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 <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Keith Randall <[email protected]>
golang · Oct 17, 2019 · f922645 · f922645
1 parent 58e8f78
commit f922645
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Showing 2 changed files with 20 additions and 3 deletions.
diff --git 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
@@ -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) }