Exemplo n.º 1
0
void
maybe_add_lambda_conv_op (tree type)
{
  bool nested = (cfun != NULL);
  bool nested_def = decl_function_context (TYPE_MAIN_DECL (type));
  tree callop = lambda_function (type);

  if (LAMBDA_EXPR_CAPTURE_LIST (CLASSTYPE_LAMBDA_EXPR (type)) != NULL_TREE)
    return;

  if (processing_template_decl)
    return;

  bool const generic_lambda_p
    = (DECL_TEMPLATE_INFO (callop)
    && DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (callop)) == callop);

  if (!generic_lambda_p && DECL_INITIAL (callop) == NULL_TREE)
    {
      /* If the op() wasn't instantiated due to errors, give up.  */
      gcc_assert (errorcount || sorrycount);
      return;
    }

  /* Non-template conversion operators are defined directly with build_call_a
     and using DIRECT_ARGVEC for arguments (including 'this').  Templates are
     deferred and the CALL is built in-place.  In the case of a deduced return
     call op, the decltype expression, DECLTYPE_CALL, used as a substitute for
     the return type is also built in-place.  The arguments of DECLTYPE_CALL in
     the return expression may differ in flags from those in the body CALL.  In
     particular, parameter pack expansions are marked PACK_EXPANSION_LOCAL_P in
     the body CALL, but not in DECLTYPE_CALL.  */

  vec<tree, va_gc> *direct_argvec = 0;
  tree decltype_call = 0, call = 0;
  tree fn_result = TREE_TYPE (TREE_TYPE (callop));

  if (generic_lambda_p)
    {
      /* Prepare the dependent member call for the static member function
	 '_FUN' and, potentially, prepare another call to be used in a decltype
	 return expression for a deduced return call op to allow for simple
	 implementation of the conversion operator.  */

      tree instance = build_nop (type, null_pointer_node);
      tree objfn = build_min (COMPONENT_REF, NULL_TREE,
			      instance, DECL_NAME (callop), NULL_TREE);
      int nargs = list_length (DECL_ARGUMENTS (callop)) - 1;

      call = prepare_op_call (objfn, nargs);
      if (type_uses_auto (fn_result))
	decltype_call = prepare_op_call (objfn, nargs);
    }
  else
    {
      direct_argvec = make_tree_vector ();
      direct_argvec->quick_push (build1 (NOP_EXPR,
					 TREE_TYPE (DECL_ARGUMENTS (callop)),
					 null_pointer_node));
    }

  /* Copy CALLOP's argument list (as per 'copy_list') as FN_ARGS in order to
     declare the static member function "_FUN" below.  For each arg append to
     DIRECT_ARGVEC (for the non-template case) or populate the pre-allocated
     call args (for the template case).  If a parameter pack is found, expand
     it, flagging it as PACK_EXPANSION_LOCAL_P for the body call.  */

  tree fn_args = NULL_TREE;
  {
    int ix = 0;
    tree src = DECL_CHAIN (DECL_ARGUMENTS (callop));
    tree tgt;

    while (src)
      {
	tree new_node = copy_node (src);

	if (!fn_args)
	  fn_args = tgt = new_node;
	else
	  {
	    TREE_CHAIN (tgt) = new_node;
	    tgt = new_node;
	  }

	mark_exp_read (tgt);

	if (generic_lambda_p)
	  {
	    if (DECL_PACK_P (tgt))
	      {
		tree a = make_pack_expansion (tgt);
		if (decltype_call)
		  CALL_EXPR_ARG (decltype_call, ix) = copy_node (a);
		PACK_EXPANSION_LOCAL_P (a) = true;
		CALL_EXPR_ARG (call, ix) = a;
	      }
	    else
	      {
		tree a = convert_from_reference (tgt);
		CALL_EXPR_ARG (call, ix) = a;
		if (decltype_call)
		  CALL_EXPR_ARG (decltype_call, ix) = copy_node (a);
	      }
	    ++ix;
	  }
	else
	  vec_safe_push (direct_argvec, tgt);

	src = TREE_CHAIN (src);
      }
  }


  if (generic_lambda_p)
    {
      if (decltype_call)
	{
	  ++processing_template_decl;
	  fn_result = finish_decltype_type
	    (decltype_call, /*id_expression_or_member_access_p=*/false,
	     tf_warning_or_error);
	  --processing_template_decl;
	}
    }
  else
    call = build_call_a (callop,
			 direct_argvec->length (),
			 direct_argvec->address ());

