mirror of
https://github.com/golang/go
synced 2024-11-23 17:20:02 -07:00
cca23a7373
This is a revert of https://go-review.googlesource.com/c/go/+/316890, which has positive effects on debugging + DWARF variable locations for register parameters when the reg abi is in effect, but also turns out to interact badly with the register allocator. Fixes #46304. Change-Id: I624bd980493411a9cde45d44fcd3c46cad796909 Reviewed-on: https://go-review.googlesource.com/c/go/+/321830 Trust: Than McIntosh <thanm@google.com> Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org>
77 lines
1.1 KiB
Go
77 lines
1.1 KiB
Go
// run
|
|
|
|
// Copyright 2021 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.
|
|
|
|
// This testcase caused a crash when the register ABI was in effect,
|
|
// on amd64 (problem with register allocation).
|
|
|
|
package main
|
|
|
|
type Op struct {
|
|
tag string
|
|
_x []string
|
|
_q [20]uint64
|
|
plist []P
|
|
}
|
|
|
|
type P struct {
|
|
tag string
|
|
_x [10]uint64
|
|
b bool
|
|
}
|
|
|
|
type M int
|
|
|
|
//go:noinline
|
|
func (w *M) walkP(p *P) *P {
|
|
np := &P{}
|
|
*np = *p
|
|
np.tag += "new"
|
|
return np
|
|
}
|
|
|
|
func (w *M) walkOp(op *Op) *Op {
|
|
if op == nil {
|
|
return nil
|
|
}
|
|
|
|
orig := op
|
|
cloned := false
|
|
clone := func() {
|
|
if !cloned {
|
|
cloned = true
|
|
op = &Op{}
|
|
*op = *orig
|
|
}
|
|
}
|
|
|
|
pCloned := false
|
|
for i := range op.plist {
|
|
if s := w.walkP(&op.plist[i]); s != &op.plist[i] {
|
|
if !pCloned {
|
|
pCloned = true
|
|
clone()
|
|
op.plist = make([]P, len(orig.plist))
|
|
copy(op.plist, orig.plist)
|
|
}
|
|
op.plist[i] = *s
|
|
}
|
|
}
|
|
|
|
return op
|
|
}
|
|
|
|
func main() {
|
|
var ww M
|
|
w := &ww
|
|
p1 := P{tag: "a"}
|
|
p1._x[1] = 9
|
|
o := Op{tag: "old", plist: []P{p1}}
|
|
no := w.walkOp(&o)
|
|
if no.plist[0].tag != "anew" {
|
|
panic("bad")
|
|
}
|
|
}
|