iron out all extra compiler warnings

gcc-9 on x86/64 has reported following issues:

 base64.c:173:17: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:230:18: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:238:18: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:242:22: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:252:18: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:256:22: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:266:18: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:315:27: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 base64.c:329:15: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 blob.c:207:11: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 blob.c:210:11: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 blob.c:243:31: error: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
 blob.c:246:31: error: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
 blob.h:245:37: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 blob.h:253:37: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 blobmsg.h:269:37: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 blobmsg_json.c:155:10: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare]
 examples/../blob.h:245:37: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 examples/../blobmsg.h:269:37: error: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Werror=sign-compare]
 json_script.c:590:7: error: this statement may fall through [-Werror=implicit-fallthrough=]

Signed-off-by: Petr Štetiar <ynezz@true.cz>

base64.c

@@ -142,7 +142,7 @@ int b64_encode(const void *_src, size_t srclength,
 	size_t datalength = 0;
 	u_char input[3] = {0};
 	u_char output[4];
-	int i;
+	size_t i;
 
 	while (2 < srclength) {
 		input[0] = *src++;
@@ -200,7 +200,8 @@ int b64_decode(const void *_src, void *dest, size_t targsize)
 {
 	const char *src = _src;
 	unsigned char *target = dest;
-	int tarindex, state, ch;
+	int state, ch;
+	size_t tarindex;
 	u_char nextbyte;
 	char *pos;
 

blob.c

@@ -186,7 +186,7 @@ blob_nest_end(struct blob_buf *buf, void *cookie)
 	buf->head = attr;
 }
 
-static const int blob_type_minlen[BLOB_ATTR_LAST] = {
+static const size_t blob_type_minlen[BLOB_ATTR_LAST] = {
 	[BLOB_ATTR_STRING] = 1,
 	[BLOB_ATTR_INT8] = sizeof(uint8_t),
 	[BLOB_ATTR_INT16] = sizeof(uint16_t),
@@ -222,12 +222,12 @@ blob_parse(struct blob_attr *attr, struct blob_attr **data, const struct blob_at
 {
 	struct blob_attr *pos;
 	int found = 0;
-	int rem;
+	size_t rem;
 
 	memset(data, 0, sizeof(struct blob_attr *) * max);
 	blob_for_each_attr(pos, attr, rem) {
 		int id = blob_id(pos);
-		int len = blob_len(pos);
+		size_t len = blob_len(pos);
 
 		if (id >= max)
 			continue;

blob.h

@@ -96,7 +96,7 @@ blob_is_extended(const struct blob_attr *attr)
 /*
  * blob_len: returns the length of the attribute's payload
  */
-static inline unsigned int
+static inline size_t
 blob_len(const struct blob_attr *attr)
 {
 	return (be32_to_cpu(attr->id_len) & BLOB_ATTR_LEN_MASK) - sizeof(struct blob_attr);
@@ -105,7 +105,7 @@ blob_len(const struct blob_attr *attr)
 /*
  * blob_raw_len: returns the complete length of an attribute (including the header)
  */
-static inline unsigned int
+static inline size_t
 blob_raw_len(const struct blob_attr *attr)
 {
 	return blob_len(attr) + sizeof(struct blob_attr);
@@ -114,7 +114,7 @@ blob_raw_len(const struct blob_attr *attr)
 /*
  * blob_pad_len: returns the padded length of an attribute (including the header)
  */
-static inline unsigned int
+static inline size_t
 blob_pad_len(const struct blob_attr *attr)
 {
 	unsigned int len = blob_raw_len(attr);

blobmsg.c

@@ -67,7 +67,7 @@ int blobmsg_check_array(const struct blob_attr *attr, int type)
 {
 	struct blob_attr *cur;
 	bool name;
-	int rem;
+	size_t rem;
 	int size = 0;
 
 	switch (blobmsg_type(attr)) {

blobmsg_json.c

@@ -146,7 +146,7 @@ static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 static void add_separator(struct strbuf *s)
 {
 	const char *indent_chars = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
-	int len;
+	size_t len;
 
