chardev/mux: convert size members to unsigned int

There is no sense to keep `focus`, `mux_cnt`, `prod`, `cons`
and `tag` variables as signed, those represent either size,
either position in array, which both are unsigned.

`focus` member of `MuxChardev` is kept signed, because initially
set to -1.

Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: qemu-devel@nongnu.org
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20241014152408.427700-5-r.peniaev@gmail.com>

chardev/char-fe.c

@@ -191,7 +191,7 @@ bool qemu_chr_fe_backend_open(CharBackend *be)
 
 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp)
 {
-    int tag = 0;
+    unsigned int tag = 0;
 
     if (s) {
         if (CHARDEV_IS_MUX(s)) {

chardev/char-mux.c

@@ -124,7 +124,8 @@ static void mux_print_help(Chardev *chr)
     }
 }
 
-static void mux_chr_send_event(MuxChardev *d, int mux_nr, QEMUChrEvent event)
+static void mux_chr_send_event(MuxChardev *d, unsigned int mux_nr,
+                               QEMUChrEvent event)
 {
     CharBackend *be = d->backends[mux_nr];
 
@@ -242,7 +243,7 @@ static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
 void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event)
 {
     MuxChardev *d = MUX_CHARDEV(chr);
-    int i;
+    unsigned int i;
 
     if (!muxes_opened) {
         return;
@@ -275,7 +276,7 @@ static GSource *mux_chr_add_watch(Chardev *s, GIOCondition cond)
 static void char_mux_finalize(Object *obj)
 {
     MuxChardev *d = MUX_CHARDEV(obj);
-    int i;
+    unsigned int i;
 
     for (i = 0; i < d->mux_cnt; i++) {
         CharBackend *be = d->backends[i];
@@ -300,11 +301,10 @@ static void mux_chr_update_read_handlers(Chardev *chr)
                                   chr->gcontext, true, false);
 }
 
-void mux_set_focus(Chardev *chr, int focus)
+void mux_set_focus(Chardev *chr, unsigned int focus)
 {
     MuxChardev *d = MUX_CHARDEV(chr);
 
-    assert(focus >= 0);
     assert(focus < d->mux_cnt);
 
     if (d->focus != -1) {

chardev/chardev-internal.h

@@ -38,14 +38,14 @@ struct MuxChardev {
     CharBackend *backends[MAX_MUX];
     CharBackend chr;
     int focus;
-    int mux_cnt;
+    unsigned int mux_cnt;
     bool term_got_escape;
     /* Intermediate input buffer catches escape sequences even if the
        currently active device is not accepting any input - but only until it
        is full as well. */
     unsigned char buffer[MAX_MUX][MUX_BUFFER_SIZE];
-    int prod[MAX_MUX];
-    int cons[MAX_MUX];
+    unsigned int prod[MAX_MUX];
+    unsigned int cons[MAX_MUX];
     int timestamps;
 
     /* Protected by the Chardev chr_write_lock.  */
@@ -59,7 +59,7 @@ DECLARE_INSTANCE_CHECKER(MuxChardev, MUX_CHARDEV,
 #define CHARDEV_IS_MUX(chr)                             \
     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_MUX)
 
-void mux_set_focus(Chardev *chr, int focus);
+void mux_set_focus(Chardev *chr, unsigned int focus);
 void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event);
 
 Object *get_chardevs_root(void);

include/chardev/char-fe.h

@@ -20,7 +20,7 @@ struct CharBackend {
     IOReadHandler *chr_read;
     BackendChangeHandler *chr_be_change;
     void *opaque;
-    int tag;
+    unsigned int tag;
     bool fe_is_open;
 };