[committed] Tweak to colors of fix-it hints

[David Malcolm <dmalcolm at redhat dot com>]

Previous, fix-it hints were printed using the color of the severity
of the diagnostic (magenta for warnings, red for errors, cyan for
notes).

This patch updates fix-it hints so that replacement text is printed in
green, to better distinguish the suggested improvement from
the current code.  For example:

spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did you mean 'color'?
   return ptr->colour;  <<< RED
               ^~~~~~   <<< RED
               color    <<< GREEN

It makes sense for the underlinings that indicate deletions to
be printed in red, so the patch changes that also.  For example:

diagnostic-test-show-locus-color.c:179:9: warning: example of a removal hint
   int a;;  <<< MAGENTA
         ^  <<< MAGENTA
         -  <<< RED

Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu.

Committed to trunk as r239787.

I've updated https://gcc.gnu.org/gcc-7/changes.html to reflect these
changes (the "screenshots" there were what motivated this patch).

gcc/ChangeLog:
	* diagnostic-color.c (color_dict): Add "fixit-insert" and
	"fixit-delete".
	(parse_gcc_colors): Update description of default GCC_COLORS.
	* diagnostic-show-locus.c (colorizer::set_fixit_hint): Delete.
	(colorizer::set_fixit_insert): New method.
	(colorizer::set_fixit_delete): New method.
	(colorizer::get_color_by_name): New method.
	(colorizer::STATE_FIXIT_INSERT): New constant.
	(colorizer::STATE_FIXIT_DELETE): New constant.
	(class colorizer): Drop "_cs" suffix from fields.  Delete "_ce"
	fields in favor of new field "m_stop_color".  Add fields
	"m_fixit_insert" and "m_fixit_delete".
	(colorizer::colorizer): Update for above changes.  Replace
	colorize_start calls with calls to get_color_by_name.
	(colorizer::begin_state): Handle STATE_FIXIT_INSERT and
	STATE_FIXIT_DELETE.  Update for field renamings.
	(colorizer::finish_state): Simplify by using m_stop_color,
	rather than multiple identical "*_ce" fields.
	(colorizer::get_color_by_name): New method.
	(layout::print_any_fixits): Print insertions and replacements
	using the "fixit-insert" color, and deletions using the
	"fixit-delete" color.
	* doc/invoke.texi (-fdiagnostics-color): Update description of
	default GCC_COLORS, and of the supported capabilities.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/diagnostic-test-show-locus-color.c
	(test_fixit_insert): Update expected output.
	(test_fixit_remove): Likewise.
	(test_fixit_replace): Likewise.
---
 gcc/diagnostic-color.c                             |  6 +-
 gcc/diagnostic-show-locus.c                        | 66 +++++++++++++---------
 gcc/doc/invoke.texi                                | 28 ++++++---
 .../plugin/diagnostic-test-show-locus-color.c      |  6 +-
 4 files changed, 67 insertions(+), 39 deletions(-)

diff --git a/gcc/diagnostic-color.c b/gcc/diagnostic-color.c
index f76c87b..42aa1b6 100644
--- a/gcc/diagnostic-color.c
+++ b/gcc/diagnostic-color.c
@@ -168,6 +168,8 @@ static struct color_cap color_dict[] =
   { "range2", SGR_SEQ (COLOR_FG_BLUE), 6, false },
   { "locus", SGR_SEQ (COLOR_BOLD), 5, false },
   { "quote", SGR_SEQ (COLOR_BOLD), 5, false },
+  { "fixit-insert", SGR_SEQ (COLOR_FG_GREEN), 12, false },
+  { "fixit-delete", SGR_SEQ (COLOR_FG_RED), 12, false },
   { NULL, NULL, 0, false }
 };
 
