memmgt.c

/*
	memmgt.c - Part of macxx, a cross assembler family for various micro-processors
	Copyright (C) 2008 David Shepperd

	This program 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 3 of the License, or
	(at your option) any later version.

	This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "token.h"
#include <stdlib.h>
#include <string.h>

long total_mem_used;
long peak_mem_used;
long misc_pool_used;

typedef struct hdr
{
	unsigned long size;
	int line;
	char *file;
#if defined(DEBUG_MALLOC)
	void *caller;
	struct hdr *next, *prev;
#endif
	unsigned long magic;
} Hdr;

#define PRE_MAGIC 	0x12345678
#define NOTALLOCED  	0x00010000
#define POST_MAGIC	0x87654321
#define NFG ((char *)0)

#if defined(DEBUG_MALLOC)
static Hdr *top, *bottom;
#endif

static char* check(Hdr *hdr)
{
	char *msg = 0;
	unsigned long *end;

	if ( hdr->magic != PRE_MAGIC )
	{
		if ( hdr->magic == (PRE_MAGIC | NOTALLOCED) )
		{
			msg = "%%%s-F-FATAL, %s:%d tried to free %08lX already free'd.\n";
		}
		else
		{
			msg = "%%%s-F-FATAL, %s:%d tried to free %08lX with corrupted header.\n";
		}
	}
	else
	{
		end = (unsigned long *)((char *)(hdr + 1) + hdr->size);
		if ( *end != POST_MAGIC )
		{
			msg = "%%%s-F-FATAL, %s:%d tried to free %08lX with corrupted tail.\n";
		}
	}
	return msg;
}

#if defined(DEBUG_MALLOC)
static void check_all(void)
{
	Hdr *h;
	char *msg;

	h = top;
	while ( h )
	{
		msg = check(h);
		if ( msg )
		{
			fprintf(stderr, msg, macxx_name, h->file, h->line, h + 1);
			abort();
		}
		h = h->next;
		if ( h == top )
			break;
	}
}
#endif

int mem_free(void *s, char *file, int line)
{
	Hdr *hdr;
	char *msg = NULL;

	if ( s == 0 )
	{
		msg = "%s:%d tried to free %08lX.\n";
	}
	else
	{
		hdr = (Hdr *)s - 1;
		msg = check(hdr);
	}
	if ( msg )
	{
		fprintf(stderr, msg, macxx_name, file, line, s);
		abort();
	}
#if defined(LLF) || defined(MACXX)
	total_mem_used -= hdr->size + sizeof(Hdr) + sizeof(long);
#endif
#if defined(DEBUG_MALLOC)
	check_all();
	if ( hdr == top )
	{
		top = hdr->next;
	}
	if ( hdr == bottom )
	{
		bottom = hdr->prev;
	}
	if ( hdr->next )
		hdr->next->prev = 0;
	if ( hdr->prev )
		hdr->prev->next = 0;
	hdr->next = hdr->prev = 0;
#endif
	free((char *)hdr);
	return (0);                  /* assume it worked */
}

void *mem_alloc(int nbytes, char *file, int line)
{
	void *s;
	Hdr *hdr;
	unsigned long *end;
	int siz;

	/* Round the caller's count by size of pointer then make it a multiple of sizeof pointer */
	nbytes = (nbytes + (sizeof(char *) - 1)) & ~(sizeof(char *) - 1);
	siz = nbytes + sizeof(Hdr) + sizeof(char *);
	hdr = (Hdr *)calloc((unsigned int)siz, (unsigned int)1);  /* get some memory from OS */
	if ( hdr == (Hdr *)0 )
	{
		fprintf(stderr, "%%%s-F-FATAL, %s:%d Ran out of memory requesting %d bytes. Used %ld so far.\n",
				macxx_name, file, line, siz, total_mem_used);
#if defined(LLF) || defined(MACXX)
		display_mem();
#endif
		fprintf(stderr, "%s", emsg);
		abort();
	}
	hdr->size = nbytes;	/* Rounded up size of region */
	hdr->file = file;	/* pointer to file name */
	hdr->line = line;	/* line number */
	hdr->magic = PRE_MAGIC;	/* surround user's buffer with known information */
	s = (void *)(hdr + 1);	/* Point to buffer to hand back to user */
	end = (unsigned long *)((char *)s + nbytes); /* Get pointer to end of buffer */
	*end = POST_MAGIC;	/* Stuff a magic number there too */
#if defined(DEBUG_MALLOC)
	if ( top == 0 )
	{
		top = hdr;
	}
	hdr->prev = bottom;
	if ( bottom )
		bottom->next = hdr;
	bottom = hdr;
	hdr->next = 0;
	check_all();
#endif
#if defined(LLF) || defined(MACXX)
	total_mem_used += siz;
	if ( total_mem_used > peak_mem_used )
		peak_mem_used = total_mem_used;
#endif
	return s;
}

