[RFC,v5,3/9] Add scoped_restore_regcache_ptid
Commit Message
When a target and its target beneath use different ptids to identify a
thread the regcaches ptid has to be set/restored when calls are passed down
to the target beneath to e.g. fetch_registers. Add a scoped_restore to
simplify this.
gdb/ChangeLog:
regcache.h (scoped_restore_regcache_ptid): New class.
---
gdb/regcache.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
Comments
On 2018-03-12 11:31 AM, Philipp Rudo wrote:
> When a target and its target beneath use different ptids to identify a
> thread the regcaches ptid has to be set/restored when calls are passed down
> to the target beneath to e.g. fetch_registers. Add a scoped_restore to
> simplify this.
Though I don't understand yet why this is needed (I'll find out when reading
the following patches), the implementation looks ok.
I don't think this is an issue (at least for now), but there is this observer
"thread_ptid_changed" that indicates when a thread changes ptid. If this
observer is triggered while we have temporarily changed a regcache's ptid,
I guess we could miss updating a regcache's ptid, as
scoped_restore_regcache_ptid will reset it to the old ptid. It's probably
not a problem but I think it's good to be aware of this.
Simon
@@ -403,6 +403,27 @@ private:
registers_changed_ptid (ptid_t ptid);
};
+/* Save/restore the current ptid of REGCACHE. */
+
+class scoped_restore_regcache_ptid
+{
+public:
+ scoped_restore_regcache_ptid (regcache *regcache)
+ : m_regcache (regcache), m_ptid (regcache->ptid ())
+ {}
+
+ ~scoped_restore_regcache_ptid ()
+ {
+ m_regcache->set_ptid (m_ptid);
+ }
+
+ DISABLE_COPY_AND_ASSIGN (scoped_restore_regcache_ptid);
+
+private:
+ regcache *m_regcache;
+ ptid_t m_ptid;
+};
+
class readonly_detached_regcache : public readable_regcache
{
public: