Home | History | Annotate | Download | only in unicode
      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 
     22 U_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  */
    101 class U_COMMON_API UMemory {
    102 public:
    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  */
    215 class U_COMMON_API UObject : public UMemory {
    216 public:
    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 
    231 protected:
    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 
    350 U_NAMESPACE_END
    351 
    352 #endif
    353