1 files changed, 724 insertions, 0 deletions

diff --git a/gcc/text-art/ruler.cc b/gcc/text-art/ruler.cc
new file mode 100644
index 0000000..3323a05
--- /dev/null
+++ b/gcc/text-art/ruler.cc
@@ -0,0 +1,724 @@
+/* Classes for printing labelled rulers.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_ALGORITHM
+#define INCLUDE_VECTOR
+#include "system.h"
+#include "coretypes.h"
+#include "pretty-print.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/ruler.h"
+#include "text-art/theme.h"
+
+using namespace text_art;
+
+void
+x_ruler::add_label (const canvas::range_t &r,
+		    styled_string text,
+		    style::id_t style_id,
+		    label_kind kind)
+{
+  m_labels.push_back (label (r, std::move (text), style_id, kind));
+  m_has_layout = false;
+}
+
+int
+x_ruler::get_canvas_y (int rel_y) const
+{
+  gcc_assert (rel_y >= 0);
+  gcc_assert (rel_y < m_size.h);
+  switch (m_label_dir)
+    {
+    default:
+      gcc_unreachable ();
+    case label_dir::ABOVE:
+      return m_size.h - (rel_y + 1);
+    case label_dir::BELOW:
+      return rel_y;
+    }
+}
+
+void
+x_ruler::paint_to_canvas (canvas &canvas,
+			  canvas::coord_t offset,
+			  const theme &theme)
+{
+  ensure_layout ();
+
+  if (0)
+    canvas.fill (canvas::rect_t (offset, m_size),
+		 canvas::cell_t ('*'));
+
+  for (size_t idx = 0; idx < m_labels.size (); idx++)
+    {
+      const label &iter_label = m_labels[idx];
+
+      /* Paint the ruler itself.  */
+      const int ruler_rel_y = get_canvas_y (0);
+      for (int rel_x = iter_label.m_range.start;
+	   rel_x < iter_label.m_range.next;
+	   rel_x++)
+	{
+	  enum theme::cell_kind kind = theme::cell_kind::X_RULER_MIDDLE;
+
+	  if (rel_x == iter_label.m_range.start)
+	    {
+	      kind = theme::cell_kind::X_RULER_LEFT_EDGE;
+	      if (idx > 0)
+		{
+		  const label &prev_label = m_labels[idx - 1];
+		  if (prev_label.m_range.get_max () == iter_label.m_range.start)
+		    kind = theme::cell_kind::X_RULER_INTERNAL_EDGE;
+		}
+	    }
+	  else if (rel_x == iter_label.m_range.get_max ())
+	    kind = theme::cell_kind::X_RULER_RIGHT_EDGE;
+	  else if (rel_x == iter_label.m_connector_x)
+	    {
+	      switch (m_label_dir)
+		{
+		default:
+		  gcc_unreachable ();
+		case label_dir::ABOVE:
+		  kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE;
+		  break;
+		case label_dir::BELOW:
+		  kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW;
+		  break;
+		}
+	    }
+	  canvas.paint (canvas::coord_t (rel_x, ruler_rel_y) + offset,
+			theme.get_cell (kind, iter_label.m_style_id));
+	}
+
+      /* Paint the connector to the text.  */
+      for (int connector_rel_y = 1;
+	   connector_rel_y < iter_label.m_text_rect.get_min_y ();
+	   connector_rel_y++)
+	{
+	  canvas.paint
+	    ((canvas::coord_t (iter_label.m_connector_x,
+			       get_canvas_y (connector_rel_y))
+	      + offset),
+	     theme.get_cell (theme::cell_kind::X_RULER_VERTICAL_CONNECTOR,
+			     iter_label.m_style_id));
+	}
+
+      /* Paint the text.  */
+      switch (iter_label.m_kind)
+	{
+	default:
+	  gcc_unreachable ();
+	case x_ruler::label_kind::TEXT:
+	  canvas.paint_text
+	    ((canvas::coord_t (iter_label.m_text_rect.get_min_x (),
+			       get_canvas_y (iter_label.m_text_rect.get_min_y ()))
+	      + offset),
+	     iter_label.m_text);
+	  break;
+
+	case x_ruler::label_kind::TEXT_WITH_BORDER:
+	  {
+	    const canvas::range_t rel_x_range
+	      (iter_label.m_text_rect.get_x_range ());
+
+	    enum theme::cell_kind inner_left_kind;
+	    enum theme::cell_kind inner_connector_kind;
+	    enum theme::cell_kind inner_right_kind;
+	    enum theme::cell_kind outer_left_kind;
+	    enum theme::cell_kind outer_right_kind;
+
+	      switch (m_label_dir)
+		{
+		default:
+		  gcc_unreachable ();
+		case label_dir::ABOVE:
+		  outer_left_kind = theme::cell_kind::TEXT_BORDER_TOP_LEFT;
+		  outer_right_kind = theme::cell_kind::TEXT_BORDER_TOP_RIGHT;
+		  inner_left_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_LEFT;
+		  inner_connector_kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW;
+		  inner_right_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_RIGHT;
+		  break;
+		case label_dir::BELOW:
+		  inner_left_kind = theme::cell_kind::TEXT_BORDER_TOP_LEFT;
+		  inner_connector_kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE;
+		  inner_right_kind = theme::cell_kind::TEXT_BORDER_TOP_RIGHT;
+		  outer_left_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_LEFT;
+		  outer_right_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_RIGHT;
+		  break;
+		}
+	    /* Inner border.  */
