gdb/alpha-osf1-tdep.c

   1 /* Target-dependent code for OSF/1 on Alpha.
   2    Copyright 2002, 2003 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program 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 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program 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 this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "frame.h"
  23 #include "gdbcore.h"
  24 #include "value.h"
  25 #include "osabi.h"
  26 #include "gdb_string.h"
  27 #include "objfiles.h"
  28
  29 #include "alpha-tdep.h"
  30
  31 static int
  32 alpha_osf1_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
  33 {
  34   return (func_name != NULL && strcmp ("__sigtramp", func_name) == 0);
  35 }
  36
  37 static CORE_ADDR
  38 alpha_osf1_sigcontext_addr (struct frame_info *frame)
  39 {
  40   struct frame_info *next_frame = get_next_frame (frame);
  41
  42   if (next_frame != NULL)
  43     return (read_memory_integer (get_frame_base (next_frame), 8));
  44   else
  45     return (read_memory_integer (get_frame_base (frame), 8));
  46 }
  47
  48 /* This is the definition of CALL_DUMMY_ADDRESS.  It's a heuristic that is used
  49    to find a convenient place in the text segment to stick a breakpoint to
  50    detect the completion of a target function call (ala call_function_by_hand).
  51  */
  52
  53 static CORE_ADDR
  54 alpha_call_dummy_address (void)
  55 {
  56   CORE_ADDR entry;
  57   struct minimal_symbol *sym;
  58
  59   entry = entry_point_address ();
  60
  61   if (entry != 0)
  62     return entry;
  63
  64   sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
  65
  66   if (!sym || MSYMBOL_TYPE (sym) != mst_text)
  67     return 0;
  68   else
  69     return SYMBOL_VALUE_ADDRESS (sym) + 4;
  70 }
  71
  72 static void
  73 alpha_osf1_init_abi (struct gdbarch_info info,
  74                      struct gdbarch *gdbarch)
  75 {
  76   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  77
  78   /* Hook into the MDEBUG frame unwinder.  */
  79   alpha_mdebug_init_abi (info, gdbarch);
  80
  81   set_gdbarch_pc_in_sigtramp (gdbarch, alpha_osf1_pc_in_sigtramp);
  82   /* The next/step support via procfs on OSF1 is broken when running
  83      on multi-processor machines. We need to use software single stepping
  84      instead.  */
  85   set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
  86
  87   /* Alpha OSF/1 inhibits execution of code on the stack.  But there is
  88      no need for a dummy on the Alpha.  PUSH_ARGUMENTS takes care of all
  89      argument handling and bp_call_dummy takes care of stopping the dummy.  */
  90   set_gdbarch_call_dummy_address (gdbarch, alpha_call_dummy_address);
  91
  92   tdep->sigcontext_addr = alpha_osf1_sigcontext_addr;
  93
  94   tdep->jb_pc = 2;
  95   tdep->jb_elt_size = 8;
  96 }
  97
  98 void
  99 _initialize_alpha_osf1_tdep (void)
 100 {
 101   gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OSF1,
 102                           alpha_osf1_init_abi);
 103 }