Source code of Windows XP (NT5)
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/***
*rtti.cxx - C++ runtime type information
*
* Copyright (c) 1994-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Implementation of C++ standard runtime type information
*
*Revision History:
* 10-17-94 JWM File created.
* 10-17-94 BWT Disable code for PPC.
* 11-11-94 JWM Now includes windows.h
* 12-01-94 JWM Added optimized cases for single & multiple inheritance
* 02-03-95 JWM FindVITargetTypeInstance() now checks offsets to
* determine ambiguity, not pointer equality
* 02-09-95 JWM Mac merge.
* 03-22-95 PML Add const for read-only compiler-gen'd structs
* 05-03-95 JWM Test visibility in FindSITargetTypeInstance().
* 08-28-95 JWM dynamic-cast of NULL ptr now returns NULL (bug 502).
* 05-10-99 PML Win64 fix: int -> ptrdiff_t
* 05-17-99 PML Remove all Macintosh support.
* 10-19-99 TGL Win64 fix: ptrdiff_t -> __int32 in PMDtoOffset.
* 03-15-00 PML Remove CC_P7_SOFT25.
* 04-21-00 PML Add exception specifications to extern "C" helpers.
* 08-23-00 PML IA64 fix: _ImageBase can't be a static global, since
* that's not thread-safe (VS7#154575).
* 08-28-00 PML IA64 fix: _ImageBase needs to be set from the address
* of the _RTTICompleteObjectLocator, not the return
* address (VS7#156255)
* 09-07-00 PML Get rid of /lib:libcp directive in obj (vs7#159463)
*
****/
#define _USE_ANSI_CPP /* Don't emit /lib:libcp directive */
#include <windows.h>
#include <rtti.h>
#include <typeinfo.h>
#if defined(_M_IA64)
static unsigned __int64 GetImageBase(PVOID);
#undef BCD_PTD
#undef CHD_PBCA
#undef CHD_PBCD
#undef COL_PTD
#undef COL_PCHD
#define BCD_PTD(bcd) BCD_PTD_IB((bcd),_ImageBase)
#define CHD_PBCA(chd) CHD_PBCA_IB((chd),_ImageBase)
#define CHD_PBCD(chd) CHD_PBCD_IB((chd),_ImageBase)
#define COL_PTD(col) COL_PTD_IB((col),_ImageBase)
#define COL_PCHD(col) COL_PCHD_IB((col),_ImageBase)
extern "C" PVOID RtlPcToFileHeader(PVOID, PVOID*);
#endif
static PVOID __cdecl FindCompleteObject(PVOID *);
static _RTTIBaseClassDescriptor * __cdecl
FindSITargetTypeInstance(PVOID,
_RTTICompleteObjectLocator *,
_RTTITypeDescriptor *,
ptrdiff_t,
_RTTITypeDescriptor *
#if defined(_M_IA64)
, unsigned __int64
#endif
);
static _RTTIBaseClassDescriptor * __cdecl
FindMITargetTypeInstance(PVOID,
_RTTICompleteObjectLocator *,
_RTTITypeDescriptor *,
ptrdiff_t,
_RTTITypeDescriptor *
#if defined(_M_IA64)
, unsigned __int64
#endif
);
static _RTTIBaseClassDescriptor * __cdecl
FindVITargetTypeInstance(PVOID,
_RTTICompleteObjectLocator *,
_RTTITypeDescriptor *,
ptrdiff_t,
_RTTITypeDescriptor *
#if defined(_M_IA64)
, unsigned __int64
#endif
);
static ptrdiff_t __cdecl PMDtoOffset(PVOID, const PMD&);
/////////////////////////////////////////////////////////////////////////////
//
// __RTCastToVoid - Implements dynamic_cast<void*>
//
// Output: Pointer to complete object containing *inptr
//
// Side-effects: NONE.
//
extern "C" PVOID __cdecl __RTCastToVoid (
PVOID inptr) // Pointer to polymorphic object
throw(...)
{
if (inptr == NULL)
return NULL;
__try {
return FindCompleteObject((PVOID *)inptr);
}
__except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
? EXCEPTION_EXECUTE_HANDLER: EXCEPTION_CONTINUE_SEARCH)
{
throw __non_rtti_object ("Access violation - no RTTI data!");
return NULL;
}
}
/////////////////////////////////////////////////////////////////////////////
//
// __RTtypeid - Implements typeid() operator
//
// Output: Pointer to type descriptor of complete object containing *inptr
//
// Side-effects: NONE.
//
extern "C" PVOID __cdecl __RTtypeid (
PVOID inptr) // Pointer to polymorphic object
throw(...)
{
if (!inptr) {
throw bad_typeid ("Attempted a typeid of NULL pointer!"); // WP 5.2.7
return NULL;
}
__try {
// Ptr to CompleteObjectLocator should be stored at vfptr[-1]
_RTTICompleteObjectLocator *pCompleteLocator =
(_RTTICompleteObjectLocator *) ((*((void***)inptr))[-1]);
#if defined(_M_IA64)
unsigned __int64 _ImageBase = GetImageBase((PVOID)pCompleteLocator);
#endif
if (!IsBadReadPtr((const void *)COL_PTD(*pCompleteLocator),
sizeof(TypeDescriptor)))
{
return (PVOID) COL_PTD(*pCompleteLocator);
}
else {
throw __non_rtti_object ("Bad read pointer - no RTTI data!");
return NULL;
}
}
__except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
? EXCEPTION_EXECUTE_HANDLER: EXCEPTION_CONTINUE_SEARCH)
{
throw __non_rtti_object ("Access violation - no RTTI data!");
return NULL;
}
}
/////////////////////////////////////////////////////////////////////////////
//
// __RTDynamicCast - Runtime implementation of dynamic_cast<> operator
//
// Output: Pointer to the appropriate sub-object, if possible; NULL otherwise
//
// Side-effects: Throws bad_cast() if cast fails & input of dynamic_cast<> is
// a reference
//
extern "C" PVOID __cdecl __RTDynamicCast (
PVOID inptr, // Pointer to polymorphic object
LONG VfDelta, // Offset of vfptr in object
PVOID SrcType, // Static type of object pointed to by inptr
PVOID TargetType, // Desired result of cast
BOOL isReference) // TRUE if input is reference, FALSE if input is ptr
throw(...)
{
PVOID pResult;
_RTTIBaseClassDescriptor *pBaseClass;
if (inptr == NULL)
return NULL;
__try {
PVOID pCompleteObject = FindCompleteObject((PVOID *)inptr);
_RTTICompleteObjectLocator *pCompleteLocator =
(_RTTICompleteObjectLocator *) ((*((void***)inptr))[-1]);
#if defined(_M_IA64)
unsigned __int64 _ImageBase = GetImageBase((PVOID)pCompleteLocator);
#endif
// Adjust by vfptr displacement, if any
inptr = (PVOID *) ((char *)inptr - VfDelta);
// Calculate offset of source object in complete object
ptrdiff_t inptr_delta = (char *)inptr - (char *)pCompleteObject;
if (!(CHD_ATTRIBUTES(*COL_PCHD(*pCompleteLocator)) & CHD_MULTINH)) {
// if not multiple inheritance
pBaseClass = FindSITargetTypeInstance(
pCompleteObject,
pCompleteLocator,
(_RTTITypeDescriptor *) SrcType,
inptr_delta,
(_RTTITypeDescriptor *) TargetType
#if defined(_M_IA64)
, _ImageBase
#endif
);
}
else if (!(CHD_ATTRIBUTES(*COL_PCHD(*pCompleteLocator)) & CHD_VIRTINH)) {
// if multiple, but not virtual, inheritance
pBaseClass = FindMITargetTypeInstance(
pCompleteObject,
pCompleteLocator,
(_RTTITypeDescriptor *) SrcType,
inptr_delta,
(_RTTITypeDescriptor *) TargetType
#if defined(_M_IA64)
, _ImageBase
#endif
);
}
else {
// if virtual inheritance
pBaseClass = FindVITargetTypeInstance(
pCompleteObject,
pCompleteLocator,
(_RTTITypeDescriptor *) SrcType,
inptr_delta,
(_RTTITypeDescriptor *) TargetType
#if defined(_M_IA64)
, _ImageBase
#endif
);
}
if (pBaseClass != NULL) {
// Calculate ptr to result base class from pBaseClass->where
pResult = ((char *) pCompleteObject) +
PMDtoOffset(pCompleteObject, pBaseClass->where);
}
else {
pResult = NULL;
if (isReference)
throw bad_cast("Bad dynamic_cast!");
}
}
__except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
? EXCEPTION_EXECUTE_HANDLER: EXCEPTION_CONTINUE_SEARCH)
{
pResult = NULL;
throw __non_rtti_object ("Access violation - no RTTI data!");
}
return pResult;
}
/////////////////////////////////////////////////////////////////////////////
//
// FindCompleteObject - Calculate member offset from PMD & this
//
// Output: pointer to the complete object containing class *inptr
//
// Side-effects: NONE.
//
static PVOID __cdecl FindCompleteObject (
PVOID *inptr) // Pointer to polymorphic object
{
// Ptr to CompleteObjectLocator should be stored at vfptr[-1]
_RTTICompleteObjectLocator *pCompleteLocator =
(_RTTICompleteObjectLocator *) ((*((void***)inptr))[-1]);
char *pCompleteObject = (char *)inptr - pCompleteLocator->offset;
// Adjust by construction displacement, if any
if (pCompleteLocator->cdOffset)
pCompleteObject += *(ptrdiff_t *)((char *)inptr - pCompleteLocator->cdOffset);
return (PVOID) pCompleteObject;
}
/////////////////////////////////////////////////////////////////////////////
//
// FindSITargetTypeInstance - workhorse routine of __RTDynamicCast() in a
// Single-Inheritance hierarchy
//
// Output: pointer to the appropriate sub-object of targetted type; NULL if
// cast fails
//
// Side-effects: NONE.
//
static _RTTIBaseClassDescriptor * __cdecl FindSITargetTypeInstance (
PVOID pCompleteObject, // pointer to complete object
_RTTICompleteObjectLocator *pCOLocator, // pointer to Locator of complete object
_RTTITypeDescriptor *pSrcTypeID, // pointer to TypeDescriptor of source object
ptrdiff_t SrcOffset, // offset of source object in complete object
_RTTITypeDescriptor *pTargetTypeID // pointer to TypeDescriptor of result of cast
#if defined(_M_IA64)
, unsigned __int64 _ImageBase
#endif
)
{
_RTTIBaseClassDescriptor *pBase;
#if defined(_M_IA64)
_RTTIBaseClassArray *pBaseClassArray;
#else
_RTTIBaseClassDescriptor * const *pBasePtr;
#endif
DWORD i;
#if defined(_M_IA64)
for (i = 0, pBaseClassArray = CHD_PBCA(*COL_PCHD(*pCOLocator));
i < CHD_NUMBASES(*COL_PCHD(*pCOLocator));
i++)
{
pBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i]);
// Test type of selected base class
if (TYPEIDS_EQ(BCD_PTD(*pBase), pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE))
{
return pBase;
}
}
#else
for (i = 0, pBasePtr = pCOLocator->pClassDescriptor->
pBaseClassArray->
arrayOfBaseClassDescriptors;
i < pCOLocator->pClassDescriptor->numBaseClasses;
i++, pBasePtr++)
{
pBase = *pBasePtr;
// Test type of selected base class
if (TYPEIDS_EQ(pBase->pTypeDescriptor, pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE))
{
return pBase;
}
}
#endif
return NULL;
}
/////////////////////////////////////////////////////////////////////////////
//
// FindMITargetTypeInstance - workhorse routine of __RTDynamicCast() in a
// Multiple-Inheritance hierarchy
//
// Output: pointer to the appropriate sub-object of targetted type; NULL if
// cast fails
//
// Side-effects: NONE.
