darling-libobjc2/objc/capabilities.h
thebeing ee7817cf57 Implement a hook that allows the compiler to register the aliases used with the
@compatibility_alias directive so that they can be resolved at runtime.
2011-03-25 20:01:43 +00:00

109 lines
3.7 KiB
C

/**
* capabilities.h - This file defines the list of capabilities. Runtime
* capabilities can be checked. You may use #ifdef to test at compile time
* whether the runtime on the current platform understands the capability.
* This does not mean that the runtime implements the capability, however.
*
* A copy of this file exists for compatibility in GNUstep's Objective-C
* framework. When using this framework in conjunction with the GNU
* Objective-C runtime, most of the features will not be supported at run time,
* even if the corresponding macros are available at compile time.
* Additionally, several are compile-time options in the GNUstep runtime, so
* although they are present in the header and understood by the runtime, they
* may not be supported by the installed runtime.
*/
#include "Availability.h"
#ifndef __GNUSTEP_CAPABILITIES_H__
# define __GNUSTEP_CAPABILITIES_H__
#ifdef __cplusplus
extern "C" {
#endif
/**
* The runtime supports zero-cost exceptions.
*/
#define OBJC_CAP_EXCEPTIONS 0
/**
* The runtime supports the @synchronize directive.
*/
#define OBJC_CAP_SYNCRONIZE 1
/**
* The runtime supports property accessors.
*/
#define OBJC_CAP_PROPERTIES 2
/**
* The runtime supports introspection on declared properties.
*/
#define OBJC_CAP_PROPERTY_INTROSPECTION 3
/**
* The runtime supports optional methods and declared properties in protocols.
*/
#define OBJC_CAP_OPTIONAL_PROTOCOLS 4
/**
* The runtime supports non-fragile instance variables.
*/
#define OBJC_CAP_NONFRAGILE_IVARS 5
/**
* The runtime supports making method lookup dependent on the types, as well as
* the name, of the selector.
*/
#define OBJC_CAP_TYPE_DEPENDENT_DISPATCH 6
/**
* The runtime was compiled in the low-memory profile. This trades some speed
* for reduced memory consumption.
*/
#define OBJC_CAP_LOW_MEMORY 7
/**
* The runtime supports developer mode. When in user mode (the default),
* loading two classes with the same name will cause the program to abort. In
* developer mode, the new class will replace the old one. If the ivar layouts
* are the same, the new class will be treated as a category. If they are
* different, then it will replace the old one in the class table, meaning that
* message sends to the class will go to the new version, but existing
* instances will not acquire the new methods.
*/
#define OBJC_DEVELOPER_MODE 8
/**
* This runtime supports the unified exception model. This means that
* Objective-C objects can be caught by either Objective-C or C++ exception
* handlers (the latter only in Objective-C++ code), irrespective of whether
* they are thrown from C++ throw of Objective-C @throw statements.
*/
#define OBJC_UNIFIED_EXCEPTION_MODEL 9
/**
* The runtime provides a hook that allows the compiler to register class
* aliases declared with the @compatibility_alias keyword. This allows the
* runtime to resolve the alias, e.g. if objc_getClass() is called with an
* alias as the argument.
*/
#define OBJC_CAP_REGISTERED_COMPATIBILITY_ALIASES 10
/**
* Macro used to require the existence of a specific capability. This creates
* a function that is called by the loader and tests that the runtime supports
* the required capability, aborting if it does not.
*/
#define OBJC_REQUIRE_CAPABILITY(x) \
__attribute__((constructor)) static void objc_test ## x(void)\
{\
if (!objc_test_capability(x))\
{\
fprintf(stderr, "Runtime does not support required feature: " #x "\n");\
exit(1);\
}\
}
/**
* Run time feature test. This function returns 1 if the runtime supports the
* specified feature or 0 if it does not.
*/
int objc_test_capability(int x) OBJC_NONPORTABLE;
#ifdef __cplusplus
}
#endif
#endif //__GNUSTEP_CAPABILITIES_H__