fn sanity_check_via_rustc_peek<'tcx, A>(
tcx: TyCtxt<'tcx>,
cursor: ResultsCursor<'_, 'tcx, A>,
)where
A: RustcPeekAt<'tcx>,Expand description
This function scans mir for all calls to the intrinsic
rustc_peek that have the expression form rustc_peek(&expr).
For each such call, determines what the dataflow bit-state is for
the L-value corresponding to expr; if the bit-state is a 1, then
that call to rustc_peek is ignored by the sanity check. If the
bit-state is a 0, then this pass emits an error message saying
“rustc_peek: bit not set”.
The intention is that one can write unit tests for dataflow by
putting code into a UI test and using rustc_peek to
make observations about the results of dataflow static analyses.
(If there are any calls to rustc_peek that do not match the
expression form above, then that emits an error as well, but those
errors are not intended to be used for unit tests.)