diagnostics: enable nested diagnostics by default [PR116253]

In GCC 15 I added an experimental nesting view in text sinks
for hierarchical diagnostics, such as C++ template problems.

This patch enables it for text sinks by default.  The old
behavior can be restored via -fno-diagnostics-show-nesting,
which the patch also adds to -fdiagnostics-plain-output.

The patch does not yet enable it for text sinks in sarif-replay.

gcc/ChangeLog:
	PR diagnostics/116253
	* common.opt (fdiagnostics-show-nesting): New option.
	(fdiagnostics-show-nesting-locations): New option.
	(fdiagnostics-show-nesting-levels): New option.
	* common.opt.urls: Regenerate.
	* diagnostics/context.cc (context::set_show_nesting): New.
	(context::set_show_nesting_locations): New.
	(context::set_show_nesting_levels): New.
	* diagnostics/context.h (context::set_show_nesting): New decl.
	(context::set_show_nesting_locations): New decl.
	(context::set_show_nesting_levels): New decl.
	* diagnostics/html-sink.cc: Tweak comment.
	* diagnostics/output-spec.cc (text_scheme_handler::make_sink):
	Rename "experimental-nesting" to "show-nesting" and enable by
	default.  Rename "experimental-nesting-show-locations" to
	"show-nesting-locations".  Rename
	"experimental-nesting-show-levels" to "show-nesting-levels".
	* diagnostics/sink.h (sink::dyn_cast_text_sink): New.
	* diagnostics/text-sink.h (text_sink::dyn_cast_text_sink): New.
	* doc/invoke.texi: Add -fdiagnostics-show-nesting,
	-fdiagnostics-show-nesting-locations, and
	-fdiagnostics-show-nesting-levels.  Update for changes to
	output-spec.cc above.
	* lto-wrapper.cc (merge_and_complain): Ignore
	OPT_fdiagnostics_show_nesting,
	OPT_fdiagnostics_show_nesting_locations, and
	OPT_fdiagnostics_show_nesting_levels.
	(append_compiler_options): Likewise.
	(append_diag_options): Likewise.
	* opts-common.cc (decode_cmdline_options_to_array): Add
	"-fno-diagnostics-show-nesting" to -fdiagnostics-plain-output.
	* opts.cc (common_handle_option): Handle the new options.
	(gen_command_line_string): Ignore the new options.
	* toplev.cc (general_init): Call set_show_nesting,
	set_show_nesting_locations, and set_show_nesting_levels on
	global_dc.

gcc/testsuite/ChangeLog:
	PR diagnostics/116253
	* g++.dg/concepts/nested-diagnostics-1-truncated.C: Update for
	renamed keys to -fdiagnostics-set-output=text
	* g++.dg/concepts/nested-diagnostics-1.C: Likewise.
	* g++.dg/concepts/nested-diagnostics-2.C: Likewise.
	* gcc.dg/plugin/diagnostic-test-nesting-no-show-nesting.c: New
	test.
	* gcc.dg/plugin/diagnostic-test-nesting-show-nesting.c: New test.
	* gcc.dg/plugin/diagnostic-test-nesting-text-indented-show-levels.c:
	Update for renamed keys to -fdiagnostics-set-output=text.
	* gcc.dg/plugin/diagnostic-test-nesting-text-indented-unicode.c:
	Likewise.
	* gcc.dg/plugin/diagnostic-test-nesting-text-indented.c: Likewise.
	* gcc.dg/plugin/plugin.exp: Add the new tests.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

22 files changed, 183 insertions, 24 deletions

diff --git a/gcc/common.opt b/gcc/common.opt
index bf38f60..c58ac13 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1620,6 +1620,18 @@ fdiagnostics-minimum-margin-width=
 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
 Set minimum width of left margin of source code when showing source.
 
