[lldb] Enable support for DWARF64 format handling (#145645)

This PR introduces support for the DWARF64 format, enabling handling of
64-bit DWARF sections as defined by the DWARF specification. The update
includes adjustments to header parsing and modification of form values
to accommodate 64-bit offsets and values.
Also Added the testcase to verify the DWARF64 format.

lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp

@@ -77,7 +77,9 @@ bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
     case DW_FORM_strp:
     case DW_FORM_line_strp:
     case DW_FORM_sec_offset:
-      m_value.uval = data.GetMaxU64(offset_ptr, 4);
+      assert(m_unit);
+      ref_addr_size = m_unit->GetFormParams().getDwarfOffsetByteSize();
+      m_value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);
       break;
     case DW_FORM_addrx1:
     case DW_FORM_strx1:
@@ -119,10 +121,7 @@ bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
       break;
     case DW_FORM_ref_addr:
       assert(m_unit);
-      if (m_unit->GetVersion() <= 2)
-        ref_addr_size = m_unit->GetAddressByteSize();
-      else
-        ref_addr_size = 4;
+      ref_addr_size = m_unit->GetFormParams().getRefAddrByteSize();
       m_value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);
       break;
     case DW_FORM_indirect:
@@ -165,7 +164,7 @@ static FormSize g_form_sizes[] = {
     {1, 1}, // 0x0b DW_FORM_data1
     {1, 1}, // 0x0c DW_FORM_flag
     {0, 0}, // 0x0d DW_FORM_sdata
-    {1, 4}, // 0x0e DW_FORM_strp
+    {0, 0}, // 0x0e DW_FORM_strp (4 bytes for DWARF32, 8 bytes for DWARF64)
     {0, 0}, // 0x0f DW_FORM_udata
     {0, 0}, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes
             // for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
@@ -175,7 +174,7 @@ static FormSize g_form_sizes[] = {
     {1, 8},  // 0x14 DW_FORM_ref8
     {0, 0},  // 0x15 DW_FORM_ref_udata
     {0, 0},  // 0x16 DW_FORM_indirect
-    {1, 4},  // 0x17 DW_FORM_sec_offset
+    {0, 0}, // 0x17 DW_FORM_sec_offset (4 bytes for DWARF32,8 bytes for DWARF64)
     {0, 0},  // 0x18 DW_FORM_exprloc
     {1, 0},  // 0x19 DW_FORM_flag_present
     {0, 0},  // 0x1a DW_FORM_strx (ULEB128)
@@ -183,7 +182,7 @@ static FormSize g_form_sizes[] = {
     {1, 4},  // 0x1c DW_FORM_ref_sup4
     {0, 0},  // 0x1d DW_FORM_strp_sup (4 bytes for DWARF32, 8 bytes for DWARF64)
     {1, 16}, // 0x1e DW_FORM_data16
-    {1, 4},  // 0x1f DW_FORM_line_strp
+    {0, 0}, // 0x1f DW_FORM_line_strp (4 bytes for DWARF32, 8 bytes for DWARF64)
     {1, 8},  // 0x20 DW_FORM_ref_sig8
 };
 
@@ -246,13 +245,9 @@ bool DWARFFormValue::SkipValue(dw_form_t form,
     return true;
 
   case DW_FORM_ref_addr:
-    ref_addr_size = 4;
     assert(unit); // Unit must be valid for DW_FORM_ref_addr objects or we will
                   // get this wrong
-    if (unit->GetVersion() <= 2)
-      ref_addr_size = unit->GetAddressByteSize();
-    else
-      ref_addr_size = 4;
+    ref_addr_size = unit->GetFormParams().getRefAddrByteSize();
     *offset_ptr += ref_addr_size;
     return true;
 
@@ -288,7 +283,9 @@ bool DWARFFormValue::SkipValue(dw_form_t form,
     case DW_FORM_sec_offset:
     case DW_FORM_strp:
     case DW_FORM_line_strp:
-      *offset_ptr += 4;
+      assert(unit);
+      ref_addr_size = unit->GetFormParams().getDwarfOffsetByteSize();
+      *offset_ptr += ref_addr_size;
       return true;
 
     // 4 byte values

lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp

@@ -1073,20 +1073,7 @@ const lldb_private::DWARFDataExtractor &DWARFUnit::GetData() const {
              : m_dwarf.GetDWARFContext().getOrLoadDebugInfoData();
 }
 
-uint32_t DWARFUnit::GetHeaderByteSize() const {
-  switch (m_header.getUnitType()) {
-  case llvm::dwarf::DW_UT_compile:
-  case llvm::dwarf::DW_UT_partial:
-    return GetVersion() < 5 ? 11 : 12;
-  case llvm::dwarf::DW_UT_skeleton:
-  case llvm::dwarf::DW_UT_split_compile:
-    return 20;
-  case llvm::dwarf::DW_UT_type:
-  case llvm::dwarf::DW_UT_split_type:
-    return GetVersion() < 5 ? 23 : 24;
-  }
-  llvm_unreachable("invalid UnitType.");
-}
+uint32_t DWARFUnit::GetHeaderByteSize() const { return m_header.getSize(); }
 
 std::optional<uint64_t>
 DWARFUnit::GetStringOffsetSectionItem(uint32_t index) const {

lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h

@@ -119,6 +119,9 @@ public:
   // Size of the CU data incl. header but without initial length.
   dw_offset_t GetLength() const { return m_header.getLength(); }
   uint16_t GetVersion() const override { return m_header.getVersion(); }
+  const llvm::dwarf::FormParams &GetFormParams() const {
+    return m_header.getFormParams();
+  }
   const llvm::DWARFAbbreviationDeclarationSet *GetAbbreviations() const;
   dw_offset_t GetAbbrevOffset() const;
   uint8_t GetAddressByteSize() const override {