cmd/compile: rename Field's Width field to Offset

gorename -from '"cmd/compile/internal/gc".Field.Width' -to Offset

Passes toolstash -cmp.

Change-Id: I310538a1f60bbab470a6375e813e9d5eb52c5bbf
Reviewed-on: https://go-review.googlesource.com/21230Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/compile/internal/gc/alg.go

@@ -566,8 +566,8 @@ func memrun(t *Type, fields []*Field, start int) (size int64, next int) {
 			break
 		}
 	}
-	end := fields[next-1].Width + fields[next-1].Type.Width
-	return end - fields[start].Width, next
+	end := fields[next-1].Offset + fields[next-1].Type.Width
+	return end - fields[start].Offset, next
 }
 
 // ispaddedfield reports whether the i'th field of struct type t is followed
@@ -579,7 +579,7 @@ func ispaddedfield(t *Type, fields []*Field, i int) bool {
 	}
 	end := t.Width
 	if i+1 < len(fields) {
-		end = fields[i+1].Width
+		end = fields[i+1].Offset
 	}
-	return fields[i].Width+fields[i].Type.Width != end
+	return fields[i].Offset+fields[i].Type.Width != end
 }

src/cmd/compile/internal/gc/align.go

@@ -18,7 +18,7 @@ func Rnd(o int64, r int64) int64 {
 func offmod(t *Type) {
 	o := int32(0)
 	for _, f := range t.Fields().Slice() {
-		f.Width = int64(o)
+		f.Offset = int64(o)
 		o += int32(Widthptr)
 		if int64(o) >= Thearch.MAXWIDTH {
 			Yyerror("interface too large")
@@ -53,7 +53,7 @@ func widstruct(errtype *Type, t *Type, o int64, flag int) int64 {
 		if f.Type.Align > 0 {
 			o = Rnd(o, int64(f.Type.Align))
 		}
-		f.Width = o // really offset for TFIELD
+		f.Offset = o
 		if f.Nname != nil {
 			// this same stackparam logic is in addrescapes
 			// in typecheck.go.  usually addrescapes runs after
@@ -388,7 +388,7 @@ func Argsize(t *Type) int {
 
 	for _, p := range recvsParamsResults {
 		for _, f := range p(t).Fields().Slice() {
-			if x := f.Width + f.Type.Width; x > w {
+			if x := f.Offset + f.Type.Width; x > w {
 				w = x
 			}
 		}

src/cmd/compile/internal/gc/cgen.go

@@ -1681,7 +1681,7 @@ func Igen(n *Node, a *Node, res *Node) {
 		a.Op = OINDREG
 		a.Reg = int16(Thearch.REGSP)
 		a.Addable = true
-		a.Xoffset = fp.Width + Ctxt.FixedFrameSize()
+		a.Xoffset = fp.Offset + Ctxt.FixedFrameSize()
 		a.Type = n.Type
 		return
 
@@ -2226,7 +2226,7 @@ func stkof(n *Node) int64 {
 
 		f := t.Results().Field(0)
 		if f != nil {
-			return f.Width + Ctxt.FixedFrameSize()
+			return f.Offset + Ctxt.FixedFrameSize()
 		}
 	}
 
@@ -2565,7 +2565,7 @@ func cgen_callret(n *Node, res *Node) {
 	nod.Reg = int16(Thearch.REGSP)
 	nod.Addable = true
 
-	nod.Xoffset = fp.Width + Ctxt.FixedFrameSize()
+	nod.Xoffset = fp.Offset + Ctxt.FixedFrameSize()
 	nod.Type = fp.Type
 	Cgen_as(res, &nod)
 }
@@ -2588,7 +2588,7 @@ func cgen_aret(n *Node, res *Node) {
 	nod1.Op = OINDREG
 	nod1.Reg = int16(Thearch.REGSP)
 	nod1.Addable = true
-	nod1.Xoffset = fp.Width + Ctxt.FixedFrameSize()
+	nod1.Xoffset = fp.Offset + Ctxt.FixedFrameSize()
 	nod1.Type = fp.Type
 
