[PATCH] D96631: [flang] Detect circularly defined procedures

[Pete Steinfeld via Phabricator via llvm-commits]

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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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D96631

Files:
  flang/include/flang/Evaluate/characteristics.h
  flang/lib/Evaluate/characteristics.cpp
  flang/test/Semantics/resolve100.f90

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