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         /* FIXME: make this a tmp expression. */
  90         expr = alloc_expression(right->pos, EXPR_ASSIGNMENT);
  91         expr->op = op;
  92         expr->left = left;
  93         expr->right = right;
  94         return expr;
  95 }
  96
  97 struct expression *binop_expression(struct expression *left, int op, struct expression *right)
  98 {
  99         struct expression *expr;
 100
 101         expr = alloc_tmp_expression(right->pos, EXPR_BINOP);
 102         expr->op = op;
 103         expr->left = left;
 104         expr->right = right;
 105         return expr;
 106 }
 107
 108 struct expression *array_element_expression(struct expression *array, struct expression *offset)
 109 {
 110         struct expression *expr;
 111
 112         expr = binop_expression(array, '+', offset);
 113         return deref_expression(expr);
 114 }
 115
 116 struct expression *symbol_expression(struct symbol *sym)
 117 {
 118         struct expression *expr;
 119
 120         expr = alloc_tmp_expression(sym->pos, EXPR_SYMBOL);
 121         expr->symbol = sym;
 122         expr->symbol_name = sym->ident;
 123         return expr;
 124 }
 125
 126 struct expression *compare_expression(struct expression *left, int op, struct expression *right)
 127 {
 128         struct expression *expr;
 129
 130         expr = alloc_tmp_expression(get_cur_pos(), EXPR_COMPARE);
 131         expr->op = op;
 132         expr->left = left;
 133         expr->right = right;
 134         return expr;
 135 }
 136
 137 struct expression *gen_expression_from_key(struct expression *arg, const char *key)
 138 {
 139         struct expression *ret;
 140         struct token *token, *end;
 141         const char *p = key;
 142         char buf[4095];
 143         char *alloc;
 144         size_t len;
 145
 146         /* The idea is that we can parse either $0->foo or $->foo */
 147         if (key[0] != '$')
 148                 return NULL;
 149         p++;
 150         while (*p >= '0' && *p <= '9')
 151                 p++;
 152         len = snprintf(buf, sizeof(buf), "%s\n", p);
 153         alloc = alloc_string(buf);
 154
 155         token = tokenize_buffer(alloc, len, &end);
 156         if (!token)
 157                 return NULL;
 158         if (token_type(token) != TOKEN_STREAMBEGIN)
 159                 return NULL;
 160         token = token->next;
 161
 162         ret = arg;
 163         while (token_type(token) == TOKEN_SPECIAL &&
 164                token->special == SPECIAL_DEREFERENCE) {
 165                 token = token->next;
 166                 if (token_type(token) != TOKEN_IDENT)
 167                         return NULL;
 168                 ret = deref_expression(ret);
 169                 ret = member_expression(ret, '*', token->ident);
 170                 token = token->next;
 171         }
 172
 173         if (token_type(token) != TOKEN_STREAMEND)
 174                 return NULL;
 175
 176         return ret;
 177 }
 178
 179 void expr_set_parent_expr(struct expression *expr, struct expression *parent)
 180 {
 181         if (!expr)
 182                 return;
 183         if (parent->smatch_flags & Fake)
 184                 return;
 185
 186         expr->parent = (unsigned long)parent | 0x1UL;
 187 }
 188
 189 void expr_set_parent_stmt(struct expression *expr, struct statement *parent)
 190 {
 191         if (!expr)
 192                 return;
 193         expr->parent = (unsigned long)parent;
 194 }
 195
 196 struct expression *expr_get_parent_expr(struct expression *expr)
 197 {
 198         if (!expr)
 199                 return NULL;
 200         if (!(expr->parent & 0x1UL))
 201                 return NULL;
 202         return (struct expression *)(expr->parent & ~0x1UL);
 203 }
 204
 205 struct statement *expr_get_parent_stmt(struct expression *expr)
 206 {
 207         if (!expr)
 208                 return NULL;
 209         if (expr->parent & 0x1UL)
 210                 return NULL;
 211         return (struct statement *)expr->parent;
 212 }
 213