qemu-e2k/scripts/qapi-types.py
Peter Maydell 83ecb22ba2 scripts/qapi-types.py: Add dummy member to empty structs
Make sure that all generated C structs have at least one field; this
avoids potential issues with attempting to malloc space for
zero-length structs in C (g_malloc(sizeof struct) would return NULL).
It also avoids an incompatibility with C++ (where an empty struct is
size 1); that isn't important to us now but might be in future.

Generated empty structures look like this:
    struct Abort
    {
        char qapi_dummy_field_for_empty_struct;
    };

This silences clang warnings like:
./qapi-types.h:3752:1: warning: empty struct has size 0 in C, size 1 in C++ [-Wextern-c-compat]
struct Abort
^

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1419359069-16611-1-git-send-email-peter.maydell@linaro.org
2015-01-20 15:19:32 +00:00

469 lines
11 KiB
Python

#
# QAPI types 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.
from ordereddict import OrderedDict
from qapi import *
import sys
import os
import getopt
import errno
def generate_fwd_struct(name, members, builtin_type=False):
if builtin_type:
return mcgen('''
typedef struct %(name)sList
{
union {
%(type)s value;
uint64_t padding;
};
struct %(name)sList *next;
} %(name)sList;
''',
type=c_type(name),
name=name)
return mcgen('''
typedef struct %(name)s %(name)s;
typedef struct %(name)sList
{
union {
%(name)s *value;
uint64_t padding;
};
struct %(name)sList *next;
} %(name)sList;
''',
name=name)
def generate_fwd_enum_struct(name, members):
return mcgen('''
typedef struct %(name)sList
{
union {
%(name)s value;
uint64_t padding;
};
struct %(name)sList *next;
} %(name)sList;
''',
name=name)
def generate_struct_fields(members):
ret = ''
for argname, argentry, optional, structured in parse_args(members):
if optional:
ret += mcgen('''
bool has_%(c_name)s;
''',
c_name=c_var(argname))
if structured:
push_indent()
ret += generate_struct({ "field": argname, "data": argentry})
pop_indent()
else:
ret += mcgen('''
%(c_type)s %(c_name)s;
''',
c_type=c_type(argentry), c_name=c_var(argname))
return ret
def generate_struct(expr):
structname = expr.get('type', "")
fieldname = expr.get('field', "")
members = expr['data']
base = expr.get('base')
ret = mcgen('''
struct %(name)s
{
''',
name=structname)
if base:
ret += generate_struct_fields({'base': base})
ret += generate_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;
''')
if len(fieldname):
fieldname = " " + fieldname
ret += mcgen('''
}%(field)s;
''',
field=fieldname)
return ret
def generate_enum_lookup(name, values):
ret = mcgen('''
const char *%(name)s_lookup[] = {
''',
name=name)
i = 0
for value in values:
ret += mcgen('''
"%(value)s",
''',
value=value)
ret += mcgen('''
NULL,
};
''')
return ret
def generate_enum(name, values):
lookup_decl = mcgen('''
extern const char *%(name)s_lookup[];
''',
name=name)
enum_decl = mcgen('''
typedef enum %(name)s
{
''',
name=name)
# append automatically generated _MAX value
enum_values = values + [ 'MAX' ]
i = 0
for value in enum_values:
enum_full_value = generate_enum_full_value(name, value)
enum_decl += mcgen('''
%(enum_full_value)s = %(i)d,
''',
enum_full_value = enum_full_value,
i=i)
i += 1
enum_decl += mcgen('''
} %(name)s;
''',
name=name)
return lookup_decl + enum_decl
def generate_anon_union_qtypes(expr):
name = expr['union']
members = expr['data']
ret = mcgen('''
const int %(name)s_qtypes[QTYPE_MAX] = {
''',
name=name)
for key in members:
qapi_type = members[key]
if builtin_type_qtypes.has_key(qapi_type):
qtype = builtin_type_qtypes[qapi_type]
elif find_struct(qapi_type):
qtype = "QTYPE_QDICT"
elif find_union(qapi_type):
qtype = "QTYPE_QDICT"
elif find_enum(qapi_type):
qtype = "QTYPE_QSTRING"
else:
assert False, "Invalid anonymous union member"
ret += mcgen('''
[ %(qtype)s ] = %(abbrev)s_KIND_%(enum)s,
''',
qtype = qtype,
abbrev = de_camel_case(name).upper(),
enum = c_fun(de_camel_case(key),False).upper())
ret += mcgen('''
};
''')
return ret
def generate_union(expr):
name = expr['union']
typeinfo = expr['data']
base = expr.get('base')
discriminator = expr.get('discriminator')
enum_define = discriminator_find_enum_define(expr)
if enum_define:
discriminator_type_name = enum_define['enum_name']
else:
discriminator_type_name = '%sKind' % (name)
ret = mcgen('''
struct %(name)s
{
%(discriminator_type_name)s kind;
union {
void *data;
''',
name=name,
discriminator_type_name=discriminator_type_name)
for key in typeinfo:
ret += mcgen('''
%(c_type)s %(c_name)s;
''',
c_type=c_type(typeinfo[key]),
c_name=c_fun(key))
ret += mcgen('''
};
''')
if base:
base_fields = find_struct(base)['data']
if discriminator:
base_fields = base_fields.copy()
del base_fields[discriminator]
ret += generate_struct_fields(base_fields)
else:
assert not discriminator
