cmd/compile: split Addrconst out of Naddr

There are only three Prog types that we were creating with an OLITERAL
Node: ATEXT, ATYPE, and AFUNCDATA. ATEXT's value we later overwrite in
defframe, and ATYPE's we don't even need. AFUNCDATA only needs integer
constants, so get rid of all the non-int constant logic and skip
creating a Node representation for the constant.

While here, there are a few other Naddr code paths that are no longer
needed, so turn those into Fatalfs.

Passes toolstash/buildall.

Change-Id: I4cc9b92c3011890afd4f31ebeba8b1b42b753cab
Reviewed-on: https://go-review.googlesource.com/30074
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -177,72 +177,45 @@ func Naddr(a *obj.Addr, n *Node) {
 		return
 	}
 
-	switch n.Op {
-	default:
-		a := a // copy to let escape into Ctxt.Dconv
+	if n.Op != ONAME {
 		Debug['h'] = 1
 		Dump("naddr", n)
 		Fatalf("naddr: bad %v %v", n.Op, Ctxt.Dconv(a))
+	}
 
-	case ONAME:
-		a.Offset = n.Xoffset
-		s := n.Sym
-		a.Node = n.Orig
-
-		//if(a->node >= (Node*)&n)
-		//	fatal("stack node");
-		if s == nil {
-			s = lookup(".noname")
-		}
-		if n.Name.Method && n.Type != nil && n.Type.Sym != nil && n.Type.Sym.Pkg != nil {
-			s = Pkglookup(s.Name, n.Type.Sym.Pkg)
-		}
-
-		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
+	a.Offset = n.Xoffset
+	s := n.Sym
+	a.Node = n.Orig
 
-		case PPARAM, PPARAMOUT:
-			a.Name = obj.NAME_PARAM
-		}
-
-		a.Sym = Linksym(s)
+	if s == nil {
+		Fatalf("naddr: nil sym %v", n)
+	}
+	if n.Name.Method && n.Type != nil && n.Type.Sym != nil && n.Type.Sym.Pkg != nil {
+		Fatalf("naddr: weird method %v", n)
+	}
 
-	case OLITERAL:
-		switch u := n.Val().U.(type) {
-		default:
-			Fatalf("naddr: const %L", n.Type)
+	a.Type = obj.TYPE_MEM
+	switch n.Class {
+	default:
+		Fatalf("naddr: ONAME class %v %d\n", n.Sym, n.Class)
 
-		case *Mpflt:
-			a.Type = obj.TYPE_FCONST
-			a.Val = u.Float64()
+	case PEXTERN, PFUNC:
+		a.Name = obj.NAME_EXTERN
 
-		case *Mpint:
-			a.Sym = nil
-			a.Type = obj.TYPE_CONST
-			a.Offset = u.Int64()
+	case PAUTO:
+		a.Name = obj.NAME_AUTO
 
-		case string:
-			datagostring(u, a)
+	case PPARAM, PPARAMOUT:
+		a.Name = obj.NAME_PARAM
+	}
 
-		case bool:
-			a.Sym = nil
-			a.Type = obj.TYPE_CONST
-			a.Offset = int64(obj.Bool2int(u))
+	a.Sym = Linksym(s)
+}
 
-		case *NilVal:
-			a.Sym = nil
-			a.Type = obj.TYPE_CONST
-			a.Offset = 0
-		}
-	}
+func Addrconst(a *obj.Addr, v int64) {
+	a.Sym = nil
+	a.Type = obj.TYPE_CONST
+	a.Offset = v
 }
 
 func newplist() *obj.Plist {

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

@@ -17,14 +17,12 @@ import (
 var makefuncdatasym_nsym int
 
 func makefuncdatasym(nameprefix string, funcdatakind int64) *Sym {
-	var nod Node
-
 	sym := lookupN(nameprefix, makefuncdatasym_nsym)
 	makefuncdatasym_nsym++
 	pnod := newname(sym)
 	pnod.Class = PEXTERN
-	Nodconst(&nod, Types[TINT32], funcdatakind)
-	Gins(obj.AFUNCDATA, &nod, pnod)
+	p := Gins(obj.AFUNCDATA, nil, pnod)
+	Addrconst(&p.From, funcdatakind)
 	return sym
 }
 
@@ -376,13 +374,11 @@ func compile(fn *Node) {
 
 	setlineno(Curfn)
 
-	var nod1 Node
-	Nodconst(&nod1, Types[TINT32], 0)
 	nam := Curfn.Func.Nname
 	if isblank(nam) {
 		nam = nil
 	}
-	ptxt := Gins(obj.ATEXT, nam, &nod1)
+	ptxt := Gins(obj.ATEXT, nam, nil)
 	ptxt.From3 = new(obj.Addr)
 	if fn.Func.Dupok {
 		ptxt.From3.Offset |= obj.DUPOK
@@ -432,8 +428,7 @@ func compile(fn *Node) {
 		}
 		switch n.Class {
 		case PAUTO, PPARAM, PPARAMOUT:
-			Nodconst(&nod1, Types[TUINTPTR], n.Type.Width)
-			p := Gins(obj.ATYPE, n, &nod1)
+			p := Gins(obj.ATYPE, n, nil)
 			p.From.Gotype = Linksym(ngotype(n))
 		}
 	}