Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2020-10-10' into staging

QAPI patches patches for 2020-10-10

# gpg: Signature made Sat 10 Oct 2020 10:43:14 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2020-10-10: (34 commits)
  qapi/visit.py: add type hint annotations
  qapi/visit.py: remove unused parameters from gen_visit_object
  qapi/visit.py: assert tag_member contains a QAPISchemaEnumType
  qapi/types.py: remove one-letter variables
  qapi/types.py: add type hint annotations
  qapi/gen.py: delint with pylint
  qapi/gen.py: update write() to be more idiomatic
  qapi/gen.py: Remove unused parameter
  qapi/gen.py: add type hint annotations
  qapi/gen: Make _is_user_module() return bool
  qapi/source.py: delint with pylint
  qapi/source.py: add type hint annotations
  qapi/commands.py: add type hint annotations
  qapi/commands.py: Don't re-bind to variable of different type
  qapi/events.py: Move comments into docstrings
  qapi/events.py: add type hint annotations
  qapi: establish mypy type-checking baseline
  qapi/common.py: move build_params into gen.py
  qapi/common.py: Convert comments into docstrings, and elaborate
  qapi/common.py: add type hint annotations
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 112 insertions, 70 deletions

diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index ca66c82b5b..b40f18eee3 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -2,7 +2,7 @@
 #
 # QAPI code generation
 #
-# Copyright (c) 2018-2019 Red Hat Inc.
+# Copyright (c) 2015-2019 Red Hat Inc.
 #
 # Authors:
 #  Markus Armbruster <armbru@redhat.com>
@@ -11,39 +11,54 @@
 # This work is licensed under the terms of the GNU GPL, version 2.
 # See the COPYING file in the top-level directory.
 
-
-import errno
+from contextlib import contextmanager
 import os
 import re
-from contextlib import contextmanager
-
-from qapi.common import *
-from qapi.schema import QAPISchemaVisitor
+from typing import (
+    Dict,
+    Iterator,
+    List,
+    Optional,
+    Tuple,
+)
+
+from .common import (
+    c_fname,
+    c_name,
+    gen_endif,
+    gen_if,
+    guardend,
+    guardstart,
+    mcgen,
+)
+from .schema import QAPISchemaObjectType, QAPISchemaVisitor
+from .source import QAPISourceInfo
 
 
 class QAPIGen:
-
-    def __init__(self, fname):
+    def __init__(self, fname: Optional[str]):
         self.fname = fname
         self._preamble = ''
         self._body = ''
 
-    def preamble_add(self, text):
+    def preamble_add(self, text: str) -> None:
         self._preamble += text
 
-    def add(self, text):
+    def add(self, text: str) -> None:
         self._body += text
 
-    def get_content(self):
+    def get_content(self) -> str:
         return self._top() + self._preamble + self._body + self._bottom()
 
-    def _top(self):
+    def _top(self) -> str:
+        # pylint: disable=no-self-use
         return ''
 
-    def _bottom(self):
+    def _bottom(self) -> str:
+        # pylint: disable=no-self-use
         return ''
 
-    def write(self, output_dir):
+    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.
@@ -51,24 +66,22 @@ class QAPIGen:
             return
         pathname = os.path.join(output_dir, self.fname)
         odir = os.path.dirname(pathname)
+
         if odir:
-            try:
-                os.makedirs(odir)
-            except os.error as e:
-                if e.errno != errno.EEXIST:
-                    raise
+            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)
-        f = open(fd, 'r+', encoding='utf-8')
-        text = self.get_content()
-        oldtext = f.read(len(text) + 1)
-        if text != oldtext:
-            f.seek(0)
-            f.truncate(0)
-            f.write(text)
-        f.close()
+        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, before, after):
+def _wrap_ifcond(ifcond: List[str], before: str, after: str) -> str:
     if before == after:
         return after   # suppress empty #if ... #endif
 
@@ -84,41 +97,62 @@ def _wrap_ifcond(ifcond, before, after):
     return out
 
 
-class QAPIGenCCode(QAPIGen):
+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'
 
-    def __init__(self, fname):
+
+class QAPIGenCCode(QAPIGen):
+    def __init__(self, fname: Optional[str]):
         super().__init__(fname)
-        self._start_if = None
+        self._start_if: Optional[Tuple[List[str], str, str]] = None
 
-    def start_if(self, ifcond):
+    def start_if(self, ifcond: List[str]) -> None:
         assert self._start_if is None
         self._start_if = (ifcond, self._body, self._preamble)
 
-    def end_if(self):
+    def end_if(self) -> None:
         assert self._start_if
         self._wrap_ifcond()
         self._start_if = None
 
-    def _wrap_ifcond(self):
+    def _wrap_ifcond(self) -> 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)
 
-    def get_content(self):
+    def get_content(self) -> str:
         assert self._start_if is None
         return super().get_content()
 
 
 class QAPIGenC(QAPIGenCCode):
-
-    def __init__(self, fname, blurb, pydoc):
+    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):
+    def _top(self) -> str:
         return mcgen('''
 /* AUTOMATICALLY GENERATED, DO NOT MODIFY */
 
@@ -134,7 +168,7 @@ class QAPIGenC(QAPIGenCCode):
 ''',
                      blurb=self._blurb, copyright=self._copyright)
 
