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   return (read_memory_integer (frame->next ? frame->next->frame
  41                                            : frame->frame, 8));
  42 }
  43
  44 /* This is the definition of CALL_DUMMY_ADDRESS.  It's a heuristic that is used
  45    to find a convenient place in the text segment to stick a breakpoint to
  46    detect the completion of a target function call (ala call_function_by_hand).
  47  */
  48
  49 static CORE_ADDR
  50 alpha_call_dummy_address (void)
  51 {
  52   CORE_ADDR entry;
  53   struct minimal_symbol *sym;
  54
  55   entry = entry_point_address ();
  56
  57   if (entry != 0)
  58     return entry;
  59
  60   sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile);
  61
  62   if (!sym || MSYMBOL_TYPE (sym) != mst_text)
  63     return 0;
  64   else
  65     return SYMBOL_VALUE_ADDRESS (sym) + 4;
  66 }
  67
  68 static void
  69 alpha_osf1_init_abi (struct gdbarch_info info,
  70                      struct gdbarch *gdbarch)
  71 {
  72   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  73
  74   set_gdbarch_pc_in_sigtramp (gdbarch, alpha_osf1_pc_in_sigtramp);
  75   /* The next/step support via procfs on OSF1 is broken when running
  76      on multi-processor machines. We need to use software single stepping
  77      instead.  */
  78   set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
  79
  80   /* Alpha OSF/1 inhibits execution of code on the stack.  But there is
  81      no need for a dummy on the Alpha.  PUSH_ARGUMENTS takes care of all
  82      argument handling and bp_call_dummy takes care of stopping the dummy.  */
  83   set_gdbarch_call_dummy_address (gdbarch, alpha_call_dummy_address);
  84
  85   tdep->sigcontext_addr = alpha_osf1_sigcontext_addr;
  86
  87   tdep->jb_pc = 2;
  88   tdep->jb_elt_size = 8;
  89 }
  90
  91 void
  92 _initialize_alpha_osf1_tdep (void)
  93 {
  94   gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OSF1,
  95                           alpha_osf1_init_abi);
  96 }