[dev.regabi] cmd/compile: more Linksym cleanup

This largely gets rid of the remaining direct Linksym calls, hopefully
enough to discourage people from following bad existing practice until
Sym.Linksym can be removed entirely.

Passes toolstash -cmp.

Change-Id: I5d8f8f703ace7256538fc79648891ede0d879dc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/280641
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

6 files changed, 46 insertions, 66 deletions

diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index 45eadf719e..1e8ac8ebb2 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -148,8 +148,8 @@ func dumpdata() {
 	dumpglobls(typecheck.Target.Externs[numExterns:])
 
 	if reflectdata.ZeroSize > 0 {
-		zero := ir.Pkgs.Map.Lookup("zero")
-		objw.Global(zero.Linksym(), int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
+		zero := ir.Pkgs.Map.Lookup("zero").Linksym()
+		objw.Global(zero, int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
 	}
 
 	addGCLocals()
diff --git a/src/cmd/compile/internal/pkginit/init.go b/src/cmd/compile/internal/pkginit/init.go
index 8e3592700c..f1ffbb5933 100644
--- a/src/cmd/compile/internal/pkginit/init.go
+++ b/src/cmd/compile/internal/pkginit/init.go
@@ -56,7 +56,7 @@ func Task() *ir.Name {
 		typecheck.Stmts(nf)
 		ir.CurFunc = nil
 		typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
-		fns = append(fns, initializers.Linksym())
+		fns = append(fns, fn.Linksym())
 	}
 	if typecheck.InitTodoFunc.Dcl != nil {
 		// We only generate temps using initTodo if there
@@ -87,7 +87,7 @@ func Task() *ir.Name {
 	task.SetType(types.Types[types.TUINT8]) // fake type
 	task.Class_ = ir.PEXTERN
 	sym.Def = task
-	lsym := sym.Linksym()
+	lsym := task.Linksym()
 	ot := 0
 	ot = objw.Uintptr(lsym, ot, 0) // state: not initialized yet
 	ot = objw.Uintptr(lsym, ot, uint64(len(deps)))
diff --git a/src/cmd/compile/internal/reflectdata/alg.go b/src/cmd/compile/internal/reflectdata/alg.go
index 5603aefa77..d23ca6c7aa 100644
--- a/src/cmd/compile/internal/reflectdata/alg.go
+++ b/src/cmd/compile/internal/reflectdata/alg.go
@@ -255,7 +255,7 @@ func genhash(t *types.Type) *obj.LSym {
 
 	// Build closure. It doesn't close over any variables, so
 	// it contains just the function pointer.
-	objw.SymPtr(closure, 0, sym.Linksym(), 0)
+	objw.SymPtr(closure, 0, fn.Linksym(), 0)
 	objw.Global(closure, int32(types.PtrSize), obj.DUPOK|obj.RODATA)
 
 	return closure
@@ -634,7 +634,7 @@ func geneq(t *types.Type) *obj.LSym {
 	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
 
 	// Generate a closure which points at the function we just generated.
-	objw.SymPtr(closure, 0, sym.Linksym(), 0)
+	objw.SymPtr(closure, 0, fn.Linksym(), 0)
 	objw.Global(closure, int32(types.PtrSize), obj.DUPOK|obj.RODATA)
 	return closure
 }
diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
index 87f381fbdd..5f88262ddf 100644
--- a/src/cmd/compile/internal/reflectdata/reflect.go
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -52,13 +52,13 @@ var (
 	signatslice []*types.Type
 
 	itabs []itabEntry
-	ptabs []ptabEntry
+	ptabs []*ir.Name
 )
 
 type typeSig struct {
 	name  *types.Sym
-	isym  *types.Sym
-	tsym  *types.Sym
+	isym  *obj.LSym
+	tsym  *obj.LSym
 	type_ *types.Type
 	mtype *types.Type
 }
@@ -327,21 +327,19 @@ func methods(t *types.Type) []*typeSig {
 	// generating code if necessary.
 	var ms []*typeSig
 	for _, f := range mt.AllMethods().Slice() {
+		if f.Sym == nil {
+			base.Fatalf("method with no sym on %v", mt)
+		}
 		if !f.IsMethod() {
-			base.Fatalf("non-method on %v method %v %v\n", mt, f.Sym, f)
+			base.Fatalf("non-method on %v method %v %v", mt, f.Sym, f)
 		}
 		if f.Type.Recv() == nil {
-			base.Fatalf("receiver with no type on %v method %v %v\n", mt, f.Sym, f)
+			base.Fatalf("receiver with no type on %v method %v %v", mt, f.Sym, f)
 		}
 		if f.Nointerface() {
 			continue
 		}
 
-		method := f.Sym
-		if method == nil {
-			break
-		}
-
 		// get receiver type for this particular method.
 		// if pointer receiver but non-pointer t and
 		// this is not an embedded pointer inside a struct,
@@ -351,29 +349,13 @@ func methods(t *types.Type) []*typeSig {
 		}
 
 		sig := &typeSig{
-			name:  method,
-			isym:  ir.MethodSym(it, method),
-			tsym:  ir.MethodSym(t, method),
+			name:  f.Sym,
+			isym:  methodWrapper(it, f),
+			tsym:  methodWrapper(t, f),
 			type_: typecheck.NewMethodType(f.Type, t),
 			mtype: typecheck.NewMethodType(f.Type, nil),
 		}
 		ms = append(ms, sig)
-
-		this := f.Type.Recv().Type
-
-		if !sig.isym.Siggen() {
-			sig.isym.SetSiggen(true)
-			if !types.Identical(this, it) {
-				genwrapper(it, f, sig.isym)
-			}
-		}
-
-		if !sig.tsym.Siggen() {
-			sig.tsym.SetSiggen(true)
-			if !types.Identical(this, t) {
-				genwrapper(t, f, sig.tsym)
-			}
-		}
 	}
 
 	return ms
@@ -407,11 +389,7 @@ func imethods(t *types.Type) []*typeSig {
 		// IfaceType.Method is not in the reflect data.
 		// Generate the method body, so that compiled
 		// code can refer to it.
-		isym := ir.MethodSym(t, f.Sym)
-		if !isym.Siggen() {
-			isym.SetSiggen(true)
-			genwrapper(t, f, isym)
-		}
+		methodWrapper(t, f)
 	}
 
 	return methods
@@ -636,8 +614,8 @@ func dextratypeData(lsym *obj.LSym, ot int, t *types.Type) int {
 
 		ot = objw.SymPtrOff(lsym, ot, nsym)
 		ot = dmethodptrOff(lsym, ot, WriteType(a.mtype))
-		ot = dmethodptrOff(lsym, ot, a.isym.Linksym())
-		ot = dmethodptrOff(lsym, ot, a.tsym.Linksym())
+		ot = dmethodptrOff(lsym, ot, a.isym)
+		ot = dmethodptrOff(lsym, ot, a.tsym)
 	}
 	return ot
 }
@@ -884,7 +862,7 @@ func ITabAddr(t, itype *types.Type) *ir.AddrExpr {
 		n.Class_ = ir.PEXTERN
 		n.SetTypecheck(1)
 		s.Def = n
-		itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: s.Linksym()})
+		itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: n.Linksym()})
 	}
 
 	n := typecheck.NodAddr(ir.AsNode(s.Def))
@@ -1281,7 +1259,7 @@ func genfun(t, it *types.Type) []*obj.LSym {
 	// so we can find the intersect in a single pass
 	for _, m := range methods {
 		if m.name == sigs[0].name {
-			out = append(out, m.isym.Linksym())
+			out = append(out, m.isym)
 			sigs = sigs[1:]
 			if len(sigs) == 0 {
 				break
@@ -1390,8 +1368,12 @@ func WriteTabs() {
 			//	name nameOff
 			//	typ  typeOff // pointer to symbol
 			// }
-			nsym := dname(p.s.Name, "", nil, true)
-			tsym := WriteType(p.t)
+			nsym := dname(p.Sym().Name, "", nil, true)
+			t := p.Type()
+			if p.Class_ != ir.PFUNC {
+				t = types.NewPtr(t)
+			}
+			tsym := WriteType(t)
 			ot = objw.SymPtrOff(s, ot, nsym)
 			ot = objw.SymPtrOff(s, ot, tsym)
 			// Plugin exports symbols as interfaces. Mark their types
@@ -1403,7 +1385,7 @@ func WriteTabs() {
 		ot = 0
 		s = base.Ctxt.Lookup("go.plugin.exports")
 		for _, p := range ptabs {
-			ot = objw.SymPtr(s, ot, p.s.Linksym(), 0)
+			ot = objw.SymPtr(s, ot, p.Linksym(), 0)
 		}
 		objw.Global(s, int32(ot), int16(obj.RODATA))
 	}
@@ -1722,13 +1704,7 @@ func CollectPTabs() {
 		if s.Pkg.Name != "main" {
 			continue
 		}
-		if n.Type().Kind() == types.TFUNC && n.Class_ == ir.PFUNC {
-			// function
-			ptabs = append(ptabs, ptabEntry{s: s, t: s.Def.Type()})
-		} else {
-			// variable
-			ptabs = append(ptabs, ptabEntry{s: s, t: types.NewPtr(s.Def.Type())})
-		}
+		ptabs = append(ptabs, n)
 	}
 }
 
