source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp - llvm-project/lldb - Git at Google

 //===-- DWARFFormValue.cpp ------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include <assert.h>

 #include "lldb/Core/Module.h"
 #include "lldb/Core/dwarf.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Utility/Stream.h"

 #include "DWARFDebugInfo.h"
 #include "DWARFFormValue.h"
 #include "DWARFUnit.h"

 class DWARFUnit;

 using namespace lldb_private;

 void DWARFFormValue::Clear() {
   m_unit = nullptr;
   m_form = 0;
   m_value = ValueTypeTag();
 }

 bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
                                   lldb::offset_t *offset_ptr) {
   if (m_form == DW_FORM_implicit_const)
     return true;

   bool indirect = false;
   bool is_block = false;
   m_value.data = nullptr;
   uint8_t ref_addr_size;
   // Read the value for the form into value and follow and DW_FORM_indirect
   // instances we run into
   do {
     indirect = false;
     switch (m_form) {
     case DW_FORM_addr:
       assert(m_unit);
       m_value.value.uval =
           data.GetMaxU64(offset_ptr, DWARFUnit::GetAddressByteSize(m_unit));
       break;
     case DW_FORM_block1:
       m_value.value.uval = data.GetU8(offset_ptr);
       is_block = true;
       break;
     case DW_FORM_block2:
       m_value.value.uval = data.GetU16(offset_ptr);
       is_block = true;
       break;
     case DW_FORM_block4:
       m_value.value.uval = data.GetU32(offset_ptr);
       is_block = true;
       break;
     case DW_FORM_data16:
       m_value.value.uval = 16;
       is_block = true;
       break;
     case DW_FORM_exprloc:
     case DW_FORM_block:
       m_value.value.uval = data.GetULEB128(offset_ptr);
       is_block = true;
       break;
     case DW_FORM_string:
       m_value.value.cstr = data.GetCStr(offset_ptr);
       break;
     case DW_FORM_sdata:
       m_value.value.sval = data.GetSLEB128(offset_ptr);
       break;
     case DW_FORM_strp:
     case DW_FORM_line_strp:
     case DW_FORM_sec_offset:
       m_value.value.uval = data.GetMaxU64(offset_ptr, 4);
       break;
     case DW_FORM_addrx1:
     case DW_FORM_strx1:
     case DW_FORM_ref1:
     case DW_FORM_data1:
     case DW_FORM_flag:
       m_value.value.uval = data.GetU8(offset_ptr);
       break;
     case DW_FORM_addrx2:
     case DW_FORM_strx2:
     case DW_FORM_ref2:
     case DW_FORM_data2:
       m_value.value.uval = data.GetU16(offset_ptr);
       break;
     case DW_FORM_addrx3:
     case DW_FORM_strx3:
       m_value.value.uval = data.GetMaxU64(offset_ptr, 3);
       break;
     case DW_FORM_addrx4:
     case DW_FORM_strx4:
     case DW_FORM_ref4:
     case DW_FORM_data4:
       m_value.value.uval = data.GetU32(offset_ptr);
       break;
     case DW_FORM_data8:
     case DW_FORM_ref8:
     case DW_FORM_ref_sig8:
       m_value.value.uval = data.GetU64(offset_ptr);
       break;
     case DW_FORM_addrx:
     case DW_FORM_loclistx:
     case DW_FORM_rnglistx:
     case DW_FORM_strx:
     case DW_FORM_udata:
     case DW_FORM_ref_udata:
     case DW_FORM_GNU_str_index:
     case DW_FORM_GNU_addr_index:
       m_value.value.uval = data.GetULEB128(offset_ptr);
       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;
       m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);
       break;
     case DW_FORM_indirect:
       m_form = data.GetULEB128(offset_ptr);
       indirect = true;
       break;
     case DW_FORM_flag_present:
       m_value.value.uval = 1;
       break;
     default:
       return false;
     }
   } while (indirect);

   if (is_block) {
     m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
     if (m_value.data != nullptr) {
       *offset_ptr += m_value.value.uval;
     }
   }

   return true;
 }

 struct FormSize {
   uint8_t valid:1, size:7;
 };
 static FormSize g_form_sizes[] = {
     {0, 0}, // 0x00 unused
     {0, 0}, // 0x01 DW_FORM_addr
     {0, 0}, // 0x02 unused
     {0, 0}, // 0x03 DW_FORM_block2
     {0, 0}, // 0x04 DW_FORM_block4
     {1, 2}, // 0x05 DW_FORM_data2
     {1, 4}, // 0x06 DW_FORM_data4
     {1, 8}, // 0x07 DW_FORM_data8
     {0, 0}, // 0x08 DW_FORM_string
     {0, 0}, // 0x09 DW_FORM_block
     {0, 0}, // 0x0a DW_FORM_block1
     {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}, // 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
     {1, 1},  // 0x11 DW_FORM_ref1
     {1, 2},  // 0x12 DW_FORM_ref2
     {1, 4},  // 0x13 DW_FORM_ref4
     {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},  // 0x18 DW_FORM_exprloc
     {1, 0},  // 0x19 DW_FORM_flag_present
     {0, 0},  // 0x1a DW_FORM_strx (ULEB128)
     {0, 0},  // 0x1b DW_FORM_addrx (ULEB128)
     {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
     {1, 8},  // 0x20 DW_FORM_ref_sig8
 };

