1 /* 2 * Copyright (C) 2012 Oracle. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt 16 */ 17 18 #include "smatch.h" 19 #include "smatch_extra.h" 20 21 static int my_id; 22 23 static void match_shift_mask(struct expression *expr) 24 { 25 struct expression *right, *shifter; 26 struct range_list *rl; 27 char *str; 28 29 expr = strip_expr(expr); 30 if (expr->type != EXPR_BINOP || expr->op != '&') 31 return; 32 33 if (get_type(expr->left) != &ullong_ctype) 34 return; 35 36 if (type_bits(get_type(expr->right)) == 64) 37 return; 38 39 right = strip_expr(expr->right); 40 if (right->type != EXPR_BINOP || right->op != SPECIAL_LEFTSHIFT) 41 return; 42 43 shifter = strip_expr(right->right); 44 get_real_absolute_rl(shifter, &rl); 45 if (rl_max(rl).uvalue < 32) 46 return; 47 48 str = expr_to_str(expr->right); 49 sm_warning("should '%s' be a 64 bit type?", str); 50 free_string(str); 51 } 52 53 static void match_shift_assignment(struct expression *expr) 54 { 55 struct symbol *left_type, *right_type; 56 struct expression *right; 57 sval_t sval; 58 sval_t bits, shifter; 59 char *name; 60 61 right = strip_expr(expr->right); 62 if (right->type != EXPR_BINOP || right->op != SPECIAL_LEFTSHIFT) 63 return; 64 65 left_type = get_type(expr->left); 66 if (left_type != &llong_ctype && left_type != &ullong_ctype) 67 return; 68 69 right_type = get_type(expr->right); 70 71 if (type_bits(right_type) == 64) 72 return; 73 74 if (get_value(right, &sval)) 75 return; 76 77 get_absolute_max(right->left, &bits); 78 get_absolute_max(right->right, &shifter); 79 80 bits = sval_cast(&ullong_ctype, bits); 81 if (sval_cmp_val(shifter, 32) < 0) { 82 sval = sval_binop(bits, SPECIAL_LEFTSHIFT, shifter); 83 if (sval_cmp_val(sval, UINT_MAX) < 0) 84 return; 85 } 86 87 name = expr_to_str_sym(right, NULL); 88 sm_warning("should '%s' be a 64 bit type?", name); 89 free_string(name); 90 } 91 92 void check_64bit_shift(int id) 93 { 94 my_id = id; 95 96 add_hook(&match_shift_assignment, ASSIGNMENT_HOOK); 97 add_hook(&match_shift_mask, BINOP_HOOK); 98 } 99