Query IDebugDataSpaces2/4 in the TTD adapter#1142
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DbgEngTTDAdapter::Start() creates its own IDebugClient7 and queries the interfaces it needs, but the base class only ever queries IDebugDataSpaces2 in ConnectToDebugServerInternal(), which the TTD adapter never goes through (it opens the trace with OpenDumpFile()). So m_debugDataSpaces2 stayed null for the whole TTD session and anything built on it silently did nothing -- GetMemoryMap() in particular returns early on a null check, so it never even called into dbgeng. Also query IDebugDataSpaces4 on both the live-debug and TTD paths. Unlike QueryVirtual, which is unimplemented for TTD replay targets, its GetValidRegionVirtual / GetNextDifferentlyValidOffsetVirtual / GetOffsetInformation do work on a trace and are useful for validating an address range. This does not fix the empty memory map widget (#1132): QueryVirtual fails on TTD targets regardless of whether the interface pointer is valid. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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July 24, 2026 18:28
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Fixes #1141.
DbgEngTTDAdapter::Start()creates its ownIDebugClient7and queries the interfaces it needs, butIDebugDataSpaces2was only ever queried by the base class inDbgEngAdapter::ConnectToDebugServerInternal()— a path the TTD adapter never takes, since it opens the trace withOpenDumpFile().m_debugDataSpaces2therefore stayednullptrfor the entire TTD session, and code depending on it silently did nothing instead of failing visibly.GetMemoryMap()is the reachable case: it returns early onif (!m_debugDataSpaces2), so under TTD it never called into dbgeng at all.This also queries
IDebugDataSpaces4on both the live-debug and TTD paths. UnlikeQueryVirtual,IDebugDataSpaces4'sGetValidRegionVirtual/GetNextDifferentlyValidOffsetVirtual/GetOffsetInformationdo work against a TTD trace and are useful for validating whether a given address range is present.What this does not do
It does not fix the empty memory map widget (#1132).
IDebugDataSpaces2::QueryVirtual— whichGetMemoryMap()walks — is unimplemented for TTD replay targets and returnsE_UNEXPECTEDeven for an address whose bytes read back fine. WinDbg's own!addressand!vprotare equally blank on a trace. Full analysis: #1132 (comment)So this is the latent half of that investigation: worth landing on its own so the interfaces are actually available and the null-pointer path stops masking real engine behavior.
Testing
IDebugDataSpaces2;IDebugDataSpaces4is purely additive.IDebugDataSpaces2andIDebugDataSpaces4were confirmed toQueryInterfacesuccessfully (S_OK) against a TTD trace using the pinned WinDbg'sdbgeng.dll(TTD 1.01.11, release 1.11.592.0), via a standalone harness. This matters becauseQUERY_DEBUG_INTERFACEthrows on failure — both interfaces are long-standing and were observed present.BN_API_PATHand no Qt 6.11.1, so the plugin was not compiled. The changes are 10 lines following the exact pattern of the adjacentQUERY_DEBUG_INTERFACE/SAFE_RELEASElines, but CI should be the real check.🤖 Generated with Claude Code