gnatdbg.records.decoded_record: handle tagged types

Change-Id: Ief21b027fe75cabe226058122448fbcca57cda09
TN: RC14-025

Author: pmderodat

gnatdbg/records.py

@@ -193,7 +193,10 @@ def process_record(r):
         # parts (case <discr> is ... end case, in Ada records) or regular
         # fields.
         for f in r.type.fields():
-            if f.name.endswith(union_suffix):
+            if f.name == '_parent':
+                process_record(r[f.name])
+
+            elif f.name.endswith(union_suffix):
                 # This is an undecoded variant part, materialized as an union
                 # field whose name has follows the <discr>___XVN pattern.
                 # Compute the corresponding discriminant and decode the union.
@@ -207,8 +210,8 @@ def process_record(r):
                 # Just recurse on that record.
                 process_record(r[f.name])
 
-            else:
-                # This is a regular field.
+            elif not f.name.startswith('_'):
+                # This is a regular field (omit compiler-generated ones)
                 result[f.name] = r[f.name]
 
     def process_union(discr_value, u):

testsuite/tests/records/derived/foo.adb

@@ -0,0 +1,20 @@
+procedure Foo is
+
+   type Base is tagged record
+      I : Integer;
+   end record;
+
+   type Derived is new Base with record
+      C : Character;
+   end record;
+
+   procedure Process (R : Base'Class) is
+   begin
+      null;
+   end Process;
+
+   R : Derived := (I => 1, C => 'A');
+
+begin
+   Process (R); --  BREAK
+end Foo;

testsuite/tests/records/derived/helpers.py

@@ -0,0 +1,7 @@
+from gnatdbg.records import decoded_record
+
+
+def print_record(name, value):
+    print('== {} =='.format(name))
+    for k, v in decoded_record(value).items():
+        print('  {}: {}'.format(k, v))

testsuite/tests/records/derived/test.py

@@ -0,0 +1,12 @@
+from support.build import gnatmake
+from support.gdb import GDBSession
+
+
+gnatmake('foo')
+gdb = GDBSession('foo')
+gdb.run_to(gdb.find_loc('foo.adb', 'BREAK'))
+gdb.test('source helpers.py', '')
+gdb.test('pi print_record("R", gdb.parse_and_eval("R"))',
+         '== R ==\n'
+         '  i: 1\n'
+         '  c: 65 \'A\'')

testsuite/tests/records/derived/test.yaml

@@ -0,0 +1 @@
+driver: python