check_return_negative_var.c

   1 /*
   2  * smatch/check_return.c
   3  *
   4  * Copyright (C) 2011 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11 #include "smatch_slist.h"
  12
  13 static int my_id;
  14
  15 static void match_return(struct expression *ret_value)
  16 {
  17         struct expression *expr;
  18         char *macro;
  19
  20         if (!ret_value)
  21                 return;
  22         expr = ret_value;
  23         if (ret_value->type != EXPR_PREOP || ret_value->op != '-')
  24                 return;
  25
  26         macro = get_macro_name(expr->unop->pos);
  27         if (macro && !strcmp(macro, "PTR_ERR")) {
  28                 sm_msg("warn: returning -%s()", macro);
  29                 return;
  30         }
  31
  32         if (!option_spammy)
  33                 return;
  34
  35         expr = get_assigned_expr(ret_value->unop);
  36         if (!expr)
  37                 return;
  38         if (expr->type != EXPR_CALL)
  39                 return;
  40
  41         sm_msg("warn: should this return really be negated?");
  42 }
  43
  44 void check_return_negative_var(int id)
  45 {
  46         if (option_project != PROJ_KERNEL)
  47                 return;
  48
  49         my_id = id;
  50         add_hook(&match_return, RETURN_HOOK);
  51 }