cmd/compile: eliminate Gins and Naddr

Preparation for eliminating Prog-related globals.

Passes toolstash-check -all.

Updates #15756

Change-Id: Ia199fcb282cc3a84903a6e92a3ce342c5faba79c
Reviewed-on: https://go-review.googlesource.com/38409
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/fmt_test.go

@@ -653,7 +653,6 @@ var knownFormats = map[string]string{
 	"cmd/compile/internal/syntax.token %d":            "",
 	"cmd/compile/internal/syntax.token %q":            "",
 	"cmd/compile/internal/syntax.token %s":            "",
-	"cmd/internal/obj.As %v":                          "",
 	"cmd/internal/src.Pos %s":                         "",
 	"cmd/internal/src.Pos %v":                         "",
 	"error %v":                                        "",

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

@@ -109,44 +109,6 @@ func isfat(t *Type) bool {
 	return false
 }
 
-// Naddr rewrites a to refer to n.
-// It assumes that a is zeroed on entry.
-func Naddr(a *obj.Addr, n *Node) {
-	if n == nil {
-		return
-	}
-
-	if n.Op != ONAME {
-		Debug['h'] = 1
-		Dump("naddr", n)
-		Fatalf("naddr: bad %v %v", n.Op, Ctxt.Dconv(a))
-	}
-
-	a.Offset = n.Xoffset
-	s := n.Sym
-
-	if s == nil {
-		Fatalf("naddr: nil sym %v", n)
-	}
-
-	a.Type = obj.TYPE_MEM
-	switch n.Class {
-	default:
-		Fatalf("naddr: ONAME class %v %d\n", n.Sym, n.Class)
-
-	case PEXTERN, PFUNC:
-		a.Name = obj.NAME_EXTERN
-
-	case PAUTO:
-		a.Name = obj.NAME_AUTO
-
-	case PPARAM, PPARAMOUT:
-		a.Name = obj.NAME_PARAM
-	}
-
-	a.Sym = Linksym(s)
-}
-
 func Addrconst(a *obj.Addr, v int64) {
 	a.Sym = nil
 	a.Type = obj.TYPE_CONST
@@ -277,17 +239,3 @@ func Patch(p *obj.Prog, to *obj.Prog) {
 	p.To.Val = to
 	p.To.Offset = to.Pc
 }
-
-// Gins inserts instruction as. f is from, t is to.
-func Gins(as obj.As, f, t *Node) *obj.Prog {
-	switch as {
-	case obj.ATEXT, obj.AFUNCDATA:
-	default:
-		Fatalf("unhandled gins op %v", as)
-	}
-
-	p := Prog(as)
-	Naddr(&p.From, f)
-	Naddr(&p.To, t)
-	return p
-}

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

@@ -316,12 +316,15 @@ func compile(fn *Node) {
 
 	setlineno(fn)
 
-	nam := fn.Func.Nname
-	if isblank(nam) {
-		nam = nil
+	ptxt := Prog(obj.ATEXT)
+	if nam := fn.Func.Nname; !isblank(nam) {
+		ptxt.From.Type = obj.TYPE_MEM
+		ptxt.From.Name = obj.NAME_EXTERN
+		ptxt.From.Sym = Linksym(nam.Sym)
+		if fn.Func.Pragma&Systemstack != 0 {
+			ptxt.From.Sym.Set(obj.AttrCFunc, true)
+		}
 	}
-	ptxt := Gins(obj.ATEXT, nam, nil)
-	fnsym := ptxt.From.Sym
 
 	ptxt.From3 = new(obj.Addr)
 	if fn.Func.Dupok() {
@@ -342,9 +345,6 @@ func compile(fn *Node) {
 	if fn.Func.ReflectMethod() {
 		ptxt.From3.Offset |= obj.REFLECTMETHOD
 	}
-	if fn.Func.Pragma&Systemstack != 0 {
-		ptxt.From.Sym.Set(obj.AttrCFunc, true)
-	}
 
 	// Clumsy but important.
 	// See test/recover.go for test cases and src/reflect/value.go
@@ -357,10 +357,10 @@ func compile(fn *Node) {
 
 	genssa(ssafn, ptxt)
 
+	fieldtrack(ptxt.From.Sym, fn.Func.FieldTrack)
+
 	obj.Flushplist(Ctxt, plist) // convert from Prog list to machine code
 	ptxt = nil                  // nil to prevent misuse; Prog may have been freed by Flushplist
-
-	fieldtrack(fnsym, fn.Func.FieldTrack)
 }
 
 func debuginfo(fnsym *obj.LSym) []*dwarf.Var {