office-gobmx/bridges/source/cpp_uno/gcc3_macosx_x86-64/cpp2uno.cxx
Stephan Bergmann ef53355355 Rudimentary support for dynamic_cast on UNO proxy objects
<https://gerrit.libreoffice.org/c/core/+/144139> "New loplugin:unocast" had
argued that uses of dynamic_cast from a UNO interface type are broken in general
(because if the source object is a proxy from the C*+ UNO bridge, its vtable's
RTTI slot will normally not be set up, which can cause a crash), and should be
replaced with uses of XUnoTunnel.  Which the various recent "loplugin:unocast
(...)" commits started to do.  However, it became clear that that is not the
most ideal way forward:  For one, getting more and more implementations of
XUnoTunnel::getSomething into existing class hierarchies is error prone, as each
such implementation must manually delegate to all its base class
implementations.  For another, uses of comphelper::getFromUnoTunnel (which often
needs to do a queryInterface to XUnoTunnel first) are easily more expensive than
uses of dynamic_cast.

Thanks to Noel, the insight here is that for the use case of a dynamic_cast from
a UNO interface type to a local C++ class type, and if the source object is a
proxy, it is sufficient that the dynamic_cast will not crash.  It will
necessarily always return null (as the proxy will never be the implementation of
a local C++ class type), so it is sufficient to fill the RTTI slots of the
proxies' vtables with dummy values.  That avoids having to set up proper RTTI
for those potentially multiple-inheritance proxy types.  (And with this in
place, all those recent "loplugin:unocast (...)" commits can be reverted again
in a next step.)

I verified the changes for the gcc3_linux_aarch64 (on macOS), gcc3_linux_intel,
gcc3_linux_x86-64, gcc3_macosx_x86-64, msvc_win32_intel, and msvc_win32_x86-64
bridges.  The changes for all the other bridges were done blindly.

(For gcc3_linux_x86-64, which already conditionally supported proper RTTI for
UBSan, setting the offset-to-top slot to non-zero had to be made conditional
too, as the dummy ProxyRtti will always pretend to be a full class rather than a
potential base class that could have a non-zero offset-to-top value.  For
msvc_win32_*, it turned out that the existing code to set up dummy XInterface
RTTI (which was there for reasons lost to history) was broken.)

Change-Id: Iec4b8067d26b14b6fb02c2fdd15e1eee20919590
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/145038
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
2023-01-04 13:49:58 +00:00

543 lines
20 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include <stdio.h>
#include <stdlib.h>
#include <typeinfo>
#include <rtl/alloc.h>
#include <sal/log.hxx>
#include <com/sun/star/uno/genfunc.hxx>
#include <com/sun/star/uno/RuntimeException.hpp>
#include <uno/data.h>
#include <typelib/typedescription.hxx>
#include <bridge.hxx>
#include <cppinterfaceproxy.hxx>
#include <types.hxx>
#include <vtablefactory.hxx>
#include "abi.hxx"
#include "call.hxx"
#include "share.hxx"
using namespace ::osl;
using namespace ::com::sun::star::uno;
// Perform the UNO call
//
// We must convert the parameters stored in gpreg, fpreg and ovrflw to UNO
// arguments and call pThis->getUnoI()->pDispatcher.
//
// gpreg: [ret *], this, [gpr params]
// fpreg: [fpr params]
// ovrflw: [gpr or fpr params (properly aligned)]
//
// [ret *] is present when we are returning a structure bigger than 16 bytes
// Simple types are returned in rax, rdx (int), or xmm0, xmm1 (fp).
// Similarly structures <= 16 bytes are in rax, rdx, xmm0, xmm1 as necessary.
//
// The return value is the same as for cpp_vtable_call.
