qemu/scripts/qapi/gen.py
John Snow 2184bca7b1 qapi: Replace List[str] with Sequence[str] for ifcond
It does happen to be a list (as of now), but we can describe it in more
general terms with no loss in accuracy to allow tuples and other
constructs.

In the future, we can write "ifcond: Sequence[str] = ()" as a default
parameter, which we could not do safely with a Mutable type like a List.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-2-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 17:10:29 +01:00

335 lines
9.9 KiB
Python

# -*- coding: utf-8 -*-
#
# QAPI code generation
#
# Copyright (c) 2015-2019 Red Hat Inc.
#
# Authors:
# Markus Armbruster <armbru@redhat.com>
# Marc-André Lureau <marcandre.lureau@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 contextlib import contextmanager
import os
import re
from typing import (
Dict,
Iterator,
Optional,
Sequence,
Tuple,
)
from .common import (
c_fname,
c_name,
gen_endif,
gen_if,
guardend,
guardstart,
mcgen,
)
from .schema import (
QAPISchemaModule,
QAPISchemaObjectType,
QAPISchemaVisitor,
)
from .source import QAPISourceInfo
class QAPIGen:
def __init__(self, fname: str):
self.fname = fname
self._preamble = ''
self._body = ''
def preamble_add(self, text: str) -> None:
self._preamble += text
def add(self, text: str) -> None:
self._body += text
def get_content(self) -> str:
return self._top() + self._preamble + self._body + self._bottom()
def _top(self) -> str:
# pylint: disable=no-self-use
return ''
def _bottom(self) -> str:
# pylint: disable=no-self-use
return ''
def write(self, output_dir: str) -> None:
# Include paths starting with ../ are used to reuse modules of the main
# schema in specialised schemas. Don't overwrite the files that are
# already generated for the main schema.
if self.fname.startswith('../'):
return
pathname = os.path.join(output_dir, self.fname)
odir = os.path.dirname(pathname)
if odir:
os.makedirs(odir, exist_ok=True)
# use os.open for O_CREAT to create and read a non-existant file
fd = os.open(pathname, os.O_RDWR | os.O_CREAT, 0o666)
with os.fdopen(fd, 'r+', encoding='utf-8') as fp:
text = self.get_content()
oldtext = fp.read(len(text) + 1)
if text != oldtext:
fp.seek(0)
fp.truncate(0)
fp.write(text)
def _wrap_ifcond(ifcond: Sequence[str], before: str, after: str) -> str:
if before == after:
return after # suppress empty #if ... #endif
assert after.startswith(before)
out = before
added = after[len(before):]
if added[0] == '\n':
out += '\n'
added = added[1:]
out += gen_if(ifcond)
out += added
out += gen_endif(ifcond)
return out
def build_params(arg_type: Optional[QAPISchemaObjectType],
boxed: bool,
extra: Optional[str] = None) -> str:
ret = ''
sep = ''
if boxed:
assert arg_type
ret += '%s arg' % arg_type.c_param_type()
sep = ', '
elif arg_type:
assert not arg_type.variants
for memb in arg_type.members:
ret += sep
sep = ', '
if memb.optional:
ret += 'bool has_%s, ' % c_name(memb.name)
ret += '%s %s' % (memb.type.c_param_type(),
c_name(memb.name))
if extra:
ret += sep + extra
return ret if ret else 'void'
class QAPIGenCCode(QAPIGen):
def __init__(self, fname: str):
super().__init__(fname)
self._start_if: Optional[Tuple[Sequence[str], str, str]] = None
def start_if(self, ifcond: Sequence[str]) -> None:
assert self._start_if is None
self._start_if = (ifcond, self._body, self._preamble)
def end_if(self) -> None:
assert self._start_if is not None
self._body = _wrap_ifcond(self._start_if[0],
self._start_if[1], self._body)
self._preamble = _wrap_ifcond(self._start_if[0],
self._start_if[2], self._preamble)
self._start_if = None
def get_content(self) -> str:
assert self._start_if is None
return super().get_content()
class QAPIGenC(QAPIGenCCode):
def __init__(self, fname: str, blurb: str, pydoc: str):
super().__init__(fname)
self._blurb = blurb
self._copyright = '\n * '.join(re.findall(r'^Copyright .*', pydoc,
re.MULTILINE))
def _top(self) -> str:
return mcgen('''
/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
/*
%(blurb)s
*
* %(copyright)s
*
* 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.
*/
''',
blurb=self._blurb, copyright=self._copyright)
def _bottom(self) -> str:
return mcgen('''
