[committed] Less verbose fix-it hints for missing header files (PR 87091)

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 95cff21..2fb348c 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -6133,7 +6133,7 @@  c_cpp_error (cpp_reader *pfile ATTRIBUTE_UNUSED, int level, int reason,
       gcc_unreachable ();
     }
   if (done_lexing)
-    richloc->set_range (0, input_location, true);
+    richloc->set_range (0, input_location, SHOW_RANGE_WITH_CARET);
   diagnostic_set_info_translated (&diagnostic, msg, ap,
 				  richloc, dlevel);
   diagnostic_override_option_index (&diagnostic,
@@ -8338,8 +8338,8 @@  maybe_suggest_missing_token_insertion (rich_location *richloc,
       location_t hint_loc = hint->get_start_loc ();
       location_t old_loc = richloc->get_loc ();
 
-      richloc->set_range (0, hint_loc, true);
-      richloc->add_range (old_loc, false);
+      richloc->set_range (0, hint_loc, SHOW_RANGE_WITH_CARET);
+      richloc->add_range (old_loc);
     }
 }
 
@@ -8477,10 +8477,16 @@  static added_includes_t *added_includes;
    location.
 
    This function is idempotent: a header will be added at most once to
-   any given file.  */
+   any given file.
+
+   If OVERRIDE_LOCATION is true, then if a fix-it is added and will be
+   printed, then RICHLOC's primary location will be replaced by that of
+   the fix-it hint (for use by "inform" notes where the location of the
+   issue has already been reported).  */
 
 void
-maybe_add_include_fixit (rich_location *richloc, const char *header)
+maybe_add_include_fixit (rich_location *richloc, const char *header,
+			 bool override_location)
 {
   location_t loc = richloc->get_loc ();
   const char *file = LOCATION_FILE (loc);
@@ -8508,6 +8514,33 @@  maybe_add_include_fixit (rich_location *richloc, const char *header)
   char *text = xasprintf ("#include %s\n", header);
   richloc->add_fixit_insert_before (include_insert_loc, text);
   free (text);
+
+  if (override_location && global_dc->show_caret)
+    {
+      /* Replace the primary location with that of the insertion point for the
+	 fix-it hint.
+
+	 We use SHOW_LINES_WITHOUT_RANGE so that we don't meaningless print a
+	 caret for the insertion point (or colorize it).
+
+	 Hence we print e.g.:
+
+	 ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:74:1: note: msg 2
+	  73 | # include <debug/vector>
+	 +++ |+#include <vector>
+	  74 | #endif
+
+	 rather than:
+
+	 ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:74:1: note: msg 2
+	  73 | # include <debug/vector>
+	 +++ |+#include <vector>
+	  74 | #endif
+	     | ^
+
+	 avoiding the caret on the first column of line 74.  */
+      richloc->set_range (0, include_insert_loc, SHOW_LINES_WITHOUT_RANGE);
+    }
 }
 
 /* Attempt to convert a braced array initializer list CTOR for array
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 9b05e60..c5e2028 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1327,7 +1327,7 @@  excess_precision_mode_join (enum flt_eval_method, enum flt_eval_method);
 extern int c_flt_eval_method (bool ts18661_p);
 extern void add_no_sanitize_value (tree node, unsigned int flags);
 
-extern void maybe_add_include_fixit (rich_location *, const char *);
+extern void maybe_add_include_fixit (rich_location *, const char *, bool);
 extern void maybe_suggest_missing_token_insertion (rich_location *richloc,
 						   enum cpp_ttype token_type,
 						   location_t prev_token_loc);
diff --git a/gcc/c-family/c-format.c b/gcc/c-family/c-format.c
index 035878f..98c49cf 100644
--- a/gcc/c-family/c-format.c
+++ b/gcc/c-family/c-format.c
@@ -4352,7 +4352,7 @@  test_type_mismatch_range_labels ()
   range_label_for_type_mismatch param_label (integer_type_node,
 					     char_type_node);
   gcc_rich_location richloc (fmt, &fmt_label);
-  richloc.add_range (param, false, &param_label);
+  richloc.add_range (param, SHOW_RANGE_WITHOUT_CARET, &param_label);
 
   test_diagnostic_context dc;
   diagnostic_show_locus (&dc, &richloc, DK_ERROR);
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
index ca259aa..7090a6f 100644
--- a/gcc/c-family/c-warn.c
+++ b/gcc/c-family/c-warn.c
@@ -2429,7 +2429,7 @@  warn_for_restrict (unsigned param_pos, tree *argarray, unsigned nargs)
     {
       arg = argarray[pos - 1];
       if (EXPR_HAS_LOCATION (arg))
-	richloc.add_range (EXPR_LOCATION (arg), false);
+	richloc.add_range (EXPR_LOCATION (arg));
     }
 
   return warning_n (&richloc, OPT_Wrestrict, arg_positions.length (),
diff --git a/gcc/c-family/known-headers.cc b/gcc/c-family/known-headers.cc
index 5524d21..b0763cf 100644
--- a/gcc/c-family/known-headers.cc
+++ b/gcc/c-family/known-headers.cc
@@ -192,7 +192,7 @@  suggest_missing_header::~suggest_missing_header ()
     return;
 
