gdbstub: clean-up vcont handling to avoid goto

We can handle all the error exit cases by using g_autofree() for the
one thing that needs cleaning up on the exit.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-31-alex.bennee@linaro.org>

gdbstub/gdbstub.c

@@ -573,15 +573,14 @@ static int gdb_handle_vcont(const char *p)
 {
     int res, signal = 0;
     char cur_action;
-    char *newstates;
     unsigned long tmp;
     uint32_t pid, tid;
     GDBProcess *process;
     CPUState *cpu;
     GDBThreadIdKind kind;
     unsigned int max_cpus = gdb_get_max_cpus();
     /* uninitialised CPUs stay 0 */
-    newstates = g_new0(char, max_cpus);
+    g_autofree char *newstates = g_new0(char, max_cpus);
 
     /* mark valid CPUs with 1 */
     CPU_FOREACH(cpu) {
@@ -597,22 +596,20 @@ static int gdb_handle_vcont(const char *p)
     res = 0;
     while (*p) {
         if (*p++ != ';') {
-            res = -ENOTSUP;
-            goto out;
+            return -ENOTSUP;
         }
 
         cur_action = *p++;
         if (cur_action == 'C' || cur_action == 'S') {
             cur_action = qemu_tolower(cur_action);
             res = qemu_strtoul(p, &p, 16, &tmp);
             if (res) {
-                goto out;
+                return res;
             }
             signal = gdb_signal_to_target(tmp);
         } else if (cur_action != 'c' && cur_action != 's') {
             /* unknown/invalid/unsupported command */
-            res = -ENOTSUP;
-            goto out;
+            return -ENOTSUP;
         }
 
         if (*p == '\0' || *p == ';') {
@@ -625,14 +622,12 @@ static int gdb_handle_vcont(const char *p)
         } else if (*p++ == ':') {
             kind = read_thread_id(p, &p, &pid, &tid);
         } else {
-            res = -ENOTSUP;
-            goto out;
+            return -ENOTSUP;
         }
 
         switch (kind) {
         case GDB_READ_THREAD_ERR:
-            res = -EINVAL;
-            goto out;
+            return -EINVAL;
 
         case GDB_ALL_PROCESSES:
             cpu = gdb_first_attached_cpu();
@@ -649,8 +644,7 @@ static int gdb_handle_vcont(const char *p)
             process = gdb_get_process(pid);
 
             if (!process->attached) {
-                res = -EINVAL;
-                goto out;
+                return -EINVAL;
             }
 
             cpu = get_first_cpu_in_process(process);
@@ -668,8 +662,7 @@ static int gdb_handle_vcont(const char *p)
 
             /* invalid CPU/thread specified */
             if (!cpu) {
-                res = -EINVAL;
-                goto out;
+                return -EINVAL;
             }
 
             /* only use if no previous match occourred */
@@ -679,12 +672,9 @@ static int gdb_handle_vcont(const char *p)
             break;
         }
     }
+
     gdbserver_state.signal = signal;
     gdb_continue_partial(newstates);
-
-out:
-    g_free(newstates);
-
     return res;
 }