smatch_flow.c

   1 /*
   2  * sparse/smatch_flow.c
   3  *
   4  * Copyright (C) 2006,2008 Dan Carpenter.
   5  *
   6  *  Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <stdio.h>
  11 #include "token.h"
  12 #include "smatch.h"
  13
  14 int __smatch_lineno = 0;
  15
  16 static char *filename;
  17 static char *cur_func;
  18 static int line_func_start;
  19 static unsigned int path_id = 0;
  20 static unsigned int path_id_next = 1;
  21
  22 char *get_filename() {  return filename; }
  23 char *get_function() { return cur_func; }
  24 int get_lineno() { return __smatch_lineno; }
  25 int get_func_pos() { return __smatch_lineno - line_func_start; }
  26
  27 static void split_statements(struct statement *stmt);
  28 static void split_symlist(struct symbol_list *sym_list);
  29 static void split_expr_list(struct expression_list *expr_list);
  30
  31 unsigned int get_path_id()
  32 {
  33         return path_id;
  34 }
  35
  36 unsigned int __split_path_id()
  37 {
  38         int tmp = path_id;
  39
  40         path_id = path_id_next++;
  41         return tmp;
  42 }
  43
  44 void __restore_path_id(int old_id)
  45 {
  46         path_id = old_id;
  47 }
  48
  49
  50
  51 void __split_expr(struct expression *expr)
  52 {
  53         if (!expr)
  54                 return;
  55
  56         __smatch_lineno = expr->pos.line;
  57         __pass_to_client(expr, EXPR_HOOK);
  58
  59         // printf("%d Debug expr_type %d\n", get_lineno(), expr->type);
  60
  61         switch (expr->type) {
  62         case EXPR_PREOP:
  63         case EXPR_POSTOP:
  64                 if (expr->op == '*')
  65                         __pass_to_client(expr, DEREF_HOOK);
  66                 __split_expr(expr->unop);
  67                 return;
  68         case EXPR_STATEMENT:
  69                 split_statements(expr->statement);
  70                 return;
  71         case EXPR_BINOP:
  72         case EXPR_COMMA:
  73         case EXPR_COMPARE:
  74         case EXPR_LOGICAL:
  75         case EXPR_ASSIGNMENT:
  76                 if (expr->type == EXPR_ASSIGNMENT)
  77                         __pass_to_client(expr, ASSIGNMENT_HOOK);
  78                 __split_expr(expr->left);
  79                 __split_expr(expr->right);
  80                 if (expr->type == EXPR_ASSIGNMENT)
  81                         __pass_to_client(expr, ASSIGNMENT_AFTER_HOOK);
  82                 return;
  83         case EXPR_DEREF:
  84                 __pass_to_client(expr, DEREF_HOOK);
  85                 __split_expr(expr->deref);
  86                 return;
  87         case EXPR_SLICE:
  88                 __split_expr(expr->base);
  89                 return;
  90         case EXPR_CAST:
  91                 __split_expr(expr->cast_expression);
  92                 return;
  93         case EXPR_SIZEOF:
  94                 /* there isn't anything to pass a client from inside a sizeof() */
  95                 return;
  96         case EXPR_CONDITIONAL:
  97         case EXPR_SELECT:
  98                 __split_true_false_paths();
  99                 __pass_to_client(expr->conditional, WHOLE_CONDITION_HOOK);
 100                 __split_whole_condition(expr->conditional);
 101                 __use_true_states();
 102                 __split_expr(expr->cond_true);
 103                 __use_false_states();
 104                 __split_expr(expr->cond_false);
 105                 __merge_true_states();
 106                 return;
 107         case EXPR_CALL:
 108                 __pass_to_client(expr, FUNCTION_CALL_HOOK);
 109                 __split_expr(expr->fn);
 110                 split_expr_list(expr->args);
 111                 __pass_to_client(expr, FUNCTION_CALL_AFTER_HOOK);
 112 #ifdef KERNEL
 113                 if (expr->fn->type == EXPR_SYMBOL &&
 114                     !strcmp(expr->fn->symbol_name->name, "panic"))
 115                         nullify_path();
 116 #endif
 117                 return;
 118         case EXPR_INITIALIZER:
 119                 split_expr_list(expr->expr_list);
 120                 return;
 121         case EXPR_IDENTIFIER:
 122                 __split_expr(expr->ident_expression);
 123                 return;
 124         case EXPR_INDEX:
 125                 __split_expr(expr->idx_expression);
 126                 return;
 127         case EXPR_POS:
 128                 __split_expr(expr->init_expr);
 129                 return;
 130         default:
 131                 return;
 132         };
 133 }
 134
 135 static int is_forever_loop(struct statement *stmt)
 136 {
 137
 138         struct expression *expr;
 139
 140         expr = stmt->iterator_pre_condition;
 141         if (!expr)
 142                 expr = stmt->iterator_post_condition;
 143         if (!expr) {
 144                 // this is a for(;;) loop...
 145                 return 1;
 146         }
 147
 148         if (expr->type == EXPR_VALUE && expr->value == 1) {
 149                 return 1;
 150         }
 151
 152         return 0;
 153 }
 154
 155 /*
 156  * Pre Loops are while and for loops.
 157  */
 158
 159 static void handle_pre_loop(struct statement *stmt)
 160 {
 161         unsigned int path_orig;
 162
 163         split_statements(stmt->iterator_pre_statement);
 164
 165         __split_true_false_paths();
 166         __push_continues();
 167         __push_breaks();
 168         if (stmt->iterator_pre_condition) {
 169                 __pass_to_client(stmt->iterator_pre_condition, WHOLE_CONDITION_HOOK);
 170                 __split_whole_condition(stmt->iterator_pre_condition);
 171         }
 172         path_orig = __split_path_id();
 173         __use_true_states();
 174
 175         split_statements(stmt->iterator_statement);
 176         split_statements(stmt->iterator_post_statement);
 177         if (is_forever_loop(stmt)) {
 178                 __pop_continues();
 179                 __pop_false_states();
 180                 nullify_path();
 181         } else {
 182                 __merge_false_states();
 183                 __merge_continues();
 184         }
 185         __merge_breaks();
 186         __restore_path_id(path_orig);
 187 }
 188
 189 /*
 190  * Post loops are do {} while();
 191  */
 192 static void handle_post_loop(struct statement *stmt)
 193 {
 194         __push_continues();
 195         __push_breaks();
 196         split_statements(stmt->iterator_statement);
 197
 198         __split_true_false_paths();
 199         __pass_to_client(stmt->iterator_post_condition, WHOLE_CONDITION_HOOK);
 200         __split_whole_condition(stmt->iterator_post_condition);
 201         /* It would prossibly be cleaner to make this all one function */
 202         __use_true_states();
 203         __use_false_states();
 204         __pop_true_states();
 205
 206         if (is_forever_loop(stmt)) {
 207                 __pop_continues();
 208                 nullify_path();
 209         } else {
 210                 __merge_continues();
 211         }
 212         __merge_breaks();
 213 }
 214
 215 static void split_statements(struct statement *stmt)
 216 {
 217         unsigned int path_orig;
 218
 219         if (!stmt)
 220                 return;
 221
 222         __smatch_lineno = stmt->pos.line;
 223         __pass_to_client(stmt, STMT_HOOK);
 224
 225         switch (stmt->type) {
 226         case STMT_DECLARATION:
 227                 __pass_declarations_to_client(stmt->declaration);
 228                 split_symlist(stmt->declaration);
 229                 return;
 230         case STMT_RETURN:
 231                 __pass_to_client(stmt, RETURN_HOOK);
 232                 __split_expr(stmt->ret_value);
 233                 nullify_path();
 234                 return;
 235         case STMT_EXPRESSION:
 236                 __split_expr(stmt->expression);
 237                 return;
 238         case STMT_COMPOUND: {
 239                 struct statement *s;
 240                 FOR_EACH_PTR(stmt->stmts, s) {
 241                         split_statements(s);
 242                 } END_FOR_EACH_PTR(s);
 243                 return;
 244         }
 245         case STMT_IF:
 246                 __split_true_false_paths();
 247                 __pass_to_client(stmt->if_conditional, WHOLE_CONDITION_HOOK);
 248                 __split_whole_condition(stmt->if_conditional);
 249                 path_orig = __split_path_id();
 250                 __use_true_states();
 251                 split_statements(stmt->if_true);
 252                 __split_path_id();
 253                 __use_false_states();
 254                 split_statements(stmt->if_false);
 255                 __merge_true_states();
 256                 __restore_path_id(path_orig);
 257                 return;
 258         case STMT_ITERATOR:
 259                 if (stmt->iterator_pre_condition)
 260                         handle_pre_loop(stmt);
 261                 else if (stmt->iterator_post_condition)
 262                         handle_post_loop(stmt);
 263                 else {
 264                         // these are for(;;) type loops.
