Implement cDAC method definition enumeration by address

[Copilot]

Implements StartEnumMethodDefinitionsByAddress, EnumMethodDefinitionByAddress, and EndEnumMethodDefinitionsByAddress for ClrDataProcess.

• Enumeration
  • Resolves method definitions from module metadata and original IL addresses.
  • Matches legacy DAC behavior for tiny and fat method headers.
• Interop conventions
  • Manages enumeration handles and child-object delegation.
  • Maps exceptions to HRESULTs and cross-validates results against the legacy DAC in debug builds.
• Coverage
  • Covers valid, empty, invalid, boundary, tiny-header, and fat-header cases across target architectures.

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[Copilot]

Copilot's findings

Comments suppressed due to low confidence (1)

src/native/managed/cdac/tests/UnitTests/IXCLRDataProcessTests.cs:326

• For tiny headers, the first address outside the IL stream is codeStart + codeSize (i.e., FirstHeaderAddress + 1 + TinyCodeSize). With TinyCodeSize = 3, FirstHeaderAddress + 3 is still inside the IL code range if you start from +1, so this boundary test should use FirstHeaderAddress + 4.

            hr = process.StartEnumMethodDefinitionsByAddress(FirstHeaderAddress + 3, &handle);
            Assert.Equal(HResults.S_OK, hr);
            try
            {
                DacComNullableByRef<IXCLRDataMethodDefinition> methodOut = new(isNullRef: false);
                Assert.Equal(HResults.S_FALSE, process.EnumMethodDefinitionByAddress(&handle, methodOut));
            }

• Files reviewed: 2/2 changed files
• Comments generated: 2

[Copilot]

Copilot's findings

Comments suppressed due to low confidence (1)

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.IXCLRDataProcess.cs:1654

• The tiny-header case uses a 0-byte adjustment for the address filter (vs headerSize). That matches the legacy DAC’s 4 * COR_ILMETHOD_DECODER::GetSize() behavior (where GetSize() is 0 for tiny), but it’s counterintuitive vs ECMA-335 and easy to “fix” incorrectly later. Add a short comment explaining the legacy parity requirement to preserve intent.

            bool isTinyHeader = headerSize == sizeof(byte);
            uint codeStartOffset = isTinyHeader ? 0 : (uint)headerSize;
            ClrDataAddress codeStart = (ilHeader + codeStartOffset).ToClrDataAddress(_target);

• Files reviewed: 2/2 changed files
• Comments generated: 0 new

[azure-pipelines]

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12 pipeline(s) were filtered out due to trigger conditions.
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[Copilot]

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Copilot]

Copilot's findings

Comments suppressed due to low confidence (1)

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.IXCLRDataProcess.cs:1612

• GCHandle.Target can throw InvalidOperationException when the handle value is not an allocated GCHandle (e.g., random/garbage non-zero handle), which would return COR_E_INVALIDOPERATION instead of E_INVALIDARG. Add an IsAllocated guard before accessing Target so invalid EndEnum handles consistently map to E_INVALIDARG.

            GCHandle gcHandle = GCHandle.FromIntPtr((IntPtr)handle);
            if (gcHandle.Target is not ProcessEnum<MethodDefinitionInfo> methodDefinitionsLocal)
                throw new ArgumentException("Invalid enumeration handle", nameof(handle));

• Files reviewed: 3/3 changed files
• Comments generated: 1