[all-commits] [llvm/llvm-project] 80f0dc: [clang][dataflow] Unsoundly treat "Unknown" as "Eq...

[Yitzhak Mandelbaum via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 80f0dc3aa4bf2097932fb789904c33d985767ecd
      https://github.com/llvm/llvm-project/commit/80f0dc3aa4bf2097932fb789904c33d985767ecd
  Author: Yitzhak Mandelbaum <yitzhakm at google.com>
  Date:   2023-09-07 (Thu, 07 Sep 2023)

  Changed paths:
    M clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
    M clang/unittests/Analysis/FlowSensitive/TransferTest.cpp

  Log Message:
  -----------
  [clang][dataflow] Unsoundly treat "Unknown" as "Equivalent" in widening.

This change makes widening act the same as equivalence checking. When the
analysis does not provide an answer regarding the equivalence of two distinct
values, the framework treats them as equivalent. This is an unsound choice that
enables convergence.

Differential Revision: https://reviews.llvm.org/D159355