Bug 950370 - Capture WebIDL example interfaces in moz.build; r=glandium

Previously, the set of WebIDL example interfaces to build was hardcoded
in the mozwebidlcodegen Python package. Unfortunately, the example
interfaces in that set were dependent on test-only bindings files,
resulting in build failures when tests were disabled (because those
test-only bindings were defined in a test directory).

In this patch, we now declare example interfaces in moz.build files
so the set of example interfaces lives next to the set of defined
bindings files. The example interfaces are defined in a test moz.build
file - in the same file declaring the bindings files that contain the
interfaces - so the example interfaces only get picked up if the
corresponding bindings are defined.

We could probably switch WebIDL moz.build variables to use lists with
flags. That would be good followup fodder. For now, let's fix the build.

--HG--
extra : rebase_source : 00070a6d560625bc84ab9b10d6848ea037f8f5ed
extra : amend_source : 0890ecef444ba58533fcfaa333773d78deafd7f3

dom/bindings/mozwebidlcodegen/__init__.py

@@ -146,23 +146,17 @@ class WebIDLCodegenManager(LoggingMixin):
         'UnionTypes.cpp',
     }
 
-    # Example interfaces to build along with the tree. Other example
-    # interfaces will need to be generated manually.
-    BUILD_EXAMPLE_INTERFACES = {
-        'TestExampleInterface',
-        'TestExampleProxyInterface',
-    }
-
     def __init__(self, config_path, inputs, exported_header_dir,
         codegen_dir, state_path, cache_dir=None, make_deps_path=None,
         make_deps_target=None):
         """Create an instance that manages WebIDLs in the build system.
 
         config_path refers to a WebIDL config file (e.g. Bindings.conf).
-        inputs is a 3-tuple describing the input .webidl files and how to
+        inputs is a 4-tuple describing the input .webidl files and how to
         process them. Members are:
             (set(.webidl files), set(basenames of exported files),
-                set(basenames of generated events files))
+                set(basenames of generated events files),
+                set(example interface names))
 
         exported_header_dir and codegen_dir are directories where generated
         files will be written to.
@@ -175,12 +169,13 @@ class WebIDLCodegenManager(LoggingMixin):
         """
         self.populate_logger()
 
-        input_paths, exported_stems, generated_events_stems = inputs
+        input_paths, exported_stems, generated_events_stems, example_interfaces = inputs
 
         self._config_path = config_path
         self._input_paths = set(input_paths)
         self._exported_stems = set(exported_stems)
         self._generated_events_stems = set(generated_events_stems)
+        self._example_interfaces = set(example_interfaces)
         self._exported_header_dir = exported_header_dir
         self._codegen_dir = codegen_dir
         self._state_path = state_path
@@ -283,7 +278,7 @@ class WebIDLCodegenManager(LoggingMixin):
             )
 
         # Process some special interfaces required for testing.
-        for interface in self.BUILD_EXAMPLE_INTERFACES:
+        for interface in self._example_interfaces:
             written = self.generate_example_files(interface)
             result.created |= written[0]
             result.updated |= written[1]
@@ -446,7 +441,7 @@ class WebIDLCodegenManager(LoggingMixin):
             stem, binding_stem, is_event, header_dir, files = self._binding_info(p)
             paths |= {f for f in files if f}
 
-        for interface in self.BUILD_EXAMPLE_INTERFACES:
+        for interface in self._example_interfaces:
             for p in self._example_paths(interface):
                 paths.add(p)
 
@@ -533,7 +528,7 @@ def create_build_system_manager(topsrcdir, topobjdir, dist_dir):
         files = json.load(fh)
 
     inputs = (files['webidls'], files['exported_stems'],
-        files['generated_events_stems'])
+        files['generated_events_stems'], files['example_interfaces'])
 
     cache_dir = os.path.join(obj_dir, '_cache')
     try:

dom/bindings/mozwebidlcodegen/test/test_mozwebidlcodegen.py

@@ -65,7 +65,8 @@ class TestWebIDLCodegenManager(unittest.TestCase):
         inputs = (
             ip,
             {mozpath.splitext(mozpath.basename(p))[0] for p in ip},
-            set()
+            set(),
+            set(),
         )
 
         return dict(

dom/bindings/test/moz.build

@@ -26,6 +26,11 @@ PREPROCESSED_TEST_WEBIDL_FILES += [
     'TestJSImplGen.webidl',
 ]
 
+WEBIDL_EXAMPLE_INTERFACES += [
+    'TestExampleInterface',
+    'TestExampleProxyInterface',
+]
+
 LOCAL_INCLUDES += [
     '/dom/bindings',
     '/js/xpconnect/src',

python/mozbuild/mozbuild/backend/common.py

@@ -14,6 +14,7 @@ from .base import BuildBackend
 
 from ..frontend.data import (
     ConfigFileSubstitution,
+    ExampleWebIDLInterface,
     HeaderFileSubstitution,
     GeneratedEventWebIDLFile,
     GeneratedWebIDLFile,
@@ -70,6 +71,7 @@ class WebIDLCollection(object):
         self.preprocessed_sources = set()
         self.test_sources = set()
         self.preprocessed_test_sources = set()
+        self.example_interfaces = set()
 
     def all_regular_sources(self):
         return self.sources | self.generated_sources | \
@@ -215,6 +217,9 @@ class CommonBackend(BuildBackend):
             self._webidls.preprocessed_sources.add(mozpath.join(
                 obj.srcdir, obj.basename))
 
+        elif isinstance(obj, ExampleWebIDLInterface):
+            self._webidls.example_interfaces.add(obj.name)
+
         else:
             return
 

python/mozbuild/mozbuild/backend/recursivemake.py

@@ -1135,6 +1135,7 @@ class RecursiveMakeBackend(CommonBackend):
             webidls=sorted(all_inputs),
             generated_events_stems=sorted(generated_events_stems),
             exported_stems=sorted(exported_stems),
+            example_interfaces=sorted(webidls.example_interfaces),
         )
 
         file_lists = mozpath.join(bindings_dir, 'file-lists.json')

python/mozbuild/mozbuild/frontend/data.py

@@ -289,6 +289,20 @@ class GeneratedWebIDLFile(SandboxDerived):
 
         self.basename = path
 
+
+class ExampleWebIDLInterface(SandboxDerived):
+    """An individual WebIDL interface to generate."""
+
+    __slots__ = (
+        'name',
+    )
+
+    def __init__(self, sandbox, name):
+        SandboxDerived.__init__(self, sandbox)
+
+        self.name = name
+
+
 class BaseProgram(SandboxDerived):
     """Sandbox container object for programs, which is a unicode string.
 

python/mozbuild/mozbuild/frontend/emitter.py

@@ -24,6 +24,7 @@ from .data import (
     GeneratedEventWebIDLFile,
     GeneratedInclude,
     GeneratedWebIDLFile,
+    ExampleWebIDLInterface,
     HeaderFileSubstitution,
     HostProgram,
     HostSimpleProgram,
@@ -321,6 +322,7 @@ class TreeMetadataEmitter(LoggingMixin):
             ('PREPROCESSED_WEBIDL_FILES', PreprocessedWebIDLFile),
             ('TEST_WEBIDL_FILES', TestWebIDLFile),
             ('WEBIDL_FILES', WebIDLFile),
+            ('WEBIDL_EXAMPLE_INTERFACES', ExampleWebIDLInterface),
         ]
         for sandbox_var, klass in simple_lists:
             for name in sandbox.get(sandbox_var, []):

python/mozbuild/mozbuild/frontend/sandbox_symbols.py

@@ -502,6 +502,14 @@ VARIABLES = {
          These will be preprocessed before being parsed and converted.
          """, 'export'),
 
+    'WEBIDL_EXAMPLE_INTERFACES': (StrictOrderingOnAppendList, list,
+        """Names of example WebIDL interfaces to build as part of the build.
+
+        Names in this list correspond to WebIDL interface names defined in
+        WebIDL files included in the build from one of the \*WEBIDL_FILES
+        variables.
+        """, 'export'),
+
     # Test declaration.
     'A11Y_MANIFESTS': (StrictOrderingOnAppendList, list,
         """List of manifest files defining a11y tests.