1 // -*- C++ -*- ARM specific Exception handling support routines.
2 // Copyright (C) 2004, 2005 Free Software Foundation, Inc.
3 //
4 // This file is part of GCC.
5 //
6 // GCC is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2, or (at your option)
9 // any later version.
10 //
11 // GCC is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 //
16 // You should have received a copy of the GNU General Public License
17 // along with GCC; see the file COPYING. If not, write to
18 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
19 // Boston, MA 02110-1301, USA.
20
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29
30 #include <cxxabi.h>
31 #include "unwind-cxx.h"
32
33 #ifdef __ARM_EABI_UNWINDER__
34
35 using namespace __cxxabiv1;
36
37
38 // Given the thrown type THROW_TYPE, pointer to a variable containing a
39 // pointer to the exception object THROWN_PTR_P and a type CATCH_TYPE to
40 // compare against, return whether or not there is a match and if so,
41 // update *THROWN_PTR_P.
42
43 extern "C" __cxa_type_match_result
__cxa_type_match(_Unwind_Exception * ue_header,const std::type_info * catch_type,bool is_reference,void ** thrown_ptr_p)44 __cxa_type_match(_Unwind_Exception* ue_header,
45 const std::type_info* catch_type,
46 bool is_reference __attribute__((__unused__)),
47 void** thrown_ptr_p)
48 {
49 if (!__is_gxx_exception_class(ue_header->exception_class))
50 return ctm_failed;
51
52 __cxa_exception* xh = __get_exception_header_from_ue(ue_header);
53 const std::type_info* throw_type = xh->exceptionType;
54 void* thrown_ptr = *thrown_ptr_p;
55
56 // Pointer types need to adjust the actual pointer, not
57 // the pointer to pointer that is the exception object.
58 // This also has the effect of passing pointer types
59 // "by value" through the __cxa_begin_catch return value.
60 if (throw_type->__is_pointer_p())
61 thrown_ptr = *(void**) thrown_ptr;
62
63 if (catch_type->__do_catch(throw_type, &thrown_ptr, 1))
64 {
65 *thrown_ptr_p = thrown_ptr;
66
67 if (typeid(*catch_type) == typeid (typeid(void*)))
68 {
69 const __pointer_type_info *catch_pointer_type =
70 static_cast<const __pointer_type_info *> (catch_type);
71 const __pointer_type_info *throw_pointer_type =
72 static_cast<const __pointer_type_info *> (throw_type);
73
74 if (typeid (*catch_pointer_type->__pointee) != typeid (void)
75 && (*catch_pointer_type->__pointee !=
76 *throw_pointer_type->__pointee))
77 return ctm_succeeded_with_ptr_to_base;
78 }
79
80 return ctm_succeeded;
81 }
82
83 return ctm_failed;
84 }
85
86 // ABI defined routine called at the start of a cleanup handler.
87 extern "C" bool
__cxa_begin_cleanup(_Unwind_Exception * ue_header)88 __cxa_begin_cleanup(_Unwind_Exception* ue_header)
89 {
90 __cxa_eh_globals *globals = __cxa_get_globals();
91 __cxa_exception *header = __get_exception_header_from_ue(ue_header);
92 bool native = __is_gxx_exception_class(header->unwindHeader.exception_class);
93
94
95 if (native)
96 {
97 header->propagationCount++;
98 // Add it to the chain if this is the first time we've seen this
99 // exception.
100 if (header->propagationCount == 1)
101 {
102 header->nextPropagatingException = globals->propagatingExceptions;
103 globals->propagatingExceptions = header;
104 }
105 }
106 else
107 {
108 // Remember the exception object, so end_cleanup can return it.
109 // These cannot be stacked, so we must abort if we already have
110 // a propagating exception.
111 if (globals->propagatingExceptions)
112 std::terminate ();
113 globals->propagatingExceptions = header;
114 }
115
116 return true;
117 }
118
119 // Do the work for __cxa_end_cleanup. Returns the currently propagating
120 // exception object.
121 extern "C" _Unwind_Exception *
__gnu_end_cleanup(void)122 __gnu_end_cleanup(void)
123 {
124 __cxa_exception *header;
125 __cxa_eh_globals *globals = __cxa_get_globals();
126
127 header = globals->propagatingExceptions;
128
129 // Check something hasn't gone horribly wrong.
130 if (!header)
131 std::terminate();
132
133 if (__is_gxx_exception_class(header->unwindHeader.exception_class))
134 {
135 header->propagationCount--;
136 if (header->propagationCount == 0)
137 {
138 // Remove exception from chain.
139 globals->propagatingExceptions = header->nextPropagatingException;
140 header->nextPropagatingException = NULL;
141 }
142 }
143 else
144 globals->propagatingExceptions = NULL;
145
146 return &header->unwindHeader;
147 }
148
149 // Assembly wrapper to call __gnu_end_cleanup without clobbering r1-r3.
150 // Also push r4 to preserve stack alignment.
151 #ifdef __thumb__
152 asm (".global __cxa_end_cleanup\n"
153 " .type __cxa_end_cleanup, \"function\"\n"
154 " .thumb_func\n"
155 "__cxa_end_cleanup:\n"
156 " push\t{r1, r2, r3, r4}\n"
157 " bl\t__gnu_end_cleanup\n"
158 " pop\t{r1, r2, r3, r4}\n"
159 " bl\t_Unwind_Resume @ Never returns\n");
160 #else
161 asm (".global __cxa_end_cleanup\n"
162 " .type __cxa_end_cleanup, \"function\"\n"
163 "__cxa_end_cleanup:\n"
164 " stmfd\tsp!, {r1, r2, r3, r4}\n"
165 " bl\t__gnu_end_cleanup\n"
166 " ldmfd\tsp!, {r1, r2, r3, r4}\n"
167 " bl\t_Unwind_Resume @ Never returns\n");
168 #endif
169
170 #endif
171