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 19 namespace clang { 20 class 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. 25 class CurrentSourceLocExprScope { 26 /// The CXXDefaultArgExpr or CXXDefaultInitExpr we're currently evaluating. 27 const Expr *DefaultExpr = nullptr; 28 29 public: 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 getDefaultExpr()35 const Expr *getDefaultExpr() const { return DefaultExpr; } 36 37 explicit CurrentSourceLocExprScope() = default; 38 39 private: CurrentSourceLocExprScope(const Expr * DefaultExpr)40 explicit CurrentSourceLocExprScope(const Expr *DefaultExpr) 41 : DefaultExpr(DefaultExpr) {} 42 43 CurrentSourceLocExprScope(CurrentSourceLocExprScope const &) = default; 44 CurrentSourceLocExprScope & 45 operator=(CurrentSourceLocExprScope const &) = default; 46 }; 47 48 class CurrentSourceLocExprScope::SourceLocExprScopeGuard { 49 public: SourceLocExprScopeGuard(const Expr * DefaultExpr,CurrentSourceLocExprScope & Current)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 ~SourceLocExprScopeGuard()58 ~SourceLocExprScopeGuard() { 59 if (Enable) 60 Current = OldVal; 61 } 62 63 private: 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