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| //===-- DWARFExpression.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 "llvm/DebugInfo/DWARF/DWARFExpression.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Support/Format.h"
#include <cassert>
#include <cstdint>
#include <vector>
using namespace llvm;
using namespace dwarf;
namespace llvm {
typedef std::vector<DWARFExpression::Operation::Description> DescVector;
static DescVector getDescriptions() {
DescVector Descriptions;
typedef DWARFExpression::Operation Op;
typedef Op::Description Desc;
Descriptions.resize(0xff);
Descriptions[DW_OP_addr] = Desc(Op::Dwarf2, Op::SizeAddr);
Descriptions[DW_OP_deref] = Desc(Op::Dwarf2);
Descriptions[DW_OP_const1u] = Desc(Op::Dwarf2, Op::Size1);
Descriptions[DW_OP_const1s] = Desc(Op::Dwarf2, Op::SignedSize1);
Descriptions[DW_OP_const2u] = Desc(Op::Dwarf2, Op::Size2);
Descriptions[DW_OP_const2s] = Desc(Op::Dwarf2, Op::SignedSize2);
Descriptions[DW_OP_const4u] = Desc(Op::Dwarf2, Op::Size4);
Descriptions[DW_OP_const4s] = Desc(Op::Dwarf2, Op::SignedSize4);
Descriptions[DW_OP_const8u] = Desc(Op::Dwarf2, Op::Size8);
Descriptions[DW_OP_const8s] = Desc(Op::Dwarf2, Op::SignedSize8);
Descriptions[DW_OP_constu] = Desc(Op::Dwarf2, Op::SizeLEB);
Descriptions[DW_OP_consts] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
Descriptions[DW_OP_dup] = Desc(Op::Dwarf2);
Descriptions[DW_OP_drop] = Desc(Op::Dwarf2);
Descriptions[DW_OP_over] = Desc(Op::Dwarf2);
Descriptions[DW_OP_pick] = Desc(Op::Dwarf2, Op::Size1);
Descriptions[DW_OP_swap] = Desc(Op::Dwarf2);
Descriptions[DW_OP_rot] = Desc(Op::Dwarf2);
Descriptions[DW_OP_xderef] = Desc(Op::Dwarf2);
Descriptions[DW_OP_abs] = Desc(Op::Dwarf2);
Descriptions[DW_OP_and] = Desc(Op::Dwarf2);
Descriptions[DW_OP_div] = Desc(Op::Dwarf2);
Descriptions[DW_OP_minus] = Desc(Op::Dwarf2);
Descriptions[DW_OP_mod] = Desc(Op::Dwarf2);
Descriptions[DW_OP_mul] = Desc(Op::Dwarf2);
Descriptions[DW_OP_neg] = Desc(Op::Dwarf2);
Descriptions[DW_OP_not] = Desc(Op::Dwarf2);
Descriptions[DW_OP_or] = Desc(Op::Dwarf2);
Descriptions[DW_OP_plus] = Desc(Op::Dwarf2);
Descriptions[DW_OP_plus_uconst] = Desc(Op::Dwarf2, Op::SizeLEB);
Descriptions[DW_OP_shl] = Desc(Op::Dwarf2);
Descriptions[DW_OP_shr] = Desc(Op::Dwarf2);
Descriptions[DW_OP_shra] = Desc(Op::Dwarf2);
Descriptions[DW_OP_xor] = Desc(Op::Dwarf2);
Descriptions[DW_OP_skip] = Desc(Op::Dwarf2, Op::SignedSize2);
Descriptions[DW_OP_bra] = Desc(Op::Dwarf2, Op::SignedSize2);
Descriptions[DW_OP_eq] = Desc(Op::Dwarf2);
Descriptions[DW_OP_ge] = Desc(Op::Dwarf2);
Descriptions[DW_OP_gt] = Desc(Op::Dwarf2);
Descriptions[DW_OP_le] = Desc(Op::Dwarf2);
Descriptions[DW_OP_lt] = Desc(Op::Dwarf2);
Descriptions[DW_OP_ne] = Desc(Op::Dwarf2);
for (uint16_t LA = DW_OP_lit0; LA <= DW_OP_lit31; ++LA)
Descriptions[LA] = Desc(Op::Dwarf2);
for (uint16_t LA = DW_OP_reg0; LA <= DW_OP_reg31; ++LA)
Descriptions[LA] = Desc(Op::Dwarf2);
for (uint16_t LA = DW_OP_breg0; LA <= DW_OP_breg31; ++LA)
Descriptions[LA] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
Descriptions[DW_OP_regx] = Desc(Op::Dwarf2, Op::SizeLEB);
Descriptions[DW_OP_fbreg] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
Descriptions[DW_OP_bregx] = Desc(Op::Dwarf2, Op::SizeLEB, Op::SignedSizeLEB);
Descriptions[DW_OP_piece] = Desc(Op::Dwarf2, Op::SizeLEB);
Descriptions[DW_OP_deref_size] = Desc(Op::Dwarf2, Op::Size1);
Descriptions[DW_OP_xderef_size] = Desc(Op::Dwarf2, Op::Size1);
