2 files changed, 40 insertions, 6 deletions

diff --git a/gdb/frame-info.c b/gdb/frame-info.c
index 584222d..40a872e 100644
--- a/gdb/frame-info.c
+++ b/gdb/frame-info.c
@@ -31,7 +31,10 @@ intrusive_list<frame_info_ptr> frame_info_ptr::frame_list;
 void
 frame_info_ptr::prepare_reinflate ()
 {
-  m_cached_id = get_frame_id (*this);
+  m_cached_level = frame_relative_level (*this);
+
+  if (m_cached_level != 0)
+    m_cached_id = get_frame_id (*this);
 }
 
 /* See frame-info-ptr.h.  */
@@ -39,9 +42,24 @@ frame_info_ptr::prepare_reinflate ()
 void
 frame_info_ptr::reinflate ()
 {
-  gdb_assert (frame_id_p (m_cached_id));
+  /* Ensure we have a valid frame level (sentinel frame or above), indicating
+     prepare_reinflate was called.  */
+  gdb_assert (m_cached_level >= -1);
+
+  if (m_ptr != nullptr)
+    {
+      /* The frame_info wasn't invalidated, no need to reinflate.  */
+      return;
+    }
+
+  /* Frame #0 needs special handling, see comment in select_frame.  */
+  if (m_cached_level == 0)
+    m_ptr = get_current_frame ().get ();
+  else
+    {
+      gdb_assert (frame_id_p (m_cached_id));
+      m_ptr = frame_find_by_id (m_cached_id).get ();
+    }
 
-  if (m_ptr == nullptr)
-    m_ptr = frame_find_by_id (m_cached_id).get ();
   gdb_assert (m_ptr != nullptr);
 }
diff --git a/gdb/frame-info.h b/gdb/frame-info.h
index 1d2d4bd..3369b11 100644
--- a/gdb/frame-info.h
+++ b/gdb/frame-info.h
@@ -56,16 +56,21 @@ public:
   }
 
   frame_info_ptr (const frame_info_ptr &other)
-    : m_ptr (other.m_ptr), m_cached_id (other.m_cached_id)
+    : m_ptr (other.m_ptr),
+      m_cached_id (other.m_cached_id),
+      m_cached_level (other.m_cached_level)
   {
     frame_list.push_back (*this);
   }
 
   frame_info_ptr (frame_info_ptr &&other)
-    : m_ptr (other.m_ptr), m_cached_id (other.m_cached_id)
+    : m_ptr (other.m_ptr),
+      m_cached_id (other.m_cached_id),
+      m_cached_level (other.m_cached_level)
   {
     other.m_ptr = nullptr;
     other.m_cached_id = null_frame_id;
+    other.m_cached_level = invalid_level;
     frame_list.push_back (*this);
   }
 
@@ -78,6 +83,7 @@ public:
   {
     m_ptr = other.m_ptr;
     m_cached_id = other.m_cached_id;
+    m_cached_level = other.m_cached_level;
     return *this;
   }
 
@@ -85,6 +91,7 @@ public:
   {
     m_ptr = nullptr;
     m_cached_id = null_frame_id;
+    m_cached_level = invalid_level;
     return *this;
   }
 
@@ -92,8 +99,10 @@ public:
   {
     m_ptr = other.m_ptr;
     m_cached_id = other.m_cached_id;
+    m_cached_level = other.m_cached_level;
     other.m_ptr = nullptr;
     other.m_cached_id = null_frame_id;
+    other.m_cached_level = invalid_level;
     return *this;
   }
 
@@ -136,6 +145,10 @@ public:
   void reinflate ();
 
 private:
+  /* We sometimes need to construct frame_info_ptr objects around the
+     sentinel_frame, which has level -1.  Therefore, make the invalid frame
+     level value -2.  */
+  static constexpr int invalid_level = -2;
 
   /* The underlying pointer.  */
   frame_info *m_ptr = nullptr;
@@ -143,6 +156,9 @@ private:
   /* The frame_id of the underlying pointer.  */
   frame_id m_cached_id = null_frame_id;
 
+  /* The frame level of the underlying pointer.  */
+  int m_cached_level = invalid_level;
+
   /* All frame_info_ptr objects are kept on an intrusive list.
      This keeps their construction and destruction costs
      reasonably small.  */