cmd/internal/gc, cmd/internal/obj: clean up string returns

An artifact of the c2go translation was
a handful of instances of code like:

var s string
s += "foo"
return s

This CL converts those to simply 'return "foo"'.

The conversion was done mechanically with the
quick-and-dirty cleanup script at
https://gist.github.com/josharian/1fa4408044c163983e62.

I then manually moved a couple of comments in fmt.go.

toolstash -cmp thinks that there are no functional changes.

Change-Id: Ic0ebdd10f0fb8de0360a1041ce5cd10ae1168be9
Reviewed-on: https://go-review.googlesource.com/6265Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/internal/gc/fmt.go

@@ -170,21 +170,15 @@ var goopnames = []string{
 func Oconv(o int, flag int) string {
 	if (flag&obj.FmtSharp != 0 /*untyped*/) || fmtmode != FDbg {
 		if o >= 0 && o < len(goopnames) && goopnames[o] != "" {
-			var fp string
-			fp += goopnames[o]
-			return fp
+			return goopnames[o]
 		}
 	}
 
 	if o >= 0 && o < len(opnames) && opnames[o] != "" {
-		var fp string
-		fp += opnames[o]
-		return fp
+		return opnames[o]
 	}
 
-	var fp string
-	fp += fmt.Sprintf("O-%d", o)
-	return fp
+	return fmt.Sprintf("O-%d", o)
 }
 
 var classnames = []string{
@@ -308,9 +302,7 @@ func Vconv(v *Val, flag int) string {
 	switch v.Ctype {
 	case CTINT:
 		if (flag&obj.FmtSharp != 0 /*untyped*/) || fmtmode == FExp {
-			var fp string
-			fp += fmt.Sprintf("%v", Bconv(v.U.Xval, obj.FmtSharp))
-			return fp
+			return fmt.Sprintf("%v", Bconv(v.U.Xval, obj.FmtSharp))
 		}
 		var fp string
 		fp += fmt.Sprintf("%v", Bconv(v.U.Xval, 0))
@@ -319,19 +311,13 @@ func Vconv(v *Val, flag int) string {
 	case CTRUNE:
 		x := Mpgetfix(v.U.Xval)
 		if ' ' <= x && x < 0x80 && x != '\\' && x != '\'' {
-			var fp string
-			fp += fmt.Sprintf("'%c'", int(x))
-			return fp
+			return fmt.Sprintf("'%c'", int(x))
 		}
 		if 0 <= x && x < 1<<16 {
-			var fp string
-			fp += fmt.Sprintf("'\\u%04x'", uint(int(x)))
-			return fp
+			return fmt.Sprintf("'\\u%04x'", uint(int(x)))
 		}
 		if 0 <= x && x <= utf8.MaxRune {
-			var fp string
-			fp += fmt.Sprintf("'\\U%08x'", uint64(x))
-			return fp
+			return fmt.Sprintf("'\\U%08x'", uint64(x))
 		}
 		var fp string
 		fp += fmt.Sprintf("('\\x00' + %v)", Bconv(v.U.Xval, 0))
@@ -339,9 +325,7 @@ func Vconv(v *Val, flag int) string {
 
 	case CTFLT:
 		if (flag&obj.FmtSharp != 0 /*untyped*/) || fmtmode == FExp {
-			var fp string
-			fp += fmt.Sprintf("%v", Fconv(v.U.Fval, 0))
-			return fp
+			return fmt.Sprintf("%v", Fconv(v.U.Fval, 0))
 		}
 		var fp string
 		fp += fmt.Sprintf("%v", Fconv(v.U.Fval, obj.FmtSharp))
@@ -349,24 +333,16 @@ func Vconv(v *Val, flag int) string {
 