 	if res.Op != OREGISTER {

src/cmd/compile/internal/gc/export.go

@@ -601,7 +601,7 @@ func dumpasmhdr() {
 			fmt.Fprintf(b, "#define %s__size %d\n", t.Sym.Name, int(t.Width))
 			for _, t := range t.Fields().Slice() {
 				if !isblanksym(t.Sym) {
-					fmt.Fprintf(b, "#define %s_%s %d\n", n.Sym.Name, t.Sym.Name, int(t.Width))
+					fmt.Fprintf(b, "#define %s_%s %d\n", n.Sym.Name, t.Sym.Name, int(t.Offset))
 				}
 			}
 		}

src/cmd/compile/internal/gc/gen.go

@@ -1235,7 +1235,7 @@ func visitComponents(t *Type, startOffset int64, f func(elem *Type, elemOffset i
 		}
 
 		for _, field := range t.Fields().Slice() {
-			if !visitComponents(field.Type, startOffset+field.Width, f) {
+			if !visitComponents(field.Type, startOffset+field.Offset, f) {
 				return false
 			}
 		}

src/cmd/compile/internal/gc/gsubr.go

@@ -551,10 +551,10 @@ func nodarg(t interface{}, fp int) *Node {
 		if first == nil {
 			Fatalf("nodarg: bad struct")
 		}
-		if first.Width == BADWIDTH {
+		if first.Offset == BADWIDTH {
 			Fatalf("nodarg: offset not computed for %v", t)
 		}
-		n.Xoffset = first.Width
+		n.Xoffset = first.Offset
 		n.Addable = true
 	case *Field:
 		if fp == 1 || fp == -1 {
@@ -568,10 +568,10 @@ func nodarg(t interface{}, fp int) *Node {
 		n = Nod(ONAME, nil, nil)
 		n.Type = t.Type
 		n.Sym = t.Sym
-		if t.Width == BADWIDTH {
+		if t.Offset == BADWIDTH {
 			Fatalf("nodarg: offset not computed for %v", t)
 		}
-		n.Xoffset = t.Width
+		n.Xoffset = t.Offset
 		n.Addable = true
 		n.Orig = t.Nname
 	default:

src/cmd/compile/internal/gc/plive.go

@@ -939,7 +939,7 @@ func onebitwalktype1(t *Type, xoffset *int64, bv Bvec) {
 	case TSTRUCT:
 		var o int64
 		for _, t1 := range t.Fields().Slice() {
-			fieldoffset := t1.Width
+			fieldoffset := t1.Offset
 			*xoffset += fieldoffset - o
 			onebitwalktype1(t1.Type, xoffset, bv)
 			o = fieldoffset + t1.Type.Width

src/cmd/compile/internal/gc/reflect.go

@@ -144,7 +144,7 @@ func mapbucket(t *Type) *Type {
 
 	// Double-check that overflow field is final memory in struct,
 	// with no padding at end. See comment above.
-	if ovf.Width != bucket.Width-int64(Widthptr) {
+	if ovf.Offset != bucket.Width-int64(Widthptr) {
 		Yyerror("bad math in mapbucket for %v", t)
 	}
 
@@ -754,7 +754,7 @@ func typeptrdata(t *Type) int64 {
 				lastPtrField = t1
 			}
 		}
-		return lastPtrField.Width + typeptrdata(lastPtrField.Type)
+		return lastPtrField.Offset + typeptrdata(lastPtrField.Type)
 
 	default:
 		Fatalf("typeptrdata: unexpected type, %v", t)
@@ -1273,7 +1273,7 @@ ok:
 			// ../../../../runtime/type.go:/structField
 			ot = dnameField(s, ot, f)
 			ot = dsymptr(s, ot, dtypesym(f.Type), 0)
-			ot = duintptr(s, ot, uint64(f.Width)) // field offset
+			ot = duintptr(s, ot, uint64(f.Offset))
 		}
 	}
 
@@ -1619,7 +1619,7 @@ func (p *GCProg) emit(t *Type, offset int64) {
 
 	case TSTRUCT:
 		for _, t1 := range t.Fields().Slice() {
-			p.emit(t1.Type, offset+t1.Width)
+			p.emit(t1.Type, offset+t1.Offset)
 		}
 	}
 }

src/cmd/compile/internal/gc/ssa.go

@@ -2565,7 +2565,7 @@ func (s *state) call(n *Node, k callKind) *ssa.Value {
 		return nil
 	}
 	fp := res.Field(0)
-	return s.entryNewValue1I(ssa.OpOffPtr, Ptrto(fp.Type), fp.Width, s.sp)
+	return s.entryNewValue1I(ssa.OpOffPtr, Ptrto(fp.Type), fp.Offset, s.sp)
 }
 
