Hi Jakub,
As Thomas reported and submitted a patch a while ago:
https://gcc.gnu.org/pipermail/gcc-patches/2019-April/519932.html
https://gcc.gnu.org/pipermail/gcc-patches/2019-May/522738.html

There's an issue with the Fortran front-end when mapping arrays: when
creating the data MEM_REF for the map clause, there's a convention of
casting the referencing pointer to 'c_char *' by
fold_convert (build_pointer_type (char_type_node), ptr).

This causes the alignment passed to the libgomp runtime for array data
hardwared to '1', and causes alignment errors on the offload target
(not always showing up, but can trigger due to slight change of clause
ordering)

This patch is not exactly Thomas' patch from 2019, but does the same
thing. The new libgomp tests are directly reused though. A lot of
scan test adjustment is also included in this patch.

Patch has been tested for no regressions for gfortran and libgomp, is
this okay for trunk?

Thanks,
Chung-Lin

Fortran: fix array alignment for OpenMP/OpenACC target mapping clauses [PR90030]

The Fortran front-end is creating maps of array data with a type of pointer to
char_type_node, which when eventually passed to libgomp during runtime, marks
the passed array with an alignment of 1, which can cause mapping alignment
errors on the offload target.

This patch removes the related fold_convert(build_pointer_type (char_type_node))
calls in fortran/trans-openmp.c, and adds gcc_asserts to ensure pointer type.

2021-11-04  Chung-Lin Tang  <cltang@codesourcery.com>
	    Thomas Schwinge <thomas@codesourcery.com>

	PR fortran/90030

gcc/fortran/ChangeLog:

	* trans-openmp.c (gfc_omp_finish_clause): Remove fold_convert to pointer
	to char_type_node, add gcc_assert of POINTER_TYPE_P.
	(gfc_trans_omp_array_section): Likewise.
	(gfc_trans_omp_clauses): Likewise.

gcc/testsuite/ChangeLog:

	* gfortran.dg/goacc/finalize-1.f: Adjust scan test.
	* gfortran.dg/gomp/affinity-clause-1.f90: Likewise.
	* gfortran.dg/gomp/affinity-clause-5.f90: Likewise.
	* gfortran.dg/gomp/defaultmap-4.f90: Likewise.
	* gfortran.dg/gomp/defaultmap-5.f90: Likewise.
	* gfortran.dg/gomp/defaultmap-6.f90: Likewise.
	* gfortran.dg/gomp/map-3.f90: Likewise.
	* gfortran.dg/gomp/pr78260-2.f90: Likewise.
	* gfortran.dg/gomp/pr78260-3.f90: Likewise.

libgomp/ChangeLog:

	* testsuite/libgomp.oacc-fortran/pr90030.f90: New test.
	* testsuite/libgomp.fortran/pr90030.f90: New test.