[PATCH v2 8/9] fortran: Support clobbering of allocatables and pointers [PR41453]

[Mikael Morin <mikael@gcc.gnu.org>]

This adds support for clobbering of allocatable and pointer scalar
variables passed as actual argument to a subroutine when the associated
dummy has the INTENT(OUT) attribute.
Support was explicitly disabled, but the clobber generation code seems
to support it well, as demonstrated by the newly added testcase.

	PR fortran/41453

gcc/fortran/ChangeLog:

	* trans-expr.cc (gfc_conv_procedure_call): Remove conditions
	on ALLOCATABLE and POINTER attributes guarding clobber
	generation.

gcc/testsuite/ChangeLog:

	* gfortran.dg/intent_optimize_7.f90: New test.
---
 gcc/fortran/trans-expr.cc                     |  2 -
 .../gfortran.dg/intent_optimize_7.f90         | 42 +++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/intent_optimize_7.f90

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 4491465c4d6..ae685157e22 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -6525,8 +6525,6 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
 			  && e->symtree
 			  && e->symtree->n.sym
 			  && !e->symtree->n.sym->attr.dimension
-			  && !e->symtree->n.sym->attr.pointer
-			  && !e->symtree->n.sym->attr.allocatable
 			  && e->ts.type != BT_CHARACTER
 			  && e->ts.type != BT_DERIVED
 			  && e->ts.type != BT_CLASS
diff --git a/gcc/testsuite/gfortran.dg/intent_optimize_7.f90 b/gcc/testsuite/gfortran.dg/intent_optimize_7.f90
new file mode 100644
index 00000000000..0146dff4e20
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/intent_optimize_7.f90
@@ -0,0 +1,42 @@
+! { dg-do run }
+! { dg-additional-options "-fno-inline -fno-ipa-modref -fdump-tree-optimized -fdump-tree-original" }
+!
+! PR fortran/41453
+! Check that the INTENT(OUT) attribute causes one clobber to be emitted in
+! the caller before each call to FOO in the *.original dump, and the
+! initialization constants to be optimized away in the *.optimized dump,
+! in the case of scalar allocatables and pointers.
+
+module x
+implicit none
+contains
+  subroutine foo(a)
+    integer, intent(out) :: a
+    a = 42
+  end subroutine foo
+end module x
+
+program main
+  use x
+  implicit none
+  integer, allocatable :: ca
+  integer, target :: ct
+  integer, pointer :: cp
+
+  allocate(ca)
+  ca = 123456789
+  call foo(ca)
+  if (ca /= 42) stop 1
+  deallocate(ca)
+
+  ct = 987654321
+  cp => ct
+  call foo(cp)
+  if (ct /= 42) stop 2
+end program main
+
+! { dg-final { scan-tree-dump-times "CLOBBER" 2 "original" } }
+! { dg-final { scan-tree-dump "\\*ca = {CLOBBER};" "original" } }
+! { dg-final { scan-tree-dump "\\*cp = {CLOBBER};" "original" } }
+! { dg-final { scan-tree-dump-not "123456789" "optimized" { target __OPTIMIZE__ } } }
+! { dg-final { scan-tree-dump-not "987654321" "optimized" { target __OPTIMIZE__ } } }
-- 
2.35.1