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![Matthew Dempsky](/assets/img/avatar_default.png)
We decide during escape analysis whether to pass closure variables by value or reference. One of the factors that's considered is whether a variable has had its address taken. However, this analysis is based only on the user-written source code, whereas order+walk may introduce rewrites that take the address of a variable (e.g., passing a uint16 key by reference to the size-generic map runtime builtins). Typically this would be harmless, albeit suboptimal. But in #43701 it manifested as needing a stack object for a function where we didn't realize we needed one up front when we generate symbols. Probably we should just generate symbols on demand, now that those routines are all concurrent-safe, but this is a first fix. Thanks to Alberto Donizetti for reporting the issue, and Cuong Manh Le for initial investigation. Fixes #43701. Change-Id: I16d87e9150723dcb16de7b43f2a8f3cd807a9437 Reviewed-on: https://go-review.googlesource.com/c/go/+/284075 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>
19 lines
290 B
Go
19 lines
290 B
Go
// compile
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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 p
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func f() {
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var st struct {
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s string
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i int16
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}
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_ = func() {
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var m map[int16]int
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m[st.i] = 0
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}
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}
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