Guard unknown ProfileFunctionId identities in the profiling report path

[Copilot]

Review feedback on the library-report mapping path: frames without an IRTextFunction carry a default ProfileFunctionId whose ModuleName/FunctionName are null, which flows into report keys and can throw ArgumentNullException during module-ID mapping (and creates unstable aggregation buckets). Two adapter signatures also disagreed with their actual null usage under <Nullable>enable</Nullable>.

ProfileData.ComputeProfile

• Normalize the frame's ProfileFunctionId before emitting a ResolvedFrame or a FunctionResolver entry, so both sides key off the same non-null identity:

var functionId = NormalizeFunctionId(details.FunctionId);
frames.Add(new ResolvedFrame(functionId, details.DebugInfo, frame.FrameRVA, ...));

// NormalizeFunctionId rebuilds via the ctor, which maps null -> string.Empty.

• The moduleIdByName lambda returns 0 for a null name rather than throwing from GetValueOrDefault.

ProfileReportMapper

• Only call moduleIdByName(id.ModuleName) when the name is non-null; unknown ids fall back to the "no module" id 0.
• resolveFunction is now Func<ProfileFunctionId, IRTextFunction?>, matching the XML doc and existing call sites (which already return null for unresolved/JIT frames). No call-site changes required.

RawProfileLibraryAdapters

• SymbolFileDescriptor? symbolFile (dereferenced with ?., passed null by callers and tests) and long[]? stackFrames / stackFrames_ (null for unknown stacks).

Note: the Core project can't be compiled in the Linux sandbox — ProfileExplorer.Profiling requires TlbImp.exe for the DIA interop — so these were verified by inspection.

[Copilot]

Pull request overview

This PR hardens the profiling report mapping pipeline against default(ProfileFunctionId) values (where ModuleName/FunctionName can be null), preventing nulls from flowing into report keys and module-ID mapping, and aligning adapter nullability annotations with actual runtime usage.

Changes:

• Normalize ProfileFunctionId in ProfileData.ComputeProfile before emitting ResolvedFrame entries and resolver keys, so aggregation/report keys are stable and non-null.
• Update ProfileReportMapper to allow resolveFunction to return null and to avoid calling moduleIdByName when the module name is null (mapping such frames to module id 0).
• Fix nullability in RawProfileLibraryAdapters for optional symbol file descriptors and optional stack frames.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/ProfileExplorerCore/Profile/Data/ProfileData.cs	Normalizes frame ProfileFunctionId before feeding the library profiler and adds a defensive module-id mapping lambda.
src/ProfileExplorerCore/Profile/Adapters/ProfileReportMapper.cs	Makes resolveFunction nullable and guards module-id mapping for null module names.
src/ProfileExplorerCore/Profile/Adapters/RawProfileLibraryAdapters.cs	Corrects nullability for optional stack frames and optional PDB identity data.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.