mirror of
https://github.com/golang/go
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71 lines
2.5 KiB
Go
71 lines
2.5 KiB
Go
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// errorcheck -0 -d=append,slice,ssa/prove/debug=1
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Check optimization results for append and slicing.
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package main
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func a1(x []int, y int) []int {
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x = append(x, y) // ERROR "append: len-only update \(in local slice\)$"
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return x
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}
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func a2(x []int, y int) []int {
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return append(x, y)
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}
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func a3(x *[]int, y int) {
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*x = append(*x, y) // ERROR "append: len-only update$"
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}
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// s1_if_false_then_anything
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func s1_if_false_then_anything(x **[]int, xs **string, i, j int) {
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z := (**x)[0:i]
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z = z[i : i+1]
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println(z) // if we get here, then we have proven that i==i+1 (this cannot happen, but the program is still being analyzed...)
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zs := (**xs)[0:i] // since i=i+1 is proven, i+1 is "in bounds", ha-ha
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zs = zs[i : i+1] // ERROR "Proved boolean IsSliceInBounds$"
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println(zs)
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}
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func s1(x **[]int, xs **string, i, j int) {
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var z []int
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z = (**x)[2:]
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z = (**x)[2:len(**x)] // ERROR "Proved boolean IsSliceInBounds$"
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z = (**x)[2:cap(**x)] // ERROR "Proved IsSliceInBounds$"
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z = (**x)[i:i] // -ERROR "Proved IsSliceInBounds"
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z = (**x)[1:i:i] // ERROR "Proved boolean IsSliceInBounds$"
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z = (**x)[i:j:0]
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z = (**x)[i:0:j] // ERROR "Disproved IsSliceInBounds$"
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z = (**x)[0:i:j] // ERROR "Proved boolean IsSliceInBounds$"
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z = (**x)[0:] // ERROR "slice: omit slice operation$"
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z = (**x)[2:8] // ERROR "Disproved Eq(32|64)$"
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z = (**x)[2:2] // ERROR "Disproved Eq(32|64)$" "Proved boolean IsSliceInBounds$"
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z = (**x)[0:i] // ERROR "Proved boolean IsSliceInBounds$"
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z = (**x)[2:i:8] // ERROR "Disproved IsSliceInBounds$" "Proved IsSliceInBounds$" "Proved boolean IsSliceInBounds$"
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z = (**x)[i:2:i] // ERROR "Proved IsSliceInBounds$" "Proved boolean IsSliceInBounds$"
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z = z[0:i] // ERROR "Proved boolean IsSliceInBounds"
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z = z[0:i : i+1]
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z = z[i : i+1] // ERROR "Proved boolean IsSliceInBounds$"
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println(z)
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var zs string
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zs = (**xs)[2:]
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zs = (**xs)[2:len(**xs)] // ERROR "Proved IsSliceInBounds$" "Proved boolean IsSliceInBounds$"
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zs = (**xs)[i:i] // -ERROR "Proved boolean IsSliceInBounds"
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zs = (**xs)[0:] // ERROR "slice: omit slice operation$"
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zs = (**xs)[2:8]
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zs = (**xs)[2:2] // ERROR "Proved boolean IsSliceInBounds$"
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zs = (**xs)[0:i] // ERROR "Proved boolean IsSliceInBounds$"
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zs = zs[0:i] // See s1_if_false_then_anything above to explain the counterfactual bounds check result below
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zs = zs[i : i+1] // ERROR "Proved boolean IsSliceInBounds$"
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println(zs)
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}
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