   gcc_rich_location richloc (get_location ());
-  maybe_add_include_fixit (&richloc, m_header_hint);
+  maybe_add_include_fixit (&richloc, m_header_hint, true);
   inform (&richloc,
 	  "%qs is defined in header %qs;"
 	  " did you forget to %<#include %s%>?",
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 9524977..2fcf429 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -3445,7 +3445,7 @@  implicitly_declare (location_t loc, tree functionid)
 		  if (header != NULL && warned)
 		    {
 		      rich_location richloc (line_table, loc);
-		      maybe_add_include_fixit (&richloc, header);
+		      maybe_add_include_fixit (&richloc, header, true);
 		      inform (&richloc,
 			      "include %qs or provide a declaration of %qD",
 			      header, decl);
diff --git a/gcc/c/c-objc-common.c b/gcc/c/c-objc-common.c
index 238af19..12e777a 100644
--- a/gcc/c/c-objc-common.c
+++ b/gcc/c/c-objc-common.c
@@ -161,7 +161,8 @@  c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
     {
       t = va_arg (*text->args_ptr, tree);
       if (set_locus)
-	text->set_location (0, DECL_SOURCE_LOCATION (t), true);
+	text->set_location (0, DECL_SOURCE_LOCATION (t),
+			    SHOW_RANGE_WITH_CARET);
     }
 
   switch (*spec)
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 82ec4af..c3bd3c3 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -10737,14 +10737,14 @@  grokdeclarator (const cp_declarator *declarator,
       if (signed_p && unsigned_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_signed]);
-	  richloc.add_range (declspecs->locations[ds_unsigned], false);
+	  richloc.add_range (declspecs->locations[ds_unsigned]);
 	  error_at (&richloc,
 		    "%<signed%> and %<unsigned%> specified together");
 	}
       else if (long_p && short_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_long]);
-	  richloc.add_range (declspecs->locations[ds_short], false);
+	  richloc.add_range (declspecs->locations[ds_short]);
 	  error_at (&richloc, "%<long%> and %<short%> specified together");
 	}
       else if (TREE_CODE (type) != INTEGER_TYPE
@@ -10888,7 +10888,7 @@  grokdeclarator (const cp_declarator *declarator,
       if (staticp == 2)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-	  richloc.add_range (declspecs->locations[ds_storage_class], false);
+	  richloc.add_range (declspecs->locations[ds_storage_class]);
 	  error_at (&richloc, "member %qD cannot be declared both %<virtual%> "
 		    "and %<static%>", dname);
 	  storage_class = sc_none;
@@ -10897,7 +10897,7 @@  grokdeclarator (const cp_declarator *declarator,
       if (constexpr_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-	  richloc.add_range (declspecs->locations[ds_constexpr], false);
+	  richloc.add_range (declspecs->locations[ds_constexpr]);
 	  error_at (&richloc, "member %qD cannot be declared both %<virtual%> "
 		    "and %<constexpr%>", dname);
 	}
@@ -11435,7 +11435,7 @@  grokdeclarator (const cp_declarator *declarator,
 		  {
 		    /* Cannot be both friend and virtual.  */
 		    gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-		    richloc.add_range (declspecs->locations[ds_friend], false);
+		    richloc.add_range (declspecs->locations[ds_friend]);
 		    error_at (&richloc, "virtual functions cannot be friends");
 		    friendp = 0;
 		  }
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 452ecb9..5bab3f3 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -4119,7 +4119,7 @@  cp_printer (pretty_printer *pp, text_info *text, const char *spec,
 
