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/* Python interface to blocks.

   Copyright (C) 2008, 2009, 2010 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 "block.h"

#include "dictionary.h"

#include "symtab.h"

#include "python-internal.h"

#include "objfiles.h"

#include "symtab.h"

typedef struct blpy_block_object {

  PyObject_HEAD

  /* The GDB block structure that represents a frame's code block.  */

  struct block *block;

  /* The backing object file.  There is no direct relationship in GDB

     between a block and an object file.  When a block is created also

     store a pointer to the object file for later use.  */

  struct objfile *objfile;

  /* Keep track of all blocks with a doubly-linked list.  Needed for

     block invalidation if the source object file has been freed.  */

  struct blpy_block_object *prev;

  struct blpy_block_object *next;

} block_object;

typedef struct {

  PyObject_HEAD

  /* The block dictionary of symbols.  */

  struct dictionary *dict;

  /* The iterator for that dictionary.  */

  struct dict_iterator iter;

  /* Has the iterator been initialized flag.  */

  int initialized_p;

  /* Pointer back to the original source block object.  Needed to

     check if the block is still valid, and has not been invalidated

     when an object file has been freed.  */

  struct blpy_block_object *source;

} block_syms_iterator_object;

/* Require a valid block.  All access to block_object->block should be

   gated by this call.  */

#define BLPY_REQUIRE_VALID(block_obj, block)            \

  do {                                                  \

    block = block_object_to_block (block_obj);          \

    if (block == NULL)                                  \

      {                                                 \

        PyErr_SetString (PyExc_RuntimeError,            \

                         _("Block is invalid."));       \

        return NULL;                                    \

      }                                                 \

  } while (0)

/* Require a valid block.  This macro is called during block iterator

   creation, and at each next call.  */

#define BLPY_ITER_REQUIRE_VALID(block_obj)                              \

  do {                                                                  \

    if (block_obj->block == NULL)                                       \

      {                                                                 \

        PyErr_SetString (PyExc_RuntimeError,                            \

                         _("Source block for iterator is invalid."));   \

        return NULL;                                                    \

      }                                                                 \

  } while (0)

static PyTypeObject block_syms_iterator_object_type;

static const struct objfile_data *blpy_objfile_data_key;

static PyObject *

blpy_iter (PyObject *self)

{

  block_syms_iterator_object *block_iter_obj;

  struct block *block = NULL;

  BLPY_REQUIRE_VALID (self, block);

  block_iter_obj = PyObject_New (block_syms_iterator_object,

                                 &block_syms_iterator_object_type);

  if (block_iter_obj == NULL)

      return NULL;

  block_iter_obj->dict = BLOCK_DICT (block);

  block_iter_obj->initialized_p = 0;

  Py_INCREF (self);

  block_iter_obj->source = (block_object *) self;

  return (PyObject *) block_iter_obj;

}

static PyObject *

blpy_get_start (PyObject *self, void *closure)

{

  struct block *block = NULL;

  BLPY_REQUIRE_VALID (self, block);

  return PyLong_FromUnsignedLongLong (BLOCK_START (block));

}

static PyObject *

blpy_get_end (PyObject *self, void *closure)

{

  struct block *block = NULL;

  BLPY_REQUIRE_VALID (self, block);

  return PyLong_FromUnsignedLongLong (BLOCK_END (block));

}

static PyObject *

blpy_get_function (PyObject *self, void *closure)

{

  struct symbol *sym;

  struct block *block = NULL;

  BLPY_REQUIRE_VALID (self, block);

  sym = BLOCK_FUNCTION (block);

  if (sym)

    return symbol_to_symbol_object (sym);

  Py_RETURN_NONE;

}

static PyObject *

blpy_get_superblock (PyObject *self, void *closure)

{

  struct block *block = NULL;

  struct block *super_block = NULL;

  block_object *self_obj  = (block_object *) self;

  BLPY_REQUIRE_VALID (self, block);

  super_block = BLOCK_SUPERBLOCK (block);

  if (super_block)

    return block_to_block_object (super_block, self_obj->objfile);

  Py_RETURN_NONE;

}

static void

blpy_dealloc (PyObject *obj)

{

  block_object *block = (block_object *) obj;

  if (block->prev)

    block->prev->next = block->next;

  else if (block->objfile)

    {

      set_objfile_data (block->objfile, blpy_objfile_data_key,

                        block->next);

    }

  if (block->next)

    block->next->prev = block->prev;

  block->block = NULL;

}

/* Given a block, and a block_object that has previously been

   allocated and initialized, populate the block_object with the

   struct block data.  Also, register the block_object life-cycle

   with the life-cycle of the the object file associated with this

   block, if needed.  */

static void

set_block (block_object *obj, struct block *block,

           struct objfile *objfile)

{

  obj->block = block;

  obj->prev = NULL;

  if (objfile)

    {

      obj->objfile = objfile;

      obj->next = objfile_data (objfile, blpy_objfile_data_key);

      if (obj->next)

        obj->next->prev = obj;

      set_objfile_data (objfile, blpy_objfile_data_key, obj);

    }

  else

    obj->next = NULL;

}

/* Create a new block object (gdb.Block) that encapsulates the struct

   block object from GDB.  */

PyObject *

block_to_block_object (struct block *block, struct objfile *objfile)

{

  block_object *block_obj;

  block_obj = PyObject_New (block_object, &block_object_type);

  if (block_obj)

    set_block (block_obj, block, objfile);

  return (PyObject *) block_obj;

}

/* Return struct block reference that is wrapped by this object.  */

struct block *

block_object_to_block (PyObject *obj)

{

  if (! PyObject_TypeCheck (obj, &block_object_type))

    return NULL;

  return ((block_object *) obj)->block;

}

/* Return a reference to the block iterator.  */

static PyObject *

blpy_block_syms_iter (PyObject *self)

{

  block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self;

  BLPY_ITER_REQUIRE_VALID (iter_obj->source);

  Py_INCREF (self);

  return self;

}

/* Return the next symbol in the iteration through the block's

   dictionary.  */

static PyObject *

blpy_block_syms_iternext (PyObject *self)

{

  block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self;

  struct symbol *sym;

  BLPY_ITER_REQUIRE_VALID (iter_obj->source);

  if (!iter_obj->initialized_p)

    {

      sym = dict_iterator_first (iter_obj->dict,  &(iter_obj->iter));

      iter_obj->initialized_p = 1;

    }

  else

    sym = dict_iterator_next (&(iter_obj->iter));

  if (sym == NULL)

    {

      PyErr_SetString (PyExc_StopIteration, _("Symbol is null."));

      return NULL;

    }

  return symbol_to_symbol_object (sym);

}

static void

blpy_block_syms_dealloc (PyObject *obj)

{

  block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) obj;

  Py_XDECREF (iter_obj->source);

}

/* Return the innermost lexical block containing the specified pc value,

   or 0 if there is none.  */

PyObject *

gdbpy_block_for_pc (PyObject *self, PyObject *args)

{

  unsigned PY_LONG_LONG pc;

  struct block *block;

  struct obj_section *section;

  struct symtab *symtab;

  if (!PyArg_ParseTuple (args, "K", &pc))

    return NULL;

  section = find_pc_mapped_section (pc);

  symtab = find_pc_sect_symtab (pc, section);

  if (!symtab || symtab->objfile == NULL)

    {

      PyErr_SetString (PyExc_RuntimeError,

                       _("Cannot locate object file for block."));

      return NULL;

    }

  block = block_for_pc (pc);

  if (block)

    return block_to_block_object (block, symtab->objfile);

  Py_RETURN_NONE;

}

/* This function is called when an objfile is about to be freed.

   Invalidate the block as further actions on the block would result

   in bad data.  All access to obj->symbol should be gated by

   BLPY_REQUIRE_VALID which will raise an exception on invalid

   blocks.  */

static void

del_objfile_blocks (struct objfile *objfile, void *datum)

{

  block_object *obj = datum;

  while (obj)

    {

      block_object *next = obj->next;

      obj->block = NULL;

      obj->objfile = NULL;

      obj->next = NULL;

      obj->prev = NULL;

      obj = next;

    }

}

void

gdbpy_initialize_blocks (void)

{

  block_object_type.tp_new = PyType_GenericNew;

  if (PyType_Ready (&block_object_type) < 0)

    return;

  block_syms_iterator_object_type.tp_new = PyType_GenericNew;

  if (PyType_Ready (&block_syms_iterator_object_type) < 0)

    return;

  /* Register an objfile "free" callback so we can properly

     invalidate blocks when an object file is about to be

     deleted.  */

  blpy_objfile_data_key

    = register_objfile_data_with_cleanup (NULL, del_objfile_blocks);

  Py_INCREF (&block_object_type);

  PyModule_AddObject (gdb_module, "Block", (PyObject *) &block_object_type);

  Py_INCREF (&block_syms_iterator_object_type);

  PyModule_AddObject (gdb_module, "BlockIterator",

                      (PyObject *) &block_syms_iterator_object_type);

}

static PyGetSetDef block_object_getset[] = {

  { "start", blpy_get_start, NULL, "Start address of the block.", NULL },

  { "end", blpy_get_end, NULL, "End address of the block.", NULL },

  { "function", blpy_get_function, NULL,

    "Symbol that names the block, or None.", NULL },

  { "superblock", blpy_get_superblock, NULL,

    "Block containing the block, or None.", NULL },

  { NULL }  /* Sentinel */

};

PyTypeObject block_object_type = {

  PyObject_HEAD_INIT (NULL)

  0,                               /*ob_size*/

  "gdb.Block",                    /*tp_name*/

  sizeof (block_object),          /*tp_basicsize*/

  0,                               /*tp_itemsize*/

  blpy_dealloc,                   /*tp_dealloc*/

  0,                               /*tp_print*/

  0,                               /*tp_getattr*/

  0,                               /*tp_setattr*/

  0,                               /*tp_compare*/

  0,                               /*tp_repr*/

  0,                               /*tp_as_number*/

  0,                               /*tp_as_sequence*/

  0,                               /*tp_as_mapping*/

  0,                               /*tp_hash */

  0,                               /*tp_call*/

  0,                               /*tp_str*/

  0,                               /*tp_getattro*/

  0,                               /*tp_setattro*/

  0,                               /*tp_as_buffer*/

  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /*tp_flags*/

  "GDB block object",             /* tp_doc */

  0,                               /* tp_traverse */

  0,                               /* tp_clear */

  0,                               /* tp_richcompare */

  0,                               /* tp_weaklistoffset */

  blpy_iter,                      /* tp_iter */

  0,                               /* tp_iternext */

  0,                               /* tp_methods */

  0,                               /* tp_members */

  block_object_getset             /* tp_getset */

};

static PyTypeObject block_syms_iterator_object_type = {

  PyObject_HEAD_INIT (NULL)

  0,                               /*ob_size*/

  "gdb.BlockIterator",            /*tp_name*/

  sizeof (block_syms_iterator_object),        /*tp_basicsize*/

  0,                               /*tp_itemsize*/

  blpy_block_syms_dealloc,        /*tp_dealloc*/

  0,                               /*tp_print*/

  0,                               /*tp_getattr*/

  0,                               /*tp_setattr*/

  0,                               /*tp_compare*/

  0,                               /*tp_repr*/

  0,                               /*tp_as_number*/

  0,                               /*tp_as_sequence*/

  0,                               /*tp_as_mapping*/

  0,                               /*tp_hash */

  0,                               /*tp_call*/

  0,                               /*tp_str*/

  0,                               /*tp_getattro*/

  0,                               /*tp_setattro*/

  0,                               /*tp_as_buffer*/

  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /*tp_flags*/

  "GDB block syms iterator object",           /*tp_doc */

  0,                               /*tp_traverse */

  0,                               /*tp_clear */

  0,                               /*tp_richcompare */

  0,                               /*tp_weaklistoffset */

  blpy_block_syms_iter,           /*tp_iter */

  blpy_block_syms_iternext,       /*tp_iternext */

};