scripts/qapi-types.py - qemu - Git at Google

 #
 # QAPI types generator
 #
 # Copyright IBM, Corp. 2011
 # Copyright (c) 2013-2016 Red Hat Inc.
 #
 # Authors:
 #  Anthony Liguori <aliguori@us.ibm.com>
 #  Markus Armbruster <armbru@redhat.com>
 #
 # This work is licensed under the terms of the GNU GPL, version 2.
 # See the COPYING file in the top-level directory.

 from qapi import *


 # variants must be emitted before their container; track what has already
 # been output
 objects_seen = set()


 def gen_fwd_object_or_array(name):
     return mcgen('''

 typedef struct %(c_name)s %(c_name)s;
 ''',
                  c_name=c_name(name))


 def gen_array(name, element_type):
     return mcgen('''

 struct %(c_name)s {
     %(c_name)s *next;
     %(c_type)s value;
 };
 ''',
                  c_name=c_name(name), c_type=element_type.c_type())


 def gen_struct_fields(members):
     ret = ''
     for memb in members:
         if memb.optional:
             ret += mcgen('''
     bool has_%(c_name)s;
 ''',
                          c_name=c_name(memb.name))
         ret += mcgen('''
     %(c_type)s %(c_name)s;
 ''',
                      c_type=memb.type.c_type(), c_name=c_name(memb.name))
     return ret


 def gen_object(name, base, members, variants):
     if name in objects_seen:
         return ''
     objects_seen.add(name)

     ret = ''
     if variants:
         for v in variants.variants:
             if (isinstance(v.type, QAPISchemaObjectType) and
                     not v.type.is_implicit()):
                 ret += gen_object(v.type.name, v.type.base,
                                   v.type.local_members, v.type.variants)

     ret += mcgen('''

 struct %(c_name)s {
 ''',
                  c_name=c_name(name))

     if base:
         ret += mcgen('''
     /* Members inherited from %(c_name)s: */
 ''',
                      c_name=base.c_name())
         ret += gen_struct_fields(base.members)
         ret += mcgen('''
     /* Own members: */
 ''')
     ret += gen_struct_fields(members)

     if variants:
         ret += gen_variants(variants)

     # Make sure that all structs have at least one field; this avoids
     # potential issues with attempting to malloc space for zero-length
     # structs in C, and also incompatibility with C++ (where an empty
     # struct is size 1).
     if not (base and base.members) and not members and not variants:
         ret += mcgen('''
     char qapi_dummy_field_for_empty_struct;
 ''')

     ret += mcgen('''
 };
 ''')

     return ret


 def gen_upcast(name, base):
     # C makes const-correctness ugly.  We have to cast away const to let
     # this function work for both const and non-const obj.
     return mcgen('''

 static inline %(base)s *qapi_%(c_name)s_base(const %(c_name)s *obj)
 {
     return (%(base)s *)obj;
 }
 ''',
                  c_name=c_name(name), base=base.c_name())


 def gen_variants(variants):
     # FIXME: What purpose does data serve, besides preventing a union that
     # has a branch named 'data'? We use it in qapi-visit.py to decide
     # whether to bypass the switch statement if visiting the discriminator
     # failed; but since we 0-initialize structs, and cannot tell what
     # branch of the union is in use if the discriminator is invalid, there
     # should not be any data leaks even without a data pointer.  Or, if
     # 'data' is merely added to guarantee we don't have an empty union,
     # shouldn't we enforce that at .json parse time?
     ret = mcgen('''
     union { /* union tag is @%(c_name)s */
         void *data;
 ''',
                 c_name=c_name(variants.tag_member.name))

     for var in variants.variants:
         # Ugly special case for simple union TODO get rid of it
         simple_union_type = var.simple_union_type()
         typ = simple_union_type or var.type
         ret += mcgen('''
         %(c_type)s %(c_name)s;
 ''',
                      c_type=typ.c_type(is_unboxed=not simple_union_type),
                      c_name=c_name(var.name))

     ret += mcgen('''
     } u;
 ''')

     return ret


 def gen_type_cleanup_decl(name):
     ret = mcgen('''

 void qapi_free_%(c_name)s(%(c_name)s *obj);
 ''',
                 c_name=c_name(name))
     return ret


 def gen_type_cleanup(name):
     ret = mcgen('''

 void qapi_free_%(c_name)s(%(c_name)s *obj)
 {
     QapiDeallocVisitor *qdv;
     Visitor *v;

     if (!obj) {
         return;
     }

     qdv = qapi_dealloc_visitor_new();
     v = qapi_dealloc_get_visitor(qdv);
     visit_type_%(c_name)s(v, NULL, &obj, NULL);
     qapi_dealloc_visitor_cleanup(qdv);
 }
 ''',
                 c_name=c_name(name))
     return ret


 class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
     def __init__(self):
         self.decl = None
         self.defn = None
         self._fwdecl = None
         self._btin = None

     def visit_begin(self, schema):
         self.decl = ''
         self.defn = ''
         self._fwdecl = ''
         self._btin = guardstart('QAPI_TYPES_BUILTIN')

     def visit_end(self):
         self.decl = self._fwdecl + self.decl
         self._fwdecl = None
         # To avoid header dependency hell, we always generate
         # declarations for built-in types in our header files and
         # simply guard them.  See also do_builtins (command line
         # option -b).
         self._btin += guardend('QAPI_TYPES_BUILTIN')
         self.decl = self._btin + self.decl
         self._btin = None

     def visit_needed(self, entity):
         # Visit everything except implicit objects
         return not (entity.is_implicit() and
                     isinstance(entity, QAPISchemaObjectType))

     def _gen_type_cleanup(self, name):
         self.decl += gen_type_cleanup_decl(name)
         self.defn += gen_type_cleanup(name)

     def visit_enum_type(self, name, info, values, prefix):
         # Special case for our lone builtin enum type
         # TODO use something cleaner than existence of info
         if not info:
             self._btin += gen_enum(name, values, prefix)
             if do_builtins:
                 self.defn += gen_enum_lookup(name, values, prefix)
         else:
             self._fwdecl += gen_enum(name, values, prefix)
             self.defn += gen_enum_lookup(name, values, prefix)

     def visit_array_type(self, name, info, element_type):
         if isinstance(element_type, QAPISchemaBuiltinType):
             self._btin += gen_fwd_object_or_array(name)
             self._btin += gen_array(name, element_type)
             self._btin += gen_type_cleanup_decl(name)
             if do_builtins:
                 self.defn += gen_type_cleanup(name)
         else:
             self._fwdecl += gen_fwd_object_or_array(name)
             self.decl += gen_array(name, element_type)
             self._gen_type_cleanup(name)

     def visit_object_type(self, name, info, base, members, variants):
         self._fwdecl += gen_fwd_object_or_array(name)
         self.decl += gen_object(name, base, members, variants)
         if base:
             self.decl += gen_upcast(name, base)
         self._gen_type_cleanup(name)

     def visit_alternate_type(self, name, info, variants):
         self._fwdecl += gen_fwd_object_or_array(name)
         self.decl += gen_object(name, None, [variants.tag_member], variants)
         self._gen_type_cleanup(name)

 # If you link code generated from multiple schemata, you want only one
 # instance of the code for built-in types.  Generate it only when
 # do_builtins, enabled by command line option -b.  See also
 # QAPISchemaGenTypeVisitor.visit_end().
 do_builtins = False

 (input_file, output_dir, do_c, do_h, prefix, opts) = \
     parse_command_line("b", ["builtins"])

 for o, a in opts:
     if o in ("-b", "--builtins"):
         do_builtins = True

 c_comment = '''
 /*
  * deallocation functions for schema-defined QAPI types
  *
  * Copyright IBM, Corp. 2011
  *
  * Authors:
  *  Anthony Liguori   <aliguori@us.ibm.com>
  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
  *
  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  * See the COPYING.LIB file in the top-level directory.
  *
  */
 '''
 h_comment = '''
 /*
  * schema-defined QAPI types
  *
  * Copyright IBM, Corp. 2011
  *
  * Authors:
  *  Anthony Liguori   <aliguori@us.ibm.com>
  *
  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  * See the COPYING.LIB file in the top-level directory.
  *
  */
 '''

 (fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
                             'qapi-types.c', 'qapi-types.h',
                             c_comment, h_comment)

 fdef.write(mcgen('''
 #include "qemu/osdep.h"
 #include "qapi/dealloc-visitor.h"
 #include "%(prefix)sqapi-types.h"
 #include "%(prefix)sqapi-visit.h"
 ''',
                  prefix=prefix))

 # To avoid circular headers, use only typedefs.h here, not qobject.h
 fdecl.write(mcgen('''
 #include "qemu/typedefs.h"
 '''))

 schema = QAPISchema(input_file)
 gen = QAPISchemaGenTypeVisitor()
 schema.visit(gen)
 fdef.write(gen.defn)
 fdecl.write(gen.decl)

 close_output(fdef, fdecl)
	#
	# QAPI types generator
	#
	# Copyright IBM, Corp. 2011
	# Copyright (c) 2013-2016 Red Hat Inc.
	#
	# Authors:
	# Anthony Liguori <aliguori@us.ibm.com>
	# Markus Armbruster <armbru@redhat.com>
	#
	# This work is licensed under the terms of the GNU GPL, version 2.
	# See the COPYING file in the top-level directory.

	from qapi import *


	# variants must be emitted before their container; track what has already
	# been output
	objects_seen = set()


	def gen_fwd_object_or_array(name):
	return mcgen('''

	typedef struct %(c_name)s %(c_name)s;
	''',
	c_name=c_name(name))


	def gen_array(name, element_type):
	return mcgen('''

	struct %(c_name)s {
	%(c_name)s *next;
	%(c_type)s value;
	};
	''',
	c_name=c_name(name), c_type=element_type.c_type())


	def gen_struct_fields(members):
	ret = ''
	for memb in members:
	if memb.optional:
	ret += mcgen('''
	bool has_%(c_name)s;
	''',
	c_name=c_name(memb.name))
	ret += mcgen('''
	%(c_type)s %(c_name)s;
	''',
	c_type=memb.type.c_type(), c_name=c_name(memb.name))
	return ret


	def gen_object(name, base, members, variants):
	if name in objects_seen:
	return ''
	objects_seen.add(name)

	ret = ''
	if variants:
	for v in variants.variants:
	if (isinstance(v.type, QAPISchemaObjectType) and
	not v.type.is_implicit()):
	ret += gen_object(v.type.name, v.type.base,
	v.type.local_members, v.type.variants)

	ret += mcgen('''

	struct %(c_name)s {
	''',
	c_name=c_name(name))

	if base:
	ret += mcgen('''
	/* Members inherited from %(c_name)s: */
	''',
	c_name=base.c_name())
	ret += gen_struct_fields(base.members)
	ret += mcgen('''
	/* Own members: */
	''')
	ret += gen_struct_fields(members)

	if variants:
	ret += gen_variants(variants)

	# Make sure that all structs have at least one field; this avoids
	# potential issues with attempting to malloc space for zero-length
	# structs in C, and also incompatibility with C++ (where an empty
	# struct is size 1).
	if not (base and base.members) and not members and not variants:
	ret += mcgen('''
	char qapi_dummy_field_for_empty_struct;
	''')

	ret += mcgen('''
	};
	''')

	return ret


	def gen_upcast(name, base):
	# C makes const-correctness ugly. We have to cast away const to let
	# this function work for both const and non-const obj.
	return mcgen('''

	static inline %(base)s qapi_%(c_name)s_base(const %(c_name)s obj)
	{
	return (%(base)s *)obj;
	}
	''',
	c_name=c_name(name), base=base.c_name())


	def gen_variants(variants):
	# FIXME: What purpose does data serve, besides preventing a union that
	# has a branch named 'data'? We use it in qapi-visit.py to decide
	# whether to bypass the switch statement if visiting the discriminator
	# failed; but since we 0-initialize structs, and cannot tell what
	# branch of the union is in use if the discriminator is invalid, there
	# should not be any data leaks even without a data pointer. Or, if
	# 'data' is merely added to guarantee we don't have an empty union,
	# shouldn't we enforce that at .json parse time?
	ret = mcgen('''
	union { /* union tag is @%(c_name)s */
	void *data;
	''',
	c_name=c_name(variants.tag_member.name))

	for var in variants.variants:
	# Ugly special case for simple union TODO get rid of it
	simple_union_type = var.simple_union_type()
	typ = simple_union_type or var.type
	ret += mcgen('''
	%(c_type)s %(c_name)s;
	''',
	c_type=typ.c_type(is_unboxed=not simple_union_type),
	c_name=c_name(var.name))

	ret += mcgen('''
	} u;
	''')

	return ret


	def gen_type_cleanup_decl(name):
	ret = mcgen('''

	void qapi_free_%(c_name)s(%(c_name)s *obj);
	''',
	c_name=c_name(name))
	return ret


	def gen_type_cleanup(name):
	ret = mcgen('''

	void qapi_free_%(c_name)s(%(c_name)s *obj)
	{
	QapiDeallocVisitor *qdv;
	Visitor *v;

