diff options
Diffstat (limited to 'include/clang/AST/ExprCXX.h')
| -rw-r--r-- | include/clang/AST/ExprCXX.h | 273 |
1 files changed, 271 insertions, 2 deletions
diff --git a/include/clang/AST/ExprCXX.h b/include/clang/AST/ExprCXX.h index 40c5a4f6a2..6161f92d3f 100644 --- a/include/clang/AST/ExprCXX.h +++ b/include/clang/AST/ExprCXX.h @@ -14,11 +14,12 @@ #ifndef LLVM_CLANG_AST_EXPRCXX_H #define LLVM_CLANG_AST_EXPRCXX_H -#include "clang/Basic/TypeTraits.h" -#include "clang/Basic/ExpressionTraits.h" #include "clang/AST/Expr.h" #include "clang/AST/UnresolvedSet.h" #include "clang/AST/TemplateBase.h" +#include "clang/Basic/ExpressionTraits.h" +#include "clang/Basic/Lambda.h" +#include "clang/Basic/TypeTraits.h" namespace clang { @@ -1007,6 +1008,274 @@ public: friend class ASTStmtReader; }; +/// \brief A C++ lambda expression, which produces a function object +/// (of unspecified type) that can be invoked later. +/// +/// Example: +/// \code +/// void low_pass_filter(std::vector<double> &values, double cutoff) { +/// values.erase(std::remove_if(values.begin(), values.end(), +// [=](double value) { return value > cutoff; }); +/// } +/// \endcode +/// +/// Lambda expressions can capture local variables, either by copying +/// the values of those local variables at the time the function +/// object is constructed (not when it is called!) or by holding a +/// reference to the local variable. These captures can occur either +/// implicitly or can be written explicitly between the square +/// brackets ([...]) that start the lambda expression. +class LambdaExpr : public Expr { + enum { + /// \brief Flag used by the Capture class to indicate that the given + /// capture was implicit. + Capture_Implicit = 0x01, + + /// \brief Flag used by the Capture class to indciate that the + /// given capture was by-copy. + Capture_ByCopy = 0x02 + }; + + /// \brief The source range that covers the lambda introducer ([...]). + SourceRange IntroducerRange; + + /// \brief The number of captures in this lambda. + unsigned NumCaptures : 16; + + /// \brief The number of explicit captures in this lambda. + unsigned NumExplicitCaptures : 13; + + /// \brief The default capture kind, which is a value of type + /// LambdaCaptureDefault. + unsigned CaptureDefault : 2; + + /// \brief Whether this lambda had an explicit parameter list vs. an + /// implicit (and empty) parameter list. + unsigned ExplicitParams : 1; + + /// \brief The location of the closing brace ('}') that completes + /// the lambda. + /// + /// The location of the brace is also available by looking up the + /// function call operator in the lambda class. However, it is + /// stored here to improve the performance of getSourceRange(), and + /// to avoid having to deserialize the function call operator from a + /// module file just to determine the source range. + SourceLocation ClosingBrace; + + // Note: The Create method allocates storage after the LambdaExpr + // object, which contains the captures, followed by the capture + // initializers, and finally the body of the lambda. The capture + // initializers and lambda body are placed next to each other so + // that the children() function can visit all of them easily. + +public: + /// \brief Describes the capture of either a variable or 'this'. + class Capture { + llvm::PointerIntPair<VarDecl *, 2> VarAndBits; + SourceLocation Loc; + SourceLocation EllipsisLoc; + + friend class ASTStmtReader; + friend class ASTStmtWriter; + + public: + /// \brief Create a new capture. + /// + /// \param Loc The source location associated with this capture. + /// + /// \param Kind The kind of capture (this, byref, bycopy). + /// + /// \param Implicit Whether the capture was implicit or explicit. + /// + /// \param Var The local variable being captured, or null if capturing this. + /// + /// \param EllipsisLoc The location of the ellipsis (...) for a + /// capture that is a pack expansion, or an invalid source + /// location to indicate that this is not a pack expansion. + Capture(SourceLocation Loc, bool Implicit, + LambdaCaptureKind Kind, VarDecl *Var = 0, + SourceLocation EllipsisLoc = SourceLocation()); + + /// \brief Determine the kind of capture. + LambdaCaptureKind getCaptureKind() const; + + /// \brief Determine whether this capture handles the C++ 'this' + /// pointer. + bool capturesThis() const { return VarAndBits.getPointer() == 0; } + + /// \brief Determine whether this capture handles a variable. + bool capturesVariable() const { return VarAndBits.getPointer() != 0; } + + /// \brief Retrieve the declaration of the local variable being + /// captured. + /// + /// This operation is only valid if this capture does not capture + /// 'this'. + VarDecl *getCapturedVar() const { + assert(!capturesThis() && "No variable available for 'this' capture"); + return VarAndBits.getPointer(); + } + + /// \brief Determine whether this was an implicit capture (not + /// written between the square brackets introducing the lambda). + bool isImplicit() const { return VarAndBits.getInt() & Capture_Implicit; } + + /// \brief Determine whether this was an explicit capture, written + /// between the square brackets introducing the lambda. + bool isExplicit() const { return !isImplicit(); } + + /// \brief Retrieve