cmd/internal/gc: fmt.Sprintf elimination and minor cleanup

Change-Id: Iaf5a7d25e6308b32c17a38afbbd46befa17aa3a4
Reviewed-on: https://go-review.googlesource.com/7629Reviewed-by: Rob Pike <r@golang.org>

src/cmd/internal/gc/bv.go

@@ -58,16 +58,8 @@ func (b *bulkBvec) next() Bvec {
 
 /* difference */
 func bvandnot(dst Bvec, src1 Bvec, src2 Bvec) {
-	var i int32
-	var w int32
-
-	if dst.n != src1.n || dst.n != src2.n {
-		Fatal("bvand: lengths %d, %d, and %d are not equal", dst.n, src1.n, src2.n)
-	}
-	i = 0
-	w = 0
-	for ; i < dst.n; i, w = i+WORDBITS, w+1 {
-		dst.b[w] = src1.b[w] &^ src2.b[w]
+	for i, x := range src1.b {
+		dst.b[i] = x &^ src2.b[i]
 	}
 }
 
@@ -152,11 +144,8 @@ func bvisempty(bv Bvec) bool {
 }
 
 func bvnot(bv Bvec) {
-	var i int32
-	var w int32
-
-	i = 0
-	w = 0
+	i := int32(0)
+	w := int32(0)
 	for ; i < bv.n; i, w = i+WORDBITS, w+1 {
 		bv.b[w] = ^bv.b[w]
 	}
@@ -164,31 +153,15 @@ func bvnot(bv Bvec) {
 
 /* union */
 func bvor(dst Bvec, src1 Bvec, src2 Bvec) {
-	var i int32
-	var w int32
-
-	if dst.n != src1.n || dst.n != src2.n {
-		Fatal("bvor: lengths %d, %d, and %d are not equal", dst.n, src1.n, src2.n)
-	}
-	i = 0
-	w = 0
-	for ; i < dst.n; i, w = i+WORDBITS, w+1 {
-		dst.b[w] = src1.b[w] | src2.b[w]
+	for i, x := range src1.b {
+		dst.b[i] = x | src2.b[i]
 	}
 }
 
 /* intersection */
 func bvand(dst Bvec, src1 Bvec, src2 Bvec) {
-	var i int32
-	var w int32
-
-	if dst.n != src1.n || dst.n != src2.n {
-		Fatal("bvor: lengths %d, %d, and %d are not equal", dst.n, src1.n, src2.n)
-	}
-	i = 0
-	w = 0
-	for ; i < dst.n; i, w = i+WORDBITS, w+1 {
-		dst.b[w] = src1.b[w] & src2.b[w]
+	for i, x := range src1.b {
+		dst.b[i] = x & src2.b[i]
 	}
 }
 

src/cmd/internal/gc/dcl.go

@@ -1470,14 +1470,17 @@ func funccompile(n *Node) {
 }
 
 func funcsym(s *Sym) *Sym {
-	p := fmt.Sprintf("%s·f", s.Name)
-	s1 := Pkglookup(p, s.Pkg)
+	if s.Fsym != nil {
+		return s.Fsym
+	}
 
+	s1 := Pkglookup(s.Name+"·f", s.Pkg)
 	if s1.Def == nil {
 		s1.Def = newname(s1)
 		s1.Def.Shortname = newname(s)
 		funcsyms = list(funcsyms, s1.Def)
 	}
+	s.Fsym = s1
 
 	return s1
 }

src/cmd/internal/gc/esc.go

@@ -436,9 +436,6 @@ func esclist(e *EscState, l *NodeList, up *Node) {
 }
 
 func esc(e *EscState, n *Node, up *Node) {
-	var ll *NodeList
-	var lr *NodeList
-
 	if n == nil {
 		return
 	}
@@ -457,7 +454,7 @@ func esc(e *EscState, n *Node, up *Node) {
 	// must happen before processing of switch body,
 	// so before recursion.
 	if n.Op == OSWITCH && n.Ntest != nil && n.Ntest.Op == OTYPESW {
-		for ll = n.List; ll != nil; ll = ll.Next { // cases
+		for ll := n.List; ll != nil; ll = ll.Next { // cases
 
