[PATCH V5 20/32] libxl IDL: generate code to parse libxl__json_object to libxl_FOO struct

[Wei Liu <wei.liu2@citrix.com>]

libxl_FOO_parse_json functions are generated.

Note that these functions are used to parse libxl__json_object to
libxl__FOO struct. They don't consume JSON string.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/gentypes.py              |  131 ++++++++++++++++++++++++++++++++++
 tools/libxl/idl.py                   |   15 ++++
 tools/libxl/idl.txt                  |    7 +-
 tools/libxl/libxl.h                  |   14 ++++
 tools/libxl/libxl_types.idl          |   29 ++++----
 tools/libxl/libxl_types_internal.idl |    4 +-
 6 files changed, 186 insertions(+), 14 deletions(-)

diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py
index d2ed12a..c51e96a 100644
--- a/tools/libxl/gentypes.py
+++ b/tools/libxl/gentypes.py
@@ -304,6 +304,116 @@ def libxl_C_type_to_json(ty, v, indent = "    "):
         s = indent + s
     return s.replace("\n", "\n%s" % indent).rstrip(indent)
 
+def libxl_C_type_parse_json(ty, w, v, indent = "    ", parent = None, discriminator = None):
+    s = ""
+    if parent is None:
+        s += "int rc = 0;\n"
+        s += "const libxl__json_object *x = o;\n"
+
+    if isinstance(ty, idl.Array):
+        if parent is None:
+            raise Exception("Array type must have a parent")
+        if discriminator is not None:
+            raise Exception("Only KeyedUnion can have discriminator")
+        lenvar = parent + ty.lenvar.name
+        s += "{\n"
+        s += "    libxl__json_object *t;\n"
+        s += "    int i;\n"
+        s += "    if (!libxl__json_object_is_array(x)) {\n"
+        s += "        rc = -1;\n"
+        s += "        goto out;\n"
+        s += "    }\n"
+        s += "    %s = x->u.array->count;\n" % lenvar
+        s += "    %s = libxl__calloc(NOGC, %s, sizeof(*%s));\n" % (v, lenvar, v)
+        s += "    if (!%s && %s != 0) {\n" % (v, lenvar)
+        s += "        rc = -1;\n"
+        s += "        goto out;\n"
+        s += "    }\n"
+        s += "    for (i=0; (t=libxl__json_array_get(x,i)); i++) {\n"
+        s += libxl_C_type_parse_json(ty.elem_type, "t", v+"[i]",
+                                     indent + "    ", parent)
+        s += "    }\n"
+        s += "    if (i != %s) {\n" % lenvar
+        s += "        rc = -1;\n"
+        s += "        goto out;\n"
+        s += "    }\n"
+        s += "}\n"
+    elif isinstance(ty, idl.Enumeration):
+        if discriminator is not None:
+            raise Exception("Only KeyedUnion can have discriminator")
+        s += "{\n"
+        s += "    const char *enum_str;\n"
+        s += "    if (!libxl__json_object_is_string(x)) {\n"
+        s += "        rc = -1;\n"
+        s += "        goto out;\n"
+        s += "    }\n"
+        s += "    enum_str = libxl__json_object_get_string(x);\n"
+        s += "    rc = %s_from_string(enum_str, %s);\n" % (ty.typename, ty.pass_arg(v, parent is None, idl.PASS_BY_REFERENCE))
+        s += "    if (rc)\n"
+        s += "        goto out;\n"
+        s += "}\n"
+    elif isinstance(ty, idl.KeyedUnion):
+        if parent is None:
+            raise Exception("KeyedUnion type must have a parent")
+        if discriminator is None:
+            raise Excpetion("KeyedUnion type must have a discriminator")
+        for f in ty.fields:
+            if f.enumname != discriminator:
+                continue
+            (nparent,fexpr) = ty.member(v, f, parent is None)
+            if f.type is not None:
+                s += libxl_C_type_parse_json(f.type, w, fexpr, indent + "    ", nparent)