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_min_y ());
+	      /* Left corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (inner_left_kind,
+					    iter_label.m_style_id));
+	      /* Edge.  */
+	      const canvas::cell_t edge_border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_HORIZONTAL,
+				  iter_label.m_style_id);
+	      const canvas::cell_t connector_border_cell
+		= theme.get_cell (inner_connector_kind,
+				  iter_label.m_style_id);
+	      for (int rel_x = rel_x_range.get_min () + 1;
+		   rel_x < rel_x_range.get_max ();
+		   rel_x++)
+		if (rel_x == iter_label.m_connector_x)
+		  canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+				 + offset),
+				connector_border_cell);
+		else
+		  canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+				 + offset),
+				edge_border_cell);
+
+	      /* Right corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (inner_right_kind,
+					    iter_label.m_style_id));
+	    }
+
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_min_y () + 1);
+	      const canvas::cell_t border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_VERTICAL,
+				  iter_label.m_style_id);
+
+	      /* Left border.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    border_cell);
+	      /* Text.  */
+	      canvas.paint_text ((canvas::coord_t (rel_x_range.get_min () + 1,
+						   rel_canvas_y)
+				  + offset),
+				 iter_label.m_text);
+	      /* Right border.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    border_cell);
+	    }
+
+	    /* Outer border.  */
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_max_y ());
+	      /* Left corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (outer_left_kind,
+					    iter_label.m_style_id));
+	      /* Edge.  */
+	      const canvas::cell_t border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_HORIZONTAL,
+				  iter_label.m_style_id);
+	      for (int rel_x = rel_x_range.get_min () + 1;
+		   rel_x < rel_x_range.get_max ();
+		   rel_x++)
+		canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+			       + offset),
+			      border_cell);
+
+	      /* Right corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (outer_right_kind,
+					    iter_label.m_style_id));
+	    }
+	  }
+	  break;
+	}
+    }
+}
+
+DEBUG_FUNCTION void
+x_ruler::debug (const style_manager &sm)
+{
+  canvas c (get_size (), sm);
+  paint_to_canvas (c, canvas::coord_t (0, 0), unicode_theme ());
+  c.debug (true);
+}
+
+x_ruler::label::label (const canvas::range_t &range,
+		       styled_string text,
+		       style::id_t style_id,
+		       label_kind kind)
+: m_range (range),
+  m_text (std::move (text)),
+  m_style_id (style_id),
+  m_kind (kind),
+  m_text_rect (canvas::coord_t (0, 0),
+	       canvas::size_t (m_text.calc_canvas_width (), 1)),
+  m_connector_x ((m_range.get_min () + m_range.get_max ()) / 2)
+{
+  if (kind == label_kind::TEXT_WITH_BORDER)
+    {
+      m_text_rect.m_size.w += 2;
+      m_text_rect.m_size.h += 2;
+    }
+}
+
+bool
+x_ruler::label::operator< (const label &other) const
+{
+  int cmp = m_range.start - other.m_range.start;
+  if (cmp)
+    return cmp < 0;
+  return m_range.next < other.m_range.next;
+}
+
+void
+x_ruler::ensure_layout ()
+{
+  if (m_has_layout)
+    return;
+  update_layout ();
+  m_has_layout = true;
+}
+
+void
+x_ruler::update_layout ()
+{
+  if (m_labels.empty ())
+    return;
+
+  std::sort (m_labels.begin (), m_labels.end ());
+
+  /* Place labels.  */
+  int ruler_width = m_labels.back ().m_range.get_next ();
+  int width_with_labels = ruler_width;
+
+  /* Get x coordinates of text parts of each label
+     (m_text_rect.m_top_left.x for each label).  */
+  for (size_t idx = 0; idx < m_labels.size (); idx++)
+    {
+      label &iter_label = m_labels[idx];
+      /* Attempt to center the text label.  */
+      int min_x;
+      if (idx > 0)
+	{
+	  /* ...but don't overlap with the connector to the left.  */
+	  int left_neighbor_connector_x = m_labels[idx - 1].m_connector_x;
+	  min_x = left_neighbor_connector_x + 1;
+	}
+      else
+	{
+	  /* ...or go beyond the leftmost column.  */
+	  min_x = 0;
+	}
+      int connector_x = iter_label.m_connector_x;
+      int centered_x
+	= connector_x - ((int)iter_label.m_text_rect.get_width () / 2);
+      int text_x = std::max (min_x, centered_x);
+      iter_label.m_text_rect.m_top_left.x = text_x;
+    }
+
+  /* Now walk backwards trying to place them vertically,
+     setting m_text_rect.m_top_left.y for each label,
+     consolidating the rows where possible.
