From f4ee9f133c60cbbf5bd7d7d1aec62e4928a9a296 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 9 Sep 2009 01:31:10 -0700
Subject: [PATCH] check type of string/map/array index expressions

R=ken
OCL=34478
CL=34480
---
 src/cmd/gc/typecheck.c   |  6 ++++++
 test/fixedbugs/bug205.go | 18 ++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 test/fixedbugs/bug205.go

diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index d364e5fcc6..cf46414cab 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -500,18 +500,24 @@ reswitch:
 
 		case TARRAY:
 			defaultlit(&n->right, types[TUINT]);
+			if(n->right->type != T && !isint[n->right->type->etype])
+				yyerror("non-integer array index %#N", n->right);
 			n->type = t->type;
 			break;
 
 		case TMAP:
 			n->etype = 0;
 			defaultlit(&n->right, t->down);
+			if(n->right->type != T && !eqtype(n->right->type, t->down))
+				yyerror("invalid map index %#N - need type %T", n->right, t->down);
 			n->type = t->type;
 			n->op = OINDEXMAP;
 			break;
 
 		case TSTRING:
 			defaultlit(&n->right, types[TUINT]);
+			if(n->right->type != T && !isint[n->right->type->etype])
+				yyerror("non-integer string index %#N", n->right);
 			n->type = types[TUINT8];
 			n->op = OINDEXSTR;
 			break;
diff --git a/test/fixedbugs/bug205.go b/test/fixedbugs/bug205.go
new file mode 100644
index 0000000000..5fb0a0d16b
--- /dev/null
+++ b/test/fixedbugs/bug205.go
@@ -0,0 +1,18 @@
+// 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
+
+var t []int
+var s string;
+var m map[string]int;
+
+func main() {
+	println(t["hi"]);	// ERROR "non-integer"
+	println(s["hi"]);	// ERROR "non-integer"
+	println(m[0]);	// ERROR "map index"
+}
+
-- 
2.48.1