[PATCH] Set breakpoint on the right line

[PATCH] Set breakpoint on the right line

[Yao Qi]

In gdb.base/watchpoint-hw-hit-once.exp, test scans source and set
breakpoint on the line having "break-at-exit",

  gdb_breakpoint [gdb_get_line_number "break-at-exit"]

However, in watchpoint-hw-hit-once.c, there are two lines having
this key word:

  dummy = 1;	/* Stub to catch break-at-exit after WATCHEE has been hit.  */
  dummy = 2;	/* break-at-exit */

so the test sets breakpoint on the first one, while I think it is
expected to set breakpoint on the second one, as far as I can tell
from the comments in watchpoint-hw-hit-once.c:

  /* Stub lines are present as no breakpoints/watchpoint gets hit if current PC
     already stays on the line PC while entering "step"/"continue".  */

This patch is to change the source matching pattern so that test
can correctly set breakpoint on the right line.  This patch fixes
a fail we found on arm-none-eabi target.  Run it again
on x86_64-linux, no result changes.

gdb/testsuite:

2014-08-12  Yao Qi  <yao@codesourcery.com>

	* gdb.base/watchpoint-hw-hit-once.exp: Set breakpoint on the
	right line.
---
 gdb/testsuite/gdb.base/watchpoint-hw-hit-once.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.exp b/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.exp
index 53de3d5..49c0d6a 100644
--- a/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.exp
+++ b/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.exp
@@ -29,7 +29,7 @@ if ![runto_main] {
 
 gdb_test "rwatch watchee"
 
-gdb_breakpoint [gdb_get_line_number "break-at-exit"]
+gdb_breakpoint [gdb_get_line_number "dummy = 2"]
 
 gdb_test "continue" "Continuing.\r\nHardware read watchpoint \[0-9\]+: watchee\r\n\r\nValue = 0\r\n.*"
 
-- 
1.9.0

Re: [PATCH] Set breakpoint on the right line

[Yao Qi]

On 08/12/2014 09:18 AM, Yao Qi wrote:
> In gdb.base/watchpoint-hw-hit-once.exp, test scans source and set
> breakpoint on the line having "break-at-exit",
> 
>   gdb_breakpoint [gdb_get_line_number "break-at-exit"]
> 
> However, in watchpoint-hw-hit-once.c, there are two lines having
> this key word:
> 
>   dummy = 1;	/* Stub to catch break-at-exit after WATCHEE has been hit.  */
>   dummy = 2;	/* break-at-exit */
> 
> so the test sets breakpoint on the first one, while I think it is
> expected to set breakpoint on the second one, as far as I can tell
> from the comments in watchpoint-hw-hit-once.c:
> 
>   /* Stub lines are present as no breakpoints/watchpoint gets hit if current PC
>      already stays on the line PC while entering "step"/"continue".  */
> 
> This patch is to change the source matching pattern so that test
> can correctly set breakpoint on the right line.  This patch fixes
> a fail we found on arm-none-eabi target.  Run it again
> on x86_64-linux, no result changes.
> 
> gdb/testsuite:
> 
> 2014-08-12  Yao Qi  <yao@codesourcery.com>
> 
> 	* gdb.base/watchpoint-hw-hit-once.exp: Set breakpoint on the
> 	right line.

Ping.  https://sourceware.org/ml/gdb-patches/2014-08/msg00190.html

-- 
Yao (齐尧)

Re: [PATCH] Set breakpoint on the right line

[Joel Brobecker]

> This patch is to change the source matching pattern so that test
> can correctly set breakpoint on the right line.  This patch fixes
> a fail we found on arm-none-eabi target.  Run it again
> on x86_64-linux, no result changes.
> 
> gdb/testsuite:
> 
> 2014-08-12  Yao Qi  <yao@codesourcery.com>
> 
> 	* gdb.base/watchpoint-hw-hit-once.exp: Set breakpoint on the
> 	right line.

I think you are right, but can you describe the error you are getting
with arm-none-eabi?

-- 
Joel

Re: [PATCH] Set breakpoint on the right line

[Yao Qi]

On 08/19/2014 02:38 PM, Joel Brobecker wrote:
> I think you are right, but can you describe the error you are getting
> with arm-none-eabi?

Sure, the fail is shown as below:

continue^M
Continuing.^M
^M
*** EXIT code 0^M
[Inferior 1 (Remote target) exited normally]^M
(gdb) FAIL: gdb.base/watchpoint-hw-hit-once.exp: continue to break-at-exit (the program exited)

I also copy it in the commit log.  Patch is pushed in.

-- 
Yao (齐尧)

Re: [PATCH] Set breakpoint on the right line

[Joel Brobecker]

> > I think you are right, but can you describe the error you are getting
> > with arm-none-eabi?
> 
> Sure, the fail is shown as below:
> 
> continue^M
> Continuing.^M
> ^M
> *** EXIT code 0^M
> [Inferior 1 (Remote target) exited normally]^M
> (gdb) FAIL: gdb.base/watchpoint-hw-hit-once.exp: continue to break-at-exit (the program exited)
> 
> I also copy it in the commit log.  Patch is pushed in.

I actually didn't pre-approve, but never mind :-).

I think I understand, now. The problem using the first break-at-exit
line was that the watchpoint would be triggering at the same location
the breakpoint was inserted. So the "continue" test right after would
never hit that breakpoint. If my understanding is correct, the patch
is officially approved :).

-- 
Joel

Re: [PATCH] Set breakpoint on the right line

[Yao Qi]

On 08/19/2014 09:48 PM, Joel Brobecker wrote:
> I actually didn't pre-approve, but never mind :-).
> 

Ur, I misunderstood you, sorry.

> I think I understand, now. The problem using the first break-at-exit
> line was that the watchpoint would be triggering at the same location
> the breakpoint was inserted. So the "continue" test right after would
> never hit that breakpoint. If my understanding is correct, the patch
> is officially approved :).

Yes, that is correct.

-- 
Yao (齐尧)

[OB/PUSHED] Remove stale comment (was: Re: [PATCH] Set breakpoint on the right line)

[Pedro Alves]

On 08/12/2014 02:18 AM, Yao Qi wrote:
> 
>   /* Stub lines are present as no breakpoints/watchpoint gets hit if current PC
>      already stays on the line PC while entering "step"/"continue".  */

I noticed that this comment is stale.  This is no longer true for
watchpoints.  I've pushed this as obvious.

-------------------------
Remove stale comment

This comment is no longer true for watchpoints since commit 31e77af2
(PR breakpoints/7143 - Watchpoint does not trigger when first set).

gdb/testsuite/

	* gdb.base/watchpoint-hw-hit-once.c (main): Update comment.
---
 gdb/testsuite/ChangeLog                         | 4 ++++
 gdb/testsuite/gdb.base/watchpoint-hw-hit-once.c | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 060c7a1..d30f7a3 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-08-19  Pedro Alves  <palves@redhat.com>
+
+	* gdb.base/watchpoint-hw-hit-once.c (main): Update comment.
+
 2014-08-19  Yao Qi  <yao@codesourcery.com>
 
 	* gdb.base/watchpoint-hw-hit-once.exp: Set breakpoint on the
diff --git a/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.c b/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.c
index 8ba8ca4..aa64f1d 100644
--- a/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.c
+++ b/gdb/testsuite/gdb.base/watchpoint-hw-hit-once.c
@@ -22,7 +22,7 @@ main (void)
 {
   volatile int dummy;
 
-  /* Stub lines are present as no breakpoints/watchpoint gets hit if current PC
+  /* Stub lines are present as no breakpoint gets hit if current PC
      already stays on the line PC while entering "step"/"continue".  */
 
   dummy = 0;	/* Stub to catch WATCHEE access after runto_main.  */
-- 
1.9.3