1 | //===----------------------------------------------------------------------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | // |
8 | // This file implements the "Exception Handling APIs" |
9 | // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef _CXA_EXCEPTION_H |
14 | #define _CXA_EXCEPTION_H |
15 | |
16 | #include <exception> // for std::unexpected_handler and std::terminate_handler |
17 | #include "cxxabi.h" |
18 | #include "unwind.h" |
19 | |
20 | namespace __cxxabiv1 { |
21 | |
22 | static const uint64_t kOurExceptionClass = 0x434C4E47432B2B00; // CLNGC++\0 |
23 | static const uint64_t kOurDependentExceptionClass = 0x434C4E47432B2B01; // CLNGC++\1 |
24 | static const uint64_t get_vendor_and_language = 0xFFFFFFFFFFFFFF00; // mask for CLNGC++ |
25 | |
26 | _LIBCXXABI_HIDDEN uint64_t __getExceptionClass (const _Unwind_Exception*); |
27 | _LIBCXXABI_HIDDEN void __setExceptionClass ( _Unwind_Exception*, uint64_t); |
28 | _LIBCXXABI_HIDDEN bool __isOurExceptionClass(const _Unwind_Exception*); |
29 | |
30 | struct _LIBCXXABI_HIDDEN __cxa_exception { |
31 | #if defined(__LP64__) || defined(_WIN64) || defined(_LIBCXXABI_ARM_EHABI) |
32 | // Now _Unwind_Exception is marked with __attribute__((aligned)), |
33 | // which implies __cxa_exception is also aligned. Insert padding |
34 | // in the beginning of the struct, rather than before unwindHeader. |
35 | void *reserve; |
36 | |
37 | // This is a new field to support C++11 exception_ptr. |
38 | // For binary compatibility it is at the start of this |
39 | // struct which is prepended to the object thrown in |
40 | // __cxa_allocate_exception. |
41 | size_t referenceCount; |
42 | #endif |
43 | |
44 | // Manage the exception object itself. |
45 | std::type_info *exceptionType; |
46 | #ifdef __wasm__ |
47 | // In Wasm, a destructor returns its argument |
48 | void *(_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *); |
49 | #else |
50 | void (_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *); |
51 | #endif |
52 | std::unexpected_handler unexpectedHandler; |
53 | std::terminate_handler terminateHandler; |
54 | |
55 | __cxa_exception *nextException; |
56 | |
57 | int handlerCount; |
58 | |
59 | #if defined(_LIBCXXABI_ARM_EHABI) |
60 | __cxa_exception* nextPropagatingException; |
61 | int propagationCount; |
62 | #else |
63 | int handlerSwitchValue; |
64 | const unsigned char *actionRecord; |
65 | const unsigned char *languageSpecificData; |
66 | void *catchTemp; |
67 | void *adjustedPtr; |
68 | #endif |
69 | |
70 | #if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI) |
71 | // This is a new field to support C++11 exception_ptr. |
72 | // For binary compatibility it is placed where the compiler |
73 | // previously added padding to 64-bit align unwindHeader. |
74 | size_t referenceCount; |
75 | #endif |
76 | _Unwind_Exception ; |
77 | }; |
78 | |
79 | // http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html |
80 | // The layout of this structure MUST match the layout of __cxa_exception, with |
81 | // primaryException instead of referenceCount. |
82 | struct _LIBCXXABI_HIDDEN __cxa_dependent_exception { |
83 | #if defined(__LP64__) || defined(_WIN64) || defined(_LIBCXXABI_ARM_EHABI) |
84 | void* reserve; // padding. |
85 | void* primaryException; |
86 | #endif |
87 | |
88 | std::type_info *exceptionType; |
