freebsd-dev/contrib/libcxxrt/typeinfo.h

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/*
* Copyright 2010-2011 PathScale, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stddef.h>
#include "abi_namespace.h"
namespace ABI_NAMESPACE
{
struct __class_type_info;
}
namespace std
{
/**
* Standard type info class. The layout of this class is specified by the
* ABI. The layout of the vtable is not, but is intended to be
* compatible with the GNU ABI.
*
* Unlike the GNU version, the vtable layout is considered semi-private.
*/
class type_info
{
public:
/**
* Virtual destructor. This class must have one virtual function to
* ensure that it has a vtable.
*/
virtual ~type_info();
bool operator==(const type_info &) const;
bool operator!=(const type_info &) const;
bool before(const type_info &) const;
const char* name() const;
type_info();
private:
type_info(const type_info& rhs);
type_info& operator= (const type_info& rhs);
const char *__type_name;
/*
* The following functions are in this order to match the
* vtable layout of libsupc++. This allows libcxxrt to be used
* with libraries that depend on this.
*
* These functions are in the public headers for libstdc++, so
* we have to assume that someone will probably call them and
* expect them to work. Their names must also match the names used in
* libsupc++, so that code linking against this library can subclass
* type_info and correctly fill in the values in the vtables.
*/
public:
/**
* Returns true if this is some pointer type, false otherwise.
*/
virtual bool __is_pointer_p() const { return false; }
/**
* Returns true if this is some function type, false otherwise.
*/
virtual bool __is_function_p() const { return false; }
/**
* Catch function. Allows external libraries to implement
* their own basic types. This is used, for example, in the
* GNUstep Objective-C runtime to allow Objective-C types to be
* caught in G++ catch blocks.
*
* The outer parameter indicates the number of outer pointers
* in the high bits. The low bit indicates whether the
* pointers are const qualified.
*/
virtual bool __do_catch(const type_info *thrown_type,
void **thrown_object,
unsigned outer) const;
/**
* Performs an upcast. This is used in exception handling to
* cast from subclasses to superclasses. If the upcast is
* possible, it returns true and adjusts the pointer. If the
* upcast is not possible, it returns false and does not adjust
* the pointer.
*/
virtual bool __do_upcast(
const ABI_NAMESPACE::__class_type_info *target,
void **thrown_object) const
{
return false;
}
};
}
namespace ABI_NAMESPACE
{
/**
* Primitive type info, for intrinsic types.
*/
struct __fundamental_type_info : public std::type_info
{
virtual ~__fundamental_type_info();
};
/**
* Type info for arrays.
*/
struct __array_type_info : public std::type_info
{
virtual ~__array_type_info();
};
/**
* Type info for functions.
*/
struct __function_type_info : public std::type_info
{
virtual ~__function_type_info();
virtual bool __is_function_p() const { return true; }
};
/**
* Type info for enums.
*/
struct __enum_type_info : public std::type_info
{
virtual ~__enum_type_info();
};
/**
* Base class for class type info. Used only for tentative definitions.
*/
struct __class_type_info : public std::type_info
{
virtual ~__class_type_info();
/**
* Function implementing dynamic casts.
*/
virtual void *cast_to(void *obj, const struct __class_type_info *other) const;
virtual bool __do_upcast(const __class_type_info *target,
void **thrown_object) const
{
return this == target;
}
};
/**
* Single-inheritance class type info. This is used for classes containing
* a single non-virtual base class at offset 0.
*/
struct __si_class_type_info : public __class_type_info
{
virtual ~__si_class_type_info();
const __class_type_info *__base_type;
virtual bool __do_upcast(
const ABI_NAMESPACE::__class_type_info *target,
void **thrown_object) const;
virtual void *cast_to(void *obj, const struct __class_type_info *other) const;
};
/**
* Type info for base classes. Classes with multiple bases store an array
* of these, one for each superclass.
*/
struct __base_class_type_info
{
const __class_type_info *__base_type;
private:
/**
* The high __offset_shift bits of this store the (signed) offset
* of the base class. The low bits store flags from
* __offset_flags_masks.
*/
long __offset_flags;
/**
* Flags used in the low bits of __offset_flags.
*/
enum __offset_flags_masks
{
/** This base class is virtual. */
__virtual_mask = 0x1,
/** This base class is public. */
__public_mask = 0x2,
/** The number of bits reserved for flags. */
__offset_shift = 8
};
public:
/**
* Returns the offset of the base class.
*/
long offset() const
{
return __offset_flags >> __offset_shift;
}
/**
* Returns the flags.
*/
long flags() const
{
return __offset_flags & ((1 << __offset_shift) - 1);
}
/**
* Returns whether this is a public base class.
*/
bool isPublic() const { return flags() & __public_mask; }
/**
* Returns whether this is a virtual base class.
*/
bool isVirtual() const { return flags() & __virtual_mask; }
};
/**
* Type info for classes with virtual bases or multiple superclasses.
*/
struct __vmi_class_type_info : public __class_type_info
{
virtual ~__vmi_class_type_info();
/** Flags describing this class. Contains values from __flags_masks. */
unsigned int __flags;
/** The number of base classes. */
unsigned int __base_count;
/**
* Array of base classes - this actually has __base_count elements, not
* 1.
*/
__base_class_type_info __base_info[1];
/**
* Flags used in the __flags field.
*/
enum __flags_masks
{
/** The class has non-diamond repeated inheritance. */
__non_diamond_repeat_mask = 0x1,
/** The class is diamond shaped. */
__diamond_shaped_mask = 0x2
};
virtual bool __do_upcast(
const ABI_NAMESPACE::__class_type_info *target,
void **thrown_object) const;
virtual void *cast_to(void *obj, const struct __class_type_info *other) const;
};
/**
* Base class used for both pointer and pointer-to-member type info.
*/
struct __pbase_type_info : public std::type_info
{
virtual ~__pbase_type_info();
/**
* Flags. Values from __masks.
*/
unsigned int __flags;
/**
* The type info for the pointee.
*/
const std::type_info *__pointee;
/**
* Masks used for qualifiers on the pointer.
*/
enum __masks
{
/** Pointer has const qualifier. */
__const_mask = 0x1,
/** Pointer has volatile qualifier. */
__volatile_mask = 0x2,
/** Pointer has restrict qualifier. */
__restrict_mask = 0x4,
/** Pointer points to an incomplete type. */
__incomplete_mask = 0x8,
/** Pointer is a pointer to a member of an incomplete class. */
__incomplete_class_mask = 0x10
};
virtual bool __do_catch(const type_info *thrown_type,
void **thrown_object,
unsigned outer) const;
};
/**
* Pointer type info.
*/
struct __pointer_type_info : public __pbase_type_info
{
virtual ~__pointer_type_info();
virtual bool __is_pointer_p() const { return true; }
};
/**
* Pointer to member type info.
*/
struct __pointer_to_member_type_info : public __pbase_type_info
{
virtual ~__pointer_to_member_type_info();
/**
* Pointer to the class containing this member.
*/
const __class_type_info *__context;
};
}