TUI: Expand TABs into spaces
Commit Message
> From: Doug Evans <xdje42@gmail.com>
> Cc: gdb-patches@sourceware.org
> Date: Tue, 27 Jan 2015 00:06:12 -0800
>
> > I did that below, but since tui_register_format is its only user,
> > keeping that function in tui-regs.c would have allowed us to make it
> > static. Wouldn't that be slightly better?
>
> That's not an invalid viewpoint, and if you want to go
> that route, fine by me. One argument for going that route
> is that if another user comes along one can always make
> it public later. Alas that doesn't always happen, and one
> ends up writing something that already exists.
> [If a year from now I need something like that the last
> place I'm going to look is tui-regs.c, whereas I will at least look
> through all the headers and generic-looking files for something.
> I wish I had a previous example at hand, I've paged out the details
> from memory and all that's left is wanting to avoid that.
> IIRC we've even had cases where something generic was used by
> multiple callers, then only one, and then someone moved it and
> made it static. If there were multiple callers once there may
> be again (depending on the situation of course) so if I'm given the
> choice I wouldn't have made that move.]
> [Also, one could argue that this function isn't even tui-specific
> and thus should go in something like gdb/utils.c or even libiberty.
> Keeping it in tui just violates what I said above about being in
> the last place someone would look.
> I opted for not getting too carried away with things: I don't
> yet see a need for expanding tabs to spaces outside of tui,
> but I could be wrong of course. Plus I wouldn't impose spending
> any time going back and forth picking the absolute best location,
> there are far more important things, and one could argue I've made
> you read too much already.]
> [OTOOH :-), if I hadn't said at least some of this the probability
> is too high that someone else would. Bleah.
> [Not saying it would be you though!]]
>
> So to make a long story short, feel free to leave it where it is or
> make it static.
I left it where it is, given that the pros and cons are inconclusive.
> > +/* Utility function to expand TABs in a STRING into spaces. STRING
> > + will be displayed starting at column COL. The returned expanded
> > + string is malloc'ed. */
>
> blank line between function comment and definition
> [I realize tui_get_register doesn't do that, but best do that with
> new code.]
Done.
> Also, I'm guessing that newlines in STRING isn't supported here, right?
> If so, mention that in the function comment.
Done.
> One could even add an assert like:
>
> gdb_assert (strchr (string, '\n') == NULL);
>
> or some such.
I didn't do this, I think that'd be too much. Having a slightly
messed-up screen is far better than having to abort the debug session,
if we ever get to this problem. The mess-up will most probably be
reported, and we will fix it.
> > +/* Expand TABs into spaces. */
>
> For reference sake, there are multiple schools of thought, and no
> fixed convention in gdb, for whether to put a comment here, and
> what it should look like. No need to change anything, and I can
> go into details if you want. Just wanted to mention the issue,
> and the acceptable choice of not having any comment here.
I had in the past requests to add such comments, so at least some of
the maintainers favor them. I left that comment intact.
The patch as I pushed it appears below. Thanks again for reviewing
it.
commit 312809f8838911dabff84d7ad3ccf341307d2b19
Author: Eli Zaretskii <eliz@gnu.org>
Date: Sat Jan 31 10:47:14 2015 +0200
Make sure TABs are expanded in TUI windows on MS-Windows.
gdb/
2015-01-31 Eli Zaretskii <eliz@gnu.org>
* tui/tui-io.c (tui_expand_tabs): New function.
(tui_puts, tui_redisplay_readline): Expand TABs into the
appropriate number of spaces.
* tui/tui-regs.c: Include tui-io.h.
(tui_register_format): Call tui_expand_tabs to expand TABs into
the appropriate number of spaces.
* tui/tui-io.h: Add prototype for tui_expand_tabs.
@@ -1,3 +1,13 @@
+2015-01-31 Eli Zaretskii <eliz@gnu.org>
+
+ * tui/tui-io.c (tui_expand_tabs): New function.
