py-symtab.c

/* Python interface to symbol tables.

   Copyright (C) 2008-2024 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 "charset.h"
#include "symtab.h"
#include "source.h"
#include "python-internal.h"
#include "objfiles.h"
#include "block.h"

struct symtab_object {
  PyObject_HEAD
  /* The GDB Symbol table structure.  */
  struct symtab *symtab;
};

extern PyTypeObject symtab_object_type
    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("symtab_object");
static const gdbpy_registry<gdbpy_memoizing_registry_storage<symtab_object,
  symtab, &symtab_object::symtab>> stpy_registry;

/* Require a valid symbol table.  All access to symtab_object->symtab
   should be gated by this call.  */
#define STPY_REQUIRE_VALID(symtab_obj, symtab)		 \
  do {							 \
    symtab = symtab_object_to_symtab (symtab_obj);	 \
    if (symtab == NULL)					 \
      {							 \
	PyErr_SetString (PyExc_RuntimeError,		 \
			 _("Symbol Table is invalid.")); \
	return NULL;					 \
      }							 \
  } while (0)

struct sal_object {
  PyObject_HEAD
  /* The GDB Symbol table and line structure.  */
  struct symtab_and_line *sal;
  /* A Symtab and line object is associated with an objfile, so keep
     track with a doubly-linked list, rooted in the objfile.  This
     allows invalidation of the underlying struct symtab_and_line
     when the objfile is deleted.  */
  sal_object *prev;
  sal_object *next;
};

/* This is called when an objfile is about to be freed.  Invalidate
   the sal object as further actions on the sal would result in bad
   data.  All access to obj->sal should be gated by
   SALPY_REQUIRE_VALID which will raise an exception on invalid symbol
   table and line objects.  */
struct salpy_invalidator
{
  void operator() (sal_object *obj)
  {
    xfree (obj->sal);
    obj->sal = nullptr;
  }
};

extern PyTypeObject sal_object_type
    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("sal_object");
static const gdbpy_registry<gdbpy_tracking_registry_storage<sal_object,
  symtab_and_line, &sal_object::sal, salpy_invalidator>> salpy_registry;

/* Require a valid symbol table and line object.  All access to
   sal_object->sal should be gated by this call.  */
#define SALPY_REQUIRE_VALID(sal_obj, sal)				\
  do {									\
    sal = sal_object_to_symtab_and_line (sal_obj);			\
    if (sal == NULL)							\
      {									\
	  PyErr_SetString (PyExc_RuntimeError,				\
			   _("Symbol Table and Line is invalid."));	\
	  return NULL;							\
	}								\
  } while (0)

static PyObject *
stpy_str (PyObject *self)
{
  PyObject *result;
  struct symtab *symtab = NULL;

  STPY_REQUIRE_VALID (self, symtab);

  result = PyUnicode_FromString (symtab_to_filename_for_display (symtab));

  return result;
}

static PyObject *
stpy_get_filename (PyObject *self, void *closure)
{
  PyObject *str_obj;
  struct symtab *symtab = NULL;
  const char *filename;

  STPY_REQUIRE_VALID (self, symtab);
  filename = symtab_to_filename_for_display (symtab);

  str_obj = host_string_to_python_string (filename).release ();
  return str_obj;
}

static PyObject *
stpy_get_objfile (PyObject *self, void *closure)
{
  struct symtab *symtab = NULL;

  STPY_REQUIRE_VALID (self, symtab);

  return objfile_to_objfile_object (symtab->compunit ()->objfile ()).release ();
}

/* Getter function for symtab.producer.  */

static PyObject *
stpy_get_producer (PyObject *self, void *closure)
{
  struct symtab *symtab = NULL;
  struct compunit_symtab *cust;

  STPY_REQUIRE_VALID (self, symtab);
  cust = symtab->compunit ();
  if (cust->producer () != nullptr)
    {
      const char *producer = cust->producer ();

      return host_string_to_python_string (producer).release ();
    }

  Py_RETURN_NONE;
}

static PyObject *
stpy_fullname (PyObject *self, PyObject *args)
{
  const char *fullname;
  struct symtab *symtab = NULL;

