Revert "fix(callgrind): aggregate (cxt==0) and underflow leaks under a sentinel cxt"

This reverts commit 4a7c1d5.

Author: not-matthias

callgrind/bbcc.c

@@ -518,13 +518,6 @@ static void handleUnderflow(BB* bb)
                "obj='%s' skip=%d\n",
                bb_addr(bb), caller->name,
                caller->file->obj->name, caller->skip);
-
-  /* A (sentinel): if the fn we'd return into is itself skipped, push
-   * the (skipped) sentinel instead so the skipped fn doesn't surface
-   * as its own fn= block in the dump. */
-  if (caller->skip)
-    caller = CLG_(get_skipped_sentinel)();
-
   CLG_(push_cxt)( caller );
 
   if (!seen_before) {
@@ -844,9 +837,6 @@ void CLG_(setup_bbcc)(BB* bb)
                    push_fn->name,
                    push_fn->file->obj->name,
                    (int)jmpkind, (int)delayed_push);
-      /* A (sentinel): substitute the (skipped) sentinel so the
-       * skipped fn doesn't appear as its own fn= block in the dump. */
-      push_fn = CLG_(get_skipped_sentinel)();
     }
     CLG_(push_cxt)(push_fn);
   }

callgrind/fn.c

@@ -336,27 +336,6 @@ static Bool name_contains(const HChar* hay, const HChar* needle)
     return False;
 }
 
-static fn_node* new_fn_node(const HChar *fnname,
-                            file_node* file, fn_node* next);
-
-/* Singleton sentinel fn_node used as a placeholder cxt when we'd
- * otherwise be forced to push a skipped fn into an empty (cxt == 0)
- * context. Keeping skip == False on the sentinel itself is crucial:
- * the (cxt == 0 && skip) check that would push it must NOT recurse
- * on the sentinel. */
-static fn_node* skipped_sentinel = NULL;
-
-fn_node* CLG_(get_skipped_sentinel)(void)
-{
-    if (skipped_sentinel) return skipped_sentinel;
-
-    obj_node* obj = CLG_(get_obj_node)(NULL);   /* anonymous "???" obj */
-    file_node* file = CLG_(get_file_node)(obj, "", "(callgrind-internal)");
-    skipped_sentinel = new_fn_node("(skipped)", file, NULL);
-    skipped_sentinel->skip = False;
-    return skipped_sentinel;
-}
-
 void CLG_(dump_python_fn_summary)(void)
 {
     Int total = 0, checked = 0, skipped = 0;

callgrind/global.h

@@ -725,7 +725,6 @@ UInt* CLG_(get_fn_entry)(Int n);
 void      CLG_(init_obj_table)(void);
 void      CLG_(count_obj_skip_checked_fns)(Int* checked, Int* skipped);
 void      CLG_(dump_python_fn_summary)(void);
-fn_node*  CLG_(get_skipped_sentinel)(void);
 obj_node* CLG_(get_obj_node)(DebugInfo* si);
 file_node* CLG_(get_file_node)(obj_node*, const HChar *dirname,
                                const HChar* filename);