1/* dw2gencfi.h - Support for generating Dwarf2 CFI information.
2   Copyright (C) 2003-2022 Free Software Foundation, Inc.
3   Contributed by Michal Ludvig <mludvig@suse.cz>
4
5   This file is part of GAS, the GNU Assembler.
6
7   GAS is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3, or (at your option)
10   any later version.
11
12   GAS is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with GAS; see the file COPYING.  If not, write to the Free
19   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
20   02110-1301, USA.  */
21
22#ifndef DW2GENCFI_H
23#define DW2GENCFI_H
24
25#include "dwarf2.h"
26
27struct symbol;
28
29extern const pseudo_typeS cfi_pseudo_table[];
30
31/* cfi_finish() is called at the end of file. It will complain if
32   the last CFI wasn't properly closed by .cfi_endproc.  */
33extern void cfi_finish (void);
34
35/* Entry points for backends to add unwind information.  */
36extern void cfi_new_fde (struct symbol *);
37extern void cfi_end_fde (struct symbol *);
38extern void cfi_set_return_column (unsigned);
39extern void cfi_set_sections (void);
40extern void cfi_add_advance_loc (struct symbol *);
41extern void cfi_add_label (const char *);
42
43extern void cfi_add_CFA_offset (unsigned, offsetT);
44extern void cfi_add_CFA_val_offset (unsigned, offsetT);
45extern void cfi_add_CFA_def_cfa (unsigned, offsetT);
46extern void cfi_add_CFA_register (unsigned, unsigned);
47extern void cfi_add_CFA_def_cfa_register (unsigned);
48extern void cfi_add_CFA_def_cfa_offset (offsetT);
49extern void cfi_add_CFA_restore (unsigned);
50extern void cfi_add_CFA_undefined (unsigned);
51extern void cfi_add_CFA_same_value (unsigned);
52extern void cfi_add_CFA_remember_state (void);
53extern void cfi_add_CFA_restore_state (void);
54
55/* Structures for md_cfi_end.  */
56
57#if defined (TE_PE) || defined (TE_PEP)
58#define SUPPORT_FRAME_LINKONCE 1
59#else
60#define SUPPORT_FRAME_LINKONCE 0
61#endif
62
63#ifdef tc_cfi_reloc_for_encoding
64#define SUPPORT_COMPACT_EH 1
65#else
66#define SUPPORT_COMPACT_EH 0
67#endif
68
69#define MULTIPLE_FRAME_SECTIONS (SUPPORT_FRAME_LINKONCE || SUPPORT_COMPACT_EH)
70
71struct cfi_insn_data
72{
73  struct cfi_insn_data *next;
74#if MULTIPLE_FRAME_SECTIONS
75  segT cur_seg;
76#endif
77  int insn;
78  union
79  {
80    struct
81    {
82      unsigned reg;
83      offsetT offset;
84    } ri;
85
86    struct
87    {
88      unsigned reg1;
89      unsigned reg2;
90    } rr;
91
92    unsigned r;
93    offsetT i;
94
95    struct
96    {
97      symbolS *lab1;
98      symbolS *lab2;
99    } ll;
100
101    struct cfi_escape_data *esc;
102
103    struct
104    {
105      unsigned reg, encoding;
106      expressionS exp;
107    } ea;
108
109    const char *sym_name;
110  } u;
111};
112
113/* An enumeration describing the Compact EH header format.  The least
114   significant bit is used to distinguish the entries.
115
116   Inline Compact:			Function offset [0]
117					Four chars of unwind data.
118   Out-of-line Compact:			Function offset [1]
119					Compact unwind data offset [0]
120   Legacy:				Function offset [1]
121					Unwind data offset [1]
122
123   The header type is initialized to EH_COMPACT_UNKNOWN until the
124   format is discovered by encountering a .fde_data entry.
125   Failure to find a .fde_data entry will cause an EH_COMPACT_LEGACY
126   header to be generated.  */
127
128enum {
129  EH_COMPACT_UNKNOWN,
130  EH_COMPACT_LEGACY,
131  EH_COMPACT_INLINE,
132  EH_COMPACT_OUTLINE,
133  EH_COMPACT_OUTLINE_DONE,
134  /* Outline if .cfi_inline_lsda used, otherwise legacy FDE.  */
135  EH_COMPACT_HAS_LSDA
136};
137
138/* Stack of old CFI data, for save/restore.  */
139struct cfa_save_data
140{
141  struct cfa_save_data *next;
142  offsetT cfa_offset;
143};
144
145/* Current open FDE entry.  */
146struct frch_cfi_data
147{
148  struct fde_entry *cur_fde_data;
149  symbolS *last_address;
150  offsetT cur_cfa_offset;
151  struct cfa_save_data *cfa_save_stack;
152};
153
154struct fde_entry
155{
156  struct fde_entry *next;
157#if MULTIPLE_FRAME_SECTIONS
158  segT cur_seg;
159#endif
160  symbolS *start_address;
161  symbolS *end_address;
162  struct cfi_insn_data *data;
163  struct cfi_insn_data **last;
164  unsigned char per_encoding;
165  unsigned char lsda_encoding;
166  int personality_id;
167  expressionS personality;
168  expressionS lsda;
169  unsigned int return_column;
170  unsigned int signal_frame;
171#if MULTIPLE_FRAME_SECTIONS
172  int handled;
173#endif
174  int eh_header_type;
175  /* Compact unwinding opcodes, not including the PR byte or LSDA.  */
176  int eh_data_size;
177  bfd_byte *eh_data;
178  /* For out of line tables and FDEs.  */
179  symbolS *eh_loc;
180  int sections;
181#ifdef tc_fde_entry_extras
182  tc_fde_entry_extras
183#endif
184};
185
186/* The list of all FDEs that have been collected.  */
187extern struct fde_entry *all_fde_data;
188
189/* Fake CFI type; outside the byte range of any real CFI insn.  */
190#define CFI_adjust_cfa_offset	0x100
191#define CFI_return_column	0x101
192#define CFI_rel_offset		0x102
193#define CFI_escape		0x103
194#define CFI_signal_frame	0x104
195#define CFI_val_encoded_addr	0x105
196#define CFI_label		0x106
197
198/* By default emit .eh_frame only, not .debug_frame.  */
199#define CFI_EMIT_eh_frame               (1 << 0)
200#define CFI_EMIT_debug_frame            (1 << 1)
201#define CFI_EMIT_target                 (1 << 2)
202#define CFI_EMIT_eh_frame_compact       (1 << 3)
203
204#endif /* DW2GENCFI_H */
205