  STPY_REQUIRE_VALID (self, symtab);

  fullname = symtab_to_fullname (symtab);

  return host_string_to_python_string (fullname).release ();
}

/* Implementation of gdb.Symtab.is_valid (self) -> Boolean.
   Returns True if this Symbol table still exists in GDB.  */

static PyObject *
stpy_is_valid (PyObject *self, PyObject *args)
{
  struct symtab *symtab = NULL;

  symtab = symtab_object_to_symtab (self);
  if (symtab == NULL)
    Py_RETURN_FALSE;

  Py_RETURN_TRUE;
}

/* Return the GLOBAL_BLOCK of the underlying symtab.  */

static PyObject *
stpy_global_block (PyObject *self, PyObject *args)
{
  struct symtab *symtab = NULL;
  const struct blockvector *blockvector;

  STPY_REQUIRE_VALID (self, symtab);

  blockvector = symtab->compunit ()->blockvector ();
  const struct block *block = blockvector->global_block ();

  return block_to_block_object (block, symtab->compunit ()->objfile ());
}

/* Return the STATIC_BLOCK of the underlying symtab.  */

static PyObject *
stpy_static_block (PyObject *self, PyObject *args)
{
  struct symtab *symtab = NULL;
  const struct blockvector *blockvector;

  STPY_REQUIRE_VALID (self, symtab);

  blockvector = symtab->compunit ()->blockvector ();
  const struct block *block = blockvector->static_block ();

  return block_to_block_object (block, symtab->compunit ()->objfile ());
}

/* Implementation of gdb.Symtab.linetable (self) -> gdb.LineTable.
   Returns a gdb.LineTable object corresponding to this symbol
   table.  */

static PyObject *
stpy_get_linetable (PyObject *self, PyObject *args)
{
  struct symtab *symtab = NULL;

  STPY_REQUIRE_VALID (self, symtab);

  return symtab_to_linetable_object (self);
}

static PyObject *
salpy_str (PyObject *self)
{
  const char *filename;
  sal_object *sal_obj;
  struct symtab_and_line *sal = nullptr;

  SALPY_REQUIRE_VALID (self, sal);

  sal_obj = (sal_object *) self;
  if (sal_obj->sal->symtab == nullptr)
    filename = "<unknown>";
  else
    filename = symtab_to_filename_for_display (sal_obj->sal->symtab);

  return PyUnicode_FromFormat ("symbol and line for %s, line %d", filename,
			       sal->line);
}

static void
stpy_dealloc (PyObject *obj)
{
  symtab_object *symtab_obj = (symtab_object *) obj;

  if (symtab_obj->symtab != nullptr)
    stpy_registry.remove (symtab_obj->symtab->compunit ()->objfile(),
			  symtab_obj);

  Py_TYPE (obj)->tp_free (obj);
}


static PyObject *
salpy_get_pc (PyObject *self, void *closure)
{
  struct symtab_and_line *sal = NULL;

  SALPY_REQUIRE_VALID (self, sal);

  return gdb_py_object_from_ulongest (sal->pc).release ();
}

/* Implementation of the get method for the 'last' attribute of
   gdb.Symtab_and_line.  */

static PyObject *
salpy_get_last (PyObject *self, void *closure)
{
  struct symtab_and_line *sal = NULL;

  SALPY_REQUIRE_VALID (self, sal);

  if (sal->end > 0)
    return gdb_py_object_from_ulongest (sal->end - 1).release ();
  else
    Py_RETURN_NONE;
}

static PyObject *
salpy_get_line (PyObject *self, void *closure)
{
  struct symtab_and_line *sal = NULL;

  SALPY_REQUIRE_VALID (self, sal);

  return gdb_py_object_from_longest (sal->line).release ();
}

static PyObject *
salpy_get_symtab (PyObject *self, void *closure)
{
  struct symtab_and_line *sal;

  SALPY_REQUIRE_VALID (self, sal);

  if (sal->symtab == nullptr)
    Py_RETURN_NONE;
  else
    return symtab_to_symtab_object (sal->symtab);
}

