[MLIR][OpenMP] Add a new AutomapToTargetData conversion pass in FIR (#151989)

Add a new `AutomapToTargetData` pass. This gathers the declare target
enter variables which have the `AUTOMAP` modifier. And adds
`omp.declare_target_enter/exit` mapping directives for `fir.allocmem`
and `fir.freemem` oeprations on the `AUTOMAP` enabled variables.

Automap Ref: OpenMP 6.0 section 7.9.7.

1 files changed, 36 insertions, 0 deletions

diff --git a/offload/test/offloading/fortran/declare-target-automap.f90 b/offload/test/offloading/fortran/declare-target-automap.f90
new file mode 100644
index 000000000000..50e8c124c25f
--- /dev/null
+++ b/offload/test/offloading/fortran/declare-target-automap.f90
@@ -0,0 +1,36 @@
+!Offloading test for AUTOMAP modifier in declare target enter
+! REQUIRES: flang, amdgpu
+
+program automap_program
+   use iso_c_binding, only: c_loc
+   use omp_lib, only: omp_get_default_device, omp_target_is_present
+   integer, parameter :: N = 10
+   integer :: i
+   integer, allocatable, target :: automap_array(:)
+   !$omp declare target enter(automap:automap_array)
+
+   ! false since the storage is not present even though the descriptor is present
+   write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
+   ! CHECK: 0
+
+   allocate (automap_array(N))
+   ! true since the storage should be allocated and reference count incremented by the allocate
+   write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
+   ! CHECK: 1
+
+   ! since storage is present this should not be a runtime error
+   !$omp target teams loop
+   do i = 1, N
+      automap_array(i) = i
+   end do
+
+   !$omp target update from(automap_array)
+   write (*, *) automap_array
+   ! CHECK: 1 2 3 4 5 6 7 8 9 10
+
+   deallocate (automap_array)
+
+   ! automap_array should have it's storage unmapped on device here
+   write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
+   ! CHECK: 0
+end program