PATCH: Problem union comparision in TUI

Andrew STUBBS
2005-10-17T14:52:57Z

[-- Attachment #1: Type: text/plain, Size: 1168 bytes --]

Hi,

I have observed this problem in the sh-elf configuration of GDB. It is
not visible in the i686-linux configuration because it uses the
following union in a different way.

/* Structure describing source line or line address */
union tui_line_or_address
{
int line_no;
CORE_ADDR addr;
};

The problem is that the union is always compared using 'addr'. In the
case where it was set using 'line_no', as it is in sh-elf, half the
union contains garbage. This appears to be killing the comparison in
tui_set_is_exec_point_at() in tui-winsource.c.

The result is that the current line is never highlighted as it should
be. I assume the reason it works on i686-linux is that that host/target
uses the addr field rather than the line_no field.

The attached patch provides one way to fix the problem. I could not
think of any way to fix the comparison because there is no way I can see
to know which mode it is using, so I have changed the type of line_no in
the union to match the type of addr. This does not seem to be the Right
Thing to do with a union (because it might as well be one variable), but
I can't see any other down side.

Andrew Stubbs

[-- Attachment #2: tui-union-compare.patch --]
[-- Type: text/plain, Size: 429 bytes --]

Index: src/gdb/tui/tui-data.h
===================================================================
--- src.orig/gdb/tui/tui-data.h 2004-03-13 14:14:01.000000000 +0000
+++ src/gdb/tui/tui-data.h 2005-10-17 14:21:23.000000000 +0100
@@ -149,7 +149,7 @@ enum tui_register_display_type
/* Structure describing source line or line address */
union tui_line_or_address
{
- int line_no;
+ CORE_ADDR line_no;
CORE_ADDR addr;
};