openmp, fortran: Add support for OpenMP declare variant directive in Fortran

2021-10-14  Kwok Cheung Yeung  <kcy@codesourcery.com>

gcc/c-family/

	* c-omp.c (c_omp_check_context_selector): Rename to
	omp_check_context_selector and move to omp-general.c.
	(c_omp_mark_declare_variant): Rename to omp_mark_declare_variant and
	move to omp-general.c.

gcc/c/

	* c-parser.c (c_finish_omp_declare_variant): Change call from
	c_omp_check_context_selector to omp_check_context_selector. Change
	call from c_omp_mark_declare_variant to omp_mark_declare_variant.

gcc/cp/

	* decl.c (omp_declare_variant_finalize_one): Change call from
	c_omp_mark_declare_variant to omp_mark_declare_variant.
	* parser.c (cp_finish_omp_declare_variant): Change call from
	c_omp_check_context_selector to omp_check_context_selector.

gcc/fortran/

	* gfortran.h (enum gfc_statement): Add ST_OMP_DECLARE_VARIANT.
	(enum gfc_omp_trait_property_kind): New.
	(struct gfc_omp_trait_property): New.
	(gfc_get_omp_trait_property): New macro.
	(struct gfc_omp_selector): New.
	(gfc_get_omp_selector): New macro.
	(struct gfc_omp_set_selector): New.
	(gfc_get_omp_set_selector): New macro.
	(struct gfc_omp_declare_variant): New.
	(gfc_get_omp_declare_variant): New macro.
	(struct gfc_namespace): Add omp_declare_variant field.
	(gfc_free_omp_declare_variant_list): New prototype.
	* match.h (gfc_match_omp_declare_variant): New prototype.
	* openmp.c (gfc_free_omp_trait_property_list): New.
	(gfc_free_omp_selector_list): New.
	(gfc_free_omp_set_selector_list): New.
	(gfc_free_omp_declare_variant_list): New.
	(gfc_match_omp_clauses): Add extra optional argument.  Handle end of
	clauses for context selectors.
	(omp_construct_selectors, omp_device_selectors,
	omp_implementation_selectors, omp_user_selectors): New.
	(gfc_match_omp_context_selector): New.
	(gfc_match_omp_context_selector_specification): New.
	(gfc_match_omp_declare_variant): New.
	* parse.c: Include tree-core.h and omp-general.h.
	(decode_omp_directive): Handle 'declare variant'.
	(case_omp_decl): Include ST_OMP_DECLARE_VARIANT.
	(gfc_ascii_statement): Handle ST_OMP_DECLARE_VARIANT.
	(gfc_parse_file): Initialize omp_requires_mask.
	* symbol.c (gfc_free_namespace): Call
	gfc_free_omp_declare_variant_list.
	* trans-decl.c (gfc_get_extern_function_decl): Call
	gfc_trans_omp_declare_variant.
	(gfc_create_function_decl): Call gfc_trans_omp_declare_variant.
	* trans-openmp.c (gfc_trans_omp_declare_variant): New.
	* trans-stmt.h (gfc_trans_omp_declare_variant): New prototype.

gcc/

	* omp-general.c (omp_check_context_selector):  Move from c-omp.c.
	(omp_mark_declare_variant): Move from c-omp.c.
	(omp_context_name_list_prop): Update for Fortran strings.
	* omp-general.h (omp_check_context_selector): New prototype.
	(omp_mark_declare_variant): New prototype.

gcc/testsuite/

	* gfortran.dg/gomp/declare-variant-1.f90: New test.
	* gfortran.dg/gomp/declare-variant-10.f90: New test.
	* gfortran.dg/gomp/declare-variant-11.f90: New test.
	* gfortran.dg/gomp/declare-variant-12.f90: New test.
	* gfortran.dg/gomp/declare-variant-13.f90: New test.
	* gfortran.dg/gomp/declare-variant-14.f90: New test.
	* gfortran.dg/gomp/declare-variant-15.f90: New test.
	* gfortran.dg/gomp/declare-variant-16.f90: New test.
	* gfortran.dg/gomp/declare-variant-17.f90: New test.
	* gfortran.dg/gomp/declare-variant-18.f90: New test.
	* gfortran.dg/gomp/declare-variant-19.f90: New test.
	* gfortran.dg/gomp/declare-variant-2.f90: New test.
	* gfortran.dg/gomp/declare-variant-2a.f90: New test.
	* gfortran.dg/gomp/declare-variant-3.f90: New test.
	* gfortran.dg/gomp/declare-variant-4.f90: New test.
	* gfortran.dg/gomp/declare-variant-5.f90: New test.
	* gfortran.dg/gomp/declare-variant-6.f90: New test.
	* gfortran.dg/gomp/declare-variant-7.f90: New test.
	* gfortran.dg/gomp/declare-variant-8.f90: New test.
	* gfortran.dg/gomp/declare-variant-9.f90: New test.

libgomp/

	* testsuite/libgomp.fortran/declare-variant-1.f90: New test.

1 files changed, 26 insertions, 0 deletions

diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c
index 7d765a0..2a454be 100644
--- a/gcc/fortran/parse.c
+++ b/gcc/fortran/parse.c
@@ -26,6 +26,8 @@ along with GCC; see the file COPYING3.  If not see
 #include <setjmp.h>
 #include "match.h"
 #include "parse.h"
+#include "tree-core.h"
+#include "omp-general.h"
 
 /* Current statement label.  Zero means no statement label.  Because new_st
    can get wiped during statement matching, we have to keep it separate.  */
@@ -860,6 +862,8 @@ decode_omp_directive (void)
 	       ST_OMP_DECLARE_SIMD);
       matchdo ("declare target", gfc_match_omp_declare_target,
 	       ST_OMP_DECLARE_TARGET);
+      matchdo ("declare variant", gfc_match_omp_declare_variant,
+	       ST_OMP_DECLARE_VARIANT);
       break;
     case 's':
       matchs ("simd", gfc_match_omp_simd, ST_OMP_SIMD);
@@ -1718,6 +1722,7 @@ next_statement (void)
 
 #define case_omp_decl case ST_OMP_THREADPRIVATE: case ST_OMP_DECLARE_SIMD: \
   case ST_OMP_DECLARE_TARGET: case ST_OMP_DECLARE_REDUCTION: \
+  case ST_OMP_DECLARE_VARIANT: \
   case ST_OMP_REQUIRES: case ST_OACC_ROUTINE: case ST_OACC_DECLARE
 
 /* Block end statements.  Errors associated with interchanging these
@@ -2361,6 +2366,9 @@ gfc_ascii_statement (gfc_statement st)
     case ST_OMP_DECLARE_TARGET:
       p = "!$OMP DECLARE TARGET";
       break;
+    case ST_OMP_DECLARE_VARIANT:
+      p = "!$OMP DECLARE VARIANT";
+      break;
     case ST_OMP_DEPOBJ:
       p = "!$OMP DEPOBJ";
       break;
@@ -6793,6 +6801,24 @@ done:
        gfc_current_ns = gfc_current_ns->sibling)
     gfc_check_omp_requires (gfc_current_ns, omp_requires);
 
+  /* Populate omp_requires_mask (needed for resolving OpenMP
+     metadirectives and declare variant).  */
+  switch (omp_requires & OMP_REQ_ATOMIC_MEM_ORDER_MASK)
+    {
+    case OMP_REQ_ATOMIC_MEM_ORDER_SEQ_CST:
+      omp_requires_mask
+	= (enum omp_requires) (omp_requires_mask | OMP_MEMORY_ORDER_SEQ_CST);
+      break;
+    case OMP_REQ_ATOMIC_MEM_ORDER_ACQ_REL:
+      omp_requires_mask
+	= (enum omp_requires) (omp_requires_mask | OMP_MEMORY_ORDER_ACQ_REL);
+      break;
+    case OMP_REQ_ATOMIC_MEM_ORDER_RELAXED:
+      omp_requires_mask
+	= (enum omp_requires) (omp_requires_mask | OMP_MEMORY_ORDER_RELAXED);
+      break;
+    }
+
   /* Do the parse tree dump.  */
   gfc_current_ns = flag_dump_fortran_original ? gfc_global_ns_list : NULL;