//===-- DWARFFormValue.cpp ------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "SyntaxHighlighting.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <limits>
using namespace llvm;
using namespace dwarf;
using namespace syntax;
namespace {
uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
// FIXME: Support DWARF64.
return (Version == 2) ? AddrSize : 4;
}
template <uint8_t AddrSize, uint8_t RefAddrSize>
ArrayRef<uint8_t> makeFixedFormSizesArrayRef() {
static const uint8_t sizes[] = {
0, // 0x00 unused
AddrSize, // 0x01 DW_FORM_addr
0, // 0x02 unused
0, // 0x03 DW_FORM_block2
0, // 0x04 DW_FORM_block4
2, // 0x05 DW_FORM_data2
4, // 0x06 DW_FORM_data4
8, // 0x07 DW_FORM_data8
0, // 0x08 DW_FORM_string
0, // 0x09 DW_FORM_block
0, // 0x0a DW_FORM_block1
1, // 0x0b DW_FORM_data1
1, // 0x0c DW_FORM_flag
0, // 0x0d DW_FORM_sdata
4, // 0x0e DW_FORM_strp
0, // 0x0f DW_FORM_udata
RefAddrSize, // 0x10 DW_FORM_ref_addr
1, // 0x11 DW_FORM_ref1
2, // 0x12 DW_FORM_ref2
4, // 0x13 DW_FORM_ref4
8, // 0x14 DW_FORM_ref8
0, // 0x15 DW_FORM_ref_udata
0, // 0x16 DW_FORM_indirect
4, // 0x17 DW_FORM_sec_offset
0, // 0x18 DW_FORM_exprloc
0, // 0x19 DW_FORM_flag_present
};
return makeArrayRef(sizes);
}
}
ArrayRef<uint8_t> DWARFFormValue::getFixedFormSizes(uint8_t AddrSize,
uint16_t Version) {
uint8_t RefAddrSize = getRefAddrSize(AddrSize, Version);
if (AddrSize == 4 && RefAddrSize == 4)
return makeFixedFormSizesArrayRef<4, 4>();
if (AddrSize == 4 && RefAddrSize == 8)
return makeFixedFormSizesArrayRef<4, 8>();
if (AddrSize == 8 && RefAddrSize == 4)
return makeFixedFormSizesArrayRef<8, 4>();
if (AddrSize == 8 && RefAddrSize == 8)
return makeFixedFormSizesArrayRef<8, 8>();
return None;
}
static const DWARFFormValue::FormClass DWARF4FormClasses[] = {
DWARFFormValue::FC_Unknown, // 0x0
DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr
DWARFFormValue::FC_Unknown, // 0x02 unused
DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2
DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4
DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2
// --- These can be FC_SectionOffset in DWARF3 and below:
DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4
DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8
// ---
DWARFFormValue::FC_String, // 0x08 DW_FORM_string
DWARFFormValue::FC_Block, // 0x09 DW_FORM_block
DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1
DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1
DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag
DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata
DWARFFormValue::FC_String, // 0x0e DW_FORM_strp
DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata
DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr
DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1
DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2
DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4
DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8
DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata
DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect
DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc
DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present
};
bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
// First, check DWARF4 form classes.
if (Form < makeArrayRef(DWARF4FormClasses).size() &&
DWARF4FormClasses[Form] == FC)
return true;
// Check more forms from DWARF4 and DWARF5 proposals.
switch (Form) {
case DW_FORM_ref_sig8:
case DW_FORM_GNU_ref_alt:
return (FC == FC_Reference);
case DW_FORM_GNU_addr_index:
return (FC == FC_Address);
case DW_FORM_GNU_str_index:
case DW_FORM_GNU_strp_alt:
return (FC == FC_String);
}
// In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
// Don't check for DWARF version here, as some producers may still do this
// by mistake.
return (Form == DW_FORM_data4 || Form == DW_FORM_data8) &&
FC == FC_SectionOffset;
}
bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
const DWARFUnit *cu) {
bool indirect = false;
bool is_block = false;
Value.data = nullptr;
// Read the value for the form into value and follow and DW_FORM_indirect
// instances we run into
do {
indirect = false;
switch (Form) {
case DW_FORM_addr:
case DW_FORM_ref_addr: {
if (!cu)
return false;
uint16_t AddrSize =
(Form == DW_FORM_addr)
? cu->getAddressByteSize()
: getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
if (AI != cu->getRelocMap()->end()) {
const std::pair<uint8_t, int64_t> &R = AI->second;
Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
} else
Value.uval = data.getUnsigned(offset_ptr, AddrSize);
break;
}
case DW_FORM_exprloc:
case DW_FORM_block:
Value.uval = data.getULEB128(offset_ptr);
is_block = true;
break;
case DW_FORM_block1:
Value.uval = data.getU8(offset_ptr);
is_block = true;
break;
case DW_FORM_block2:
Value.uval = data.getU16(offset_ptr);
is_block = true;
break;
case DW_FORM_block4:
Value.uval = data.getU32(offset_ptr);
is_block = true;
break;
case DW_FORM_data1:
case DW_FORM_ref1:
case DW_FORM_flag:
Value.uval = data.getU8(offset_ptr);
break;
case DW_FORM_data2:
case DW_FORM_ref2:
Value.uval = data.getU16(offset_ptr);
break;
case DW_FORM_data4:
case DW_FORM_ref4: {
Value.uval = data.getU32(offset_ptr);
if (!cu)
break;
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
if (AI != cu->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
case DW_FORM_data8:
case DW_FORM_ref8:
Value.uval = data.getU64(offset_ptr);
break;
case DW_FORM_sdata:
Value.sval = data.getSLEB128(offset_ptr);
break;
case DW_FORM_udata:
case DW_FORM_ref_udata:
Value.uval = data.getULEB128(offset_ptr);
break;
case DW_FORM_string:
Value.cstr = data.getCStr(offset_ptr);
break;
case DW_FORM_indirect:
Form = data.getULEB128(offset_ptr);
indirect = true;
break;
case DW_FORM_sec_offset:
case DW_FORM_strp:
case DW_FORM_GNU_ref_alt:
case DW_FORM_GNU_strp_alt: {
// FIXME: This is 64-bit for DWARF64.
Value.uval = data.getU32(offset_ptr);
if (!cu)
break;
RelocAddrMap::const_iterator AI =
cu->getRelocMap()->find(*offset_ptr - 4);
if (AI != cu->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
case DW_FORM_flag_present:
Value.uval = 1;
break;
case DW_FORM_ref_sig8:
Value.uval = data.getU64(offset_ptr);
break;
case DW_FORM_GNU_addr_index:
case DW_FORM_GNU_str_index:
Value.uval = data.getULEB128(offset_ptr);
break;
default:
return false;
}
} while (indirect);
if (is_block) {
StringRef str = data.getData().substr(*offset_ptr, Value.uval);
Value.data = nullptr;
if (!str.empty()) {
Value.data = reinterpret_cast<const uint8_t *>(str.data());
*offset_ptr += Value.uval;
}
}
return true;
}
bool
DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
const DWARFUnit *cu) const {
return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
}
bool
DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
uint32_t *offset_ptr, const DWARFUnit *cu) {
return skipValue(form, debug_info_data, offset_ptr, cu->getVersion(),
cu->getAddressByteSize());
}
bool DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
uint32_t *offset_ptr, uint16_t Version,
uint8_t AddrSize) {
bool indirect = false;
do {
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: {
uint64_t size = debug_info_data.getULEB128(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block1: {
uint8_t size = debug_info_data.getU8(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block2: {
uint16_t size = debug_info_data.getU16(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block4: {
uint32_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 += AddrSize;
return true;
case DW_FORM_ref_addr:
*offset_ptr += getRefAddrSize(AddrSize, Version);
return true;
// 0 byte values - implied from the form.
case DW_FORM_flag_present:
return true;
// 1 byte values
case DW_FORM_data1:
case DW_FORM_flag:
case DW_FORM_ref1:
*offset_ptr += 1;
return true;
// 2 byte values
case DW_FORM_data2:
case DW_FORM_ref2:
*offset_ptr += 2;
return true;
// 4 byte values
case DW_FORM_data4:
case DW_FORM_ref4:
*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_APPLE_db_str:
case DW_FORM_sdata:
case DW_FORM_udata:
case DW_FORM_ref_udata:
case DW_FORM_GNU_str_index:
case DW_FORM_GNU_addr_index:
debug_info_data.getULEB128(offset_ptr);
return true;
case DW_FORM_indirect:
indirect = true;
form = debug_info_data.getULEB128(offset_ptr);
break;
// FIXME: 4 for DWARF32, 8 for DWARF64.
