gcc/objc/objc-api.h

/* GNU Objective-C Runtime API.
   Copyright (C) 1993, 1995, 1996, 1997 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

GNU CC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* As a special exception, if you link this library with files compiled
   with GCC to produce an executable, this does not cause the resulting
   executable to be covered by the GNU General Public License.  This
   exception does not however invalidate any other reasons why the
   executable file might be covered by the GNU General Public License. */

#ifndef __objc_api_INCLUDE_GNU
#define __objc_api_INCLUDE_GNU

#include "objc/objc.h"
#include "objc/hash.h"
#include "objc/thr.h"
#include <stdio.h>
#include <stdarg.h>

/* For functions which return Method_t */
#define METHOD_NULL	(Method_t)0
                                                /* Boolean typedefs */
/*
** Method descriptor returned by introspective Object methods.
** This is really just the first part of the more complete objc_method
** structure defined below and used internally by the runtime.
*/
struct objc_method_description
{
    SEL name;			/* this is a selector, not a string */
    char *types;		/* type encoding */
};

/* Filer types used to describe Ivars and Methods.  */
#define _C_ID       '@'
#define _C_CLASS    '#'
#define _C_SEL      ':'
#define _C_CHR      'c'
#define _C_UCHR     'C'
#define _C_SHT      's'
#define _C_USHT     'S'
#define _C_INT      'i'
#define _C_UINT     'I'
#define _C_LNG      'l'
#define _C_ULNG     'L'
#define _C_FLT      'f'
#define _C_DBL      'd'
#define _C_BFLD     'b'
#define _C_VOID     'v'
#define _C_UNDEF    '?'
#define _C_PTR      '^'
#define _C_CHARPTR  '*'
#define _C_ATOM     '%'
#define _C_ARY_B    '['
#define _C_ARY_E    ']'
#define _C_UNION_B  '('
#define _C_UNION_E  ')'
#define _C_STRUCT_B '{'
#define _C_STRUCT_E '}'


/*
** Error handling
**
** Call objc_error() or objc_verror() to record an error; this error
** routine will generally exit the program but not necessarily if the
** user has installed his own error handler.
**
** Call objc_set_error_handler to assign your own function for
** handling errors.  The function should return YES if it is ok
** to continue execution, or return NO or just abort if the
** program should be stopped.  The default error handler is just to
** print a message on stderr.
**
** The error handler function should be of type objc_error_handler
** The first parameter is an object instance of relevance.
** The second parameter is an error code.
** The third parameter is a format string in the printf style.
** The fourth parameter is a variable list of arguments.
*/
extern void objc_error(id object, int code, const char* fmt, ...);
extern void objc_verror(id object, int code, const char* fmt, va_list ap);
typedef BOOL (*objc_error_handler)(id, int code, const char *fmt, va_list ap);
objc_error_handler objc_set_error_handler(objc_error_handler func);

/*
** Error codes
** These are used by the runtime library, and your
** error handling may use them to determine if the error is
** hard or soft thus whether execution can continue or abort.
*/
#define OBJC_ERR_UNKNOWN 0             /* Generic error */

#define OBJC_ERR_OBJC_VERSION 1        /* Incorrect runtime version */
#define OBJC_ERR_GCC_VERSION 2         /* Incorrect compiler version */
#define OBJC_ERR_MODULE_SIZE 3         /* Bad module size */
#define OBJC_ERR_PROTOCOL_VERSION 4    /* Incorrect protocol version */

#define OBJC_ERR_MEMORY 10             /* Out of memory */

#define OBJC_ERR_RECURSE_ROOT 20       /* Attempt to archive the root
					  object more than once. */
#define OBJC_ERR_BAD_DATA 21           /* Didn't read expected data */
#define OBJC_ERR_BAD_KEY 22            /* Bad key for object */
#define OBJC_ERR_BAD_CLASS 23          /* Unknown class */
#define OBJC_ERR_BAD_TYPE 24           /* Bad type specification */
#define OBJC_ERR_NO_READ 25            /* Cannot read stream */
#define OBJC_ERR_NO_WRITE 26           /* Cannot write stream */
#define OBJC_ERR_STREAM_VERSION 27     /* Incorrect stream version */
#define OBJC_ERR_BAD_OPCODE 28         /* Bad opcode */

#define OBJC_ERR_UNIMPLEMENTED 30      /* Method is not implemented */

#define OBJC_ERR_BAD_STATE 40          /* Bad thread state */

/*
** Set this variable nonzero to print a line describing each
** message that is sent.  (this is currently disabled)
*/
extern BOOL objc_trace;


/* For every class which happens to have statically allocated instances in
   this module, one OBJC_STATIC_INSTANCES is allocated by the compiler.
   INSTANCES is NULL terminated and points to all statically allocated
   instances of this class.  */
struct objc_static_instances
{
  char *class_name;
  id instances[0];
};

/*
** Whereas a Module (defined further down) is the root (typically) of a file,
** a Symtab is the root of the class and category definitions within the
** module.  
** 
** A Symtab contains a variable length array of pointers to classes and
** categories  defined in the module. 
*/
typedef struct objc_symtab {
  unsigned long sel_ref_cnt;                     /* Unknown. */
  SEL        refs;                              /* Unknown. */
  unsigned short cls_def_cnt;                   /* Number of classes compiled
                                                  (defined) in the module. */
  unsigned short cat_def_cnt;                   /* Number of categories 
                                                  compiled (defined) in the 
                                                  module. */

  void      *defs[1];                           /* Variable array of pointers.
                                                  cls_def_cnt of type Class 
                                                  followed by cat_def_cnt of
                                                  type Category_t, followed
						  by a NULL terminated array
						  of objc_static_instances. */
} Symtab,   *Symtab_t;


/*
** The compiler generates one of these structures for each module that
** composes the executable (eg main.m).  
** 
** This data structure is the root of the definition tree for the module.  
** 
** A collect program runs between ld stages and creates a ObjC ctor array. 
** That array holds a pointer to each module structure of the executable. 
*/
typedef struct objc_module {
  unsigned long version;                        /* Compiler revision. */
  unsigned long size;                           /* sizeof(Module). */
  const char* name;                             /* Name of the file where the 
                                                  module was generated.   The 
                                                  name includes the path. */

  Symtab_t    symtab;                           /* Pointer to the Symtab of
                                                  the module.  The Symtab
                                                  holds an array of 
						  pointers to 
                                                  the classes and categories 
                                                  defined in the module. */
} Module, *Module_t;


/*
** The compiler generates one of these structures for a class that has
** instance variables defined in its specification. 
*/
typedef struct objc_ivar* Ivar_t;
typedef struct objc_ivar_list {
  int   ivar_count;                             /* Number of structures (Ivar) 
                                                  contained in the list.  One
                                                  structure per instance 
                                                  variable defined in the
                                                  class. */
  struct objc_ivar {
    const char* ivar_name;                      /* Name of the instance
                                                  variable as entered in the
                                                  class definition. */
    const char* ivar_type;                      /* Description of the Ivar's
                                                  type.  Useful for 
                                                  debuggers. */
    int        ivar_offset;                    /* Byte offset from the base 
                                                  address of the instance 
                                                  structure to the variable. */

  } ivar_list[1];                               /* Variable length 
                                                  structure. */
} IvarList, *IvarList_t;


/*
** The compiler generates one (or more) of these structures for a class that
** has methods defined in its specification. 
** 
** The implementation of a class can be broken into separate pieces in a file
** and categories can break them across modules. To handle this problem is a
** singly linked list of methods. 
*/
typedef struct objc_method Method;
typedef Method* Method_t;
typedef struct objc_method_list {
  struct objc_method_list*  method_next;      /* This variable is used to link 
                                                a method list to another.  It 
                                                is a singly linked list. */
  int            method_count;               /* Number of methods defined in 
                                                this structure. */
  struct objc_method {
    SEL         method_name;                  /* This variable is the method's 
                                                name.  It is a char*. 
                                                  The unique integer passed to 
                                                objc_msg_send is a char* too.  
                                                It is compared against 
                                                method_name using strcmp. */
    const char* method_types;                 /* Description of the method's
                                                parameter list.  Useful for
                                                debuggers. */
    IMP         method_imp;                   /* Address of the method in the 
                                                executable. */
  } method_list[1];                           /* Variable length 
                                                structure. */
} MethodList, *MethodList_t;

struct objc_protocol_list {
  struct objc_protocol_list *next;
  int count;
  Protocol *list[1];
};

/*
** This is used to assure consistent access to the info field of 
** classes
*/
#ifndef HOST_BITS_PER_LONG
#define HOST_BITS_PER_LONG  (sizeof(long)*8)
#endif 

#define __CLS_INFO(cls) ((cls)->info)
#define __CLS_ISINFO(cls, mask) ((__CLS_INFO(cls)&mask)==mask)
#define __CLS_SETINFO(cls, mask) (__CLS_INFO(cls) |= mask)

/* The structure is of type MetaClass */
#define _CLS_META 0x2L
#define CLS_ISMETA(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_META))


/* The structure is of type Class */
#define _CLS_CLASS 0x1L
#define CLS_ISCLASS(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_CLASS))

/*
** The class is initialized within the runtime.  This means that 
** it has had correct super and sublinks assigned
*/
#define _CLS_RESOLV 0x8L
#define CLS_ISRESOLV(cls) __CLS_ISINFO(cls, _CLS_RESOLV)
#define CLS_SETRESOLV(cls) __CLS_SETINFO(cls, _CLS_RESOLV)

/*
** The class has been send a +initialize message or a such is not 
** defined for this class
*/
#define _CLS_INITIALIZED 0x04L
#define CLS_ISINITIALIZED(cls) __CLS_ISINFO(cls, _CLS_INITIALIZED)
#define CLS_SETINITIALIZED(cls) __CLS_SETINFO(cls, _CLS_INITIALIZED)

/*
** The class number of this class.  This must be the same for both the 
** class and it's meta class object
*/
#define CLS_GETNUMBER(cls) (__CLS_INFO(cls) >> (HOST_BITS_PER_LONG/2))
#define CLS_SETNUMBER(cls, num) \
  ({ (cls)->info <<= (HOST_BITS_PER_LONG/2); \
     (cls)->info >>= (HOST_BITS_PER_LONG/2); \
     __CLS_SETINFO(cls, (((unsigned long)num) << (HOST_BITS_PER_LONG/2))); })

/*
** The compiler generates one of these structures for each category.  A class
** may have many categories and contain both instance and factory methods.  
*/
typedef struct objc_category {
  const char*   category_name;                /* Name of the category.  Name
                                                contained in the () of the
                                                category definition. */
  const char*   class_name;                   /* Name of the class to which
                                                the category belongs. */
  MethodList_t  instance_methods;             /* Linked list of instance
                                                methods defined in the 
                                                category. NULL indicates no
                                                instance methods defined. */
  MethodList_t  class_methods;                /* Linked list of factory 
                                                methods defined in the
                                                category.  NULL indicates no
                                                class methods defined. */
  struct objc_protocol_list *protocols;	      /* List of Protocols 
					         conformed to */
} Category, *Category_t;

/*
** Structure used when a message is send to a class's super class.  The
** compiler generates one of these structures and passes it to
** objc_msg_super.
*/
typedef struct objc_super {
  id      self;                           /* Id of the object sending
                                                the message. */
  Class class;                              /* Object's super class. */
} Super, *Super_t;

IMP objc_msg_lookup_super(Super_t super, SEL sel);

retval_t objc_msg_sendv(id, SEL, arglist_t);



/*
** This is a hook which is called by objc_lookup_class and
** objc_get_class if the runtime is not able to find the class.
** This may e.g. try to load in the class using dynamic loading.
** The function is guaranteed to be passed a non-NULL name string.
*/
extern Class (*_objc_lookup_class)(const char *name);

/*
** This is a hook which is called by __objc_exec_class every time a class
** or a category is loaded into the runtime.  This may e.g. help a
** dynamic loader determine the classes that have been loaded when
** an object file is dynamically linked in.
*/
extern void (*_objc_load_callback)(Class class, Category* category);

/*
** Hook functions for allocating, copying and disposing of instances
*/
extern id (*_objc_object_alloc)(Class class);
extern id (*_objc_object_copy)(id object);
extern id (*_objc_object_dispose)(id object);

/*
** Standard functions for memory allocation and disposal.
** Users should use these functions in their ObjC programs so
** that they work properly with garbage collectors as well as
** can take advantage of the exception/error handling available.
*/
void *
objc_malloc(size_t size);

void *
objc_atomic_malloc(size_t size);

void *
objc_valloc(size_t size);

void *
objc_realloc(void *mem, size_t size);

void *
objc_calloc(size_t nelem, size_t size);

void
objc_free(void *mem);

/*
** Hook functions for memory allocation and disposal.
** This makes it easy to substitute garbage collection systems
** such as Boehm's GC by assigning these function pointers
** to the GC's allocation routines.  By default these point
** to the ANSI standard malloc, realloc, free, etc.
**
** Users should call the normal objc routines above for
** memory allocation and disposal within their programs.
*/
extern void *(*_objc_malloc)(size_t);
extern void *(*_objc_atomic_malloc)(size_t);
extern void *(*_objc_valloc)(size_t);
extern void *(*_objc_realloc)(void *, size_t);
extern void *(*_objc_calloc)(size_t, size_t);
extern void (*_objc_free)(void *);

Method_t class_get_class_method(MetaClass class, SEL aSel);

Method_t class_get_instance_method(Class class, SEL aSel);

Class class_pose_as(Class impostor, Class superclass);

Class objc_get_class(const char *name);

Class objc_lookup_class(const char *name);

Class objc_next_class(void **enum_state);

const char *sel_get_name(SEL selector);

const char *sel_get_type(SEL selector);

SEL sel_get_uid(const char *name);

SEL sel_get_any_uid(const char *name);

SEL sel_get_any_typed_uid(const char *name);

SEL sel_get_typed_uid(const char *name, const char*);

SEL sel_register_name(const char *name);

SEL sel_register_typed_name(const char *name, const char*type);


BOOL sel_is_mapped (SEL aSel);

extern id class_create_instance(Class class);

static inline const char *
class_get_class_name(Class class)
{
  return CLS_ISCLASS(class)?class->name:((class==Nil)?"Nil":0);
}

static inline long
class_get_instance_size(Class class)
{
  return CLS_ISCLASS(class)?class->instance_size:0;
}

static inline MetaClass
class_get_meta_class(Class class)
{
  return CLS_ISCLASS(class)?class->class_pointer:Nil;
}

static inline Class
class_get_super_class(Class class)
{
  return CLS_ISCLASS(class)?class->super_class:Nil;
}

static inline int
class_get_version(Class class)
{
  return CLS_ISCLASS(class)?class->version:-1;
}

static inline BOOL
class_is_class(Class class)
{
  return CLS_ISCLASS(class);
}

static inline BOOL
class_is_meta_class(Class class)
{
  return CLS_ISMETA(class);
}


static inline void
class_set_version(Class class, long version)
{
  if (CLS_ISCLASS(class))
    class->version = version;
}

static inline IMP
method_get_imp(Method_t method)
{
  return (method!=METHOD_NULL)?method->method_imp:(IMP)0;
}

IMP get_imp (Class class, SEL sel);

/* Redefine on NeXTSTEP so as not to conflict with system function */
#ifdef __NeXT__
#define object_copy	gnu_object_copy
#define object_dispose	gnu_object_dispose
#endif

id object_copy(id object);

id object_dispose(id object);

static inline Class
object_get_class(id object)
{
  return ((object!=nil)
	  ? (CLS_ISCLASS(object->class_pointer)
	     ? object->class_pointer
	     : (CLS_ISMETA(object->class_pointer)
		? (Class)object
		: Nil))
	  : Nil);
}

static inline const char *
object_get_class_name(id object)
{
  return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
                         ?object->class_pointer->name
                         :((Class)object)->name)
                       :"Nil");
}

static inline MetaClass
object_get_meta_class(id object)
{
  return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
                         ?object->class_pointer->class_pointer
                         :(CLS_ISMETA(object->class_pointer)
                           ?object->class_pointer
                           :Nil))
                       :Nil);
}

static inline Class
object_get_super_class
(id object)
{
  return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
                         ?object->class_pointer->super_class
                         :(CLS_ISMETA(object->class_pointer)
                           ?((Class)object)->super_class
                           :Nil))
                       :Nil);
}

static inline BOOL
object_is_class(id object)
{
  return CLS_ISCLASS((Class)object);
}

static inline BOOL
object_is_instance(id object)
{
  return (object!=nil)&&CLS_ISCLASS(object->class_pointer);
}

static inline BOOL
object_is_meta_class(id object)
{
  return CLS_ISMETA((Class)object);
}

struct sarray* 
objc_get_uninstalled_dtable();

#endif /* not __objc_api_INCLUDE_GNU */