LibreOffice Module bridges (master)  1
gcc3_macosx_x86-64/except.cxx
Go to the documentation of this file.
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /*
3  * This file is part of the LibreOffice project.
4  *
5  * This Source Code Form is subject to the terms of the Mozilla Public
6  * License, v. 2.0. If a copy of the MPL was not distributed with this
7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8  *
9  * This file incorporates work covered by the following license notice:
10  *
11  * Licensed to the Apache Software Foundation (ASF) under one or more
12  * contributor license agreements. See the NOTICE file distributed
13  * with this work for additional information regarding copyright
14  * ownership. The ASF licenses this file to you under the Apache
15  * License, Version 2.0 (the "License"); you may not use this file
16  * except in compliance with the License. You may obtain a copy of
17  * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18  */
19 
20 #include <sal/config.h>
21 
22 #include <cassert>
23 #include <new>
24 #include <stdio.h>
25 #include <string.h>
26 #include <typeinfo>
27 
28 #include <cxxabi.h>
29 #include <dlfcn.h>
30 
31 #include <com/sun/star/uno/RuntimeException.hpp>
32 #include <com/sun/star/uno/genfunc.hxx>
33 #include <sal/log.hxx>
34 #include <osl/mutex.hxx>
35 #include <rtl/strbuf.hxx>
36 #include <rtl/ustrbuf.hxx>
37 #include <typelib/typedescription.h>
38 #include <uno/any2.h>
39 #include <unordered_map>
40 #include "share.hxx"
41 
42 using namespace ::osl;
43 using namespace ::com::sun::star::uno;
44 
45 namespace CPPU_CURRENT_NAMESPACE {
46 
47 namespace {
48 
49 struct Fake_type_info {
50  virtual ~Fake_type_info() = delete;
51  char const * name;
52 };
53 
54 struct Fake_class_type_info: Fake_type_info {
55  virtual ~Fake_class_type_info() override = delete;
56 };
57 
58 struct Fake_si_class_type_info: Fake_class_type_info {
59  virtual ~Fake_si_class_type_info() override = delete;
60  void const * base;
61 };
62 
63 struct Base {};
64 struct Derived: Base {};
65 
66 std::type_info * createFake_class_type_info(char const * name) {
67  char * buf = new char[sizeof (Fake_class_type_info)];
68 
69  *reinterpret_cast<void **>(buf) = *reinterpret_cast<void * const *>(
70  &typeid(Base));
71  // copy __cxxabiv1::__class_type_info vtable into place
72  Fake_class_type_info * fake = reinterpret_cast<Fake_class_type_info *>(buf);
73  fake->name = name;
74  return reinterpret_cast<std::type_info *>(
75  static_cast<Fake_type_info *>(fake));
76 }
77 
78 std::type_info * createFake_si_class_type_info(
79  char const * name, std::type_info const * base)
80 {
81  char * buf = new char[sizeof (Fake_si_class_type_info)];
82 
83  *reinterpret_cast<void **>(buf) = *reinterpret_cast<void * const *>(
84  &typeid(Derived));
85  // copy __cxxabiv1::__si_class_type_info vtable into place
86  Fake_si_class_type_info * fake
87  = reinterpret_cast<Fake_si_class_type_info *>(buf);
88  fake->name = name;
89  fake->base = base;
90  return reinterpret_cast<std::type_info *>(
91  static_cast<Fake_type_info *>(fake));
92 }
93 
94 }
95 
96 #ifdef __GNUC__
97 #pragma GCC diagnostic push
98 #pragma GCC diagnostic ignored "-Wunused-function"
99 #endif
100 void dummy_can_throw_anything( char const * )
101 {
102 }
103 #ifdef __GNUC__
104 #pragma GCC diagnostic pop
105 #endif
106 
107 static OUString toUNOname( char const * p )
108 {
109 #if OSL_DEBUG_LEVEL > 1
110  char const * start = p;
111 #endif
112 
113  // example: N3com3sun4star4lang24IllegalArgumentExceptionE
114 
115  OUStringBuffer buf( 64 );
116  assert( 'N' == *p );
117  ++p; // skip N
118 
119  while ('E' != *p)
120  {
121  // read chars count
122  long n = *p++ - '0';
123  while ('0' <= *p && '9' >= *p)
124  {
125  n *= 10;
126  n += (*p++ - '0');
127  }
128  buf.appendAscii( p, n );
129  p += n;
130  if ('E' != *p)
131  buf.append( '.' );
132  }
133 
134 #if OSL_DEBUG_LEVEL > 1
135  OUString ret( buf.makeStringAndClear() );
136  OString c_ret( OUStringToOString( ret, RTL_TEXTENCODING_ASCII_US ) );
137  fprintf( stderr, "> toUNOname(): %s => %s\n", start, c_ret.getStr() );
138  return ret;
139 #else
140  return buf.makeStringAndClear();
141 #endif
142 }
143 
144 namespace {
145 
146 class RTTI
147 {
148  typedef std::unordered_map< OUString, std::type_info * > t_rtti_map;
149 
150  Mutex m_mutex;
151  t_rtti_map m_rttis;
152  t_rtti_map m_generatedRttis;
153 
154  void * m_hApp;
155 
156 public:
157  RTTI();
158  ~RTTI();
159 
160  std::type_info * getRTTI( typelib_CompoundTypeDescription * );
161 };
162 
163 }
164 
165 RTTI::RTTI()
166  : m_hApp( dlopen( nullptr, RTLD_LAZY ) )
167 {
168 }
169 
170 RTTI::~RTTI()
171 {
172  dlclose( m_hApp );
173 }
174 
175 
176 std::type_info * RTTI::getRTTI( typelib_CompoundTypeDescription *pTypeDescr )
177 {
178  std::type_info * rtti;
179 
180  OUString const & unoName = OUString::unacquired(&pTypeDescr->aBase.pTypeName);
181 
182  MutexGuard guard( m_mutex );
183  t_rtti_map::const_iterator iFind( m_rttis.find( unoName ) );
184  if (iFind == m_rttis.end())
185  {
186  // RTTI symbol
187  OStringBuffer buf( 64 );
188  buf.append( "_ZTIN" );
189  sal_Int32 index = 0;
190  do
191  {
192  OUString token( unoName.getToken( 0, '.', index ) );
193  buf.append( token.getLength() );
194  OString c_token( OUStringToOString( token, RTL_TEXTENCODING_ASCII_US ) );
195  buf.append( c_token );
196  }
197  while (index >= 0);
198  buf.append( 'E' );
199 
200  OString symName( buf.makeStringAndClear() );
201  rtti = static_cast<std::type_info *>(dlsym( m_hApp, symName.getStr() ));
202 
203  if (rtti)
204  {
205  std::pair< t_rtti_map::iterator, bool > insertion(
206  m_rttis.insert( t_rtti_map::value_type( unoName, rtti ) ) );
207  SAL_WARN_IF( !insertion.second,
208  "bridges",
209  "inserting new rtti failed" );
210  }
211  else
212  {
213  // try to lookup the symbol in the generated rtti map
214  t_rtti_map::const_iterator iFind2( m_generatedRttis.find( unoName ) );
215  if (iFind2 == m_generatedRttis.end())
216  {
217  // we must generate it !
218  // symbol and rtti-name is nearly identical,
219  // the symbol is prefixed with _ZTI
220  char * rttiName = strdup(symName.getStr() + 4);
221  if (rttiName == nullptr) {
222  throw std::bad_alloc();
223  }
224 #if OSL_DEBUG_LEVEL > 1
225  fprintf( stderr,"generated rtti for %s\n", rttiName );
226 #endif
227  if (pTypeDescr->pBaseTypeDescription)
228  {
229  // ensure availability of base
230  std::type_info * base_rtti = getRTTI(
231  pTypeDescr->pBaseTypeDescription );
232  rtti = createFake_si_class_type_info(rttiName, base_rtti);
233  }
234  else
235  {
236  rtti = createFake_class_type_info(rttiName);
237  }
238 
239  std::pair< t_rtti_map::iterator, bool > insertion(
240  m_generatedRttis.insert( t_rtti_map::value_type( unoName, rtti ) ) );
241  SAL_WARN_IF( !insertion.second,
242  "bridges",
243  "inserting new generated rtti failed" );
244  }
245  else // taking already generated rtti
246  {
247  rtti = iFind2->second;
248  }
249  }
250  }
251  else
252  {
253  rtti = iFind->second;
254  }
255 
256  return rtti;
257 }
258 
259 
260 static void deleteException( void * pExc )
261 {
262  __cxa_exception const * header = static_cast<__cxa_exception const *>(pExc) - 1;
263  // The libcxxabi commit
264  // <http://llvm.org/viewvc/llvm-project?view=revision&revision=303175>
265  // "[libcxxabi] Align unwindHeader on a double-word boundary" towards
266  // LLVM 5.0 changed the size of __cxa_exception by adding
267  //
268  // __attribute__((aligned))
269  //
270  // to the final member unwindHeader, on x86-64 effectively adding a hole of
271  // size 8 in front of that member (changing its offset from 88 to 96,
272  // sizeof(__cxa_exception) from 120 to 128, and alignof(__cxa_exception)
273  // from 8 to 16); a hack to dynamically determine whether we run against a
274  // LLVM 5 libcxxabi is to look at the exceptionDestructor member, which must
275  // point to this function (the use of __cxa_exception in fillUnoException is
