gdb/i386-cygwin-tdep.c

   1 /* Target-dependent code for Cygwin running on i386's, for GDB.
   2
   3    Copyright (C) 2003-2020 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 "i386-tdep.h"
  23 #include "windows-tdep.h"
  24 #include "regset.h"
  25 #include "gdb_obstack.h"
  26 #include "xml-support.h"
  27 #include "gdbcore.h"
  28 #include "inferior.h"
  29
  30 /* Core file support.  */
  31
  32 /* This vector maps GDB's idea of a register's number into an address
  33    in the windows exception context vector.  */
  34
  35 static int i386_windows_gregset_reg_offset[] =
  36 {
  37   176, /* eax */
  38   172, /* ecx */
  39   168, /* edx */
  40   164, /* ebx */
  41
  42   196, /* esp */
  43   180, /* ebp */
  44   160, /* esi */
  45   156, /* edi */
  46
  47   184, /* eip */
  48   192, /* eflags */
  49   188, /* cs */
  50   200, /* ss */
  51
  52   152, /* ds */
  53   148, /* es */
  54   144, /* fs */
  55   140, /* gs */
  56
  57   56, /* FloatSave.RegisterArea[0 * 10] */
  58   66, /* FloatSave.RegisterArea[1 * 10] */
  59   76, /* FloatSave.RegisterArea[2 * 10] */
  60   86, /* FloatSave.RegisterArea[3 * 10] */
  61   96, /* FloatSave.RegisterArea[4 * 10] */
  62   106, /* FloatSave.RegisterArea[5 * 10] */
  63   116, /* FloatSave.RegisterArea[6 * 10] */
  64   126, /* FloatSave.RegisterArea[7 * 10] */
  65
  66   28, /* FloatSave.ControlWord */
  67   32, /* FloatSave.StatusWord */
  68   36, /* FloatSave.TagWord */
  69   44, /* FloatSave.ErrorSelector */
  70   40, /* FloatSave.ErrorOffset */
  71   52, /* FloatSave.DataSelector */
  72   48, /* FloatSave.DataOffset */
  73   44, /* FloatSave.ErrorSelector */
  74
  75   /* XMM0-7 */
  76   364, /* ExtendedRegisters[10*16] */
  77   380, /* ExtendedRegisters[11*16] */
  78   396, /* ExtendedRegisters[12*16] */
  79   412, /* ExtendedRegisters[13*16] */
  80   428, /* ExtendedRegisters[14*16] */
  81   444, /* ExtendedRegisters[15*16] */
  82   460, /* ExtendedRegisters[16*16] */
  83   476, /* ExtendedRegisters[17*16] */
  84
  85   /* MXCSR */
  86   228 /* ExtendedRegisters[24] */
  87 };
  88
  89 #define I386_WINDOWS_SIZEOF_GREGSET 716
  90
  91 struct cpms_data
  92 {
  93   struct gdbarch *gdbarch;
  94   struct obstack *obstack;
  95   int module_count;
  96 };
  97
  98 static void
  99 core_process_module_section (bfd *abfd, asection *sect, void *obj)
 100 {
 101   struct cpms_data *data = (struct cpms_data *) obj;
 102   enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);
 103
 104   char *module_name;
 105   size_t module_name_size;
 106   CORE_ADDR base_addr;
 107
 108   gdb_byte *buf = NULL;
 109
 110   if (!startswith (sect->name, ".module"))
 111     return;
 112
 113   buf = (gdb_byte *) xmalloc (bfd_section_size (sect) + 1);
 114   if (!buf)
 115     {
 116       printf_unfiltered ("memory allocation failed for %s\n", sect->name);
 117       goto out;
 118     }
 119   if (!bfd_get_section_contents (abfd, sect,
 120                                  buf, 0, bfd_section_size (sect)))
 121     goto out;
 122
 123
 124
 125   /* A DWORD (data_type) followed by struct windows_core_module_info.  */
 126
 127   base_addr =
 128     extract_unsigned_integer (buf + 4, 4, byte_order);
 129
 130   module_name_size =
 131     extract_unsigned_integer (buf + 8, 4, byte_order);
 132
 133   if (12 + module_name_size > bfd_section_size (sect))
 134     goto out;
 135   module_name = (char *) buf + 12;
 136
 137   /* The first module is the .exe itself.  */
 138   if (data->module_count != 0)
 139     windows_xfer_shared_library (module_name, base_addr,
 140                                  data->gdbarch, data->obstack);
 141   data->module_count++;
 142
 143 out:
 144   if (buf)
 145     xfree (buf);
 146   return;