 	case CTCPLX:
 		if (flag&obj.FmtSharp != 0 /*untyped*/) || fmtmode == FExp {
-			var fp string
-			fp += fmt.Sprintf("(%v+%vi)", Fconv(&v.U.Cval.Real, 0), Fconv(&v.U.Cval.Imag, 0))
-			return fp
+			return fmt.Sprintf("(%v+%vi)", Fconv(&v.U.Cval.Real, 0), Fconv(&v.U.Cval.Imag, 0))
 		}
 		if mpcmpfltc(&v.U.Cval.Real, 0) == 0 {
-			var fp string
-			fp += fmt.Sprintf("%vi", Fconv(&v.U.Cval.Imag, obj.FmtSharp))
-			return fp
+			return fmt.Sprintf("%vi", Fconv(&v.U.Cval.Imag, obj.FmtSharp))
 		}
 		if mpcmpfltc(&v.U.Cval.Imag, 0) == 0 {
-			var fp string
-			fp += fmt.Sprintf("%v", Fconv(&v.U.Cval.Real, obj.FmtSharp))
-			return fp
+			return fmt.Sprintf("%v", Fconv(&v.U.Cval.Real, obj.FmtSharp))
 		}
 		if mpcmpfltc(&v.U.Cval.Imag, 0) < 0 {
-			var fp string
-			fp += fmt.Sprintf("(%v%vi)", Fconv(&v.U.Cval.Real, obj.FmtSharp), Fconv(&v.U.Cval.Imag, obj.FmtSharp))
-			return fp
+			return fmt.Sprintf("(%v%vi)", Fconv(&v.U.Cval.Real, obj.FmtSharp), Fconv(&v.U.Cval.Imag, obj.FmtSharp))
 		}
 		var fp string
 		fp += fmt.Sprintf("(%v+%vi)", Fconv(&v.U.Cval.Real, obj.FmtSharp), Fconv(&v.U.Cval.Imag, obj.FmtSharp))
@@ -379,9 +355,7 @@ func Vconv(v *Val, flag int) string {
 
 	case CTBOOL:
 		if v.U.Bval != 0 {
-			var fp string
-			fp += "true"
-			return fp
+			return "true"
 		}
 		var fp string
 		fp += "false"
@@ -393,17 +367,13 @@ func Vconv(v *Val, flag int) string {
 		return fp
 	}
 
-	var fp string
-	fp += fmt.Sprintf("<ctype=%d>", v.Ctype)
-	return fp
+	return fmt.Sprintf("<ctype=%d>", v.Ctype)
 }
 
 // Fmt "%Z": escaped string literals
 func Zconv(sp *Strlit, flag int) string {
 	if sp == nil {
-		var fp string
-		fp += "<nil>"
-		return fp
+		return "<nil>"
 	}
 
 	// NOTE: Keep in sync with ../ld/go.c:/^Zconv.
@@ -491,13 +461,9 @@ var etnames = []string{
 // Fmt "%E": etype
 func Econv(et int, flag int) string {
 	if et >= 0 && et < len(etnames) && etnames[et] != "" {
-		var fp string
-		fp += etnames[et]
-		return fp
+		return etnames[et]
 	}
-	var fp string
-	fp += fmt.Sprintf("E-%d", et)
-	return fp
+	return fmt.Sprintf("E-%d", et)
 }
 
 // Fmt "%S": syms
@@ -506,16 +472,12 @@ func symfmt(s *Sym, flag int) string {
 		switch fmtmode {
 		case FErr: // This is for the user
 			if s.Pkg == localpkg {
-				var fp string
-				fp += s.Name
-				return fp
+				return s.Name
 			}
 
 			// If the name was used by multiple packages, display the full path,
 			if s.Pkg.Name != "" && Pkglookup(s.Pkg.Name, nil).Npkg > 1 {
-				var fp string
-				fp += fmt.Sprintf("\"%v\".%s", Zconv(s.Pkg.Path, 0), s.Name)
-				return fp
+				return fmt.Sprintf("\"%v\".%s", Zconv(s.Pkg.Path, 0), s.Name)
 			}
 			var fp string
 			fp += fmt.Sprintf("%s.%s", s.Pkg.Name, s.Name)
@@ -528,9 +490,7 @@ func symfmt(s *Sym, flag int) string {
 
