[cDAC] Implement DacDbi API GetMetaDataFileInfoFromPEFile

[rcj1]

• Adding API

bool GetFileHeadersInfo(ModuleHandle handle, out uint timeStamp, out uint imageSize);

• Implement the DacDbi API.

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[Copilot]

Pull request overview

This PR updates the cDAC Loader contract to obtain module path information from PEAssembly/PEImage (including a diagnostic filename hint for in-memory modules) and adds PE header parsing (timestamp + SizeOfImage) to support implementing the DacDbi GetMetaDataFileInfoFromPEFile API in the legacy layer.

Changes:

• Replace GetPath(ModuleHandle) with GetPath(TargetPointer peAssemblyPtr, bool fallbackToHint = false) and add GetFileHeadersInfo(...) on ILoader.
• Move exported “path” data from Module to PEImage (Path + ModuleFileNameHint) and plumb native CDAC descriptors accordingly.
• Add/adjust unit + dump tests and update Loader contract documentation to reflect the new API shape.

Show a summary per file

File	Description
src/native/managed/cdac/tests/UnitTests/MockDescriptors/MockDescriptors.RuntimeMutableTypeSystem.cs	Removes mocked Module.Path field from layout.
src/native/managed/cdac/tests/UnitTests/MockDescriptors/MockDescriptors.Loader.cs	Removes mocked Module.Path plumbing and related builder inputs.
src/native/managed/cdac/tests/UnitTests/LoaderTests.cs	Adds tests + PE-image target builder for new Loader APIs.
src/native/managed/cdac/tests/DumpTests/LoaderDumpTests.cs	Updates dump test to call GetPath(GetPEAssembly(handle)).
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.cs	Updates legacy SOS path queries to use PEAssembly-based GetPath.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.cs	Implements GetMetaDataFileInfoFromPEFile using new Loader APIs.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataModule.cs	Updates module path/in-memory detection to use PEAssembly-based GetPath.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/PEImage.cs	Adds PEImage.Path + PEImage.ModuleFileNameHint fields to contract data.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/Module.cs	Removes Module.Path field from contract data.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/ImageOptionalHeader.cs	Adds SizeOfImage raw offset field.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/ImageFileHeader.cs	Adds TimeDateStamp raw offset field.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/Loader_1.cs	Implements new Loader APIs and removes GetPath(ModuleHandle).
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/ILoader.cs	Public interface change: adds new members and removes GetPath(ModuleHandle).
src/coreclr/vm/peimage.h	Exposes PEImage path + hint buffers via CDAC offsets.
src/coreclr/vm/datadescriptor/datadescriptor.inc	Removes Module.Path descriptor; adds PEImage.Path + ModuleFileNameHint.
src/coreclr/vm/ceeload.h	Removes cdac_data<Module>::Path offset.
src/coreclr/inc/sstring.h	Adds cdac_data<SString>::Buffer helper offset.
src/coreclr/inc/sbuffer.h	Adds friend access needed for cdac_data<SString> offset computation.
docs/design/datacontracts/Loader.md	Updates contract docs for new GetPath / GetFileHeadersInfo and data fields.

Copilot's findings

• Files reviewed: 19/19 changed files
• Comments generated: 7

[Copilot]

Copilot's findings

• Files reviewed: 24/24 changed files
• Comments generated: 5

[Copilot]

Copilot's findings

• Files reviewed: 24/24 changed files
• Comments generated: 4

[Copilot]

Copilot's findings

• Files reviewed: 24/24 changed files
• Comments generated: 3

[Copilot]

Copilot's findings

• Files reviewed: 24/24 changed files
• Comments generated: 5

[noahfalk]

LGTM modulo a few comments inline

[Copilot]

Copilot's findings

• Files reviewed: 19/19 changed files
• Comments generated: 6

[github-actions]

Copilot Code Review

Holistic Assessment

Motivation: Justified. This implements the GetMetaDataFileInfoFromPEFile DacDbi API in the cDAC, refactored from VMPTR_PEAssembly to VMPTR_Module (renamed to GetModuleMetaDataFileInfo). The module-level indirection simplifies callers and is architecturally sound since the caller always has a module, not a raw PEAssembly.

Approach: Sound. The new ILoader.GetFileHeadersInfo contract method follows established patterns (TryGetPEImage, FindNTHeaders), and the DacDbiImpl implementation correctly validates against legacy DAC in debug builds.

Summary: ⚠️ Needs Human Review. The implementation is correct and well-tested. Two advisory items warrant a human look: the path-fallback pattern is duplicated across three call sites, and the cDAC does not replicate the native COR header presence check inside GetFileHeadersInfo. Neither is blocking — the debug validation against the legacy DAC will catch any mismatch at runtime.

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Detailed Findings

Detailed Findings

✅ Contract implementation — GetFileHeadersInfo is correct

The new Loader_1.GetFileHeadersInfo properly:

• Initializes out parameters to 0 on all paths.
• Returns false for null PEImage, null loaded layout, and Webcil images (which lack NT headers).
• Reuses existing TryGetPEImage and FindNTHeaders helpers, consistent with sibling methods like TryGetLoadedImageContents and IsModuleMapped.
• PE header offsets are correct: TimeDateStamp at offset 4 in IMAGE_FILE_HEADER, SizeOfImage at offset 56 in IMAGE_OPTIONAL_HEADER (same for PE32 and PE32+).

✅ DacDbi interface change — API rename is safe

Per the cDAC instructions (.github/instructions/cdac.instructions.md), the DacDbi COM interface is internal and unstable for .NET 11 dev branches. The rename from GetMetaDataFileInfoFromPEFile(VMPTR_PEAssembly) to GetModuleMetaDataFileInfo(VMPTR_Module) is correctly propagated across the IDL, native C++ headers, and managed interface.

✅ Debug validation

The #if DEBUG block in DacDbiImpl.GetModuleMetaDataFileInfo correctly validates result, timestamp, image size, and path against the legacy DAC. This will catch behavioral divergences at runtime.

✅ Tests are well-structured

Three test cases cover the important scenarios:

• Happy path: timestamp and image size read correctly.
• Null loaded image layout: returns false with zeroed outputs.
• Webcil format: returns false with zeroed outputs.

The shared CreatePETarget helper correctly constructs a minimal PE image in memory using BinaryPrimitives.WriteUInt32LittleEndian at the real PE format offsets.

⚠️ Path-fallback pattern is duplicated — advisory

The try-GetPath → catch VirtualReadException → GetFileName → if-empty → GetFileName pattern now appears in three places:

1. DacDbiImpl.GetModulePath (line ~231)
2. DacDbiImpl.GetModuleMetaDataFileInfo (line ~3435)
3. ClrDataModule.GetFileName (line ~506)

Consider extracting this into a shared helper (e.g., GetBestAvailablePath(ModuleHandle)) to reduce duplication. This is advisory — not blocking for this PR, but worth considering as a follow-up.

💡 Design doc pseudocode diverges from implementation

Loader.md pseudocode for GetFileHeadersInfo uses TryGetLoadedImageContents and omits the Webcil format check. The actual implementation uses TryGetPEImage + explicit Webcil check (correctly, since Webcil lacks NT headers). Consider updating the pseudocode to reflect the Webcil guard, since it documents a real behavioral contract.

Note

This review was generated by GitHub Copilot.

Generated by Code Review for issue #129484 · ● 44.2M · ◷

[rcj1]

/ba-g #129820