gas/dw2gencfi.h

   1 /* dw2gencfi.h - Support for generating Dwarf2 CFI information.
   2    Copyright (C) 2003-2018 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
  29 extern 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.  */
  33 extern void cfi_finish (void);
  34
  35 /* Entry points for backends to add unwind information.  */
  36 extern void cfi_new_fde (struct symbol *);
  37 extern void cfi_end_fde (struct symbol *);
  38 extern void cfi_set_return_column (unsigned);
  39 extern void cfi_set_sections (void);
  40 extern void cfi_add_advance_loc (struct symbol *);
  41 extern void cfi_add_label (const char *);
  42
  43 extern void cfi_add_CFA_offset (unsigned, offsetT);
  44 extern void cfi_add_CFA_val_offset (unsigned, offsetT);
  45 extern void cfi_add_CFA_def_cfa (unsigned, offsetT);
  46 extern void cfi_add_CFA_register (unsigned, unsigned);
  47 extern void cfi_add_CFA_def_cfa_register (unsigned);
  48 extern void cfi_add_CFA_def_cfa_offset (offsetT);
  49 extern void cfi_add_CFA_restore (unsigned);
  50 extern void cfi_add_CFA_undefined (unsigned);
  51 extern void cfi_add_CFA_same_value (unsigned);
  52 extern void cfi_add_CFA_remember_state (void);
  53 extern 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
  71 struct 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
 128 enum {
 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 enum pointer_auth_key {
 139   AARCH64_PAUTH_KEY_A,
 140   AARCH64_PAUTH_KEY_B
 141 };
 142
 143 /* Stack of old CFI data, for save/restore.  */
 144 struct cfa_save_data
 145 {
 146   struct cfa_save_data *next;
 147   offsetT cfa_offset;
 148 };
 149
 150 /* Current open FDE entry.  */
 151 struct frch_cfi_data
 152 {
 153   struct fde_entry *cur_fde_data;
 154   symbolS *last_address;
 155   offsetT cur_cfa_offset;
 156   struct cfa_save_data *cfa_save_stack;
 157 };
 158
 159 struct fde_entry
 160 {
 161   struct fde_entry *next;
 162 #if MULTIPLE_FRAME_SECTIONS
 163   segT cur_seg;
 164 #endif
 165   symbolS *start_address;
 166   symbolS *end_address;
 167   struct cfi_insn_data *data;
 168   struct cfi_insn_data **last;
 169   unsigned char per_encoding;
 170   unsigned char lsda_encoding;
 171   int personality_id;
 172   expressionS personality;
 173   expressionS lsda;
 174   unsigned int return_column;
 175   unsigned int signal_frame;
 176 #if MULTIPLE_FRAME_SECTIONS
 177   int handled;
 178 #endif
 179   int eh_header_type;
 180   /* Compact unwinding opcodes, not including the PR byte or LSDA.  */
 181   int eh_data_size;
 182   bfd_byte *eh_data;
 183   /* For out of line tables and FDEs.  */
 184   symbolS *eh_loc;
 185   int sections;
 186   /* The pointer authentication key used.  Only used for AArch64.  */
 187   enum pointer_auth_key pauth_key;
 188 };
 189
 190 /* The list of all FDEs that have been collected.  */
 191 extern struct fde_entry *all_fde_data;
 192
 193 /* Fake CFI type; outside the byte range of any real CFI insn.  */
 194 #define CFI_adjust_cfa_offset   0x100
 195 #define CFI_return_column       0x101
 196 #define CFI_rel_offset          0x102
 197 #define CFI_escape              0x103
 198 #define CFI_signal_frame        0x104
 199 #define CFI_val_encoded_addr    0x105
 200 #define CFI_label               0x106
 201
 202 /* By default emit .eh_frame only, not .debug_frame.  */
 203 #define CFI_EMIT_eh_frame               (1 << 0)
 204 #define CFI_EMIT_debug_frame            (1 << 1)
 205 #define CFI_EMIT_target                 (1 << 2)
 206 #define CFI_EMIT_eh_frame_compact       (1 << 3)
 207
 208 #endif /* DW2GENCFI_H */