1*1f5207b7SJohn Levon /* 2*1f5207b7SJohn Levon * Copyright (C) 2017 Oracle. 3*1f5207b7SJohn Levon * 4*1f5207b7SJohn Levon * This program is free software; you can redistribute it and/or 5*1f5207b7SJohn Levon * modify it under the terms of the GNU General Public License 6*1f5207b7SJohn Levon * as published by the Free Software Foundation; either version 2 7*1f5207b7SJohn Levon * of the License, or (at your option) any later version. 8*1f5207b7SJohn Levon * 9*1f5207b7SJohn Levon * This program is distributed in the hope that it will be useful, 10*1f5207b7SJohn Levon * but WITHOUT ANY WARRANTY; without even the implied warranty of 11*1f5207b7SJohn Levon * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12*1f5207b7SJohn Levon * GNU General Public License for more details. 13*1f5207b7SJohn Levon * 14*1f5207b7SJohn Levon * You should have received a copy of the GNU General Public License 15*1f5207b7SJohn Levon * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt 16*1f5207b7SJohn Levon */ 17*1f5207b7SJohn Levon 18*1f5207b7SJohn Levon /* 19*1f5207b7SJohn Levon * Say you have assign a function to a function pointer and you assign a 20*1f5207b7SJohn Levon * pointer to the data argument then we want to record some information about 21*1f5207b7SJohn Levon * the argument. Right now what I mainly want to record is the type of it, I 22*1f5207b7SJohn Levon * guess. 23*1f5207b7SJohn Levon * 24*1f5207b7SJohn Levon */ 25*1f5207b7SJohn Levon 26*1f5207b7SJohn Levon #include "smatch.h" 27*1f5207b7SJohn Levon #include "smatch_extra.h" 28*1f5207b7SJohn Levon #include "smatch_slist.h" 29*1f5207b7SJohn Levon #include <ctype.h> 30*1f5207b7SJohn Levon 31*1f5207b7SJohn Levon static int my_id; 32*1f5207b7SJohn Levon 33*1f5207b7SJohn Levon static int assigns_parameters(struct expression *fn, struct expression *arg) 34*1f5207b7SJohn Levon { 35*1f5207b7SJohn Levon int fn_param, arg_param; 36*1f5207b7SJohn Levon char buf[32]; 37*1f5207b7SJohn Levon 38*1f5207b7SJohn Levon fn_param = get_param_num(fn); 39*1f5207b7SJohn Levon if (fn_param < 0) 40*1f5207b7SJohn Levon return 0; 41*1f5207b7SJohn Levon 42*1f5207b7SJohn Levon arg_param = get_param_num(arg); 43*1f5207b7SJohn Levon if (arg_param < 0) 44*1f5207b7SJohn Levon return 0; 45*1f5207b7SJohn Levon 46*1f5207b7SJohn Levon snprintf(buf, sizeof(buf), "%d", arg_param); 47*1f5207b7SJohn Levon sql_insert_return_implies(FN_ARG_LINK, fn_param, "$", buf); 48*1f5207b7SJohn Levon return 1; 49*1f5207b7SJohn Levon } 50*1f5207b7SJohn Levon 51*1f5207b7SJohn Levon static void link_function_arg(struct expression *fn, int param, struct expression *arg) 52*1f5207b7SJohn Levon { 53*1f5207b7SJohn Levon struct symbol *type; 54*1f5207b7SJohn Levon 55*1f5207b7SJohn Levon if (!fn || !arg) 56*1f5207b7SJohn Levon return; 57*1f5207b7SJohn Levon if (assigns_parameters(fn, arg)) 58*1f5207b7SJohn Levon return; 59*1f5207b7SJohn Levon 60*1f5207b7SJohn Levon type = get_type(arg); 61*1f5207b7SJohn Levon if (!type || type->type != SYM_PTR) 62*1f5207b7SJohn Levon return; 63*1f5207b7SJohn Levon type = get_real_base_type(type); 64*1f5207b7SJohn Levon if (!type) 65*1f5207b7SJohn Levon return; 66*1f5207b7SJohn Levon // FIXME: param shouldn't always be 0? 