openmp: Provide fixit hints for -Wdeprecated-openmp diagnostics from C++ FE

I think especially the linear clause -Wdeprecated-openmp diagnostics
will be complete nightmare for users, when they have
linear (ref (x, y, z))
or
linear (uval (a, b, c) : 2)
they will have no clue what the new syntax is.

Here is an attempt to provide fixit hints from the C++ FE for most
of these warnings, and even -fdiagnostics-generate-patch can then be
useful for porting.

2025-12-13  Jakub Jelinek  <jakub@redhat.com>

	* parser.cc (cp_parser_omp_clause_reduction): Provide fixit hints
	for -Wdeprecated-openmp diagnostics.
	(cp_parser_omp_clause_linear): Likewise.
	(cp_parser_omp_clause_depend): Likewise.
	(cp_parser_omp_clause_map): Likewise.  Reset num_commas after the
	diagnostics.
	(cp_parser_omp_clause_proc_bind): Provide fixit hints for
	-Wdeprecated-openmp diagnostics.
	(cp_parser_omp_all_clauses): Move -Wdeprecated-openmp diagnostics
	for to vs. enter here, add fixit hints for it.
	(cp_parser_omp_master):Add MASTER_LOC argument.  Provide fixit hints
	for -Wdeprecated-openmp diagnostics.
	(cp_parser_omp_parallel): Adjust cp_parser_omp_master caller.
	(cp_parser_omp_declare_target): Don't emit -Wdeprecated-openmp
	warning for to vs. enter here.
	(cp_parser_omp_metadirective): Provide fixit hints for
	-Wdeprecated-openmp diagnostics.
	(cp_parser_omp_construct): Adjust cp_parser_omp_master caller.

	* g++.dg/gomp/deprecate-1.C: New test.

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index a0acd9cf6f3eb95f356d6610b76d5326536fd7ee..214dababeb5551e50d85e44093b010c4cf961730 100644 (file)
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -42168,9 +42168,14 @@ cp_parser_omp_clause_reduction (cp_parser *parser, enum omp_clause_code kind,
     case CPP_MULT: code = MULT_EXPR; break;
     case CPP_MINUS:
       if (is_omp)
-       warning_at (cp_lexer_peek_token (parser->lexer)->location,
-                   OPT_Wdeprecated_openmp,
-                   "%<-%> operator for reductions deprecated in OpenMP 5.2");
+       {
+         location_t loc = cp_lexer_peek_token (parser->lexer)->location;
+         gcc_rich_location richloc (loc);
+         richloc.add_fixit_replace ("+");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
+                     "%<-%> operator for reductions deprecated in "
+                     "OpenMP 5.2");
+       }
       code = MINUS_EXPR;
       break;
     case CPP_AND: code = BIT_AND_EXPR; break;
@@ -43041,6 +43046,9 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
   bool colon;
   enum omp_clause_linear_kind kind = OMP_CLAUSE_LINEAR_DEFAULT;
   bool old_linear_modifier = false;
+  location_t mod_loc = UNKNOWN_LOCATION, after_colon_loc = UNKNOWN_LOCATION;
+  location_t rm1_loc = UNKNOWN_LOCATION, rm2_loc = UNKNOWN_LOCATION;
+  location_t close_loc = UNKNOWN_LOCATION;
 
