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// C++ ABI Level 1 ABI documented at:
9// https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef __UNWIND_H__
14#define __UNWIND_H__
15
16#include <__libunwind_config.h>
17
18#include <stdint.h>
19#include <stddef.h>
20
21#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__) && defined(_WIN32)
22#include <windows.h>
23#include <ntverp.h>
24#endif
25
26#if defined(__APPLE__)
27#define LIBUNWIND_UNAVAIL __attribute__ (( unavailable ))
28#else
29#define LIBUNWIND_UNAVAIL
30#endif
31
32typedef enum {
33 _URC_NO_REASON = 0,
34 _URC_OK = 0,
35 _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
36 _URC_FATAL_PHASE2_ERROR = 2,
37 _URC_FATAL_PHASE1_ERROR = 3,
38 _URC_NORMAL_STOP = 4,
39 _URC_END_OF_STACK = 5,
40 _URC_HANDLER_FOUND = 6,
41 _URC_INSTALL_CONTEXT = 7,
42 _URC_CONTINUE_UNWIND = 8,
43#if defined(_LIBUNWIND_ARM_EHABI)
44 _URC_FAILURE = 9
45#endif
46} _Unwind_Reason_Code;
47
48typedef enum {
49 _UA_SEARCH_PHASE = 1,
50 _UA_CLEANUP_PHASE = 2,
51 _UA_HANDLER_FRAME = 4,
52 _UA_FORCE_UNWIND = 8,
53 _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
54} _Unwind_Action;
55
56typedef struct _Unwind_Context _Unwind_Context; // opaque
57
58#if defined(_LIBUNWIND_ARM_EHABI)
59#include <unwind_arm_ehabi.h>
60#else
61#include <unwind_itanium.h>
62#endif
63
64typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
65 (int version,
66 _Unwind_Action actions,
67 _Unwind_Exception_Class exceptionClass,
68 _Unwind_Exception* exceptionObject,
69 struct _Unwind_Context* context,
70 void* stop_parameter);
71
72#ifdef __cplusplus
73extern "C" {
74#endif
75
76extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
77extern uintptr_t
78 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
79#ifdef __USING_SJLJ_EXCEPTIONS__
80extern _Unwind_Reason_Code
81 _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
82 _Unwind_Stop_Fn stop, void *stop_parameter);
83#else
84extern _Unwind_Reason_Code
85 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
86 _Unwind_Stop_Fn stop, void *stop_parameter);
87#endif
88
89#ifdef __USING_SJLJ_EXCEPTIONS__
90typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t;
91extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
92extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
93#endif
94
95//
96// The following are semi-supported extensions to the C++ ABI
97//
98
99//
100// called by __cxa_rethrow().
101//
102#ifdef __USING_SJLJ_EXCEPTIONS__
103extern _Unwind_Reason_Code
104 _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object);
105#else
106extern _Unwind_Reason_Code
107 _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object);
108#endif
109
110// _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
111// _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
112// or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
113typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
114 void *);
115extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
116
117// _Unwind_GetCFA is a gcc extension that can be called from within a
118// personality handler to get the CFA (stack pointer before call) of
119// current frame.
120extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
121
122
123// _Unwind_GetIPInfo is a gcc extension that can be called from within a
124// personality handler. Similar to _Unwind_GetIP() but also returns in
125// *ipBefore a non-zero value if the instruction pointer is at or before the
126// instruction causing the unwind. Normally, in a function call, the IP returned
127// is the return address which is after the call instruction and may be past the
128// end of the function containing the call instruction.
129extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
130 int *ipBefore);
131
132
133// __register_frame() is used with dynamically generated code to register the
134// FDE for a generated (JIT) code. The FDE must use pc-rel addressing to point
135// to its function and optional LSDA.
136// __register_frame() has existed in all versions of Mac OS X, but in 10.4 and
137// 10.5 it was buggy and did not actually register the FDE with the unwinder.
138// In 10.6 and later it does register properly.
139extern void __register_frame(const void *fde);
140extern void __deregister_frame(const void *fde);
141
142// _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
143// an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind
144// info" which the runtime uses in preference to DWARF unwind info. This
145// function will only work if the target function has an FDE but no compact
146// unwind info.
147struct dwarf_eh_bases {
148 uintptr_t tbase;
149 uintptr_t dbase;
150 uintptr_t func;
151};
152extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *);
153
154
155// This function attempts to find the start (address of first instruction) of
156// a function given an address inside the function. It only works if the
157// function has an FDE (DWARF unwind info).
158// This function is unimplemented on Mac OS X 10.6 and later. Instead, use
159// _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
160extern void *_Unwind_FindEnclosingFunction(void *pc);
161
162// Mac OS X does not support text-rel and data-rel addressing so these functions
163// are unimplemented.
164extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context)
165 LIBUNWIND_UNAVAIL;
166extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context)
167 LIBUNWIND_UNAVAIL;
168
169// Mac OS X 10.4 and 10.5 had implementations of these functions in
170// libgcc_s.dylib, but they never worked.
171/// These functions are no longer available on Mac OS X.
172extern void __register_frame_info_bases(const void *fde, void *ob, void *tb,
173 void *db) LIBUNWIND_UNAVAIL;
174extern void __register_frame_info(const void *fde, void *ob)
175 LIBUNWIND_UNAVAIL;
176extern void __register_frame_info_table_bases(const void *fde, void *ob,
177 void *tb, void *db)
178 LIBUNWIND_UNAVAIL;
179extern void __register_frame_info_table(const void *fde, void *ob)
180 LIBUNWIND_UNAVAIL;
181extern void __register_frame_table(const void *fde)
182 LIBUNWIND_UNAVAIL;
183extern void *__deregister_frame_info(const void *fde)
184 LIBUNWIND_UNAVAIL;
185extern void *__deregister_frame_info_bases(const void *fde)
186 LIBUNWIND_UNAVAIL;
187
188#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
189#ifndef _WIN32
190typedef struct _EXCEPTION_RECORD EXCEPTION_RECORD;
191typedef struct _CONTEXT CONTEXT;
192typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT;
193#elif !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
194typedef struct _DISPATCHER_CONTEXT DISPATCHER_CONTEXT;
195#endif
196// This is the common wrapper for GCC-style personality functions with SEH.
197extern EXCEPTION_DISPOSITION _GCC_specific_handler(EXCEPTION_RECORD *exc,
198 void *frame, CONTEXT *ctx,
199 DISPATCHER_CONTEXT *disp,
200 _Unwind_Personality_Fn pers);
201#endif
202
203#ifdef __cplusplus
204}
205#endif
206
207#endif // __UNWIND_H__
208