cmd/compile: fix -d=checkptr for named unsafe.Pointer types

We need to explicitly convert pointers to unsafe.Pointer before
passing to the runtime checkptr instrumentation in case the user
declared their own type with underlying type unsafe.Pointer.

Updates #22218.
Fixes #34966.

Change-Id: I3baa2809d77f8257167cd78f57156f819130baa8
Reviewed-on: https://go-review.googlesource.com/c/go/+/201782
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 57cb59783f145cd916636ea2a3c81e1ad5a1ff6f..ebae392808bb015e4c54f988db11a1123a4c4d2d 100644 (file)
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -2392,6 +2392,9 @@ func conv(n *Node, t *types.Type) *Node {
 // convnop converts node n to type t using the OCONVNOP op
 // and typechecks the result with ctxExpr.
 func convnop(n *Node, t *types.Type) *Node {
+       if types.Identical(n.Type, t) {
+               return n
+       }
        n = nod(OCONVNOP, n, nil)
        n.Type = t
        n = typecheck(n, ctxExpr)
@@ -3915,7 +3918,7 @@ func walkCheckPtrAlignment(n *Node, init *Nodes) *Node {
        }
 
        n.Left = cheapexpr(n.Left, init)
-       init.Append(mkcall("checkptrAlignment", nil, init, n.Left, typename(n.Type.Elem())))
+       init.Append(mkcall("checkptrAlignment", nil, init, convnop(n.Left, types.Types[TUNSAFEPTR]), typename(n.Type.Elem())))
        return n
 }
 
@@ -3956,7 +3959,7 @@ func walkCheckPtrArithmetic(n *Node, init *Nodes) *Node {
                case OCONVNOP:
                        if n.Left.Type.Etype == TUNSAFEPTR {
                                n.Left = cheapexpr(n.Left, init)
-                               originals = append(originals, n.Left)
+                               originals = append(originals, convnop(n.Left, types.Types[TUNSAFEPTR]))
                        }
                }
        }
@@ -3968,7 +3971,7 @@ func walkCheckPtrArithmetic(n *Node, init *Nodes) *Node {
        slice.Esc = EscNone
        slice.SetTransient(true)
 
-       init.Append(mkcall("checkptrArithmetic", nil, init, n, slice))
+       init.Append(mkcall("checkptrArithmetic", nil, init, convnop(n, types.Types[TUNSAFEPTR]), slice))
        return n
 }
 

diff --git a/test/fixedbugs/issue34966.go b/test/fixedbugs/issue34966.go
new file mode 100644 (file)
index 0000000..f920e71
--- /dev/null
+++ b/test/fixedbugs/issue34966.go
@@ -0,0 +1,14 @@
+// compile -d=checkptr
+
+// Copyright 2019 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
+
+import "unsafe"
+
+type ptr unsafe.Pointer
+
+func f(p ptr) *int { return (*int)(p) }
+func g(p ptr) ptr  { return ptr(uintptr(p) + 1) }