ret += mcgen('''
};
''')
if discriminator == {}:
ret += mcgen('''
extern const int %(name)s_qtypes[];
''',
name=name)
return ret
def generate_type_cleanup_decl(name):
ret = mcgen('''
void qapi_free_%(type)s(%(c_type)s obj);
''',
c_type=c_type(name),type=name)
return ret
def generate_type_cleanup(name):
ret = mcgen('''
void qapi_free_%(type)s(%(c_type)s obj)
{
QapiDeallocVisitor *md;
Visitor *v;
if (!obj) {
return;
}
md = qapi_dealloc_visitor_new();
v = qapi_dealloc_get_visitor(md);
visit_type_%(type)s(v, &obj, NULL, NULL);
qapi_dealloc_visitor_cleanup(md);
}
''',
c_type=c_type(name),type=name)
return ret
try:
opts, args = getopt.gnu_getopt(sys.argv[1:], "chbp:i:o:",
["source", "header", "builtins",
"prefix=", "input-file=", "output-dir="])
except getopt.GetoptError, err:
print str(err)
sys.exit(1)
output_dir = ""
input_file = ""
prefix = ""
c_file = 'qapi-types.c'
h_file = 'qapi-types.h'
do_c = False
do_h = False
do_builtins = False
for o, a in opts:
if o in ("-p", "--prefix"):
prefix = a
elif o in ("-i", "--input-file"):
input_file = a
elif o in ("-o", "--output-dir"):
output_dir = a + "/"
elif o in ("-c", "--source"):
do_c = True
elif o in ("-h", "--header"):
do_h = True
elif o in ("-b", "--builtins"):
do_builtins = True
if not do_c and not do_h:
do_c = True
do_h = True
c_file = output_dir + prefix + c_file
h_file = output_dir + prefix + h_file
try:
os.makedirs(output_dir)
except os.error, e:
if e.errno != errno.EEXIST:
raise
def maybe_open(really, name, opt):
if really:
return open(name, opt)
else:
import StringIO
return StringIO.StringIO()
fdef = maybe_open(do_c, c_file, 'w')
fdecl = maybe_open(do_h, h_file, 'w')
fdef.write(mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
/*
* 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.
*
*/
#include "qapi/dealloc-visitor.h"
#include "%(prefix)sqapi-types.h"
#include "%(prefix)sqapi-visit.h"
''', prefix=prefix))
fdecl.write(mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
/*
* 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.
*
*/
#ifndef %(guard)s
#define %(guard)s
#include <stdbool.h>
#include <stdint.h>
''',
guard=guardname(h_file)))
exprs = parse_schema(input_file)
exprs = filter(lambda expr: not expr.has_key('gen'), exprs)
fdecl.write(guardstart("QAPI_TYPES_BUILTIN_STRUCT_DECL"))
for typename in builtin_types:
fdecl.write(generate_fwd_struct(typename, None, builtin_type=True))
fdecl.write(guardend("QAPI_TYPES_BUILTIN_STRUCT_DECL"))
for expr in exprs:
ret = "\n"
if expr.has_key('type'):
ret += generate_fwd_struct(expr['type'], expr['data'])
elif expr.has_key('enum'):
ret += generate_enum(expr['enum'], expr['data']) + "\n"
ret += generate_fwd_enum_struct(expr['enum'], expr['data'])
fdef.write(generate_enum_lookup(expr['enum'], expr['data']))
elif expr.has_key('union'):
ret += generate_fwd_struct(expr['union'], expr['data']) + "\n"
enum_define = discriminator_find_enum_define(expr)
if not enum_define:
ret += generate_enum('%sKind' % expr['union'], expr['data'].keys())
fdef.write(generate_enum_lookup('%sKind' % expr['union'],
expr['data'].keys()))
if expr.get('discriminator') == {}:
fdef.write(generate_anon_union_qtypes(expr))
else:
continue
fdecl.write(ret)
# to avoid header dependency hell, we always generate declarations
# for built-in types in our header files and simply guard them
fdecl.write(guardstart("QAPI_TYPES_BUILTIN_CLEANUP_DECL"))
for typename in builtin_types:
fdecl.write(generate_type_cleanup_decl(typename + "List"))
fdecl.write(guardend("QAPI_TYPES_BUILTIN_CLEANUP_DECL"))
# ...this doesn't work for cases where we link in multiple objects that
# have the functions defined, so we use -b option to provide control
# over these cases
if do_builtins:
fdef.write(guardstart("QAPI_TYPES_BUILTIN_CLEANUP_DEF"))
for typename in builtin_types:
fdef.write(generate_type_cleanup(typename + "List"))
fdef.write(guardend("QAPI_TYPES_BUILTIN_CLEANUP_DEF"))
for expr in exprs:
ret = "\n"
if expr.has_key('type'):
ret += generate_struct(expr) + "\n"
ret += generate_type_cleanup_decl(expr['type'] + "List")
fdef.write(generate_type_cleanup(expr['type'] + "List") + "\n")
ret += generate_type_cleanup_decl(expr['type'])
fdef.write(generate_type_cleanup(expr['type']) + "\n")
elif expr.has_key('union'):
ret += generate_union(expr)
ret += generate_type_cleanup_decl(expr['union'] + "List")
fdef.write(generate_type_cleanup(expr['union'] + "List") + "\n")
ret += generate_type_cleanup_decl(expr['union'])
fdef.write(generate_type_cleanup(expr['union']) + "\n")
elif expr.has_key('enum'):
ret += generate_type_cleanup_decl(expr['enum'] + "List")
fdef.write(generate_type_cleanup(expr['enum'] + "List") + "\n")
else:
continue
fdecl.write(ret)
fdecl.write('''
#endif
''')
fdecl.flush()
fdecl.close()
fdef.flush()
fdef.close()