+fdiagnostics-show-nesting
+Common Var(flag_diagnostics_show_nesting) Init(1)
+Use indentation to show nesting of diagnostics in text output.
+
+fdiagnostics-show-nesting-locations
+Common Var(flag_diagnostics_show_nesting_locations) Init(1)
+Show location information when showing nested diagnostics.
+
+fdiagnostics-show-nesting-levels
+Common Var(flag_diagnostics_show_nesting_levels) Init(0)
+Show nesting levels as numbers when showing nested diagnostics.
+
 fdisable-
 Common Joined RejectNegative Var(common_deferred_options) Defer
 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2	Disable an optimization pass.
diff --git a/gcc/common.opt.urls b/gcc/common.opt.urls
index 38dd9d3..0bc36c4 100644
--- a/gcc/common.opt.urls
+++ b/gcc/common.opt.urls
@@ -640,6 +640,15 @@ UrlSuffix(gcc/Diagnostic-Message-Formatting-Options.html#index-fdiagnostics-text
 fdiagnostics-minimum-margin-width=
 UrlSuffix(gcc/Diagnostic-Message-Formatting-Options.html#index-fdiagnostics-minimum-margin-width)
 
+fdiagnostics-show-nesting
+UrlSuffix(gcc/Diagnostic-Message-Formatting-Options.html#index-fdiagnostics-show-nesting)
+
+fdiagnostics-show-nesting-locations
+UrlSuffix(gcc/Diagnostic-Message-Formatting-Options.html#index-fdiagnostics-show-nesting-locations)
+
+fdiagnostics-show-nesting-levels
+UrlSuffix(gcc/Diagnostic-Message-Formatting-Options.html#index-fdiagnostics-show-nesting-levels)
+
 fdisable-
 UrlSuffix(gcc/Developer-Options.html#index-fdisable-)
 
diff --git a/gcc/diagnostics/context.cc b/gcc/diagnostics/context.cc
index e127c8f..c948246 100644
--- a/gcc/diagnostics/context.cc
+++ b/gcc/diagnostics/context.cc
@@ -288,6 +288,33 @@ context::urls_init (int value)
 	(m_reference_printer->get_url_format ());
 }
 
+void
+context::set_show_nesting (bool val)
+{
+  for (auto sink_ : m_sinks)
+    if (sink_->follows_reference_printer_p ())
+      if (auto text_sink_ = sink_->dyn_cast_text_sink ())
+	text_sink_->set_show_nesting (val);
+}
+
+void
+context::set_show_nesting_locations (bool val)
+{
+  for (auto sink_ : m_sinks)
+    if (sink_->follows_reference_printer_p ())
+      if (auto text_sink_ = sink_->dyn_cast_text_sink ())
+	text_sink_->set_show_locations_in_nesting (val);
+}
+
+void
+context::set_show_nesting_levels (bool val)
+{
+  for (auto sink_ : m_sinks)
+    if (sink_->follows_reference_printer_p ())
+      if (auto text_sink_ = sink_->dyn_cast_text_sink ())
+	text_sink_->set_show_nesting_levels (val);
+}
+
 /* Create the file_cache, if not already created, and tell it how to
    translate files on input.  */
 void
diff --git a/gcc/diagnostics/context.h b/gcc/diagnostics/context.h
index df44a9b..dea4588 100644
--- a/gcc/diagnostics/context.h
+++ b/gcc/diagnostics/context.h
@@ -392,6 +392,9 @@ public:
   }
   void set_show_path_depths (bool val) { m_show_path_depths = val; }
   void set_show_option_requested (bool val) { m_show_option_requested = val; }
+  void set_show_nesting (bool val);
+  void set_show_nesting_locations (bool val);
+  void set_show_nesting_levels (bool val);
   void set_max_errors (int val) { m_max_errors = val; }
   void set_escape_format (enum diagnostics_escape_format val)
   {
diff --git a/gcc/diagnostics/html-sink.cc b/gcc/diagnostics/html-sink.cc
index 9309bd6..448d461 100644
--- a/gcc/diagnostics/html-sink.cc
+++ b/gcc/diagnostics/html-sink.cc
@@ -560,7 +560,7 @@ html_builder::on_report_diagnostic (const diagnostic_info &diagnostic,
     }
 }
 
-// For ease of comparison with experimental-nesting-show-levels=yes
+// For ease of comparison with show-nesting-levels=yes
 
 static void
 add_nesting_level_attr (xml::element &element,
diff --git a/gcc/diagnostics/output-spec.cc b/gcc/diagnostics/output-spec.cc
index 83f128c..13565f9 100644
--- a/gcc/diagnostics/output-spec.cc
+++ b/gcc/diagnostics/output-spec.cc
@@ -368,7 +368,7 @@ text_scheme_handler::make_sink (const context &ctxt,
 				const scheme_name_and_params &parsed_arg) const
 {
   bool show_color = pp_show_color (dc.get_reference_printer ());
-  bool show_nesting = false;
+  bool show_nesting = true;
   bool show_locations_in_nesting = true;
   bool show_levels = false;
   for (auto& iter : parsed_arg.m_kvs)
@@ -381,21 +381,21 @@ text_scheme_handler::make_sink (const context &ctxt,
 	    return nullptr;
 	  continue;
 	}
-      if (key == "experimental-nesting")
+      if (key == "show-nesting")
 	{
 	  if (!parse_bool_value (ctxt, unparsed_arg, key, value,
 				 show_nesting))
 	    return nullptr;
 	  continue;
 	}
-      if (key == "experimental-nesting-show-locations")
+      if (key == "show-nesting-locations")
 	{
 	  if (!parse_bool_value (ctxt, unparsed_arg, key, value,
 				 show_locations_in_nesting))
 	    return nullptr;
 	  continue;
 	}
-      if (key == "experimental-nesting-show-levels")
+      if (key == "show-nesting-levels")
 	{
 	  if (!parse_bool_value (ctxt, unparsed_arg, key, value, show_levels))
 	    return nullptr;
@@ -405,9 +405,9 @@ text_scheme_handler::make_sink (const context &ctxt,
       /* Key not found.  */
       auto_vec<const char *> known_keys;
       known_keys.safe_push ("color");
-      known_keys.safe_push ("experimental-nesting");
-      known_keys.safe_push ("experimental-nesting-show-locations");
-      known_keys.safe_push ("experimental-nesting-show-levels");
+      known_keys.safe_push ("show-nesting");
+      known_keys.safe_push ("show-nesting-locations");
+      known_keys.safe_push ("show-nesting-levels");
       ctxt.report_unknown_key (unparsed_arg, key, get_scheme_name (),
 			       known_keys);
       return nullptr;
diff --git a/gcc/diagnostics/sink.h b/gcc/diagnostics/sink.h
index e1a3790..24eb707 100644
--- a/gcc/diagnostics/sink.h
+++ b/gcc/diagnostics/sink.h
@@ -36,6 +36,8 @@ class sink
 public:
   virtual ~sink () {}
 
+  virtual text_sink *dyn_cast_text_sink () { return nullptr; }
+
   virtual void dump_kind (FILE *out) const = 0;
   virtual void dump (FILE *out, int indent) const;
 
diff --git a/gcc/diagnostics/text-sink.h b/gcc/diagnostics/text-sink.h
index e567ec8..f280e72 100644
--- a/gcc/diagnostics/text-sink.h
+++ b/gcc/diagnostics/text-sink.h
@@ -51,6 +51,8 @@ public:
   {}
   ~text_sink ();
 
+  text_sink *dyn_cast_text_sink () final override { return this; }
+
   void dump_kind (FILE *out) const override
   {
     fprintf (out, "text_sink");
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 33ae98c..28466c4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -322,6 +322,9 @@ Objective-C and Objective-C++ Dialects}.
 -fno-diagnostics-show-cwe
 -fno-diagnostics-show-rules
 -fno-diagnostics-show-highlight-colors
+-fno-diagnostics-show-nesting
+-fno-diagnostics-show-nesting-locations
+-fdiagnostics-show-nesting-levels
 -fdiagnostics-minimum-margin-width=@var{width}
 -fdiagnostics-parseable-fixits  -fdiagnostics-generate-patch
 -fdiagnostics-show-template-tree  -fno-elide-type
@@ -5429,7 +5432,8 @@ options:
 -fdiagnostics-urls=never
 -fdiagnostics-path-format=separate-events
 -fdiagnostics-text-art-charset=none
--fno-diagnostics-show-event-links}
+-fno-diagnostics-show-event-links
+-fno-diagnostics-show-nesting}
 In the future, if GCC changes the default appearance of its diagnostics, the
 corresponding option to disable the new behavior will be added to this list.
 
@@ -6051,6 +6055,40 @@ emoji variant of the character).
 The default is @samp{emoji}, except when the environment variable @env{LANG}
 is set to @samp{C}, in which case the default is @samp{ascii}.
 
+@opindex fno-diagnostics-show-nesting
+@opindex fdiagnostics-show-nesting
+@item -fno-diagnostics-show-nesting
+Some GCC diagnostics have an internal tree-like structure of nested
+sub-diagnostics, such as for problems when instantiating C++ templates.
+
+By default GCC uses indentation and bullet points in its text output to
+show the nesting structure of these diagnostics, moves location
+information to separate lines to make the structure clearer, and
+eliminates redundant repeated information.
+
+Selecting @option{-fno-diagnostics-show-nesting} suppresses this
+indentation, reformatting, and elision, restoring an older `look'' for the
+diagnostics.
+
+@opindex fno-diagnostics-show-nesting-locations
+@opindex fdiagnostics-show-nesting-locations
+@item -fno-diagnostics-show-nesting-locations
+
+When @option{fdiagnostics-show-nesting} is enabled, file names and
+line- and column- numbers are displayed on separate lines from the
+messages.  This location information can be disabled altogether with
+@option{-fno-diagnostics-show-nesting-locations}.
+This option exists for use by GCC developers, for writing DejaGnu test cases.
+
+@opindex fdiagnostics-show-nesting-levels
+@opindex fno-diagnostics-show-nesting-levels
+@item -fdiagnostics-show-nesting-levels
+When @option{fdiagnostics-show-nesting} is enabled, use
+@option{fdiagnostics-show-nesting-levels} to also display numbers
+showing the depth of the nesting.
+This option exists for use by GCC developers for debugging nested
+diagnostics, but may be of use to plugin authors.
+
 @opindex fdiagnostics-format
 @item -fdiagnostics-format=@var{FORMAT}
 Select a different format for printing diagnostics.
@@ -6099,18 +6137,18 @@ Supported keys are:
 Override colorization settings from @option{-fdiagnostics-color} for this
 text output.
 
-@item experimental-nesting=@r{[}yes@r{|}no@r{]}
-Enable an experimental mode that emphasizes hierarchical relationships
-within diagnostics messages, displaying location information on separate
-lines.
+@item show-nesting=@r{[}yes@r{|}no@r{]}
+Enable a mode that emphasizes hierarchical relationships
+within diagnostics messages, as per @option{-fdiagnostics-show-nesting}.
+Defaults to @code{yes}.
 
-@item experimental-nesting-show-locations=@r{[}yes@r{|}no@r{]}
-If @code{experimental-nesting=yes}, then by default locations are
+@item show-nesting-locations=@r{[}yes@r{|}no@r{]}
+If @code{show-nesting=yes}, then by default locations are
 shown; set this key to @code{no} to disable printing such locations.
 This exists for use by GCC developers, for writing DejaGnu test cases.
 
-@item experimental-nesting-show-levels=@r{[}yes@r{|}no@r{]}
-This is a debugging option for use with @code{experimental-nesting=yes}.
+@item show-nesting-levels=@r{[}yes@r{|}no@r{]}
+This is a debugging option for use with @code{show-nesting=yes}.
 Set this key to @code{yes} to print explicit nesting levels in the output.
 This exists for use by GCC developers.
 
diff --git a/gcc/lto-wrapper.cc b/gcc/lto-wrapper.cc
index 03fca97..dbe3ad0 100644
--- a/gcc/lto-wrapper.cc
+++ b/gcc/lto-wrapper.cc
@@ -320,6 +320,9 @@ merge_and_complain (vec<cl_decoded_option> &decoded_options,
 	case OPT_fdiagnostics_show_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
+	case OPT_fdiagnostics_show_nesting:
+	case OPT_fdiagnostics_show_nesting_locations:
+	case OPT_fdiagnostics_show_nesting_levels:
 	case OPT_fshow_column:
 	case OPT_fcommon:
 	case OPT_fgnu_tm:
@@ -739,6 +742,9 @@ append_compiler_options (obstack *argv_obstack, vec<cl_decoded_option> opts)
 	case OPT_fdiagnostics_show_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
+	case OPT_fdiagnostics_show_nesting:
+	case OPT_fdiagnostics_show_nesting_locations:
+	case OPT_fdiagnostics_show_nesting_levels:
 	case OPT_fshow_column:
 	case OPT_fPIC:
 	case OPT_fpic:
@@ -801,6 +807,9 @@ append_diag_options (obstack *argv_obstack, vec<cl_decoded_option> opts)
 	case OPT_fdiagnostics_show_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
+	case OPT_fdiagnostics_show_nesting:
+	case OPT_fdiagnostics_show_nesting_locations:
+	case OPT_fdiagnostics_show_nesting_levels:
 	case OPT_fshow_column:
 	  break;
 	default:
diff --git a/gcc/opts-common.cc b/gcc/opts-common.cc
index e6d7f4d..379402e 100644
--- a/gcc/opts-common.cc
+++ b/gcc/opts-common.cc
@@ -1096,7 +1096,8 @@ decode_cmdline_options_to_array (unsigned int argc, const char **argv,
 	    "-fdiagnostics-urls=never",
 	    "-fdiagnostics-path-format=separate-events",
 	    "-fdiagnostics-text-art-charset=none",
-	    "-fno-diagnostics-show-event-links"
+	    "-fno-diagnostics-show-event-links",
+	    "-fno-diagnostics-show-nesting"
 	    /* We don't put "-fno-diagnostics-show-highlight-colors" here
 	       as -fdiagnostics-color=never makes it redundant.  */
 	  };
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 1468b09..a02d017 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -3052,6 +3052,18 @@ common_handle_option (struct gcc_options *opts,
       dc->set_show_option_requested (value);
       break;
 
+    case OPT_fdiagnostics_show_nesting:
+      dc->set_show_nesting (value);
+      break;
+
+    case OPT_fdiagnostics_show_nesting_locations:
+      dc->set_show_nesting_locations (value);
+      break;
+
+    case OPT_fdiagnostics_show_nesting_levels:
+      dc->set_show_nesting_levels (value);
+      break;
+
     case OPT_fdiagnostics_minimum_margin_width_:
       dc->get_source_printing_options ().min_margin_width = value;
       break;
@@ -3880,6 +3892,9 @@ gen_command_line_string (cl_decoded_option *options,
       case OPT_fdiagnostics_show_line_numbers:
       case OPT_fdiagnostics_color_:
       case OPT_fdiagnostics_format_:
+      case OPT_fdiagnostics_show_nesting:
+      case OPT_fdiagnostics_show_nesting_locations:
+      case OPT_fdiagnostics_show_nesting_levels:
       case OPT_fverbose_asm:
       case OPT____:
       case OPT__sysroot_:
diff --git a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1-truncated.C b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1-truncated.C
index 0cb1610..5b5e3fe 100644
--- a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1-truncated.C
+++ b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1-truncated.C
@@ -1,6 +1,6 @@
 // { dg-do compile { target c++17 } }
 // { dg-options "-fconcepts" }
-// { dg-additional-options "-fdiagnostics-set-output=text:experimental-nesting=yes,experimental-nesting-show-locations=no" }
+// { dg-additional-options "-fdiagnostics-set-output=text:show-nesting=yes,show-nesting-locations=no" }
 
 struct dog {};
 struct cat {};
diff --git a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1.C b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1.C
index e642676..a071b55 100644
--- a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1.C
+++ b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-1.C
@@ -1,6 +1,6 @@
 // { dg-do compile { target c++17 } }
 // { dg-options "-fconcepts" }
-// { dg-additional-options "-fdiagnostics-set-output=text:experimental-nesting=yes,experimental-nesting-show-locations=no" }
+// { dg-additional-options "-fdiagnostics-set-output=text:show-nesting=yes,show-nesting-locations=no" }
 // { dg-additional-options "-fconcepts-diagnostics-depth=3" }
 
 struct dog {};
diff --git a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-2.C b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-2.C
index cc15f11..9530bc1 100644
--- a/gcc/testsuite/g++.dg/concepts/nested-diagnostics-2.C
+++ b/gcc/testsuite/g++.dg/concepts/nested-diagnostics-2.C
@@ -1,6 +1,6 @@
 // { dg-do compile { target c++17 } }
 // { dg-options "-fconcepts" }
-// { dg-additional-options "-fdiagnostics-set-output=text:experimental-nesting=yes,experimental-nesting-show-locations=no" }
+// { dg-additional-options "-fdiagnostics-set-output=text:show-nesting=yes,show-nesting-locations=no" }
 
 struct dog{};
 struct cat{};
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-no-show-nesting.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-no-show-nesting.c
new file mode 100644
index 0000000..3492899
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-no-show-nesting.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-fno-diagnostics-show-nesting" } */
+
+extern void foo (void);
+
+void test_nesting (void)
+{
+  foo (); /* { dg-error "top-level error" } */
+}
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-show-nesting.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-show-nesting.c
new file mode 100644
index 0000000..8fc2edb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-show-nesting.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-fdiagnostics-show-nesting" } */
+
+extern void foo (void);
+
+void test_nesting (void)
+{
+  foo (); /* { dg-error "top-level error" } */
+}
+
+/* { dg-begin-multiline-output "" }
+  * child 0
+    * grandchild 0 0
+    * grandchild 0 1
+    * grandchild 0 2
+  * child 1
+    * grandchild 1 0
+    * grandchild 1 1
+    * grandchild 1 2
+  * child 2
+    * grandchild 2 0
+    * grandchild 2 1
+    * grandchild 2 2
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-show-levels.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-show-levels.c
index f44c8eb..4be52fe 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-show-levels.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-show-levels.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-fdiagnostics-set-output=text:experimental-nesting=yes,experimental-nesting-show-levels=yes" } */
+/* { dg-options "-fdiagnostics-set-output=text:show-nesting=yes,show-nesting-levels=yes" } */
 
 extern void foo (void);
 
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-unicode.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-unicode.c
index 39e29f7..c069c3f 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-unicode.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented-unicode.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-fdiagnostics-set-output=text:experimental-nesting=yes -fdiagnostics-text-art-charset=unicode" } */
+/* { dg-options "-fdiagnostics-set-output=text:show-nesting=yes -fdiagnostics-text-art-charset=unicode" } */
 
 extern void foo (void);
 
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented.c
index e103429..a35254d 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-nesting-text-indented.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-fdiagnostics-set-output=text:experimental-nesting=yes" } */
+/* { dg-options "-fdiagnostics-set-output=text:show-nesting=yes" } */
 
 extern void foo (void);
 
diff --git a/gcc/testsuite/gcc.dg/plugin/plugin.exp b/gcc/testsuite/gcc.dg/plugin/plugin.exp
index 3bb6063..c7cc36c 100644
--- a/gcc/testsuite/gcc.dg/plugin/plugin.exp
+++ b/gcc/testsuite/gcc.dg/plugin/plugin.exp
@@ -112,6 +112,8 @@ set plugin_test_list [list \
 	  diagnostic-test-graphs-html.c \
 	  diagnostic-test-graphs-sarif.c } \
     { diagnostic_plugin_test_nesting.cc \
+	  diagnostic-test-nesting-show-nesting.c \
+	  diagnostic-test-nesting-no-show-nesting.c \
 	  diagnostic-test-nesting-text-plain.c \
 	  diagnostic-test-nesting-text-indented.c \
 	  diagnostic-test-nesting-text-indented-show-levels.c \
diff --git a/gcc/toplev.cc b/gcc/toplev.cc
index d349d83..d264674 100644
--- a/gcc/toplev.cc
+++ b/gcc/toplev.cc
@@ -1094,6 +1094,12 @@ general_init (const char *argv0, bool init_signals, unique_argv original_argv)
     = global_options_init.x_flag_show_column;
   global_dc->set_show_highlight_colors
     (global_options_init.x_flag_diagnostics_show_highlight_colors);
+  global_dc->set_show_nesting
+    (global_options_init.x_flag_diagnostics_show_nesting);
+  global_dc->set_show_nesting_locations
+    (global_options_init.x_flag_diagnostics_show_nesting_locations);
+  global_dc->set_show_nesting_levels
+    (global_options_init.x_flag_diagnostics_show_nesting_levels);
   global_dc->set_internal_error_callback (internal_error_function);
   const unsigned lang_mask = lang_hooks.option_lang_mask ();
   global_dc->set_option_id_manager