 llvm::Optional<uint8_t>
 DWARFFormValue::GetFixedSize(dw_form_t form, const DWARFUnit *u) {
   if (form <= DW_FORM_ref_sig8 && g_form_sizes[form].valid)
     return g_form_sizes[form].size;
   if (form == DW_FORM_addr && u)
     return u->GetAddressByteSize();
   return llvm::None;
 }

 llvm::Optional<uint8_t> DWARFFormValue::GetFixedSize() const {
   return GetFixedSize(m_form, m_unit);
 }

 bool DWARFFormValue::SkipValue(const DWARFDataExtractor &debug_info_data,
                                lldb::offset_t *offset_ptr) const {
   return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_unit);
 }

 bool DWARFFormValue::SkipValue(dw_form_t form,
                                const DWARFDataExtractor &debug_info_data,
                                lldb::offset_t *offset_ptr,
                                const DWARFUnit *unit) {
   uint8_t ref_addr_size;
   switch (form) {
   // Blocks if inlined data that have a length field and the data bytes inlined
   // in the .debug_info
   case DW_FORM_exprloc:
   case DW_FORM_block: {
     dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr);
     *offset_ptr += size;
   }
     return true;
   case DW_FORM_block1: {
     dw_uleb128_t size = debug_info_data.GetU8(offset_ptr);
     *offset_ptr += size;
   }
     return true;
   case DW_FORM_block2: {
     dw_uleb128_t size = debug_info_data.GetU16(offset_ptr);
     *offset_ptr += size;
   }
     return true;
   case DW_FORM_block4: {
     dw_uleb128_t size = debug_info_data.GetU32(offset_ptr);
     *offset_ptr += size;
   }
     return true;

   // Inlined NULL terminated C-strings
   case DW_FORM_string:
     debug_info_data.GetCStr(offset_ptr);
     return true;

   // Compile unit address sized values
   case DW_FORM_addr:
     *offset_ptr += DWARFUnit::GetAddressByteSize(unit);
     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;
     *offset_ptr += ref_addr_size;
     return true;

   // 0 bytes values (implied from DW_FORM)
   case DW_FORM_flag_present:
   case DW_FORM_implicit_const:
     return true;

     // 1 byte values
     case DW_FORM_addrx1:
     case DW_FORM_data1:
     case DW_FORM_flag:
     case DW_FORM_ref1:
     case DW_FORM_strx1:
       *offset_ptr += 1;
       return true;

     // 2 byte values
     case DW_FORM_addrx2:
     case DW_FORM_data2:
     case DW_FORM_ref2:
     case DW_FORM_strx2:
       *offset_ptr += 2;
       return true;

     // 3 byte values
     case DW_FORM_addrx3:
     case DW_FORM_strx3:
       *offset_ptr += 3;
       return true;

     // 32 bit for DWARF 32, 64 for DWARF 64
     case DW_FORM_sec_offset:
     case DW_FORM_strp:
     case DW_FORM_line_strp:
       *offset_ptr += 4;
       return true;

     // 4 byte values
     case DW_FORM_addrx4:
     case DW_FORM_data4:
     case DW_FORM_ref4:
     case DW_FORM_strx4:
       *offset_ptr += 4;
       return true;

     // 8 byte values
     case DW_FORM_data8:
     case DW_FORM_ref8:
     case DW_FORM_ref_sig8:
       *offset_ptr += 8;
       return true;

     // 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:
       debug_info_data.Skip_LEB128(offset_ptr);
       return true;

   case DW_FORM_indirect: {
     dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr);
     return DWARFFormValue::SkipValue(indirect_form, debug_info_data, offset_ptr,
                                      unit);
   }

   default:
     break;
   }
   return false;
 }

 void DWARFFormValue::Dump(Stream &s) const {
   uint64_t uvalue = Unsigned();
   bool unit_relative_offset = false;