   matching_parens parens;
   if (!parens.require_open (parser))
@@ -43059,12 +43067,12 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
        kind = OMP_CLAUSE_LINEAR_UVAL;
       if (cp_lexer_nth_token_is (parser->lexer, 2, CPP_OPEN_PAREN))
        {
+         mod_loc = cp_lexer_peek_token (parser->lexer)->location;
+         rm1_loc = make_location (mod_loc, mod_loc,
+                                  cp_lexer_peek_nth_token (parser->lexer,
+                                                           2)->location);
          cp_lexer_consume_token (parser->lexer);
          old_linear_modifier = true;
-         warning_at (cp_lexer_peek_token (parser->lexer)->location,
-                     OPT_Wdeprecated_openmp,
-                     "specifying the list items as arguments to the "
-                     "modifiers is deprecated since OpenMP 5.2");
        }
       else
        kind = OMP_CLAUSE_LINEAR_DEFAULT;
@@ -43075,8 +43083,20 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
                                            &colon);
   else
     {
+      size_t end = cp_parser_skip_balanced_tokens (parser, 1);
+      cp_token *next = UNKNOWN_LOCATION;
+      if (end > 1
+         && cp_lexer_nth_token_is (parser->lexer, end - 1, CPP_CLOSE_PAREN))
+       {
+         rm2_loc = cp_lexer_peek_nth_token (parser->lexer, end - 1)->location;
+         next = cp_lexer_peek_nth_token (parser->lexer, end);
+       }
       nlist = cp_parser_omp_var_list (parser, OMP_CLAUSE_LINEAR, list);
+      if (next && cp_lexer_peek_token (parser->lexer) != next)
+       rm2_loc = UNKNOWN_LOCATION;
       colon = cp_lexer_next_token_is (parser->lexer, CPP_COLON);
+      if (!colon && cp_lexer_next_token_is (parser->lexer, CPP_CLOSE_PAREN))
+       close_loc = cp_lexer_peek_token (parser->lexer)->location;
       if (colon)
        cp_parser_require (parser, CPP_COLON, RT_COLON);
       else if (!parens.require_close (parser))
@@ -43192,6 +43212,7 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
               && cp_lexer_nth_token_is (parser->lexer, 2, CPP_CLOSE_PAREN))
        {
          cp_token *token = cp_lexer_peek_token (parser->lexer);
+         after_colon_loc = token->location;
          cp_parser_parse_tentatively (parser);
          step = cp_parser_id_expression (parser, /*template_p=*/false,
                                          /*check_dependency_p=*/true,
@@ -43209,7 +43230,13 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
            step = NULL_TREE;
        }
       if (!step)
-       step = cp_parser_assignment_expression (parser);
+       {
+         after_colon_loc = cp_lexer_peek_token (parser->lexer)->location;
+         step = cp_parser_assignment_expression (parser);
+       }
+
+      if (cp_lexer_next_token_is (parser->lexer, CPP_CLOSE_PAREN))
+       close_loc = cp_lexer_peek_token (parser->lexer)->location;
 
       if (!parens.require_close (parser))
        cp_parser_skip_to_closing_parenthesis (parser, /*recovering=*/true,
@@ -43227,6 +43254,42 @@ cp_parser_omp_clause_linear (cp_parser *parser, tree list,
       OMP_CLAUSE_LINEAR_OLD_LINEAR_MODIFIER (c) = old_linear_modifier;
     }
 
+  if (old_linear_modifier)
+    {
+      gcc_rich_location richloc (mod_loc);
+      if (rm2_loc != UNKNOWN_LOCATION && close_loc != UNKNOWN_LOCATION)
+       {
+         richloc.add_fixit_remove (rm1_loc);
+         if (after_colon_loc != UNKNOWN_LOCATION)
+           {
+             richloc.add_fixit_remove (rm2_loc);
+             if (kind == OMP_CLAUSE_LINEAR_REF)
+               richloc.add_fixit_insert_before (after_colon_loc,
+                                                "ref, step (");
+             else if (kind == OMP_CLAUSE_LINEAR_VAL)
+               richloc.add_fixit_insert_before (after_colon_loc,
+                                                "val, step (");
+             else if (kind == OMP_CLAUSE_LINEAR_UVAL)
+               richloc.add_fixit_insert_before (after_colon_loc,
+                                                "uval, step (");
+             else
+               gcc_unreachable ();
+             richloc.add_fixit_insert_before (close_loc, ")");
+           }
+         else if (kind == OMP_CLAUSE_LINEAR_REF)
+           richloc.add_fixit_replace (rm2_loc, " : ref");
+         else if (kind == OMP_CLAUSE_LINEAR_VAL)
+           richloc.add_fixit_replace (rm2_loc, " : val");
+         else if (kind == OMP_CLAUSE_LINEAR_UVAL)
+           richloc.add_fixit_replace (rm2_loc, " : uval");
+         else
+           gcc_unreachable ();
+       }
+      warning_at (&richloc, OPT_Wdeprecated_openmp,
+                 "specifying the list items as arguments to the "
+                 "modifiers is deprecated since OpenMP 5.2");
+    }
+
   return nlist;
 }
 
@@ -43675,14 +43738,18 @@ cp_parser_omp_clause_depend (cp_parser *parser, tree list, location_t loc)
        kind = OMP_CLAUSE_DEPEND_DEPOBJ;
       else if (strcmp ("sink", p) == 0)
        {
-         warning_at (loc, OPT_Wdeprecated_openmp,
+         gcc_rich_location richloc (loc);
+         richloc.add_fixit_replace ("doacross");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
                      "%<sink%> modifier with %<depend%> clause deprecated "
                      "since OpenMP 5.2, use with %<doacross%>");
          dkind = OMP_CLAUSE_DOACROSS_SINK;
        }
       else if (strcmp ("source", p) == 0)
        {
-         warning_at (loc, OPT_Wdeprecated_openmp,
+         gcc_rich_location richloc (loc);
+         richloc.add_fixit_replace ("doacross");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
                      "%<source%> modifier with %<depend%> clause deprecated "
                      "since OpenMP 5.2, use with %<doacross%>");
          dkind = OMP_CLAUSE_DOACROSS_SOURCE;
@@ -44271,10 +44338,15 @@ cp_parser_omp_clause_map (cp_parser *parser, tree list, bool declare_mapper_p)
          return list;
        }
       ++num_identifiers;
-      if (num_identifiers - 1 != num_commas)
-       warning_at (clause_loc, OPT_Wdeprecated_openmp,
-                   "%<map%> clause modifiers without comma separation is "
-                   "deprecated since OpenMP 5.2");
+      if (num_identifiers - 1 > num_commas)
+       {
+         gcc_rich_location richloc (clause_loc);
+         richloc.add_fixit_insert_before (tok->location, ",");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
+                     "%<map%> clause modifiers without comma separation is "
+                     "deprecated since OpenMP 5.2");
+       }
+      num_commas = num_identifiers - 1;
     }
 
   if (cp_lexer_next_token_is (parser->lexer, CPP_NAME)
@@ -44517,7 +44589,11 @@ cp_parser_omp_clause_proc_bind (cp_parser *parser, tree list,
        kind = OMP_CLAUSE_PROC_BIND_PRIMARY;
       else if (strcmp ("master", p) == 0)
        {
-         warning_at (location, OPT_Wdeprecated_openmp,
+         gcc_rich_location richloc (location);
+         location_t master_loc
+           = cp_lexer_peek_token (parser->lexer)->location;
+         richloc.add_fixit_replace (master_loc, "primary");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
                      "%<master%> affinity deprecated since OpenMP 5.1, "
                      "use %<primary%>");
          kind = OMP_CLAUSE_PROC_BIND_MASTER;
@@ -45603,6 +45679,11 @@ cp_parser_omp_all_clauses (cp_parser *parser, omp_clause_mask mask,
        case PRAGMA_OMP_CLAUSE_TO:
          if ((mask & (OMP_CLAUSE_MASK_1 << PRAGMA_OMP_CLAUSE_LINK)) != 0)
            {
+             gcc_rich_location richloc (token->location);
+             richloc.add_fixit_replace ("enter");
+             warning_at (&richloc, OPT_Wdeprecated_openmp,
+                         "%<to%> clause with %<declare target%> deprecated "
+                         "since OpenMP 5.2, use %<enter%>");
              tree nl = cp_parser_omp_var_list (parser, OMP_CLAUSE_ENTER,
                                                clauses);
              for (tree c = nl; c != clauses; c = OMP_CLAUSE_CHAIN (c))
@@ -49236,12 +49317,15 @@ static tree cp_parser_omp_taskloop (cp_parser *, cp_token *, char *,
 static tree
 cp_parser_omp_master (cp_parser *parser, cp_token *pragma_tok,
                      char *p_name, omp_clause_mask mask, tree *cclauses,
-                     bool *if_p)
+                     bool *if_p, location_t master_loc)
 {
   tree clauses, sb, ret;
   unsigned int save;
   location_t loc = cp_lexer_peek_token (parser->lexer)->location;
-  warning_at (loc, OPT_Wdeprecated_openmp,
+  gcc_rich_location richloc (master_loc ? master_loc : loc);
+  if (master_loc != UNKNOWN_LOCATION)
+    richloc.add_fixit_replace (master_loc, "masked");
+  warning_at (&richloc, OPT_Wdeprecated_openmp,
              "%<master%> construct deprecated since OpenMP 5.1, use "
              "%<masked%>");
 
