Fix dereferencing of pointers to empty classes

llvm-svn: 291350

lldb/packages/Python/lldbsuite/test/python_api/value/empty_class/Makefile

@@ -0,0 +1,5 @@
+LEVEL = ../../../make
+
+CXX_SOURCES := main.cpp
+
+include $(LEVEL)/Makefile.rules

lldb/packages/Python/lldbsuite/test/python_api/value/empty_class/TestValueAPIEmptyClass.py

@@ -0,0 +1,60 @@
+from __future__ import print_function
+
+import os
+import time
+import re
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class ValueAPIEmptyClassTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @add_test_categories(['pyapi'])
+    def test(self):
+        self.build()
+        exe = os.path.join(os.getcwd(), 'a.out')
+        line = line_number('main.cpp', '// Break at this line')
+
+        # Create a target by the debugger.
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        # Create the breakpoint inside function 'main'.
+        breakpoint = target.BreakpointCreateByLocation('main.cpp', line)
+        self.assertTrue(breakpoint, VALID_BREAKPOINT)
+
+        # Now launch the process, and do not stop at entry point.
+        process = target.LaunchSimple(
+            None, None, self.get_process_working_directory())
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        # Get Frame #0.
+        self.assertTrue(process.GetState() == lldb.eStateStopped)
+        thread = lldbutil.get_stopped_thread(
+            process, lldb.eStopReasonBreakpoint)
+        self.assertTrue(
+            thread.IsValid(),
+            "There should be a thread stopped due to breakpoint condition")
+        frame0 = thread.GetFrameAtIndex(0)
+
+        # Verify that we can access to a frame variable with an empty class type
+        e = frame0.FindVariable('e')
+        self.assertTrue(e.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(e)
+        self.assertEqual(e.GetNumChildren(), 0)
+
+        # Verify that we can acces to a frame variable what is a pointer to an
+        # empty class
+        ep = frame0.FindVariable('ep')
+        self.assertTrue(ep.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(ep)
+
+        # Verify that we can dereference a pointer to an empty class
+        epd = ep.Dereference()
+        self.assertTrue(epd.IsValid(), VALID_VARIABLE)
+        self.DebugSBValue(epd)
+        self.assertEqual(epd.GetNumChildren(), 0)
+

lldb/packages/Python/lldbsuite/test/python_api/value/empty_class/main.cpp

@@ -0,0 +1,16 @@
+//===-- main.cpp ------------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+class Empty {};
+
+int main (int argc, char const *argv[]) {
+  Empty e;
+  Empty* ep = new Empty;
+  return 0; // Break at this line
+}

lldb/source/Symbol/ClangASTContext.cpp

@@ -6752,8 +6752,7 @@ CompilerType ClangASTContext::GetChildCompilerTypeAtIndex(
     }
     break;
 
-  case clang::Type::Pointer:
-    if (idx_is_valid) {
+  case clang::Type::Pointer: {
     CompilerType pointee_clang_type(GetPointeeType(type));
 
     // Don't dereference "void *" pointers
@@ -6787,8 +6786,8 @@ CompilerType ClangASTContext::GetChildCompilerTypeAtIndex(
         return pointee_clang_type;
       }
     }
-    }
     break;
+  }
 
   case clang::Type::LValueReference:
   case clang::Type::RValueReference: