1 // Copyright (C) 2011 The Android Open Source Project
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions
6 // are met:
7 // 1. Redistributions of source code must retain the above copyright
8 //    notice, this list of conditions and the following disclaimer.
9 // 2. Redistributions in binary form must reproduce the above copyright
10 //    notice, this list of conditions and the following disclaimer in the
11 //    documentation and/or other materials provided with the distribution.
12 // 3. Neither the name of the project nor the names of its contributors
13 //    may be used to endorse or promote products derived from this software
14 //    without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 // ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 // SUCH DAMAGE.
27 //
28 // pbase_type_info.cc: Methods for __pbase_type_info.
29 
30 #include "cxxabi_defines.h"
31 #include "typeinfo"
32 
33 #if __cplusplus < 201103L
34 extern "C" std::type_info _ZTIDn;
35 #endif
36 
37 namespace __cxxabiv1
38 {
~__pbase_type_info()39   __pbase_type_info::~__pbase_type_info()
40   {
41   }
42 
can_catch(const __shim_type_info * thr_type,void * & adjustedPtr) const43   bool __pbase_type_info::can_catch(const __shim_type_info* thr_type,
44                                     void*& adjustedPtr) const {
45     if (can_catch_typeinfo_wrapper(thr_type, adjustedPtr, first_time_init)) {
46       return true;
47     }
48 
49 #if __cplusplus >= 201103L
50     // In C++ 11, the type of nullptr is std::nullptr_t, but nullptr can be
51     // casted to every pointer types.  Thus, we can return true whenever
52     // the exception object is an instance of std::nullptr_t.
53     return (*thr_type == typeid(decltype(nullptr)));
54 #else
55     return (*thr_type == _ZTIDn);
56 #endif
57   }
58 
can_catch_typeinfo_wrapper(const __shim_type_info * thr_type,void * & adjustedPtr,unsigned tracker) const59   bool __pbase_type_info::can_catch_typeinfo_wrapper(const __shim_type_info* thr_type,
60                                                      void*& adjustedPtr,
61                                                      unsigned tracker) const {
62     if (*this == *thr_type) {
63       return true;
64     }
65 
66     if (typeid(*this) != typeid(*thr_type)) {
67       return false;
68     }
69     const __pbase_type_info *thrown_type =
70         static_cast<const __pbase_type_info *>(thr_type);
71 
72     // Both side must be the same cv-qualified
73     if (~__flags & thrown_type->__flags) {
74       return false;
75     }
76 
77     // Handle the annoying constness problem
78     // Ref: http://www.parashift.com/c++-faq-lite/constptrptr-conversion.html
79     if (tracker == first_time_init &&
80         (tracker & keep_constness) != keep_constness &&
81         (tracker & after_gap) != after_gap) {
82       tracker |= keep_constness;
83     } else {
84       tracker &= ~first_time_init;
85     }
86 
87     if ((tracker & first_time_init) != first_time_init &&
88         (tracker & after_gap) == after_gap) {
89       return false;
90     }
91 
92     if (!(__flags & __const_mask)) {
93       tracker |= after_gap;
94     }
95 
96     return can_catch_ptr(thrown_type, adjustedPtr, tracker);
97   }
98 
can_catch_ptr(const __pbase_type_info * thrown_type,void * & adjustedPtr,unsigned tracker) const99   bool __pbase_type_info::can_catch_ptr(const __pbase_type_info* thrown_type,
100                                         void*& adjustedPtr,
101                                         unsigned tracker) const {
102     bool result;
103     if (do_can_catch_ptr(thrown_type, adjustedPtr, tracker,
104                          result)) {
105       return result;
106     }
107 
108     const __pbase_type_info* ptr_pointee =
109         dynamic_cast<const __pbase_type_info*>(__pointee);
110 
111     if (ptr_pointee) {
112       return ptr_pointee->can_catch_typeinfo_wrapper(thrown_type->__pointee,
113                                                      adjustedPtr,
114                                                      tracker);
115     } else {
116       return __pointee->can_catch(thrown_type->__pointee, adjustedPtr);
117     }
118   }
119 } // namespace __cxxabiv1
120