gdb_foreach_feature() enumerates features that are useful to identify
registers. gdb_read_register() actually reads registers.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 include/exec/gdbstub.h |  6 ++++++
 gdbstub/gdbstub.c      | 20 +++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index 5bfaaa0306..cb6b3b17bd 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -59,6 +59,12 @@ void gdb_feature_builder_end(const GDBFeatureBuilder *builder);
 
 const GDBFeature *gdb_find_static_feature(const char *xmlname);
 
+void gdb_foreach_feature(CPUState *cpu,
+                         void (* callback)(void *, const GDBFeature *, int),
+                         void *opaque);
+
+int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
+
 void gdb_set_stop_cpu(CPUState *cpu);
 
 /* in gdbstub-xml.c, generated by scripts/feature_to_c.py */
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 9217fc7900..215d5d4fa5 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -483,7 +483,25 @@ const GDBFeature *gdb_find_static_feature(const char *xmlname)
     g_assert_not_reached();
 }
 
-static int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
+void gdb_foreach_feature(CPUState *cpu,
+                         void (* callback)(void *, const GDBFeature *, int),
+                         void *opaque)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+    GDBRegisterState *r;
+
+    if (!cc->gdb_core_feature) {
+        return;
+    }
+
+    callback(opaque, cc->gdb_core_feature, 0);
+
+    for (r = cpu->gdb_regs; r; r = r->next) {
+        callback(opaque, r->feature, r->base_reg);
+    }
+}
+
+int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
     CPUArchState *env = cpu->env_ptr;
-- 
2.42.0