fix all implicit conversion between signed/unsigned pointers

sadly the C language does not specify any such implicit conversion, so
this is not a matter of just fixing warnings (as gcc treats it) but
actual errors. i would like to revisit a number of these changes and
possibly revise the types used to reduce the number of casts required.

6 files changed, 16 insertions, 20 deletions

diff --git a/src/string/strcasecmp.c b/src/string/strcasecmp.c
index dd879052..02fd5f8c 100644
--- a/src/string/strcasecmp.c
+++ b/src/string/strcasecmp.c
@@ -3,7 +3,7 @@
 
 int strcasecmp(const char *_l, const char *_r)
 {
-	const unsigned char *l=_l, *r=_r;
+	const unsigned char *l=(void *)_l, *r=(void *)_r;
 	for (; *l && *r && (*l == *r || tolower(*l) == tolower(*r)); l++, r++);
 	return tolower(*l) - tolower(*r);
 }
diff --git a/src/string/strcspn.c b/src/string/strcspn.c
index 439b7be4..c843ff97 100644
--- a/src/string/strcspn.c
+++ b/src/string/strcspn.c
@@ -3,18 +3,16 @@
 #define BITOP(a,b,op) \
  ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
 
-size_t strcspn(const char *_s, const char *_c)
+size_t strcspn(const char *s, const char *c)
 {
-	const unsigned char *s = _s;
-	const unsigned char *c = _c;
-	const unsigned char *a = s;
+	const char *a = s;
 	size_t byteset[32/sizeof(size_t)];
 
 	if (!c[0]) return strlen(s);
 	if (!c[1]) return (s=strchr(s, *c)) ? s-a : strlen(a);
 
 	memset(byteset, 0, sizeof byteset);
-	for (; *c && BITOP(byteset, *c, |=); c++);
-	for (; *s && !BITOP(byteset, *s, &); s++);
+	for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++);
+	for (; *s && !BITOP(byteset, *(unsigned char *)s, &); s++);
 	return s-a;
 }
diff --git a/src/string/strncasecmp.c b/src/string/strncasecmp.c
index 4f9230e1..24659721 100644
--- a/src/string/strncasecmp.c
+++ b/src/string/strncasecmp.c
@@ -3,7 +3,7 @@
 
 int strncasecmp(const char *_l, const char *_r, size_t n)
 {
-	const unsigned char *l=_l, *r=_r;
+	const unsigned char *l=(void *)_l, *r=(void *)_r;
 	if (!n--) return 0;
 	for (; *l && *r && n && (*l == *r || tolower(*l) == tolower(*r)); l++, r++, n--);
 	return tolower(*l) - tolower(*r);
diff --git a/src/string/strncmp.c b/src/string/strncmp.c
index 52ba0323..e228843f 100644
--- a/src/string/strncmp.c
+++ b/src/string/strncmp.c
@@ -2,7 +2,7 @@
 
 int strncmp(const char *_l, const char *_r, size_t n)
 {
-	const unsigned char *l=_l, *r=_r;
+	const unsigned char *l=(void *)_l, *r=(void *)_r;
 	if (!n--) return 0;
 	for (; *l && *r && n && *l == *r ; l++, r++, n--);
 	return *l - *r;
diff --git a/src/string/strspn.c b/src/string/strspn.c
index 59b063e5..9543dad0 100644
--- a/src/string/strspn.c
+++ b/src/string/strspn.c
@@ -3,11 +3,9 @@
 #define BITOP(a,b,op) \
  ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
 
-size_t strspn(const char *_s, const char *_c)
+size_t strspn(const char *s, const char *c)
 {
-	const unsigned char *s = _s;
-	const unsigned char *c = _c;
-	const unsigned char *a = s;
+	const char *a = s;
 	size_t byteset[32/sizeof(size_t)] = { 0 };
 
 	if (!c[0]) return 0;
@@ -16,7 +14,7 @@ size_t strspn(const char *_s, const char *_c)
 		return s-a;
 	}
 
-	for (; *c && BITOP(byteset, *c, |=); c++);
-	for (; *s && BITOP(byteset, *s, &); s++);
+	for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++);
+	for (; *s && BITOP(byteset, *(unsigned char *)s, &); s++);
 	return s-a;
 }
diff --git a/src/string/strstr.c b/src/string/strstr.c
index 4d536a73..683cdd01 100644
--- a/src/string/strstr.c
+++ b/src/string/strstr.c
@@ -109,7 +109,7 @@ static char *twoway_strstr(const unsigned char *h, const unsigned char *n)
 		if (z-h < l) {
 			/* Fast estimate for MIN(l,63) */
 			size_t grow = l | 63;
-			const char *z2 = memchr(z, 0, grow);
+			const unsigned char *z2 = memchr(z, 0, grow);
 			if (z2) {
 				z = z2;
 				if (z-h < l) return 0;
@@ -156,11 +156,11 @@ char *strstr(const char *h, const char *n)
 	h = strchr(h, *n);
 	if (!h || !n[1]) return (char *)h;
 	if (!h[1]) return 0;
-	if (!n[2]) return twobyte_strstr(h, n);
+	if (!n[2]) return twobyte_strstr((void *)h, (void *)n);
 	if (!h[2]) return 0;
-	if (!n[3]) return threebyte_strstr(h, n);
+	if (!n[3]) return threebyte_strstr((void *)h, (void *)n);
 	if (!h[3]) return 0;
-	if (!n[4]) return fourbyte_strstr(h, n);
+	if (!n[4]) return fourbyte_strstr((void *)h, (void *)n);
 
-	return twoway_strstr(h, n);
+	return twoway_strstr((void *)h, (void *)n);
 }