Dead code in ClrDataAccess::EnumMemoryRegionsWorkerCustom due to hardcoded eFlavor

[SnowCoderX]

Description

In ClrDataAccess::EnumMemoryRegionsWorkerCustom, the dump flavor selection logic is unreachable because the local variable eFlavor is explicitly hardcoded to DUMP_FLAVOR_Default.
The function contains logic for DUMP_FLAVOR_CriticalCLRState and DUMP_FLAVOR_NonHeapCLRState, but these branches can never be executed.

Reproduction Steps

Source: /src/coreclr/debug/daccess/enummem.cpp

Locate ClrDataAccess::EnumMemoryRegionsWorkerCustom.

Observe eFlavor = DUMP_FLAVOR_Default; at the beginning of the function.

Observe that eFlavor is never reassigned before the if/else if chain.

Code:

HRESULT ClrDataAccess::EnumMemoryRegionsWorkerCustom()
{
    // ...
    ECustomDumpFlavor eFlavor;
    eFlavor = DUMP_FLAVOR_Default; // Hardcoded value

    m_enumMemFlags = CLRDATA_ENUM_MEM_MINI;
    Flush();

    if (eFlavor == DUMP_FLAVOR_Mini) 
    {
        // Executed if DUMP_FLAVOR_Default == DUMP_FLAVOR_Mini
    }
    else if (eFlavor == DUMP_FLAVOR_CriticalCLRState) // ALWAYS UNREACHABLE
    {
        // ...
    }
    else if (eFlavor == DUMP_FLAVOR_NonHeapCLRState) // ALWAYS UNREACHABLE
    {
        // ...
    }
    // ...
}

Expected behavior

The eFlavor variable should be initialized from a dynamic source (such as the global g_ECustomDumpFlavor mentioned in the comments) or passed as a parameter, allowing the DAC to correctly execute different enumeration paths for different dump flavors.

Actual behavior

The variable is fixed to a constant value, making the logic for CriticalCLRState and NonHeapCLRState dead code. Static analysis tools (SVACE) flag these blocks as unreachable.

Regression?

No, this appears to be a long-standing issue or an incomplete implementation of the custom dump feature in the DAC.

Known Workarounds

None. It is currently impossible to trigger the non-default dump flavor paths through this worker.

Configuration

Target Framework: .NET / CoreCLR

Component: DAC (Data Access Component)

Architecture: All

Other information

Found by Linux Verification Center (linuxtesting.org) with SVACE.

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