  CALL_FROM_THUNK_P (call) = 1;

  tree stattype = build_function_type (fn_result, FUNCTION_ARG_CHAIN (callop));

  /* First build up the conversion op.  */

  tree rettype = build_pointer_type (stattype);
  tree name = mangle_conv_op_name_for_type (rettype);
  tree thistype = cp_build_qualified_type (type, TYPE_QUAL_CONST);
  tree fntype = build_method_type_directly (thistype, rettype, void_list_node);
  tree convfn = build_lang_decl (FUNCTION_DECL, name, fntype);
  tree fn = convfn;
  DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (callop);

  if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn
      && DECL_ALIGN (fn) < 2 * BITS_PER_UNIT)
    DECL_ALIGN (fn) = 2 * BITS_PER_UNIT;

  SET_OVERLOADED_OPERATOR_CODE (fn, TYPE_EXPR);
  grokclassfn (type, fn, NO_SPECIAL);
  set_linkage_according_to_type (type, fn);
  rest_of_decl_compilation (fn, toplevel_bindings_p (), at_eof);
  DECL_IN_AGGR_P (fn) = 1;
  DECL_ARTIFICIAL (fn) = 1;
  DECL_NOT_REALLY_EXTERN (fn) = 1;
  DECL_DECLARED_INLINE_P (fn) = 1;
  DECL_ARGUMENTS (fn) = build_this_parm (fntype, TYPE_QUAL_CONST);
  if (nested_def)
    DECL_INTERFACE_KNOWN (fn) = 1;

  if (generic_lambda_p)
    fn = add_inherited_template_parms (fn, DECL_TI_TEMPLATE (callop));

  add_method (type, fn, NULL_TREE);

  /* Generic thunk code fails for varargs; we'll complain in mark_used if
     the conversion op is used.  */
  if (varargs_function_p (callop))
    {
      DECL_DELETED_FN (fn) = 1;
      return;
    }

  /* Now build up the thunk to be returned.  */

  name = get_identifier ("_FUN");
  tree statfn = build_lang_decl (FUNCTION_DECL, name, stattype);
  fn = statfn;
  DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (callop);
  if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn
      && DECL_ALIGN (fn) < 2 * BITS_PER_UNIT)
    DECL_ALIGN (fn) = 2 * BITS_PER_UNIT;
  grokclassfn (type, fn, NO_SPECIAL);
  set_linkage_according_to_type (type, fn);
  rest_of_decl_compilation (fn, toplevel_bindings_p (), at_eof);
  DECL_IN_AGGR_P (fn) = 1;
  DECL_ARTIFICIAL (fn) = 1;
  DECL_NOT_REALLY_EXTERN (fn) = 1;
  DECL_DECLARED_INLINE_P (fn) = 1;
  DECL_STATIC_FUNCTION_P (fn) = 1;
  DECL_ARGUMENTS (fn) = fn_args;
  for (tree arg = fn_args; arg; arg = DECL_CHAIN (arg))
    {
      /* Avoid duplicate -Wshadow warnings.  */
      DECL_NAME (arg) = NULL_TREE;
      DECL_CONTEXT (arg) = fn;
    }
  if (nested_def)
    DECL_INTERFACE_KNOWN (fn) = 1;

  if (generic_lambda_p)
    fn = add_inherited_template_parms (fn, DECL_TI_TEMPLATE (callop));

  add_method (type, fn, NULL_TREE);

  if (nested)
    push_function_context ();
  else
    /* Still increment function_depth so that we don't GC in the
       middle of an expression.  */
    ++function_depth;

  /* Generate the body of the thunk.  */

  start_preparsed_function (statfn, NULL_TREE,
			    SF_PRE_PARSED | SF_INCLASS_INLINE);
  if (DECL_ONE_ONLY (statfn))
    {
      /* Put the thunk in the same comdat group as the call op.  */
      cgraph_node::get_create (statfn)->add_to_same_comdat_group
	(cgraph_node::get_create (callop));
    }
  tree body = begin_function_body ();
  tree compound_stmt = begin_compound_stmt (0);
  if (!generic_lambda_p)
    {
      set_flags_from_callee (call);
      if (MAYBE_CLASS_TYPE_P (TREE_TYPE (call)))
	call = build_cplus_new (TREE_TYPE (call), call, tf_warning_or_error);
    }
  call = convert_from_reference (call);
  finish_return_stmt (call);

  finish_compound_stmt (compound_stmt);
  finish_function_body (body);

  fn = finish_function (/*inline*/2);
  if (!generic_lambda_p)
    expand_or_defer_fn (fn);

  /* Generate the body of the conversion op.  */

  start_preparsed_function (convfn, NULL_TREE,
			    SF_PRE_PARSED | SF_INCLASS_INLINE);
  body = begin_function_body ();
  compound_stmt = begin_compound_stmt (0);

  /* decl_needed_p needs to see that it's used.  */
  TREE_USED (statfn) = 1;
  finish_return_stmt (decay_conversion (statfn, tf_warning_or_error));

  finish_compound_stmt (compound_stmt);
  finish_function_body (body);

  fn = finish_function (/*inline*/2);
  if (!generic_lambda_p)
    expand_or_defer_fn (fn);

  if (nested)
    pop_function_context ();
  else
    --function_depth;
}
Exemplo n.º 2
0
tree
do_friend (tree ctype, tree declarator, tree decl,
           tree attrlist, enum overload_flags flags,
           bool funcdef_flag)
{
    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
    gcc_assert (!ctype || MAYBE_CLASS_TYPE_P (ctype));

    /* Every decl that gets here is a friend of something.  */
    DECL_FRIEND_P (decl) = 1;

    /* Unfortunately, we have to handle attributes here.  Normally we would
       handle them in start_decl_1, but since this is a friend decl start_decl_1
       never gets to see it.  */

    /* Set attributes here so if duplicate decl, will have proper attributes.  */
    cplus_decl_attributes (&decl, attrlist, 0);

    if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
    {
        declarator = TREE_OPERAND (declarator, 0);
        if (is_overloaded_fn (declarator))
            declarator = DECL_NAME (get_first_fn (declarator));
    }

    if (ctype)
    {
        /* CLASS_TEMPLATE_DEPTH counts the number of template headers for
        the enclosing class.  FRIEND_DEPTH counts the number of template
         headers used for this friend declaration.  TEMPLATE_MEMBER_P is
         true if a template header in FRIEND_DEPTH is intended for
         DECLARATOR.  For example, the code

           template <class T> struct A {
             template <class U> struct B {
               template <class V> template <class W>
        	 friend void C<V>::f(W);
             };
           };

         will eventually give the following results

         1. CLASS_TEMPLATE_DEPTH equals 2 (for `T' and `U').
         2. FRIEND_DEPTH equals 2 (for `V' and `W').
         3. TEMPLATE_MEMBER_P is true (for `W').  */

        int class_template_depth = template_class_depth (current_class_type);
        int friend_depth = processing_template_decl - class_template_depth;
        /* We will figure this out later.  */
        bool template_member_p = false;

        tree cname = TYPE_NAME (ctype);
        if (TREE_CODE (cname) == TYPE_DECL)
            cname = DECL_NAME (cname);

        /* A method friend.  */
        if (flags == NO_SPECIAL && declarator == cname)
            DECL_CONSTRUCTOR_P (decl) = 1;

        grokclassfn (ctype, decl, flags);

        if (friend_depth)
        {
            if (!uses_template_parms_level (ctype, class_template_depth
                                            + friend_depth))
                template_member_p = true;
        }

        /* A nested class may declare a member of an enclosing class
        to be a friend, so we do lookup here even if CTYPE is in
         the process of being defined.  */
        if (class_template_depth
                || COMPLETE_TYPE_P (ctype)
                || (CLASS_TYPE_P (ctype) && TYPE_BEING_DEFINED (ctype)))
        {
            if (DECL_TEMPLATE_INFO (decl))
                /* DECL is a template specialization.  No need to
                   build a new TEMPLATE_DECL.  */
                ;
            else if (class_template_depth)
                /* We rely on tsubst_friend_function to check the
                   validity of the declaration later.  */
                decl = push_template_decl_real (decl, /*is_friend=*/true);
            else
                decl = check_classfn (ctype, decl,
                                      template_member_p
                                      ? current_template_parms
                                      : NULL_TREE);

            if (template_member_p && decl && TREE_CODE (decl) == FUNCTION_DECL)
                decl = DECL_TI_TEMPLATE (decl);

            if (decl)
                add_friend (current_class_type, decl, /*complain=*/true);
        }
        else
            error ("member %qD declared as friend before type %qT defined",
                   decl, ctype);
    }
    /* A global friend.
       @@ or possibly a friend from a base class ?!?  */
    else if (TREE_CODE (decl) == FUNCTION_DECL)
    {
        int is_friend_template = PROCESSING_REAL_TEMPLATE_DECL_P ();

        /* Friends must all go through the overload machinery,
        even though they may not technically be overloaded.

         Note that because classes all wind up being top-level
         in their scope, their friend wind up in top-level scope as well.  */
        if (funcdef_flag)
            SET_DECL_FRIEND_CONTEXT (decl, current_class_type);

        if (! DECL_USE_TEMPLATE (decl))
        {
            /* We must check whether the decl refers to template
               arguments before push_template_decl_real adds a
               reference to the containing template class.  */
            int warn = (warn_nontemplate_friend
                        && ! funcdef_flag && ! is_friend_template
                        && current_template_parms
                        && uses_template_parms (decl));

            if (is_friend_template
                    || template_class_depth (current_class_type) != 0)
                /* We can't call pushdecl for a template class, since in
                   general, such a declaration depends on template
                   parameters.  Instead, we call pushdecl when the class
                   is instantiated.  */
                decl = push_template_decl_real (decl, /*is_friend=*/true);
            else if (current_function_decl)
            {
                /* This must be a local class.  11.5p11:

                If a friend declaration appears in a local class (9.8) and
                 the name specified is an unqualified name, a prior
                 declaration is looked up without considering scopes that
                 are outside the innermost enclosing non-class scope. For a
                 friend function declaration, if there is no prior
                 declaration, the program is ill-formed.  */
                tree t = lookup_name_innermost_nonclass_level (DECL_NAME (decl));
                if (t)
                    decl = pushdecl_maybe_friend (decl, /*is_friend=*/true);
                else
                {
                    error ("friend declaration %qD in local class without "
                           "prior declaration", decl);
                    return error_mark_node;
                }
            }
            else
            {
                /* We can't use pushdecl, as we might be in a template
                class specialization, and pushdecl will insert an
                 unqualified friend decl into the template parameter
                 scope, rather than the namespace containing it.  */
                tree ns = decl_namespace_context (decl);

                push_nested_namespace (ns);
                decl = pushdecl_namespace_level (decl, /*is_friend=*/true);
                pop_nested_namespace (ns);
            }

            if (warn)
            {
                static int explained;
                bool warned;

                warned = warning (OPT_Wnon_template_friend, "friend declaration "
                                  "%q#D declares a non-template function", decl);
                if (! explained && warned)
                {
                    inform (input_location, "(if this is not what you intended, make sure "
                            "the function template has already been declared "
                            "and add <> after the function name here) ");
                    explained = 1;
                }
            }
        }

        if (decl == error_mark_node)
            return error_mark_node;

        add_friend (current_class_type,
                    is_friend_template ? DECL_TI_TEMPLATE (decl) : decl,
                    /*complain=*/true);
        DECL_FRIEND_P (decl) = 1;
    }

    return decl;
}