Fix LLDB crash accessing unknown DW_FORM_* attributes

Current LLDB (that is without DWZ support) crashes accessing Fedora debug info:
READ of size 8 at 0x60200000ffc8 thread T0
    #0 in DWARFDebugInfoEntry::BuildAddressRangeTable(SymbolFileDWARF*, DWARFCompileUnit const*, DWARFDebugAranges*) const tools/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp:1336

Greg Clayton: We will need a warning to be emitted in
SymbolFileDWARF::CalculateAbilities() stating we won't parse the DWARF due to
"unsupported DW_FORM value of 0x1f20".

Patch has been mostly written by Greg Clayton.

Differential revision: https://reviews.llvm.org/D35622

llvm-svn: 309581

1 files changed, 14 insertions, 0 deletions

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 7a4d894af10..82d68574c49 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -532,6 +532,20 @@ uint32_t SymbolFileDWARF::CalculateAbilities() {
       if (section)
         debug_abbrev_file_size = section->GetFileSize();
 
+      DWARFDebugAbbrev *abbrev = DebugAbbrev();
+      if (abbrev) {
+        std::set<dw_form_t> invalid_forms;
+        abbrev->GetUnsupportedForms(invalid_forms);
+        if (!invalid_forms.empty()) {
+          StreamString error;
+          error.Printf("unsupported DW_FORM value%s:", invalid_forms.size() > 1 ? "s" : "");
+          for (auto form : invalid_forms)
+            error.Printf(" %#x", form);
+          m_obj_file->GetModule()->ReportWarning("%s", error.GetString().str().c_str());
+          return 0;
+        }
+      }
+
       section =
           section_list->FindSectionByType(eSectionTypeDWARFDebugLine, true)
               .get();