 // etypesign returns the signed-ness of e, for integer/pointer etypes.
@@ -4127,7 +4127,7 @@ func fieldIdx(n *Node) int {
 			i++
 			continue
 		}
-		if t1.Width != n.Xoffset {
+		if t1.Offset != n.Xoffset {
 			panic("field offset doesn't match")
 		}
 		return i

src/cmd/compile/internal/gc/type.go

@@ -167,7 +167,11 @@ type Field struct {
 	Nname *Node
 
 	Type *Type // field type
-	Width int64   // TODO(mdempsky): Rename to offset.
+
+	// Offset in bytes of this field or method within its enclosing struct
+	// or interface Type.
+	Offset int64
+
 	Note *string // literal string annotation
 }
 
@@ -226,7 +230,7 @@ func typ(et EType) *Type {
 
 func newField() *Field {
 	return &Field{
-		Width: BADWIDTH,
+		Offset: BADWIDTH,
 	}
 }
 
@@ -672,7 +676,7 @@ func (t *Type) FieldType(i int) ssa.Type {
 	return t.Field(i).Type
 }
 func (t *Type) FieldOff(i int) int64 {
-	return t.Field(i).Width
+	return t.Field(i).Offset
 }
 
 func (t *Type) NumElem() int64 {

src/cmd/compile/internal/gc/typecheck.go

@@ -2407,7 +2407,7 @@ func looktypedot(n *Node, t *Type, dostrcmp int) bool {
 		}
 
 		n.Sym = methodsym(n.Sym, t, 0)
-		n.Xoffset = f1.Width
+		n.Xoffset = f1.Offset
 		n.Type = f1.Type
 		n.Op = ODOTINTER
 		return true
@@ -2433,7 +2433,7 @@ func looktypedot(n *Node, t *Type, dostrcmp int) bool {
 	}
 
 	n.Sym = methodsym(n.Sym, t, 0)
-	n.Xoffset = f2.Width
+	n.Xoffset = f2.Offset
 	n.Type = f2.Type
 	n.Op = ODOTMETH
 	return true
@@ -2482,10 +2482,10 @@ func lookdot(n *Node, t *Type, dostrcmp int) *Field {
 		if f2 != nil {
 			Yyerror("%v is both field and method", n.Sym)
 		}
-		if f1.Width == BADWIDTH {
+		if f1.Offset == BADWIDTH {
 			Fatalf("lookdot badwidth %v %p", f1, f1)
 		}
-		n.Xoffset = f1.Width
+		n.Xoffset = f1.Offset
 		n.Type = f1.Type
 		if obj.Fieldtrack_enabled > 0 {
 			dotField[typeSym{t.Orig, s}] = f1
@@ -2552,7 +2552,7 @@ func lookdot(n *Node, t *Type, dostrcmp int) *Field {
 		}
 
 		n.Sym = methodsym(n.Sym, n.Left.Type, 0)
-		n.Xoffset = f2.Width
+		n.Xoffset = f2.Offset
 		n.Type = f2.Type
 
 		//		print("lookdot found [%p] %T\n", f2->type, f2->type);
@@ -3060,7 +3060,7 @@ func typecheckcomplit(n *Node) *Node {
 				n1 = assignconv(n1, f.Type, "field value")
 				n1 = Nod(OKEY, newname(f.Sym), n1)
 				n1.Left.Type = structkey
-				n1.Left.Xoffset = f.Width
+				n1.Left.Xoffset = f.Offset
 				n1.Left.Typecheck = 1
 				ls[i1] = n1
 				f = it.Next()
@@ -3110,7 +3110,7 @@ func typecheckcomplit(n *Node) *Node {
 
 				l.Left = newname(s)
 				l.Left.Type = structkey
-				l.Left.Xoffset = f.Width
+				l.Left.Xoffset = f.Offset
 				l.Left.Typecheck = 1
 				s = f.Sym
 				fielddup(newname(s), hash)