//
static _RTTIBaseClassDescriptor * __cdecl FindMITargetTypeInstance (
PVOID pCompleteObject, // pointer to complete object
_RTTICompleteObjectLocator *pCOLocator, // pointer to Locator of complete object
_RTTITypeDescriptor *pSrcTypeID, // pointer to TypeDescriptor of source object
ptrdiff_t SrcOffset, // offset of source object in complete object
_RTTITypeDescriptor *pTargetTypeID // pointer to TypeDescriptor of result of cast
#if defined(_M_IA64)
, unsigned __int64 _ImageBase
#endif
)
{
_RTTIBaseClassDescriptor *pBase, *pSubBase;
#if defined(_M_IA64)
_RTTIBaseClassArray *pBaseClassArray;
#else
_RTTIBaseClassDescriptor * const *pBasePtr, * const *pSubBasePtr;
#endif
DWORD i, j;
#if defined(_M_IA64)
// First, try down-casts
for (i = 0, pBaseClassArray = CHD_PBCA(*COL_PCHD(*pCOLocator));
i < CHD_NUMBASES(*COL_PCHD(*pCOLocator));
i++)
{
pBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i]);
// Test type of selected base class
if (TYPEIDS_EQ(BCD_PTD(*pBase), pTargetTypeID)) {
// If base class is proper type, see if it contains our instance
// of source class
for (j = 0;
j < pBase->numContainedBases;
j++)
{
pSubBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i+1+j]);
if (TYPEIDS_EQ(BCD_PTD(*pSubBase), pSrcTypeID) &&
(PMDtoOffset(pCompleteObject, pSubBase->where) == SrcOffset))
{
// Yes, this is the proper instance of source class
return pBase;
}
}
}
}
// Down-cast failed, try cross-cast
for (i = 0, pBaseClassArray = CHD_PBCA(*COL_PCHD(*pCOLocator));
i < CHD_NUMBASES(*COL_PCHD(*pCOLocator));
i++)
{
pBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i]);
// Check if base class has proper type, is accessible & is unambiguous
if (TYPEIDS_EQ(BCD_PTD(*pBase), pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_AMBIGUOUS))
{
return pBase;
}
}
#else
// First, try down-casts
for (i = 0, pBasePtr = pCOLocator->pClassDescriptor->
pBaseClassArray->
arrayOfBaseClassDescriptors;
i < pCOLocator->pClassDescriptor->numBaseClasses;
i++, pBasePtr++)
{
pBase = *pBasePtr;
// Test type of selected base class
if (TYPEIDS_EQ(pBase->pTypeDescriptor, pTargetTypeID)) {
// If base class is proper type, see if it contains our instance
// of source class
for (j = 0, pSubBasePtr = pBasePtr+1;
j < pBase->numContainedBases;
j++, pSubBasePtr++)
{
pSubBase = *pSubBasePtr;
if (TYPEIDS_EQ(pSubBase->pTypeDescriptor, pSrcTypeID) &&
(PMDtoOffset(pCompleteObject, pSubBase->where) == SrcOffset))
{
// Yes, this is the proper instance of source class
return pBase;
}
}
}
}
// Down-cast failed, try cross-cast
for (i = 0, pBasePtr = pCOLocator->pClassDescriptor->
pBaseClassArray->
arrayOfBaseClassDescriptors;
i < pCOLocator->pClassDescriptor->numBaseClasses;
i++, pBasePtr++)
{
pBase = *pBasePtr;
// Check if base class has proper type, is accessible & is unambiguous
if (TYPEIDS_EQ(pBase->pTypeDescriptor, pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_AMBIGUOUS))
{
return pBase;
}
}
#endif
return NULL;
}
/////////////////////////////////////////////////////////////////////////////
//
// FindVITargetTypeInstance - workhorse routine of __RTDynamicCast() in a
// Virtual-Inheritance hierarchy
//
// Output: pointer to the appropriate sub-object of targetted type; NULL if
// cast fails
//
// Side-effects: NONE.
//
static _RTTIBaseClassDescriptor * __cdecl FindVITargetTypeInstance (
PVOID pCompleteObject, // pointer to complete object
_RTTICompleteObjectLocator *pCOLocator, // pointer to Locator of complete object
_RTTITypeDescriptor *pSrcTypeID, // pointer to TypeDescriptor of source object
ptrdiff_t SrcOffset, // offset of source object in complete object
_RTTITypeDescriptor *pTargetTypeID // pointer to TypeDescriptor of result of cast
#if defined(_M_IA64)
, unsigned __int64 _ImageBase
#endif
)
{
_RTTIBaseClassDescriptor *pBase, *pSubBase;
#if defined(_M_IA64)
_RTTIBaseClassArray *pBaseClassArray;
#else
_RTTIBaseClassDescriptor * const *pBasePtr, * const *pSubBasePtr;
#endif
_RTTIBaseClassDescriptor *pResult = NULL;
