smatch_expressions.c

   1 #include "smatch.h"
   2 #include "smatch_extra.h"
   3
   4 __ALLOCATOR(struct expression, "temporary expr", tmp_expression);
   5
   6 static struct position get_cur_pos(void)
   7 {
   8         static struct position pos;
   9         static struct position none;
  10         struct expression *expr;
  11         struct statement *stmt;
  12
  13         expr = last_ptr_list((struct ptr_list *)big_expression_stack);
  14         stmt = last_ptr_list((struct ptr_list *)big_statement_stack);
  15         if (expr)
  16                 pos = expr->pos;
  17         else if (stmt)
  18                 pos = stmt->pos;
  19         else
  20                 pos = none;
  21         return pos;
  22 }
  23
  24 struct expression *alloc_tmp_expression(struct position pos, int type)
  25 {
  26         struct expression *expr;
  27
  28         expr = __alloc_tmp_expression(0);
  29         expr->smatch_flags |= Fake;
  30         expr->type = type;
  31         expr->pos = pos;
  32         return expr;
  33 }
  34
  35 void free_tmp_expressions(void)
  36 {
  37         clear_tmp_expression_alloc();
  38 }
  39
  40 struct expression *zero_expr(void)
  41 {
  42         struct expression *zero;
  43
  44         zero = alloc_tmp_expression(get_cur_pos(), EXPR_VALUE);
  45         zero->value = 0;
  46         zero->ctype = &int_ctype;
  47         return zero;
  48 }
  49
  50 struct expression *value_expr(long long val)
  51 {
  52         struct expression *expr;
  53
  54         if (!val)
  55                 return zero_expr();
  56
  57         expr = alloc_tmp_expression(get_cur_pos(), EXPR_VALUE);
  58         expr->value = val;
  59         expr->ctype = &llong_ctype;
  60         return expr;
  61 }
  62
  63 struct expression *member_expression(struct expression *deref, int op, struct ident *member)
  64 {
  65         struct expression *expr;
  66
  67         expr = alloc_tmp_expression(deref->pos, EXPR_DEREF);
  68         expr->op = op;
  69         expr->deref = deref;
  70         expr->member = member;
  71         expr->member_offset = -1;
  72         return expr;
  73 }
  74
  75 struct expression *deref_expression(struct expression *expr)
  76 {
  77         struct expression *preop;
  78
  79         preop = alloc_tmp_expression(expr->pos, EXPR_PREOP);
  80         preop->unop = expr;
  81         preop->op = '*';
  82         return preop;
  83 }
  84
  85 struct expression *assign_expression(struct expression *left, int op, struct expression *right)
  86 {
  87         struct expression *expr;
  88
  89         expr = alloc_tmp_expression(right->pos, EXPR_ASSIGNMENT);
  90         expr->op = op;
  91         expr->left = left;
  92         expr->right = right;
  93         return expr;
  94 }
  95
  96 struct expression *binop_expression(struct expression *left, int op, struct expression *right)
  97 {
  98         struct expression *expr;
  99
 100         expr = alloc_tmp_expression(right->pos, EXPR_BINOP);
 101         expr->op = op;
 102         expr->left = left;
 103         expr->right = right;
 104         return expr;
 105 }
 106
 107 struct expression *array_element_expression(struct expression *array, struct expression *offset)
 108 {
 109         struct expression *expr;
 110
 111         expr = binop_expression(array, '+', offset);
 112         return deref_expression(expr);
 113 }
 114
 115 struct expression *symbol_expression(struct symbol *sym)
 116 {
 117         struct expression *expr;
 118
 119         expr = alloc_tmp_expression(sym->pos, EXPR_SYMBOL);
 120         expr->symbol = sym;
 121         expr->symbol_name = sym->ident;
 122         return expr;
 123 }
 124
 125 struct expression *compare_expression(struct expression *left, int op, struct expression *right)
 126 {
 127         struct expression *expr;
 128
 129         expr = alloc_tmp_expression(get_cur_pos(), EXPR_COMPARE);
 130         expr->op = op;
 131         expr->left = left;
 132         expr->right = right;
 133         return expr;
 134 }
 135
 136 struct expression *gen_expression_from_key(struct expression *arg, const char *key)
 137 {
 138         struct expression *ret;
 139         struct token *token, *end;
 140         const char *p = key;
 141         char buf[4095];
 142         char *alloc;
 143         size_t len;
 144
 145         /* The idea is that we can parse either $0->foo or $->foo */
 146         if (key[0] != '$')
 147                 return NULL;
 148         p++;
 149         while (*p >= '0' && *p <= '9')
 150                 p++;
 151         len = snprintf(buf, sizeof(buf), "%s\n", p);
 152         alloc = alloc_string(buf);
 153
 154         token = tokenize_buffer(alloc, len, &end);
 155         if (!token)
 156                 return NULL;
 157         if (token_type(token) != TOKEN_STREAMBEGIN)
 158                 return NULL;
 159         token = token->next;
 160
 161         ret = arg;
 162         while (token_type(token) == TOKEN_SPECIAL &&
 163                token->special == SPECIAL_DEREFERENCE) {
 164                 token = token->next;
 165                 if (token_type(token) != TOKEN_IDENT)
 166                         return NULL;
 167                 ret = deref_expression(ret);
 168                 ret = member_expression(ret, '*', token->ident);
 169                 token = token->next;
 170         }
 171
 172         if (token_type(token) != TOKEN_STREAMEND)
 173                 return NULL;
 174
 175         return ret;
 176 }
 177
 178 void expr_set_parent_expr(struct expression *expr, struct expression *parent)
 179 {
 180         if (!expr)
 181                 return;
 182         if (parent->smatch_flags & Fake)
 183                 return;
 184
 185         expr->parent = (unsigned long)parent | 0x1UL;
 186 }
 187
 188 void expr_set_parent_stmt(struct expression *expr, struct statement *parent)
 189 {
 190         if (!expr)
 191                 return;
 192         expr->parent = (unsigned long)parent;
 193 }
 194
 195 struct expression *expr_get_parent_expr(struct expression *expr)
 196 {
 197         if (!expr)
 198                 return NULL;
 199         if (!(expr->parent & 0x1UL))
 200                 return NULL;
 201         return (struct expression *)(expr->parent & ~0x1UL);
 202 }
 203
 204 struct statement *expr_get_parent_stmt(struct expression *expr)
 205 {
 206         if (!expr)
 207                 return NULL;
 208         if (expr->parent & 0x1UL)
 209                 return NULL;
 210         return (struct statement *)expr->parent;
 211 }
 212