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| author | Robert Griesemer <gri@golang.org> | 2017-06-22 15:35:35 -0700 |
|---|---|---|
| committer | Robert Griesemer <gri@golang.org> | 2017-06-22 23:31:45 +0000 |
| commit | 47e659b01fa0e90906f2294e396ff2be03032966 (patch) | |
| tree | 8bdfe5e361e1723c75f4052cf2586175cdd21ee6 | |
| parent | 3a5f746766efb3e89c78eabc81176960e394ec61 (diff) | |
| download | go-47e659b01fa0e90906f2294e396ff2be03032966.tar.gz go-47e659b01fa0e90906f2294e396ff2be03032966.zip | |
cmd/compile: fix array slice expression bounds check
Fixes #20749.
Change-Id: Ic6a7edc858575c4cb8b2e2ca97ee0c4b69f22c27
Reviewed-on: https://go-review.googlesource.com/46466
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
| -rw-r--r-- | src/cmd/compile/internal/gc/typecheck.go | 2 | ||||
| -rw-r--r-- | test/fixedbugs/issue20749.go | 15 |
2 files changed, 16 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go index f21cc8f826..bff278b7ae 100644 --- a/src/cmd/compile/internal/gc/typecheck.go +++ b/src/cmd/compile/internal/gc/typecheck.go @@ -2261,7 +2261,7 @@ func checksliceindex(l *Node, r *Node, tp *types.Type) bool { if r.Int64() < 0 { yyerror("invalid slice index %v (index must be non-negative)", r) return false - } else if tp != nil && tp.NumElem() > 0 && r.Int64() > tp.NumElem() { + } else if tp != nil && tp.NumElem() >= 0 && r.Int64() > tp.NumElem() { yyerror("invalid slice index %v (out of bounds for %d-element array)", r, tp.NumElem()) return false } else if Isconst(l, CTSTR) && r.Int64() > int64(len(l.Val().U.(string))) { diff --git a/test/fixedbugs/issue20749.go b/test/fixedbugs/issue20749.go new file mode 100644 index 0000000000..af9ff3fbed --- /dev/null +++ b/test/fixedbugs/issue20749.go @@ -0,0 +1,15 @@ +// errorcheck + +// Copyright 2017 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 p + +// Verify that the compiler complains even if the array +// has length 0. +var a [0]int +var _ = a[2:] // ERROR "invalid slice index 2" + +var b [1]int +var _ = b[2:] // ERROR "invalid slice index 2" |