[PATCH] D43036: Use a stable topological sort instead of std::stable_sort in DIE *DwarfCompileUnit::createScopeChildrenDIE()

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added a comment.

In https://reviews.llvm.org/D43036#1001124, @vsapsai wrote:

> Sorting algorithm looks correct to me and in debugger it works as expected. I don't think we are going to visit `DbgVariable` more than 3 times so time complexity is reasonable too.
>
> There is a problem with `SmallDenseSet` size and other than that maybe improve testing? Some of the ideas: make variables in order "array, unrelated, vla_expr" to expose problem with std::stable_sort; have dependencies that aren't local variables (this can be already covered by other tests); have more than 8 local variables that is not a power of 2.


This really difficult because we can only very indirectly influence the order in which variables appear in the LexcicalScopes data structure from LLVM IR input. But I'll try!


https://reviews.llvm.org/D43036