+    elif isinstance(ty, idl.Struct) and (parent is None or ty.json_parse_fn is None):
+        if discriminator is not None:
+            raise Exception("Only KeyedUnion can have discriminator")
+        for f in [f for f in ty.fields if not f.const and not f.type.private]:
+            if isinstance(f.type, idl.KeyedUnion):
+                for x in f.type.fields:
+                    s += "if (libxl__json_map_get(\"%s\", %s, JSON_MAP)) {\n" % \
+                         (f.type.keyvar.name + "." + x.name, w)
+                    s += "    x = libxl__json_map_get(\"%s\", %s, JSON_MAP);\n" % \
+                         (f.type.keyvar.name + "." + x.name, w)
+
+                    (nparent, fexpr) = ty.member(v, f.type.keyvar, parent is None)
+                    s += "    %s = %s;\n" % (fexpr, x.enumname)
+
+                    (nparent,fexpr) = ty.member(v, f, parent is None)
+                    #s += "XXX %s %s %s\n" % (nparent, fexpr, f.name)
+                    s += libxl_C_type_parse_json(f.type, "x", fexpr, "", nparent, x.enumname)
+                    #s += "YYY\n"
+                    s += "}\n"
+            else:
+                s += "if (libxl__json_map_get(\"%s\", %s, %s)) {\n" % (f.name, w, f.type.json_parse_type)
+                s += "    x = libxl__json_map_get(\"%s\", %s, %s);\n" % (f.name, w, f.type.json_parse_type)
+                (nparent,fexpr) = ty.member(v, f, parent is None)
+                s += libxl_C_type_parse_json(f.type, "x", fexpr, "    ", nparent)
+                s += "    x = x->parent;\n"
+                s += "}\n"
+    else:
+        if discriminator is not None:
+            raise Exception("Only KeyedUnion can have discriminator")
+        if ty.json_parse_fn is not None:
+            s += "rc = %s(gc, %s, &%s);\n" % (ty.json_parse_fn, w, v)
+            s += "if (rc)\n"
+            s += "    goto out;\n"
+
+    if parent is None:
+        s += "out:\n"
+        s += "return rc;\n"
+
+    if s != "":
+        s = indent +s
+    return s.replace("\n", "\n%s" % indent).rstrip(indent)
+
+def libxl_C_type_from_json(ty, v, w, indent = "    "):
+    s = ""
+    parse = "(libxl__json_parse_callback)&%s_parse_json" % ty.typename
+    s += "return libxl__object_from_json(ctx, \"%s\", %s, %s, %s);\n" % (ty.typename, parse, v, w)
+
+    if s != "":
+        s = indent + s
+    return s.replace("\n", "\n%s" % indent).rstrip(indent)
+
 def libxl_C_enum_to_string(ty, e, indent = "    "):
     s = ""
     s += "switch(%s) {\n" % e
@@ -382,6 +492,8 @@ if __name__ == '__main__':
                                                ku.keyvar.type.make_arg(ku.keyvar.name)))
         if ty.json_gen_fn is not None:
             f.write("%schar *%s_to_json(libxl_ctx *ctx, %s);\n" % (ty.hidden(), ty.typename, ty.make_arg("p")))
+        if ty.json_parse_fn is not None:
+            f.write("%sint %s_from_json(libxl_ctx *ctx, %s, const char *s);\n" % (ty.hidden(), ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
         if isinstance(ty, idl.Enumeration):
             f.write("%sconst char *%s_to_string(%s);\n" % (ty.hidden(), ty.typename, ty.make_arg("p")))
             f.write("%sint %s_from_string(const char *s, %s);\n" % (ty.hidden(), ty.typename, ty.make_arg("e", passby=idl.PASS_BY_REFERENCE)))
@@ -411,6 +523,10 @@ if __name__ == '__main__':
     for ty in [ty for ty in types if ty.json_gen_fn is not None]:
         f.write("%syajl_gen_status %s_gen_json(yajl_gen hand, %s);\n" % (ty.hidden(), ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
 
