cmd/compile/internal/gc: clean up closure.go

Change-Id: I01bfab595c50582c5adf958dcecbd58524dbc28f
Reviewed-on: https://go-review.googlesource.com/28212
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/compile/internal/gc/closure.go b/src/cmd/compile/internal/gc/closure.go
index 66c710f8e532ba10ed434ce721cb5cd496c3e04b..ccf15b8e838b45b18728549f0dabd3468cafffe5 100644 (file)
--- a/src/cmd/compile/internal/gc/closure.go
+++ b/src/cmd/compile/internal/gc/closure.go
@@ -10,9 +10,6 @@ import (
 
 // function literals aka closures
 func closurehdr(ntype *Node) {
-       var name *Node
-       var a *Node
-
        n := Nod(OCLOSURE, nil, nil)
        n.Func.Ntype = ntype
        n.Func.Depth = Funcdepth
@@ -31,11 +28,11 @@ func closurehdr(ntype *Node) {
        ntype.List.Set(nil)
        ntype.Rlist.Set(nil)
        for _, n1 := range n.List.Slice() {
-               name = n1.Left
+               name := n1.Left
                if name != nil {
                        name = newname(name.Sym)
                }
-               a = Nod(ODCLFIELD, name, n1.Right)
+               a := Nod(ODCLFIELD, name, n1.Right)
                a.Isddd = n1.Isddd
                if name != nil {
                        name.Isddd = a.Isddd
@@ -43,7 +40,7 @@ func closurehdr(ntype *Node) {
                ntype.List.Append(a)
        }
        for _, n2 := range n.Rlist.Slice() {
-               name = n2.Left
+               name := n2.Left
                if name != nil {
                        name = newname(name.Sym)
                }
@@ -164,14 +161,15 @@ func closurename(n *Node) *Sym {
        gen := 0
        outer := ""
        prefix := ""
-       if n.Func.Outerfunc == nil {
+       switch {
+       case n.Func.Outerfunc == nil:
                // Global closure.
                outer = "glob."
 
                prefix = "func"
                closurename_closgen++
                gen = closurename_closgen
-       } else if n.Func.Outerfunc.Op == ODCLFUNC {
+       case n.Func.Outerfunc.Op == ODCLFUNC:
                // The outermost closure inside of a named function.
                outer = n.Func.Outerfunc.Func.Nname.Sym.Name
 
@@ -187,14 +185,14 @@ func closurename(n *Node) *Sym {
                        closurename_closgen++
                        gen = closurename_closgen
                }
-       } else if n.Func.Outerfunc.Op == OCLOSURE {
+       case n.Func.Outerfunc.Op == OCLOSURE:
                // Nested closure, recurse.
                outer = closurename(n.Func.Outerfunc).Name
 
                prefix = ""
                n.Func.Outerfunc.Func.Closgen++
                gen = n.Func.Outerfunc.Func.Closgen
-       } else {
+       default:
                Fatalf("closurename called for %v", Nconv(n, FmtShort))
        }
        n.Sym = Lookupf("%s.%s%d", outer, prefix, gen)
@@ -374,15 +372,13 @@ func transformclosure(xfunc *Node) {
                // The closure is not called, so it is going to stay as closure.
                var body []*Node
                offset := int64(Widthptr)
-               var addr *Node
-               var cv *Node
                for _, v := range func_.Func.Cvars.Slice() {
                        if v.Op == OXXX {
                                continue
                        }
 
                        // cv refers to the field inside of closure OSTRUCTLIT.
-                       cv = Nod(OCLOSUREVAR, nil, nil)
+                       cv := Nod(OCLOSUREVAR, nil, nil)
 
                        cv.Type = v.Type
                        if !v.Name.Byval {
@@ -401,7 +397,7 @@ func transformclosure(xfunc *Node) {
                        } else {
                                // Declare variable holding addresses taken from closure
                                // and initialize in entry prologue.
-                               addr = newname(Lookupf("&%s", v.Sym.Name))
+                               addr := newname(Lookupf("&%s", v.Sym.Name))
                                addr.Name.Param.Ntype = Nod(OIND, typenod(v.Type), nil)
                                addr.Class = PAUTO
                                addr.Used = true
@@ -481,12 +477,11 @@ func walkclosure(func_ *Node, init *Nodes) *Node {
        typ := Nod(OTSTRUCT, nil, nil)
 
        typ.List.Set1(Nod(ODCLFIELD, newname(Lookup(".F")), typenod(Types[TUINTPTR])))
-       var typ1 *Node
        for _, v := range func_.Func.Cvars.Slice() {
                if v.Op == OXXX {
                        continue
                }
-               typ1 = typenod(v.Type)
+               typ1 := typenod(v.Type)
                if !v.Name.Byval {
                        typ1 = Nod(OIND, typ1, nil)
                }
@@ -579,21 +574,17 @@ func makepartialcall(fn *Node, t0 *Type, meth *Sym) *Node {
        Curfn = nil
 
        xtype := Nod(OTFUNC, nil, nil)
-       i := 0
        var l []*Node
        var callargs []*Node
        ddd := false
        xfunc := Nod(ODCLFUNC, nil, nil)
        Curfn = xfunc
-       var fld *Node
-       var n *Node
-       for _, t := range t0.Params().Fields().Slice() {
-               n = newname(LookupN("a", i))
-               i++
+       for i, t := range t0.Params().Fields().Slice() {
+               n := newname(LookupN("a", i))
                n.Class = PPARAM
                xfunc.Func.Dcl = append(xfunc.Func.Dcl, n)
                callargs = append(callargs, n)
-               fld = Nod(ODCLFIELD, n, typenod(t.Type))
+               fld := Nod(ODCLFIELD, n, typenod(t.Type))
                if t.Isddd {
                        fld.Isddd = true
                        ddd = true
@@ -603,12 +594,10 @@ func makepartialcall(fn *Node, t0 *Type, meth *Sym) *Node {
        }
 
        xtype.List.Set(l)
-       i = 0
        l = nil
        var retargs []*Node
-       for _, t := range t0.Results().Fields().Slice() {
-               n = newname(LookupN("r", i))
-               i++
+       for i, t := range t0.Results().Fields().Slice() {
+               n := newname(LookupN("r", i))
                n.Class = PPARAMOUT
                xfunc.Func.Dcl = append(xfunc.Func.Dcl, n)
                retargs = append(retargs, n)