   pp_string (pp, result);
   if (set_locus && t != NULL)
-    text->set_location (0, location_of (t), true);
+    text->set_location (0, location_of (t), SHOW_RANGE_WITH_CARET);
   return true;
 #undef next_tree
 #undef next_tcode
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 8c7f685..540ff21 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -5630,7 +5630,7 @@  maybe_suggest_missing_std_header (location_t location, tree name)
   if (cxx_dialect >= header_hint->min_dialect)
     {
       const char *header = header_hint->header;
-      maybe_add_include_fixit (&richloc, header);
+      maybe_add_include_fixit (&richloc, header, true);
       inform (&richloc,
 	      "%<std::%s%> is defined in header %qs;"
 	      " did you forget to %<#include %s%>?",
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 49d476b..d8d4301 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -4133,7 +4133,7 @@  cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
 	      else if (curr_type != CPP_STRING)
 		{
 		  rich_location rich_loc (line_table, tok->location);
-		  rich_loc.add_range (last_tok_loc, false);
+		  rich_loc.add_range (last_tok_loc);
 		  error_at (&rich_loc,
 			    "unsupported non-standard concatenation "
 			    "of string literals");
@@ -17755,7 +17755,7 @@  cp_parser_elaborated_type_specifier (cp_parser* parser,
 	  || cp_parser_is_keyword (token, RID_STRUCT))
 	{
 	  gcc_rich_location richloc (token->location);
-	  richloc.add_range (input_location, false);
+	  richloc.add_range (input_location);
 	  richloc.add_fixit_remove ();
 	  pedwarn (&richloc, 0, "elaborated-type-specifier for "
 		   "a scoped enum must not use the %qD keyword",
@@ -28390,7 +28390,7 @@  set_and_check_decl_spec_loc (cp_decl_specifier_seq *decl_specs,
 	  gcc_rich_location richloc (location);
 	  if (gnu != decl_specs->gnu_thread_keyword_p)
 	    {
-	      richloc.add_range (decl_specs->locations[ds_thread], false);
+	      richloc.add_range (decl_specs->locations[ds_thread]);
 	      error_at (&richloc,
 			"both %<__thread%> and %<thread_local%> specified");
 	    }
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index efed9a1..a7266e3 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -26077,7 +26077,7 @@  listify (tree arg)
   if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
     {    
       gcc_rich_location richloc (input_location);
-      maybe_add_include_fixit (&richloc, "<initializer_list>");
+      maybe_add_include_fixit (&richloc, "<initializer_list>", false);
       error_at (&richloc,
 		"deducing from brace-enclosed initializer list"
 		" requires %<#include <initializer_list>%>");
diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c
index 6692fb7..94a9219 100644
--- a/gcc/cp/rtti.c
+++ b/gcc/cp/rtti.c
@@ -317,7 +317,7 @@  typeid_ok_p (void)
   if (!COMPLETE_TYPE_P (const_type_info_type_node))
     {
       gcc_rich_location richloc (input_location);
-      maybe_add_include_fixit (&richloc, "<typeinfo>");
+      maybe_add_include_fixit (&richloc, "<typeinfo>", false);
       error_at (&richloc,
 		"must %<#include <typeinfo>%> before using"
 		" %<typeid%>");
diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c
index d305ada..6ce8a0f 100644
--- a/gcc/diagnostic-show-locus.c
+++ b/gcc/diagnostic-show-locus.c
@@ -126,7 +126,7 @@  class layout_range
  public:
   layout_range (const expanded_location *start_exploc,
 		const expanded_location *finish_exploc,
-		bool show_caret_p,
+		enum range_display_kind range_display_kind,
 		const expanded_location *caret_exploc,
 		const range_label *label);
 
@@ -135,7 +135,7 @@  class layout_range
 
   layout_point m_start;
   layout_point m_finish;
-  bool m_show_caret_p;
+  enum range_display_kind m_range_display_kind;
   layout_point m_caret;
   const range_label *m_label;
 };
@@ -412,12 +412,12 @@  colorizer::get_color_by_name (const char *name)
 
 layout_range::layout_range (const expanded_location *start_exploc,
 			    const expanded_location *finish_exploc,
-			    bool show_caret_p,
+			    enum range_display_kind range_display_kind,
 			    const expanded_location *caret_exploc,
 			    const range_label *label)
 : m_start (*start_exploc),
   m_finish (*finish_exploc),
-  m_show_caret_p (show_caret_p),
+  m_range_display_kind (range_display_kind),
   m_caret (*caret_exploc),
   m_label (label)
 {
@@ -545,7 +545,7 @@  make_range (int start_line, int start_col, int end_line, int end_col)
     = {"test.c", start_line, start_col, NULL, false};
   const expanded_location finish_exploc
     = {"test.c", end_line, end_col, NULL, false};
-  return layout_range (&start_exploc, &finish_exploc, false,
+  return layout_range (&start_exploc, &finish_exploc, SHOW_RANGE_WITHOUT_CARET,
 		       &start_exploc, NULL);
 }
 
@@ -986,13 +986,13 @@  layout::maybe_add_location_range (const location_range *loc_range,
     return false;
   if (finish.file != m_exploc.file)
     return false;
-  if (loc_range->m_show_caret_p)
+  if (loc_range->m_range_display_kind == SHOW_RANGE_WITH_CARET)
     if (caret.file != m_exploc.file)
       return false;
 
   /* Sanitize the caret location for non-primary ranges.  */
   if (m_layout_ranges.length () > 0)
-    if (loc_range->m_show_caret_p)
+    if (loc_range->m_range_display_kind == SHOW_RANGE_WITH_CARET)
       if (!compatible_locations_p (loc_range->m_loc, m_primary_loc))
 	/* Discard any non-primary ranges that can't be printed
 	   sanely relative to the primary location.  */
@@ -1000,7 +1000,7 @@  layout::maybe_add_location_range (const location_range *loc_range,
 
   /* Everything is now known to be in the correct source file,
      but it may require further sanitization.  */
-  layout_range ri (&start, &finish, loc_range->m_show_caret_p, &caret,
+  layout_range ri (&start, &finish, loc_range->m_range_display_kind, &caret,
 		   loc_range->m_label);
 
   /* If we have a range that finishes before it starts (perhaps
@@ -1037,7 +1037,7 @@  layout::maybe_add_location_range (const location_range *loc_range,
 	return false;
       if (!will_show_line_p (finish.line))
 	return false;
-      if (loc_range->m_show_caret_p)
+      if (loc_range->m_range_display_kind == SHOW_RANGE_WITH_CARET)
 	if (!will_show_line_p (caret.line))
 	  return false;
     }
@@ -1362,8 +1362,12 @@  layout::should_print_annotation_line_p (linenum_type row) const
   layout_range *range;
   int i;
   FOR_EACH_VEC_ELT (m_layout_ranges, i, range)
-    if (range->intersects_line_p (row))
-      return true;
+    {
+      if (range->m_range_display_kind == SHOW_LINES_WITHOUT_RANGE)
+	return false;
+      if (range->intersects_line_p (row))
+	return true;
+    }
   return false;
 }
 
