qemu/scripts/qapi/gen.py
Markus Armbruster 1889e57a71 qapi: Simplify QAPISchemaIfCond's interface for generating C
QAPISchemaIfCond.cgen() is only ever used like

    gen_if(ifcond.cgen())

and

    gen_endif(ifcond.cgen())

Simplify to

    ifcond.gen_if()

and

    ifcond.gen_endif()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210831123809.1107782-2-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[Import statements tidied up with isort]
2021-09-03 17:06:40 +02:00

333 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,
Tuple,
)
from .common import (
c_fname,
c_name,
guardend,
guardstart,
mcgen,
)
from .schema import (
QAPISchemaIfCond,
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: QAPISchemaIfCond, 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 += ifcond.gen_if()
out += added
out += ifcond.gen_endif()
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[QAPISchemaIfCond, str, str]] = None
def start_if(self, ifcond: QAPISchemaIfCond) -> 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: QAPISchemaIfCond, *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))