WIP: cDAC AMD64-only calling-convention port + ByRefLike walker + Win-x64 CallSiteLayout dump tests [NO-REVIEW]#128488
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Recovered from a dangling git stash that was previously lost. Includes: - Per-arch ArgIterator port under src/native/managed/cdac/.../Contracts/CallingConvention/ (X86, AMD64-Unix, AMD64-Windows, Arm32, Arm64, RiscV64+LoongArch64) atop ArgIteratorBase / ArgIteratorData / ArgIteratorFactory / TransitionBlockLayout. - New ICallingConvention contract and CallingConvention_1 implementation that drives the iterators from a decoded signature. - New data descriptor entries for TransitionBlock + ArgumentRegisters (src/coreclr/vm/datadescriptor/datadescriptor.inc, src/coreclr/vm/class.h). - GcScanner refactored to consume CallSiteLayout for caller-stack promotion; CallingConvention contract fetched lazily so stack-walk tests that do not register it still work. - Test suite under src/native/managed/cdac/tests/CallingConvention/ covering 214 per-arch cases, plus MockDescriptors.CallingConvention support and RuntimeTypeSystemGetVectorSizeTests. Post-recovery cleanup applied on top of the original stash: - Files relocated from Contracts/StackWalk/CallingConvention/ to Contracts/CallingConvention/; helper namespace renamed to Contracts.CallingConventionHelpers (matches Contracts/GCInfo/ pattern). - Collapsed the abstract AMD64UnixArgIterator + CdacAMD64UnixArgIterator pair into a single concrete AMD64UnixArgIterator. - Dropped vestigial extraObjectFirstArg / extraFunctionPointerArg ctor parameters that were never set to true in any caller. - Fixed API drift vs. current origin/main (GenericContextLoc-based check, non-generic ArgIterator types, Target.FieldInfo.TypeName). Builds cdac.slnx clean (0 errors, 0 warnings). Test result: 2469 passed, 0 failed, 16 skipped. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
- Add IRuntimeTypeSystem.EnumerateInstanceFieldDescs and LookupApproxFieldTypeHandle primitives - Implement GcRefEnumeration.EnumerateByRefLikeRoots walker (recursive field scan) - Update CallingConvention_1.ComputeValueTypeHandle to populate handle for ByRefLike args - GcScanner.ReportArgument dispatches to ByRefLike walker via rts.IsByRefLike - Consolidate duplicate LookupApproxFieldTypeHandle/ResolveFieldTypeHandle helpers - Add unit tests for ByRefLike dispatch in GcScannerReportArgumentTests Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Rebuild the CallSiteLayout debuggee as a 54-frame deep chain that
exercises every interesting AMD64 calling-convention shape (categories
A-H: empty/int/double argbanks, mixed reg banks, managed ref args,
small/large value types, ByRefLike + Span<T>, instance/retbuf/generic/
vararg specials, Vector64/128/256/512, composite kitchen-sink frames).
All 54 frames stay live to Environment.FailFast so a single dump
captures the whole matrix on the FailFast thread.
Replace CallSiteLayoutDumpTests with:
- CallSiteLayoutDumpTestsBase: shared DumpTestBase subclass providing
CollectChainMethods / LayoutFor / AssertSingle{ByRef,ByValueVT,
ManagedRef} helpers.
- CallSiteLayoutDumpTests_WinX64: 46 [ConditionalTheory] tests gated
by [SkipOnOS=windows], [SkipOnArch=x64], [SkipOnVersion=net10.0]
asserting the explicit Win-x64 layout (IsPassedByRef, slot offsets,
ValueTypeHandle populated/null) for every frame.
The tests are expectation-snapshots derived from the AMD64 Windows ABI.
They pin cDAC ICallingConvention.ComputeCallSiteLayout output to the
hand-derived spec. Independent ground-truth validation via SOS
!clrstack -gc + transition frames is a tracked follow-up; the current
SOS path exercises ComputeCallSiteLayout only on InlinedCallFrames.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Trim the v3 calling-convention port down to AMD64 (Windows + SysV/Unix) to keep the PR surface area small while we iterate on the design and SOS-parity validation. Removed: - Per-arch iterators: X86ArgIterator, Arm32ArgIterator, Arm64ArgIterator, RiscV64LoongArch64ArgIterator. - Per-arch unit tests: X86CallingConventionTests, Arm32CallingConventionTests, Arm64CallingConventionTests. - Non-AMD64 entries in CallConvCases (X86, Arm32, Arm64Windows, Arm64Apple, LoongArch64, RiscV64). - Reference to X86CallingConventionTests from the harness comment. Kept: - AMD64WindowsArgIterator + AMD64UnixArgIterator + SystemVStructClassifier. - Shared infrastructure (ArgIteratorBase, ArgIteratorData, ArgIteratorFactory, TransitionBlockLayout, ArgTypeInfo, ArgTypeInfoSignatureProvider, CallingConvention_1). - AMD64WindowsCallingConventionTests + AMD64UnixCallingConventionTests + the cross-arch CallingConventionTests harness. - ByRefLike walker + 46 Win-x64 CallSiteLayout dump tests (unchanged). ArgIteratorFactory.Create now throws NotSupportedException for any architecture other than X64. Other arches will be reintroduced incrementally on follow-up branches once the AMD64 surface is reviewed and merged. Tests: 2463 passed, 0 failed, 16 skipped (down from 2558 = removed 95 non-AMD64 unit tests). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
These were per-arch ABI notes used while drafting the calling-convention port. Now that v4 is AMD64-only and the relevant content lives in the AMD64 unit tests and dump-test expectations, the folder is no longer needed. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Contributor
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Tagging subscribers to this area: @steveisok, @tommcdon, @dotnet/dotnet-diag |
Severely cut down on the doc comments added in this branch. The code is WIP and the comments will be reintroduced (much more focused) once the shape stabilizes. This removes ~700 lines of /// summary/remarks/list blocks from new calling-convention iterators, contracts, tests, and the dump-test debuggee, plus the doc comments added on top of existing modified files (ContractRegistry, IRuntimeTypeSystem, RuntimeTypeSystem_1, GcScanner, DumpTestHelpers, SkipOnArchAttribute). Pre-existing doc comments on those files are preserved. Tests: 2463 passed, 0 failed, 16 skipped. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Match the surrounding one-line `/// Gets an instance of the X contract for the target.` convention on `ContractRegistry.CallingConvention`. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
WIP planning artifact; not needed in the repo. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The previous strip removed lines on doc-comment blocks where my edits had expanded a pre-existing summary, leaving orphaned text. Restore: - SkipOnArchAttribute class summary back to origin/main verbatim (the strip removed the first two lines of the original summary). - GcScanner.ReportArgument: drop the empty <summary>/</summary> shell on this newly-added helper. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pull request overview
This PR adds a new cDAC calling-convention contract and supporting infrastructure so stack-walking/GC scanning can compute call-site layouts (incl. value-type decomposition and ByRefLike scanning) from decoded signatures, with expanded unit + dump-test coverage and updated CoreCLR data-descriptor entries required by the new logic.
Changes:
- Introduces
ICallingConvention+CallingConvention_1and AMD64 (Windows/SysV)ArgIteratorimplementations to computeCallSiteLayoutfrom signatures. - Refactors transition-frame GC root promotion to use
CallSiteLayout, adding embedded-ref enumeration for value types and a ByRefLike field-walker. - Extends the RTS contract and CoreCLR data descriptors (e.g.,
EEClass.BaseSizePadding, new globals) and adds new unit/dump tests plus ABI documentation.
Reviewed changes
Copilot reviewed 46 out of 46 changed files in this pull request and generated 5 comments.
Show a summary per file
| File | Description |
|---|---|
| src/native/managed/cdac/tests/RuntimeTypeSystemGetVectorSizeTests.cs | Adds unit tests for IRuntimeTypeSystem.GetVectorSize. |
| src/native/managed/cdac/tests/MockDescriptors/MockDescriptors.RuntimeTypeSystem.cs | Extends mock RTS to support new globals and EEClass padding. |
| src/native/managed/cdac/tests/MockDescriptors/MockDescriptors.CallingConvention.cs | Adds test helpers for TransitionBlock + FieldDesc + vector/valuetype MT setup. |
| src/native/managed/cdac/tests/MockDescriptors/Layout.cs | Allows negative field “offsets” in mock layout builder (ABI constant encoding). |
| src/native/managed/cdac/tests/MethodTableTests.cs | Adds contract type/globals for typedref + FEATURE_HFA and tests for IsHFA. |
| src/native/managed/cdac/tests/GcRefEnumerationTests.cs | Adds unit tests for value-type embedded-ref enumeration. |
| src/native/managed/cdac/tests/DumpTests/SkipOnArchAttribute.cs | Extends skip attribute to support include-only mode. |
| src/native/managed/cdac/tests/DumpTests/RunDumpTests.ps1 | Adds RuntimeConfiguration MSBuild property wiring. |
| src/native/managed/cdac/tests/DumpTests/DumpTestHelpers.cs | Adds GetTypeName helper for dump tests. |
