gas/gen-sframe.h

   1 /* gen-sframe.h - Support for generating SFrame.
   2    Copyright (C) 2022-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 #ifndef GENSFRAME_H
  22 #define GENSFRAME_H
  23
  24 #define SFRAME_FRE_ELEM_LOC_REG         0
  25 #define SFRAME_FRE_ELEM_LOC_STACK       1
  26
  27 /* SFrame Frame Row Entry (FRE).
  28
  29    A frame row entry is a slice of the frame and can be valid for a set of
  30    program instructions.  It keeps all information needed to retrieve the CFA
  31    and the Return Address (RA) if tracked.
  32
  33    A frame row entry effectively stores accumulated information gathered by
  34    interpreting multiple CFI instructions.  More precisely, it is a
  35    self-sufficient record in its own right.  Only the subset of information
  36    necessary for unwinding is stored: Given a PC, how to retrieve the CFA and
  37    the RA.
  38 */
  39
  40 struct sframe_row_entry
  41 {
  42   /* A linked list.  */
  43   struct sframe_row_entry *next;
  44
  45   /* Start and end of the frame row entry.  */
  46   symbolS *pc_begin;
  47   symbolS *pc_end;
  48
  49   /* A frame row entry is a merge candidate if new information can be updated
  50      on it.  */
  51   bool merge_candidate;
  52
  53   /* Whether the return address is mangled with pauth code.  */
  54   bool mangled_ra_p;
  55
  56   /* Track CFA base (architectural) register ID.  */
  57   unsigned int cfa_base_reg;
  58   /* Offset from the CFA base register for recovering CFA.  */
  59   offsetT cfa_offset;
  60
  61   /* Track the other register used as base register for CFA.  Specify whether
  62      it is in register or memory.  */
  63   unsigned int base_reg;
  64   unsigned int bp_loc;
  65   /* If the other register is stashed on stack, note the offset.  */
  66   offsetT bp_offset;
  67
  68   /* Track RA location.  Specify whether it is in register or memory.  */
  69   unsigned int ra_loc;
  70   /* If RA is stashed on stack, note the offset.  */
  71   offsetT ra_offset;
  72 };
  73
  74 /* SFrame Function Description Entry.  */
  75
  76 struct sframe_func_entry
  77 {
  78   /* A linked list.  */
  79   struct sframe_func_entry *next;
  80
  81   /* Reference to the FDE created from CFI in dw2gencfi.  Some information
  82      like the start_address and the segment is made available via this
  83      member.  */
  84   const struct fde_entry *dw_fde;
  85
  86   /* Reference to the first FRE for this function.  */
  87   struct sframe_row_entry *sframe_fres;
  88
  89   unsigned int num_fres;
  90 };
  91
  92 /* SFrame Function Description Entry Translation Context.  */
  93
  94 struct sframe_xlate_ctx
  95 {
  96   /* Reference to the FDE created from CFI in dw2gencfi.  Information
  97      like the FDE start_address, end_address and the cfi insns are
  98      made available via this member.  */
  99   const struct fde_entry *dw_fde;
 100
 101   /* List of FREs in the current FDE translation context, bounded by first_fre
 102      and last_fre.  */
 103
 104   /* Keep track of the first FRE for the purpose of restoring state if
 105      necessary (for DW_CFA_restore).  */
 106   struct sframe_row_entry *first_fre;
 107   /* The last FRE in the list.  */
 108   struct sframe_row_entry *last_fre;
 109
 110   /* The current FRE under construction.  */
 111   struct sframe_row_entry *cur_fre;
 112   /* Remember FRE for an eventual restore.  */
 113   struct sframe_row_entry *remember_fre;
 114
 115   unsigned num_xlate_fres;
 116 };
 117
 118 /* Error codes for SFrame translation context.  */
 119 enum sframe_xlate_err
 120 {
 121   /* Success.  */
 122   SFRAME_XLATE_OK = 0,
 123   /* Error.  */
 124   SFRAME_XLATE_ERROR = 1,
 125   /* Detailed error codes.  */
 126   SFRAME_XLATE_ERR_INVAL = -1,
 127   SFRAME_XLATE_ERR_NOTREPRESENTED = -2,
 128 };
 129
 130 /* Callback to create the abi/arch identifier for SFrame section.  */
 131
 132 unsigned char
 133 sframe_get_abi_arch_callback (const char *target_arch,
 134                               int big_endian_p);
 135
 136 /* The list of all FDEs with data in SFrame internal representation.  */
 137
 138 extern struct sframe_func_entry *all_sframe_fdes;
 139
 140 /* SFrame version specific operations structure.  */
 141
 142 struct sframe_version_ops
 143 {
 144   unsigned char format_version;    /* SFrame format version.  */
 145   /* set SFrame FRE info.  */
 146   unsigned char (*set_fre_info) (unsigned int, unsigned int, unsigned int,
 147                                  bool);
 148   /* set SFrame Func info.  */
 149   unsigned char (*set_func_info) (unsigned int, unsigned int, unsigned int);
 150 };
 151
 152 /* Generate SFrame stack trace info and prepare contents for the output.
 153    outout_sframe ()  is called at the end of file.  */
 154
 155 extern void output_sframe (segT sframe_seg);
 156
 157 #endif /* GENSFRAME_H */