smatch_modification_hooks.c

   1 /*
   2  * sparse/smatch_modification_hooks.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #define _GNU_SOURCE
  11 #include <search.h>
  12 #include <stdlib.h>
  13 #include <stdio.h>
  14 #include "smatch.h"
  15
  16 struct mcall_back {
  17         modification_hook *call_back;
  18         void *info;
  19 };
  20
  21 ALLOCATOR(mcall_back, "modification call backs");
  22 DECLARE_PTR_LIST(mod_cb_list, struct mcall_back);
  23
  24 static struct hsearch_data var_hash;
  25
  26 static struct mcall_back *alloc_mcall_back(modification_hook *call_back,
  27                                            void *info)
  28 {
  29         struct mcall_back *cb;
  30
  31         cb = __alloc_mcall_back(0);
  32         cb->call_back = call_back;
  33         cb->info = info;
  34         return cb;
  35 }
  36
  37 static struct mod_cb_list *get_mcall_backs(const char *look_for)
  38 {
  39         ENTRY e, *ep;
  40
  41         e.key = (char *)look_for;
  42         hsearch_r(e, FIND, &ep, &var_hash);
  43         if (!ep)
  44                 return NULL;
  45         return (struct mod_cb_list *)ep->data;
  46 }
  47
  48 static void add_mcall_back(const char *look_for, struct mcall_back *cb)
  49 {
  50         ENTRY e, *ep;
  51         char *old_key = NULL;
  52
  53         e.key = alloc_string(look_for);
  54         hsearch_r(e, FIND, &ep, &var_hash);
  55         if (!ep) {
  56                 struct mod_cb_list *list = NULL;
  57
  58                 add_ptr_list(&list, cb);
  59                 e.data = list;
  60         } else {
  61                 old_key = e.key;
  62                 e.key = ep->key;
  63                 add_ptr_list((struct mod_cb_list **)&ep->data, cb);
  64                 e.data = ep->data;
  65         }
  66         if (!hsearch_r(e, ENTER, &ep, &var_hash)) {
  67                 printf("Error hash table too small in smatch_modification_hooks.c\n");
  68                 exit(1);
  69         }
  70         free_string(old_key);
  71 }
  72
  73 void add_modification_hook(const char *variable, modification_hook *call_back, void *info)
  74 {
  75         struct mcall_back *cb;
  76
  77         cb = alloc_mcall_back(call_back, info);
  78         add_mcall_back(variable, cb);
  79 }
  80
  81 static void call_call_backs(struct mod_cb_list *list,
  82                         const char *variable,
  83                         struct symbol *sym,
  84                         struct expression *expr)
  85 {
  86         struct mcall_back *tmp;
  87
  88         FOR_EACH_PTR(list, tmp) {
  89                 (tmp->call_back)(variable, sym, expr, tmp->info);
  90         } END_FOR_EACH_PTR(tmp);
  91 }
  92
  93
  94 static void match_assign(struct expression *expr)
  95 {
  96         struct mod_cb_list *call_backs;
  97         struct expression *left;
  98         struct symbol *sym;
  99         char *name;
 100
 101         left = strip_expr(expr->left);
 102         name = get_variable_from_expr(left, &sym);
 103         if (!name)
 104                 return;
 105         call_backs = get_mcall_backs(name);
 106         if (!call_backs)
 107                 goto free;
 108         call_call_backs(call_backs, name, sym, expr);
 109 free:
 110         free_string(name);
 111 }
 112
 113 static void match_end_func(struct symbol *sym)
 114 {
 115         hdestroy_r(&var_hash);
 116         hcreate_r(1000, &var_hash);
 117 }
 118
 119 void register_modification_hooks(int id)
 120 {
 121         hcreate_r(1000, &var_hash);
 122         add_hook(&match_assign, ASSIGNMENT_HOOK);
 123         add_hook(&match_end_func, END_FUNC_HOOK);
 124 }
 125