gdb: make inferior_list use intrusive_list

Change inferior_list, the global list of inferiors, to use
intrusive_list.  I think most other changes are somewhat obvious
fallouts from this change.

There is a small change in behavior in scoped_mock_context.  Before this
patch, constructing a scoped_mock_context would replace the whole
inferior list with only the new mock inferior.  Tests using two
scoped_mock_contexts therefore needed to manually link the two inferiors
together, as the second scoped_mock_context would bump the first mock
inferior from the thread list.  With this patch, a scoped_mock_context
adds its mock inferior to the inferior list on construction, and removes
it on destruction.  This means that tests run with mock inferiors in the
inferior list in addition to any pre-existing inferiors (there is always
at least one).  There is no possible pid clash problem, since each
scoped mock inferior uses its own process target, and pids are per
process target.

Co-Authored-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I7eb6a8f867d4dcf8b8cd2dcffd118f7270756018

1 files changed, 41 insertions, 27 deletions

diff --git a/gdb/thread-iter.c b/gdb/thread-iter.c
index a1cdd02..31b7a36 100644
--- a/gdb/thread-iter.c
+++ b/gdb/thread-iter.c
@@ -26,15 +26,18 @@
 all_threads_iterator::all_threads_iterator (begin_t)
 {
   /* Advance M_INF/M_THR to the first thread's position.  */
-  for (m_inf = inferior_list; m_inf != NULL; m_inf = m_inf->next)
+
+  for (inferior &inf : inferior_list)
     {
-      auto thr_iter = m_inf->thread_list.begin ();
-      if (thr_iter != m_inf->thread_list.end ())
+      auto thr_iter = inf.thread_list.begin ();
+      if (thr_iter != inf.thread_list.end ())
 	{
+	  m_inf = &inf;
 	  m_thr = &*thr_iter;
 	  return;
 	}
     }
+  m_inf = nullptr;
   m_thr = nullptr;
 }
 
@@ -43,6 +46,7 @@ all_threads_iterator::all_threads_iterator (begin_t)
 void
 all_threads_iterator::advance ()
 {
+  intrusive_list<inferior>::iterator inf_iter (m_inf);
   intrusive_list<thread_info>::iterator thr_iter (m_thr);
 
   /* The loop below is written in the natural way as-if we'd always
@@ -50,8 +54,9 @@ all_threads_iterator::advance ()
      the algorithm to the actual current position.  */
   goto start;
 
-  for (; m_inf != NULL; m_inf = m_inf->next)
+  for (; inf_iter != inferior_list.end (); ++inf_iter)
     {
+      m_inf = &*inf_iter;
       thr_iter = m_inf->thread_list.begin ();
       while (thr_iter != m_inf->thread_list.end ())
 	{
@@ -86,16 +91,21 @@ all_matching_threads_iterator::all_matching_threads_iterator
   gdb_assert ((filter_target == nullptr && filter_ptid == minus_one_ptid)
 	      || filter_target->stratum () == process_stratum);
 
-  for (m_inf = inferior_list; m_inf != NULL; m_inf = m_inf->next)
-    if (m_inf_matches ())
-      for (auto thr_iter = m_inf->thread_list.begin ();
-	   thr_iter != m_inf->thread_list.end ();
-	   ++thr_iter)
-	if (thr_iter->ptid.matches (m_filter_ptid))
+  for (inferior &inf : inferior_list)
+    {
+      m_inf = &inf;
+      if (m_inf_matches ())
+	for (auto thr_iter = m_inf->thread_list.begin ();
+	     thr_iter != m_inf->thread_list.end ();
+	     ++thr_iter)
 	  {
-	    m_thr = &*thr_iter;
-	    return;
+	    if (thr_iter->ptid.matches (m_filter_ptid))
+	      {
+		m_thr = &*thr_iter;
+		return;
+	      }
 	  }
+    }
 
   m_thr = nullptr;
 }
@@ -105,6 +115,7 @@ all_matching_threads_iterator::all_matching_threads_iterator
 void
 all_matching_threads_iterator::advance ()
 {
+  intrusive_list<inferior>::iterator inf_iter (m_inf);
   intrusive_list<thread_info>::iterator thr_iter (m_thr);
 
   /* The loop below is written in the natural way as-if we'd always
@@ -112,21 +123,24 @@ all_matching_threads_iterator::advance ()
      the algorithm to the actual current position.  */
   goto start;
 
-  for (; m_inf != NULL; m_inf = m_inf->next)
-    if (m_inf_matches ())
-      {
-	thr_iter = m_inf->thread_list.begin ();
-	while (thr_iter != m_inf->thread_list.end ())
-	  {
-	    if (thr_iter->ptid.matches (m_filter_ptid))
-	      {
-		m_thr = &*thr_iter;
-		return;
-	      }
-	  start:
-	    ++thr_iter;
-	  }
-      }
+  for (; inf_iter != inferior_list.end (); ++inf_iter)
+    {
+      m_inf = &*inf_iter;
+      if (m_inf_matches ())
+	{
+	  thr_iter = m_inf->thread_list.begin ();
+	  while (thr_iter != m_inf->thread_list.end ())
+	    {
+	      if (thr_iter->ptid.matches (m_filter_ptid))
+		{
+		  m_thr = &*thr_iter;
+		  return;
+		}
+	    start:
+	      ++thr_iter;
+	    }
+	}
+    }
 
   m_thr = nullptr;
 }