[AST] Store the callee and argument expressions of CallExpr in a trailing array.

[riccibruno]

Summary

Since CallExpr::setNumArgs has been removed, it is now possible to store the callee expression and the argument expressions of CallExpr in a trailing array. This saves one pointer per CallExpr, CXXOperatorCallExpr,
CXXMemberCallExpr, CUDAKernelCallExpr and UserDefinedLiteral.

Since CallExpr is used as a base of the above classes we cannot use llvm::TrailingObjects. Instead we store
the offset in bytes from the this pointer to the start of the trailing objects and manually do the casts + arithmetic.

Some notes:

1. I did not try to fit the number of arguments in the bit-fields of Stmt. This leaves some space for future additions and avoid the discussion about whether x bits are sufficient to hold the number of arguments.
2. It would be perfectly possible to recompute the offset to the trailing objects before accessing the trailing objects. However the trailing objects are frequently accessed and benchmarks show that it is slightly faster to just load the offset from the bit-fields. Additionally, because of 1), we have plenty of space in the bit-fields of Stmt.

[rjmccall]

I agree with not packing the argument count in.

include/clang/AST/Stmt.h

439

If we're not packing anything into these bits anyway, it would be really nice if this could just be loaded as a byte, i.e. if it were 8 bits wide and allocated at a bit offset that's a multiple of 8. That should be reasonably maintainable with a modest amount of arithmetic and static_assert-ing.

[riccibruno]

Make OffsetToTrailingObjects byte sized and aligned to a byte multiple.

[rjmccall]

Thanks, looks great.

include/clang/AST/Expr.h

 
 /// CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
 /// CallExpr itself represents a normal function call, e.g., "f(x, 2)",
 /// while its subclasses may represent alternative syntax that (semantically)
 /// results in a function call. For example, CXXOperatorCallExpr is
 /// a subclass for overloaded operator calls that use operator syntax, e.g.,
 /// "str1 + str2" to resolve to a function call.
 class CallExpr : public Expr {
-  enum { FN=0, PREARGS_START=1 };
-  Stmt **SubExprs;
+  enum { FN = 0, PREARGS_START = 1 };
+
+  /// The number of arguments in the call expression.
   unsigned NumArgs;
+
+  /// The location of the right parenthese. This has a different meaning for
+  /// the derived classes of CallExpr.
   SourceLocation RParenLoc;
 
   void updateDependenciesFromArg(Expr *Arg);
 
+  // CallExpr store some data in trailing objects. However since CallExpr
+  // is used a base of other expression classes we cannot use
+  // llvm::TrailingObjects. Instead we manually perform the pointer arithmetic
+  // and casts.
+  //
+  // The trailing objects are in order:
+  //
+  // * A single "Stmt *" for the callee expression.
+  //
+  // * An array of getNumPreArgs() "Stmt *" for the pre-argument expressions.
+  //
+  // * An array of getNumArgs() "Stmt *" for the argument expressions.
+  //
+  // Note that we store the offset in bytes from the this pointer to the start
+  // of the trailing objects. It would be perfectly possible to compute it
+  // based on the dynamic kind of the CallExpr. However 1.) we have plenty of
+  // space in the bit-fields of Stmt. 2.) It was benchmarked to be faster to
+  // compute this once and then load the offset from the bit-fields of Stmt,
+  // instead of re-computing the offset each time the trailing objects are
+  // accessed.
+
+  /// Return a pointer to the start of the trailing array of "Stmt *".
+  Stmt **getTrailingStmts() {
+    return reinterpret_cast<Stmt **>(reinterpret_cast<char *>(this) +
+                                     CallExprBits.OffsetToTrailingObjects);
+  }
+  Stmt *const *getTrailingStmts() const {
+    return const_cast<CallExpr *>(this)->getTrailingStmts();
+  }
+
+  /// Map a statement class to the appropriate offset in bytes from the
+  /// this pointer to the trailing objects.
+  static unsigned offsetToTrailingObjects(StmtClass SC);
+
 public:
   enum class ADLCallKind : bool { NotADL, UsesADL };
   static constexpr ADLCallKind NotADL = ADLCallKind::NotADL;
   static constexpr ADLCallKind UsesADL = ADLCallKind::UsesADL;
 
 protected:
-  // These versions of the constructor are for derived classes.
-  CallExpr(const ASTContext &C, StmtClass SC, Expr *fn,
-           ArrayRef<Expr *> preargs, ArrayRef<Expr *> args, QualType t,
-           ExprValueKind VK, SourceLocation rparenloc, unsigned MinNumArgs = 0,
-           ADLCallKind UsesADL = NotADL);
-  CallExpr(const ASTContext &C, StmtClass SC, Expr *fn, ArrayRef<Expr *> args,
-           QualType t, ExprValueKind VK, SourceLocation rparenloc,
-           unsigned MinNumArgs = 0, ADLCallKind UsesADL = NotADL);
-  CallExpr(const ASTContext &C, StmtClass SC, unsigned NumPreArgs,
-           unsigned NumArgs, EmptyShell Empty);
-
-  Stmt *getPreArg(unsigned i) {
-    assert(i < getNumPreArgs() && "Prearg access out of range!");
-    return SubExprs[PREARGS_START+i];
-  }
-  const Stmt *getPreArg(unsigned i) const {
-    assert(i < getNumPreArgs() && "Prearg access out of range!");
-    return SubExprs[PREARGS_START+i];
-  }
-  void setPreArg(unsigned i, Stmt *PreArg) {
-    assert(i < getNumPreArgs() && "Prearg access out of range!");
-    SubExprs[PREARGS_START+i] = PreArg;
+  /// Build a call expression, assuming that appropriate storage has been
+  /// allocated for the trailing objects.
+  CallExpr(StmtClass SC, Expr *Fn, ArrayRef<Expr *> PreArgs,
+           ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+           SourceLocation RParenLoc, unsigned MinNumArgs, ADLCallKind UsesADL);
+
+  /// Build an empty call expression, for deserialization.
+  CallExpr(StmtClass SC, unsigned NumPreArgs, unsigned NumArgs,
+           EmptyShell Empty);
+
+  /// Return the size in bytes needed for the trailing objects.
+  /// Used by the derived classes to allocate the right amount of storage.
+  static unsigned sizeOfTrailingObjects(unsigned NumPreArgs, unsigned NumArgs) {
+    return (1 + NumPreArgs + NumArgs) * sizeof(Stmt *);
+  }
+
+  Stmt *getPreArg(unsigned I) {
+    assert(I < getNumPreArgs() && "Prearg access out of range!");
+    return getTrailingStmts()[PREARGS_START + I];
+  }
+  const Stmt *getPreArg(unsigned I) const {
+    assert(I < getNumPreArgs() && "Prearg access out of range!");
+    return getTrailingStmts()[PREARGS_START + I];
+  }
+  void setPreArg(unsigned I, Stmt *PreArg) {
+    assert(I < getNumPreArgs() && "Prearg access out of range!");
+    getTrailingStmts()[PREARGS_START + I] = PreArg;
   }
 
   unsigned getNumPreArgs() const { return CallExprBits.NumPreArgs; }
 
 public:
-  /// Build a call expression. MinNumArgs specifies the minimum number of
-  /// arguments. The actual number of arguments will be the greater of
-  /// args.size() and MinNumArgs.
-  CallExpr(const ASTContext &C, Expr *fn, ArrayRef<Expr *> args, QualType t,
-           ExprValueKind VK, SourceLocation rparenloc, unsigned MinNumArgs = 0,
+  /// Create a call expression. Fn is the callee expression, Args is the
+  /// argument array, Ty is the type of the call expression (which is *not*
+  /// the return type in general), VK is the value kind of the call expression
+  /// (lvalue, rvalue, ...), and RParenLoc is the location of the right
+  /// parenthese in the call expression. MinNumArgs specifies the minimum
+  /// number of arguments. The actual number of arguments will be the greater
+  /// of Args.size() and MinNumArgs. This is used in a few places to allocate
+  /// enough storage for the default arguments. UsesADL specifies whether the
+  /// callee was found through argument-dependent lookup.
+  ///
+  /// Note that you can use CreateTemporary if you need a temporary call
+  /// expression on the stack.
+  static CallExpr *Create(const ASTContext &Ctx, Expr *Fn,
+                          ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+                          SourceLocation RParenLoc, unsigned MinNumArgs = 0,
                           ADLCallKind UsesADL = NotADL);
 
-  /// Build an empty call expression.
-  CallExpr(const ASTContext &C, unsigned NumArgs, EmptyShell Empty);
+  /// Create a temporary call expression with no arguments in the memory
+  /// pointed to by Mem. Mem must points to at least sizeof(CallExpr)
+  /// + sizeof(Stmt *) bytes of storage, aligned to alignof(CallExpr):
+  ///
+  /// \code{.cpp}
+  ///   llvm::AlignedCharArray<alignof(CallExpr),
+  ///                          sizeof(CallExpr) + sizeof(Stmt *)> Buffer;
+  ///   CallExpr *TheCall = CallExpr::CreateTemporary(Buffer.buffer, etc);
+  /// \endcode
+  static CallExpr *CreateTemporary(void *Mem, Expr *Fn, QualType Ty,
+                                   ExprValueKind VK, SourceLocation RParenLoc,
+                                   ADLCallKind UsesADL = NotADL);
 
-  const Expr *getCallee() const { return cast<Expr>(SubExprs[FN]); }
-  Expr *getCallee() { return cast<Expr>(SubExprs[FN]); }
-  void setCallee(Expr *F) { SubExprs[FN] = F; }
+  /// Create an empty call expression, for deserialization.
+  static CallExpr *CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
+                               EmptyShell Empty);
+
+  Expr *getCallee() { return cast<Expr>(getTrailingStmts()[FN]); }
+  const Expr *getCallee() const { return cast<Expr>(getTrailingStmts()[FN]); }
+  void setCallee(Expr *F) { getTrailingStmts()[FN] = F; }
 
   ADLCallKind getADLCallKind() const {
     return static_cast<ADLCallKind>(CallExprBits.UsesADL);
   }
   void setADLCallKind(ADLCallKind V = UsesADL) {
     CallExprBits.UsesADL = static_cast<bool>(V);
   }
   bool usesADL() const { return getADLCallKind() == UsesADL; }
 
-  Decl *getCalleeDecl();
+  Decl *getCalleeDecl() { return getCallee()->getReferencedDeclOfCallee(); }
   const Decl *getCalleeDecl() const {
-    return const_cast<CallExpr*>(this)->getCalleeDecl();
+    return getCallee()->getReferencedDeclOfCallee();
   }
 
-  /// If the callee is a FunctionDecl, return it. Otherwise return 0.
-  FunctionDecl *getDirectCallee();
+  /// If the callee is a FunctionDecl, return it. Otherwise return null.
+  FunctionDecl *getDirectCallee() {
+    return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
+  }
   const FunctionDecl *getDirectCallee() const {
-    return const_cast<CallExpr*>(this)->getDirectCallee();
+    return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
   }
 
   /// getNumArgs - Return the number of actual arguments to this call.
-  ///
   unsigned getNumArgs() const { return NumArgs; }
 
   /// Retrieve the call arguments.
   Expr **getArgs() {
-    return reinterpret_cast<Expr **>(SubExprs+getNumPreArgs()+PREARGS_START);
+    return reinterpret_cast<Expr **>(getTrailingStmts() + PREARGS_START +
+                                     getNumPreArgs());
   }
   const Expr *const *getArgs() const {
-    return reinterpret_cast<Expr **>(SubExprs + getNumPreArgs() +
-                                     PREARGS_START);
+    return reinterpret_cast<const Expr *const *>(
+        getTrailingStmts() + PREARGS_START + getNumPreArgs());
   }
 
   /// getArg - Return the specified argument.
   Expr *getArg(unsigned Arg) {
-    assert(Arg < NumArgs && "Arg access out of range!");
-    return cast_or_null<Expr>(SubExprs[Arg + getNumPreArgs() + PREARGS_START]);
+    assert(Arg < getNumArgs() && "Arg access out of range!");
+    return getArgs()[Arg];
   }
   const Expr *getArg(unsigned Arg) const {
-    assert(Arg < NumArgs && "Arg access out of range!");
-    return cast_or_null<Expr>(SubExprs[Arg + getNumPreArgs() + PREARGS_START]);
+    assert(Arg < getNumArgs() && "Arg access out of range!");
+    return getArgs()[Arg];
   }
 
