[PATCH][RFC] Add quotes for constexpr keyword.

[Martin Liška <mliska at suse dot cz>]

On 11/06/2017 07:29 PM, Martin Sebor wrote:
> Sorry for being late with my comment.  I just spotted this minor
> formatting issue.  Even though GCC isn't (yet) consistent about
> it the keyword "constexpr" should be quoted in the error message
> below (and, eventually, in all diagnostic messages).  Since the
> patch has been committed by now this is just a reminder for us
> to try to keep this in mind in the future.

Hi.

I've prepared patch for that. If it's desired, I can fix test-suite follow-up.
Do we want to change it also for error messages like:
"call to non-constexpr function"
"constexpr call flows off the end of the function"

Thanks,
Martin

>From eb554d8778be239a2edb06d21f98bda7e5153765 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Wed, 15 Nov 2017 08:41:12 +0100
Subject: [PATCH] Add quotes for constexpr keyword.

gcc/cp/ChangeLog:

2017-11-15  Martin Liska  <mliska@suse.cz>

	* class.c (finalize_literal_type_property): Add quotes for
	constexpr keyword.
	(explain_non_literal_class): Likewise.
	* constexpr.c (ensure_literal_type_for_constexpr_object): Likewise.
	(is_valid_constexpr_fn): Likewise.
	(check_constexpr_ctor_body): Likewise.
	(register_constexpr_fundef): Likewise.
	(explain_invalid_constexpr_fn): Likewise.
	(cxx_eval_builtin_function_call): Likewise.
	(cxx_eval_call_expression): Likewise.
	(cxx_eval_loop_expr): Likewise.
	(potential_constant_expression_1): Likewise.
	* decl.c (check_previous_goto_1): Likewise.
	(check_goto): Likewise.
	(grokfndecl): Likewise.
	(grokdeclarator): Likewise.
	* error.c (maybe_print_constexpr_context): Likewise.
	* method.c (process_subob_fn): Likewise.
	(defaulted_late_check): Likewise.
	* parser.c (cp_parser_compound_statement): Likewise.
---
 gcc/cp/class.c     |  4 ++--
 gcc/cp/constexpr.c | 35 ++++++++++++++++++-----------------
 gcc/cp/decl.c      | 12 ++++++------
 gcc/cp/error.c     |  4 ++--
 gcc/cp/method.c    |  6 +++---
 gcc/cp/parser.c    |  2 +-
 6 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 586a32c436f..529f37f24ee 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -5368,7 +5368,7 @@ finalize_literal_type_property (tree t)
 	  DECL_DECLARED_CONSTEXPR_P (fn) = false;
 	  if (!DECL_GENERATED_P (fn)
 	      && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic,
-			  "enclosing class of constexpr non-static member "
+			  "enclosing class of %<constexpr%> non-static member "
 			  "function %q+#D is not a literal type", fn))
 	    explain_non_literal_class (t);
 	}
@@ -5406,7 +5406,7 @@ explain_non_literal_class (tree t)
     {
       inform (UNKNOWN_LOCATION,
 	      "  %q+T is not an aggregate, does not have a trivial "
-	      "default constructor, and has no constexpr constructor that "
+	      "default constructor, and has no %<constexpr%> constructor that "
 	      "is not a copy or move constructor", t);
       if (type_has_non_user_provided_default_constructor (t))
 	/* Note that we can't simply call locate_ctor because when the
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index d6b6843e804..e0a4133d89b 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -94,8 +94,8 @@ ensure_literal_type_for_constexpr_object (tree decl)
 	{
 	  if (DECL_DECLARED_CONSTEXPR_P (decl))
 	    {
-	      error ("the type %qT of constexpr variable %qD is not literal",
-		     type, decl);
+	      error ("the type %qT of %<constexpr%> variable %qD "
+		     "is not literal", type, decl);
 	      explain_non_literal_class (type);
 	    }
 	  else
@@ -177,7 +177,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
     {
       ret = false;
       if (complain)
-	error ("inherited constructor %qD is not constexpr",
+	error ("inherited constructor %qD is not %<constexpr%>",
 	       DECL_INHERITED_CTOR (fun));
     }
   else
@@ -189,7 +189,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
 	    ret = false;
 	    if (complain)
 	      {
-		error ("invalid type for parameter %d of constexpr "
+		error ("invalid type for parameter %d of %<constexpr%> "
 		       "function %q+#D", DECL_PARM_INDEX (parm), fun);
 		explain_non_literal_class (TREE_TYPE (parm));
 	      }
@@ -201,7 +201,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
       ret = false;
       if (complain)
 	inform (DECL_SOURCE_LOCATION (fun),
-		"lambdas are implicitly constexpr only in C++17 and later");
+		"lambdas are implicitly %<constexpr%> only in C++17 and later");
     }
   else if (!DECL_CONSTRUCTOR_P (fun))
     {
@@ -211,7 +211,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
 	  ret = false;
 	  if (complain)
 	    {
-	      error ("invalid return type %qT of constexpr function %q+D",
+	      error ("invalid return type %qT of %<constexpr%> function %q+D",
 		     rettype, fun);
 	      explain_non_literal_class (rettype);
 	    }
@@ -225,7 +225,7 @@ is_valid_constexpr_fn (tree fun, bool complain)
 	  ret = false;
 	  if (complain
 	      && pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic,
-			  "enclosing class of constexpr non-static member "
+			  "enclosing class of %<constexpr%> non-static member "
 			  "function %q+#D is not a literal type", fun))
 	    explain_non_literal_class (DECL_CONTEXT (fun));
 	}
@@ -494,7 +494,7 @@ check_constexpr_ctor_body (tree last, tree list, bool complain)
   if (!ok)
     {
       if (complain)
-	error ("constexpr constructor does not have empty body");
+	error ("%<constexpr%> constructor does not have empty body");
       DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false;
     }
   return ok;
@@ -845,7 +845,8 @@ register_constexpr_fundef (tree fun, tree body)
   if (massaged == NULL_TREE || massaged == error_mark_node)
     {
       if (!DECL_CONSTRUCTOR_P (fun))
-	error ("body of constexpr function %qD not a return-statement", fun);
+	error ("body of %<constexpr%> function %qD not a return-statement",
+	       fun);
       return NULL;
     }
 