 		case FTypeId:
 			if flag&obj.FmtUnsigned != 0 /*untyped*/ {
-				var fp string
-				fp += fmt.Sprintf("%s.%s", s.Pkg.Name, s.Name)
-				return fp // dcommontype, typehash
+				return fmt.Sprintf("%s.%s", s.Pkg.Name, s.Name) // dcommontype, typehash
 			}
 			var fp string
 			fp += fmt.Sprintf("%s.%s", s.Pkg.Prefix, s.Name)
@@ -541,15 +501,13 @@ func symfmt(s *Sym, flag int) string {
 				Fatal("exporting synthetic symbol %s", s.Name)
 			}
 			if s.Pkg != builtinpkg {
-				var fp string
-				fp += fmt.Sprintf("@\"%v\".%s", Zconv(s.Pkg.Path, 0), s.Name)
-				return fp
+				return fmt.Sprintf("@\"%v\".%s", Zconv(s.Pkg.Path, 0), s.Name)
 			}
 		}
 	}
 
-	if flag&obj.FmtByte != 0 /*untyped*/ { // FmtByte (hh) implies FmtShort (h)
-
+	if flag&obj.FmtByte != 0 /*untyped*/ {
+		// FmtByte (hh) implies FmtShort (h)
 		// skip leading "type." in method name
 		p := s.Name
 		if i := strings.LastIndex(s.Name, "."); i >= 0 {
@@ -558,19 +516,13 @@ func symfmt(s *Sym, flag int) string {
 
 		// exportname needs to see the name without the prefix too.
 		if (fmtmode == FExp && !exportname(p)) || fmtmode == FDbg {
-			var fp string
-			fp += fmt.Sprintf("@\"%v\".%s", Zconv(s.Pkg.Path, 0), p)
-			return fp
+			return fmt.Sprintf("@\"%v\".%s", Zconv(s.Pkg.Path, 0), p)
 		}
 
-		var fp string
-		fp += p
-		return fp
+		return p
 	}
 
-	var fp string
-	fp += s.Name
-	return fp
+	return s.Name
 }
 
 var basicnames = []string{
@@ -599,25 +551,19 @@ var basicnames = []string{
 
 func typefmt(t *Type, flag int) string {
 	if t == nil {
-		var fp string
-		fp += "<T>"
-		return fp
+		return "<T>"
 	}
 
 	if t == bytetype || t == runetype {
 		// in %-T mode collapse rune and byte with their originals.
 		if fmtmode != FTypeId {
-			var fp string
-			fp += fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtShort))
-			return fp
+			return fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtShort))
 		}
 		t = Types[t.Etype]
 	}
 
 	if t == errortype {
-		var fp string
-		fp += "error"
-		return fp
+		return "error"
 	}
 
 	// Unless the 'l' flag was specified, if the type has a name, just print that name.
@@ -626,34 +572,24 @@ func typefmt(t *Type, flag int) string {
 		case FTypeId:
 			if flag&obj.FmtShort != 0 /*untyped*/ {
 				if t.Vargen != 0 {
-					var fp string
-					fp += fmt.Sprintf("%v·%d", Sconv(t.Sym, obj.FmtShort), t.Vargen)
-					return fp
+					return fmt.Sprintf("%v·%d", Sconv(t.Sym, obj.FmtShort), t.Vargen)
 				}
-				var fp string
-				fp += fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtShort))
-				return fp
+				return fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtShort))
 			}
 
 			if flag&obj.FmtUnsigned != 0 /*untyped*/ {
-				var fp string
-				fp += fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtUnsigned))
-				return fp
+				return fmt.Sprintf("%v", Sconv(t.Sym, obj.FmtUnsigned))
 			}
 			fallthrough
 
 			// fallthrough
 		case FExp:
 			if t.Sym.Pkg == localpkg && t.Vargen != 0 {
-				var fp string
-				fp += fmt.Sprintf("%v·%d", Sconv(t.Sym, 0), t.Vargen)
-				return fp
+				return fmt.Sprintf("%v·%d", Sconv(t.Sym, 0), t.Vargen)
 			}
 		}
 