@@ -1752,22 +1728,28 @@ func CollectPTabs() {
 //
 //	rcvr - U
 //	method - M func (t T)(), a TFIELD type struct
-//	newnam - the eventual mangled name of this function
-func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
-	if false && base.Flag.LowerR != 0 {
-		fmt.Printf("genwrapper rcvrtype=%v method=%v newnam=%v\n", rcvr, method, newnam)
+func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
+	newnam := ir.MethodSym(rcvr, method.Sym)
+	lsym := newnam.Linksym()
+	if newnam.Siggen() {
+		return lsym
+	}
+	newnam.SetSiggen(true)
+
+	if types.Identical(rcvr, method.Type.Recv().Type) {
+		return lsym
 	}
 
 	// Only generate (*T).M wrappers for T.M in T's own package.
 	if rcvr.IsPtr() && rcvr.Elem() == method.Type.Recv().Type &&
 		rcvr.Elem().Sym() != nil && rcvr.Elem().Sym().Pkg != types.LocalPkg {
-		return
+		return lsym
 	}
 
 	// Only generate I.M wrappers for I in I's own package
 	// but keep doing it for error.Error (was issue #29304).
 	if rcvr.IsInterface() && rcvr.Sym() != nil && rcvr.Sym().Pkg != types.LocalPkg && rcvr != types.ErrorType {
-		return
+		return lsym
 	}
 
 	base.Pos = base.AutogeneratedPos
@@ -1827,10 +1809,6 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 		}
 	}
 
-	if false && base.Flag.LowerR != 0 {
-		ir.DumpList("genwrapper body", fn.Body)
-	}
-
 	typecheck.FinishFuncBody()
 	if base.Debug.DclStack != 0 {
 		types.CheckDclstack()
@@ -1850,6 +1828,8 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 
 	ir.CurFunc = nil
 	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+
+	return lsym
 }
 
 var ZeroSize int64
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 15c023d332..3c94ec4c95 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -4578,7 +4578,7 @@ func (s *state) openDeferExit() {
 				call = s.newValue3A(ssa.OpClosureCall, types.TypeMem, aux, codeptr, v, s.mem())
 			}
 		} else {
-			aux := ssa.StaticAuxCall(fn.Sym().Linksym(), ACArgs, ACResults)
+			aux := ssa.StaticAuxCall(fn.(*ir.Name).Linksym(), ACArgs, ACResults)
 			if testLateExpansion {
 				callArgs = append(callArgs, s.mem())
 				call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
diff --git a/src/cmd/compile/internal/staticdata/data.go b/src/cmd/compile/internal/staticdata/data.go
index 260731244f..27d9cec06d 100644
--- a/src/cmd/compile/internal/staticdata/data.go
+++ b/src/cmd/compile/internal/staticdata/data.go
@@ -209,7 +209,7 @@ func slicedata(pos src.XPos, s string) *ir.Name {
 	symnode := typecheck.NewName(sym)
 	sym.Def = symnode
 
-	lsym := sym.Linksym()
+	lsym := symnode.Linksym()
 	off := dstringdata(lsym, 0, s, pos, "slice")
 	objw.Global(lsym, int32(off), obj.NOPTR|obj.LOCAL)