   /// setArg - Set the specified argument.
   void setArg(unsigned Arg, Expr *ArgExpr) {
-    assert(Arg < NumArgs && "Arg access out of range!");
-    SubExprs[Arg+getNumPreArgs()+PREARGS_START] = ArgExpr;
+    assert(Arg < getNumArgs() && "Arg access out of range!");
+    getArgs()[Arg] = ArgExpr;
   }
 
   /// Reduce the number of arguments in this call expression. This is used for
   /// example during error recovery to drop extra arguments. There is no way
   /// to perform the opposite because: 1.) We don't track how much storage
   /// we have for the argument array 2.) This would potentially require growing
-  /// the argument array, something we cannot support since the arguments will
-  /// be stored in a trailing array in the future.
-  /// (TODO: update this comment when this is done).
+  /// the argument array, something we cannot support since the arguments are
+  /// stored in a trailing array.
   void shrinkNumArgs(unsigned NewNumArgs) {
-    assert((NewNumArgs <= NumArgs) &&
+    assert((NewNumArgs <= getNumArgs()) &&
            "shrinkNumArgs cannot increase the number of arguments!");
     NumArgs = NewNumArgs;
   }
 
   typedef ExprIterator arg_iterator;
   typedef ConstExprIterator const_arg_iterator;
   typedef llvm::iterator_range<arg_iterator> arg_range;
   typedef llvm::iterator_range<const_arg_iterator> const_arg_range;
 
   arg_range arguments() { return arg_range(arg_begin(), arg_end()); }
   const_arg_range arguments() const {
     return const_arg_range(arg_begin(), arg_end());
   }
 
-  arg_iterator arg_begin() { return SubExprs+PREARGS_START+getNumPreArgs(); }
-  arg_iterator arg_end() {
-    return SubExprs+PREARGS_START+getNumPreArgs()+getNumArgs();
+  arg_iterator arg_begin() {
+    return getTrailingStmts() + PREARGS_START + getNumPreArgs();
   }
+  arg_iterator arg_end() { return arg_begin() + getNumArgs(); }
+
   const_arg_iterator arg_begin() const {
-    return SubExprs+PREARGS_START+getNumPreArgs();
-  }
-  const_arg_iterator arg_end() const {
-    return SubExprs+PREARGS_START+getNumPreArgs()+getNumArgs();
+    return getTrailingStmts() + PREARGS_START + getNumPreArgs();
   }
+  const_arg_iterator arg_end() const { return arg_begin() + getNumArgs(); }
 
   /// This method provides fast access to all the subexpressions of
   /// a CallExpr without going through the slower virtual child_iterator
   /// interface.  This provides efficient reverse iteration of the
   /// subexpressions.  This is currently used for CFG construction.
-  ArrayRef<Stmt*> getRawSubExprs() {
-    return llvm::makeArrayRef(SubExprs,
-                              getNumPreArgs() + PREARGS_START + getNumArgs());
+  ArrayRef<Stmt *> getRawSubExprs() {
+    return llvm::makeArrayRef(getTrailingStmts(),
+                              PREARGS_START + getNumPreArgs() + getNumArgs());
   }
 
   /// getNumCommas - Return the number of commas that must have been present in
   /// this function call.
-  unsigned getNumCommas() const { return NumArgs ? NumArgs - 1 : 0; }
+  unsigned getNumCommas() const { return getNumArgs() ? getNumArgs() - 1 : 0; }
 
   /// getBuiltinCallee - If this is a call to a builtin, return the builtin ID
   /// of the callee. If not, return 0.
   unsigned getBuiltinCallee() const;
 
   /// Returns \c true if this is a call to a builtin which does not
   /// evaluate side-effects within its arguments.
   bool isUnevaluatedBuiltinCall(const ASTContext &Ctx) const;
public:
   SourceLocation getBeginLoc() const LLVM_READONLY;
   SourceLocation getEndLoc() const LLVM_READONLY;
 
   /// Return true if this is a call to __assume() or __builtin_assume() with
   /// a non-value-dependent constant parameter evaluating as false.
   bool isBuiltinAssumeFalse(const ASTContext &Ctx) const;
 
   bool isCallToStdMove() const {
-    const FunctionDecl* FD = getDirectCallee();
+    const FunctionDecl *FD = getDirectCallee();
     return getNumArgs() == 1 && FD && FD->isInStdNamespace() &&
            FD->getIdentifier() && FD->getIdentifier()->isStr("move");
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() >= firstCallExprConstant &&
            T->getStmtClass() <= lastCallExprConstant;
   }
 
   // Iterators
   child_range children() {
-    return child_range(&SubExprs[0],
-                       &SubExprs[0]+NumArgs+getNumPreArgs()+PREARGS_START);
+    return child_range(getTrailingStmts(), getTrailingStmts() + PREARGS_START +
+                                               getNumPreArgs() + getNumArgs());
   }
 
   const_child_range children() const {
-    return const_child_range(&SubExprs[0], &SubExprs[0] + NumArgs +
-                                               getNumPreArgs() + PREARGS_START);
+    return const_child_range(getTrailingStmts(),
+                             getTrailingStmts() + PREARGS_START +
+                                 getNumPreArgs() + getNumArgs());
   }
 };
 
 /// Extra data stored in some MemberExpr objects.
 struct MemberExprNameQualifier {
   /// The nested-name-specifier that qualifies the name, including
   /// source-location information.
   NestedNameSpecifierLoc QualifierLoc;

include/clang/AST/ExprCXX.h

 /// normal call, this AST node provides better information about the
 /// syntactic representation of the call.
 ///
 /// In a C++ template, this expression node kind will be used whenever
 /// any of the arguments are type-dependent. In this case, the
 /// function itself will be a (possibly empty) set of functions and
 /// function templates that were found by name lookup at template
 /// definition time.
-class CXXOperatorCallExpr : public CallExpr {
+class CXXOperatorCallExpr final : public CallExpr {
+  friend class ASTStmtReader;
+  friend class ASTStmtWriter;
+
   /// The overloaded operator.
   OverloadedOperatorKind Operator;
 
   SourceRange Range;
 
   // Only meaningful for floating point types.
   FPOptions FPFeatures;
 
+  // CXXOperatorCallExpr has some trailing objects belonging
+  // to CallExpr. See CallExpr for the details.
+
   SourceRange getSourceRangeImpl() const LLVM_READONLY;
 
+  CXXOperatorCallExpr(OverloadedOperatorKind OpKind, Expr *Fn,
+                      ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+                      SourceLocation OperatorLoc, FPOptions FPFeatures,
+                      ADLCallKind UsesADL);
+
+  CXXOperatorCallExpr(unsigned NumArgs, EmptyShell Empty);
+
 public:
-  friend class ASTStmtReader;
-  friend class ASTStmtWriter;
+  static CXXOperatorCallExpr *
+  Create(const ASTContext &Ctx, OverloadedOperatorKind OpKind, Expr *Fn,
+         ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+         SourceLocation OperatorLoc, FPOptions FPFeatures,
+         ADLCallKind UsesADL = NotADL);
 
-  CXXOperatorCallExpr(ASTContext &C, OverloadedOperatorKind Op, Expr *fn,
-                      ArrayRef<Expr *> args, QualType t, ExprValueKind VK,
-                      SourceLocation operatorloc, FPOptions FPFeatures,
-                      ADLCallKind UsesADL = NotADL)
-      : CallExpr(C, CXXOperatorCallExprClass, fn, args, t, VK, operatorloc,
-                 /*MinNumArgs=*/0, UsesADL),
-        Operator(Op), FPFeatures(FPFeatures) {
-    Range = getSourceRangeImpl();
-  }
-
-  explicit CXXOperatorCallExpr(ASTContext &C, unsigned NumArgs,
-                               EmptyShell Empty)
-      : CallExpr(C, CXXOperatorCallExprClass, /*NumPreArgs=*/0, NumArgs,
-                 Empty) {}
+  static CXXOperatorCallExpr *CreateEmpty(const ASTContext &Ctx,
+                                          unsigned NumArgs, EmptyShell Empty);
 
-  /// Returns the kind of overloaded operator that this
-  /// expression refers to.
+  /// Returns the kind of overloaded operator that this expression refers to.
   OverloadedOperatorKind getOperator() const { return Operator; }
 
   static bool isAssignmentOp(OverloadedOperatorKind Opc) {
     return Opc == OO_Equal || Opc == OO_StarEqual ||
            Opc == OO_SlashEqual || Opc == OO_PercentEqual ||
            Opc == OO_PlusEqual || Opc == OO_MinusEqual ||
            Opc == OO_LessLessEqual || Opc == OO_GreaterGreaterEqual ||
            Opc == OO_AmpEqual || Opc == OO_CaretEqual ||

 /// Represents a call to a member function that
 /// may be written either with member call syntax (e.g., "obj.func()"
 /// or "objptr->func()") or with normal function-call syntax
 /// ("func()") within a member function that ends up calling a member
 /// function. The callee in either case is a MemberExpr that contains
 /// both the object argument and the member function, while the
 /// arguments are the arguments within the parentheses (not including
 /// the object argument).
-class CXXMemberCallExpr : public CallExpr {
+class CXXMemberCallExpr final : public CallExpr {
+  // CXXMemberCallExpr has some trailing objects belonging
+  // to CallExpr. See CallExpr for the details.
+
+  CXXMemberCallExpr(Expr *Fn, ArrayRef<Expr *> Args, QualType Ty,
+                    ExprValueKind VK, SourceLocation RP, unsigned MinNumArgs);
+
+  CXXMemberCallExpr(unsigned NumArgs, EmptyShell Empty);
+
 public:
-  CXXMemberCallExpr(ASTContext &C, Expr *fn, ArrayRef<Expr *> args, QualType t,
+  static CXXMemberCallExpr *Create(const ASTContext &Ctx, Expr *Fn,
+                                   ArrayRef<Expr *> Args, QualType Ty,
                                    ExprValueKind VK, SourceLocation RP,
-                    unsigned MinNumArgs = 0)
-      : CallExpr(C, CXXMemberCallExprClass, fn, args, t, VK, RP, MinNumArgs,
-                 NotADL) {}
+                                   unsigned MinNumArgs = 0);
 
-  CXXMemberCallExpr(ASTContext &C, unsigned NumArgs, EmptyShell Empty)
-      : CallExpr(C, CXXMemberCallExprClass, /*NumPreArgs=*/0, NumArgs, Empty) {}
+  static CXXMemberCallExpr *CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
+                                        EmptyShell Empty);
 
   /// Retrieves the implicit object argument for the member call.
   ///
   /// For example, in "x.f(5)", this returns the sub-expression "x".
   Expr *getImplicitObjectArgument() const;
 
   /// Retrieves the declaration of the called method.
   CXXMethodDecl *getMethodDecl() const;
public:
   }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXMemberCallExprClass;
   }
 };
 
 /// Represents a call to a CUDA kernel function.
-class CUDAKernelCallExpr : public CallExpr {
-private:
+class CUDAKernelCallExpr final : public CallExpr {
   enum { CONFIG, END_PREARG };
 
+  // CUDAKernelCallExpr has some trailing objects belonging
+  // to CallExpr. See CallExpr for the details.
+
+  CUDAKernelCallExpr(Expr *Fn, CallExpr *Config, ArrayRef<Expr *> Args,
+                     QualType Ty, ExprValueKind VK, SourceLocation RP,
+                     unsigned MinNumArgs);
+
+  CUDAKernelCallExpr(unsigned NumArgs, EmptyShell Empty);
+
 public:
-  CUDAKernelCallExpr(ASTContext &C, Expr *fn, CallExpr *Config,
-                     ArrayRef<Expr *> args, QualType t, ExprValueKind VK,
-                     SourceLocation RP, unsigned MinNumArgs = 0)
-      : CallExpr(C, CUDAKernelCallExprClass, fn, Config, args, t, VK, RP,
-                 MinNumArgs, NotADL) {}
-
-  CUDAKernelCallExpr(ASTContext &C, unsigned NumArgs, EmptyShell Empty)
-      : CallExpr(C, CUDAKernelCallExprClass, /*NumPreArgs=*/END_PREARG, NumArgs,
-                 Empty) {}
+  static CUDAKernelCallExpr *Create(const ASTContext &Ctx, Expr *Fn,
+                                    CallExpr *Config, ArrayRef<Expr *> Args,
+                                    QualType Ty, ExprValueKind VK,
+                                    SourceLocation RP, unsigned MinNumArgs = 0);
+
+  static CUDAKernelCallExpr *CreateEmpty(const ASTContext &Ctx,
+                                         unsigned NumArgs, EmptyShell Empty);
 
   const CallExpr *getConfig() const {
     return cast_or_null<CallExpr>(getPreArg(CONFIG));
   }
   CallExpr *getConfig() { return cast_or_null<CallExpr>(getPreArg(CONFIG)); }
 