@@ -905,7 +906,7 @@ explain_invalid_constexpr_fn (tree fun)
 	 input_location set to our caller's location.  */
       input_location = DECL_SOURCE_LOCATION (fun);
       inform (input_location,
-	      "%qD is not usable as a constexpr function because:", fun);
+	      "%qD is not usable as a %<constexpr%> function because:", fun);
     }
   /* First check the declaration.  */
   if (is_valid_constexpr_fn (fun, true))
@@ -1194,7 +1195,7 @@ cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun,
 	     comes from cp_maybe_instrument_return.  */
 	  if (DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE
 	      && EXPR_LOCATION (t) == BUILTINS_LOCATION)
-	    error ("constexpr call flows off the end of the function");
+	    error ("%<constexpr%> call flows off the end of the function");
 	  else
 	    {
 	      new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t),
@@ -1465,7 +1466,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
   if (TREE_CODE (fun) != FUNCTION_DECL)
     {
       if (!ctx->quiet && !*non_constant_p)
-	error_at (loc, "expression %qE does not designate a constexpr "
+	error_at (loc, "expression %qE does not designate a %<constexpr%> "
 		  "function", fun);
       *non_constant_p = true;
       return t;
@@ -1484,7 +1485,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
       if (!ctx->quiet)
 	{
 	  if (!lambda_static_thunk_p (fun))
-	    error_at (loc, "call to non-constexpr function %qD", fun);
+	    error_at (loc, "call to non-%<constexpr%> function %qD", fun);
 	  explain_invalid_constexpr_fn (fun);
 	}
       *non_constant_p = true;
@@ -1618,7 +1619,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
   if (!depth_ok)
     {
       if (!ctx->quiet)
-	error ("constexpr evaluation depth exceeds maximum of %d (use "
+	error ("%<constexpr%> evaluation depth exceeds maximum of %d (use "
 	       "-fconstexpr-depth= to increase the maximum)",
 	       max_constexpr_depth);
       *non_constant_p = true;
@@ -1701,7 +1702,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
 	      if (result == NULL_TREE && !*non_constant_p)
 		{
 		  if (!ctx->quiet)
-		    error ("constexpr call flows off the end "
+		    error ("%<constexpr%> call flows off the end "
 			   "of the function");
 		  *non_constant_p = true;
 		}
@@ -3847,7 +3848,7 @@ cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t,
 	{
 	  if (!ctx->quiet)
 	    error_at (EXPR_LOC_OR_LOC (t, input_location),
-		      "constexpr loop iteration count exceeds limit of %d "
+		      "%<constexpr%> loop iteration count exceeds limit of %d "
 		      "(use -fconstexpr-loop-limit= to increase the limit)",
 		      constexpr_loop_limit);
 	  *non_constant_p = true;
@@ -5214,7 +5215,7 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
 		  {
 		    if (flags & tf_error)
 		      {
-			error_at (loc, "call to non-constexpr function %qD",
+			error_at (loc, "call to non-%<constexpr%> function %qD",
 				  fun);
 			explain_invalid_constexpr_fn (fun);
 		      }
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 041893db937..77103ae5b03 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -3180,7 +3180,7 @@ check_previous_goto_1 (tree decl, cp_binding_level* level, tree names,
 	case sk_block:
 	  if (!saw_cxif && level_for_constexpr_if (b->level_chain))
 	    {
-	      inf = N_("enters constexpr if statement");
+	      inf = N_("enters %<constexpr%> if statement");
 	      loc = EXPR_LOCATION (b->level_chain->this_entity);
 	      saw_cxif = true;
 	    }
@@ -3315,7 +3315,7 @@ check_goto (tree decl)
       else if (ent->in_transaction_scope)
 	inform (input_location, "  enters synchronized or atomic statement");
       else if (ent->in_constexpr_if)
-	inform (input_location, "  enters constexpr if statement");
+	inform (input_location, "  enters %<constexpr%> if statement");
     }
 
   if (ent->in_omp_scope)
@@ -8606,7 +8606,7 @@ grokfndecl (tree ctype,
       if (inlinep & 1)
 	error ("cannot declare %<::main%> to be inline");
       if (inlinep & 2)
-	error ("cannot declare %<::main%> to be constexpr");
+	error ("cannot declare %<::main%> to be %<constexpr%>");
       if (!publicp)
 	error ("cannot declare %<::main%> to be static");
       inlinep = 0;
@@ -12050,7 +12050,7 @@ grokdeclarator (const cp_declarator *declarator,
 			   unqualified_id);
 		else if (constexpr_p && !initialized)
 		  {
-		    error ("constexpr static data member %qD must have an "
+		    error ("%<constexpr%> static data member %qD must have an "
 			   "initializer", decl);
 		    constexpr_p = false;
 		  }
@@ -12278,8 +12278,8 @@ grokdeclarator (const cp_declarator *declarator,
 	  }
 	else if (constexpr_p && DECL_EXTERNAL (decl))
 	  {
-	    error ("declaration of constexpr variable %qD is not a definition",
-		   decl);
+	    error ("declaration of %<constexpr%> variable %qD "
+		   "is not a definition", decl);
 	    constexpr_p = false;
 	  }
 
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 2537713b5c9..5c78f76db07 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -3584,11 +3584,11 @@ maybe_print_constexpr_context (diagnostic_context *context)
       const char *s = expr_as_string (t, 0);
       if (context->show_column)
 	pp_verbatim (context->printer,
-		     _("%r%s:%d:%d:%R   in constexpr expansion of %qs"),
+		     _("%r%s:%d:%d:%R   in %<constexpr%> expansion of %qs"),
 		     "locus", xloc.file, xloc.line, xloc.column, s);
       else
 	pp_verbatim (context->printer,
-		     _("%r%s:%d:%R   in constexpr expansion of %qs"),
+		     _("%r%s:%d:%R   in %<constexpr%> expansion of %qs"),
 		     "locus", xloc.file, xloc.line, s);
       pp_newline (context->printer);
     }
diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index 714b5087991..534aaa32fd5 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -1293,7 +1293,7 @@ process_subob_fn (tree fn, tree *spec_p, bool *trivial_p,
       if (diag)
 	{
 	  inform (DECL_SOURCE_LOCATION (fn),
-		  "defaulted constructor calls non-constexpr %qD", fn);
+		  "defaulted constructor calls non-%<constexpr%> %qD", fn);
 	  explain_invalid_constexpr_fn (fn);
 	}
     }
@@ -2257,8 +2257,8 @@ defaulted_late_check (tree fn)
       if (!CLASSTYPE_TEMPLATE_INSTANTIATION (ctx))
 	{
 	  error ("explicitly defaulted function %q+D cannot be declared "
-		 "as constexpr because the implicit declaration is not "
-		 "constexpr:", fn);
+		 "as %<constexpr%> because the implicit declaration is not "
+		 "%<constexpr%>:", fn);
 	  explain_implicit_non_constexpr (fn);
 	}
       DECL_DECLARED_CONSTEXPR_P (fn) = false;
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 1860bf0f175..6c132da49ee 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -11292,7 +11292,7 @@ cp_parser_compound_statement (cp_parser *parser, tree in_statement_expr,
   if (DECL_DECLARED_CONSTEXPR_P (current_function_decl)
       && !function_body && cxx_dialect < cxx14)
     pedwarn (input_location, OPT_Wpedantic,
-	     "compound-statement in constexpr function");
+	     "compound-statement in %<constexpr%> function");
   /* Begin the compound-statement.  */
   compound_stmt = begin_compound_stmt (bcs_flags);
   /* If the next keyword is `__label__' we have a label declaration.  */
-- 
2.14.3