Clean up source file error reporting

print_source_lines_base reopens the source file every time that a
source line is to be printed.  However, there's no need to do this so
frequently -- it's enough to do it when switching source files, and
otherwise rely on the cache.

The code seems to try to avoid these multiple opens; at a guess I'd
say something just got confused along the way.

This patch fixes the problem by reorganizing the code both to make it
more clear, and to ensure that reopens only occur when the "last
source visited" changes.

gdb/ChangeLog
2019-08-06  Tom Tromey  <tromey@adacore.com>

	* source.c (last_source_error): Now bool.
	(print_source_lines_base): Make "noprint" bool.  Only open
	source file when last_source_visited changes.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7f4c3ba5eda6f2915a1946fc47a164efa2b64282..9bcd47d389b081fbd1f165a90f6d99fe2e4df676 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2019-08-06  Tom Tromey  <tromey@adacore.com>
+
+       * source.c (last_source_error): Now bool.
+       (print_source_lines_base): Make "noprint" bool.  Only open
+       source file when last_source_visited changes.
+
 2019-08-06  Tom Tromey  <tromey@adacore.com>
 
        * annotate.c (annotate_source_line): Use g_source_cache.

diff --git a/gdb/source.c b/gdb/source.c
index e0050f1fb8200850d984e2a805037ea0de6f1a51..066666c7ca3f0ca50428c545c7d6a40bf03bf25c 100644 (file)
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -129,7 +129,7 @@ static int first_line_listed;
    Used to prevent repeating annoying "No such file or directories" msgs.  */
 
 static struct symtab *last_source_visited = NULL;
-static int last_source_error = 0;
+static bool last_source_error = false;
 \f
 /* Return the first line listed by print_source_lines.
    Used by command interpreters to request listing from
@@ -1129,8 +1129,7 @@ static void
 print_source_lines_base (struct symtab *s, int line, int stopline,
                         print_source_lines_flags flags)
 {
-  scoped_fd desc;
-  int noprint = 0;
+  bool noprint = false;
   int nlines = stopline - line;
   struct ui_out *uiout = current_uiout;
 
@@ -1144,26 +1143,27 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
   if (uiout->test_flags (ui_source_list))
     {
       /* Only prints "No such file or directory" once.  */
-      if ((s != last_source_visited) || (!last_source_error))
+      if (s == last_source_visited)
        {
-         last_source_visited = s;
-         desc = open_source_file (s);
-         if (desc.get () < 0)
+         if (last_source_error)
            {
-             last_source_error = desc.get ();
-             noprint = 1;
+             flags |= PRINT_SOURCE_LINES_NOERROR;
+             noprint = true;
            }
        }
       else
        {
-         flags |= PRINT_SOURCE_LINES_NOERROR;
-         noprint = 1;
+         last_source_visited = s;
+         scoped_fd desc = open_source_file (s);
+         last_source_error = desc.get () < 0;
+         if (last_source_error)
+           noprint = true;
        }
     }
   else
     {
       flags |= PRINT_SOURCE_LINES_NOERROR;
-      noprint = 1;
+      noprint = true;
     }
 
   if (noprint)
@@ -1209,8 +1209,6 @@ print_source_lines_base (struct symtab *s, int line, int stopline,
       return;
     }
 
-  last_source_error = 0;
-
   /* If the user requested a sequence of lines that seems to go backward
      (from high to low line numbers) then we don't print anything.  */
   if (stopline <= line)