   /// Sets the kernel configuration expression.
   ///

 /// written as a user-defined literal (C++11 [lit.ext]).
 ///
 /// Represents a user-defined literal, e.g. "foo"_bar or 1.23_xyz. While this
 /// is semantically equivalent to a normal call, this AST node provides better
 /// information about the syntactic representation of the literal.
 ///
 /// Since literal operators are never found by ADL and can only be declared at
 /// namespace scope, a user-defined literal is never dependent.
-class UserDefinedLiteral : public CallExpr {
+class UserDefinedLiteral final : public CallExpr {
+  friend class ASTStmtReader;
+  friend class ASTStmtWriter;
+
   /// The location of a ud-suffix within the literal.
   SourceLocation UDSuffixLoc;
 
+  // UserDefinedLiteral has some trailing objects belonging
+  // to CallExpr. See CallExpr for the details.
+
+  UserDefinedLiteral(Expr *Fn, ArrayRef<Expr *> Args, QualType Ty,
+                     ExprValueKind VK, SourceLocation LitEndLoc,
+                     SourceLocation SuffixLoc);
+
+  UserDefinedLiteral(unsigned NumArgs, EmptyShell Empty);
+
 public:
-  friend class ASTStmtReader;
-  friend class ASTStmtWriter;
+  static UserDefinedLiteral *Create(const ASTContext &Ctx, Expr *Fn,
+                                    ArrayRef<Expr *> Args, QualType Ty,
+                                    ExprValueKind VK, SourceLocation LitEndLoc,
+                                    SourceLocation SuffixLoc);
 
-  UserDefinedLiteral(const ASTContext &C, Expr *Fn, ArrayRef<Expr *> Args,
-                     QualType T, ExprValueKind VK, SourceLocation LitEndLoc,
-                     SourceLocation SuffixLoc)
-      : CallExpr(C, UserDefinedLiteralClass, Fn, Args, T, VK, LitEndLoc,
-                 /*MinNumArgs=*/0, NotADL),
-        UDSuffixLoc(SuffixLoc) {}
-
-  explicit UserDefinedLiteral(const ASTContext &C, unsigned NumArgs,
-                              EmptyShell Empty)
-      : CallExpr(C, UserDefinedLiteralClass, /*NumPreArgs=*/0, NumArgs, Empty) {
-  }
+  static UserDefinedLiteral *CreateEmpty(const ASTContext &Ctx,
+                                         unsigned NumArgs, EmptyShell Empty);
 
   /// The kind of literal operator which is invoked.
   enum LiteralOperatorKind {
     /// Raw form: operator "" X (const char *)
     LOK_Raw,
 
     /// Raw form: operator "" X<cs...> ()
     LOK_Template,

include/clang/AST/Stmt.h

class CallExprBitfields {
     friend class CallExpr;
 
     unsigned : NumExprBits;
 
     unsigned NumPreArgs : 1;
 
     /// True if the callee of the call expression was found using ADL.
     unsigned UsesADL : 1;
+
+    /// The offset in bytes from the this pointer to the start of the
+    /// trailing objects belonging to CallExpr.
+    unsigned OffsetToTrailingObjects : 6;
   };
+  enum { NumCallExprBits = NumExprBits + 8 };
 
   class MemberExprBitfields {
     friend class MemberExpr;
 
     unsigned : NumExprBits;
 
     /// IsArrow - True if this is "X->F", false if this is "X.F".
     unsigned IsArrow : 1;

lib/AST/ASTImporter.cpp

ExpectedStmt ASTNodeImporter::VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
   QualType ToType;
   SourceLocation ToRParenLoc;
   std::tie(ToCallee, ToType, ToRParenLoc) = *Imp;
 
   SmallVector<Expr *, 4> ToArgs(E->getNumArgs());
   if (Error Err = ImportContainerChecked(E->arguments(), ToArgs))
     return std::move(Err);
 
-  return new (Importer.getToContext()) CXXMemberCallExpr(
-      Importer.getToContext(), ToCallee, ToArgs, ToType, E->getValueKind(),
-      ToRParenLoc);
+  return CXXMemberCallExpr::Create(Importer.getToContext(), ToCallee, ToArgs,
+                                   ToType, E->getValueKind(), ToRParenLoc);
 }
 
 ExpectedStmt ASTNodeImporter::VisitCXXThisExpr(CXXThisExpr *E) {
   ExpectedType ToTypeOrErr = import(E->getType());
   if (!ToTypeOrErr)
     return ToTypeOrErr.takeError();
 
   ExpectedSLoc ToLocationOrErr = import(E->getLocation());
ExpectedStmt ASTNodeImporter::VisitCallExpr(CallExpr *E) {
   std::tie(ToCallee, ToType, ToRParenLoc) = *Imp;
 
   unsigned NumArgs = E->getNumArgs();
   llvm::SmallVector<Expr *, 2> ToArgs(NumArgs);
   if (Error Err = ImportContainerChecked(E->arguments(), ToArgs))
      return std::move(Err);
 
   if (const auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
-    return new (Importer.getToContext()) CXXOperatorCallExpr(
+    return CXXOperatorCallExpr::Create(
         Importer.getToContext(), OCE->getOperator(), ToCallee, ToArgs, ToType,
         OCE->getValueKind(), ToRParenLoc, OCE->getFPFeatures(),
         OCE->getADLCallKind());
   }
 
-  return new (Importer.getToContext()) CallExpr(
-      Importer.getToContext(), ToCallee, ToArgs, ToType, E->getValueKind(),
-      ToRParenLoc, /*MinNumArgs=*/0, E->getADLCallKind());
+  return CallExpr::Create(Importer.getToContext(), ToCallee, ToArgs, ToType,
+                          E->getValueKind(), ToRParenLoc, /*MinNumArgs=*/0,
+                          E->getADLCallKind());
 }
 
 ExpectedStmt ASTNodeImporter::VisitLambdaExpr(LambdaExpr *E) {
   CXXRecordDecl *FromClass = E->getLambdaClass();
   auto ToClassOrErr = import(FromClass);
   if (!ToClassOrErr)
     return ToClassOrErr.takeError();
   CXXRecordDecl *ToClass = *ToClassOrErr;

lib/AST/Expr.cpp

OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
   }
 }
 
 
 //===----------------------------------------------------------------------===//
 // Postfix Operators.
 //===----------------------------------------------------------------------===//
 
-CallExpr::CallExpr(const ASTContext &C, StmtClass SC, Expr *fn,
-                   ArrayRef<Expr *> preargs, ArrayRef<Expr *> args, QualType t,
-                   ExprValueKind VK, SourceLocation rparenloc,
-                   unsigned MinNumArgs, ADLCallKind UsesADL)
-    : Expr(SC, t, VK, OK_Ordinary, fn->isTypeDependent(),
-           fn->isValueDependent(), fn->isInstantiationDependent(),
-           fn->containsUnexpandedParameterPack()),
-      RParenLoc(rparenloc) {
-  CallExprBits.UsesADL = static_cast<bool>(UsesADL);
-
-  NumArgs = std::max<unsigned>(args.size(), MinNumArgs);
-  unsigned NumPreArgs = preargs.size();
+CallExpr::CallExpr(StmtClass SC, Expr *Fn, ArrayRef<Expr *> PreArgs,
+                   ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+                   SourceLocation RParenLoc, unsigned MinNumArgs,
+                   ADLCallKind UsesADL)
+    : Expr(SC, Ty, VK, OK_Ordinary, Fn->isTypeDependent(),
+           Fn->isValueDependent(), Fn->isInstantiationDependent(),
+           Fn->containsUnexpandedParameterPack()),
+      RParenLoc(RParenLoc) {
+  NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
+  unsigned NumPreArgs = PreArgs.size();
   CallExprBits.NumPreArgs = NumPreArgs;
+  assert((NumPreArgs == getNumPreArgs()) && "NumPreArgs overflow!");
+
+  unsigned OffsetToTrailingObjects = offsetToTrailingObjects(SC);
+  CallExprBits.OffsetToTrailingObjects = OffsetToTrailingObjects;
+  assert((CallExprBits.OffsetToTrailingObjects == OffsetToTrailingObjects) &&
+         "OffsetToTrailingObjects overflow!");
 
-  SubExprs = new (C) Stmt *[NumArgs + PREARGS_START + NumPreArgs];
-  SubExprs[FN] = fn;
-  for (unsigned i = 0; i != NumPreArgs; ++i) {
-    updateDependenciesFromArg(preargs[i]);
-    SubExprs[i+PREARGS_START] = preargs[i];
+  CallExprBits.UsesADL = static_cast<bool>(UsesADL);
+
+  setCallee(Fn);
+  for (unsigned I = 0; I != NumPreArgs; ++I) {
+    updateDependenciesFromArg(PreArgs[I]);
+    setPreArg(I, PreArgs[I]);
   }
-  for (unsigned i = 0; i != args.size(); ++i) {
-    updateDependenciesFromArg(args[i]);
-    SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
+  for (unsigned I = 0; I != Args.size(); ++I) {
+    updateDependenciesFromArg(Args[I]);
+    setArg(I, Args[I]);
   }
-  for (unsigned i = args.size(); i != NumArgs; ++i) {
-    SubExprs[i + PREARGS_START + NumPreArgs] = nullptr;
+  for (unsigned I = Args.size(); I != NumArgs; ++I) {
+    setArg(I, nullptr);
   }
 }
 
-CallExpr::CallExpr(const ASTContext &C, StmtClass SC, Expr *fn,
-                   ArrayRef<Expr *> args, QualType t, ExprValueKind VK,
-                   SourceLocation rparenloc, unsigned MinNumArgs,
-                   ADLCallKind UsesADL)
-    : CallExpr(C, SC, fn, ArrayRef<Expr *>(), args, t, VK, rparenloc,
-               MinNumArgs, UsesADL) {}
-
-CallExpr::CallExpr(const ASTContext &C, Expr *fn, ArrayRef<Expr *> args,
-                   QualType t, ExprValueKind VK, SourceLocation rparenloc,
-                   unsigned MinNumArgs, ADLCallKind UsesADL)
-    : CallExpr(C, CallExprClass, fn, ArrayRef<Expr *>(), args, t, VK, rparenloc,
-               MinNumArgs, UsesADL) {}
-
-CallExpr::CallExpr(const ASTContext &C, StmtClass SC, unsigned NumPreArgs,
-                   unsigned NumArgs, EmptyShell Empty)
+CallExpr::CallExpr(StmtClass SC, unsigned NumPreArgs, unsigned NumArgs,
+                   EmptyShell Empty)
     : Expr(SC, Empty), NumArgs(NumArgs) {
   CallExprBits.NumPreArgs = NumPreArgs;
-  SubExprs = new (C) Stmt *[NumArgs + PREARGS_START + NumPreArgs];
+  assert((NumPreArgs == getNumPreArgs()) && "NumPreArgs overflow!");
+
+  unsigned OffsetToTrailingObjects = offsetToTrailingObjects(SC);
+  CallExprBits.OffsetToTrailingObjects = OffsetToTrailingObjects;
+  assert((CallExprBits.OffsetToTrailingObjects == OffsetToTrailingObjects) &&
+         "OffsetToTrailingObjects overflow!");
 }
 
