gdb/i386-cygwin-tdep.c

   1 /* Target-dependent code for Cygwin running on i386's, for GDB.
   2
   3    Copyright (C) 2003, 2007, 2008 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 "gdb_string.h"
  23 #include "i386-tdep.h"
  24 #include "i386-cygwin-tdep.h"
  25 #include "regset.h"
  26 #include "gdb_obstack.h"
  27 #include "xml-support.h"
  28 #include "gdbcore.h"
  29 #include "solib.h"
  30 #include "solib-target.h"
  31
  32 /* Core file support.  */
  33
  34 /* This vector maps GDB's idea of a register's number into an address
  35    in the win32 exception context vector.  */
  36
  37 static int i386_win32_gregset_reg_offset[] =
  38 {
  39   176, /* eax */
  40   172, /* ecx */
  41   168, /* edx */
  42   164, /* ebx */
  43
  44   196, /* esp */
  45   180, /* ebp */
  46   160, /* esi */
  47   156, /* edi */
  48
  49   184, /* eip */
  50   192, /* eflags */
  51   188, /* cs */
  52   200, /* ss */
  53
  54   152, /* ds */
  55   148, /* es */
  56   144, /* fs */
  57   140, /* gs */
  58
  59   56, /* FloatSave.RegisterArea[0 * 10] */
  60   66, /* FloatSave.RegisterArea[1 * 10] */
  61   76, /* FloatSave.RegisterArea[2 * 10] */
  62   86, /* FloatSave.RegisterArea[3 * 10] */
  63   96, /* FloatSave.RegisterArea[4 * 10] */
  64   106, /* FloatSave.RegisterArea[5 * 10] */
  65   116, /* FloatSave.RegisterArea[6 * 10] */
  66   126, /* FloatSave.RegisterArea[7 * 10] */
  67
  68   28, /* FloatSave.ControlWord */
  69   32, /* FloatSave.StatusWord */
  70   36, /* FloatSave.TagWord */
  71   44, /* FloatSave.ErrorSelector */
  72   40, /* FloatSave.ErrorOffset */
  73   52, /* FloatSave.DataSelector */
  74   48, /* FloatSave.DataOffset */
  75   44, /* FloatSave.ErrorSelector */
  76
  77   /* XMM0-7 */
  78   364, /* ExtendedRegisters[10*16] */
  79   380, /* ExtendedRegisters[11*16] */
  80   396, /* ExtendedRegisters[12*16] */
  81   412, /* ExtendedRegisters[13*16] */
  82   428, /* ExtendedRegisters[14*16] */
  83   444, /* ExtendedRegisters[15*16] */
  84   460, /* ExtendedRegisters[16*16] */
  85   476, /* ExtendedRegisters[17*16] */
  86
  87   /* MXCSR */
  88   228 /* ExtendedRegisters[24] */
  89 };
  90
  91 #define I386_WIN32_SIZEOF_GREGSET 716
  92
  93 /* Return the appropriate register set for the core section identified
  94    by SECT_NAME and SECT_SIZE.  */
  95
  96 static const struct regset *
  97 i386_win32_regset_from_core_section (struct gdbarch *gdbarch,
  98                                      const char *sect_name, size_t sect_size)
  99 {
 100   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 101
 102   if (strcmp (sect_name, ".reg") == 0
 103       && sect_size == I386_WIN32_SIZEOF_GREGSET)
 104     {
 105       if (tdep->gregset == NULL)
 106         tdep->gregset = regset_alloc (gdbarch, i386_supply_gregset,
 107                                       i386_collect_gregset);
 108       return tdep->gregset;
 109     }
 110
 111   return NULL;
 112 }
 113
 114 void
 115 win32_xfer_shared_library (const char* so_name, CORE_ADDR load_addr,
 116                            struct obstack *obstack)
 117 {
 118   char *p;
 119   obstack_grow_str (obstack, "<library name=\"");
 120   p = xml_escape_text (so_name);
 121   obstack_grow_str (obstack, p);
 122   xfree (p);
 123   obstack_grow_str (obstack, "\"><segment address=\"0x");
 124   /* The symbols in a dll are offset by 0x1000, which is the the
 125      offset from 0 of the first byte in an image - because of the file
 126      header and the section alignment. */
 127   p = paddr_nz (load_addr + 0x1000);
 128   obstack_grow_str (obstack, p);
 129   obstack_grow_str (obstack, "\"/></library>");
 130 }
 131
 132 struct cpms_data
 133 {
 134   struct obstack *obstack;
 135   int module_count;
 136 };
 137
 138 static void
 139 core_process_module_section (bfd *abfd, asection *sect, void *obj)
 140 {
 141   struct cpms_data *data = obj;
 142
 143   char *module_name;
 144   size_t module_name_size;
 145   CORE_ADDR base_addr;
 146
 147   char *buf = NULL;
 148
 149   if (strncmp (sect->name, ".module", 7) != 0)
 150     return;
 151
 152   buf = xmalloc (bfd_get_section_size (sect) + 1);
 153   if (!buf)
 154     {
 155       printf_unfiltered ("memory allocation failed for %s\n", sect->name);