@@ -2102,13 +2106,18 @@  layout::get_state_at_point (/* Inputs.  */
   int i;
   FOR_EACH_VEC_ELT (m_layout_ranges, i, range)
     {
+      if (range->m_range_display_kind == SHOW_LINES_WITHOUT_RANGE)
+	/* Bail out early, so that such ranges don't affect underlining or
+	   source colorization.  */
+	continue;
+
       if (range->contains_point (row, column))
 	{
 	  out_state->range_idx = i;
 
 	  /* Are we at the range's caret?  is it visible? */
 	  out_state->draw_caret_p = false;
-	  if (range->m_show_caret_p
+	  if (range->m_range_display_kind == SHOW_RANGE_WITH_CARET
 	      && row == range->m_caret.m_line
 	      && column == range->m_caret.m_column)
 	    out_state->draw_caret_p = true;
@@ -2267,11 +2276,11 @@  gcc_rich_location::add_location_if_nearby (location_t loc)
   layout layout (global_dc, this, DK_ERROR);
   location_range loc_range;
   loc_range.m_loc = loc;
-  loc_range.m_show_caret_p = false;
+  loc_range.m_range_display_kind = SHOW_RANGE_WITHOUT_CARET;
   if (!layout.maybe_add_location_range (&loc_range, true))
     return false;
 
-  add_range (loc, false);
+  add_range (loc);
   return true;
 }
 
@@ -2421,8 +2430,8 @@  test_one_liner_multiple_carets_and_ranges ()
   dc.caret_chars[2] = 'C';
 
   rich_location richloc (line_table, foo);
-  richloc.add_range (bar, true);
-  richloc.add_range (field, true);
+  richloc.add_range (bar, SHOW_RANGE_WITH_CARET);
+  richloc.add_range (field, SHOW_RANGE_WITH_CARET);
   diagnostic_show_locus (&dc, &richloc, DK_ERROR);
   ASSERT_STREQ ("\n"
 		" foo = bar.field;\n"
@@ -2543,7 +2552,7 @@  test_one_liner_fixit_replace_equal_secondary_range ()
   location_t finish = linemap_position_for_column (line_table, 15);
   rich_location richloc (line_table, equals);
   location_t field = make_location (start, start, finish);
-  richloc.add_range (field, false);
+  richloc.add_range (field);
   richloc.add_fixit_replace (field, "m_field");
   diagnostic_show_locus (&dc, &richloc, DK_ERROR);
   /* The replacement range is indicated in the annotation line,
@@ -2690,8 +2699,8 @@  test_one_liner_labels ()
     text_range_label label1 ("1");
     text_range_label label2 ("2");
     gcc_rich_location richloc (foo, &label0);
-    richloc.add_range (bar, false, &label1);
-    richloc.add_range (field, false, &label2);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
+    richloc.add_range (field, SHOW_RANGE_WITHOUT_CARET, &label2);
 
     {
       test_diagnostic_context dc;
@@ -2722,8 +2731,8 @@  test_one_liner_labels ()
     text_range_label label1 ("label 1");
     text_range_label label2 ("label 2");
     gcc_rich_location richloc (foo, &label0);
-    richloc.add_range (bar, false, &label1);
-    richloc.add_range (field, false, &label2);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
+    richloc.add_range (field, SHOW_RANGE_WITHOUT_CARET, &label2);
 
     test_diagnostic_context dc;
     diagnostic_show_locus (&dc, &richloc, DK_ERROR);
@@ -2744,8 +2753,8 @@  test_one_liner_labels ()
     text_range_label label1 ("bbbb");
     text_range_label label2 ("c");
     gcc_rich_location richloc (foo, &label0);
-    richloc.add_range (bar, false, &label1);
-    richloc.add_range (field, false, &label2);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
+    richloc.add_range (field, SHOW_RANGE_WITHOUT_CARET, &label2);
 
     test_diagnostic_context dc;
     diagnostic_show_locus (&dc, &richloc, DK_ERROR);
@@ -2764,8 +2773,8 @@  test_one_liner_labels ()
     text_range_label label1 ("1");
     text_range_label label2 ("2");
     gcc_rich_location richloc (field, &label0);
-    richloc.add_range (bar, false, &label1);
-    richloc.add_range (foo, false, &label2);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
+    richloc.add_range (foo, SHOW_RANGE_WITHOUT_CARET, &label2);
 
     test_diagnostic_context dc;
     diagnostic_show_locus (&dc, &richloc, DK_ERROR);
@@ -2784,8 +2793,8 @@  test_one_liner_labels ()
     text_range_label label1 ("label 1");
     text_range_label label2 ("label 2");
     gcc_rich_location richloc (bar, &label0);
-    richloc.add_range (bar, false, &label1);
-    richloc.add_range (bar, false, &label2);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
+    richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label2);
 
