[Qemu-devel] Re: [PATCH 01/15] qapi: add code generator for qmp-types (v2)

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 11 Mar 2011 17:05:31 -0600
Anthony Liguori <aliguori@us.ibm.com> wrote:

> Only generate qmp-types.[ch].  These files contain the type definitions for
> QMP along with the alloc/free functions for these types.  Functions to convert
> enum values to integers and vice versa are also included.
> 
> qmp-types is used both within QEMU and within libqmp
> 
> Special alloc/free functions are provided to ensure that all structures are
> padded when allocated.  This makes sure that libqmp can provide a forward
> compatible interface since all additions to a structure will have a boolean
> enable flag.
> 
> The free function is convenient since individual structures may have pointers
> that also require freeing.

I like the way you split the code generator, makes review easier.

Two general comments:

 1. It doesn't seem to do any error detection, schema syntax errors seem
    to completely break the script

 2. Would nice to have a test suite

More comments below.

> 
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> ---
> v1 -> v2
>  - modify code generator to use multiline strings instead of prints
>  - support proxy commands
>  - support async commands
> 
> diff --git a/Makefile b/Makefile
> index 6b1d716..6b9fd69 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -4,6 +4,7 @@ GENERATED_HEADERS = config-host.h trace.h qemu-options.def
>  ifeq ($(TRACE_BACKEND),dtrace)
>  GENERATED_HEADERS += trace-dtrace.h
>  endif
> +GENERATED_HEADERS += qmp-types.h
>  
>  ifneq ($(wildcard config-host.mak),)
>  # Put the all: rule here so that config-host.mak can contain dependencies.
> @@ -146,6 +147,14 @@ trace-dtrace.o: trace-dtrace.dtrace $(GENERATED_HEADERS)
>  
>  simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
>  
> +qmp-types.c: $(SRC_PATH)/qmp-schema.json $(SRC_PATH)/qmp-gen.py
> +	$(call quiet-command,python $(SRC_PATH)/qmp-gen.py --types-body < $< > $@, "  GEN   $@")
> +
> +qmp-types.h: $(SRC_PATH)/qmp-schema.json $(SRC_PATH)/qmp-gen.py
> +	$(call quiet-command,python $(SRC_PATH)/qmp-gen.py --types-header < $< > $@, "  GEN   $@")
> +
> +qmp-types.o: qmp-types.c qmp-types.h
> +
>  version.o: $(SRC_PATH)/version.rc config-host.mak
>  	$(call quiet-command,$(WINDRES) -I. -o $@ $<,"  RC    $(TARGET_DIR)$@")
>  
> diff --git a/Makefile.objs b/Makefile.objs
> index 69f0383..710d99f 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -15,7 +15,7 @@ oslib-obj-$(CONFIG_POSIX) += oslib-posix.o
>  
>  block-obj-y = cutils.o cache-utils.o qemu-malloc.o qemu-option.o module.o
>  block-obj-y += nbd.o block.o aio.o aes.o qemu-config.o
> -block-obj-y += error.o
> +block-obj-y += error.o qmp-types.o
>  block-obj-$(CONFIG_POSIX) += posix-aio-compat.o
>  block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
>  
> diff --git a/ordereddict.py b/ordereddict.py
> new file mode 100644
> index 0000000..e17269f
> --- /dev/null
> +++ b/ordereddict.py

Would be good to mention in the log you're adding this. You've said you'd
do it iirc.