 156       goto out;
 157     }
 158   if (!bfd_get_section_contents (abfd, sect,
 159                                  buf, 0, bfd_get_section_size (sect)))
 160     goto out;
 161
 162
 163
 164   /* A DWORD (data_type) followed by struct win32_core_module_info.  */
 165
 166   base_addr =
 167     extract_unsigned_integer (buf + 4, 4);
 168
 169   module_name_size =
 170     extract_unsigned_integer (buf + 8, 4);
 171
 172   module_name = buf + 12;
 173   if (module_name - buf + module_name_size > bfd_get_section_size (sect))
 174     goto out;
 175
 176   /* The first module is the .exe itself.  */
 177   if (data->module_count != 0)
 178     win32_xfer_shared_library (module_name, base_addr, data->obstack);
 179   data->module_count++;
 180
 181 out:
 182   if (buf)
 183     xfree (buf);
 184   return;
 185 }
 186
 187 static LONGEST
 188 win32_core_xfer_shared_libraries (struct gdbarch *gdbarch,
 189                                   gdb_byte *readbuf,
 190                                   ULONGEST offset, LONGEST len)
 191 {
 192   struct obstack obstack;
 193   const char *buf;
 194   LONGEST len_avail;
 195   struct cpms_data data = { &obstack, 0 };
 196
 197   obstack_init (&obstack);
 198   obstack_grow_str (&obstack, "<library-list>\n");
 199   bfd_map_over_sections (core_bfd,
 200                          core_process_module_section,
 201                          &data);
 202   obstack_grow_str0 (&obstack, "</library-list>\n");
 203
 204   buf = obstack_finish (&obstack);
 205   len_avail = strlen (buf);
 206   if (offset >= len_avail)
 207     return 0;
 208
 209   if (len > len_avail - offset)
 210     len = len_avail - offset;
 211   memcpy (readbuf, buf + offset, len);
 212
 213   obstack_free (&obstack, NULL);
 214   return len;
 215 }
 216
 217 static CORE_ADDR
 218 i386_cygwin_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
 219 {
 220   return i386_pe_skip_trampoline_code (pc, NULL);
 221 }
 222
 223 static void
 224 i386_cygwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 225 {
 226   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 227
 228   set_gdbarch_skip_trampoline_code (gdbarch, i386_cygwin_skip_trampoline_code);
 229
 230   set_gdbarch_skip_main_prologue (gdbarch, i386_skip_main_prologue);
 231
 232   tdep->struct_return = reg_struct_return;
 233
 234   tdep->gregset_reg_offset = i386_win32_gregset_reg_offset;
 235   tdep->gregset_num_regs = ARRAY_SIZE (i386_win32_gregset_reg_offset);
 236   tdep->sizeof_gregset = I386_WIN32_SIZEOF_GREGSET;
 237
 238   set_solib_ops (gdbarch, &solib_target_so_ops);
 239
 240   /* Core file support.  */
 241   set_gdbarch_regset_from_core_section
 242     (gdbarch, i386_win32_regset_from_core_section);
 243   set_gdbarch_core_xfer_shared_libraries
 244     (gdbarch, win32_core_xfer_shared_libraries);
 245 }
 246
 247 static enum gdb_osabi
 248 i386_cygwin_osabi_sniffer (bfd *abfd)
 249 {
 250   char *target_name = bfd_get_target (abfd);
 251
 252   /* Interix also uses pei-i386.
 253      We need a way to distinguish between the two. */
 254   if (strcmp (target_name, "pei-i386") == 0)
 255     return GDB_OSABI_CYGWIN;
 256
 257   /* Cygwin uses elf core dumps.  Do not claim all ELF executables,
 258      check whether there is a .reg section of proper size.  */
 259   if (strcmp (target_name, "elf32-i386") == 0)
 260     {
 261       asection *section = bfd_get_section_by_name (abfd, ".reg");
 262       if (section
 263           && bfd_section_size (abfd, section) == I386_WIN32_SIZEOF_GREGSET)
 264         return GDB_OSABI_CYGWIN;
 265     }
 266
 267   return GDB_OSABI_UNKNOWN;
 268 }
 269
 270 /* Provide a prototype to silence -Wmissing-prototypes.  */
 271 void _initialize_i386_cygwin_tdep (void);
 272
 273 void
 274 _initialize_i386_cygwin_tdep (void)
 275 {
 276   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
 277                                   i386_cygwin_osabi_sniffer);
 278
 279   /* Cygwin uses elf core dumps.  */
 280   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
 281                                   i386_cygwin_osabi_sniffer);
 282
 283   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_CYGWIN,
 284                           i386_cygwin_init_abi);
 285 }