C++ TREE_ADDRESSABLE函数代码示例

void
mark_addressable (tree x)
{
  while (handled_component_p (x))
    x = TREE_OPERAND (x, 0);
  if (TREE_CODE (x) == MEM_REF
      && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
    x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
  if (TREE_CODE (x) != VAR_DECL
      && TREE_CODE (x) != PARM_DECL
      && TREE_CODE (x) != RESULT_DECL)
    return;
  TREE_ADDRESSABLE (x) = 1;

  /* Also mark the artificial SSA_NAME that points to the partition of X.  */
  if (TREE_CODE (x) == VAR_DECL
      && !DECL_EXTERNAL (x)
      && !TREE_STATIC (x)
      && cfun->gimple_df != NULL
      && cfun->gimple_df->decls_to_pointers != NULL)
    {
      tree *namep = cfun->gimple_df->decls_to_pointers->get (x);
      if (namep)
	TREE_ADDRESSABLE (*namep) = 1;
    }
}

void
cp_genericize (tree fndecl)
{
  tree t;
  struct pointer_set_t *p_set;

  /* Fix up the types of parms passed by invisible reference.  */
  for (t = DECL_ARGUMENTS (fndecl); t; t = TREE_CHAIN (t))
    if (TREE_ADDRESSABLE (TREE_TYPE (t)))
      {
	/* If a function's arguments are copied to create a thunk,
	   then DECL_BY_REFERENCE will be set -- but the type of the
	   argument will be a pointer type, so we will never get
	   here.  */
	gcc_assert (!DECL_BY_REFERENCE (t));
	gcc_assert (DECL_ARG_TYPE (t) != TREE_TYPE (t));
	TREE_TYPE (t) = DECL_ARG_TYPE (t);
	DECL_BY_REFERENCE (t) = 1;
	TREE_ADDRESSABLE (t) = 0;
	relayout_decl (t);
      }

  /* Do the same for the return value.  */
  if (TREE_ADDRESSABLE (TREE_TYPE (DECL_RESULT (fndecl))))
    {
      t = DECL_RESULT (fndecl);
      TREE_TYPE (t) = build_reference_type (TREE_TYPE (t));
      DECL_BY_REFERENCE (t) = 1;
      TREE_ADDRESSABLE (t) = 0;
      relayout_decl (t);
    }

  /* If we're a clone, the body is already GIMPLE.  */
  if (DECL_CLONED_FUNCTION_P (fndecl))
    return;

  /* We do want to see every occurrence of the parms, so we can't just use
     walk_tree's hash functionality.  */
  p_set = pointer_set_create ();
  cp_walk_tree (&DECL_SAVED_TREE (fndecl), cp_genericize_r, p_set, NULL);
  pointer_set_destroy (p_set);

  /* Do everything else.  */
  c_genericize (fndecl);

  gcc_assert (bc_label[bc_break] == NULL);
  gcc_assert (bc_label[bc_continue] == NULL);
}

tree
make_alias_for (tree function, tree newid)
{
    tree alias = build_decl (FUNCTION_DECL, newid, TREE_TYPE (function));
    DECL_LANG_SPECIFIC (alias) = DECL_LANG_SPECIFIC (function);
    cxx_dup_lang_specific_decl (alias);
    DECL_CONTEXT (alias) = NULL;
    TREE_READONLY (alias) = TREE_READONLY (function);
    TREE_THIS_VOLATILE (alias) = TREE_THIS_VOLATILE (function);
    TREE_PUBLIC (alias) = 0;
    DECL_INTERFACE_KNOWN (alias) = 1;
    DECL_NOT_REALLY_EXTERN (alias) = 1;
    DECL_THIS_STATIC (alias) = 1;
    DECL_SAVED_FUNCTION_DATA (alias) = NULL;
    DECL_DESTRUCTOR_P (alias) = 0;
    DECL_CONSTRUCTOR_P (alias) = 0;
    DECL_CLONED_FUNCTION (alias) = NULL_TREE;
    DECL_EXTERNAL (alias) = 0;
    DECL_ARTIFICIAL (alias) = 1;
    DECL_NO_STATIC_CHAIN (alias) = 1;
    DECL_PENDING_INLINE_P (alias) = 0;
    DECL_INLINE (alias) = 0;
    DECL_DECLARED_INLINE_P (alias) = 0;
    DECL_DEFERRED_FN (alias) = 0;
    DECL_USE_TEMPLATE (alias) = 0;
    DECL_TEMPLATE_INSTANTIATED (alias) = 0;
    DECL_TEMPLATE_INFO (alias) = NULL;
    DECL_INITIAL (alias) = error_mark_node;
    TREE_ADDRESSABLE (alias) = 1;
    TREE_USED (alias) = 1;
    SET_DECL_ASSEMBLER_NAME (alias, DECL_NAME (alias));
    TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias)) = 1;
    return alias;
}

static bool
suitable_for_tail_call_opt_p (void)
{
  tree param;

  /* alloca (until we have stack slot life analysis) inhibits
     sibling call optimizations, but not tail recursion.  */
  if (cfun->calls_alloca)
    return false;

  /* If we are using sjlj exceptions, we may need to add a call to
     _Unwind_SjLj_Unregister at exit of the function.  Which means
     that we cannot do any sibcall transformations.  */
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ
      && current_function_has_exception_handlers ())
    return false;

  /* Any function that calls setjmp might have longjmp called from
     any called function.  ??? We really should represent this
     properly in the CFG so that this needn't be special cased.  */
  if (cfun->calls_setjmp)
    return false;

  /* ??? It is OK if the argument of a function is taken in some cases,
     but not in all cases.  See PR15387 and PR19616.  Revisit for 4.1.  */
  for (param = DECL_ARGUMENTS (current_function_decl);
       param;
       param = DECL_CHAIN (param))
    if (TREE_ADDRESSABLE (param))
      return false;

  return true;
}

static inline void
unpack_ts_base_value_fields (struct bitpack_d *bp, tree expr)
{
  /* Note that the code for EXPR has already been unpacked to create EXPR in
     streamer_alloc_tree.  */
  if (!TYPE_P (expr))
    {
      TREE_SIDE_EFFECTS (expr) = (unsigned) bp_unpack_value (bp, 1);
      TREE_CONSTANT (expr) = (unsigned) bp_unpack_value (bp, 1);
      TREE_READONLY (expr) = (unsigned) bp_unpack_value (bp, 1);

      /* TREE_PUBLIC is used on types to indicate that the type
	 has a TYPE_CACHED_VALUES vector.  This is not streamed out,
	 so we skip it here.  */
      TREE_PUBLIC (expr) = (unsigned) bp_unpack_value (bp, 1);
    }
  else
    bp_unpack_value (bp, 4);
  TREE_ADDRESSABLE (expr) = (unsigned) bp_unpack_value (bp, 1);
  TREE_THIS_VOLATILE (expr) = (unsigned) bp_unpack_value (bp, 1);
  if (DECL_P (expr))
    DECL_UNSIGNED (expr) = (unsigned) bp_unpack_value (bp, 1);
  else if (TYPE_P (expr))
    TYPE_UNSIGNED (expr) = (unsigned) bp_unpack_value (bp, 1);
  else
    bp_unpack_value (bp, 1);
  TREE_ASM_WRITTEN (expr) = (unsigned) bp_unpack_value (bp, 1);
  if (TYPE_P (expr))
    TYPE_ARTIFICIAL (expr) = (unsigned) bp_unpack_value (bp, 1);
  else
    TREE_NO_WARNING (expr) = (unsigned) bp_unpack_value (bp, 1);
  TREE_NOTHROW (expr) = (unsigned) bp_unpack_value (bp, 1);
  TREE_STATIC (expr) = (unsigned) bp_unpack_value (bp, 1);
  if (TREE_CODE (expr) != TREE_BINFO)
    TREE_PRIVATE (expr) = (unsigned) bp_unpack_value (bp, 1);
  else
    bp_unpack_value (bp, 1);
  TREE_PROTECTED (expr) = (unsigned) bp_unpack_value (bp, 1);
  TREE_DEPRECATED (expr) = (unsigned) bp_unpack_value (bp, 1);
  if (TYPE_P (expr))
    {
      if (AGGREGATE_TYPE_P (expr))
	TYPE_REVERSE_STORAGE_ORDER (expr) = (unsigned) bp_unpack_value (bp, 1);
      else
	TYPE_SATURATING (expr) = (unsigned) bp_unpack_value (bp, 1);
      TYPE_ADDR_SPACE (expr) = (unsigned) bp_unpack_value (bp, 8);
    }
  else if (TREE_CODE (expr) == BIT_FIELD_REF || TREE_CODE (expr) == MEM_REF)
    {
      REF_REVERSE_STORAGE_ORDER (expr) = (unsigned) bp_unpack_value (bp, 1);
      bp_unpack_value (bp, 8);
    }
  else if (TREE_CODE (expr) == SSA_NAME)
    {
      SSA_NAME_IS_DEFAULT_DEF (expr) = (unsigned) bp_unpack_value (bp, 1);
      bp_unpack_value (bp, 8);
    }
  else
    bp_unpack_value (bp, 9);
}

