[v7,7/7] Extended-remote follow fork documentation
Commit Message
This patch contains the accumulated documentation changes for the
rest of the extended-remote follow fork patchset.
[Eli, you have reviewed parts of this before, but there are some new
bits as well. Sorry for all the iterations.]
Thanks
--Don
gdb/
2015-04-08 Don Breazeal <donb@codesourcery.com>
* NEWS: Announce fork support in the RSP and support
for fork debugging in extended mode.
gdb/doc/
2015-04-08 Don Breazeal <donb@codesourcery.com>
* gdb.texinfo (Forks): Note that fork debugging is
supported in extended mode.
(Remote Configuration): Add fork event features to table
of packet settings.
(Stop Reply Packets): Add fork events to list of stop reasons.
(General Query Packets): Add fork events to tables of
'gdbfeatures' and 'stub features' supported in the qSupported
packet, as well as to the list containing stub feature
details.
---
gdb/NEWS | 24 ++++++++++++++++
gdb/doc/gdb.texinfo | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 103 insertions(+)
Comments
> From: Don Breazeal <donb@codesourcery.com>
> Date: Fri, 10 Apr 2015 10:09:46 -0700
>
> This patch contains the accumulated documentation changes for the
> rest of the extended-remote follow fork patchset.
Thanks.
> gdb/NEWS | 24 ++++++++++++++++
This part is OK.
> +@cindex fork events, remote reply
> +@item fork
> +The packet indicates that @code{fork} was called, and @var{r}
What does that @var{r} refer to? The previous text mentions
@var{n}:@var{r} pairs, but there's no @var{n} in this description, so
it doesn't seem to fit. What am I missing?
> +shared. The @var{r} part is ignored. This packet is only
^^
Two spaces.
OK with those fixed.
On 4/10/2015 10:56 AM, Eli Zaretskii wrote:
>> From: Don Breazeal <donb@codesourcery.com>
>> Date: Fri, 10 Apr 2015 10:09:46 -0700
>>
>
>> +@cindex fork events, remote reply
>> +@item fork
>> +The packet indicates that @code{fork} was called, and @var{r}
>
> What does that @var{r} refer to? The previous text mentions
> @var{n}:@var{r} pairs, but there's no @var{n} in this description, so
> it doesn't seem to fit. What am I missing?
Maybe I'm the one who is missing something. I thought that the @var{n}
was implied by '@item fork', because of this text above:
If @var{n} is a recognized @dfn{stop reason},
In this case @var{n} is a stop reason. Subsequently '@item fork' is in
this table:
The currently defined stop reasons are:
@table @samp
I pretty much just copied what had been done for shared library events
in the same table. Should I do this differently? I see that swbreak
and hwbreak aren't the same as the other items.
Thanks
--Don
> Date: Fri, 10 Apr 2015 11:15:30 -0700
> From: "Breazeal, Don" <donb@codesourcery.com>
> CC: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
>
> >> +@cindex fork events, remote reply
> >> +@item fork
> >> +The packet indicates that @code{fork} was called, and @var{r}
> >
> > What does that @var{r} refer to? The previous text mentions
> > @var{n}:@var{r} pairs, but there's no @var{n} in this description, so
> > it doesn't seem to fit. What am I missing?
>
> Maybe I'm the one who is missing something. I thought that the @var{n}
> was implied by '@item fork', because of this text above:
>
> If @var{n} is a recognized @dfn{stop reason},
Sheesh! 2 pages ago...
> In this case @var{n} is a stop reason. Subsequently '@item fork' is in
> this table:
>
> The currently defined stop reasons are:
>
> @table @samp
>
> I pretty much just copied what had been done for shared library events
> in the same table. Should I do this differently? I see that swbreak
> and hwbreak aren't the same as the other items.
Never mind, let's leave it as it is.
Thanks.
@@ -101,6 +101,30 @@ hwbreak stop reason
vFile:fstat:
Return information about files on the remote system.
+fork stop reason
+ Indicates that a fork system call was executed.
+
+vfork stop reason
+ Indicates that a vfork system call was executed.
