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jtie_tconv_object.hpp
1 /*
2  Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
3 
4  This program is free software; you can redistribute it and/or modify
5  it under the terms of the GNU General Public License as published by
6  the Free Software Foundation; version 2 of the License.
7 
8  This program is distributed in the hope that it will be useful,
9  but WITHOUT ANY WARRANTY; without even the implied warranty of
10  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  GNU General Public License for more details.
12 
13  You should have received a copy of the GNU General Public License
14  along with this program; if not, write to the Free Software
15  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17 /*
18  * jtie_tconv_object.hpp
19  */
20 
21 #ifndef jtie_tconv_object_hpp
22 #define jtie_tconv_object_hpp
23 
24 #include <jni.h>
25 
26 #include "jtie_tconv.hpp"
27 #include "jtie_tconv_idcache_impl.hpp"
28 
29 // ---------------------------------------------------------------------------
30 // Java object <-> C class object type conversions
31 // ---------------------------------------------------------------------------
32 
41 struct _jtie_Object : _jobject {
42 };
43 
44 // XXX, document: type specifying an Object mapping with a class name
45 
46 // trait type wrapping named-parametrized Object mappings for specialization
47 // XXX make use of
48 // JTIE_DEFINE_METHOD_MEMBER_INFO( _jtie_ObjectMapper< T > )
49 // to replace
50 // static const char * const class_name;
51 // static const char * const member_name;
52 // static const char * const member_descriptor;
53 // typedef _jmethodID * memberID_t;
54 template< typename J >
55 struct _jtie_ObjectMapper : _jtie_Object {
56  // the name of the Java peer class in the JVM format (i.e., '/'-separated)
57  static const char * const class_name;
58 
59  // the name, descriptor, and JNI type of the class's no-arg c'tor
60  static const char * const member_name;
61  static const char * const member_descriptor;
62  typedef _jmethodID * memberID_t;
63 };
64 
65 // XXX static initialization <-> multiple compilation units <-> jtie_lib.hpp
66 template< typename J >
67 const char * const _jtie_ObjectMapper< J >::class_name
68  = J::class_name; // XXX static initialization order dependency?
69 
70 template< typename J >
71 const char * const _jtie_ObjectMapper< J >::member_name
72  = "<init>";
73 
74 template< typename J >
75 const char * const _jtie_ObjectMapper< J >::member_descriptor
76  = "()V";
77 
78 // Design note:
79 //
80 // As of pre-C++0x, string literals cannot be used as template arguments
81 // which must be integral constants with external linkage.
82 //
83 // So, we cannot declare:
84 //
85 // template< const char * >
86 // struct _jtie_ClassNamedObject : _jtie_Object {
87 // static const char * const java_internal_class_name;
88 // };
89 //
90 // As a feasible workaround, we require the application to provide a
91 // trait type for each class, e.g.
92 //
93 // struct _m_A : _jobject {
94 // static const char * const java_internal_class_name;
95 // };
96 // const char * const _m_A::java_internal_class_name = "myjapi/A";
97 //
98 // and we retrieve the class name from there.
99 
129 #define JTIE_DEFINE_PEER_CLASS_MAPPING( C, T ) \
130  struct T { \
131  static const char * const class_name; \
132  }; \
133  typedef ttrait< jobject, C, _jtie_ObjectMapper< T > * \
134  > ttrait_##T##_t; \
135  typedef ttrait< jobject, const C, _jtie_ObjectMapper< T > * \
136  > ttrait_##T##_ct; \
137  typedef ttrait< jobject, C &, _jtie_ObjectMapper< T > * \
138  > ttrait_##T##_r; \
139  typedef ttrait< jobject, const C &, _jtie_ObjectMapper< T > * \
140  > ttrait_##T##_cr; \
141  typedef ttrait< jobject, C *, _jtie_ObjectMapper< T > * \
142  > ttrait_##T##_p; \
143  typedef ttrait< jobject, const C *, _jtie_ObjectMapper< T > * \
144  > ttrait_##T##_cp; \
145  typedef ttrait< jobject, C * const, _jtie_ObjectMapper< T > * \
146  > ttrait_##T##_pc; \
147  typedef ttrait< jobject, const C * const, _jtie_ObjectMapper< T > * \
148  > ttrait_##T##_cpc;
149 
150 #if 0 // XXX cleanup this unsupported mapping
151 
152  * Naming convention:
153  * type alias: specifies a mapping:
154  * ttrait_<T>_a J <-> C *
155  * ttrait_<T>_ca J <-> const C *
156  * ttrait_<T>_ac J <-> C * const
157  * ttrait_<T>_cac J <-> const C * const
158 
175 #define JTIE_DEFINE_ARRAY_PTR_TYPE_MAPPING( J, C, T ) \
176  typedef ttrait< J *, C * \
177  > ttrait_##T##_0p_a; \
178  typedef ttrait< J *, const C * \
179  > ttrait_##T##_0cp_a; \
180  typedef ttrait< J *, C * const \
181  > ttrait_##T##_0pc_a; \
182  typedef ttrait< J *, const C * const \
183  > ttrait_##T##_0cpc_a;
184 
201 #define JTIE_DEFINE_ARRAY_PTR_LENGTH1_TYPE_MAPPING( J, C, T ) \
202  typedef ttrait< J *, C *, _jtie_j_ArrayMapper< _jtie_j_BoundedArray< J, 1 > > * \
203  > ttrait_##T##_1p_a; \
204  typedef ttrait< J *, const C *, _jtie_j_ArrayMapper< _jtie_j_BoundedArray< J, 1 > > * \
205  > ttrait_##T##_1cp_a; \
206  typedef ttrait< J *, C * const, _jtie_j_ArrayMapper< _jtie_j_BoundedArray< J, 1 > > * \
207  > ttrait_##T##_1pc_a; \
208  typedef ttrait< J *, const C * const, _jtie_j_ArrayMapper< _jtie_j_BoundedArray< J, 1 > > * \
209  > ttrait_##T##_1cpc_a;
210 
211 // XXX and this is how it's done
212  typedef ttrait< jobjectArray, C *, \
213  _jtie_j_ArrayMapper< \
214  _jtie_j_BoundedArray< \
215  _jtie_ObjectMapper< J >, \
216  1 > \
217  > * \
218  > ttrait_##J##_1a; \
219 
220 #endif // XXX cleanup this unsupported mapping
221 
222 // XXX to document
223 // XXX static initialization <-> multiple compilation units <-> jtie_lib.hpp
224 // XXX replace
225 // template struct MemberId< _jtie_ObjectMapper< T > >;
226 // template struct MemberIdCache< _jtie_ObjectMapper< T > >;
227 // with
228 // JTIE_INSTANTIATE_CLASS_MEMBER_INFO_X(_jtie_ObjectMapper< T >,
229 // JCN, "<init>", "()V")
230 #define JTIE_INSTANTIATE_PEER_CLASS_MAPPING( T, JCN ) \
231  const char * const T::class_name = JCN; \
232  template struct _jtie_ObjectMapper< T >; \
233  template struct MemberId< _jtie_ObjectMapper< T > >; \
234  template struct MemberIdCache< _jtie_ObjectMapper< T > >;
235 
236 // ---------------------------------------------------------------------------
237 
238 #endif // jtie_tconv_object_hpp