gdb/dicos-tdep.c

   1 /* Target-dependent, architecture-independent code for DICOS, for GDB.
   2
   3    Copyright (C) 2009-2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   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.
  11
  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.
  16
  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/>.  */
  19
  20 #include "defs.h"
  21 #include "osabi.h"
  22 #include "solib.h"
  23 #include "solib-target.h"
  24 #include "inferior.h"
  25 #include "dicos-tdep.h"
  26
  27 void
  28 dicos_init_abi (struct gdbarch *gdbarch)
  29 {
  30   set_solib_ops (gdbarch, &solib_target_so_ops);
  31
  32   /* Every process, although has its own address space, sees the same
  33      list of shared libraries.  There's no "main executable" in DICOS,
  34      so this accounts for all code.  */
  35   set_gdbarch_has_global_solist (gdbarch, 1);
  36
  37   /* The DICOS breakpoint API takes care of magically making
  38      breakpoints visible to all inferiors.  */
  39   set_gdbarch_has_global_breakpoints (gdbarch, 1);
  40
  41   /* There's no (standard definition of) entry point or a guaranteed
  42      text location with a symbol where to place the call dummy, so we
  43      need it on the stack.  Rely on i386_gdbarch_init used also for
  44      amd64 to set up ON_STACK inferior calls.  */
  45
  46   /* DICOS rewinds the PC itself.  */
  47   set_gdbarch_decr_pc_after_break (gdbarch, 0);
  48 }
  49
  50 /* Return true if ABFD is a dicos load module.  HEADER_SIZE is the
  51    expected size of the "header" section in bytes.  */
  52
  53 int
  54 dicos_load_module_p (bfd *abfd, int header_size)
  55 {
  56   long storage_needed;
  57   int ret = 0;
  58   asymbol **symbol_table = NULL;
  59   const char *symname = "Dicos_loadModuleInfo";
  60   asection *section;
  61
  62   /* DICOS files don't have a .note.ABI-tag marker or something
  63      similar.  We do know there's always a "header" section of
  64      HEADER_SIZE bytes (size depends on architecture), and there's
  65      always a "Dicos_loadModuleInfo" symbol defined.  Look for the
  66      section first, as that should be cheaper.  */
  67
  68   section = bfd_get_section_by_name (abfd, "header");
  69   if (!section)
  70     return 0;
  71
  72   if (bfd_section_size (abfd, section) != header_size)
  73     return 0;
  74
  75   /* Dicos LMs always have a "Dicos_loadModuleInfo" symbol
  76      defined.  Look for it.  */
  77
  78   storage_needed = bfd_get_symtab_upper_bound (abfd);
  79   if (storage_needed < 0)
  80     {
  81       warning (_("Can't read elf symbols from %s: %s"),
  82                bfd_get_filename (abfd),
  83                bfd_errmsg (bfd_get_error ()));
  84       return 0;
  85     }
  86
  87   if (storage_needed > 0)
  88     {
  89       long i, symcount;
  90
  91       symbol_table = (asymbol **) xmalloc (storage_needed);
  92       symcount = bfd_canonicalize_symtab (abfd, symbol_table);
  93
  94       if (symcount < 0)
  95         warning (_("Can't read elf symbols from %s: %s"),
  96                  bfd_get_filename (abfd),
  97                  bfd_errmsg (bfd_get_error ()));
  98       else
  99         {
 100           for (i = 0; i < symcount; i++)
 101             {
 102               asymbol *sym = symbol_table[i];
 103               if (sym->name != NULL
 104                   && symname[0] == sym->name[0]
 105                   && strcmp (symname + 1, sym->name + 1) == 0)
 106                 {
 107                   ret = 1;
 108                   break;
 109                 }
 110             }
 111         }
 112     }
 113
 114   xfree (symbol_table);
 115   return ret;
 116 }