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[patch v8 05/24] frame: artificial frame id's
- From: Markus Metzger <markus dot t dot metzger at intel dot com>
- To: jan dot kratochvil at redhat dot com
- Cc: gdb-patches at sourceware dot org, Pedro Alves <palves at redhat dot com>
- Date: Thu, 12 Dec 2013 10:15:28 +0100
- Subject: [patch v8 05/24] frame: artificial frame id's
- Authentication-results: sourceware.org; auth=none
- References: <1386839747-8860-1-git-send-email-markus dot t dot metzger at intel dot com>
At the moment, a frame must have a stack - except for the outer frame.
When we analyze the recorded execution for "record btrace" to detect
function calls and compute a back trace at some point in the recorded
execution history, we will end up with frames without a stack.
To prepare for this, support frame_id's without a stack component.
CC: Pedro Alves <palves@redhat.com>
2013-12-12 Markus Metzger <markus.t.metzger@intel.com>
* frame.h (frame_id_build_artificial): New.
* frame.c (frame_id_build_artificial): New.
(frame_id_p): An artificial frame is valid.
(frame_id_eq): A frame is equal to itself.
---
gdb/frame.c | 30 +++++++++++++++++++++++-------
gdb/frame.h | 6 ++++++
2 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/gdb/frame.c b/gdb/frame.c
index ddd5e70..37d780e 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -526,6 +526,21 @@ frame_id_build_wild (CORE_ADDR stack_addr)
return id;
}
+/* See frame.h. */
+
+struct frame_id
+frame_id_build_artificial (CORE_ADDR code_addr,
+ CORE_ADDR special_addr)
+{
+ struct frame_id id = null_frame_id;
+
+ id.code_addr = code_addr;
+ id.code_addr_p = 1;
+ id.special_addr = special_addr;
+ id.special_addr_p = 1;
+ return id;
+}
+
int
frame_id_p (struct frame_id l)
{
@@ -536,6 +551,9 @@ frame_id_p (struct frame_id l)
/* outer_frame_id is also valid. */
if (!p && memcmp (&l, &outer_frame_id, sizeof (l)) == 0)
p = 1;
+ /* An artificial frame is also valid. */
+ if (!p && l.code_addr_p && l.special_addr_p)
+ p = 1;
if (frame_debug)
{
fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l=");
@@ -559,13 +577,11 @@ frame_id_eq (struct frame_id l, struct frame_id r)
{
int eq;
- if (!l.stack_addr_p && l.special_addr_p
- && !r.stack_addr_p && r.special_addr_p)
- /* The outermost frame marker is equal to itself. This is the
- dodgy thing about outer_frame_id, since between execution steps
- we might step into another function - from which we can't
- unwind either. More thought required to get rid of
- outer_frame_id. */
+ if (memcmp (&l, &r, sizeof (l)) == 0)
+ /* Every frame is equal to itself.
+ This is the dodgy thing about outer_frame_id, since between execution
+ steps we might step into another function - from which we can't unwind
+ either. More thought required to get rid of outer_frame_id. */
eq = 1;
else if (!l.stack_addr_p || !r.stack_addr_p)
/* Like a NaN, if either ID is invalid, the result is false.
diff --git a/gdb/frame.h b/gdb/frame.h
index e4e6b25..71f07dd 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -174,6 +174,12 @@ extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
as the special identifier address are set to indicate wild cards. */
extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
+/* Construct an artificial frame ID. The first parameter is the frame's
+ constant code address (typically the function entry point), and the
+ second the frame's special identifier address. */
+extern struct frame_id frame_id_build_artificial (CORE_ADDR code_addr,
+ CORE_ADDR special_addr);
+
/* Returns non-zero when L is a valid frame (a valid frame has a
non-zero .base). The outermost frame is valid even without an
ID. */
--
1.8.3.1