static int cpp2uno_call(
bridges::cpp_uno::shared::CppInterfaceProxy * pThis,
const typelib_TypeDescription * pMemberTypeDescr,
typelib_TypeDescriptionReference * pReturnTypeRef, // 0 indicates void return
sal_Int32 nParams, typelib_MethodParameter * pParams,
void ** gpreg, void ** fpreg, void ** ovrflw,
sal_uInt64 * pRegisterReturn /* space for register return */ )
{
unsigned int nr_gpr = 0; //number of gpr registers used
unsigned int nr_fpr = 0; //number of fpr registers used
// return
typelib_TypeDescription * pReturnTypeDescr = nullptr;
if (pReturnTypeRef)
TYPELIB_DANGER_GET( &pReturnTypeDescr, pReturnTypeRef );
x86_64::ReturnKind returnKind
= (pReturnTypeRef == nullptr || pReturnTypeRef->eTypeClass == typelib_TypeClass_VOID)
? x86_64::ReturnKind::RegistersGeneral : x86_64::getReturnKind(pReturnTypeRef);
void * pUnoReturn = nullptr;
void * pCppReturn = nullptr; // complex return ptr: if != 0 && != pUnoReturn, reconversion need
if ( pReturnTypeDescr )
{
if ( returnKind == x86_64::ReturnKind::Memory )
{
pCppReturn = *gpreg++;
nr_gpr++;
pUnoReturn = ( bridges::cpp_uno::shared::relatesToInterfaceType( pReturnTypeDescr )
? alloca( pReturnTypeDescr->nSize )
: pCppReturn ); // direct way
}
else
pUnoReturn = pRegisterReturn; // direct way for simple types
}
// pop this
gpreg++;
nr_gpr++;
// stack space
// parameters
void ** pUnoArgs = static_cast<void **>(alloca( 4 * sizeof(void *) * nParams ));
void ** pCppArgs = pUnoArgs + nParams;
// indices of values this have to be converted (interface conversion cpp<=>uno)
sal_Int32 * pTempIndices = reinterpret_cast<sal_Int32 *>(pUnoArgs + (2 * nParams));
// type descriptions for reconversions
typelib_TypeDescription ** ppTempParamTypeDescr = reinterpret_cast<typelib_TypeDescription **>(pUnoArgs + (3 * nParams));
sal_Int32 nTempIndices = 0;
for ( sal_Int32 nPos = 0; nPos < nParams; ++nPos )
{
const typelib_MethodParameter & rParam = pParams[nPos];
if ( !rParam.bOut && bridges::cpp_uno::shared::isSimpleType( rParam.pTypeRef ) ) // value
{
int nUsedGPR = 0;
int nUsedSSE = 0;
#ifndef NDEBUG
bool bFitsRegisters =
#endif
x86_64::examine_argument( rParam.pTypeRef, nUsedGPR, nUsedSSE );
// Simple types must fit exactly one register on x86_64
assert(bFitsRegisters && ( ( nUsedSSE == 1 && nUsedGPR == 0 ) || ( nUsedSSE == 0 && nUsedGPR == 1 ) ));
if ( nUsedSSE == 1 )
{
if ( nr_fpr < x86_64::MAX_SSE_REGS )
{
pCppArgs[nPos] = pUnoArgs[nPos] = fpreg++;
nr_fpr++;
}
else
pCppArgs[nPos] = pUnoArgs[nPos] = ovrflw++;
}
else if ( nUsedGPR == 1 )
{
if ( nr_gpr < x86_64::MAX_GPR_REGS )
{
pCppArgs[nPos] = pUnoArgs[nPos] = gpreg++;
nr_gpr++;
}
else
pCppArgs[nPos] = pUnoArgs[nPos] = ovrflw++;
}
}
else // ref
{
typelib_TypeDescription * pParamTypeDescr = nullptr;
TYPELIB_DANGER_GET( &pParamTypeDescr, rParam.pTypeRef );
void *pCppStack;
if ( nr_gpr < x86_64::MAX_GPR_REGS )
{
pCppArgs[nPos] = pCppStack = *gpreg++;
nr_gpr++;
}
else
pCppArgs[nPos] = pCppStack = *ovrflw++;
if (! rParam.bIn) // is pure out
{
// uno out is unconstructed mem!
pUnoArgs[nPos] = alloca( pParamTypeDescr->nSize );
pTempIndices[nTempIndices] = nPos;
// will be released at reconversion
ppTempParamTypeDescr[nTempIndices++] = pParamTypeDescr;
}
else if ( bridges::cpp_uno::shared::relatesToInterfaceType( pParamTypeDescr ) ) // is in/inout
{
uno_copyAndConvertData( pUnoArgs[nPos] = alloca( pParamTypeDescr->nSize ),
pCppStack, pParamTypeDescr,
pThis->getBridge()->getCpp2Uno() );
pTempIndices[nTempIndices] = nPos; // has to be reconverted
// will be released at reconversion
ppTempParamTypeDescr[nTempIndices++] = pParamTypeDescr;
}
else // direct way
{
pUnoArgs[nPos] = pCppStack;
// no longer needed
TYPELIB_DANGER_RELEASE( pParamTypeDescr );
}
}
}
// ExceptionHolder
uno_Any aUnoExc; // Any will be constructed by callee
uno_Any * pUnoExc = &aUnoExc;
// invoke uno dispatch call
(*pThis->getUnoI()->pDispatcher)( pThis->getUnoI(), pMemberTypeDescr, pUnoReturn, pUnoArgs, &pUnoExc );
// in case an exception occurred...
if ( pUnoExc )
{
// destruct temporary in/inout params
for ( ; nTempIndices--; )
{
sal_Int32 nIndex = pTempIndices[nTempIndices];
if (pParams[nIndex].bIn) // is in/inout => was constructed
uno_destructData( pUnoArgs[nIndex], ppTempParamTypeDescr[nTempIndices], nullptr );
TYPELIB_DANGER_RELEASE( ppTempParamTypeDescr[nTempIndices] );
}
if (pReturnTypeDescr)
TYPELIB_DANGER_RELEASE( pReturnTypeDescr );
CPPU_CURRENT_NAMESPACE::raiseException( &aUnoExc, pThis->getBridge()->getUno2Cpp() ); // has to destruct the any
// is here for dummy
return 0;
}
else // else no exception occurred...
{
// temporary params
for ( ; nTempIndices--; )
{
sal_Int32 nIndex = pTempIndices[nTempIndices];
typelib_TypeDescription * pParamTypeDescr = ppTempParamTypeDescr[nTempIndices];
if ( pParams[nIndex].bOut ) // inout/out
{
// convert and assign
uno_destructData( pCppArgs[nIndex], pParamTypeDescr, cpp_release );
uno_copyAndConvertData( pCppArgs[nIndex], pUnoArgs[nIndex], pParamTypeDescr,
pThis->getBridge()->getUno2Cpp() );
}
// destroy temp uno param
uno_destructData( pUnoArgs[nIndex], pParamTypeDescr, nullptr );
TYPELIB_DANGER_RELEASE( pParamTypeDescr );
}
// return
if ( pCppReturn ) // has complex return
{
if ( pUnoReturn != pCppReturn ) // needs reconversion
{
uno_copyAndConvertData( pCppReturn, pUnoReturn, pReturnTypeDescr,
pThis->getBridge()->getUno2Cpp() );
// destroy temp uno return
uno_destructData( pUnoReturn, pReturnTypeDescr, nullptr );
}
// complex return ptr is set to return reg
*reinterpret_cast<void **>(pRegisterReturn) = pCppReturn;
}
if ( pReturnTypeDescr )
{
TYPELIB_DANGER_RELEASE( pReturnTypeDescr );
}
switch (returnKind) {
case x86_64::ReturnKind::RegistersFpInt:
return 0;
case x86_64::ReturnKind::RegistersIntFp:
return 1;
default:
return -1;
}
}
}
// Returns -1 for the general case where potential return values from privateSnippetExecutor can be
// copied from pRegisterReturn to both %rax and %rdx (in that order) and to %xmm0 and %xmm1 (in that
// order)---each specific return type will only require a subset of that copy operations, but the
// other copies to those non--callee-saved registers will be redundant and harmless. Returns 0 for
// the special case where return values from privateSnippetExecutor must be copied from
// pRegisterReturn to %xmm0 and %rax (in that order). Returns 1 for the special case where return
// privateSnippetExecutor must be copied from pRegisterReturn to %rax and %xmm0 (in that order).
int cpp_vtable_call(
sal_Int32 nFunctionIndex, sal_Int32 nVtableOffset,
void ** gpreg, void ** fpreg, void ** ovrflw,
sal_uInt64 * pRegisterReturn /* space for register return */ )
{
// gpreg: [ret *], this, [other gpr params]
// fpreg: [fpr params]
// ovrflw: [gpr or fpr params (properly aligned)]
void * pThis;
if ( nFunctionIndex & 0x80000000 )
{
nFunctionIndex &= 0x7fffffff;
pThis = gpreg[1];
}
else
{
pThis = gpreg[0];
}
pThis = static_cast<char *>( pThis ) - nVtableOffset;
bridges::cpp_uno::shared::CppInterfaceProxy * pCppI =
bridges::cpp_uno::shared::CppInterfaceProxy::castInterfaceToProxy( pThis );
typelib_InterfaceTypeDescription * pTypeDescr = pCppI->getTypeDescr();
if ( nFunctionIndex >= pTypeDescr->nMapFunctionIndexToMemberIndex )
