[LLDB] - Add support for DW_FORM_implicit_const.

LLDB does not support this DWARF5 form atm.
At least gcc emits it in some cases when doing optimization
for abbreviations.

As far I can tell, clang does not support it yet, though
the rest LLVM code already knows about it.

The patch adds the support.

Differential revision: https://reviews.llvm.org/D52689

llvm-svn: 344328

1 files changed, 5 insertions, 1 deletions

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFAbbreviationDeclaration.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFAbbreviationDeclaration.cpp
index a765be0b46d..d78b9ab10f5 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFAbbreviationDeclaration.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFAbbreviationDeclaration.cpp
@@ -41,9 +41,13 @@ bool DWARFAbbreviationDeclaration::Extract(const DWARFDataExtractor &data,
     while (data.ValidOffset(*offset_ptr)) {
       dw_attr_t attr = data.GetULEB128(offset_ptr);
       dw_form_t form = data.GetULEB128(offset_ptr);
+      DWARFFormValue::ValueType val;
+
+      if (form == DW_FORM_implicit_const)
+        val.value.sval = data.GetULEB128(offset_ptr);
 
       if (attr && form)
-        m_attributes.push_back(DWARFAttribute(attr, form));
+        m_attributes.push_back(DWARFAttribute(attr, form, val));
       else
         break;
     }