-CallExpr::CallExpr(const ASTContext &C, unsigned NumArgs, EmptyShell Empty)
-    : CallExpr(C, CallExprClass, /*NumPreArgs=*/0, NumArgs, Empty) {}
+CallExpr *CallExpr::Create(const ASTContext &Ctx, Expr *Fn,
+                           ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+                           SourceLocation RParenLoc, unsigned MinNumArgs,
+                           ADLCallKind UsesADL) {
+  unsigned NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem =
+      Ctx.Allocate(sizeof(CallExpr) + SizeOfTrailingObjects, alignof(CallExpr));
+  return new (Mem) CallExpr(CallExprClass, Fn, /*PreArgs=*/{}, Args, Ty, VK,
+                            RParenLoc, MinNumArgs, UsesADL);
+}
+
+CallExpr *CallExpr::CreateTemporary(void *Mem, Expr *Fn, QualType Ty,
+                                    ExprValueKind VK, SourceLocation RParenLoc,
+                                    ADLCallKind UsesADL) {
+  assert(!(reinterpret_cast<uintptr_t>(Mem) % alignof(CallExpr)) &&
+         "Misaligned memory in CallExpr::CreateTemporary!");
+  return new (Mem) CallExpr(CallExprClass, Fn, /*PreArgs=*/{}, /*Args=*/{}, Ty,
+                            VK, RParenLoc, /*MinNumArgs=*/0, UsesADL);
+}
+
+CallExpr *CallExpr::CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
+                                EmptyShell Empty) {
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem =
+      Ctx.Allocate(sizeof(CallExpr) + SizeOfTrailingObjects, alignof(CallExpr));
+  return new (Mem) CallExpr(CallExprClass, /*NumPreArgs=*/0, NumArgs, Empty);
+}
+
+unsigned CallExpr::offsetToTrailingObjects(StmtClass SC) {
+  switch (SC) {
+  case CallExprClass:
+    return sizeof(CallExpr);
+  case CXXOperatorCallExprClass:
+    return sizeof(CXXOperatorCallExpr);
+  case CXXMemberCallExprClass:
+    return sizeof(CXXMemberCallExpr);
+  case UserDefinedLiteralClass:
+    return sizeof(UserDefinedLiteral);
+  case CUDAKernelCallExprClass:
+    return sizeof(CUDAKernelCallExpr);
+  default:
+    llvm_unreachable("unexpected class deriving from CallExpr!");
+  }
+}
 
 void CallExpr::updateDependenciesFromArg(Expr *Arg) {
   if (Arg->isTypeDependent())
     ExprBits.TypeDependent = true;
   if (Arg->isValueDependent())
     ExprBits.ValueDependent = true;
   if (Arg->isInstantiationDependent())
     ExprBits.InstantiationDependent = true;
   if (Arg->containsUnexpandedParameterPack())
     ExprBits.ContainsUnexpandedParameterPack = true;
 }
 
-FunctionDecl *CallExpr::getDirectCallee() {
-  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
-}
-
-Decl *CallExpr::getCalleeDecl() {
-  return getCallee()->getReferencedDeclOfCallee();
-}
-
 Decl *Expr::getReferencedDeclOfCallee() {
   Expr *CEE = IgnoreParenImpCasts();
 
   while (SubstNonTypeTemplateParmExpr *NTTP
                                 = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
     CEE = NTTP->getReplacement()->IgnoreParenCasts();
   }
 

lib/AST/ExprCXX.cpp

if (!Arg->isDefaultArgument()) {
         break;
       }
     }
   }
 
   return End;
 }
 
+CXXOperatorCallExpr::CXXOperatorCallExpr(OverloadedOperatorKind OpKind,
+                                         Expr *Fn, ArrayRef<Expr *> Args,
+                                         QualType Ty, ExprValueKind VK,
+                                         SourceLocation OperatorLoc,
+                                         FPOptions FPFeatures,
+                                         ADLCallKind UsesADL)
+    : CallExpr(CXXOperatorCallExprClass, Fn, /*PreArgs=*/{}, Args, Ty, VK,
+               OperatorLoc, /*MinNumArgs=*/0, UsesADL),
+      Operator(OpKind), FPFeatures(FPFeatures) {
+  Range = getSourceRangeImpl();
+}
+
+CXXOperatorCallExpr::CXXOperatorCallExpr(unsigned NumArgs, EmptyShell Empty)
+    : CallExpr(CXXOperatorCallExprClass, /*NumPreArgs=*/0, NumArgs, Empty) {}
+
+CXXOperatorCallExpr *CXXOperatorCallExpr::Create(
+    const ASTContext &Ctx, OverloadedOperatorKind OpKind, Expr *Fn,
+    ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+    SourceLocation OperatorLoc, FPOptions FPFeatures, ADLCallKind UsesADL) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned NumArgs = Args.size();
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CXXOperatorCallExpr) + SizeOfTrailingObjects,
+                           alignof(CXXOperatorCallExpr));
+  return new (Mem) CXXOperatorCallExpr(OpKind, Fn, Args, Ty, VK, OperatorLoc,
+                                       FPFeatures, UsesADL);
+}
+
+CXXOperatorCallExpr *CXXOperatorCallExpr::CreateEmpty(const ASTContext &Ctx,
+                                                      unsigned NumArgs,
+                                                      EmptyShell Empty) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CXXOperatorCallExpr) + SizeOfTrailingObjects,
+                           alignof(CXXOperatorCallExpr));
+  return new (Mem) CXXOperatorCallExpr(NumArgs, Empty);
+}
+
 SourceRange CXXOperatorCallExpr::getSourceRangeImpl() const {
   OverloadedOperatorKind Kind = getOperator();
   if (Kind == OO_PlusPlus || Kind == OO_MinusMinus) {
     if (getNumArgs() == 1)
       // Prefix operator
       return SourceRange(getOperatorLoc(), getArg(0)->getEndLoc());
     else
       // Postfix operator
       return SourceRange(getArg(0)->getBeginLoc(), getOperatorLoc());
   } else if (Kind == OO_Arrow) {
     return getArg(0)->getSourceRange();
   } else if (Kind == OO_Call) {
     return SourceRange(getArg(0)->getBeginLoc(), getRParenLoc());
   } else if (Kind == OO_Subscript) {
     return SourceRange(getArg(0)->getBeginLoc(), getRParenLoc());
   } else if (getNumArgs() == 1) {
     return SourceRange(getOperatorLoc(), getArg(0)->getEndLoc());
   } else if (getNumArgs() == 2) {
     return SourceRange(getArg(0)->getBeginLoc(), getArg(1)->getEndLoc());
   } else {
     return getOperatorLoc();
   }
 }
 
+CXXMemberCallExpr::CXXMemberCallExpr(Expr *Fn, ArrayRef<Expr *> Args,
+                                     QualType Ty, ExprValueKind VK,
+                                     SourceLocation RP, unsigned MinNumArgs)
+    : CallExpr(CXXMemberCallExprClass, Fn, /*PreArgs=*/{}, Args, Ty, VK, RP,
+               MinNumArgs, NotADL) {}
+
+CXXMemberCallExpr::CXXMemberCallExpr(unsigned NumArgs, EmptyShell Empty)
+    : CallExpr(CXXMemberCallExprClass, /*NumPreArgs=*/0, NumArgs, Empty) {}
+
+CXXMemberCallExpr *CXXMemberCallExpr::Create(const ASTContext &Ctx, Expr *Fn,
+                                             ArrayRef<Expr *> Args, QualType Ty,
+                                             ExprValueKind VK,
+                                             SourceLocation RP,
+                                             unsigned MinNumArgs) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CXXMemberCallExpr) + SizeOfTrailingObjects,
+                           alignof(CXXMemberCallExpr));
+  return new (Mem) CXXMemberCallExpr(Fn, Args, Ty, VK, RP, MinNumArgs);
+}
+
+CXXMemberCallExpr *CXXMemberCallExpr::CreateEmpty(const ASTContext &Ctx,
+                                                  unsigned NumArgs,
+                                                  EmptyShell Empty) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CXXMemberCallExpr) + SizeOfTrailingObjects,
+                           alignof(CXXMemberCallExpr));
+  return new (Mem) CXXMemberCallExpr(NumArgs, Empty);
+}
+
 Expr *CXXMemberCallExpr::getImplicitObjectArgument() const {
   const Expr *Callee = getCallee()->IgnoreParens();
   if (const auto *MemExpr = dyn_cast<MemberExpr>(Callee))
     return MemExpr->getBase();
   if (const auto *BO = dyn_cast<BinaryOperator>(Callee))
     if (BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI)
       return BO->getLHS();
 

 SourceLocation CXXFunctionalCastExpr::getBeginLoc() const {
   return getTypeInfoAsWritten()->getTypeLoc().getBeginLoc();
 }
 
 SourceLocation CXXFunctionalCastExpr::getEndLoc() const {
   return RParenLoc.isValid() ? RParenLoc : getSubExpr()->getEndLoc();
 }
 
+UserDefinedLiteral::UserDefinedLiteral(Expr *Fn, ArrayRef<Expr *> Args,
+                                       QualType Ty, ExprValueKind VK,
+                                       SourceLocation LitEndLoc,
+                                       SourceLocation SuffixLoc)
+    : CallExpr(UserDefinedLiteralClass, Fn, /*PreArgs=*/{}, Args, Ty, VK,
+               LitEndLoc, /*MinNumArgs=*/0, NotADL),
+      UDSuffixLoc(SuffixLoc) {}
+
+UserDefinedLiteral::UserDefinedLiteral(unsigned NumArgs, EmptyShell Empty)
+    : CallExpr(UserDefinedLiteralClass, /*NumPreArgs=*/0, NumArgs, Empty) {}
+
+UserDefinedLiteral *UserDefinedLiteral::Create(const ASTContext &Ctx, Expr *Fn,
+                                               ArrayRef<Expr *> Args,
+                                               QualType Ty, ExprValueKind VK,
+                                               SourceLocation LitEndLoc,
+                                               SourceLocation SuffixLoc) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned NumArgs = Args.size();
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(UserDefinedLiteral) + SizeOfTrailingObjects,
+                           alignof(UserDefinedLiteral));
+  return new (Mem) UserDefinedLiteral(Fn, Args, Ty, VK, LitEndLoc, SuffixLoc);
+}
+
+UserDefinedLiteral *UserDefinedLiteral::CreateEmpty(const ASTContext &Ctx,
+                                                    unsigned NumArgs,
+                                                    EmptyShell Empty) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(UserDefinedLiteral) + SizeOfTrailingObjects,
+                           alignof(UserDefinedLiteral));
+  return new (Mem) UserDefinedLiteral(NumArgs, Empty);
+}
+
 UserDefinedLiteral::LiteralOperatorKind
 UserDefinedLiteral::getLiteralOperatorKind() const {
   if (getNumArgs() == 0)
     return LOK_Template;
   if (getNumArgs() == 2)
     return LOK_String;
 
   assert(getNumArgs() == 1 && "unexpected #args in literal operator call");
TypeTraitExpr *TypeTraitExpr::Create(const ASTContext &C, QualType T,
   return new (Mem) TypeTraitExpr(T, Loc, Kind, Args, RParenLoc, Value);
 }
 
 TypeTraitExpr *TypeTraitExpr::CreateDeserialized(const ASTContext &C,
                                                  unsigned NumArgs) {
   void *Mem = C.Allocate(totalSizeToAlloc<TypeSourceInfo *>(NumArgs));
   return new (Mem) TypeTraitExpr(EmptyShell());
 }
+
+CUDAKernelCallExpr::CUDAKernelCallExpr(Expr *Fn, CallExpr *Config,
+                                       ArrayRef<Expr *> Args, QualType Ty,
+                                       ExprValueKind VK, SourceLocation RP,
+                                       unsigned MinNumArgs)
+    : CallExpr(CUDAKernelCallExprClass, Fn, /*PreArgs=*/Config, Args, Ty, VK,
+               RP, MinNumArgs, NotADL) {}
+
+CUDAKernelCallExpr::CUDAKernelCallExpr(unsigned NumArgs, EmptyShell Empty)
+    : CallExpr(CUDAKernelCallExprClass, /*NumPreArgs=*/END_PREARG, NumArgs,
+               Empty) {}
+
+CUDAKernelCallExpr *
+CUDAKernelCallExpr::Create(const ASTContext &Ctx, Expr *Fn, CallExpr *Config,
+                           ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
+                           SourceLocation RP, unsigned MinNumArgs) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/END_PREARG, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CUDAKernelCallExpr) + SizeOfTrailingObjects,
+                           alignof(CUDAKernelCallExpr));
+  return new (Mem) CUDAKernelCallExpr(Fn, Config, Args, Ty, VK, RP, MinNumArgs);
+}
+
+CUDAKernelCallExpr *CUDAKernelCallExpr::CreateEmpty(const ASTContext &Ctx,
+                                                    unsigned NumArgs,
+                                                    EmptyShell Empty) {
+  // Allocate storage for the trailing objects of CallExpr.
+  unsigned SizeOfTrailingObjects =
+      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/END_PREARG, NumArgs);
+  void *Mem = Ctx.Allocate(sizeof(CUDAKernelCallExpr) + SizeOfTrailingObjects,
+                           alignof(CUDAKernelCallExpr));
+  return new (Mem) CUDAKernelCallExpr(NumArgs, Empty);
+}

lib/Analysis/BodyFarm.cpp

static CallExpr *create_call_once_funcptr_call(ASTContext &C, ASTMaker M,
   } else if (Ty->isLValueReferenceType()
              && Call->getType()->isPointerType()
              && Call->getType()->getPointeeType()->isFunctionType()){
     SubExpr = Call;
   } else {
     llvm_unreachable("Unexpected state");
   }
 
-  return new (C)
-      CallExpr(C, SubExpr, CallArgs, C.VoidTy, VK_RValue, SourceLocation());
+  return CallExpr::Create(C, SubExpr, CallArgs, C.VoidTy, VK_RValue,
+                          SourceLocation());
 }
 
 static CallExpr *create_call_once_lambda_call(ASTContext &C, ASTMaker M,
                                               const ParmVarDecl *Callback,
                                               CXXRecordDecl *CallbackDecl,
                                               ArrayRef<Expr *> CallArgs) {
   assert(CallbackDecl != nullptr);
   assert(CallbackDecl->isLambda());
   FunctionDecl *callOperatorDecl = CallbackDecl->getLambdaCallOperator();
   assert(callOperatorDecl != nullptr);
 
   DeclRefExpr *callOperatorDeclRef =
       DeclRefExpr::Create(/* Ctx =*/ C,
                           /* QualifierLoc =*/ NestedNameSpecifierLoc(),
                           /* TemplateKWLoc =*/ SourceLocation(),
                           const_cast<FunctionDecl *>(callOperatorDecl),
                           /* RefersToEnclosingVariableOrCapture=*/ false,
                           /* NameLoc =*/ SourceLocation(),
                           /* T =*/ callOperatorDecl->getType(),
                           /* VK =*/ VK_LValue);
 
-  return new (C)
-      CXXOperatorCallExpr(/*AstContext=*/C, OO_Call, callOperatorDeclRef,
-                          /*args=*/CallArgs,
-                          /*QualType=*/C.VoidTy,
-                          /*ExprValueType=*/VK_RValue,
-                          /*SourceLocation=*/SourceLocation(), FPOptions());
+  return CXXOperatorCallExpr::Create(
+      /*AstContext=*/C, OO_Call, callOperatorDeclRef,
 }
 
 /// Create a fake body for std::call_once.
 /// Emulates the following function body:
 ///
 /// \code
 /// typedef struct once_flag_s {
 ///   unsigned long __state = 0;
static Stmt *create_dispatch_once(ASTContext &C, const FunctionDecl *D) {
   //    *predicate = ~0l;
   //    block();
   //  }
   // }
 
   ASTMaker M(C);
 
   // (1) Create the call.
-  CallExpr *CE = new (C) CallExpr(
+  CallExpr *CE = CallExpr::Create(
       /*ASTContext=*/C,
       /*StmtClass=*/M.makeLvalueToRvalue(/*Expr=*/Block),
       /*args=*/None,
       /*QualType=*/C.VoidTy,
       /*ExprValueType=*/VK_RValue,
       /*SourceLocation=*/SourceLocation());
 
   // (2) Create the assignment to the predicate.
static Stmt *create_dispatch_sync(ASTContext &C, const FunctionDecl *D) {
   //
   // void dispatch_sync(dispatch_queue_t queue, void (^block)(void)) {
   //   block();
   // }
   //
   ASTMaker M(C);
   DeclRefExpr *DR = M.makeDeclRefExpr(PV);
   ImplicitCastExpr *ICE = M.makeLvalueToRvalue(DR, Ty);
-  CallExpr *CE = new (C) CallExpr(C, ICE, None, C.VoidTy, VK_RValue,
-                                  SourceLocation());
+  CallExpr *CE =
+      CallExpr::Create(C, ICE, None, C.VoidTy, VK_RValue, SourceLocation());
   return CE;
 }
 
 static Stmt *create_OSAtomicCompareAndSwap(ASTContext &C, const FunctionDecl *D)
 {
   // There are exactly 3 arguments.
   if (D->param_size() != 3)
     return nullptr;

lib/CodeGen/CGObjC.cpp

CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
 
   DeclRefExpr SrcExpr(getContext(), &SrcDecl, false, SrcTy,
                       VK_RValue, SourceLocation());
   UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
                     VK_LValue, OK_Ordinary, SourceLocation(), false);
 
   Expr *Args[2] = { &DST, &SRC };
   CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
-  CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(),
-                              Args, DestTy->getPointeeType(),
-                              VK_LValue, SourceLocation(), FPOptions());
+  CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
+      C, OO_Equal, CalleeExp->getCallee(), Args, DestTy->getPointeeType(),
 
-  EmitStmt(&TheCall);
+  EmitStmt(TheCall);
 
   FinishFunction();
   HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
   CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
   return HelperFn;
 }
 
 llvm::Constant *

lib/Frontend/Rewrite/RewriteModernObjC.cpp

RewriteModernObjC::SynthesizeCallToFunctionDecl(FunctionDecl *FD,
   // Now, we cast the reference to a pointer to the objc_msgSend type.
   QualType pToFunc = Context->getPointerType(msgSendType);
   ImplicitCastExpr *ICE =
     ImplicitCastExpr::Create(*Context, pToFunc, CK_FunctionToPointerDecay,
                              DRE, nullptr, VK_RValue);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
 
-  CallExpr *Exp =  new (Context) CallExpr(*Context, ICE, Args,
-                                          FT->getCallResultType(*Context),
-                                          VK_RValue, EndLoc);
+  CallExpr *Exp = CallExpr::Create(
+      *Context, ICE, Args, FT->getCallResultType(*Context), VK_RValue, EndLoc);
   return Exp;
 }
 
 static bool scanForProtocolRefs(const char *startBuf, const char *endBuf,
                                 const char *&startRef, const char *&endRef) {
   while (startBuf < endBuf) {
     if (*startBuf == '<')
       startRef = startBuf; // mark the start.
Stmt *RewriteModernObjC::RewriteObjCBoxedExpr(ObjCBoxedExpr *Exp) {
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                   cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(StartLoc, EndLoc, cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *CE = new (Context)
-      CallExpr(*Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, EndLoc);
+  CallExpr *CE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                  VK_RValue, EndLoc);
   ReplaceStmt(Exp, CE);
   return CE;
 }
 
 Stmt *RewriteModernObjC::RewriteObjCArrayLiteralExpr(ObjCArrayLiteral *Exp) {
   // synthesize declaration of helper functions needed in this routine.
   if (!SelGetUidFunctionDecl)
     SynthSelGetUidFunctionDecl();
unsigned UnsignedIntSize =
     static_cast<unsigned>(Context->getTypeSize(Context->UnsignedIntTy));
   Expr *count = IntegerLiteral::Create(*Context,
                                        llvm::APInt(UnsignedIntSize, NumElements),
                                        Context->UnsignedIntTy, SourceLocation());
   InitExprs.push_back(count);
   for (unsigned i = 0; i < NumElements; i++)
     InitExprs.push_back(Exp->getElement(i));
   Expr *NSArrayCallExpr =
-    new (Context) CallExpr(*Context, NSArrayDRE, InitExprs,
-                           NSArrayFType, VK_LValue, SourceLocation());
+      CallExpr::Create(*Context, NSArrayDRE, InitExprs, NSArrayFType, VK_LValue,
+                       SourceLocation());
 
   FieldDecl *ARRFD = FieldDecl::Create(*Context, nullptr, SourceLocation(),
                                     SourceLocation(),
                                     &Context->Idents.get("arr"),
                                     Context->getPointerType(Context->VoidPtrTy),
                                     nullptr, /*BitWidth=*/nullptr,
                                     /*Mutable=*/true, ICIS_NoInit);
   MemberExpr *ArrayLiteralME = new (Context)
Stmt *RewriteModernObjC::RewriteObjCArrayLiteralExpr(ObjCArrayLiteral *Exp) {
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                   cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(StartLoc, EndLoc, cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *CE = new (Context)
-      CallExpr(*Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, EndLoc);
+  CallExpr *CE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                  VK_RValue, EndLoc);
   ReplaceStmt(Exp, CE);
   return CE;
 }
 
 Stmt *RewriteModernObjC::RewriteObjCDictionaryLiteralExpr(ObjCDictionaryLiteral *Exp) {
   // synthesize declaration of helper functions needed in this routine.
   if (!SelGetUidFunctionDecl)
     SynthSelGetUidFunctionDecl();
Stmt *RewriteModernObjC::RewriteObjCDictionaryLiteralExpr(ObjCDictionaryLiteral *Exp) {
   for (unsigned i = 0; i < NumElements; i++) {
     ObjCDictionaryElement Element = Exp->getKeyValueElement(i);
     KeyExprs.push_back(Element.Key);
     ValueExprs.push_back(Element.Value);
   }
 
   // (const id [])objects
   Expr *NSValueCallExpr =
-    new (Context) CallExpr(*Context, NSDictDRE, ValueExprs,
-                           NSDictFType, VK_LValue, SourceLocation());
+      CallExpr::Create(*Context, NSDictDRE, ValueExprs, NSDictFType, VK_LValue,
+                       SourceLocation());
 
   FieldDecl *ARRFD = FieldDecl::Create(*Context, nullptr, SourceLocation(),
                                        SourceLocation(),
                                        &Context->Idents.get("arr"),
                                        Context->getPointerType(Context->VoidPtrTy),
                                        nullptr, /*BitWidth=*/nullptr,
                                        /*Mutable=*/true, ICIS_NoInit);
   MemberExpr *DictLiteralValueME = new (Context)
       MemberExpr(NSValueCallExpr, false, SourceLocation(), ARRFD,
                  SourceLocation(), ARRFD->getType(), VK_LValue, OK_Ordinary);
   QualType ConstIdT = Context->getObjCIdType().withConst();
   CStyleCastExpr * DictValueObjects =
     NoTypeInfoCStyleCastExpr(Context,
                              Context->getPointerType(ConstIdT),
                              CK_BitCast,
                              DictLiteralValueME);
   // (const id <NSCopying> [])keys
-  Expr *NSKeyCallExpr =
-    new (Context) CallExpr(*Context, NSDictDRE, KeyExprs,
-                           NSDictFType, VK_LValue, SourceLocation());
+  Expr *NSKeyCallExpr = CallExpr::Create(
+      *Context, NSDictDRE, KeyExprs, NSDictFType, VK_LValue, SourceLocation());
 
   MemberExpr *DictLiteralKeyME = new (Context)
       MemberExpr(NSKeyCallExpr, false, SourceLocation(), ARRFD,
                  SourceLocation(), ARRFD->getType(), VK_LValue, OK_Ordinary);
 
   CStyleCastExpr * DictKeyObjects =
     NoTypeInfoCStyleCastExpr(Context,
                              Context->getPointerType(ConstIdT),
Stmt *RewriteModernObjC::RewriteObjCDictionaryLiteralExpr(ObjCDictionaryLiteral *Exp) {
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                   cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(StartLoc, EndLoc, cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *CE = new (Context)
-      CallExpr(*Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, EndLoc);
+  CallExpr *CE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                  VK_RValue, EndLoc);
   ReplaceStmt(Exp, CE);
   return CE;
 }
 
 // struct __rw_objc_super {
 //   struct objc_object *object; struct objc_object *superClass;
 // };
 QualType RewriteModernObjC::getSuperStructType() {
Expr *RewriteModernObjC::SynthMsgSendStretCallExpr(FunctionDecl *MsgSendStretFlavor,
   InsertText(FunLocStart, str);
   ++stretCount;
 
   // AST for __Stretn(receiver, args).s;
   IdentifierInfo *ID = &Context->Idents.get(name);
   FunctionDecl *FD =
       FunctionDecl::Create(*Context, TUDecl, SourceLocation(), SourceLocation(),
                            ID, FuncType, nullptr, SC_Extern, false, false);
-  DeclRefExpr *DRE = new (Context) DeclRefExpr(*Context, FD, false, castType,
-                                               VK_RValue, SourceLocation());
-  CallExpr *STCE = new (Context) CallExpr(*Context, DRE, MsgExprs,
-                                          castType, VK_LValue, SourceLocation());
+  DeclRefExpr *DRE = new (Context)
+      DeclRefExpr(*Context, FD, false, castType, VK_RValue, SourceLocation());
+  CallExpr *STCE = CallExpr::Create(*Context, DRE, MsgExprs, castType,
+                                    VK_LValue, SourceLocation());
 