{
SAL_WARN(
"bridges",
"illegal " << OUString::unacquired(&pTypeDescr->aBase.pTypeName)
<< " vtable index " << nFunctionIndex << "/"
<< pTypeDescr->nMapFunctionIndexToMemberIndex);
throw RuntimeException(
("illegal " + OUString::unacquired(&pTypeDescr->aBase.pTypeName)
+ " vtable index " + OUString::number(nFunctionIndex) + "/"
+ OUString::number(pTypeDescr->nMapFunctionIndexToMemberIndex)),
reinterpret_cast<XInterface *>( pCppI ) );
}
// determine called method
sal_Int32 nMemberPos = pTypeDescr->pMapFunctionIndexToMemberIndex[nFunctionIndex];
assert(nMemberPos < pTypeDescr->nAllMembers);
TypeDescription aMemberDescr( pTypeDescr->ppAllMembers[nMemberPos] );
int eRet;
switch ( aMemberDescr.get()->eTypeClass )
{
case typelib_TypeClass_INTERFACE_ATTRIBUTE:
{
typelib_TypeDescriptionReference *pAttrTypeRef =
reinterpret_cast<typelib_InterfaceAttributeTypeDescription *>( aMemberDescr.get() )->pAttributeTypeRef;
if ( pTypeDescr->pMapMemberIndexToFunctionIndex[nMemberPos] == nFunctionIndex )
{
// is GET method
eRet = cpp2uno_call( pCppI, aMemberDescr.get(), pAttrTypeRef,
0, nullptr, // no params
gpreg, fpreg, ovrflw, pRegisterReturn );
}
else
{
// is SET method
typelib_MethodParameter aParam;
aParam.pTypeRef = pAttrTypeRef;
aParam.bIn = true;
aParam.bOut = false;
eRet = cpp2uno_call( pCppI, aMemberDescr.get(),
nullptr, // indicates void return
1, &aParam,
gpreg, fpreg, ovrflw, pRegisterReturn );
}
break;
}
case typelib_TypeClass_INTERFACE_METHOD:
{
// is METHOD
switch ( nFunctionIndex )
{
case 1: // acquire()
pCppI->acquireProxy(); // non virtual call!
eRet = 0;
break;
case 2: // release()
pCppI->releaseProxy(); // non virtual call!
eRet = 0;
break;
case 0: // queryInterface() opt
{
typelib_TypeDescription * pTD = nullptr;
TYPELIB_DANGER_GET( &pTD, static_cast<Type *>( gpreg[2] )->getTypeLibType() );
if ( pTD )
{
XInterface * pInterface = nullptr;
(*pCppI->getBridge()->getCppEnv()->getRegisteredInterface)
( pCppI->getBridge()->getCppEnv(),
reinterpret_cast<void **>(&pInterface),
pCppI->getOid().pData,
reinterpret_cast<typelib_InterfaceTypeDescription *>( pTD ) );
if ( pInterface )
{
::uno_any_construct( static_cast<uno_Any *>( gpreg[0] ),
&pInterface, pTD, cpp_acquire );
pInterface->release();
TYPELIB_DANGER_RELEASE( pTD );
reinterpret_cast<void **>( pRegisterReturn )[0] = gpreg[0];
eRet = 0;
break;
}
TYPELIB_DANGER_RELEASE( pTD );
}
[[fallthrough]]; // else perform queryInterface()
}
default:
{
typelib_InterfaceMethodTypeDescription *pMethodTD =
reinterpret_cast<typelib_InterfaceMethodTypeDescription *>( aMemberDescr.get() );
eRet = cpp2uno_call( pCppI, aMemberDescr.get(),
pMethodTD->pReturnTypeRef,
pMethodTD->nParams,
pMethodTD->pParams,
gpreg, fpreg, ovrflw, pRegisterReturn );
}
}
break;
}
default:
{
throw RuntimeException("no member description found!",
reinterpret_cast<XInterface *>( pCppI ) );
}
}
return eRet;
}
const int codeSnippetSize = 24;
// Generate a trampoline that redirects method calls to
// privateSnippetExecutor().
//
// privateSnippetExecutor() saves all the registers that are used for
// parameter passing on x86_64, and calls the cpp_vtable_call().
// When it returns, privateSnippetExecutor() sets the return value.
//
// Note: The code snippet we build here must not create a stack frame,
// otherwise the UNO exceptions stop working thanks to non-existing
// unwinding info.
static unsigned char * codeSnippet( unsigned char * code,
sal_Int32 nFunctionIndex, sal_Int32 nVtableOffset,
bool bHasHiddenParam )
{
sal_uInt64 nOffsetAndIndex = ( static_cast<sal_uInt64>(nVtableOffset) << 32 ) | static_cast<sal_uInt64>(nFunctionIndex);
if ( bHasHiddenParam )
nOffsetAndIndex |= 0x80000000;
// movq $<nOffsetAndIndex>, %r10
*reinterpret_cast<sal_uInt16 *>( code ) = 0xba49;
*reinterpret_cast<sal_uInt16 *>( code + 2 ) = nOffsetAndIndex & 0xFFFF;
*reinterpret_cast<sal_uInt32 *>( code + 4 ) = nOffsetAndIndex >> 16;
*reinterpret_cast<sal_uInt16 *>( code + 8 ) = nOffsetAndIndex >> 48;
// movq $<address of the privateSnippetExecutor>, %r11
*reinterpret_cast<sal_uInt16 *>( code + 10 ) = 0xbb49;
*reinterpret_cast<sal_uInt32 *>( code + 12 )
= reinterpret_cast<sal_uInt64>(privateSnippetExecutor);
*reinterpret_cast<sal_uInt32 *>( code + 16 )
= reinterpret_cast<sal_uInt64>(privateSnippetExecutor) >> 32;
// jmpq *%r11
*reinterpret_cast<sal_uInt32 *>( code + 20 ) = 0x00e3ff49;
#if OSL_DEBUG_LEVEL > 1
fprintf(stderr,
"==> codeSnippet, functionIndex=%d%s, vtableOffset=%d\n",
nFunctionIndex, (bHasHiddenParam ? "|0x80000000":""), nVtableOffset);
#endif
return code + codeSnippetSize;
}
struct bridges::cpp_uno::shared::VtableFactory::Slot { void const * fn; };
bridges::cpp_uno::shared::VtableFactory::Slot *
bridges::cpp_uno::shared::VtableFactory::mapBlockToVtable(void * block)
{
return static_cast< Slot * >(block) + 2;
}
std::size_t bridges::cpp_uno::shared::VtableFactory::getBlockSize(
sal_Int32 slotCount)
{
return (slotCount + 2) * sizeof (Slot) + slotCount * codeSnippetSize;
}
namespace {
// Some dummy type whose RTTI is used in the synthesized proxy vtables to make uses of dynamic_cast
// on such proxy objects not crash:
struct ProxyRtti {};
}
bridges::cpp_uno::shared::VtableFactory::Slot *
bridges::cpp_uno::shared::VtableFactory::initializeBlock(
void * block, sal_Int32 slotCount, sal_Int32,
typelib_InterfaceTypeDescription *)
{
Slot * slots = mapBlockToVtable(block);
slots[-2].fn = nullptr;
slots[-1].fn = &typeid(ProxyRtti);
return slots + slotCount;
}
unsigned char * bridges::cpp_uno::shared::VtableFactory::addLocalFunctions(
Slot ** slots, unsigned char * code,
typelib_InterfaceTypeDescription const * type, sal_Int32 nFunctionOffset,
sal_Int32 functionCount, sal_Int32 nVtableOffset )
{
const sal_PtrDiff writetoexecdiff = 0;
(*slots) -= functionCount;
Slot * s = *slots;
for ( sal_Int32 nPos = 0; nPos < type->nMembers; ++nPos )
{
typelib_TypeDescription * pTD = nullptr;
TYPELIB_DANGER_GET( &pTD, type->ppMembers[ nPos ] );
assert(pTD);
if ( typelib_TypeClass_INTERFACE_ATTRIBUTE == pTD->eTypeClass )
{
typelib_InterfaceAttributeTypeDescription *pAttrTD =
reinterpret_cast<typelib_InterfaceAttributeTypeDescription *>( pTD );
// get method
(s++)->fn = code + writetoexecdiff;
code = codeSnippet( code, nFunctionOffset++, nVtableOffset,
x86_64::return_in_hidden_param( pAttrTD->pAttributeTypeRef ) );
if ( ! pAttrTD->bReadOnly )
{
// set method
(s++)->fn = code + writetoexecdiff;
code = codeSnippet( code, nFunctionOffset++, nVtableOffset, false );
}
}
else if ( typelib_TypeClass_INTERFACE_METHOD == pTD->eTypeClass )
{
typelib_InterfaceMethodTypeDescription *pMethodTD =
reinterpret_cast<typelib_InterfaceMethodTypeDescription *>( pTD );
(s++)->fn = code + writetoexecdiff;
code = codeSnippet( code, nFunctionOffset++, nVtableOffset,
x86_64::return_in_hidden_param( pMethodTD->pReturnTypeRef ) );
}
else
assert(false);
TYPELIB_DANGER_RELEASE( pTD );
}
return code;
}
void bridges::cpp_uno::shared::VtableFactory::flushCode(
SAL_UNUSED_PARAMETER unsigned char const *,
SAL_UNUSED_PARAMETER unsigned char const * )
{}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */