[cdac] Add GetArrayData to Object contract, partially implement ISOSDacInterface::GetObjectData by elinor-fung · Pull Request #105534 · dotnet/runtime

elinor-fung · 2024-07-26T01:56:12Z

Add Array data descriptor
Add GetArrayData to Object contract
- Introduces a dependency on RuntimeTypeSystem contract
Make cDAC implement ISOSDacInterface::GetObjectData except for handling CCW/RCWs
- Returns E_NOTIMPL when runtime supports COM
- Validated in debugger that cDAC and DAC return the same values for some test single and multidimensional arrays
Pull out shared test helpers for adding different data to the mock target

Contributes to #99302

Ran SOS unit tests from the dotnet/diagnostics repo using a private build to replace the two latest runtimes (not the one that matches the sdk) used in the tests.

…data descriptor

dotnet-policy-service · 2024-07-26T01:56:44Z

Tagging subscribers to this area: @tommcdon
See info in area-owners.md if you want to be subscribed.

elinor-fung · 2024-07-26T22:14:22Z

src/native/managed/cdacreader/tests/MockDescriptors.cs

+    private static readonly Target.TypeInfo MethodTableTypeInfo = new()
+    {
+        Fields = {
+            { nameof(Data.MethodTable.MTFlags), new() { Offset = 4, Type = DataType.uint32}},
+            { nameof(Data.MethodTable.BaseSize), new() { Offset = 8, Type = DataType.uint32}},
+            { nameof(Data.MethodTable.MTFlags2), new() { Offset = 12, Type = DataType.uint32}},
+            { nameof(Data.MethodTable.EEClassOrCanonMT), new () { Offset = 16, Type = DataType.nuint}},
+            { nameof(Data.MethodTable.Module), new () { Offset = 24, Type = DataType.pointer}},
+            { nameof(Data.MethodTable.ParentMethodTable), new () { Offset = 40, Type = DataType.pointer}},
+            { nameof(Data.MethodTable.NumInterfaces), new () { Offset = 48, Type = DataType.uint16}},
+            { nameof(Data.MethodTable.NumVirtuals), new () { Offset = 50, Type = DataType.uint16}},
+            { nameof(Data.MethodTable.PerInstInfo), new () { Offset = 56, Type = DataType.pointer}},
+        }
+    };
+
+    private static readonly Target.TypeInfo EEClassTypeInfo = new Target.TypeInfo()
+    {
+        Fields = {
+            { nameof (Data.EEClass.MethodTable), new () { Offset = 8, Type = DataType.pointer}},
+            { nameof (Data.EEClass.CorTypeAttr), new () { Offset = 16, Type = DataType.uint32}},
+            { nameof (Data.EEClass.NumMethods), new () { Offset = 20, Type = DataType.uint16}},
+            { nameof (Data.EEClass.InternalCorElementType), new () { Offset = 22, Type = DataType.uint8}},
+            { nameof (Data.EEClass.NumNonVirtualSlots), new () { Offset = 24, Type = DataType.uint16}},
+        }
+    };


These were copied out of MethodTableTests

elinor-fung · 2024-07-26T22:14:51Z

src/native/managed/cdacreader/tests/MockDescriptors.cs

+        },
+    };
+
+    public static class RuntimeTypeSystem


With the exception of AddGlobalPointers and AddArrayClass, these were copied out of MethodTableTests

elinor-fung · 2024-07-26T22:17:00Z

src/native/managed/cdacreader/tests/MockDescriptors.cs

+        private static MockMemorySpace.Builder AddStringMethodTablePointer(TargetTestHelpers targetTestHelpers, MockMemorySpace.Builder builder)
+        {
+            MockMemorySpace.HeapFragment fragment = new() { Name = "Address of String Method Table", Address = TestStringMethodTableGlobalAddress, Data = new byte[targetTestHelpers.PointerSize] };
+            targetTestHelpers.WritePointer(fragment.Data, TestStringMethodTableAddress);
+            return builder.AddHeapFragments([
+                fragment,
+                new () { Name = "String Method Table", Address = TestStringMethodTableAddress, Data = new byte[targetTestHelpers.PointerSize] }
+            ]);
+        }
+
+        internal static MockMemorySpace.Builder AddObject(TargetTestHelpers targetTestHelpers, MockMemorySpace.Builder builder, TargetPointer address, TargetPointer methodTable)
+        {
+            MockMemorySpace.HeapFragment fragment = new() { Name = $"Object : MT = '{methodTable}'", Address = address, Data = new byte[targetTestHelpers.SizeOfTypeInfo(ObjectTypeInfo)] };
+            Span<byte> dest = fragment.Data;
+            targetTestHelpers.WritePointer(dest.Slice(ObjectTypeInfo.Fields["m_pMethTab"].Offset), methodTable);
+            return builder.AddHeapFragment(fragment);
+        }
+
+        internal static MockMemorySpace.Builder AddStringObject(TargetTestHelpers targetTestHelpers, MockMemorySpace.Builder builder, TargetPointer address, string value)
+        {
+            int size = targetTestHelpers.SizeOfTypeInfo(ObjectTypeInfo) + targetTestHelpers.SizeOfTypeInfo(StringTypeInfo) + value.Length * sizeof(char);
+            MockMemorySpace.HeapFragment fragment = new() { Name = $"String = '{value}'", Address = address, Data = new byte[size] };
+            Span<byte> dest = fragment.Data;
+            targetTestHelpers.WritePointer(dest.Slice(ObjectTypeInfo.Fields["m_pMethTab"].Offset), TestStringMethodTableAddress);
+            targetTestHelpers.Write(dest.Slice(StringTypeInfo.Fields["m_StringLength"].Offset), (uint)value.Length);
+            MemoryMarshal.Cast<char, byte>(value).CopyTo(dest.Slice(StringTypeInfo.Fields["m_FirstChar"].Offset));
+            return builder.AddHeapFragment(fragment);
+        }