+    for ty in [ty for ty in types if ty.json_parse_fn is not None]:
+        f.write("%sint %s_parse_json(libxl__gc *gc, const libxl__json_object *o, %s);\n" % \
+                (ty.hidden(), ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
+
     f.write("\n")
     f.write("""#endif /* %s */\n""" % header_json_define)
     f.close()
@@ -478,4 +594,19 @@ if __name__ == '__main__':
         f.write("}\n")
         f.write("\n")
 
+    for ty in [t for t in types if t.json_parse_fn is not None]:
+        f.write("int %s_parse_json(libxl__gc *gc, const libxl__json_object *%s, %s)\n" % (ty.typename,"o",ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
+        f.write("{\n")
+        f.write(libxl_C_type_parse_json(ty, "o", "p"))
+        f.write("}\n")
+        f.write("\n")
+
+        f.write("int %s_from_json(libxl_ctx *ctx, %s, const char *s)\n" % (ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
+        f.write("{\n")
+        if not isinstance(ty, idl.Enumeration):
+            f.write("    %s_init(p);\n" % ty.typename)
+        f.write(libxl_C_type_from_json(ty, "p", "s"))
+        f.write("}\n")
+        f.write("\n")
+
     f.close()
diff --git a/tools/libxl/idl.py b/tools/libxl/idl.py
index 8b118dd..747e3ee 100644
--- a/tools/libxl/idl.py
+++ b/tools/libxl/idl.py
@@ -66,8 +66,12 @@ class Type(object):
 
         if self.typename is not None and not self.private:
             self.json_gen_fn = kwargs.setdefault('json_gen_fn', self.typename + "_gen_json")
+            self.json_parse_type = kwargs.setdefault('json_parse_type', "JSON_ANY")
+            self.json_parse_fn = kwargs.setdefault('json_parse_fn', self.typename + "_parse_json")
         else:
             self.json_gen_fn = kwargs.setdefault('json_gen_fn', None)
+            self.json_parse_type = kwargs.setdefault('json_parse_type', None)
+            self.json_parse_fn = kwargs.setdefault('json_parse_fn', None)
 
         self.autogenerate_json = kwargs.setdefault('autogenerate_json', True)
 
@@ -119,6 +123,9 @@ class Number(Builtin):
         kwargs.setdefault('dispose_fn', None)
         kwargs.setdefault('signed', False)
         kwargs.setdefault('json_gen_fn', "yajl_gen_integer")
+        kwargs.setdefault('json_parse_type', "JSON_INTEGER")
+        # json_parse_fn might be overriden on specific type
+        kwargs.setdefault('json_parse_fn', "libxl__int_parse_json")
         self.signed = kwargs['signed']
         Builtin.__init__(self, ctype, **kwargs)
 
@@ -126,6 +133,7 @@ class UInt(Number):
     def __init__(self, w, **kwargs):
         kwargs.setdefault('namespace', None)
         kwargs.setdefault('dispose_fn', None)
+        kwargs.setdefault('json_parse_fn', "libxl__uint%d_parse_json" % w)
         Number.__init__(self, "uint%d_t" % w, **kwargs)
 
         self.width = w
@@ -142,6 +150,7 @@ class EnumerationValue(object):
 class Enumeration(Type):
     def __init__(self, typename, values, **kwargs):
         kwargs.setdefault('dispose_fn', None)
+        kwargs.setdefault('json_parse_type', "JSON_STRING")
         Type.__init__(self, typename, **kwargs)
 
         self.value_namespace = kwargs.setdefault('value_namespace',
@@ -171,6 +180,7 @@ class Field(object):
 class Aggregate(Type):
     """A type containing a collection of other types"""
     def __init__(self, kind, typename, fields, **kwargs):
+        kwargs.setdefault('json_parse_type', "JSON_MAP")
         Type.__init__(self, typename, **kwargs)
 
