We can do better with the SBValue.linked_list_iter() API by supplying a default

end of list test function as __eol_test__.

The simple example can be reduced to:

    for t in task_head.linked_list_iter('next'):
        print t

Modify the test program to exercise the API for both cases: supplying or not
supplying an end of list test function.

llvm-svn: 136144

lldb/scripts/Python/modify-python-lldb.py

@@ -89,10 +89,21 @@ def lldb_iter(obj, getsize, getelem):
 # which takes an SBValue and returns True if EOL is reached and False if not.
 #
 linked_list_iter_def = '''
+    def __eol_test__(val):
+        """Default function for end of list test takes an SBValue object.
+
+        Return True if val is invalid or it corresponds to a null pointer.
+        Otherwise, return False.
+        """
+        if not val or int(val.GetValue(), 0) == 0:
+            return True
+        else:
+            return False
+
     # ==================================================
     # Iterator for lldb.SBValue treated as a linked list
     # ==================================================
-    def linked_list_iter(self, next_item_name, end_of_list_test):
+    def linked_list_iter(self, next_item_name, end_of_list_test=__eol_test__):
         """Generator adaptor to support iteration for SBValue as a linked list.
 
         linked_list_iter() is a special purpose iterator to treat the SBValue as
@@ -101,18 +112,11 @@ linked_list_iter_def = '''
         end-of-list test function which takes an SBValue for an item and returns
         True if EOL is reached and False if not.
 
+        The end_of_list_test arg, if omitted, defaults to the __eol_test__
+        function above.
+
         For example,
 
-        def eol(val):
-            \'\'\'Test function to determine end of list.\'\'\'
-            # End of list is reached if either the value object is invalid
-            # or it corresponds to a null pointer.
-            if not val or int(val.GetValue(), 16) == 0:
-                return True
-
-            # Otherwise, return False.
-            return False
-
         # Get Frame #0.
         ...
 
@@ -120,7 +124,7 @@ linked_list_iter_def = '''
         task_head = frame0.FindVariable('task_head')
         ...
 
-        for t in task_head.linked_list_iter('next', eol):
+        for t in task_head.linked_list_iter('next'):
             print t
         """
         try:

lldb/test/python_api/value/linked_list/TestValueAPILinkedList.py

@@ -54,16 +54,6 @@ class ValueAsLinkedListTestCase(TestBase):
         process = target.LaunchSimple(None, None, os.getcwd())
         self.assertTrue(process, PROCESS_IS_VALID)
 
-        def eol(val):
-            """Test function to determine end of list."""
-            # End of list is reached if either the value object is invalid
-            # or it corresponds to a null pointer.
-            if not val or int(val.GetValue(), 16) == 0:
-                return True
-
-            # Otherwise, return False.
-            return False
-
         # Get Frame #0.
         self.assertTrue(process.GetState() == lldb.eStateStopped)
         thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonBreakpoint)
@@ -80,6 +70,32 @@ class ValueAsLinkedListTestCase(TestBase):
         list = []
 
         cvf = lldbutil.ChildVisitingFormatter(indent_child=2)
+        for t in task_head.linked_list_iter('next'):
+            self.assertTrue(t, VALID_VARIABLE)
+            # Make sure that 'next' corresponds to an SBValue with pointer type.
+            self.assertTrue(t.TypeIsPointerType())
+            if self.TraceOn():
+                print cvf.format(t)
+            list.append(int(t.GetChildMemberWithName("id").GetValue()))
+
+        # Sanity checks that the we visited all the items (no more, no less).
+        if self.TraceOn():
+            print "visited IDs:", list
+        self.assertTrue(visitedIDs == list)
+
+        # Let's exercise the linked_list_iter() API again, this time supplying
+        # our end of list test function.
+        def eol(val):
+            """Test function to determine end of list."""
+            # End of list is reached if either the value object is invalid
+            # or it corresponds to a null pointer.
+            if not val or int(val.GetValue(), 16) == 0:
+                return True
+
+            # Otherwise, return False.
+            return False
+
+        list = []
         for t in task_head.linked_list_iter('next', eol):
             self.assertTrue(t, VALID_VARIABLE)
             # Make sure that 'next' corresponds to an SBValue with pointer type.