     test_diagnostic_context dc;
     diagnostic_show_locus (&dc, &richloc, DK_ERROR);
diff --git a/gcc/fortran/error.c b/gcc/fortran/error.c
index 7e882ba..b3b0138 100644
--- a/gcc/fortran/error.c
+++ b/gcc/fortran/error.c
@@ -953,7 +953,7 @@  gfc_format_decoder (pretty_printer *pp, text_info *text, const char *spec,
 	  = linemap_position_for_loc_and_offset (line_table,
 						 loc->lb->location,
 						 offset);
-	text->set_location (loc_num, src_loc, true);
+	text->set_location (loc_num, src_loc, SHOW_RANGE_WITH_CARET);
 	pp_string (pp, result[loc_num]);
 	return true;
       }
diff --git a/gcc/gcc-rich-location.c b/gcc/gcc-rich-location.c
index 2576c73..81beb61 100644
--- a/gcc/gcc-rich-location.c
+++ b/gcc/gcc-rich-location.c
@@ -47,7 +47,7 @@  gcc_rich_location::add_expr (tree expr, range_label *label)
   gcc_assert (expr);
 
   if (CAN_HAVE_RANGE_P (expr))
-    add_range (EXPR_LOCATION (expr), false, label);
+    add_range (EXPR_LOCATION (expr), SHOW_RANGE_WITHOUT_CARET, label);
 }
 
 /* If T is an expression, add a range for it to the rich_location,
diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c
index 02967d0..7dd900b 100644
--- a/gcc/pretty-print.c
+++ b/gcc/pretty-print.c
@@ -705,10 +705,11 @@  static void pp_quoted_string (pretty_printer *, const char *, size_t = -1);
    For use e.g. when implementing "+" in client format decoders.  */
 
 void
-text_info::set_location (unsigned int idx, location_t loc, bool show_caret_p)
+text_info::set_location (unsigned int idx, location_t loc,
+			 enum range_display_kind range_display_kind)
 {
   gcc_checking_assert (m_richloc);
-  m_richloc->set_range (idx, loc, show_caret_p);
+  m_richloc->set_range (idx, loc, range_display_kind);
 }
 
 location_t
diff --git a/gcc/pretty-print.h b/gcc/pretty-print.h
index 0d67e30..2decc51 100644
--- a/gcc/pretty-print.h
+++ b/gcc/pretty-print.h
@@ -36,7 +36,8 @@  struct text_info
   void **x_data;
   rich_location *m_richloc;
 
-  void set_location (unsigned int idx, location_t loc, bool caret_p);
+  void set_location (unsigned int idx, location_t loc,
+		     enum range_display_kind range_display_kind);
   location_t get_location (unsigned int index_of_location) const;
 };
 
diff --git a/gcc/substring-locations.c b/gcc/substring-locations.c
index 1981394..faf7884 100644
--- a/gcc/substring-locations.c
+++ b/gcc/substring-locations.c
@@ -171,7 +171,7 @@  format_warning_n_va (const substring_loc &fmt_loc,
   gcc_rich_location richloc (primary_loc, primary_label);
 
   if (param_loc != UNKNOWN_LOCATION)
-    richloc.add_range (param_loc, false, param_label);
+    richloc.add_range (param_loc, SHOW_RANGE_WITHOUT_CARET, param_label);
 
   if (!err && corrected_substring && substring_within_range)
     richloc.add_fixit_replace (fmt_substring_range, corrected_substring);
diff --git a/gcc/testsuite/gcc.dg/empty.h b/gcc/testsuite/gcc.dg/empty.h
new file mode 100644
index 0000000..e69de29
diff --git a/gcc/testsuite/gcc.dg/fixits-pr84852-1.c b/gcc/testsuite/gcc.dg/fixits-pr84852-1.c
index 98087ab..346626b 100644
--- a/gcc/testsuite/gcc.dg/fixits-pr84852-1.c
+++ b/gcc/testsuite/gcc.dg/fixits-pr84852-1.c
@@ -13,13 +13,10 @@ 
 int foo (void) { return strlen(""); }
 
 /* { dg-warning "incompatible implicit declaration of built-in function 'strlen'" "" { target *-*-* } -812156810 } */
-/* { dg-message "include '<string.h>' or provide a declaration of 'strlen'" "" { target *-*-* } -812156810 } */
+/* { dg-message "include '<string.h>' or provide a declaration of 'strlen'" "" { target *-*-* } 1 } */
 #if 0
 { dg-begin-multiline-output "" }
 +#include <string.h>
  /* This is padding (to avoid the output containing DejaGnu directives).  */
 { dg-end-multiline-output "" }
 #endif
-
-/* We need this, to consume a stray line marker for the bogus line.  */
-/* { dg-regexp ".*fixits-pr84852-1.c:-812156810:25:" } */
diff --git a/gcc/testsuite/gcc.dg/fixits-pr84852-2.c b/gcc/testsuite/gcc.dg/fixits-pr84852-2.c
index 0674ef5..9bc70f5 100644
--- a/gcc/testsuite/gcc.dg/fixits-pr84852-2.c
+++ b/gcc/testsuite/gcc.dg/fixits-pr84852-2.c
@@ -13,13 +13,10 @@ 
 int foo (void) { return strlen(""); }
 