	if (!obj) {
	return;
	}

	qdv = qapi_dealloc_visitor_new();
	v = qapi_dealloc_get_visitor(qdv);
	visit_type_%(c_name)s(v, NULL, &obj, NULL);
	qapi_dealloc_visitor_cleanup(qdv);
	}
	''',
	c_name=c_name(name))
	return ret


	class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
	def __init__(self):
	self.decl = None
	self.defn = None
	self._fwdecl = None
	self._btin = None

	def visit_begin(self, schema):
	self.decl = ''
	self.defn = ''
	self._fwdecl = ''
	self._btin = guardstart('QAPI_TYPES_BUILTIN')

	def visit_end(self):
	self.decl = self._fwdecl + self.decl
	self._fwdecl = None
	# To avoid header dependency hell, we always generate
	# declarations for built-in types in our header files and
	# simply guard them. See also do_builtins (command line
	# option -b).
	self._btin += guardend('QAPI_TYPES_BUILTIN')
	self.decl = self._btin + self.decl
	self._btin = None

	def visit_needed(self, entity):
	# Visit everything except implicit objects
	return not (entity.is_implicit() and
	isinstance(entity, QAPISchemaObjectType))

	def _gen_type_cleanup(self, name):
	self.decl += gen_type_cleanup_decl(name)
	self.defn += gen_type_cleanup(name)

	def visit_enum_type(self, name, info, values, prefix):
	# Special case for our lone builtin enum type
	# TODO use something cleaner than existence of info
	if not info:
	self._btin += gen_enum(name, values, prefix)
	if do_builtins:
	self.defn += gen_enum_lookup(name, values, prefix)
	else:
	self._fwdecl += gen_enum(name, values, prefix)
	self.defn += gen_enum_lookup(name, values, prefix)

	def visit_array_type(self, name, info, element_type):
	if isinstance(element_type, QAPISchemaBuiltinType):
	self._btin += gen_fwd_object_or_array(name)
	self._btin += gen_array(name, element_type)
	self._btin += gen_type_cleanup_decl(name)
	if do_builtins:
	self.defn += gen_type_cleanup(name)
	else:
	self._fwdecl += gen_fwd_object_or_array(name)
	self.decl += gen_array(name, element_type)
	self._gen_type_cleanup(name)

	def visit_object_type(self, name, info, base, members, variants):
	self._fwdecl += gen_fwd_object_or_array(name)
	self.decl += gen_object(name, base, members, variants)
	if base:
	self.decl += gen_upcast(name, base)
	self._gen_type_cleanup(name)

	def visit_alternate_type(self, name, info, variants):
	self._fwdecl += gen_fwd_object_or_array(name)
	self.decl += gen_object(name, None, [variants.tag_member], variants)
	self._gen_type_cleanup(name)

	# If you link code generated from multiple schemata, you want only one
	# instance of the code for built-in types. Generate it only when
	# do_builtins, enabled by command line option -b. See also
	# QAPISchemaGenTypeVisitor.visit_end().
	do_builtins = False

	(input_file, output_dir, do_c, do_h, prefix, opts) = \
	parse_command_line("b", ["builtins"])

	for o, a in opts:
	if o in ("-b", "--builtins"):
	do_builtins = True

	c_comment = '''
	/*
	* deallocation functions for schema-defined QAPI types
	*
	* Copyright IBM, Corp. 2011
	*
	* Authors:
	* Anthony Liguori <aliguori@us.ibm.com>
	* Michael Roth <mdroth@linux.vnet.ibm.com>
	*
	* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
	* See the COPYING.LIB file in the top-level directory.
	*
	*/
	'''
	h_comment = '''
	/*
	* schema-defined QAPI types
	*
	* Copyright IBM, Corp. 2011
	*
	* Authors:
	* Anthony Liguori <aliguori@us.ibm.com>
	*
	* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
	* See the COPYING.LIB file in the top-level directory.
	*
	*/
	'''

	(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
	'qapi-types.c', 'qapi-types.h',
	c_comment, h_comment)

	fdef.write(mcgen('''
	#include "qemu/osdep.h"
	#include "qapi/dealloc-visitor.h"
	#include "%(prefix)sqapi-types.h"
	#include "%(prefix)sqapi-visit.h"
	''',
	prefix=prefix))

	# To avoid circular headers, use only typedefs.h here, not qobject.h
	fdecl.write(mcgen('''
	#include "qemu/typedefs.h"
	'''))

	schema = QAPISchema(input_file)
	gen = QAPISchemaGenTypeVisitor()
	schema.visit(gen)
	fdef.write(gen.defn)
	fdecl.write(gen.decl)

	close_output(fdef, fdecl)