+     The y cooordinates are stored with respect to label_dir::BELOW.  */
+  int label_y = 2;
+  for (int idx = m_labels.size () - 1; idx >= 0; idx--)
+    {
+      label &iter_label = m_labels[idx];
+      /* Does it fit on the same row as the text label to the right?  */
+      size_t text_len = iter_label.m_text_rect.get_width ();
+      /* Get the x-coord of immediately beyond iter_label's text.  */
+      int next_x = iter_label.m_text_rect.get_min_x () + text_len;
+      if (idx < (int)m_labels.size () - 1)
+	{
+	  if (next_x >= m_labels[idx + 1].m_text_rect.get_min_x ())
+	    {
+	      /* If not, start a new row.  */
+	      label_y += m_labels[idx + 1].m_text_rect.get_height ();
+	    }
+	}
+      iter_label.m_text_rect.m_top_left.y = label_y;
+      width_with_labels = std::max (width_with_labels, next_x);
+    }
+
+  m_size = canvas::size_t (width_with_labels,
+			   label_y + m_labels[0].m_text_rect.get_height ());
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+static void
+assert_x_ruler_streq (const location &loc,
+		      x_ruler &ruler,
+		      const theme &theme,
+		      const style_manager &sm,
+		      bool styled,
+		      const char *expected_str)
+{
+  canvas c (ruler.get_size (), sm);
+  ruler.paint_to_canvas (c, canvas::coord_t (0, 0), theme);
+  if (0)
+    c.debug (styled);
+  assert_canvas_streq (loc, c, styled, expected_str);
+}
+
+#define ASSERT_X_RULER_STREQ(RULER, THEME, SM, STYLED, EXPECTED_STR)	\
+  SELFTEST_BEGIN_STMT							\
+    assert_x_ruler_streq ((SELFTEST_LOCATION),				\
+			  (RULER),					\
+			  (THEME),					\
+			  (SM),						\
+			  (STYLED),					\
+			  (EXPECTED_STR));				\
+  SELFTEST_END_STMT
+
+static void
+test_single ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain, x_ruler::label_kind::TEXT);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~~~~+~~~~|\n"
+      "     |\n"
+      "    foo\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┤\n"
+      "     │\n"
+      "    foo\n"));
+}
+
+static void
+test_single_above ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::ABOVE);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "hello world"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("hello world\n"
+      "     |\n"
+      "|~~~~+~~~~|\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("hello world\n"
+      "     │\n"
+      "├────┴────┤\n"));
+}
+
+static void
+test_multiple_contiguous ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~~~~+~~~~|~+~~|\n"
+      "     |      |\n"
+      "    foo    bar\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "    foo    bar\n"));
+}
+
+static void
+test_multiple_contiguous_above ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::ABOVE);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("    foo    bar\n"
+      "     |      |\n"
+      "|~~~~+~~~~|~+~~|\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("    foo    bar\n"
+      "     │      │\n"
+      "├────┴────┼─┴──┤\n"));
+}
+
+static void
+test_multiple_contiguous_abutting_labels ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "12345678"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "1234678"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │   1234678\n"
+      " 12345678\n"));
+}
+
+static void
+test_multiple_contiguous_overlapping_labels ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "123456789"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "12346789"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │  12346789\n"
+      " 123456789\n"));
+}
+static void
+test_abutting_left_border ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 6),
+	       styled_string (sm, "this is a long label"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├─┬──┤\n"
+      "  │\n"
+      "this is a long label\n"));
+}
+
+static void
+test_too_long_to_consolidate_vertically ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11),
+	       styled_string (sm, "long string A"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16),
+	       styled_string (sm, "long string B"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │long string B\n"
+      "long string A\n"));
+}
+
+static void
+test_abutting_neighbor ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11),