67*1f5207b7SJohn Levon sql_insert_fn_data_link(fn, PASSES_TYPE, param, "$", type_to_str(type)); 68*1f5207b7SJohn Levon } 69*1f5207b7SJohn Levon 70*1f5207b7SJohn Levon char *next_param_name; 71*1f5207b7SJohn Levon struct symbol *next_param_sym; 72*1f5207b7SJohn Levon struct expression *next_fn; 73*1f5207b7SJohn Levon static void match_assign_param(struct expression *expr) 74*1f5207b7SJohn Levon { 75*1f5207b7SJohn Levon struct symbol *sym; 76*1f5207b7SJohn Levon char *name; 77*1f5207b7SJohn Levon 78*1f5207b7SJohn Levon if (!next_param_name) 79*1f5207b7SJohn Levon return; 80*1f5207b7SJohn Levon 81*1f5207b7SJohn Levon name = expr_to_var_sym(expr->left, &sym); 82*1f5207b7SJohn Levon if (!name || !sym) { 83*1f5207b7SJohn Levon free_string(name); 84*1f5207b7SJohn Levon return; 85*1f5207b7SJohn Levon } 86*1f5207b7SJohn Levon 87*1f5207b7SJohn Levon if (sym != next_param_sym || 88*1f5207b7SJohn Levon strcmp(name, next_param_name) != 0) 89*1f5207b7SJohn Levon return; 90*1f5207b7SJohn Levon 91*1f5207b7SJohn Levon link_function_arg(next_fn, 0, strip_expr(expr->right)); 92*1f5207b7SJohn Levon 93*1f5207b7SJohn Levon next_param_name = 0; 94*1f5207b7SJohn Levon next_param_sym = NULL; 95*1f5207b7SJohn Levon next_fn = NULL; 96*1f5207b7SJohn Levon } 97*1f5207b7SJohn Levon 98*1f5207b7SJohn Levon static int get_arg_ptr(void *_arg_ptr, int argc, char **argv, char **azColName) 99*1f5207b7SJohn Levon { 100*1f5207b7SJohn Levon char **arg_ptr = _arg_ptr; 101*1f5207b7SJohn Levon 102*1f5207b7SJohn Levon *arg_ptr = NULL; 103*1f5207b7SJohn Levon if (argc != 1) 104*1f5207b7SJohn Levon return 0; 105*1f5207b7SJohn Levon *arg_ptr = alloc_string(argv[0]); 106*1f5207b7SJohn Levon return 0; 107*1f5207b7SJohn Levon } 108*1f5207b7SJohn Levon 109*1f5207b7SJohn Levon static char *get_data_member(char *fn_member, struct expression *expr, struct symbol **sym) 110*1f5207b7SJohn Levon { 111*1f5207b7SJohn Levon struct symbol *tmp_sym; 112*1f5207b7SJohn Levon char *fn_str; 113*1f5207b7SJohn Levon char *arg_ptr = NULL; 114*1f5207b7SJohn Levon char *end_type; 115*1f5207b7SJohn Levon int len_ptr, len_str; 116*1f5207b7SJohn Levon char buf[128]; 117*1f5207b7SJohn Levon 118*1f5207b7SJohn Levon *sym = NULL; 119*1f5207b7SJohn Levon run_sql(get_arg_ptr, &arg_ptr, 120*1f5207b7SJohn Levon "select data from fn_ptr_data_link where fn_ptr = '%s';", fn_member); 121*1f5207b7SJohn Levon if (!arg_ptr) 122*1f5207b7SJohn Levon return NULL; 123*1f5207b7SJohn Levon end_type = strchr(arg_ptr, '>'); 124*1f5207b7SJohn Levon if (!end_type) 125*1f5207b7SJohn Levon return NULL; 126*1f5207b7SJohn Levon end_type++; 127*1f5207b7SJohn Levon fn_str = expr_to_var_sym(expr, &tmp_sym); 128*1f5207b7SJohn Levon if (!fn_str || !tmp_sym) 129*1f5207b7SJohn Levon return NULL; 130*1f5207b7SJohn Levon len_ptr = strlen(fn_member); 131*1f5207b7SJohn Levon len_str = strlen(fn_str); 132*1f5207b7SJohn Levon while (len_str > 0 && len_ptr > 0) { 133*1f5207b7SJohn Levon if (fn_str[len_str - 1] != fn_member[len_ptr - 1]) 134*1f5207b7SJohn Levon break; 135*1f5207b7SJohn Levon if (fn_str[len_str - 1] == '>') 136*1f5207b7SJohn Levon break; 137*1f5207b7SJohn Levon len_str--; 138*1f5207b7SJohn Levon len_ptr--; 139*1f5207b7SJohn Levon } 140*1f5207b7SJohn Levon 141*1f5207b7SJohn Levon strncpy(buf, fn_str, sizeof(buf)); 142*1f5207b7SJohn Levon snprintf(buf + len_str, sizeof(buf) - len_str, end_type); 143*1f5207b7SJohn Levon *sym = tmp_sym; 144*1f5207b7SJohn Levon return alloc_string(buf); 145*1f5207b7SJohn Levon } 146*1f5207b7SJohn Levon 147*1f5207b7SJohn Levon static void match_assign_function(struct expression *expr) 148*1f5207b7SJohn Levon { 149*1f5207b7SJohn Levon struct expression *right, *arg; 150*1f5207b7SJohn Levon struct symbol *sym; 151*1f5207b7SJohn Levon char *data_member; 152*1f5207b7SJohn Levon struct symbol *type; 153*1f5207b7SJohn Levon char *member_name; 