gcc/analyzer/call-details.cc

/* Helper class for handling a call with specific arguments.
   Copyright (C) 2020-2023 Free Software Foundation, Inc.
   Contributed by David Malcolm <dmalcolm@redhat.com>.

This file is part of GCC.

GCC 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, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#define INCLUDE_MEMORY
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "function.h"
#include "basic-block.h"
#include "gimple.h"
#include "diagnostic-core.h"
#include "analyzer/analyzer.h"
#include "analyzer/analyzer-logging.h"
#include "diagnostic.h"
#include "tree-diagnostic.h" /* for default_tree_printer.  */
#include "gimple-pretty-print.h"
#include "analyzer/region-model.h"
#include "analyzer/call-details.h"

#if ENABLE_ANALYZER

namespace ana {

/* class call_details.  */

/* call_details's ctor.  */

call_details::call_details (const gcall *call, region_model *model,
			    region_model_context *ctxt)
: m_call (call), m_model (model), m_ctxt (ctxt),
  m_lhs_type (NULL_TREE), m_lhs_region (NULL)
{
  m_lhs_type = NULL_TREE;
  if (tree lhs = gimple_call_lhs (call))
    {
      m_lhs_region = model->get_lvalue (lhs, ctxt);
      m_lhs_type = TREE_TYPE (lhs);
    }
}

/* Get the manager from m_model.  */

region_model_manager *
call_details::get_manager () const
{
  return m_model->get_manager ();
}

/* Get any logger associated with this object.  */

logger *
call_details::get_logger () const
{
  if (m_ctxt)
    return m_ctxt->get_logger ();
  else
    return NULL;
}

/* Get any uncertainty_t associated with the region_model_context.  */

uncertainty_t *
call_details::get_uncertainty () const
{
  if (m_ctxt)
    return m_ctxt->get_uncertainty ();
  else
    return NULL;
}

/* If the callsite has a left-hand-side region, set it to RESULT
   and return true.
   Otherwise do nothing and return false.  */

bool
call_details::maybe_set_lhs (const svalue *result) const
{
  gcc_assert (result);
  if (m_lhs_region)
    {
      m_model->set_value (m_lhs_region, result, m_ctxt);
      return true;
    }
  else
    return false;
}

/* Return the number of arguments used by the call statement.  */

unsigned
call_details::num_args () const
{
  return gimple_call_num_args (m_call);
}

/* Return true if argument IDX is a size_t (or compatible with it).  */

bool
call_details::arg_is_size_p (unsigned idx) const
{
  return types_compatible_p (get_arg_type (idx), size_type_node);
}

/* Get the location of the call statement.  */

location_t
call_details::get_location () const
{
  return m_call->location;
}

/* Get argument IDX at the callsite as a tree.  */

tree
call_details::get_arg_tree (unsigned idx) const
{
  return gimple_call_arg (m_call, idx);
}

/* Get the type of argument IDX.  */

tree
call_details::get_arg_type (unsigned idx) const
{
  return TREE_TYPE (gimple_call_arg (m_call, idx));
}

/* Get argument IDX at the callsite as an svalue.  */

const svalue *
call_details::get_arg_svalue (unsigned idx) const
{
  tree arg = get_arg_tree (idx);
  return m_model->get_rvalue (arg, m_ctxt);
}

/* Attempt to get the string literal for argument IDX, or return NULL
   otherwise.
   For use when implementing "__analyzer_*" functions that take
   string literals.  */

const char *
call_details::get_arg_string_literal (unsigned idx) const
{
  const svalue *str_arg = get_arg_svalue (idx);
  if (const region *pointee = str_arg->maybe_get_region ())
    if (const string_region *string_reg = pointee->dyn_cast_string_region ())
      {
	tree string_cst = string_reg->get_string_cst ();
	return TREE_STRING_POINTER (string_cst);
      }
  return NULL;
}

/* Attempt to get the fndecl used at this call, if known, or NULL_TREE
   otherwise.  */

tree
call_details::get_fndecl_for_call () const
{
  return m_model->get_fndecl_for_call (m_call, m_ctxt);
}

/* Dump a multiline representation of this call to PP.  */

void
call_details::dump_to_pp (pretty_printer *pp, bool simple) const
{
  pp_string (pp, "gcall: ");
  pp_gimple_stmt_1 (pp, m_call, 0 /* spc */, TDF_NONE /* flags */);
  pp_newline (pp);
  pp_string (pp, "return region: ");
  if (m_lhs_region)
    m_lhs_region->dump_to_pp (pp, simple);
  else
    pp_string (pp, "NULL");
  pp_newline (pp);
  for (unsigned i = 0; i < gimple_call_num_args (m_call); i++)
    {
      const svalue *arg_sval = get_arg_svalue (i);
      pp_printf (pp, "arg %i: ", i);
      arg_sval->dump_to_pp (pp, simple);
      pp_newline (pp);
    }
}

/* Dump a multiline representation of this call to stderr.  */

DEBUG_FUNCTION void
call_details::dump (bool simple) const
{
  pretty_printer pp;
  pp_format_decoder (&pp) = default_tree_printer;
  pp_show_color (&pp) = pp_show_color (global_dc->printer);
  pp.buffer->stream = stderr;
  dump_to_pp (&pp, simple);
  pp_flush (&pp);
}

/* Get a conjured_svalue for this call for REG,
   and purge any state already relating to that conjured_svalue.  */

const svalue *
call_details::get_or_create_conjured_svalue (const region *reg) const
{
  region_model_manager *mgr = m_model->get_manager ();
  return mgr->get_or_create_conjured_svalue (reg->get_type (), m_call, reg,
					     conjured_purge (m_model, m_ctxt));
}

} // namespace ana

#endif /* #if ENABLE_ANALYZER */