-		var fp string
-		fp += fmt.Sprintf("%v", Sconv(t.Sym, 0))
-		return fp
+		return fmt.Sprintf("%v", Sconv(t.Sym, 0))
 	}
 
 	var fp string
@@ -1228,9 +1164,7 @@ func exprfmt(n *Node, prec int) string {
 	}
 
 	if n == nil {
-		var f string
-		f += "<N>"
-		return f
+		return "<N>"
 	}
 
 	nprec := opprec[n.Op]
@@ -1239,9 +1173,7 @@ func exprfmt(n *Node, prec int) string {
 	}
 
 	if prec > nprec {
-		var f string
-		f += fmt.Sprintf("(%v)", Nconv(n, 0))
-		return f
+		return fmt.Sprintf("(%v)", Nconv(n, 0))
 	}
 
 	switch n.Op {
@@ -1262,26 +1194,18 @@ func exprfmt(n *Node, prec int) string {
 
 	case OLITERAL: // this is a bit of a mess
 		if n.Orig != nil && n.Orig != n {
-			var f string
-			f += exprfmt(n.Orig, prec)
-			return f
+			return exprfmt(n.Orig, prec)
 		}
 		if fmtmode == FErr && n.Sym != nil {
-			var f string
-			f += fmt.Sprintf("%v", Sconv(n.Sym, 0))
-			return f
+			return fmt.Sprintf("%v", Sconv(n.Sym, 0))
 		}
 		if n.Type != nil && n.Type != Types[n.Type.Etype] && n.Type != idealbool && n.Type != idealstring {
 			// Need parens when type begins with what might
 			// be misinterpreted as a unary operator: * or <-.
 			if Isptr[n.Type.Etype] != 0 || (n.Type.Etype == TCHAN && n.Type.Chan == Crecv) {
-				var f string
-				f += fmt.Sprintf("(%v)(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
-				return f
+				return fmt.Sprintf("(%v)(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
 			} else {
-				var f string
-				f += fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
-				return f
+				return fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Vconv(&n.Val, 0))
 			}
 		}
 
@@ -1293,14 +1217,10 @@ func exprfmt(n *Node, prec int) string {
 	// _ becomes ~b%d internally; print as _ for export
 	case ONAME:
 		if fmtmode == FExp && n.Sym != nil && n.Sym.Name[0] == '~' && n.Sym.Name[1] == 'b' {
-			var f string
-			f += fmt.Sprintf("_")
-			return f
+			return fmt.Sprintf("_")
 		}
 		if fmtmode == FExp && n.Sym != nil && !isblank(n) && n.Vargen > 0 {
-			var f string
-			f += fmt.Sprintf("%v·%d", Sconv(n.Sym, 0), n.Vargen)
-			return f
+			return fmt.Sprintf("%v·%d", Sconv(n.Sym, 0), n.Vargen)
 		}
 
 		// Special case: explicit name of func (*T) method(...) is turned into pkg.(*T).method,
@@ -1308,13 +1228,9 @@ func exprfmt(n *Node, prec int) string {
 		// These nodes have the special property that they are names with a left OTYPE and a right ONAME.
 		if fmtmode == FExp && n.Left != nil && n.Left.Op == OTYPE && n.Right != nil && n.Right.Op == ONAME {
 			if Isptr[n.Left.Type.Etype] != 0 {
-				var f string
-				f += fmt.Sprintf("(%v).%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
-				return f
+				return fmt.Sprintf("(%v).%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
 			} else {
-				var f string
-				f += fmt.Sprintf("%v.%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
-				return f
+				return fmt.Sprintf("%v.%v", Tconv(n.Left.Type, 0), Sconv(n.Right.Sym, obj.FmtShort|obj.FmtByte))
 			}
 		}
 		fallthrough
@@ -1328,9 +1244,7 @@ func exprfmt(n *Node, prec int) string {
 
 	case OTYPE:
 		if n.Type == nil && n.Sym != nil {
-			var f string
-			f += fmt.Sprintf("%v", Sconv(n.Sym, 0))
-			return f
+			return fmt.Sprintf("%v", Sconv(n.Sym, 0))
 		}
 		var f string
 		f += fmt.Sprintf("%v", Tconv(n.Type, 0))
@@ -1338,9 +1252,7 @@ func exprfmt(n *Node, prec int) string {
 