/* Dummy declaration to prevent empty .o file */
char qapi_dummy_%(name)s;
''',
name=c_fname(self.fname))
class QAPIGenH(QAPIGenC):
def _top(self) -> str:
return super()._top() + guardstart(self.fname)
def _bottom(self) -> str:
return guardend(self.fname)
@contextmanager
def ifcontext(ifcond: Sequence[str], *args: QAPIGenCCode) -> Iterator[None]:
"""
A with-statement context manager that wraps with `start_if()` / `end_if()`.
:param ifcond: A sequence of conditionals, passed to `start_if()`.
:param args: any number of `QAPIGenCCode`.
Example::
with ifcontext(ifcond, self._genh, self._genc):
modify self._genh and self._genc ...
Is equivalent to calling::
self._genh.start_if(ifcond)
self._genc.start_if(ifcond)
modify self._genh and self._genc ...
self._genh.end_if()
self._genc.end_if()
"""
for arg in args:
arg.start_if(ifcond)
yield
for arg in args:
arg.end_if()
class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
def __init__(self,
prefix: str,
what: str,
blurb: str,
pydoc: str):
self._prefix = prefix
self._what = what
self._genc = QAPIGenC(self._prefix + self._what + '.c',
blurb, pydoc)
self._genh = QAPIGenH(self._prefix + self._what + '.h',
blurb, pydoc)
def write(self, output_dir: str) -> None:
self._genc.write(output_dir)
self._genh.write(output_dir)
class QAPISchemaModularCVisitor(QAPISchemaVisitor):
def __init__(self,
prefix: str,
what: str,
user_blurb: str,
builtin_blurb: Optional[str],
pydoc: str):
self._prefix = prefix
self._what = what
self._user_blurb = user_blurb
self._builtin_blurb = builtin_blurb
self._pydoc = pydoc
self._current_module: Optional[str] = None
self._module: Dict[str, Tuple[QAPIGenC, QAPIGenH]] = {}
self._main_module: Optional[str] = None
@property
def _genc(self) -> QAPIGenC:
assert self._current_module is not None
return self._module[self._current_module][0]
@property
def _genh(self) -> QAPIGenH:
assert self._current_module is not None
return self._module[self._current_module][1]
@staticmethod
def _module_dirname(name: str) -> str:
if QAPISchemaModule.is_user_module(name):
return os.path.dirname(name)
return ''
def _module_basename(self, what: str, name: str) -> str:
ret = '' if QAPISchemaModule.is_builtin_module(name) else self._prefix
if QAPISchemaModule.is_user_module(name):
basename = os.path.basename(name)
ret += what
if name != self._main_module:
ret += '-' + os.path.splitext(basename)[0]
else:
assert QAPISchemaModule.is_system_module(name)
ret += re.sub(r'-', '-' + name[2:] + '-', what)
return ret
def _module_filename(self, what: str, name: str) -> str:
return os.path.join(self._module_dirname(name),
self._module_basename(what, name))
def _add_module(self, name: str, blurb: str) -> None:
if QAPISchemaModule.is_user_module(name):
if self._main_module is None:
self._main_module = name
basename = self._module_filename(self._what, name)
genc = QAPIGenC(basename + '.c', blurb, self._pydoc)
genh = QAPIGenH(basename + '.h', blurb, self._pydoc)
self._module[name] = (genc, genh)
self._current_module = name
@contextmanager
def _temp_module(self, name: str) -> Iterator[None]:
old_module = self._current_module
self._current_module = name
yield
self._current_module = old_module
def write(self, output_dir: str, opt_builtins: bool = False) -> None:
for name in self._module:
if QAPISchemaModule.is_builtin_module(name) and not opt_builtins:
continue
(genc, genh) = self._module[name]
genc.write(output_dir)
genh.write(output_dir)
def _begin_builtin_module(self) -> None:
pass
def _begin_user_module(self, name: str) -> None:
pass
def visit_module(self, name: str) -> None:
if QAPISchemaModule.is_builtin_module(name):
if self._builtin_blurb:
self._add_module(name, self._builtin_blurb)
self._begin_builtin_module()
else:
# The built-in module has not been created. No code may
# be generated.
self._current_module = None
else:
assert QAPISchemaModule.is_user_module(name)
self._add_module(name, self._user_blurb)
self._begin_user_module(name)
def visit_include(self, name: str, info: Optional[QAPISourceInfo]) -> None:
relname = os.path.relpath(self._module_filename(self._what, name),
os.path.dirname(self._genh.fname))
self._genh.preamble_add(mcgen('''
#include "%(relname)s.h"
''',
relname=relname))