1/*
2******************************************************************************
3*
4*   Copyright (C) 2002-2010, International Business Machines
5*   Corporation and others.  All Rights Reserved.
6*
7******************************************************************************
8*   file name:  uobject.h
9*   encoding:   US-ASCII
10*   tab size:   8 (not used)
11*   indentation:4
12*
13*   created on: 2002jun26
14*   created by: Markus W. Scherer
15*/
16
17#ifndef __UOBJECT_H__
18#define __UOBJECT_H__
19
20#include "unicode/utypes.h"
21
22U_NAMESPACE_BEGIN
23
24/**
25 * \file
26 * \brief C++ API: Common ICU base class UObject.
27 */
28
29/**  U_OVERRIDE_CXX_ALLOCATION - Define this to override operator new and
30 *                               delete in UMemory. Enabled by default for ICU.
31 *
32 *         Enabling forces all allocation of ICU object types to use ICU's
33 *         memory allocation. On Windows, this allows the ICU DLL to be used by
34 *         applications that statically link the C Runtime library, meaning that
35 *         the app and ICU will be using different heaps.
36 *
37 * @stable ICU 2.2
38 */
39#ifndef U_OVERRIDE_CXX_ALLOCATION
40#define U_OVERRIDE_CXX_ALLOCATION 1
41#endif
42
43/**
44 * \def U_HAVE_PLACEMENT_NEW
45 *  Define this to define the placement new and
46 *                          delete in UMemory for STL.
47 *
48 * @stable ICU 2.6
49 */
50#ifndef U_HAVE_PLACEMENT_NEW
51#define U_HAVE_PLACEMENT_NEW 1
52#endif
53
54
55/**
56 * \def U_HAVE_DEBUG_LOCATION_NEW
57 * Define this to define the MFC debug
58 * version of the operator new.
59 *
60 * @stable ICU 3.4
61 */
62#ifndef U_HAVE_DEBUG_LOCATION_NEW
63#define U_HAVE_DEBUG_LOCATION_NEW 0
64#endif
65
66/**
67 * @{
68 * \def U_NO_THROW
69 *         Define this to define the throw() specification so
70 *                 certain functions do not throw any exceptions
71 *
72 *         UMemory operator new methods should have the throw() specification
73 *         appended to them, so that the compiler adds the additional NULL check
74 *         before calling constructors. Without, if <code>operator new</code> returns NULL the
75 *         constructor is still called, and if the constructor references member
76 *         data, (which it typically does), the result is a segmentation violation.
77 *
78 * @draft ICU 4.2
79 */
80#ifndef U_NO_THROW
81#define U_NO_THROW throw()
82#endif
83
84/** @} */
85
86/**
87 * UMemory is the common ICU base class.
88 * All other ICU C++ classes are derived from UMemory (starting with ICU 2.4).
89 *
90 * This is primarily to make it possible and simple to override the
91 * C++ memory management by adding new/delete operators to this base class.
92 *
93 * To override ALL ICU memory management, including that from plain C code,
94 * replace the allocation functions declared in cmemory.h
95 *
96 * UMemory does not contain any virtual functions.
97 * Common "boilerplate" functions are defined in UObject.
98 *
99 * @stable ICU 2.4
100 */
101class U_COMMON_API UMemory {
102public:
103
104/* test versions for debugging shaper heap memory problems */
105#ifdef SHAPER_MEMORY_DEBUG
106    static void * NewArray(int size, int count);
107    static void * GrowArray(void * array, int newSize );
108    static void   FreeArray(void * array );
109#endif
110
111#if U_OVERRIDE_CXX_ALLOCATION
112    /**
113     * Override for ICU4C C++ memory management.
114     * simple, non-class types are allocated using the macros in common/cmemory.h
115     * (uprv_malloc(), uprv_free(), uprv_realloc());
116     * they or something else could be used here to implement C++ new/delete
117     * for ICU4C C++ classes
118     * @stable ICU 2.4
119     */
120    static void * U_EXPORT2 operator new(size_t size) U_NO_THROW;
121
122    /**
123     * Override for ICU4C C++ memory management.
