btrace: Remove struct btrace_function::flow.

This used to hold a pair of pointers to the previous and next function segment
in execution flow order.  It is no longer necessary as the previous and next
function segments now are simply the previous and next elements in the vector
of function segments.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b0353584a1058b7f1b5016640a0300feed311cf4..45ea2b63fd32e1461ed97cdefee299199c89b94c 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2017-05-30  Tim Wiederhake  <tim.wiederhake@intel.com>
+
+       * btrace.c (ftrace_new_function, ftrace_fixup_level,
+       ftrace_connect_bfun, ftrace_bridge_gap, btrace_bridge_gaps,
+       btrace_insn_next, btrace_insn_prev): Remove references to
+       btrace_thread_info::flow.
+       * btrace.h (struct btrace_function): Remove FLOW.
+
 2017-05-30  Tim Wiederhake  <tim.wiederhake@intel.com>
 
        * btrace.c (ftrace_find_call_by_number): New function.

diff --git a/gdb/btrace.c b/gdb/btrace.c
index f0b8eebdcf9c9f43d60f6fb135257e084ad5e9b3..43c5e8b271ee9f46637565ea68632b957226facb 100644 (file)
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -242,10 +242,6 @@ ftrace_new_function (struct btrace_thread_info *btinfo,
     {
       struct btrace_function *prev = btinfo->functions.back ();
 
-      gdb_assert (prev->flow.next == NULL);
-      prev->flow.next = bfun;
-      bfun->flow.prev = prev;
-
       bfun->number = prev->number + 1;
       bfun->insn_offset = prev->insn_offset + ftrace_call_num_insn (prev);
       bfun->level = prev->level;
@@ -693,10 +689,12 @@ ftrace_match_backtrace (struct btrace_thread_info *btinfo,
   return matches;
 }
 
-/* Add ADJUSTMENT to the level of BFUN and succeeding function segments.  */
+/* Add ADJUSTMENT to the level of BFUN and succeeding function segments.
+   BTINFO is the branch trace information for the current thread.  */
 
 static void
-ftrace_fixup_level (struct btrace_function *bfun, int adjustment)
+ftrace_fixup_level (struct btrace_thread_info *btinfo,
+                   struct btrace_function *bfun, int adjustment)
 {
   if (adjustment == 0)
     return;
@@ -704,8 +702,11 @@ ftrace_fixup_level (struct btrace_function *bfun, int adjustment)
   DEBUG_FTRACE ("fixup level (%+d)", adjustment);
   ftrace_debug (bfun, "..bfun");
 
-  for (; bfun != NULL; bfun = bfun->flow.next)
-    bfun->level += adjustment;
+  while (bfun != NULL)
+    {
+      bfun->level += adjustment;
+      bfun = ftrace_find_call_by_number (btinfo, bfun->number + 1);
+    }
 }
 
 /* Recompute the global level offset.  Traverse the function trace and compute
@@ -758,7 +759,7 @@ ftrace_connect_bfun (struct btrace_thread_info *btinfo,
   next->segment.prev = prev;
 
   /* We may have moved NEXT to a different function level.  */
-  ftrace_fixup_level (next, prev->level - next->level);
+  ftrace_fixup_level (btinfo, next, prev->level - next->level);
 
   /* If we run out of back trace for one, let's use the other's.  */
   if (prev->up == 0)
@@ -831,7 +832,8 @@ ftrace_connect_bfun (struct btrace_thread_info *btinfo,
 
                     Otherwise we will fix up CALLER's level when we connect it
                     to PREV's caller in the next iteration.  */
-                 ftrace_fixup_level (caller, prev->level - caller->level - 1);
+                 ftrace_fixup_level (btinfo, caller,
+                                     prev->level - caller->level - 1);
                  break;
                }
 
@@ -929,7 +931,7 @@ ftrace_bridge_gap (struct btrace_thread_info *btinfo,
      To catch this, we already fix up the level here where we can start at RHS
      instead of at BEST_R.  We will ignore the level fixup when connecting
      BEST_L to BEST_R as they will already be on the same level.  */
-  ftrace_fixup_level (rhs, best_l->level - best_r->level);
+  ftrace_fixup_level (btinfo, rhs, best_l->level - best_r->level);
 
   ftrace_connect_backtrace (btinfo, best_l, best_r);
 
