Highlight source code using GNU Source Highlight

This changes gdb to highlight source using GNU Source Highlight, if it
is available.

This affects the output of the "list" command and also the TUI source
window.

No new test because I didn't see a way to make it work when Source
Highlight is not found.

gdb/ChangeLog
2018-12-28  Tom Tromey  <tom@tromey.com>

	* utils.h (can_emit_style_escape): Declare.
	* utils.c (can_emit_style_escape): No longer static.
	* cli/cli-style.c (set_style_enabled): New function.
	(_initialize_cli_style): Use it.
	* tui/tui-winsource.c (tui_show_source_line): Use tui_puts.
	(tui_alloc_source_buffer): Change how source lines are allocated.
	* tui/tui-source.c (copy_source_line): New function.
	(tui_set_source_content): Use source cache.
	* tui/tui-io.h (tui_puts): Update.
	* tui/tui-io.c (tui_puts_internal): Add window parameter.
	(tui_puts): Likewise.
	(tui_redisplay_readline): Update.
	* tui/tui-data.c (free_content_elements): Change how source window
	contents are freed.
	* source.c (forget_cached_source_info): Clear the source cache.
	(print_source_lines_base): Use the source cache.
	* source-cache.h: New file.
	* source-cache.c: New file.
	* configure.ac: Check for GNU Source Highlight library.
	* configure: Update.
	* config.in: Update.
	* Makefile.in (SRCHIGH_LIBS, SRCHIGH_CFLAGS): New variables.
	(INTERNAL_CFLAGS_BASE): Add SRCHIGH_CFLAGS.
	(CLIBS): Add SRCHIGH_LIBS.
	(COMMON_SFILES): Add source-cache.c.
	(HFILES_NO_SRCDIR): Add source-cache.h.

1 files changed, 19 insertions, 19 deletions

diff --git a/gdb/source.c b/gdb/source.c
index 575e46c..66ef883 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -45,6 +45,7 @@
 #include "common/scoped_fd.h"
 #include <algorithm>
 #include "common/pathstuff.h"
+#include "source-cache.h"
 
 #define OPEN_MODE (O_RDONLY | O_BINARY)
 #define FDOPEN_MODE FOPEN_RB
@@ -393,6 +394,7 @@ forget_cached_source_info (void)
       forget_cached_source_info_for_objfile (objfile);
     }
 
+  g_source_cache.clear ();
   last_source_visited = NULL;
 }
 
@@ -1344,25 +1346,18 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
 
   last_source_error = 0;
 
-  if (s->line_charpos == 0)
-    find_source_lines (s, desc.get ());
-
-  if (line < 1 || line > s->nlines)
+  std::string lines;
+  if (!g_source_cache.get_source_lines (s, line, stopline - 1, &lines))
     error (_("Line number %d out of range; %s has %d lines."),
 	   line, symtab_to_filename_for_display (s), s->nlines);
 
-  if (lseek (desc.get (), s->line_charpos[line - 1], 0) < 0)
-    perror_with_name (symtab_to_filename_for_display (s));
-
-  gdb_file_up stream = desc.to_file (FDOPEN_MODE);
-  clearerr (stream.get ());
-
+  const char *iter = lines.c_str ();
   while (nlines-- > 0)
     {
       char buf[20];
 
-      c = fgetc (stream.get ());
-      if (c == EOF)
+      c = *iter++;
+      if (c == '\0')
 	break;
       last_line_listed = current_source_line;
       if (flags & PRINT_SOURCE_LINES_FILENAME)
@@ -1374,7 +1369,7 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
       uiout->text (buf);
       do
 	{
-	  if (c < 040 && c != '\t' && c != '\n' && c != '\r')
+	  if (c < 040 && c != '\t' && c != '\n' && c != '\r' && c != '\033')
 	    {
 	      xsnprintf (buf, sizeof (buf), "^%c", c + 0100);
 	      uiout->text (buf);
@@ -1384,12 +1379,13 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
 	  else if (c == '\r')
 	    {
 	      /* Skip a \r character, but only before a \n.  */
-	      int c1 = fgetc (stream.get ());
-
-	      if (c1 != '\n')
+	      if (iter[1] == '\n')
+		{
+		  ++iter;
+		  c = '\n';
+		}
+	      else
 		printf_filtered ("^%c", c + 0100);
-	      if (c1 != EOF)
-		ungetc (c1, stream.get ());
 	    }
 	  else
 	    {
@@ -1397,8 +1393,12 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
 	      uiout->text (buf);
 	    }
 	}
-      while (c != '\n' && (c = fgetc (stream.get ())) >= 0);
+      while (c != '\n' && (c = *iter++) != '\0');
+      if (c == '\0')
+	break;
     }
+  if (lines.back () != '\n')
+    uiout->text ("\n");
 }
 
 /* Show source lines from the file of symtab S, starting with line