1//===--- CurrentSourceLocExprScope.h ----------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines types used to track the current context needed to evaluate
10// a SourceLocExpr.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_CURRENTSOURCELOCEXPRSCOPE_H
15#define LLVM_CLANG_AST_CURRENTSOURCELOCEXPRSCOPE_H
16
17#include <cassert>
18
19namespace clang {
20class Expr;
21
22/// Represents the current source location and context used to determine the
23/// value of the source location builtins (ex. __builtin_LINE), including the
24/// context of default argument and default initializer expressions.
25class CurrentSourceLocExprScope {
26 /// The CXXDefaultArgExpr or CXXDefaultInitExpr we're currently evaluating.
27 const Expr *DefaultExpr = nullptr;
28
29public:
30 /// A RAII style scope guard used for tracking the current source
31 /// location and context as used by the source location builtins
32 /// (ex. __builtin_LINE).
33 class SourceLocExprScopeGuard;
34
35 const Expr *getDefaultExpr() const { return DefaultExpr; }
36
37 explicit CurrentSourceLocExprScope() = default;
38
39private:
40 explicit CurrentSourceLocExprScope(const Expr *DefaultExpr)
41 : DefaultExpr(DefaultExpr) {}
42
43 CurrentSourceLocExprScope(CurrentSourceLocExprScope const &) = default;
44 CurrentSourceLocExprScope &
45 operator=(CurrentSourceLocExprScope const &) = default;
46};
47
48class CurrentSourceLocExprScope::SourceLocExprScopeGuard {
49public:
50 SourceLocExprScopeGuard(const Expr *DefaultExpr,
51 CurrentSourceLocExprScope &Current)
52 : Current(Current), OldVal(Current), Enable(false) {
53 assert(DefaultExpr && "the new scope should not be empty");
54 if ((Enable = (Current.getDefaultExpr() == nullptr)))
55 Current = CurrentSourceLocExprScope(DefaultExpr);
56 }
57
58 ~SourceLocExprScopeGuard() {
59 if (Enable)
60 Current = OldVal;
61 }
62
63private:
64 SourceLocExprScopeGuard(SourceLocExprScopeGuard const &) = delete;
65 SourceLocExprScopeGuard &operator=(SourceLocExprScopeGuard const &) = delete;
66
67 CurrentSourceLocExprScope &Current;
68 CurrentSourceLocExprScope OldVal;
69 bool Enable;
70};
71
72} // end namespace clang
73
74#endif // LLVM_CLANG_AST_CURRENTSOURCELOCEXPRSCOPE_H
75