+
+vforkdone stop reason
+ Indicates that a vfork child of the specified process has executed
+ an exec or exit, allowing the vfork parent to resume execution.
+
+fork-events and vfork-events features in qSupported
+ The qSupported packet allows GDB to request support for fork and
+ vfork events using new 'gdbfeatures' fork-events and vfork-events,
+ and the qSupported response can contain the corresponding
+ 'stubfeatures'. Set and show commands can be used to display
+ whether these features are enabled.
+
+* Extended-remote fork events
+
+ ** GDB now has support for fork events on extended-remote Linux
+ targets. For targets with Linux kernels 2.5.60 and later, this
+ enables follow-fork-mode and detach-on-fork for both fork and
+ vfork, as well as fork and vfork catchpoints.
+
* The info record command now shows the recording format and the
branch tracing configuration for the current thread when using
the btrace record target.
@@ -3142,6 +3142,9 @@ create additional processes using the @code{fork} or @code{vfork} functions.
Currently, the only platforms with this feature are HP-UX (11.x and later
only?) and @sc{gnu}/Linux (kernel version 2.5.60 and later).
+The fork debugging commands are supported in both native mode and when
+connected to @code{gdbserver} using @kbd{target extended-remote}.
+
By default, when a program forks, @value{GDBN} will continue to debug
the parent process and the child process will run unimpeded.
@@ -19848,6 +19851,14 @@ are:
@tab @code{hwbreak stop reason}
@tab @code{hbreak}
+@item @code{fork-event-feature}
+@tab @code{fork stop reason}
+@tab @code{fork}
+
+@item @code{vfork-event-feature}
+@tab @code{vfork stop reason}
+@tab @code{vfork}
+
@end multitable
@node Remote Stub
@@ -35286,6 +35297,45 @@ The @var{r} part must be left empty.
The same remarks about @samp{qSupported} and non-stop mode above
apply.
+
+@cindex fork events, remote reply
+@item fork
+The packet indicates that @code{fork} was called, and @var{r}
+is the ptid of the new child process. This packet is only
+applicable to targets that support fork events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+@cindex vfork events, remote reply
+@item vfork
+The packet indicates that @code{vfork} was called, and @var{r}
+is the ptid of the new child process. This packet is only
+applicable to targets that support vfork events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+@cindex vforkdone events, remote reply
+@item vforkdone
+The packet indicates that a child process created by a vfork
+has either called @code{exec} or terminated, so that the
+address spaces of the parent and child process are no longer
+shared. The @var{r} part is ignored. This packet is only
+applicable to targets that support vforkdone events.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
@end table
@item W @var{AA}
@@ -35878,6 +35928,18 @@ reason in stop replies. @xref{swbreak stop reason}, for details.
@item hwbreak
This feature indicates whether @value{GDBN} supports the hwbreak stop
reason in stop replies. @xref{swbreak stop reason}, for details.
+
+@item fork-events
+This feature indicates whether @value{GDBN} supports fork event
+extensions to the remote protocol. @value{GDBN} does not use such
+extensions unless the stub also reports that it supports them by
+including @samp{fork-events+} in its @samp{qSupported} reply.
+
+@item vfork-events
+This feature indicates whether @value{GDBN} supports vfork event
+extensions to the remote protocol. @value{GDBN} does not use such
+extensions unless the stub also reports that it supports them by
+including @samp{vfork-events+} in its @samp{qSupported} reply.
@end table
Stubs should ignore any unknown values for
@@ -36116,6 +36178,16 @@ These are the currently defined stub features and their properties:
@tab @samp{-}
@tab No
+@item @samp{fork-events}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{vfork-events}
+@tab No
+@tab @samp{-}
+@tab No
+
@end multitable
These are the currently defined stub features, in more detail:
@@ -36304,6 +36376,13 @@ breakpoints.
The remote stub reports the @samp{hwbreak} stop reason for hardware
breakpoints.
+@item fork-events
+The remote stub reports the @samp{fork} stop reason for fork events.
+
+@item vfork-events
+The remote stub reports the @samp{vfork} stop reason for vfork events
+and vforkdone events.
+
@end table
@item qSymbol::