fieldType.hpp revision 2273:1d1603768966 
1/*
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24
25#ifndef SHARE_VM_RUNTIME_FIELDTYPE_HPP
26#define SHARE_VM_RUNTIME_FIELDTYPE_HPP
27
28#include "memory/allocation.hpp"
29#include "oops/symbol.hpp"
30
31// Note: FieldType should be based on the SignatureIterator (or vice versa).
32//       In any case, this structure should be re-thought at some point.
33
34// A FieldType is used to determine the type of a field from a signature string.
35
36// Information returned by get_array_info, which is scoped to decrement
37// reference count if a Symbol is created in the case of T_OBJECT
38class FieldArrayInfo : public StackObj {
39  friend class FieldType;  // field type can set these fields.
40  int       _dimension;
41  Symbol*   _object_key;
42 public:
43  int       dimension()    { return _dimension; }
44  Symbol*   object_key()   { return _object_key; }
45  // basic constructor
46  FieldArrayInfo() : _dimension(0), _object_key(NULL) {}
47  // destructor decrements object key's refcount if created
48  ~FieldArrayInfo() { if (_object_key != NULL) _object_key->decrement_refcount(); }
49};
50
51
52class FieldType: public AllStatic {
53 private:
54  static void skip_optional_size(Symbol* signature, int* index);
55  static bool is_valid_array_signature(Symbol* signature);
56 public:
57
58  // Return basic type
59  static BasicType basic_type(Symbol* signature);
60
61  // Testing
62  static bool is_array(Symbol* signature) { return signature->utf8_length() > 1 && signature->byte_at(0) == '[' && is_valid_array_signature(signature); }
63
64  static bool is_obj(Symbol* signature) {
65     int sig_length = signature->utf8_length();
66     // Must start with 'L' and end with ';'
67     return (sig_length >= 2 &&
68             (signature->byte_at(0) == 'L') &&
69             (signature->byte_at(sig_length - 1) == ';'));
70  }
71
72  // Parse field and extract array information. Works for T_ARRAY only.
73  static BasicType get_array_info(Symbol* signature, FieldArrayInfo& ai, TRAPS);
74};
75
76#endif // SHARE_VM_RUNTIME_FIELDTYPE_HPP
77