@@ -196,7 +198,9 @@ colorize_stop (bool show_color)
 }
 
 /* Parse GCC_COLORS.  The default would look like:
-   GCC_COLORS='error=01;31:warning=01;35:note=01;36:range1=32:range2=34;locus=01:quote=01'
+   GCC_COLORS='error=01;31:warning=01;35:note=01;36:\
+   range1=32:range2=34:locus=01:quote=01:\
+   fixit-insert=32:fixit-delete=31'
    No character escaping is needed or supported.  */
 static bool
 parse_gcc_colors (void)
diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c
index 32b1078..94b7349 100644
--- a/gcc/diagnostic-show-locus.c
+++ b/gcc/diagnostic-show-locus.c
@@ -79,24 +79,29 @@ class colorizer
 
   void set_range (int range_idx) { set_state (range_idx); }
   void set_normal_text () { set_state (STATE_NORMAL_TEXT); }
-  void set_fixit_hint () { set_state (0); }
+  void set_fixit_insert () { set_state (STATE_FIXIT_INSERT); }
+  void set_fixit_delete () { set_state (STATE_FIXIT_DELETE); }
 
  private:
   void set_state (int state);
   void begin_state (int state);
   void finish_state (int state);
+  const char *get_color_by_name (const char *);
 
  private:
   static const int STATE_NORMAL_TEXT = -1;
+  static const int STATE_FIXIT_INSERT  = -2;
+  static const int STATE_FIXIT_DELETE  = -3;
 
   diagnostic_context *m_context;
   diagnostic_t m_diagnostic_kind;
   int m_current_state;
-  const char *m_caret_cs;
-  const char *m_caret_ce;
-  const char *m_range1_cs;
-  const char *m_range2_cs;
-  const char *m_range_ce;
+  const char *m_caret;
+  const char *m_range1;
+  const char *m_range2;
+  const char *m_fixit_insert;
+  const char *m_fixit_delete;
+  const char *m_stop_color;
 };
 
 /* A point within a layout_range; similar to an expanded_location,
@@ -247,10 +252,11 @@ colorizer::colorizer (diagnostic_context *context,
   m_diagnostic_kind (diagnostic_kind),
   m_current_state (STATE_NORMAL_TEXT)
 {
-  m_caret_ce = colorize_stop (pp_show_color (context->printer));
-  m_range1_cs = colorize_start (pp_show_color (context->printer), "range1");
-  m_range2_cs = colorize_start (pp_show_color (context->printer), "range2");
-  m_range_ce = colorize_stop (pp_show_color (context->printer));
+  m_range1 = get_color_by_name ("range1");
+  m_range2 = get_color_by_name ("range2");
+  m_fixit_insert = get_color_by_name ("fixit-insert");
+  m_fixit_delete = get_color_by_name ("fixit-delete");
+  m_stop_color = colorize_stop (pp_show_color (context->printer));
 }
 
 /* The destructor for "colorize".  If colorization is on, print a code to
@@ -285,6 +291,14 @@ colorizer::begin_state (int state)
     case STATE_NORMAL_TEXT:
       break;
 
+    case STATE_FIXIT_INSERT:
+      pp_string (m_context->printer, m_fixit_insert);
+      break;
+
+    case STATE_FIXIT_DELETE:
+      pp_string (m_context->printer, m_fixit_delete);
+      break;
+
     case 0:
       /* Make range 0 be the same color as the "kind" text
 	 (error vs warning vs note).  */
@@ -295,11 +309,11 @@ colorizer::begin_state (int state)
       break;
 
     case 1:
-      pp_string (m_context->printer, m_range1_cs);
+      pp_string (m_context->printer, m_range1);
       break;
 
     case 2:
-      pp_string (m_context->printer, m_range2_cs);
+      pp_string (m_context->printer, m_range2);
       break;
 
     default:
@@ -314,21 +328,17 @@ colorizer::begin_state (int state)
 void
 colorizer::finish_state (int state)
 {
-  switch (state)
-    {
-    case STATE_NORMAL_TEXT:
-      break;
+  if (state != STATE_NORMAL_TEXT)
+    pp_string (m_context->printer, m_stop_color);
+}
 
-    case 0:
-      pp_string (m_context->printer, m_caret_ce);
-      break;
+/* Get the color code for NAME (or the empty string if
+   colorization is disabled).  */
 
-    default:
-      /* Within a range.  */
-      gcc_assert (state > 0);
-      pp_string (m_context->printer, m_range_ce);
-      break;
-    }
+const char *
+colorizer::get_color_by_name (const char *name)
+{
+  return colorize_start (pp_show_color (m_context->printer), name);
 }
 
