1 files changed, 53 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/implicit_pure_1.f90 b/gcc/testsuite/gfortran.dg/implicit_pure_1.f90
new file mode 100644
index 00000000000..d4a5a364e59
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/implicit_pure_1.f90
@@ -0,0 +1,53 @@
+! { dg-do run }
+!
+! PR fortran/51218
+!
+! Contributed by Harald Anlauf
+!
+
+module a
+  implicit none
+  integer :: neval = 0
+contains
+  subroutine inc_eval
+    neval = neval + 1
+  end subroutine inc_eval
+end module a
+
+module b
+  use a
+  implicit none
+contains
+  function f(x) ! Should be implicit pure
+    real :: f
+    real, intent(in) :: x
+    f = x
+  end function f
+
+  function g(x) ! Should NOT be implicit pure
+    real :: g
+    real, intent(in) :: x
+    call inc_eval
+    g = x
+  end function g
+end module b
+
+program gfcbug114a
+  use a
+  use b
+  implicit none
+  real :: x = 1, y = 1, t, u, v, w
+  if (neval /= 0) call abort ()
+  t = f(x)*f(y)
+  if (neval /= 0) call abort ()
+  u = f(x)*f(y) + f(x)*f(y)
+  if (neval /= 0) call abort ()
+  v = g(x)*g(y)
+  if (neval /= 2) call abort ()
+  w = g(x)*g(y) + g(x)*g(y)
+  if (neval /= 6) call abort ()
+  if (t /= 1.0 .or. u /= 2.0 .or. v /= 1.0 .or. w /= 2) call abort ()
+end program gfcbug114a
+
+! { dg-final { scan-module "b" "IMPLICIT_PURE" } }
+! { dg-final { cleanup-modules "b" } }