> @@ -0,0 +1,128 @@
> +# Copyright (c) 2009 Raymond Hettinger
> +#
> +# Permission is hereby granted, free of charge, to any person
> +# obtaining a copy of this software and associated documentation files
> +# (the "Software"), to deal in the Software without restriction,
> +# including without limitation the rights to use, copy, modify, merge,
> +# publish, distribute, sublicense, and/or sell copies of the Software,
> +# and to permit persons to whom the Software is furnished to do so,
> +# subject to the following conditions:
> +#
> +#     The above copyright notice and this permission notice shall be
> +#     included in all copies or substantial portions of the Software.
> +#
> +#     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> +#     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
> +#     OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> +#     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
> +#     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
> +#     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> +#     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> +#     OTHER DEALINGS IN THE SOFTWARE.
> +
> +from UserDict import DictMixin
> +
> +class OrderedDict(dict, DictMixin):
> +
> +    def __init__(self, *args, **kwds):
> +        if len(args) > 1:
> +            raise TypeError('expected at most 1 arguments, got %d' % len(args))
> +        try:
> +            self.__end
> +        except AttributeError:
> +            self.clear()
> +        self.update(*args, **kwds)
> +
> +    def clear(self):
> +        self.__end = end = []
> +        end += [None, end, end]         # sentinel node for doubly linked list
> +        self.__map = {}                 # key --> [key, prev, next]
> +        dict.clear(self)
> +
> +    def __setitem__(self, key, value):
> +        if key not in self:
> +            end = self.__end
> +            curr = end[1]
> +            curr[2] = end[1] = self.__map[key] = [key, curr, end]
> +        dict.__setitem__(self, key, value)
> +
> +    def __delitem__(self, key):
> +        dict.__delitem__(self, key)
> +        key, prev, next = self.__map.pop(key)
> +        prev[2] = next
> +        next[1] = prev
> +
> +    def __iter__(self):
> +        end = self.__end
> +        curr = end[2]
> +        while curr is not end:
> +            yield curr[0]
> +            curr = curr[2]
> +
> +    def __reversed__(self):
> +        end = self.__end
> +        curr = end[1]
> +        while curr is not end:
> +            yield curr[0]
> +            curr = curr[1]
> +
> +    def popitem(self, last=True):
> +        if not self:
> +            raise KeyError('dictionary is empty')
> +        if last:
> +            key = reversed(self).next()
> +        else:
> +            key = iter(self).next()
> +        value = self.pop(key)
> +        return key, value
> +
> +    def __reduce__(self):
> +        items = [[k, self[k]] for k in self]
> +        tmp = self.__map, self.__end
> +        del self.__map, self.__end
> +        inst_dict = vars(self).copy()
> +        self.__map, self.__end = tmp
> +        if inst_dict:
> +            return (self.__class__, (items,), inst_dict)
> +        return self.__class__, (items,)
> +
> +    def keys(self):
> +        return list(self)
> +
> +    setdefault = DictMixin.setdefault
> +    update = DictMixin.update
> +    pop = DictMixin.pop
> +    values = DictMixin.values
> +    items = DictMixin.items
> +    iterkeys = DictMixin.iterkeys
> +    itervalues = DictMixin.itervalues
> +    iteritems = DictMixin.iteritems
> +
> +    def __repr__(self):
> +        if not self:
> +            return '%s()' % (self.__class__.__name__,)
> +        return '%s(%r)' % (self.__class__.__name__, self.items())
> +
> +    def copy(self):
> +        return self.__class__(self)
> +
> +    @classmethod
> +    def fromkeys(cls, iterable, value=None):
> +        d = cls()
> +        for key in iterable:
> +            d[key] = value
> +        return d
> +
> +    def __eq__(self, other):
> +        if isinstance(other, OrderedDict):
> +            if len(self) != len(other):
> +                return False
> +            for p, q in  zip(self.items(), other.items()):
> +                if p != q:
> +                    return False
> +            return True
> +        return dict.__eq__(self, other)
> +
> +    def __ne__(self, other):
> +        return not self == other
> +
> diff --git a/qmp-gen.py b/qmp-gen.py
> new file mode 100644
> index 0000000..cded2f6
> --- /dev/null
> +++ b/qmp-gen.py
> @@ -0,0 +1,516 @@
> +##
> +# QAPI Code Generator
> +#
> +# Copyright IBM, Corp. 2011
> +#
> +# Authors:
> +#  Anthony Liguori   <aliguori@us.ibm.com>
> +#
> +# This work is licensed under the terms of the GNU GPL, version 2.  See
> +# the COPYING file in the top-level directory.
> +##

This misses basic documentation, like all supported types, functions, etc.

This seems to exist in the qmp-schema.json file introduced by patch 07/15. If
that's the case, then it's a better idea to add that file to this this patch,
only with the doc bits.

> +import sys
> +from ordereddict import OrderedDict
> +
> +enum_types = []
> +event_types = {}
> +
> +def qmp_is_proxy_cmd(name):
> +    return name.startswith('guest-')
> +
> +def qmp_is_async_cmd(name):
> +    return name.startswith('guest-')
> +
> +def qmp_is_stateful_cmd(name):
> +    return name in ['qmp_capabilities', 'put-event', 'getfd', 'closefd']

Care to document what this is for?