 			// ll->n->nname is the variable per case
 			if ll.N.Nname != nil {
@@ -522,7 +519,7 @@ func esc(e *EscState, n *Node, up *Node) {
 
 	case OSWITCH:
 		if n.Ntest != nil && n.Ntest.Op == OTYPESW {
-			for ll = n.List; ll != nil; ll = ll.Next { // cases
+			for ll := n.List; ll != nil; ll = ll.Next { // cases
 
 				// ntest->right is the argument of the .(type),
 				// ll->n->nname is the variable per case
@@ -574,8 +571,8 @@ func esc(e *EscState, n *Node, up *Node) {
 
 	case OAS2: // x,y = a,b
 		if count(n.List) == count(n.Rlist) {
-			ll = n.List
-			lr = n.Rlist
+			ll := n.List
+			lr := n.Rlist
 			for ; ll != nil; ll, lr = ll.Next, lr.Next {
 				escassign(e, ll.N, lr.N)
 			}
@@ -602,7 +599,7 @@ func esc(e *EscState, n *Node, up *Node) {
 		escassign(e, &e.theSink, n.Left.Left)
 
 		escassign(e, &e.theSink, n.Left.Right) // ODDDARG for call
-		for ll = n.Left.List; ll != nil; ll = ll.Next {
+		for ll := n.Left.List; ll != nil; ll = ll.Next {
 			escassign(e, &e.theSink, ll.N)
 		}
 
@@ -613,8 +610,9 @@ func esc(e *EscState, n *Node, up *Node) {
 
 		// esccall already done on n->rlist->n. tie it's escretval to n->list
 	case OAS2FUNC: // x,y = f()
-		lr = n.Rlist.N.Escretval
+		lr := n.Rlist.N.Escretval
 
+		var ll *NodeList
 		for ll = n.List; lr != nil && ll != nil; lr, ll = lr.Next, ll.Next {
 			escassign(e, ll.N, lr.N)
 		}
@@ -623,7 +621,7 @@ func esc(e *EscState, n *Node, up *Node) {
 		}
 
 	case ORETURN:
-		ll = n.List
+		ll := n.List
 		if count(n.List) == 1 && Curfn.Type.Outtuple > 1 {
 			// OAS2FUNC in disguise
 			// esccall already done on n->list->n
@@ -631,7 +629,7 @@ func esc(e *EscState, n *Node, up *Node) {
 			ll = n.List.N.Escretval
 		}
 
-		for lr = Curfn.Dcl; lr != nil && ll != nil; lr = lr.Next {
+		for lr := Curfn.Dcl; lr != nil && ll != nil; lr = lr.Next {
 			if lr.N.Op != ONAME || lr.N.Class != PPARAMOUT {
 				continue
 			}
@@ -649,7 +647,7 @@ func esc(e *EscState, n *Node, up *Node) {
 
 	case OAPPEND:
 		if !n.Isddd {
-			for ll = n.List.Next; ll != nil; ll = ll.Next {
+			for ll := n.List.Next; ll != nil; ll = ll.Next {
 				escassign(e, &e.theSink, ll.N) // lose track of assign to dereference
 			}
 		}
@@ -666,19 +664,19 @@ func esc(e *EscState, n *Node, up *Node) {
 			n.Escloopdepth = e.loopdepth
 
 			// Values make it to memory, lose track.
-			for ll = n.List; ll != nil; ll = ll.Next {
+			for ll := n.List; ll != nil; ll = ll.Next {
 				escassign(e, &e.theSink, ll.N.Right)
 			}
 		} else {
 			// Link values to array.
-			for ll = n.List; ll != nil; ll = ll.Next {
+			for ll := n.List; ll != nil; ll = ll.Next {
 				escassign(e, n, ll.N.Right)
 			}
 		}
 
 		// Link values to struct.
 	case OSTRUCTLIT:
-		for ll = n.List; ll != nil; ll = ll.Next {
+		for ll := n.List; ll != nil; ll = ll.Next {
 			escassign(e, n, ll.N.Right)
 		}
 
@@ -704,7 +702,7 @@ func esc(e *EscState, n *Node, up *Node) {
 		n.Escloopdepth = e.loopdepth
 
 		// Keys and values make it to memory, lose track.
-		for ll = n.List; ll != nil; ll = ll.Next {
+		for ll := n.List; ll != nil; ll = ll.Next {
 			escassign(e, &e.theSink, ll.N.Left)
 			escassign(e, &e.theSink, ll.N.Right)
 		}
@@ -713,7 +711,7 @@ func esc(e *EscState, n *Node, up *Node) {
 	case OCLOSURE:
 		var a *Node
 		var v *Node
-		for ll = n.Cvars; ll != nil; ll = ll.Next {
+		for ll := n.Cvars; ll != nil; ll = ll.Next {
 			v = ll.N
 			if v.Op == OXXX { // unnamed out argument; see dcl.c:/^funcargs
 				continue
@@ -953,9 +951,7 @@ func escassign(e *EscState, dst *Node, src *Node) {
 }
 
 func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) int {
-	var em int
-
-	em = parsetag(note)
+	em := parsetag(note)
 
 	if em == EscUnknown {
 		escassign(e, &e.theSink, src)
@@ -992,8 +988,6 @@ func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) int
 // different for methods vs plain functions and for imported vs
 // this-package
 func esccall(e *EscState, n *Node, up *Node) {
-	var ll *NodeList
-	var lr *NodeList
 	var fntype *Type
 
 	var fn *Node
@@ -1017,7 +1011,7 @@ func esccall(e *EscState, n *Node, up *Node) {
 		fntype = n.Left.Type
 	}
 
-	ll = n.List
+	ll := n.List
 	if n.List != nil && n.List.Next == nil {
 		a := n.List.N
 		if a.Type.Etype == TSTRUCT && a.Type.Funarg != 0 { // f(g()).
@@ -1033,7 +1027,7 @@ func esccall(e *EscState, n *Node, up *Node) {
 		}
 
 		// set up out list on this call node
-		for lr = fn.Ntype.Rlist; lr != nil; lr = lr.Next {
+		for lr := fn.Ntype.Rlist; lr != nil; lr = lr.Next {
 			n.Escretval = list(n.Escretval, lr.N.Left) // type.rlist ->  dclfield -> ONAME (PPARAMOUT)
 		}
 
@@ -1043,7 +1037,7 @@ func esccall(e *EscState, n *Node, up *Node) {
 		}
 
 		var src *Node
-		for lr = fn.Ntype.List; ll != nil && lr != nil; ll, lr = ll.Next, lr.Next {
+		for lr := fn.Ntype.List; ll != nil && lr != nil; ll, lr = ll.Next, lr.Next {
 			src = ll.N
 			if lr.N.Isddd && !n.Isddd {
 				// Introduce ODDDARG node to represent ... allocation.

src/cmd/internal/gc/go.go

@@ -126,6 +126,7 @@ type Sym struct {
 	Lastlineno int32  // last declaration for diagnostic
 	Origpkg    *Pkg   // original package for . import
 	Lsym       *obj.LSym
+	Fsym       *Sym // funcsym
 }
 
 type Type struct {

src/cmd/internal/gc/mparith1.go

@@ -15,7 +15,7 @@ import (
 func mpcmpfixflt(a *Mpint, b *Mpflt) int {
 	var c Mpflt
 
-	buf := fmt.Sprintf("%v", Bconv(a, 0))
+	buf := Bconv(a, 0)
 	mpatoflt(&c, buf)
 	return mpcmpfltflt(&c, b)
 }
@@ -23,7 +23,7 @@ func mpcmpfixflt(a *Mpint, b *Mpflt) int {
 func mpcmpfltfix(a *Mpflt, b *Mpint) int {
 	var c Mpflt
 
-	buf := fmt.Sprintf("%v", Bconv(b, 0))
+	buf := Bconv(b, 0)
 	mpatoflt(&c, buf)
 	return mpcmpfltflt(a, &c)
 }

src/cmd/internal/gc/obj.go

@@ -7,6 +7,7 @@ package gc
 import (
 	"cmd/internal/obj"
 	"fmt"
+	"strconv"
 )
 
