From a41f2ad77a642e70f46caa8261746c651f5dc2ad Mon Sep 17 00:00:00 2001

From: Josh Stone <jistone@redhat.com>

Date: Mon, 2 Dec 2013 14:34:07 -0800

Subject: [PATCH] Use proper set operations for symtab dupe checks

In query_symtab_func_info, rather than full set iteration to check an

address in alias_dupes, just use set::insert().second as a test.  This

is what sets are designed to be algorithmically good at.

This also has the benefit of adding to alias_dupes, so duplicates within

the symbol table itself will still only be probed once.  (If we didn't

want that effect, we would just use set::count() to test membership.)

---

 tapsets.cxx | 22 ++++------------------

 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/tapsets.cxx b/tapsets.cxx

index f1a5843..b3cfa0e 100644

--- a/tapsets.cxx

+++ b/tapsets.cxx

@@ -1003,24 +1003,10 @@ query_symtab_func_info (func_info & fi, dwarf_query * q)

   // If there are already probes in this module, lets not duplicate.

   // This can come from other weak symbols/aliases or existing

-  // matches from Dwarf DIE functions.

-  if (q->alias_dupes.size() > 0)

-    {

-      for (set<Dwarf_Addr>::iterator it=q->alias_dupes.begin(); it!=q->alias_dupes.end(); ++it)

-	{

-	  // If we've already got a probe at that pc, skip it

-	  if (*it == addr)

-	    return;

-	  if (*it != addr && ++it==q->alias_dupes.end())

-	    {

-	      // Build a probe at this point

-	      query_func_info(addr, fi, q);

-	      return;

-	    }

-	}

-    }

-  else

-    query_func_info(addr,fi,q);

+  // matches from Dwarf DIE functions.  Try to add this addr to the

+  // collection, and only continue if it was new.

+  if (q->alias_dupes.insert(addr).second)

+    query_func_info(addr, fi, q);

 }

 void

-- 

1.8.3.1