> +
> +def c_var(name):
> +    return '_'.join(name.split('-'))
> +
> +def genindent(count):
> +    ret = ""
> +    for i in range(count):
> +        ret += " "
> +    return ret
> +
> +indent_level = 0
> +
> +def push_indent():
> +    global indent_level
> +    indent_level += 4
> +
> +def pop_indent():
> +    global indent_level
> +    indent_level -= 4
> +
> +def cgen(code, **kwds):
> +    indent = genindent(indent_level)
> +    lines = code.split('\n')
> +    lines = map(lambda x: indent + x, lines)
> +    return '\n'.join(lines) % kwds + '\n'
> +
> +def mcgen(code, **kwds):
> +    return cgen('\n'.join(code.split('\n')[1:-1]), **kwds)
> +
> +def is_dict(obj):
> +    if type(obj) in [dict, OrderedDict]:
> +        return True
> +    return False
> +
> +def qmp_array_type_to_c(typename):
> +    if type(typename) == list or is_dict(typename):
> +        return qmp_type_to_c(typename)
> +    elif typename == 'int':
> +        return 'IntArray *'
> +    elif typename == 'str':
> +        return 'StringArray *'
> +    elif typename == 'bool':
> +        return 'BoolArray *'
> +    elif typename == 'number':
> +        return 'DoubleArray *'
> +    else:
> +        return qmp_type_to_c(typename)
> +
> +def qmp_type_should_free(typename):
> +    if (type(typename) == list or
> +        typename == 'str' or
> +        (typename not in ['int', 'bool', 'number'] and
> +         typename not in enum_types and not typename.isupper())):
> +        return True
> +    return False
> +
> +def qmp_free_func(typename):
> +    if type(typename) == list:
> +        return qmp_free_func(typename[0])
> +    elif typename == 'str':
> +        return 'qemu_free'
> +    else:
> +        return 'qmp_free_%s' % (de_camel_case(typename))
> +
> +def qmp_type_is_event(typename):
> +    if type(typename) == str and typename.isupper():
> +        return True
> +    return False
> +
> +def qmp_type_to_c(typename, retval=False, indent=0):
> +    if type(typename) == list:
> +        return qmp_array_type_to_c(typename[0])
> +    elif is_dict(typename):
> +        string = 'struct {\n'
> +        for argname, argtype, optional in parse_args(typename):
> +            if optional:
> +                string += "%sbool has_%s;\n" % (genindent(indent + 4), c_var(argname))
> +            string += "%s%s %s;\n" % (genindent(indent + 4),
> +                                      qmp_type_to_c(argtype, True,
> +                                                    indent=(indent + 4)),
> +                                      c_var(argname))
> +        string += "%s}" % genindent(indent)
> +        return string
> +    elif typename == 'int':
> +        return 'int64_t'
> +    elif not retval and typename == 'str':
> +        return 'const char *'
> +    elif retval and typename == 'str':
> +        return 'char *'
> +    elif typename == 'bool':
> +        return 'bool'
> +    elif typename == 'number':
> +        return 'double'
> +    elif typename == 'none':
> +        return 'void'
> +    elif typename in enum_types:
> +        return typename
> +    elif qmp_type_is_event(typename):
> +        return 'struct %s *' % qmp_event_to_c(typename)
> +    else:
> +        return 'struct %s *' % typename
> +
> +def qmp_type_to_qobj(typename):
> +    return 'qmp_marshal_type_%s' % typename
> +
> +def qmp_type_from_qobj(typename):
> +    return 'qmp_unmarshal_type_%s' % typename
> +
> +def parse_args(typeinfo):
> +    for member in typeinfo:
> +        argname = member
> +        argtype = typeinfo[member]
> +        optional = False
> +        if member.startswith('*'):
> +            argname = member[1:]
> +            optional = True
> +        yield (argname, argtype, optional)
> +
> +def de_camel_case(name):
> +    new_name = ''
> +    for ch in name:
> +        if ch.isupper() and new_name:
> +            new_name += '_'
> +        new_name += ch.lower()
> +    return new_name
> +
> +def camel_case(name):
> +    new_name = ''
> +    first = True
> +    for ch in name:
> +        if ch in ['_', '-']:
> +            first = True
> +        elif first:
> +            new_name += ch.upper()
> +            first = False
> +        else:
> +            new_name += ch.lower()
> +    return new_name
> +
> +def qmp_event_to_c(name):
> +    return '%sEvent' % camel_case(name)
> +
> +def qmp_event_func_to_c(name):
> +    return '%sFunc' % camel_case(name)
> +
> +def enum_abbreviation(name):
> +    ab = ''
> +    for ch in name:
> +        if ch.isupper():
> +            ab += ch
> +    return ab
> +
> +def gen_type_declaration(name, typeinfo):
> +    ret = ''
> +    if type(typeinfo) == str:
> +        ret += mcgen('''
> +
> +typedef %(type)s %(name)s;
> +''',
> +                     type=qmp_type_to_c(typeinfo),
> +                     name=name)
> +    elif is_dict(typeinfo) and not name.isupper():
> +        ret += mcgen('''
> +
> +typedef struct %(name)s %(name)s;
> +struct %(name)s {
> +''', name=name)
> +        for argname, argtype, optional in parse_args(typeinfo):
> +            if optional:
> +                ret += cgen('    bool has_%(c_name)s;',
> +                            c_name=c_var(argname))
> +            ret += cgen('    %(type)s %(c_name)s;',
> +                        type=qmp_type_to_c(argtype, True, indent=4),
> +                        c_name=c_var(argname))
> +        ret += mcgen('''
> +    %(c_name)s *next;
> +};
> +
> +%(name)s *qmp_alloc_%(dcc_name)s(void);
> +void qmp_free_%(dcc_name)s(%(name)s *obj);
> +''',
> +                     c_name=c_var(name), name=name,
> +                     dcc_name=de_camel_case(name))
> +    elif is_dict(typeinfo) and name.isupper():
> +        arglist = ['void *opaque']
> +        for argname, argtype, optional in parse_args(typeinfo):
> +            arglist.append('%s %s' % (qmp_type_to_c(argtype), argname))
> +        ret += mcgen('''
> +
> +typedef void (%(event_func)s)(%(args)s);
> +
> +typedef struct %(c_event)s {
> +    QmpSignal *signal;
> +    %(event_func)s *func;
> +} %(c_event)s;
> +''',
> +                     event_func=qmp_event_func_to_c(name),
> +                     args=', '.join(arglist),
> +                     c_event=qmp_event_to_c(name))
> +    return ret
> +
> +def gen_metatype_free(typeinfo, prefix):
> +    ret = ''
> +
> +    for argname, argtype, optional in parse_args(typeinfo):
> +        if type(argtype) == list:
> +            argtype = argtype[0]
> +
> +        if is_dict(argtype):
> +            if optional:
> +                ret += cgen('    if (%(prefix)shas_%(c_name)s) {',
> +                            prefix=prefix, c_name=c_var(argname))
> +                push_indent()
> +            ret += gen_metatype_free(argtype, '%s%s.' % (prefix, argname))
> +            if optional:
> +                pop_indent()
> +                ret += cgen('    }')
> +        elif qmp_type_should_free(argtype):
> +            if optional:
> +                ret += mcgen('''
> +    if (%(prefix)shas_%(c_name)s) {
> +        %(free)s(%(prefix)s%(c_name)s);
> +    }
> +''',
> +                             prefix=prefix, c_name=c_var(argname),
> +                             free=qmp_free_func(argtype))
> +            else:
> +                ret += mcgen('''
> +    %(free)s(%(prefix)s%(c_name)s);
> +''',
> +                             prefix=prefix, c_name=c_var(argname),
> +                             free=qmp_free_func(argtype))
> +
> +    return ret
> +
> +def gen_type_definition(name, typeinfo):
> +    return mcgen('''
> +
> +void qmp_free_%(dcc_name)s(%(name)s *obj)
> +{
> +    if (!obj) {
> +        return;
> +    }
> +%(type_free)s