 265                         handle_pre_loop(stmt);
 266                 }
 267                 return;
 268         case STMT_SWITCH:
 269                 __split_expr(stmt->switch_expression);
 270                 __save_switch_states();
 271                 __push_default();
 272                 __push_breaks();
 273                 nullify_path();
 274                 path_orig = get_path_id();
 275                 split_statements(stmt->switch_statement);
 276                 if (!__pop_default())
 277                         __merge_switches();
 278                 __pop_switches();
 279                 __merge_breaks();
 280                 __restore_path_id(path_orig);
 281                 return;
 282         case STMT_CASE:
 283                 __split_path_id();
 284                 __merge_switches();
 285                 if (!stmt->case_expression)
 286                         __set_default();
 287                 __split_expr(stmt->case_expression);
 288                 __split_expr(stmt->case_to);
 289                 split_statements(stmt->case_statement);
 290                 return;
 291         case STMT_LABEL:
 292                 if (stmt->label &&
 293                     stmt->label->type == SYM_LABEL &&
 294                     stmt->label->ident) {
 295                         __merge_gotos(stmt->label->ident->name);
 296                 }
 297                 split_statements(stmt->label_statement);
 298                 return;
 299         case STMT_GOTO:
 300                 __split_expr(stmt->goto_expression);
 301                 if (stmt->goto_label && stmt->goto_label->type == SYM_NODE) {
 302                         if (!strcmp(stmt->goto_label->ident->name, "break")) {
 303                                 __process_breaks();
 304                         } else if (!strcmp(stmt->goto_label->ident->name,
 305                                            "continue")) {
 306                                 __process_continues();
 307                         }
 308                 } else if (stmt->goto_label &&
 309                            stmt->goto_label->type == SYM_LABEL &&
 310                            stmt->goto_label->ident) {
 311                         __save_gotos(stmt->goto_label->ident->name);
 312                 }
 313                 nullify_path();
 314                 return;
 315         case STMT_NONE:
 316                 return;
 317         case STMT_ASM:
 318                 __split_expr(stmt->asm_string);
 319                 //__split_expr(stmt->asm_outputs);
 320                 //__split_expr(stmt->asm_inputs);
 321                 //__split_expr(stmt->asm_clobbers);
 322                 return;
 323         case STMT_CONTEXT:
 324                 return;
 325         case STMT_RANGE:
 326                 __split_expr(stmt->range_expression);
 327                 __split_expr(stmt->range_low);
 328                 __split_expr(stmt->range_high);
 329                 return;
 330         }
 331 }
 332
 333 static void split_expr_list(struct expression_list *expr_list)
 334 {
 335         struct expression *expr;
 336         FOR_EACH_PTR(expr_list, expr) {
 337                 __split_expr(expr);
 338         } END_FOR_EACH_PTR(expr);
 339 }
 340
 341
 342 static void split_sym(struct symbol *sym)
 343 {
 344         if (!sym)
 345                 return;
 346         if (!(sym->namespace & NS_SYMBOL))
 347                 return;
 348
 349         __pass_to_client(sym, SYM_HOOK);
 350         split_statements(sym->stmt);
 351         __split_expr(sym->array_size);
 352         split_symlist(sym->arguments);
 353         split_symlist(sym->symbol_list);
 354         split_statements(sym->inline_stmt);
 355         split_symlist(sym->inline_symbol_list);
 356         __split_expr(sym->initializer);
 357 }
 358
 359 static void split_symlist(struct symbol_list *sym_list)
 360 {
 361         struct symbol *sym;
 362
 363         FOR_EACH_PTR(sym_list, sym) {
 364                 split_sym(sym);
 365         } END_FOR_EACH_PTR(sym);
 366 }
 367
 368 static void split_functions(struct symbol_list *sym_list)
 369 {
 370         struct symbol *sym;
 371
 372         FOR_EACH_PTR(sym_list, sym) {
 373                 struct symbol *base_type;
 374                 base_type = get_base_type(sym);
 375                 if (sym->type == SYM_NODE && base_type->type == SYM_FN) {
 376                         if (base_type->stmt)
 377                                 line_func_start = base_type->stmt->pos.line;
 378                         if (sym->ident)
 379                                 cur_func = sym->ident->name;
 380                         __smatch_lineno = sym->pos.line;
 381                         __pass_to_client(sym, FUNC_DEF_HOOK);
 382                         split_statements(base_type->stmt);
 383                         __pass_to_client(sym, END_FUNC_HOOK);
 384                         cur_func = NULL;
 385                         line_func_start = 0;
 386                         clear_all_states();
 387
 388                 } else {
 389                         __pass_to_client(sym, BASE_HOOK);
 390                 }
 391         } END_FOR_EACH_PTR(sym);
 392 }
 393
 394 void smatch (int argc, char **argv)
 395 {
 396
 397         struct string_list *filelist = NULL;
 398         struct symbol_list *sym_list;
 399
 400         if (argc < 2) {
 401                 printf("Usage:  smatch <filename.c>\n");
 402                 exit(1);
 403         }
 404         sparse_initialize(argc, argv, &filelist);
 405         FOR_EACH_PTR_NOTAG(filelist, filename) {
 406                 sym_list = __sparse(filename);
 407                 split_functions(sym_list);
 408         } END_FOR_EACH_PTR_NOTAG(filename);
 409 }