mirror of
https://github.com/golang/go
synced 2024-07-21 01:55:06 +00:00
60e6afb689
types2 have already errored about any spec-required overflows, and division by zero. CL 469595 unintentionally fixed typecheck not to error about overflows, but zero division is still be checked during tcArith. This causes unsafe operations with variable size failed to compile, instead of raising runtime error. Fixes #60601 Change-Id: I7bea2821099556835c920713397f7c5d8a4025ac Reviewed-on: https://go-review.googlesource.com/c/go/+/501735 Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
51 lines
862 B
Go
51 lines
862 B
Go
// run
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// Copyright 2023 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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package main
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import (
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"strings"
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"unsafe"
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)
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func shift[T any]() int64 {
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return 1 << unsafe.Sizeof(*new(T))
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}
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func div[T any]() uintptr {
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return 1 / unsafe.Sizeof(*new(T))
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}
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func add[T any]() int64 {
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return 1<<63 - 1 + int64(unsafe.Sizeof(*new(T)))
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}
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func main() {
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shift[[62]byte]()
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shift[[63]byte]()
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shift[[64]byte]()
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shift[[100]byte]()
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shift[[1e6]byte]()
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add[[1]byte]()
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shouldPanic("divide by zero", func() { div[[0]byte]() })
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}
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func shouldPanic(str string, f func()) {
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defer func() {
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err := recover()
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if err == nil {
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panic("did not panic")
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}
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s := err.(error).Error()
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if !strings.Contains(s, str) {
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panic("got panic " + s + ", want " + str)
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}
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}()
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f()
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}
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