 /* Implementation of class layout_range.  */
@@ -1098,7 +1108,7 @@ layout::print_any_fixits (int row, const rich_location *richloc)
 		int start_column
 		  = LOCATION_COLUMN (insert->get_location ());
 		move_to_column (&column, start_column);
-		m_colorizer.set_fixit_hint ();
+		m_colorizer.set_fixit_insert ();
 		pp_string (m_pp, insert->get_string ());
 		m_colorizer.set_normal_text ();
 		column += insert->get_length ();
@@ -1122,7 +1132,7 @@ layout::print_any_fixits (int row, const rich_location *richloc)
 		    || replace->get_length () == 0)
 		  {
 		    move_to_column (&column, start_column);
-		    m_colorizer.set_fixit_hint ();
+		    m_colorizer.set_fixit_delete ();
 		    for (; column <= finish_column; column++)
 		      pp_character (m_pp, '-');
 		    m_colorizer.set_normal_text ();
@@ -1133,7 +1143,7 @@ layout::print_any_fixits (int row, const rich_location *richloc)
 		if (replace->get_length () > 0)
 		  {
 		    move_to_column (&column, start_column);
-		    m_colorizer.set_fixit_hint ();
+		    m_colorizer.set_fixit_insert ();
 		    pp_string (m_pp, replace->get_string ());
 		    m_colorizer.set_normal_text ();
 		    column += replace->get_length ();
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 1f04501..efe2a36 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -3343,13 +3343,13 @@ for 88-color and 256-color modes background colors.
 
 The default @env{GCC_COLORS} is
 @smallexample
-error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01
+error=01;31:warning=01;35:note=01;36:range1=32:range2=34:locus=01:quote=01:fixit-insert=32:fixit-delete=31
 @end smallexample
 @noindent
 where @samp{01;31} is bold red, @samp{01;35} is bold magenta,
-@samp{01;36} is bold cyan, @samp{01;32} is bold green and
-@samp{01} is bold. Setting @env{GCC_COLORS} to the empty
-string disables colors.
+@samp{01;36} is bold cyan, @samp{32} is green, @samp{34} is blue,
+@samp{01} is bold, and @samp{31} is red.
+Setting @env{GCC_COLORS} to the empty string disables colors.
 Supported capabilities are as follows.
 
 @table @code
@@ -3365,9 +3365,13 @@ SGR substring for warning: markers.
 @vindex note GCC_COLORS @r{capability}
 SGR substring for note: markers.
 
-@item caret=
-@vindex caret GCC_COLORS @r{capability}
-SGR substring for caret line.
+@item range1=
+@vindex range1 GCC_COLORS @r{capability}
+SGR substring for first additional range.
+
+@item range2=
+@vindex range2 GCC_COLORS @r{capability}
+SGR substring for second additional range.
 
 @item locus=
 @vindex locus GCC_COLORS @r{capability}
@@ -3377,6 +3381,16 @@ SGR substring for location information, @samp{file:line} or
 @item quote=
 @vindex quote GCC_COLORS @r{capability}
 SGR substring for information printed within quotes.
+
+@item fixit-insert=
+@vindex fixit-insert GCC_COLORS @r{capability}
+SGR substring for fix-it hints suggesting text to
+be inserted or replaced.
+
+@item fixit-delete=
+@vindex fixit-delete GCC_COLORS @r{capability}
+SGR substring for fix-it hints suggesting text to
+be deleted.
 @end table
 
 @item -fno-diagnostics-show-option
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-show-locus-color.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-show-locus-color.c
index ff2f4d4..712375e 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-show-locus-color.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-show-locus-color.c
@@ -161,7 +161,7 @@ void test_fixit_insert (void)
 /* { dg-begin-multiline-output "" }
     int a[2][2] = { 0, 1 , 2, 3 };
                     ^~~~
-                    {   }
+                    {   }
    { dg-end-multiline-output "" } */
 #endif
 }
@@ -175,7 +175,7 @@ void test_fixit_remove (void)
 /* { dg-begin-multiline-output "" }
    int a;;
          ^
-         -
+         -
    { dg-end-multiline-output "" } */
 #endif
 }
@@ -189,7 +189,7 @@ void test_fixit_replace (void)
 /* { dg-begin-multiline-output "" }
    gtk_widget_showall (dlg);
    ^~~~~~~~~~~~~~~~~~
-   gtk_widget_show_all
+   gtk_widget_show_all
    { dg-end-multiline-output "" } */
 #endif
 }
-- 
1.8.5.3