276  // unaffected, as it only accesses members towards the start of the struct,
277  // through a pointer known to actually point at the start). The libcxxabi commit
278  // <https://github.com/llvm/llvm-project/commit/9ef1daa46edb80c47d0486148c0afc4e0d83ddcf>
279  // "Insert padding before the __cxa_exception header to ensure the thrown" in LLVM 6
280  // removes the need for this hack, so it can be removed again once we can be sure that we only
281  // run against libcxxabi from LLVM >= 6:
282  if (header->exceptionDestructor != &deleteException) {
283  header = reinterpret_cast<__cxa_exception const *>(
284  reinterpret_cast<char const *>(header) - 8);
286  }
287  typelib_TypeDescription * pTD = nullptr;
288  OUString unoName( toUNOname( header->exceptionType->name() ) );
289  ::typelib_typedescription_getByName( &pTD, unoName.pData );
290  assert(pTD && "### unknown exception type! leaving out destruction => leaking!!!");
291  if (pTD)
292  {
293  ::uno_destructData( pExc, pTD, cpp_release );
294  ::typelib_typedescription_release( pTD );
295  }
296 }
297 
298 void raiseException( uno_Any * pUnoExc, uno_Mapping * pUno2Cpp )
299 {
300 #if OSL_DEBUG_LEVEL > 1
301  OString cstr(
303  OUString::unacquired( &pUnoExc->pType->pTypeName ),
304  RTL_TEXTENCODING_ASCII_US ) );
305  fprintf( stderr, "> uno exception occurred: %s\n", cstr.getStr() );
306 #endif
307  void * pCppExc;
308  std::type_info * rtti;
309 
310  {
311  // construct cpp exception object
312  typelib_TypeDescription * pTypeDescr = nullptr;
313  TYPELIB_DANGER_GET( &pTypeDescr, pUnoExc->pType );
314  assert(pTypeDescr);
315  if (! pTypeDescr)
316  {
317  throw RuntimeException(
318  "cannot get typedescription for type " +
319  OUString::unacquired( &pUnoExc->pType->pTypeName ) );
320  }
321 
322  pCppExc = __cxxabiv1::__cxa_allocate_exception( pTypeDescr->nSize );
323  ::uno_copyAndConvertData( pCppExc, pUnoExc->pData, pTypeDescr, pUno2Cpp );
324 
325  // destruct uno exception
326  ::uno_any_destruct( pUnoExc, nullptr );
327  // avoiding locked counts
328  static RTTI rtti_data;
329  rtti = rtti_data.getRTTI(reinterpret_cast<typelib_CompoundTypeDescription*>(pTypeDescr));
330  TYPELIB_DANGER_RELEASE( pTypeDescr );
331  assert(rtti && "### no rtti for throwing exception!");
332  if (! rtti)
333  {
334  throw RuntimeException(
335  "no rtti for type " +
336  OUString::unacquired( &pUnoExc->pType->pTypeName ) );
337  }
338  }
339 
340  __cxxabiv1::__cxa_throw( pCppExc, rtti, deleteException );
341 }
342 
343 void fillUnoException(uno_Any * pUnoExc, uno_Mapping * pCpp2Uno)
344 {
345  __cxa_exception * header = __cxa_get_globals()->caughtExceptions;
346  if (! header)
347  {
348  RuntimeException aRE( "no exception header!" );
349  Type const & rType = cppu::UnoType<decltype(aRE)>::get();
350  uno_type_any_constructAndConvert( pUnoExc, &aRE, rType.getTypeLibType(), pCpp2Uno );
351  SAL_WARN("bridges", aRE.Message);
352  return;
353  }
354 
355  // Very bad HACK to find out whether we run against a libcxxabi that has a new
356  // __cxa_exception::reserved member at the start, introduced with LLVM 10
357  // <https://github.com/llvm/llvm-project/commit/674ec1eb16678b8addc02a4b0534ab383d22fa77>
358  // "[libcxxabi] Insert padding in __cxa_exception struct for compatibility". The layout of the
359  // start of __cxa_exception is
360  //
361  // [8 byte void *reserve]
362  // 8 byte size_t referenceCount
363  //
364  // where the (bad, hacky) assumption is that reserve (if present) is null
365  // (__cxa_allocate_exception in at least LLVM 11 zero-fills the object, and nothing actively
366  // sets reserve) while referenceCount is non-null (__cxa_throw sets it to 1, and
367  // __cxa_decrement_exception_refcount destroys the exception as soon as it drops to 0; for a
368  // __cxa_dependent_exception, the referenceCount member is rather
369  //
370  // 8 byte void* primaryException
371  //
372  // but which also will always be set to a non-null value in __cxa_rethrow_primary_exception).
