asmsh/breakpoints.c

/* Copyright Yann Weber <asmsh@yannweb.net>
   This file is part of asmsh.

   asmsh 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 any later version.
   
   asmsh 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 asmsh. If not, see <https://www.gnu.org/licenses/>.
*/
#include "breakpoints.h"

/** Efficient search of a breakpoint address
 *
 * @param brks pointer on the breakpoint list
 * @param addr the address to search
 * @param idx a pointer on the breakpoint index
 * @return -1 if not found else 0
 *
 * @note idx is set to a value suitable for insertion if value is not found
 */
static int asmsh_brk_index(asmsh_brk_t *brks, unsigned long addr, size_t *idx);


int asmsh_brk_init(asmsh_brk_t *brks)
{
	brks->addrs = NULL;
	brks->sz = 0;

	return 0;
}


void asmsh_brk_free(asmsh_brk_t *brks)
{
	free(brks->addrs);
}


int asmsh_brk_add(asmsh_brk_t *brks, unsigned long addr)
{
	size_t idx;
	int ret;

	void *tmp;

	ret = asmsh_brk_index(brks, addr, &idx);

	if(ret == 0)
	{
		return 1;
	}
	if(brks->sz > 0)
	{
		tmp = realloc(brks->addrs, sizeof(*brks->addrs)*(brks->sz + 1));
		if(tmp == NULL)
		{
			int err = errno;
			asmsh_log_perror("Unable to reallocate breakpoint list");
			errno = err;
			return -1;
		}
		brks->addrs=tmp;
	}
	else
	{
		if(!(brks->addrs = malloc(sizeof(*brks->addrs))))
		{
			int err = errno;
			asmsh_log_perror("Unable to allocate breakpoint list");
			errno = err;
			return -1;
		}
	}
	if(idx == brks->sz)
	{
		brks->addrs[brks->sz] = addr;
	}
	else
	{
		memmove(&(brks->addrs[idx+1]),&(brks->addrs[idx]),
				(brks->sz - idx)*sizeof(*brks->addrs));
		brks->addrs[idx] = addr;
	}
	brks->sz++;
	return 0;
}

int asmsh_brk_del(asmsh_brk_t *brks, unsigned long addr)
{
	size_t idx;
	int ret;

	void *tmp;

	ret = asmsh_brk_index(brks, addr, &idx);

	if(ret < 0)
	{
		return 1;
	}
	brks->sz--;
	if(idx < brks->sz)
	{
		memmove(&(brks->addrs[idx]), &(brks->addrs[idx+1]),
				sizeof(*brks->addrs)*brks->sz);
	}
	if(brks->sz)
	{
		tmp = realloc(brks->addrs, brks->sz);
		if(tmp == NULL)
		{
			int err = errno;
			asmsh_log_perror("Unable to reallocate breakpoint list when removing");
			errno = err;
			return -1;
		}
		brks->addrs=tmp;
	}
	else
	{
		free(brks->addrs);
		brks->addrs = NULL;
	}
	return 0;
}

int asmsh_brk_isset(asmsh_brk_t *brks, unsigned long addr)
{
	size_t idx;
	return asmsh_brk_index(brks, addr, &idx) == 0;
}

static int asmsh_brk_index(asmsh_brk_t *brks, unsigned long addr, size_t *idx)
{
	size_t beg, end, mid;

	if(brks->sz == 0)
	{
		*idx = 0;
		return -1;
	}

	beg = 0;
	end = brks->sz;
	
	while(end >= beg)
	{
		mid = (beg + end)  / 2;
		if(brks->addrs[mid] == addr)
		{
			*idx = mid;
			return 0;
		}
		else if(brks->addrs[mid] > addr)
		{
			if(mid == 0) { break; }
			end = mid - 1;
		}
		else
		{
			beg = mid + 1;
			if(beg >= brks->sz) { break; }
		}
	}
	*idx = beg;
	return -1;

}