Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 377 insertions, 0 deletions

diff --git a/clang-r353983/include/clang/AST/CXXInheritance.h b/clang-r353983/include/clang/AST/CXXInheritance.h
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+//===- CXXInheritance.h - C++ Inheritance -----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides routines that help analyzing C++ inheritance hierarchies.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_CXXINHERITANCE_H
+#define LLVM_CLANG_AST_CXXINHERITANCE_H
+
+#include "clang/AST/DeclBase.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclarationName.h"
+#include "clang/AST/Type.h"
+#include "clang/AST/TypeOrdering.h"
+#include "clang/Basic/Specifiers.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/iterator_range.h"
+#include <list>
+#include <memory>
+#include <utility>
+
+namespace clang {
+
+class ASTContext;
+class NamedDecl;
+
+/// Represents an element in a path from a derived class to a
+/// base class.
+///
+/// Each step in the path references the link from a
+/// derived class to one of its direct base classes, along with a
+/// base "number" that identifies which base subobject of the
+/// original derived class we are referencing.
+struct CXXBasePathElement {
+  /// The base specifier that states the link from a derived
+  /// class to a base class, which will be followed by this base
+  /// path element.
+  const CXXBaseSpecifier *Base;
+
+  /// The record decl of the class that the base is a base of.
+  const CXXRecordDecl *Class;
+
+  /// Identifies which base class subobject (of type
+  /// \c Base->getType()) this base path element refers to.
+  ///
+  /// This value is only valid if \c !Base->isVirtual(), because there
+  /// is no base numbering for the zero or one virtual bases of a
+  /// given type.
+  int SubobjectNumber;
+};
+
+/// Represents a path from a specific derived class
+/// (which is not represented as part of the path) to a particular
+/// (direct or indirect) base class subobject.
+///
+/// Individual elements in the path are described by the \c CXXBasePathElement
+/// structure, which captures both the link from a derived class to one of its
+/// direct bases and identification describing which base class
+/// subobject is being used.
+class CXXBasePath : public SmallVector<CXXBasePathElement, 4> {
+public:
+  /// The access along this inheritance path.  This is only
+  /// calculated when recording paths.  AS_none is a special value
+  /// used to indicate a path which permits no legal access.
+  AccessSpecifier Access = AS_public;
+
+  CXXBasePath() = default;
+
+  /// The set of declarations found inside this base class
+  /// subobject.
+  DeclContext::lookup_result Decls;
+
+  void clear() {
+    SmallVectorImpl<CXXBasePathElement>::clear();
+    Access = AS_public;
+  }
+};
+
+/// BasePaths - Represents the set of paths from a derived class to
+/// one of its (direct or indirect) bases. For example, given the
+/// following class hierarchy:
+///
+/// @code
+/// class A { };
+/// class B : public A { };
+/// class C : public A { };
+/// class D : public B, public C{ };
+/// @endcode
+///
+/// There are two potential BasePaths to represent paths from D to a
+/// base subobject of type A. One path is (D,0) -> (B,0) -> (A,0)
+/// and another is (D,0)->(C,0)->(A,1). These two paths actually
+/// refer to two different base class subobjects of the same type,
+/// so the BasePaths object refers to an ambiguous path. On the
+/// other hand, consider the following class hierarchy:
+///
+/// @code
+/// class A { };
+/// class B : public virtual A { };
+/// class C : public virtual A { };
+/// class D : public B, public C{ };
+/// @endcode
+///
+/// Here, there are two potential BasePaths again, (D, 0) -> (B, 0)
+/// -> (A,v) and (D, 0) -> (C, 0) -> (A, v), but since both of them
+/// refer to the same base class subobject of type A (the virtual
+/// one), there is no ambiguity.
+class CXXBasePaths {
+  friend class CXXRecordDecl;
+
+  /// The type from which this search originated.
+  CXXRecordDecl *Origin = nullptr;
+
+  /// Paths - The actual set of paths that can be taken from the
+  /// derived class to the same base class.
+  std::list<CXXBasePath> Paths;
+
+  /// ClassSubobjects - Records the class subobjects for each class
+  /// type that we've seen. The first element IsVirtBase says
+  /// whether we found a path to a virtual base for that class type,
+  /// while NumberOfNonVirtBases contains the number of non-virtual base
+  /// class subobjects for that class type. The key of the map is
+  /// the cv-unqualified canonical type of the base class subobject.
+  struct IsVirtBaseAndNumberNonVirtBases {
+    unsigned IsVirtBase : 1;
+    unsigned NumberOfNonVirtBases : 31;
+  };
+  llvm::SmallDenseMap<QualType, IsVirtBaseAndNumberNonVirtBases, 8>
+      ClassSubobjects;
+
+  /// VisitedDependentRecords - Records the dependent records that have been
+  /// already visited.
+  llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedDependentRecords;
+
+  /// DetectedVirtual - The base class that is virtual.
+  const RecordType *DetectedVirtual = nullptr;
+
+  /// ScratchPath - A BasePath that is used by Sema::lookupInBases
+  /// to help build the set of paths.
+  CXXBasePath ScratchPath;
+
+  /// Array of the declarations that have been found. This
+  /// array is constructed only if needed, e.g., to iterate over the
+  /// results within LookupResult.
+  std::unique_ptr<NamedDecl *[]> DeclsFound;
+  unsigned NumDeclsFound = 0;
+
+  /// FindAmbiguities - Whether Sema::IsDerivedFrom should try find
+  /// ambiguous paths while it is looking for a path from a derived
+  /// type to a base type.
+  bool FindAmbiguities;
+
+  /// RecordPaths - Whether Sema::IsDerivedFrom should record paths
+  /// while it is determining whether there are paths from a derived
+  /// type to a base type.
+  bool RecordPaths;
+
+  /// DetectVirtual - Whether Sema::IsDerivedFrom should abort the search
+  /// if it finds a path that goes across a virtual base. The virtual class
+  /// is also recorded.
+  bool DetectVirtual;
+
+  void ComputeDeclsFound();
+
+  bool lookupInBases(ASTContext &Context, const CXXRecordDecl *Record,
+                     CXXRecordDecl::BaseMatchesCallback BaseMatches,
+                     bool LookupInDependent = false);
+
+public:
+  using paths_iterator = std::list<CXXBasePath>::iterator;
+  using const_paths_iterator = std::list<CXXBasePath>::const_iterator;
+  using decl_iterator = NamedDecl **;
+
+  /// BasePaths - Construct a new BasePaths structure to record the
+  /// paths for a derived-to-base search.
+  explicit CXXBasePaths(bool FindAmbiguities = true, bool RecordPaths = true,
+                        bool DetectVirtual = true)
+      : FindAmbiguities(FindAmbiguities), RecordPaths(RecordPaths),
+        DetectVirtual(DetectVirtual) {}
+
+  paths_iterator begin() { return Paths.begin(); }
+  paths_iterator end()   { return Paths.end(); }
+  const_paths_iterator begin() const { return Paths.begin(); }
+  const_paths_iterator end()   const { return Paths.end(); }
+
+  CXXBasePath&       front()       { return Paths.front(); }
+  const CXXBasePath& front() const { return Paths.front(); }
+
+  using decl_range = llvm::iterator_range<decl_iterator>;
+
+  decl_range found_decls();
+
+  /// Determine whether the path from the most-derived type to the
+  /// given base type is ambiguous (i.e., it refers to multiple subobjects of
+  /// the same base type).
+  bool isAmbiguous(CanQualType BaseType);
+
+  /// Whether we are finding multiple paths to detect ambiguities.
+  bool isFindingAmbiguities() const { return FindAmbiguities; }
+
+  /// Whether we are recording paths.
+  bool isRecordingPaths() const { return RecordPaths; }
+
+  /// Specify whether we should be recording paths or not.
+  void setRecordingPaths(bool RP) { RecordPaths = RP; }
+
+  /// Whether we are detecting virtual bases.
+  bool isDetectingVirtual() const { return DetectVirtual; }
+
+  /// The virtual base discovered on the path (if we are merely
+  /// detecting virtuals).
+  const RecordType* getDetectedVirtual() const {
+    return DetectedVirtual;
+  }
+
+  /// Retrieve the type from which this base-paths search
+  /// began
+  CXXRecordDecl *getOrigin() const { return Origin; }
+  void setOrigin(CXXRecordDecl *Rec) { Origin = Rec; }
+
+  /// Clear the base-paths results.
+  void clear();
+
+  /// Swap this data structure's contents with another CXXBasePaths
+  /// object.
+  void swap(CXXBasePaths &Other);
+};
+
+/// Uniquely identifies a virtual method within a class
+/// hierarchy by the method itself and a class subobject number.
+struct UniqueVirtualMethod {
+  /// The overriding virtual method.
+  CXXMethodDecl *Method = nullptr;
+
+  /// The subobject in which the overriding virtual method
+  /// resides.
+  unsigned Subobject = 0;
+
+  /// The virtual base class subobject of which this overridden
+  /// virtual method is a part. Note that this records the closest
+  /// derived virtual base class subobject.
+  const CXXRecordDecl *InVirtualSubobject = nullptr;
+
+  UniqueVirtualMethod() = default;
+
+  UniqueVirtualMethod(CXXMethodDecl *Method, unsigned Subobject,
+                      const CXXRecordDecl *InVirtualSubobject)
+      : Method(Method), Subobject(Subobject),
+        InVirtualSubobject(InVirtualSubobject) {}
+
+  friend bool operator==(const UniqueVirtualMethod &X,
+                         const UniqueVirtualMethod &Y) {
+    return X.Method == Y.Method && X.Subobject == Y.Subobject &&
+      X.InVirtualSubobject == Y.InVirtualSubobject;
+  }
+
+  friend bool operator!=(const UniqueVirtualMethod &X,
+                         const UniqueVirtualMethod &Y) {
+    return !(X == Y);
+  }
+};
+
+/// The set of methods that override a given virtual method in
+/// each subobject where it occurs.
+///
+/// The first part of the pair is the subobject in which the
+/// overridden virtual function occurs, while the second part of the
+/// pair is the virtual method that overrides it (including the
+/// subobject in which that virtual function occurs).
+class OverridingMethods {
+  using ValuesT = SmallVector<UniqueVirtualMethod, 4>;
+  using MapType = llvm::MapVector<unsigned, ValuesT>;
+
+  MapType Overrides;
+
+public:
+  // Iterate over the set of subobjects that have overriding methods.
+  using iterator = MapType::iterator;
+  using const_iterator = MapType::const_iterator;
+
+  iterator begin() { return Overrides.begin(); }
+  const_iterator begin() const { return Overrides.begin(); }
+  iterator end() { return Overrides.end(); }
+  const_iterator end() const { return Overrides.end(); }
+  unsigned size() const { return Overrides.size(); }
+
+  // Iterate over the set of overriding virtual methods in a given
+  // subobject.
+  using overriding_iterator =
+      SmallVectorImpl<UniqueVirtualMethod>::iterator;
+  using overriding_const_iterator =
+      SmallVectorImpl<UniqueVirtualMethod>::const_iterator;
+
+  // Add a new overriding method for a particular subobject.
+  void add(unsigned OverriddenSubobject, UniqueVirtualMethod Overriding);
+
+  // Add all of the overriding methods from "other" into overrides for
+  // this method. Used when merging the overrides from multiple base
+  // class subobjects.
+  void add(const OverridingMethods &Other);
+
+  // Replace all overriding virtual methods in all subobjects with the
+  // given virtual method.
+  void replaceAll(UniqueVirtualMethod Overriding);
+};
+
+/// A mapping from each virtual member function to its set of
+/// final overriders.
+///
+/// Within a class hierarchy for a given derived class, each virtual
+/// member function in that hierarchy has one or more "final
+/// overriders" (C++ [class.virtual]p2). A final overrider for a
+/// virtual function "f" is the virtual function that will actually be
+/// invoked when dispatching a call to "f" through the
+/// vtable. Well-formed classes have a single final overrider for each
+/// virtual function; in abstract classes, the final overrider for at
+/// least one virtual function is a pure virtual function. Due to
+/// multiple, virtual inheritance, it is possible for a class to have
+/// more than one final overrider. Athough this is an error (per C++
+/// [class.virtual]p2), it is not considered an error here: the final
+/// overrider map can represent multiple final overriders for a
+/// method, and it is up to the client to determine whether they are
+/// problem. For example, the following class \c D has two final
+/// overriders for the virtual function \c A::f(), one in \c C and one
+/// in \c D:
+///
+/// \code
+///   struct A { virtual void f(); };
+///   struct B : virtual A { virtual void f(); };
+///   struct C : virtual A { virtual void f(); };
+///   struct D : B, C { };
+/// \endcode
+///
+/// This data structure contains a mapping from every virtual
+/// function *that does not override an existing virtual function* and
+/// in every subobject where that virtual function occurs to the set
+/// of virtual functions that override it. Thus, the same virtual
+/// function \c A::f can actually occur in multiple subobjects of type
+/// \c A due to multiple inheritance, and may be overridden by
+/// different virtual functions in each, as in the following example:
+///
+/// \code
+///   struct A { virtual void f(); };
+///   struct B : A { virtual void f(); };
+///   struct C : A { virtual void f(); };
+///   struct D : B, C { };
+/// \endcode
+///
+/// Unlike in the previous example, where the virtual functions \c
+/// B::f and \c C::f both overrode \c A::f in the same subobject of
+/// type \c A, in this example the two virtual functions both override
+/// \c A::f but in *different* subobjects of type A. This is
+/// represented by numbering the subobjects in which the overridden
+/// and the overriding virtual member functions are located. Subobject
+/// 0 represents the virtual base class subobject of that type, while
+/// subobject numbers greater than 0 refer to non-virtual base class
+/// subobjects of that type.
+class CXXFinalOverriderMap
+  : public llvm::MapVector<const CXXMethodDecl *, OverridingMethods> {};
+
+/// A set of all the primary bases for a class.
+class CXXIndirectPrimaryBaseSet
+  : public llvm::SmallSet<const CXXRecordDecl*, 32> {};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_AST_CXXINHERITANCE_H