void *mem_calloc(int nbytes, char *file, int line)
{
	void *retV = mem_alloc(nbytes, file, line);
	if ( retV )
		memset(retV, 0, nbytes);
	return retV;
}

void* mem_realloc(void *old, int nbytes, char *file, int line)
{
	void *s;
	Hdr *hdr;
#if defined(DEBUG_MALLOC)
	Hdr * prev,*next;
#endif
	int siz;
	unsigned long *end;

	if ( old != 0 )
	{
		hdr = (Hdr *)old - 1;
		siz = hdr->size;
		if ( hdr->magic != PRE_MAGIC )
		{
			fprintf(stderr, "%%%s-F-FATAL, %s:%d realloc'd %08lX with corrupted header.\n",
					macxx_name, file, line, (unsigned long)old);
			abort();
		}
#if defined(LLF) || defined(MACXX)
		total_mem_used -= siz + sizeof(Hdr) + sizeof(long);
#endif
		end = (unsigned long *)((char *)old + hdr->size);
		if ( *end != POST_MAGIC )
		{
			fprintf(stderr, "%%%s-F-FATAL, %s:%d realloc'd %08lX with corrupted trailer.\n",
					macxx_name, file, line, (unsigned long)old);
			if ( hdr->line > 0 )
				fprintf(stderr, "              area allocated by %s:%d\n", hdr->file, hdr->line);
			abort();
		}
#if defined(DEBUG_MALLOC)
		check_all();
		next = hdr->next;
		prev = hdr->prev;
#endif
		*end = 0;

		/* Round up user's size and make it a multiple of sizeof pointer */
		nbytes = (nbytes + (sizeof(char *) - 1)) & ~(sizeof(char *) - 1);
		siz = nbytes + sizeof(Hdr) + sizeof(long);
		s = (void *)realloc(hdr, siz);
		if ( s == NFG )
		{
			fprintf(stderr, "%%%s-F-FATAL, %s:%d ran out of memory realloc'ing %ld bytes to %d. Used %ld so far.\n",
					macxx_name, file, line, hdr->size, siz, total_mem_used);
#if defined(LLF) || defined(MACXX)
			display_mem();
#endif
			fprintf(stderr, "%s", emsg);
			abort();
		}
		hdr = (Hdr *)s;
		hdr->file = file;	/* Pointer to filename */
		hdr->line = line;	/* line number */
		hdr->magic = PRE_MAGIC;	/* Marker */
		if ( nbytes > hdr->size )
		{     /* 0 the newly alloc'd  area if it got bigger */
			s = (char *)(hdr + 1) + hdr->size;
			memset(s, 0, nbytes - hdr->size);
		}
		s = (void *)(hdr + 1);	/* Compute pointer to user's buffer */
		end = (unsigned long *)((char *)s + nbytes); /* Compute pointer to end of buffer */
		*end = POST_MAGIC;	/* deposit a marker */
		hdr->size = nbytes;	/* record the new buffer size */
#if defined(DEBUG_MALLOC)
		hdr->next = next;
		hdr->prev = prev;
		if ( next )
			next->prev = hdr;
		if ( prev )
			prev->next = hdr;
		if ( top == prev )
			top = hdr;
#endif
#if defined(LLF) || defined(MACXX)
		total_mem_used += siz;
		if ( total_mem_used > peak_mem_used )
			peak_mem_used = total_mem_used;
#endif
		return s;
	}
	else
	{
		return mem_alloc(nbytes, file, line);
	}
}