/*
 *	newdel.cpp. 
 *	
 *	example of functions for new, delete and global constructors
 *	for gnu c++ for the net yaroze
 *
 *	12-7-97	
 */

#include <libps.h>
#include <malloc.h>
#include <stdio.h>


//	prototypes
void * __builtin_new(size_t size);
void * __builtin_vec_new(size_t size);
void __builtin_vec_delete(void *ptr);
void __builtin_delete(void *ptr);
extern "C"
{
	//	start is located in libps.a
	void _start(void);
	void _xxstart(void);
}

//	__CTOR_LIST__ symbol created by linker
typedef void (*func_ptr) (void);
extern func_ptr __CTOR_LIST__[];

//	define a dummy class with a constructor that takes
//	a parameter to make sure that there is a __CTOR_LIST__
//	generated, otherwise you get a linker error from 
//	_xxstart
class __always_have_a_non_default_constructor_global
{
	public:
		__always_have_a_non_default_constructor_global(int g) {x=g;};
		int x;
		
};

//	here is the global
__always_have_a_non_default_constructor_global __always_have_this_global(5);

void *__builtin_new(size_t size)
{
	void *ptr;

	// Apparently malloc (0) can be a bit unpredictable
	if (size==0)
	{
		size = 1;
	}
	ptr = (void *)malloc(size);
	if (ptr==NULL)
	{
			printf("new failed - out of heap\n");
	}
	return ptr;
}

void *__builtin_vec_new(size_t size)
{
	return __builtin_new(size);
}

void __builtin_delete(void *ptr)
{
	if (ptr!=NULL)
	{
		free(ptr);
	}
}

void __builtin_vec_delete(void *ptr)
{
	__builtin_delete(ptr);
}

extern "C"
{
	void _xxstart(void)
	{
		unsigned int h;
		unsigned int nptrs;
		
		//	on some systems, __CTOR_LIST__[0] contains the number
		//	of pointers to global initialisation functions
		nptrs=(unsigned int)__CTOR_LIST__[0];
		if 	(nptrs==(unsigned int)-1)
		{
			//	on others, it is -1 and you see how many
			//	pointers there are because the array is
			//	null terminated
			nptrs=0;
			while (__CTOR_LIST__[nptrs+1]!=NULL)
			{
				nptrs++;
			}
		}

		//	Call the initialisation functions in reverse order (?)
		for (h=nptrs; h>=1; h--)						
		{
			__CTOR_LIST__[h]();					
		}
			
		//	call libps start function - this will call main()
		_start();
	}
}