cmd/internal/gc: type of str[i] is byte, not uint8

Fixes golang#8745. Change-Id: Id0641e3c0f259812b41ed871e83c68740feb2b19 Reviewed-on: https://go-review.googlesource.com/10261 Reviewed-by: Austin Clements <[email protected]>
zfy3000163 · May 19, 2015 · c735064 · c735064
1 parent 913db76
commit c735064
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diff --git a/src/cmd/internal/gc/typecheck.go b/src/cmd/internal/gc/typecheck.go
@@ -1027,7 +1027,7 @@ OpSwitch:
 		case TSTRING, TARRAY:
 			indexlit(&n.Right)
 			if t.Etype == TSTRING {
-				n.Type = Types[TUINT8]
+				n.Type = bytetype
 			} else {
 				n.Type = t.Type
 			}

diff --git a/test/fixedbugs/issue8745.go b/test/fixedbugs/issue8745.go
@@ -0,0 +1,13 @@
+// errorcheck
+
+// Copyright 2015 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.
+
+// Check that the error says s[2] is a byte, not a uint8.
+
+package p
+
+func f(s string) {
+	var _ float64 = s[2] // ERROR "cannot use.*type byte.*as type float64"
+}