openmp: Improve Fortran Diagnostics for Linear Clause

This patch improves diagnostics for the linear clause,
providing a more accurate and intuitive recommendation
for remediation if the deprecated syntax is used.
Additionally updates the relevant test to reflect the
changed verbiage of the warning.

gcc/fortran/ChangeLog:

	* openmp.cc (gfc_match_omp_clauses): New diagnostic logic.

libgomp/ChangeLog:

	* testsuite/libgomp.fortran/pr84418-1.f90: Fix verbiage of
	dg-warning to reflect updated warning.

diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc
index dddb42f2d998c1ed21cd5f5d2ada428fe2d115ef..5823ac41fa51b515271a8a1015fe0223bac94099 100644 (file)
--- a/gcc/fortran/openmp.cc
+++ b/gcc/fortran/openmp.cc
@@ -3481,11 +3481,6 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
                  gfc_current_locus = old_loc;
                  break;
                }
-             if (old_linear_modifier)
-               gfc_warning (OPT_Wdeprecated_openmp,
-                            "Specification of the list items as arguments to "
-                            "the modifiers at %L is deprecated since "
-                            "OpenMP 5.2", &saved_loc);
              if (linear_op != OMP_LINEAR_DEFAULT)
                {
                  if (gfc_match (" :") == MATCH_YES)
@@ -3509,6 +3504,52 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
                      goto error;
                    }
                }
+             if (old_linear_modifier)
+               {
+                 char var_names[512]{};
+                 int count, offset = 0;
+                 for (gfc_omp_namelist *n = *head; n; n = n->next)
+                   {
+                     if (!n->next)
+                       count = snprintf (var_names + offset,
+                                         sizeof (var_names) - offset,
+                                         "%s", n->sym->name);
+                     else
+                       count = snprintf (var_names + offset,
+                                         sizeof (var_names) - offset,
+                                         "%s, ", n->sym->name);
+                     if (count < 0 || count >= ((int)sizeof (var_names))
+                                               - offset)
+                       {
+                         snprintf (var_names, 512, "%s, ..., ",
+                                   (*head)->sym->name);
+                         while (n->next)
+                           n = n->next;
+                         offset = strlen (var_names);
+                         snprintf (var_names + offset,
+                                   sizeof (var_names) - offset,
+                                   "%s", n->sym->name);
+                         break;
+                       }
+                     offset += count;
+                   }
+                 char *var_names_for_warn = var_names;
+                 const char *op_name;
+                 switch (linear_op)
+                   {
+                     case OMP_LINEAR_REF: op_name = "ref"; break;
+                     case OMP_LINEAR_VAL: op_name = "val"; break;
+                     case OMP_LINEAR_UVAL: op_name = "uval"; break;
+                     default: gcc_unreachable ();
+                   }
+                 gfc_warning (OPT_Wdeprecated_openmp,
+                              "Specification of the list items as "
+                              "arguments to the modifiers at %L is "
+                              "deprecated; since OpenMP 5.2, use "
+                              "%<linear(%s : %s%s)%>", &saved_loc,
+                              var_names_for_warn, op_name,
+                              step == nullptr ? "" : ", step(...)");
+               }
              else if (end_colon)
                {
                  bool has_error = false;

diff --git a/libgomp/testsuite/libgomp.fortran/pr84418-1.f90 b/libgomp/testsuite/libgomp.fortran/pr84418-1.f90
index 65dae5d0b0b06bd652736484d01f65774326ff30..b86dfe5d92ad426f4cf6cc9f9949cb4662eeea1a 100644 (file)
--- a/libgomp/testsuite/libgomp.fortran/pr84418-1.f90
+++ b/libgomp/testsuite/libgomp.fortran/pr84418-1.f90
@@ -3,6 +3,7 @@
 ! { dg-options "-fno-inline" }
 ! { dg-additional-options "-msse2" { target sse2_runtime } }
 ! { dg-additional-options "-mavx" { target avx_runtime } }
+! { dg-warning "Specification of the list items as arguments to the modifiers at \\(1\\) is deprecated; since OpenMP 5.2, use 'linear\\(x, y : ref\\)' \\\[-Wdeprecated-openmp\\\]" "" { target *-*-* } 24 }
 
   real :: a(1024), b(1024), c(1024)
   integer :: i
@@ -20,7 +21,7 @@
 contains
   real function foo (x, y)
     real :: x, y
-    !$omp declare simd linear (ref (x, y)) ! { dg-warning "Specification of the list items as arguments to the modifiers at \\(1\\) is deprecated since OpenMP 5.2 \\\[-Wdeprecated-openmp\\\]" }
+    !$omp declare simd linear (ref (x, y))
     foo = x + y
   end function
 end