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Diffstat (limited to 'include/clang/AST/ExprCXX.h')
-rw-r--r-- | include/clang/AST/ExprCXX.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/include/clang/AST/ExprCXX.h b/include/clang/AST/ExprCXX.h index a970579737..1b1019e554 100644 --- a/include/clang/AST/ExprCXX.h +++ b/include/clang/AST/ExprCXX.h @@ -2987,6 +2987,64 @@ public: // Iterators child_range children() { return child_range(); } }; + +/// \brief Represents a prvalue temporary that written into memory so that +/// a reference can bind to it. +/// +/// Prvalue expressions are materialized when they need to have an address +/// in memory for a reference to bind to. This happens when binding a +/// reference to the result of a conversion, e.g., +/// +/// \code +/// const int &r = 1.0; +/// \endcode +/// +/// Here, 1.0 is implicitly converted to an \c int. That resulting \c int is +/// then materialized via a \c MaterializeTemporaryExpr, and the reference +/// binds to the temporary. \c MaterializeTemporaryExprs are always glvalues +/// (either an lvalue or an xvalue, depending on the kind of reference binding +/// to it), maintaining the invariant that references always bind to glvalues. +class MaterializeTemporaryExpr : public Expr { + /// \brief The temporary-generating expression whose value will be + /// materialized. + Stmt *Temporary; + + friend class ASTStmtReader; + friend class ASTStmtWriter; + +public: + MaterializeTemporaryExpr(Expr *Temporary, bool BoundToLvalueReference) + : Expr(MaterializeTemporaryExprClass, Temporary->getType(), + BoundToLvalueReference? VK_LValue : VK_XValue, OK_Ordinary, + Temporary->isTypeDependent(), Temporary->isValueDependent(), + Temporary->containsUnexpandedParameterPack()), + Temporary(Temporary) { } + + MaterializeTemporaryExpr(EmptyShell Empty) + : Expr(MaterializeTemporaryExprClass, Empty) { } + + /// \brief Retrieve the temporary-generating subexpression whose value will + /// be materialized into a glvalue. + Expr *GetTemporaryExpr() const { return reinterpret_cast<Expr *>(Temporary); } + + /// \brief Determine whether this materialized temporary is bound to an + /// lvalue reference; otherwise, it's bound to an rvalue reference. + bool BoundToLvalueReference() const { + return getValueKind() == VK_LValue; + } + + SourceRange getSourceRange() const { return Temporary->getSourceRange(); } + + static bool classof(const Stmt *T) { + return T->getStmtClass() == MaterializeTemporaryExprClass; + } + static bool classof(const MaterializeTemporaryExpr *) { + return true; + } + + // Iterators + child_range children() { return child_range(&Temporary, &Temporary + 1); } +}; } // end namespace clang |