[Mono-bugs] [Bug 480093] New: Cannot inspect instance members: Cannot read 8 bytes from target memory at address 0x00000000

[bugzilla_noreply at novell.com]

https://bugzilla.novell.com/show_bug.cgi?id=480093


           Summary: Cannot inspect instance members: Cannot read 8 bytes
                    from target memory at address 0x00000000
    Classification: Mono
           Product: Mono: Debugger
           Version: SVN
          Platform: x86-64
        OS/Version: openSUSE 11.1
            Status: NEW
          Severity: Major
          Priority: P5 - None
         Component: backend
        AssignedTo: martin at novell.com
        ReportedBy: mhutchinson at novell.com
         QAContact: mono-bugs at lists.ximian.com
          Found By: ---


Using MonoDevelop to debug MonoDevelop, on Mono trunk, I set a breakpoint in
main/src/core/MonoDevelop.Projects/MonoDevelop.Projects.Formats.MSBuild/MSBuildProjectHandler.cs,
line 408.

I cannot inspect any instance members, though locals work. This seems to be be
due to the "Cannot read 8 bytes from target memory at address 0x00000000" error
when trying to access "this".

There are a number of errors in the terminal. I list them below.

One of:
UNKNOWN TYPE: MONO_TYPE_TYPEDBYREF

One of:
UNKNOWN TYPE: 78

Many of:
Cannot insert breakpoint 3: Location is invalid.

Many of:
Mono.Debugger.TargetMemoryException: Cannot read 8 bytes from target memory at
address 0x00000000
  at Mono.Debugger.Backend.Inferior.read_buffer (TargetAddress address, Int32
size) [0x00047] in /home/michael/mono/monohead/debugger/backend/Inferior.cs:880 
  at Mono.Debugger.Backend.Inferior.ReadLongInteger (TargetAddress address)
[0x0000c] in /home/michael/mono/monohead/debugger/backend/Inferior.cs:927 
  at Mono.Debugger.Backend.Inferior.ReadAddress (TargetAddress address)
[0x0003a] in /home/michael/mono/monohead/debugger/backend/Inferior.cs:944 
  at Mono.Debugger.Languages.Mono.MonoRuntime.MonoTypeGetData
(Mono.Debugger.TargetMemoryAccess memory, TargetAddress type) [0x00000] in
/home/michael/mono/monohead/debugger/languages/mono/MonoRuntime.cs:192 
  at (wrapper remoting-invoke-with-check)
Mono.Debugger.Languages.Mono.MonoRuntime:MonoTypeGetData
(Mono.Debugger.TargetMemoryAccess,Mono.Debugger.TargetAddress)
  at Mono.Debugger.Languages.Mono.MonoLanguageBackend.ReadType
(Mono.Debugger.TargetMemoryAccess memory, TargetAddress address) [0x00000] in
/home/michael/mono/monohead/debugger/languages/mono/MonoLanguageBackend.cs:506 
  at Mono.Debugger.Languages.Mono.MonoLanguageBackend.ReadGenericClass
(Mono.Debugger.TargetMemoryAccess memory, TargetAddress address, Boolean
handle_nullable) [0x0002b] in
/home/michael/mono/monohead/debugger/languages/mono/MonoLanguageBackend.cs:617 
  at Mono.Debugger.Languages.Mono.MonoLanguageBackend.ReadType
(Mono.Debugger.TargetMemoryAccess memory, MonoTypeEnum type, TargetAddress
data) [0x001bb] in
/home/michael/mono/monohead/debugger/languages/mono/MonoLanguageBackend.cs:591 
  at Mono.Debugger.Languages.Mono.MonoLanguageBackend.ReadType
(Mono.Debugger.TargetMemoryAccess memory, TargetAddress address) [0x0002a] in
/home/michael/mono/monohead/debugger/languages/mono/MonoLanguageBackend.cs:510 
  at (wrapper remoting-invoke-with-check)
Mono.Debugger.Languages.Mono.MonoLanguageBackend:ReadType
(Mono.Debugger.TargetMemoryAccess,Mono.Debugger.TargetAddress)
  at Mono.Debugger.Languages.Mono.MonoClassInfo.GetFields
(Mono.Debugger.TargetMemoryAccess target) [0x00076] in
/home/michael/mono/monohead/debugger/languages/mono/MonoClassInfo.cs:136 
  at Mono.Debugger.Languages.Mono.MonoClassInfo.<GetFields>m__3A
(Mono.Debugger.TargetMemoryAccess target) [0x00000] in
/home/michael/mono/monohead/debugger/languages/mono/MonoClassInfo.cs:153 
  at
Mono.Debugger.Backend.SingleSteppingEngine+<DoTargetAccess>c__AnonStorey5.<>m__8
(Mono.Debugger.Thread , System.Object ) [0x00000] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:812 
  at Mono.Debugger.Backend.SingleSteppingEngine+<Invoke>c__AnonStorey1C.<>m__22
(Mono.Debugger.Thread , System.Object ) [0x00000] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:1966 
  at Mono.Debugger.Backend.SingleSteppingEngine.SendCommand
(Mono.Debugger.TargetAccessDelegate target) [0x00022] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:627 
  at Mono.Debugger.Backend.SingleSteppingEngine.Invoke
(Mono.Debugger.TargetAccessDelegate func, System.Object data) [0x0001b] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:1965 
  at Mono.Debugger.Backend.ThreadManager.engine_thread_main () [0x00154] in
/home/michael/mono/monohead/debugger/backend/ThreadManager.cs:350 

