gdb/dicos-tdep.c

   1 /* Target-dependent, architecture-independent code for DICOS, for GDB.
   2
   3    Copyright (C) 2009-2020 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 #include "gdbarch.h"
  27
  28 void
  29 dicos_init_abi (struct gdbarch *gdbarch)
  30 {
  31   set_solib_ops (gdbarch, &solib_target_so_ops);
  32
  33   /* Every process, although has its own address space, sees the same
  34      list of shared libraries.  There's no "main executable" in DICOS,
  35      so this accounts for all code.  */
  36   set_gdbarch_has_global_solist (gdbarch, 1);
  37
  38   /* The DICOS breakpoint API takes care of magically making
  39      breakpoints visible to all inferiors.  */
  40   set_gdbarch_has_global_breakpoints (gdbarch, 1);
  41
  42   /* There's no (standard definition of) entry point or a guaranteed
  43      text location with a symbol where to place the call dummy, so we
  44      need it on the stack.  Rely on i386_gdbarch_init used also for
  45      amd64 to set up ON_STACK inferior calls.  */
  46
  47   /* DICOS rewinds the PC itself.  */
  48   set_gdbarch_decr_pc_after_break (gdbarch, 0);
  49 }
  50
  51 /* Return true if ABFD is a dicos load module.  HEADER_SIZE is the
  52    expected size of the "header" section in bytes.  */
  53
  54 int
  55 dicos_load_module_p (bfd *abfd, int header_size)
  56 {
  57   long storage_needed;
  58   int ret = 0;
  59   asymbol **symbol_table = NULL;
  60   const char *symname = "Dicos_loadModuleInfo";
  61   asection *section;
  62
  63   /* DICOS files don't have a .note.ABI-tag marker or something
  64      similar.  We do know there's always a "header" section of
  65      HEADER_SIZE bytes (size depends on architecture), and there's
  66      always a "Dicos_loadModuleInfo" symbol defined.  Look for the
  67      section first, as that should be cheaper.  */
  68
  69   section = bfd_get_section_by_name (abfd, "header");
  70   if (!section)
  71     return 0;
  72
  73   if (bfd_section_size (section) != header_size)
  74     return 0;
  75
  76   /* Dicos LMs always have a "Dicos_loadModuleInfo" symbol
  77      defined.  Look for it.  */
  78
  79   storage_needed = bfd_get_symtab_upper_bound (abfd);
  80   if (storage_needed < 0)
  81     {
  82       warning (_("Can't read elf symbols from %s: %s"),
  83                bfd_get_filename (abfd),
  84                bfd_errmsg (bfd_get_error ()));
  85       return 0;
  86     }
  87
  88   if (storage_needed > 0)
  89     {
  90       long i, symcount;
  91
  92       symbol_table = (asymbol **) xmalloc (storage_needed);
  93       symcount = bfd_canonicalize_symtab (abfd, symbol_table);
  94
  95       if (symcount < 0)
  96         warning (_("Can't read elf symbols from %s: %s"),
  97                  bfd_get_filename (abfd),
  98                  bfd_errmsg (bfd_get_error ()));
  99       else
 100         {
 101           for (i = 0; i < symcount; i++)
 102             {
 103               asymbol *sym = symbol_table[i];
 104               if (sym->name != NULL
 105                   && symname[0] == sym->name[0]
 106                   && strcmp (symname + 1, sym->name + 1) == 0)
 107                 {
 108                   ret = 1;
 109                   break;
 110                 }
 111             }
 112         }
 113     }
 114
 115   xfree (symbol_table);
 116   return ret;
 117 }