1*1f5207b7SJohn Levon /* 2*1f5207b7SJohn Levon * Copyright (C) 2013 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 * The way I'm detecting missing breaks is if there is an assignment inside a 20*1f5207b7SJohn Levon * switch statement which is over written. 21*1f5207b7SJohn Levon * 22*1f5207b7SJohn Levon */ 23*1f5207b7SJohn Levon 24*1f5207b7SJohn Levon #include "smatch.h" 25*1f5207b7SJohn Levon #include "smatch_slist.h" 26*1f5207b7SJohn Levon 27*1f5207b7SJohn Levon static int my_id; 28*1f5207b7SJohn Levon static struct expression *skip_this; 29*1f5207b7SJohn Levon 30*1f5207b7SJohn Levon /* 31*1f5207b7SJohn Levon * It goes like this: 32*1f5207b7SJohn Levon * - Allocate a state which stores the switch expression. I wanted to 33*1f5207b7SJohn Levon * just have a state &assigned but we need to know the switch statement where 34*1f5207b7SJohn Levon * it was assigned. 35*1f5207b7SJohn Levon * - If it gets used then we change it to &used. 36*1f5207b7SJohn Levon * - For unmatched states we use &used (because of cleanness, not because we need 37*1f5207b7SJohn Levon * to). 38*1f5207b7SJohn Levon * - If we merge inside a case statement and one of the states is &assigned (or 39*1f5207b7SJohn Levon * if it is &nobreak) then &nobreak is used. 40*1f5207b7SJohn Levon * 41*1f5207b7SJohn Levon * We print an error when we assign something to a &no_break symbol. 42*1f5207b7SJohn Levon * 43*1f5207b7SJohn Levon */ 44*1f5207b7SJohn Levon 45*1f5207b7SJohn Levon STATE(used); 46*1f5207b7SJohn Levon STATE(no_break); 47*1f5207b7SJohn Levon 48*1f5207b7SJohn Levon static int in_switch_stmt; 49*1f5207b7SJohn Levon 50*1f5207b7SJohn Levon static struct smatch_state *alloc_my_state(struct expression *expr) 51*1f5207b7SJohn Levon { 52*1f5207b7SJohn Levon struct smatch_state *state; 53*1f5207b7SJohn Levon char *name; 54*1f5207b7SJohn Levon 55*1f5207b7SJohn Levon state = __alloc_smatch_state(0); 56*1f5207b7SJohn Levon expr = strip_expr(expr); 57*1f5207b7SJohn Levon name = expr_to_str(expr); 58*1f5207b7SJohn Levon if (!name) 59*1f5207b7SJohn Levon name = alloc_string(""); 60*1f5207b7SJohn Levon state->name = alloc_sname(name); 61*1f5207b7SJohn Levon free_string(name); 62*1f5207b7SJohn Levon state->data = expr; 63*1f5207b7SJohn Levon return state; 64*1f5207b7SJohn Levon } 65*1f5207b7SJohn Levon 66*1f5207b7SJohn Levon struct expression *last_print_expr; 67*1f5207b7SJohn Levon static void print_missing_break(struct expression *expr) 68*1f5207b7SJohn Levon { 69*1f5207b7SJohn Levon char *name; 70*1f5207b7SJohn Levon 71*1f5207b7SJohn Levon if (get_switch_expr() == last_print_expr) 72*1f5207b7SJohn Levon return; 73*1f5207b7SJohn Levon last_print_expr = get_switch_expr(); 74*1f5207b7SJohn Levon 75*1f5207b7SJohn Levon name = expr_to_var(expr); 76*1f5207b7SJohn Levon sm_warning("missing break? reassigning '%s'", name); 77*1f5207b7SJohn Levon free_string(name); 78*1f5207b7SJohn Levon } 79*1f5207b7SJohn Levon 80*1f5207b7SJohn Levon static void match_assign(struct expression *expr) 81*1f5207b7SJohn Levon { 82*1f5207b7SJohn Levon struct expression *left; 83*1f5207b7SJohn Levon 84*1f5207b7SJohn Levon if (expr->op != '=') 85*1f5207b7SJohn Levon return; 86*1f5207b7SJohn Levon if (!get_switch_expr()) 87*1f5207b7SJohn Levon return; 88*1f5207b7SJohn Levon left = strip_expr(expr->left); 89*1f5207b7SJohn Levon if (get_state_expr(my_id, left) == &no_break) 90*1f5207b7SJohn Levon print_missing_break(left); 91*1f5207b7SJohn Levon 92*1f5207b7SJohn Levon set_state_expr(my_id, left, alloc_my_state(get_switch_expr())); 93*1f5207b7SJohn Levon skip_this = left; 94*1f5207b7SJohn Levon } 95*1f5207b7SJohn Levon 96*1f5207b7SJohn Levon static void match_symbol(struct expression *expr) 97*1f5207b7SJohn Levon { 98*1f5207b7SJohn Levon if (outside_of_function()) 