Bug 557383 - Virtual method support

Broadly speaking, this change adds the concept of <vfunc> to the .gir.
The typelib already had most of the infrastructure for virtual functions,
though there is one API addition.

The scanner assumes that any class callback slot that doesn't match
a signal name is a virtual.  In the .gir, we write out *both* the <method>
wrapper and a <vfunc>.  If we can determine an association between
them (based on the names matching, or a new Virtual: annotation),
then we notate that in the .gir.

The typelib gains an association from the vfunc to the function, if
it exists.  This will be useful for bindings since they already know
how to consume FunctionInfo.

1 files changed, 63 insertions, 10 deletions

diff --git a/giscanner/glibtransformer.py b/giscanner/glibtransformer.py
index 5a7a96d..61d4cef 100644
--- a/giscanner/glibtransformer.py
+++ b/giscanner/glibtransformer.py
@@ -27,12 +27,13 @@ import subprocess
 
 from .ast import (Alias, Bitfield, Callback, Constant, Enum, Function, Member,
                   Namespace, Parameter, Property, Record, Return, Type, Union,
-                  Field, type_name_from_ctype,
+                  Field, VFunction, type_name_from_ctype,
                   default_array_types, TYPE_UINT8, PARAM_TRANSFER_FULL)
 from .transformer import Names
 from .glibast import (GLibBoxed, GLibEnum, GLibEnumMember, GLibFlags,
                       GLibInterface, GLibObject, GLibSignal, GLibBoxedStruct,
-                      GLibBoxedUnion, GLibBoxedOther, GLibRecord, type_names)
+                      GLibBoxedUnion, GLibBoxedOther, GLibRecord,
+                      type_names)
 from .utils import to_underscores, to_underscores_noprefix
 
 default_array_types['guchar*'] = TYPE_UINT8
@@ -159,6 +160,10 @@ class GLibTransformer(object):
             except KeyError, e:
                 print "WARNING: DELETING node %s: %s" % (node.name, e)
                 self._remove_attribute(node.name)
+        # Another pass, since we need to have the methods parsed
+        # in order to correctly modify them after class/record
+        # pairing
+        for (ns, node) in nodes:
             # associate GtkButtonClass with GtkButton
             if isinstance(node, Record):
                 self._pair_class_record(node)
@@ -167,7 +172,9 @@ class GLibTransformer(object):
         self._resolve_quarks()
         # Fourth pass: ensure all types are known
         if not self._noclosure:
-            self._validate(nodes)
+            self._resolve_types(nodes)
+
+        self._validate(nodes)
 
         # Create a new namespace with what we found
         namespace = Namespace(self._namespace_name, self._namespace_version)
@@ -573,10 +580,43 @@ class GLibTransformer(object):
         for field in maybe_class.fields:
             if isinstance(field, Field):
                 field.writable = False
-        # TODO: remove this, we should be computing vfuncs instead
-        if isinstance(pair_class, GLibInterface):
-            for field in maybe_class.fields[1:]:
-                pair_class.fields.append(field)
+
+        # Loop through fields to determine which are virtual
+        # functions and which are signal slots by
+        # assuming everything that doesn't share a name
+        # with a known signal is a virtual slot.
+        for field in maybe_class.fields:
+            if not isinstance(field, Callback):
+                continue
+            # Check the first parameter is the object
+            if len(field.parameters) == 0:
+                continue
+            firstparam_type = field.parameters[0].type
+            if firstparam_type != pair_class:
+                continue
+            # Also double check we don't have a signal with this
+            # name.
+            matched_signal = False
+            for signal in pair_class.signals:
+                if signal.name.replace('-', '_') == field.name:
+                    matched_signal = True
+                    break
+            if matched_signal:
+                continue
+            vfunc = VFunction.from_callback(field)
+            pair_class.virtual_methods.append(vfunc)
+
+        # Take the set of virtual methods we found, and try
+        # to pair up with any matching methods using the
+        # name+signature.
+        for vfunc in pair_class.virtual_methods:
+            for method in pair_class.methods:
+                if (method.name != vfunc.name or
+                    method.retval != vfunc.retval or
+                    method.parameters != vfunc.parameters):
+                    continue
+                vfunc.invoker = method.name
+
         gclass_struct = GLibRecord.from_record(class_struct)
         self._remove_attribute(class_struct.name)
         self._add_attribute(gclass_struct, True)
@@ -903,9 +943,7 @@ class GLibTransformer(object):
     def _resolve_alias(self, alias):
         alias.target = self._resolve_type_name(alias.target, alias.target)
 
-    # Validation
-
-    def _validate(self, nodes):
+    def _resolve_types(self, nodes):
         nodes = list(self._names.names.itervalues())
         i = 0
         self._validating = True
@@ -925,3 +963,18 @@ class GLibTransformer(object):
             i += 1
             self._print_statistics()
         self._validating = False
+
+    # Validation
+
+    def _validate_interface(self, iface):
+        for vfunc in iface.virtual_methods:
+            if not vfunc.invoker:
+                print ("warning: Interface %r virtual function %r " + \
+                    "has no known invoker") % (iface.name, vfunc.name)
+
+    # This function is called at the very end, before we hand back the
+    # completed namespace to the writer.  Add static analysis checks here.
+    def _validate(self, nodes):
+        for (name, node) in nodes:
+            if isinstance(node, GLibInterface):
+                self._validate_interface(node)