static tree
build_equiv_decl (tree union_type, bool is_init)
{
  tree decl;

  if (is_init)
    {
      decl = gfc_create_var (union_type, "equiv");
      TREE_STATIC (decl) = 1;
      return decl;
    }

  decl = build_decl (VAR_DECL, NULL, union_type);
  DECL_ARTIFICIAL (decl) = 1;

  DECL_COMMON (decl) = 1;

  TREE_ADDRESSABLE (decl) = 1;
  TREE_USED (decl) = 1;

  /* The source location has been lost, and doesn't really matter.
     We need to set it to something though.  */
  gfc_set_decl_location (decl, &gfc_current_locus);

  gfc_add_decl_to_function (decl);

  return decl;
}

static tree
make_fname_decl ()
{
    const char *name = lang_hooks.decl_printable_name (current_function_decl, 0);
    tree decl, type, init;
    size_t length = strlen (name);

    type = build_array_type (build_type_variant (char_type_node, true, false),
                             build_index_type (size_int (length)));

    decl = build_decl (UNKNOWN_LOCATION, VAR_DECL,
                       get_identifier ("__function_name__"), type);

    TREE_STATIC (decl) = 1;
    TREE_READONLY (decl) = 1;
    DECL_ARTIFICIAL (decl) = 1;

    init = build_string (length + 1, name);
    TREE_TYPE (init) = type;
    TREE_READONLY (init) = 1;
    DECL_READ_P (decl) = 1;
    DECL_INITIAL (decl) = init;

    TREE_USED (decl) = 1;
    TREE_ADDRESSABLE (decl) = 1;
    DECL_CONTEXT (decl) = current_function_decl;

    return decl;
}

static tree
build_equiv_decl (tree union_type, bool is_init)
{
  tree decl;
  char name[15];
  static int serial = 0;

  if (is_init)
    {
      decl = gfc_create_var (union_type, "equiv");
      TREE_STATIC (decl) = 1;
      return decl;
    }

  snprintf (name, sizeof (name), "equiv.%d", serial++);
  decl = build_decl (VAR_DECL, get_identifier (name), union_type);
  DECL_ARTIFICIAL (decl) = 1;
  DECL_IGNORED_P (decl) = 1;

  if (!gfc_can_put_var_on_stack (DECL_SIZE_UNIT (decl)))
    TREE_STATIC (decl) = 1;

  TREE_ADDRESSABLE (decl) = 1;
  TREE_USED (decl) = 1;

  /* The source location has been lost, and doesn't really matter.
     We need to set it to something though.  */
  gfc_set_decl_location (decl, &gfc_current_locus);

  gfc_add_decl_to_function (decl);

  return decl;
}

static void
update_cloned_parm (tree parm, tree cloned_parm, bool first)
{
  DECL_ABSTRACT_ORIGIN (cloned_parm) = parm;

