qapi: Record 'include' directives in intermediate representation

The include directive permits modular QAPI schemata, but the generated
code is monolithic all the same.  To permit generating modular code,
the front end needs to pass more information on inclusions to the back
ends.  The commit before last added the necessary information to the
parse tree.  This commit adds it to the intermediate representation
and its QAPISchemaVisitor.  A later commit will use this to to
generate modular code.

New entity QAPISchemaInclude represents inclusions.  Call new visitor
method visit_include() for it, so visitors can see the sub-modules a
module includes.

Note that unlike other entities, QAPISchemaInclude has no name, and is
therefore not added to entity_dict.

New QAPISchemaEntity attribute @module names the entity's source file.
Call new visitor method visit_module() when it changes during a visit,
so visitors can keep track of the module being visited.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-18-armbru@redhat.com>
[eblake: avoid accidental deletion of self._predefining]
Signed-off-by: Eric Blake <eblake@redhat.com>

scripts/qapi/common.py

@@ -984,8 +984,9 @@ def check_exprs(exprs):
 
 class QAPISchemaEntity(object):
     def __init__(self, name, info, doc):
-        assert isinstance(name, str)
+        assert name is None or isinstance(name, str)
         self.name = name
+        self.module = None
         # For explicitly defined entities, info points to the (explicit)
         # definition.  For builtins (and their arrays), info is None.
         # For implicitly defined entities, info points to a place that
@@ -1014,10 +1015,16 @@ def visit_begin(self, schema):
     def visit_end(self):
         pass
 
+    def visit_module(self, fname):
+        pass
+
     def visit_needed(self, entity):
         # Default to visiting everything
         return True
 
+    def visit_include(self, fname, info):
+        pass
+
     def visit_builtin_type(self, name, info, json_type):
         pass
 
@@ -1044,6 +1051,16 @@ def visit_event(self, name, info, arg_type, boxed):
         pass
 
 
+class QAPISchemaInclude(QAPISchemaEntity):
+
+    def __init__(self, fname, info):
+        QAPISchemaEntity.__init__(self, None, info, None)
+        self.fname = fname
+
+    def visit(self, visitor):
+        visitor.visit_include(self.fname, self.info)
+
+
 class QAPISchemaType(QAPISchemaEntity):
     # Return the C type for common use.
     # For the types we commonly box, this is a pointer type.
@@ -1471,6 +1488,7 @@ def visit(self, visitor):
 
 class QAPISchema(object):
     def __init__(self, fname):
+        self._fname = fname
         parser = QAPISchemaParser(open(fname, 'r'))
         exprs = check_exprs(parser.exprs)
         self.docs = parser.docs
@@ -1485,9 +1503,13 @@ def __init__(self, fname):
     def _def_entity(self, ent):
         # Only the predefined types are allowed to not have info
         assert ent.info or self._predefining
-        assert ent.name not in self._entity_dict
+        assert ent.name is None or ent.name not in self._entity_dict
         self._entity_list.append(ent)
-        self._entity_dict[ent.name] = ent
+        if ent.name is not None:
+            self._entity_dict[ent.name] = ent
+        if ent.info:
+            ent.module = os.path.relpath(ent.info['file'],
+                                         os.path.dirname(self._fname))
 
     def lookup_entity(self, name, typ=None):
         ent = self._entity_dict.get(name)
@@ -1498,6 +1520,15 @@ def lookup_entity(self, name, typ=None):
     def lookup_type(self, name):
         return self.lookup_entity(name, QAPISchemaType)
 
+    def _def_include(self, expr, info, doc):
+        include = expr['include']
+        assert doc is None
+        main_info = info
+        while main_info['parent']:
+            main_info = main_info['parent']
+        fname = os.path.relpath(include, os.path.dirname(main_info['file']))
+        self._def_entity(QAPISchemaInclude(fname, info))
+
     def _def_builtin_type(self, name, json_type, c_type):
         self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
         # TODO As long as we have QAPI_TYPES_BUILTIN to share multiple
@@ -1680,7 +1711,7 @@ def _def_exprs(self, exprs):
             elif 'event' in expr:
                 self._def_event(expr, info, doc)
             elif 'include' in expr:
-                pass
+                self._def_include(expr, info, doc)
             else:
                 assert False
 
@@ -1690,8 +1721,12 @@ def check(self):
 
     def visit(self, visitor):
         visitor.visit_begin(self)
+        module = None
         for entity in self._entity_list:
             if visitor.visit_needed(entity):
+                if entity.module != module:
+                    module = entity.module
+                    visitor.visit_module(module)
                 entity.visit(visitor)
         visitor.visit_end()
 

tests/qapi-schema/comments.out

@@ -1,4 +1,5 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module comments.json
 enum Status ['good', 'bad', 'ugly']

tests/qapi-schema/doc-bad-section.out

@@ -1,6 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module doc-bad-section.json
 enum Enum ['one', 'two']
 doc symbol=Enum
     body=

tests/qapi-schema/doc-good.out

@@ -1,6 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module doc-good.json
 enum Enum ['one', 'two']
 object Base
     member base1: Enum optional=False

tests/qapi-schema/event-case.out

@@ -1,5 +1,6 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module event-case.json
 event oops None
    boxed=False

tests/qapi-schema/ident-with-escape.out

@@ -1,6 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module ident-with-escape.json
 object q_obj_fooA-arg
     member bar1: str optional=False
 command fooA q_obj_fooA-arg -> None

tests/qapi-schema/include-relpath.out

@@ -1,4 +1,9 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module include-relpath.json
+include include/relpath.json
+module include/relpath.json
+include include-relpath-sub.json
+module include-relpath-sub.json
 enum Status ['good', 'bad', 'ugly']

tests/qapi-schema/include-repetition.out

@@ -1,4 +1,14 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module include-repetition.json
+include comments.json
+module comments.json
 enum Status ['good', 'bad', 'ugly']
+module include-repetition.json
+include include-repetition-sub.json
+module include-repetition-sub.json
+include comments.json
+include comments.json
+module include-repetition.json
+include comments.json

tests/qapi-schema/include-simple.out

@@ -1,4 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module include-simple.json
+include include-simple-sub.json
+module include-simple-sub.json
 enum Status ['good', 'bad', 'ugly']

tests/qapi-schema/indented-expr.out

@@ -1,6 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module indented-expr.json
 command eins None -> None
    gen=True success_response=True boxed=False
 command zwei None -> None

tests/qapi-schema/qapi-schema-test.out

@@ -1,6 +1,7 @@
 object q_empty
 enum QType ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist', 'qbool']
     prefix QTYPE
+module qapi-schema-test.json
 object TestStruct
     member integer: int optional=False
     member boolean: bool optional=False

tests/qapi-schema/test-qapi.py

@@ -16,6 +16,13 @@
 
 
 class QAPISchemaTestVisitor(QAPISchemaVisitor):
+
+    def visit_module(self, name):
+        print('module %s' % name)
+
+    def visit_include(self, name, info):
+        print('include %s' % name)
+
     def visit_enum_type(self, name, info, values, prefix):
         print('enum %s %s' % (name, values))
         if prefix: