add different allocator support

Author: mateoconlechuga

src/libc/allocator.src

@@ -0,0 +1,51 @@
+	assume	adl=1
+
+	section	.text
+	public	_malloc, _calloc, _free, _realloc
+
+	public	_calloc
+_calloc:
+	pop	de
+	pop	bc
+	ex	(sp),hl
+	push	bc
+	push	de
+	call	__imulu
+	push	hl
+	call	_malloc
+	add	hl,de
+	xor	a,a
+	sbc	hl,de
+	ld	e,a
+	push	de
+	push	hl
+	call	nz,_memset
+	pop	hl
+	pop	de
+	pop	bc
+	ret
+
+if defined ALLOCATOR_SIMPLE
+
+_malloc := __simple_malloc
+_free := __simple_free
+_realloc := __simple_realloc
+
+end if
+
+if defined ALLOCATOR_STANDARD
+
+_malloc := __standard_malloc
+_free := __standard_free
+_realloc := __standard_realloc
+
+end if
+
+	extern  __simple_free
+	extern  __simple_malloc
+	extern  __simple_realloc
+	extern  __standard_malloc
+	extern  __standard_free
+	extern  __standard_realloc
+	extern	__imulu
+	extern	_memset

src/libc/allocator_simple.src

@@ -0,0 +1,48 @@
+	assume	adl = 1
+
+	section	.text
+
+	public	__simple_malloc
+__simple_malloc:
+	pop	bc
+	ex	(sp),de
+	push	bc
+	ld	bc,(_heap_ptr)
+	push	bc
+	pop	iy
+	add	iy,de
+	lea	hl,iy
+	or	a,a
+	sbc	hl,bc
+	jr	c,.null
+	ld	de,___heaptop
+	lea	hl,iy
+	or	a,a
+	sbc	hl,de
+	jr	nc,.null
+	ld	(_heap_ptr),iy
+	push	bc
+	pop	hl
+	ret
+.null:
+	or	a,a
+	sbc	hl,hl
+	ret
+
+	public	__simple_free
+__simple_free:
+	ret
+
+	public	__simple_realloc
+__simple_realloc:
+	or	a,a
+	sbc	hl,hl
+	ret
+
+	section .data
+	private _heap_ptr
+_heap_ptr:
+	dl	___heapbot
+
+	extern	___heaptop
+	extern	___heapbot

src/libc/allocator_standard.c

@@ -0,0 +1,119 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+typedef struct __attribute__((packed)) block
+{
+    struct block *ptr;
+    size_t size;
+} __attribute__((packed)) block_t;
+
+extern uint8_t __heapbot[];
+extern uint8_t __heaptop[];
+static uintptr_t heap_ptr = (uintptr_t)__heapbot;
+static block_t _alloc_base;
+
+void *_standard_malloc(size_t alloc_size)
+{
+    block_t *q;
+    block_t *r;
+
+    /* add size of block header to real size */
+    const size_t size = alloc_size + sizeof(block_t);
+    if (size < alloc_size)
+    {
+        return NULL;
+    }
+
+    for (block_t *p = &_alloc_base; (q = p->ptr); p = q)
+    {
+        if (q->size >= size)
+        {
+            if (q->size <= size + sizeof(block_t))
+            {
+                p->ptr = q->ptr;
+            }
+            else
+            {
+                q->size -= size;
+                q = (block_t*)(((uint8_t*)q) + q->size);
+                q->size = size;
+            }
+
+            return q + 1;
+        }
+    }
+
+    /* compute next heap pointer */
+    if (heap_ptr + size < heap_ptr || heap_ptr + size >= (uintptr_t)__heaptop)
+    {
+        return NULL;
+    }
+
+    r = (block_t*)heap_ptr;
+    r->size = size;
+
+    heap_ptr = heap_ptr + size;
+
+    return r + 1;
+}
+
+void _standard_free(void *ptr)
+{
+    if (ptr != NULL)
+    {
+        block_t *p;
+        block_t *q;
+
+        q = (block_t*)ptr - 1;
+
+        for (p = &_alloc_base; p->ptr && p->ptr < q; p = p->ptr);
+
+        if ((uint8_t*)p->ptr == ((uint8_t*)q) + q->size)
+        {
+            q->size += p->ptr->size;
+            q->ptr = p->ptr->ptr;
+        }
+        else
+        {
+            q->ptr = p->ptr;
+        }
+
+        if (((uint8_t*)p) + p->size == (uint8_t*)q)
+        {
+            p->size += q->size;
+            p->ptr = q->ptr;
+        }
+        else
+        {
+            p->ptr = q;
+        }
+    }
+}
+
+void *_standard_realloc(void *ptr, size_t size)
+{
+    block_t *h;
+    void *p;
+
+    if (ptr == NULL)
+    {
+        return malloc(size);
+    }
+
+    h = (block_t*)((uint8_t*)ptr - sizeof(block_t));
+
+    if (h->size >= (size + sizeof(block_t)))
+    {
+        return ptr;
+    }
+
+    if ((p = malloc(size)))
+    {
+        memcpy(p, ptr, size);
+        free(ptr);
+    }
+
+    return p;
+}

src/libc/calloc.src

@@ -18,24 +18,12 @@ typedef struct {
   long long quot;
 } lldiv_t;
 
-typedef char __align;
-union header {
-  struct {
-    union header *ptr;
-    unsigned int size;
-  } s;
-  __align x;
-};
-typedef union header _HEADER;
-
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
 
 #define RAND_MAX 8388607
 
-#define HEADER _HEADER
 #define allocp _allocp
-#define NALLOC 50
 
 __BEGIN_DECLS