 /* { dg-warning "incompatible implicit declaration of built-in function 'strlen'" "" { target *-*-* } -812156810 } */
-/* { dg-message "include '<string.h>' or provide a declaration of 'strlen'" "" { target *-*-* } -812156810 } */
+/* { dg-message "include '<string.h>' or provide a declaration of 'strlen'" "" { target *-*-* } 1 } */
 #if 0
 { dg-begin-multiline-output "" }
 +#include <string.h>
  /* This is padding (to avoid the output containing DejaGnu directives).  */
 { dg-end-multiline-output "" }
 #endif
-
-/* We need this, to consume a stray line marker for the bogus line.  */
-/* { dg-regexp ".*fixits-pr84852-2.c:-812156810:25:" } */
diff --git a/gcc/testsuite/gcc.dg/missing-header-fixit-3.c b/gcc/testsuite/gcc.dg/missing-header-fixit-3.c
index 7c72b1d..a692b4d 100644
--- a/gcc/testsuite/gcc.dg/missing-header-fixit-3.c
+++ b/gcc/testsuite/gcc.dg/missing-header-fixit-3.c
@@ -7,18 +7,15 @@ 
 void test (int i, int j)
 {
   printf ("%i of %i\n", i, j); /* { dg-warning "implicit declaration" } */
-  /* { dg-message "include '<stdio.h>' or provide a declaration of 'printf'" "" { target *-*-* } .-1 } */
+  /* { dg-message "include '<stdio.h>' or provide a declaration of 'printf'" "" { target *-*-* } 1 } */
 #if 0
 /* { dg-begin-multiline-output "" }
 9 |   printf ("%i of %i\n", i, j);
   |   ^~~~~~
    { dg-end-multiline-output "" } */
 /* { dg-begin-multiline-output "" }
-+++ |+#include <stdio.h>
-  1 | /* Example of a fix-it hint that adds a #include directive,
-....
-  9 |   printf ("%i of %i\n", i, j);
-    |   ^~~~~~
++ |+#include <stdio.h>
+1 | /* Example of a fix-it hint that adds a #include directive,
    { dg-end-multiline-output "" } */
 #endif
 }
diff --git a/gcc/testsuite/gcc.dg/missing-header-fixit-4.c b/gcc/testsuite/gcc.dg/missing-header-fixit-4.c
new file mode 100644
index 0000000..0ed3e2c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/missing-header-fixit-4.c
@@ -0,0 +1,23 @@ 
+/* Example of a fix-it hint that adds a #include directive,
+   adding them after a pre-existing #include directive.  */
+#include "empty.h"
+int the_next_line;
+
+/* { dg-options "-fdiagnostics-show-caret -fdiagnostics-show-line-numbers" } */
+
+void test (int i, int j)
+{
+  printf ("%i of %i\n", i, j); /* { dg-line printf } */
+  /* { dg-warning "implicit declaration of function" "" { target *-*-* } printf } */
+  /* { dg-warning "incompatible implicit declaration" "" { target *-*-* } printf } */
+  /* { dg-begin-multiline-output "" }
+10 |   printf ("%i of %i\n", i, j);
+   |   ^~~~~~
+   { dg-end-multiline-output "" } */
+  /* { dg-message "include '<stdio.h>' or provide a declaration of 'printf'" "" { target *-*-* } 4 } */
+  /* { dg-begin-multiline-output "" }
+3 | #include "empty.h"
++ |+#include <stdio.h>
+4 | int the_next_line;
+   { dg-end-multiline-output "" } */
+}
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_show_locus.c b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
index 3d78538..a55efaf 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
@@ -145,9 +145,11 @@  custom_diagnostic_finalizer (diagnostic_context *context,
 
 static void
 add_range (rich_location *richloc, location_t start, location_t finish,
-	   bool show_caret_p, const range_label *label = NULL)
+	   enum range_display_kind range_display_kind
+	     = SHOW_RANGE_WITHOUT_CARET,
+	   const range_label *label = NULL)
 {
-  richloc->add_range (make_location (start, start, finish), show_caret_p,
+  richloc->add_range (make_location (start, start, finish), range_display_kind,
 		      label);
 }
 
@@ -176,8 +178,8 @@  test_show_locus (function *fun)
     {
       const int line = fnstart_line + 2;
       rich_location richloc (line_table, get_loc (line, 15));
-      add_range (&richloc, get_loc (line, 10), get_loc (line, 14), false);
-      add_range (&richloc, get_loc (line, 16), get_loc (line, 16), false);
+      add_range (&richloc, get_loc (line, 10), get_loc (line, 14));
+      add_range (&richloc, get_loc (line, 16), get_loc (line, 16));
       warning_at (&richloc, 0, "test");
     }
 
@@ -185,8 +187,8 @@  test_show_locus (function *fun)
     {
       const int line = fnstart_line + 2;
       rich_location richloc (line_table, get_loc (line, 24));
-      add_range (&richloc, get_loc (line, 6), get_loc (line, 22), false);
-      add_range (&richloc, get_loc (line, 26), get_loc (line, 43), false);
+      add_range (&richloc, get_loc (line, 6), get_loc (line, 22));
+      add_range (&richloc, get_loc (line, 26), get_loc (line, 43));
       warning_at (&richloc, 0, "test");
     }
 
