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Re: [RFA,RFC] TARGET_ADJUST_BREAKPOINT_ADDRESS - patch 3 of 4
- From: Kevin Buettner <kevinb at redhat dot com>
- To: Michael Snyder <msnyder at redhat dot com>
- Cc: Kevin Buettner <kevinb at redhat dot com>, Eli Zaretskii <eliz at elta dot co dot il>, gdb-patches at sources dot redhat dot com
- Date: Mon, 13 Oct 2003 16:54:16 -0700
- Subject: Re: [RFA,RFC] TARGET_ADJUST_BREAKPOINT_ADDRESS - patch 3 of 4
- References: <1031004064353.ZM25456@localhost.localdomain> <3F83486D.7080004@redhat.com>
On Oct 7, 4:12pm, Michael Snyder wrote:
> Your arguments are convincing, and your code looks optimal.
> Unlike 3 years ago, I'm now familiar with the FRV architecture,
> so I feel much more comfortable giving my approval.
Thanks. Here's what I've checked in:
* breakpoint.h (struct breakpoint): Add new member
``requested_address''.
* breakpoint.c (breakpoint_adjustment_warning)
(adjust_breakpoint_address): New static functions.
(print_it_typical): Issue warning if breakpoint's address is different
from its requested address.
(set_raw_breakpoint, set_longjmp_resume_breakpoint, watch_command_1)
(breakpoint_re_set_one): Set breakpoint's
``requested_address'' field. Set ``address'' field to the
result of calling adjust_breakpoint_address() on the requested
address.
Index: breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.131
diff -u -p -r1.131 breakpoint.c
--- breakpoint.c 6 Oct 2003 19:27:12 -0000 1.131
+++ breakpoint.c 13 Oct 2003 23:33:25 -0000
@@ -97,6 +97,10 @@ struct breakpoint *set_raw_breakpoint (s
static void check_duplicates (struct breakpoint *);
+static void breakpoint_adjustment_warning (CORE_ADDR, CORE_ADDR, int, int);
+
+static CORE_ADDR adjust_breakpoint_address (CORE_ADDR bpaddr);
+
static void describe_other_breakpoints (CORE_ADDR, asection *);
static void breakpoints_info (char *, int);
@@ -2023,6 +2027,10 @@ print_it_typical (bpstat bs)
{
case bp_breakpoint:
case bp_hardware_breakpoint:
+ if (bs->breakpoint_at->address != bs->breakpoint_at->requested_address)
+ breakpoint_adjustment_warning (bs->breakpoint_at->requested_address,
+ bs->breakpoint_at->address,
+ bs->breakpoint_at->number, 1);
annotate_breakpoint (bs->breakpoint_at->number);
ui_out_text (uiout, "\nBreakpoint ");
if (ui_out_is_mi_like_p (uiout))
@@ -3840,6 +3848,54 @@ check_duplicates (struct breakpoint *bpt
}
}
+static void
+breakpoint_adjustment_warning (CORE_ADDR from_addr, CORE_ADDR to_addr,
+ int bnum, int have_bnum)
+{
+ char astr1[40];
+ char astr2[40];
+
+ strcpy (astr1, local_hex_string_custom ((unsigned long) from_addr, "08l"));
+ strcpy (astr2, local_hex_string_custom ((unsigned long) to_addr, "08l"));
+ if (have_bnum)
+ warning ("Breakpoint %d address previously adjusted from %s to %s.",
+ bnum, astr1, astr2);
+ else
+ warning ("Breakpoint address adjusted from %s to %s.", astr1, astr2);
+}
+
+/* Adjust a breakpoint's address to account for architectural constraints
+ on breakpoint placement. Return the adjusted address. Note: Very
+ few targets require this kind of adjustment. For most targets,
+ this function is simply the identity function. */
+
+static CORE_ADDR
+adjust_breakpoint_address (CORE_ADDR bpaddr)
+{
+ if (!gdbarch_adjust_breakpoint_address_p (current_gdbarch))
+ {
+ /* Very few targets need any kind of breakpoint adjustment. */
+ return bpaddr;
+ }
+ else
+ {
+ CORE_ADDR adjusted_bpaddr;
+
+ /* Some targets have architectural constraints on the placement
+ of breakpoint instructions. Obtain the adjusted address. */
+ adjusted_bpaddr = gdbarch_adjust_breakpoint_address (current_gdbarch,
+ bpaddr);
+
+ /* An adjusted breakpoint address can significantly alter
+ a user's expectations. Print a warning if an adjustment
+ is required. */
+ if (adjusted_bpaddr != bpaddr)
+ breakpoint_adjustment_warning (bpaddr, adjusted_bpaddr, 0, 0);
+
+ return adjusted_bpaddr;
+ }
+}
+
/* set_raw_breakpoint() is a low level routine for allocating and
partially initializing a breakpoint of type BPTYPE. The newly
created breakpoint's address, section, source file name, and line
@@ -3862,7 +3918,8 @@ set_raw_breakpoint (struct symtab_and_li
b = (struct breakpoint *) xmalloc (sizeof (struct breakpoint));
memset (b, 0, sizeof (*b));
- b->address = sal.pc;
+ b->requested_address = sal.pc;
+ b->address = adjust_breakpoint_address (b->requested_address);
if (sal.symtab == NULL)
b->source_file = NULL;
else
@@ -4353,7 +4410,8 @@ set_longjmp_resume_breakpoint (CORE_ADDR
ALL_BREAKPOINTS (b)
if (b->type == bp_longjmp_resume)
{
- b->address = pc;
+ b->requested_address = pc;
+ b->address = adjust_breakpoint_address (b->requested_address);
b->enable_state = bp_enabled;
b->frame_id = frame_id;
check_duplicates (b);
@@ -5468,7 +5526,9 @@ watch_command_1 (char *arg, int accessfl
scope_breakpoint->frame_id = get_frame_id (prev_frame);
/* Set the address at which we will stop. */
- scope_breakpoint->address = get_frame_pc (prev_frame);
+ scope_breakpoint->requested_address = get_frame_pc (prev_frame);
+ scope_breakpoint->address =
+ adjust_breakpoint_address (scope_breakpoint->requested_address);
/* The scope breakpoint is related to the watchpoint. We
will need to act on them together. */
@@ -6832,7 +6892,8 @@ breakpoint_re_set_one (void *bint)
savestring (sals.sals[i].symtab->filename,
strlen (sals.sals[i].symtab->filename));
b->line_number = sals.sals[i].line;
- b->address = sals.sals[i].pc;
+ b->requested_address = sals.sals[i].pc;
+ b->address = adjust_breakpoint_address (b->requested_address);
/* Used to check for duplicates here, but that can
cause trouble, as it doesn't check for disabled
Index: breakpoint.h
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.h,v
retrieving revision 1.22
diff -u -p -r1.22 breakpoint.h
--- breakpoint.h 6 Oct 2003 19:27:12 -0000 1.22
+++ breakpoint.h 13 Oct 2003 23:33:25 -0000
@@ -227,6 +227,14 @@ struct breakpoint
simulators). NULL is not a special value for this field. */
CORE_ADDR address;
+ /* Address at which breakpoint was requested, either by the user or
+ by GDB for internal breakpoints. This will usually be the same
+ as ``address'' (above) except for cases in which
+ ADJUST_BREAKPOINT_ADDRESS has computed a different address at
+ which to place the breakpoint in order to comply with a
+ processor's architectual constraints. */
+ CORE_ADDR requested_address;
+
/* Line number of this address. */
int line_number;