cmd/internal/dwarf: replace Sym.Length with Context.Size

Preparatory refactoring before next CL.

Change-Id: I06fb4670b933fddff1a2a70f3cf1eb124cbd86ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/524899
Auto-Submit: Matthew Dempsky <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>

Author: mdempsky

src/cmd/internal/dwarf/dwarf.go

@@ -40,7 +40,6 @@ var logDwarf bool
 
 // Sym represents a symbol.
 type Sym interface {
-	Length(dwarfContext interface{}) int64
 }
 
 // A Var represents a local variable or a function parameter.
@@ -189,6 +188,7 @@ type InlCall struct {
 // A Context specifies how to add data to a Sym.
 type Context interface {
 	PtrSize() int
+	Size(s Sym) int64
 	AddInt(s Sym, size int, i int64)
 	AddBytes(s Sym, b []byte)
 	AddAddress(s Sym, t interface{}, ofs int64)
@@ -1322,7 +1322,7 @@ func putInlinedFunc(ctxt Context, s *FnState, callIdx int) error {
 	putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, callee)
 
 	if abbrev == DW_ABRV_INLINED_SUBROUTINE_RANGES {
-		putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, s.Ranges.Length(ctxt), s.Ranges)
+		putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, ctxt.Size(s.Ranges), s.Ranges)
 		s.PutRanges(ctxt, ic.Ranges)
 	} else {
 		st := ic.Ranges[0].Start
@@ -1535,7 +1535,7 @@ func putscope(ctxt Context, s *FnState, scopes []Scope, curscope int32, fnabbrev
 			putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE, DW_FORM_addr, DW_CLS_ADDRESS, scope.Ranges[0].End, s.StartPC)
 		} else {
 			Uleb128put(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_RANGES)
-			putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_RANGES, DW_FORM_sec_offset, DW_CLS_PTR, s.Ranges.Length(ctxt), s.Ranges)
+			putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_RANGES, DW_FORM_sec_offset, DW_CLS_PTR, ctxt.Size(s.Ranges), s.Ranges)
 
 			s.PutRanges(ctxt, scope.Ranges)
 		}
@@ -1684,7 +1684,7 @@ func putvar(ctxt Context, s *FnState, v *Var, absfn Sym, fnabbrev, inlIndex int,
 	}
 
 	if abbrevUsesLoclist(abbrev) {
-		putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, s.Loc.Length(ctxt), s.Loc)
+		putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, ctxt.Size(s.Loc), s.Loc)
 		v.PutLocationList(s.Loc, s.StartPC)
 	} else {
 		loc := encbuf[:0]

src/cmd/internal/obj/dwarf.go

@@ -207,6 +207,9 @@ type dwCtxt struct{ *Link }
 func (c dwCtxt) PtrSize() int {
 	return c.Arch.PtrSize
 }
+func (c dwCtxt) Size(s dwarf.Sym) int64 {
+	return s.(*LSym).Size
+}
 func (c dwCtxt) AddInt(s dwarf.Sym, size int, i int64) {
 	ls := s.(*LSym)
 	ls.WriteInt(c.Link, ls.Size, size, i)
@@ -315,10 +318,6 @@ func (ctxt *Link) dwarfSym(s *LSym) (dwarfInfoSym, dwarfLocSym, dwarfRangesSym,
 	return fn.dwarfInfoSym, fn.dwarfLocSym, fn.dwarfRangesSym, fn.dwarfAbsFnSym, fn.dwarfDebugLinesSym
 }
 
-func (s *LSym) Length(dwarfContext interface{}) int64 {
-	return s.Size
-}
-
 // textPos returns the source position of the first instruction (prog)
 // of the specified function.
 func textPos(fn *LSym) src.XPos {

src/cmd/link/internal/ld/dwarf.go

@@ -73,15 +73,14 @@ type dwctxt struct {
 // DwAttr objects contain references to symbols via this type.
 type dwSym loader.Sym
 
-func (s dwSym) Length(dwarfContext interface{}) int64 {
-	l := dwarfContext.(dwctxt).ldr
-	return int64(len(l.Data(loader.Sym(s))))
-}
-
 func (c dwctxt) PtrSize() int {
 	return c.arch.PtrSize
 }
 
+func (c dwctxt) Size(s dwarf.Sym) int64 {
+	return int64(len(c.ldr.Data(loader.Sym(s.(dwSym)))))
+}
+
 func (c dwctxt) AddInt(s dwarf.Sym, size int, i int64) {
 	ds := loader.Sym(s.(dwSym))
 	dsu := c.ldr.MakeSymbolUpdater(ds)