case DW_FORM_sec_offset:
case DW_FORM_strp:
case DW_FORM_GNU_ref_alt:
case DW_FORM_GNU_strp_alt:
*offset_ptr += 4;
return true;
default:
return false;
}
} while (indirect);
return true;
}
void
DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
uint64_t uvalue = Value.uval;
bool cu_relative_offset = false;
switch (Form) {
case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break;
case DW_FORM_GNU_addr_index: {
OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
uint64_t Address;
if (cu->getAddrOffsetSectionItem(uvalue, Address))
OS << format("0x%016" PRIx64, Address);
else
OS << "<no .debug_addr section>";
break;
}
case DW_FORM_flag_present: OS << "true"; break;
case DW_FORM_flag:
case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break;
case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break;
case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break;
case DW_FORM_ref_sig8:
case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break;
case DW_FORM_string:
OS << '"';
OS.write_escaped(Value.cstr);
OS << '"';
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 (Form) {
case DW_FORM_exprloc:
case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break;
case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
default: break;
}
const uint8_t* data_ptr = Value.data;
if (data_ptr) {
// uvalue contains size of block
const uint8_t* end_data_ptr = data_ptr + uvalue;
while (data_ptr < end_data_ptr) {
OS << format("%2.2x ", *data_ptr);
++data_ptr;
}
}
else
OS << "NULL";
}
break;
case DW_FORM_sdata: OS << Value.sval; break;
case DW_FORM_udata: OS << Value.uval; break;
case DW_FORM_strp: {
OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
dumpString(OS, cu);
break;
}
case DW_FORM_GNU_str_index: {
OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
dumpString(OS, cu);
break;
}
case DW_FORM_GNU_strp_alt: {
OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue);
dumpString(OS, cu);
break;
}
case DW_FORM_ref_addr:
OS << format("0x%016" PRIx64, uvalue);
break;
case DW_FORM_ref1:
cu_relative_offset = true;
OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
break;
case DW_FORM_ref2:
cu_relative_offset = true;
OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
break;
case DW_FORM_ref4:
cu_relative_offset = true;
OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
break;
case DW_FORM_ref8:
cu_relative_offset = true;
OS << format("cu + 0x%8.8" PRIx64, uvalue);
break;
case DW_FORM_ref_udata:
cu_relative_offset = true;
OS << format("cu + 0x%" PRIx64, uvalue);
break;
case DW_FORM_GNU_ref_alt:
OS << format("<alt 0x%" PRIx64 ">", uvalue);
break;
// All DW_FORM_indirect attributes should be resolved prior to calling
// this function
case DW_FORM_indirect:
OS << "DW_FORM_indirect";
break;
// Should be formatted to 64-bit for DWARF64.
case DW_FORM_sec_offset:
OS << format("0x%08x", (uint32_t)uvalue);
break;
default:
OS << format("DW_FORM(0x%4.4x)", Form);
break;
}
if (cu_relative_offset) {
OS << " => {";
WithColor(OS, syntax::Address).get()
<< format("0x%8.8" PRIx64, uvalue + (cu ? cu->getOffset() : 0));
OS << "}";
}
}
void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
Optional<const char *> DbgStr = getAsCString(U);
if (DbgStr.hasValue()) {
raw_ostream &COS = WithColor(OS, syntax::String);
COS << '"';
COS.write_escaped(DbgStr.getValue());
COS << '"';
}
}
Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
if (!isFormClass(FC_String))
return None;
if (Form == DW_FORM_string)
return Value.cstr;
// FIXME: Add support for DW_FORM_GNU_strp_alt
if (Form == DW_FORM_GNU_strp_alt || U == nullptr)
return None;
uint32_t Offset = Value.uval;
if (Form == DW_FORM_GNU_str_index) {
uint32_t StrOffset;
if (!U->getStringOffsetSectionItem(Offset, StrOffset))
return None;
Offset = StrOffset;
}
if (const char *Str = U->getStringExtractor().getCStr(&Offset)) {
return Str;
}
return None;
}
Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
if (!isFormClass(FC_Address))
return None;
if (Form == DW_FORM_GNU_addr_index) {
uint32_t Index = Value.uval;
uint64_t Result;
if (!U || !U->getAddrOffsetSectionItem(Index, Result))
return None;
return Result;
}
return Value.uval;
}
Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
if (!isFormClass(FC_Reference))
return None;
switch (Form) {
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
if (!U)
return None;
return Value.uval + U->getOffset();
case DW_FORM_ref_addr:
return Value.uval;
// FIXME: Add proper support for DW_FORM_ref_sig8 and DW_FORM_GNU_ref_alt.
default:
return None;
}
}
Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
if (!isFormClass(FC_SectionOffset))
return None;
return Value.uval;
}
Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag))
|| Form == DW_FORM_sdata)
return None;
return Value.uval;
}
Optional<int64_t> DWARFFormValue::getAsSignedConstant() const {
if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) ||
(Form == DW_FORM_udata && uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval))
return None;
switch (Form) {
case DW_FORM_data4:
return int32_t(Value.uval);
case DW_FORM_data2:
return int16_t(Value.uval);
case DW_FORM_data1:
return int8_t(Value.uval);
case DW_FORM_sdata:
case DW_FORM_data8:
default:
return Value.sval;
}
}
Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc))
return None;
return makeArrayRef(Value.data, Value.uval);
}