smatch_function_ptrs.c

   1 /*
   2  * smatch/smatch_function_ptrs.c
   3  *
   4  * Copyright (C) 2013 Oracle.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * Track how functions are saved as various struct members or passed as
  12  * parameters.
  13  *
  14  */
  15
  16 #include "smatch.h"
  17 #include "smatch_slist.h"
  18
  19 static int my_id;
  20
  21 static void match_passes_function_pointer(struct expression *expr)
  22 {
  23         struct expression *arg, *tmp;
  24         struct symbol *type;
  25         char *called_name;
  26         char *fn_name;
  27         char ptr_name[256];
  28         int i;
  29
  30
  31         i = -1;
  32         FOR_EACH_PTR(expr->args, arg) {
  33                 i++;
  34
  35                 tmp = strip_expr(arg);
  36                 if (tmp->type == EXPR_PREOP && tmp->op == '&')
  37                         tmp = strip_expr(tmp->unop);
  38                 type = get_type(tmp);
  39                 if (!type || type->type != SYM_FN)
  40                         continue;
  41
  42                 called_name = expr_to_var(expr->fn);
  43                 if (!called_name)
  44                         return;
  45                 fn_name = expr_to_var(tmp);
  46                 if (!fn_name)
  47                         goto free;
  48
  49                 snprintf(ptr_name, sizeof(ptr_name), "%s param %d", called_name, i);
  50                 sql_insert_function_ptr(fn_name, ptr_name);
  51 free:
  52                 free_string(fn_name);
  53                 free_string(called_name);
  54         } END_FOR_EACH_PTR(arg);
  55
  56 }
  57
  58 static void match_function_assign(struct expression *expr)
  59 {
  60         struct expression *right = expr->right;
  61         struct symbol *sym;
  62         char *fn_name;
  63         char *ptr_name;
  64
  65         if (right->type == EXPR_PREOP && right->op == '&')
  66                 right = strip_expr(right->unop);
  67         if (right->type != EXPR_SYMBOL)
  68                 return;
  69         sym = get_type(right);
  70         if (!sym || sym->type != SYM_FN)
  71                 return;
  72
  73         fn_name = expr_to_var(right);
  74         ptr_name = get_fnptr_name(expr->left);
  75         if (!fn_name || !ptr_name)
  76                 goto free;
  77
  78         sql_insert_function_ptr(fn_name, ptr_name);
  79
  80 free:
  81         free_string(fn_name);
  82         free_string(ptr_name);
  83 }
  84
  85 void register_function_ptrs(int id)
  86 {
  87         my_id = id;
  88
  89         if (!option_info)
  90                 return;
  91
  92         add_hook(&match_passes_function_pointer, FUNCTION_CALL_HOOK);
  93         add_hook(&match_function_assign, ASSIGNMENT_HOOK);
  94 }