Sebastian Redl | a55e52c | 2008-11-25 22:21:31 +0000 | [diff] [blame^] | 1 | //===--- AstGuard.h - Parser Ownership Tracking Utilities -------*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file defines RAII objects for managing ExprTy* and StmtTy*. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #ifndef LLVM_CLANG_PARSE_ASTGUARD_H |
| 15 | #define LLVM_CLANG_PARSE_ASTGUARD_H |
| 16 | |
| 17 | #include "clang/Parse/Action.h" |
| 18 | #include "llvm/ADT/SmallVector.h" |
| 19 | |
| 20 | namespace clang |
| 21 | { |
| 22 | /// RAII guard for freeing StmtTys and ExprTys on early exit in the parser. |
| 23 | /// Instantiated for statements and expressions (Action::DeleteStmt and |
| 24 | /// Action::DeleteExpr). |
| 25 | template <void (Action::*Destroyer)(void*)> |
| 26 | class ASTGuard { |
| 27 | Action &Actions; |
| 28 | void *Node; |
| 29 | |
| 30 | void destroy() { |
| 31 | if (Node) |
| 32 | (Actions.*Destroyer)(Node); |
| 33 | } |
| 34 | |
| 35 | ASTGuard(const ASTGuard&); // DO NOT IMPLEMENT |
| 36 | // Reference member prevents copy assignment. |
| 37 | |
| 38 | public: |
| 39 | explicit ASTGuard(Action &actions) : Actions(actions), Node(0) {} |
| 40 | ASTGuard(Action &actions, void *node) |
| 41 | : Actions(actions), Node(node) {} |
| 42 | template <unsigned N> |
| 43 | ASTGuard(Action &actions, const Action::ActionResult<N> &res) |
| 44 | : Actions(actions), Node(res.Val) {} |
| 45 | ~ASTGuard() { destroy(); } |
| 46 | |
| 47 | void reset(void *element) { |
| 48 | destroy(); |
| 49 | Node = element; |
| 50 | } |
| 51 | template <unsigned N> |
| 52 | void reset(const Action::ActionResult<N> &res) { |
| 53 | reset(res.Val); |
| 54 | } |
| 55 | void *take() { |
| 56 | void *Temp = Node; |
| 57 | Node = 0; |
| 58 | return Temp; |
| 59 | } |
| 60 | void *get() const { return Node; } |
| 61 | }; |
| 62 | |
| 63 | typedef ASTGuard<&Action::DeleteStmt> StmtGuard; |
| 64 | typedef ASTGuard<&Action::DeleteExpr> ExprGuard; |
| 65 | |
| 66 | /// RAII SmallVector wrapper that holds Action::ExprTy* and similar, |
| 67 | /// automatically freeing them on destruction unless it's been disowned. |
| 68 | /// Instantiated for statements and expressions (Action::DeleteStmt and |
| 69 | /// Action::DeleteExpr). |
| 70 | template <void (Action::*Destroyer)(void*), unsigned N> |
| 71 | class ASTVector : public llvm::SmallVector<void*, N> { |
| 72 | private: |
| 73 | Action &Actions; |
| 74 | bool Owns; |
| 75 | |
| 76 | void destroy() { |
| 77 | if (Owns) { |
| 78 | while (!this->empty()) { |
| 79 | (Actions.*Destroyer)(this->back()); |
| 80 | this->pop_back(); |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | ASTVector(const ASTVector&); // DO NOT IMPLEMENT |
| 86 | // Reference member prevents copy assignment. |
| 87 | |
| 88 | public: |
| 89 | ASTVector(Action &actions) : Actions(actions), Owns(true) {} |
| 90 | |
| 91 | ~ASTVector() { destroy(); } |
| 92 | |
| 93 | void **take() { |
| 94 | Owns = false; |
| 95 | return &(*this)[0]; |
| 96 | } |
| 97 | }; |
| 98 | |
| 99 | /// A SmallVector of statements, with stack size 32 (as that is the only one |
| 100 | /// used.) |
| 101 | typedef ASTVector<&Action::DeleteStmt, 32> StmtVector; |
| 102 | /// A SmallVector of expressions, with stack size 12 (the maximum used.) |
| 103 | typedef ASTVector<&Action::DeleteExpr, 12> ExprVector; |
| 104 | } |
| 105 | |
| 106 | #endif |