99*1f5207b7SJohn Levon return; 100*1f5207b7SJohn Levon if (!get_switch_expr()) 101*1f5207b7SJohn Levon return; 102*1f5207b7SJohn Levon 103*1f5207b7SJohn Levon expr = strip_expr(expr); 104*1f5207b7SJohn Levon if (expr == skip_this) 105*1f5207b7SJohn Levon return; 106*1f5207b7SJohn Levon set_state_expr(my_id, expr, &used); 107*1f5207b7SJohn Levon } 108*1f5207b7SJohn Levon 109*1f5207b7SJohn Levon static struct smatch_state *unmatched_state(struct sm_state *sm) 110*1f5207b7SJohn Levon { 111*1f5207b7SJohn Levon return &used; 112*1f5207b7SJohn Levon } 113*1f5207b7SJohn Levon 114*1f5207b7SJohn Levon static int in_case; 115*1f5207b7SJohn Levon static struct smatch_state *merge_hook(struct smatch_state *s1, struct smatch_state *s2) 116*1f5207b7SJohn Levon { 117*1f5207b7SJohn Levon struct expression *switch_expr; 118*1f5207b7SJohn Levon 119*1f5207b7SJohn Levon if (s1 == &no_break || s2 == &no_break) 120*1f5207b7SJohn Levon return &no_break; 121*1f5207b7SJohn Levon if (!in_case) 122*1f5207b7SJohn Levon return &used; 123*1f5207b7SJohn Levon switch_expr = get_switch_expr(); 124*1f5207b7SJohn Levon if (s1->data == switch_expr || s2->data == switch_expr) 125*1f5207b7SJohn Levon return &no_break; 126*1f5207b7SJohn Levon return &used; 127*1f5207b7SJohn Levon } 128*1f5207b7SJohn Levon 129*1f5207b7SJohn Levon static void match_stmt(struct statement *stmt) 130*1f5207b7SJohn Levon { 131*1f5207b7SJohn Levon if (stmt->type == STMT_CASE) 132*1f5207b7SJohn Levon in_case = 1; 133*1f5207b7SJohn Levon else 134*1f5207b7SJohn Levon in_case = 0; 135*1f5207b7SJohn Levon } 136*1f5207b7SJohn Levon 137*1f5207b7SJohn Levon static void match_switch(struct statement *stmt) 138*1f5207b7SJohn Levon { 139*1f5207b7SJohn Levon if (stmt->type != STMT_SWITCH) 140*1f5207b7SJohn Levon return; 141*1f5207b7SJohn Levon 142*1f5207b7SJohn Levon in_switch_stmt++; 143*1f5207b7SJohn Levon } 144*1f5207b7SJohn Levon 145*1f5207b7SJohn Levon static void delete_my_states(int owner) 146*1f5207b7SJohn Levon { 147*1f5207b7SJohn Levon struct state_list *slist = NULL; 148*1f5207b7SJohn Levon struct sm_state *sm; 149*1f5207b7SJohn Levon 150*1f5207b7SJohn Levon FOR_EACH_MY_SM(owner, __get_cur_stree(), sm) { 151*1f5207b7SJohn Levon add_ptr_list(&slist, sm); 152*1f5207b7SJohn Levon } END_FOR_EACH_SM(sm); 153*1f5207b7SJohn Levon 154*1f5207b7SJohn Levon FOR_EACH_PTR(slist, sm) { 155*1f5207b7SJohn Levon delete_state(sm->owner, sm->name, sm->sym); 156*1f5207b7SJohn Levon } END_FOR_EACH_PTR(sm); 157*1f5207b7SJohn Levon 158*1f5207b7SJohn Levon free_slist(&slist); 159*1f5207b7SJohn Levon } 160*1f5207b7SJohn Levon 161*1f5207b7SJohn Levon static void match_switch_end(struct statement *stmt) 162*1f5207b7SJohn Levon { 163*1f5207b7SJohn Levon 164*1f5207b7SJohn Levon if (stmt->type != STMT_SWITCH) 165*1f5207b7SJohn Levon return; 166*1f5207b7SJohn Levon 167*1f5207b7SJohn Levon in_switch_stmt--; 168*1f5207b7SJohn Levon 169*1f5207b7SJohn Levon if (!in_switch_stmt) 170*1f5207b7SJohn Levon delete_my_states(my_id); 171*1f5207b7SJohn Levon } 172*1f5207b7SJohn Levon 173*1f5207b7SJohn Levon void check_missing_break(int id) 174*1f5207b7SJohn Levon { 175*1f5207b7SJohn Levon my_id = id; 176*1f5207b7SJohn Levon 177*1f5207b7SJohn Levon if (!option_spammy) 178*1f5207b7SJohn Levon return; 179*1f5207b7SJohn Levon 180*1f5207b7SJohn Levon add_unmatched_state_hook(my_id, &unmatched_state); 181*1f5207b7SJohn Levon add_merge_hook(my_id, &merge_hook); 182*1f5207b7SJohn Levon 183*1f5207b7SJohn Levon add_hook(&match_assign, ASSIGNMENT_HOOK); 184*1f5207b7SJohn Levon add_hook(&match_symbol, SYM_HOOK); 185*1f5207b7SJohn Levon add_hook(&match_stmt, STMT_HOOK); 186*1f5207b7SJohn Levon add_hook(&match_switch, STMT_HOOK); 187*1f5207b7SJohn Levon add_hook(&match_switch_end, STMT_HOOK_AFTER); 188*1f5207b7SJohn Levon } 189