         if self.typename is not None:
@@ -257,6 +267,8 @@ class KeyedUnion(Aggregate):
 void = Builtin("void *", namespace = None)
 bool = Builtin("bool", namespace = None,
                json_gen_fn = "yajl_gen_bool",
+               json_parse_type = "JSON_BOOL",
+               json_parse_fn = "libxl__bool_parse_json",
                autogenerate_json = False)
 
 size_t = Number("size_t", namespace = None)
@@ -270,12 +282,15 @@ uint64 = UInt(64, json_gen_fn = "libxl__uint64_gen_json")
 
 string = Builtin("char *", namespace = None, dispose_fn = "free",
                  json_gen_fn = "libxl__string_gen_json",
+                 json_parse_type = "JSON_STRING | JSON_NULL",
+                 json_parse_fn = "libxl__string_parse_json",
                  autogenerate_json = False)
 
 class Array(Type):
     """An array of the same type"""
     def __init__(self, elem_type, lenvar_name, **kwargs):
         kwargs.setdefault('dispose_fn', 'free')
+        kwargs.setdefault('json_parse_type', 'JSON_ARRAY')
         Type.__init__(self, namespace=elem_type.namespace, typename=elem_type.rawname + " *", **kwargs)
 
         lv_kwargs = dict([(x.lstrip('lenvar_'),y) for (x,y) in kwargs.items() if x.startswith('lenvar_')])
diff --git a/tools/libxl/idl.txt b/tools/libxl/idl.txt
index 6a53dd8..484d5d7 100644
--- a/tools/libxl/idl.txt
+++ b/tools/libxl/idl.txt
@@ -65,9 +65,14 @@ Type.json_gen_fn: (default: typename + "_gen_json" or None if type == None)
  The name of the C function which will generate a YAJL data structure
  representing this type.
 
+Type.json_parse_fn: (default: typename + "_parse_json" or None if type == None)
+
+ The name of the C function which will parse a libxl JSON structure
+ representing this type to C type.
+
 Type.autogenerate_json: (default: True)
 
- Indicates if the above named Type.json_gen_fn should be autogenerated.
+ Indicates if the above named Type.json_*_fn should be autogenerated.
 
 Other simple type-Classes
 -------------------------
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 5b0de1c..88f3b02 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -291,6 +291,20 @@
  *
  *    Generates a JSON object from "p" in the form of a NULL terminated
  *    string.
+ *
+ * <type *> libxl_<type>_from_json(const char *json)
+ * int      libxl_<type>_from_json(const char *json)
+ *
+ *    Parses "json" and returns:
+ *
+ *    an int value, if <type> is enumeration type. The value is the enum value
+ *    representing the respective string in "json".
+ *
+ *    an instance of <type>, if <type> is aggregate type. The returned
+ *    instance has its fields filled in by the parser according to "json".
+ *
+ *    If the parsing fails, caller cannot rely on the value / instance
+ *    returned.
  */
 #ifndef LIBXL_H
 #define LIBXL_H
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 35da8ba..ff175f4 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -5,19 +5,24 @@
 
 namespace("libxl_")
 
-libxl_defbool = Builtin("defbool", passby=PASS_BY_REFERENCE,
+libxl_defbool = Builtin("defbool", json_parse_type="JSON_STRING", passby=PASS_BY_REFERENCE,
                         init_val="LIBXL__DEFBOOL_DEFAULT")
 