| src/native/managed/cdac/tests/DumpTests/DumpTestBase.cs | Implements include-only skip semantics for dump-arch filtering. |
| src/native/managed/cdac/tests/DumpTests/Debuggees/CallSiteLayout/CallSiteLayout.csproj | Adds a new Windows-only dump-test debuggee project. |
| src/native/managed/cdac/tests/DumpTests/CallSiteLayoutDumpTestsBase.cs | Adds shared dump-test base for CallSiteLayout validation. |
| src/native/managed/cdac/tests/CallingConvention/TEST_INVENTORY.md | Adds coverage inventory for calling-convention tests. |
| src/native/managed/cdac/tests/CallingConvention/SyntheticVectorMetadata.cs | Adds synthetic metadata generator for intrinsic vector name/token tests. |
| src/native/managed/cdac/tests/CallingConvention/SignatureBlobBuilder.cs | Adds a signature-blob builder for stored-sig-based tests. |
| src/native/managed/cdac/tests/CallingConvention/CallingConventionTests.cs | Adds cross-arch contract invariants tests for ICallingConvention. |
| src/native/managed/cdac/tests/CallingConvention/CallingConventionTestHelpers.cs | Adds end-to-end harness to build mock targets + stored-sig methods. |
| src/native/managed/cdac/tests/CallingConvention/CallConvCases.cs | Defines AMD64 Windows/Unix test cases and TransitionBlock constants. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/RuntimeTypeSystemHelpers/MethodTableFlags_1.cs | Adds flag bits and accessors for HFA/ByRefLike/IntrinsicType. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/EEClass.cs | Adds BaseSizePadding to the managed EEClass data view. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/CoreCLRContracts.cs | Registers the new ICallingConvention contract. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/StackWalk/GC/GcTypeKind.cs | Splits GC kind classification into a dedicated helper. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/StackWalk/GC/GcScanner.cs | Switches transition-frame root reporting to be CallSiteLayout-driven. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/StackWalk/GC/GcRefEnumeration.cs | Adds embedded-ref enumeration + ByRefLike field-walk helpers. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/StackWalk/GC/GcSignatureTypeProvider.cs | Removes legacy signature-based GC classification provider. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/RuntimeTypeSystem_1.cs | Adds HFA/vector sizing, field enumeration APIs, and metadata reader helper. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/TransitionBlockLayout.cs | Adds descriptor-backed TransitionBlock layout reader. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/CallingConvention_1.cs | Implements signature decode + ArgIterator driving to compute CallSiteLayout. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgTypeInfoSignatureProvider.cs | Adds signature provider that resolves ArgTypeInfo directly. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgTypeInfo.cs | Adds type info model incl. HFA element sizing logic. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgIteratorFactory.cs | Adds per-arch iterator selection (currently X64 only). |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgIteratorData.cs | Adds shared iterator input model and SysV struct descriptor types. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgIteratorBase.cs | Adds shared iterator base for hidden args, sizing, retbuf policy. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/AMD64WindowsArgIterator.cs | Adds Windows AMD64 argument placement implementation. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/AMD64UnixArgIterator.cs | Adds SysV AMD64 argument placement + struct classification integration. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Constants.cs | Adds new globals names (FEATURE_HFA, typedref MT, etc.). |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/IRuntimeTypeSystem.cs | Adds new public RTS APIs (vector size, instance field bytes, field enumeration). |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/ICallingConvention.cs | Adds new public calling-convention contract + layout record types. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/ContractRegistry.cs | Adds CallingConvention contract accessor. |
| src/coreclr/vm/datadescriptor/datadescriptor.inc | Adds EEClass/BaseSizePadding field + new globals + CallingConvention contract. |
| src/coreclr/vm/class.h | Wires cdac_data<EEClass>::BaseSizePadding to m_cbBaseSizePadding. |
| cdac-calling-conventions/x86.md | Adds ABI documentation (x86). |
| cdac-calling-conventions/README.md | Adds doc index for per-arch calling conventions. |
| cdac-calling-conventions/arm64.md | Adds ABI documentation (ARM64). |
| cdac-calling-conventions/arm32.md | Adds ABI documentation (ARM32). |
| cdac-calling-conventions/amd64-windows.md | Adds ABI documentation (AMD64 Windows). |
| cdac-calling-conventions/amd64-unix.md | Adds ABI documentation (AMD64 SysV). |
Comments suppressed due to low confidence (1)
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CallingConvention/ArgTypeInfo.cs:206
- ComputeHfaElementSize() uses GetFieldDescList(current) and treats it as “the first field”. But EnumerateInstanceFieldDescs was added explicitly because statics can be intermixed in the FieldDesc array; GetFieldDescList can therefore point at a static field and misclassify the HFA element type/size. Suggest using EnumerateInstanceFieldDescs(current) and selecting the first instance field instead of assuming the first FieldDesc is an instance field.