   switch (m_form) {
   case DW_FORM_addr:
     DumpAddress(s.AsRawOstream(), uvalue, sizeof(uint64_t));
     break;
   case DW_FORM_flag:
   case DW_FORM_data1:
     s.PutHex8(uvalue);
     break;
   case DW_FORM_data2:
     s.PutHex16(uvalue);
     break;
   case DW_FORM_sec_offset:
   case DW_FORM_data4:
     s.PutHex32(uvalue);
     break;
   case DW_FORM_ref_sig8:
   case DW_FORM_data8:
     s.PutHex64(uvalue);
     break;
   case DW_FORM_string:
     s.QuotedCString(AsCString());
     break;
   case DW_FORM_exprloc:
   case DW_FORM_block:
   case DW_FORM_block1:
   case DW_FORM_block2:
   case DW_FORM_block4:
     if (uvalue > 0) {
       switch (m_form) {
       case DW_FORM_exprloc:
       case DW_FORM_block:
         s.Printf("<0x%" PRIx64 "> ", uvalue);
         break;
       case DW_FORM_block1:
         s.Printf("<0x%2.2x> ", (uint8_t)uvalue);
         break;
       case DW_FORM_block2:
         s.Printf("<0x%4.4x> ", (uint16_t)uvalue);
         break;
       case DW_FORM_block4:
         s.Printf("<0x%8.8x> ", (uint32_t)uvalue);
         break;
       default:
         break;
       }

       const uint8_t *data_ptr = m_value.data;
       if (data_ptr) {
         const uint8_t *end_data_ptr =
             data_ptr + uvalue; // uvalue contains size of block
         while (data_ptr < end_data_ptr) {
           s.Printf("%2.2x ", *data_ptr);
           ++data_ptr;
         }
       } else
         s.PutCString("NULL");
     }
     break;

   case DW_FORM_sdata:
     s.PutSLEB128(uvalue);
     break;
   case DW_FORM_udata:
     s.PutULEB128(uvalue);
     break;
   case DW_FORM_strp:
   case DW_FORM_line_strp: {
     const char *dbg_str = AsCString();
     if (dbg_str) {
       s.QuotedCString(dbg_str);
     } else {
       s.PutHex32(uvalue);
     }
   } break;

   case DW_FORM_ref_addr: {
     assert(m_unit); // Unit must be valid for DW_FORM_ref_addr objects or we
                     // will get this wrong
     if (m_unit->GetVersion() <= 2)
       DumpAddress(s.AsRawOstream(), uvalue, sizeof(uint64_t) * 2);
     else
       DumpAddress(s.AsRawOstream(), uvalue,
                   4 * 2); // 4 for DWARF32, 8 for DWARF64, but we don't
                           // support DWARF64 yet
     break;
   }
   case DW_FORM_ref1:
     unit_relative_offset = true;
     break;
   case DW_FORM_ref2:
     unit_relative_offset = true;
     break;
   case DW_FORM_ref4:
     unit_relative_offset = true;
     break;
   case DW_FORM_ref8:
     unit_relative_offset = true;
     break;
   case DW_FORM_ref_udata:
     unit_relative_offset = true;
     break;

   // All DW_FORM_indirect attributes should be resolved prior to calling this
   // function
   case DW_FORM_indirect:
     s.PutCString("DW_FORM_indirect");
     break;
   case DW_FORM_flag_present:
     break;
   default:
     s.Printf("DW_FORM(0x%4.4x)", m_form);
     break;
   }

   if (unit_relative_offset) {
     assert(m_unit); // Unit must be valid for DW_FORM_ref forms that are compile
                     // unit relative or we will get this wrong
     s.Printf("{0x%8.8" PRIx64 "}", uvalue + m_unit->GetOffset());
   }
 }

 const char *DWARFFormValue::AsCString() const {
   DWARFContext &context = m_unit->GetSymbolFileDWARF().GetDWARFContext();

   if (m_form == DW_FORM_string)
     return m_value.value.cstr;
   if (m_form == DW_FORM_strp)
     return context.getOrLoadStrData().PeekCStr(m_value.value.uval);

   if (m_form == DW_FORM_GNU_str_index || m_form == DW_FORM_strx ||
       m_form == DW_FORM_strx1 || m_form == DW_FORM_strx2 ||
       m_form == DW_FORM_strx3 || m_form == DW_FORM_strx4) {

     llvm::Optional<uint64_t> offset =
         m_unit->GetStringOffsetSectionItem(m_value.value.uval);
     if (!offset)
       return nullptr;
     return context.getOrLoadStrData().PeekCStr(*offset);
   }

   if (m_form == DW_FORM_line_strp)
     return context.getOrLoadLineStrData().PeekCStr(m_value.value.uval);

   return nullptr;
 }

 dw_addr_t DWARFFormValue::Address() const {
   SymbolFileDWARF &symbol_file = m_unit->GetSymbolFileDWARF();

   if (m_form == DW_FORM_addr)
     return Unsigned();

   assert(m_unit);
   assert(m_form == DW_FORM_GNU_addr_index || m_form == DW_FORM_addrx ||
          m_form == DW_FORM_addrx1 || m_form == DW_FORM_addrx2 ||
          m_form == DW_FORM_addrx3 || m_form == DW_FORM_addrx4);

   uint32_t index_size = m_unit->GetAddressByteSize();
   dw_offset_t addr_base = m_unit->GetAddrBase();
   lldb::offset_t offset = addr_base + m_value.value.uval * index_size;
   return symbol_file.GetDWARFContext().getOrLoadAddrData().GetMaxU64(
       &offset, index_size);
 }

 DWARFDIE DWARFFormValue::Reference() const {
   uint64_t value = m_value.value.uval;
   switch (m_form) {
   case DW_FORM_ref1:
   case DW_FORM_ref2:
   case DW_FORM_ref4:
   case DW_FORM_ref8:
   case DW_FORM_ref_udata:
     assert(m_unit); // Unit must be valid for DW_FORM_ref forms that are compile
                     // unit relative or we will get this wrong
     value += m_unit->GetOffset();
     if (!m_unit->ContainsDIEOffset(value)) {
       m_unit->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
           "DW_FORM_ref* DIE reference 0x%" PRIx64 " is outside of its CU",
           value);
       return {};
     }
     return const_cast<DWARFUnit *>(m_unit)->GetDIE(value);

   case DW_FORM_ref_addr: {
     DWARFUnit *ref_cu =
         m_unit->GetSymbolFileDWARF().DebugInfo().GetUnitContainingDIEOffset(
             DIERef::Section::DebugInfo, value);
     if (!ref_cu) {
       m_unit->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
           "DW_FORM_ref_addr DIE reference 0x%" PRIx64 " has no matching CU",
           value);
       return {};
     }
     return ref_cu->GetDIE(value);
   }

   case DW_FORM_ref_sig8: {
     DWARFTypeUnit *tu =
         m_unit->GetSymbolFileDWARF().DebugInfo().GetTypeUnitForHash(value);
     if (!tu)
       return {};
     return tu->GetDIE(tu->GetTypeOffset());
   }

   default:
     return {};
   }
 }

 uint64_t DWARFFormValue::Reference(dw_offset_t base_offset) const {
   uint64_t value = m_value.value.uval;
   switch (m_form) {
   case DW_FORM_ref1:
   case DW_FORM_ref2:
   case DW_FORM_ref4:
   case DW_FORM_ref8:
   case DW_FORM_ref_udata:
     return value + base_offset;

   case DW_FORM_ref_addr:
   case DW_FORM_ref_sig8:
   case DW_FORM_GNU_ref_alt:
     return value;

   default:
     return DW_INVALID_OFFSET;
   }
 }

 const uint8_t *DWARFFormValue::BlockData() const { return m_value.data; }

 bool DWARFFormValue::IsBlockForm(const dw_form_t form) {
   switch (form) {
   case DW_FORM_exprloc:
   case DW_FORM_block:
   case DW_FORM_block1:
   case DW_FORM_block2:
   case DW_FORM_block4:
     return true;
   }
   return false;
 }

 bool DWARFFormValue::IsDataForm(const dw_form_t form) {
   switch (form) {
   case DW_FORM_sdata:
   case DW_FORM_udata:
   case DW_FORM_data1:
   case DW_FORM_data2:
   case DW_FORM_data4:
   case DW_FORM_data8:
     return true;
   }
   return false;
 }

 bool DWARFFormValue::FormIsSupported(dw_form_t form) {
   switch (form) {
     case DW_FORM_addr:
     case DW_FORM_addrx:
     case DW_FORM_loclistx:
     case DW_FORM_rnglistx:
     case DW_FORM_block2:
     case DW_FORM_block4:
     case DW_FORM_data2:
     case DW_FORM_data4:
     case DW_FORM_data8:
     case DW_FORM_string:
     case DW_FORM_block:
     case DW_FORM_block1:
     case DW_FORM_data1:
     case DW_FORM_flag:
     case DW_FORM_sdata:
     case DW_FORM_strp:
     case DW_FORM_line_strp:
     case DW_FORM_strx:
     case DW_FORM_strx1:
     case DW_FORM_strx2:
     case DW_FORM_strx3:
     case DW_FORM_strx4:
     case DW_FORM_udata:
     case DW_FORM_ref_addr:
     case DW_FORM_ref1:
     case DW_FORM_ref2:
     case DW_FORM_ref4:
     case DW_FORM_ref8:
     case DW_FORM_ref_udata:
     case DW_FORM_indirect:
     case DW_FORM_sec_offset:
     case DW_FORM_exprloc:
     case DW_FORM_flag_present:
     case DW_FORM_ref_sig8:
     case DW_FORM_GNU_str_index:
     case DW_FORM_GNU_addr_index:
     case DW_FORM_implicit_const:
       return true;
     default:
       break;
   }
   return false;
 }
	//===-- DWARFFormValue.cpp ------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include <assert.h>

