private-typeinfo.h

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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
 
#ifndef __PRIVATE_TYPEINFO_H_
#define __PRIVATE_TYPEINFO_H_
 
#include "cxxabi-config.h"
 
#include <stddef.h>
#include <typeinfo>
 
namespace __cxxabiv1 {
 
class _LIBCXXABI_TYPE_VIS __shim_type_info : public std::type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__shim_type_info();
 
  _LIBCXXABI_HIDDEN virtual void noop1() const;
  _LIBCXXABI_HIDDEN virtual void noop2() const;
};
 
class _LIBCXXABI_TYPE_VIS __fundamental_type_info : public __shim_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__fundamental_type_info();
};
 
class _LIBCXXABI_TYPE_VIS __array_type_info : public __shim_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__array_type_info();
};
 
class _LIBCXXABI_TYPE_VIS __function_type_info : public __shim_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__function_type_info();
};
 
class _LIBCXXABI_TYPE_VIS __enum_type_info : public __shim_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__enum_type_info();
};
 
enum path_accessibility : unsigned char {
  unknown_path = 0,
  public_path,
  not_public_path,
};
 
enum tribool : unsigned char {
  unknown = 0,
  // public_path,
  // not_public_path,
  yes,
  no
};
 
class _LIBCXXABI_TYPE_VIS __class_type_info;
 
struct _LIBCXXABI_HIDDEN __dynamic_cast_info {
  // const data supplied to the search:
 
  const __class_type_info *dst_type;
  const void *static_ptr;
  const __class_type_info *static_type;
  ptrdiff_t src2dst_offset;
 
  // Data that represents the answer:
 
  // pointer to a dst_type which has (static_ptr, static_type) above it
  const void *dst_ptr_leading_to_static_ptr;
  // pointer to a dst_type which does not have (static_ptr, static_type) above
  // it
  const void *dst_ptr_not_leading_to_static_ptr;
 
  // The following three paths are either unknown, public_path or
  // not_public_path. access of path from dst_ptr_leading_to_static_ptr to
  // (static_ptr, static_type)
  path_accessibility path_dst_ptr_to_static_ptr;
  // access of path from (dynamic_ptr, dynamic_type) to (static_ptr,
  // static_type)
  //    when there is no dst_type along the path
  path_accessibility path_dynamic_ptr_to_static_ptr;
  // access of path from (dynamic_ptr, dynamic_type) to dst_type
  //    (not used if there is a (static_ptr, static_type) above a dst_type).
  path_accessibility path_dynamic_ptr_to_dst_ptr;
 
  // Number of dst_types below (static_ptr, static_type)
  unsigned char number_to_static_ptr;
  // Number of dst_types not below (static_ptr, static_type)
  unsigned char number_to_dst_ptr;
 
  // Data that helps stop the search before the entire tree is searched:
 
  // is_dst_type_derived_from_static_type is either unknown, yes or no.
  tribool is_dst_type_derived_from_static_type;
  // Number of dst_type in tree.  If 0, then that means unknown.
  unsigned char number_of_dst_type;
  // communicates to a dst_type node that (static_ptr, static_type) was found
  //    above it.
  bool found_our_static_ptr;
  // communicates to a dst_type node that a static_type was found
  //    above it, but it wasn't (static_ptr, static_type)
  bool found_any_static_type;
  // Set whenever a search can be stopped
  bool search_done;
};
 
// Has no base class
class _LIBCXXABI_TYPE_VIS __class_type_info : public __shim_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__class_type_info();
 
  _LIBCXXABI_HIDDEN void
  process_static_type_above_dst(__dynamic_cast_info *, const void *,
                                const void *, path_accessibility) const;
  _LIBCXXABI_HIDDEN void
  process_static_type_below_dst(__dynamic_cast_info *, const void *,
                                path_accessibility) const;
  _LIBCXXABI_HIDDEN void process_found_base_class(__dynamic_cast_info *, void *,
                                                  path_accessibility) const;
  _LIBCXXABI_HIDDEN void devirt_search_above_dst(__dynamic_cast_info *,
                                                 const void *, const void *,
                                                 path_accessibility,
                                                 bool) const;
  _LIBCXXABI_HIDDEN void devirt_search_below_dst(__dynamic_cast_info *,
                                                 const void *,
                                                 path_accessibility,
                                                 bool) const;
  template <class type_info_most_derived>
  _LIBCXXABI_HIDDEN static void
  invoke_search_above_dst(const __class_type_info *, __dynamic_cast_info *,
                          const void *, const void *, path_accessibility, bool);
  template <class type_info_most_derived>
  _LIBCXXABI_HIDDEN static void
  invoke_search_below_dst(const __class_type_info *, __dynamic_cast_info *,
                          const void *, path_accessibility, bool);
 
private:
  _LIBCXXABI_HIDDEN
  void search_above_dst(__dynamic_cast_info *, const void *, const void *,
                        path_accessibility, bool) const;
 
