#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "alloc-pool.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "builtins.h"
#include "options.h"
#include "gimple-range.h"
#include "attribs.h"
#include "attr-callback.h"

Include dependency graph for attr-callback.cc:

Functions
tree	callback_build_attr (unsigned fn_idx, unsigned arg_count...)
bool	callback_is_special_cased (tree decl, gcall *stmt)
tree	callback_special_case_attr (tree decl)
int	callback_get_fn_index (tree cb_attr)
tree	callback_fetch_attr_by_edge (cgraph_edge e, cgraph_edge carrying)
auto_vec< int >	callback_get_arg_mapping (cgraph_edge e, cgraph_edge carrying)
int	callback_fetch_fn_position (cgraph_edge e, cgraph_edge carrying)
static tree	get_nth_list_elem (tree list, unsigned idx)
tree	handle_callback_attribute (tree node, tree name, tree args, int ARG_UNUSED(flags), bool no_add_attrs)
bool	callback_edge_useful_p (cgraph_edge *e)
size_t	callback_num_args (tree attr)

Function Documentation

◆ callback_build_attr()

tree callback_build_attr	(	unsigned	fn_idx,
		unsigned	arg_count... )

Callback attribute handling
Copyright (C) 2025 Free Software Foundation, Inc.
Contributed by Josef Melcr <jmelcr@gcc.gnu.org>

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify
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.

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/>.

Returns a callback attribute with callback index FN_IDX, and ARG_COUNT
arguments specified by VA_ARGS.

References build_int_cst(), build_tree_list(), CALLBACK_ATTR_IDENT, get_identifier(), i, integer_type_node, NULL, NULL_TREE, PASS_MEM_STAT, TREE_CHAIN, and tree_cons().

Referenced by callback_special_case_attr(), and set_call_expr_flags().

◆ callback_edge_useful_p()

bool callback_edge_useful_p ( cgraph_edge * e )

Returns TRUE if E is considered useful in the callgraph, FALSE otherwise.  If
this predicate returns FALSE, then E wasn't used to optimize its callee and
can be safely removed from the callgraph.

References gcc_checking_assert.

Referenced by purge_useless_callback_edges().

◆ callback_fetch_attr_by_edge()

tree callback_fetch_attr_by_edge	(	cgraph_edge *	e,
		cgraph_edge *	carrying )

For a given callback pair, retrieves the callback attribute used
to create E from the callee of CARRYING.

References cgraph_edge::call_stmt, CALLBACK_ATTR_IDENT, callback_get_fn_index(), callback_is_special_cased(), callback_special_case_attr(), cgraph_edge::callee, symtab_node::decl, DECL_ATTRIBUTES, gcc_checking_assert, lookup_attribute(), cgraph_edge::lto_stmt_uid, NULL_TREE, and TREE_CHAIN.

Referenced by callback_fetch_fn_position(), and callback_get_arg_mapping().

◆ callback_fetch_fn_position()

int callback_fetch_fn_position	(	cgraph_edge *	e,
		cgraph_edge *	carrying )

For a callback pair, returns the 0-based index of the address of
E's callee in the argument list of CARRYING's callee decl.

References callback_fetch_attr_by_edge(), and callback_get_fn_index().

Referenced by cgraph_edge::redirect_call_stmt_to_callee().

◆ callback_get_arg_mapping()

auto_vec< int > callback_get_arg_mapping	(	cgraph_edge *	e,
		cgraph_edge *	carrying )

Given an instance of callback attribute, return the 0-base indices
of arguments passed to the callback.  For a callback function taking
n parameters, returns a vector of n indices of their values in the parameter
list of it's caller.  Indices with unknown positions contain -1.

References callback_fetch_attr_by_edge(), CB_UNKNOWN_POS, gcc_checking_assert, NULL_TREE, TREE_CHAIN, TREE_INT_CST_LOW, and TREE_VALUE.

Referenced by ipa_compute_jump_functions_for_edge().

◆ callback_get_fn_index()

int callback_get_fn_index ( tree cb_attr )

Given an instance of callback attribute, return the 0-based
index of the called function in question.

References TREE_INT_CST_LOW, and TREE_VALUE.

Referenced by callback_fetch_attr_by_edge(), callback_fetch_fn_position(), handle_callback_attribute(), and ipa_compute_jump_functions_for_edge().

◆ callback_is_special_cased()

bool callback_is_special_cased	(	tree	decl,
		gcall *	stmt )

Returns TRUE if a function should be treated as if it had a callback
attribute despite the DECL not having it.  STMT can be passed NULL
if the call statement is not available at the time, for example WPA, but it
should be called with the statement itself whenever possible.

References fndecl_built_in_p(), gimple_call_arg(), and null_pointer_node.

Referenced by callback_fetch_attr_by_edge(), ipa_compute_jump_functions_for_edge(), purge_useless_callback_edges(), cgraph_edge::redirect_call_stmt_to_callee(), and cgraph_node::verify_node().

◆ callback_num_args()

size_t callback_num_args ( tree attr )

Returns the number of arguments the callback function described by ATTR
takes.

References NULL_TREE, TREE_CHAIN, and TREE_VALUE.

Referenced by init_callback_edge_summary().

◆ callback_special_case_attr()

tree callback_special_case_attr ( tree decl )

Returns an attribute for a special cased function.

References callback_build_attr(), fndecl_built_in_p(), and gcc_unreachable.

Referenced by callback_fetch_attr_by_edge(), and ipa_compute_jump_functions_for_edge().

◆ get_nth_list_elem()

tree get_nth_list_elem	(	tree	list,
		unsigned	idx )

static

Returns the element at index idx in the list or NULL_TREE if
the list isn't long enough.  NULL_TREE is used as the endpoint.

References i, NULL_TREE, TREE_CHAIN, and TREE_VALUE.

Referenced by handle_callback_attribute().

◆ handle_callback_attribute()

tree handle_callback_attribute	(	tree *	node,
		tree	name,
		tree	args,
		int	ARG_UNUSEDflags,
		bool *	no_add_attrs )

Handle a "callback" attribute; arguments as in
struct attribute_spec.handler.

References arg_type, CALLBACK_ATTR_IDENT, callback_get_fn_index(), CB_UNKNOWN_POS, DECL_ATTRIBUTES, DECL_SOURCE_LOCATION, error_at(), get_nth_list_elem(), list_length(), lookup_attribute(), NULL_TREE, TREE_CHAIN, TREE_CODE, TREE_INT_CST_LOW, TREE_TYPE, TREE_VALUE, TYPE_ARG_TYPES, types_compatible_p(), and void_list_node.

Functions