 	case OTARRAY:
 		if n.Left != nil {
-			var f string
-			f += fmt.Sprintf("[]%v", Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("[]%v", Nconv(n.Left, 0))
 		}
 		var f string
 		f += fmt.Sprintf("[]%v", Nconv(n.Right, 0))
@@ -1365,13 +1277,9 @@ func exprfmt(n *Node, prec int) string {
 
 		default:
 			if n.Left != nil && n.Left.Op == OTCHAN && n.Left.Sym == nil && n.Left.Etype == Crecv {
-				var f string
-				f += fmt.Sprintf("chan (%v)", Nconv(n.Left, 0))
-				return f
+				return fmt.Sprintf("chan (%v)", Nconv(n.Left, 0))
 			} else {
-				var f string
-				f += fmt.Sprintf("chan %v", Nconv(n.Left, 0))
-				return f
+				return fmt.Sprintf("chan %v", Nconv(n.Left, 0))
 			}
 		}
 		fallthrough
@@ -1393,14 +1301,10 @@ func exprfmt(n *Node, prec int) string {
 
 	case OCLOSURE:
 		if fmtmode == FErr {
-			var f string
-			f += "func literal"
-			return f
+			return "func literal"
 		}
 		if n.Nbody != nil {
-			var f string
-			f += fmt.Sprintf("%v { %v }", Tconv(n.Type, 0), Hconv(n.Nbody, 0))
-			return f
+			return fmt.Sprintf("%v { %v }", Tconv(n.Type, 0), Hconv(n.Nbody, 0))
 		}
 		var f string
 		f += fmt.Sprintf("%v { %v }", Tconv(n.Type, 0), Hconv(n.Closure.Nbody, 0))
@@ -1411,26 +1315,18 @@ func exprfmt(n *Node, prec int) string {
 		if fmtmode == FErr {
 			if n.Right != nil && n.Right.Type != nil && n.Implicit == 0 {
 				if ptrlit {
-					var f string
-					f += fmt.Sprintf("&%v literal", Tconv(n.Right.Type.Type, 0))
-					return f
+					return fmt.Sprintf("&%v literal", Tconv(n.Right.Type.Type, 0))
 				} else {
-					var f string
-					f += fmt.Sprintf("%v literal", Tconv(n.Right.Type, 0))
-					return f
+					return fmt.Sprintf("%v literal", Tconv(n.Right.Type, 0))
 				}
 			}
 
-			var f string
-			f += "composite literal"
-			return f
+			return "composite literal"
 		}
 
 		if fmtmode == FExp && ptrlit {
 			// typecheck has overwritten OIND by OTYPE with pointer type.
-			var f string
-			f += fmt.Sprintf("(&%v{ %v })", Tconv(n.Right.Type.Type, 0), Hconv(n.List, obj.FmtComma))
-			return f
+			return fmt.Sprintf("(&%v{ %v })", Tconv(n.Right.Type.Type, 0), Hconv(n.List, obj.FmtComma))
 		}
 
 		var f string
@@ -1439,9 +1335,7 @@ func exprfmt(n *Node, prec int) string {
 
 	case OPTRLIT:
 		if fmtmode == FExp && n.Left.Implicit != 0 {
-			var f string
-			f += fmt.Sprintf("%v", Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("%v", Nconv(n.Left, 0))
 		}
 		var f string
 		f += fmt.Sprintf("&%v", Nconv(n.Left, 0))
@@ -1479,14 +1373,10 @@ func exprfmt(n *Node, prec int) string {
 	case OARRAYLIT,
 		OMAPLIT:
 		if fmtmode == FErr {
-			var f string
-			f += fmt.Sprintf("%v literal", Tconv(n.Type, 0))
-			return f
+			return fmt.Sprintf("%v literal", Tconv(n.Type, 0))
 		}
 		if fmtmode == FExp && n.Implicit != 0 {
-			var f string
-			f += fmt.Sprintf("{ %v }", Hconv(n.List, obj.FmtComma))
-			return f
+			return fmt.Sprintf("{ %v }", Hconv(n.List, obj.FmtComma))
 		}
 		var f string
 		f += fmt.Sprintf("(%v{ %v })", Tconv(n.Type, 0), Hconv(n.List, obj.FmtComma))
@@ -1496,25 +1386,17 @@ func exprfmt(n *Node, prec int) string {
 		if n.Left != nil && n.Right != nil {
 			if fmtmode == FExp && n.Left.Type != nil && n.Left.Type.Etype == TFIELD {
 				// requires special handling of field names
-				var f string
-				f += fmt.Sprintf("%v:%v", Sconv(n.Left.Sym, obj.FmtShort|obj.FmtByte), Nconv(n.Right, 0))
-				return f
+				return fmt.Sprintf("%v:%v", Sconv(n.Left.Sym, obj.FmtShort|obj.FmtByte), Nconv(n.Right, 0))
 			} else {
-				var f string
-				f += fmt.Sprintf("%v:%v", Nconv(n.Left, 0), Nconv(n.Right, 0))
-				return f
+				return fmt.Sprintf("%v:%v", Nconv(n.Left, 0), Nconv(n.Right, 0))
 			}
 		}
 
