gdb/trad-frame.c - gdb

Data types defined

Functions defined

Source code

  1. /* Traditional frame unwind support, for GDB the GNU Debugger.

  3.    Copyright (C) 2003-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  7.    This program 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 of the License, or
  10.    (at your option) any later version.

  12.    This program 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.

  17.    You should have received a copy of the GNU General Public License
  18.    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

  20. #include "defs.h"
  21. #include "frame.h"
  22. #include "trad-frame.h"
  23. #include "regcache.h"
  24. #include "frame-unwind.h"
  25. #include "value.h"

  27. ‌struct trad_frame_cache
  28. {
  29.   struct frame_info *this_frame;
  30.   CORE_ADDR this_base;
  31.   struct trad_frame_saved_reg *prev_regs;
  32.   struct frame_id this_id;
  33. };

  35. struct trad_frame_cache *
  36. ‌trad_frame_cache_zalloc (struct frame_info *this_frame)
  37. {
  38.   struct trad_frame_cache *this_trad_cache;

  40.   this_trad_cache = FRAME_OBSTACK_ZALLOC (struct trad_frame_cache);
  41.   this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (this_frame);
  42.   this_trad_cache->this_frame = this_frame;
  43.   return this_trad_cache;
  44. }

  46. /* A traditional frame is unwound by analysing the function prologue
  47.    and using the information gathered to track registers.  For
  48.    non-optimized frames, the technique is reliable (just need to check
  49.    for all potential instruction sequences).  */

  51. struct trad_frame_saved_reg *
  52. ‌trad_frame_alloc_saved_regs (struct frame_info *this_frame)
  53. {
  54.   int regnum;
  55.   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  56.   int numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
  57.   struct trad_frame_saved_reg *this_saved_regs
  58.     = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg);

  60.   for (regnum = 0; regnum < numregs; regnum++)
  61.     {
  62.       this_saved_regs[regnum].realreg = regnum;
  63.       this_saved_regs[regnum].addr = -1;
  64.     }
  65.   return this_saved_regs;
  66. }

  68. enum { TF_REG_VALUE = -1, TF_REG_UNKNOWN = -2 };

  70. int
  71. ‌trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
  72. {
  73.   return (this_saved_regs[regnum].realreg == TF_REG_VALUE);
  74. }

  76. int
  77. ‌trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
  78. {
  79.   return (this_saved_regs[regnum].realreg >= 0
  80.           && this_saved_regs[regnum].addr != -1);
  81. }

  83. int
  84. ‌trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[],
  85.                       int regnum)
  86. {
  87.   return (this_saved_regs[regnum].realreg >= 0
  88.           && this_saved_regs[regnum].addr == -1);
  89. }

  91. void
  92. ‌trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[],
  93.                       int regnum, LONGEST val)
  94. {
  95.   /* Make the REALREG invalid, indicating that the ADDR contains the
  96.      register's value.  */
  97.   this_saved_regs[regnum].realreg = TF_REG_VALUE;
  98.   this_saved_regs[regnum].addr = val;
  99. }

  101. void
  102. ‌trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache,
  103.                           int regnum, LONGEST val)
  104. {
  105.   /* External interface for users of trad_frame_cache
  106.      (who cannot access the prev_regs object directly).  */
  107.   trad_frame_set_value (this_trad_cache->prev_regs, regnum, val);
  108. }

  110. void
  111. ‌trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache,
  112.                             int regnum, int realreg)
  113. {
  114.   this_trad_cache->prev_regs[regnum].realreg = realreg;
  115.   this_trad_cache->prev_regs[regnum].addr = -1;
  116. }

  118. void
  119. ‌trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache,
  120.                          int regnum, CORE_ADDR addr)
  121. {
  122.   this_trad_cache->prev_regs[regnum].addr = addr;
  123. }

  125. void
  126. ‌trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[],
  127.                         int regnum)
  128. {
  129.   /* Make the REALREG invalid, indicating that the value is not known.  */
  130.   this_saved_regs[regnum].realreg = TF_REG_UNKNOWN;
  131.   this_saved_regs[regnum].addr = -1;
  132. }

  134. struct value *
  135. ‌trad_frame_get_prev_register (struct frame_info *this_frame,
  136.                               struct trad_frame_saved_reg this_saved_regs[],
  137.                               int regnum)
  138. {
  139.   if (trad_frame_addr_p (this_saved_regs, regnum))
  140.     /* The register was saved in memory.  */
  141.     return frame_unwind_got_memory (this_frame, regnum,
  142.                                     this_saved_regs[regnum].addr);
  143.   else if (trad_frame_realreg_p (this_saved_regs, regnum))
  144.     return frame_unwind_got_register (this_frame, regnum,
  145.                                       this_saved_regs[regnum].realreg);
  146.   else if (trad_frame_value_p (this_saved_regs, regnum))
  147.     /* The register's value is available.  */
  148.     return frame_unwind_got_constant (this_frame, regnum,
  149.                                       this_saved_regs[regnum].addr);
  150.   else
  151.     return frame_unwind_got_optimized (this_frame, regnum);
  152. }

  154. struct value *
  155. ‌trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
  156.                          struct frame_info *this_frame,
  157.                          int regnum)
  158. {
  159.   return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs,
  160.                                        regnum);
  161. }

  163. void
  164. ‌trad_frame_set_id (struct trad_frame_cache *this_trad_cache,
  165.                    struct frame_id this_id)
  166. {
  167.   this_trad_cache->this_id = this_id;
  168. }

  170. void
  171. ‌trad_frame_get_id (struct trad_frame_cache *this_trad_cache,
  172.                    struct frame_id *this_id)
  173. {
  174.   (*this_id) = this_trad_cache->this_id;
  175. }

  177. void
  178. ‌trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache,
  179.                           CORE_ADDR this_base)
  180. {
  181.   this_trad_cache->this_base = this_base;
  182. }

  184. CORE_ADDR
  185. ‌trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache)
  186. {
  187.   return this_trad_cache->this_base;
  188. }