Add C++ API

Change-Id: Iff634f22d43470e2dc028387b3816257fd7b4156
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 262 insertions, 0 deletions

diff --git a/src/vpp-api/vapi/vapi_cpp_gen.py b/src/vpp-api/vapi/vapi_cpp_gen.py
new file mode 100755
index 00000000000..6e9f5d3f46f
--- /dev/null
+++ b/src/vpp-api/vapi/vapi_cpp_gen.py
@@ -0,0 +1,262 @@
+#!/usr/bin/env python3
+
+import argparse
+import os
+import sys
+import logging
+from vapi_c_gen import CField, CStruct, CSimpleType, CStructType, CMessage, \
+    json_to_c_header_name
+from vapi_json_parser import JsonParser
+
+
+class CppField(CField):
+    def __init__(
+            self,
+            field_name,
+            field_type,
+            array_len=None,
+            nelem_field=None):
+        super().__init__(field_name, field_type, array_len, nelem_field)
+
+
+class CppStruct(CStruct):
+    def __init__(self, name, fields):
+        super().__init__(name, fields)
+
+
+class CppSimpleType (CSimpleType):
+
+    def __init__(self, name):
+        super().__init__(name)
+
+
+class CppStructType (CStructType, CppStruct):
+    def __init__(self, definition, typedict, field_class):
+        super().__init__(definition, typedict, field_class)
+
+
+class CppMessage (CMessage):
+    def __init__(self, logger, definition, typedict,
+                 struct_type_class, simple_type_class, field_class):
+        super().__init__(logger, definition, typedict, struct_type_class,
+                         simple_type_class, field_class)
+
+    def get_swap_to_be_template_instantiation(self):
+        return "\n".join([
+            "template <> inline void vapi_swap_to_be<%s>(%s *msg)" %
+            (self.get_c_name(), self.get_c_name()),
+            "{",
+            "  %s(msg);" % self.get_swap_to_be_func_name(),
+            "}",
+        ])
+
+    def get_swap_to_host_template_instantiation(self):
+        return "\n".join([
+            "template <> inline void vapi_swap_to_host<%s>(%s *msg)" %
+            (self.get_c_name(), self.get_c_name()),
+            "{",
+            "  %s(msg);" % self.get_swap_to_host_func_name(),
+            "}",
+        ])
+
+    def get_alloc_template_instantiation(self):
+        return "\n".join([
+            "template <> inline %s* vapi_alloc<%s%s>"
+            "(Connection &con%s)" %
+            (self.get_c_name(), self.get_c_name(),
+                ", size_t" * len(self.get_alloc_vla_param_names()),
+                "".join([", size_t %s" % n for n in
+                         self.get_alloc_vla_param_names()])
+             ),
+            "{",
+            "  %s* result = %s(con.vapi_ctx%s);" %
+            (self.get_c_name(), self.get_alloc_func_name(),
+                "".join([", %s" % n
+                         for n in self.get_alloc_vla_param_names()])),
+            "#if VAPI_CPP_DEBUG_LEAKS",
+            "  con.on_shm_data_alloc(result);",
+            "#endif",
+            "  return result;",
+            "}",
+        ])
+
+    def get_cpp_name(self):
+        return "%s%s" % (self.name[0].upper(), self.name[1:])
+
+    def get_req_template_name(self):
+        if self.is_dump():
+            template = "Dump"
+        else:
+            template = "Request"
+
+        return "%s<%s, %s%s>" % (
+            template,
+            self.get_c_name(),
+            self.reply.get_c_name(),
+            "".join([", size_t"] * len(self.get_alloc_vla_param_names()))
+        )
+
+    def get_req_template_instantiation(self):
+        return "template class %s;" % self.get_req_template_name()
+
+    def get_type_alias(self):
+        return "using %s = %s;" % (
+            self.get_cpp_name(), self.get_req_template_name())
+
+    def get_reply_template_name(self):
+        return "Msg<%s>" % (self.get_c_name())
+
+    def get_reply_type_alias(self):
+        return "using %s = %s;" % (
+            self.get_cpp_name(), self.get_reply_template_name())
+
+    def get_msg_class_instantiation(self):
+        return "template class Msg<%s>;" % self.get_c_name()
+
+    def get_get_msg_id_t_instantiation(self):
+        return "\n".join([
+            ("template <> inline vapi_msg_id_t vapi_get_msg_id_t<%s>()"
+                % self.get_c_name()),
+            "{",
+            "  return ::%s; " % self.get_msg_id_name(),
+            "}",
+            "",
+            ("template <> inline vapi_msg_id_t "
+             "vapi_get_msg_id_t<Msg<%s>>()" % self.get_c_name()),
+            "{",
+            "  return ::%s; " % self.get_msg_id_name(),
+            "}",
+        ])
+
+    def get_cpp_constructor(self):
+        return '\n'.join([
+            ('static void __attribute__((constructor)) '
+             '__vapi_cpp_constructor_%s()'
+             % self.name),
+            '{',
+            ('  vapi::vapi_msg_set_msg_id<%s>(%s);' % (
+                self.get_c_name(), self.get_msg_id_name())),
+            '}',
+        ])
+
+
+def gen_json_header(parser, logger, j, io, gen_h_prefix, add_debug_comments):
+    logger.info("Generating header `%s'" % io.name)
+    orig_stdout = sys.stdout
+    sys.stdout = io
+    include_guard = "__included_hpp_%s" % (
+        j.replace(".", "_").replace("/", "_").replace("-", "_"))
+    print("#ifndef %s" % include_guard)
+    print("#define %s" % include_guard)
+    print("")
+    print("#include <vapi/vapi.hpp>")
+    print("#include <%s%s>" % (gen_h_prefix, json_to_c_header_name(j)))
+    print("")
+    print("namespace vapi {")
+    print("")
+    for m in parser.messages_by_json[j].values():
+        # utility functions need to go first, otherwise internal instantiation
+        # causes headaches ...
