qapi/common.py: add type hint annotations

Annotations do not change runtime behavior.
This commit *only* adds annotations.

Note that build_params() cannot be fully annotated due to import
dependency issues.  The commit after next will take care of it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20201009161558.107041-16-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/common.py

@@ -12,6 +12,7 @@
 # See the COPYING file in the top-level directory.
 
 import re
+from typing import Optional, Sequence
 
 
 EATSPACE = '\033EATSPACE.'
@@ -22,7 +23,7 @@
 # ENUMName -> ENUM_NAME, EnumName1 -> ENUM_NAME1
 # ENUM_NAME -> ENUM_NAME, ENUM_NAME1 -> ENUM_NAME1, ENUM_Name2 -> ENUM_NAME2
 # ENUM24_Name -> ENUM24_NAME
-def camel_to_upper(value):
+def camel_to_upper(value: str) -> str:
     c_fun_str = c_name(value, False)
     if value.isupper():
         return c_fun_str
@@ -41,7 +42,9 @@ def camel_to_upper(value):
     return new_name.lstrip('_').upper()
 
 
-def c_enum_const(type_name, const_name, prefix=None):
+def c_enum_const(type_name: str,
+                 const_name: str,
+                 prefix: Optional[str] = None) -> str:
     if prefix is not None:
         type_name = prefix
     return camel_to_upper(type_name) + '_' + c_name(const_name, False).upper()
@@ -56,7 +59,7 @@ def c_enum_const(type_name, const_name, prefix=None):
 # into substrings of a generated C function name.
 # '__a.b_c' -> '__a_b_c', 'x-foo' -> 'x_foo'
 # protect=True: 'int' -> 'q_int'; protect=False: 'int' -> 'int'
-def c_name(name, protect=True):
+def c_name(name: str, protect: bool = True) -> str:
     # ANSI X3J11/88-090, 3.1.1
     c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
                      'default', 'do', 'double', 'else', 'enum', 'extern',
@@ -131,24 +134,24 @@ def decrease(self, amount: int = 4) -> None:
 
 # Generate @code with @kwds interpolated.
 # Obey indent, and strip EATSPACE.
-def cgen(code, **kwds):
+def cgen(code: str, **kwds: object) -> str:
     raw = code % kwds
     if indent:
         raw = re.sub(r'^(?!(#|$))', str(indent), raw, flags=re.MULTILINE)
     return re.sub(re.escape(EATSPACE) + r' *', '', raw)
 
 
-def mcgen(code, **kwds):
+def mcgen(code: str, **kwds: object) -> str:
     if code[0] == '\n':
         code = code[1:]
     return cgen(code, **kwds)
 
 
-def c_fname(filename):
+def c_fname(filename: str) -> str:
     return re.sub(r'[^A-Za-z0-9_]', '_', filename)
 
 
-def guardstart(name):
+def guardstart(name: str) -> str:
     return mcgen('''
 #ifndef %(name)s
 #define %(name)s
@@ -157,7 +160,7 @@ def guardstart(name):
                  name=c_fname(name).upper())
 
 
-def guardend(name):
+def guardend(name: str) -> str:
     return mcgen('''
 
 #endif /* %(name)s */
@@ -165,7 +168,7 @@ def guardend(name):
                  name=c_fname(name).upper())
 
 
-def gen_if(ifcond):
+def gen_if(ifcond: Sequence[str]) -> str:
     ret = ''
     for ifc in ifcond:
         ret += mcgen('''
@@ -174,7 +177,7 @@ def gen_if(ifcond):
     return ret
 
 
-def gen_endif(ifcond):
+def gen_endif(ifcond: Sequence[str]) -> str:
     ret = ''
     for ifc in reversed(ifcond):
         ret += mcgen('''
@@ -183,7 +186,9 @@ def gen_endif(ifcond):
     return ret
 
 
-def build_params(arg_type, boxed, extra=None):
+def build_params(arg_type,
+                 boxed: bool,
+                 extra: Optional[str] = None) -> str:
     ret = ''
     sep = ''
     if boxed: