[PATCH 04/26] qapi/source.py: Add default arguments to QAPISourceInfo

[John Snow]

The parser tries to create an object as QAPISourceInfo(None, None,
None). Add some defaults to QAPISourceInfo such that we don't need to
pass explicit as many explicit nothings.

Having the defaults nearby the code in source.py also helps remind us
that they might be unset.

Using a numerical 0 to mean "no line" is nicer to type than using None
for the same.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 scripts/qapi/parser.py | 2 +-
 scripts/qapi/source.py | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
index d0f35fe03e..db4e9ae872 100644
--- a/scripts/qapi/parser.py
+++ b/scripts/qapi/parser.py
@@ -67,7 +67,7 @@ def __init__(self, fname, previously_included=None, 
incl_info=None):
             with open(self._fname, 'r', encoding='utf-8') as fp:
                 self.src = fp.read()
         except IOError as e:
-            raise QAPISemError(incl_info or QAPISourceInfo(None, None, None),
+            raise QAPISemError(incl_info or QAPISourceInfo(None),
                                "can't read %s file '%s': %s"
                                % ("include" if incl_info else "schema",
                                   self._fname,
diff --git a/scripts/qapi/source.py b/scripts/qapi/source.py
index ba991d798f..d1de9e36b1 100644
--- a/scripts/qapi/source.py
+++ b/scripts/qapi/source.py
@@ -30,7 +30,10 @@ def __init__(self) -> None:
 class QAPISourceInfo:
     T = TypeVar('T', bound='QAPISourceInfo')
 
-    def __init__(self: T, fname: str, line: int, parent: Optional[T]):
+    def __init__(self: T,
+                 fname: str,
+                 line: int = 0,
+                 parent: Optional[T] = None):
         self.fname = fname
         self.line = line
         self.parent = parent
@@ -53,7 +56,7 @@ def loc(self) -> str:
         if self.fname is None:
             return sys.argv[0]
         ret = self.fname
-        if self.line is not None:
+        if self.line:
             ret += ':%d' % self.line
         return ret
 
-- 
2.26.2