tree 3e7d751b30cf1bc5196729e4ee7ed4cfbf401d5c
parent d9e86b368ed49a36b64c9a863e1138925752c7e0
author Peter Steinfeld <psteinfeld@nvidia.com> 1613165338 -0800
committer Copybara-Service <copybara-worker@google.com> 1613725402 -0800

[flang] Detect circularly defined procedures

It's possible to define a procedure that has a procedure dummy argument which
names the procedure that contains it.  This was causing the compiler to fall
into an infinite loop when characterizing a call to the procedure.

Following a suggestion from Peter, I fixed this be maintaining a set of
procedure symbols that had already been seen while characterizing a procedure.
This required passing a new parameter to the functions that characterized a
Procedure, a DummyArgument, and a DummyProcedure.

I also added several tests that will crash the compiler without this change.

Differential Revision: https://reviews.llvm.org/D96631

GitOrigin-RevId: 77dc203cd0f65a8dbd71f3814e0cc3199c791980