-    def _bottom(self):
+    def _bottom(self) -> str:
         return mcgen('''
 
 /* Dummy declaration to prevent empty .o file */
@@ -144,19 +178,20 @@ char qapi_dummy_%(name)s;
 
 
 class QAPIGenH(QAPIGenC):
-
-    def _top(self):
+    def _top(self) -> str:
         return super()._top() + guardstart(self.fname)
 
-    def _bottom(self):
+    def _bottom(self) -> str:
         return guardend(self.fname)
 
 
 @contextmanager
-def ifcontext(ifcond, *args):
-    """A 'with' statement context manager to wrap with start_if()/end_if()
+def ifcontext(ifcond: List[str], *args: QAPIGenCCode) -> Iterator[None]:
+    """
+    A with-statement context manager that wraps with `start_if()` / `end_if()`.
 
-    *args: any number of QAPIGenCCode
+    :param ifcond: A list of conditionals, passed to `start_if()`.
+    :param args: any number of `QAPIGenCCode`.
 
     Example::
 
@@ -179,8 +214,11 @@ def ifcontext(ifcond, *args):
 
 
 class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
-
-    def __init__(self, prefix, what, blurb, pydoc):
+    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',
@@ -188,38 +226,42 @@ class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
         self._genh = QAPIGenH(self._prefix + self._what + '.h',
                               blurb, pydoc)
 
-    def write(self, output_dir):
+    def write(self, output_dir: str) -> None:
         self._genc.write(output_dir)
         self._genh.write(output_dir)
 
 
 class QAPISchemaModularCVisitor(QAPISchemaVisitor):
-
-    def __init__(self, prefix, what, user_blurb, builtin_blurb, pydoc):
+    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._genc = None
-        self._genh = None
-        self._module = {}
-        self._main_module = None
+        self._genc: Optional[QAPIGenC] = None
+        self._genh: Optional[QAPIGenH] = None
+        self._module: Dict[Optional[str], Tuple[QAPIGenC, QAPIGenH]] = {}
+        self._main_module: Optional[str] = None
 
     @staticmethod
-    def _is_user_module(name):
-        return name and not name.startswith('./')
+    def _is_user_module(name: Optional[str]) -> bool:
+        return bool(name and not name.startswith('./'))
 
     @staticmethod
-    def _is_builtin_module(name):
+    def _is_builtin_module(name: Optional[str]) -> bool:
         return not name
 
-    def _module_dirname(self, what, name):
+    def _module_dirname(self, name: Optional[str]) -> str:
         if self._is_user_module(name):
             return os.path.dirname(name)
         return ''
 
-    def _module_basename(self, what, name):
+    def _module_basename(self, what: str, name: Optional[str]) -> str:
         ret = '' if self._is_builtin_module(name) else self._prefix
         if self._is_user_module(name):
             basename = os.path.basename(name)
@@ -231,27 +273,27 @@ class QAPISchemaModularCVisitor(QAPISchemaVisitor):
             ret += re.sub(r'-', '-' + name + '-', what)
         return ret
 
-    def _module_filename(self, what, name):
-        return os.path.join(self._module_dirname(what, name),
+    def _module_filename(self, what: str, name: Optional[str]) -> str:
+        return os.path.join(self._module_dirname(name),
                             self._module_basename(what, name))
 
-    def _add_module(self, name, blurb):
+    def _add_module(self, name: Optional[str], blurb: str) -> None:
         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._genc, self._genh = self._module[name]
 
-    def _add_user_module(self, name, blurb):
+    def _add_user_module(self, name: str, blurb: str) -> None:
         assert self._is_user_module(name)
         if self._main_module is None:
             self._main_module = name
         self._add_module(name, blurb)
 
-    def _add_system_module(self, name, blurb):
+    def _add_system_module(self, name: Optional[str], blurb: str) -> None:
         self._add_module(name and './' + name, blurb)
 
-    def write(self, output_dir, opt_builtins=False):
+    def write(self, output_dir: str, opt_builtins: bool = False) -> None:
         for name in self._module:
             if self._is_builtin_module(name) and not opt_builtins:
                 continue
@@ -259,13 +301,13 @@ class QAPISchemaModularCVisitor(QAPISchemaVisitor):
             genc.write(output_dir)
             genh.write(output_dir)
 
-    def _begin_system_module(self, name):
+    def _begin_system_module(self, name: None) -> None:
         pass
 
-    def _begin_user_module(self, name):
+    def _begin_user_module(self, name: str) -> None:
         pass
 
-    def visit_module(self, name):
+    def visit_module(self, name: Optional[str]) -> None:
         if name is None:
             if self._builtin_blurb:
                 self._add_system_module(None, self._builtin_blurb)
@@ -279,7 +321,7 @@ class QAPISchemaModularCVisitor(QAPISchemaVisitor):
             self._add_user_module(name, self._user_blurb)
             self._begin_user_module(name)
 
-    def visit_include(self, name, info):
+    def visit_include(self, name: str, info: QAPISourceInfo) -> None:
         relname = os.path.relpath(self._module_filename(self._what, name),
                                   os.path.dirname(self._genh.fname))
         self._genh.preamble_add(mcgen('''