+        if add_debug_comments:
+            print("/* m.get_swap_to_be_template_instantiation() */")
+        print("%s" % m.get_swap_to_be_template_instantiation())
+        print("")
+        if add_debug_comments:
+            print("/* m.get_swap_to_host_template_instantiation() */")
+        print("%s" % m.get_swap_to_host_template_instantiation())
+        print("")
+        if add_debug_comments:
+            print("/* m.get_get_msg_id_t_instantiation() */")
+        print("%s" % m.get_get_msg_id_t_instantiation())
+        print("")
+        if add_debug_comments:
+            print("/* m.get_cpp_constructor() */")
+        print("%s" % m.get_cpp_constructor())
+        print("")
+        if not m.is_reply():
+            if add_debug_comments:
+                print("/* m.get_alloc_template_instantiation() */")
+            print("%s" % m.get_alloc_template_instantiation())
+            print("")
+        if add_debug_comments:
+            print("/* m.get_msg_class_instantiation() */")
+        print("%s" % m.get_msg_class_instantiation())
+        print("")
+        if m.is_reply():
+            if add_debug_comments:
+                print("/* m.get_reply_type_alias() */")
+            print("%s" % m.get_reply_type_alias())
+            continue
+        if add_debug_comments:
+            print("/* m.get_req_template_instantiation() */")
+        print("%s" % m.get_req_template_instantiation())
+        print("")
+        if add_debug_comments:
+            print("/* m.get_type_alias() */")
+        print("%s" % m.get_type_alias())
+        print("")
+    print("}")  # namespace vapi
+
+    print("#endif")
+    sys.stdout = orig_stdout
+
+
+def json_to_cpp_header_name(json_name):
+    if json_name.endswith(".json"):
+        return "%s.vapi.hpp" % os.path.splitext(json_name)[0]
+    raise Exception("Unexpected json name `%s'!" % json_name)
+
+
+def gen_cpp_headers(parser, logger, prefix, gen_h_prefix,
+                    add_debug_comments=False):
+    if prefix == "" or prefix is None:
+        prefix = ""
+    else:
+        prefix = "%s/" % prefix
+    if gen_h_prefix is None:
+        gen_h_prefix = ""
+    else:
+        gen_h_prefix = "%s/" % gen_h_prefix
+    for j in parser.json_files:
+        with open('%s%s' % (prefix, json_to_cpp_header_name(j)), "w") as io:
+            gen_json_header(parser, logger, j, io,
+                            gen_h_prefix, add_debug_comments)
+
+
+if __name__ == '__main__':
+    try:
+        verbose = int(os.getenv("V", 0))
+    except:
+        verbose = 0
+
+    if verbose >= 2:
+        log_level = 10
+    elif verbose == 1:
+        log_level = 20
+    else:
+        log_level = 40
+
+    logging.basicConfig(stream=sys.stdout, level=log_level)
+    logger = logging.getLogger("VAPI CPP GEN")
+    logger.setLevel(log_level)
+
+    argparser = argparse.ArgumentParser(description="VPP C++ API generator")
+    argparser.add_argument('files', metavar='api-file', action='append',
+                           type=str, help='json api file'
+                           '(may be specified multiple times)')
+    argparser.add_argument('--prefix', action='store', default=None,
+                           help='path prefix')
+    argparser.add_argument('--gen-h-prefix', action='store', default=None,
+                           help='generated C header prefix')
+    args = argparser.parse_args()
+
+    jsonparser = JsonParser(logger, args.files,
+                            simple_type_class=CppSimpleType,
+                            struct_type_class=CppStructType,
+                            field_class=CppField,
+                            message_class=CppMessage)
+
+    gen_cpp_headers(jsonparser, logger, args.prefix, args.gen_h_prefix)
+
+    for e in jsonparser.exceptions:
+        logger.error(e)