"Wasteful virtuals" "virtuals with no overrides" has false positives with multiple levels of inheritance

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
cpp, csharp
Domain
tooling

Research direction

Start by tracing the "wasteful virtuals" heuristic, especially the "virtuals with no overrides" list, using the A/B/C inheritance example in the issue. Reproduce the false positive and verify that A::DoStuff is no longer reported when an override exists through an intermediate derived class.

Written by the indexing model from the issue text.

Description

Describe the bug
I was using the "wasteful virtuals" heuristic to try and optimize a large binary. The "virtuals with no overrides" list specifically is easy gains. However, one of the methods flagged does have overrides and removing the virtual keyword introduced a build break.

On closer inspection the problem seems to be that the virtual method and the override has at least one other derived class in the middle.

The heirarchy is roughly as follows:

class A
{
public:
   virtual void DoStuff() { }
};

class B : public A
{ };

class C : public B
{
public:
    void DoStuff() override { }
};

In this case A::DoStuff is considered a wasteful virtual even though C::DoStuff overrides it. Removing the virtual keyword will introduce a build break.

Expected behavior
This method should not be considered wasteful.

Screenshots
N/A

Environment Details
OS is Windows 11.
SizeBench is latest version from the Store at this time (on a different device so I don't have the exact version handy).

Additional context
N/A

Dominant language
C#
Stars
175
Forks
20
PR merge metrics
No merged PRs in 30d

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