the source location of the capture. + /// + /// For an explicit capture, this returns the location of the + /// explicit capture in the source. For an implicit capture, this + /// returns the location at which the variable or 'this' was first + /// used. + SourceLocation getLocation() const { return Loc; } + + /// \brief Determine whether this capture is a pack expansion, + /// which captures a function parameter pack. + bool isPackExpansion() const { return EllipsisLoc.isValid(); } + + /// \brief Retrieve the location of the ellipsis for a capture + /// that is a pack expansion. + SourceLocation getEllipsisLoc() const { + assert(isPackExpansion() && "No ellipsis location for a non-expansion"); + return EllipsisLoc; + } + }; + +private: + /// \brief Construct a lambda expression. + LambdaExpr(QualType T, SourceRange IntroducerRange, + LambdaCaptureDefault CaptureDefault, + ArrayRef<Capture> Captures, + bool ExplicitParams, + ArrayRef<Expr *> CaptureInits, + SourceLocation ClosingBrace); + + Stmt **getStoredStmts() const { + LambdaExpr *This = const_cast<LambdaExpr *>(this); + return reinterpret_cast<Stmt **>(reinterpret_cast<Capture *>(This + 1) + + NumCaptures); + } + +public: + /// \brief Construct a new lambda expression. + static LambdaExpr *Create(ASTContext &C, + CXXRecordDecl *Class, + SourceRange IntroducerRange, + LambdaCaptureDefault CaptureDefault, + ArrayRef<Capture> Captures, + bool ExplicitParams, + ArrayRef<Expr *> CaptureInits, + SourceLocation ClosingBrace); + + /// \brief Determine the default capture kind for this lambda. + LambdaCaptureDefault getCaptureDefault() const { + return static_cast<LambdaCaptureDefault>(CaptureDefault); + } + + /// \brief An iterator that walks over the captures of the lambda, + /// both implicit and explicit. + typedef const Capture *capture_iterator; + + /// \brief Retrieve an iterator pointing to the first lambda capture. + capture_iterator capture_begin() const { + return reinterpret_cast<const Capture *>(this + 1); + } + + /// \brief Retrieve an iterator pointing past the end of the + /// sequence of lambda captures. + capture_iterator capture_end() const { + return capture_begin() + NumCaptures; + } + + /// \brief Retrieve an iterator pointing to the first explicit + /// lambda capture. + capture_iterator explicit_capture_begin() const { + return capture_begin(); + } + + /// \brief Retrieve an iterator pointing past the end of the sequence of + /// explicit lambda captures. + capture_iterator explicit_capture_end() const { + return capture_begin() + NumExplicitCaptures; + } + + /// \brief Retrieve an iterator pointing to the first implicit + /// lambda capture. + capture_iterator implicit_capture_begin() const { + return explicit_capture_end(); + } + + /// \brief Retrieve an iterator pointing past the end of the sequence of + /// implicit lambda captures. + capture_iterator implicit_capture_end() const { + return capture_end(); + } + + /// \brief Iterator that walks over the capture initialization + /// arguments. + typedef Expr **capture_init_iterator; + + /// \brief Retrieve the first initialization argument for this + /// lambda expression (which initializes the first capture field). + capture_init_iterator capture_init_begin() const { + return reinterpret_cast<Expr **>(getStoredStmts() + 1); + } + + /// \brief Retrieve the iterator pointing one past the last + /// initialization argument for this lambda expression (which + /// initializes the first capture field). + capture_init_iterator capture_init_end() const { + return capture_init_begin() + NumCaptures; + } + + /// \brief Retrieve the source range covering the lambda introducer, + /// which contains the explicit capture list surrounded by square + /// brackets ([...]). + SourceRange getIntroducerRange() const { return IntroducerRange; } + + /// \brief Retrieve the class that corresponds to the lambda, which + /// stores the captures in its fields and provides the various + /// operations permitted on a lambda (copying, calling). + CXXRecordDecl *getLambdaClass() const; + + /// \brief Retrieve the function call operator associated with this + /// lambda expression. + CXXMethodDecl *getCallOperator() const; + + /// \brief Retrieve the body of the lambda. + CompoundStmt *getBody() const { + return reinterpret_cast<CompoundStmt *>(getStoredStmts()[NumCaptures]); + } + + /// \brief Determine whether the lambda is mutable, meaning that any + /// captures values can be modified. + bool isMutable() const; + + /// \brief Determine whether this lambda has an explicit parameter + /// list vs. an implicit (empty) parameter list. + bool hasExplicitParameters() const { return ExplicitParams; } + + static bool classof(const Stmt *T) { + return T->getStmtClass() == LambdaExprClass; + } + static bool classof(const LambdaExpr *) { return true; } + + SourceRange getSourceRange() const { + return SourceRange(IntroducerRange.getBegin(), ClosingBrace); + } + + child_range children() { + return child_range(getStoredStmts(), getStoredStmts() + NumCaptures + 1); + } + + friend class ASTStmtReader; + friend class ASTStmtWriter; +}; + /// CXXScalarValueInitExpr - [C++ 5.2.3p2] /// Expression "T()" which creates a value-initialized rvalue of type /// T, which is a non-class type. |