Descriptions[DW_OP_nop] = Desc(Op::Dwarf2);
Descriptions[DW_OP_push_object_address] = Desc(Op::Dwarf3);
Descriptions[DW_OP_call2] = Desc(Op::Dwarf3, Op::Size2);
Descriptions[DW_OP_call4] = Desc(Op::Dwarf3, Op::Size4);
Descriptions[DW_OP_call_ref] = Desc(Op::Dwarf3, Op::SizeRefAddr);
Descriptions[DW_OP_form_tls_address] = Desc(Op::Dwarf3);
Descriptions[DW_OP_call_frame_cfa] = Desc(Op::Dwarf3);
Descriptions[DW_OP_bit_piece] = Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeLEB);
Descriptions[DW_OP_implicit_value] =
Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeBlock);
Descriptions[DW_OP_stack_value] = Desc(Op::Dwarf3);
Descriptions[DW_OP_GNU_push_tls_address] = Desc(Op::Dwarf3);
Descriptions[DW_OP_addrx] = Desc(Op::Dwarf4, Op::SizeLEB);
Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB);
Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB);
Descriptions[DW_OP_GNU_entry_value] = Desc(Op::Dwarf4, Op::SizeLEB);
Descriptions[DW_OP_convert] = Desc(Op::Dwarf5, Op::BaseTypeRef);
Descriptions[DW_OP_entry_value] = Desc(Op::Dwarf5, Op::SizeLEB);
return Descriptions;
}
static DWARFExpression::Operation::Description getOpDesc(unsigned OpCode) {
// FIXME: Make this constexpr once all compilers are smart enough to do it.
static DescVector Descriptions = getDescriptions();
// Handle possible corrupted or unsupported operation.
if (OpCode >= Descriptions.size())
return {};
return Descriptions[OpCode];
}
static uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
return (Version == 2) ? AddrSize : 4;
}
bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version,
uint8_t AddressSize, uint64_t Offset) {
Opcode = Data.getU8(&Offset);
Desc = getOpDesc(Opcode);
if (Desc.Version == Operation::DwarfNA) {
EndOffset = Offset;
return false;
}
for (unsigned Operand = 0; Operand < 2; ++Operand) {
unsigned Size = Desc.Op[Operand];
unsigned Signed = Size & Operation::SignBit;
if (Size == Operation::SizeNA)
break;
switch (Size & ~Operation::SignBit) {
case Operation::Size1:
Operands[Operand] = Data.getU8(&Offset);
if (Signed)
Operands[Operand] = (int8_t)Operands[Operand];
break;
case Operation::Size2:
Operands[Operand] = Data.getU16(&Offset);
if (Signed)
Operands[Operand] = (int16_t)Operands[Operand];
break;
case Operation::Size4:
Operands[Operand] = Data.getU32(&Offset);
if (Signed)
Operands[Operand] = (int32_t)Operands[Operand];
break;
case Operation::Size8:
Operands[Operand] = Data.getU64(&Offset);
break;
case Operation::SizeAddr:
if (AddressSize == 8) {
Operands[Operand] = Data.getU64(&Offset);
} else if (AddressSize == 4) {
Operands[Operand] = Data.getU32(&Offset);
} else {
assert(AddressSize == 2);
Operands[Operand] = Data.getU16(&Offset);
}
break;
case Operation::SizeRefAddr:
if (getRefAddrSize(AddressSize, Version) == 8) {
Operands[Operand] = Data.getU64(&Offset);
} else if (getRefAddrSize(AddressSize, Version) == 4) {
Operands[Operand] = Data.getU32(&Offset);
} else {
assert(getRefAddrSize(AddressSize, Version) == 2);
Operands[Operand] = Data.getU16(&Offset);
}
break;
case Operation::SizeLEB:
if (Signed)
Operands[Operand] = Data.getSLEB128(&Offset);
else
Operands[Operand] = Data.getULEB128(&Offset);
break;
case Operation::BaseTypeRef:
Operands[Operand] = Data.getULEB128(&Offset);
break;
case Operation::SizeBlock:
// We need a size, so this cannot be the first operand
if (Operand == 0)
return false;
// Store the offset of the block as the value.