373  // As described in the definition of __cxa_exception
374  // (bridges/source/cpp_uno/gcc3_macosx_x86-64/share.hxx), this hack (together with the "#if 0"
375  // there) can be dropped once we can be sure that we only run against new libcxxabi that has the
376  // reserve member:
377  if (*reinterpret_cast<void **>(header) == nullptr) {
378  header = reinterpret_cast<__cxa_exception *>(reinterpret_cast<void **>(header) + 1);
379  }
380 
381  std::type_info *exceptionType = __cxxabiv1::__cxa_current_exception_type();
382 
383  typelib_TypeDescription * pExcTypeDescr = nullptr;
384  OUString unoName( toUNOname( exceptionType->name() ) );
385 #if OSL_DEBUG_LEVEL > 1
386  OString cstr_unoName( OUStringToOString( unoName, RTL_TEXTENCODING_ASCII_US ) );
387  fprintf( stderr, "> c++ exception occurred: %s\n", cstr_unoName.getStr() );
388 #endif
389  typelib_typedescription_getByName( &pExcTypeDescr, unoName.pData );
390  if (nullptr == pExcTypeDescr)
391  {
392  RuntimeException aRE( "exception type not found: " + unoName );
393  Type const & rType = cppu::UnoType<decltype(aRE)>::get();
394  uno_type_any_constructAndConvert( pUnoExc, &aRE, rType.getTypeLibType(), pCpp2Uno );
395  SAL_WARN("bridges", aRE.Message);
396  }
397  else
398  {
399  // construct uno exception any
400  uno_any_constructAndConvert( pUnoExc, header->adjustedPtr, pExcTypeDescr, pCpp2Uno );
401  typelib_typedescription_release( pExcTypeDescr );
402  }
403 }
404 
405 }
406 
407 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
Type
static void deleteException(void *pExc)
void const * base
static OUString toUNOname(char const *p)
struct _uno_Mapping uno_Mapping
Definition: msvc/except.hxx:32
void fillUnoException(uno_Any *pExc, uno_Mapping *pCpp2Uno)
sal_Int64 n
t_rtti_map m_rttis
std::type_info * __cxa_current_exception_type()
void SAL_CALL uno_type_any_constructAndConvert(uno_Any *pDest, void *pSource, typelib_TypeDescriptionReference *pType, uno_Mapping *mapping) SAL_THROW_EXTERN_C()
void SAL_CALL uno_any_constructAndConvert(uno_Any *pDest, void *pSource, typelib_TypeDescription *pTypeDescr, uno_Mapping *mapping) SAL_THROW_EXTERN_C()
const BorderLinePrimitive2D *pCandidateB assert(pCandidateA)
const sal_Int8 header[]
OString OUStringToOString(std::u16string_view str, ConnectionSettings const *settings)
struct _uno_Any uno_Any
Definition: msvc/except.hxx:31
static OUString toUNOname(OUString const &rRTTIname)
t_rtti_map m_generatedRttis
Base
type_info * getRTTI(typelib_CompoundTypeDescription *)
char const * name
tuple index
struct _typelib_TypeDescription typelib_TypeDescription
Definition: msvc/except.hxx:52
void SAL_CALL typelib_typedescription_release(typelib_TypeDescription *pTD) SAL_THROW_EXTERN_C()
void SAL_CALL typelib_typedescription_getByName(typelib_TypeDescription **ppRet, rtl_uString *pName) SAL_THROW_EXTERN_C()
std::unordered_map< OUString, type_info * > t_rtti_map
void * __cxa_allocate_exception(size_t thrown_size)
#define SAL_WARN_IF(condition, area, stream)
void * p
CPPU_CURRENT_NAMESPACE::__cxa_eh_globals * __cxa_get_globals()
#define SAL_WARN(area, stream)
void dummy_can_throw_anything(char const *)
void __cxa_throw(void *thrown_exception, std::type_info *tinfo, void(*dest)(void *)) __attribute__((noreturn))