These were copied out of ObjectTests

elinor-fung · 2024-07-26T22:28:12Z

src/coreclr/vm/object.h

+{
+    static constexpr size_t m_NumComponents = offsetof(ArrayBase, m_NumComponents);
+
+    static constexpr INT32* s_arrayBoundsZero = &ArrayBase::s_arrayBoundsZero;


I put this in here to expose the static without just making it public, but it is a bit weird to be under cdac_offsets. Do we want to rename offsets to something more general about cdac info? Or we could add something like a separate template<typename T> struct cdac_globals.

I think we should rename it. in #104999 Jeremy is adding some cdac_offsets<Foo>::NestedStructSize constants because Foo has a private NestedStruct.

We could just name it cdac<T> or data_contract<T>

Will rename to cdac<T> in a follow-up.

elinor-fung · 2024-07-26T22:29:20Z

src/coreclr/debug/daccess/request.cpp

+    // For an object pointer, this attempts to read the number of components.
+    // This expects that the first member after the MethodTable pointer (from Object)
+    // is a 32-bit integer representing the number of components.
+    // This holds for ArrayBase and StringObject - see coreclr/vm/object.h


Is there better / more explicit comments or doc that I could point to here?

elinor-fung added 9 commits July 23, 2024 19:47

Add Array class, object header size and zero array bounds globals to …

b5fae0c

…data descriptor

Call cDAC for GetObjectData

cdbbe94

Add GetArrayData to Object contract

8533532

Add comments to DACGetNumComponents

c4c9b6a

Implement ISOSDacInterface::GetObjectData - doesn't handle RCW/CCW

00eefee

Check COM interop feature flag

7c36b2c

Update doc

94e6aa3

Add tests

9f9a7e6

Pull out shared helpers from MethodTableTests

8077da9

ghost added the area-Diagnostics-coreclr label Jul 26, 2024

dotnet-policy-service bot assigned elinor-fung Jul 26, 2024

elinor-fung mentioned this pull request Jul 26, 2024

[cdac] Implement !PrintException #99302

Closed

25 tasks

elinor-fung requested review from AaronRobinsonMSFT and lambdageek July 26, 2024 01:57

elinor-fung commented Jul 26, 2024

View reviewed changes

lambdageek approved these changes Jul 29, 2024

View reviewed changes

elinor-fung merged commit 868d756 into dotnet:main Jul 29, 2024

elinor-fung deleted the cdac-object-data branch July 29, 2024 18:27

elinor-fung mentioned this pull request Jul 29, 2024

Rename cdac_offsets to cdac_data #105657

Merged

github-actions bot locked and limited conversation to collaborators Aug 30, 2024

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[cdac] Add GetArrayData to Object contract, partially implement ISOSDacInterface::GetObjectData#105534

[cdac] Add GetArrayData to Object contract, partially implement ISOSDacInterface::GetObjectData#105534
elinor-fung merged 9 commits intodotnet:mainfrom
elinor-fung:cdac-object-data

elinor-fung commented Jul 26, 2024 •

edited

Loading

Uh oh!

dotnet-policy-service bot commented Jul 26, 2024

Uh oh!

elinor-fung Jul 26, 2024

Uh oh!

elinor-fung Jul 26, 2024

Uh oh!

elinor-fung Jul 26, 2024

Uh oh!

elinor-fung Jul 26, 2024

Uh oh!

lambdageek Jul 27, 2024

Uh oh!

elinor-fung Jul 29, 2024

Uh oh!

elinor-fung Jul 26, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

elinor-fung commented Jul 26, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

dotnet-policy-service bot commented Jul 26, 2024

Uh oh!

elinor-fung Jul 26, 2024

Choose a reason for hiding this comment

Uh oh!

elinor-fung Jul 26, 2024

Choose a reason for hiding this comment

Uh oh!

elinor-fung Jul 26, 2024

Choose a reason for hiding this comment

Uh oh!

elinor-fung Jul 26, 2024

Choose a reason for hiding this comment

Uh oh!

lambdageek Jul 27, 2024

Choose a reason for hiding this comment

Uh oh!

elinor-fung Jul 29, 2024

Choose a reason for hiding this comment

Uh oh!

elinor-fung Jul 26, 2024

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

elinor-fung commented Jul 26, 2024 •

edited

Loading