 	if (!s->indent)
 		return;
@@ -279,7 +279,7 @@ static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, i
 {
 	struct blob_attr *pos;
 	bool first = true;
-	int rem = len;
+	size_t rem = len;
 
 	blobmsg_puts(s, (array ? "[" : "{" ), 1);
 	s->indent_level++;

examples/blobmsg-example.c

@@ -15,7 +15,7 @@ static const char *indent_str = "\t\t\t\t\t\t\t\t\t\t\t\t\t";
 static void dump_attr_data(struct blob_attr *data, int indent, int next_indent);
 
 static void
-dump_table(struct blob_attr *head, int len, int indent, bool array)
+dump_table(struct blob_attr *head, size_t len, int indent, bool array)
 {
 	struct blob_attr *attr;
 	struct blobmsg_hdr *hdr;

examples/json_script-example.c

@@ -14,7 +14,7 @@ static void handle_command(struct json_script_ctx *ctx, const char *name,
 	struct blob_attr *data, struct blob_attr *vars)
 {
 	struct blob_attr *cur;
-	int rem;
+	size_t rem;
 
 	fprintf(stdout, "%s", name);
 	blobmsg_for_each_attr(cur, data, rem)

json_script.c

@@ -95,7 +95,7 @@ const char *json_script_find_var(struct json_script_ctx *ctx, struct blob_attr *
 				 const char *name)
 {
 	struct blob_attr *cur;
-	int rem;
+	size_t rem;
 
 	blobmsg_for_each_attr(cur, vars, rem) {
 		if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
@@ -164,7 +164,7 @@ static int handle_case(struct json_call *call, struct blob_attr *expr)
 {
 	struct blob_attr *tb[3], *cur;
 	const char *var;
-	int rem;
+	size_t rem;
 
 	json_get_tuple(expr, tb, BLOBMSG_TYPE_STRING, BLOBMSG_TYPE_TABLE);
 	if (!tb[1] || !tb[2])
@@ -233,7 +233,7 @@ static int expr_eq_regex(struct json_call *call, struct blob_attr *expr, bool re
 	struct json_script_ctx *ctx = call->ctx;
 	struct blob_attr *tb[3], *cur;
 	const char *var;
-	int rem;
+	size_t rem;
 
 	json_get_tuple(expr, tb, BLOBMSG_TYPE_STRING, 0);
 	if (!tb[1] || !tb[2])
@@ -277,7 +277,7 @@ static int handle_expr_has(struct json_call *call, struct blob_attr *expr)
 {
 	struct json_script_ctx *ctx = call->ctx;
 	struct blob_attr *tb[3], *cur;
-	int rem;
+	size_t rem;
 
 	json_get_tuple(expr, tb, 0, 0);
 	if (!tb[1])
@@ -306,7 +306,8 @@ static int handle_expr_has(struct json_call *call, struct blob_attr *expr)
 static int expr_and_or(struct json_call *call, struct blob_attr *expr, bool and)
 {
 	struct blob_attr *cur;
-	int ret, rem;
+	int ret;
+	size_t rem;
 	int i = 0;
 
 	blobmsg_for_each_attr(cur, expr, rem) {
@@ -515,7 +516,8 @@ static int cmd_process_strings(struct json_call *call, struct blob_attr *attr)
 	struct json_script_ctx *ctx = call->ctx;
 	struct blob_attr *cur;
 	int args = -1;
-	int rem, ret;
+	int ret;
+	size_t rem;
 	void *c;
 
 	blob_buf_init(&ctx->buf, 0);
@@ -572,7 +574,7 @@ static int json_process_cmd(struct json_call *call, struct blob_attr *block)
 {
 	struct json_script_ctx *ctx = call->ctx;
 	struct blob_attr *cur;
-	int rem;
+	size_t rem;
 	int ret;
 	int i = 0;
 
@@ -589,6 +591,7 @@ static int json_process_cmd(struct json_call *call, struct blob_attr *block)
 		case BLOBMSG_TYPE_STRING:
 			if (!i)
 				return __json_process_cmd(call, block);
+			/* fall through */
 		default:
 			ret = json_process_cmd(call, cur);
 			if (ret < -1)