Operands[Operand] = Offset;
Offset += Operands[Operand - 1];
break;
default:
llvm_unreachable("Unknown DWARFExpression Op size");
}
OperandEndOffsets[Operand] = Offset;
}
EndOffset = Offset;
return true;
}
static bool prettyPrintRegisterOp(raw_ostream &OS, uint8_t Opcode,
uint64_t Operands[2],
const MCRegisterInfo *MRI, bool isEH) {
if (!MRI)
return false;
uint64_t DwarfRegNum;
unsigned OpNum = 0;
if (Opcode == DW_OP_bregx || Opcode == DW_OP_regx)
DwarfRegNum = Operands[OpNum++];
else if (Opcode >= DW_OP_breg0 && Opcode < DW_OP_bregx)
DwarfRegNum = Opcode - DW_OP_breg0;
else
DwarfRegNum = Opcode - DW_OP_reg0;
if (Optional<unsigned> LLVMRegNum = MRI->getLLVMRegNum(DwarfRegNum, isEH)) {
if (const char *RegName = MRI->getName(*LLVMRegNum)) {
if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
Opcode == DW_OP_bregx)
OS << format(" %s%+" PRId64, RegName, Operands[OpNum]);
else
OS << ' ' << RegName;
return true;
}
}
return false;
}
bool DWARFExpression::Operation::print(raw_ostream &OS,
const DWARFExpression *Expr,
const MCRegisterInfo *RegInfo,
DWARFUnit *U,
bool isEH) {
if (Error) {
OS << "<decoding error>";
return false;
}
StringRef Name = OperationEncodingString(Opcode);
assert(!Name.empty() && "DW_OP has no name!");
OS << Name;
if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
(Opcode >= DW_OP_reg0 && Opcode <= DW_OP_reg31) ||
Opcode == DW_OP_bregx || Opcode == DW_OP_regx)
if (prettyPrintRegisterOp(OS, Opcode, Operands, RegInfo, isEH))
return true;
for (unsigned Operand = 0; Operand < 2; ++Operand) {
unsigned Size = Desc.Op[Operand];
unsigned Signed = Size & Operation::SignBit;
if (Size == Operation::SizeNA)
break;
if (Size == Operation::BaseTypeRef && U) {
auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
if (Die && Die.getTag() == dwarf::DW_TAG_base_type) {
OS << format(" (0x%08" PRIx64 ")", U->getOffset() + Operands[Operand]);
if (auto Name = Die.find(dwarf::DW_AT_name))
OS << " \"" << Name->getAsCString() << "\"";
} else {
OS << format(" <invalid base_type ref: 0x%" PRIx64 ">",
Operands[Operand]);
}
} else if (Size == Operation::SizeBlock) {
uint64_t Offset = Operands[Operand];
for (unsigned i = 0; i < Operands[Operand - 1]; ++i)
OS << format(" 0x%02x", Expr->Data.getU8(&Offset));
} else {
if (Signed)
OS << format(" %+" PRId64, (int64_t)Operands[Operand]);
else if (Opcode != DW_OP_entry_value &&
Opcode != DW_OP_GNU_entry_value)
OS << format(" 0x%" PRIx64, Operands[Operand]);
}
}
return true;
}
void DWARFExpression::print(raw_ostream &OS, const MCRegisterInfo *RegInfo,
DWARFUnit *U, bool IsEH) const {
uint32_t EntryValExprSize = 0;
for (auto &Op : *this) {
if (!Op.print(OS, this, RegInfo, U, IsEH)) {
uint64_t FailOffset = Op.getEndOffset();
while (FailOffset < Data.getData().size())
OS << format(" %02x", Data.getU8(&FailOffset));
return;
}
if (Op.getCode() == DW_OP_entry_value ||
Op.getCode() == DW_OP_GNU_entry_value) {
OS << "(";
EntryValExprSize = Op.getRawOperand(0);
continue;
}
if (EntryValExprSize) {
EntryValExprSize--;
if (EntryValExprSize == 0)
OS << ")";
}
if (Op.getEndOffset() < Data.getData().size())
OS << ", ";
}
}
bool DWARFExpression::Operation::verify(DWARFUnit *U) {
for (unsigned Operand = 0; Operand < 2; ++Operand) {
unsigned Size = Desc.Op[Operand];
if (Size == Operation::SizeNA)
break;
if (Size == Operation::BaseTypeRef) {
auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
if (!Die || Die.getTag() != dwarf::DW_TAG_base_type) {
Error = true;
return false;
}
}
}
return true;
}
bool DWARFExpression::verify(DWARFUnit *U) {
for (auto &Op : *this)
if (!Op.verify(U))
return false;
return true;
}
} // namespace llvm
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