 /*
@@ -155,16 +156,18 @@ func Linksym(s *Sym) *obj.LSym {
 	if s.Lsym != nil {
 		return s.Lsym
 	}
+	var name string
 	if isblanksym(s) {
-		s.Lsym = obj.Linklookup(Ctxt, "_", 0)
+		name = "_"
 	} else if s.Linkname != "" {
-		s.Lsym = obj.Linklookup(Ctxt, s.Linkname, 0)
+		name = s.Linkname
 	} else {
-		p := fmt.Sprintf("%s.%s", s.Pkg.Prefix, s.Name)
-		s.Lsym = obj.Linklookup(Ctxt, p, 0)
+		name = s.Pkg.Prefix + "." + s.Name
 	}
 
-	return s.Lsym
+	ls := obj.Linklookup(Ctxt, name, 0)
+	s.Lsym = ls
+	return ls
 }
 
 func duintxx(s *Sym, off int, v uint64, wid int) int {
@@ -211,7 +214,7 @@ func stringsym(s string) *Sym {
 		// small strings get named by their contents,
 		// so that multiple modules using the same string
 		// can share it.
-		symname = fmt.Sprintf("%q", s)
+		symname = strconv.Quote(s)
 		pkg = gostringpkg
 	}
 

src/cmd/internal/gc/reflect.go

@@ -477,7 +477,7 @@ func dimportpath(p *Pkg) {
 		dimportpath_gopkg.Name = "go"
 	}
 
-	nam := fmt.Sprintf("importpath.%s.", p.Prefix)
+	nam := "importpath." + p.Prefix + "."
 
 	n := Nod(ONAME, nil, nil)
 	n.Sym = Pkglookup(nam, dimportpath_gopkg)
@@ -808,7 +808,7 @@ func dcommontype(s *Sym, ot int, t *Type) int {
 		ot = duintptr(s, ot, 0)
 	}
 
-	p := fmt.Sprintf("%v", Tconv(t, obj.FmtLeft|obj.FmtUnsigned))
+	p := Tconv(t, obj.FmtLeft|obj.FmtUnsigned)
 
 	//print("dcommontype: %s\n", p);
 	ot = dgostringptr(s, ot, p) // string
@@ -825,19 +825,11 @@ func dcommontype(s *Sym, ot int, t *Type) int {
 }
 
 func typesym(t *Type) *Sym {
-	p := fmt.Sprintf("%v", Tconv(t, obj.FmtLeft))
-	s := Pkglookup(p, typepkg)
-
-	//print("typesym: %s -> %+S\n", p, s);
-
-	return s
+	return Pkglookup(Tconv(t, obj.FmtLeft), typepkg)
 }
 
 func tracksym(t *Type) *Sym {
-	p := fmt.Sprintf("%v.%s", Tconv(t.Outer, obj.FmtLeft), t.Sym.Name)
-	s := Pkglookup(p, trackpkg)
-
-	return s
+	return Pkglookup(Tconv(t.Outer, obj.FmtLeft)+"."+t.Sym.Name, trackpkg)
 }
 
 func typelinksym(t *Type) *Sym {
@@ -849,7 +841,7 @@ func typelinksym(t *Type) *Sym {
 	// disambiguate. The names are a little long but they are
 	// discarded by the linker and do not end up in the symbol
 	// table of the final binary.
-	p := fmt.Sprintf("%v/%v", Tconv(t, obj.FmtLeft|obj.FmtUnsigned), Tconv(t, obj.FmtLeft))
+	p := Tconv(t, obj.FmtLeft|obj.FmtUnsigned) + "/" + Tconv(t, obj.FmtLeft)
 
 	s := Pkglookup(p, typelinkpkg)
 
@@ -859,7 +851,7 @@ func typelinksym(t *Type) *Sym {
 }
 
 func typesymprefix(prefix string, t *Type) *Sym {
-	p := fmt.Sprintf("%s.%v", prefix, Tconv(t, obj.FmtLeft))
+	p := prefix + "." + Tconv(t, obj.FmtLeft)
 	s := Pkglookup(p, typepkg)
 
