unwind-arm.h revision 369446
150479Speter/*
21553Srgrimes * Copyright 2012 David Chisnall. All rights reserved.
380029Sobrien *
480029Sobrien * Permission is hereby granted, free of charge, to any person obtaining a copy
580029Sobrien * of this software and associated documentation files (the "Software"), to
61553Srgrimes * deal in the Software without restriction, including without limitation the
774816Sru * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
880029Sobrien * sell copies of the Software, and to permit persons to whom the Software is
91553Srgrimes * furnished to do so, subject to the following conditions:
1080029Sobrien *
1180029Sobrien * The above copyright notice and this permission notice shall be
1280029Sobrien * included in all copies or substantial portions of the Software.
1380029Sobrien *
1480029Sobrien * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
1558904Sshin * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
1680029Sobrien * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
1758904Sshin * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
1817637Speter * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
1917637Speter * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
2017637Speter * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
2180029Sobrien */
2217637Speter
2358904Sshin/* For uint32_t and uint64_t */
2458804Sshin#include <stdint.h>
2558804Sshin
2658904Sshin/**
2718584Sfenner * ARM-specific unwind definitions.  These are taken from the ARM EHABI
2842624Ssimokawa * specification.
2942624Ssimokawa */
3080029Sobrien typedef enum
3142624Ssimokawa{
3242624Ssimokawa	_URC_NO_REASON = 0,
3380029Sobrien	_URC_OK = 0,                /* operation completed successfully */
3418584Sfenner	_URC_FOREIGN_EXCEPTION_CAUGHT = 1,
3518584Sfenner	_URC_END_OF_STACK = 5,
3636799Simp	_URC_HANDLER_FOUND = 6,
3780029Sobrien	_URC_INSTALL_CONTEXT = 7,
3880029Sobrien	_URC_CONTINUE_UNWIND = 8,
3918584Sfenner	_URC_FAILURE = 9,            /* unspecified failure of some kind */
401553Srgrimes	_URC_FATAL_PHASE1_ERROR = _URC_FAILURE
41} _Unwind_Reason_Code;
42
43typedef int _Unwind_Action;
44
45typedef uint32_t _Unwind_State;
46#ifdef __clang__
47static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME  = 0;
48static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1;
49static const _Unwind_State _US_UNWIND_FRAME_RESUME   = 2;
50static const _Unwind_State _US_ACTION_MASK           = 3;
51#else // GCC fails at knowing what a constant expression is
52#	define _US_VIRTUAL_UNWIND_FRAME  0
53#	define _US_UNWIND_FRAME_STARTING 1
54#	define _US_UNWIND_FRAME_RESUME   2
55#	define _US_ACTION_MASK           3
56#endif
57
58typedef struct _Unwind_Context _Unwind_Context;
59
60typedef uint32_t _Unwind_EHT_Header;
61
62struct _Unwind_Exception
63{
64	uint64_t exception_class;
65	void (*exception_cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception *);
66	/* Unwinder cache, private fields for the unwinder's use */
67	struct
68	{
69		uint32_t reserved1;
70		uint32_t reserved2;
71		uint32_t reserved3;
72		uint32_t reserved4;
73		uint32_t reserved5;
74	/* init reserved1 to 0, then don't touch */
75	} unwinder_cache;
76	/* Propagation barrier cache (valid after phase 1): */
77	struct
78	{
79		uint32_t sp;
80		uint32_t bitpattern[5];
81	} barrier_cache;
82	/* Cleanup cache (preserved over cleanup): */
83	struct
84	{
85		uint32_t bitpattern[4];
86	} cleanup_cache;
87	/* Pr cache (for pr's benefit): */
88	struct
89	{
90		/** function start address */
91		uint32_t fnstart;
92		/** pointer to EHT entry header word */
93		_Unwind_EHT_Header *ehtp;
94		/** additional data */
95		uint32_t additional;
96		uint32_t reserved1;
97	} pr_cache;
98	/** Force alignment of next item to 8-byte boundary */
99	long long int :0;
100};
101
102/* Unwinding functions */
103_Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *ucbp);
104void _Unwind_Resume(struct _Unwind_Exception *ucbp);
105void _Unwind_Complete(struct _Unwind_Exception *ucbp);
106void _Unwind_DeleteException(struct _Unwind_Exception *ucbp);
107void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context*);
108
109typedef enum
110{
111	_UVRSR_OK = 0,
112	_UVRSR_NOT_IMPLEMENTED = 1,
113	_UVRSR_FAILED = 2
114} _Unwind_VRS_Result;
115typedef enum
116{
117	_UVRSC_CORE = 0,
118	_UVRSC_VFP = 1,
119	_UVRSC_WMMXD = 3,
120	_UVRSC_WMMXC = 4
121} _Unwind_VRS_RegClass;
122typedef enum
123{
124	_UVRSD_UINT32 = 0,
125	_UVRSD_VFPX = 1,
126	_UVRSD_UINT64 = 3,
127	_UVRSD_FLOAT = 4,
128	_UVRSD_DOUBLE = 5
129} _Unwind_VRS_DataRepresentation;
130
131_Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context,
132                                   _Unwind_VRS_RegClass regclass,
133                                   uint32_t regno,
134                                   _Unwind_VRS_DataRepresentation representation,
135                                   void *valuep);
136_Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context,
137                                   _Unwind_VRS_RegClass regclass,
138                                   uint32_t regno,
139                                   _Unwind_VRS_DataRepresentation representation,
140                                   void *valuep);
141
142/* Return the base-address for data references.  */
143extern unsigned long _Unwind_GetDataRelBase(struct _Unwind_Context *);
144
145/* Return the base-address for text references.  */
146extern unsigned long _Unwind_GetTextRelBase(struct _Unwind_Context *);
147extern unsigned long _Unwind_GetRegionStart(struct _Unwind_Context *);
148
149typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) (struct _Unwind_Context *,
150						 void *);
151extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *);
152extern _Unwind_Reason_Code
153	  _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *);
154
155/**
156 * The next set of functions are compatibility extensions, implementing Itanium
157 * ABI functions on top of ARM ones.
158 */
159
160#define _UA_SEARCH_PHASE	1
161#define _UA_CLEANUP_PHASE	2
162#define _UA_HANDLER_FRAME	4
163#define _UA_FORCE_UNWIND	8
164
165static inline unsigned long _Unwind_GetGR(struct _Unwind_Context *context, int reg)
166{
167	unsigned long val;
168	_Unwind_VRS_Get(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
169	return val;
170}
171static inline  void _Unwind_SetGR(struct _Unwind_Context *context, int reg, unsigned long val)
172{
173	_Unwind_VRS_Set(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
174}
175static inline unsigned long _Unwind_GetIP(_Unwind_Context *context)
176{
177	// Low bit store the thumb state - discard it
178	return _Unwind_GetGR(context, 15) & ~1;
179}
180static inline void _Unwind_SetIP(_Unwind_Context *context, unsigned long val)
181{
182	// The lowest bit of the instruction pointer indicates whether we're in
183	// thumb or ARM mode.  This is assumed to be fixed throughout a function,
184	// so must be propagated when setting the program counter.
185	unsigned long thumbState = _Unwind_GetGR(context, 15) & 1;
186   _Unwind_SetGR(context, 15, (val | thumbState));
187}
188
189/** GNU API function that unwinds the frame */
190_Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*, struct _Unwind_Context*);
191
192
193#define DECLARE_PERSONALITY_FUNCTION(name) \
194_Unwind_Reason_Code name(_Unwind_State state,\
195                         struct _Unwind_Exception *exceptionObject,\
196                         struct _Unwind_Context *context);
197
198#define BEGIN_PERSONALITY_FUNCTION(name) \
199_Unwind_Reason_Code name(_Unwind_State state,\
200                         struct _Unwind_Exception *exceptionObject,\
201                         struct _Unwind_Context *context)\
202{\
203	int version = 1;\
204	uint64_t exceptionClass = exceptionObject->exception_class;\
205	int actions;\
206	switch (state)\
207	{\
208		default: return _URC_FAILURE;\
209		case _US_VIRTUAL_UNWIND_FRAME:\
210		{\
211			actions = _UA_SEARCH_PHASE;\
212			break;\
213		}\
214		case _US_UNWIND_FRAME_STARTING:\
215		{\
216			actions = _UA_CLEANUP_PHASE;\
217			if (exceptionObject->barrier_cache.sp == _Unwind_GetGR(context, 13))\
218			{\
219				actions |= _UA_HANDLER_FRAME;\
220			}\
221			break;\
222		}\
223		case _US_UNWIND_FRAME_RESUME:\
224		{\
225			return continueUnwinding(exceptionObject, context);\
226			break;\
227		}\
228	}\
229	_Unwind_SetGR (context, 12, reinterpret_cast<unsigned long>(exceptionObject));\
230
231#define CALL_PERSONALITY_FUNCTION(name) name(state,exceptionObject,context)
232