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

 #
 # QAPI types generator
 #
 # Copyright IBM, Corp. 2011
 # Copyright (c) 2013-2015 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 *


 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 {
     union {
         %(c_type)s value;
         uint64_t padding;
     };
     %(c_name)s *next;
 };
 ''',
                  c_name=c_name(name), c_type=element_type.c_type())


 def gen_struct_field(name, typ, optional):
     ret = ''

     if optional:
         ret += mcgen('''
     bool has_%(c_name)s;
 ''',
                      c_name=c_name(name))
     ret += mcgen('''
     %(c_type)s %(c_name)s;
 ''',
                  c_type=typ.c_type(), c_name=c_name(name))
     return ret


 def gen_struct_fields(members):
     ret = ''

     for memb in members:
         ret += gen_struct_field(memb.name, memb.type, memb.optional)
     return ret


 def gen_struct(name, base, members):
     ret = mcgen('''

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

     if base:
         ret += gen_struct_field('base', base, False)

     ret += gen_struct_fields(members)

     # 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 not members:
         ret += mcgen('''
     char qapi_dummy_field_for_empty_struct;
 ''')

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

     return ret


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

 extern const int %(c_name)s_qtypes[];
 ''',
                  c_name=c_name(name))


 def gen_alternate_qtypes(name, variants):
     ret = mcgen('''

 const int %(c_name)s_qtypes[QTYPE_MAX] = {
 ''',
                 c_name=c_name(name))

     for var in variants.variants:
         qtype = var.type.alternate_qtype()
         assert qtype

         ret += mcgen('''
     [%(qtype)s] = %(enum_const)s,
 ''',
                      qtype=qtype,
                      enum_const=c_enum_const(variants.tag_member.type.name,
                                              var.name))

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


 def gen_union(name, base, variants):
     ret = mcgen('''

 struct %(c_name)s {
 ''',
                 c_name=c_name(name))
     if base:
         ret += mcgen('''
     /* Members inherited from %(c_name)s: */
 ''',
                      c_name=c_name(base.name))
         ret += gen_struct_fields(base.members)
         ret += mcgen('''
     /* Own members: */
 ''')
     else:
         ret += mcgen('''
     %(c_type)s kind;
 ''',
                      c_type=c_name(variants.tag_member.type.name))

     # 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;
 ''',
                  # TODO ugly special case for simple union
                  # Use same tag name in C as on the wire to get rid of
                  # it, then: c_name=c_name(variants.tag_member.name)
                  c_name=c_name(variants.tag_name or 'kind'))

     for var in variants.variants:
         # Ugly special case for simple union TODO get rid of it
         typ = var.simple_union_type() or var.type
         ret += mcgen('''
         %(c_type)s %(c_name)s;
 ''',
                      c_type=typ.c_type(),
                      c_name=c_name(var.name))

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

     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, &obj, NULL, 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._fwdefn = None
         self._btin = None

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

     def visit_end(self):
         self.decl = self._fwdecl + self.decl
         self._fwdecl = None
         self.defn = self._fwdefn + self.defn
         self._fwdefn = 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):
         self._fwdecl += gen_enum(name, values, prefix)
         self._fwdefn += 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)
         if variants:
             assert not members      # not implemented
             self.decl += gen_union(name, base, variants)
         else:
             self.decl += gen_struct(name, base, members)
         self._gen_type_cleanup(name)

     def visit_alternate_type(self, name, info, variants):
         self._fwdecl += gen_fwd_object_or_array(name)
         self._fwdefn += gen_alternate_qtypes(name, variants)
         self.decl += gen_union(name, None, variants)
         self.decl += gen_alternate_qtypes_decl(name)
         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 "qapi/dealloc-visitor.h"
 #include "%(prefix)sqapi-types.h"
 #include "%(prefix)sqapi-visit.h"
 ''',
                  prefix=prefix))

 fdecl.write(mcgen('''
 #include <stdbool.h>
 #include <stdint.h>
 #include "qapi/qmp/qobject.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) 2013-2015 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 *


