shithub: asif

Info  •  Files  •  Log  •  Branches

vec: fix memory corruption and legibility improvements

--- a/asif.h

+++ b/asif.h

@@ -22,8 +22,8 @@

 typedef struct VShard VShard;

 typedef struct Vector Vector;

 struct VShard{

-	void *p;

-	void *head;

+	uchar *p;

+	uchar *head;

 	int len;

 	VShard *prev;

 	VShard *next;

--- a/vec.c

+++ b/vec.c

@@ -26,7 +26,7 @@

 	VShard *s;

 	s = emalloc(sizeof *s);

-	s->p = emalloc(v->elsz * Shardsz);

+	s->p = emalloc(Shardsz * v->elsz);

 	s->head = s->p;

 	shardlink(v, s);

 	return s;

@@ -53,16 +53,18 @@

 	assert(s != &v->vl);

 	assert(i >= 0 && i < s->len);

-	p = (uchar *)s->head + i * v->elsz;

+	p = s->head + i * v->elsz;

+	assert(p < s->p + Shardsz * v->elsz);

 	memcpy(v->tmp, p, v->elsz);

 	s->len--;

 	v->len--;

 	if(i == 0)

-		s->head = (uchar *)s->head + v->elsz;

+		s->head += v->elsz;

 	if(s->len == 0){

 		shardunlink(v, s);

 		shardlink(v, s);

 	}

+	assert(s->head >= s->p && s->head < s->p + Shardsz * v->elsz);

 	return v->tmp;

 }

@@ -69,7 +71,6 @@

 void *

 vechpop(Vector *v)

 {

-	uchar *p;

 	VShard *s;

 	if(v->len <= 0)

@@ -98,11 +99,13 @@

 	uchar *p;

 	VShard *s;

-	for(s=v->vl.prev; s != &v->vl && s->len >= Shardsz; s=s->prev)

-		;

+	for(s=v->vl.prev; s != &v->vl; s=s->prev)

+		if(s->len + (s->head - s->p) / v->elsz < Shardsz)

+			break;

 	if(s == &v->vl)

 		s = shard(v);

-	p = (uchar *)s->head + s->len * v->elsz;

+	p = s->head + s->len * v->elsz;

+	assert(p >= s->p && p < s->p + Shardsz * v->elsz);

 	memcpy(p, e, v->elsz);

 	s->len++;

 	v->len++;

@@ -111,7 +114,6 @@

 void *

 vecget(Vector *v, int i)

 {

-	uchar *p;

 	VShard *s;

 	assert(i >= 0 && i < v->len);

@@ -120,7 +122,7 @@

 	assert(s != &v->vl);

 	assert(s->len > 0);

 	assert(i >= 0 && i < s->len);

-	return (uchar *)s->head + i * v->elsz;

+	return s->head + i * v->elsz;

 }

 Vector *

@@ -127,7 +129,6 @@

 vec(int elsz)

 {

 	Vector *v;

-	VShard *s;

 	assert(elsz > 0);

 	v = emalloc(sizeof *v);