[PATCH, OpenACC 2.7, v2] Implement host_data must have use_device clause requirement

[Chung-Lin Tang <chunglin.tang@siemens.com>]

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On 2023/6/16 5:13 PM, Thomas Schwinge wrote:
> OK with one small change, please -- unless there's a reason for doing it
> this way:
> 
>> --- a/gcc/fortran/trans-openmp.cc
>> +++ b/gcc/fortran/trans-openmp.cc
>> @@ -4677,6 +4677,12 @@ gfc_trans_oacc_construct (gfc_code *code)
>>       break;
>>        case EXEC_OACC_HOST_DATA:
>>       construct_code = OACC_HOST_DATA;
>> +     if (code->ext.omp_clauses->lists[OMP_LIST_USE_DEVICE] == NULL)
>> +       {
>> +         error_at (gfc_get_location (&code->loc),
>> +                   "%<host_data%> construct requires %<use_device%> clause");
>> +         return NULL_TREE;
>> +       }
>>       break;
>>        default:
>>       gcc_unreachable ();
> The OpenMP "must contain at least one [...] clause" checks are done in
> 'gcc/fortran/openmp.cc:resolve_omp_clauses'.  For consistency (or, to let
> 'gcc/fortran/trans-openmp.cc' continue to just deal with "directive
> translation"), do similar for OpenACC 'host_data'?  (..., and we later
> accordingly adjust 'gcc/fortran/openmp.cc:gfc_match_oacc_update', too?)

Hi Thomas,
I've adjusted the Fortran implementation as you described. Yes, I agree this way
more fits current Fortran FE conventions.

I've re-tested the attached v2 patch, will commit later this week if no major
objections.

Thanks,
Chung-Lin

gcc/c/ChangeLog:

	* c-parser.cc (c_parser_oacc_host_data): Add checking requiring OpenACC
	host_data construct to have an use_device clause.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_oacc_host_data): Add checking requiring OpenACC
	host_data construct to have an use_device clause.

gcc/fortran/ChangeLog:

	* openmp.cc (resolve_omp_clauses): Add checking requiring
	OpenACC host_data construct to have an use_device clause.

gcc/testsuite/ChangeLog:

	* c-c++-common/goacc/host_data-2.c: Adjust testcase.
	* gfortran.dg/goacc/host_data-error.f90: New testcase.
	* gfortran.dg/goacc/pr71704.f90: Adjust testcase.

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diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 24a6eb6e459..80920b31f83 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -18461,8 +18461,13 @@ c_parser_oacc_host_data (location_t loc, c_parser *parser, bool *if_p)
   tree stmt, clauses, block;
 
   clauses = c_parser_oacc_all_clauses (parser, OACC_HOST_DATA_CLAUSE_MASK,
-				       "#pragma acc host_data");
-
+				       "#pragma acc host_data", false);
+  if (!omp_find_clause (clauses, OMP_CLAUSE_USE_DEVICE_PTR))
+    {
+      error_at (loc, "%<host_data%> construct requires %<use_device%> clause");
+      return error_mark_node;
+    }
+  clauses = c_finish_omp_clauses (clauses, C_ORT_ACC);
   block = c_begin_omp_parallel ();
   add_stmt (c_parser_omp_structured_block (parser, if_p));
   stmt = c_finish_oacc_host_data (loc, clauses, block);
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 5e2b5cba57e..beb5b632e5e 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -45895,8 +45895,15 @@ cp_parser_oacc_host_data (cp_parser *parser, cp_token *pragma_tok, bool *if_p)
   unsigned int save;
 
   clauses = cp_parser_oacc_all_clauses (parser, OACC_HOST_DATA_CLAUSE_MASK,
-					"#pragma acc host_data", pragma_tok);
-
+					"#pragma acc host_data", pragma_tok,
+					false);
+  if (!omp_find_clause (clauses, OMP_CLAUSE_USE_DEVICE_PTR))
+    {
+      error_at (pragma_tok->location,
+		"%<host_data%> construct requires %<use_device%> clause");
+      return error_mark_node;
+    }
+  clauses = finish_omp_clauses (clauses, C_ORT_ACC);
   block = begin_omp_parallel ();
   save = cp_parser_begin_omp_structured_block (parser);
   cp_parser_statement (parser, NULL_TREE, false, if_p);
diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc
index 8efc4b3ecfa..f7af02845de 100644
--- a/gcc/fortran/openmp.cc
+++ b/gcc/fortran/openmp.cc
@@ -8764,6 +8764,12 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		   "%<MERGEABLE%> clause", &omp_clauses->detach->where);
     }
 
+  if (openacc
+      && code->op == EXEC_OACC_HOST_DATA
+      && omp_clauses->lists[OMP_LIST_USE_DEVICE] == NULL)
+    gfc_error ("%<host_data%> construct at %L requires %<use_device%> clause",
+	       &code->loc);
+
   if (omp_clauses->assume)
     gfc_resolve_omp_assumptions (omp_clauses->assume);
 }
diff --git a/gcc/testsuite/c-c++-common/goacc/host_data-2.c b/gcc/testsuite/c-c++-common/goacc/host_data-2.c
index b3093e575ff..862a764eb3a 100644
--- a/gcc/testsuite/c-c++-common/goacc/host_data-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/host_data-2.c
@@ -8,7 +8,9 @@ void
 f (void)
 {
   int v2 = 3;
-#pragma acc host_data copy(v2) /* { dg-error ".copy. is not valid for ..pragma acc host_data." } */
+#pragma acc host_data copy(v2)
+  /* { dg-error ".copy. is not valid for ..pragma acc host_data." "" { target *-*-* } .-1 } */
+  /* { dg-error ".host_data. construct requires .use_device. clause" "" { target *-*-* } .-2 } */
   ;
 
 #pragma acc host_data use_device(v2)
@@ -20,6 +22,9 @@ f (void)
   /* { dg-error ".use_device_ptr. variable is neither a pointer nor an array" "" { target c } .-1 } */
   /* { dg-error ".use_device_ptr. variable is neither a pointer, nor an array nor reference to pointer or array" "" { target c++ } .-2 } */
   ;
+
+#pragma acc host_data /* { dg-error ".host_data. construct requires .use_device. clause" } */
+  ;
 }
 
 
diff --git a/gcc/testsuite/gfortran.dg/goacc/host_data-error.f90 b/gcc/testsuite/gfortran.dg/goacc/host_data-error.f90
new file mode 100644
index 00000000000..bd262989410
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/goacc/host_data-error.f90
@@ -0,0 +1,6 @@
+! { dg-do compile }
+
+subroutine foo ()
+!$acc host_data ! { dg-error "'host_data' construct at .1. requires 'use_device' clause" }
+!$acc end host_data
+end
diff --git a/gcc/testsuite/gfortran.dg/goacc/pr71704.f90 b/gcc/testsuite/gfortran.dg/goacc/pr71704.f90
index 0235e85d42a..31724c8b046 100644
--- a/gcc/testsuite/gfortran.dg/goacc/pr71704.f90
+++ b/gcc/testsuite/gfortran.dg/goacc/pr71704.f90
@@ -47,8 +47,9 @@ real function f8 ()
   f8 = 1
 end
 
-real function f9 ()
-!$acc host_data
+real function f9 (a)
+  integer a(:)
+!$acc host_data use_device(a)
 !$acc end host_data
   f8 = 1
 end