Re: Don't disable the current display in throw_exception

Pedro Alves
2011-08-08T14:28:41Z

On Friday 05 August 2011 21:22:28, Daniel Jacobowitz wrote:
> Seconded! Does this also fix the bug where if you display a variable,
> and it is temporarily at a bad address, the display is disabled?

Nope...

> Or is that still the case? That always drives me nuts - yes, I know foo
> is NULL, but I want GDB to go back to displaying *foo when it comes
> back.

That one doesn't look hard. Below's a quick patch at it (not regtested).
Here's what I get:

(top-gdb) display
2: *argv = 0x7fffffffe37c "/home/pedro/gdb/try_catch/build/gdb/gdb"
(top-gdb) p argv = 0
$2 = (char **) 0x0
(top-gdb) display
2: *argv = <error: Cannot access memory at address 0x0>

Do I still get cookie? :-P :-)

> I don't know what the "infinite recursion" in question is.

Not sure either. Maybe something with infcalls. I guess
we'd have to go look at a gdb from when any error brought
you back to the top level.

--
Pedro Alves

---
gdb/printcmd.c | 45 ++++++++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 19 deletions(-)

Index: src/gdb/printcmd.c
===================================================================
--- src.orig/gdb/printcmd.c 2011-08-05 16:34:30.000000000 +0100
+++ src/gdb/printcmd.c 2011-08-08 15:12:23.908548270 +0100
@@ -1656,14 +1656,6 @@ undisplay_command (char *args, int from_
dont_repeat ();
}

-/* Cleanup that just disables the current display. */
-
-static void
-disable_current_display_cleanup (void *arg)
-{
- disable_current_display ();
-}
-
/* Display a single auto-display.
Do nothing if the display cannot be printed in the current context,
or if the display is disabled. */
@@ -1723,8 +1715,8 @@ do_one_display (struct display *d)
if (!within_current_scope)
return;

+ old_chain = make_cleanup_restore_integer (&current_display_number);
current_display_number = d->number;
- old_chain = make_cleanup (disable_current_display_cleanup, NULL);

annotate_display_begin ();
printf_filtered ("%d", d->number);
@@ -1732,8 +1724,7 @@ do_one_display (struct display *d)
printf_filtered (": ");
if (d->format.size)
{
- CORE_ADDR addr;
- struct value *val;
+ volatile struct gdb_exception ex;

annotate_display_format ();

@@ -1755,18 +1746,26 @@ do_one_display (struct display *d)
else
printf_filtered (" ");

- val = evaluate_expression (d->exp);
- addr = value_as_address (val);
- if (d->format.format == 'i')
- addr = gdbarch_addr_bits_remove (d->exp->gdbarch, addr);
-
annotate_display_value ();

- do_examine (d->format, d->exp->gdbarch, addr);
+ TRY_CATCH (ex, RETURN_MASK_ERROR)
+ {
+ struct value *val;
+ CORE_ADDR addr;
+
+ val = evaluate_expression (d->exp);
+ addr = value_as_address (val);
+ if (d->format.format == 'i')
+ addr = gdbarch_addr_bits_remove (d->exp->gdbarch, addr);
+ do_examine (d->format, d->exp->gdbarch, addr);
+ }
+ if (ex.reason < 0)
+ fprintf_filtered (gdb_stdout, _("<error: %s>\n"), ex.message);
}
else
{
struct value_print_options opts;
+ volatile struct gdb_exception ex;

annotate_display_format ();

@@ -1784,8 +1783,16 @@ do_one_display (struct display *d)

get_formatted_print_options (&opts, d->format.format);
opts.raw = d->format.raw;
- print_formatted (evaluate_expression (d->exp),
- d->format.size, &opts, gdb_stdout);
+
+ TRY_CATCH (ex, RETURN_MASK_ERROR)
+ {
+ struct value *val;
+
+ val = evaluate_expression (d->exp);
+ print_formatted (val, d->format.size, &opts, gdb_stdout);
+ }
+ if (ex.reason < 0)
+ fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
printf_filtered ("\n");
}