[Lldb-commits] [PATCH] Fixed symbol ordering to be stable with overlapping symbols.

[Richard Mitton]

If two symbols A and B have the same address, then doing lookups at that address will return different symbols depending on whether an offset was used.

e.g.  if A==B==0x100000
0x100000 -> A
0x100007 -> B

This would result in spurious labels when disassembling a function with an alias. This patch fixes it by ensuring we always return the first symbol covering an address.


http://llvm-reviews.chandlerc.com/D1690

Files:
  include/lldb/Core/RangeMap.h

Index: include/lldb/Core/RangeMap.h
===================================================================
--- include/lldb/Core/RangeMap.h
+++ include/lldb/Core/RangeMap.h
@@ -1229,16 +1229,11 @@
                 typename Collection::const_iterator end = m_entries.end();
                 typename Collection::const_iterator pos = std::lower_bound (begin, end, entry, BaseLessThan);
                 
+                while(pos != begin && pos[-1].Contains(addr))
+                    --pos;
+
                 if (pos != end && pos->Contains(addr))
-                {
                     return std::distance (begin, pos);
-                }
-                else if (pos != begin)
-                {
-                    --pos;
-                    if (pos->Contains(addr))
-                        return std::distance (begin, pos);
-                }
             }
             return UINT32_MAX;
         }
@@ -1257,19 +1252,12 @@
                 typename Collection::iterator begin = m_entries.begin();
                 typename Collection::iterator end = m_entries.end();
                 typename Collection::iterator pos = std::lower_bound (begin, end, entry, BaseLessThan);
+
+                while(pos != begin && pos[-1].Contains(addr))
+                    --pos;
                 
                 if (pos != end && pos->Contains(addr))
-                {
                     return &(*pos);
-                }
-                else if (pos != begin)
-                {
-                    --pos;
-                    if (pos->Contains(addr))
-                    {
-                        return &(*pos);
-                    }
-                }
             }
             return NULL;
         }
@@ -1288,18 +1276,11 @@
                 typename Collection::const_iterator end = m_entries.end();
                 typename Collection::const_iterator pos = std::lower_bound (begin, end, entry, BaseLessThan);
                 
+                while(pos != begin && pos[-1].Contains(addr))
+                    --pos;
+
                 if (pos != end && pos->Contains(addr))
-                {
-                    return &(*pos); 
-                }
-                else if (pos != begin)
-                {
-                    --pos;
-                    if (pos->Contains(addr))
-                    {
-                        return &(*pos); 
-                    }
-                }
+                    return &(*pos);
             }
             return NULL;
         }
@@ -1316,18 +1297,11 @@
                 typename Collection::const_iterator end = m_entries.end();
                 typename Collection::const_iterator pos = std::lower_bound (begin, end, range, BaseLessThan);
                 
+                while(pos != begin && pos[-1].Contains(range))
+                    --pos;
+
                 if (pos != end && pos->Contains(range))
-                {
-                    return &(*pos); 
-                }
-                else if (pos != begin)
-                {
-                    --pos;
-                    if (pos->Contains(range))
-                    {
-                        return &(*pos); 
-                    }
-                }
+                    return &(*pos);
             }
             return NULL;
         }
@@ -1501,12 +1475,15 @@
                 typename Collection::iterator end = m_entries.end();
                 typename Collection::iterator pos = std::lower_bound (begin, end, entry, BaseLessThan);
                 
+                while(pos != begin && pos[-1].addr == addr)
+                    --pos;
+
                 if (pos != end)
                 {
                     if (pos->addr == addr || !exact_match_only)
                         return &(*pos);
                 }
-           }
+            }
             return NULL;
         }
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