When using --mlir-debug-counter=pass-execution-skip=N, the MLIR debug
counter can skip the internal PDL-to-PDLInterp lowering pass that runs
inside FrozenRewritePatternSet's constructor. This caused an assertion
failure in PDLByteCode::Generator::generate() because the PDL module
wasn't properly converted to the interpreter dialect.
The fix adds a check after the PDL lowering pipeline runs to verify that
the expected matcher function symbol was produced. If the symbol is
absent (e.g., because the lowering was skipped by a debug counter),
bytecode generation is skipped entirely and PDL patterns are not
applied. This allows debug counter bisection to work without crashing.
Fixes#131441Fixes#128342
Assisted-by: Claude Code
5e3202749a