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![Matthew Dempsky](/assets/img/avatar_default.png)
Like other builtin functions, unsafe.Add's len operand is allowed to be variable sized. However, unlike other builtins, it doesn't get lowered to a runtime function call, so we never end up coercing it to a specific type. As a result, we could end up constructing an OpAddPtr value but with a less-than-ptr-sized addend operand. This CL fixes this by always coercing the second operand to uintptr during SSA construction. Theoretically, we could do this during walk instead, but the frontend doesn't allow converting negative constants to uintptr. Fixes #48536. Change-Id: Ib0619ea79df58b256b250fec967a6d3c8afea631 Reviewed-on: https://go-review.googlesource.com/c/go/+/351592 Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
30 lines
500 B
Go
30 lines
500 B
Go
// run
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// Copyright 2021 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 "unsafe"
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var i = 257
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func main() {
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var buf [10]byte
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p0 := unsafe.Pointer(&buf[0])
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p1 := unsafe.Pointer(&buf[1])
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if p := unsafe.Add(p0, uint8(i)); p != p1 {
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println("FAIL:", p, "!=", p1)
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}
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var x uint8
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if i != 0 {
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x = 1
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}
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if p := unsafe.Add(p0, x); p != p1 {
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println("FAIL:", p, "!=", p1)
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}
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}
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