Author: Sam McCall Date: 2020-10-27T08:36:35+01:00 New Revision: c6a05eb62f2ab392eba4e7a056e95c821587ae47
URL: https://github.com/llvm/llvm-project/commit/c6a05eb62f2ab392eba4e7a056e95c821587ae47 DIFF: https://github.com/llvm/llvm-project/commit/c6a05eb62f2ab392eba4e7a056e95c821587ae47.diff LOG: [Syntax] Disallow invalid Node operations Copy/move break invariants (move could be fixed). Node/Tree should have no public constructors, they're abstract. Destructor is private to enforce arena allocation. (Making the constructor of all subclasses private doesn't seem worthwhile) Differential Revision: https://reviews.llvm.org/D90163 Added: Modified: clang/include/clang/Tooling/Syntax/Tree.h Removed: ################################################################################ diff --git a/clang/include/clang/Tooling/Syntax/Tree.h b/clang/include/clang/Tooling/Syntax/Tree.h index 5840a86199eb..c6430452a94d 100644 --- a/clang/include/clang/Tooling/Syntax/Tree.h +++ b/clang/include/clang/Tooling/Syntax/Tree.h @@ -76,10 +76,20 @@ enum class NodeRole : uint8_t; /// A node in a syntax tree. Each node is either a Leaf (representing tokens) or /// a Tree (representing language constructrs). class Node { -public: +protected: /// Newly created nodes are detached from a tree, parent and sibling links are /// set when the node is added as a child to another one. Node(NodeKind Kind); + /// Nodes are allocated on Arenas; the destructor is never called. + ~Node() = default; + +public: + /// Nodes cannot simply be copied without violating tree invariants. + Node(const Node &) = delete; + Node &operator=(const Node &) = delete; + /// Idiomatically, nodes are allocated on an Arena and never moved. + Node(Node &&) = delete; + Node &operator=(Node &&) = delete; NodeKind getKind() const { return static_cast<NodeKind>(Kind); } NodeRole getRole() const { return static_cast<NodeRole>(Role); } @@ -153,7 +163,6 @@ class Leaf final : public Node { /// A node that has children and represents a syntactic language construct. class Tree : public Node { public: - using Node::Node; static bool classof(const Node *N); Node *getFirstChild() { return FirstChild; } @@ -170,6 +179,7 @@ class Tree : public Node { } protected: + using Node::Node; /// Find the first node with a corresponding role. Node *findChild(NodeRole R); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
