Where possible, pass around a ClassDecl or a CanType instead of a
SILType that might wrap a metatype; the unwrapping logic was
repeated in several places.
Also add a FIXME for a bug I found by inspection.
* [SILOptimizer] Don't diagnose infinite recursion if a branch terminates the program
This patch augments the infinite recursion checker to not warn if a
branch terminates, but still warns if a branch calls into something with
@_semantics("programtermination_point"). This way, calling fatalError
doesn't disqualify you for the diagnostic, but calling exit does.
This also removes the warning workaround in the standard library, and
annotates the internal _assertionFailure functions as
programtermination_points, so they get this treatment too.
* Fix formatting in SILInstructions.cpp
* Re-add missing test
This patch augments the infinite recursion checker to not warn if a
branch terminates, but still warns if a branch calls into something with
`@_semantics("arc.programtermination_point")`. This way, calling `fatalError`
doesn't disqualify you for the diagnostic, but calling `exit` does.
This also removes the warning workaround in the standard library, and
annotates the internal _assertionFailure functions as
`programtermination_point`s, so they get this treatment too.
* [SILOptimizer] Clean up infinite recursion diagnostic pass
NFC. This cleans up the pass to avoid the extra lambda and to clear up
the ordering of what check is supposed to come before what.
* Address review comments
Add a new warning that detects when a function will call itself
recursively on all code paths. Attempts to invoke functions like this
may cause unbounded stack growth at least or undefined behavior in the
worst cases.
The detection code is implemented as DFS for a reachable exit path in
a given SILFunction.
