1//===--- CurrentSourceLocExprScope.h ----------------------------*- 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 types used to track the current context needed to evaluate
11// a SourceLocExpr.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_AST_CURRENT_SOURCE_LOC_EXPR_SCOPE_H
16#define LLVM_CLANG_AST_CURRENT_SOURCE_LOC_EXPR_SCOPE_H
17
18#include <cassert>
19
20namespace clang {
21class Expr;
22
23/// Represents the current source location and context used to determine the
24/// value of the source location builtins (ex. __builtin_LINE), including the
25/// context of default argument and default initializer expressions.
26class CurrentSourceLocExprScope {
27 /// The CXXDefaultArgExpr or CXXDefaultInitExpr we're currently evaluating.
28 const Expr *DefaultExpr = nullptr;
29
30public:
31 /// A RAII style scope guard used for tracking the current source
32 /// location and context as used by the source location builtins
33 /// (ex. __builtin_LINE).
34 class SourceLocExprScopeGuard;
35
36 const Expr *getDefaultExpr() const { return DefaultExpr; }
37
38 explicit CurrentSourceLocExprScope() = default;
39
40private:
41 explicit CurrentSourceLocExprScope(const Expr *DefaultExpr)
42 : DefaultExpr(DefaultExpr) {}
43
44 CurrentSourceLocExprScope(CurrentSourceLocExprScope const &) = default;
45 CurrentSourceLocExprScope &
46 operator=(CurrentSourceLocExprScope const &) = default;
47};
48
49class CurrentSourceLocExprScope::SourceLocExprScopeGuard {
50public:
51 SourceLocExprScopeGuard(const Expr *DefaultExpr,
52 CurrentSourceLocExprScope &Current)
53 : Current(Current), OldVal(Current), Enable(false) {
54 assert(DefaultExpr && "the new scope should not be empty");
55 if ((Enable = (Current.getDefaultExpr() == nullptr)))
56 Current = CurrentSourceLocExprScope(DefaultExpr);
57 }
58
59 ~SourceLocExprScopeGuard() {
60 if (Enable)
61 Current = OldVal;
62 }
63
64private:
65 SourceLocExprScopeGuard(SourceLocExprScopeGuard const &) = delete;
66 SourceLocExprScopeGuard &operator=(SourceLocExprScopeGuard const &) = delete;
67
68 CurrentSourceLocExprScope &Current;
69 CurrentSourceLocExprScope OldVal;
70 bool Enable;
71};
72
73} // end namespace clang
74
75#endif // LLVM_CLANG_AST_CURRENT_SOURCE_LOC_EXPR_SCOPE_H
76