 		if n.Left == nil && n.Right != nil {
-			var f string
-			f += fmt.Sprintf(":%v", Nconv(n.Right, 0))
-			return f
+			return fmt.Sprintf(":%v", Nconv(n.Right, 0))
 		}
 		if n.Left != nil && n.Right == nil {
-			var f string
-			f += fmt.Sprintf("%v:", Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("%v:", Nconv(n.Left, 0))
 		}
 		var f string
 		f += ":"
@@ -1573,14 +1455,10 @@ func exprfmt(n *Node, prec int) string {
 		OSTRARRAYRUNE,
 		ORUNESTR:
 		if n.Type == nil || n.Type.Sym == nil {
-			var f string
-			f += fmt.Sprintf("(%v)(%v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("(%v)(%v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
 		}
 		if n.Left != nil {
-			var f string
-			f += fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
 		}
 		var f string
 		f += fmt.Sprintf("%v(%v)", Tconv(n.Type, 0), Hconv(n.List, obj.FmtComma))
@@ -1600,14 +1478,10 @@ func exprfmt(n *Node, prec int) string {
 		OPRINT,
 		OPRINTN:
 		if n.Left != nil {
-			var f string
-			f += fmt.Sprintf("%v(%v)", Oconv(int(n.Op), obj.FmtSharp), Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("%v(%v)", Oconv(int(n.Op), obj.FmtSharp), Nconv(n.Left, 0))
 		}
 		if n.Isddd != 0 {
-			var f string
-			f += fmt.Sprintf("%v(%v...)", Oconv(int(n.Op), obj.FmtSharp), Hconv(n.List, obj.FmtComma))
-			return f
+			return fmt.Sprintf("%v(%v...)", Oconv(int(n.Op), obj.FmtSharp), Hconv(n.List, obj.FmtComma))
 		}
 		var f string
 		f += fmt.Sprintf("%v(%v)", Oconv(int(n.Op), obj.FmtSharp), Hconv(n.List, obj.FmtComma))
@@ -1630,19 +1504,13 @@ func exprfmt(n *Node, prec int) string {
 		OMAKECHAN,
 		OMAKESLICE:
 		if n.List != nil { // pre-typecheck
-			var f string
-			f += fmt.Sprintf("make(%v, %v)", Tconv(n.Type, 0), Hconv(n.List, obj.FmtComma))
-			return f
+			return fmt.Sprintf("make(%v, %v)", Tconv(n.Type, 0), Hconv(n.List, obj.FmtComma))
 		}
 		if n.Right != nil {
-			var f string
-			f += fmt.Sprintf("make(%v, %v, %v)", Tconv(n.Type, 0), Nconv(n.Left, 0), Nconv(n.Right, 0))
-			return f
+			return fmt.Sprintf("make(%v, %v, %v)", Tconv(n.Type, 0), Nconv(n.Left, 0), Nconv(n.Right, 0))
 		}
 		if n.Left != nil && (n.Op == OMAKESLICE || !isideal(n.Left.Type)) {
-			var f string
-			f += fmt.Sprintf("make(%v, %v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
-			return f
+			return fmt.Sprintf("make(%v, %v)", Tconv(n.Type, 0), Nconv(n.Left, 0))
 		}
 		var f string
 		f += fmt.Sprintf("make(%v)", Tconv(n.Type, 0))
@@ -1713,9 +1581,7 @@ func exprfmt(n *Node, prec int) string {
 		return f
 	}
 
