sdcc-3.9.0 fork implementing GNU assembler syntax

This fork aims to provide better support for stm8-binutils

1 files changed, 135 insertions, 0 deletions

diff --git a/device/lib/realloc.c b/device/lib/realloc.c
new file mode 100644
index 0000000..ba01530
--- /dev/null
+++ b/device/lib/realloc.c
@@ -0,0 +1,135 @@
+/*-------------------------------------------------------------------------
+   realloc.c - allocate memory.
+
+   Copyright (C) 2015, Philipp Klaus Krause, pkk@spth.de
+
+   This library is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 2, or (at your option) any
+   later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License 
+   along with this library; see the file COPYING. If not, write to the
+   Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA.
+
+   As a special exception, if you link this library with other files,
+   some of which are compiled with SDCC, to produce an executable,
+   this library does not by itself cause the resulting executable to
+   be covered by the GNU General Public License. This exception does
+   not however invalidate any other reasons why the executable file
+   might be covered by the GNU General Public License.
+-------------------------------------------------------------------------*/
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+
+#if defined(__SDCC_mcs51) || defined(__SDCC_ds390) || defined(__SDCC_ds400)
+#define HEAPSPACE __xdata
+#elif defined(__SDCC_pdk13) || defined(__SDCC_pdk14) || defined(__SDCC_pdk15)
+#define HEAPSPACE __near
+#else
+#define HEAPSPACE
+#endif
+
+typedef struct header HEAPSPACE header_t;
+
+struct header
+{
+	header_t *next;
+	header_t *next_free;
+};
+
+extern header_t *HEAPSPACE __sdcc_heap_free;
+
+void __sdcc_heap_init(void);
+
+#if defined(__SDCC_mcs51) || defined(__SDCC_ds390) || defined(__SDCC_ds400)
+void HEAPSPACE *realloc(void *ptr, size_t size)
+#else
+void *realloc(void *ptr, size_t size)
+#endif
+{
+	void HEAPSPACE *ret;
+	header_t *h, *next_free, *prev_free;
+	header_t *HEAPSPACE *f, *HEAPSPACE *pf;
+	size_t blocksize, oldblocksize, maxblocksize;
+
+#if defined(__SDCC_mcs51) || defined(__SDCC_ds390) || defined(__SDCC_ds400) || defined(__SDCC_hc08) || defined(__SDCC_s08)
+	if(!__sdcc_heap_free)
+		__sdcc_heap_init();
+#endif
+
+	if(!ptr)
+		return(malloc(size));
+
+	if(!size)
+	{
+		free(ptr);
+		return(0);
+	}
+
+	prev_free = 0, pf = 0;
+	for(h = __sdcc_heap_free, f = &__sdcc_heap_free; h && h < ptr; prev_free = h, pf = f, f = &(h->next_free), h = h->next_free); // Find adjacent blocks in free list
+	next_free = h;
+
+	if(!size || size + offsetof(struct header, next_free) < size)
+		return(0);
+	blocksize = size + offsetof(struct header, next_free);
+	if(blocksize < sizeof(struct header)) // Requiring a minimum size makes it easier to implement free(), and avoid memory leaks.
+		blocksize = sizeof(struct header);
+
+	h = (void HEAPSPACE *)((char HEAPSPACE *)(ptr) - offsetof(struct header, next_free));
+	oldblocksize = (char HEAPSPACE *)(h->next) - (char HEAPSPACE *)h;
+
+	maxblocksize = oldblocksize;
+	if(prev_free && prev_free->next == h) // Can merge with previous block
+		maxblocksize += (char HEAPSPACE *)h - (char HEAPSPACE *)prev_free;
+	if(next_free == h->next) // Can merge with next block
+		maxblocksize += (char HEAPSPACE *)(next_free->next) - (char HEAPSPACE *)next_free;
+
+	if(blocksize <= maxblocksize) // Can resize in place.
+	{
+		if(prev_free && prev_free->next == h) // Always move into previous block to defragment
+		{
+			memmove(prev_free, h, blocksize <= oldblocksize ? blocksize : oldblocksize);
+			h = prev_free;
+			*pf = next_free;
+			f = pf;
+		}
+
+		if(next_free && next_free == h->next) // Merge with following block
+		{
+			h->next = next_free->next;
+			*f = next_free->next_free;
+		}
+
+		if(maxblocksize >= blocksize + sizeof(struct header)) // Create new block from free space
+		{
+			header_t *const newheader = (header_t *const)((char HEAPSPACE *)h + blocksize);
+			newheader->next = h->next;
+			newheader->next_free = *f;
+			*f = newheader;
+			h->next = newheader;
+		}
+
+		return(&(h->next_free));
+	}
+
+	if(ret = malloc(size))
+	{
+		size_t oldsize = oldblocksize - offsetof(struct header, next_free);
+		memcpy(ret, ptr, size <= oldsize ? size : oldsize);
+		free(ptr);
+		return(ret);
+	}
+
+	return(0);
+}
+