124     * See new().
125     * @stable ICU 2.4
126     */
127    static void * U_EXPORT2 operator new[](size_t size) U_NO_THROW;
128
129    /**
130     * Override for ICU4C C++ memory management.
131     * simple, non-class types are allocated using the macros in common/cmemory.h
132     * (uprv_malloc(), uprv_free(), uprv_realloc());
133     * they or something else could be used here to implement C++ new/delete
134     * for ICU4C C++ classes
135     * @stable ICU 2.4
136     */
137    static void U_EXPORT2 operator delete(void *p) U_NO_THROW;
138
139    /**
140     * Override for ICU4C C++ memory management.
141     * See delete().
142     * @stable ICU 2.4
143     */
144    static void U_EXPORT2 operator delete[](void *p) U_NO_THROW;
145
146#if U_HAVE_PLACEMENT_NEW
147    /**
148     * Override for ICU4C C++ memory management for STL.
149     * See new().
150     * @stable ICU 2.6
151     */
152    static inline void * U_EXPORT2 operator new(size_t, void *ptr) U_NO_THROW { return ptr; }
153
154    /**
155     * Override for ICU4C C++ memory management for STL.
156     * See delete().
157     * @stable ICU 2.6
158     */
159    static inline void U_EXPORT2 operator delete(void *, void *) U_NO_THROW {}
160#endif /* U_HAVE_PLACEMENT_NEW */
161#if U_HAVE_DEBUG_LOCATION_NEW
162    /**
163      * This method overrides the MFC debug version of the operator new
164      *
165      * @param size   The requested memory size
166      * @param file   The file where the allocation was requested
167      * @param line   The line where the allocation was requested
168      */
169    static void * U_EXPORT2 operator new(size_t size, const char* file, int line) U_NO_THROW;
170    /**
171      * This method provides a matching delete for the MFC debug new
172      *
173      * @param p      The pointer to the allocated memory
174      * @param file   The file where the allocation was requested
175      * @param line   The line where the allocation was requested
176      */
177    static void U_EXPORT2 operator delete(void* p, const char* file, int line) U_NO_THROW;
178#endif /* U_HAVE_DEBUG_LOCATION_NEW */
179#endif /* U_OVERRIDE_CXX_ALLOCATION */
180
181    /*
182     * Assignment operator not declared. The compiler will provide one
183     * which does nothing since this class does not contain any data members.
184     * API/code coverage may show the assignment operator as present and
185     * untested - ignore.
186     * Subclasses need this assignment operator if they use compiler-provided
187     * assignment operators of their own. An alternative to not declaring one
188     * here would be to declare and empty-implement a protected or public one.
189    UMemory &UMemory::operator=(const UMemory &);
190     */
191};
192
193/**
194 * UObject is the common ICU "boilerplate" class.
195 * UObject inherits UMemory (starting with ICU 2.4),
196 * and all other public ICU C++ classes
197 * are derived from UObject (starting with ICU 2.2).
198 *
199 * UObject contains common virtual functions like for ICU's "poor man's RTTI".
200 * It does not contain default implementations of virtual methods
201 * like getDynamicClassID to allow derived classes such as Format
202 * to declare these as pure virtual.
203 *
204 * The clone() function is not available in UObject because it is not
205 * implemented by all ICU classes.
206 * Many ICU services provide a clone() function for their class trees,
207 * defined on the service's C++ base class, and all subclasses within that
208 * service class tree return a pointer to the service base class
209 * (which itself is a subclass of UObject).
210 * This is because some compilers do not support covariant (same-as-this)
211 * return types; cast to the appropriate subclass if necessary.
212 *
213 * @stable ICU 2.2
214 */
215class U_COMMON_API UObject : public UMemory {
216public:
217    /**
218     * Destructor.
219     *
220     * @stable ICU 2.2
221     */
222    virtual ~UObject();
223
224    /**
225     * ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.