  /* We may have taken its address.  */
  TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm);

  /* The definition might have different constness.  */
  TREE_READONLY (cloned_parm) = TREE_READONLY (parm);

  TREE_USED (cloned_parm) = !first || TREE_USED (parm);

  /* The name may have changed from the declaration.  */
  DECL_NAME (cloned_parm) = DECL_NAME (parm);
  DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm);
  TREE_TYPE (cloned_parm) = TREE_TYPE (parm);
}

tree
copy_var_decl (tree var, tree name, tree type)
{
  tree copy = build_decl (DECL_SOURCE_LOCATION (var), VAR_DECL, name, type);

  TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (var);
  TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (var);
  DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (var);
  DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (var);
  DECL_IGNORED_P (copy) = DECL_IGNORED_P (var);
  DECL_CONTEXT (copy) = DECL_CONTEXT (var);
  TREE_NO_WARNING (copy) = TREE_NO_WARNING (var);
  TREE_USED (copy) = 1;
  DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
  DECL_ATTRIBUTES (copy) = DECL_ATTRIBUTES (var);

  return copy;
}

static void
mark_address_taken (tree ref)
{
  tree var;

  /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
     as the only thing we take the address of.  If VAR is a structure,
     taking the address of a field means that the whole structure may
     be referenced using pointer arithmetic.  See PR 21407 and the
     ensuing mailing list discussion.  */
  var = get_base_address (ref);
  if (var)
    {
      if (DECL_P (var))
	TREE_ADDRESSABLE (var) = 1;
      else if (TREE_CODE (var) == MEM_REF
	       && TREE_CODE (TREE_OPERAND (var, 0)) == ADDR_EXPR
	       && DECL_P (TREE_OPERAND (TREE_OPERAND (var, 0), 0)))
	TREE_ADDRESSABLE (TREE_OPERAND (TREE_OPERAND (var, 0), 0)) = 1;
    }
}

static void
mark_addressable_1 (tree x)
{
  if (!currently_expanding_to_rtl)
    {
      TREE_ADDRESSABLE (x) = 1;
      return;
    }

  if (!mark_addressable_queue)
    mark_addressable_queue = new hash_set<tree>();
  mark_addressable_queue->add (x);
}

/* Check whether the given decl, generally a VAR_DECL or PARM_DECL, is
   eligible for instrumentation.  For the mudflap1 pass, this implies
   that it should be registered with the libmudflap runtime.  For the
   mudflap2 pass this means instrumenting an indirection operation with
   respect to the object.
*/
static int
mf_decl_eligible_p (tree decl)
{
  return ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
          /* The decl must have its address taken.  In the case of
             arrays, this flag is also set if the indexes are not
             compile-time known valid constants.  */
          && TREE_ADDRESSABLE (decl)    /* XXX: not sufficient: return-by-value structs! */
          /* The type of the variable must be complete.  */
          && COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (decl))
	  /* The decl hasn't been decomposed somehow.  */
	  && !DECL_HAS_VALUE_EXPR_P (decl));
}

static void
pack_ts_base_value_fields (struct bitpack_d *bp, tree expr)
{
  bp_pack_value (bp, TREE_CODE (expr), 16);
  if (!TYPE_P (expr))
    {
      bp_pack_value (bp, TREE_SIDE_EFFECTS (expr), 1);
      bp_pack_value (bp, TREE_CONSTANT (expr), 1);
      bp_pack_value (bp, TREE_READONLY (expr), 1);

