Hi All,

This bug emerged in a large code and involves possible recursion with a
"hidden" module procedure; ie. where the symtree name starts with '@'. This
throws the format decoder. As the last message in the PR shows, I have
vacillated between silently passing on the possible recursion or adding an
alternative warning message. In the end, as a conservative choice I went
for emitting the message.

In the course of trying to develop a compact test case, I found that type
bound procedures were not being tested for recursion and that class
dummies, with intent out, were being incorrectly initialized with an empty
default initializer. Both of these have been fixed.

Unfortunately, the most compact reproducer that Tomas was able to come up
with required more than 100kbytes of module files. I tried from the bottom
up but failed. Both the tests check the fixes for the other bugs.

Regtests on x86_64 - OK for mainline and, in a couple of weeks, 13-branch?

Paul

Fortran: Fix wrong recursive errors and class initialization [PR112407]

2024-03-30  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
PR fortran/112407
*resolve.cc (resolve_procedure_expression): Change the test for
for recursion in the case of hidden procedures from modules.
(resolve_typebound_static): Add warning for possible recursive
calls to typebound procedures.
* trans-expr.cc (gfc_trans_class_init_assign): Do not apply
default initializer to class dummy where component initializers
are all null.

gcc/testsuite/
PR fortran/112407
* gfortran.dg/pr112407a.f90: New test.
* gfortran.dg/pr112407b.f90: New test.