226     *
227     * @stable ICU 2.2
228     */
229    virtual UClassID getDynamicClassID() const = 0;
230
231protected:
232    // the following functions are protected to prevent instantiation and
233    // direct use of UObject itself
234
235    // default constructor
236    // commented out because UObject is abstract (see getDynamicClassID)
237    // inline UObject() {}
238
239    // copy constructor
240    // commented out because UObject is abstract (see getDynamicClassID)
241    // inline UObject(const UObject &other) {}
242
243#if 0
244    // TODO Sometime in the future. Implement operator==().
245    // (This comment inserted in 2.2)
246    // some or all of the following "boilerplate" functions may be made public
247    // in a future ICU4C release when all subclasses implement them
248
249    // assignment operator
250    // (not virtual, see "Taligent's Guide to Designing Programs" pp.73..74)
251    // commented out because the implementation is the same as a compiler's default
252    // UObject &operator=(const UObject &other) { return *this; }
253
254    // comparison operators
255    virtual inline UBool operator==(const UObject &other) const { return this==&other; }
256    inline UBool operator!=(const UObject &other) const { return !operator==(other); }
257
258    // clone() commented out from the base class:
259    // some compilers do not support co-variant return types
260    // (i.e., subclasses would have to return UObject * as well, instead of SubClass *)
261    // see also UObject class documentation.
262    // virtual UObject *clone() const;
263#endif
264
265    /*
266     * Assignment operator not declared. The compiler will provide one
267     * which does nothing since this class does not contain any data members.
268     * API/code coverage may show the assignment operator as present and
269     * untested - ignore.
270     * Subclasses need this assignment operator if they use compiler-provided
271     * assignment operators of their own. An alternative to not declaring one
272     * here would be to declare and empty-implement a protected or public one.
273    UObject &UObject::operator=(const UObject &);
274     */
275
276// Future implementation for RTTI that support subtyping. [alan]
277//
278//  public:
279//     /**
280//      * @internal
281//      */
282//     static UClassID getStaticClassID();
283//
284//     /**
285//      * @internal
286//      */
287//     UBool instanceOf(UClassID type) const;
288};
289
290/**
291 * This is a simple macro to add ICU RTTI to an ICU object implementation.
292 * This does not go into the header. This should only be used in *.cpp files.
293 *
294 * @param myClass The name of the class that needs RTTI defined.
295 * @internal
296 */
297#define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass) \
298    UClassID U_EXPORT2 myClass::getStaticClassID() { \
299        static char classID = 0; \
300        return (UClassID)&classID; \
301    } \
302    UClassID myClass::getDynamicClassID() const \
303    { return myClass::getStaticClassID(); }
304
305
306/**
307 * This macro adds ICU RTTI to an ICU abstract class implementation.
308 * This macro should be invoked in *.cpp files.  The corresponding
309 * header should declare getStaticClassID.
310 *
311 * @param myClass The name of the class that needs RTTI defined.
312 * @internal
313 */
314#define UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass) \
315    UClassID U_EXPORT2 myClass::getStaticClassID() { \
316        static char classID = 0; \
317        return (UClassID)&classID; \
318    }
319
320/**
321 * This is a simple macro to express that a class and its subclasses do not offer
322 * ICU's "poor man's RTTI".
323 * Beginning with ICU 4.6, ICU requires C++ compiler RTTI.
324 * This does not go into the header. This should only be used in *.cpp files.
325 * Use this with a private getDynamicClassID() in an immediate subclass of UObject.
326 *
327 * @param myClass The name of the class that needs RTTI defined.
328 * @internal
329 */
330#define UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION(myClass) \
331    UClassID myClass::getDynamicClassID() const { return NULL; }
332
333// /**
334//  * This macro adds ICU RTTI to an ICU concrete class implementation.
335//  * This macro should be invoked in *.cpp files.  The corresponding
336//  * header should declare getDynamicClassID and getStaticClassID.
337//  *
338//  * @param myClass The name of the class that needs RTTI defined.
339//  * @param myParent The name of the myClass's parent.
340//  * @internal
341//  */
342/*#define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass, myParent) \
343    UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass, myParent) \
344    UClassID myClass::getDynamicClassID() const { \
345        return myClass::getStaticClassID(); \
346    }
347*/
348
349
350U_NAMESPACE_END
351
352#endif
353