1 files changed, 50 insertions, 0 deletions
diff --git a/src/runtime/checkptr.go b/src/runtime/checkptr.go
new file mode 100644
index 0000000000..040a19a39c
--- /dev/null
+++ b/src/runtime/checkptr.go
@@ -0,0 +1,50 @@
+// 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 runtime
+
+import "unsafe"
+
+type ptrAlign struct {
+	ptr   unsafe.Pointer
+	align uintptr
+}
+
+func checkptrAlignment(p unsafe.Pointer, elem *_type) {
+	// TODO(mdempsky): What about fieldAlign?
+	if uintptr(p)&(uintptr(elem.align)-1) != 0 {
+		panic(ptrAlign{p, uintptr(elem.align)})
+	}
+}
+
+type ptrArith struct {
+	ptr       unsafe.Pointer
+	originals []unsafe.Pointer
+}
+
+func checkptrArithmetic(p unsafe.Pointer, originals []unsafe.Pointer) {
+	if 0 < uintptr(p) && uintptr(p) < minLegalPointer {
+		panic(ptrArith{p, originals})
+	}
+
+	base := checkptrBase(p)
+	if base == 0 {
+		return
+	}
+
+	for _, original := range originals {
+		if base == checkptrBase(original) {
+			return
+		}
+	}
+
+	panic(ptrArith{p, originals})
+}
+
+func checkptrBase(p unsafe.Pointer) uintptr {
+	base, _, _ := findObject(uintptr(p), 0, 0)
+	// TODO(mdempsky): If base == 0, then check if p points to the
+	// stack or a global variable.
+	return base
+}