A few of:
System.NullReferenceException: Object reference not set to an instance of an
object
  at DebuggerServer.ObjectUtil.GetTypeMembers (DebuggerServer.EvaluationContext
ctx, Mono.Debugger.Languages.TargetType t, Boolean staticOnly, Boolean
includeFields, Boolean includeProps, Boolean includeMethods, ReqMemberAccess
access) [0x00102] in
/home/michael/mono/monohead/monodevelop/extras/MonoDevelop.Debugger.Mdb/Mono.Debugging.Server.Mdb/ObjectUtil.cs:667 
  at DebuggerServer.Util+<GetMembers>c__Iterator1.MoveNext () [0x00027] in
/home/michael/mono/monohead/monodevelop/extras/MonoDevelop.Debugger.Mdb/Mono.Debugging.Server.Mdb/Util.cs:227 
  at DebuggerServer.Util.GetObjectValueChildren
(DebuggerServer.EvaluationContext ctx, Mono.Debugger.Languages.TargetObject
obj, Int32 firstItemIndex, Int32 count, Boolean dereferenceProxy) [0x00187] in
/home/michael/mono/monohead/monodevelop/extras/MonoDevelop.Debugger.Mdb/Mono.Debugging.Server.Mdb/Util.cs:147 
  at DebuggerServer.Util.GetObjectValueChildren
(DebuggerServer.EvaluationContext ctx, Mono.Debugger.Languages.TargetObject
obj, Int32 firstItemIndex, Int32 count) [0x00000] in
/home/michael/mono/monohead/monodevelop/extras/MonoDevelop.Debugger.Mdb/Mono.Debugging.Server.Mdb/Util.cs:120 
  at DebuggerServer.ValueReference.GetChildren (ObjectPath path, Int32 index,
Int32 count) [0x00000] in
/home/michael/mono/monohead/monodevelop/extras/MonoDevelop.Debugger.Mdb/Mono.Debugging.Server.Mdb/ValueReference.cs:148 

Several of:
Mono.Debugger.TargetException: Cannot access variables of type `System.Void'
  at Mono.Debugger.Languages.Mono.MonoVoidType.DoGetObject
(Mono.Debugger.TargetMemoryAccess target,
Mono.Debugger.Languages.TargetLocation location) [0x00000] in
/home/michael/mono/monohead/debugger/languages/mono/MonoVoidType.cs:72 
  at Mono.Debugger.Languages.TargetType.GetObject
(Mono.Debugger.TargetMemoryAccess target,
Mono.Debugger.Languages.TargetLocation location) [0x00000] in
/home/michael/mono/monohead/debugger/languages/TargetType.cs:86 
  at (wrapper remoting-invoke-with-check)
Mono.Debugger.Languages.TargetType:GetObject
(Mono.Debugger.TargetMemoryAccess,Mono.Debugger.Languages.TargetLocation)
  at Mono.Debugger.Languages.Mono.MonoVariable.GetObject
(Mono.Debugger.StackFrame frame, Mono.Debugger.TargetMemoryAccess target)
[0x0004c] in
/home/michael/mono/monohead/debugger/languages/mono/MonoVariable.cs:141 
  at Mono.Debugger.Languages.TargetVariable+<GetObject>c__AnonStorey2.<>m__4
(Mono.Debugger.TargetMemoryAccess target) [0x00000] in
/home/michael/mono/monohead/debugger/languages/TargetVariable.cs:46 
  at
Mono.Debugger.Backend.SingleSteppingEngine+<DoTargetAccess>c__AnonStorey5.<>m__8
(Mono.Debugger.Thread , System.Object ) [0x00000] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:812 
  at Mono.Debugger.Backend.SingleSteppingEngine+<Invoke>c__AnonStorey1C.<>m__22
(Mono.Debugger.Thread , System.Object ) [0x00000] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:1966 
  at Mono.Debugger.Backend.SingleSteppingEngine.SendCommand
(Mono.Debugger.TargetAccessDelegate target) [0x00022] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:627 
  at Mono.Debugger.Backend.SingleSteppingEngine.Invoke
(Mono.Debugger.TargetAccessDelegate func, System.Object data) [0x0001b] in
/home/michael/mono/monohead/debugger/backend/SingleSteppingEngine.cs:1965 
  at Mono.Debugger.Backend.ThreadManager.engine_thread_main () [0x00154] in
/home/michael/mono/monohead/debugger/backend/ThreadManager.cs:350

-- 
Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.