gas/dw2gencfi.h

   1 /* dw2gencfi.h - Support for generating Dwarf2 CFI information.
   2    Copyright (C) 2003-2024 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
  27 struct symbol;
  28 struct fde_entry;
  29
  30 extern int all_cfi_sections;
  31
  32 extern const pseudo_typeS cfi_pseudo_table[];
  33
  34 #ifndef tc_cfi_frame_initial_instructions
  35 #define tc_cfi_frame_initial_instructions() ((void)0)
  36 #endif
  37
  38 #ifndef tc_cfi_startproc
  39 # define tc_cfi_startproc() ((void)0)
  40 #endif
  41
  42 #ifndef tc_cfi_endproc
  43 # define tc_cfi_endproc(fde) ((void) (fde))
  44 #endif
  45
  46 /* Parse CFI assembler directive .cfi_sections.  This is an external function
  47    because SCFI functionality also uses the same implementation.  */
  48 extern void dot_cfi_sections (int);
  49
  50 /* cfi_finish() is called at the end of file. It will complain if
  51    the last CFI wasn't properly closed by .cfi_endproc.  */
  52 extern void cfi_finish (void);
  53
  54 /* Entry points for backends to add unwind information.  */
  55 extern void cfi_new_fde (struct symbol *);
  56 extern void cfi_end_fde (struct symbol *);
  57 extern void cfi_set_last_fde (struct fde_entry *fde);
  58 extern void cfi_set_return_column (unsigned);
  59 extern void cfi_set_sections (void);
  60 extern void cfi_add_advance_loc (struct symbol *);
  61 extern void cfi_add_label (const char *);
  62
  63 extern void cfi_add_CFA_offset (unsigned, offsetT);
  64 extern void cfi_add_CFA_val_offset (unsigned, offsetT);
  65 extern void cfi_add_CFA_def_cfa (unsigned, offsetT);
  66 extern void cfi_add_CFA_register (unsigned, unsigned);
  67 extern void cfi_add_CFA_def_cfa_register (unsigned);
  68 extern void cfi_add_CFA_def_cfa_offset (offsetT);
  69 extern void cfi_add_CFA_restore (unsigned);
  70 extern void cfi_add_CFA_undefined (unsigned);
  71 extern void cfi_add_CFA_same_value (unsigned);
  72 extern void cfi_add_CFA_remember_state (void);
  73 extern void cfi_add_CFA_restore_state (void);
  74
  75 /* Structures for md_cfi_end.  */
  76
  77 #if defined (TE_PE) || defined (TE_PEP)
  78 #define SUPPORT_FRAME_LINKONCE 1
  79 #else
  80 #define SUPPORT_FRAME_LINKONCE 0
  81 #endif
  82
  83 #ifdef tc_cfi_reloc_for_encoding
  84 #define SUPPORT_COMPACT_EH 1
  85 #else
  86 #define SUPPORT_COMPACT_EH 0
  87 #endif
  88
  89 #ifndef TARGET_MULTIPLE_EH_FRAME_SECTIONS
  90 #define TARGET_MULTIPLE_EH_FRAME_SECTIONS 0
  91 #endif
  92
  93 #define MULTIPLE_FRAME_SECTIONS (SUPPORT_FRAME_LINKONCE || SUPPORT_COMPACT_EH \
  94                                  || TARGET_MULTIPLE_EH_FRAME_SECTIONS)
  95
  96 struct cfi_insn_data
  97 {
  98   struct cfi_insn_data *next;
  99 #if MULTIPLE_FRAME_SECTIONS
 100   segT cur_seg;
 101 #endif
 102   int insn;
 103   union
 104   {
 105     struct
 106     {
 107       unsigned reg;
 108       offsetT offset;
 109     } ri;
 110
 111     struct
 112     {
 113       unsigned reg1;
 114       unsigned reg2;
 115     } rr;
 116
 117     unsigned r;
 118     offsetT i;
 119
 120     struct
 121     {
 122       symbolS *lab1;
 123       symbolS *lab2;
 124     } ll;
 125
 126     struct cfi_escape_data *esc;
 127
 128     struct
 129     {
 130       unsigned reg, encoding;
 131       expressionS exp;
 132     } ea;
 133
 134     const char *sym_name;
 135   } u;
 136 };
 137
 138 /* An enumeration describing the Compact EH header format.  The least
 139    significant bit is used to distinguish the entries.
 140
 141    Inline Compact:                      Function offset [0]
 142                                         Four chars of unwind data.
 143    Out-of-line Compact:                 Function offset [1]
 144                                         Compact unwind data offset [0]
 145    Legacy:                              Function offset [1]
 146                                         Unwind data offset [1]
 147
 148    The header type is initialized to EH_COMPACT_UNKNOWN until the
 149    format is discovered by encountering a .fde_data entry.
 150    Failure to find a .fde_data entry will cause an EH_COMPACT_LEGACY
 151    header to be generated.  */
 152
 153 enum {
 154   EH_COMPACT_UNKNOWN,
 155   EH_COMPACT_LEGACY,
 156   EH_COMPACT_INLINE,
 157   EH_COMPACT_OUTLINE,
 158   EH_COMPACT_OUTLINE_DONE,
 159   /* Outline if .cfi_inline_lsda used, otherwise legacy FDE.  */
 160   EH_COMPACT_HAS_LSDA
 161 };
 162
 163 /* Stack of old CFI data, for save/restore.  */
 164 struct cfa_save_data
 165 {
 166   struct cfa_save_data *next;
 167   offsetT cfa_offset;
 168 };
 169
 170 /* Current open FDE entry.  */
 171 struct frch_cfi_data
 172 {
 173   struct fde_entry *cur_fde_data;
 174   symbolS *last_address;
 175   offsetT cur_cfa_offset;
 176   struct cfa_save_data *cfa_save_stack;
 177 };
 178
 179 struct fde_entry
 180 {
 181   struct fde_entry *next;
 182 #if MULTIPLE_FRAME_SECTIONS
 183   segT cur_seg;
 184 #endif
 185   symbolS *start_address;
 186   symbolS *end_address;
 187   struct cfi_insn_data *data;
 188   struct cfi_insn_data **last;
 189   unsigned char per_encoding;
 190   unsigned char lsda_encoding;
 191   int personality_id;
 192   expressionS personality;
 193   expressionS lsda;
 194   unsigned int return_column;
 195   unsigned int signal_frame;
 196 #if MULTIPLE_FRAME_SECTIONS
 197   int handled;
 198 #endif
 199   int eh_header_type;
 200   /* Compact unwinding opcodes, not including the PR byte or LSDA.  */
 201   int eh_data_size;
 202   bfd_byte *eh_data;
 203   /* For out of line tables and FDEs.  */
 204   symbolS *eh_loc;
 205   int sections;
 206 #ifdef tc_fde_entry_extras
 207   tc_fde_entry_extras
 208 #endif
 209 };
 210
 211 /* The list of all FDEs that have been collected.  */
 212 extern struct fde_entry *all_fde_data;
 213
 214 /* Fake CFI type; outside the byte range of any real CFI insn.  */
 215 #define CFI_adjust_cfa_offset   0x100
 216 #define CFI_return_column       0x101
 217 #define CFI_rel_offset          0x102
 218 #define CFI_escape              0x103
 219 #define CFI_signal_frame        0x104
 220 #define CFI_val_encoded_addr    0x105
 221 #define CFI_label               0x106
 222
 223 /* By default emit .eh_frame only, not .debug_frame.  */
 224 #define CFI_EMIT_eh_frame               (1 << 0)
 225 #define CFI_EMIT_debug_frame            (1 << 1)
 226 #define CFI_EMIT_target                 (1 << 2)
 227 #define CFI_EMIT_eh_frame_compact       (1 << 3)
 228 #define CFI_EMIT_sframe                 (1 << 4)
 229
 230 #endif /* DW2GENCFI_H */