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