Adding upstream version 1.22.1.upstream/1.22.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/ir/copy.go b/src/cmd/compile/internal/ir/copy.go
new file mode 100644
index 0000000..d30f7bc
--- /dev/null
+++ b/src/cmd/compile/internal/ir/copy.go
@@ -0,0 +1,43 @@
+// Copyright 2020 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 ir
+
+import (
+	"cmd/internal/src"
+)
+
+// Copy returns a shallow copy of n.
+func Copy(n Node) Node {
+	return n.copy()
+}
+
+// DeepCopy returns a “deep” copy of n, with its entire structure copied
+// (except for shared nodes like ONAME, ONONAME, OLITERAL, and OTYPE).
+// If pos.IsKnown(), it sets the source position of newly allocated Nodes to pos.
+func DeepCopy(pos src.XPos, n Node) Node {
+	var edit func(Node) Node
+	edit = func(x Node) Node {
+		switch x.Op() {
+		case ONAME, ONONAME, OLITERAL, ONIL, OTYPE:
+			return x
+		}
+		x = Copy(x)
+		if pos.IsKnown() {
+			x.SetPos(pos)
+		}
+		EditChildren(x, edit)
+		return x
+	}
+	return edit(n)
+}
+
+// DeepCopyList returns a list of deep copies (using DeepCopy) of the nodes in list.
+func DeepCopyList(pos src.XPos, list []Node) []Node {
+	var out []Node
+	for _, n := range list {
+		out = append(out, DeepCopy(pos, n))
+	}
+	return out
+}