gc: remove m[k] = x, false

R=ken2
CC=golang-dev
https://golang.org/cl/5376076

src/cmd/gc/esc.c

@@ -222,7 +222,6 @@ esc(Node *n)
 	case OAS2RECV:		// v, ok = <-ch
 	case OAS2MAPR:		// v, ok = m[k]
 	case OAS2DOTTYPE:	// v, ok = x.(type)
-	case OAS2MAPW:		// m[k] = x, ok
 		escassign(n->list->n, n->rlist->n);
 		break;
 

src/cmd/gc/fmt.c

@@ -802,7 +802,6 @@ stmtfmt(Fmt *f, Node *n)
 	case OAS2DOTTYPE:
 	case OAS2FUNC:
 	case OAS2MAPR:
-	case OAS2MAPW:
 	case OAS2RECV:
 		fmtprint(f, "%,H = %,H", n->list, n->rlist);
 		break;
@@ -981,7 +980,6 @@ static int opprec[] = {
 	[OAS2DOTTYPE] = -1,
 	[OAS2FUNC] = -1,
 	[OAS2MAPR] = -1,
-	[OAS2MAPW] = -1,
 	[OAS2RECV] = -1,
 	[OASOP] = -1,
 	[OBREAK] = -1,

src/cmd/gc/go.h

@@ -425,7 +425,7 @@ enum
 	OAPPEND,
 	OARRAYBYTESTR, OARRAYRUNESTR,
 	OSTRARRAYBYTE, OSTRARRAYRUNE,
-	OAS, OAS2, OAS2MAPW, OAS2FUNC, OAS2RECV, OAS2MAPR, OAS2DOTTYPE,
+	OAS, OAS2, OAS2FUNC, OAS2RECV, OAS2MAPR, OAS2DOTTYPE,
 	OASOP,
 	OBAD,
 	OCALL, OCALLFUNC, OCALLMETH, OCALLINTER,

src/cmd/gc/typecheck.c

@@ -2334,7 +2334,7 @@ typecheckas2(Node *n)
 {
 	int cl, cr;
 	NodeList *ll, *lr;
-	Node *l, *r, *rr;
+	Node *l, *r;
 	Iter s;
 	Type *t;
 
@@ -2373,16 +2373,7 @@ typecheckas2(Node *n)
 	if(cl == 1 && cr == 2 && l->op == OINDEXMAP) {
 		if(l->type == T)
 			goto out;
-		n->op = OAS2MAPW;
-		n->rlist->n = assignconv(r, l->type, "assignment");
-		rr = n->rlist->next->n;
-		n->rlist->next->n = assignconv(rr, types[TBOOL], "assignment");
-		if(isconst(rr, CTBOOL) && !rr->val.u.bval) {
-			n->op = ODELETE;
-			n->list = list(list1(l->left), l->right);
-			n->right = n->rlist->n;
-			n->rlist = nil;
-		}
+		yyerror("assignment count mismatch: %d = %d (use delete)", cl, cr);
 		goto out;
 	}
 

src/cmd/gc/walk.c

@@ -183,7 +183,6 @@ walkstmt(Node **np)
 	case OAS2DOTTYPE:
 	case OAS2RECV:
 	case OAS2FUNC:
-	case OAS2MAPW:
 	case OAS2MAPR:
 	case OCLOSE:
 	case OCOPY:
@@ -644,17 +643,6 @@ walkexpr(Node **np, NodeList **init)
 		n = mkcall1(mapfndel("mapdelete", t), t->down, init, typename(t), l, r);
 		goto ret;
 
-	case OAS2MAPW:
-		// map[] = a,b - mapassign2
-		// a,b = m[i];
-		*init = concat(*init, n->ninit);
-		n->ninit = nil;
-		walkexprlistsafe(n->list, init);
-		l = n->list->n;
-		t = l->left->type;
-		n = mkcall1(mapfn("mapassign2", t), T, init, typename(t), l->left, l->right, n->rlist->n, n->rlist->next->n);
-		goto ret;
-
 	case OAS2DOTTYPE:
 		// a,b = i.(T)
 		*init = concat(*init, n->ninit);

src/pkg/runtime/hashmap.c

@@ -1000,34 +1000,6 @@ runtime·mapassign1(MapType *t, Hmap *h, ...)
 	runtime·mapassign(t, h, ak, av);
 }
 
-// mapassign2(mapType *type, hmap *map[any]any, key any, val any, pres bool);
-#pragma textflag 7
-void
-runtime·mapassign2(MapType *t, Hmap *h, ...)
-{
-	byte *ak, *av, *ap;
-
-	if(h == nil)
-		runtime·panicstring("assignment to entry in nil map");
-
-	ak = (byte*)&h + h->ko2;
-	av = (byte*)&h + h->vo2;
-	ap = (byte*)&h + h->po2;
-
-	if(*ap == false)
-		av = nil;	// delete
-
-	runtime·mapassign(t, h, ak, av);
-
-	if(debug) {
-		runtime·prints("mapassign2: map=");
-		runtime·printpointer(h);
-		runtime·prints("; key=");
-		h->keyalg->print(h->keysize, ak);
-		runtime·prints("\n");
-	}
-}
-
 // mapdelete(mapType *type, hmap *map[any]any, key any)
 #pragma textflag 7
 void

test/fixedbugs/bug220.go

-// $G $D/$F.go || echo BUG: bug220
-
-// Copyright 2009 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-func main() {
-	m := make(map[int]map[uint]float64)
-
-	m[0] = make(map[uint]float64), false // 6g used to reject this
-	m[1] = nil
-}

test/fixedbugs/bug242.go

@@ -93,7 +93,8 @@ func main() {
 
 	m[13] = 'B'
 	//  13        14
-	m[gint()] = gbyte(), false
+	delete(m, gint())
+	gbyte()
 	if _, present := m[13]; present {
 		println("bad map removal")
 		panic("fail")

test/named1.go

@@ -41,7 +41,6 @@ func main() {
 	asBool(i < j)  // ERROR "cannot use.*type bool.*as type Bool"
 
 	_, b = m[2] // ERROR "cannot .* bool.*type Bool"
-	m[2] = 1, b // ERROR "cannot use.*type Bool.*as type bool"
 
 	var inter interface{}
 	_, b = inter.(Map) // ERROR "cannot .* bool.*type Bool"