[Lldb-commits] [lldb] [lldb][NFCI] Remove duplicated code in DWARFParser (PR #69531)

[David Blaikie via lldb-commits]

================
@@ -73,137 +69,18 @@ bool DWARFDebugInfoEntry::Extract(const DWARFDataExtractor &data,
   m_tag = abbrevDecl->getTag();
   m_has_children = abbrevDecl->hasChildren();
   // Skip all data in the .debug_info or .debug_types for the attributes
-  dw_form_t form;
   for (const auto &attribute : abbrevDecl->attributes()) {
-    form = attribute.Form;
-    std::optional<uint8_t> fixed_skip_size =
-        DWARFFormValue::GetFixedSize(form, cu);
-    if (fixed_skip_size)
-      offset += *fixed_skip_size;
-    else {
-      bool form_is_indirect = false;
-      do {
-        form_is_indirect = false;
-        uint32_t form_size = 0;
-        switch (form) {
-        // Blocks if inlined data that have a length field and the data bytes
-        // inlined in the .debug_info/.debug_types
-        case DW_FORM_exprloc:
-        case DW_FORM_block:
-          form_size = data.GetULEB128(&offset);
-          break;
-        case DW_FORM_block1:
-          form_size = data.GetU8_unchecked(&offset);
-          break;
-        case DW_FORM_block2:
-          form_size = data.GetU16_unchecked(&offset);
-          break;
-        case DW_FORM_block4:
-          form_size = data.GetU32_unchecked(&offset);
-          break;
-
-        // Inlined NULL terminated C-strings
-        case DW_FORM_string:
-          data.GetCStr(&offset);
-          break;
-
-        // Compile unit address sized values
-        case DW_FORM_addr:
-          form_size = cu->GetAddressByteSize();
-          break;
-        case DW_FORM_ref_addr:
-          if (cu->GetVersion() <= 2)
-            form_size = cu->GetAddressByteSize();
-          else
-            form_size = 4;
-          break;
+    if (DWARFFormValue::SkipValue(attribute.Form, data, offset_ptr, cu))
+      continue;
 
-        // 0 sized form
-        case DW_FORM_flag_present:
-          form_size = 0;
-          break;
-
-        // 1 byte values
-        case DW_FORM_addrx1:
-        case DW_FORM_data1:
-        case DW_FORM_flag:
-        case DW_FORM_ref1:
-        case DW_FORM_strx1:
-          form_size = 1;
-          break;
-
-        // 2 byte values
-        case DW_FORM_addrx2:
-        case DW_FORM_data2:
-        case DW_FORM_ref2:
-        case DW_FORM_strx2:
-          form_size = 2;
-          break;
-
-        // 3 byte values
-        case DW_FORM_addrx3:
-        case DW_FORM_strx3:
-          form_size = 3;
-          break;
-
-        // 4 byte values
-        case DW_FORM_addrx4:
-        case DW_FORM_data4:
-        case DW_FORM_ref4:
-        case DW_FORM_strx4:
-          form_size = 4;
-          break;
-
-        // 8 byte values
-        case DW_FORM_data8:
-        case DW_FORM_ref8:
-        case DW_FORM_ref_sig8:
-          form_size = 8;
-          break;
-
-        // signed or unsigned LEB 128 values
-        case DW_FORM_addrx:
-        case DW_FORM_loclistx:
-        case DW_FORM_rnglistx:
-        case DW_FORM_sdata:
-        case DW_FORM_udata:
-        case DW_FORM_ref_udata:
-        case DW_FORM_GNU_addr_index:
-        case DW_FORM_GNU_str_index:
-        case DW_FORM_strx:
-          data.Skip_LEB128(&offset);
----------------
dwblaikie wrote:

One loss seems to be that the other code uses the `get` rather than `skip` version of the LEB parsing DataExtractor functions - so maybe those should be changed/improved (or, if that optimization isn't worthwhile, perhaps we can remove the skip versions)?

Otherwies all the cases seemed to be handled equivalently between the removed code and the new code path.

https://github.com/llvm/llvm-project/pull/69531