[RFC PATCH 15/18] qapi: Support empty modules

[Kevin Wolf <kwolf@redhat.com>]

If you added an include file that doesn't contain any definitions, no
source files would be generated for it. However, in other source files,
you would still get an #include for the header files of the empty
module.

The intended behaviour is that empty source files are created for empty
modules. This patch makes QAPISchema keep a list of all modules
(including empty ones) and modifies visit() to first visit all modules
in that list.

Some test reference outputs need to be updated due to the additional
visitor calls.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 scripts/qapi/schema.py                   | 9 +++++++++
 tests/qapi-schema/comments.out           | 2 ++
 tests/qapi-schema/doc-bad-section.out    | 2 ++
 tests/qapi-schema/doc-good.out           | 2 ++
 tests/qapi-schema/empty.out              | 2 ++
 tests/qapi-schema/event-case.out         | 2 ++
 tests/qapi-schema/include-repetition.out | 4 ++++
 tests/qapi-schema/include-simple.out     | 3 +++
 tests/qapi-schema/indented-expr.out      | 2 ++
 tests/qapi-schema/qapi-schema-test.out   | 4 ++++
 10 files changed, 32 insertions(+)

diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 38041098bd..e1b034d67d 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -749,6 +749,7 @@ class QAPISchema(object):
         self.docs = parser.docs
         self._entity_list = []
         self._entity_dict = {}
+        self._modules = [os.path.basename(fname)]
         self._predefining = True
         self._def_predefineds()
         self._predefining = False
@@ -800,6 +801,8 @@ class QAPISchema(object):
             main_info = main_info.parent
         fname = os.path.relpath(include, os.path.dirname(main_info.fname))
         self._def_entity(QAPISchemaInclude(fname, info))
+        if fname not in self._modules:
+            self._modules.append(fname)
 
     def _def_builtin_type(self, name, json_type, c_type):
         self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
@@ -1033,6 +1036,12 @@ class QAPISchema(object):
         visitor.visit_begin(self)
         module = None
         visitor.visit_module(module)
+
+        # Make sure that all modules are visited, even if they contain no
+        # entities
+        for module in self._modules:
+            visitor.visit_module(module)
+
         for entity in self._entity_list:
             if visitor.visit_needed(entity):
                 if entity.module != module:
diff --git a/tests/qapi-schema/comments.out b/tests/qapi-schema/comments.out
index 273f0f54e1..fa7e95d1cc 100644
--- a/tests/qapi-schema/comments.out
+++ b/tests/qapi-schema/comments.out
@@ -1,4 +1,6 @@
 module None
+module comments.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/doc-bad-section.out b/tests/qapi-schema/doc-bad-section.out
index 367e2a1c3e..331237cfbe 100644
--- a/tests/qapi-schema/doc-bad-section.out
+++ b/tests/qapi-schema/doc-bad-section.out
@@ -1,4 +1,6 @@
 module None
+module doc-bad-section.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/doc-good.out b/tests/qapi-schema/doc-good.out
index d3bca343eb..8f3577bb21 100644
--- a/tests/qapi-schema/doc-good.out
+++ b/tests/qapi-schema/doc-good.out
@@ -1,4 +1,6 @@
 module None
+module doc-good.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/empty.out b/tests/qapi-schema/empty.out
index 5b53d00702..3671cbbe59 100644
--- a/tests/qapi-schema/empty.out
+++ b/tests/qapi-schema/empty.out
@@ -1,4 +1,6 @@
 module None
+module empty.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/event-case.out b/tests/qapi-schema/event-case.out
index ec8a1406e4..2b2d8548e9 100644
--- a/tests/qapi-schema/event-case.out
+++ b/tests/qapi-schema/event-case.out
@@ -1,4 +1,6 @@
 module None
+module event-case.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/include-repetition.out b/tests/qapi-schema/include-repetition.out
index 5423983239..ebaac1813d 100644
--- a/tests/qapi-schema/include-repetition.out
+++ b/tests/qapi-schema/include-repetition.out
@@ -1,4 +1,8 @@
 module None
+module include-repetition.json
+module comments.json
+module include-repetition-sub.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/include-simple.out b/tests/qapi-schema/include-simple.out
index 061f81e509..dea51f9738 100644
--- a/tests/qapi-schema/include-simple.out
+++ b/tests/qapi-schema/include-simple.out
@@ -1,4 +1,7 @@
 module None
+module include-simple.json
+module include-simple-sub.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/indented-expr.out b/tests/qapi-schema/indented-expr.out
index bffdf6756d..d4cffb9c1b 100644
--- a/tests/qapi-schema/indented-expr.out
+++ b/tests/qapi-schema/indented-expr.out
@@ -1,4 +1,6 @@
 module None
+module indented-expr.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index 98031da96f..93c944a2fb 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -1,4 +1,8 @@
 module None
+module qapi-schema-test.json
+module include/sub-module.json
+module sub-sub-module.json
+module None
 object q_empty
 enum QType
     prefix QTYPE
-- 
2.20.1