1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/* protocol.h: PROTOCOL INHERITANCE DEFINITIONS
 *
 * $Id: //info.ravenbrook.com/project/mps/custom/cet/version/1.114/code/protocol.h#1 $
 * Copyright (c) 2001 Ravenbrook Limited.  See end of file for license.
 */

#ifndef protocol_h
#define protocol_h

#include "config.h"
#include "mpmtypes.h"


/* Name derivation macros. These are not intended to be used */
/* outside of this file */

#define DERIVE_LOCAL(name) protocol ## name
#define DERIVE_STRUCT(name) name ## Struct
#define DERIVE_ENSURE(name) name ## Get
#define DERIVE_ENSURE_OLD(name) Ensure ## name
#define DERIVE_ENSURE_INTERNAL(name) protocolGet ## name
#define DERIVE_GUARDIAN(name) protocol ## name ## Guardian
#define DERIVE_STATIC_STORAGE(name) protocol ## name ## Struct


/* Macro to set the superclass field. This is not intended */
/* to be used outside this file. This is a polymorphic macro */
/* named as a function. See <design/protocol/#introspect.c-lang> */

#define ProtocolClassSetSuperclassPoly(class, super) \
  (((ProtocolClass)(class))->superclass) = (ProtocolClass)(super)


/* DEFINE_CLASS -- the standard macro for defining a ProtocolClass */

#define DEFINE_CLASS(className, var) \
  static Bool DERIVE_GUARDIAN(className) = FALSE; \
  static DERIVE_STRUCT(className) DERIVE_STATIC_STORAGE(className); \
  static void DERIVE_ENSURE_INTERNAL(className)(className); \
  extern className DERIVE_ENSURE(className)(void); \
  className DERIVE_ENSURE(className)(void) \
  { \
    if (DERIVE_GUARDIAN(className) == FALSE) { \
      LockClaimGlobalRecursive(); \
      if (DERIVE_GUARDIAN(className) == FALSE) { \
        DERIVE_ENSURE_INTERNAL(className) \
          (&DERIVE_STATIC_STORAGE(className)); \
        DERIVE_GUARDIAN(className) = TRUE; \
      } \
      LockReleaseGlobalRecursive(); \
    } \
    return &DERIVE_STATIC_STORAGE(className); \
  } \
  /* old name for backward compatibility */ \
  extern className DERIVE_ENSURE_OLD(className)(void); \
  className DERIVE_ENSURE_OLD(className)(void) \
  { \
    return DERIVE_ENSURE(className)(); \
  } \
  static void DERIVE_ENSURE_INTERNAL(className) (className var)


/* INHERIT_CLASS -- the standard macro for inheriting from a superclass */

#define INHERIT_CLASS(this, parentName) \
  BEGIN \
    parentName DERIVE_LOCAL(parentName) = DERIVE_ENSURE(parentName)(); \
    *this = *(DERIVE_LOCAL(parentName)); \
    ProtocolClassSetSuperclassPoly(this, DERIVE_LOCAL(parentName)); \
  END


/* DEFINE_ALIAS_CLASS -- define a new class for the same type
 *
 * A convenience macro. Aliases the structure and pointer types
 * for className to be the same as typeName, and then defines
 * the class className.
 */
#define DEFINE_ALIAS_CLASS(className, typeName, var) \
  typedef typeName className; \
  typedef DERIVE_STRUCT(typeName) DERIVE_STRUCT(className); \
  DEFINE_CLASS(className, var)



#define ProtocolClassSig ((Sig)0x519B60C7) /* SIGnature PROtocol CLass */
#define ProtocolInstSig  ((Sig)0x519B6014) /* SIGnature PROtocol INst */


/* ProtocolClass -- the class containing the support for the protocol */

typedef struct ProtocolClassStruct *ProtocolClass;


/* ProtocolInst -- the instance structure for support of the protocol */

typedef struct ProtocolInstStruct *ProtocolInst;