154*1f5207b7SJohn Levon 155*1f5207b7SJohn Levon right = strip_expr(expr->right); 156*1f5207b7SJohn Levon if (right->type == EXPR_PREOP && right->op == '&') 157*1f5207b7SJohn Levon right = strip_expr(right->unop); 158*1f5207b7SJohn Levon 159*1f5207b7SJohn Levon type = get_type(right); 160*1f5207b7SJohn Levon if (type && type->type == SYM_PTR) 161*1f5207b7SJohn Levon type = get_real_base_type(type); 162*1f5207b7SJohn Levon if (!type || type->type != SYM_FN) 163*1f5207b7SJohn Levon return; 164*1f5207b7SJohn Levon 165*1f5207b7SJohn Levon member_name = get_member_name(expr->left); 166*1f5207b7SJohn Levon if (!member_name) 167*1f5207b7SJohn Levon return; 168*1f5207b7SJohn Levon 169*1f5207b7SJohn Levon data_member = get_data_member(member_name, expr->left, &sym); 170*1f5207b7SJohn Levon if (!data_member || !sym) { 171*1f5207b7SJohn Levon free_string(data_member); 172*1f5207b7SJohn Levon data_member = NULL; 173*1f5207b7SJohn Levon } 174*1f5207b7SJohn Levon 175*1f5207b7SJohn Levon arg = get_assigned_expr_name_sym(data_member, sym); 176*1f5207b7SJohn Levon if (arg) { 177*1f5207b7SJohn Levon link_function_arg(right, 0, arg); 178*1f5207b7SJohn Levon } else { 179*1f5207b7SJohn Levon next_param_name = data_member; 180*1f5207b7SJohn Levon next_param_sym = sym; 181*1f5207b7SJohn Levon next_fn = right; 182*1f5207b7SJohn Levon } 183*1f5207b7SJohn Levon } 184*1f5207b7SJohn Levon 185*1f5207b7SJohn Levon static int is_recursive_call(struct expression *call) 186*1f5207b7SJohn Levon { 187*1f5207b7SJohn Levon if (call->fn->type != EXPR_SYMBOL) 188*1f5207b7SJohn Levon return 0; 189*1f5207b7SJohn Levon if (call->fn->symbol == cur_func_sym) 190*1f5207b7SJohn Levon return 1; 191*1f5207b7SJohn Levon return 0; 192*1f5207b7SJohn Levon } 193*1f5207b7SJohn Levon 194*1f5207b7SJohn Levon static void check_passes_fn_and_data(struct expression *call, struct expression *fn, char *key, char *value) 195*1f5207b7SJohn Levon { 196*1f5207b7SJohn Levon struct expression *arg; 197*1f5207b7SJohn Levon struct symbol *type; 198*1f5207b7SJohn Levon int data_nr; 199*1f5207b7SJohn Levon 200*1f5207b7SJohn Levon if (is_recursive_call(call)) 201*1f5207b7SJohn Levon return; 202*1f5207b7SJohn Levon 203*1f5207b7SJohn Levon type = get_type(fn); 204*1f5207b7SJohn Levon if (!type || type->type != SYM_FN) 205*1f5207b7SJohn Levon return; 206*1f5207b7SJohn Levon 207*1f5207b7SJohn Levon if (!isdigit(value[0])) 208*1f5207b7SJohn Levon return; 209*1f5207b7SJohn Levon data_nr = atoi(value); 210*1f5207b7SJohn Levon arg = get_argument_from_call_expr(call->args, data_nr); 211*1f5207b7SJohn Levon if (!arg) 212*1f5207b7SJohn Levon return; 213*1f5207b7SJohn Levon link_function_arg(fn, 0, arg); 214*1f5207b7SJohn Levon } 215*1f5207b7SJohn Levon 216*1f5207b7SJohn Levon static void match_end_func(struct symbol *sym) 217*1f5207b7SJohn Levon { 218*1f5207b7SJohn Levon next_param_sym = NULL; 219*1f5207b7SJohn Levon next_fn = NULL; 220*1f5207b7SJohn Levon } 221*1f5207b7SJohn Levon 222*1f5207b7SJohn Levon void register_about_fn_ptr_arg(int id) 223*1f5207b7SJohn Levon { 224*1f5207b7SJohn Levon my_id = id; 225*1f5207b7SJohn Levon 226*1f5207b7SJohn Levon if (0 && !option_info) 227*1f5207b7SJohn Levon return; 228*1f5207b7SJohn Levon add_hook(match_assign_param, ASSIGNMENT_HOOK); 229*1f5207b7SJohn Levon add_hook(match_assign_function, ASSIGNMENT_HOOK); 230*1f5207b7SJohn Levon select_return_implies_hook(FN_ARG_LINK, &check_passes_fn_and_data); 231*1f5207b7SJohn Levon add_hook(&match_end_func, END_FUNC_HOOK); 232*1f5207b7SJohn Levon } 233