	#include "lldb/Core/Module.h"
	#include "lldb/Core/dwarf.h"
	#include "lldb/Symbol/ObjectFile.h"
	#include "lldb/Utility/Stream.h"

	#include "DWARFDebugInfo.h"
	#include "DWARFFormValue.h"
	#include "DWARFUnit.h"

	class DWARFUnit;

	using namespace lldb_private;

	void DWARFFormValue::Clear() {
	m_unit = nullptr;
	m_form = 0;
	m_value = ValueTypeTag();
	}

	bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
	lldb::offset_t *offset_ptr) {
	if (m_form == DW_FORM_implicit_const)
	return true;

	bool indirect = false;
	bool is_block = false;
	m_value.data = nullptr;
	uint8_t ref_addr_size;
	// Read the value for the form into value and follow and DW_FORM_indirect
	// instances we run into
	do {
	indirect = false;
	switch (m_form) {
	case DW_FORM_addr:
	assert(m_unit);
	m_value.value.uval =
	data.GetMaxU64(offset_ptr, DWARFUnit::GetAddressByteSize(m_unit));
	break;
	case DW_FORM_block1:
	m_value.value.uval = data.GetU8(offset_ptr);
	is_block = true;
	break;
	case DW_FORM_block2:
	m_value.value.uval = data.GetU16(offset_ptr);
	is_block = true;
	break;
	case DW_FORM_block4:
	m_value.value.uval = data.GetU32(offset_ptr);
	is_block = true;
	break;
	case DW_FORM_data16:
	m_value.value.uval = 16;
	is_block = true;
	break;
	case DW_FORM_exprloc:
	case DW_FORM_block:
	m_value.value.uval = data.GetULEB128(offset_ptr);
	is_block = true;
	break;
	case DW_FORM_string:
	m_value.value.cstr = data.GetCStr(offset_ptr);
	break;
	case DW_FORM_sdata:
	m_value.value.sval = data.GetSLEB128(offset_ptr);
	break;
	case DW_FORM_strp:
	case DW_FORM_line_strp:
	case DW_FORM_sec_offset:
	m_value.value.uval = data.GetMaxU64(offset_ptr, 4);
	break;
	case DW_FORM_addrx1:
	case DW_FORM_strx1:
	case DW_FORM_ref1:
	case DW_FORM_data1:
	case DW_FORM_flag:
	m_value.value.uval = data.GetU8(offset_ptr);
	break;
	case DW_FORM_addrx2:
	case DW_FORM_strx2:
	case DW_FORM_ref2:
	case DW_FORM_data2:
	m_value.value.uval = data.GetU16(offset_ptr);
	break;
	case DW_FORM_addrx3:
	case DW_FORM_strx3:
	m_value.value.uval = data.GetMaxU64(offset_ptr, 3);
	break;
	case DW_FORM_addrx4:
	case DW_FORM_strx4:
	case DW_FORM_ref4:
	case DW_FORM_data4:
	m_value.value.uval = data.GetU32(offset_ptr);
	break;
	case DW_FORM_data8:
	case DW_FORM_ref8:
	case DW_FORM_ref_sig8:
	m_value.value.uval = data.GetU64(offset_ptr);
	break;
	case DW_FORM_addrx:
	case DW_FORM_loclistx:
	case DW_FORM_rnglistx:
	case DW_FORM_strx:
	case DW_FORM_udata:
	case DW_FORM_ref_udata:
	case DW_FORM_GNU_str_index:
	case DW_FORM_GNU_addr_index:
	m_value.value.uval = data.GetULEB128(offset_ptr);
	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;
	m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size);
	break;
	case DW_FORM_indirect:
	m_form = data.GetULEB128(offset_ptr);
	indirect = true;
	break;
	case DW_FORM_flag_present:
	m_value.value.uval = 1;
	break;
	default:
	return false;
	}
	} while (indirect);

	if (is_block) {
	m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
	if (m_value.data != nullptr) {
	*offset_ptr += m_value.value.uval;
	}
	}

	return true;
	}

	struct FormSize {
	uint8_t valid:1, size:7;
	};
	static FormSize g_form_sizes[] = {
	{0, 0}, // 0x00 unused
	{0, 0}, // 0x01 DW_FORM_addr
	{0, 0}, // 0x02 unused
	{0, 0}, // 0x03 DW_FORM_block2
	{0, 0}, // 0x04 DW_FORM_block4
	{1, 2}, // 0x05 DW_FORM_data2
	{1, 4}, // 0x06 DW_FORM_data4
	{1, 8}, // 0x07 DW_FORM_data8
	{0, 0}, // 0x08 DW_FORM_string
	{0, 0}, // 0x09 DW_FORM_block
	{0, 0}, // 0x0a DW_FORM_block1
	{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}, // 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
	{1, 1}, // 0x11 DW_FORM_ref1
	{1, 2}, // 0x12 DW_FORM_ref2
	{1, 4}, // 0x13 DW_FORM_ref4
	{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}, // 0x18 DW_FORM_exprloc
	{1, 0}, // 0x19 DW_FORM_flag_present
	{0, 0}, // 0x1a DW_FORM_strx (ULEB128)
	{0, 0}, // 0x1b DW_FORM_addrx (ULEB128)
	{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
	{1, 8}, // 0x20 DW_FORM_ref_sig8
	};

	llvm::Optional<uint8_t>
	DWARFFormValue::GetFixedSize(dw_form_t form, const DWARFUnit *u) {
	if (form <= DW_FORM_ref_sig8 && g_form_sizes[form].valid)
	return g_form_sizes[form].size;
	if (form == DW_FORM_addr && u)
	return u->GetAddressByteSize();
	return llvm::None;
	}

	llvm::Optional<uint8_t> DWARFFormValue::GetFixedSize() const {
	return GetFixedSize(m_form, m_unit);
	}

	bool DWARFFormValue::SkipValue(const DWARFDataExtractor &debug_info_data,
	lldb::offset_t *offset_ptr) const {
	return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_unit);
	}

	bool DWARFFormValue::SkipValue(dw_form_t form,
	const DWARFDataExtractor &debug_info_data,
	lldb::offset_t *offset_ptr,
	const DWARFUnit *unit) {
	uint8_t ref_addr_size;
	switch (form) {
	// Blocks if inlined data that have a length field and the data bytes inlined
	// in the .debug_info
	case DW_FORM_exprloc:
	case DW_FORM_block: {
	dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr);
	*offset_ptr += size;
	}
	return true;
	case DW_FORM_block1: {
	dw_uleb128_t size = debug_info_data.GetU8(offset_ptr);
	*offset_ptr += size;
	}
	return true;
	case DW_FORM_block2: {
	dw_uleb128_t size = debug_info_data.GetU16(offset_ptr);
	*offset_ptr += size;
	}
	return true;
	case DW_FORM_block4: {
	dw_uleb128_t size = debug_info_data.GetU32(offset_ptr);
	*offset_ptr += size;
	}
	return true;

	// Inlined NULL terminated C-strings
	case DW_FORM_string:
	debug_info_data.GetCStr(offset_ptr);
	return true;

	// Compile unit address sized values
	case DW_FORM_addr:
	*offset_ptr += DWARFUnit::GetAddressByteSize(unit);
	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;
	*offset_ptr += ref_addr_size;
	return true;

	// 0 bytes values (implied from DW_FORM)
	case DW_FORM_flag_present:
	case DW_FORM_implicit_const:
	return true;

	// 1 byte values
	case DW_FORM_addrx1:
	case DW_FORM_data1:
	case DW_FORM_flag:
	case DW_FORM_ref1:
	case DW_FORM_strx1:
	*offset_ptr += 1;
	return true;

	// 2 byte values
	case DW_FORM_addrx2:
	case DW_FORM_data2:
	case DW_FORM_ref2:
	case DW_FORM_strx2:
	*offset_ptr += 2;
	return true;

	// 3 byte values
	case DW_FORM_addrx3:
	case DW_FORM_strx3:
	*offset_ptr += 3;
	return true;

	// 32 bit for DWARF 32, 64 for DWARF 64
	case DW_FORM_sec_offset:
	case DW_FORM_strp:
	case DW_FORM_line_strp:
	*offset_ptr += 4;
	return true;

	// 4 byte values
	case DW_FORM_addrx4:
	case DW_FORM_data4:
	case DW_FORM_ref4:
	case DW_FORM_strx4:
	*offset_ptr += 4;
	return true;

	// 8 byte values
	case DW_FORM_data8:
	case DW_FORM_ref8:
	case DW_FORM_ref_sig8:
	*offset_ptr += 8;
	return true;

	// 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:
	debug_info_data.Skip_LEB128(offset_ptr);
	return true;

	case DW_FORM_indirect: {
	dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr);
	return DWARFFormValue::SkipValue(indirect_form, debug_info_data, offset_ptr,
	unit);
	}

	default:
	break;
	}
	return false;
	}

	void DWARFFormValue::Dump(Stream &s) const {
	uint64_t uvalue = Unsigned();
	bool unit_relative_offset = false;

