From: Russ Cox <rsc@golang.org>
Date: Mon, 24 Aug 2009 20:41:47 +0000 (-0700)
Subject: bug197
X-Git-Tag: weekly.2009-11-06~786
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=14be733a253d5b47910ad8c46b6070880a120a96;p=gostls13.git

bug197

R=ken
OCL=33765
CL=33765
---

diff --git a/src/cmd/gc/const.c b/src/cmd/gc/const.c
index d774773a43..1433eb9ba5 100644
--- a/src/cmd/gc/const.c
+++ b/src/cmd/gc/const.c
@@ -77,6 +77,8 @@ convlit1(Node **np, Type *t, int explicit)
 		return;
 	if(eqtype(t, n->type))
 		return;
+	if(!explicit && n->type->etype != TIDEAL && n->type != idealstring && n->type->etype != TNIL)
+		return;
 
 //dump("convlit1", n);
 	if(n->op == OLITERAL) {
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 09b8da7695..f7d6f83c97 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -330,7 +330,7 @@ enum
 	OCMPIFACE, OCMPSTR,
 	OCOMPLIT, OMAPLIT, OSTRUCTLIT, OARRAYLIT,
 	OCOMPSLICE, OCOMPMAP,
-	OCONV, OCONVNOP, OCONVA2S, OCONVIFACE, OCONVSLICE,
+	OCONV, OCONVNOP, OCONVIFACE, OCONVSLICE,
 	ODCL, ODCLFUNC, ODCLFIELD, ODCLCONST, ODCLTYPE,
 	ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OXDOT,
 	ODOTTYPE,
diff --git a/src/cmd/gc/print.c b/src/cmd/gc/print.c
index bb79037258..70d80c5e6a 100644
--- a/src/cmd/gc/print.c
+++ b/src/cmd/gc/print.c
@@ -258,6 +258,9 @@ exprfmt(Fmt *f, Node *n, int prec)
 		break;
 
 	case OCONV:
+	case OCONVNOP:
+	case OCONVSLICE:
+	case OCONVIFACE:
 		fmtprint(f, "%T(", n->type);
 		exprfmt(f, n->left, 0);
 		fmtprint(f, ")");
diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index bca203ee64..43351796b7 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -87,6 +87,8 @@ reswitch:
 		ok |= Erv;
 		if(n->iota && !(top & Eiota))
 			yyerror("use of iota not in constant initializer");
+		if(n->val.ctype == CTSTR)
+			n->type = idealstring;
 		goto ret;
 
 	case ONONAME:
@@ -1268,7 +1270,9 @@ typecheckconv(Node *nconv, Node *n, Type *t, int explicit)
 	if(n->type == T)
 		return n;
 
-	if(cvttype(t, n->type) && n->op == OLITERAL) {
+	if(n->op == OLITERAL)
+	if(explicit || n->type->etype == TIDEAL || n->type == idealstring || n->type->etype == TNIL)
+	if(cvttype(t, n->type)) {
 		// can convert literal in place
 		// TODO(rsc) is this needed?
 		n1 = nod(OXXX, N, N);
@@ -1286,6 +1290,10 @@ typecheckconv(Node *nconv, Node *n, Type *t, int explicit)
 		return n;
 
 	case 0:
+		if(nconv) {
+			nconv->op = OCONVNOP;
+			return nconv;
+		}
 		return n;
 	}
 
diff --git a/test/fixedbugs/bug197.go b/test/fixedbugs/bug197.go
new file mode 100644
index 0000000000..501b94ce0f
--- /dev/null
+++ b/test/fixedbugs/bug197.go
@@ -0,0 +1,33 @@
+// errchk $G $D/$F.go
+
+// 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
+
+type T int
+type U int
+
+var x int
+
+var t T = int(0)	// ERROR "cannot use"
+var t1 T = int(x)	// ERROR "cannot use"
+var u U = int(0)	// ERROR "cannot use"
+var u1 U = int(x)	// ERROR "cannot use"
+
+type S string
+var s S
+
+var s1 = s + "hello"
+var s2 = "hello" + s
+var s3 = s + string("hello")	// ERROR "invalid operation"
+var s4 = string("hello") + s	// ERROR "invalid operation"
+
+var r string
+
+var r1 = r + "hello"
+var r2 = "hello" + r
+var r3 = r + string("hello")
+var r4 = string("hello") + r
+