@@ -49615,6 +49699,7 @@ cp_parser_omp_parallel (cp_parser *parser, cp_token *pragma_tok,
     {
       tree id = cp_lexer_peek_token (parser->lexer)->u.value;
       const char *p = IDENTIFIER_POINTER (id);
+      location_t ploc = cp_lexer_peek_token (parser->lexer)->location;
       if (cclauses == NULL && strcmp (p, "masked") == 0)
        {
          tree cclauses_buf[C_OMP_CLAUSE_SPLIT_COUNT];
@@ -49653,11 +49738,11 @@ cp_parser_omp_parallel (cp_parser *parser, cp_token *pragma_tok,
          cp_lexer_consume_token (parser->lexer);
          if (!flag_openmp)  /* flag_openmp_simd  */
            return cp_parser_omp_master (parser, pragma_tok, p_name, mask,
-                                        cclauses, if_p);
+                                        cclauses, if_p, ploc);
          block = begin_omp_parallel ();
          save = cp_parser_begin_omp_structured_block (parser);
          tree ret = cp_parser_omp_master (parser, pragma_tok, p_name, mask,
-                                          cclauses, if_p);
+                                          cclauses, if_p, ploc);
          cp_parser_end_omp_structured_block (parser, save);
          stmt = finish_omp_parallel (cclauses[C_OMP_CLAUSE_SPLIT_PARALLEL],
                                      block);
@@ -52993,10 +53078,6 @@ cp_parser_omp_declare_target (cp_parser *parser, cp_token *pragma_tok)
     }
   for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
     {
-      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_ENTER && OMP_CLAUSE_ENTER_TO (c))
-       warning_at (OMP_CLAUSE_LOCATION (c), OPT_Wdeprecated_openmp,
-                   "%<to%> clause with %<declare target%> deprecated since "
-                   "OpenMP 5.2, use %<enter%>");
       if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_DEVICE_TYPE)
        device_type |= OMP_CLAUSE_DEVICE_TYPE_KIND (c);
       if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_INDIRECT)
@@ -53418,9 +53499,13 @@ cp_parser_omp_metadirective (cp_parser *parser, cp_token *pragma_tok,
       const char *p
        = IDENTIFIER_POINTER (cp_lexer_peek_token (parser->lexer)->u.value);
       if (strcmp (p, "default") == 0)
-       warning_at (match_loc, OPT_Wdeprecated_openmp,
-                   "%<default%> clause on metadirectives deprecated since "
-                   "OpenMP 5.2, use %<otherwise%>");
+       {
+         gcc_rich_location richloc (match_loc);
+         richloc.add_fixit_replace ("otherwise");
+         warning_at (&richloc, OPT_Wdeprecated_openmp,
+                     "%<default%> clause on metadirectives deprecated since "
+                     "OpenMP 5.2, use %<otherwise%>");
+       }
       cp_lexer_consume_token (parser->lexer);
       bool default_p
        = strcmp (p, "default") == 0 || strcmp (p, "otherwise") == 0;
@@ -55209,7 +55294,7 @@ cp_parser_omp_construct (cp_parser *parser, cp_token *pragma_tok, bool *if_p)
     case PRAGMA_OMP_MASTER:
       strcpy (p_name, "#pragma omp");
       stmt = cp_parser_omp_master (parser, pragma_tok, p_name, mask, NULL,
-                                  if_p);
+                                  if_p, UNKNOWN_LOCATION);
       break;
     case PRAGMA_OMP_PARALLEL:
       strcpy (p_name, "#pragma omp");

diff --git a/gcc/testsuite/g++.dg/gomp/deprecate-1.C b/gcc/testsuite/g++.dg/gomp/deprecate-1.C
new file mode 100644 (file)
index 0000000..37ff86a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/deprecate-1.C
@@ -0,0 +1,124 @@
+/* { dg-additional-options "-fdiagnostics-show-caret -Wdeprecated-openmp" } */
+
+#pragma omp declare simd linear (val(a) : 1)   /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (val(a) : 1)
+                                  ^~~
+                                  ---- -   -
+                                           val, step (1)
+   { dg-end-multiline-output "" } */
+#pragma omp declare simd linear (val(b))       /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (val(b))
+                                  ^~~
+                                  ---- -
+                                        : val
+   { dg-end-multiline-output "" } */
+int foo (int a, int b);
+
+#pragma omp declare simd linear (ref(a) : 1)   /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (ref(a) : 1)
+                                  ^~~
+                                  ---- -   -
+                                           ref, step (1)
+   { dg-end-multiline-output "" } */
+#pragma omp declare simd linear (ref(b))       /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (ref(b))
+                                  ^~~
+                                  ---- -
+                                        : ref
+   { dg-end-multiline-output "" } */
+int baz (int &a, int &b);
+
+#pragma omp declare simd linear (uval(a) : 1)  /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (uval(a) : 1)
+                                  ^~~~
+                                  ----- -   -
+                                            uval, step (1)
+   { dg-end-multiline-output "" } */
+#pragma omp declare simd linear (uval(b))      /* { dg-warning "specifying the list items as arguments to the modifiers is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare simd linear (uval(b))
+                                  ^~~~
+                                  ----- -
+                                         : uval
+   { dg-end-multiline-output "" } */
+int qux (int &a, int &b);
+
+int v;
+#pragma omp declare target to (v)              /* { dg-warning "'to' clause with 'declare target' deprecated since OpenMP 5.2, use 'enter'" } */
+/* { dg-begin-multiline-output "" }
+ #pragma omp declare target to (v)
+                            ^~
+                            enter
+   { dg-end-multiline-output "" } */
+
+void
+bar ()
+{
+  int r = 0;
+  #pragma omp parallel reduction (-:r)         /* { dg-warning "'-' operator for reductions deprecated in OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp parallel reduction (-:r)
+                                   ^
+                                   +
+   { dg-end-multiline-output "" } */
+  ++r;
+  #pragma omp for ordered (1)
+  for (int i = 0; i < 64; i++)
+    {
+      #pragma omp ordered depend (sink: i - 1) /* { dg-warning "'sink' modifier with 'depend' clause deprecated since OpenMP 5.2, use with 'doacross'" } */
+/* { dg-begin-multiline-output "" }
+       #pragma omp ordered depend (sink: i - 1)
+                           ^~~~~~
+                           doacross
+   { dg-end-multiline-output "" } */
+      #pragma omp ordered depend (source)      /* { dg-warning "'source' modifier with 'depend' clause deprecated since OpenMP 5.2, use with 'doacross'" } */
+/* { dg-begin-multiline-output "" }
+       #pragma omp ordered depend (source)
+                           ^~~~~~
+                           doacross
+   { dg-end-multiline-output "" } */
+    }
+  #pragma omp target map (always close present, tofrom: r)     /* { dg-warning "'map' clause modifiers without comma separation is deprecated since OpenMP 5.2" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp target map (always close present, tofrom: r)
+                          ^
+                                  ,
+   #pragma omp target map (always close present, tofrom: r)
+                          ^
+                                        ,
+   { dg-end-multiline-output "" } */
+  ;
+  #pragma omp parallel proc_bind (master)      /* { dg-warning "'master' affinity deprecated since OpenMP 5.1, use 'primary'" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp parallel proc_bind (master)
+                        ^~~~~~~~~
+                                   ------
+                                   primary
+   { dg-end-multiline-output "" } */
+  ;
+  #pragma omp parallel master                  /* { dg-warning "'master' construct deprecated since OpenMP 5.1, use 'masked'" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp parallel master
+                        ^~~~~~
+                        masked
+   { dg-end-multiline-output "" } */
+  ;
+  #pragma omp master                           /* { dg-warning "'master' construct deprecated since OpenMP 5.1, use 'masked'" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp master
+                                                                                                                                    ^
+   { dg-end-multiline-output "" } */
+  ;
+  #pragma omp metadirective when (device={arch("blahblah")}: nothing) default (nothing)                /* { dg-warning "'default' clause on metadirectives deprecated since OpenMP 5.2, use 'otherwise'" } */
+/* { dg-begin-multiline-output "" }
+   #pragma omp metadirective when (device={arch("blahblah")}: nothing) default (nothing)
+                                                                       ^~~~~~~
+                                                                       otherwise
+   { dg-end-multiline-output "" } */
+  ;
+}