[RFA] Use i386_use_watchpoints for go32v2, bds and windows native

Pierre Muller
2009-02-08T23:22:57Z

I started a while ago to write
a patch to add support for hardware watchpoints
in windows gdbserver.

After some success in writing the adequate code,
I realized that this could not work with
a GDB compiled for cygwin in 'target remote' mode.

The reason is the following:
cygwin native nm-cygwin.h header
includes nm-i386.h header
with I386_USE_GENERIC_WATCHPOINTS defined,
but not I386_WATCHPOINTS_IN_TARGET_VECTOR.

This then defines the macros
target_insert_watchpoint
and
target_remove_watchpoint
and thus even after
setting 'target remote'
the same i386_insert_watchpoint
function is still called, whereas remote_insert_watchpoint
should be called.
Using 'set debug target 1' also allows to see
that the current_target->to_insert_watchpoint
is not called for current cygwin native GDB.

The correction of this problem is easy, as it is already implemented
for linux.
The patch only adds
#define I386_WATCHPOINTS_IN_TARGET_VECTOR
to all config/i386/nm-*.h
that defines I386_USE_GENERIC_WATCHPOINTS
before including nm-i386.h
and add the corresponding call
to i386_use_watchpoints (target)
in the native file when the target vector gets
defined.

I found only three places where this happens:
nm-go32.h with native go32-nat.c
nm-fbsd.h with native i386bsd-nat.c
and
nm-cygwin.h and nm-cygwin64.h with native windows-nat.c

I was able to test that FreeBSD
compiles with that patch, and that
the 'set debug target 1'
does write 'target_insert_watchpoint'
(which is not the case without the patch).

Pierre Muller
Pascal language support maintainer for GDB

PS1: Cygwin testsuite runs show
no significant change.

PS2: It could have seemed more logical to
insert the call to i386_use_watchpoints
to i386-windows-nat.c and amd64-windows-nat.c
in case we later support other processors for windows,
but the required functions
cygwin_set_dr, cygwin_set_dr7 and cygwin_get_dr6
are also in windows-nat.c file,
and there is still a lot of code that is i386
specific in that file...

ChangeLog entry:

2009-02-08 Pierre Muller <muller@ics.u-strasbg.fr>

* Extend use of i386_use_watchpoints to all i386 native files
using hardware watchpoints.
go32-nat.c (init_go32_ops): Call i386_use_watchpoints.
i386bsd-nat.c (i386bsd_target): Ditto.
windows-nat.c (init_windows_ops): Ditto.
config/i386/nm-cygwin.h: Define I386_WATCHPOINTS_IN_TARGET_VECTOR.
config/i386/nm-cygwin64.h: Ditto.
config/i386/nm-fbsd.h: Ditto.
config/i386/nm-go32.h: Ditto.

Index: gdb/go32-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/go32-nat.c,v
retrieving revision 1.63
diff -u -p -r1.63 go32-nat.c
--- gdb/go32-nat.c 6 Feb 2009 22:21:26 -0000 1.63
+++ gdb/go32-nat.c 8 Feb 2009 22:27:44 -0000
@@ -910,6 +910,9 @@ init_go32_ops (void)
go32_ops.to_has_stack = 1;
go32_ops.to_has_registers = 1;
go32_ops.to_has_execution = 1;
+
+ i386_use_watchpoints (&go32_ops);
+
go32_ops.to_magic = OPS_MAGIC;

/* Initialize child's cwd as empty to be initialized when starting
Index: gdb/i386bsd-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/i386bsd-nat.c,v
retrieving revision 1.41
diff -u -p -r1.41 i386bsd-nat.c
--- gdb/i386bsd-nat.c 3 Jan 2009 05:57:52 -0000 1.41
+++ gdb/i386bsd-nat.c 8 Feb 2009 22:27:44 -0000
@@ -248,6 +248,7 @@ i386bsd_target (void)
t = inf_ptrace_target ();
t->to_fetch_registers = i386bsd_fetch_inferior_registers;
t->to_store_registers = i386bsd_store_inferior_registers;
+ i386_use_watchpoints (t);
return t;
}

Index: gdb/windows-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-nat.c,v
retrieving revision 1.179
diff -u -p -r1.179 windows-nat.c
--- gdb/windows-nat.c 6 Feb 2009 22:21:26 -0000 1.179
+++ gdb/windows-nat.c 8 Feb 2009 22:27:46 -0000
@@ -2135,6 +2135,8 @@ init_windows_ops (void)
windows_ops.to_has_registers = 1;
windows_ops.to_has_execution = 1;
windows_ops.to_pid_to_exec_file = windows_pid_to_exec_file;
+ i386_use_watchpoints (&windows_ops);
+
windows_ops.to_magic = OPS_MAGIC;
}

Index: gdb/config/i386/nm-cygwin.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-cygwin.h,v
retrieving revision 1.8
diff -u -p -r1.8 nm-cygwin.h
--- gdb/config/i386/nm-cygwin.h 3 Jan 2009 05:57:54 -0000 1.8
+++ gdb/config/i386/nm-cygwin.h 8 Feb 2009 22:27:46 -0000
@@ -20,6 +20,7 @@
void dll_symbol_command (char *, int);

#define I386_USE_GENERIC_WATCHPOINTS
+#define I386_WATCHPOINTS_IN_TARGET_VECTOR

#include "i386/nm-i386.h"

Index: gdb/config/i386/nm-cygwin64.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-cygwin64.h,v
retrieving revision 1.1
diff -u -p -r1.1 nm-cygwin64.h
--- gdb/config/i386/nm-cygwin64.h 11 Jan 2009 13:15:56 -0000 1.1
+++ gdb/config/i386/nm-cygwin64.h 8 Feb 2009 22:27:46 -0000
@@ -19,6 +19,7 @@
void dll_symbol_command (char *, int);

#define I386_USE_GENERIC_WATCHPOINTS
+#define I386_WATCHPOINTS_IN_TARGET_VECTOR

#include "i386/nm-i386.h"

Index: gdb/config/i386/nm-fbsd.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-fbsd.h,v
retrieving revision 1.18
diff -u -p -r1.18 nm-fbsd.h
--- gdb/config/i386/nm-fbsd.h 3 Jan 2009 05:57:54 -0000 1.18
+++ gdb/config/i386/nm-fbsd.h 8 Feb 2009 22:27:46 -0000
@@ -23,6 +23,7 @@

#ifdef HAVE_PT_GETDBREGS
#define I386_USE_GENERIC_WATCHPOINTS
+#define I386_WATCHPOINTS_IN_TARGET_VECTOR
#endif

#include "i386/nm-i386.h"
Index: gdb/config/i386/nm-go32.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-go32.h,v
retrieving revision 1.8
diff -u -p -r1.8 nm-go32.h
--- gdb/config/i386/nm-go32.h 3 Jan 2009 05:57:54 -0000 1.8
+++ gdb/config/i386/nm-go32.h 8 Feb 2009 22:27:46 -0000
@@ -18,6 +18,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#define I386_USE_GENERIC_WATCHPOINTS
+#define I386_WATCHPOINTS_IN_TARGET_VECTOR

#include "i386/nm-i386.h"