 	//print("algsym: %s -> %+S\n", p, s);
@@ -900,7 +892,7 @@ func typename(t *Type) *Node {
 }
 
 func weaktypesym(t *Type) *Sym {
-	p := fmt.Sprintf("%v", Tconv(t, obj.FmtLeft))
+	p := Tconv(t, obj.FmtLeft)
 	s := Pkglookup(p, weaktypepkg)
 
 	//print("weaktypesym: %s -> %+S\n", p, s);
@@ -962,9 +954,6 @@ func isreflexive(t *Type) bool {
 }
 
 func dtypesym(t *Type) *Sym {
-	var n int
-	var t1 *Type
-
 	// Replace byte, rune aliases with real type.
 	// They've been separate internally to make error messages
 	// better, but we have to merge them in the reflect tables.
@@ -1048,16 +1037,16 @@ ok:
 		ot = duintptr(s, ot, uint64(t.Chan))
 
 	case TFUNC:
-		for t1 = getthisx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getthisx(t).Type; t1 != nil; t1 = t1.Down {
 			dtypesym(t1.Type)
 		}
 		isddd := false
-		for t1 = getinargx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getinargx(t).Type; t1 != nil; t1 = t1.Down {
 			isddd = t1.Isddd
 			dtypesym(t1.Type)
 		}
 
-		for t1 = getoutargx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getoutargx(t).Type; t1 != nil; t1 = t1.Down {
 			dtypesym(t1.Type)
 		}
 
@@ -1069,7 +1058,7 @@ ok:
 		ot = int(Rnd(int64(ot), int64(Widthptr)))
 
 		ot = dsymptr(s, ot, s, ot+2*(Widthptr+2*Widthint))
-		n = t.Thistuple + t.Intuple
+		n := t.Thistuple + t.Intuple
 		ot = duintxx(s, ot, uint64(n), Widthint)
 		ot = duintxx(s, ot, uint64(n), Widthint)
 		ot = dsymptr(s, ot, s, ot+1*(Widthptr+2*Widthint)+n*Widthptr)
@@ -1077,22 +1066,22 @@ ok:
 		ot = duintxx(s, ot, uint64(t.Outtuple), Widthint)
 
 		// slice data
-		for t1 = getthisx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getthisx(t).Type; t1 != nil; t1 = t1.Down {
 			ot = dsymptr(s, ot, dtypesym(t1.Type), 0)
 			n++
 		}
-		for t1 = getinargx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getinargx(t).Type; t1 != nil; t1 = t1.Down {
 			ot = dsymptr(s, ot, dtypesym(t1.Type), 0)
 			n++
 		}
-		for t1 = getoutargx(t).Type; t1 != nil; t1 = t1.Down {
+		for t1 := getoutargx(t).Type; t1 != nil; t1 = t1.Down {
 			ot = dsymptr(s, ot, dtypesym(t1.Type), 0)
 			n++
 		}
 
 	case TINTER:
 		m := imethods(t)
-		n = 0
+		n := 0
 		for a := m; a != nil; a = a.link {
 			dtypesym(a.type_)
 			n++
@@ -1164,9 +1153,9 @@ ok:
 		// ../../runtime/type.go:/StructType
 	// for security, only the exported fields.
 	case TSTRUCT:
-		n = 0
+		n := 0
 
-		for t1 = t.Type; t1 != nil; t1 = t1.Down {
+		for t1 := t.Type; t1 != nil; t1 = t1.Down {
 			dtypesym(t1.Type)
 			n++
 		}
@@ -1176,7 +1165,7 @@ ok:
 		ot = dsymptr(s, ot, s, ot+Widthptr+2*Widthint)
 		ot = duintxx(s, ot, uint64(n), Widthint)
 		ot = duintxx(s, ot, uint64(n), Widthint)
-		for t1 = t.Type; t1 != nil; t1 = t1.Down {
+		for t1 := t.Type; t1 != nil; t1 = t1.Down {
 			// ../../runtime/type.go:/structField
 			if t1.Sym != nil && t1.Embedded == 0 {
 				ot = dgostringptr(s, ot, t1.Sym.Name)
@@ -1479,11 +1468,9 @@ func proggenskip(g *ProgGen, off int64, v int64) {
 
 // Emit insArray instruction.
 func proggenarray(g *ProgGen, len int64) {
-	var i int32
-
 	proggendataflush(g)
 	proggenemit(g, obj.InsArray)
-	for i = 0; i < int32(Widthptr); i, len = i+1, len>>8 {
+	for i := int32(0); i < int32(Widthptr); i, len = i+1, len>>8 {
 		proggenemit(g, uint8(len))
 	}
 }

src/cmd/internal/gc/reg.go

@@ -243,8 +243,7 @@ func mkvar(f *Flow, a *obj.Addr) Bits {
 		}
 	}
 
-	var node *Node
-	node, _ = a.Node.(*Node)
+	node, _ := a.Node.(*Node)
 	if node == nil || node.Op != ONAME || node.Orig == nil {
 		return zbits
 	}

src/cmd/internal/gc/subr.go

@@ -291,7 +291,9 @@ func LookupBytes(name []byte) *Sym {
 
 var initSyms []*Sym
 
-var nopkg = new(Pkg)
+var nopkg = &Pkg{
+	Syms: make(map[string]*Sym),
+}
 
 func (pkg *Pkg) Lookup(name string) *Sym {
 	if pkg == nil {
@@ -306,12 +308,9 @@ func (pkg *Pkg) Lookup(name string) *Sym {
 		Pkg:     pkg,
 		Lexical: LNAME,
 	}
-	if s.Name == "init" {
+	if name == "init" {
 		initSyms = append(initSyms, s)
 	}
-	if pkg.Syms == nil {
-		pkg.Syms = make(map[string]*Sym)
-	}
 	pkg.Syms[name] = s
 	return s
 }
@@ -1028,16 +1027,13 @@ func eqtype1(t1 *Type, t2 *Type, assumed_equal *TypePairList) bool {
 		t1 = t1.Type
 		t2 = t2.Type
 		for ; t1 != nil && t2 != nil; t1, t2 = t1.Down, t2.Down {
-			var ta *Type
-			var tb *Type
-
 			if t1.Etype != TSTRUCT || t2.Etype != TSTRUCT {
 				Fatal("func missing struct: %v %v", Tconv(t1, 0), Tconv(t2, 0))
 			}
 
 			// Loop over fields in structs, ignoring argument names.
-			ta = t1.Type
-			tb = t2.Type
+			ta := t1.Type
+			tb := t2.Type
 			for ; ta != nil && tb != nil; ta, tb = ta.Down, tb.Down {
 				if ta.Etype != TFIELD || tb.Etype != TFIELD {
 					Fatal("func struct missing field: %v %v", Tconv(ta, 0), Tconv(tb, 0))
@@ -1320,8 +1316,12 @@ func convertop(src *Type, dst *Type, why *string) int {
 	return 0
 }
 
-// Convert node n for assignment to type t.
 func assignconv(n *Node, t *Type, context string) *Node {
+	return assignconvfn(n, t, func() string { return context })
+}
+
+// Convert node n for assignment to type t.
+func assignconvfn(n *Node, t *Type, context func() string) *Node {
 	if n == nil || n.Type == nil || n.Type.Broke != 0 {
 		return n
 	}
@@ -1357,7 +1357,7 @@ func assignconv(n *Node, t *Type, context string) *Node {
 	var why string
 	op := assignop(n.Type, t, &why)
 	if op == 0 {
-		Yyerror("cannot use %v as type %v in %s%s", Nconv(n, obj.FmtLong), Tconv(t, 0), context, why)
+		Yyerror("cannot use %v as type %v in %s%s", Nconv(n, obj.FmtLong), Tconv(t, 0), context(), why)
 		op = OCONV
 	}
 
@@ -1570,10 +1570,10 @@ func typehash(t *Type) uint32 {
 		// hide method receiver from Tpretty
 		t.Thistuple = 0
 
-		p = fmt.Sprintf("%v", Tconv(t, obj.FmtLeft|obj.FmtUnsigned))
+		p = Tconv(t, obj.FmtLeft|obj.FmtUnsigned)
 		t.Thistuple = 1
 	} else {
-		p = fmt.Sprintf("%v", Tconv(t, obj.FmtLeft|obj.FmtUnsigned))
+		p = Tconv(t, obj.FmtLeft|obj.FmtUnsigned)
 	}
 
 	//print("typehash: %s\n", p);
@@ -3457,6 +3457,7 @@ func mkpkg(path string) *Pkg {
 	p := new(Pkg)
 	p.Path = path
 	p.Prefix = pathtoprefix(path)
+	p.Syms = make(map[string]*Sym)
 	pkgMap[path] = p
 	pkgs = append(pkgs, p)
 	return p

src/cmd/internal/gc/typecheck.go

@@ -1362,9 +1362,7 @@ OpSwitch:
 			}
 		}
 
-		descbuf := fmt.Sprintf("argument to %v", Nconv(n.Left, 0))
-		desc := descbuf
-		typecheckaste(OCALL, n.Left, n.Isddd, getinargx(t), n.List, desc)
+		typecheckaste(OCALL, n.Left, n.Isddd, getinargx(t), n.List, func() string { return fmt.Sprintf("argument to %v", Nconv(n.Left, 0)) })
 		ok |= Etop
 		if t.Outtuple == 0 {
 			break OpSwitch
@@ -2127,7 +2125,7 @@ OpSwitch:
 		if Curfn.Type.Outnamed != 0 && n.List == nil {
 			break OpSwitch
 		}
-		typecheckaste(ORETURN, nil, false, getoutargx(Curfn.Type), n.List, "return argument")
+		typecheckaste(ORETURN, nil, false, getoutargx(Curfn.Type), n.List, func() string { return "return argument" })
 		break OpSwitch
 
 	case ORETJMP:
@@ -2604,7 +2602,7 @@ func downcount(t *Type) int {
 /*
  * typecheck assignment: type list = expression list
  */
-func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList, desc string) {
+func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList, desc func() string) {
 	var t *Type
 	var n *Node
 	var n1 int
@@ -2641,7 +2639,7 @@ func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList,
 								if call != nil {
 									Yyerror("cannot use %v as type %v in argument to %v%s", Tconv(tn.Type, 0), Tconv(tl.Type.Type, 0), Nconv(call, 0), why)
 								} else {
-									Yyerror("cannot use %v as type %v in %s%s", Tconv(tn.Type, 0), Tconv(tl.Type.Type, 0), desc, why)
+									Yyerror("cannot use %v as type %v in %s%s", Tconv(tn.Type, 0), Tconv(tl.Type.Type, 0), desc(), why)
 								}
 							}
 						}
@@ -2656,7 +2654,7 @@ func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList,
 						if call != nil {
 							Yyerror("cannot use %v as type %v in argument to %v%s", Tconv(tn.Type, 0), Tconv(tl.Type, 0), Nconv(call, 0), why)
 						} else {
-							Yyerror("cannot use %v as type %v in %s%s", Tconv(tn.Type, 0), Tconv(tl.Type, 0), desc, why)
+							Yyerror("cannot use %v as type %v in %s%s", Tconv(tn.Type, 0), Tconv(tl.Type, 0), desc(), why)
 						}
 					}
 
@@ -2708,7 +2706,7 @@ func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList,
 				n = nl.N
 				setlineno(n)
 				if n.Type != nil {
-					nl.N = assignconv(n, t, desc)
+					nl.N = assignconvfn(n, t, desc)
 				}
 				goto out
 			}
@@ -2717,7 +2715,7 @@ func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList,
 				n = nl.N
 				setlineno(nl.N)
 				if n.Type != nil {
-					nl.N = assignconv(n, t.Type, desc)
+					nl.N = assignconvfn(n, t.Type, desc)
 				}
 			}
 
@@ -2730,7 +2728,7 @@ func typecheckaste(op int, call *Node, isddd bool, tstruct *Type, nl *NodeList,
 		n = nl.N
 		setlineno(n)
 		if n.Type != nil {
-			nl.N = assignconv(n, t, desc)
+			nl.N = assignconvfn(n, t, desc)
 		}
 		nl = nl.Next
 	}
@@ -3395,10 +3393,7 @@ func checkassignto(src *Type, dst *Node) {
 }
 
 func typecheckas2(n *Node) {
-	var ll *NodeList
-	var lr *NodeList
-
-	for ll = n.List; ll != nil; ll = ll.Next {
+	for ll := n.List; ll != nil; ll = ll.Next {
 		// delicate little dance.
 		ll.N = resolve(ll.N)
 
