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| author | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2024-03-07 14:49:30 +0700 |
|---|---|---|
| committer | Than McIntosh <thanm@google.com> | 2024-03-26 19:24:40 +0000 |
| commit | e71b0b1fee7df59a99ab6b5192854695d21ff688 (patch) | |
| tree | cef76a7e2d5291dab3d93fb3f76fbf38249fd950 | |
| parent | 9508eae5d11a518dd650f8964d0201b9fa1760c1 (diff) | |
| download | go-e71b0b1fee7df59a99ab6b5192854695d21ff688.tar.gz go-e71b0b1fee7df59a99ab6b5192854695d21ff688.zip | |
[release-branch.go1.22] cmd/compile: fix copying SSA-able variables optimization
CL 541715 added an optimization to copy SSA-able variables.
When handling m[k] = append(m[k], ...) case, it uses ir.SameSafeExpr to
check that m[k] expressions are the same, then doing type assertion to
convert the map index to ir.IndexExpr node. However, this assertion is
not safe for m[k] expression in append(m[k], ...), since it may be
wrapped by ir.OCONVNOP node.
Fixing this by un-wrapping any ir.OCONVNOP before doing type assertion.
Fixes #66178
Change-Id: I9ff7165ab97bc7f88d0e9b7b31604da19a8ca206
Reviewed-on: https://go-review.googlesource.com/c/go/+/569716
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/569818
Reviewed-by: David Chase <drchase@google.com>
| -rw-r--r-- | src/cmd/compile/internal/walk/order.go | 7 | ||||
| -rw-r--r-- | test/fixedbugs/issue66096.go | 17 |
2 files changed, 23 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go index 179fbdb99e..de180a4a8d 100644 --- a/src/cmd/compile/internal/walk/order.go +++ b/src/cmd/compile/internal/walk/order.go @@ -643,7 +643,12 @@ func (o *orderState) stmt(n ir.Node) { indexLHS.Index = o.cheapExpr(indexLHS.Index) call := n.Y.(*ir.CallExpr) - indexRHS := call.Args[0].(*ir.IndexExpr) + arg0 := call.Args[0] + // ir.SameSafeExpr skips OCONVNOPs, so we must do the same here (#66096). + for arg0.Op() == ir.OCONVNOP { + arg0 = arg0.(*ir.ConvExpr).X + } + indexRHS := arg0.(*ir.IndexExpr) indexRHS.X = indexLHS.X indexRHS.Index = indexLHS.Index diff --git a/test/fixedbugs/issue66096.go b/test/fixedbugs/issue66096.go new file mode 100644 index 0000000000..f8621a18b4 --- /dev/null +++ b/test/fixedbugs/issue66096.go @@ -0,0 +1,17 @@ +// compile + +// Copyright 2024 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package p + +type Message struct { + Header map[string][]string +} + +func f() { + m := Message{Header: map[string][]string{}} + m.Header[""] = append([]string(m.Header[""]), "") + _ = m +} |