[Lldb-commits] [lldb] r226299 - Take extra care to ensure we don't deref a NULL pointer.

[Greg Clayton]

Author: gclayton
Date: Fri Jan 16 12:59:48 2015
New Revision: 226299

URL: http://llvm.org/viewvc/llvm-project?rev=226299&view=rev
Log:
Take extra care to ensure we don't deref a NULL pointer.


Modified:
    lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp

Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp?rev=226299&r1=226298&r2=226299&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp (original)
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp Fri Jan 16 12:59:48 2015
@@ -2294,22 +2294,26 @@ DWARFDebugInfoEntry::GetAbbreviationDecl
     if (dwarf2Data)
     {
         offset = GetOffset();
-        
-        const DWARFAbbreviationDeclaration* abbrev_decl = cu->GetAbbreviations()->GetAbbreviationDeclaration (m_abbr_idx);
-        if (abbrev_decl)
+
+        const DWARFAbbreviationDeclarationSet *abbrev_set = cu->GetAbbreviations();
+        if (abbrev_set)
         {
-            // Make sure the abbreviation code still matches. If it doesn't and
-            // the DWARF data was mmap'ed, the backing file might have been modified
-            // which is bad news.
-            const uint64_t abbrev_code = dwarf2Data->get_debug_info_data().GetULEB128 (&offset);
-        
-            if (abbrev_decl->Code() == abbrev_code)
-                return abbrev_decl;
+            const DWARFAbbreviationDeclaration* abbrev_decl = abbrev_set->GetAbbreviationDeclaration (m_abbr_idx);
+            if (abbrev_decl)
+            {
+                // Make sure the abbreviation code still matches. If it doesn't and
+                // the DWARF data was mmap'ed, the backing file might have been modified
+                // which is bad news.
+                const uint64_t abbrev_code = dwarf2Data->get_debug_info_data().GetULEB128 (&offset);
             
-            dwarf2Data->GetObjectFile()->GetModule()->ReportErrorIfModifyDetected ("0x%8.8x: the DWARF debug information has been modified (abbrev code was %u, and is now %u)", 
-                                                                                   GetOffset(),
-                                                                                   (uint32_t)abbrev_decl->Code(),
-                                                                                   (uint32_t)abbrev_code);
+                if (abbrev_decl->Code() == abbrev_code)
+                    return abbrev_decl;
+                
+                dwarf2Data->GetObjectFile()->GetModule()->ReportErrorIfModifyDetected ("0x%8.8x: the DWARF debug information has been modified (abbrev code was %u, and is now %u)", 
+                                                                                       GetOffset(),
+                                                                                       (uint32_t)abbrev_decl->Code(),
+                                                                                       (uint32_t)abbrev_code);
+            }
         }
     }
     offset = DW_INVALID_OFFSET;