# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1474836244 -7200
# Node ID 760d93c5c2e9f8b7ecde62d0109da5c62cc84640
# Parent  43f1d3df67a0fd5e38af24f367079f112c2aa7b6
Attempt to define attribute access plans.

diff -r 43f1d3df67a0 -r 760d93c5c2e9 deducer.py
--- a/deducer.py	Sat Sep 24 22:44:45 2016 +0200
+++ b/deducer.py	Sun Sep 25 22:44:04 2016 +0200
@@ -19,7 +19,7 @@
 this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
-from common import get_attrname_from_location, get_attrnames, \
+from common import first, get_attrname_from_location, get_attrnames, \
                    init_item, make_key, sorted_output, \
                    CommonOutput
 from encoders import encode_attrnames, encode_access_location, \
@@ -136,6 +136,7 @@
         self.write_mutations()
         self.write_accessors()
         self.write_accesses()
+        self.write_access_plans()
 
     def write_mutations(self):
 
@@ -437,6 +438,26 @@
 
                 # Otherwise, no convenient guard can be defined.
 
+    def write_access_plans(self):
+
+        "Each attribute access is written out as a plan."
+
+        f_attrs = open(join(self.output, "attribute_plans"), "w")
+
+        try:
+            locations = self.referenced_attrs.keys()
+            locations.sort()
+
+            for location in locations:
+                base, traversed, attrnames, attr = self.get_access(location)
+                print >>f_attrs, encode_access_location(location), base, \
+                                 ".".join(traversed) or "{}", \
+                                 ".".join(attrnames) or "{}", \
+                                 attr or "{}"
+
+        finally:
+            f_attrs.close()
+
     def classify_accesses(self):
 
         "For each program location, classify accesses."
@@ -1615,4 +1636,59 @@
 
         return attrs
 
+    def get_access(self, location):
+
+        "Return details of the access at the given 'location'."
+
+        const_access = self.const_accesses.has_key(location)
+        if const_access:
+            location = self.const_accesses[location]
+
+        path, name, attrname_str, version = location
+        attrnames = attrname_str.split(".")
+        attrname = attrnames[0]
+
+        # Obtain only reference information.
+
+        attrs = []
+        objtypes = []
+        for attrtype, objtype, attr in self.referenced_attrs[location]:
+            attrs.append(attr)
+            objtypes.append(objtype)
+
+        # Identify the last static attribute.
+
+        if const_access:
+            base = len(objtypes) == 1 and first(objtypes)
+        else:
+            ref = self.importer.identify("%s.%s" % (path, name))
+            if not ref:
+                base = name
+            else:
+                base = ref.get_origin()
+
+        traversed = []
+
+        # Traverse remaining attributes.
+
+        while len(attrs) == 1:
+            attr = first(attrs)
+
+            traversed.append(attrname)
+            del attrnames[0]
+
+            if not attrnames:
+                break
+
+            if attr.static():
+                base = attr.get_origin()
+                traversed = []
+
+            attrname = attrnames[0]
+            attrs = self.importer.get_attributes(attr, attrname)
+        else:
+            attr = None
+
+        return base, traversed, attrnames, attr and attr.get_name()
+
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r 43f1d3df67a0 -r 760d93c5c2e9 tests/chain.py
--- a/tests/chain.py	Sat Sep 24 22:44:45 2016 +0200
+++ b/tests/chain.py	Sun Sep 25 22:44:04 2016 +0200
@@ -2,7 +2,8 @@
     class D:
         class E:
             def m(self, x):
-                return x
+                self.x = x
+                return self.x.__len__
             n = 123
         p = "456"
 
@@ -16,7 +17,7 @@
     i = C.D.p.__len__
     inst = e()
     method = inst.m
-    return method(5)
+    return method("5")
 
 result1 = main()
 c = C
@@ -28,4 +29,4 @@
 i = C.D.p.__len__
 inst = e()
 method = inst.m
-result2 = method(5)
+result2 = method("5")