ObjFW  Check-in [85ff529ac5]

#ifndef __STDC_CONSTANT_MACROS
# define __STDC_CONSTANT_MACROS
#endif

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

/*! @file */

#ifndef __has_feature
# define __has_feature(x) 0
#endif

#ifndef __has_attribute
# define __has_attribute(x) 0

 * @brief An Objective-C boolean representing false.
 *
 * @note This is a legacy from before C had a boolean type. Prefer the standard
 *	 C99 false instead!
 */
#define NO false



/*!
 * @brief A pointer to a class.
 */
typedef struct objc_class *Class;

/*!
 * @brief A pointer to any object.

	Class _Nonnull class;
#endif
};

#ifdef __cplusplus
extern "C" {
#endif

/*!
 * @brief Registers a selector with the specified name with the runtime.
 *
 * @param name The name for the selector to register
 * @return The registered selector
 */
extern SEL _Nonnull sel_registerName(const char *_Nonnull name);

/*!
 * @brief Returns the name of the specified selector.
 *
 * @param selector The selector whose name should be returned
 * @return The name of the specified selector
 */
extern const char *_Nonnull sel_getName(SEL _Nonnull selector);

/*!
 * @brief Checks two selectors for equality.
 *
 * Selectors are considered equal if they have the same name - any type
 * encoding is ignored.
 *
 * @param selector1 The first selector
 * @param selector2 The second selector
 * @return Whether the two selectors are equal
 */
extern bool sel_isEqual(SEL _Nonnull selector1, SEL _Nonnull selector2);

/*!
 * @brief Allocates a new class and its metaclass.
 *
 * @param superclass The superclass for the new class
 * @param name The name for the new class
 * @param extraBytes Extra bytes to add to the instance size
 * @return A new, unregistered class pair
 */
extern Class _Nonnull objc_allocateClassPair(Class _Nullable superclass,
    const char *_Nonnull name, size_t extraBytes);

/*!
 * @brief Registers an already allocated class pair.
 *
 * @param class_ The class pair to register
 */
extern void objc_registerClassPair(Class _Nonnull class_);

/*!
 * @brief Gets the list of all classes known to the runtime.
 *
 * @param buffer An array of Class to write to. If the buffer does not have
 *		 enough space, the result is truncated.
 * @param count The number of classes for which there is space in `buffer`
 * @return The number of classes written
 */
extern unsigned int objc_getClassList(Class _Nonnull *_Nullable buffer,
    unsigned int count);

/*!
 * @brief Copies the list of all classes known to the runtime.
 *
 * This is like @ref objc_getClassList, but allocates a buffer large enough for
 * all classes.
 *
 * @param length An optional pointer to an `unsigned int` that will be set to
 *		 the number of classes returned
 * @return An array of classes, terminated by `Nil`. You need to call `free()`
 *	   on it when done.
 */
extern Class _Nonnull *_Nonnull objc_copyClassList(
    unsigned int *_Nullable length);

/*!
 * @brief Returns whether the specified class is a metaclass.
 *
 * @param class_ The class which should be examined
 * @return Whether the specified class is a metaclass
 */
extern bool class_isMetaClass(Class _Nullable class_);

/*!
 * @brief Returns the name of the specified class.
 *
 * @param class_ The class whose name should be returned
 * @return The name of the specified class
 */
extern const char *_Nullable class_getName(Class _Nullable class_);

/*!
 * @brief Returns the superclass of the specified class.
 *
 * @param class_ The class whose superclass should be returned
 * @return The superclass of the specified class
 */
extern Class _Nullable class_getSuperclass(Class _Nullable class_);

/*!
 * @brief Returns the instance size of the specified class.
 *
 * @param class_ The class whose instance size should be returned
 * @return The instance size of the specified class
 */
extern unsigned long class_getInstanceSize(Class _Nullable class_);

/*!
 * @brief Returns whether the specified class responds to the specified
 *	  selector.
 *
 * @param class_ The class which should be examined
 * @param selector The selector which should be checked
 * @return Whether the specified class responds to the specified selector
 */
extern bool class_respondsToSelector(Class _Nullable class_,
    SEL _Nonnull selector);

/*!
 * @brief Returns whether the specified class conforms to the specified
 *	  protocol.
 *
 * @param class_ The class which should be examined
 * @param protocol The protocol for which conformance should be checked
 * @return Whether the specified class conforms to the specified protocol
 */
extern bool class_conformsToProtocol(Class _Nullable class_,
    Protocol *_Nonnull protocol);

/*!
 * @brief Returns the class's method implementation for the specified selector.
 *
 * @warning If the method uses the struct return ABI, you need to use
 *	    @ref class_getMethodImplementation_stret instead! Depending on the
 *	    ABI, small structs might not use the struct return ABI.
 *
 * @param class_ The class whose method implementation should be returned
 * @param selector The selector for the method whose implementation should be
 *		   returned
 * @return The class's metod implementation for the specified selector
 */
extern IMP _Nullable class_getMethodImplementation(Class _Nullable class_,
    SEL _Nonnull selector);

/*!
 * @brief Returns the class's method implementation for the specified selector.
 *
 * @warning If the method does not use use the struct return ABI, you need to
 *	    use @ref class_getMethodImplementation instead! Depending on the
 *	    ABI, small structs might not use the struct return ABI.
 *
 * @param class_ The class whose method implementation should be returned
 * @param selector The selector for the method whose implementation should be
 *		   returned
 * @return The class's metod implementation for the specified selector
 */
extern IMP _Nullable class_getMethodImplementation_stret(Class _Nullable class_,
    SEL _Nonnull selector);

/*!
 * @brief Returns the class's instance method for the specified selector
 *
 * @param class_ The class whose instance method should be returned
 * @param selector The selector of the instance method to return
 * @return The class's instance method for the specified selector
 */
extern Method _Nullable class_getInstanceMethod(Class _Nullable class_,
    SEL _Nonnull selector);

/*!
 * @brief Adds the specified method to the class.
 *
 * @param class_ The class to which to add the method
 * @param selector The selector for the method to add
 * @param implementation The implementation of the method to add
 * @param typeEncoding The type encoding of the method to add
 * @return Whether the specified method was added
 */
extern bool class_addMethod(Class _Nonnull class_, SEL _Nonnull selector,
    IMP _Nonnull implementation, const char *_Nullable typeEncoding);

/*!
 * @brief Replaces or adds the specified method of the class.
 *
 * @param class_ The class to which to replace the method
 * @param selector The selector for the method to replace
 * @param implementation The implementation of the method to replace
 * @param typeEncoding The type encoding of the method to replace. Only used if
 *		       the method does not exist yet.
 * @return The old implementation of the method
 */
extern IMP _Nullable class_replaceMethod(Class _Nonnull class_,
    SEL _Nonnull selector, IMP _Nonnull implementation,
    const char *_Nullable typeEncoding);

/*!
 * @brief Returns the object's class.
 *
 * @param object The object whose class should be returned
 * @return The object's class
 */
extern Class _Nullable object_getClass(id _Nullable object);

/*!
 * @brief Sets the object's class.
 *
 * This can be used to swizzle an object's class.
 *
 * @param object The object whose class should be set
 * @param class_ The new class for the object
 * @return The old class of the object
 */
extern Class _Nullable object_setClass(id _Nullable object,
    Class _Nonnull class_);

/*!
 * @brief Returns the object's class name.
 *
 * @param object The object whose class name should be returned
 * @return The object's class name
 */
extern const char *_Nullable object_getClassName(id _Nullable object);

/*!
 * @brief Returns the name of the specified protocol.
 *
 * @param protocol The protocol whose name should be returned
 * @return The name of the specified protocol
 */
extern const char *_Nonnull protocol_getName(Protocol *_Nonnull protocol);

/*!
 * @brief Returns whether two protocols are equal.
 *
 * @param protocol1 The first protocol
 * @param protocol2 The second protocol
 * @return Whether the two protocols are equal
 */
extern bool protocol_isEqual(Protocol *_Nonnull protocol1,
    Protocol *_Nonnull protocol2);

/*!
 * @brief Returns whether the first protocol conforms to the second protocol.
 *
 * @param protocol1 The first protocol
 * @param protocol2 The second protocol
 * @return Whether the first protocol conforms to the second protocol
 */
extern bool protocol_conformsToProtocol(Protocol *_Nonnull protocol1,
    Protocol *_Nonnull protocol2);

/*!
 * @brief Copies the method list of the specified class.
 *
 * @param class_ The class whose method list should be copied
 * @param outCount An optional pointer to an `unsigned int` that should be set
 *		   to the number of methods returned
 * @return An array of methods, terminated by `NULL`. You need to call `free()`
 *	   on it when done.
 */
extern Method _Nullable *_Nullable class_copyMethodList(Class _Nullable class_,
    unsigned int *_Nullable outCount);

/*!
 * @brief Returns the name of the specified method.
 *
 * @param method The method whose name should be returned
 * @return The name of the specified method
 */
extern SEL _Nonnull method_getName(Method _Nonnull method);

/*!
 * @brief Returns the type encoding of the specified method.
 *
 * @param method The method whose type encoding should be returned
 * @return The type encoding of the specified method
 */
extern const char *_Nullable method_getTypeEncoding(Method _Nonnull method);

/*!
 * @brief Copies the instance variable list of the specified class.
 *
 * @param class_ The class whose instance variable list should be copied
 * @param outCount An optional pointer to an `unsigned int` that should be set
 *		   to the number of instance variables returned
 * @return An array of instance variables, terminated by `NULL`. You need to
 *	   call `free()` on it when done.
 */
extern Ivar _Nullable *_Nullable class_copyIvarList(Class _Nullable class_,
    unsigned int *_Nullable outCount);

/*!
 * @brief Returns the name of the specified instance variable.
 *
 * @param ivar The instance variable whose name should be returned
 * @return The name of the specified instance variable
 */
extern const char *_Nonnull ivar_getName(Ivar _Nonnull ivar);

/*!
 * @brief Returns the type encoding of the specified instance variable.
 *
 * @param ivar The instance variable whose type encoding should be returned
 * @return The type encoding of the specified instance variable
 */
extern const char *_Nonnull ivar_getTypeEncoding(Ivar _Nonnull ivar);

/*!
 * @brief Returns the offset of the specified instance variable.
 *
 * @param ivar The instance variable whose offset should be returned
 * @return The offset of the specified instance variable
 */
extern ptrdiff_t ivar_getOffset(Ivar _Nonnull ivar);

/*!
 * @brief Copies the property list of the specified class.
 *
 * @param class_ The class whose property list should be copied
 * @param outCount An optional pointer to an `unsigned int` that should be set
 *		   to the number of properties returned
 * @return An array of properties, terminated by `NULL`. You need to call
 *	   `free()` on it when done.
 */
extern objc_property_t _Nullable *_Nullable class_copyPropertyList(
    Class _Nullable class_, unsigned int *_Nullable outCount);

/*!
 * @brief Returns the name of the specified property.
 *
 * @param property The property whose name should be returned
 * @return The name of the specified property
 */
extern const char *_Nonnull property_getName(objc_property_t _Nonnull property);

/*!
 * @brief Copies the specified attribute value.
 *
 * @param property The property whose attribute value should be copied
 * @param name The name of the attribute value to copy
 * @return A copy of the attribute value. You need to call `free()` on it when
 *	   done.
 */
extern char *_Nullable property_copyAttributeValue(
    objc_property_t _Nonnull property, const char *_Nonnull name);

/*!
 * @brief Exits the Objective-C runtime.
 *
 * This frees all data structures used by the runtime, after which Objective-C
 * can no longer be used inside the current process. This is only useful for
 * debugging.
 */
extern void objc_exit(void);

/*!
 * @brief Sets the handler for uncaught exceptions.
 *
 * @param handler The new handler for uncaught exceptions
 * @return The old handler for uncaught exceptions
 */
extern _Nullable objc_uncaught_exception_handler_t
    objc_setUncaughtExceptionHandler(
    objc_uncaught_exception_handler_t _Nullable handler);

/*!
 * @brief Sets the forwarding handler for unimplemented methods.
 *
 * @param forward The forwarding handler for regular methods
 * @param stretForward The forwarding handler for methods using the struct
 *		       return ABI
 */
extern void objc_setForwardHandler(IMP _Nullable forward,
    IMP _Nullable stretForward);

/*!
 * @brief Sets the handler for mutations during enumeration.
 *
 * @param handler The handler for mutations during enumeration
 */
extern void objc_setEnumerationMutationHandler(
    objc_enumeration_mutation_handler_t _Nullable handler);

/*!
 * @brief Constructs an instance of the specified class in the specified array
 *	  of bytes.
 *
 * @param class_ The class of which to construct an instance
 * @param bytes An array of bytes of at least the length of the instance size.
 *		Must be properly aligned for the class.
 * @return The constructed instance
 */
extern id _Nullable objc_constructInstance(Class _Nullable class_,
    void *_Nullable bytes);

/*!
 * @brief Destructs the specified object.
 *
 * @param object The object to destruct
 * @return The array of bytes that was used to back the instance
 */
extern void *_Nullable objc_destructInstance(id _Nullable object);

/*!
 * @brief Creates a new autorelease pool and puts it on top of the stack of
 *	  autorelease pools.
 *
 * @return A new autorelease pool, which is now on the top of the stack of
 *	   autorelease pools
 */
extern void *_Null_unspecified objc_autoreleasePoolPush(void);

/*!
 * @brief Drains the specified autorelease pool and all pools on top of it and
 *	  removes it from the stack of autorelease pools.
 *
 * @param pool The pool which should be drained together with all pools on top
 *	       of it
 */
extern void objc_autoreleasePoolPop(void *_Null_unspecified pool);

/*!
 * @brief Adds the specified object to the topmost autorelease pool.
 *
 * This is only to be used to implement the `autorelease` method in a root
 * class.
 *
 * @param object The object to add to the topmost autorelease pool
 * @return The autoreleased object
 */
extern id _Nullable _objc_rootAutorelease(id _Nullable object);

/*
 * Used by the compiler, but can also be called manually.
 *
 * These declarations are also required to prevent Clang's implicit
 * declarations which include __declspec(dllimport) on Windows.

Class
objc_allocateClassPair(Class superclass, const char *name, size_t extraBytes)
{
	struct objc_class *class, *metaclass;
	Class iter, rootclass = Nil;

	if (extraBytes > LONG_MAX)
		OBJC_ERROR("extraBytes out of range!")

	if ((class = calloc(1, sizeof(*class))) == NULL ||
	    (metaclass = calloc(1, sizeof(*class))) == NULL)
		OBJC_ERROR("Not enough memory to allocate class pair for class "
		    "%s!", name)

	class->isa = metaclass;