Patchwork [v8,7/7] Extended-remote follow fork documentation

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Submitter Don Breazeal
Date April 17, 2015, 8:58 p.m.
Message ID <1429304325-13878-8-git-send-email-donb@codesourcery.com>
Download mbox | patch
Permalink /patch/6312/
State New
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Comments

Don Breazeal - April 17, 2015, 8:58 p.m.
This patch contains the accumulated documentation changes for the
rest of the extended-remote follow fork patchset.

On 4/15/2015 8:46 AM, Pedro Alves wrote:
> On 04/10/2015 09:43 PM, Don Breazeal wrote:
> 
>>  @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
> 
> I don't think we document what a ptid is --- that's an internal
> gdb implementation detail.  This should probably say that it's the
> thread id of the new child process, and cross reference
> to "thread-id syntax".

I've made this change.

> 
>> +applicable to targets that support fork events.
> 
> Thanks,
> Pedro Alves
> 

Thanks
--Don

gdb/
2015-04-17  Don Breazeal  <donb@codesourcery.com>

	* NEWS: Announce fork support in the RSP and support
	  for fork debugging in extended mode.

gdb/doc/
2015-04-17  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 | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
Pedro Alves - April 23, 2015, 2:20 p.m.
On 04/17/2015 09:58 PM, Don Breazeal wrote:
> This patch contains the accumulated documentation changes for the
> rest of the extended-remote follow fork patchset.

Thanks, looks good to me, protocol/substance-wise.

Patch

diff --git a/gdb/NEWS b/gdb/NEWS
index c24195e..93da9e9 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -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.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 6255c14..688f594 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -3135,6 +3135,9 @@  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.
 
@@ -19919,6 +19922,14 @@  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
@@ -35357,6 +35368,49 @@  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 thread ID of the new child process.  Refer to
+@ref{thread-id syntax} for the format of the @var{thread-id}
+field.  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 thread ID of the new child process. Refer to
+@ref{thread-id syntax} for the format of the @var{thread-id}
+field.  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}
@@ -35949,6 +36003,18 @@  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
@@ -36187,6 +36253,16 @@  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:
@@ -36375,6 +36451,13 @@  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::