[Patch] Fortran: %re/%im fixes for OpenMP/OpenACC + gfc_is_simplify_contiguous

[Tobias Burnus <tobias@codesourcery.com>]

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Found when looking at Julian's 3/4 OpenACC patch, which has not
yet been committed (and needs still to be revised a bit.)

The fix (a) avoids an ICE when Julian's patch has been applied.
The patch (b) just makes one error message less confusing.

The testcase shows that only %re/%im run reach the new code as
%kind/%len are != EXPR_VARIABLE. (The error message is slightly
misleading if the 'list item'/'var' is not a variable.)


(a) We need to handle REF_INQUIRY gfc_is_simplify_contiguous.

That function is used for 'is_contiguous(a(:)%re)', but it works
without this patch and simplifies already to .false.
And it is used in openmp.c, which can ICE without this patch.

(b) Just makes the error message nicer - as only EXPR_VARIABLE
reaches that code, only %re and %im are mentioned in the
error message.

(Actually, it is not completely clear whether %re/%im are invalid
or not; I think they should be – but one can argue otherwise.
For OpenMP I just saw that it is tacked internally in Issue 2661,
for OpenACC it is tracked as Issue 346 – but neither has been
discussed, yet.)

OK for mainline?

Tobias

PS: '%re'/'%im' permit accessing the real/imaginary part of a
complex variable as lvalue (in the C++ sense) and also permit
"var(:)%re = 1.0", which real(z) or imag(z) does not permit.

var%kind == kind(var), but derived types also permit
parameterized derived types (PDT), which can use '%foo' for respective
'len' and 'kind' components.

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Fortran: %re/%im fixes for OpenMP/OpenACC + gfc_is_simplify_contiguous

gcc/fortran/ChangeLog:

	* expr.c (gfc_is_simplify_contiguous): Handle REF_INQUIRY, i.e.
	%im and %re which are EXPR_VARIABLE.
	* openmp.c (resolve_omp_clauses): Diagnose %re/%im explicitly.

gcc/testsuite/ChangeLog:

	* gfortran.dg/goacc-gomp/ref_inquiry.f90: New test.

 gcc/fortran/expr.c                                 |  2 ++
 gcc/fortran/openmp.c                               |  8 +++++
 .../gfortran.dg/goacc-gomp/ref_inquiry.f90         | 42 ++++++++++++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 4f456fc629a..92a6700568d 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -5854,6 +5854,8 @@ gfc_is_simply_contiguous (gfc_expr *expr, bool strict, bool permit_element)
 	part_ref  = ref;
       else if (ref->type == REF_SUBSTRING)
 	return false;
+      else if (ref->type == REF_INQUIRY)
+	return false;
       else if (ref->u.ar.type != AR_ELEMENT)
 	ar = &ref->u.ar;
     }
diff --git a/gcc/fortran/openmp.c b/gcc/fortran/openmp.c
index 797f6c86b62..f0307c801a5 100644
--- a/gcc/fortran/openmp.c
+++ b/gcc/fortran/openmp.c
@@ -5219,6 +5219,14 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 				&& array_ref->next->type == REF_SUBSTRING)))
 		      gfc_error ("Unexpected substring reference in %s clause "
 				 "at %L", name, &n->where);
+		    else if (array_ref && array_ref->type == REF_INQUIRY)
+		      {
+			gcc_assert (array_ref->u.i == INQUIRY_RE
+				    || array_ref->u.i == INQUIRY_IM);
+			gfc_error ("Unexpected complex-parts designator "
+				   "reference in %s clause at %L",
+				   name, &n->where);
+		      }
 		    else if (!resolved
 			|| n->expr->expr_type != EXPR_VARIABLE
 			|| array_ref->next
diff --git a/gcc/testsuite/gfortran.dg/goacc-gomp/ref_inquiry.f90 b/gcc/testsuite/gfortran.dg/goacc-gomp/ref_inquiry.f90
new file mode 100644
index 00000000000..f92a6632af9
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/goacc-gomp/ref_inquiry.f90
@@ -0,0 +1,42 @@
+implicit none
+type t
+  integer :: i
+  character :: c
+  complex :: z
+end type t
+
+integer :: i
+character(kind=4, len=5) :: c
+complex :: z, zz(5)
+type(t) :: x
+
+print *, is_contiguous(zz(:)%re)
+
+! EXPR_VARIABLE / Cf. also OpenMP spec issue 2661
+!$omp target enter data map(to: z%re)    ! { dg-error "Unexpected complex-parts designator" }
+!$omp target enter data map(to: z%im)    ! { dg-error "Unexpected complex-parts designator" }
+!$omp target enter data map(to: x%z%re)  ! { dg-error "Unexpected complex-parts designator" }
+!$omp target enter data map(to: x%z%im)  ! { dg-error "Unexpected complex-parts designator" }
+
+! Fails differently as it is not a variable (EXPR_VARIABLE)
+!$omp target enter data map(to: i%kind, c%len)     ! { dg-error "not a proper array section" }
+!$omp target enter data map(to: x%i%kind, x%c%len) ! { dg-error "not a proper array section" }
+
+! Likewise for OpenACC
+!$acc enter data copyin(i%kind, c%len)     ! { dg-error "not a proper array section" }
+!$acc enter data copyin(x%i%kind)          ! { dg-error "not a proper array section" }
+!$acc enter data copyin(x%c%len)           ! { dg-error "not a proper array section" }
+!$acc update self(i%kind, c%len)           ! { dg-error "not a proper array section" }
+!$acc update self(x%i%kind)                ! { dg-error "not a proper array section" }
+!$acc update self(x%c%len)                 ! { dg-error "not a proper array section" }
+
+! EXPR_VARIABLE / cf. OpenACC spec issue 346
+!$acc enter data copyin(z%re)   ! { dg-error "Unexpected complex-parts designator" }
+!$acc enter data copyin(z%im)   ! { dg-error "Unexpected complex-parts designator" }
+!$acc enter data copyin(x%z%re) ! { dg-error "Unexpected complex-parts designator" }
+!$acc enter data copyin(x%z%im) ! { dg-error "Unexpected complex-parts designator" }
+!$acc update self(z%re)         ! { dg-error "Unexpected complex-parts designator" }
+!$acc update self(z%im)         ! { dg-error "Unexpected complex-parts designator" }
+!$acc update self(zz%re)
+!$acc update self(zz%im)
+end