	switch (m_form) {
	case DW_FORM_addr:
	DumpAddress(s.AsRawOstream(), uvalue, sizeof(uint64_t));
	break;
	case DW_FORM_flag:
	case DW_FORM_data1:
	s.PutHex8(uvalue);
	break;
	case DW_FORM_data2:
	s.PutHex16(uvalue);
	break;
	case DW_FORM_sec_offset:
	case DW_FORM_data4:
	s.PutHex32(uvalue);
	break;
	case DW_FORM_ref_sig8:
	case DW_FORM_data8:
	s.PutHex64(uvalue);
	break;
	case DW_FORM_string:
	s.QuotedCString(AsCString());
	break;
	case DW_FORM_exprloc:
	case DW_FORM_block:
	case DW_FORM_block1:
	case DW_FORM_block2:
	case DW_FORM_block4:
	if (uvalue > 0) {
	switch (m_form) {
	case DW_FORM_exprloc:
	case DW_FORM_block:
	s.Printf("<0x%" PRIx64 "> ", uvalue);
	break;
	case DW_FORM_block1:
	s.Printf("<0x%2.2x> ", (uint8_t)uvalue);
	break;
	case DW_FORM_block2:
	s.Printf("<0x%4.4x> ", (uint16_t)uvalue);
	break;
	case DW_FORM_block4:
	s.Printf("<0x%8.8x> ", (uint32_t)uvalue);
	break;
	default:
	break;
	}

	const uint8_t *data_ptr = m_value.data;
	if (data_ptr) {
	const uint8_t *end_data_ptr =
	data_ptr + uvalue; // uvalue contains size of block
	while (data_ptr < end_data_ptr) {
	s.Printf("%2.2x ", *data_ptr);
	++data_ptr;
	}
	} else
	s.PutCString("NULL");
	}
	break;

	case DW_FORM_sdata:
	s.PutSLEB128(uvalue);
	break;
	case DW_FORM_udata:
	s.PutULEB128(uvalue);
	break;
	case DW_FORM_strp:
	case DW_FORM_line_strp: {
	const char *dbg_str = AsCString();
	if (dbg_str) {
	s.QuotedCString(dbg_str);
	} else {
	s.PutHex32(uvalue);
	}
	} break;

	case DW_FORM_ref_addr: {
	assert(m_unit); // Unit must be valid for DW_FORM_ref_addr objects or we
	// will get this wrong
	if (m_unit->GetVersion() <= 2)
	DumpAddress(s.AsRawOstream(), uvalue, sizeof(uint64_t) * 2);
	else
	DumpAddress(s.AsRawOstream(), uvalue,
	4 * 2); // 4 for DWARF32, 8 for DWARF64, but we don't
	// support DWARF64 yet
	break;
	}
	case DW_FORM_ref1:
	unit_relative_offset = true;
	break;
	case DW_FORM_ref2:
	unit_relative_offset = true;
	break;
	case DW_FORM_ref4:
	unit_relative_offset = true;
	break;
	case DW_FORM_ref8:
	unit_relative_offset = true;
	break;
	case DW_FORM_ref_udata:
	unit_relative_offset = true;
	break;

	// All DW_FORM_indirect attributes should be resolved prior to calling this
	// function
	case DW_FORM_indirect:
	s.PutCString("DW_FORM_indirect");
	break;
	case DW_FORM_flag_present:
	break;
	default:
	s.Printf("DW_FORM(0x%4.4x)", m_form);
	break;
	}

	if (unit_relative_offset) {
	assert(m_unit); // Unit must be valid for DW_FORM_ref forms that are compile
	// unit relative or we will get this wrong
	s.Printf("{0x%8.8" PRIx64 "}", uvalue + m_unit->GetOffset());
	}
	}

	const char *DWARFFormValue::AsCString() const {
	DWARFContext &context = m_unit->GetSymbolFileDWARF().GetDWARFContext();

	if (m_form == DW_FORM_string)
	return m_value.value.cstr;
	if (m_form == DW_FORM_strp)
	return context.getOrLoadStrData().PeekCStr(m_value.value.uval);

	if (m_form == DW_FORM_GNU_str_index \|\| m_form == DW_FORM_strx \|\|
	m_form == DW_FORM_strx1 \|\| m_form == DW_FORM_strx2 \|\|
	m_form == DW_FORM_strx3 \|\| m_form == DW_FORM_strx4) {

	llvm::Optional<uint64_t> offset =
	m_unit->GetStringOffsetSectionItem(m_value.value.uval);
	if (!offset)
	return nullptr;
	return context.getOrLoadStrData().PeekCStr(*offset);
	}

	if (m_form == DW_FORM_line_strp)
	return context.getOrLoadLineStrData().PeekCStr(m_value.value.uval);

	return nullptr;
	}

	dw_addr_t DWARFFormValue::Address() const {
	SymbolFileDWARF &symbol_file = m_unit->GetSymbolFileDWARF();

	if (m_form == DW_FORM_addr)
	return Unsigned();

	assert(m_unit);
	assert(m_form == DW_FORM_GNU_addr_index \|\| m_form == DW_FORM_addrx \|\|
	m_form == DW_FORM_addrx1 \|\| m_form == DW_FORM_addrx2 \|\|
	m_form == DW_FORM_addrx3 \|\| m_form == DW_FORM_addrx4);

	uint32_t index_size = m_unit->GetAddressByteSize();
	dw_offset_t addr_base = m_unit->GetAddrBase();
	lldb::offset_t offset = addr_base + m_value.value.uval * index_size;
	return symbol_file.GetDWARFContext().getOrLoadAddrData().GetMaxU64(
	&offset, index_size);
	}