  _LIBCXXABI_HIDDEN void search_below_dst(__dynamic_cast_info *, const void *,
                                          path_accessibility, bool) const;
};
 
// Has one non-virtual public base class at offset zero
class _LIBCXXABI_TYPE_VIS __si_class_type_info : public __class_type_info {
public:
  const __class_type_info *__base_type;
 
  _LIBCXXABI_HIDDEN virtual ~__si_class_type_info();
 
  _LIBCXXABI_HIDDEN void search_above_dst(__dynamic_cast_info *, const void *,
                                          const void *, path_accessibility,
                                          bool) const;
  _LIBCXXABI_HIDDEN void search_below_dst(__dynamic_cast_info *, const void *,
                                          path_accessibility, bool) const;
};
 
struct _LIBCXXABI_HIDDEN __base_class_type_info {
public:
  const __class_type_info *__base_type;
  long __offset_flags;
 
  enum __offset_flags_masks {
    __virtual_mask = 0x1,
    __public_mask = 0x2, // base is public
    __offset_shift = 8
  };
 
  void search_above_dst(__dynamic_cast_info *, const void *, const void *,
                        path_accessibility, bool) const;
  void search_below_dst(__dynamic_cast_info *, const void *, path_accessibility,
                        bool) const;
};
 
// Has one or more base classes
class _LIBCXXABI_TYPE_VIS __vmi_class_type_info : public __class_type_info {
public:
  unsigned int __flags;
  unsigned int __base_count;
  __base_class_type_info __base_info[1];
 
  enum __flags_masks {
    __non_diamond_repeat_mask = 0x1, // has two or more distinct base class
                                     //    objects of the same type
    __diamond_shaped_mask = 0x2      // has base class object with two or
                                     //    more derived objects
  };
 
  _LIBCXXABI_HIDDEN virtual ~__vmi_class_type_info();
 
  _LIBCXXABI_HIDDEN void search_above_dst(__dynamic_cast_info *, const void *,
                                          const void *, path_accessibility,
                                          bool) const;
  _LIBCXXABI_HIDDEN void search_below_dst(__dynamic_cast_info *, const void *,
                                          path_accessibility, bool) const;
};
 
class _LIBCXXABI_TYPE_VIS __pbase_type_info : public __shim_type_info {
public:
  unsigned int __flags;
  const __shim_type_info *__pointee;
 
  enum __masks {
    __const_mask = 0x1,
    __volatile_mask = 0x2,
    __restrict_mask = 0x4,
    __incomplete_mask = 0x8,
    __incomplete_class_mask = 0x10,
    __transaction_safe_mask = 0x20,
    // This implements the following proposal from cxx-abi-dev (not yet part of
    // the ABI document):
    //
    //   http://sourcerytools.com/pipermail/cxx-abi-dev/2016-October/002986.html
    //
    // This is necessary for support of http://wg21.link/p0012, which permits
    // throwing noexcept function and member function pointers and catching
    // them as non-noexcept pointers.
    __noexcept_mask = 0x40,
 
    // Flags that cannot be removed by a standard conversion.
    __no_remove_flags_mask = __const_mask | __volatile_mask | __restrict_mask,
    // Flags that cannot be added by a standard conversion.
    __no_add_flags_mask = __transaction_safe_mask | __noexcept_mask
  };
 
  _LIBCXXABI_HIDDEN virtual ~__pbase_type_info();
};
 
class _LIBCXXABI_TYPE_VIS __pointer_type_info : public __pbase_type_info {
public:
  _LIBCXXABI_HIDDEN virtual ~__pointer_type_info();
};
 
class _LIBCXXABI_TYPE_VIS __pointer_to_member_type_info
    : public __pbase_type_info {
public:
  const __class_type_info *__context;
 
  _LIBCXXABI_HIDDEN virtual ~__pointer_to_member_type_info();
};
 
} // namespace __cxxabiv1
 
#endif // __PRIVATE_TYPEINFO_H_