@@ -195,9 +197,8 @@  test_show_locus (function *fun)
       const int line = fnstart_line + 2;
       text_range_label label ("label");
       rich_location richloc (line_table, get_loc (line + 1, 7), &label);
-      add_range (&richloc, get_loc (line, 7), get_loc (line, 23), false);
-      add_range (&richloc, get_loc (line + 1, 9), get_loc (line + 1, 26),
-		 false);
+      add_range (&richloc, get_loc (line, 7), get_loc (line, 23));
+      add_range (&richloc, get_loc (line + 1, 9), get_loc (line + 1, 26));
       warning_at (&richloc, 0, "test");
     }
 
@@ -208,10 +209,10 @@  test_show_locus (function *fun)
       text_range_label label1 ("label 1");
       text_range_label label2 ("label 2");
       rich_location richloc (line_table, get_loc (line + 5, 7), &label0);
-      add_range (&richloc, get_loc (line, 7), get_loc (line + 4, 65), false,
-		 &label1);
+      add_range (&richloc, get_loc (line, 7), get_loc (line + 4, 65),
+		 SHOW_RANGE_WITHOUT_CARET, &label1);
       add_range (&richloc, get_loc (line + 5, 9), get_loc (line + 10, 61),
-		 false, &label2);
+		 SHOW_RANGE_WITHOUT_CARET, &label2);
       warning_at (&richloc, 0, "test");
     }
 
@@ -250,7 +251,8 @@  test_show_locus (function *fun)
 					    get_loc (line, 90),
 					    get_loc (line, 98)),
 			     &label0);
-      richloc.add_range (get_loc (line, 35), false, &label1);
+      richloc.add_range (get_loc (line, 35), SHOW_RANGE_WITHOUT_CARET,
+			 &label1);
       richloc.add_fixit_replace ("bar * foo");
       warning_at (&richloc, 0, "test");
       global_dc->show_ruler_p = false;
@@ -270,7 +272,8 @@  test_show_locus (function *fun)
 					    get_loc (line, 98)),
 			     &label0);
       richloc.add_fixit_replace ("bar * foo");
-      richloc.add_range (get_loc (line, 34), false, &label1);
+      richloc.add_range (get_loc (line, 34), SHOW_RANGE_WITHOUT_CARET,
+			 &label1);
       warning_at (&richloc, 0, "test");
       global_dc->show_ruler_p = false;
     }
@@ -282,7 +285,7 @@  test_show_locus (function *fun)
       location_t caret_a = get_loc (line, 7);
       location_t caret_b = get_loc (line, 11);
       rich_location richloc (line_table, caret_a);
-      add_range (&richloc, caret_b, caret_b, true);
+      add_range (&richloc, caret_b, caret_b, SHOW_RANGE_WITH_CARET);
       global_dc->caret_chars[0] = 'A';
       global_dc->caret_chars[1] = 'B';
       warning_at (&richloc, 0, "test");
@@ -400,7 +403,7 @@  test_show_locus (function *fun)
       location_t caret_a = get_loc (line, 5);
       location_t caret_b = get_loc (line - 1, 19);
       rich_location richloc (line_table, caret_a);
-      richloc.add_range (caret_b, true);
+      richloc.add_range (caret_b, SHOW_RANGE_WITH_CARET);
       global_dc->caret_chars[0] = '1';
       global_dc->caret_chars[1] = '2';
       warning_at (&richloc, 0, "test");
@@ -449,7 +452,7 @@  test_show_locus (function *fun)
 		      location_t word
 			= make_location (start_of_word, start_of_word,
 					 end_of_word);
-		      richloc.add_range (word, true, &label);
+		      richloc.add_range (word, SHOW_RANGE_WITH_CARET, &label);
 
 		      /* Add a fixit, converting to upper case.  */
 		      char_span word_span = content.subspan (start_idx, idx - start_idx);
diff --git a/gcc/tree-diagnostic.c b/gcc/tree-diagnostic.c
index 6b03b31..c4a200f 100644
--- a/gcc/tree-diagnostic.c
+++ b/gcc/tree-diagnostic.c
@@ -290,7 +290,7 @@  default_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
     }
 
   if (set_locus)
-    text->set_location (0, DECL_SOURCE_LOCATION (t), true);
+    text->set_location (0, DECL_SOURCE_LOCATION (t), SHOW_RANGE_WITH_CARET);
 
   if (DECL_P (t))
     {
diff --git a/gcc/tree-pretty-print.c b/gcc/tree-pretty-print.c
index 6221427..990cc21 100644
--- a/gcc/tree-pretty-print.c
+++ b/gcc/tree-pretty-print.c
@@ -3962,7 +3962,7 @@  newline_and_indent (pretty_printer *pp, int spc)
 void
 percent_K_format (text_info *text, location_t loc, tree block)
 {
-  text->set_location (0, loc, true);
+  text->set_location (0, loc, SHOW_RANGE_WITH_CARET);
   gcc_assert (pp_ti_abstract_origin (text) != NULL);
   *pp_ti_abstract_origin (text) = NULL;
 
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 4f0ff87..e74ccbb 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -1283,6 +1283,36 @@  typedef struct
 
 class range_label;
 