	DWARFDIE DWARFFormValue::Reference() const {
	uint64_t value = m_value.value.uval;
	switch (m_form) {
	case DW_FORM_ref1:
	case DW_FORM_ref2:
	case DW_FORM_ref4:
	case DW_FORM_ref8:
	case DW_FORM_ref_udata:
	assert(m_unit); // Unit must be valid for DW_FORM_ref forms that are compile
	// unit relative or we will get this wrong
	value += m_unit->GetOffset();
	if (!m_unit->ContainsDIEOffset(value)) {
	m_unit->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
	"DW_FORM_ref* DIE reference 0x%" PRIx64 " is outside of its CU",
	value);
	return {};
	}
	return const_cast<DWARFUnit *>(m_unit)->GetDIE(value);

	case DW_FORM_ref_addr: {
	DWARFUnit *ref_cu =
	m_unit->GetSymbolFileDWARF().DebugInfo().GetUnitContainingDIEOffset(
	DIERef::Section::DebugInfo, value);
	if (!ref_cu) {
	m_unit->GetSymbolFileDWARF().GetObjectFile()->GetModule()->ReportError(
	"DW_FORM_ref_addr DIE reference 0x%" PRIx64 " has no matching CU",
	value);
	return {};
	}
	return ref_cu->GetDIE(value);
	}

	case DW_FORM_ref_sig8: {
	DWARFTypeUnit *tu =
	m_unit->GetSymbolFileDWARF().DebugInfo().GetTypeUnitForHash(value);
	if (!tu)
	return {};
	return tu->GetDIE(tu->GetTypeOffset());
	}

	default:
	return {};
	}
	}

	uint64_t DWARFFormValue::Reference(dw_offset_t base_offset) const {
	uint64_t value = m_value.value.uval;
	switch (m_form) {
	case DW_FORM_ref1:
	case DW_FORM_ref2:
	case DW_FORM_ref4:
	case DW_FORM_ref8:
	case DW_FORM_ref_udata:
	return value + base_offset;

	case DW_FORM_ref_addr:
	case DW_FORM_ref_sig8:
	case DW_FORM_GNU_ref_alt:
	return value;

	default:
	return DW_INVALID_OFFSET;
	}
	}

	const uint8_t *DWARFFormValue::BlockData() const { return m_value.data; }

	bool DWARFFormValue::IsBlockForm(const dw_form_t form) {
	switch (form) {
	case DW_FORM_exprloc:
	case DW_FORM_block:
	case DW_FORM_block1:
	case DW_FORM_block2:
	case DW_FORM_block4:
	return true;
	}
	return false;
	}

	bool DWARFFormValue::IsDataForm(const dw_form_t form) {
	switch (form) {
	case DW_FORM_sdata:
	case DW_FORM_udata:
	case DW_FORM_data1:
	case DW_FORM_data2:
	case DW_FORM_data4:
	case DW_FORM_data8:
	return true;
	}
	return false;
	}

	bool DWARFFormValue::FormIsSupported(dw_form_t form) {
	switch (form) {
	case DW_FORM_addr:
	case DW_FORM_addrx:
	case DW_FORM_loclistx:
	case DW_FORM_rnglistx:
	case DW_FORM_block2:
	case DW_FORM_block4:
	case DW_FORM_data2:
	case DW_FORM_data4:
	case DW_FORM_data8:
	case DW_FORM_string:
	case DW_FORM_block:
	case DW_FORM_block1:
	case DW_FORM_data1:
	case DW_FORM_flag:
	case DW_FORM_sdata:
	case DW_FORM_strp:
	case DW_FORM_line_strp:
	case DW_FORM_strx:
	case DW_FORM_strx1:
	case DW_FORM_strx2:
	case DW_FORM_strx3:
	case DW_FORM_strx4:
	case DW_FORM_udata:
	case DW_FORM_ref_addr:
	case DW_FORM_ref1:
	case DW_FORM_ref2:
	case DW_FORM_ref4:
	case DW_FORM_ref8:
	case DW_FORM_ref_udata:
	case DW_FORM_indirect:
	case DW_FORM_sec_offset:
	case DW_FORM_exprloc:
	case DW_FORM_flag_present:
	case DW_FORM_ref_sig8:
	case DW_FORM_GNU_str_index:
	case DW_FORM_GNU_addr_index:
	case DW_FORM_implicit_const:
	return true;
	default:
	break;
	}
	return false;
	}