gdbstub: Introduce gdb_find_static_feature()

This function is useful to determine the number of registers exposed to
GDB from the XML name.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231025093128.33116-3-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231106185112.2755262-10-alex.bennee@linaro.org>

gdbstub/gdbstub.c

@@ -422,6 +422,19 @@ static const char *get_feature_xml(const char *p, const char **newp,
     return NULL;
 }
 
+const GDBFeature *gdb_find_static_feature(const char *xmlname)
+{
+    const GDBFeature *feature;
+
+    for (feature = gdb_static_features; feature->xmlname; feature++) {
+        if (!strcmp(feature->xmlname, xmlname)) {
+            return feature;
+        }
+    }
+
+    g_assert_not_reached();
+}
+
 static int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);

include/exec/gdbstub.h

@@ -44,6 +44,14 @@ void gdb_register_coprocessor(CPUState *cpu,
  */
 int gdbserver_start(const char *port_or_device);
 
+/**
+ * gdb_find_static_feature() - Find a static feature.
+ * @xmlname: The name of the XML.
+ *
+ * Return: The static feature.
+ */
+const GDBFeature *gdb_find_static_feature(const char *xmlname);
+
 void gdb_set_stop_cpu(CPUState *cpu);
 
 /* in gdbstub-xml.c, generated by scripts/feature_to_c.py */