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 #define SFRAME_FRE_BASE_REG_INVAL       ((unsigned int)-1)
  28
  29 /* SFrame Frame Row Entry (FRE).
  30
  31    A frame row entry is a slice of the frame and can be valid for a set of
  32    program instructions.  It keeps all information needed to retrieve the CFA
  33    and the Return Address (RA) if tracked.
  34
  35    A frame row entry effectively stores accumulated information gathered by
  36    interpreting multiple CFI instructions.  More precisely, it is a
  37    self-sufficient record in its own right.  Only the subset of information
  38    necessary for unwinding is stored: Given a PC, how to retrieve the CFA and
  39    the RA.
  40 */
  41
  42 struct sframe_row_entry
  43 {
  44   /* A linked list.  */
  45   struct sframe_row_entry *next;
  46
  47   /* Start and end of the frame row entry.  */
  48   symbolS *pc_begin;
  49   symbolS *pc_end;
  50
  51   /* A frame row entry is a merge candidate if new information can be updated
  52      on it.  */
  53   bool merge_candidate;
  54
  55   /* Whether the return address is mangled with pauth code.  */
  56   bool mangled_ra_p;
  57
  58   /* Track CFA base (architectural) register ID.  */
  59   unsigned int cfa_base_reg;
  60   /* Offset from the CFA base register for recovering CFA.  */
  61   offsetT cfa_offset;
  62
  63   /* Track the other register used as base register for CFA.  Specify whether
  64      it is in register or memory.  */
  65   unsigned int base_reg;
  66   unsigned int bp_loc;
  67   /* If the other register is stashed on stack, note the offset.  */
  68   offsetT bp_offset;
  69
  70   /* Track RA location.  Specify whether it is in register or memory.  */
  71   unsigned int ra_loc;
  72   /* If RA is stashed on stack, note the offset.  */
  73   offsetT ra_offset;
  74 };
  75
  76 /* SFrame Function Description Entry.  */
  77
  78 struct sframe_func_entry
  79 {
  80   /* A linked list.  */
  81   struct sframe_func_entry *next;
  82
  83   /* Reference to the FDE created from CFI in dw2gencfi.  Some information
  84      like the start_address and the segment is made available via this
  85      member.  */
  86   const struct fde_entry *dw_fde;
  87
  88   /* Reference to the first FRE for this function.  */
  89   struct sframe_row_entry *sframe_fres;
  90
  91   unsigned int num_fres;
  92 };
  93
  94 /* SFrame Function Description Entry Translation Context.  */
  95
  96 struct sframe_xlate_ctx
  97 {
  98   /* Reference to the FDE created from CFI in dw2gencfi.  Information
  99      like the FDE start_address, end_address and the cfi insns are
 100      made available via this member.  */
 101   const struct fde_entry *dw_fde;
 102
 103   /* List of FREs in the current FDE translation context, bounded by first_fre
 104      and last_fre.  */
 105
 106   /* Keep track of the first FRE for the purpose of restoring state if
 107      necessary (for DW_CFA_restore).  */
 108   struct sframe_row_entry *first_fre;
 109   /* The last FRE in the list.  */
 110   struct sframe_row_entry *last_fre;
 111
 112   /* The current FRE under construction.  */
 113   struct sframe_row_entry *cur_fre;
 114   /* Remember FRE for an eventual restore.  */
 115   struct sframe_row_entry *remember_fre;
 116
 117   unsigned num_xlate_fres;
 118 };
 119
 120 /* Error codes for SFrame translation context.  */
 121 enum sframe_xlate_err
 122 {
 123   /* Success.  */
 124   SFRAME_XLATE_OK = 0,
 125   /* Error.  */
 126   SFRAME_XLATE_ERROR = 1,
 127   /* Detailed error codes.  */
 128   SFRAME_XLATE_ERR_INVAL = -1,
 129   SFRAME_XLATE_ERR_NOTREPRESENTED = -2,
 130 };
 131
 132 /* Callback to create the abi/arch identifier for SFrame section.  */
 133
 134 unsigned char
 135 sframe_get_abi_arch_callback (const char *target_arch,
 136                               int big_endian_p);
 137
 138 /* The list of all FDEs with data in SFrame internal representation.  */
 139
 140 extern struct sframe_func_entry *all_sframe_fdes;
 141
 142 /* SFrame version specific operations structure.  */
 143
 144 struct sframe_version_ops
 145 {
 146   unsigned char format_version;    /* SFrame format version.  */
 147   /* set SFrame FRE info.  */
 148   unsigned char (*set_fre_info) (unsigned int, unsigned int, unsigned int,
 149                                  bool);
 150   /* set SFrame Func info.  */
 151   unsigned char (*set_func_info) (unsigned int, unsigned int, unsigned int);
 152 };
 153
 154 /* Generate SFrame stack trace info and prepare contents for the output.
 155    outout_sframe ()  is called at the end of file.  */
 156
 157 extern void output_sframe (segT sframe_seg);
 158
 159 #endif /* GENSFRAME_H */