 	Type()	Type;
 	Open()	bool;
-	Len()	uint64;
-	Elem(i uint64)	Value;
+	Len()	int;
+	Elem(i int)	Value;
 }
 
 type OpenArrayValueStruct struct {
 	Common;
 	elemtype	Type;
-	elemsize	uint64;
+	elemsize	int;
 }
 
 /*
@@ -539,32 +539,32 @@ func (v *OpenArrayValueStruct) Open() bool {
 	return true
 }
 
-func (v *OpenArrayValueStruct) Len() uint64 {
-	return uint64(*AddrToPtrInt32(v.addr+8));
+func (v *OpenArrayValueStruct) Len() int {
+	return int(*AddrToPtrInt32(v.addr+8));
 }
 
-func (v *OpenArrayValueStruct) Elem(i uint64) Value {
+func (v *OpenArrayValueStruct) Elem(i int) Value {
 	base := *AddrToPtrAddr(v.addr);
-	return NewValueAddr(v.elemtype, base + i * v.elemsize);
+	return NewValueAddr(v.elemtype, base + Addr(i * v.elemsize));
 }
 
 type FixedArrayValueStruct struct {
 	Common;
 	elemtype	Type;
-	elemsize	uint64;
-	len	uint64;
+	elemsize	int;
+	len	int;
 }
 
 func (v *FixedArrayValueStruct) Open() bool {
 	return false
 }
 
-func (v *FixedArrayValueStruct) Len() uint64 {
+func (v *FixedArrayValueStruct) Len() int {
 	return v.len
 }
 
-func (v *FixedArrayValueStruct) Elem(i uint64) Value {
-	return NewValueAddr(v.elemtype, v.addr + i * v.elemsize);
+func (v *FixedArrayValueStruct) Elem(i int) Value {
+	return NewValueAddr(v.elemtype, v.addr + Addr(i * v.elemsize));
 	return nil
 }
 
@@ -658,7 +658,7 @@ func StructCreator(typ Type, addr Addr) Value {
 	v := &StructValueStruct{ Common{StructKind, typ, addr}, new([]Value, nfield) };
 	for i := 0; i < nfield; i++ {
 		name, ftype, str, offset := t.Field(i);
-		v.field[i] = NewValueAddr(ftype, addr + offset);
+		v.field[i] = NewValueAddr(ftype, addr + Addr(offset));
 	}
 	v.typ = typ;
 	return v;