1 /* Exception handling and frame unwind runtime interface routines.
2 Copyright (C) 2001, 2003 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
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 the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
21 /* As a special exception, if you include this header file into source
22 files compiled by GCC, this header file does not by itself cause
23 the resulting executable to be covered by the GNU General Public
24 License. This exception does not however invalidate any other
25 reasons why the executable file might be covered by the GNU General
28 /* This is derived from the C++ ABI for IA-64. Where we diverge
29 for cross-architecture compatibility are noted with "@@@". */
35 /* Level 1: Base ABI */
37 /* @@@ The IA-64 ABI uses uint64 throughout. Most places this is
38 inefficient for 32-bit and smaller machines. */
39 typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
40 typedef signed _Unwind_Sword __attribute__((__mode__(__word__)));
41 #if defined(__ia64__) && defined(__hpux__)
42 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__word__)));
44 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__)));
46 typedef unsigned _Unwind_Internal_Ptr __attribute__((__mode__(__pointer__)));
48 /* @@@ The IA-64 ABI uses a 64-bit word to identify the producer and
49 consumer of an exception. We'll go along with this for now even on
50 32-bit machines. We'll need to provide some other option for
51 16-bit machines and for machines with > 8 bits per byte. */
52 typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__)));
54 /* The unwind interface uses reason codes in several contexts to
55 identify the reasons for failures or other actions. */
59 _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
60 _URC_FATAL_PHASE2_ERROR = 2,
61 _URC_FATAL_PHASE1_ERROR = 3,
63 _URC_END_OF_STACK = 5,
64 _URC_HANDLER_FOUND = 6,
65 _URC_INSTALL_CONTEXT = 7,
66 _URC_CONTINUE_UNWIND = 8
67 } _Unwind_Reason_Code;
70 /* The unwind interface uses a pointer to an exception header object
71 as its representation of an exception being thrown. In general, the
72 full representation of an exception object is language- and
73 implementation-specific, but it will be prefixed by a header
74 understood by the unwind interface. */
76 struct _Unwind_Exception;
78 typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
79 struct _Unwind_Exception *);
81 struct _Unwind_Exception
83 _Unwind_Exception_Class exception_class;
84 _Unwind_Exception_Cleanup_Fn exception_cleanup;
85 _Unwind_Word private_1;
86 _Unwind_Word private_2;
88 /* @@@ The IA-64 ABI says that this structure must be double-word aligned.
89 Taking that literally does not make much sense generically. Instead we
90 provide the maximum alignment required by any type for the machine. */
91 } __attribute__((__aligned__));
94 /* The ACTIONS argument to the personality routine is a bitwise OR of one
95 or more of the following constants. */
96 typedef int _Unwind_Action;
98 #define _UA_SEARCH_PHASE 1
99 #define _UA_CLEANUP_PHASE 2
100 #define _UA_HANDLER_FRAME 4
101 #define _UA_FORCE_UNWIND 8
102 #define _UA_END_OF_STACK 16
104 /* This is an opaque type used to refer to a system-specific data
105 structure used by the system unwinder. This context is created and
106 destroyed by the system, and passed to the personality routine
108 struct _Unwind_Context;
110 /* Raise an exception, passing along the given exception object. */
111 extern _Unwind_Reason_Code _Unwind_RaiseException (struct _Unwind_Exception *);
113 /* Raise an exception for forced unwinding. */
115 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
116 (int, _Unwind_Action, _Unwind_Exception_Class,
117 struct _Unwind_Exception *, struct _Unwind_Context *, void *);
119 extern _Unwind_Reason_Code _Unwind_ForcedUnwind (struct _Unwind_Exception *,
123 /* Helper to invoke the exception_cleanup routine. */
124 extern void _Unwind_DeleteException (struct _Unwind_Exception *);
126 /* Resume propagation of an existing exception. This is used after
127 e.g. executing cleanup code, and not to implement rethrowing. */
128 extern void _Unwind_Resume (struct _Unwind_Exception *);
130 /* These functions are used for communicating information about the unwind
131 context (i.e. the unwind descriptors and the user register state) between
132 the unwind library and the personality routine and landing pad. Only
133 selected registers maybe manipulated. */
135 extern _Unwind_Word _Unwind_GetGR (struct _Unwind_Context *, int);
136 extern void _Unwind_SetGR (struct _Unwind_Context *, int, _Unwind_Word);
138 extern _Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *);
139 extern void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr);
141 /* @@@ Retrieve the CFA of the given context. */
142 extern _Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *);
144 extern void *_Unwind_GetLanguageSpecificData (struct _Unwind_Context *);
146 extern _Unwind_Ptr _Unwind_GetRegionStart (struct _Unwind_Context *);
149 /* The personality routine is the function in the C++ (or other language)
150 runtime library which serves as an interface between the system unwind
151 library and language-specific exception handling semantics. It is
152 specific to the code fragment described by an unwind info block, and
153 it is always referenced via the pointer in the unwind info block, and
154 hence it has no ABI-specified name.
156 Note that this implies that two different C++ implementations can
157 use different names, and have different contents in the language
158 specific data area. Moreover, that the language specific data
159 area contains no version info because name of the function invoked
160 provides more effective versioning by detecting at link time the
161 lack of code to handle the different data format. */
163 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)
164 (int, _Unwind_Action, _Unwind_Exception_Class,
165 struct _Unwind_Exception *, struct _Unwind_Context *);
167 /* @@@ The following alternate entry points are for setjmp/longjmp
170 struct SjLj_Function_Context;
171 extern void _Unwind_SjLj_Register (struct SjLj_Function_Context *);
172 extern void _Unwind_SjLj_Unregister (struct SjLj_Function_Context *);
174 extern _Unwind_Reason_Code _Unwind_SjLj_RaiseException
175 (struct _Unwind_Exception *);
176 extern _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind
177 (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *);
178 extern void _Unwind_SjLj_Resume (struct _Unwind_Exception *);
180 /* @@@ The following provide access to the base addresses for text
181 and data-relative addressing in the LDSA. In order to stay link
182 compatible with the standard ABI for IA-64, we inline these. */
187 static inline _Unwind_Ptr
188 _Unwind_GetDataRelBase (struct _Unwind_Context *_C)
190 /* The GP is stored in R1. */
191 return _Unwind_GetGR (_C, 1);
194 static inline _Unwind_Ptr
195 _Unwind_GetTextRelBase (struct _Unwind_Context *_C __attribute__ ((__unused__)))
201 extern _Unwind_Ptr _Unwind_GetDataRelBase (struct _Unwind_Context *);
202 extern _Unwind_Ptr _Unwind_GetTextRelBase (struct _Unwind_Context *);
205 /* @@@ Given an address, return the entry point of the function that
207 extern void * _Unwind_FindEnclosingFunction (void *pc);