      /* TREE_PUBLIC is used on types to indicate that the type
	 has a TYPE_CACHED_VALUES vector.  This is not streamed out,
	 so we skip it here.  */
      bp_pack_value (bp, TREE_PUBLIC (expr), 1);
    }
  else
    bp_pack_value (bp, 0, 4);
  bp_pack_value (bp, TREE_ADDRESSABLE (expr), 1);
  bp_pack_value (bp, TREE_THIS_VOLATILE (expr), 1);
  if (DECL_P (expr))
    bp_pack_value (bp, DECL_UNSIGNED (expr), 1);
  else if (TYPE_P (expr))
    bp_pack_value (bp, TYPE_UNSIGNED (expr), 1);
  else
    bp_pack_value (bp, 0, 1);
  /* We write debug info two times, do not confuse the second one.
     The only relevant TREE_ASM_WRITTEN use is on SSA names.  */
  bp_pack_value (bp, (TREE_CODE (expr) != SSA_NAME
		      ? 0 : TREE_ASM_WRITTEN (expr)), 1);
  if (TYPE_P (expr))
    bp_pack_value (bp, TYPE_ARTIFICIAL (expr), 1);
  else
    bp_pack_value (bp, TREE_NO_WARNING (expr), 1);
  bp_pack_value (bp, TREE_NOTHROW (expr), 1);
  bp_pack_value (bp, TREE_STATIC (expr), 1);
  if (TREE_CODE (expr) != TREE_BINFO)
    bp_pack_value (bp, TREE_PRIVATE (expr), 1);
  bp_pack_value (bp, TREE_PROTECTED (expr), 1);
  bp_pack_value (bp, TREE_DEPRECATED (expr), 1);
  if (TYPE_P (expr))
    {
      bp_pack_value (bp, TYPE_SATURATING (expr), 1);
      bp_pack_value (bp, TYPE_ADDR_SPACE (expr), 8);
    }
  else if (TREE_CODE (expr) == SSA_NAME)
    bp_pack_value (bp, SSA_NAME_IS_DEFAULT_DEF (expr), 1);
  else
    bp_pack_value (bp, 0, 1);
}

static tree
make_alias_for_thunk (tree function)
{
  tree alias;
  char buf[256];

#if defined (TARGET_IS_PE_COFF)
  if (DECL_ONE_ONLY (function))
    return function;
#endif

  ASM_GENERATE_INTERNAL_LABEL (buf, "LTHUNK", thunk_labelno);
  thunk_labelno++;
  alias = build_decl (FUNCTION_DECL, get_identifier (buf),
		      TREE_TYPE (function));
  DECL_LANG_SPECIFIC (alias) = DECL_LANG_SPECIFIC (function);
  cxx_dup_lang_specific_decl (alias);
  DECL_CONTEXT (alias) = NULL;
  TREE_READONLY (alias) = TREE_READONLY (function);
  TREE_THIS_VOLATILE (alias) = TREE_THIS_VOLATILE (function);
  TREE_PUBLIC (alias) = 0;
  DECL_INTERFACE_KNOWN (alias) = 1;
  DECL_NOT_REALLY_EXTERN (alias) = 1;
  DECL_THIS_STATIC (alias) = 1;
  DECL_SAVED_FUNCTION_DATA (alias) = NULL;
  DECL_DESTRUCTOR_P (alias) = 0;
  DECL_CONSTRUCTOR_P (alias) = 0;
  DECL_CLONED_FUNCTION (alias) = NULL_TREE;
  DECL_EXTERNAL (alias) = 0;
  DECL_ARTIFICIAL (alias) = 1;
  DECL_NO_STATIC_CHAIN (alias) = 1;
  DECL_PENDING_INLINE_P (alias) = 0;
  DECL_INLINE (alias) = 0;
  DECL_DECLARED_INLINE_P (alias) = 0;
  DECL_DEFERRED_FN (alias) = 0;
  DECL_USE_TEMPLATE (alias) = 0;
  DECL_TEMPLATE_INSTANTIATED (alias) = 0;
  DECL_TEMPLATE_INFO (alias) = NULL;
  DECL_INITIAL (alias) = error_mark_node;
  TREE_ADDRESSABLE (alias) = 1;
  TREE_USED (alias) = 1;
  SET_DECL_ASSEMBLER_NAME (alias, DECL_NAME (alias));
  TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias)) = 1;
  if (!flag_syntax_only)
    assemble_alias (alias, DECL_ASSEMBLER_NAME (function));
  return alias;
}