1// errorcheck -0 -d=append,slice
2
3// Copyright 2015 The Go Authors.  All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Check optimization results for append and slicing.
8
9package main
10
11func a1(x []int, y int) []int {
12	x = append(x, y) // ERROR "append: len-only update"
13	return x
14}
15
16func a2(x []int, y int) []int {
17	return append(x, y) // ERROR "append: full update"
18}
19
20func a3(x *[]int, y int) {
21	*x = append(*x, y) // ERROR "append: len-only update"
22}
23
24func s1(x **[]int, xs **string, i, j int) {
25	var z []int
26	z = (**x)[2:]         // ERROR "slice: omit check for 2nd index"
27	z = (**x)[2:len(**x)] // not yet: "slice: reuse len" "slice: omit check for 2nd index"
28	z = (**x)[2:cap(**x)] // not yet: "slice: reuse cap" "slice: omit check for 2nd index"
29	z = (**x)[i:i]        // ERROR "slice: reuse 1st index" "slice: omit check for 1st index" "slice: result len == 0"
30	z = (**x)[1:i:i]      // ERROR "slice: reuse 2nd index" "slice: omit check for 2nd index" "slice: result cap == result len"
31	z = (**x)[i:j:0]      // ERROR "slice: omit check for 3rd index"
32	z = (**x)[i:0:j]      // ERROR "slice: omit check for 2nd index"
33	z = (**x)[0:i:j]      // ERROR "slice: omit check for 1st index" "slice: skip base adjustment for 1st index 0"
34	z = (**x)[0:]         // ERROR "slice: omit slice operation"
35	z = (**x)[2:8]        // ERROR "slice: omit check for 1st index" "slice: result len == 6"
36	z = (**x)[2:2]        // ERROR "slice: omit check for 1st index" "slice: result len == 0"
37	z = (**x)[0:i]        // ERROR "slice: omit check for 1st index" "slice: skip base adjustment for 1st index 0"
38	z = (**x)[2:i:8]      // ERROR "slice: result cap == 6"
39	z = (**x)[i:2:i]      // ERROR "slice: reuse 1st index" "slice: result cap == 0" "slice: skip base adjustment for cap == 0"
40
41	z = z[0:i]       // ERROR "slice: omit check for 1st index" "slice: result cap not computed" "slice: skip base adjustment for 1st index 0" "slice: len-only update"
42	z = z[0:i : i+1] // ERROR "slice: omit check for 1st index" "slice: skip base adjustment for 1st index 0" "slice: len/cap-only update"
43	z = z[i : i+1]
44
45	println(z)
46
47	var zs string
48	zs = (**xs)[2:]          // ERROR "slice: omit check for 2nd index"
49	zs = (**xs)[2:len(**xs)] // not yet: "slice: reuse len" "slice: omit check for 2nd index"
50	zs = (**xs)[i:i]         // ERROR "slice: reuse 1st index" "slice: omit check for 1st index" "slice: result len == 0" "slice: skip base adjustment for string len == 0"
51	zs = (**xs)[0:]          // ERROR "slice: omit slice operation"
52	zs = (**xs)[2:8]         // ERROR "slice: omit check for 1st index" "slice: result len == 6"
53	zs = (**xs)[2:2]         // ERROR "slice: omit check for 1st index" "slice: result len == 0" "slice: skip base adjustment for string len == 0"
54	zs = (**xs)[0:i]         // ERROR "slice: omit check for 1st index" "slice: skip base adjustment for 1st index 0"
55
56	zs = zs[0:i] // ERROR "slice: omit check for 1st index" "slice: skip base adjustment for 1st index 0" "slice: len-only update"
57	zs = zs[i : i+1]
58	println(zs)
59}
60