Shrink-to-fit our std::vector<DWARFDebugInfoEntry> collections and save 20%

to 30% of memory. The size doubling was killing us and we ended up with up to
just under 50% of empty capacity. Cleaning this up saves us a ton of memory.

llvm-svn: 145086

1 files changed, 10 insertions, 0 deletions

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp
index aa8699f0ad2..096710cd258 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp
@@ -271,7 +271,17 @@ DWARFCompileUnit::ExtractDIEsIfNeeded (bool cu_die_only)
         }
         fprintf (stderr, "warning: DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8x in '%s'\n", GetOffset(), offset, path);
     }
+
+    // Since std::vector objects will double their size, we really need to
+    // make a new array with the perfect size so we don't end up wasting
+    // space. So here we copy and swap to make sure we don't have any extra
+    // memory taken up.
     
+    if (m_die_array.size () < m_die_array.capacity())
+    {
+        DWARFDebugInfoEntry::collection exact_size_die_array (m_die_array.begin(), m_die_array.end());
+        exact_size_die_array.swap (m_die_array);
+    }
     LogSP log (LogChannelDWARF::GetLogIfAll (DWARF_LOG_DEBUG_INFO));
     if (log)
     {