Indentation.

> +
> +    %(free)s(obj->next);

I'm not sure I understand how this is used. You free the entire list by freeing
one of them?

> +    qemu_free(obj);
> +}
> +
> +%(name)s *qmp_alloc_%(dcc_name)s(void)
> +{
> +    BUILD_ASSERT(sizeof(%(name)s) < 512);
> +    return qemu_mallocz(512);
> +}

Why is this needed?

> +''',
> +                dcc_name=de_camel_case(name), name=name,
> +                free=qmp_free_func(name),
> +                type_free=gen_metatype_free(typeinfo, 'obj->'))
> +
> +def gen_enum_declaration(name, entries):
> +    ret = mcgen('''
> +
> +typedef enum %(name)s {
> +''', name=name)
> +    i = 0
> +    for entry in entries:
> +        ret += cgen('    %(abrev)s_%(name)s = %(value)d,',
> +                    abrev=enum_abbreviation(name),
> +                    name=entry.upper(), value=i)
> +        i += 1
> +    ret += mcgen('''
> +} %(name)s;
> +
> +%(name)s qmp_type_%(dcc_name)s_from_str(const char *str, Error **errp);
> +const char *qmp_type_%(dcc_name)s_to_str(%(name)s value, Error **errp);
> +''',
> +                 name=name, dcc_name=de_camel_case(name))
> +    return ret
> +
> +def gen_enum_definition(name, entries):
> +    ret = mcgen('''
> +
> +%(name)s qmp_type_%(dcc_name)s_from_str(const char *str, Error **errp)
> +{
> +''',
> +                name=name,
> +                dcc_name=de_camel_case(name))
> +    first = True
> +    for entry in entries:
> +        prefix = '} else '
> +        if first:
> +            prefix = ''
> +            first = False
> +        ret += mcgen('''
> +    %(prefix)sif (strcmp(str, "%(entry)s") == 0) {
> +        return %(abrev)s_%(value)s;
> +''',
> +                     prefix=prefix, entry=entry,
> +                     abrev=enum_abbreviation(name), value=entry.upper())
> +
> +    ret += mcgen('''
> +    } else {
> +        error_set(errp, QERR_ENUM_VALUE_INVALID, "%(name)s", str);
> +        return %(abrev)s_%(value)s;
> +    }

This seems to return the first defined value, isn't it better to automatically
generate the first value as ENUM_ERROR and return that instead?

Also, %(abrev) seems to be "ME". Not sure where it's defined, but isn't it
better to call it "QMP"?


> +}
> +
> +const char *qmp_type_%(dcc_name)s_to_str(%(name)s value, Error **errp)
> +{
> +''',
> +                 name=name, abrev=enum_abbreviation(name),
> +                 value=entries[0].upper(), dcc_name=de_camel_case(name))
> +
> +    first = True
> +    for entry in entries:
> +        enum = '%s_%s' % (enum_abbreviation(name), entry.upper())
> +        prefix = '} else '
> +        if first:
> +            prefix = ''
> +            first = False
> +        ret += mcgen('''
> +    %(prefix)sif (value == %(enum)s) {
> +        return "%(entry)s";
> +''',
> +                     entry=entry, prefix=prefix, enum=enum)
> +    ret += mcgen('''
> +    } else {
> +        char buf[32];
> +        snprintf(buf, sizeof(buf), "%%d", value);
> +        error_set(errp, QERR_ENUM_VALUE_INVALID, "%(name)s", buf);
> +        return NULL;
> +    }
> +}
> +''',
> +                 name=name)
> +    return ret
> +
> +def tokenize(data):
> +    while len(data):
> +        if data[0] in ['{', '}', ':', ',', '[', ']']:
> +            yield data[0]
> +            data = data[1:]
> +        elif data[0] in ' \n':
> +            data = data[1:]
> +        elif data[0] == "'":
> +            data = data[1:]
> +            string = ''
> +            while data[0] != "'":
> +                string += data[0]
> +                data = data[1:]
> +            data = data[1:]
> +            yield string
> +
> +def parse_value(tokens):
> +    if tokens[0] == '{':
> +        ret = OrderedDict()
> +        tokens = tokens[1:]
> +        while tokens[0] != '}':
> +            key = tokens[0]
> +            tokens = tokens[1:] 
> +
> +            tokens = tokens[1:] # :
> +
> +            value, tokens = parse_value(tokens)
> +
> +            if tokens[0] == ',':
> +                tokens = tokens[1:]
> +
> +            ret[key] = value
> +        tokens = tokens[1:]
> +        return ret, tokens
> +    elif tokens[0] == '[':
> +        ret = []
> +        tokens = tokens[1:]
> +        while tokens[0] != ']':
> +            value, tokens = parse_value(tokens)
> +            if tokens[0] == ',':
> +                tokens = tokens[1:]
> +            ret.append(value)
> +        tokens = tokens[1:]
> +        return ret, tokens
> +    else:
> +        return tokens[0], tokens[1:]
> +
> +def ordered_eval(string):
> +    return parse_value(map(lambda x: x, tokenize(string)))[0]
> +#    return eval(string)
> +
> +def generate(kind):
> +    global enum_types
> +    global event_types
> +    global indent_level
> +
> +    enum_types = []
> +    event_types = {}
> +    indent_level = 0
> +
> +    ret = mcgen('''
> +/* THIS FILE IS AUTOMATICALLY GENERATED, DO NOT EDIT */
> +''')
> +
> +    if kind == 'types-header':
> +        ret += mcgen('''
> +#ifndef QMP_TYPES_H
> +#define QMP_TYPES_H
> +
> +#include "qmp-types-core.h"
> +''')
> +    elif kind == 'types-body':
> +        ret += mcgen('''
> +#include "qmp-types.h"
> +#include "qmp-marshal-types.h"
> +''')

The "qmp-marshal-types.h" file doesn't exist, so this patch doesn't compile
breaking git bisect.

Two more comments about the hunk above:

 1. The generated code doesn't have license information

 2. There are several if 'types-body' elif 'types-header', better to have two
    different functions instead? Maybe a class... this would kill the global
    variables above

> +    

Extra whitespaces, this file has plenty of them.

> +    exprs = []
> +    expr = ''
> +    
> +    for line in sys.stdin:
> +        if line.startswith('#') or line == '\n':
> +            continue
> +    
> +        if line.startswith(' '):
> +            expr += line
> +        elif expr:
> +            s = ordered_eval(expr)
> +            exprs.append(s)
> +            expr = line
> +        else:
> +            expr += line
> +    
> +    if expr:
> +        s = ordered_eval(expr)
> +        exprs.append(s)
> +    
> +    for s in exprs:
> +       if s.has_key('type'):
> +           name = s['type']
> +           data = s['data']
> +
> +           if kind == 'types-body':
> +               ret += gen_type_definition(name, data)
> +           elif kind == 'types-header':
> +               ret += gen_type_declaration(name, data)
> +       elif s.has_key('enum'):
> +           name = s['enum']
> +           data = s['data']
> +
> +           enum_types.append(s['enum'])
> +           if kind == 'types-header':
> +               ret += gen_enum_declaration(name, data)
> +           elif kind == 'types-body':
> +               ret += gen_enum_definition(name, data)
> +       elif s.has_key('event'):
> +           name = s['event']
> +           data = {}
> +           if s.has_key('data'):
> +               data = s['data']
> +
> +           event_types[name] = data
> +           if kind == 'types-header':
> +               ret += gen_type_declaration(name, data)
> +       elif s.has_key('command'):
> +            name = s['command']
> +            options = {}
> +            if s.has_key('data'):
> +                options = s['data']
> +            retval = 'none'
> +            if s.has_key('returns'):
> +                retval = s['returns']
> +
> +    if kind.endswith('header'):
> +        ret += cgen('#endif')
> +
> +    return ret
> +
> +def main(args):
> +    if len(args) != 1:
> +        return 1
> +    if not args[0].startswith('--'):
> +        return 1
> +
> +    kind = args[0][2:]
> +
> +    ret = generate(kind)
> +
> +    sys.stdout.write(ret)
> +
> +    return 0
> +
> +if __name__ == '__main__':
> +    sys.exit(main(sys.argv[1:]))
> diff --git a/qmp-schema.json b/qmp-schema.json
> new file mode 100644
> index 0000000..e69de29
> diff --git a/qmp-types-core.h b/qmp-types-core.h
> new file mode 100644
> index 0000000..a018ba7
> --- /dev/null
> +++ b/qmp-types-core.h
> @@ -0,0 +1,29 @@
> +/*
> + * QAPI
> + *
> + * Copyright IBM, Corp. 2011
> + *
> + * Authors:
> + *  Anthony Liguori   <aliguori@us.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.  See
> + * the COPYING.LIB file in the top-level directory.
> + */
> +#ifndef QMP_TYPES_CORE_H
> +#define QMP_TYPES_CORE_H
> +
> +#include <stdint.h>
> +#include <stdbool.h>
> +#include "error.h"
> +
> +typedef struct QmpSignal QmpSignal;
> +typedef struct QmpCommandState QmpCommandState;
> +typedef struct QmpState QmpState;
> +
> +#define BUILD_ASSERT(cond) do {     \
> +    (void)sizeof(int[-1+!!(cond)]); \
> +} while (0)
> +
> +#define BUILD_BUG() BUILD_ASSERT(0)
> +
> +#endif