DWORD i, j;
#if defined(_M_IA64)
for (i = 0, pBaseClassArray = CHD_PBCA(*COL_PCHD(*pCOLocator));
i < CHD_NUMBASES(*COL_PCHD(*pCOLocator));
i++)
{
pBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i]);
// Test type of selected base class
if (TYPEIDS_EQ(BCD_PTD(*pBase), pTargetTypeID)) {
// If base class is proper type, see if it contains our instance
// of source class
for (j = 0;
j < pBase->numContainedBases;
j++)
{
pSubBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i+1+j]);
if (TYPEIDS_EQ(BCD_PTD(*pSubBase), pSrcTypeID) &&
(PMDtoOffset(pCompleteObject, pSubBase->where) == SrcOffset))
{
// Yes, this is the proper instance of source class - make
// sure it is unambiguous. Ambiguity now determined by
// inequality of offsets of source class within complete
// object, not pointer inequality
if ((pResult != NULL) &&
(PMDtoOffset(pCompleteObject, pResult->where) !=
PMDtoOffset(pCompleteObject, pBase->where)))
{
// We already found an earlier instance, hence
// ambiguity
return NULL;
}
else {
// Unambiguous
pResult = pBase;
}
}
}
}
}
if (pResult != NULL)
return pResult;
// Down-cast failed, try cross-cast
for (i = 0, pBaseClassArray = CHD_PBCA(*COL_PCHD(*pCOLocator));
i < CHD_NUMBASES(*COL_PCHD(*pCOLocator));
i++)
{
pBase = CHD_PBCD(pBaseClassArray->arrayOfBaseClassDescriptors[i]);
// Check if base class has proper type, is accessible & is unambiguous
if (TYPEIDS_EQ(BCD_PTD(*pBase), pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_AMBIGUOUS))
{
return pBase;
}
}
#else
// First, try down-casts
for (i = 0, pBasePtr = pCOLocator->pClassDescriptor->
pBaseClassArray->
arrayOfBaseClassDescriptors;
i < pCOLocator->pClassDescriptor->numBaseClasses;
i++, pBasePtr++)
{
pBase = *pBasePtr;
// Test type of selected base class
if (TYPEIDS_EQ(pBase->pTypeDescriptor, pTargetTypeID)) {
// If base class is proper type, see if it contains our instance
// of source class
for (j = 0, pSubBasePtr = pBasePtr+1;
j < pBase->numContainedBases;
j++, pSubBasePtr++)
{
pSubBase = *pSubBasePtr;
if (TYPEIDS_EQ(pSubBase->pTypeDescriptor, pSrcTypeID) &&
(PMDtoOffset(pCompleteObject, pSubBase->where) == SrcOffset))
{
// Yes, this is the proper instance of source class - make
// sure it is unambiguous. Ambiguity now determined by
// inequality of offsets of source class within complete
// object, not pointer inequality
if ((pResult != NULL) &&
(PMDtoOffset(pCompleteObject, pResult->where) !=
PMDtoOffset(pCompleteObject, pBase->where)))
{
// We already found an earlier instance, hence
// ambiguity
return NULL;
}
else {
// Unambiguous
pResult = pBase;
}
}
}
}
}
if (pResult != NULL)
return pResult;
// Down-cast failed, try cross-cast
for (i = 0, pBasePtr = pCOLocator->pClassDescriptor->
pBaseClassArray->
arrayOfBaseClassDescriptors;
i < pCOLocator->pClassDescriptor->numBaseClasses;
i++, pBasePtr++)
{
pBase = *pBasePtr;
// Check if base class has proper type, is accessible & is unambiguous
if (TYPEIDS_EQ(pBase->pTypeDescriptor, pTargetTypeID) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_NOTVISIBLE) &&
!(BCD_ATTRIBUTES(*pBase) & BCD_AMBIGUOUS))
{
return pBase;
}
}
#endif
return NULL;
}
/////////////////////////////////////////////////////////////////////////////
//
// PMDtoOffset - Calculate member offset from PMD & this
//
// Output: The offset of the base within the complete object.
//
// Side-effects: NONE.
//
static ptrdiff_t __cdecl PMDtoOffset(
PVOID pThis, // ptr to complete object
const PMD& pmd) // pointer-to-member-data structure
{
ptrdiff_t RetOff = 0;
if (pmd.pdisp >= 0) {
// if base is in the virtual part of class
RetOff = pmd.pdisp;
RetOff += *(__int32*)((char*)*(ptrdiff_t*)((char*)pThis + RetOff) +
pmd.vdisp);
}
RetOff += pmd.mdisp;
return RetOff;
}
#if defined(_M_IA64)
static unsigned __int64 GetImageBase(PVOID pCallerPC)
{
unsigned __int64 _ImageBase;
_ImageBase = (unsigned __int64)RtlPcToFileHeader(
pCallerPC,
(PVOID*)&_ImageBase);
return _ImageBase;
}
#endif