 147 }
 148
 149 static ULONGEST
 150 windows_core_xfer_shared_libraries (struct gdbarch *gdbarch,
 151                                   gdb_byte *readbuf,
 152                                   ULONGEST offset, ULONGEST len)
 153 {
 154   struct obstack obstack;
 155   const char *buf;
 156   ULONGEST len_avail;
 157   struct cpms_data data = { gdbarch, &obstack, 0 };
 158
 159   obstack_init (&obstack);
 160   obstack_grow_str (&obstack, "<library-list>\n");
 161   bfd_map_over_sections (core_bfd,
 162                          core_process_module_section,
 163                          &data);
 164   obstack_grow_str0 (&obstack, "</library-list>\n");
 165
 166   buf = (const char *) obstack_finish (&obstack);
 167   len_avail = strlen (buf);
 168   if (offset >= len_avail)
 169     return 0;
 170
 171   if (len > len_avail - offset)
 172     len = len_avail - offset;
 173   memcpy (readbuf, buf + offset, len);
 174
 175   obstack_free (&obstack, NULL);
 176   return len;
 177 }
 178
 179 /* This is how we want PTIDs from core files to be printed.  */
 180
 181 static std::string
 182 i386_windows_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
 183 {
 184   if (ptid.lwp () != 0)
 185     return string_printf ("Thread 0x%lx", ptid.lwp ());
 186
 187   return normal_pid_to_str (ptid);
 188 }
 189
 190 static CORE_ADDR
 191 i386_cygwin_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
 192 {
 193   return i386_pe_skip_trampoline_code (frame, pc, NULL);
 194 }
 195
 196 static const char *
 197 i386_cygwin_auto_wide_charset (void)
 198 {
 199   return "UTF-16";
 200 }
 201
 202 static void
 203 i386_cygwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 204 {
 205   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 206
 207   windows_init_abi (info, gdbarch);
 208
 209   set_gdbarch_skip_trampoline_code (gdbarch, i386_cygwin_skip_trampoline_code);
 210
 211   set_gdbarch_skip_main_prologue (gdbarch, i386_skip_main_prologue);
 212
 213   tdep->struct_return = reg_struct_return;
 214
 215   tdep->gregset_reg_offset = i386_windows_gregset_reg_offset;
 216   tdep->gregset_num_regs = ARRAY_SIZE (i386_windows_gregset_reg_offset);
 217   tdep->sizeof_gregset = I386_WINDOWS_SIZEOF_GREGSET;
 218
 219   tdep->sizeof_fpregset = 0;
 220
 221   /* Core file support.  */
 222   set_gdbarch_core_xfer_shared_libraries
 223     (gdbarch, windows_core_xfer_shared_libraries);
 224   set_gdbarch_core_pid_to_str (gdbarch, i386_windows_core_pid_to_str);
 225
 226   set_gdbarch_auto_wide_charset (gdbarch, i386_cygwin_auto_wide_charset);
 227 }
 228
 229 static enum gdb_osabi
 230 i386_cygwin_osabi_sniffer (bfd *abfd)
 231 {
 232   const char *target_name = bfd_get_target (abfd);
 233
 234   if (strcmp (target_name, "pei-i386") == 0)
 235     return GDB_OSABI_CYGWIN;
 236
 237   /* Cygwin uses elf core dumps.  Do not claim all ELF executables,
 238      check whether there is a .reg section of proper size.  */
 239   if (strcmp (target_name, "elf32-i386") == 0)
 240     {
 241       asection *section = bfd_get_section_by_name (abfd, ".reg");
 242       if (section
 243           && bfd_section_size (section) == I386_WINDOWS_SIZEOF_GREGSET)
 244         return GDB_OSABI_CYGWIN;
 245     }
 246
 247   return GDB_OSABI_UNKNOWN;
 248 }
 249
 250 void
 251 _initialize_i386_cygwin_tdep (void)
 252 {
 253   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
 254                                   i386_cygwin_osabi_sniffer);
 255
 256   /* Cygwin uses elf core dumps.  */
 257   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
 258                                   i386_cygwin_osabi_sniffer);
 259
 260   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_CYGWIN,
 261                           i386_cygwin_init_abi);
 262 }