+ (tui_puts, tui_redisplay_readline): Expand TABs into the
+ appropriate number of spaces.
+ * tui/tui-regs.c: Include tui-io.h.
+ (tui_register_format): Call tui_expand_tabs to expand TABs into
+ the appropriate number of spaces.
+ * tui/tui-io.h: Add prototype for tui_expand_tabs.
+
2015-01-30 Doug Evans <dje@google.com>
* NEWS: "info source" command now display producer string if present.
@@ -178,7 +178,20 @@
else if (tui_skip_line != 1)
{
tui_skip_line = -1;
- waddch (w, c);
+ /* Expand TABs, since ncurses on MS-Windows doesn't. */
+ if (c == '\t')
+ {
+ int line, col;
+
+ getyx (w, line, col);
+ do
+ {
+ waddch (w, ' ');
+ col++;
+ } while ((col % 8) != 0);
+ }
+ else
+ waddch (w, c);
}
else if (c == '\n')
tui_skip_line = -1;
@@ -256,6 +269,16 @@
waddch (w, '^');
waddch (w, CTRL_CHAR (c) ? UNCTRL (c) : '?');
}
+ else if (c == '\t')
+ {
+ /* Expand TABs, since ncurses on MS-Windows doesn't. */
+ getyx (w, line, col);
+ do
+ {
+ waddch (w, ' ');
+ col++;
+ } while ((col % 8) != 0);
+ }
else
{
waddch (w, c);
@@ -724,6 +747,59 @@
return ch;
}
+/* Utility function to expand TABs in a STRING into spaces. STRING
+ will be displayed starting at column COL, and is assumed to include
+ no newlines. The returned expanded string is malloc'ed. */
+
+char *
+tui_expand_tabs (const char *string, int col)
+{
+ int n_adjust;
+ const char *s;
+ char *ret, *q;
+
+ /* 1. How many additional characters do we need? */
+ for (n_adjust = 0, s = string; s; )
+ {
+ s = strpbrk (s, "\t");
+ if (s)
+ {
+ col += (s - string) + n_adjust;
+ /* Adjustment for the next tab stop, minus one for the TAB
+ we replace with spaces. */
+ n_adjust += 8 - (col % 8) - 1;
+ s++;
+ }
+ }
+
+ /* Allocate the copy. */
+ ret = q = xmalloc (strlen (string) + n_adjust + 1);
+
+ /* 2. Copy the original string while replacing TABs with spaces. */
+ for (s = string; s; )
+ {
+ char *s1 = strpbrk (s, "\t");
+ if (s1)
+ {
+ if (s1 > s)
+ {
+ strncpy (q, s, s1 - s);
+ q += s1 - s;
+ col += s1 - s;
+ }
+ do {
+ *q++ = ' ';
+ col++;
+ } while ((col % 8) != 0);
+ s1++;
+ }
+ else
+ strcpy (q, s);
+ s = s1;
+ }
+
+ return ret;
+}
/* Cleanup when a resize has occured.
Returns the character that must be processed. */
@@ -41,6 +41,9 @@
changed the edited text. */
extern void tui_redisplay_readline (void);
+/* Expand TABs into spaces. */
+extern char *tui_expand_tabs (const char *, int);
+
extern struct ui_out *tui_out;
extern struct ui_out *tui_old_uiout;
@@ -36,6 +36,7 @@
#include "tui/tui-wingeneral.h"
#include "tui/tui-file.h"
#include "tui/tui-regs.h"
+#include "tui/tui-io.h"
#include "reggroups.h"
#include "valprint.h"
@@ -693,7 +694,9 @@ static enum tui_status tui_get_register (struct frame_info *frame,
if (s && s[1] == 0)
*s = 0;
- ret = xstrdup (p);
+ /* Expand tabs into spaces, since ncurses on MS-Windows doesn't. */
+ ret = tui_expand_tabs (p, 0);
+
do_cleanups (cleanups);
return ret;