-	var f string
-	f += fmt.Sprintf("<node %v>", Oconv(int(n.Op), 0))
-	return f
+	return fmt.Sprintf("<node %v>", Oconv(int(n.Op), 0))
 }
 
 func nodefmt(n *Node, flag int) string {
@@ -1730,13 +1596,9 @@ func nodefmt(n *Node, flag int) string {
 
 	if flag&obj.FmtLong != 0 /*untyped*/ && t != nil {
 		if t.Etype == TNIL {
-			var f string
-			f += fmt.Sprintf("nil")
-			return f
+			return fmt.Sprintf("nil")
 		} else {
-			var f string
-			f += fmt.Sprintf("%v (type %v)", Nconv(n, 0), Tconv(t, 0))
-			return f
+			return fmt.Sprintf("%v (type %v)", Nconv(n, 0), Tconv(t, 0))
 		}
 	}
 
@@ -1746,9 +1608,7 @@ func nodefmt(n *Node, flag int) string {
 		return stmtfmt(n)
 	}
 
-	var f string
-	f += exprfmt(n, 0)
-	return f
+	return exprfmt(n, 0)
 }
 
 var dumpdepth int
@@ -1872,15 +1732,11 @@ func Sconv(s *Sym, flag int) string {
 	}
 
 	if s == nil {
-		var fp string
-		fp += "<S>"
-		return fp
+		return "<S>"
 	}
 
 	if s.Name == "_" {
-		var fp string
-		fp += "_"
-		return fp
+		return "_"
 	}
 
 	sf := flag
@@ -1899,15 +1755,11 @@ func Sconv(s *Sym, flag int) string {
 //	  'u' package name, not prefix (FTypeId mode, sticky)
 func Tconv(t *Type, flag int) string {
 	if t == nil {
-		var fp string
-		fp += "<T>"
-		return fp
+		return "<T>"
 	}
 
 	if t.Trecur > 4 {
-		var fp string
-		fp += "<...>"
-		return fp
+		return "<...>"
 	}
 
 	t.Trecur++
@@ -1940,9 +1792,7 @@ func Tconv(t *Type, flag int) string {
 //	  '+h' in debug mode, don't recurse, no multiline output
 func Nconv(n *Node, flag int) string {
 	if n == nil {
-		var fp string
-		fp += "<N>"
-		return fp
+		return "<N>"
 	}
 	sf := flag
 	sm := setfmode(&flag)
@@ -1973,9 +1823,7 @@ func Nconv(n *Node, flag int) string {
 // Flags: all those of %N plus ',': separate with comma's instead of semicolons.
 func Hconv(l *NodeList, flag int) string {
 	if l == nil && fmtmode == FDbg {
-		var fp string
-		fp += "<nil>"
-		return fp
+		return "<nil>"
 	}
 
 	sf := flag

src/cmd/internal/gc/mparith1.go

@@ -594,9 +594,8 @@ func Bconv(xval *Mpint, flag int) string {
 		p--
 		buf[p] = '-'
 	}
-	var fp string
-	fp += string(buf[p:])
-	return fp
+
+	return string(buf[p:])
 }
 
 func Fconv(fvp *Mpflt, flag int) string {

src/cmd/internal/obj/i386/list8.go

@@ -77,10 +77,7 @@ func Pconv(p *obj.Prog) string {
 }
 
 func Aconv(i int) string {
-	var fp string
-
-	fp += Anames[i]
-	return fp
+	return Anames[i]
 }
 
 var Register = []string{

src/cmd/internal/obj/x86/list6.go

@@ -89,10 +89,7 @@ func Pconv(p *obj.Prog) string {
 }
 
 func Aconv(i int) string {
-	var fp string
-
-	fp += Anames[i]
-	return fp
+	return Anames[i]
 }
 
 var Register = []string{