@@ -3420,8 +3415,8 @@ func typecheckas2(n *Node) {
 	var r *Node
 	if cl == cr {
 		// easy
-		ll = n.List
-		lr = n.Rlist
+		ll := n.List
+		lr := n.Rlist
 		for ; ll != nil; ll, lr = ll.Next, lr.Next {
 			if ll.N.Type != nil && lr.N.Type != nil {
 				lr.N = assignconv(lr.N, ll.N.Type, "assignment")
@@ -3457,7 +3452,7 @@ func typecheckas2(n *Node) {
 			n.Op = OAS2FUNC
 			var s Iter
 			t := Structfirst(&s, &r.Type)
-			for ll = n.List; ll != nil; ll = ll.Next {
+			for ll := n.List; ll != nil; ll = ll.Next {
 				if t.Type != nil && ll.N.Type != nil {
 					checkassignto(t.Type, ll.N)
 				}
@@ -3516,7 +3511,7 @@ mismatch:
 out:
 	n.Typecheck = 1
 
-	for ll = n.List; ll != nil; ll = ll.Next {
+	for ll := n.List; ll != nil; ll = ll.Next {
 		if ll.N.Typecheck == 0 {
 			typecheck(&ll.N, Erv|Easgn)
 		}

src/cmd/internal/gc/walk.go

@@ -948,7 +948,7 @@ func walkexpr(np **Node, init **NodeList) {
 			ll = list(ll, typename(n.Type))
 		}
 		if !Isinter(n.Left.Type) && !isnilinter(n.Type) {
-			sym := Pkglookup(fmt.Sprintf("%v.%v", Tconv(n.Left.Type, obj.FmtLeft), Tconv(n.Type, obj.FmtLeft)), itabpkg)
+			sym := Pkglookup(Tconv(n.Left.Type, obj.FmtLeft)+"."+Tconv(n.Type, obj.FmtLeft), itabpkg)
 			if sym.Def == nil {
 				l := Nod(ONAME, nil, nil)
 				l.Sym = sym
@@ -1631,9 +1631,6 @@ func ascompatee1(op int, l *Node, r *Node, init **NodeList) *Node {
 }
 
 func ascompatee(op int, nl *NodeList, nr *NodeList, init **NodeList) *NodeList {
-	var ll *NodeList
-	var lr *NodeList
-
 	/*
 	 * check assign expression list to
 	 * a expression list. called in
@@ -1641,16 +1638,16 @@ func ascompatee(op int, nl *NodeList, nr *NodeList, init **NodeList) *NodeList {
 	 */
 
 	// ensure order of evaluation for function calls
-	for ll = nl; ll != nil; ll = ll.Next {
+	for ll := nl; ll != nil; ll = ll.Next {
 		ll.N = safeexpr(ll.N, init)
 	}
-	for lr = nr; lr != nil; lr = lr.Next {
+	for lr := nr; lr != nil; lr = lr.Next {
 		lr.N = safeexpr(lr.N, init)
 	}
 
 	var nn *NodeList
-	ll = nl
-	lr = nr
+	ll := nl
+	lr := nr
 	for ; ll != nil && lr != nil; ll, lr = ll.Next, lr.Next {
 		// Do not generate 'x = x' during return. See issue 4014.
 		if op == ORETURN && ll.N == lr.N {
@@ -1798,7 +1795,7 @@ func dumptypes(nl **Type, what string) string {
 		} else {
 			fmt_ += ", "
 		}
-		fmt_ += fmt.Sprintf("%v", Tconv(l, 0))
+		fmt_ += Tconv(l, 0)
 	}
 
 	if first != 0 {
@@ -1820,7 +1817,7 @@ func dumpnodetypes(l *NodeList, what string) string {
 		} else {
 			fmt_ += ", "
 		}
-		fmt_ += fmt.Sprintf("%v", Tconv(r.Type, 0))
+		fmt_ += Tconv(r.Type, 0)
 	}
 
 	if first != 0 {