[all-commits] [llvm/llvm-project] 11140c: [mlir] mark ChangeResult as nodiscard (#76147)

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 11140cc238b8c4124e6f9efacb1601f81da096a0
      https://github.com/llvm/llvm-project/commit/11140cc238b8c4124e6f9efacb1601f81da096a0
  Author: Oleksandr "Alex" Zinenko <zinenko at google.com>
  Date:   2023-12-21 (Thu, 21 Dec 2023)

  Changed paths:
    M mlir/include/mlir/Analysis/DataFlowFramework.h
    M mlir/lib/Analysis/DataFlow/LivenessAnalysis.cpp
    M mlir/test/lib/Analysis/TestDataFlowFramework.cpp

  Log Message:
  -----------
  [mlir] mark ChangeResult as nodiscard (#76147)

This enum is used by dataflow analyses to indicate whether further
propagation is necessary to reach the fix point. Accidentally discarding
such a value will likely lead to propagation stopping early, leading to
incomplete or incorrect results. The most egregious example is the
duality between `join` on the analysis class, which triggers propagation
internally, and `join` on the lattice class that does not and expects
the caller to trigger it depending on the returned `ChangeResult`.