/* ProtocolCoerceInstMethod -- coerce "pro" to an instance of "interface"
 *
 * If "pro" is an instance of "interface", then returns TRUE
 * and sets coerceResult to point directly to the part of "pro"
 * which contains the slots for "interface"
 * RHSK  2006-04-05  s/interface/interfaceIn/: job000605, suspect msvc bug.
 */
typedef Bool (*ProtocolCoerceInstMethod)(ProtocolInst *coerceResult,
                                         ProtocolInst pro,
                                         ProtocolClass interfaceIn);

/* ProtocolCoerceClassMethod -- coerce "proClass" to an "interface" class
 *
 * If "proClass" is a subclass of "interface", then returns TRUE
 * and sets coerceResult to point directly to the part of
 * "proClass" which contains the slots for "interface".
 * RHSK  2006-04-05  s/interface/interfaceIn/: job000605, suspect msvc bug.
 */
typedef Bool (*ProtocolCoerceClassMethod)(ProtocolClass *coerceResult,
                                          ProtocolClass proClass,
                                          ProtocolClass interfaceIn);



typedef struct ProtocolClassStruct {
  Sig sig;                               /* <design/sig/> */
  ProtocolClass superclass;              /* the superclass */
  ProtocolCoerceInstMethod coerceInst;   /* coerce instance to super */
  ProtocolCoerceClassMethod coerceClass; /* coerce class to superclass */
} ProtocolClassStruct;


typedef struct ProtocolInstStruct {
  Sig sig;                      /* <design/sig/> */
  ProtocolClass class;          /* the class  */
} ProtocolInstStruct;


/* ProtocolClassGet -- Returns the root of the protocol class hierarchy
 *
 * Function name conforms to standard conventions for
 * protocols.
 */
extern ProtocolClass ProtocolClassGet(void);


/* Checking functions */

extern Bool ProtocolClassCheck(ProtocolClass class);
extern Bool ProtocolInstCheck(ProtocolInst pro);


/* ProtocolIsSubclass - use macro IsSubclass to access this.
 *
 * A predicate for testing subclass relationships.
 * A protocol class is always a subclass of itself.
 */
extern Bool ProtocolIsSubclass(ProtocolClass sub, ProtocolClass super);


/* Protocol introspection interface */

/* The following are macros because of the need to cast */
/* subtypes of ProtocolClass. Nevertheless they are named */
/* as functions. See <design/protocol/#introspect.c-lang> */


#define ProtocolClassSuperclassPoly(class) \
  (((ProtocolClass)(class))->superclass)

#define ClassOfPoly(inst) ((ProtocolInst)(inst)->class)

#define IsSubclassPoly(sub, super) \
   ProtocolIsSubclass((ProtocolClass)(sub), (ProtocolClass)(super))


/* SUPERCLASS  - get the superclass object, given a class name
 *
 * Returns the superclass, with type ProtocolClass. Clients will
 * probably wish to cast this. See
 * <design/protocol/#int.static-superclass>
 */
#define SUPERCLASS(className)  \
  ProtocolClassSuperclassPoly(DERIVE_ENSURE(className)())


#endif /* protocol_h */


/* C. COPYRIGHT AND LICENSE
 *
 * Copyright (C) 2001-2002 Ravenbrook Limited <http://www.ravenbrook.com/>.
 * All rights reserved.  This is an open source license.  Contact
 * Ravenbrook for commercial licensing options.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * 3. Redistributions in any form must be accompanied by information on how
 * to obtain complete source code for this software and any accompanying
 * software that uses this software.  The source code must either be
 * included in the distribution or be available for no more than the cost
 * of distribution plus a nominal fee, and must be freely redistributable
 * under reasonable conditions.  For an executable file, complete source
 * code means the source code for all modules it contains. It does not
 * include source code for modules or files that typically accompany the
 * major components of the operating system on which the executable file
 * runs.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */