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| author | Keith Randall <khr@golang.org> | 2025-04-24 08:38:56 -0700 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-04-24 11:02:26 -0700 |
| commit | 3452d80da3cf4f08da0f5905b1aa19cec475936e (patch) | |
| tree | fd4d18d93afe50ee0ba033ef1b681340a4294970 | |
| parent | 3009566a46f19e9c94df4cf51cc374763698cba0 (diff) | |
| download | go-3452d80da3cf4f08da0f5905b1aa19cec475936e.tar.xz | |
cmd/compile: add cast in range loop final value computation
When replacing a loop where the iteration variable has a named type,
we need to compute the last iteration value as i = T(len(a)-1), not
just i = len(a)-1.
Fixes #73491
Change-Id: Ic1cc3bdf8571a40c10060f929a9db8a888de2b70
Reviewed-on: https://go-review.googlesource.com/c/go/+/667815
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Keith Randall <khr@google.com>
| -rw-r--r-- | src/cmd/compile/internal/walk/range.go | 2 | ||||
| -rw-r--r-- | test/fixedbugs/issue73491.go | 25 |
2 files changed, 26 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/walk/range.go b/src/cmd/compile/internal/walk/range.go index a1e5442a69..3d3547b84b 100644 --- a/src/cmd/compile/internal/walk/range.go +++ b/src/cmd/compile/internal/walk/range.go @@ -605,7 +605,7 @@ func arrayClear(wbPos src.XPos, a ir.Node, nrange *ir.RangeStmt) ir.Node { // For array range clear, also set "i = len(a) - 1" if nrange != nil { - idx := ir.NewAssignStmt(base.Pos, nrange.Key, ir.NewBinaryExpr(base.Pos, ir.OSUB, ir.NewUnaryExpr(base.Pos, ir.OLEN, a), ir.NewInt(base.Pos, 1))) + idx := ir.NewAssignStmt(base.Pos, nrange.Key, typecheck.Conv(ir.NewBinaryExpr(base.Pos, ir.OSUB, ir.NewUnaryExpr(base.Pos, ir.OLEN, a), ir.NewInt(base.Pos, 1)), nrange.Key.Type())) n.Body.Append(idx) } diff --git a/test/fixedbugs/issue73491.go b/test/fixedbugs/issue73491.go new file mode 100644 index 0000000000..4137088bde --- /dev/null +++ b/test/fixedbugs/issue73491.go @@ -0,0 +1,25 @@ +// build + +// Copyright 2025 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 main + +type T int + +const K T = 5 + +type P struct { + a [K]*byte +} + +//go:noinline +func f(p *P) { + for i := range K { + p.a[i] = nil + } +} +func main() { + f(nil) +} |