+/* A hint to diagnostic_show_locus on how to print a source range within a
+   rich_location.
+
+   Typically this is SHOW_RANGE_WITH_CARET for the 0th range, and
+   SHOW_RANGE_WITHOUT_CARET for subsequent ranges,
+   but the Fortran frontend uses SHOW_RANGE_WITH_CARET repeatedly for
+   printing things like:
+
+       x = x + y
+           1   2
+       Error: Shapes for operands at (1) and (2) are not conformable
+
+   where "1" and "2" are notionally carets.  */
+
+enum range_display_kind
+{
+  /* Show the pertinent source line(s), the caret, and underline(s).  */
+  SHOW_RANGE_WITH_CARET,
+
+  /* Show the pertinent source line(s) and underline(s), but don't
+     show the caret (just an underline).  */
+  SHOW_RANGE_WITHOUT_CARET,
+
+  /* Just show the source lines; don't show the range itself.
+     This is for use when displaying some line-insertion fix-it hints (for
+     showing the user context on the change, for when it doesn't make sense
+     to highlight the first column on the next line).  */
+  SHOW_LINES_WITHOUT_RANGE
+};
+
 /* A location within a rich_location: a caret&range, with
    the caret potentially flagged for display, and an optional
    label.  */
@@ -1291,16 +1321,7 @@  struct location_range
 {
   source_location m_loc;
 
-  /* Should a caret be drawn for this range?  Typically this is
-     true for the 0th range, and false for subsequent ranges,
-     but the Fortran frontend overrides this for rendering things like:
-
-       x = x + y
-           1   2
-       Error: Shapes for operands at (1) and (2) are not conformable
-
-     where "1" and "2" are notionally carets.  */
-  bool m_show_caret_p;
+  enum range_display_kind m_range_display_kind;
 
   /* If non-NULL, the label for this range.  */
   const range_label *m_label;
@@ -1567,6 +1588,18 @@  class fixit_hint;
    added via
      richloc.add_fixit_replace ("color");
 
+   Example J: fix-it hint: line insertion
+   **************************************
+
+     3 | #include <stddef.h>
+     + |+#include <stdio.h>
+     4 | int the_next_line;
+
+   This rich location has a single range at line 4 column 1, marked
+   with SHOW_LINES_WITHOUT_RANGE (to avoid printing a meaningless caret
+   on the "i" of int).  It has a insertion fix-it hint of the string
+   "#include <stdio.h>\n".
+
    Adding a fix-it hint can fail: for example, attempts to insert content
    at the transition between two line maps may fail due to there being no
    source_location (aka location_t) value to express the new location.
@@ -1610,11 +1643,14 @@  class rich_location
   source_location get_loc (unsigned int idx) const;
 
   void
-  add_range (source_location loc,  bool show_caret_p,
+  add_range (source_location loc,
+	     enum range_display_kind range_display_kind
+	       = SHOW_RANGE_WITHOUT_CARET,
 	     const range_label *label = NULL);
 
   void
-  set_range (unsigned int idx, source_location loc, bool show_caret_p);
+  set_range (unsigned int idx, source_location loc,
+	     enum range_display_kind range_display_kind);
 
   unsigned int get_num_locations () const { return m_ranges.count (); }
 
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index f0e6318..31a2b7a 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -1998,7 +1998,7 @@  rich_location::rich_location (line_maps *set, source_location loc,
   m_seen_impossible_fixit (false),
   m_fixits_cannot_be_auto_applied (false)
 {
-  add_range (loc, true, label);
+  add_range (loc, SHOW_RANGE_WITH_CARET, label);
 }
 
 /* The destructor for class rich_location.  */
@@ -2074,18 +2074,19 @@  rich_location::override_column (int column)
 /* Add the given range.  */
 
 void
-rich_location::add_range (source_location loc, bool show_caret_p,
+rich_location::add_range (source_location loc,
+			  enum range_display_kind range_display_kind,
 			  const range_label *label)
 {
   location_range range;
   range.m_loc = loc;
-  range.m_show_caret_p = show_caret_p;
+  range.m_range_display_kind = range_display_kind;
   range.m_label = label;
   m_ranges.push (range);
 }
 
 /* Add or overwrite the location given by IDX, setting its location to LOC,
-   and setting its "should my caret be printed" flag to SHOW_CARET_P.
+   and setting its m_range_display_kind to RANGE_DISPLAY_KIND.
 
    It must either overwrite an existing location, or add one *exactly* on
    the end of the array.
@@ -2099,19 +2100,19 @@  rich_location::add_range (source_location loc, bool show_caret_p,
 
 void
 rich_location::set_range (unsigned int idx, source_location loc,
-			  bool show_caret_p)
+			  enum range_display_kind range_display_kind)
 {
   /* We can either overwrite an existing range, or add one exactly
      on the end of the array.  */
   linemap_assert (idx <= m_ranges.count ());
 
   if (idx == m_ranges.count ())
-    add_range (loc,  show_caret_p);
+    add_range (loc, range_display_kind);
   else
     {
       location_range *locrange = get_range (idx);
       locrange->m_loc = loc;
-      locrange->m_show_caret_p = show_caret_p;
+      locrange->m_range_display_kind = range_display_kind;
     }
 
   if (idx == 0)