-libxl_domid = Builtin("domid", json_gen_fn = "yajl_gen_integer", autogenerate_json = False)
-libxl_devid = Builtin("devid", json_gen_fn = "yajl_gen_integer", autogenerate_json = False, signed = True, init_val="-1")
-libxl_uuid = Builtin("uuid", passby=PASS_BY_REFERENCE)
-libxl_mac = Builtin("mac", passby=PASS_BY_REFERENCE)
-libxl_bitmap = Builtin("bitmap", dispose_fn="libxl_bitmap_dispose", passby=PASS_BY_REFERENCE)
-libxl_cpuid_policy_list = Builtin("cpuid_policy_list", dispose_fn="libxl_cpuid_dispose", passby=PASS_BY_REFERENCE)
-
-libxl_string_list = Builtin("string_list", dispose_fn="libxl_string_list_dispose", passby=PASS_BY_REFERENCE)
-libxl_key_value_list = Builtin("key_value_list", dispose_fn="libxl_key_value_list_dispose", passby=PASS_BY_REFERENCE)
-libxl_hwcap = Builtin("hwcap", passby=PASS_BY_REFERENCE)
+libxl_domid = Builtin("domid", json_gen_fn = "yajl_gen_integer", json_parse_fn = "libxl__uint32_parse_json",
+                      json_parse_type = "JSON_INTEGER", autogenerate_json = False)
+libxl_devid = Builtin("devid", json_gen_fn = "yajl_gen_integer", json_parse_fn = "libxl__int_parse_json",
+                      json_parse_type = "JSON_INTEGER", autogenerate_json = False, signed = True, init_val="-1")
+libxl_uuid = Builtin("uuid", json_parse_type="JSON_STRING", passby=PASS_BY_REFERENCE)
+libxl_mac = Builtin("mac", json_parse_type="JSON_STRING", passby=PASS_BY_REFERENCE)
+libxl_bitmap = Builtin("bitmap", json_parse_type="JSON_ARRAY", dispose_fn="libxl_bitmap_dispose", passby=PASS_BY_REFERENCE)
+libxl_cpuid_policy_list = Builtin("cpuid_policy_list", json_parse_type="JSON_ARRAY",
+                                  dispose_fn="libxl_cpuid_dispose", passby=PASS_BY_REFERENCE)
+
+libxl_string_list = Builtin("string_list", json_parse_type="JSON_ARRAY",
+                            dispose_fn="libxl_string_list_dispose", passby=PASS_BY_REFERENCE)
+libxl_key_value_list = Builtin("key_value_list", json_parse_type="JSON_MAP",
+                               dispose_fn="libxl_key_value_list_dispose", passby=PASS_BY_REFERENCE)
+libxl_hwcap = Builtin("hwcap", json_parse_type="JSON_ARRAY", passby=PASS_BY_REFERENCE)
 
 #
 # Specific integer types
@@ -582,7 +587,7 @@ libxl_event_type = Enumeration("event_type", [
 
 libxl_ev_user = UInt(64)
 
-libxl_ev_link = Builtin("ev_link", passby=PASS_BY_REFERENCE, private=True)
+libxl_ev_link = Builtin("ev_link", json_parse_type="JSON_STRING", passby=PASS_BY_REFERENCE, private=True)
 
 libxl_event = Struct("event",[
     ("link",     libxl_ev_link),
diff --git a/tools/libxl/libxl_types_internal.idl b/tools/libxl/libxl_types_internal.idl
index a964851..17533f1 100644
--- a/tools/libxl/libxl_types_internal.idl
+++ b/tools/libxl/libxl_types_internal.idl
@@ -1,7 +1,9 @@
 namespace("libxl__")
 hidden(True)
 
-libxl_domid = Builtin("domid", namespace="libxl_", json_gen_fn = "yajl_gen_integer")
+libxl_domid = Builtin("domid", namespace="libxl_", json_gen_fn = "yajl_gen_integer",
+		      json_parse_fn = "libxl__uint32_parse_json", json_parse_type = "JSON_INTEGER",
+		      autogenerate_json = False)
 
 libxl__qmp_message_type = Enumeration("qmp_message_type", [
     (1, "QMP"),
-- 
1.7.10.4