}
}
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| // Validate that T (the element type) is a primitive type, matching the runtime check. | ||
| TypeHandle typeArg = GetInstantiation(typeHandle)[0]; | ||
| CorElementType elemType = GetSignatureCorElementType(typeArg); | ||
| bool isPrimitive = (elemType >= CorElementType.I1 && elemType <= CorElementType.R8) | ||
| || elemType == CorElementType.I | ||
| || elemType == CorElementType.U; | ||
| return isPrimitive ? vectorSize : 0; |
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| break; | ||
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| ILoader loader = target.Contracts.Loader; | ||
| ModuleHandle moduleHandle = loader.GetModuleHandleFromModulePtr(modulePtr); | ||
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| IEcmaMetadata ecmaMetadata = target.Contracts.EcmaMetadata; | ||
| MetadataReader? reader = ecmaMetadata.GetMetadata(moduleHandle); | ||
| if (reader is null) | ||
| return null; | ||
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| TypeDefinitionHandle typeDef = MetadataTokens.TypeDefinitionHandle((int)(token & 0x00FFFFFF)); | ||
| return reader.GetString(reader.GetTypeDefinition(typeDef).Name); | ||
| } | ||
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| /// <summary> | ||
| /// Resolves the method name for a <see cref="MethodDescHandle"/> using the | ||
| /// RuntimeTypeSystem, Loader, and EcmaMetadata contracts. Returns <c>null</c> |
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| NumThreadStaticFields = target.ReadField<ushort>(address, type, nameof(NumThreadStaticFields)); | ||
| FieldDescList = target.ReadPointerField(address, type, nameof(FieldDescList)); | ||
| NumNonVirtualSlots = target.ReadField<ushort>(address, type, nameof(NumNonVirtualSlots)); | ||
| BaseSizePadding = target.ReadField<byte>(address, type, nameof(BaseSizePadding)); |
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| int? VarArgCookieOffset, | ||
| IReadOnlyList<ArgLayout> Arguments); | ||
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| public interface ICallingConvention : IContract | ||
| { | ||
| static string IContract.Name { get; } = nameof(CallingConvention); |
3 tasks
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Author
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Closing -- outdated WIP. Will revisit if/when the AMD64 calling-convention + ByRefLike walker direction is picked up again. |
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This PR's content was generated with AI assistance (GitHub Copilot CLI). Please review carefully.
NO-REVIEW/ WIP - opened for experimentation and CI snapshots; please do not review.Scope
Slimmed alternative to #128487. This branch contains only the AMD64 (Windows + SysV/Unix) portion of the cDAC calling-convention port, plus the ByRefLike walker and the Win-x64
CallSiteLayoutdump tests. Other architectures (X86, Arm32, Arm64, RiscV64, LoongArch64) are removed and will be reintroduced incrementally on follow-up branches once the AMD64 surface is reviewed.Commits
e636a32- cDAC shared calling-convention port (per-arch ArgIterator base + AMD64 Windows/SysV variants +ICallingConventioncontract + per-arch unit tests).837a8b1- ByRefLike GC ref enumeration walker (GcRefEnumeration.EnumerateByRefLikeRoots) +IRuntimeTypeSystem.EnumerateInstanceFieldDescs+LookupApproxFieldTypeHandle+ scanner dispatch.55a4b12- 54-frameCallSiteLayoutdebuggee + 46 Win-x64 dump tests covering empty/int/double/mixed/ref/by-value VT/large VT/ByRefLike/special slot/vector/composite shapes.cc6395c- (v4 only) Trim per-arch iterators/tests for X86/Arm32/Arm64/RiscV64/LoongArch64 from the v3 surface.Validation status
local/jitCallSiteLayout.dmpafter rebuilding+republishingmscordaccore_universal.dllto the Release testhost.!clrstack -gcparity: byte-identical between legacy DAC and cDAC on the current debuggee, but a poison-pill experiment confirmed this comparison does not exerciseComputeCallSiteLayouton managed frames (only on transition frames, which the debuggee doesn't currently force). The Win-x64 tests are therefore expectation-snapshots derived from the AMD64 ABI table, not parity tests against the native DAC. A follow-up debuggee that puts each signature behind a[DllImport]/InlinedCallFrameis tracked in the plan.Relationship to #128487
Same parent commits (
e636a32,837a8b1,55a4b12); this branch just adds the AMD64-only trim commit on top. Reviewers can choose which surface to evaluate; we'll close the other one once a direction is picked.