/*
 * Copyright 2023 Linaro Ltd.
 *
 * 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 2
 * 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/copyleft/gpl.txt
 */

#include "smatch.h"
#include "smatch_slist.h"
#include "smatch_extra.h"

static int my_id;

static struct statement *get_if_statement(struct expression *expr)
{
	struct statement *stmt, *parent;
	struct expression *tmp;
	int count = 0;

	stmt = get_parent_stmt(expr);
	if (!stmt)
		return NULL;
	stmt = stmt_get_parent_stmt(stmt);
	while (stmt &&
	       stmt->pos.line == expr->pos.line &&
	       stmt->pos.pos == expr->pos.pos) {
		if (count++ >= 5)
			break;
		parent = stmt_get_parent_stmt(stmt);
		if (!parent) {
			tmp = stmt_get_parent_expr(stmt);
			parent = get_parent_stmt(tmp);
		}
		stmt = parent;
	}

	if (!stmt)
		return NULL;
	if (stmt->type == STMT_COMPOUND)
		stmt = stmt_get_parent_stmt(stmt);
	if (!stmt || stmt->type != STMT_IF)
		return NULL;

	return stmt;
}

static struct expression *get_condition_var(struct expression *expr)
{
	expr = strip_expr(expr);

	if (expr->type == EXPR_COMPARE &&
	    (expr->op == SPECIAL_NOTEQUAL || expr->op == '<') &&
	    expr_is_zero(expr->right))
		return expr->left;

	return expr;
}

static void match_warn(const char *fn, struct expression *expr, void *_unused)
{
	struct statement *stmt;
	struct expression *var;

	stmt = get_if_statement(expr);
	if (!stmt)
		return;
	var = get_condition_var(stmt->if_conditional);
	if (!is_EPROBE_DEFER(var))
		return;

	sm_msg("EPROBE_DEFER path should not print warnings");
}

void check_eprobe_defer_is_silent(int id)
{
	const char *warn_fn[] = {
		"_dev_emerg", "_dev_crit", "_dev_alert", "_dev_err",
		"_dev_warn", "_dev_notice", "printk", "_printk"};
	int i;

	my_id = id;

	if (option_project != PROJ_KERNEL)
		return;

	for (i = 0; i < ARRAY_SIZE(warn_fn); i++)
		add_function_hook(warn_fn[i], &match_warn, NULL);
}