go/test/fixedbugs/issue29215.go
Keith Randall 443990742e cmd/compile: ignore out-of-bounds reads from readonly constants
Out-of-bounds reads of globals can happen in dead code. For code
like this:

s := "a"
if len(s) == 3 {
   load s[0], s[1], and s[2]
}

The out-of-bounds loads are dead code, but aren't removed yet
when lowering. We need to not panic when compile-time evaluating
those loads. This can only happen for dead code, so the result
doesn't matter.

Fixes #29215

Change-Id: I7fb765766328b9524c6f2a1e6ab8d8edd9875097
Reviewed-on: https://go-review.googlesource.com/c/154057
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
2018-12-20 17:34:32 +00:00

19 lines
371 B
Go

// compile
// Copyright 2018 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 f() {
var s string
var p, q bool
s = "a"
for p {
p = false == (true != q)
s = ""
}
_ = s == "bbb"
}