89 | void (_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *); |
90 | std::unexpected_handler unexpectedHandler; |
91 | std::terminate_handler terminateHandler; |
92 | |
93 | __cxa_exception *nextException; |
94 | |
95 | int handlerCount; |
96 | |
97 | #if defined(_LIBCXXABI_ARM_EHABI) |
98 | __cxa_exception* nextPropagatingException; |
99 | int propagationCount; |
100 | #else |
101 | int handlerSwitchValue; |
102 | const unsigned char *actionRecord; |
103 | const unsigned char *languageSpecificData; |
104 | void * catchTemp; |
105 | void *adjustedPtr; |
106 | #endif |
107 | |
108 | #if !defined(__LP64__) && !defined(_WIN64) && !defined(_LIBCXXABI_ARM_EHABI) |
109 | void* primaryException; |
110 | #endif |
111 | _Unwind_Exception ; |
112 | }; |
113 | |
114 | // Verify the negative offsets of different fields. |
115 | static_assert(sizeof(_Unwind_Exception) + |
116 | offsetof(__cxa_exception, unwindHeader) == |
117 | sizeof(__cxa_exception), |
118 | "unwindHeader has wrong negative offsets" ); |
119 | static_assert(sizeof(_Unwind_Exception) + |
120 | offsetof(__cxa_dependent_exception, unwindHeader) == |
121 | sizeof(__cxa_dependent_exception), |
122 | "unwindHeader has wrong negative offsets" ); |
123 | |
124 | #if defined(_LIBCXXABI_ARM_EHABI) |
125 | static_assert(offsetof(__cxa_exception, propagationCount) + |
126 | sizeof(_Unwind_Exception) + sizeof(void*) == |
127 | sizeof(__cxa_exception), |
128 | "propagationCount has wrong negative offset" ); |
129 | static_assert(offsetof(__cxa_dependent_exception, propagationCount) + |
130 | sizeof(_Unwind_Exception) + sizeof(void*) == |
131 | sizeof(__cxa_dependent_exception), |
132 | "propagationCount has wrong negative offset" ); |
133 | #elif defined(__LP64__) || defined(_WIN64) |
134 | static_assert(offsetof(__cxa_exception, adjustedPtr) + |
135 | sizeof(_Unwind_Exception) + sizeof(void*) == |
136 | sizeof(__cxa_exception), |
137 | "adjustedPtr has wrong negative offset" ); |
138 | static_assert(offsetof(__cxa_dependent_exception, adjustedPtr) + |
139 | sizeof(_Unwind_Exception) + sizeof(void*) == |
140 | sizeof(__cxa_dependent_exception), |
141 | "adjustedPtr has wrong negative offset" ); |
142 | #else |
143 | static_assert(offsetof(__cxa_exception, referenceCount) + |
144 | sizeof(_Unwind_Exception) + sizeof(void*) == |
145 | sizeof(__cxa_exception), |
146 | "referenceCount has wrong negative offset" ); |
147 | static_assert(offsetof(__cxa_dependent_exception, primaryException) + |
148 | sizeof(_Unwind_Exception) + sizeof(void*) == |
149 | sizeof(__cxa_dependent_exception), |
150 | "primaryException has wrong negative offset" ); |
151 | #endif |
152 | |
153 | struct _LIBCXXABI_HIDDEN __cxa_eh_globals { |
154 | __cxa_exception * caughtExceptions; |
155 | unsigned int uncaughtExceptions; |
156 | #if defined(_LIBCXXABI_ARM_EHABI) |
157 | __cxa_exception* propagatingExceptions; |
158 | #endif |
159 | }; |
160 | |
161 | extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals (); |
162 | extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals_fast (); |
163 | |
164 | extern "C" _LIBCXXABI_FUNC_VIS void * __cxa_allocate_dependent_exception (); |
165 | extern "C" _LIBCXXABI_FUNC_VIS void __cxa_free_dependent_exception (void * dependent_exception); |
166 | |
167 | } // namespace __cxxabiv1 |
168 | |
169 | #endif // _CXA_EXCEPTION_H |
170 | |