[PATCH v3 07/25] gdbstub: Introduce GDBFeatureBuilder

[Akihiko Odaki]

GDBFeatureBuilder unifies the logic to generate dynamic GDBFeature.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 include/exec/gdbstub.h | 20 ++++++++++++++
 gdbstub/gdbstub.c      | 59 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index d0dcc99ed4..1f4608d4f9 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -16,6 +16,11 @@ typedef struct GDBFeature {
     int num_regs;
 } GDBFeature;
 
+typedef struct GDBFeatureBuilder {
+    GDBFeature *feature;
+    GPtrArray *xml;
+} GDBFeatureBuilder;
+
 
 /* Get or set a register.  Returns the size of the register.  */
 typedef int (*gdb_get_reg_cb)(CPUArchState *env, GByteArray *buf, int reg);
@@ -34,6 +39,21 @@ void gdb_register_coprocessor(CPUState *cpu,
  */
 int gdbserver_start(const char *port_or_device);
 
+void gdb_feature_builder_init(GDBFeatureBuilder *builder, GDBFeature *feature,
+                              const char *name, const char *xmlname);
+
+void gdb_feature_builder_append_tag(const GDBFeatureBuilder *builder,
+                                    const char *format, ...)
+    G_GNUC_PRINTF(2, 3);
+
+void gdb_feature_builder_append_reg(const GDBFeatureBuilder *builder,
+                                    const char *name,
+                                    int bitsize,
+                                    const char *type,
+                                    const char *group);
+
+void gdb_feature_builder_end(const GDBFeatureBuilder *builder);
+
 const GDBFeature *gdb_find_static_feature(const char *xmlname);
 
 void gdb_set_stop_cpu(CPUState *cpu);
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 293e8ea439..32e88de431 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -414,6 +414,65 @@ static const char *get_feature_xml(const char *p, const 
char **newp,
     return name ? gdb_static_features[i].xml : NULL;
 }
 
+void gdb_feature_builder_init(GDBFeatureBuilder *builder, GDBFeature *feature,
+                              const char *name, const char *xmlname)
+{
+    char *header = g_markup_printf_escaped(
+        "<?xml version=\"1.0\"?>"
+        "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
+        "<feature name=\"%s\">",
+        name);
+
+    builder->feature = feature;
+    builder->xml = g_ptr_array_new();
+    g_ptr_array_add(builder->xml, header);
+    feature->xmlname = xmlname;
+    feature->num_regs = 0;
+}
+
+void gdb_feature_builder_append_tag(const GDBFeatureBuilder *builder,
+                                    const char *format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    g_ptr_array_add(builder->xml, g_markup_vprintf_escaped(format, ap));
+    va_end(ap);
+}
+
+void gdb_feature_builder_append_reg(const GDBFeatureBuilder *builder,
+                                    const char *name,
+                                    int bitsize,
+                                    const char *type,
+                                    const char *group)
+{
+    if (group) {
+        gdb_feature_builder_append_tag(
+            builder,
+            "<reg name=\"%s\" bitsize=\"%d\" type=\"%s\" group=\"%s\"/>",
+            name, bitsize, type, group);
+    } else {
+        gdb_feature_builder_append_tag(
+            builder, "<reg name=\"%s\" bitsize=\"%d\" type=\"%s\"/>",
+            name, bitsize, type);
+    }
+
+    builder->feature->num_regs++;
+}
+
+void gdb_feature_builder_end(const GDBFeatureBuilder *builder)
+{
+    g_ptr_array_add(builder->xml, (void *)"</feature>");
+    g_ptr_array_add(builder->xml, NULL);
+
+    builder->feature->xml = g_strjoinv(NULL, (void *)builder->xml->pdata);
+
+    for (guint i = 0; i < builder->xml->len - 2; i++) {
+        g_free(g_ptr_array_index(builder->xml, i));
+    }
+
+    g_ptr_array_free(builder->xml, TRUE);
+}
+
 const GDBFeature *gdb_find_static_feature(const char *xmlname)
 {
     const GDBFeature *feature;
-- 
2.41.0