@@ -942,12 +944,14 @@ ftrace_bridge_gap (struct btrace_thread_info *btinfo,
 static void
 btrace_bridge_gaps (struct thread_info *tp, VEC (bfun_s) **gaps)
 {
+  struct btrace_thread_info *btinfo;
   VEC (bfun_s) *remaining;
   struct cleanup *old_chain;
   int min_matches;
 
   DEBUG ("bridge gaps");
 
+  btinfo = &tp->btrace;
   remaining = NULL;
   old_chain = make_cleanup (VEC_cleanup (bfun_s), &remaining);
 
@@ -976,20 +980,20 @@ btrace_bridge_gaps (struct thread_info *tp, VEC (bfun_s) **gaps)
                 all but the leftmost gap in such a sequence.
 
                 Also ignore gaps at the beginning of the trace.  */
-             lhs = gap->flow.prev;
+             lhs = ftrace_find_call_by_number (btinfo, gap->number - 1);
              if (lhs == NULL || lhs->errcode != 0)
                continue;
 
              /* Skip gaps to the right.  */
-             for (rhs = gap->flow.next; rhs != NULL; rhs = rhs->flow.next)
-               if (rhs->errcode == 0)
-                 break;
+             rhs = ftrace_find_call_by_number (btinfo, gap->number + 1);
+             while (rhs != NULL && rhs->errcode != 0)
+               rhs = ftrace_find_call_by_number (btinfo, rhs->number + 1);
 
              /* Ignore gaps at the end of the trace.  */
              if (rhs == NULL)
                continue;
 
-             bridged = ftrace_bridge_gap (&tp->btrace, lhs, rhs, min_matches);
+             bridged = ftrace_bridge_gap (btinfo, lhs, rhs, min_matches);
 
              /* Keep track of gaps we were not able to bridge and try again.
                 If we just pushed them to the end of GAPS we would risk an
@@ -1019,7 +1023,7 @@ btrace_bridge_gaps (struct thread_info *tp, VEC (bfun_s) **gaps)
 
   /* We may omit this in some cases.  Not sure it is worth the extra
      complication, though.  */
-  ftrace_compute_global_level_offset (&tp->btrace);
+  ftrace_compute_global_level_offset (btinfo);
 }
 
 /* Compute the function branch trace from BTS trace.  */
@@ -2372,7 +2376,7 @@ btrace_insn_next (struct btrace_insn_iterator *it, unsigned int stride)
        {
          const struct btrace_function *next;
 
-         next = bfun->flow.next;
+         next = ftrace_find_call_by_number (it->btinfo, bfun->number + 1);
          if (next == NULL)
            break;
 
@@ -2402,7 +2406,7 @@ btrace_insn_next (struct btrace_insn_iterator *it, unsigned int stride)
        {
          const struct btrace_function *next;
 
-         next = bfun->flow.next;
+         next = ftrace_find_call_by_number (it->btinfo, bfun->number + 1);
          if (next == NULL)
            {
              /* We stepped past the last function.
@@ -2451,7 +2455,7 @@ btrace_insn_prev (struct btrace_insn_iterator *it, unsigned int stride)
        {
          const struct btrace_function *prev;
 
-         prev = bfun->flow.prev;
+         prev = ftrace_find_call_by_number (it->btinfo, bfun->number - 1);
          if (prev == NULL)
            break;
 

diff --git a/gdb/btrace.h b/gdb/btrace.h
index 8323887486ba1e9fb4b59c547afae0291c45abc4..cd3f3467c9b968dceb0ca1cf44a7add4aaf6d7a9 100644 (file)
--- a/gdb/btrace.h
+++ b/gdb/btrace.h
@@ -151,9 +151,6 @@ struct btrace_function
      two segments: one before the call and another after the return.  */
   struct btrace_func_link segment;
 
-  /* The previous and next function in control flow order.  */
-  struct btrace_func_link flow;
-
   /* The function segment number of the directly preceding function segment in
      a (fake) call stack.  Will be zero if there is no such function segment in
      the record.  */