/* Implementation of gdb.Symtab_and_line.is_valid (self) -> Boolean.
   Returns True if this Symbol table and line object still exists GDB.  */

static PyObject *
salpy_is_valid (PyObject *self, PyObject *args)
{
  struct symtab_and_line *sal;

  sal = sal_object_to_symtab_and_line (self);
  if (sal == NULL)
    Py_RETURN_FALSE;

  Py_RETURN_TRUE;
}

static void
salpy_dealloc (PyObject *self)
{
  sal_object *self_sal = (sal_object *) self;

  if (self_sal->sal != nullptr && self_sal->sal->symtab != nullptr)
    salpy_registry.remove (self_sal->sal->symtab->compunit ()->objfile (),
			   self_sal);

  xfree (self_sal->sal);
  Py_TYPE (self)->tp_free (self);
}

/* Given a sal, and a sal_object that has previously been allocated
   and initialized, populate the sal_object with the struct sal data.
   Also, register the sal_object life-cycle with the life-cycle of the
   object file associated with this sal, if needed.  If a failure
   occurs during the sal population, this function will return -1.  */
static void
set_sal (sal_object *sal_obj, struct symtab_and_line sal)
{
  sal_obj->sal = ((struct symtab_and_line *)
		  xmemdup (&sal, sizeof (struct symtab_and_line),
			   sizeof (struct symtab_and_line)));
  sal_obj->prev = nullptr;
  sal_obj->next = nullptr;

  /* If the SAL does not have a symtab, we do not add it to the
     objfile cleanup observer linked list.  */
  symtab *symtab = sal_obj->sal->symtab;
  if (symtab != nullptr)
    salpy_registry.add (symtab->compunit ()->objfile (), sal_obj);
}

/* Given a symtab, and a symtab_object that has previously been
   allocated and initialized, populate the symtab_object with the
   struct symtab data.  Also, register the symtab_object life-cycle
   with the life-cycle of the object file associated with this
   symtab, if needed.  */
static void
set_symtab (symtab_object *obj, struct symtab *symtab)
{
  obj->symtab = symtab;
  if (symtab != nullptr)
    stpy_registry.add (symtab->compunit ()->objfile (), obj);
}

/* Create a new symbol table (gdb.Symtab) object that encapsulates the
   symtab structure from GDB.  */
PyObject *
symtab_to_symtab_object (struct symtab *symtab)
{
  symtab_object *symtab_obj;

  /* Look if there's already a gdb.Symtab object for given SYMTAB
     and if so, return it.  */
  if (symtab != nullptr)
    {
      symtab_obj = stpy_registry.lookup (symtab->compunit ()->objfile (),
					 symtab);
      if (symtab_obj != nullptr)
	return (PyObject*)symtab_obj;
    }

  symtab_obj = PyObject_New (symtab_object, &symtab_object_type);
  if (symtab_obj)
    set_symtab (symtab_obj, symtab);

  return (PyObject *) symtab_obj;
}

/* Create a new symtab and line (gdb.Symtab_and_line) object
   that encapsulates the symtab_and_line structure from GDB.  */
PyObject *
symtab_and_line_to_sal_object (struct symtab_and_line sal)
{
  sal_object *sal_obj;

  sal_obj = PyObject_New (sal_object, &sal_object_type);
  if (sal_obj != nullptr)
    set_sal (sal_obj, sal);

  return (PyObject *) sal_obj;
}

/* Return struct symtab_and_line reference that is wrapped by this
   object.  */
struct symtab_and_line *
sal_object_to_symtab_and_line (PyObject *obj)
{
  if (! PyObject_TypeCheck (obj, &sal_object_type))
    return NULL;
  return ((sal_object *) obj)->sal;
}

/* Return struct symtab reference that is wrapped by this object.  */
struct symtab *
symtab_object_to_symtab (PyObject *obj)
{
  if (! PyObject_TypeCheck (obj, &symtab_object_type))
    return NULL;
  return ((symtab_object *) obj)->symtab;
}

static int CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
gdbpy_initialize_symtabs (void)
{
  symtab_object_type.tp_new = PyType_GenericNew;
  if (gdbpy_type_ready (&symtab_object_type) < 0)
    return -1;

  sal_object_type.tp_new = PyType_GenericNew;
  if (gdbpy_type_ready (&sal_object_type) < 0)
    return -1;

  return 0;
}

GDBPY_INITIALIZE_FILE (gdbpy_initialize_symtabs);



static gdb_PyGetSetDef symtab_object_getset[] = {
  { "filename", stpy_get_filename, NULL,
    "The symbol table's source filename.", NULL },
  { "objfile", stpy_get_objfile, NULL, "The symtab's objfile.",
    NULL },
  { "producer", stpy_get_producer, NULL,
    "The name/version of the program that compiled this symtab.", NULL },
  {NULL}  /* Sentinel */
};

static PyMethodDef symtab_object_methods[] = {
  { "is_valid", stpy_is_valid, METH_NOARGS,
    "is_valid () -> Boolean.\n\
Return true if this symbol table is valid, false if not." },
  { "fullname", stpy_fullname, METH_NOARGS,
    "fullname () -> String.\n\
Return the symtab's full source filename." },
  { "global_block", stpy_global_block, METH_NOARGS,
    "global_block () -> gdb.Block.\n\
Return the global block of the symbol table." },
  { "static_block", stpy_static_block, METH_NOARGS,
    "static_block () -> gdb.Block.\n\
Return the static block of the symbol table." },
    { "linetable", stpy_get_linetable, METH_NOARGS,
    "linetable () -> gdb.LineTable.\n\
Return the LineTable associated with this symbol table" },
  {NULL}  /* Sentinel */
};

PyTypeObject symtab_object_type = {
  PyVarObject_HEAD_INIT (NULL, 0)
  "gdb.Symtab",			  /*tp_name*/
  sizeof (symtab_object),	  /*tp_basicsize*/
  0,				  /*tp_itemsize*/
  stpy_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*/
  stpy_str,			  /*tp_str*/
  0,				  /*tp_getattro*/
  0,				  /*tp_setattro*/
  0,				  /*tp_as_buffer*/
  Py_TPFLAGS_DEFAULT,		  /*tp_flags*/
  "GDB symtab object",		  /*tp_doc */
  0,				  /*tp_traverse */
  0,				  /*tp_clear */
  0,				  /*tp_richcompare */
  0,				  /*tp_weaklistoffset */
  0,				  /*tp_iter */
  0,				  /*tp_iternext */
  symtab_object_methods,	  /*tp_methods */
  0,				  /*tp_members */
  symtab_object_getset		  /*tp_getset */
};

static gdb_PyGetSetDef sal_object_getset[] = {
  { "symtab", salpy_get_symtab, NULL, "Symtab object.", NULL },
  { "pc", salpy_get_pc, NULL, "Return the symtab_and_line's pc.", NULL },
  { "last", salpy_get_last, NULL,
    "Return the symtab_and_line's last address.", NULL },
  { "line", salpy_get_line, NULL,
    "Return the symtab_and_line's line.", NULL },
  {NULL}  /* Sentinel */
};

static PyMethodDef sal_object_methods[] = {
  { "is_valid", salpy_is_valid, METH_NOARGS,
    "is_valid () -> Boolean.\n\
Return true if this symbol table and line is valid, false if not." },
  {NULL}  /* Sentinel */
};

PyTypeObject sal_object_type = {
  PyVarObject_HEAD_INIT (NULL, 0)
  "gdb.Symtab_and_line",	  /*tp_name*/
  sizeof (sal_object),		  /*tp_basicsize*/
  0,				  /*tp_itemsize*/
  salpy_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*/
  salpy_str,			  /*tp_str*/
  0,				  /*tp_getattro*/
  0,				  /*tp_setattro*/
  0,				  /*tp_as_buffer*/
  Py_TPFLAGS_DEFAULT,		  /*tp_flags*/
  "GDB symtab_and_line object",	  /*tp_doc */
  0,				  /*tp_traverse */
  0,				  /*tp_clear */
  0,				  /*tp_richcompare */
  0,				  /*tp_weaklistoffset */
  0,				  /*tp_iter */
  0,				  /*tp_iternext */
  sal_object_methods,		  /*tp_methods */
  0,				  /*tp_members */
  sal_object_getset		  /*tp_getset */
};