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/* $Id$ */

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/** @file alloc_func.hpp Functions related to the allocation of memory */

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#ifndef ALLOC_FUNC_HPP

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#define ALLOC_FUNC_HPP

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/**

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 * Functions to exit badly with an error message.

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 * It has to be linked so the error messages are not

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 * duplicated in each object file making the final

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 * binary needlessly large.

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 */

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void NORETURN MallocError(size_t size);

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void NORETURN ReallocError(size_t size);

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/**

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 * Simplified allocation function that allocates the specified number of

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 * elements of the given type. It also explicitly casts it to the requested

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 * type.

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 * @note throws an error when there is no memory anymore.

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 * @note the memory contains garbage data (i.e. possibly non-zero values).

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 * @param T the type of the variable(s) to allocation.

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 * @param num_elements the number of elements to allocate of the given type.

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 * @return NULL when num_elements == 0, non-NULL otherwise.

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 */

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{

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	/*

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	 * MorphOS cannot handle 0 elements allocations, or rather that always

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	 * returns NULL. So we do that for *all* allocations, thus causing it

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	 * to behave the same on all OSes.

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	 */

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	if (num_elements == 0) return NULL;

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	T *t_ptr = (T*)malloc(num_elements * sizeof(T));

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	if (t_ptr == NULL) MallocError(num_elements * sizeof(T));

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	return t_ptr;

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}

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/**

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 * Simplified allocation function that allocates the specified number of

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 * elements of the given type. It also explicitly casts it to the requested

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 * type.

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 * @note throws an error when there is no memory anymore.

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 * @note the memory contains all zero values.

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 * @param T the type of the variable(s) to allocation.

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 * @param num_elements the number of elements to allocate of the given type.

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 * @return NULL when num_elements == 0, non-NULL otherwise.

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 */

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{

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	/*

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	 * MorphOS cannot handle 0 elements allocations, or rather that always

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	 * returns NULL. So we do that for *all* allocations, thus causing it

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	 * to behave the same on all OSes.

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	 */

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	if (num_elements == 0) return NULL;

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	T *t_ptr = (T*)calloc(num_elements, sizeof(T));

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	if (t_ptr == NULL) MallocError(num_elements * sizeof(T));

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	return t_ptr;

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}

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/**

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 * Simplified reallocation function that allocates the specified number of

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 * elements of the given type. It also explicitly casts it to the requested

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 * type. It extends/shrinks the memory allocation given in t_ptr.

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 * @note throws an error when there is no memory anymore.

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 * @note the memory contains all zero values.

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 * @param T the type of the variable(s) to allocation.

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 * @param t_ptr the previous allocation to extend/shrink.

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 * @param num_elements the number of elements to allocate of the given type.

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 * @return NULL when num_elements == 0, non-NULL otherwise.

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 */

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{

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	/*

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	 * MorphOS cannot handle 0 elements allocations, or rather that always

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	 * returns NULL. So we do that for *all* allocations, thus causing it

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	 * to behave the same on all OSes.

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	 */

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	if (num_elements == 0) {

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		free(t_ptr);

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		return NULL;

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	}

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	t_ptr = (T*)realloc(t_ptr, num_elements * sizeof(T));

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	if (t_ptr == NULL) ReallocError(num_elements * sizeof(T));

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	return t_ptr;

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}

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/** alloca() has to be called in the parent function, so define AllocaM() as a macro */

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#define AllocaM(T, num_elements) ((T*)alloca((num_elements) * sizeof(T)))

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#endif /* ALLOC_FUNC_HPP */