   FieldDecl *FieldD = FieldDecl::Create(*Context, nullptr, SourceLocation(),
                                     SourceLocation(),
                                     &Context->Idents.get("s"),
                                     returnType, nullptr,
                                     /*BitWidth=*/nullptr,
                                     /*Mutable=*/true, ICIS_NoInit);
   MemberExpr *ME = new (Context)
case ObjCMessageExpr::SuperClass: {
     Expr *SuperRep;
 
     if (LangOpts.MicrosoftExt) {
       SynthSuperConstructorFunctionDecl();
       // Simulate a constructor call...
       DeclRefExpr *DRE = new (Context)
           DeclRefExpr(*Context, SuperConstructorFunctionDecl, false, superType,
                       VK_LValue, SourceLocation());
-      SuperRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                        superType, VK_LValue,
-                                        SourceLocation());
+      SuperRep = CallExpr::Create(*Context, DRE, InitExprs, superType,
+                                  VK_LValue, SourceLocation());
       // The code for super is a little tricky to prevent collision with
       // the structure definition in the header. The rewriter has it's own
       // internal definition (__rw_objc_super) that is uses. This is why
       // we need the cast below. For example:
       // (struct __rw_objc_super *)&__rw_objc_super((id)self, (id)objc_getClass("SUPER"))
       //
       SuperRep = new (Context) UnaryOperator(SuperRep, UO_AddrOf,
                                Context->getPointerType(SuperRep->getType()),
InitExprs.push_back(
                                CK_BitCast, Cls));
     // struct __rw_objc_super
     QualType superType = getSuperStructType();
     Expr *SuperRep;
 
     if (LangOpts.MicrosoftExt) {
       SynthSuperConstructorFunctionDecl();
       // Simulate a constructor call...
-      DeclRefExpr *DRE = new (Context) DeclRefExpr(*Context,
-                                                   SuperConstructorFunctionDecl,
-                                                   false, superType, VK_LValue,
-                                                   SourceLocation());
-      SuperRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                        superType, VK_LValue, SourceLocation());
+      DeclRefExpr *DRE = new (Context)
+          DeclRefExpr(*Context, SuperConstructorFunctionDecl, false, superType,
+                      VK_LValue, SourceLocation());
+      SuperRep = CallExpr::Create(*Context, DRE, InitExprs, superType,
+                                  VK_LValue, SourceLocation());
       // The code for super is a little tricky to prevent collision with
       // the structure definition in the header. The rewriter has it's own
       // internal definition (__rw_objc_super) that is uses. This is why
       // we need the cast below. For example:
       // (struct __rw_objc_super *)&__rw_objc_super((id)self, (id)objc_getClass("SUPER"))
       //
       SuperRep = new (Context) UnaryOperator(SuperRep, UO_AddrOf,
                                Context->getPointerType(SuperRep->getType()),
Stmt *RewriteModernObjC::SynthMessageExpr(ObjCMessageExpr *Exp,
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                   cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(StartLoc, EndLoc, cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *CE = new (Context)
-      CallExpr(*Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, EndLoc);
+  CallExpr *CE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                  VK_RValue, EndLoc);
   Stmt *ReplacingStmt = CE;
   if (MsgSendStretFlavor) {
     // We have the method which returns a struct/union. Must also generate
     // call to objc_msgSend_stret and hang both varieties on a conditional
     // expression which dictate which one to envoke depending on size of
     // method's return type.
 
     Expr *STCE = SynthMsgSendStretCallExpr(MsgSendStretFlavor,
Stmt *RewriteModernObjC::SynthesizeBlockCall(CallExpr *Exp, const Expr *BlockExp) {
   SmallVector<Expr*, 8> BlkExprs;
   // Add the implicit argument.
   BlkExprs.push_back(BlkCast);
   // Add the user arguments.
   for (CallExpr::arg_iterator I = Exp->arg_begin(),
        E = Exp->arg_end(); I != E; ++I) {
     BlkExprs.push_back(*I);
   }
-  CallExpr *CE = new (Context) CallExpr(*Context, PE, BlkExprs,
-                                        Exp->getType(), VK_RValue,
-                                        SourceLocation());
+  CallExpr *CE = CallExpr::Create(*Context, PE, BlkExprs, Exp->getType(),
+                                  VK_RValue, SourceLocation());
   return CE;
 }
 
 // We need to return the rewritten expression to handle cases where the
 // DeclRefExpr is embedded in another expression being rewritten.
 // For example:
 //
 // int main() {
if (ImportedBlockDecls.size()) {
     // generate BLOCK_HAS_COPY_DISPOSE(have helper funcs) | BLOCK_HAS_DESCRIPTOR
     int flag = (BLOCK_HAS_COPY_DISPOSE | BLOCK_HAS_DESCRIPTOR);
     unsigned IntSize =
       static_cast<unsigned>(Context->getTypeSize(Context->IntTy));
     Expr *FlagExp = IntegerLiteral::Create(*Context, llvm::APInt(IntSize, flag),
                                            Context->IntTy, SourceLocation());
     InitExprs.push_back(FlagExp);
   }
-  NewRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                  FType, VK_LValue, SourceLocation());
+  NewRep = CallExpr::Create(*Context, DRE, InitExprs, FType, VK_LValue,
+                            SourceLocation());
 
   if (GlobalBlockExpr) {
     assert (!GlobalConstructionExp &&
             "SynthBlockInitExpr - GlobalConstructionExp must be null");
     GlobalConstructionExp = NewRep;
     NewRep = DRE;
   }
 

lib/Frontend/Rewrite/RewriteObjC.cpp

RewriteObjC::SynthesizeCallToFunctionDecl(FunctionDecl *FD,
   // Now, we cast the reference to a pointer to the objc_msgSend type.
   QualType pToFunc = Context->getPointerType(msgSendType);
   ImplicitCastExpr *ICE =
     ImplicitCastExpr::Create(*Context, pToFunc, CK_FunctionToPointerDecay,
                              DRE, nullptr, VK_RValue);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
 
-  CallExpr *Exp = new (Context) CallExpr(*Context, ICE, Args,
-                                         FT->getCallResultType(*Context),
-                                         VK_RValue, EndLoc);
+  CallExpr *Exp = CallExpr::Create(
+      *Context, ICE, Args, FT->getCallResultType(*Context), VK_RValue, EndLoc);
   return Exp;
 }
 
 static bool scanForProtocolRefs(const char *startBuf, const char *endBuf,
                                 const char *&startRef, const char *&endRef) {
   while (startBuf < endBuf) {
     if (*startBuf == '<')
       startRef = startBuf; // mark the start.
CallExpr *RewriteObjC::SynthMsgSendStretCallExpr(FunctionDecl *MsgSendStretFlavor,
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                             cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(SourceLocation(), SourceLocation(), cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *STCE = new (Context) CallExpr(
-      *Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, SourceLocation());
+  CallExpr *STCE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                    VK_RValue, SourceLocation());
   return STCE;
 }
 
 Stmt *RewriteObjC::SynthMessageExpr(ObjCMessageExpr *Exp,
                                     SourceLocation StartLoc,
                                     SourceLocation EndLoc) {
   if (!SelGetUidFunctionDecl)
     SynthSelGetUidFunctionDecl();
case ObjCMessageExpr::SuperClass: {
     Expr *SuperRep;
 
     if (LangOpts.MicrosoftExt) {
       SynthSuperConstructorFunctionDecl();
       // Simulate a constructor call...
       DeclRefExpr *DRE = new (Context)
           DeclRefExpr(*Context, SuperConstructorFunctionDecl, false, superType,
                       VK_LValue, SourceLocation());
-      SuperRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                        superType, VK_LValue,
-                                        SourceLocation());
+      SuperRep = CallExpr::Create(*Context, DRE, InitExprs, superType,
+                                  VK_LValue, SourceLocation());
       // The code for super is a little tricky to prevent collision with
       // the structure definition in the header. The rewriter has it's own
       // internal definition (__rw_objc_super) that is uses. This is why
       // we need the cast below. For example:
       // (struct objc_super *)&__rw_objc_super((id)self, (id)objc_getClass("SUPER"))
       //
       SuperRep = new (Context) UnaryOperator(SuperRep, UO_AddrOf,
                                Context->getPointerType(SuperRep->getType()),
case ObjCMessageExpr::SuperInstance:{
     Expr *SuperRep;
 
     if (LangOpts.MicrosoftExt) {
       SynthSuperConstructorFunctionDecl();
       // Simulate a constructor call...
       DeclRefExpr *DRE = new (Context)
           DeclRefExpr(*Context, SuperConstructorFunctionDecl, false, superType,
                       VK_LValue, SourceLocation());
-      SuperRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                        superType, VK_LValue, SourceLocation());
+      SuperRep = CallExpr::Create(*Context, DRE, InitExprs, superType,
+                                  VK_LValue, SourceLocation());
       // The code for super is a little tricky to prevent collision with
       // the structure definition in the header. The rewriter has it's own
       // internal definition (__rw_objc_super) that is uses. This is why
       // we need the cast below. For example:
       // (struct objc_super *)&__rw_objc_super((id)self, (id)objc_getClass("SUPER"))
       //
       SuperRep = new (Context) UnaryOperator(SuperRep, UO_AddrOf,
                                Context->getPointerType(SuperRep->getType()),
Stmt *RewriteObjC::SynthMessageExpr(ObjCMessageExpr *Exp,
   castType = Context->getPointerType(castType);
   cast = NoTypeInfoCStyleCastExpr(Context, castType, CK_BitCast,
                                   cast);
 
   // Don't forget the parens to enforce the proper binding.
   ParenExpr *PE = new (Context) ParenExpr(StartLoc, EndLoc, cast);
 
   const FunctionType *FT = msgSendType->getAs<FunctionType>();
-  CallExpr *CE = new (Context)
-      CallExpr(*Context, PE, MsgExprs, FT->getReturnType(), VK_RValue, EndLoc);
+  CallExpr *CE = CallExpr::Create(*Context, PE, MsgExprs, FT->getReturnType(),
+                                  VK_RValue, EndLoc);
   Stmt *ReplacingStmt = CE;
   if (MsgSendStretFlavor) {
     // We have the method which returns a struct/union. Must also generate
     // call to objc_msgSend_stret and hang both varieties on a conditional
     // expression which dictate which one to envoke depending on size of
     // method's return type.
 
     CallExpr *STCE = SynthMsgSendStretCallExpr(MsgSendStretFlavor,
Stmt *RewriteObjC::SynthesizeBlockCall(CallExpr *Exp, const Expr *BlockExp) {
   SmallVector<Expr*, 8> BlkExprs;
   // Add the implicit argument.
   BlkExprs.push_back(BlkCast);
   // Add the user arguments.
   for (CallExpr::arg_iterator I = Exp->arg_begin(),
        E = Exp->arg_end(); I != E; ++I) {
     BlkExprs.push_back(*I);
   }
-  CallExpr *CE = new (Context) CallExpr(*Context, PE, BlkExprs,
-                                        Exp->getType(), VK_RValue,
-                                        SourceLocation());
+  CallExpr *CE = CallExpr::Create(*Context, PE, BlkExprs, Exp->getType(),
+                                  VK_RValue, SourceLocation());
   return CE;
 }
 
 // We need to return the rewritten expression to handle cases where the
 // BlockDeclRefExpr is embedded in another expression being rewritten.
 // For example:
 //
 // int main() {
if (ImportedBlockDecls.size()) {
     // generate BLOCK_HAS_COPY_DISPOSE(have helper funcs) | BLOCK_HAS_DESCRIPTOR
     int flag = (BLOCK_HAS_COPY_DISPOSE | BLOCK_HAS_DESCRIPTOR);
     unsigned IntSize =
       static_cast<unsigned>(Context->getTypeSize(Context->IntTy));
     Expr *FlagExp = IntegerLiteral::Create(*Context, llvm::APInt(IntSize, flag),
                                            Context->IntTy, SourceLocation());
     InitExprs.push_back(FlagExp);
   }
-  NewRep = new (Context) CallExpr(*Context, DRE, InitExprs,
-                                  FType, VK_LValue, SourceLocation());
-  NewRep = new (Context) UnaryOperator(NewRep, UO_AddrOf,
-                             Context->getPointerType(NewRep->getType()),
-                             VK_RValue, OK_Ordinary, SourceLocation(), false);
+  NewRep = CallExpr::Create(*Context, DRE, InitExprs, FType, VK_LValue,
+                            SourceLocation());
+  NewRep = new (Context) UnaryOperator(
+      NewRep, UO_AddrOf, Context->getPointerType(NewRep->getType()), VK_RValue,
+      OK_Ordinary, SourceLocation(), false);
   NewRep = NoTypeInfoCStyleCastExpr(Context, FType, CK_BitCast,
                                     NewRep);
   BlockDeclRefs.clear();
   BlockByRefDecls.clear();
   BlockByRefDeclsPtrSet.clear();
   BlockByCopyDecls.clear();
   BlockByCopyDeclsPtrSet.clear();
   ImportedBlockDecls.clear();

lib/Sema/SemaExpr.cpp

if (isa<CXXPseudoDestructorExpr>(Fn)) {
       if (!ArgExprs.empty()) {
         // Pseudo-destructor calls should not have any arguments.
         Diag(Fn->getBeginLoc(), diag::err_pseudo_dtor_call_with_args)
             << FixItHint::CreateRemoval(
                    SourceRange(ArgExprs.front()->getBeginLoc(),
                                ArgExprs.back()->getEndLoc()));
       }
 
-      return new (Context)
-          CallExpr(Context, Fn, None, Context.VoidTy, VK_RValue, RParenLoc);
+      return CallExpr::Create(Context, Fn, /*Args=*/{}, Context.VoidTy,
+                              VK_RValue, RParenLoc);
     }
     if (Fn->getType() == Context.PseudoObjectTy) {
       ExprResult result = CheckPlaceholderExpr(Fn);
       if (result.isInvalid()) return ExprError();
       Fn = result.get();
     }
 
     // Determine whether this is a dependent call inside a C++ template,
     // in which case we won't do any semantic analysis now.
     if (Fn->isTypeDependent() || Expr::hasAnyTypeDependentArguments(ArgExprs)) {
       if (ExecConfig) {
-        return new (Context) CUDAKernelCallExpr(
+        return CUDAKernelCallExpr::Create(
             Context, Fn, cast<CallExpr>(ExecConfig), ArgExprs,
             Context.DependentTy, VK_RValue, RParenLoc);
       } else {
 
         tryImplicitlyCaptureThisIfImplicitMemberFunctionAccessWithDependentArgs(
             *this, dyn_cast<UnresolvedMemberExpr>(Fn->IgnoreParens()),
             Fn->getBeginLoc());
 
-        return new (Context) CallExpr(
-            Context, Fn, ArgExprs, Context.DependentTy, VK_RValue, RParenLoc);
+        return CallExpr::Create(Context, Fn, ArgExprs, Context.DependentTy,
+                                VK_RValue, RParenLoc);
       }
     }
 
     // Determine whether this is a call to an object (C++ [over.call.object]).
     if (Fn->getType()->isRecordType())
       return BuildCallToObjectOfClassType(Scope, Fn, LParenLoc, ArgExprs,
                                           RParenLoc);
 
ExprResult Sema::ActOnCallExpr(Scope *Scope, Expr *Fn, SourceLocation LParenLoc,
 
   // Check for overloaded calls.  This can happen even in C due to extensions.
   if (Fn->getType() == Context.OverloadTy) {
     OverloadExpr::FindResult find = OverloadExpr::find(Fn);
 
     // We aren't supposed to apply this logic if there's an '&' involved.
     if (!find.HasFormOfMemberPointer) {
       if (Expr::hasAnyTypeDependentArguments(ArgExprs))
-        return new (Context) CallExpr(
-            Context, Fn, ArgExprs, Context.DependentTy, VK_RValue, RParenLoc);
+        return CallExpr::Create(Context, Fn, ArgExprs, Context.DependentTy,
+                                VK_RValue, RParenLoc);
       OverloadExpr *ovl = find.Expression;
       if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(ovl))
         return BuildOverloadedCallExpr(
             Scope, Fn, ULE, LParenLoc, ArgExprs, RParenLoc, ExecConfig,
             /*AllowTypoCorrection=*/true, find.IsAddressOfOperand);
       return BuildCallToMemberFunction(Scope, Fn, LParenLoc, ArgExprs,
                                        RParenLoc);
     }
ExprResult Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl,
   // in the call expression.
   const auto *Proto = dyn_cast_or_null<FunctionProtoType>(FuncT);
   unsigned NumParams = Proto ? Proto->getNumParams() : 0;
 
   CallExpr *TheCall;
   if (Config) {
     assert(UsesADL == ADLCallKind::NotADL &&
            "CUDAKernelCallExpr should not use ADL");
-    TheCall = new (Context)
-        CUDAKernelCallExpr(Context, Fn, cast<CallExpr>(Config), Args, ResultTy,
-                           VK_RValue, RParenLoc, NumParams);
+    TheCall =
+        CUDAKernelCallExpr::Create(Context, Fn, cast<CallExpr>(Config), Args,
+                                   ResultTy, VK_RValue, RParenLoc, NumParams);
   } else {
-    TheCall = new (Context) CallExpr(Context, Fn, Args, ResultTy, VK_RValue,
-                                     RParenLoc, NumParams, UsesADL);
+    TheCall = CallExpr::Create(Context, Fn, Args, ResultTy, VK_RValue,
   }
 
   if (!getLangOpts().CPlusPlus) {
     // C cannot always handle TypoExpr nodes in builtin calls and direct
     // function calls as their argument checking don't necessarily handle
     // dependent types properly, so make sure any TypoExprs have been
     // dealt with.
     ExprResult Result = CorrectDelayedTyposInExpr(TheCall);
ExprResult Sema::CheckPlaceholderExpr(Expr *E) {
 
   case BuiltinType::BuiltinFn: {
     // Accept __noop without parens by implicitly converting it to a call expr.
     auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
     if (DRE) {
       auto *FD = cast<FunctionDecl>(DRE->getDecl());
       if (FD->getBuiltinID() == Builtin::BI__noop) {
         E = ImpCastExprToType(E, Context.getPointerType(FD->getType()),
-                              CK_BuiltinFnToFnPtr).get();
-        return new (Context) CallExpr(Context, E, None, Context.IntTy,
-                                      VK_RValue, SourceLocation());
+                              CK_BuiltinFnToFnPtr)
+                .get();
+        return CallExpr::Create(Context, E, /*Args=*/{}, Context.IntTy,
       }
     }
 
     Diag(E->getBeginLoc(), diag::err_builtin_fn_use);
     return ExprError();
   }
 
   // Expressions of unknown type.

lib/Sema/SemaExprCXX.cpp

ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
   if (HadMultipleCandidates)
     ME->setHadMultipleCandidates(true);
   MarkMemberReferenced(ME);
 
   QualType ResultType = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultType);
   ResultType = ResultType.getNonLValueExprType(Context);
 
-  CXXMemberCallExpr *CE = new (Context) CXXMemberCallExpr(
-      Context, ME, None, ResultType, VK, Exp.get()->getEndLoc());
+  CXXMemberCallExpr *CE = CXXMemberCallExpr::Create(
+      Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc());
 
   if (CheckFunctionCall(Method, CE,
                         Method->getType()->castAs<FunctionProtoType>()))
     return ExprError();
 
   return CE;
 }
 

lib/Sema/SemaOpenMP.cpp

if (DeclareReductionRef.isUsable()) {
       }
       FunctionProtoType::ExtProtoInfo EPI;
       QualType Params[] = {PtrRedTy, PtrRedTy};
       QualType FnTy = Context.getFunctionType(Context.VoidTy, Params, EPI);
       auto *OVE = new (Context) OpaqueValueExpr(
           ELoc, Context.getPointerType(FnTy), VK_RValue, OK_Ordinary,
           S.DefaultLvalueConversion(DeclareReductionRef.get()).get());
       Expr *Args[] = {LHS.get(), RHS.get()};
-      ReductionOp = new (Context)
-          CallExpr(Context, OVE, Args, Context.VoidTy, VK_RValue, ELoc);
+      ReductionOp =
+          CallExpr::Create(Context, OVE, Args, Context.VoidTy, VK_RValue, ELoc);
     } else {
       ReductionOp = S.BuildBinOp(
           Stack->getCurScope(), ReductionId.getBeginLoc(), BOK, LHSDRE, RHSDRE);
       if (ReductionOp.isUsable()) {
         if (BOK != BO_LT && BOK != BO_GT) {
           ReductionOp =
               S.BuildBinOp(Stack->getCurScope(), ReductionId.getBeginLoc(),
                            BO_Assign, LHSDRE, ReductionOp.get());

lib/Sema/SemaOverload.cpp

Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
   }
 
   ExprValueKind VK = Expr::getValueKindForType(ConversionType);
 
   // Note that it is safe to allocate CallExpr on the stack here because
   // there are 0 arguments (i.e., nothing is allocated using ASTContext's
   // allocator).
   QualType CallResultType = ConversionType.getNonLValueExprType(Context);
-  CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
-                From->getBeginLoc());
+
+  llvm::AlignedCharArray<alignof(CallExpr), sizeof(CallExpr) + sizeof(Stmt *)>
+      Buffer;
+  CallExpr *TheTemporaryCall = CallExpr::CreateTemporary(
+      Buffer.buffer, &ConversionFn, CallResultType, VK, From->getBeginLoc());
+
   ImplicitConversionSequence ICS =
-    TryCopyInitialization(*this, &Call, ToType,
+      TryCopyInitialization(*this, TheTemporaryCall, ToType,
                             /*SuppressUserConversions=*/true,
                             /*InOverloadResolution=*/false,
                             /*AllowObjCWritebackConversion=*/false);
 
   switch (ICS.getKind()) {
   case ImplicitConversionSequence::StandardConversion:
     Candidate.FinalConversion = ICS.Standard;
 
     // C++ [over.ics.user]p3:
     //   If the user-defined conversion is specified by a specialization of a
     //   conversion function template, the second standard conversion sequence
#endif
   if (getLangOpts().MSVCCompat &&
       CurContext->isDependentContext() && !isSFINAEContext() &&
       (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
 
     OverloadCandidateSet::iterator Best;
     if (CandidateSet->empty() ||
         CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best) ==
             OR_No_Viable_Function) {
-      // In Microsoft mode, if we are inside a template class member function then
-      // create a type dependent CallExpr. The goal is to postpone name lookup
-      // to instantiation time to be able to search into type dependent base
-      // classes.
-      CallExpr *CE = new (Context) CallExpr(
-          Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
+      // In Microsoft mode, if we are inside a template class member function
+      // then create a type dependent CallExpr. The goal is to postpone name
+      // lookup to instantiation time to be able to search into type dependent
+      // base classes.
+      CallExpr *CE = CallExpr::Create(Context, Fn, Args, Context.DependentTy,
+                                      VK_RValue, RParenLoc);
       CE->setTypeDependent(true);
       CE->setValueDependent(true);
       CE->setInstantiationDependent(true);
       *Result = CE;
       return true;
     }
   }
 
Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
   ArrayRef<Expr *> ArgsArray(Args, NumArgs);
 
   if (Input->isTypeDependent()) {
     if (Fns.empty())
       return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
                                          VK_RValue, OK_Ordinary, OpLoc, false);
 
     CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
-    UnresolvedLookupExpr *Fn
-      = UnresolvedLookupExpr::Create(Context, NamingClass,
-                                     NestedNameSpecifierLoc(), OpNameInfo,
-                                     /*ADL*/ true, IsOverloaded(Fns),
-                                     Fns.begin(), Fns.end());
-    return new (Context)
-        CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
-                            VK_RValue, OpLoc, FPOptions());
+    UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
+        Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
+        /*ADL*/ true, IsOverloaded(Fns), Fns.begin(), Fns.end());
+    return CXXOperatorCallExpr::Create(Context, Op, Fn, ArgsArray,
+                                       Context.DependentTy, VK_RValue, OpLoc,
+                                       FPOptions());
   }
 
   // Build an empty overload set.
   OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
 
   // Add the candidates from the given function set.
   AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
 
if (FnDecl) {
         return ExprError();
 
       // Determine the result type.
       QualType ResultTy = FnDecl->getReturnType();
       ExprValueKind VK = Expr::getValueKindForType(ResultTy);
       ResultTy = ResultTy.getNonLValueExprType(Context);
 
       Args[0] = Input;
-      CallExpr *TheCall = new (Context)
-          CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray, ResultTy,
-                              VK, OpLoc, FPOptions(), Best->IsADLCandidate);
+      CallExpr *TheCall = CXXOperatorCallExpr::Create(
+          Context, Op, FnExpr.get(), ArgsArray, ResultTy, VK, OpLoc,
+          FPOptions(), Best->IsADLCandidate);
 
       if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
         return ExprError();
 
       if (CheckFunctionCall(FnDecl, TheCall,
                             FnDecl->getType()->castAs<FunctionProtoType>()))
         return ExprError();
 
if (Fns.empty()) {
           Context.DependentTy, Context.DependentTy, OpLoc,
           FPFeatures);
     }
 
     // FIXME: save results of ADL from here?
     CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
     // TODO: provide better source location info in DNLoc component.
     DeclarationNameInfo OpNameInfo(OpName, OpLoc);
-    UnresolvedLookupExpr *Fn
-      = UnresolvedLookupExpr::Create(Context, NamingClass,
-                                     NestedNameSpecifierLoc(), OpNameInfo,
-                                     /*ADL*/PerformADL, IsOverloaded(Fns),
-                                     Fns.begin(), Fns.end());
-    return new (Context)
-        CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
-                            VK_RValue, OpLoc, FPFeatures);
+    UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
+        Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
+        /*ADL*/ PerformADL, IsOverloaded(Fns), Fns.begin(), Fns.end());
+    return CXXOperatorCallExpr::Create(Context, Op, Fn, Args,
+                                       Context.DependentTy, VK_RValue, OpLoc,
+                                       FPFeatures);
   }
 
   // Always do placeholder-like conversions on the RHS.
   if (checkPlaceholderForOverload(*this, Args[1]))
     return ExprError();
 
   // Do placeholder-like conversion on the LHS; note that we should
   // not get here with a PseudoObject LHS.
case OR_Success: {
         if (FnExpr.isInvalid())
           return ExprError();
 
         // Determine the result type.
         QualType ResultTy = FnDecl->getReturnType();
         ExprValueKind VK = Expr::getValueKindForType(ResultTy);
         ResultTy = ResultTy.getNonLValueExprType(Context);
 
-        CXXOperatorCallExpr *TheCall = new (Context)
-            CXXOperatorCallExpr(Context, Op, FnExpr.get(), Args, ResultTy, VK,
-                                OpLoc, FPFeatures, Best->IsADLCandidate);
+        CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
+            Context, Op, FnExpr.get(), Args, ResultTy, VK, OpLoc, FPFeatures,
+            Best->IsADLCandidate);
 
         if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
                                 FnDecl))
           return ExprError();
 
         ArrayRef<const Expr *> ArgsArray(Args, 2);
         const Expr *ImplicitThis = nullptr;
         // Cut off the implicit 'this'.
if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
     UnresolvedLookupExpr *Fn
       = UnresolvedLookupExpr::Create(Context, NamingClass,
                                      NestedNameSpecifierLoc(), OpNameInfo,
                                      /*ADL*/ true, /*Overloaded*/ false,
                                      UnresolvedSetIterator(),
                                      UnresolvedSetIterator());
     // Can't add any actual overloads yet
 
-    return new (Context)
-        CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
-                            Context.DependentTy, VK_RValue, RLoc, FPOptions());
+    return CXXOperatorCallExpr::Create(Context, OO_Subscript, Fn, Args,
+                                       Context.DependentTy, VK_RValue, RLoc,
+                                       FPOptions());
   }
 
   // Handle placeholders on both operands.
   if (checkPlaceholderForOverload(*this, Args[0]))
     return ExprError();
   if (checkPlaceholderForOverload(*this, Args[1]))
     return ExprError();
 
case OR_Success: {
           return ExprError();
 
         // Determine the result type
         QualType ResultTy = FnDecl->getReturnType();
         ExprValueKind VK = Expr::getValueKindForType(ResultTy);
         ResultTy = ResultTy.getNonLValueExprType(Context);
 
         CXXOperatorCallExpr *TheCall =
-          new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
-                                            FnExpr.get(), Args,
-                                            ResultTy, VK, RLoc,
-                                            FPOptions());
+            CXXOperatorCallExpr::Create(Context, OO_Subscript, FnExpr.get(),
+                                        Args, ResultTy, VK, RLoc, FPOptions());
 
         if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
           return ExprError();
 
         if (CheckFunctionCall(Method, TheCall,
                               Method->getType()->castAs<FunctionProtoType>()))
           return ExprError();
 
if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
     if (difference) {
       std::string qualsString = difference.getAsString();
       Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
         << fnType.getUnqualifiedType()
         << qualsString
         << (qualsString.find(' ') == std::string::npos ? 1 : 2);
     }
 
-    CXXMemberCallExpr *call
-      = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
-                                        resultType, valueKind, RParenLoc,
-                                        proto->getNumParams());
+    CXXMemberCallExpr *call =
+        CXXMemberCallExpr::Create(Context, MemExprE, Args, resultType,
+                                  valueKind, RParenLoc, proto->getNumParams());
 
     if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getBeginLoc(),
                             call, nullptr))
       return ExprError();
 
     if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
       return ExprError();
 
     if (CheckOtherCall(call, proto))
       return ExprError();
 
     return MaybeBindToTemporary(call);
   }
 
   if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
-    return new (Context)
-        CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
+    return CallExpr::Create(Context, MemExprE, Args, Context.VoidTy, VK_RValue,
+                            RParenLoc);
 
   UnbridgedCastsSet UnbridgedCasts;
   if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
     return ExprError();
 
   MemberExpr *MemExpr;
   CXXMethodDecl *Method = nullptr;
   DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
 
   QualType ResultType = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultType);
   ResultType = ResultType.getNonLValueExprType(Context);
 
   assert(Method && "Member call to something that isn't a method?");
   const auto *Proto = Method->getType()->getAs<FunctionProtoType>();
   CXXMemberCallExpr *TheCall =
-    new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
-                                    ResultType, VK, RParenLoc,
-                                    Proto->getNumParams());
+      CXXMemberCallExpr::Create(Context, MemExprE, Args, ResultType, VK,
+                                RParenLoc, Proto->getNumParams());
 
   // Check for a valid return type.
   if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
                           TheCall, Method))
     return ExprError();
 
   // Convert the object argument (for a non-static member function call).
   // We only need to do this if there was actually an overload; otherwise
Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
 
   DiagnoseSentinelCalls(Method, LParenLoc, Args);
 
   // Once we've built TheCall, all of the expressions are properly owned.
   QualType ResultTy = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultTy);
   ResultTy = ResultTy.getNonLValueExprType(Context);
 
-  CXXOperatorCallExpr *TheCall = new (Context)
-      CXXOperatorCallExpr(Context, OO_Call, NewFn.get(), MethodArgs, ResultTy,
-                          VK, RParenLoc, FPOptions());
+  CXXOperatorCallExpr *TheCall =
+      CXXOperatorCallExpr::Create(Context, OO_Call, NewFn.get(), MethodArgs,
+                                  ResultTy, VK, RParenLoc, FPOptions());
 
   if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
     return true;
 
   if (CheckFunctionCall(Method, TheCall, Proto))
     return true;
 
   return MaybeBindToTemporary(TheCall);
Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
   ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
                                             Base, HadMultipleCandidates, OpLoc);
   if (FnExpr.isInvalid())
     return ExprError();
 
   QualType ResultTy = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultTy);
   ResultTy = ResultTy.getNonLValueExprType(Context);
-  CXXOperatorCallExpr *TheCall =
-    new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
-                                      Base, ResultTy, VK, OpLoc, FPOptions());
+  CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
+      Context, OO_Arrow, FnExpr.get(), Base, ResultTy, VK, OpLoc, FPOptions());
 
   if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
     return ExprError();
 
   if (CheckFunctionCall(Method, TheCall,
                         Method->getType()->castAs<FunctionProtoType>()))
     return ExprError();
 
if (InputInit.isInvalid())
       return true;
     ConvArgs[ArgIdx] = InputInit.get();
   }
 
   QualType ResultTy = FD->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultTy);
   ResultTy = ResultTy.getNonLValueExprType(Context);
 
-  UserDefinedLiteral *UDL =
-    new (Context) UserDefinedLiteral(Context, Fn.get(),
-                                     llvm::makeArrayRef(ConvArgs, Args.size()),
-                                     ResultTy, VK, LitEndLoc, UDSuffixLoc);
+  UserDefinedLiteral *UDL = UserDefinedLiteral::Create(
+      Context, Fn.get(), llvm::makeArrayRef(ConvArgs, Args.size()), ResultTy,
+      VK, LitEndLoc, UDSuffixLoc);
 
   if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
     return ExprError();
 
   if (CheckFunctionCall(FD, UDL, nullptr))
     return ExprError();
 
   return MaybeBindToTemporary(UDL);

lib/Sema/TreeTransform.h

ExprResult RebuildShuffleVectorExpr(SourceLocation BuiltinLoc,
     Expr *Callee = new (SemaRef.Context)
         DeclRefExpr(SemaRef.Context, Builtin, false,
                     SemaRef.Context.BuiltinFnTy, VK_RValue, BuiltinLoc);
     QualType CalleePtrTy = SemaRef.Context.getPointerType(Builtin->getType());
     Callee = SemaRef.ImpCastExprToType(Callee, CalleePtrTy,
                                        CK_BuiltinFnToFnPtr).get();
 
     // Build the CallExpr
-    ExprResult TheCall = new (SemaRef.Context) CallExpr(
+    ExprResult TheCall = CallExpr::Create(
         SemaRef.Context, Callee, SubExprs, Builtin->getCallResultType(),
         Expr::getValueKindForType(Builtin->getReturnType()), RParenLoc);
 
     // Type-check the __builtin_shufflevector expression.
     return SemaRef.SemaBuiltinShuffleVector(cast<CallExpr>(TheCall.get()));
   }
 
   /// Build a new convert vector expression.

lib/Serialization/ASTReaderStmt.cpp

case EXPR_ARRAY_SUBSCRIPT:
       S = new (Context) ArraySubscriptExpr(Empty);
       break;
 
     case EXPR_OMP_ARRAY_SECTION:
       S = new (Context) OMPArraySectionExpr(Empty);
       break;
 
     case EXPR_CALL:
-      S = new (Context) CallExpr(
-          Context, /* NumArgs=*/Record[ASTStmtReader::NumExprFields],
-          Empty);
+      S = CallExpr::CreateEmpty(
+          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
     case EXPR_MEMBER: {
       // We load everything here and fully initialize it at creation.
       // That way we can use MemberExpr::Create and don't have to duplicate its
       // logic with a MemberExpr::CreateEmpty.
 
       assert(Record.getIdx() == 0);
case STMT_OMP_TARGET_TEAMS_DISTRIBUTE_SIMD_DIRECTIVE: {
       auto NumClauses = Record[ASTStmtReader::NumStmtFields];
       auto CollapsedNum = Record[ASTStmtReader::NumStmtFields + 1];
       S = OMPTargetTeamsDistributeSimdDirective::CreateEmpty(
           Context, NumClauses, CollapsedNum, Empty);
       break;
     }
 
     case EXPR_CXX_OPERATOR_CALL:
-      S = new (Context) CXXOperatorCallExpr(
-          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields],
-          Empty);
+      S = CXXOperatorCallExpr::CreateEmpty(
+          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
     case EXPR_CXX_MEMBER_CALL:
-      S = new (Context) CXXMemberCallExpr(
-          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields],
-          Empty);
+      S = CXXMemberCallExpr::CreateEmpty(
+          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
     case EXPR_CXX_CONSTRUCT:
       S = new (Context) CXXConstructExpr(Empty);
       break;
 
     case EXPR_CXX_INHERITED_CTOR_INIT:
       S = new (Context) CXXInheritedCtorInitExpr(Empty);
case EXPR_CXX_CONST_CAST:
       break;
 
     case EXPR_CXX_FUNCTIONAL_CAST:
       S = CXXFunctionalCastExpr::CreateEmpty(Context,
                        /*PathSize*/ Record[ASTStmtReader::NumExprFields]);
       break;
 
     case EXPR_USER_DEFINED_LITERAL:
-      S = new (Context) UserDefinedLiteral(
+      S = UserDefinedLiteral::CreateEmpty(
           Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
     case EXPR_CXX_STD_INITIALIZER_LIST:
       S = new (Context) CXXStdInitializerListExpr(Empty);
       break;
 
     case EXPR_CXX_BOOL_LITERAL:
case EXPR_CXX_FOLD:
       S = new (Context) CXXFoldExpr(Empty);
       break;
 
     case EXPR_OPAQUE_VALUE:
       S = new (Context) OpaqueValueExpr(Empty);
       break;
 
     case EXPR_CUDA_KERNEL_CALL:
-      S = new (Context) CUDAKernelCallExpr(
+      S = CUDAKernelCallExpr::CreateEmpty(
           Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
     case EXPR_ASTYPE:
       S = new (Context) AsTypeExpr(Empty);
       break;
 
     case EXPR_PSEUDO_OBJECT: {