+	       styled_string (sm, "very long string A"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16),
+	       styled_string (sm, "very long string B"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │very long string B\n"
+      "very long string A\n"));
+}
+
+static void
+test_gaps ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5),
+	       styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 15),
+	       styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~+~|     |~+~|\n"
+      "  |         |\n"
+      " foo       bar\n"));
+}
+
+static void
+test_styled ()
+{
+  style_manager sm;
+  style s1, s2;
+  s1.m_bold = true;
+  s1.m_fg_color = style::named_color::YELLOW;
+  s2.m_bold = true;
+  s2.m_fg_color = style::named_color::BLUE;
+  style::id_t sid1 = sm.get_or_create_id (s1);
+  style::id_t sid2 = sm.get_or_create_id (s2);
+
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5), styled_string (sm, "foo"), sid1);
+  r.add_label (canvas::range_t (10, 15), styled_string (sm, "bar"), sid2);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~+~|     |~+~|\n"
+      "  |         |\n"
+      " foo       bar\n"));
+}
+
+static void
+test_borders ()
+{
+  style_manager sm;
+  {
+    x_ruler r (x_ruler::label_dir::BELOW);
+    r.add_label (canvas::range_t (0, 5),
+		 styled_string (sm, "label 1"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    r.add_label (canvas::range_t (10, 15),
+		 styled_string (sm, "label 2"),
+		 style::id_plain);
+    r.add_label (canvas::range_t (20, 25),
+		 styled_string (sm, "label 3"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    ASSERT_X_RULER_STREQ
+      (r, ascii_theme (), sm, true,
+       "|~+~|     |~+~|     |~+~|\n"
+       "  |         |         |\n"
+       "  |      label 2  +---+---+\n"
+       "+-+-----+         |label 3|\n"
+       "|label 1|         +-------+\n"
+       "+-------+\n");
+    ASSERT_X_RULER_STREQ
+      (r, unicode_theme (), sm, true,
+       "├─┬─┤     ├─┬─┤     ├─┬─┤\n"
+       "  │         │         │\n"
+       "  │      label 2  ╭───┴───╮\n"
+       "╭─┴─────╮         │label 3│\n"
+       "│label 1│         ╰───────╯\n"
+       "╰───────╯\n");
+  }
+  {
+    x_ruler r (x_ruler::label_dir::ABOVE);
+    r.add_label (canvas::range_t (0, 5),
+		 styled_string (sm, "label 1"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    r.add_label (canvas::range_t (10, 15),
+		 styled_string (sm, "label 2"),
+		 style::id_plain);
+    r.add_label (canvas::range_t (20, 25),
+		 styled_string (sm, "label 3"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    ASSERT_X_RULER_STREQ
+      (r, ascii_theme (), sm, true,
+       "+-------+\n"
+       "|label 1|         +-------+\n"
+       "+-+-----+         |label 3|\n"
+       "  |      label 2  +---+---+\n"
+       "  |         |         |\n"
+       "|~+~|     |~+~|     |~+~|\n");
+    ASSERT_X_RULER_STREQ
+      (r, unicode_theme (), sm, true,
+       "╭───────╮\n"
+       "│label 1│         ╭───────╮\n"
+       "╰─┬─────╯         │label 3│\n"
+       "  │      label 2  ╰───┬───╯\n"
+       "  │         │         │\n"
+       "├─┴─┤     ├─┴─┤     ├─┴─┤\n");
+  }
+}
+
+static void
+test_emoji ()
+{
+  style_manager sm;
+
+  styled_string s;
+  s.append (styled_string (0x26A0, /* U+26A0 WARNING SIGN.  */
+			   true));
+  s.append (styled_string (sm, "  "));
+  s.append (styled_string (sm, "this is a warning"));
+
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5),
+	       std::move (s),
+	       style::id_plain,
+	       x_ruler::label_kind::TEXT_WITH_BORDER);
+
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     "|~+~|\n"
+     "  |\n"
+     "+-+------------------+\n"
+     "|⚠️  this is a warning|\n"
+     "+--------------------+\n");
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_ruler_cc_tests ()
+{
+  test_single ();
+  test_single_above ();
+  test_multiple_contiguous ();
+  test_multiple_contiguous_above ();
+  test_multiple_contiguous_abutting_labels ();
+  test_multiple_contiguous_overlapping_labels ();
+  test_abutting_left_border ();
+  test_too_long_to_consolidate_vertically ();
+  test_abutting_neighbor ();
+  test_gaps ();
+  test_styled ();
+  test_borders ();
+  test_emoji ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */