/* Copyright (C) 2008-2012 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "windows-tdep.h"
#include "gdb_obstack.h"
#include "xml-support.h"
#include "gdbarch.h"
#include "target.h"
#include "value.h"
#include "inferior.h"
#include "command.h"
#include "gdbcmd.h"
#include "gdbthread.h"

struct cmd_list_element *info_w32_cmdlist;

typedef struct thread_information_block_32
  {
    uint32_t current_seh;			/* %fs:0x0000 */
    uint32_t current_top_of_stack; 		/* %fs:0x0004 */
    uint32_t current_bottom_of_stack;		/* %fs:0x0008 */
    uint32_t sub_system_tib;			/* %fs:0x000c */
    uint32_t fiber_data;			/* %fs:0x0010 */
    uint32_t arbitrary_data_slot;		/* %fs:0x0014 */
    uint32_t linear_address_tib;		/* %fs:0x0018 */
    uint32_t environment_pointer;		/* %fs:0x001c */
    uint32_t process_id;			/* %fs:0x0020 */
    uint32_t current_thread_id;			/* %fs:0x0024 */
    uint32_t active_rpc_handle;			/* %fs:0x0028 */
    uint32_t thread_local_storage;		/* %fs:0x002c */
    uint32_t process_environment_block;		/* %fs:0x0030 */
    uint32_t last_error_number;			/* %fs:0x0034 */
  }
thread_information_32;

typedef struct thread_information_block_64
  {
    uint64_t current_seh;			/* %gs:0x0000 */
    uint64_t current_top_of_stack; 		/* %gs:0x0008 */
    uint64_t current_bottom_of_stack;		/* %gs:0x0010 */
    uint64_t sub_system_tib;			/* %gs:0x0018 */
    uint64_t fiber_data;			/* %gs:0x0020 */
    uint64_t arbitrary_data_slot;		/* %gs:0x0028 */
    uint64_t linear_address_tib;		/* %gs:0x0030 */
    uint64_t environment_pointer;		/* %gs:0x0038 */
    uint64_t process_id;			/* %gs:0x0040 */
    uint64_t current_thread_id;			/* %gs:0x0048 */
    uint64_t active_rpc_handle;			/* %gs:0x0050 */
    uint64_t thread_local_storage;		/* %gs:0x0058 */
    uint64_t process_environment_block;		/* %gs:0x0060 */
    uint64_t last_error_number;			/* %gs:0x0068 */
  }
thread_information_64;


static const char* TIB_NAME[] =
  {
    " current_seh                 ",	/* %fs:0x0000 */
    " current_top_of_stack        ", 	/* %fs:0x0004 */
    " current_bottom_of_stack     ",	/* %fs:0x0008 */
    " sub_system_tib              ",	/* %fs:0x000c */
    " fiber_data                  ",	/* %fs:0x0010 */
    " arbitrary_data_slot         ",	/* %fs:0x0014 */
    " linear_address_tib          ",	/* %fs:0x0018 */
    " environment_pointer         ",	/* %fs:0x001c */
    " process_id                  ",	/* %fs:0x0020 */
    " current_thread_id           ",	/* %fs:0x0024 */
    " active_rpc_handle           ",	/* %fs:0x0028 */
    " thread_local_storage        ",	/* %fs:0x002c */
    " process_environment_block   ",	/* %fs:0x0030 */
    " last_error_number           "	/* %fs:0x0034 */
  };

static const int MAX_TIB32 =
  sizeof (thread_information_32) / sizeof (uint32_t);
static const int MAX_TIB64 =
  sizeof (thread_information_64) / sizeof (uint64_t);
static const int FULL_TIB_SIZE = 0x1000;

static int maint_display_all_tib = 0;

/* Define Thread Local Base pointer type.  */

static struct type *
windows_get_tlb_type (struct gdbarch *gdbarch)
{
  static struct gdbarch *last_gdbarch = NULL;
  static struct type *last_tlb_type = NULL;
  struct type *dword_ptr_type, *dword32_type, *void_ptr_type;
  struct type *peb_ldr_type, *peb_ldr_ptr_type;
  struct type *peb_type, *peb_ptr_type, *list_type, *list_ptr_type;
  struct type *module_list_ptr_type;
  struct type *tib_type, *seh_type, *tib_ptr_type, *seh_ptr_type;

  /* Do not rebuild type if same gdbarch as last time.  */
  if (last_tlb_type && last_gdbarch == gdbarch)
    return last_tlb_type;
  
  dword_ptr_type = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch),
				 1, "DWORD_PTR");
  dword32_type = arch_integer_type (gdbarch, 32,
				 1, "DWORD32");
  void_ptr_type = lookup_pointer_type (builtin_type (gdbarch)->builtin_void);

  /* list entry */

  list_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (list_type) = xstrdup ("list");

  list_ptr_type = arch_type (gdbarch, TYPE_CODE_PTR,
			    TYPE_LENGTH (void_ptr_type), NULL);

  module_list_ptr_type = void_ptr_type;

  append_composite_type_field (list_type, "forward_list",
			       module_list_ptr_type);
  append_composite_type_field (list_type, "backward_list",
			       module_list_ptr_type);

  /* Structured Exception Handler */

  seh_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (seh_type) = xstrdup ("seh");

  seh_ptr_type = arch_type (gdbarch, TYPE_CODE_PTR,
			    TYPE_LENGTH (void_ptr_type), NULL);
  TYPE_TARGET_TYPE (seh_ptr_type) = seh_type;

  append_composite_type_field (seh_type, "next_seh", seh_ptr_type);
  append_composite_type_field (seh_type, "handler",
			       builtin_type (gdbarch)->builtin_func_ptr);

  /* struct _PEB_LDR_DATA */
  peb_ldr_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (peb_ldr_type) = xstrdup ("peb_ldr_data");

  append_composite_type_field (peb_ldr_type, "length", dword32_type);
  append_composite_type_field (peb_ldr_type, "initialized", dword32_type);
  append_composite_type_field (peb_ldr_type, "ss_handle", void_ptr_type);
  append_composite_type_field (peb_ldr_type, "in_load_order", list_type);
  append_composite_type_field (peb_ldr_type, "in_memory_order", list_type);
  append_composite_type_field (peb_ldr_type, "in_init_order", list_type);
  append_composite_type_field (peb_ldr_type, "entry_in_progress",
			       void_ptr_type);
  peb_ldr_ptr_type = arch_type (gdbarch, TYPE_CODE_PTR,
			    TYPE_LENGTH (void_ptr_type), NULL);
  TYPE_TARGET_TYPE (peb_ldr_ptr_type) = peb_ldr_type;


  /* struct process environment block */
  peb_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (peb_type) = xstrdup ("peb");

  /* First bytes contain several flags.  */
  append_composite_type_field (peb_type, "flags", dword_ptr_type);
  append_composite_type_field (peb_type, "mutant", void_ptr_type);
  append_composite_type_field (peb_type, "image_base_address", void_ptr_type);
  append_composite_type_field (peb_type, "ldr", peb_ldr_ptr_type);
  append_composite_type_field (peb_type, "process_parameters", void_ptr_type);
  append_composite_type_field (peb_type, "sub_system_data", void_ptr_type);
  append_composite_type_field (peb_type, "process_heap", void_ptr_type);
  append_composite_type_field (peb_type, "fast_peb_lock", void_ptr_type);
  peb_ptr_type = arch_type (gdbarch, TYPE_CODE_PTR,
			    TYPE_LENGTH (void_ptr_type), NULL);
  TYPE_TARGET_TYPE (peb_ptr_type) = peb_type;


  /* struct thread information block */
  tib_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
  TYPE_NAME (tib_type) = xstrdup ("tib");

  /* uint32_t current_seh;			%fs:0x0000 */
  append_composite_type_field (tib_type, "current_seh", seh_ptr_type);
  /* uint32_t current_top_of_stack; 		%fs:0x0004 */
  append_composite_type_field (tib_type, "current_top_of_stack",
			       void_ptr_type);
  /* uint32_t current_bottom_of_stack;		%fs:0x0008 */
  append_composite_type_field (tib_type, "current_bottom_of_stack",
			       void_ptr_type);
  /* uint32_t sub_system_tib;			%fs:0x000c */
  append_composite_type_field (tib_type, "sub_system_tib", void_ptr_type);

  /* uint32_t fiber_data;			%fs:0x0010 */
  append_composite_type_field (tib_type, "fiber_data", void_ptr_type);
  /* uint32_t arbitrary_data_slot;		%fs:0x0014 */
  append_composite_type_field (tib_type, "arbitrary_data_slot", void_ptr_type);
  /* uint32_t linear_address_tib;		%fs:0x0018 */
  append_composite_type_field (tib_type, "linear_address_tib", void_ptr_type);
  /* uint32_t environment_pointer;		%fs:0x001c */
  append_composite_type_field (tib_type, "environment_pointer", void_ptr_type);
  /* uint32_t process_id;			%fs:0x0020 */
  append_composite_type_field (tib_type, "process_id", dword_ptr_type);
  /* uint32_t current_thread_id;		%fs:0x0024 */
  append_composite_type_field (tib_type, "thread_id", dword_ptr_type);
  /* uint32_t active_rpc_handle;		%fs:0x0028 */
  append_composite_type_field (tib_type, "active_rpc_handle", dword_ptr_type);
  /* uint32_t thread_local_storage;		%fs:0x002c */
  append_composite_type_field (tib_type, "thread_local_storage",
			       void_ptr_type);
  /* uint32_t process_environment_block;	%fs:0x0030 */
  append_composite_type_field (tib_type, "process_environment_block",
			       peb_ptr_type);
  /* uint32_t last_error_number;		%fs:0x0034 */
  append_composite_type_field (tib_type, "last_error_number", dword_ptr_type);

  tib_ptr_type = arch_type (gdbarch, TYPE_CODE_PTR,
			    TYPE_LENGTH (void_ptr_type), NULL);
  TYPE_TARGET_TYPE (tib_ptr_type) = tib_type;

  last_tlb_type = tib_ptr_type;
  last_gdbarch = gdbarch;

  return tib_ptr_type;
}

/* The $_tlb convenience variable is a bit special.  We don't know
   for sure the type of the value until we actually have a chance to
   fetch the data.  The type can change depending on gdbarch, so it is
   also dependent on which thread you have selected.  */

/* This function implements the lval_computed support for reading a
   $_tlb value.  */

static void
tlb_value_read (struct value *val)
{
  CORE_ADDR tlb;
  struct type *type = check_typedef (value_type (val));

  if (!target_get_tib_address (inferior_ptid, &tlb))
    error (_("Unable to read tlb"));
  store_typed_address (value_contents_raw (val), type, tlb);
}

/* This function implements the lval_computed support for writing a
   $_tlb value.  */

static void
tlb_value_write (struct value *v, struct value *fromval)
{
  error (_("Impossible to change the Thread Local Base"));
}

static const struct lval_funcs tlb_value_funcs =
  {
    tlb_value_read,
    tlb_value_write
  };


/* Return a new value with the correct type for the tlb object of
   the current thread using architecture GDBARCH.  Return a void value
   if there's no object available.  */

static struct value *
tlb_make_value (struct gdbarch *gdbarch, struct internalvar *var)
{
  if (target_has_stack && !ptid_equal (inferior_ptid, null_ptid))
    {
      struct type *type = windows_get_tlb_type (gdbarch);
      return allocate_computed_value (type, &tlb_value_funcs, NULL);
    }

  return allocate_value (builtin_type (gdbarch)->builtin_void);
}


/* Display thread information block of a given thread.  */

static int
display_one_tib (ptid_t ptid)
{
  gdb_byte *tib = NULL;
  gdb_byte *index;
  CORE_ADDR thread_local_base;
  ULONGEST i, val, max, max_name, size, tib_size;
  ULONGEST sizeof_ptr = gdbarch_ptr_bit (target_gdbarch);
  enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);

  if (sizeof_ptr == 64)
    {
      size = sizeof (uint64_t);
      tib_size = sizeof (thread_information_64);
      max = MAX_TIB64;
    }
  else
    {
      size = sizeof (uint32_t);
      tib_size = sizeof (thread_information_32);
      max = MAX_TIB32;
    }

  max_name = max;

  if (maint_display_all_tib)
    {
      tib_size = FULL_TIB_SIZE;
      max = tib_size / size;
    }
  
  tib = alloca (tib_size);

  if (target_get_tib_address (ptid, &thread_local_base) == 0)
    {
      printf_filtered (_("Unable to get thread local base for %s\n"),
	target_pid_to_str (ptid));
      return -1;
    }

  if (target_read (&current_target, TARGET_OBJECT_MEMORY,
		   NULL, tib, thread_local_base, tib_size) != tib_size)
    {
      printf_filtered (_("Unable to read thread information "
			 "block for %s at address %s\n"),
	target_pid_to_str (ptid), 
	paddress (target_gdbarch, thread_local_base));
      return -1;
    }

  printf_filtered (_("Thread Information Block %s at %s\n"),
		   target_pid_to_str (ptid),
		   paddress (target_gdbarch, thread_local_base));

  index = (gdb_byte *) tib;

  /* All fields have the size of a pointer, this allows to iterate 
     using the same for loop for both layouts.  */
  for (i = 0; i < max; i++)
    {
      val = extract_unsigned_integer (index, size, byte_order);
      if (i < max_name)
	printf_filtered (_("%s is 0x%s\n"), TIB_NAME[i], phex (val, size));
      else if (val != 0)
	printf_filtered (_("TIB[0x%s] is 0x%s\n"), phex (i * size, 2),
			 phex (val, size));
      index += size;
    } 
  return 1;  
}

/* Display thread information block of a thread specified by ARGS.
   If ARGS is empty, display thread information block of current_thread
   if current_thread is non NULL.
   Otherwise ARGS is parsed and converted to a integer that should
   be the windows ThreadID (not the internal GDB thread ID).  */

static void
display_tib (char * args, int from_tty)
{
  if (args)
    {
      struct thread_info *tp;
      int gdb_id = value_as_long (parse_and_eval (args));

      tp = find_thread_id (gdb_id);

      if (!tp)
	error (_("Thread ID %d not known."), gdb_id);

      if (!target_thread_alive (tp->ptid))
	error (_("Thread ID %d has terminated."), gdb_id);

      display_one_tib (tp->ptid);
    }
  else if (!ptid_equal (inferior_ptid, null_ptid))
    display_one_tib (inferior_ptid);
}

void
windows_xfer_shared_library (const char* so_name, CORE_ADDR load_addr,
			     struct gdbarch *gdbarch, struct obstack *obstack)
{
  char *p;
  obstack_grow_str (obstack, "<library name=\"");
  p = xml_escape_text (so_name);
  obstack_grow_str (obstack, p);
  xfree (p);
  obstack_grow_str (obstack, "\"><segment address=\"");
  /* The symbols in a dll are offset by 0x1000, which is the
     offset from 0 of the first byte in an image - because of the file
     header and the section alignment.  */
  obstack_grow_str (obstack, paddress (gdbarch, load_addr + 0x1000));
  obstack_grow_str (obstack, "\"/></library>");
}

static void
show_maint_show_all_tib (struct ui_file *file, int from_tty,
		struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file, _("Show all non-zero elements of "
			    "Thread Information Block is %s.\n"), value);
}

static void
info_w32_command (char *args, int from_tty)
{
  help_list (info_w32_cmdlist, "info w32 ", class_info, gdb_stdout);
}

static int w32_prefix_command_valid = 0;
void
init_w32_command_list (void)
{
  if (!w32_prefix_command_valid)
    {
      add_prefix_cmd ("w32", class_info, info_w32_command,
		      _("Print information specific to Win32 debugging."),
		      &info_w32_cmdlist, "info w32 ", 0, &infolist);
      w32_prefix_command_valid = 1;
    }
}

void
_initialize_windows_tdep (void)
{
  init_w32_command_list ();
  add_cmd ("thread-information-block", class_info, display_tib,
	   _("Display thread information block."),
	   &info_w32_cmdlist);
  add_alias_cmd ("tib", "thread-information-block", class_info, 1,
		 &info_w32_cmdlist);

  add_setshow_boolean_cmd ("show-all-tib", class_maintenance,
			   &maint_display_all_tib, _("\
Set whether to display all non-zero fields of thread information block."), _("\
Show whether to display all non-zero fields of thread information block."), _("\
Use \"on\" to enable, \"off\" to disable.\n\
If enabled, all non-zero fields of thread information block are displayed,\n\
even if their meaning is unknown."),
			   NULL,
			   show_maint_show_all_tib,
			   &maintenance_set_cmdlist,
			   &maintenance_show_cmdlist);

  /* Explicitly create without lookup, since that tries to create a
     value with a void typed value, and when we get here, gdbarch
     isn't initialized yet.  At this point, we're quite sure there
     isn't another convenience variable of the same name.  */
  create_internalvar_type_lazy ("_tlb", tlb_make_value);
}