	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 {
	union {
	%(c_type)s value;
	uint64_t padding;
	};
	%(c_name)s *next;
	};
	''',
	c_name=c_name(name), c_type=element_type.c_type())


	def gen_struct_field(name, typ, optional):
	ret = ''

	if optional:
	ret += mcgen('''
	bool has_%(c_name)s;
	''',
	c_name=c_name(name))
	ret += mcgen('''
	%(c_type)s %(c_name)s;
	''',
	c_type=typ.c_type(), c_name=c_name(name))
	return ret


	def gen_struct_fields(members):
	ret = ''

	for memb in members:
	ret += gen_struct_field(memb.name, memb.type, memb.optional)
	return ret


	def gen_struct(name, base, members):
	ret = mcgen('''

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

	if base:
	ret += gen_struct_field('base', base, False)

	ret += gen_struct_fields(members)

	# 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 not members:
	ret += mcgen('''
	char qapi_dummy_field_for_empty_struct;
	''')

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

	return ret


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

	extern const int %(c_name)s_qtypes[];
	''',
	c_name=c_name(name))


	def gen_alternate_qtypes(name, variants):
	ret = mcgen('''

	const int %(c_name)s_qtypes[QTYPE_MAX] = {
	''',
	c_name=c_name(name))

	for var in variants.variants:
	qtype = var.type.alternate_qtype()
	assert qtype

	ret += mcgen('''
	[%(qtype)s] = %(enum_const)s,
	''',
	qtype=qtype,
	enum_const=c_enum_const(variants.tag_member.type.name,
	var.name))

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


	def gen_union(name, base, variants):
	ret = mcgen('''

	struct %(c_name)s {
	''',
	c_name=c_name(name))
	if base:
	ret += mcgen('''
	/* Members inherited from %(c_name)s: */
	''',
	c_name=c_name(base.name))
	ret += gen_struct_fields(base.members)
	ret += mcgen('''
	/* Own members: */
	''')
	else:
	ret += mcgen('''
	%(c_type)s kind;
	''',
	c_type=c_name(variants.tag_member.type.name))

	# 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;
	''',
	# TODO ugly special case for simple union
	# Use same tag name in C as on the wire to get rid of
	# it, then: c_name=c_name(variants.tag_member.name)
	c_name=c_name(variants.tag_name or 'kind'))

	for var in variants.variants:
	# Ugly special case for simple union TODO get rid of it
	typ = var.simple_union_type() or var.type
	ret += mcgen('''
	%(c_type)s %(c_name)s;
	''',
	c_type=typ.c_type(),
	c_name=c_name(var.name))

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

	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, &obj, NULL, 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._fwdefn = None
	self._btin = None

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

	def visit_end(self):
	self.decl = self._fwdecl + self.decl
	self._fwdecl = None
	self.defn = self._fwdefn + self.defn
	self._fwdefn = 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):
	self._fwdecl += gen_enum(name, values, prefix)
	self._fwdefn += 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)
	if variants:
	assert not members # not implemented
	self.decl += gen_union(name, base, variants)
	else:
	self.decl += gen_struct(name, base, members)
	self._gen_type_cleanup(name)

	def visit_alternate_type(self, name, info, variants):
	self._fwdecl += gen_fwd_object_or_array(name)
	self._fwdefn += gen_alternate_qtypes(name, variants)
	self.decl += gen_union(name, None, variants)
	self.decl += gen_alternate_qtypes_decl(name)
	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 "qapi/dealloc-visitor.h"
	#include "%(prefix)sqapi-types.h"
	#include "%(prefix)sqapi-visit.h"
	''',
	prefix=prefix))

	fdecl.write(mcgen('''
	#include <stdbool.h>
	#include <stdint.h>
	#include "qapi/qmp/qobject.h"
	'''))

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

	close_output(fdef, fdecl)